CZ351495A3 - Multilayer structure of tissue paper containing biologically degradable chemical softening mixtures and binding materials - Google Patents

Abstract

Multi-layered tissue paper webs comprising biodegradable chemical softener compositions and binder materials are disclosed. The multi-layered tissue webs are useful in the manufacture of soft, absorbent paper products such as facial tissues and/or toilet tissues. The multi-layered tissue paper products contain a biodegradable chemical softening composition, preferably comprising a mixture of an ester-functional quaternary ammonium compound and a polyhydroxy compound. Preferred ester-functional quaternary ammonium compounds include diester dialkyl dimethyl ammonium salts such as diester di(touch hardened)tallow dimethyl ammonium chloride, diester di(hydrogenated)tallow dimethyl ammonium chloride. Preferred polyhydroxy compounds are selected from the group consisting of glycerol, sorbitols, polyglycerols having a weight average molecular weight of from about 150 to about 800, polyoxyethylene glycols and polyoxypropylene glycols having a weight average molecular weight from about 200 to 4,000. The multi-layered tissue paper webs also contain an effective amount of binder materials to control linting and/or to offset the loss in tensile strength, if any, resulting from the use of the chemical softening compositions. The binder materials are selected from the various wet and dry strength additives, and retention aids used in the paper making art. Preferably, the majority of the biodegradable chemical softening compositions will be disposed on the outer layers of the multi-layered tissue paper products where they are most effective. The binder materials are typically dispersed throughout the multi-layered product to control linting. In other words, the chemical softening compositions and the binder materials can be selectively distributed within the multi-layered tissue paper web to enhance the softness, absorbency, and/or lint resistance of a particular layer or ply.

Description

Technical field

The invention relates to a multi-ply tissue paper structure, and more particularly to a multi-ply tissue paper structure. containing biodegradable chemical softening compositions and binder materials. These processed structures can be used to produce soft, resistant paper products, cosmetic wipes, and absorbent and tear toilet papers such as e.g.

BACKGROUND OF THE INVENTION

Paper structures and / or layers, sometimes referred to as tissue paper or tissue, are widely used in modern society. Items such as. for example, cosmetic wipes and toilet papers are essential business items. It has long been recognized. that the four important physical attributes of these products are their strength, softness. absorbency, especially when operating in wet conditions. and their resistance to tearing. when moistened. Research and development efforts

- 2 aimed at improving each of these aspects without seriously reducing the other, as well as improving two or three of these attributes simultaneously.

Strength means the ability of the product, and its forming structures, to maintain physical integrity during use and to resist tearing, cracking and crushing, under user conditions, particularly wet conditions.

Softness means the tactile sensation experienced by the consumer when he / she wears the product, wipes it against his skin or during crumpled hands. This tactile perception is provided by a combination of several physical properties. Overall, the rigidity of the paper structure from which the product is made is considered by one of the most important experts to be skilled in the art. Stiffness is usually considered to be directly dependent on the dry tensile strength and stiffness of the fibers forming the structure.

Absorbency is a measure of the ability of a given article, and its forming structures, to absorb a quantity of liquid, especially aqueous solutions or dispersions. Total absorbency is generally perceived by the consumer as a combination of the total amount of fluid absorbed by a given multilayer tissue paper mass upon saturation, as well as the rate at which it absorbs the fluid.

The resistance to tearing (friction, pulping) of the fibrous product, and its forming structures, is to hold together from a < - > In other words, the higher this resistance is, the lower the susceptibility of resins to the strength of the stranded structure to it.

It is widely known to use a lokra to increase the strength of paper structures. For example, estelt describes a number of such materials and their chemical composition in Cellulose Chemistry and Technology, Volume 13, pages 813-825 (1979). Freimark et al. in U.S. Pat. No. 3,755,220, issued Aug. 28, 1973, teaches that certain chemical additives, known as disintegrating agents, interfere with the natural bonding of the fibers to each other, which occurs during the formation of the layers in the papermaking process. This limitation of bonding results in a softer or less coarse layer of paper. Freimark et al. they continue to argue that the use of wet strength resins in conjunction with the use of release agents leads to compensation for the undesirable effects of the release agents. Indeed, these release agents limit the dry tensile strength and the wet tensile strength.

Shaw, in U.S. Patent 3,821,068, issued June 28, 1974, also states that chemical disintegrants can be used to reduce stiffness and thus increase the softness of the structure.

-he dv-á-bného — papír .------------------------------------ Chemical disintegrants have already been reported in various references, such as in US Patent 3,554,862, issued to Hervey et al. January 12, 1971. These materials include quaternary ammonium salts, such as cocotrimethyl ammonium chloride, o-trimethyl ammonium chloride, and stearyl trimethyl ammonium chloride.

Emanuelson et al. U.S. Pat. No. 4,144,122, issued March 13, 1979, discloses the use of complex quaternary ammonium salts such as bis (and 1-alkoxy (2-hydroxy) propylene) quaternary ammonium chlorides to soften the structures. These authors also attempt to overcome any decrease in absorbency caused by the disintegrating agents using nonionic surfactants such as ethylene oxide and propylene oxide adducts of fatty alcohols.

Armak Company of Chicago, Illinois, in its bulletin 76-17 (1977), discloses the use of tallow hydrogenated dimethyl ammonium chloride in combination with fatty acid esters of lyoxyethylene glycols to impart both softness and absorbency to tissue paper structures.

One exemplary result of research conducted to improve paper structures is described in U.S. Patent 3,301,746 issued to Sanford and Sisson on January 31, 1967.

Despite the high quality of the paper structures produced by the process described in this patent and the commercial success of the products made from these structures, research efforts to find improved products continue.

For example, Becker et al. in U.S. Pat. No. 4,158,594, issued January 19, 1979, disclose a method which it claims to form a rigid, soft, fibrous layer. More specifically, they state that the strength of the tissue paper structure (which can be softened by the addition of chemical release agents) can be increased by adhering, during processing, one surface of the structure to the creping surface in a fine pattern configuration using a binder material (such as acrylic emulsion, a water-soluble resin or elastomeric binder material) that has been adhered to one surface of the structure and to the creping surface in a fine pattern configuration and creping the structure from the creping surface to form the layer material.

Traditional quaternary ammonium compounds, such as the well-known dialkyldimethylammonium salts (for example, dimethyl ammonium tallow diacid, dimethyl ammonium tallow diacid, dimethylammonium hydrogenated tallow, etc., etc.) are effective chemical disintegrating agents. However, these quaternary ammonium compounds are hydrophobic and not biodegradable and can adversely affect the absorbency of the treated paper structures. Applicants have discovered that mixing a biodegradable quaternary ammonium compound with a polyhydroxy compound (such as glycerol, sorbitols, lyglycerols or lyoxyethylene glycols) will increase both softness and absorbency of fibrous cellulosic materials.

Unfortunately, the use of biodegradable chemical softener compositions containing a biodegradable quaternary ammonium compound and a polyhydroxy compound can reduce the tear resistance of the treated paper structures. Applicants have discovered that tear resistance can be increased by using suitable binder materials such as dry and wet strength resins and retention aids known in the paper making art.

The present invention is applicable to tissue paper in general, but particularly applicable to a multi-layered tissue paper web, such as those described in U.S. Patent 3,994,771, issued to Morgan Jr. ' et al. On Nov. 30, 1976, and incorporated herein by reference.

It is an object of the present invention to provide soft, absorbent and tear resistant multi-ply tissue paper products.

It is also an object of the present invention to provide a process for the preparation of soft sorbents and sorbents and odo-1-. .alpha.-.alpha. - .beta.-eh -----pp-oduz-buz, multilayer tissue paper.

