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1. Mechanism of Elvanol in Paper Surface Treatment In the modern paper industry, surface treatment has become an important means of increasing the added value of paper. Printability, surface strength, and barrier properties against oils and solvents all highly depend on the material selection of the surface sizing or coating system. Elvanol polyvinyl alcohol, as a high-performance water-based film-forming material, is widely used in paper surface treatment.     Elvanol is a fully or highly hydrolyzed polyvinyl alcohol with excellent film-forming ability. Its regular molecular chain structure allows it to form a continuous and dense film during drying, significantly improving the surface strength and barrier properties of the paper. Compared to using starch alone, the film formed by Elvanol is tougher, has stronger chemical resistance to oils, waxes, and solvents, and exhibits higher water resistance.   Using Elvanol in the sizing press or calendering stage can significantly improve the paper's resistance to linting, dusting, and cracking. Even at low addition levels (approximately 10% solids content), it can achieve surface strength and folding strength superior to traditional starch systems. This characteristic makes it particularly suitable for high-filler paper, recycled fiber paper, and paper types requiring high printability.   In addition, Elvanol has good compatibility and can coexist stably with modified starch, CMC, alginates, wax emulsions, and common papermaking additives, providing greater flexibility for papermaking process adjustments.   2. Application Advantages of Elvanol in Improving Barrier, Strength, and Printing Performance ♣ Surface Barrier Properties Elvanol is one of the most powerful water-based barrier film-forming materials in the paper industry. The film it forms has a natural barrier effect against oils, greases, and organic solvents, and is therefore often used in applications such as greaseproof paper, oil-resistant packaging paper, and copier paper. In oil-resistant systems, Elvanol can also serve as an effective carrier for fluorochemicals, improving the stability and efficiency of the overall barrier system.   ♣ Surface Strength and Structural Stability Compared to starch-sized paper, paper treated with Elvanol exhibits superior resistance to surface abrasion, cracking, and linting. Its high bonding strength effectively binds fibers and fine surface particles, reducing linting and dusting, thereby lowering the frequency of blanket contamination and downtime for cleaning during printing. This advantage is particularly evident in high-speed offset printing and high-precision printing. At the same time, Elvanol allows for a higher proportion of fillers or recycled fibers while maintaining strength, helping paper mills control costs while maintaining paper performance.   ♣  Printability and Coating Suitability Elvanol-treated paper surfaces are smoother and have excellent ink holdout. Due to its oil and solvent resistance, ink does not easily penetrate the paper base, resulting in higher print gloss and image clarity. In pigment sizing systems, Elvanol, as a binder, exhibits significantly stronger binding power than acrylic emulsions, styrene-butadiene latex, casein, and starch, and can replace traditional binders at certain ratios, optimizing the pigment/binder ratio.   3. Typical Elvanol Grades and Application Characteristics in Papermaking Based on different paper types and process requirements, we offer a variety of product grades with different viscosities and structures. The following are commonly used grades in the papermaking industry and their application characteristics: Grade Polymer Type Viscosity Level Key Functions Typical Uses Elvanol 71-30 Fully hydrolyzed PVOH Medium Film forming, binding, grease resistance Surface sizing; FWA carrier; lint and dust control; grease-resistant papers Elvanol 80-18 Fully hydrolyzed PVOH Medium Grease barrier, high solids stability Grease-proof packaging papers; high-solids sizing and coating Elvanol 75-15 Fully hydrolyzed PVOH Medium–Low Binder reinforcement Starch reinforcement; lint reduction; high-solids sizing and coating   In optical brightening systems, Elvanol acts as a carrier for fluorescent whitening agents (FWAs), significantly improving whitening efficiency. Adding Elvanol at 0.5–2.5% of the pigment weight in pigment systems results in significantly better whitening effects than using FWA alone, while also reducing the amount of traditional carriers such as starch and casein.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Food and consumer goods packaging is undergoing significant technological upgrades. On the one hand, the market demands longer food shelf life and reduced reliance on preservatives; on the other hand, sustainable development and regulatory compliance are driving the transformation of packaging materials towards recyclability and biodegradability. In this context, the demand for barrier properties in paper and cardboard packaging has increased significantly, especially in terms of oxygen, grease, and mineral oil barrier properties. Traditional plastic films (such as PE and PP) have limited oxygen barrier performance, while multi-layer composite materials, although offering excellent performance, increase the difficulty of recycling and compliance. In contrast, water-based barrier coatings can significantly improve the functionality of the material without significantly altering the paper substrate structure, giving paper packaging performance close to that of high-barrier materials while maintaining good recyclability. Among the many water-based barrier materials, polyvinyl alcohol (PVOH) system coatings have become an important solution for current paper-based packaging barrier technology due to their excellent oxygen and grease barrier properties and mature industrial application base. The KURARAY POVAL (POVAL 6-98), ELVANOL, and EXCEVAL series of products are representative material systems based on PVOH.   1. PVOH Barrier Mechanism and Performance Advantages in Paper Packaging Polyvinyl alcohol is a non-ionic, water-soluble, linear crystalline polymer, whose molecular chains can form a large number of hydrogen bonds. This highly ordered molecular arrangement makes it difficult for oxygen molecules to diffuse, which is the fundamental reason for its excellent oxygen barrier performance. Under suitable coating and drying conditions, the PVOH coating can form a dense and continuous film layer, thereby significantly reducing the oxygen transmission rate (OTR) of the paper substrate material. In addition, the hydrophilic nature of PVOH makes it equally outstanding in blocking grease and mineral oil, which is particularly crucial for the packaging of bread, coffee, baked goods, etc. By coating ordinary starch-based paper with EXCEVAL HR-3010, with a coating weight of only 7 g/m², the OTR (Oxygen Transmission Rate) can be reduced from >2000 mL/m²/d to <1 mL/m²/d (23℃, 50% RH), demonstrating extremely high barrier efficiency.   ♠ Compared to other common barrier materials, PVOH is a leading material in terms of oxygen barrier performance: Polyethylene, Polypropylene: Weak barrier PET, PA6: Medium barrier PVDC: High barrier but with environmental concerns EVOH / PVOH: Extremely high oxygen barrier performance   At the same time, PVOH has been certified by BfR and FDA for food contact regulations, making it safe for use in food packaging systems, which is an important prerequisite for its widespread use in the packaging coating field.   2. PVOH Barrier Coating Product System and Typical Performance Parameters We offer a variety of PVOH product models suitable for paper-based packaging barrier coatings. Different models vary in viscosity, barrier focus, and application suitability, allowing for selection based on actual needs. The following is a performance comparison table: From an application perspective, low-viscosity models (such as EXCEVAL AQ-4104) are more suitable for high-speed coating or low-coating weight systems, while high-viscosity models (such as ELVANOL 71-30) are beneficial for forming thicker, denser barrier layers. The above products are compatible with various common coating processes, such as blade coating, gravure coating, or curtain coating, and have good process compatibility.   In summary, water-based barrier coatings based on PVOH provide a well-balanced solution for paper-based packaging in terms of performance, sustainability, and regulatory compliance, especially suitable for food packaging scenarios sensitive to oxygen and grease.