EP0840823B1

EP0840823B1 - Tissue products with improved softness

Info

Publication number: EP0840823B1
Application number: EP96925328A
Authority: EP
Inventors: Duane Gerard Krzysik; Charles Wilson Colman; Mike Thomas Goulet; Peter Michael Radovanovich; Wen Zyo Schroeder; Michael John Smith
Original assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Current assignee: Kimberly Clark Worldwide Inc; Kimberly Clark Corp
Priority date: 1995-07-21
Filing date: 1996-07-16
Publication date: 2003-07-09
Anticipated expiration: 2016-07-16
Also published as: WO1997004170A1; CO4560507A1; KR19990035770A; ZA965677B; TR199800096T2; CN1207785A; AU6546596A; MX9800373A; AU710263B2; PL326892A1; JP2001502760A; DE69629031T2; EP0840823A1; BR9611422A; DE69629031D1; AR002886A1; DE69629031T8; CA2223807A1

Description

Background of the Invention

In the field of tissue development and production, considerable efforts have been directed toward improving the softness of the tissue. This has been approached in a variety of ways, generally by either improving the tissue basesheet or by adding chemicals to the tissue to provide improved feel. The addition of mineral oil or polysiloxanes, for example, are chemicals which provide a more smooth feel to the surface of the tissue. However, further improvements to softness can be attained, as well as providing other benefits such as skin moisturization, through the identification and appropriate application of certain ingredients.

U.S. Patent No. 5,217,576 describes a soft absorbent tissue paper with high temporary wet strength. The tissue paper webs comprise papermaking fibers, from about 0.01 % to about 2.0 % by weight of a quaternary ammonium compound wherein two substituents on the ammonium nitrogen are C12-C18-aliphatic hydrocarbon radicals, from about 0.01 % to about 2.0 % by weight of a polyhydroxy plasticizer and from about 0.01 % to about 3.0 % by weight of a water-soluble temporary wet strength resin. The polyhydroxy plasticizer can be polyethylene glycol.

U.S. Patent No. 4,943,350 discloses soft, absorbent and bulky cellulosic fibrous webs which impart a soothing or emollient effect to the human skin when used for wiping or drying while essentially retaining their water-absorbent property and strength. The webs have been treated with triquaternary phospholipid complexes derived from fatty acids such as stearic, lauric, linoleic and myristic.

Summary of the Invention

It has now been discovered that topically treating the tissue with certain softening chemical compositions renders the surface of the tissue especially soft and smooth. In general, the invention resides in a tissue which has been topically treated with a hydrophilic softening composition comprising one or more of propylene glycol, polyethylene glycol, polypropylene glycol, and/or other hydrophilic solvents and one or more organic surface modifiers (hereinafter defined).

More specifically, the invention resides in a tissue comprising from about 0.5 to about 30 dry weight percent, based on the weight of fiber, of a softening composition comprising one or more hydrophilic solvents selected from the group consisting of water, propylene glycol, polypropylene glycol and polyethylene glycol, and one or more surface modifiers selected from the group consisting of quaternary ammonium compounds having the following structure:

wherein

X = methyl sulfate or other compatible counterion; and

R = aliphatic, saturated or unsaturated C₈-C₂₂, with the proviso that the tissue does not comprise glycerin.

Suitable organoreactive polysiloxanes include the following structures:

and

wherein

R =: amine, carboxy, hydroxy, or epoxy;
n =: 3 or greater;
x =: 1 to 1000; and
y =: 1 to 25.

The add-on amount of the hydrophilic softening composition containing the surface modifier(s) and the hydrophilic solvent(s) is from about 0.5 to about 30 dry weight percent based on the weight of the tissue, more specifically from about 1 to about 10 dry weight percent. Water can be added to the formulation to reduce the viscosity of the composition and to make the formulation more suitable for application.

The amount of the surface modifier in the hydrophilic softening composition can be from about 0.2 to about 80 weight percent, more specifically from about 0.5 to about 50 weight percent, and still more specifically from about 1 to about 20 weight percent.