. These and other objects are achieved by the present invention, which will be readily understood by reading the following description.

SUMMARY OF THE INVENTION

The present invention provides soft, absorbent, tear resistant products comprising fiber forming paper, biodegradable chemical softening compositions, and binder materials. Brief, biodegradable chemical softening compositions include a mixture of:

(a) from about 0.01% to 3.0% of a biodegradable quaternary ammonium compound, preferably having the formula:

R ₂ (CH ₂ ) _n - Y - R ₃ x (CH ₂ ) n

R ₃ or (CH ₂ ) n - Y - R:

ΧRx · or

R ₃ -Y-CH ₂

ΟΗ - CH ₂ - N * - (R 2) x R ₃ - Y in which:

each R 2 hydroxyalkyl group is alkyl benzyl

Cx-C8 or a group or hydrocarbyl mixture thereof; each R x is C 12 -C 22 or substituted hydrocarbyl or mixtures thereof; each R a is hydrocarbyl Cxx-Cax or substituted hydrocarbyl or mixtures thereof; Y is -O-C (O) - or

- C (O) - O - or mixtures thereof; n for example chloride, nitrate and the like; and

- NH - C (O) - or C (O) - NH is 1 to 4 and X - is a suitable anion, bromide, methylsulfate, ethylsulfate, from about

0.01% to the selected level

3.0% polyhydroxy compound; glycerol, sorbitol, polyglycerols having an average molecular weight of about 150 to 800 and polyoxyethylene glycols and polyoxypropylene glycols having an average molecular weight of about 200 to 4000. *

Preferably, the weight ratio of the biodegradable quaternary aramonium compound to the polyhydroxy compound ranges from about 1.0: 0.1 to 0.1: 1.0. It has been found that a biodegradable chemical softening composition is more effective when the polyhydroxy compound is mixed with the biodegradable quaternary ammonium compound at a temperature at which both compounds are miscible.

Compounds having the following formulas are suitable for use in the present invention.

ff (CH ₃ ) ₂ - η * - ((CH ₂ ) ₂ - 0 - C - (R ₃ ) = Cl0 n

(CH ₃ ) ₂ - N * - ((CH ₂ ) 2 - o - c - r ₃ ClI

R _(CH3) (HO- (CH) ₃₎ ((CH ₂₎

CH ₃ SOa a

O lt r ₃ - c - o - ch ₂ · 'CH - CH ₂ - N * - (R ₂ ) ₃ Clr ₃ - c - on

O

C 1 -C 6 or hydroxyalkyl or mixtures thereof; each C1 2 - C 2 | or mixtures thereof;

monoester diacids in which:

each R 2 is alkyl, benzyl R 1 is hydrocarbyl substituted hydrocarbyl or each R ₃ is C 11 -C 21 hydrocarbyl, or substituted hydrocarbyl or mixtures thereof;

These compounds can be considered to be mono or diester variations of the well-known dialkyldimetylamoniových salt such as dimethylammonium diester ditallow, diesterdisteary1dimety 1amoniumch1orid, dimethylammonium monoester ditallow, diraetylamoniummetyl sulfate hydrogenated diester ditallow, dimethyl ammonium chloride hydrogenated diester ditallow, dimethyl ammonium chloride hydrogenated ^- jTjičh Tallow and mixtures thereof with diester variations of non-hydrogenated tallow dimethylammonium chloride, tallow ammonium chloride dimers (DEDTHTDMAC) and tallow hydrogenated dimethylammonium chloride (DEDHTDMAC), and preferably mixtures thereof. Depending on the characteristics of the product, the saturation level of tallow diacids may be adjusted from non-hydrogenated (soft) to touch to partially or fully hydrogenated (solid).

Without wishing to be bound by theory, it is believed that the ester moiety (s) confer on these compounds biodegradability and, importantly, the quaternary ammonium compounds with the ester functional group used herein biodegrade faster than traditional dialkyldimethylammonium chemical softeners.

Examples of polyhydroxy compounds useful in the present invention include glycerol, sorbitols, polyglycerols having an average molecular weight of from about 150 to about 800 and polyoxyethylenes having an average molecular weight of from about 200 to about 4,000, preferably polyoxyethylene glycols with an average molecular weight of from about 150 to about 800. about 200 to 600.

--------- p ₀ -j _em - -p. ₀ -jj.- _v - ₀ - _is related to wet and wet conditions, and retention aids known in the art. These materials increase the tear resistance of the tissue paper structures of the present invention as well as counteract any decrease in tensile strength caused by biodegradable chemical softening compositions. Examples of suitable binder materials include permanent wet strength resins (ie, Kymene 557H, sold by Hercules Incorporated of Wilmington, DE), temporary wet strength resins (ie, National starch 78-0080, sold by National Starch and Chemical Corporation of New York) York, NY), dry strength resins (ie, Acco ° 514, Acco ° 711, sold by the American Cyanamide Company of Wayne, New Jersey) and retention aid resins (ie, Percol ° 175, sold by Allied Colloids of Suffolk, Virginia).

Briefly, the process for producing the multi-ply tissue web structures of the present invention comprises the steps of forming the multi-ply web material from the above components, depositing the multi-ply web on a perforated surface such as a Foudrinier screen and removing water therefrom. - All percentages, ratios and proportions in this material are by weight unless otherwise stated.

Overview of the figures in the drawing

Although the specification in question ends with the claims specifically emphasizing and clearly claiming the subject matter considered to be the invention, it is believed that the invention will be more readily understood from the following descriptions taken in conjunction with the accompanying drawings in which:

Giant. 1 is a schematic cross-sectional view of a three-ply toilet paper according to the present invention;

Giant. 2 is a schematic cross-sectional view of a cosmetic napkin of two sub-layers, each composed of two layers according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Although this specification is completed by the claims specifically emphasizing and clearly claiming the subject matter considered to be the invention, it is believed that the invention will be more readily understood by reading the following detailed description and the appended examples.

As used herein, the term tear resistance of the fibrous product, and its forming layers, is understood to mean their ability to hold together under user conditions, particularly wet conditions. In other words, the higher this tear resistance, the lower the susceptibility of the structure to it.

As used herein, the term binder refers to resins of varying wet and dry strength and retention aids known in the art of paper making.

As used herein, the term water-soluble refers to materials that are water-soluble at least up to 3% at 25%.

As used herein, the term tissue paper structure, structure, paper layer, and paper product all refer to paper layers produced by a process comprising the steps of forming an aqueous paper making material, depositing the paper making material on a perforated surface such as e.g. Foudrinier sieve and removal of water from this material either by gravity or vacuum assisted dewatering, with or without compression and evaporation.

----------_ T a k —j_and k_s-e_ — _ in this mat. The aqueous paper-making material is an aqueous slurry of the paper-forming fibers and chemicals described herein.

As used herein, the term multilayer tissue paper structure, multilayer paper structure, multilayer paper layer, and multilayer paper product, all refer to paper layers prepared from two or more layers of aqueous paper making material, preferably composed of different types of paper. fibers, fibers of relatively long softwood, and relatively short hardwood fibers, which are used in the manufacture of tissue paper. These layers are preferably formed from deposits of separate streams of sparse fiber slurries on one or more endless perforated screens. When the individual layers are initially formed on separate screens, these layers are subsequently wet-bonded to form a layered composite structure.

OF

The first step of the process of the present invention is the formation of an aqueous paper making material. This material includes paper making fibers (sometimes also referred to as wood pulp or pulp) and a mixture of at least one biodegradable ammonium compound, polyhydroxy compound and binder materials, all of which will be described hereinafter.