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Chloroprene latex is a type of water-based polymer material formed from chloroprene rubber through emulsion polymerization or re-emulsification processes. This series has great adhesion, strong weather resistance, and high flame retardancy, and it can be used in many ways. The series is divided into two main types: anionic chloroprene latex (SNL series) and cationic chloroprene latex (CRL series). These types are based on different ionic properties and can be used in construction, transportation, industrial bonding, surface reinforcement, coating, and impregnation.   1. SNL Series Core Performance and Technological Advantages ♠ Superior Bonding Strength and Initial Tack In adhesive formulation design, initial tack is a key factor determining production efficiency. SNL series latexes exhibit extremely strong affinity for various substrates, including metals, fabrics, glass fibers, and even porous sponge materials. ♠ Comprehensive Environmental Resistance Unlike natural latex, which is prone to aging, the SNL series inherits the excellent properties of chloroprene rubber (CR). It possesses excellent resistance to ozone, weathering, oil, and chemical corrosion. ♠ Environmental Protection and Process Adaptability In today's increasingly stringent environmental regulations, the water-based, non-toxic, and solvent-free characteristics of the SNL series are one of its biggest competitive advantages. It not only eliminates the health and safety hazards caused by volatile organic compounds (VOCs), but also has a "non-irritating" characteristic.   2. Main Model Performance Characteristics and Application Areas 2.1 SNL-511A Anionic Chloroprene Latex SNL-511A (Neoprene 842A) is a gel-type anionic chloroprene latex with a slower crystallization rate, easy spraying, good flame retardancy, and wide material compatibility. It can be used alone or in combination with natural latex or other synthetic latexes to replace some natural latex applications. Its main application characteristics include: Fast-setting spraying application: It can be used in black asphalt waterproof coating systems, suitable for waterproofing and seepage prevention in water plants, pools, sewage tanks, underground foundation treatment, tunnel and subway construction, roofs, balconies, etc. Engineering Applications: Waterproof coatings for roads, water conservancy projects, canals, subways, etc.; seepage-proof coatings for reservoirs, underground landfills, etc.; corrosion protection and waterproofing for roof steel structure panels. Industrial Applications: Suitable for industrial coatings, impregnated products, composite material adhesives, and can also be used as a bonding substitute for sponge products. SNL-511A's flame retardancy, sprayability, and wide-range adhesion make it a commonly used variety in engineering waterproofing and industrial protective materials.     2.2 SNL-5042 Anionic Neoprene Latex SNL-5042 (Denka Neoprene 750) is characterized by strong initial tack, fast bonding speed, high bond strength, good storage stability, no need for solvents, non-toxicity, ozone resistance, oil resistance, chemical corrosion resistance, and excellent flame retardancy. Its main applications include: Water-based adhesive systems: Footwear materials, flooring, PVC flooring, foam, mattresses, fiber cloth, aluminum foil, glass cloth, etc. Building materials: Bonding of cement, mortar, adhesive mortar, etc., improving the durability and bond strength of the construction site. Transportation and Industrial Products: Adhesive materials for industries such as railway vehicles, automobiles, furniture, and electronic components. This model's fast-drying and strong adhesion characteristics make it particularly suitable for high-efficiency assembly and rapid construction scenarios. 2.3 CRL-50KL Cationic Neoprene Latex CRL-50KL (Denka Neoprene 571) is a cationic latex with positively charged emulsion particles, thus maintaining stability and preventing aggregation even in environments containing Ca²⁺ and Na⁺. Key features include: Excellent weather resistance: Ozone and aging resistant, suitable for long-term exposure environments. Good film-forming properties and high strength: Dense and high-strength film, suitable for structural applications such as waterproofing, corrosion protection, and bonding. Compatible with various substrates: Strong affinity for materials such as cement, fiber, steel, wood, and fiberglass. ♠ Main applications include: Modified bitumen waterproofing materials, rigid waterproofing layers, ship deck coatings, etc. Fiber impregnation, bonding mortars, wood protection, and fiberglass product treatment, etc. Applications include fire-retardant materials, corrosion-resistant coatings, and structural surface reinforcement. The salt resistance and high adhesion of cationic systems make them widely applicable in cement, steel, and composite materials.   3. Packaging, Appearance, and Transportation/Storage Requirements Neoprene latex products are typically white or off-white emulsions. According to available data, the SNL and CRL series products are mostly packaged in 1100 kg ± 2 kg plastic drums for easy transportation and large-scale application. Transportation and storage requirements include: Maintaining a well-ventilated and dry environment during storage and transportation, avoiding direct sunlight and high temperatures. Recommended storage temperature: 5–30℃; if the storage temperature is below 23℃, the shelf life of the product is 6 months from the date of production. Avoid damaging the packaging and keep it sealed to prevent impurities from entering and affecting stability. These storage and transportation requirements ensure that the emulsion remains uniform, non-gelling, and non-stratified before use, guaranteeing the safety and consistency of application and processing.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In the field of specialty rubber materials, chloroprene rubber (CR) has long held an irreplaceable position due to its excellent weather resistance, flame resistance, oil resistance, and chemical corrosion resistance. Among the various types of chloroprene rubber, sulfur-modified chloroprene rubber, with its unique molecular structure design, exhibits excellent physical and mechanical properties and adhesion, making it a key focus in the rubber products industry. This article will delve into the SN32 and SN12 series of sulfur-modified chloroprene rubber produced using a low-conversion polymerization process. These two series of products, through specific process control, overcome the challenges of Mooney viscosity stability in traditional sulfur-modified rubber, providing a more uniform and reliable raw material choice for industrial products.     1. Characteristics of Sulfur-Modified Process and Advantages of Low-Conversion Polymerization The core of sulfur-modified chloroprene rubber lies in the introduction of sulfur as a regulator during the polymerization process, and the use of thiuram for chain termination. Compared with traditional thiol-modified rubber, sulfur-modified rubber generally has higher tear strength, better adhesion, and superior dynamic fatigue performance. The SN32 and SN12 series discussed here are based on a low-conversion emulsion polymerization process. This process is key to improving product quality stability: Uniformity of Mooney viscosity: By strictly controlling the monomer conversion rate during polymerization, it effectively avoids polymer gelation or excessively broad molecular weight distribution caused by over-reaction. This means that each batch of rubber produced maintains a very narrow range of Mooney viscosity fluctuations, greatly improving the consistency of compounding and processing in downstream factories. Optimization of molecular chain structure: This process, combined with advanced molecular weight regulation technology, results in chloroprene rubber with low crystallinity. Low crystallinity means that the material is softer at room temperature and less prone to premature hardening, thus ensuring the flexibility and service life of the products. Improved processing safety: Through precise polymerization control, these two series of products significantly improve the processing safety of the rubber compound while maintaining the high strength of sulfur-modified rubber, reducing the risk of dead stock and scorching.   2. SN32 Series The SN32 series is positioned as a general-purpose sulfur-modified chloroprene rubber. From a molecular structure perspective, it undergoes a special adjustment of the degree of mechanical shearing and chain scission. According to technical data, the SN32 series has a lower degree of molecular chain mechanical shearing and scission than the SN12 series, but its thermal stability is stronger than the SN12 series. This characteristic determines that SN32 performs better in high-temperature environments.   