Other optional ingredients include aloe, humectants, skin protectants, preservatives, and feel modifiers. Suitable humectants, include lactic acid and its salts, sugars, glycerin, ethoxylated glycerin, ethoxylated lanolin, corn syrup, hydrolyzed starch hydrolysate, urea, and sorbitol. Suitable skin protectants include allentoin, kaolin, allantoin and zinc oxide. Suitable preservatives include Quaternium-15, organic acids, parabens, DMDM hydantoin, diazolidinyl urea, methylchloroisothiazoline, methylisothiazolin, sodium hydroxymethyl glycinate, imidazolidinyl urea, and the like. Suitable feel modifiers include corn starch, oat flour, talc, boron nitride, and cyclodextrin.

The hydrophilic softening composition, which can be in the form of a solution or suspension, can be applied to the dry tissue surface by any suitable means, such as spraying or printing.

The tissue to which the hydrophilic formulation is applied can be any tissue useful as facial tissue, bath tissue, or towels. Such can be produced by throughdrying or wet-pressing tissue making processes and can be creped or uncreped, layered or blended (not layered). The finished tissue product can be one-ply, two-ply or three or more plies. Either the dryer side or the air side of the tissue can be oriented outwardly in the final tissue product.

EXAMPLES Example 1

A hydrophilic solution consisting of 50 parts by weight propylene glycol, 28.5 parts by weight of a softener/debonder composition (quaternary imidazolinium, fatty acid alkoxylate and polyether with 200-800 molecular weight, identified as DPSC 5299-8, Witco Corporation) and 21.5 parts by weight water. The propylene glycol and DPSC 5299-8 were mixed together until uniform. Then the water was added and the mixture stirred until a homogeneous solution was achieved. Using a gravure printing method, the resulting hydrophilic solution was applied to the outer surfaces of the two outer plies of a three-ply, blended, wet-pressed creped tissue having a basis weight of 41.6 grams per square meter. The furnish of each ply consisted of a blend of 50 percent eucalyptus hardwood, 14 percent northern hardwood kraft, and 36 percent northern softwood kraft fibers. The add-on amount was about 1 dry weight percent based on the total weight of the three-ply tissue. The resulting tissue had a fuzzy softness.

Example 2

A hydrophilic solution consisting of 90 parts by weight propylene glycol and 10 parts by weight DPSC 5299-8 was prepared. The propylene glycol and the DPSC 5299-8 were mixed together until a homogeneous solution was achieved. The resulting hydrophilic solution was applied to the outer surfaces of the two outer plies of a three-ply, blended, wet-pressed creped tissue (as described in Example 1) having a basis weight of 41.6 grams per square meter using a gravure printing method. The add-on amounts were about 1, 3, and 10 dry weight percent based on the total weight of the tissue. The resulting tissues had a fuzzy softness, with the higher add-on tissues feeling softer.

Example 3

A hydrophilic solution was prepared consisting of 70 parts by weight propylene glycol, 10 parts by weight DPSC 5299-8 and 20 parts by weight of a second quaternary ammonium compound (olealkonium chloride, 50 percent active, identified as Mackernium KP, McIntyre Group, LTD.). The propylene glycol and the DPSC 5299-8 were mixed together. The Mackernium KP was added and stirred until homogeneous. Using a gravure printing method, the resulting hydrophilic solution was applied to the outer surfaces of the two outer plies of a three-ply blended, wet-pressed creped tissue as described in Example 1 and a three-ply layered, wet-pressed creped tissue having a basis weight of about 41.6 grams per square meter. Each of the plies of the layered tissue contained three layers. The dryer side outer layer consisted of eucalyptus fibers. The inner layer contained 28 percent northern hardwood kraft and 72 percent northern softwood kraft fibers. The air side outer layer contained northern hardwood kraft and northern softwood kraft fibers. Kymene® 557H (Hercules, Inc.) was added at 0.16 - 0.34 weight percent based on dry fiber in all layers. A wet strength agent (Parez® 631NC from Cytec Industries, Inc.) was added at 0.45 - 0.55 weight percent based on dry fiber in the inner layer and the airside layer. The three-ply tissue was plied together such that the two outer surfaces were dryer side layers. The add-on amounts of the hydrophilic solution were about 1 and 2 dry weight percent based on the total weight of the tissue. The resulting tissue products were very soft, with the higher add-on tissues being softer.

