MXPA98000374A - Method for the manufacture of soft tisu with soft volume and softness of superfi - Google Patents

Abstract

The present invention relates to tissue products having improved softness properties and method for making them. Specifically, improved softness is achieved by incorporating one or more softeners / debonders into the fiber supply at the wet end of the forming machine of the formation, followed by a topical treatment with one or more softeners / debonders after which the tissue has dried. The result is a tissue product with an added volume and a smooth surface feel, both properties contributing to the improved softness characteristics

Description

METHOD FOR THE MANUFACTURE OF SOFT TISSUE WITH SOFTNESS PE VOLUME AND SOFT SURFACE Background of the Invention The improvement of the softness of the tissues is a continuous objective in the manufacture of tissues. In general, the above efforts have been directed to reduce the interfiber bond within the tissue structure or by coating the tissue surface with chemicals which improve the surface feel. The softness, however, is a perceived property of the tissues comprising many factors including the softness of the volume and the smoothness of the surface. To date, efforts have tended to focus on one or the other. Therefore, there is a need for a method which improves both the smoothness of volume and the smoothness of the surface.

Synthesis of the Invention It has now been discovered that the softness of the tissues can be improved by the combined addition of one or more softeners / debonders (hereinafter defined) to the tissue manufacturing supply, followed by a second addition of one or more softeners / debonders. to the surface of the dried tissue. The initial introduction of the softener / debonder to the supply provides more softness of volume to the tissue, while the subsequent topical application imparts a smoother or smoother surface sensation. The combination results in a very soft feeling tissue product.

More specifically, the invention resides in a method for making soft tissue comprising: (a) forming an aqueous suspension of papermaking fibers having from about 0.01 to about 6 percent by weight based on the dry fiber of one or more softener / debonders; (b) forming a tissue by depositing the aqueous suspension of fibers to make paper on a forming fabric; (c) draining and drying the fabric; and (d) topically applying to the dried fabric from about 0.01 to about 10 weight percent, based on the dry fiber, of one or more softeners / debonders. The softener / debonder which is applied topically to the dry fabric may be the same softener / debonder added to the supply prior to the formation of the tissue, or this may be different.

As used here, the term "softener / debonder" is a chemical compound selected from the group consisting of quaternary ammonium compounds, quaternized protein compounds, phospholipids, silicone quaternaries, phosphocopolyol dimethicone / hydrolysed wheat protein copolymer, quaternized, organoreactive polysiloxanes, and glycols of silicone.

Suitable quaternary ammonium compounds have the following structures: CHj CH.-N-R 3 \ wherein X = chloride, methyl sulfate, or other compatible counter ion; Y = C8 - C22 saturated or unsaturated, aliphatic; CH, i 3 R-N-R, wherein X = chloride, methyl sulfate, or other compatible counter ion; R = C8 - C22 saturated or unsaturated, aliphatic; Rx = benzyl or epoxy group; wherein X = chloride, methyl sulfate, or other compatible counter ion; Y R = C8 - C22 saturated or unsaturated, aliphatic; wherein X = chloride, methyl sulfate, or other compatible counter ion; R = C8 - C22 saturated or unsaturated, aliphatic; Y Rj = 2-hydroxyethyl or 2-hydroxypropyl; CH, R wherein R = C6-C22 saturated or unsaturated, normal or branched, aliphatic; X = chloride, methyl sulfate, ethyl sulfate, or other compatible counter ion; Rx = 2-hydroxyethyl or polyethoxyethanol; Y n = 1 to 50; CH. i «CH, -0H where R = C8 -22 ' X = methyl sulfate, chloride, or other compatible counter ion; CH.-N-R 3 i wherein R = C 8 -C 22, saturated or unsaturated, normal or branched, aliphatic alkyl; Y X = chloride, methyl sulfate or other compatible counter ion.

CH. i 3 CH, • N-R i CH, wherein R = C 8 -C 22 saturated or unsaturated, aliphatic; or alilo-; or R '-0-CH2-CH2-CH2- wherein R' = C4-C18 normal or branched; Y X = chloride, sulfate or any other compatible counter ion.