It is envisaged that wood pulp in all its variations will normally include the fiber forming paper used in the present invention. However, other cellulosic flush mashes such as cotton liners, bagasse, rayon, etc. may also be used, and none is excluded. The wood pulps used herein include chemical pulps such as Rraft, sulphite and sulphate pulps, as well as mechanical pulps. pulps containing, for example, wood pulp, electromechanical pulp such as chemo-thermomechanical pulp (CTMP). Pulps of both declining and coniferous trees can be used.

Both hardwood and softwood pulp as well as mixtures thereof may be used. The terms hardwood pulp refer to fibrous fibers derived from the woody substance of the deciduous trees (angiosperms), while soft hardwoods refer to fibrous fibers derived from the woody substance of conifers (gymnosperms). Hardwood fibers such as, for example, eucalyptus, are particularly suitable for the outer layers of the multilayer paper structure described herein, while Kraft northern wood pulps are preferred for the inner layer (s) or sub-layer (s). Also useful in the present invention are fibers derived from recycled paper, which may include any or all of the above categories, as well as other non-fibrous materials such as fillers and adhesives used to facilitate the manufacture of the original paper.

Biodegradable chemical softening mixtures

The present invention comprises, as an essential component, a mixture of a biodegradable quaternary ammonium compound and a polyhydroxy compound. The ratio of biodegradable ammonium quaternary compound to polyhydroxy compound ranges from about 1.0: 0.1 to 0.1: 1.0; preferably, the weight ratio of the biodegradable quaternary ammonium compound to the 1-hydroxy compound is about 1.0: 0.3 to 0.3: 1.0; more preferably, the weight ratio of the biodegradable quaternary ammonium compound t

and a polyhydroxy compound of about 1.0: 0.7 to 0.7: 1.0, although this ratio will vary depending on the molecular weight of the particular polyhydroxy compound and / or the biodegradable quaternary ammonium compound used.

All of these types of compounds will be described in more detail below.

A. Biodegradable quaternary ammonium compound

The biodegradable chemical softening composition contains as an essential component from about 0.01% to about 3.00% by weight, with TNE _____ front _0,01 from about% to about 1.00% by weight of biodegradable quaternary ammonium compound, preferably biodegradovate1 ^The Non. '7' quaternary ammonium compounds with the following formula:

R ₂ (CH ₂ ) _n - Y - R ₃ .V * XR ₂ (CH ₂ ) _n - Y - R ₃ or

R ₃ (CH ₂₎ n - Y - R ₃

N * XR ₂ RI

or 4 0 rt r ₃ - c - 0 - CH2 CH - CH2 - N * - (R ₂ ) ₃ X r ₃ - C - 0 n 0 in which everyone with R 2 is alkyl Ci-Ce or hydroxyalkyl group, benzyl group or theirs

mixtures; each R 1 is C 12 -C 22 hydrocarbyl, or substituted hydrocarbyl, or mixtures thereof; each R ₃ is C ₁₁ -C ₂₁ hydrocarbyl, or substituted hydrocarbyl or mixtures thereof; Y is

- 0 - C (0) - or - C (0) - 0 - or - NH - C (0) or - C (0)

- NH -, or mixtures thereof; n is 1-4 and X is a suitable anion such as chloride, bromide, methyl sulfate, ethyl sulfate, nitrate and the like.

As Ed. Swern in Bailey's Industrial Oil and Fat Products, Third Edition, John Wiley & Sons / New York, 1964), tallow is a naturally occurring material with varying composites. Typically, 78% or more of the tallow fatty acids contain 16 or 18 carbon atoms. Typically, half of the fatty acids present in tallow are unsaturated, primarily in the form of oleic acid. Synthetic as well as natural tallow are within the scope of this invention. It is also known that, depending on the characteristics of a given product, the saturation level of tallow diacid can be adjusted from non-hydrogenated (soft) to touch, to partially or fully hydrogenated (solid). All of the above saturation levels are expressly indicated within the scope of this invention.

It is understood that the substituents R 1, R ₂ , R a, may optionally be replaced by various groups such as alkoxy, hydroxyl or may be branched, but such materials are not preferred herein. Preferably each R 1 is C 1 -C 18 alkyl and / or alkenyl, most preferably each R 1 is straight chain C 1 -C 18 alkyl and / or alkenyl. Each R 2 is preferably methyl or hydroxyethyl. R a is preferably C 1 -C 1 alkyl. and / or alkenyl, most preferably R a is straight chain C 15 -C 17 alkyl and / or alkenyl, and X - is chloride or methyl sulfate. In addition, the quaternary ammonium compounds -s-ste-ro-u-functional-group-olefin -te-1-na -obs ah ον-at-to-d-10% mono (long chain alkyl) derivatives, e.g., (R2) 2-N '- ((CH 2) 2 OH) ((CH 2) 2 OC (0) R ₃₎ X "as minor gradients which can act as emulsifiers and are useful in the present invention.

Specific examples of quaternary ester functional groups with the above structures useful in the present invention include the well-known diesterdialkyldimethyl ammonium salts such as tallow dimethyl ammonium chloride, tallow diamethyl ammonium chloride, diester dihydroxymethylsulfate diester, diester dimethyl ammonium methylsulfate. tallow, dimethylammonium chloride of hydrogenated tallow diester diacids, and mixtures thereof. Particular preference is given to dimethylammonium chloride of diester diacids from tallow and dimethylammonium chloride of hydrogenated di-ester diacids from tallow. These particular materials are available from Sherex Chemical Company Inc. of Dublin, Ohio, under the trade name ADOGEN DDMC ° ‘.

Di-quat variations of the ester-functional quaternary ammonium compound may also be used and are considered to be within the scope of the present invention. These compounds have the formula:

O (R2) 2 (R2) 2 O n i r n

R ₃ -CO- (CH 2) 2 - N * - (CH ₂ ) _n - N * - (CH ₂ ) 2 - O - C - R ₃ 2X-

In the above structure, each R 2 is C 1 -C 6 alkyl or hydroxyalkyl, R ₃ is C 11 -C ₁₈ hydrocarbyl, n is 2 to 4, and X 4 is a suitable anion such as a haloid (for example chloride or bromide) or methyl sulfate. Preferably each R ₃ is C 1 -C 1 alkyl. and / or alkenyl, most preferably each R _{3 is} straight chain C 13 -C ₁₇ alkyl and / or alkenyl, and R 2 is methyl.

B. Polyhydroxy Compound

The biodegradable chemical softening composition comprises as main component from about 0.01% to 3.00% by weight, preferably from about 0.01% to 1.00% by weight of the polyhydroxy compound.

Examples of polyhydroxy compounds useful in the present invention include glycerol, sorbitols, polyglycerols having an average molecular weight of from about 150 to about 800 and polyoxyethylene glycols and polyoxypropylene glycols having an average molecular weight of from about 200 to about 4,000, preferably from about 200 to 1,000, most preferably from about 200 to 1,000. 200 to about 600. Particular preference is given to polyoxyethylene glycols of average

Mixtures of the aforementioned polyhydroxyl compounds may also be used in the art. For example, mixtures of glycerol and polyoxyethylene glycols having an average molecular weight of from about 200 to 1,000, preferably from about 200 to 600, are useful in the present invention. Preferably, the weight ratio between glycerol and polyoxyethylene glycol is in the range of about 10: 1 to 1:10.

A particularly preferred polyhydroxy compound is a polyoxyethylene glycol having an average molecular weight of about 400. This material is available from -Union - Carbide Company of Danbury, Connecticut, under the trade name PEG-400.

