Лако-красочные материалы — производство

Parts by weight (wet)

60% Natural rubber latex 167

50% Dispersion of zinc dibutylthiocarbamate 2

10% Solution of ammonium caseinate 10

2. Adhesives for the carpet industry. Formulations for backing carpets of hessian and polypropylene staple construction are given below.

Ingredients are to be mixed in the order given above. The stabilizer, thiourea, water, and antioxidant must be completely dispersed in the mix before adding the whiting. The whiting must be completely dispersed in the mix before adding thickeners.

5. Tire cord adhesive

Parts by weight (wet)

60% Natural rubber latex 125

40% Vinyl pyridine latex 62.5

Water 507

Resorcinol-formaldehyde resin solution 266.3

Water 240

Sodium hydroxide 0.3

Resorcinol 11

40% Formaldehyde solution 15

Mature for 6 h at 25°C

Solution adhesives consist of solid rubber dissolved in a solvent such as toluene, naphtha, or trichloroethane. The solvent used will depend on the drying and flammability consid­erations in the application. Milled raw rubber can be shredded and agitated in the solvent until a clear solution is obtained. Other components are added at this stage and mixed uniformly. Alternatively, the solid rubber can be compounded with other components and the mix dissolved in the solvent.

Solution adhesives are applied at 10-25% total solids content by spray, doctor knife, reverse roll coater, roller, or by spatula or trowel. The adhesive is dried at room tempera­ture or in air ovens, care being taken to eliminate the fire and health hazards associated with some solvents.

The toughness and durability of the bond may be improved by using vulcanizable rubber solution adhesives. These are normally supplied as two components which are mixed prior to use. Component A is prepared as follows:

Component B is prepared as follows: To 100 parts of component A, add 4 parts of a 10% solution of a dithiocarbamate accelerator. The mixed adhesive will vulcanize at room temperature or at a higher temperature, if required. Typical vulcanizing time at room temperature is 3-4 days.