POLYCHLOROPRENE-BASED BONDING ADHESIVES

1 . An adhesive composition comprising:

i. a solids component, said solids component including a rubber component that includes polychloroprene; and

ii. a solvent component, where the solvent component includes from 150 to 500 parts by weight t-butyl acetate, from 50 to 300 parts by weight acetone, from 5 to 100 parts by weight methyl acetate, and where the solvent component further includes 5 to 300 parts by weight toluene per 100 parts by weight rubber.

2 . The composition of claim 1 , where the solvent component includes from 285 to 310 parts by weight t-butyl acetate, from 170 to 190 parts by weight acetone, and from 15 to 25 parts by weight methyl acetate, per 100 parts by weight rubber.

3 . The composition of claim 2 where the solvent component further includes 35 to 45 parts by weight toluene per 100 parts by weight rubber.

4 . The composition of claim 1 , where the rubber component further includes poly-(styrene-co-butadiene).

5 . The composition of claim 1 , where the rubber component is devoid of a complementary rubber, and where the solids component includes an adhesion promoter.

6 . An adhesive composition comprising:

i. a solids component, said solids component including a rubber component, a synthetic thermosetting resin, and a hydrocarbon resin, where the rubber component includes polychloroprene; and

ii. a solvent component, said solvent component including 150 to 500 parts by weight t-butyl acetate, from 50 to 300 parts by weight acetone, from 5 to 100 parts by weight methyl acetate, and where the solvent component further includes 5 to 300 parts by weight toluene per 100 parts by weight rubber per 100 parts by weight rubber.

7 . The adhesive composition of claim 6 , where the rubber component includes at least 70% by weight polychloroprene.

8 . The adhesive composition of claim 7 , where the solids component is substantially devoid of a rubber other than polychloroprene.

9 . The adhesive composition of claim 8 , where the polychloroprene includes a first polychloroprene characterized by a solution viscosity of from 70 to 215 mPa•s and a second polychloroprene characterized by a solution viscosity of from about 700 to about 1,000 MPa•s.

10 . The adhesive composition of claim 9 , where the solids component includes at least 20 parts by weight thermosetting resin per 100 parts by weight rubber.

11 . The adhesive composition of claim 10 , where the solids component includes at least 10 parts by weight hydrocarbon resin per 100 parts by weight rubber.

12 . The adhesive composition of claim 11 , where the solids component further includes at least 1 part by weight magnesium oxide per 100 parts by weight rubber.

13 . The adhesive composition of claim 12 , where the solids component includes at least 0.5 parts by weight zinc oxide per 100 parts by weight rubber.

14 . The adhesive composition of claim 13 , where the solids component includes at least 0.1 parts by weight antioxidant per 100 parts by weight rubber.

15 . The adhesive composition of claim 14 , where the solids component includes at least 0.5 parts by weight adhesion promoter per 100 parts by weight rubber.

16 . The adhesive composition of claim 15 , where the adhesion promoter is chlorinated polypropylene.

17 . A method of contact bonding a roofing membrane to a substrate, the method comprising:

iii. applying a contact adhesive composition to a portion of a roofing membrane panel to form a wet film on the membrane panel;

iv. applying a contact adhesive composition to at least a portion of a substrate to form a wet film on the substrate;

v. allowing the wet film on the membrane and the wet film on the substrate to set up for desirable contact bonding; and

vi. mating the membrane to the substrate, where the adhesive composition includes

a. a solids component, said solids component including a rubber component, a synthetic thermosetting resin, and a hydrocarbon resin, where the rubber component includes polychloroprene; and

b. a solvent component, said solvent component including t-butyl acetate, toluene, acetone, and methyl acetate.