Model SN321 SN322 SN323 Mooney Viscosity(100℃1+4) 37-49 50-65 66-75 Mooney Scorch (MSt5) min≥ 25 25 25 500% Modulus (Mpa) 2-5 2-5 2-5 Tensile Strength (MPa) ≥ 22 22 22 Elongation at Break (%) ≥ 800 800 800 Volatile Matter (%) ≤ 1.3 1.3 1.3 Ash Content % ≤ 1.0 1.0 1.0   ♠ Physical and Mechanical Properties and Processing Characteristics The SN32 series exhibits excellent physical and mechanical properties, with tensile strength greater than 22 MPa and elongation at break above 800%. Compared with the traditional CR322(such as Polychloroprene Rubber CR3221), the advantages of the SN32 series are mainly reflected in the processing stage: Easy to plasticize and compound: The rubber compound absorbs powder quickly and disperses evenly. Excellent extrusion molding: The rubber sheet surface is flat and smooth, with low shrinkage, which is crucial for manufacturing extruded products requiring high dimensional accuracy (such as sealing strips and hoses). Good appearance quality: The surface of the product is smooth after vulcanization, with a low defect rate. ♠ Grade Subdivision  The SN32 series is subdivided into three main grades according to different Mooney viscosity (ML100℃ 1+4), corresponding to different hardness and processing requirements: SN321 (Mooney 37-49): Low viscosity, good fluidity, suitable for complex mold injection molding. SN322 (Mooney 50-65): Medium viscosity, most versatile. SN323 (Mooney 66-75): High viscosity, higher physical strength, suitable for high-load products. ♠ Key Applications Thanks to its excellent oil resistance, chemical resistance, ozone aging resistance, and non-flammability, the SN32 series is widely used in mining conveyor belts, power transmission belts, dust covers, and various sealing parts. In particular, its excellent thermal stability makes it perform outstandingly in power transmission components involving frictional heat generation.   3. SN12 Series ♠ Outstanding Scorching Safety and Anti-Aging Properties The most significant feature of the SN12 series is its long scorching time. In rubber processing, scorch time determines the "safety window" of the operation. A longer scorch time means that the rubber compound is less prone to premature vulcanization (scorch) during high-temperature mixing and molding, which is crucial for thick products or injection molding processes with complex structures. Furthermore, the SN12 series blended rubber exhibits superior vulcanization characteristics, particularly in terms of aging resistance. Data shows that its products have better aging resistance than the GNA type, and also possess good electrical properties and weather resistance.   Model SN121 SN122 TBD-102 Mooney Viscosity(100℃1+4) 30-50 51-65 30-50 Mooney Scorch (MSt5) min≥ 25 25 25 500% Modulus (Mpa) 2-5 2-5 2-5 Tensile Strength (MPa) ≥ 23 23 23 Elongation at Break (%) ≥ 850 850 850 Volatile Matter (%) ≤ 0.8 0.8 0.8 Ash Content % ≤ 1.0 1.0 1.0   ♠ Physical Performance Advantages Although both are sulfur-cured types, the SN12 series has slightly higher tensile strength (≥23 MPa) and elongation at break (≥850%) than the SN32 series. This indicates that the SN12 series has greater molecular chain flexibility and toughness, allowing it to withstand greater deformation without damage. ♠ Differences between SN122 and SN121 The main difference lies in Mooney viscosity; SN122 (51-65) is slightly higher than SN121 (30-50). Users can choose based on the power of their mixing equipment and process requirements. ♠ Comparison with CR121 Compared to traditional CR121(such as Polychloroprene Rubber CR1212), the SN12 series has better processing performance, especially in plasticizing, mixing, and extrusion molding, with less shrinkage and better product appearance quality.   4. Application Scenario Analysis and Series Selection Recommendations Both the SN32 and SN12 series possess the characteristic "all-round" properties of chloroprene rubber: oil resistance, heat resistance, flame retardancy, and suitability for rubber products with special requirements for comprehensive performance. However, in actual engineering applications, engineers should select materials based on specific needs. ♠ Power Transmission and Mining Fields (Conveyor Belts, Drive Belts) This is the core application area for sulfur-cured chloroprene rubber. Mining conveyor belts require extremely high flame retardancy and wear resistance, as well as good adhesion between the rubber compound and the reinforcing materials (such as nylon and polyester canvas). Recommendation: If thermal stability of the rubber compound is important (e.g., drive belts in high-temperature environments), the SN32 series is the preferred choice. Recommendation: If tear strength and a long scorch time are important (facilitating long-term vulcanization molding of large conveyor belts), the SN12 series is more suitable. ♠ Cable Sheathing and Seals Cable sheathing requires materials with good weather resistance, ozone resistance, and certain electrical insulation properties. The SN32 series, with its excellent extrusion surface smoothness and low shrinkage, is ideal for extruded cable sheathing and profiled sealing strips, ensuring dimensional accuracy and aesthetic appearance of the finished product. ♠ Hoses and Vibration Damping Products The high elongation and tensile strength of the SN12 series make it perform exceptionally well in hoses and damping pads subjected to high-pressure deformation. Its excellent dynamic fatigue resistance can effectively extend the service life of damping products.   The SN32 and SN12 series sulfur-modified chloroprene rubber, produced using a low conversion rate polymerization process, represents the advanced level of current domestic synthetic rubber technology. The SN32 series excels in thermal stability and processing appearance, while the SN12 series is known for its scorch safety and high strength and elongation properties. These two series not only meet the standards of comparable high-end international products (such as DuPont, Lanxess, and Denka) in various physical and chemical indicators, but also achieve uniform and stable Mooney viscosity through process innovation, solving a major pain point of processing instability for rubber product manufacturers. They are ideal base materials for manufacturing high-quality rubber products.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Thiol-modified chloroprene rubber plays a crucial role in adhesive chloroprene rubber systems due to its unique polymerization control mechanism. Thiol-modified products, especially the SN24 series, SN244X series, and SN23 series, are widely used in shoe adhesives, spray adhesives, high-grade universal adhesives, architectural decorative adhesives, and automotive interiors.   1. Mechanism of Thiol Modification During the polymerization of chloroprene rubber (CR), modifiers significantly affect the polymerization rate, molecular weight, distribution, and controllability of the polymerization process. Thiol modifiers, due to their moderate reactivity, are widely used in the production of adhesive chloroprene rubber. 1.1 More Stable Polymerization Process Thiol modification effectively controls chain growth, maintaining suitable molecular weight and distribution, resulting in good solubility and stable processing properties. This directly affects adhesive viscosity, film-forming characteristics, and long-term storage stability. 1.2 Determining Initial Tack and Final Strength of Adhesives Taking the SN24 series as an example, the molecular structure obtained through thiol regulation exhibits superior film-forming strength. When grafted with MMA (methyl methacrylate), it significantly improves adhesion to various substrates, resulting in higher initial tack and final bond strength. 1.3 Affecting Open Time and Working Window The SN23 series is specifically designed for "adjustable open time." Through meticulous control of the molecular structure, it provides more flexible application times for the footwear and decoration industries, effectively improving operational convenience and production efficiency. Thiol regulation is not merely simple polymerization control; it is a core technical means influencing the application performance of the entire adhesive system, providing a strong technical foundation for complex bonding scenarios.   2. Performance and Application Value of the SN24/SN244X Series Among thiol-regulated chloroprene rubbers, the SN24 and SN244X series are the products with the highest market attention. SN24 focuses on bond strength and grafting applications, while SN244X further optimizes solubility, color, and weather resistance, resulting in more comprehensive overall performance. 