Claims
- 1. A cover sheet adapted to be permeated by an alkaline processing composition comprising a transparent support having thereon a neutralizing layer and a polymeric timing layer comprising
- (i) from about 1 to about 30 weight percent of a hydrophilic component comprising a polymerized monovinyl ester of a polybasic acid, and
- (ii) the balance comprising a hydrophobic component comprising a polymerized alkyl vinyl ester and a polymerized aryl vinyl ester.
- 2. The cover sheet of claim 1 wherein said polymer comprises the following recurring units: ##STR26## wherein R.sup.1 is a straight or branched chain alkyl group of from 1 to about 10 carbon atoms or aralkyl group of from about 7 to about 10 carbon atoms;
- R.sup.2 is a substituted or unsubstituted aryl group of from 6 to about 12 carbon atoms;
- R.sup.3 is a straight or branched aliphatic group having from 1 to about 20 carbon atoms or an aromatic group having from about 6 to about 20 carbon atoms, said group being substituted with at least one free carboxylic acid group, free sulfonic acid group, free phosphoric acid group or salt thereof;
- x is from about 1 to about 30 weight percent; and
- y+z is from about 99 to about 70 weight percent, the ratio of y:z ranging from about 15:85 to about 70:30.
- 3. The cover sheet of claim 1 wherein R.sup.1 is methyl, ethyl or propyl, R.sup.2 is phenyl, chlorophenyl or cyanophenyl and R.sup.3 is carboxybutyl, carboxyhexyl or carboxyethyl.
- 4. The cover sheet of claim 1 wherein R.sup.1 is methyl, R.sup.2 is phenyl and R.sup.3 is carboxybutyl.
Parent Case Info
This is a division of application Ser. No. 462,501 filed Jan. 31, 1983 now U.S. Pat. No. 4,440,848.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4123275 |
Karino et al. |
Oct 1978 |
|
4199362 |
Yoshida et al. |
Apr 1980 |
|
Divisions (1)
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Number |
Date |
Country |
Parent |
462501 |
Jan 1983 |
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