Suitable quaternized protein compounds include the following structures: or CH, OH II R C-NH- (CH2) -N-CH2-CH-CH2-R2 CH, where R? = ci2"C22 saturated or unsaturated radical of fatty acid; R2 = hydrolyzed soy protein, hydrolyzed silk protein, collagen, half keratin or hydrolyzed wheat protein; Y X "= chloride, lactate or other compatible counter ion; wherein Rx = C12 - C22 fatty acid radical, saturated or unsaturated; R2 = hydrolyzed collagen or keratin moiety; and X = chloride, lactate or other compatible counterion.

Suitable phospholipids include, without limitation, those having the following structures: (B), + xA + aM where x = 1 to 3; x + y = 3; a = 0 to 2; B = 0 or OM; A = an anion; M = a cation; Y R, Ri & R 2 may be the same or different, are alkyl, substituted alkyl, alkyl aryl or alkenyl groups of up to 16 carbon atoms and the total carbon atoms of R + Rx + R 2 = a to 24; where x = 1 to 3; x + y = 3; a = 0 to 2; 15 B = 0 or OM; A = an anion; M = a cation; Y R5, R6 may be the same or different, are alkyl, hydroxyalkyl, carboxyalkyl of up to C6, or polyoxyalkylene of up to C10; or R5, R6 and the Nitrogen is attached to represent an N-heterocycle; and R, = one amidoamide moiety of the formula: 0 R, R4-C-N- (CH2) n- where n = 2 to 6; R3 = hydrogen or alkyl, hydroxyalkyl or alkenyl of up to 6 carbons; or cycloalkyl of up to 6 carbon atoms, or polyoxyalkylene of up to 10 carbon atoms; Y R4 = alkyl, alkenyl, alkoxy or hydroxyalkyl, C5-C21 or aryl or alkaryl up to C20; twenty R-2A 25 where A = an anion; M = a cation; R, Ra & R2 may be the same or different, are alkyl groups, substituted alkyl, alkyl aryl or altkenyl of up to 16 carbon atoms, and the total carbon atoms of R + Ri + R2 = 10 to 24; Y Rx 2 = 10 to 24; and R 'is a half amidoamine 10 of the structure: 0 R, R8-C-N- (CH2) n-15 wherein n = 2 to 6; R3 = hydrogen or alkyl, hydroxyalkyl or alkenyl of up to 6 carbons; or cycloalkyl of up to 6 carbon atoms, or polyoxyalkylene of up to 10 carbon atoms; Y R8 = has the following structure: where n = 3 or greater; p = 1 to 1000; = 1 to 25 Suitable silicone quaternaries include the following structure: wherein R = alkyl group, C12-C18; Z = -CH2-CH2-CH2-o- (CH2) 3-; X = alkoxy, chloride or other compatible counterion; Y n = 1 to 50 Suitable organoreactive polysiloxanes include the following structures: CH3 .H.3 Hj CH3 l i l i CH3-YES-O- (Si-0) x- (Si-0) y-Si-CH3 l i l i CH3 CH3 CHCH3 CH3 \ CH2 I R Y CH3 CH3 CH3 / / / R- (CH2) n-Si-0- (Si-0) x-Si- (CH2) n -R \ \ \ CH3 CH3 CH3 Y H3 CH3 CH3 \\ R- (CH2) n-Si-0- (Si-0) X-Si-CH3 \ \ \ CH3 CH3 CH3 wherein R = amine, carboxy, hydroxy, or epoxy; n = 3 or greater; x = 1 to 1000; and y = 1 to 25.

Suitable silicone glycols include the following structure.

CH, CH, CH, CH, CH3-YES-0- (Si-0) x- (Si-0) y-Si-CH3 CH, CH, R CH, OR (CH2-CH2-0) n-R1 CH3 fifteen . wherein R = alkyl group, Cx-C6; Rx = acetate or hydroxy group; x = 1 to 1000; 20 y = 1 to 50; m = 1 to 30; Y n = 1 to 30.

When a smoothing / deburring combination is desired, the combination can be added to the thick supply simultaneously or separately. The combinations may contain one or more compounds of the groups mentioned above and added to the solution either in a premixed or individually dosed form.