2.1 SN24 Series: High-strength, graftable, and widely applicable basic products   ♠ Key features of the SN24 series include: Thiol-modified system for stable molecular weight control MMA grafting adaptability, further improving adhesion to substrates such as metals, leather, and rubber High initial tack and excellent final bond strength Suitable for fast bonding systems ♠ Typical applications: Shoe adhesives in the footwear industry Spray adhesives in the furniture and packaging industries Advanced all-purpose adhesives and engineering adhesives Chloroprene Rubber SN-242A is a widely used product, extensively adopted in footwear adhesive applications due to its strength, fast bonding speed, and ease of use. 2.2 SN244X Series: Upgraded Products with High Solubility, Light Color, and High Weather Resistance Chloroprene Rubber SN-244X series optimizes several key properties based on SN24, making it a higher-end and more stable thiol-modified chloroprene rubber.   ♠ Key advantages include: Faster dissolving speed, improving production efficiency Lighter glue color, suitable for light-colored or appearance-sensitive products High initial bond strength, long holding time, and better weather resistance Less prone to aging after bonding, suitable for outdoor or strong light environments ♠ Typical applications: High-end shoe adhesives Construction and decoration adhesives Automotive interior bonding Furniture and decoration industries For companies requiring "fast dissolution + strong adhesion + high weather resistance," the SN244X series is a typical choice.   3. SN23 Series: Complementary Products Specifically Designed for Adjusting Open Time Unlike the direct application of SN24 and SN244X, the SN23 series acts as a "modifier" in adhesive chloroprene systems. Its core value is adjusting the open time.   3.1 Why is open time so critical? In adhesive applications, too short an open time leads to application difficulties; too long an open time reduces efficiency. Different seasons, application temperatures, and substrate conditions can all cause fluctuations in the final bonding effect. The SN23 series allows for precise adjustment of the adhesive's drying speed and operating window, ensuring stable performance under various environmental conditions. 3.2 Enhanced results when used in conjunction with SN24/SN244X The SN23 series is typically not used alone, but rather in combination with SN24 and SN244X, serving the following purposes: Extending or optimizing adhesive open time Improving sprayability and application feel Optimizing the balance between initial and final bond speeds Enhancing adaptability to complex processes Typical products such as SN236T and SN237T possess suitable solution viscosity and good stability, making them highly valuable in the footwear and industrial adhesive industries.   As industries such as footwear manufacturing, furniture decoration, and automotive interiors demand increasingly higher performance from adhesives, adhesive-grade neoprene rubber is entering a stage of development focused on higher performance, greater controllability, and greater stability.   ♣ The thiol-modified SN24, SN244X, and SN23 series are key components of this trend: SN24 – High strength, graftable, and comprehensive adhesive properties SN244X – An upgraded solution offering fast dissolution, light color, and high weather resistance SN23 – An open-time modifier product that makes production more controllable.   Through proper combination, these adhesives can create more stable, easier-to-process, and more adaptable neoprene adhesive systems, bringing higher efficiency and better bonding quality to end-user industries.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In the dry-mix mortar industry, the performance of redispersible polymer powder (RDP) directly determines the bonding strength and flexibility of tile adhesives, exterior wall putties, and thermal insulation mortars. As the source of RDP production, the physicochemical properties of VAE emulsions form the cornerstone of all these properties. Today, we will delve into two specialized VAE emulsions designed specifically for RDP production—DiverSol 628 (VAE CW40-758) and DiverSol 688 (VAE CW40-718). 1. Balance between High Solids Content and Rheological Properties For RDP (polymer powder) manufacturers, spray drying is the most energy-intensive process. The solids content of the emulsion raw materials directly affects production efficiency and energy costs. DiverSol 628 and DiverSol 688 demonstrate extremely high industrial economics in this regard. In the VAE emulsion field, a solids content of around 60% is considered high. This means that the amount of water that needs to be evaporated during the spray drying process is significantly reduced. Compared to conventional 55% solids content emulsions, using the DiverSol series not only significantly reduces heat consumption but also substantially increases the unit output of spray towers. Besides solids content, viscosity is crucial for atomization performance. DiverSol 628/688 have a viscosity range of 500 ~ 4000 mPa·s (25℃). This wide viscosity range, combined with its excellent flow properties, provides powder manufacturers with a wide process window: Good atomization: Appropriately low viscosity helps the emulsion form tiny droplets at the nozzle, resulting in more uniform particle size distribution in the dried powder, and better flowability after blending. Shear stability: Under high-speed pumping and spray shearing, the emulsion remains stable and is less prone to emulsion breakage and nozzle clogging. Furthermore, both products use polyvinyl alcohol (PVA) as a protective colloid system. This system is standard in RDP production because polyvinyl alcohol not only stabilizes the emulsion but also acts as a protective film during the redispersibility of the adhesive powder, preventing the powder particles from clumping in water and ensuring rapid dispersion of the final dry mortar after water addition.   2. Differentiated Formulation Strategy Based on Tg Value Although DiverSol 628 and 688 are highly consistent in their basic physical properties (appearance, solid content, viscosity, pH), they take two completely different technical directions in their core thermal performance indicator—glass transition temperature (Tg), targeting "rigid" and "flexible" applications respectively. 2.1 DiverSol 628: High Tg Leads to Rigidity and High Strength ♣ Tg Range: 10 ~ 20°C ♣ Technical Characteristics: A Tg higher than room temperature means that the movement of polymer molecular chains is restricted after film formation, resulting in a film with higher hardness and cohesiveness. ♣ Application Advantages: RDP produced using 628 is more suitable for applications requiring high bond strength and surface hardness. For example: Tile adhesive: Provides strong tensile strength, preventing heavy tiles from slipping. Floor mortar and self-leveling compound: High Tg helps improve the abrasion resistance and hardness of the floor surface. Gypsum-based applications: Enhances the strength of gypsum products. 2.2 DiverSol 688: Low Tg provides flexibility and crack resistance. ♣ Tg range: -15 ~ 0℃ ♣ Technical characteristics: Significantly lower Tg than room temperature, the film is in a highly elastic state after formation, the film is soft, and has excellent elongation. ♣ Application advantages: RDP produced using 688 has its core selling points in flexibility and weather resistance. It effectively absorbs the deformation stress of the substrate, suitable for: External wall insulation systems: Prevents cracking of the insulation layer in environments with large temperature variations. Flexible putty: Provides excellent crack resistance, adapting to minor vibrations or settlement of the wall. Repair mortar: Provides necessary bridging ability when repairing old and cracked substrates.   3. Industrial Compatibility and Green Environmental Protection In actual industrial production, VAE emulsions not only need excellent performance but also must possess good "compatibility," meaning they must be compatible with other raw materials. 3.1 Broad Chemical Compatibility DiverSol 628/688 were formulated with the complexity of downstream applications in mind. These two emulsions typically exhibit good compatibility with various thickeners, plasticizers, solvents, and fillers. This is crucial for RDP manufacturers, as anti-caking agents or other modifying agents are often added to the emulsion before spray drying. Good compatibility ensures the homogeneity of the mixture, preventing stratification or flocculation. 3.2 Environmental Protection and Aging Resistance With increasingly stringent GB standards for the environmental protection of building materials, the environmental properties of raw materials have become a critical indicator. Plasticizer-Free Design: Both products are formulated without plasticizers. This means that the film-forming flexibility of the emulsion comes from the internal plasticizing effect of the ethylene monomer, rather than from added small-molecule plasticizers. This not only prevents later-stage brittleness caused by plasticizer migration but also ensures excellent aging resistance. Low Residual Monomer: The residual vinyl acetate monomer content is strictly controlled below 0.5%, making it an environmentally friendly product. 