The biodegradable chemical softening composition described above, i.e. the composition. The biodegradable quaternary ammonium compounds and the polyhydroxy compound are preferably diluted to the desired concentration of the quat and polyhydroxy compound dispersion prior to addition to the aqueous slurry of paper-forming fibers or paper-making material at the wet end of the paper making machine at a suitable point by a Fourdrinier screen. layer forming stage. However, application of the above-described biodegradable chemical softening composition following formation of the wet paper structure and prior to its complete development. In addition, the advantages of wet strength and wet strength are expressly included within the scope of the present invention. of the invention.

It has been found that biodegradable chemical softening compositions are more effective when the biodegradable quaternary ammonium compound and the polyhydroxy compound are first premixed together before being added to the papermaking material. A preferred method, as described in more detail in Example 1, consists first of heating the polyhydroxy compound to a temperature of about 66 ° C (150 °) and then adding the biodegradable quaternary ammonium compound to the hot polyhydroxy compound to form a homogeneous fluid. The weight ratio of the quaternary ammonium compound and the polyhydroxy compound ranges from about 1.0: 0.1 to 0.1: 1.0; preferably the weight ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound is about 1.0: 0.3 to 0.3: 1.0: more preferably the weight ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound is about 1.0: 0.7 to 0.7: 1.0, although the ratio will vary depending on the molecular weight of the particular polyhydroxy compound and / or the biodegradable quaternary ammonium compound used.

Unexpectedly, the adsorption of the polyhydroxy compound into the paper has been found to be significantly enhanced when premixed with the biodegradable quaternary ammonium compound and added to the paper as described above. In fact, at least 20% of the polyhydroxy compound and the biodegradable quaternary ammonium compound added to the fibrous cellulose are retained; preferably, the retention level of the polyhydroxy compound and the biodegradable quaternary ammonium compound is from about 50% to about 90% of the added levels.

Importantly, adsorption occurs at a concentration and within a time frame that is practical for use during papermaking. In order to better understand the surprisingly high paper retention rate of the polyhydroxy compound, the properties of the melted solution and the aqueous dispersion of dimethylammonium chloride to the touch of hardened tallow diester diacids (DEDTHTDMAC) and polyoxyethylene glycol 400 were studied.

Without wishing to be bound by theory or otherwise limiting the present invention, the following discussion is offered to explain how the quaternary ammonium compound with an ester functional group promotes adsorption of the polyhydroxy compound by paper.

DEDTHTDMAC (dimethylammonium chloride to the touch of hardened tallow diester diacids) exists as a mixture in the liquid crystal and crystalline phase equilibrium. X-rays indicate that commercial DEDTHTDMAC is, in fact, a liquid crystal phase showing no evidence of crystalline states.

Mixtures of DEDTHTDMAC with PEG-400

A phase study of these two materials using a step dilution method demonstrates that their physical behavior is similar to the dimethylammonium chloride of tallow hydrogenated diacids. These compounds are miscible over a wide temperature range (> 50 ° C), suggesting that dispersions can be prepared from these mixtures over a comparable temperature range. There is no upper limit on the miscibility temperature. X-rays indicate that the crystal-liquid phase mixture actually exists in the DEDTHTDMAC / PEG 400 mixtures.

Mixtures of DEDTHTDMAC with glycerol

The 1: 1 weight ratio of DEDTHTDMAC and glycerol appears (from direct observation and X-ray data) to be a liquid phase. Although glycerol can form liquid crystal phases in conjunction with other agents, it does not appear to be the case in this system in this mixture.

Mixtures of DEDTHTDMAC with PEG-400

A phase study of these two materials using a step dilution method demonstrates that their physical behavior is similar to DEDTHTDMAC. These compounds are miscible over a wide temperature range (> 67 °), suggesting that dispersions can be prepared from these mixtures over a comparable temperature range. There is no upper limit of miscibility temperature.

Physical state of quats / polyhydrosuccinates / water mixtures

A dispersion of each of these materials can be prepared by diluting the mixture which is maintained at a temperature at which the polyhydroxy compound and the quaternary ammonium salt with an ester function are miscible with water. Neither DEDTHTDMAC nor DEDHTDMAC are water-soluble, so diluting one or the other of the dry phase with water precipitates the quaternary ammonium compound with the ester function as small particles. The polyhydroxy compound is soluble with water in all ratios, so it is not precipitated.

Adding mixtures of two equal portions of DEDTHTDMAC and polyhydroxy compounds (eg, glycerol, PEG-400, etc.) to water to form a mixture containing about 1% DEDTHTDMAC will precipitate DEDTHTDMAC. Most likely, the DEDTHTDMAC phase will be close to room temperature with a lamellar liquid crystal.

Colloidal structure of dispersions

The liquid crystal phase in the diluted mixtures exists as bubbles, mostly closed and spherical. The formation of such a dispersion is likely to result from the high osmotic pressure gradients that currently exist during this process. The origin of these pressure gradients is the spatial gradients formed in a given mixture (and thermodynamic activity) of water. Since the liquid phase of DEDTHTDMAC / glycerol mixtures can exist over a wide temperature range, dispersion can also be produced over a wide temperature range.

Crystalline electron microscopy demonstrates that the particles present are about 0.1 to 1.0 mm in size and of very variable structures. Some are layered (curved or flat), while others are closed bubbles. The membranes of all of these particles are molecular size layers in which the upper groups are exposed to water and the posterior is believed that the PEG's associated portions are together, with the core particles.

The use of dispersions prepared in this manner on the paper results in the attachment of the ester-functional quaternary ammonium ion to the paper, strongly promoting adsorption of the polyhydroxy compound by the paper and producing it and wettability retention.

the desired softness modification

State of dispersions

When the dispersions described above are cooled, the material may partially crystallize within the colloidal particles. However, it is likely that reaching the equilibrium state will require a long time (possibly months) for these irregular particles whose membranes are either liquid crystal or irregular crystalline phases to react with the paper.

Dioaegraaova not described herein are used before equilibrium is reached.

Bubbles containing biodegradable quatas and polyhydroxy compounds (eg, glycerol, PEG 400, etc.) are believed to disintegrate upon drying the fibrous cellulosic material. Once the bubble is ruptured, most of the PEG component can penetrate into the interior of the cellulosic fiber to increase its resilience. Importantly, certain PEG is retained on the surface of the fiber where it acts to increase the absorbency rate of the cellulose fibers. As a result of the ion interaction, the cationic portion of the biodegradable quat component remains on the cellulose surface. fiber, where it improves the surface feel and softness of the paper product.

a base component of from about 0.01% to 1.00% by weight of the wet group of resins

Binding materials

The invention includes as

0.01% to 3.00%, preferably from a binder material selected from permanent strength, temporary wet strength resins, dry strength resins, and the resins are assisted by the resin. h__s_mě.s_í _.___ P o. j_i.v_Q5ié ___ ..

the materials act as a tear resistance control, as well as to compensate for a decrease in tensile strength, if any, caused by biodegradable chemical compositions.

If permanent wet strength is desired, the binder materials may be selected from the following group of chemicals: polyamideepichlorohydrin, polyacrylamides, styrene-butadiene latexes; insoluble polyvinyl alcohol1; ureaformaldehyde; polyethyleneimine; chitosan polymers and mixtures thereof. Polyamide epichlorohydrin resins are wet strength cationic resins found to be particularly useful. Suitable types of these resins are described in U.S. Pat. No. 3,700,623, issued October 24, 1972, and 3,772,076, issued 13.

