Description

Styrene/Butyl Methacrylate Copolymer is a synthetic polymer engineered by the copolymerization of styrene and butyl methacrylate monomers. This versatile material is valued for its balanced properties, offering a unique combination of hardness, clarity, and weatherability. It serves as a critical performance additive and film-forming agent in advanced coatings, adhesives, and specialty plastics for industries demanding high durability and aesthetic finish.

Application

• Industrial & Protective Coatings: Used as a binder or modifier in metal, wood, and plastic coatings to enhance gloss retention, chemical resistance, and outdoor durability.
• Automotive Refinish & OEM Paints: Imparts excellent flow, leveling, and UV stability in clear coats and pigmented automotive paint systems.
• Adhesives & Sealants: Acts as a key film-forming polymer in pressure-sensitive adhesives (PSAs) and construction sealants, providing strong adhesion and flexibility.
• Printing Inks: Serves as a resin component in overprint varnishes and specialty inks to improve rub resistance, gloss, and drying characteristics.
• Plastic Modification: Utilized as a processing aid or impact modifier to tailor the mechanical and surface properties of engineering plastics.
• Textile & Leather Finishes: Applied in coatings for fabrics and leather to provide a protective, flexible, and water-resistant finish.

Basic Information

Product Name	Styrene/Butyl Methacrylate Copolymer
CAS No.	25213-39-2
Molecular Formula	(C8H8·C8H14O2)n
Molecular Weight	Varies by monomer ratio and polymerization degree
Synonyms	Styrene Butyl Methacrylate Copolymer; Butyl Methacrylate Styrene Copolymer; Poly(styrene-co-butyl methacrylate); SBM Copolymer; SBMA; Acrylic Styrene Copolymer; Butyl Methacrylate-Styrene Resin; Joncryl 678 (example trade name); Paraloid B-66 (example trade name)
EINECS	Contact for details

Quality Control

Our Styrene/Butyl Methacrylate Copolymer is manufactured under a strict quality management system. Each batch is tested against stringent in-house specifications to ensure consistent performance in viscosity, solids content, glass transition temperature (Tg), and monomer residue. A Certificate of Analysis (COA) detailing these parameters is provided with every shipment to guarantee traceability and compliance with your formulation requirements.

Storage

Preserve in a tightly closed container, protected from light. Store in a cool, dry, and well-ventilated area at room temperature (15-25°C). Keep away from heat sources and open flames. Under recommended conditions, the product has a typical shelf life of 24 months from the date of manufacture.

Specification

Item	Specification
Appearance	Clear, colorless to pale yellow pellets or solution
Solid Content	≥ 98.5% (Pellet) / 40-50% (Solution, typical)
Viscosity (Solution, 25°C)	200 - 800 mPa·s (Grade dependent)
Glass Transition Temperature (Tg)	40 - 70 °C (Grade dependent)
Acid Value	≤ 1.0 mg KOH/g
Residual Monomer (Styrene)	≤ 1000 ppm
Residual Monomer (Butyl Methacrylate)	≤ 1000 ppm
Color (Gardner)	≤ 2

Note: Specifications can be tailored. Please contact us for the detailed technical data sheet of a specific grade.