3.3 Storage and Handling Guidelines While the product boasts excellent performance, proper handling is equally important. Due to the presence of trace monomers, it is recommended to handle the product in a well-ventilated environment and wear protective equipment. Storage temperature should be controlled between 5°C and 40°C; freezing is strictly prohibited. It is particularly important to note that if the product has undergone long-distance transportation or long-term storage (shelf life 6 months), it is recommended to filter and stir before use to eliminate any potential lumps or crusts.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In the field of building waterproofing, polymer cement waterproof coatings have always been a market favorite due to their environmental friendliness, high film strength, and good compatibility with damp substrates. As the core raw material of JS coatings, the performance of the polymer emulsion directly determines the success or failure of the final waterproof layer. Today, we will delve into DiverSol 779P (VAE CW40-705) and DiverSol 777 (VAE CW40-705). By interpreting the data of these two products, which conform to GB/T 23445-2009 Type II standard, we will analyze the key technical aspects of high-performance waterproof emulsions in practical applications.   1. Technical Characteristics and Performance Highlights of Two Special VAE Emulsion Both DiverSol 777 and 779P are plasticizer-free VAE Emulsion (Vinyl Acetate–ethylene Copolymer Emulsion) , presenting as a milky white water-based system. They maintain relatively consistent key indicators such as solid content, viscosity, pH, and glass transition temperature (Tg), which helps to maintain stable performance in different application scenarios.     ♠ Industry Significance in Performance: Low Tg for Flexibility: Suitable for Type II waterproof coatings requiring low-temperature flexibility and crack resistance; the film exhibits good elongation after drying, adapting to slight substrate displacement and temperature changes. Excellent Compatibility with Cement Systems: The PVA protective colloid improves the dispersibility of the emulsion when mixed with cement and fillers; significantly improves the sag resistance and thixotropic properties of cement paste. Plasticizer-Free Formulation: Reduces VOC emissions and enhances environmental friendliness; more stable in the formulation, preventing performance degradation due to migration. Adaptability to Wet Environments: Forms a film on damp, cold substrates without chalking or early cracking.   2. Application Logic and Formulation Synergy in Waterproof Building Coatings 2.1 Mechanism of Action in Waterproof Coating Systems ♣ VAE emulsions play three roles in cement-based waterproof coatings: Providing flexibility: filling the "brittleness gap" of the cement system; Improving water resistance: forming a continuous polymer film in the pores after cement hydration; Promoting workability: improving thixotropy, reducing sagging, and improving the smoothness of application.   The low Tg characteristics of DiverSol 777 and 779P enable the polymer phase to form a continuous film structure at room temperature or even low temperature, thereby effectively improving the coating density. It forms an interpenetrating network (IPN) structure with the cement hydrate, enhancing adhesion and crack resistance, which are fundamental properties that Type II waterproof coatings must meet.   2.2 Key Performance Improvement Points in Waterproofing Systems (1) Improved Flexibility and Crack Resistance The addition rate of the emulsion is usually 10–20% of the total mass of the system. The DiverSol series can achieve the following within this range: Increased tensile strength Increased elongation Buffering ability for mortar shrinkage cracks (2) Anti-sagging and workability 779P emphasizes "good anti-sagging performance" in its description. Its thixotropy is suitable for: Facade construction Multi-corner structures such as bathrooms Stability control of thick coating operations (3) Durability and water resistance The polyvinyl alcohol protective colloid system after film formation can make the emulsion evenly distributed in the cement pores: Reduce water absorption Improve freeze-thaw cycle stability Delay the alkaline erosion of cement paste (4) Strong substrate adaptability Both emulsions can be applied under "low temperature or high humidity conditions", especially suitable for: Rainy season construction areas Underground structures Brick and concrete building bases that are prone to dampness   3. Engineering value, storage and transportation and production operation points   3.1 Engineering value manifestation In building engineering applications, waterproofing systems usually face challenges such as diverse substrates, complex construction environments and high durability requirements. The selection of a suitable VAE emulsion not only affects product test indicators but also long-term operational stability. The value of DiverSol 777 and 779P to engineering projects is mainly reflected in: (1) Improved overall construction efficiency Good thixotropy, easier application, and reduced rework Strong adaptability to wet substrates, eliminating the need for prolonged drying of the substrate (2) Effectively extends the service life of the waterproofing system The continuous polymer phase reduces the path of moisture intrusion Strong crack resistance, especially suitable for areas with slight structural movement, such as bathroom corners and roof panel joints (3) Wide range of applications Waterproofing for bathrooms, kitchens, and balconies\Basement and foundation protection layers Roof coatings Flexible waterproofing primers for interior and exterior walls Premixed waterproofing slurry for engineering projects (4) Compliant with environmental trends Plasticizer-free, water-based, and low-residue, helping the product pass environmental building material certification or meet VOC requirements   3.2 Storage Specifications (1) Storage Environment and Shelf Life Temperature Control: The emulsion must be stored in a sheltered area and must not be frozen. Storage temperature should be strictly controlled between 5°C and 40°C. Once VAE emulsions freeze, they are usually irreversible after demulsification, resulting in direct economic losses. Shelf Life Management: Under suitable conditions and in their original, unopened packaging, DiverSol 779P and 777 have a minimum shelf life of 6 months. It is recommended that factories implement a "first-in, first-out" (FIFO) inventory management principle. (2) Pretreatment and Usage Precautions Filtration and Stirring: During transportation and storage, soft lumps or a skin may form on the surface of the emulsion, a common physical phenomenon in polymer dispersions. Therefore, filtration is strongly recommended before use. Especially if the product has been stored for a long time, thorough stirring is essential before use to ensure homogeneity. Preservative Treatment: Preservatives are added to the product at the factory to prevent microbial contamination. However, once the container is opened or transferred to another storage tank, the original preservative system may be insufficient to resist new microbial attacks. If the product cannot be used immediately, the user must take appropriate precautions (such as sealing for storage) or add a suitable preservative after transfer. (3) Safety Precautions Although the DiverSol series is considered safe for its intended use, as a chemical feedstock, it contains trace amounts of residual vinyl acetate monomer (controlled below 0.5%). Therefore, adequate ventilation should be maintained in the operating area. Operators should wear protective clothing, gloves, and goggles. In case of skin or eye splashes, rinse immediately with water.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