November, 1973, both to Keim and incorporated herein by reference. One commercial success of useful polyamide epichlorohydrin resins is Hercules, Inc. of Wilmington, Delaware, selling it under the trademark Kymeme ° 557H.

Polyacrylamide resins have also been found to be useful as wet strength resins or retention aids. These resins are described in U.S. Patent 3,556,932, issued January 19, 1971 to Cosci et al. and 3,556,933, issued January 19, 1971 to Williams et al., both patents incorporated herein by reference. One of the commercial successes of 22 laminated resin resins is -American Cyanamide Co. of Stanford,

Connecticut, selling one of them under the brand Parez ° 631

NC. Another commercial success polyakry1ami- _t dových cationic resins are Allied Colloids of Suffolk, Virginia, and Hercules, Inc. of Wilmington, Delaware, sold under the trademarks Percol ° 175 and Reten ° 1232.

Still other water-soluble cationic resins suitable for use in the present invention are ureaformaldehyde and melamine-formaldehyde resins. The more common functional groups of these polyfunctional resins are nitrogen-containing groups such as amine groups and methylol groups attached to nitrogen. Polyethylene enrain-type resins are also useful in the present invention.

If temporary wet strength is desired, the binder materials may be selected from the following group of starch based temporary wet strength resins: starch based cationic dialdehyde resin (such as Caldas manufactured by Japan Carlet or Cobond 1,000 manufactured by National Starch); dialdehyde starch; and / or the resin disclosed in U.S. Pat. No. 4,981,557, issued Jan. 1, 1991 to Bjorquist and incorporated herein by reference.

If permanent dry strength is desired, the binder materials may be selected from the following group of materials: polyacrylamide (as a combination of Cypro 514 and Accostrength 711, manufactured by American Cyanamid of Wayne, N.J.); starch (such as corn or potato); polyvinyl alcohol (such as Airvol 540 from Air Products Inc of Allentown, PA); guar and carob mannogactans; polyacrylate latexes; and / or carboxymethyl cellulose (such as Acqualon CMC-T from Aqualon Co., Wilmington, DE). Generally, a suitable starch for practicing the present invention is characterized by water solubility and hydrophilicity. Exemplary starch materials include corn and potato starch, although this is not intended to limit the scale of suitable starch materials; and particularly preferred is a waxy corn starch, industrial known as amioca described, in Araioca Schopmayer, Food Starch. Araioca starch differs from conventional corn starch in that it is completely amylopectin, while conventional corn starch contains both amylopectin and amylosis. Various unique characteristics arai.o ca. starch. are further

- starch from waxy maize,. H.

Industries, December 1945, pp. 106-108 (Volume, p. 1 476

- 1,478). The starch may be granulated or dispersed, although granular form is preferred. It is preferably sufficiently cooked to inflate the granules. More preferably, the starch granules are inflated, eg by cooking, to a point just prior to the dispersion of the starch granules. These highly inflated starch granules are called fully cooked. Conditions for __________d ispe r z_i ____ s_e ____ c_e.l k o ve .____ m o.h.o_u.

the size of the starch granules, in which the degree of crystallinity of the granules is present, and the amount of amvlose present. Fully cooked ammonium starch, for example, can be prepared by heating an "aqueous slurry of consistency of about 4X starch granules at about 190 ° F (88 ° C) for between about 30 and 40 minutes. Other exemplary starch materials for use include modified cationic starches as modified having nitrogen containing groups such as amine groups and methylol groups attached to nitrogen, available from National Starch and Chemical Company, Bridgewater, New Jersey. These modified starch materials are used primarily as an additive to the fiber making material to increase wet and / or dry strength. Because such modified materials are more expensive than the latter, it is preferred.

to be unadjusted

The methods and applications comprise the same as those previously described by reference, preferably by adding to the use of other chemical additives, at the end of the wet process, by spraying; and less preferably, by printing. The binder may be used on the tissue paper itself, simultaneously with, before or after the addition of the plasticizer, absorbent and / or aesthetic additives. Preferably, at least an effective amount of a binder, preferably starch, is applied to the layer to provide tear control and the associated increase in dry strength relative to the binder of the untreated but otherwise identical layer. Preferably, between about 0.01% and 3.0% binder is retained in the dry layer, calculated on the basis of the dry fiber weight, more preferably between about 0.1% and 1.0% binder material, preferably starch based.

The second step in the process of the present invention is the deposition of the multilayer paper making material using the above-described softening composition and binder material as additives, on the perforated surface and the third step is the removal of water from the so settled material. Techniques and equipment for accomplishing these two processing steps will be apparent to those skilled in the paper making technique. Preferred embodiments of the multi-ply tissue paper of the present invention comprise from about 0.01% to about 3.0%, more preferably from about 0.1% to 1.0% by weight, based on the dry weight of the fibers, biodegradable softener composition and binder materials described herein. .

The present invention is generally applicable to multilayer tissue paper, including, but not limited to, traditional piston-pressed multilayer tissue paper, thickened multilayer tissue paper with a large volume pattern, and bulk bulk non-compressed multilayer tissue paper. Multilayer tissue paper products made therefrom may be assembled with a single layer or with multiple sub-layers. Fabric structures formed from laminated paper structures are described in Morgan Jr. U.S. Patent 3,994,771. et al., issued 3Ό ^- ; those stopadug 1976 “and I would like to refuse the wall. Overall, the wet laid composite, soft, bulky, and absorbent paper structure is prepared from one or more layers of paper making material, which are preferably comprised of different types of fibers. The layers are preferably formed from a deposit of separate streams of slurry of material, the fibers used are typically relatively long of softwood and relatively short of hardwood on one or more endless perforated screens. If the individual layers are formed initially on separate screens, these layers are subsequently joined to form a layered composite structure. This structure is subsequently adapted to the surface of the drying / imprinting fabric with open mesh by applying a hydraulic force to the structure and thereafter by thermal pre-drying the fabric as part of the low density paper making process. The layered structure may be stratified with respect to the fiber type, or the fiber content of the layers may be substantially the same. The multilayer tissue paper preferably has a basis weight of between 10 g / m ² and about 65 g / m ² , a density of about 0.60 g / m ³ or less, preferably a basis weight of less than about 35 g / m ³ or less, and a density of? , 30 g / cm ³ or less. Most preferably, the density will be between 0g / cm ³ and 0.20 g / cm ³ .

The multi-ply tissue paper structures of the present invention comprise at least two superimposed layers, a first layer and at least a second layer adjacent the first. Preferably, the multilayer tissue paper comprises three superimposed layers, inner or central and two outer layers, with a central spaced between the two outer layers. Preferably, the two outer layers comprise a primary fiber constituent of about 60% or more by weight of relatively short paper-forming fibers with an average fiber between about 0.2 and 1.5 mm. These short paper-forming fibers are typically hardwood fibers, preferably eucalyptus fibers. Alternatively, cheap short fiber sources such as sulfite fibers, thermo-mechanical fibers, chemo-thermo-technical fibers, recycled fibers containing fractionated fibers from recycled fibers and mixtures thereof may be used in one or both outer layers or mixed in the inner layer if need. The inner layer preferably comprises a primary fibrous constituent of about 60% or more by weight of the relatively long fiber forming paper with an average length of at least about 2.0 mm. These long paper-forming fibers are typically softwood fibers, preferably Kraft fibers of northern softwoods. Giant. 1 is a schematic cross-sectional view of a single ply toilet paper of three sub-layers of the present invention. Referring to FIG. 1, this three-layer structure 10 comprises three superimposed layers, an inner layer 12 and two outer layers 11. The outer layers 11 are primarily composed of short paper forming fibers 16 while the inner layer 12 is composed primarily of long paper forming fibers 17.