Example 4

A hydrophilic solution was prepared consisting of 50 parts by weight propylene glycol, 20 parts by weight DPSC 5299-8 and 30 parts by weight Mackernium KP. The propylene glycol and the DPSC 5299-8 were mixed together. The Mackernium KP was added and stirred until homogeneous. Using a gravure printing method, the resulting hydrophilic solution was applied to the outer surfaces of the two outer plies of a three-ply, blended, wet-pressed creped tissue as described in Example 1 and a three-ply layered, wet-pressed creped tissue as described in Example 3. The add-on amounts were about 1 and 2 dry weight percent based on the weight of the tissue. The resulting tissue products were very soft, with the higher add-on tissues being softer.

Example 5

A hydrophilic solution consisting of 80 parts by weight propylene glycol, 10 parts by weight of DPSC 5299-8 and 10 parts by weight of an organoreactive polysiloxane (identified as FTS-226, 40 percent active, OSi Specialties, Inc.). The propylene glycol and DPSC 5299-8 were mixed together until uniform. Then the FTS-226 was added and the mixture stirred until a homogeneous solution was achieved. Using a gravure printing method, the resulting hydrophilic solution was applied to the outer surfaces of the two outer plies of a three-ply, blended, wet-pressed creped tissue as described in Example 1. The add-on amount was about 1 and 5 dry weight percent based on the weight of the tissue. The resulting tissue had a flannelly softness.

Example 6

A hydrophilic solution consisting of 40 parts by weight propylene glycol, 10 parts by weight DPSC 5299-8 and 50 parts by weight FTS-226. The propylene glycol and the DPSC 5299-8 were mixed together until uniform. Then the FTS-226 was added and the mixture stirred until a homogeneous solution achieved. Using a gravure printing method, the resulting hydrophilic solution was applied to a blended three-ply, wet-pressed creped tissue as described in Example 1 and a layered, three-ply, wet-pressed creped tissue as described in Example 3. The add-on amount was about 1 and 2 dry weight percent based on the weight of the tissue. The resulting tissues had a flannelly softness.

Example 7

A hydrophilic solution consisting of 55 parts by weight propylene glycol, 20 parts by weight DPSC 5299-8 and 25 parts by weight FTS-226. The propylene glycol and the DPSC 5299-8 were mixed together until uniform. The FTS-226 was added and the mixture stirred until a homogeneous solution achieved. Using a gravure printing method, the resulting hydrophilic solution was applied to both a blended, three-ply, wet-pressed creped tissue as described in Example 1 and a layered, three-ply, wet-pressed creped tissue as described in Example 3. The add-on amount was about 1 and 2 dry weight percent based on the weight of the tissues. The resulting tissues had a flannelly softness with the higher add-on tissue being softer.

Claims

A tissue comprising a quatemary ammonium compound, characterized in that it comprises from about 0.5 to about 30 dry weight percent, based on the weight of fiber, of a softening composition comprising one or more hydrophilic solvents selected from the group consisting of water, propylene glycol, polypropylene glycol and polyethylene glycol, and one or more of a quatemary ammonium compound having the following structure:
wherein

X =

methyl sulfate or other compatible counterion; and

R =

aliphatic, saturated or unsaturated C₈ - C₂₂;

with the proviso that the tissue does not comprise glycerin.
The tissue of Claim 1 wherein the softening composition further comprises an organoreactive polysiloxane which is selected from the organoreactive polysiloxanes having the following structures: and

and
wherein

R =

amine, carboxy, hydroxy, or epoxy;

n =

3 or greater;

x =

1 to 1000; and

y =

1 to 25.