In the rapidly evolving field of industrial adhesives, finding a product that combines strength, flexibility, and durability has always been a challenge. Today, we introduce VINNAPAS EP 705K , an innovative polymer dispersion designed for modern, demanding applications. Its unique properties provide superior solutions for a variety of complex bonding needs. VINNAPAS EP 705K (VAE CW 40-758) is a Vinyl acetate-ethylene copolymer emulsion dispersion protected by polyvinyl alcohol (PVOH). It has a moderate viscosity and is produced without the addition of formaldehyde donors, giving it advantages in environmental friendliness and application safety. The unique main chain structure of this polymer endows the dried film with two core characteristics: strength and flexibility. More importantly, these properties are maintained even under water immersion or temperature fluctuations.     ♠ Overview of Superior Adhesive Performance: Excellent adhesion to a variety of plastic surfaces. Durable and flexible bonded joints. High cohesion, ensuring the structural strength of the adhesive itself. Chemical stability: It remains chemically stable at both low and high pH levels. VINNAPAS EP 705K (ULS) offers excellent compatibility, being compatible with a wide range of polyvinyl acetate (PVAc) polymers, rubber latexes, EVCL dispersions, and other VAE dispersions. It is also compatible with a variety of resins, solvents, plasticizers, and other modifiers, providing formulators with significant flexibility for product customization and performance optimization. In terms of applications, as a multi-functional adhesive, it reliably bonds a variety of substrates, including paper, wood, cotton fabric, nylon fabric, cardboard, polyurethane foam, and certain types of coated paperboard.   ♠ Key application areas This product offers significant advantages in packaging and lamination applications, with typical applications including: Packaging: such as windowed carton and box forming, envelope manufacturing. Lamination: wood lamination and low-cost veneer veneering, PVC lamination and OPP wet lamination, film-to-wood lamination. Other applications: Flooring installation, paper packaging and processing, bags and handbags, and textiles or interiors.   ♠ Processing and Storage Recommendations VINNAPAS EP 705K exhibits good stability on high-speed machines and is suitable for a variety of applications, including roll coating, extrusion, and spray coating.   ♠ Storage Guidelines Proper storage is crucial to maintain optimal product performance: Shelf Life: When stored in its original, unopened container at temperatures between 5°C and 30°C, the product has a shelf life of 9 months from the date of manufacture. Container Recommendations: Due to the weakly acidic nature of this dispersion, iron or galvanized iron equipment and containers are not recommended, as corrosion may cause discoloration. Containers and equipment made of ceramic, rubber, or enamel materials, appropriately finished stainless steel, or plastics (such as rigid PVC, polyethylene, or polyester resin) are recommended. Freeze Protection: Freezing of the product must be prevented. Pre-use Treatment: Filtration is recommended before use as the polymer dispersion may form a surface film or clumps during storage or transportation.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Q: What are the forms of S-LEC? ⇓⇑ A: S-LEC is a powdered resin with good toughness, strong adhesion, and excellent dispersibility. S-LEC is non-toxic, odorless, colorless, and transparent. It can be dissolved in solvents or formed into films, thus it can be processed by various methods and applied in a wide range of fields.   Q: What are the forms of S-LEC? ⇓⇑ A: The standard form of S-LEC is a white powder, but it is also available in granular and liquid forms. The availability of different grades of S-LEC varies. Please contact our company for details.   Q: How to use S-LEC?                                                                                                                    ⇓⇑ A:The most common use is to dissolve S-LEC in organic solvents and mix it with various powders (such as inorganic powders and pigments). It can also be melted by heating. Through heating processes, S-LEC can be made into sheets or ued as a raw material for adhesives.   Q: Which solvents can S-LEC dissolve in? ⇓⇑ A: S-LEC is soluble in a variety of solvents, such as alcohols, esters, ketones, and aromatic solvents. The types of solvents that S-LEC can dissolve in vary depending on its grade.   Q: What are the benefits of using S-LEC?  ⇓⇑ A: S-LEC improves coating toughness, enhances adhesion to other materials, and achieves uniform dispersion in solutions such as pastes and inks. Furthermore, it offers a variety of unique benefits that aid in product development.   Q: What products are S-LEC used in? ⇓⇑ A: S-LEC can be used as an interlayer film in laminated glass, a ceramic adhesive, and a printed circuit board adhesive, as well as in paints, inks, and many other products.   Q: How does S-LEC differ from other resins? ⇓⇑ A: The most distinctive feature of S-LEC is the simultaneous presence of both polar and non-polar groups in its resin. This unique structure allows for customized processing to meet specific customer application requirements.   Q: What is the specific impact of hydroxyl content on water resistance/chemical resistance? ⇓⇑ A: Higher hydroxyl content (e.g., S-LEC B BX-1, S-LEC B BX-L) results in stronger resin polarity, slightly increasing water sensitivity, but leading to stronger adhesion to polar substrates such as glass and metals. Grades with low hydroxyl content (such as S-LEC B BM-1, S-LEC B BM-5) exhibit stronger hydrophobicity, resulting in better water and chemical resistance.   Q: What are the storage and shelf-life requirements for S-LEC? ⇓⇑ A: S-LEC resin should be stored in a dry, cool, and well-ventilated place, avoiding direct sunlight and moisture. The packaging should be tightly sealed. Specific shelf-life details should be found in the property data sheet for the corresponding grade, but it can typically last for several years under proper storage conditions.   Q: Will S-LEC decompose or yellow at high temperatures? ⇓⇑ A: S-LEC has good thermal stability. However, during high-temperature processing (typically referring to sintering or extrusion), it is essential to ensure operation within the recommended temperature range. Its low combustion residue is a key advantage when used in adhesives requiring complete burnout, but prolonged exposure to extremely high temperatures before sintering should be avoided to prevent initial degradation.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Polyvinyl butyral resin S-LEC B and polyvinyl acetal resin S-LEC K are among the most widely used and reliable polymer materials in today's industrial fields. The success of these materials comes from their special chemical structure. It's a careful mix of hydroxyl groups, which help with adhesion and reactivity, and acetal units, which add flexibility and water resistance to the molecular chain. Because of this balance, they can be used as either thermoplastic or thermosetting resins. They are important in many industries, including electronics, cars, coatings, and printing. 1. Electronics and Energy Sector In precision manufacturing, many materials need temporary binders to hold their shape before the final molding process. After molding, these binders have to fully break down and evaporate when exposed to high heat. S-LEC B/K resins are a good option for this purpose because they mix well, stick properly, and their thermal decomposition can be controlled. ♣ Ceramic and Metal Powder Binders Applications: Molding of ceramic or metal powders in flat panel displays (FPDs), solar cells, and various electronic components. Value: As a powder binder, S-LEC B/K effectively disperses particles and provides good dimensional stability, ensuring the integrity of the green body structure before sintering. The resin decomposes cleanly during high-temperature sintering, according to thermogravimetric analysis. Decomposition mainly happens between 300°C and 500°C. This prevents leftover material from negatively impacting the final performance of the electronic parts. Specific Grades: Specific S-LEC B grades with high molecular weights are advised for this use because of their strong film durability and bond. ♣ Printed Circuit Board Adhesives S-LEC B/K resins are typically used in combination with thermosetting resins such as phenolic resins as adhesives between printed circuit board prepregs and copper foil. Their contributions include: Flexibility and Solderability: The flexibility provided by S-LEC B/K improves the stress absorption capacity of the cured resin system, helping to enhance the adhesive layer's resistance to thermal shock and ensuring excellent peel resistance. High Tg Advantage: In PWB applications with extremely high heat resistance requirements, the high glass transition temperature (Tg) grades of S-LEC K (e.g., S-LEC K KS-5 or S-LEC K KS-10) are even more important, providing the necessary thermal stability to withstand subsequent processing temperatures.   