In an alternative preferred embodiment of the present invention, the multilayer tissue paper products are formed by placing at least two multilayer tissue paper structures side by side. Xapř. the bilayer paper may be made by including the first bilayer paper structure, and the second bilayer paper by placing them side by side. In this example, each sub-layer is formed by two layers of tissue paper comprising a layer. The first layer preferably and the second preferably fibers the first layer and the second comprises hard softwood fibers. The two sub-layers and the layers are joined such that the short hardwood fibers of each sub-layer are faced out and the long-fiber layers in. Giant. 2 is a schematic two-layer wipe according to FIG. 2, the structure 20 of the two layers 15 in a side-by-side position. Each and the outside of the softwood are a face cut view of the cosmetic of the invention.

The outer layers 18 are primarily composed of short paper-forming fibers 16. whereas inner layers 19 are comprised primarily of long paper making fibers 17. milks of BN can 'be ~ ~ ~ Manufacture formed ky ~ z ~~ e ~ lr ~ c tTře ViTšTěV ^- Phe * DV; brnré'ho paper positioning multilayer structures adjacent.

It should not be inferred from the above that the present invention is limited to tissue paper products comprising three layers - one to two layers and the like. Tissue paper products comprising three or more sub-layers in combination with each layer containing one or more layers are also are intended to be included within the scope of this invention.

Preferably, most of the biodegradable quaternary are found to be the most effective ammonium softening compounds and polyhydroxy compounds contained in at least one of the outer layers of the multi-ply tissue paper structure of the present invention. More preferably, most of the biodegradable quaternary ammonium compound and polyhydroxy compound are contained in both outer layers. It was a biodegradable chemical softening composition when added to the outer layers or sub-layers of tissue paper products. There, a mixture of biodegradable quaternary ammonium compound and polyhydroxy compound increases the softness and absorbency of the multi-ply paper products of the present invention. Referring to FIG. 1 and 2, a biodegradable chemical softening composition comprising a mixture of a biodegradable quaternary ammonium compound and a polyhydroxy compound is exemplified by dark circles 14. From FIG. 1 and 2, it can be seen that most of the biodegradable chemical composition 14 is contained in the outer layers 11 and 18, respectively.

• ÍS ..

However, it has also been found that the tear resistance of multilayer tissue products decreases with the introduction of a biodegradable quaternary ammonium compound and a polyhydroxy compound. Thus, binder materials are used to control tear and increase tensile strength. Preferably, the binder is contained in the inner layer and at least one of the outer layers of the multi-ply tissue paper structures of the invention. More preferably, the binder is contained throughout the multilayer product, i.e., the inner and outer layers. Referring to FIG. 1 and 2, the binder material is illustrated by white rings 13. From these figures it can be seen that most of the binder materials 13 are contained in the inner layers 12 and 12, respectively. 19 Dec In an alternative preferred form (not shown), most of the binder is contained in at least one outer layer, more preferably both outer layers of the multilayer product.

By combining a biodegradable chemical softening composition composed of a biodegradable quaternary ammonium compound and a polyhydroxy compound in conjunction with a binder material, superior softness, absorbency and tear resistance are achieved. Optionally, adding most of the biodegradable chemical softening composition to the tissue paper outer layer (s) increases its efficiency. The binder material is typically dispersed through a sheet of paper to control its tearing. However, as a biodegradable chemical softening composition, binder materials can optionally be added where they are most needed.

Traditionally pressed multilayer tissue paper and methods of making it are known in the art. This paper is usually made by depositing the papermaking material on a perforated forming mesh, often referred to as a Fourdrinier mesh. Once the material is deposited on the forming mesh, it is called a structure. The structure is dewatered by conversion to a dewatering felt, pressing the structure and drying at elevated temperature. The techniques and conventional equipment for making the structures of the present invention are well known to those skilled in the art. In a typical process, a low consistency pulp material is provided in a pressurized headbox. This headbox has an opening for supplying a thin deposit of fiber material to the Fourdrinier screen and forms a wet structure. The web is then typically dewatered to a fiber consistency of between about 7% and about 25% (total wet weight basis of the web) by vacuum dewatering and further dewatering by compression operations in which the web is subjected to pressures of opposing mechanical members, such as rollers.

The dewatered structure is then further pressed during transfer and dried with a jet drum apparatus known in the art as a Yankee dryer. The Yankee dryer can be pressurized by mechanical means, such as an opposed cylindrical roller pushing against the structure. Vacuum can also be used to push against the Yankee surface. Multiple Yankee dryer drums can be used, whereby additional compression is optionally performed between the rolls. The multiple structures that are formed are hereinafter referred to as traditional, pressed multilayer tissue paper structures. These layers are considered compressed because the structure is subjected to substantial mechanical compression forces while the fibers are wet and then dried in a compressed state.

The patterned multi-layered tissue paper is characterized in that it has a relatively large volume array with a relatively low fiber density and an array of densified zones with a relatively high fiber density. Large-volume fields are alternatively referred to as pillow regions. The densified zones may be discreetly spaced from one another within a large volume field, or may be joined together, either wholly or partially, within a large volume field. Preferred processes for producing patterned multi-layered " tissue " tissue paper are described in U.S. Pat. No. 3,301

No. 746, issued to Sanford and Sisson on January 31, 1976, U.S. Pat. No. 3,974,025, issued to Peter G. Ayers on August 10, 1976, and patent. US 4,191,609 issued to Paul D.

Trokhan on March 4, 1980, and U.S. Patent 4,637,859, issued to Paul D. Trokhan on January 20, 1987, all of which are incorporated herein by reference.

Generally, densified pattern structures are preferably prepared by depositing paper making material on a perforated forming screen such as a Fourdrinier screen to form a wet structure and then stacking the structure side by side against the array of entrainers. The structure is pressed against an array of these slides, resulting in densified zones in the structure locally corresponding to the points of contact between them and the wet structure. The rest of the structure is not compressed during this operation and is referred to as a large volume field. The large-volume field may be further compressed by applying hydrostatic pressure, such as in a vacuum-type device or a blow dryer. The structure is dewatered and optionally pre-dried in such a way as to substantially avoid compressing the large volume field. This is preferably achieved by a hydrostatic.

by pressure such as in a vacuum-type device or a blow-through dryer, or alternatively by mechanically compressing the structure against a group of carriers in which the large-volume field is not compressed. Dewatering operations, optional pre-drying, and densified zone formation may be integrated or partially integrated to limit the total number of steps performed. After dewatering, optional pre-drying and formation of the densified zones, the structure is dried to completion, preferably still avoiding. mechanical pressing. Preferably, from about 8% to about 55% of the surface of the multilayer tissue paper comprises densified sites with a relative density of at least 125% of the bulk density of the large volume.

The support group is preferably an impression carrier material by the deployment of rings (contact points), which are a group of carriers facilitating the formation of zones when applying pressure. The ring pattern forms a grouping of slides previously referred to. The impression carrier materials are disclosed in U.S. Patent 3,301,746 to Sanford et al

Sisson, issued January 31, 1967, U.S. Pat. No. 3,821,068, Salvucci Jr. et al. et al., issued May 21, 1974; U.S. Pat. No. 3,974,025 to Ayers, issued August 10, 1976;

US 1971, 1969,

No. 573,164, Freidberg, U.S. Pat. No. 3, U.S. Pat., Et al., Issued Mar. 30, 473,576, Amneus, issued October 21, 3,239,065;

December 1980, and U.S. Pat. No. 4,528,239 to Trokhan, et al., T9-8-5, which are incorporated herein by reference. zd-e — all references incorporated.

