Strong and soft creped tissue paper and process for making the same by use of biodegradable crepe facilitating compositions

Claims

What is claimed is:

1. A soft creped tissue paper comprising:

a) papermaking fibers; and

b) a biodegradable crepe facilitating composition comprising:

i) from about 0.02% to about 1.0% by weight, of a biodegradable bonding inhibitor, based on the dry weight of the papermaking fibers, having the formula: ##STR6## wherein each R.sub.2 substituent is a C1-C6 alkyl or hydroxyalkyl group, benzyl group or mixtures thereof; each R.sub.1 substituent is a C12-C22 hydrocarbyl group, or substituted hydrocarbyl group or mixtures thereof; each R.sub.3 substituent is a C11-C23 hydrocarbyl group, or substituted hydrocarbyl or mixtures thereof; Y is --O--C(O)-- or --C(O)--O-- or --NH--C(O)-- or --C(O)--NH-- or mixtures thereof; n is 1 to 4 and X.dbd. is a suitable anion;

ii) from about 0.02% to about 0.5% by weight, of a water soluble carboxymethyl cellulose, based on the dry weight of the papermaking fibers, wherein said carboxymethyl cellulose has a degree of substitution ranging from about 0.3 to about 1.4; and

iii) from about 0.05% to about 3.0% by weight, of a cationic starch, based on the dry weight of the papermaking fibers, wherein said cationic starch has a degree of substitution ranging from about 0.01 to about 0.1.

2. The tissue paper of claim 1 wherein said bonding inhibitor is present in a ratio relative to the carboxymethyl cellulose of about 1:5 to about 5:1 and wherein said bonding inhibitor is a biodegradable quaternary ammonium compound.

3. The tissue paper of claim 2 wherein said papermaking fibers comprise a blend of hardwood fibers and softwood fibers, said hardwood fibers comprising at least about 50% and said softwood fibers comprising at least about 10% of said papermaking fibers.

4. The tissue paper of claim 3 wherein said tissue paper comprises at least two superposed layers, an inner layer and at least one outer layer contiguous with said inner layer.

5. The tissue paper of claim 4 wherein said tissue paper comprises three superposed layers, an inner layer and two outer layers, said inner layer being located between two said outer layers.

6. The tissue paper of claim 5 wherein said inner layer comprises softwood fibers having an average length greater than at least about 2.0 mm, and said outer layers comprise hardwood fibers of having an average length less than about 1.0 mm.

7. The tissue paper of claim 6 wherein the softwood fibers comprise northern softwood Kraft fibers and the hardwood fibers comprise eucalyptus Kraft fibers.

8. The tissue paper of claim 7 wherein the crepe facilitating composition is contained in at least one of said outer layers.

9. The tissue paper of claim 8 wherein the crepe facilitating composition is contained in both of said outer layers.

10. The tissue paper of claim 2 wherein said creped tissue paper is pattern densified paper.

11. The tissue paper of claim 2 wherein the carboxymethyl cellulose has a molecular weight ranging from about 90,000 to about 700,000.

12. The tissue paper of claim 2 wherein the cationic starch is derived from waxy maize.

13. The tissue paper of claim 2 wherein R.sub.2 is methyl, R.sub.3 is C15-C17 alkyl or alkenyl and R.sub.1 is C16-C18 alkyl or alkenyl.

14. The tissue paper of claim 2 wherein Y is --O--C(O)-- or --C(O)--O--.

15. The tissue paper of claim 13 wherein X.sup.- is chloride or methyl sulfate.

16. The tissue paper of claim 2 wherein the R.sub.3 substituent is derived from vegetable oil sources.

17. The tissue paper of claim 2 wherein said biodegradable bonding inhibitor is present in a ratio relative to the carboxymethyl cellulose of about 1:2 to about 2:1.