2. Coatings and Varnishes S-LEC B/K resin is also useful in coatings and varnishes because it sticks well to many surfaces like metals, plastics, and glass. Also, it works well with other resins for crosslinking, which is a key advantage. ♣ Wash Primer Main Function: This is one of the most classic applications of S-LEC B/K. It is a pretreatment primer for metals such as steel and aluminum, effectively improving the adhesion of subsequent topcoats to the metal surface and providing short-term rust protection. Applications: Widely used in structural components requiring underlying protection, such as ships, bridges, automotive refinish paints, and rail vehicles. Formulation Advantages: S-LEC B/K shows great compatibility by creating strong bonds with many topcoats, such as those made from PVC, melamine, or oil-based phenolic coatings. ♣ Metallic Varnishes and Baking Coatings S-LEC B/K, when mixed with phenolic resin pre-condensate, can be used to create high-quality baking coatings for food containers. Its addition significantly improves the toughness, adhesion, and service durability of the coating. In metal foil varnishes, this resin provides a transparent, flexible protective layer. ♣ Leather Coatings S-LEC B grades, due to their unique chemical structure, offer high flexibility and low-temperature impact resistance, making them particularly suitable for leather coatings. Leather surfaces coated with S-LEC B resin exhibit excellent elongation at room temperature, with no significant loss of performance even at low temperatures, forming a soft and resilient film on the leather.   3. Printing Inks In the printing ink field, S-LEC B/K resin acts as a pigment binder and dispersant, suitable for flexographic and gravure printing. Key Properties: Grades suitable for inks are typically low-viscosity S-LEC B/K, such as S-LEC B BL-10. Function: The resin ensures uniform dispersion of pigments in solvents and provides strong adhesion to substrates (such as plastic films) after ink curing. Its non-toxic and odorless properties make it advantageous in food packaging and applications where odor is critical.   4. Specialized Adhesive Applications Besides its application in PWB (Polarization and Welding), S-LEC B/K is also used as a key adhesive, either alone or in combination with other materials. ♣ Enamelled Coil Bonding Dipping or coating the enameled wire of a coil with an S-LEC B/K solution and then heating to melt or cure the resin achieves strong bonding and fixation between conductors. This is used in the manufacture of coils for motors and transformers, improving structural stability and insulation. ♣ Adhesive Formulation Substrates S-LEC B/K has hydroxyl groups in its structure, which allows it to cross-link with materials like isocyanates or epoxy resins. This process creates composite adhesives that have good heat resistance, toughness, and adhesive properties.   5. Other Miscellaneous Applications The versatility of S-LEC B/K resin also makes it play an important role in many niche professional fields. ♣ Reflective Film Adhesive In the manufacture of reflective films (such as road traffic signs), S-LEC B/K serves as an adhesive for the reflective layer of glass beads. Its advantages lie in its high film transparency, excellent dispersion of pigments (such as aluminum powder), and strong adhesion to plastic films such as PET. ♣ Magnetic Recording Tape Coating The resin exhibits excellent dispersibility and adhesion to magnetic powders, making it suitable for use as a magnetic powder coating adhesive in advanced magnetic recording tapes (such as audio and video tapes). ♣ Dye Transfer Ribbon Inks In sublimation transfer technology, S-LEC B/K resin is used to manufacture dye inks due to its excellent dispersibility for sublimated dyes.   The S-LEC B/K resin series has found widespread use in modern industry because its chemical structure can be modified to provide good adhesion, crosslinking, flexibility, and a wide glass transition temperature range. S-LEC B is used in both flexible and traditional coatings, while S-LEC K is used in high glass transition temperature electronic adhesives. These resins are important high-performance materials that help to advance industrial innovation and improve products.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

S-LEC B and S-LEC K are types of polymers that work well in coatings, adhesives, and electronics. They can handle many different and difficult jobs because of how their molecules are arranged. Specifically, their solubility and how they handle heat are carefully managed. 1. Solubility Characteristics: The Structural Basis for Solvent Selection S-LEC B/K resins are quite soluble, dissolving in alcohols, esters, ketones, and aromatics, especially well in alcohols. Solubility differences among grades show variations in their chemical makeup. 1.1 The Mechanism of Structure's Influence on Solubility Solubility is primarily constrained by the contradictory relationship between the hydroxyl content and acetal content on the resin molecular chain. Hydroxyl Content: Hydroxyl groups exhibit polarity; resins with a greater amount of hydroxyl content show increased hydrophilicity and polarity. Because of this, the resin will dissolve better in polar solvents like alcohols and become more reactive with thermosetting resins. Still, too much hydroxyl content can make the resin less flexible and more vulnerable to water damage. Acetal Content: Acetal units are nonpolar groups. The higher the acetal content, the more pronounced the nonpolar characteristics of the resin. This makes it more soluble in nonpolar solvents and improves its flexibility, water resistance, and compatibility with other nonpolar resins. 1.2 Solubility Differences Between Models Analysis of the solubility table reveals different solvent preferences for different models: S-LEC B low molecular weight, high hydroxyl grades (e.g., S-LEC B BL-1): These grades have a high hydroxyl content (e.g., BL-1H has a hydroxyl content of approximately 30 mol%), therefore exhibiting complete solubility in most alcohol solvents (e.g., methanol, ethanol, isopropanol) and strongly polar solvents (e.g., N,N-dimethylformamide). S-LEC K high Tg grades (e.g., S-LEC K KS-1): S-LEC K resins are designed to provide high thermal stability, and their molecular structure can be more tightly packed. Some KS grades, though still polar due to their hydroxyl content (around 25 mol%), either swell or partially dissolve in alcohols like methanol and ethanol. This suggests the acetal structure affects how well these polar solvents wet the molecules. This behavior shows the distinct properties of their chemical composition. 1.3 Advantages of Mixed Solvents One characteristic of S-LEC B/K is that it allows for a wider range of water tolerance in solvents. Furthermore, using mixed solvents generally produces better dissolution results because: Reduced viscosity: Mixed solvents help reduce the overall viscosity of the solution, facilitating application handling. Storage stability: Mixed solvents help maintain stable solution viscosity, which is beneficial for long-term storage. Optimized solubility: The polar/non-polar balance of the mixed solvents allows for more effective wetting of the three structural units of the resin.   2. Thermodynamic Properties: The Dominant Role of Tg and Softening Point The thermal properties, like the glass transition temperature (Tg) and softening point, are key to how well a resin holds up and can be molded at high temperatures. The S-LEC B/K series comes in a variety of Tg values, ranging from 59°C to 110°C. This allows them to be used in situations requiring flexibility at low temperatures or heat resistance when things get hot. 2.1 Structural Differences in Glass Transition Temperature (Tg) S-LEC K (High Tg Type): S-LEC K resin utilizes shorter acetaldehyde side chains (R:CH3), resulting in a denser molecular chain packing and achieving the highest Tg value in the series. For example, both KS-3 and KS-5 can reach a Tg of 110°C, making them ideal materials for applications requiring high thermal stability, such as bonding electronic components. S-LEC B (General Purpose and Flexible Type): S-LEC B employs longer butyraldehyde side chains (R: -CH2CH2CH3), increasing the spacing between molecular chains and free volume, resulting in a relatively low Tg. For example, BL-10 has a Tg of only 59℃. This lower Tg endows S-LEC B with excellent toughness and flexibility, exhibiting outstanding impact resistance at low temperatures. 2.2 Synergistic Effect of Tg and Molecular Weight On the Tg graph (Figure 9), the Tg of the same acetal type (e.g., S-LEC B) generally shows a slight increasing trend with increasing molecular weight. For example, the Tg range of medium molecular weight grades (e.g., BM-1) and high molecular weight grades (e.g., BH-3) is roughly between 60℃ and 70℃. Higher molecular weight contributes to improved thermodynamic stability of the polymer. 