Preferably, the papermaking material is first formed into a wet structure on a perforated forming mesh such as a Fourdrinier mesh. This structure is dewatered and converted into the impression material. Alternatively, the papermaking material may initially be deposited on a perforated entrainment device, which also acts as an impression material. Once formed, the wet structure is dewatered and, preferably, the absorbent structure of the multi-ply tissue paper. Particularly preferred uses of the multi-ply tissue paper of the present invention are cosmetic wipes and toilet paper products. For example, the two multi-ply tissue paper structures of the present invention may be joined to form tissue products or toilet paper products.

Determination of molecular weight ·

A. Introduction

The main distinguishing characteristic of polymeric materials is their molecular size. The properties that have allowed polymers to be used in a variety of applications are derived almost entirely from their macromolecular nature. In order to fully characterize these materials, it is essential to have some means of determining their molecular weights and molecular weight distributions. It is more accurate to use the term relative molecular weight than molecular weight, but the latter is more widely used in polymer technology. It is not always practical to determine molecular weight distributions. However, it is becoming more common practice to use chromatographic techniques. Rather, reference is made to the expression of molecular size in terms of molecular weight averages.

B. Molecular weight averages

Considering the simple molecular weight distribution, which represents the weight fraction (wi) of molecules with relative molecular weight (Mi), several useful average values can be defined. Averaging performed on the basis of the number of molecules (Ni) of special size (Mi) gives the number of average molecular weight:

_ $ li Ν ' _t Μ i

Ni »= ------- ies Ni hydrogenated tallow diester diacids (DEDHTDMAC) (ie ADOGEN DDMC °) retained by tissue paper can be determined by extracting DEDHTDMAC solvent through an organic solvent, followed by anionic / cationic titration using dimidium bromide as an indicator; the level of polyhydroxy compound such as PEG-400 can be determined by extraction in an aqueous solvent such as water, followed by gas chromatography, or by colorimetric techniques to determine the level of PEG-400 in the extract. The methods are exemplary and do not intend to exclude other methods that may be useful for determining the levels of particular tissue-retained components.

B. Hydrophilicity (absorbence)

Hydrophilicity of multi-ply tissue refers generally to the tendency of multi-ply tissue to be moistened with water. The hydrophilicity of the multilayer tissue paper can be somewhat quantified by determining the time period required for the multilayer tissue paper soaked with water. This period of time is completely called the wetting time. In order to ensure a consistent and repeatable wetting time test, the following wetting time determination procedure may be used; first, a conditioned unit layer sample is provided (external conditions for testing paper samples are 23 + 1 ° and 50 + 2% RH as specified by the TAPPI T 40.2 Method), approximately 4-3 / Θ inches x 4-3 / 4 inches (about 11.1 cm x ~ s TRUCTURE T2craj-in-rcevr ST * é HRO silk ^- rities'; ~ a "second" the layer is folded into four (4) juxtaposed squares and then crumpled into a ball approximately 0.75 inches (about 1.9 cm) to about 1 inch (about 2.5 cm) in diameter, thirdly, the sphere packed layer is laid on the surface area of distilled water at 23 ± 1 ° C while the timer is on; the timer is stopped and read when the wetting to the ball of the collapsed layer is complete, and the complete wetting is monitored visually.

However, the hydrophilicity characteristics of the multilayer tissue paper of the present invention can be determined immediately after manufacture, but a significant increase in hydrophobicity, i.e., after aging of the paper after manufacture, may occur during the first weeks after manufacture of the multilayer tissue paper. Thus, wetting times are preferably measured at the end of such a two week period. Accordingly, wetting times measured after two weeks are referred to as wetting times after two weeks.

C. Biodegradability

Suitable, substantially anhydrous, self-emulsifiable biodegradable chemical softening compositions for use in the present invention are biodegradable. The term biodegradability in this material refers to the complete breakdown of a substance by microorganisms into carbon dioxide, water, biomass and inorganic materials. The potential of biodegradation can be estimated by measuring carbon dioxide release and dissolved organic carbon leakage from some medium containing a test substance such as one carbon source and energy and a dissolved bacterial inoculum obtained from a sludge of homogenized, activated sludge. See. Larson: Estimation of the potential of biodegradation of xenobiotic organic chemicals, Applied and Environment Microbiology, Volume 38 (1979), pp. 1153-61, which describes a suitable method for estimating biodegradability. Using this method, a substance is readily biodegradable if it has a higher carbon dioxide release than 70% and a removal of more than 90% dissolved organic carbon within 28 days. The softeners used in the present invention meet these biodegradability measures.

C. Density

The density of the multi-ply tissue paper as used herein is the average density calculated as the basis weight of the paper divided by the caliper, with the corresponding unit conversions incorporated. The caliper of the multi-ply tissue paper used in this material is the thickness of the paper subjected to a compressive load of 95 g / in ² (15.5 g / cm ² ).

D. Tearing

Dry

Dry tear can be measured using a Suther1and abrasion tester, a piece of black felt, a four pound weight, and a Hunter colorimeter. The Sutherland tester is a motor-driven instrumént moving the sample back and forth over a stationary sample. A piece of black felt is attached to a four pound weight. The tester then rubs or moves the loaded felt over the stationary sample five times. The L value of the Hunter's black felt colorimeter is determined before and after abrasion, and the difference in its two readings is a dry tear measurement. Other methods known in the prior art for measuring dry tear can also be used.

Wet

A suitable procedure for measuring the wet tear property of fabric samples is described in U.S. Patent 4,950,545, Walter et al., Issued August 21, 1990 and incorporated herein by reference. This procedure essentially comprises the passage of a fabric pattern (paper).

through two steel cylinders, one of which is partially immersed in a water bath. The lint from the sample fabric is transferred to a steel cylinder that is moistened in a water bath. By rotating the steel cylinder, the material is discharged into a water bath, which is then collected and calculated. See. 5, 45, 6, 27 of Walter et al. Other methods known in the prior art for measuring wet tear can also be used.

Optional gradients

Other chemicals used in papermaking as well as the papermaking material can be added to the biodegradable chemical softener composition described herein as long as it does not significantly and adversely affect the softening, absorbency of the fibrous material and the positive function of the biodegradable chemical softener composition.

For example, surface active agents may be used to treat the multi-ply tissue paper structures of the present invention. The level of agent, if used, is preferably from about 0.01% to 2.0% by weight, based on the dry fiber weight of the multi-ply tissue paper. The reagents preferably have alkyl chains with eight-atom atoms and anionic agents are linear alkylsulfonates and alkylbenzenesulfonates. Exemplary nonionic agents are alkyl glycosides containing alkyl glycoside esters such as Crodesta SL-40, available from Crod, Inc. (New York, NY); alkyl glycosidesters are described in U.S. Patent 4 oil 389, W. K. Langdon et al., issued March 8, 1977; and alkyl polyethoxy esters such as Pegosperse 200 ML, from Glyco Chemicals (Greenwich, CT) and IGEPAL RC-520 from Rhone Poulenc Corporation (Cranbury, NJ).

The above list of optional chemical additives is intended to exemplify their nature and is not intended to limit the scope of the invention. The following examples also illustrate the working technique of the invention but do not limit the invention.

Example 1

The purpose of the example is to illustrate a method that can be used to treat a substantially anhydrous, self-emulsifiable, biodegradable chemical softener composition comprising a mixture of dimethylammonium chloride to a touched hardened tallow diester diacid (DEDTHTDMAC) and polyoxyethylene glycol 400 (PEG-400).

