S-LEC B BX-L

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

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