The final tissue sheet comprises from about 0.01 to about 6 percent (by weight of the fiber) of the softener / debonders added to the wet end of the tissue manufacturing process, individually or in combination. More preferably, the final tissue sheet comprises from about 0.1 to about 3 percent of the softener / debonder added at the wet end, based on the weight of the fiber.

The softener / debonder is used for the topical treatment can be delivered in an aqueous solution or dissolved in a suitable solvent such as propylene glycol, ethylene glycol, polyethylene glycol, isopropyl alcohol, methanol, ethanol or other organic solvents. These can be applied to the surface of the base sheet individually or in combination with others. It is preferred that the composition for topical treatment comprises from about 1 to about 100 weight percent of the softener / debonder (individually or in combination) more preferably from about 35 to about 80 weight percent. It is also preferred that the softener / debonder be topically added to the tissue sheet in an aggregate ratio of from about 0.01 to about 10 weight percent of the fiber, and more preferably from about 0.1 to about 2 weight. percent by weight of the fiber.

Suitable methods for topical treatment include, but are not limited to, spraying, rotogravure printing, tail knife coating, flexographic printing, and the like.

Examples Example 1 i A wet crepe tissue was made of two strata using a layered head box. The first supply layer (the layer that finally makes contact with the surface of the Yankee dryer) contained hardwood fiber of eucalyptus and provided 60 percent by dry weight of the tissue sheet. The remaining 40 percent of the tissue sheet was provided through a second supply layer consisting of soft wood kraft pulp from the north. The total basis weight of the sheet was 7.3 pounds per 2880 square feet of tissue placed by air. Two strength agents were added to the fiber supply layers before the headbox. Parez 631NC (a glyoxalated polyacrylamide from Cytec Industries, Inc.) was dosed into the thick supply of softwood at 0.08 to 0.1 percent of the total fiber weight. Another resistance agent, Kymene 557 LX (commercially available from Hercules, Inc.) was dosed within both the supply thickness of hardwood and softwood at 0.05 and 0.1 percent of the total fiber weight, respectively.

A quaternary ammonium compound softener / debonder (methyl-1-oleyl amidoethyl-2-oleyl sulfate methyl imidazolinium identified as Varisoft 3690 available from Witco Corporation, 90 percent active material) was added to the thick supply of hardwood at 0.17 percent of the total fiber weight.

After drying and creping, the tissue sheet was folded together with a type of sheet to form a two-layer tissue. The hardwood layer of both layers was rotogravure printed with a 40 percent organoreactive polysiloxane emulsion (FTS-226 made by OSi Specialties, Inc.) at an aggregate amount of 1 percent per layer based on the weight of the fiber. The resulting tissue product had an increased volume with an improved surface smoothness.

Example 2 A tissue was made into layers of two layers as described in Example 1, except that instead of the rotogravure-printing of both layers with an organoreactive polysiloxane, both layers were instead coated with a silicone phospholipid (Mona Industries, Inc. ., Item Code # 54146, Lot 2426, 25-30% active) having the following structure: wherein A = chloride ion; M = sodium ion; R ^ - K = -CH3 R may be alkyl, substituted alkyl, alkylaryl or altkenyl groups of up to 16 carbon atoms, and the total carbon atoms of R + RL + R2 = 10 to 24; Y R 'is one amidoamine half of the structure: OR R, R8-C-N- (CH2) n- where n = 3; R3 = hydrogen; Y R8 = has the following structure where n = 3; p = 90; q = 1 A tail knife coater was used to apply the silicone phospholipid. The knife angle was set at 30 ° and the knife pressures were varied between 20 and 40 psi to deliver different levels of addition. The resulting tissue products had an increased volume and a smooth surface sensation.

Example 3 A tissue of two strata was made as described in Example 2, except that both strata were coated with a quaternary ammonium compound (olealconium chloride, Mackernium KP and by Mclntyre Group, LTD., 50% active) having the structure: The resulting tissue products had an increased volume and smooth surface sensation.

