Claims
- 1. Paper containing a cationic grafted starch copolymer comprising starch, nonionic vinyl monomer, and cationic vinyl monomer wherein:
- (a) said starch is present in amounts from about 10% to about 90% of the copolymer, and at least about 5% of the starch is cationic starch;
- (b) said nonionic vinyl monomer is present in amounts from about 90% to about 10% of the copolymer; and
- (c) said cationic vinyl monomer is present in amounts from about 5% to about 80% of the copolymer.
- 2. The paper of claim 1 wherein between about 2 pounds and about 25 pounds of the copolymer is added per ton of paper pulp.
- 3. The paper of claim 1 wherein from about pounds to about 15 pounds of copolymer per ton of paper pulp is added.
- 4. The paper of claim 1 wherein the starch used is essentially 100% cationic starch.
- 5. The paper of claim 4 wherein copolymer contains from about 20% to about 70% starch.
- 6. The paper of claim 1 wherein the cationic vinyl monomer is selected from the group consisting of the methyl chloride quaternary salt of dimethylaminoethyl methacrylate, the dimethyl sulfate quaternary salt of dimethylaminoethyl methacrylate, and the methyl chloride quaternary salt of methyl diallyl amine.
- 7. The paper of claim 1 wherein the cationic starch grafted copolymer is added to the paper pulp essentially in the form of crude reaction product.
- 8. Paper containing from about 2 pounds to about 25 pounds of a cationic grafted starch copolymer per ton of paper pulp, wherein said cationic grafted starch copolymer comprises:
- (a) from about 25% to about 55% cationic starch;
- (b) from about 35% to about 70% acrylamide; and
- (c) from about 5% to about 10% cationic vinyl monomer.
- 9. The paper of claim 8 wherein the cationic vinyl monomer is selected from the group consisting of the methyl chloride quaternary salt of dimethylaminoethyl methacrylate, the dimethyl sulfate quaternary salt of dimethylaminoethyl methacrylate, and the methyl chloride quaternary salt of methyl diallyl amine.
- 10. A method of preparing paper having improved dry tensile strength which comprises adding as a wet-end additive cationic grafted starch copolymer comprising starch, nonionic vinyl monomer, and a cationic vinyl monomer wherein:
- (a) said starch is present in amounts of from about 10% to about 90% of the copolymer, and at least about 5% of the starch is cationic starch;
- (b) said nonionic vinyl monomer is present in amounts of from about 90% to about 10% of the copolymer; and
- (c) said cationic vinyl monomer is present in amounts of from about 5% to about 80% of the copolymer.
- 11. The method of claim 10 wherein the cationic grafted, starch copolymer is added to the paper pulp essentially in the form of crude reaction product.
- 12. A method of preparing paper having improved dry tensile strength which comprises adding as a wet-end additive from about 2 pounds to about 25 pounds per ton of paper pulp of a cationic grafted starch copolymer comprising:
- (a) from about 25% to about 55% cationic starch;
- (b) from about 35% to about 70% acrylamide; and
- (c) from about 5% to about 10% cationic vinyl monomer.
- 13. The method of claim 12 wherein the cationic vinyl monomer is selected from the group consisting of the methyl chloride quaternary salt of dimethylaminoethyl methacrylate, the dimethyl sulfate quaternary salt of dimethylaminoethyl methacrylate, and the methyl chloride quaternary salt of methyl diallyl amine.
Parent Case Info
This is a division of application Ser. No. 710,191 filed Mar. 11, 1985 and now U.S. Pat. No. 4,684,708.
US Referenced Citations (5)
Foreign Referenced Citations (2)
Number |
Date |
Country |
2822321 |
Dec 1978 |
DEX |
0090699 |
Jul 1980 |
JPX |
Divisions (1)
|
Number |
Date |
Country |
Parent |
710191 |
Mar 1985 |
|