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US4874431A Expired / Lapsed US ⏱️ 0.0 years remaining

Low volatility water repellents

Assignee: Dow Silicones Corp
•
Filing: 1988-07-14
•
Granted: 1989-10-17
•
Expires: 2008-07-14
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Abstract

Abstract A method of reducing the volatility and decreasing the evaporation loss of water repellent compositions containing a solution of an alkylalkoxysilane and a carrier prior to application of the composition to a porous substrate by acidifying the solution in order to cause rapid equilibriation of the alkylalkoxysilane and the carrier to a constant steady state condition, adding to the acidified hydrolyzed alkylalkoxsilane solution at least one metal salt catalyst to further increase the hydrolysis rate of the alkylalkoxysilane and to complete the hydrolysis and the condensation of the alkylalkoxysilane, adding at least one surface depositing agent to the acidified hydrolyzed alkylalkoxysilane solution in order to reduce evaporation of un-reacted alkylalkoxysilane, and maintaining the solution in a substantially anhydrous condition, so that the amount of hydrolyzed silane absorbed by the porous substrate and the percentage of water excluded from the porous substrate by the repellent composition are increased.

Inventors

  • 👤 Kenneth C. Fey
  • 👤 Alan L. Freiberg
  • 👤 John G. Price

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-11-08 05:20
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/45; C04B41/46; C04B41/49; C04B41/4905; C04B41/4922

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 146 words
A method of reducing the volatility and decreasing the evaporation loss of water repellent compositions containing a solution of an alkylalkoxysilane with C 1 to C 6 alkyl groups on silicon, or a blend of alkylalkoxysilanes each having C 1 to C 6 alkyl groups on silicon, and a carrier selected from the group consisting of (i) alcohols, (ii) mineral spirits, and (iii) glycol ethers, for application to a porous substrate, comprising adding to the solution at least one metal salt catalyst, and adding to the solution an effective amount of surface depositing water beading agent, the surface depositing water beading agent being selected from the group consisting of: a. ##STR3## where X=10 to 100, b. an amine salt functional siloxane copolymer, c. trimethylsilyl endcapped polysilicate, d. ##STR4## where x=0 to 800, e. a room temperature curable silicone rubber, and f. (Me 3 SiO) 4 Si.
Claim 2
Independent Claim 146 words
A method of reducing the volatility and decreasing the evaporation loss of water repellent compositions containing a solution of an alkylalkoxysilane with C 1 to C 6 alkyl groups on silicon, or a blend of alkylalkoxysilanes each having C 1 to C 6 alkyl groups on silicon, and a carrier selected from the group consisting of (i) alcohols, (ii) mineral spirits, and (iii) glycol ethers, for application to a porous substrate, comprising adding to the solution at least one metal salt catalyst, and adding to the solution an effective amount of surface depositing water beading agent, the surface depositing water beading agent being selected from the group consisting of: a. ##STR3## where X=10 to 100, b. an amine salt functional siloxane copolymer, c. trimethylsilyl endcapped polysilicate, d. ##STR4## where x=0 to 800, e. a room temperature curable silicone rubber, and f. (Me 3 SiO) 4 Si.
Claim 3
Dependent Claim 18 words
The method of claim 1 including the step of acidifying the solution to a constant steady state condition.
Claim 4
Dependent Claim 17 words
The method of claim 2 including the step of maintaining the solution in a substantially anhydrous condition.
Claim 5
Dependent Claim 13 words
The method in claim 3 wherein the solution is acidified with hydrochloric acid.
Claim 6
Dependent Claim 32 words
The method of claim 4 wherein the acid is added to the solution to provide a concentration in the amount of about ten parts per million based on the weight of solution.
Claim 7
Dependent Claim 13 words
The method according to claim 5 wherein the metal salt catalyst is tetraisopropyltitanate.
Claim 8
Dependent Claim 21 words
The method according to claim 6 wherein the alkylalkoxysilane is present in an amount by weight of less than forty percent.
Claim 9
Dependent Claim 25 words
The method of claim 7 wherein the metal salt catalyst and the surface depositing agent constitute in combination by weight less than about five percent.

References Cited (Backward Citations)

US3388089A Cited
US3766123A Cited
US3832203A Cited
GB1444221A Cited
US4209432A Cited
US4478911A Cited
US4436856A Cited
US4648904A Cited
US4648904B1 Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1992-10-16 1993-04-17 1993-10-17 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1996-10-16 1997-04-17 1997-10-17 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 2000-10-16 2001-04-17 2001-10-17 $7700.00 Window Closed / Lapsed

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