Example 4 A tissue was made in layers of two layers as described in Example 2, except that both layers were coated with a silicone quaternary compound (Abilquat 3272 made from Goldschmidt Chemical Corporation, 50% active) having the following structure: CH, CH, CH, CH, ++ R-N-Z- (S 1 -0) n-Si-Z- [1-R 2 CH 3 COO "CH, CH, CH, CH, where R = alkyl group, C12 - C1 8 i Z = -CH2-CH2-CH2-0- (CH2) 3-; Y The resulting tissue products have an increased volume and increased smooth surface feel.

Example 5 A base sheet was made into layers of two layers as described in Example 2, except that both layers were printed with an aqueous composition comprising 50% organopolydimethylsiloxane (FTS-226) and a 50% quaternary ammonium compound (Mackernium KP). The resulting tissue products had an increased surface and volume sensation.

Example 6 A base sheet was made into two layer layers as described in Example 1, except that both layers were coated with an aqueous composition comprising 40% quaternary ammonium compound (Mackernium NLE made by MeIntyre Group, LTD.) , 40% organopolydimethylsiloxane (FTS-226) and 20% water. Mackernium NLE is a 100 percent active epoxypropyl alkylamidopropyl diammonium chloride.

The resulting tissue products have an increased volume and smooth surface feel.

Example 7 A base sheet was made into layers of two layers as described in Example 2, except that both layers were coated with an aqueous composition comprising 25% of a quaternary ammonium compound (Mackernium KP), 25% organopolysiloxane (FTS-). 226) and 50% propylene glycol. The resulting tissue products had an increased volume and smooth surface sensation.

Example 8 A dried tissue was made through uncreped air and from a stratum using a layered headbox. The two outer layers contained hardwood kraft pulp of bleached eucalyptus through a Maule shaft disperser with a force input of 80 kilowatts at a consistency of about 34 percent and at a temperature of 184OF. The two outer layers constituted 70 percent of the tissue sheet per fiber weight. The middle layer constituted the remaining 30 percent of the tissue and consisted of softwood kraft pulp from the bleached north. The total basis weight of the sheet was 33.9 grams per square meter of air dried tissue. The inner layer was refined to obtain sufficient dry strength in the final product. A wet strength agent (Parez 631NC) was dosed into the inner layer at a rate of 5 kilograms per ton or 0.5 percent of the weight of the fiber. A softener / debonder (quaternary imidazolinium, polyether fatty acid alkoxylate with 200-800 molecular weight, identified as DPSC 5299-8 from Witco Corporation) was added to the two outer layers at a rate of 5.25 kilograms per metric ton (0.525). percent) of the total fiber weight. The thick supply of all the layers was diluted to approximately 0.12 percent consistency prior to the formation, dewatering and drying of the tissue.

After drying, the tissue was coated with a silicone diquatural compound (Abilquat 3272) similar to Example 4. The resulting tissue product had a softer surface feel compared to the tissue without the coating.

It will be appreciated from the foregoing examples, given for the purposes of illustration, that they should not be considered as limiting the scope of the invention which is defined by the following claims and all equivalents thereof.

Claims (24)

R E I V I N D I C A C I O N S

1. A method for making a soft tissue comprising: (a) forming an aqueous suspension of papermaking fibers having from about 0.01 to about 6 weight percent, based on the dry fiber, of one or more softener / debonders; (b) forming a tissue by depositing the aqueous suspension of the fibers to make paper on a forming fabric; (c) draining and drying the tissue; Y (d) topically applying to the dried tissue fabric from about 0.01 to about 10 weight percent, based on the dry fiber, of one or more softeners / debonders.

2. The method as claimed in clause 1, characterized in that the softener / debonder is selected from the group consisting of quaternary ammonium compounds, quaternized protein compounds, phospholipids, silicone quaternaries, organoreactive polysiloxanes and silicone glycols.

3. The method as claimed in clause 1, characterized in that the amount of softener / debonder added to the fiber suspension is from about 0.1 to about 3 percent by dry weight based on the amount of fiber.

4. The method as claimed in clause 1, characterized in that the amount of softener / debonder applied topically to the dried fabric is from about 0.1 to about 10 percent by dry weight, based on the amount of the fiber.

