Kemlock – Adhesives for rubber and metal

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Chemlok® 250 Kemlock – Rubber and Metal Adhesive. 1. Applications: General-purpose, single-coat thermoset adhesive for rubber and metal. II. Features: 1. Wide applicability, capable of bonding various rubbers with metals and other substrates through vulcanization. Rubbers include: natural rubber, polyisoprene rubber, styrene-butadiene rubber, cis-butadiene rubber, neoprene rubber, nitrile rubber, butyl rubber, ethylene-propylene-diene monomer rubber, and chloroprene rubber ； The substrates include metals such as carbon steel, alloy steel, stainless steel, aluminum, copper, copper alloys, magnesium, zinc, as well as some plastics and textile fibers. 2. Single-component, single-coat type, with simple processing. III. Performance: Composition: A mixture of polymers, organic compounds, and mineral fillers that is dissolved or uniformly dispersed in an organic solvent system. Color: Black. Viscosity: (25°C) 200–550 cps. Solid content: 23.5%–27.5% (by weight). Specific gravity: 1.11–1.16. Flash point: 33°C. Diluents: Toluene, xylene, chlorinated solvents. Solvents: Xylene, trichloroethylene. Shelf life: 12 months for unopened containers at 25°C. IV. Processing: ☆ Surface treatment: Mechanical treatment (sandblasting) followed by degreasing, or chemical treatment, to remove machining oils, rust, or other oxide layers. When using steel grit (beads) to spray ordinary steel, cast iron, and other ferromagnetic metals, the time allowed for storage after surface treatment should be controlled so as to prevent oxidation and rusting from occurring again ； Spray quartz sand on stainless steel, aluminum, brass, zinc, and other non-ferromagnetic metals, and the gluing must be completed within 90 minutes after surface treatment. ☆ Dilution: The adhesive can be applied directly without dilution. If necessary for practical use, it can also be appropriately diluted with the aforementioned diluent. When adding the diluent, it should be added slowly while stirring continuously. To prevent precipitation caused by accidental operations. ☆ Stirring: It must be thoroughly stirred before applying the adhesive; it can be used only after a uniform mixture is achieved. ☆ Coating: CH250 is evenly applied to the surface of substrates such as metal using brushing, rolling, dipping, rolling, or transfer methods. ☆ Glue application tip: When brushing on the glue, make sure to maintain a uniform thickness of the glue layer ； During dip coating, it can be diluted with high-grade xylene at a concentration of 10–25% of the original solution volume, so as to maintain a viscosity of 30–48 seconds (Zahn #2 cup). By adjusting the withdrawal speed appropriately, dripping and runoff can be reduced ； During spraying, it can be diluted with high-grade xylene at a ratio of 25–50% of the original solution volume, so as to maintain a viscosity of 21–24 seconds (Zahn #2 cup), thereby preventing dry spraying from affecting adhesion. ☆ Glue application thickness: When applied in a single layer, the dry film thickness should be controlled at 17.8–30.5 μm ； When applying the coating, control it at 15.2～20.3μm. ☆ Drying: Dry at room temperature for at least 20–40 minutes. ☆ Stop/Release: The glued parts can be vulcanized immediately after drying at a maximum temperature of 65°C, as needed. It is important to store them in a dry environment and to avoid exposing them to high humidity for long periods of time. ☆ Vulcanization: Once the parts to be bonded are placed in the hot mold, the rubber should be filled in quickly and the molds closed to prevent the adhesive from pre-curing and becoming ineffective, thereby ensuring that both the adhesive and the rubber vulcanize simultaneously and achieving optimal bonding properties. The actual vulcanization conditions depend on the rubber compound’s vulcanization conditions. ☆ Avoid exposure to high-humidity air during handling and storage. V. Precautions: 1. It should be stored in a dry and cool place, away from heat sources and open flames. 2. The solvent is volatile; please seal the container tightly after use. 3. Solvent vapors are harmful; ensure proper fire prevention and ventilation in the workplace to prevent long-term inhalation or skin contact.