PVB Resin B-02HX

Polyvinyl butyral (PVB), due to its excellent transparency, toughness, superior metal adhesion, and good film-forming properties, occupies an important position in coatings, adhesives, printing inks, and safety glass interlayers. By adjusting the degree of polymerization (molecular weight), degree of acetalization, and residual hydroxyl content, PVB is endowed with diverse physicochemical properties, forming a matrix of specifications to meet different industrial needs.     1. Core Specification System: Performance Comparison of HX, SY, and TX Series The differences in PVB specifications are mainly reflected in two dimensions: viscosity (molecular weight) and degree of acetalization. 1.1 Differences in Viscosity (Molecular Weight) Grades Viscosity is a core indicator determining the processing fluidity and film strength of PVB. ♠ Low-viscosity grades (PVB Resin B-02HX, CCP B-03HX): Performance characteristics: Excellent dissolution speed and low viscosity at high solid content, with strong permeability. Key applications: Mainly used in printing inks, metal foil coatings, and penetrating primers. Due to its shorter molecular chains, it provides a smooth film surface and good wettability. ♠ Medium-viscosity grades (CCP B-06HX, Changchun PVB B-08HX): Performance characteristics: Balances processability and toughness, making it the most widely used "all-rounder" grade. Key applications: Widely used in wood coatings (sealers) and ceramic adhesives. Its viscosity is sufficient to maintain pigment suspension while ensuring the strength of the green body after sintering. ♠ High-viscosity grades (Changchun PVB B-17HX, PVB B-20HXB): Performance characteristics: High molecular weight, resulting in extremely high impact strength and tensile strength after film formation. Key applications: Primarily used in safety helmets/composite materials and peelable protective films. In these areas, PVB provides strong structural support, preventing materials from shattering under stress. 1.2 Trade-off between Degree of Acetalization and Polarity ♣ HX series (standard type): The degree of acetalization ranges from 72-88wt%, providing good general solubility (e.g., in alcohol solvents). ♣SY series (high degree of acetalization): This series has a higher butyral group content. Comparative Advantages: Increased acetal content means enhanced hydrophobicity. Compared to the HX series, the SY series exhibits superior solubility in non-polar solvents (such as methyl ethyl ketone and toluene mixtures), lower water absorption, and better dimensional stability. It is commonly used in special paints or precision electronic adhesives requiring excellent water resistance. ♣ TX Series (Special Modification): Comparative Advantages: Designed for high-temperature processing environments. Its optimized residual hydroxyl group distribution significantly improves heat resistance after crosslinking with resins. Key Applications: Specifically used in printed circuit boards (PCB) and copper foil adhesives, capable of withstanding the high temperatures during the soldering process.   2. Comparison of Solubility Behavior in Different Solvent Systems The performance of PVB is highly dependent on the choice of solvent. The manual indicates that PVB is readily soluble in alcohols, ketones, and esters, but insoluble in pure hydrocarbons. Solvent Strength Comparison: Alcohols (such as ethanol and isopropanol) are the most commonly used solvents, providing stable viscosity; while adding a small amount of aromatic solvents (such as toluene and xylene) not only reduces costs but also effectively lowers system viscosity and improves coating efficiency. Effect of Water Content: PVB is extremely sensitive to water. The manual emphasizes that even a very small amount of water in the solvent can lead to a sharp increase in solution viscosity, or even gelation. Therefore, in safety glass or optical films requiring high transparency, the solvent specifications must be strictly controlled.   3. Comparison of PVB's Functional Roles in Multiple Fields Adhesion vs. Sintering Residue (Ceramic Industry) In ceramic adhesives, compared to other organic resins, PVB's advantage lies in its extremely high green strength. It allows the powder to be tightly packed in the mold and has a "residue-free" characteristic during the sintering process, ensuring the electrical performance and mechanical structure of the ceramic product. Anti-corrosion Function vs. Decorative Function (Metal Coating) In wash primers, PVB reacts with chromates and phosphates to form a chemically bonded layer on the metal surface, providing excellent anti-corrosion performance. This contrasts sharply with its role as purely a leveling agent and film-forming agent in baked enamel coatings for metal cans. Enhanced Toughness (Resin Modification) When PVB is used in combination with epoxy resin or phenolic resin, its function shifts from being the "main film-forming component" to a "modifier." Compared to the brittleness of pure epoxy resin, the addition of PVB significantly improves impact toughness and adhesion to metals due to the incorporation of long-chain PVB into the cross-linked network formed during the resin curing process.   Low-viscosity grades prioritize flow and penetration, making them ideal for inks and primers; High-viscosity grades prioritize strength and toughness, making them core components for structural materials and protective films; High acetal content and modified grades (SY/TX) provide specialized solutions for extreme environments requiring water and heat resistance.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Compatibility The compatibility of Butvar polyvinyl butyral resins (PVB) with various plasticizers, modifiers, and additional resins is extensively documented. Butvar is readily amenable to compounding with other additives to improve its physical and chemical characteristics. Plasticizers are frequently utilized to enhance flexibility across a wider temperature spectrum, as noted in Table 9.   Crosslinking agents, including Santolink phenolic and Resimene amino resins, are employed to provide superior toughness and thermal stability. The compatibility of Butvar polyvinyl butyral resins (Butvar B-98 &  PVB WWW-A-20) with other modifiers and resins is illustrated in Table 10.   Insolubilizing Reactions Numerous applications of vinyl acetal resins involve curing processes that utilize thermosetting resins to achieve the desired property balance. The free hydroxyl groups present in vinyl acetal resins serve as reactive sites for chemical interaction, allowing for the insolubilization of the resins. Generally, any chemical reagent or resinous material capable of reacting with secondary alcohols will interact with polyvinyl butyral (Butvar B-76 & WWW-A-30) to reduce its solubility. The characteristics of coatings can vary significantly depending on the type and quantity of crosslinking agents employed.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com

Butvar brand resins generally are soluble in alcohols, glycol ethers, and certain mixtures of polar and nonpolar solvents. In general, Butvar B-98 (PVB Resin B-05SY) resin will show the same general compatibility characteristics as Butvar B-90 (PVB Resin B-02HX) and, therefore, should prove advantageous where physical and chemical properties of B-90 are desired but lower solution viscosities are necessary. The same is true for Butvar B-79 in relation to Butvar B-76.     The lower hydroxyl content of Butvar B-76 and Butvar B-79 permits solubility in a wider variety of organic solvents as compared to the other grades of Butvar. One notable exception, however, is the insolubility of Butvar B-76 and Butvar B-79 in methanol. All other types of Butvar contain sufficient hydroxyl groups to allow for solubility in alcohol and in hydroxyl-containing solvents. The presence of both butyral and hydroxyl groups permits solution in mixtures of alcohol and aromatics. Viscosities of Butvar resin solutions containing mixed solvents depend on the ratio of alcohol to aromatic. Viscosity curves for Butvar B-76, Butvar B-90, and Butvar B-98 in Graph 2 show minimum points in the general vicinity of 50% alcohol: 50% aromatic.     A common solvent for all of the Butvar resins is a combination of 60 parts toluene and 40 parts ethanol (95%) by weight. For compositions of Butvar, methyl alcohol will tend to give the lowest viscosity and, therefore, will permit the use of higher solids when used as a component of a solvent blend. When much more than 10% to 15% alcohol is used in a formulation for spray application, blushing may result. They are useful as starting points in the development of solvent blends for the other types.   Website: www.elephchem.com Whatsapp: (+)86 13851435272 E-mail: admin@elephchem.com