2.3 Softening Point The softening point is an important indicator for measuring the hot melting behavior of resins. The softening point diagram (Figure 10) shows that the S-LEC B/K grades have a wide softening point range, from approximately 100°C to over 200°C. Consistent with the Tg trend, high Tg grades of S-LEC K, such as KS-5, can achieve softening points above 200°C, giving this resin a significant advantage in hot-melt applications and high-temperature processing.   3. Thermal Decomposition Behavior: TG Analysis Insights Thermogravimetric analysis (TG) is used to study the mass loss of resins during heating, revealing their thermal decomposition characteristics. TG analysis of S-LEC B grades (e.g., BM-S and BM-2) shows differences under different atmospheres: Inert Atmosphere (N2): Under nitrogen, the resin exhibits a relatively simple and rapid mass loss process. Decomposition typically begins around 350°C and completes major decomposition around 450°C. Oxidizing Atmosphere (Air): Under air, the decomposition process typically presents a multi-stage mass loss curve. The first stage of decomposition occurs between 300°C and 400°C, followed by a second stage of oxidative decomposition at approximately 450°C to 550°C, ultimately potentially leading to complete combustion.   The solubility and thermodynamic properties of S-LEC B and S-LEC K resins form the basis for their versatile applications. By precisely controlling the side chains (butyraldehyde and acetaldehyde) of the acetal units, as well as the ratio of hydroxyl groups to molecular weight, this series of resins achieves the following objectives: Solubility: Solvent mixtures balance polar (hydroxyl) and non-polar (acetal) characteristics to suit different coating types. Mixing solvents helps reach the required application viscosity. Thermodynamic Properties: Flexible switching between the high Tg of S-LEC K (up to 110°C) and the low Tg of S-LEC B (down to 59°C) ensures a wide range of applications, from low-temperature flexibility to high-temperature heat resistance.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

High-performance resins hold a unique position in the landscape of modern industrial materials due to their superior comprehensive properties. Among many similar products, polyvinyl butyral resins S-LEC B and S-LEC K, with their unique and flexible chemical structures, have become key solutions in fields ranging from high-precision electronics manufacturing to specialty coatings. S-LEC B was first introduced in the 1930s, initially used in industry as an interlayer film for safety glass, establishing its position among high-performance polymers. S-LEC K, as a functional extension of this series, focuses on applications with stringent requirements for heat resistance due to its high glass transition temperature (Tg). Although both are collectively referred to as the S-LEC B/K series, their performance differences are rooted in their sophisticated chemical structure design.   1. Core Chemical Structure: The Source of Performance Both S-LEC B and S-LEC K are derived from polyvinyl alcohol (PVA). These are prepared by reacting PVA with specific aldehydes in a reaction called acetalization. Due to limitations in the manufacturing process, the acetalization reaction cannot be completed completely, resulting in the final resin molecular chain retaining three crucial structural units that collectively determine the final product's properties:     ♠Acetal Unit: This is the core functional unit of the resin, imparting hydrophobicity and flexibility to the material. The fundamental difference between S-LEC B and S-LEC K lies in the side chain (R group) of this unit: S-LEC B: The aldehyde group R used in acetalization is -CH2CH2CH3. The longer side chain gives S-LEC B superior flexibility and solubility in nonpolar solvents. S-LEC K: The aldehyde group R used in acetalization is -CH3. The shorter side chain results in a more compact packing of molecular chains, giving S-LEC K a higher glass transition temperature (Tg) and better thermal stability. ♣Hydroxyl Unit (OH):The unit refers to the part of PVA that hasn't reacted and remains within the resin molecule in a specific ratio. The hydroxyl group gives the resin good adhesion—particularly to polar surfaces like metals and glass—and makes it attract water. More crucially, this hydroxyl group lets the resin form cross-links with resins that harden when heated, like epoxy resins and isocyanates. This hardening broadens the resin's use. ♣Acetyl Unit: These trace units remain because of incomplete breakdown during PVA production. The proportions of these three units in the molecular chain, precisely controlled through the manufacturing process, constitute the vast spectrum of the S-LEC B/K series resin grades.   2. Performance Regulation: A Precise Balance of Influencing Factors The physical and chemical properties of this series of resins are not fixed but are precisely regulated by the following three core factors: 2.1 The Unity of Opposites and Hydroxyl Content The acetal and hydroxyl content in the molecular structure usually exhibit an inverse relationship, and their balance directly determines the key properties of the resin: Flexibility and Water Resistance: The higher the acetal content, the more pronounced the non-polar characteristics of the resin, the better the flexibility, water resistance, and compatibility with non-polar resins. Adhesion and Reactivity: The amount of hydroxyl groups present strongly affects how well a resin sticks, particularly when polar adsorption is needed. At the same time, the hydroxyl content also influences how the resin reacts with thermosetting resins and how easily it dissolves in polar solvents. 2.2 The Decisive Role of Molecular Weight in Application Performance The molecular weight (degree of polymerization) of the resin directly affects the following crucial application characteristics: Film Toughness: The higher the molecular weight, the stronger the toughness of the film or coating made from the resin. Solution Viscosity: Molecular weight is the main factor affecting solution viscosity. At a given solids content, higher molecular weight grades offer higher solution viscosity, making them suitable for certain thickening or high-viscosity applications. Adhesion: Molecular weight also significantly impacts final adhesive strength. The S-LEC B/K series offers a wide molecular weight range, from approximately 14,000 to 130,000. Engineers can choose materials based on the needed viscosity, strength, and flexibility by picking different acetal contents. 2.3 Thermodynamic Properties: Tg and Heat Resistance Stability The glass transition temperature (Tg) is a core indicator of a material's heat resistance. This series of resins covers a Tg range from 59°C to 110°C, enabling them to meet the needs of applications ranging from low-temperature applications requiring high flexibility to high-temperature applications requiring high stability: Advantages of S-LEC K: S-LEC K acetal resins, such as S-LEC K KS-1, S-LEC K KS-5, and S-LEC K KS-10, usually show the highest glass transition temperature (Tg), reaching up to 110°C. This makes them good for uses needing high heat resistance and a high softening point—some types can reach 200°C. Examples include bonding printed circuit boards and in difficult electronic parts. Advantages of S-LEC B: S-LEC B acetal resins, which have lower glass transition temperatures, provide good impact resistance at low temperatures and increased flexibility.   3. Functional Expansion: Crosslinking Reaction and Thermosetting Potential     The S-LEC B/K series is not limited to use as a thermoplastic material. Because it has many hydroxyl groups, this substance can crosslink and cure when mixed with different thermosetting resins like phenolic resins, epoxy resins, or isocyanates. This crosslinking capability is a significant advantage in industrial applications, allowing engineers to combine the superior toughness, adhesion, and flexibility of thermoplastic resins with the high heat resistance, chemical resistance, and mechanical strength of thermosetting resins through formulation design. The result is composite materials that perform well, overcoming the limits of single resins. For instance, this crosslinking and curing process is key to achieving the needed performance in high-end coatings and adhesives.   S-LEC B and S-LEC K resins are important types of high-performance polymers. These resins are valued because their properties, like flexibility and adhesion, can be adjusted. This is achieved by carefully managing the acetal side chains (using butyraldehyde or acetaldehyde) and the amount of hydroxyl content in the resin. This meticulous control over molecular structure ensures that S-LEC B/K can continuously provide high-performance material solutions for multiple key industrial sectors, including electronics, automotive, coatings, and adhesives.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com