18. A soft creped tissue paper comprising:

a) papermaking fibers; and

b) a biodegradable crepe facilitating composition comprising:

i) from about 0.02% to about 1.0% by weight, of a biodegradable bonding inhibitor, based on the dry weight of the papermaking fibers, having the formula: ##STR7## wherein each R.sub.2 is a C1-C4 alkyl or hydroxyalkyl group, benzyl group, or mixtures thereof; each R.sub.3 is a C11-C23 hydrocarbyl or substituted hydrocarbyl group or mixtures thereof; Y is --O--C(O)-- or --C(O)--O-- or --NH--C(O) or --C(O)--NH-- or mixtures thereof and X.sup.- is a suitable anion;

ii) from about 0.02% to about 0.5% by weight, of a water soluble carboxymethyl cellulose, based on the dry weight of the papermaking fibers, wherein said carboxymethyl cellulose has a degree of substitution ranging from about 0.3 to about 1.4; and

iii) from about 0.05% to about 3.0% by weight, of a cationic starch, based on the dry weight of the papermaking fibers, wherein said cationic starch has a degree of substitution ranging from about 0.01 to about 0.1.

19. The tissue paper of claim 18 wherein each R.sub.2 is methyl, R.sub.3 is C15-C17 alkyl or alkenyl and R.sub.1 is C16-C18 alkyl or alkenyl.

20. The tissue paper of claim 18 wherein Y is --O--C(O)-- or --C(O)--O--,

21. The tissue paper of claim 18 wherein X.sup.- is chloride or methyl sulfate.

22. The tissue paper of claim 18 wherein the R.sub.3 substituent is derived from vegetable oil sources.

23. A process of making a creped tissue paper comprising the steps of:

a) forming an aqueous slurry of paper making fibers,

b) adding a crepe facilitating composition comprising:

i) from about 0.02% to about 1.0% by weight, of a biodegradable bonding inhibitor, based on the dry weight of the papermaking fibers, having the formula: ##STR8## wherein each R.sub.2 substituent is a C1-C6 alkyl or hydroxyalkyl group, benzyl group or mixtures thereof; each R.sub.1 substituent is a C12-C22 hydrocarbyl group, or substituted hydrocarbyl group or mixtures thereof; each R.sub.3 substituent is a C11-C23 hydrocarbyl group, or substituted hydrocarbyl or mixtures thereof; Y is --O--C(O)-- or --C(O)--O-- or --NH--C(O)-- or --C(O)--NH-- or mixtures thereof; n is 1 to 4 and X.dbd. is a suitable anion;

ii) from about 0.02% to about 0.5% by weight, of a water soluble carboxymethyl cellulose, based on the dry weight of the papermaking fibers, wherein said carboxymethyl cellulose has a degree of substitution ranging from about 0.3 to about 1.4; and

iii) from about 0.05% to about 3.0% by weight, of a cationic starch, based on the dry weight of the papermaking fibers, wherein said cationic starch has a degree of substitution ranging from about 0.01 to about 0.1;

wherein said biodegradable bonding inhibitor is present in a ratio relative to the carboxymethyl cellulose of about 1:5 to about 5:1;

c) depositing the papermaking fibers on a foraminous surface so that the excess water used to form the slurry is removed forming an embryonic web;

d) transferring the embryonic web to a carrier surface upon which the water removal continues forming a semi-dry web, said carrier surface being selected from the group consisting of paper making felts and forming fabrics;

e) transferring the semi-dry web and securing it to the surface of a Yankee dryer upon which the drying is continued until the web reaches a substantially dry condition;

f) removing the dried web from the Yankee dryer by means of a creping blade; and

g) winding the creped web on a reel.

24. The process of claim 23 wherein the constituents of said crepe facilitating composition are added separately as aqueous dispersions to said aqueous slurry of papermaking fibers prior to depositing the fibers on said foraminous surface.

25. The process of claim 24 wherein the quaternary ammonium compound is added prior to the cationic starch,

26. The process of claim 25 wherein the carboxymethyl cellulose is added to said aqueous slurry before the quaternary ammonium bonding inhibitor.

27. The process of claim 23 wherein said carrier surface is a forming fabric such that said tissue paper is pattern densified.

28. The process of claim 27 wherein the moisture content of the semi-dry web at the point of transfer to the Yankee surface is less than about 40%.

29. The process of claim 28 wherein hot air is forced through said semi-dry web while the semi-dry web is on said forming fabric to form a low density structure.

30. The process of claim 23 wherein said web is secured to the Yankee dryer by means of an adhesive selected from the group consisting of partially hydrolyzed polyvinyl alcohol resin, polyamide resin, polyamine resin, mineral oil, and mixtures thereof.

31. The process of claim 30 wherein said adhesive is selected from the group consisting of polyamide epichlorhydrin resin, mineral oil, and mixtures thereof.