Rubber Adhesive RA-65

RA-65 is a supported rubber bonding agent based on Hexamethoxymethylmelamine (HMMM) with silica as carrier. It functions as a methylene donor in the RFS bonding system. When combined with resorcinol-based methylene acceptors (such as RE resin, GLR-20, etc.), it releases methylene groups during vulcanization and forms an adhesive resin layer at the interface between rubber and reinforcing materials. It greatly improves the bonding strength between rubber and steel cord, nylon, polyester, rayon and other fiber reinforcements. As a pre-dispersed powder, RA-65 avoids the melting and sticking issues of pure crystalline HMMM. It features good flowability and non-caking property, easier for mixing processing. It is widely used in tires, conveyor belts and rubber hoses.

• Reliable bonding performance: stably provides methylene groups, works synergistically with resorcinol resin for high bonding retention, good heat and humidity resistance;
• Pre-dispersed formulation: HMMM supported on silica, free-flowing powder, no melting or sticking on mixing rolls;
• Good processability: low dusting, stable feeding & dosing, excellent dispersion during final mixing;
• Better storage stability than neat crystalline HMMM, resistant to caking and sticking;
• Minor influence on basic vulcanization characteristics and physical properties of rubber compounds.

• Radial tires (steel cord & textile cord bonding);
• Steel cord conveyor belts, fabric reinforced conveyor belts;
• High-pressure rubber hoses, hydraulic hoses and fiber reinforced rubber goods;
• Other rubber composite products requiring strong rubber-to-reinforcement bonding.

Keep tightly sealed in cool, dry and well-ventilated warehouse. Keep away from heat, fire and direct sunlight. Storage temperature ≤30℃. Prevent moisture absorption. Do not store together with strong oxidants, strong acids or alkalis.

Shelf life: 12 months under proper storage with original unopened packaging. 

25kg per bag, inner PE liner and outer kraft paper bag with lamination. Customized package available upon request.

1. Does RA-65 work alone for adhesion? 

No. It must be used together with resorcinol-based methylene acceptors (such as RE resin, GLR-20 etc.) to form a complete RFS bonding system. It cannot deliver bonding effect by itself.

2. What is the difference between RA-65 and pure HMMM crystal? 

Pure HMMM is crystalline and easy to melt, turn sticky and cake during mixing. RA-65 is HMMM loaded on silica, free-flowing powder, non-sticking on mill rolls, lower dust and better storage stability. The bonding mechanism is identical.

3. What are the main applications of RA-65?

It is widely used in radial tires, steel cord / fabric conveyor belts, high-pressure hydraulic hoses and other rubber composite products that need strong bonding between rubber and steel cord, nylon, polyester or rayon.