Claims
- 1. A hot-melt, silicone pressure sensitive adhesive composition, comprising a mixture of (i) a silicate resin, (ii) a silicone fluid, and (iii) an alkylmethylsiloxane wax which decreases dynamic viscosity of the adhesive composition at temperatures equal to or below about 200.degree. C.
- 2. The adhesive composition of claim 1, wherein the alkylmethylsiloxane wax is selected from the group consisting of waxes having the following formulations:
- (RMeSiO).sub.x
- wherein R is C.sub.n H.sub.2n+1, Me is CH.sub.3, 14.ltoreq.n.ltoreq.28, and X is an integer from 4 to 6;
- RMe.sub.2 SiOSiMe.sub.2 R
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18;
- RMe.sub.2 SiOSiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- RMeSi(OSiMe.sub.3).sub.2
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- Me.sub.3 SiO(RMeSiO).sub.x (R'MeSiO).sub.y SiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18, R' is H or C.sub.n H.sub.2n+1 and n.gtoreq.1, when R' is H or CH.sub.3 then the ratio of X:Y is greater than 1:3;
- RSiO.sub.3/2
- wherein R is C.sub.n H.sub.2n+1, and n.gtoreq.1; and mixtures thereof.
- 3. The adhesive composition of claim 1, wherein the alkylmethylsiloxane wax is present in an amount between about 1.0 and about 25.0 percent by weight based on total adhesive composition weight.
- 4. The adhesive composition of claim 1, wherein the alkylmethylsiloxane wax is present in an amount between about 5 percent and about 15 percent by weight based on total adhesive composition weight.
- 5. The adhesive composition of claim 1, wherein the silicone pressure sensitive adhesive containing the alkylmethylsiloxane wax has a dynamic viscosity less than or equal to 800 poise at a temperature equal to or below 200.degree. C.
- 6. A hot-melt, silicone pressure sensitive adhesive composition, comprising:
- (a) between about 30 and about 70 percent by weight silicate resin;
- (b) between about 22 and about 60 percent by weight silicone fluid; and
- (c) between about 1.0 and about 25 percent by weight based of an alkylmethylsiloxane wax,
- all weight percents being based on total composition weight, and said alkylmethylsiloxane wax decreasing dynamic viscosity of the resultant adhesive composition at temperatures ranging from about 50.degree. C. to about 200.degree. C.
- 7. The adhesive composition of claim 6, wherein the alkylmethylsiloxane wax is selected from the group consisting of waxes having the following formulations:
- (RMeSiO).sub.x
- wherein R is C.sub.n H.sub.2n+1, Me is CH.sub.3, 14.ltoreq.n.ltoreq.28, and X is an integer from 4 to 6;
- RMe.sub.2 SiOSiMe.sub.2 R
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18;
- RMe.sub.2 SiOSiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- RMeSi(OSiMe.sub.3).sub.2
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- Me.sub.3 SiO(RMeSiO).sub.x (R'MeSiO).sub.y SiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18, R' is H or C.sub.n H.sub.2n+1 and n.gtoreq.1, when R' is H or CH.sub.3 then the ratio of X:Y is greater than 1:3;
- RSiO.sub.3/2
- wherein R is C.sub.n H.sub.2n+1, and n.gtoreq.1; and mixtures thereof.
- 8. The adhesive composition of claim 1, wherein the silicate resin is a benzene-soluble resinous copolymer containing silicon-bonded hydroxyl radicals and consisting essentially of triorganosiloxy units of the formula R.sub.3 SiO.sub.1/2 and tetra functional siloxy units of the formula SiO.sub.4/2 in a ratio of about 0.6 to 0.9 triorganosiloxy units for each tetra functional siloxy unit present in the copolymer, wherein each R is a monovalent radical independently selected from the group consisting of hydrocarbon radicals of from 1 to 6 inclusive carbon atoms, and the silicone fluid is a silanol-endstopped polydiorganosiloxane fluid.
- 9. The adhesive composition of claim 1, wherein the silicate resin is a cohydrolysis product of a trialkyl hydrolyzable silane and an alkyl silicate, wherein the cohydrolysis product contains a plurality of silicon-bonded hydroxy groups, and the silicone fluid is a linear organopolysiloxane fluid containing silicon-bonded hydroxy groups.
- 10. A hot-melt, silicone pressure sensitive adhesive composition, comprising:
- a mixture of
- (i) between about 30 and about 70 percent by weight of a silicate resin,
- (ii) between about 22 and about 60 percent by weight of a silicone fluid, and
- (iii) between about 1.0 and about 25.0 percent by weight of an alkylmethylsiloxane wax which decreases the dynamic viscosity of the adhesive composition at temperatures equal to or below about 200.degree. C., the alkylmethylsiloxane wax selected from the group consisting of waxes having the following formulations:
- (RMeSiO).sub.x
- wherein R is C.sub.n H.sub.2n+1, Me is CH.sub.3, 14.ltoreq.n.ltoreq.28, and X is an integer from 4 to 6;
- RMe.sub.2 SiOSiMe.sub.2 R
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18;
- RMe.sub.2 SiOSiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- RMeSi (OSiMe.sub.3).sub.2
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.24;
- Me.sub.3 SiO(RMeSiO).sub.x (R'MeSiO).sub.y SiMe.sub.3
- wherein Me is CH.sub.3, R is C.sub.n H.sub.2n+1, and n.gtoreq.18, R' is H or C.sub.n H.sub.2n+1 and n.gtoreq.1, when R' is H or CH.sub.3 then the ratio of X:Y is greater than 1:3;
- RSiO.sub.3/2
- wherein R is C.sub.n H.sub.2n+1, and n.gtoreq.1; and mixtures thereof,
- the percents by weight based on the total adhesive composition weight, the adhesive composition having a dynamic viscosity less than or equal to 800 poise at a temperature equal to or below 200.degree. C.
Parent Case Info
This is a division of U.S. patent application Ser. No. 07/733,573, filed Jul. 22, 1991, now U.S. Pat. No. 5,300,299.
US Referenced Citations (8)
Foreign Referenced Citations (2)
Number |
Date |
Country |
0443759 |
Aug 1991 |
EPX |
0452034 |
Oct 1991 |
EPX |
Divisions (1)
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Number |
Date |
Country |
Parent |
733573 |
Jul 1991 |
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