5. The method as claimed in clause 1, characterized in that at least one of the softener / debonders is a quaternary ammonium compound having the following structure: wherein X = chloride, methyl sulfate, or other compatible counter ion; and R = C 8 -C 22 saturated or unsaturated, aliphatic.

6 The method as claimed in clause 1, characterized in that at least one of the softener / debonders is a quaternary ammonium compound having the following structure: CH3 R-N-R i R wherein X = chloride, methyl sulfate, or other compatible counter ion; R = C8 - C22 saturated or unsaturated, aliphatic; Y Rx = benzyl or epoxy group.

7. The method as claimed in clause 1, characterized in that at least one of the softener / debonders is a quaternary ammonium compound having the following structure: wherein X = chloride, methyl sulfate, or other compatible counter ion; Y R = CB - C2, saturated or unsaturated, aliphatic.

8. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonder is a quaternary ammonium compound having the following structure: CvH, 2 / CH, 3 N / \ R-C-NH-CH, • CH2 R, II 2 0 wherein X = methyl sulfate, chloride, or other compatible counter ion; R = C8 - C22 saturated or unsaturated, normal, aliphatic; Ra = 2 -hydroxyethyl or 2-hydroxypropyl.

9. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonder is a quaternary ammonium compound having the following structure: CH3 ri > n wherein R = C 8 -C 22 saturated or unsaturated, normal or branched, aliphatic; X = chloride, methyl sulfate, ethyl sulfate, or other compatible counter ion; Rx = 2 -hydroxyethyl or polyethoxyethanol; Y n = 1 to 50.

10. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonder is a quaternary ammonium compound having the following structure: wherein R = C "- C 22 'X = methyl sulfate, chloride or other compatible contrain.

11. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonder is a quaternary ammonium compound having the following structure: CH, i 3 CH, • N-R i CH, wherein R = C 8 -C 22 saturated or unsaturated, aliphatic; or alilo-; or R '-0-CH2-CH2-CH2- wherein R' = C4-C18 normal or branched; Y X = chloride, sulfate or any other compatible counter ion.

12. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonder is a quaternary ammonium compound having the following structure: wherein R = C 8 -C 22, saturated or unsaturated, normal or branched, aliphatic alkyl; Y X = chloride, methyl sulfate, or other compatible contraction.

13. The method as claimed in clause 1, characterized in that at least one of the softener / debonders is a quaternized protein compound having the following structure: 0 CH, OH II \\ R C-NH- (CH2) -N-CH2-CH-CH2-R2 CH, wherein Rr = C 12 -C 22 fatty acid radical, saturated or unsaturated; R2 = hydrolyzed soy protein, hydrolyzed silk protein, hydrolyzed wheat protein, half collagen or half keratin; Y X = chloride, lactate or other compatible counter ion

14. The method as claimed in clause 1, characterized in that at least one of the softener / debonders is a quaternized protein compound having the following structure: where R? = ci2"C22 fatty acid radical, saturated or unsaturated; R2 = hydrolyzed collagen or keratin moiety; Y X = chloride, lactate or other compatible counter ion

15. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonders is a phospholipid having the following structure: where x = 1 to 3; X + y = 3; a = 0 to 2; B = O U OM; A = an anion; M = a cation; Y R, R1 & R2 may be the same or different, are alkyl, substituted alkyl, alkyl aryl or alkenyl groups of up to 16 carbon atoms and the total carbon atoms of R + Rx + R2 = 10 to 24.

16. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonders is a phospholipid having the following structure: + 0 R. '-Ni-CH-2-CiH-CH.-0 -P- (B) y + xA + aM R. OH where X = 1 to 3; x + y = 3; a = 0 to 2; 5 B = O U OM; A = an anion; M = a cation; and R5, R6 may be the same or different, are alkyl, hydroxyalkyl, carboxyalkyl of up to C6, or polyoxyalkylene of up to C10; or R5, R6 and nitrogen can be linked to represent an N-15 heterocycle; and i t R7 = one amidoamide moiety of the formula: 0 R3 20 11 I R4-C-N- (CH2) n- where n = 2 to 6; R3 = hydrogen or alkyl, hydroxyalkyl or alkenyl of up to 6 carbons; or cycloalkyl of up to 6 carbon atoms, or polyoxyalkylene of up to 10 carbon atoms; Y R4 = alkyl, alkenyl, alkoxy or hydroxyalkyl, C5-C21 or aryl or alkaryl up to C20.

