Claims
- 1. In a process for reverse coating a sheet-form textile substrate with adhesive-coating and surface-coating polyurethane solutions, the improvement comprising preparing the polyurethane solutions using a single organic solvent which is polar and controlling the coating behavior of the adhesive-coating solution by varying its water content between about 1 and 15 weight % based on the weight of the solution.
- 2. The reverse coating process of claim 1 wherein the single organic polar solvent is selected from the group consisting of dimethyl formamide, dimethyl acetamide, monomethyl formamide, monomethyl acetamide, N-methyl pyrrolidone, tetrahydrofuran and methyl ethyl ketone.
- 3. The reverse coating process of claim 2 wherein the organic polar solvent in the surface-coating and the adhesive-coating solutions is dimethyl formamide.
- 4. The reverse coating process of claim 1 wherein the water content of the adhesive coating solution is between about 2 and 10% by weight based on the weight of the solution.
- 5. The reverse coating process of claim 1 wherein the polyurethanes in solution are segmented, substantially linear and built up from reactants selected from the group consisting of dihydroxy polyesters, dihydroxy polyethers, aromatic diisocyanates, aliphatic diisocyanates, glycols and diamines.
- 6. The reverse coating process of claim 5 wherein the hydroxy bearing reactants are selected from the group consisting of dihydroxy polyesters of molecular weights of about 800 to 7500, dihydroxy polyethers of molecular weights of about 800 to 7500, dihydroxy polycarbonates of molecular weights of about 800 to 7500 and glycols with molecular weights of about 62 to 450.
- 7. The reverse coating process of claim 6 wherein the polyethers are selected from the group consisting of dihydroxy butylene glycol polyether and dihydroxy propylene glycol polyether and the polycarbonate is built up from 1,6-hexane diol and diaryl carbonate.
- 8. The reverse coating process of claim 1 wherein the diisocyanate used to make the polyurethanes in solution is 4,4'-diphenylmethane diisocyanate.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2431846 |
Jul 1974 |
DEX |
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Parent Case Info
This is a continuation of application Ser. No. 592,011 filed June 30, 1975 and now abandoned.
US Referenced Citations (5)
Continuations (1)
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Number |
Date |
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Parent |
592011 |
Jun 1975 |
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