17. The tissue as claimed in clause 1, characterized in that at least one of the softener / debonders is a phospholipid having the following structure: R- where A = an anion; M = a cation; R, R: & R2 may be the same or different, are alkyl, substituted alkyl, alkyl aryl or alkenyl groups of up to 16 carbon atoms and the total carbon atoms of R + R1 + R2 = 10 to 24; and R 'is one amidoa moiety of the structure: OR R3 R8-C-N- (CH2) n- where n = 2 to 6; R3 = hydrogen or alkyl, hydroxyalkyl or alkenyl of up to 6 carbons; or cycloalkyl of up to 6 carbon atoms, or polyoxyalkylene of up to 10 carbon atoms; Y fifteen ! R8 = has the following structure: where n = 3 or greater, p = 1 to 1000; 25 q = 1 to 25

18. The method as claimed in clause 1, characterized in that at least one of the softeners / debonders is a silicone quaternary having the following structure: R- wherein R = alkyl group, C12-C18; Z = -CH2-CH2-CH2-0- (CH2) 3-; X = alkoxy, chloride or other compatible counterion; n = 1 to 50.

19. The method as claimed in clause 1, characterized in that at least one of the softeners / debonders is an organoreactive polysiloxane having the following structure: CH3 CH3 CH3 CH3 l i l i CH3-YES-0- (Si-0) x- (Si-0) y-YES-CH3 l i l i CH3 CH3 CHCH3 CH3 \ CH, R wherein R = amine, carboxy, hydroxy, or epoxy; n = 3 or greater; x = 1 to 1000; and y = 1 to 25.

20. The method as claimed in clause 1, characterized in that at least one of the softeners / debonders is an organoreactive polysiloxane having the following structure: CH3 CH3 LH / / / R- (CH2) n-Si-0- (Si-0) X-Si- (CH2) n -R \ \ \ CH3 CH3 CH3 wherein R = amine, carboxy, hydroxy, or epoxy; n = 3 or greater; x = 1 to 1000; and y = 1 to 25.

21. The method as claimed in clause 1, characterized in that at least one of the softeners / debonders is an organoreactive polysiloxane having the following structure: CH3 CH3 CH3 / / / R- (CH2) n-Si -0- (Si -0) X- Si - CH3 \\ \ wherein R = amine, carboxy, hydroxy, or epoxy; n = 3 or greater; x = 1 to 1000; Y y = 1 to 25.

22. The method as claimed in clause 1, characterized in that at least one of the softener / debonder is a silicone glycol having the following formula: CH, CH, CH, CH, CH3-Si-0- (Si-0) x- (Si-0) y-Si-CH3 (CH2-CH2-0) ,. (CU2 - CU2 -0) n-R1 CH3 wherein R = alkyl group, C1-C6; R1 = acetate or hydroxy group; x = 1 to 1000; y = 1 to 50, - rn = 1 to 30; Y n = 1 to 30.

23. The method as claimed in clause 1, characterized in that at least one of the softeners / debonders is a copolymer of phosphocopolyol dimethicone / quaternized hydrolyzed wheat protein.

24. The method as claimed in clause 1, characterized in that the softener / debonder added to the dried fabric is carried by a solvent selected from the group consisting of water, propylene glycol, ethylene glycol, polyethylene glycol, isopropyl alcohol, methanol and ethanol. E S U M E N The invention relates to tissue products having improved softness properties and method for making them. Specifically, improved smoothness is achieved by incorporating one or more softeners / debonders into the fiber supply at the wet end of the tissue machine prior to forming, followed by a topical treatment with one or more softeners / debonders after that the tissue has dried. The result is a tissue product with an added volume and a smooth surface feel, both properties contributing to the improved softness characteristics.