An anhydrous, self-emulsifiable, biodegradable chemical softener composition is prepared according to the following procedure: 1. Separately weigh the equivalent weights of DEDTHTDMAC and PEG-400; 2. PEG is heated to about 66 ° C (150 ° F); 3. DEDTHTDMAC is dissolved in PEG to form a fusible solution at a temperature of about 66 ° C (150 ° F); 4. Adequate mixing is provided to form a homogeneous mixture of DEDTHTDMAC in PEG-400; 5. The homogeneous mixture (4) is cooled to solid form at room temperature.

The substantially anhydrous, self-emulsifiable biodegradable chemical softener composition (5) can be premixed (steps 1-5 above) at a given chemical supplier (e.g., Sherex company of Dublin, Ohio) and then economically sent to end users of the biodegradable chemical softener composition where dissolved to the desired concentration.

Example 2

The purpose of this example is to illustrate a method that can be used to treat a substantially anhydrous, self-migratable, biodegradable chemical softener mixture comprising a mixture of dimethylammonium chloride to a touched hardened tallow diester diacid (DEDTHTDMAC) and a mixture of glycerol and PEG-400.

A substantially anhydrous, self-emulsifiable biodegradable mixture of chovad-1 softeners and, if applicable, the following procedure: 1. A mixture of glycerol and PEG-400 is mixed in a weight ratio of about 75:25; 2. Separately weigh the equivalent weight of DEDTHTDMAC and mixture (1); 3. The mixture (1) is heated to about 66 ° C (150 ° F); 4. DEDTHTDMAC is dissolved in (3) to form a fusible solution at a temperature of about 66 ° C (150 ° F); 5. Adequate mixing is provided to form a homogeneous mixture of DEDTHTDMAC in (3); 6. The homogeneous mixture (5) is cooled to solid form at room temperature.

A substantially anhydrous, self-migrating biodegradable chemical softener composition (6) can be premixed (steps 1-6 above) at a given chemical supplier (e.g., Sherex company of Dublin, Ohio) and then economically shipped to end users of the biodegradable chemical softener composition where be dissolved to the desired concentration.

Example 3

The purpose of this example is to illustrate the method of using blow drying and the techniques of making ply paper

---------- -k -v-Y- _FQ BE - Soft - ABS-ke ORP and the tearing up of lava r a c ~ í it whom you and Tet-layered tissue paper treated with a chemical emollient comprising dimethyl ammonium chloride to the touch of hardened tallow diester diacids (DEDTHTDMAC) and polyoxyethylene glycol 400 (PEG-400); and a temporary wet strength resin.

An experimental Fourdrinier paper machine was used in the working technique of the present invention. First, a chemical softener mixture is prepared according to the procedure of Example 1, wherein the homogeneous premixed mixture of DEDTHTDMAC and solid polyhydroxy compounds is redissolved at about 66 ° C (150 ° F). This dissolved mixture is then dispersed in a conditioned water tank (pH 3 3, temperature 6666 ° C) to form a submicron bubble dispersion. The particle size of the bubble dispersion is determined using an optical microscope technique. The particle size ranges from about 0.1 to 1.0 microns.

Second, a 3% by weight aqueous slurry of NSK is formed in a traditional pulper. The NSK slurry is softened and a 2% temporary wet strength resin solution (i.e., National starch 78-0080 sold by National Starch and Chemical Corporation of New) is added to the NSK batch tube.

York, NY) at a dosage of 0-75% by weight of dry fibers. Adsorption. temporary wet strength resin for NSK fibers is increased by in-line mixer. The NSK slurry is diluted to about 0.2% consistency in the vane pump.

Third, a 3% by weight aqueous slurry of eucalyptus fibers is formed in a traditional pulper. A 2% temporary wet strength resin solution (i.e., National starch 78-0080 sold by National Starch and Chemical Corporation of New York, NY) is added to the eucalyptus feed tube in front of its pump at a rate of 0.1% by weight of dry fibers; and a 1% solution of the biodegradable chemical softening composition is added to the eucalyptus feed tube upstream of the in-line mixer at a rate of 0.2% by weight of the dry fibers. The eucalyptus slurry is diluted to about 0.2% consistency in the vane pump.

The processed paper making material mixture (30% of NSK / 70% of eucalyptus) is mixed in a headbox and placed on a Fourdrinier screen to form the embryonic structure. This strainer drains, which is assisted by a sprayer and vacuum boxes. The Fourdrinier screen is a 5 shed, satin weave configuration with 84 monofibers in the longitudinal direction and 76 monofibers in the transverse direction per inch (about 2.5 cm), respectively. The embryonic wet structure is converted from a photopolymer sieve, with a fiber consistency of about 15% at the transfer point, to a photopolymer fabric with 562 linear Idaho cells per square inch (6.45 em ² ), a knuckle area 40% and 9 mils (about 0.022 cm) of photopolymer depth.

Further dewatering is uuiaóeuu structure a fiber consistency of about 28%. The patterned structure is pre-dried by blowing air to a fiber consistency of about 65% by weight. The structure is then adhered to the surface of a Yankee dryer by spraying a creping adhesive containing 0.25% aqueous polyvinyl alcohol (PVA) solution. The fiber consistency is increased to an estimated 96%, before dry creping of the structure with a scraper

- 41 knife. which has a bevel angle of about 25 degrees and is positioned with respect to the Yankee dryer. to provide an angle of incidence of about 81 degrees; the Yankee dryer is operated at about 800 feet per minute (about 244 meters per minute). The dry structure is formed into a roller at a speed of 700 feet per minute (214 meters per minute).

This structure is refined into a single layered tissue paper product. The multilayer tissue paper has a basis weight of about 0.0879kg / m ² , the content is as much as 0.2% biodegradable chemical softening composition and about 0.3% temporary wet strength resin. What is important is. that the resulting multilayer tissue paper is soft, absorbent, has good tear resistance and is suitable for use on cosmetic tissues and / or toilet paper.

Example 4

The purpose of this example is to illustrate a method of making paper using blow-through drying to produce soft paper. absorbent and tear resistant toilet, multi-layered tissue paper, treated with a blend of chemical softener containing dimethylammonium chloride to the touch of hardened tallow diester diacids (DEDTHTDMAC) and a blend of a polyhydroxy compound (Glycerol / PEG-400) and an additive dry strength resin.

An experimental Eourdrinier paper machine was used in the working technique of the present invention. First. a chemical softener mixture is prepared according to the procedure of Example 2. wherein the homogeneous premixed mixture of DEDTHTDMAC and the solid polyhydroxy compound is redissolved at a temperature of about 66 ° C (150 ° F). This dissolved mixture is then dispersed in a treated water tank (pH - 3 temperature - 66 ° C) to form a submicron bubble dispersion. The particle size of the bubble dispersion is determined using an optical microscope technique. The particle size ranges from about 0.1 to 1.0 microns.

Second, a 3% by weight aqueous slurry of NSK is formed in a traditional pulper. The NSK slurry is softened and a 2% dry strength resin solution (i.e., Acco ° 514, Acco ° 711, sold) is added to the NSK batch tube.

American Cyanamid Company of Fairfleld. OH) at a dose of 0.2¾ by weight of dry fibers. The adsorption of the dry strength resin to the NSK fibers is increased by an in-line mixer. The NSK slurry is diluted to about 0.2% consistency in the vane pump.

Third, a 3% by weight aqueous slurry of eucalyptus fibers is formed in a traditional pulper. 2% dry strength resin solution (i.e., Acco ° 514, Acco ° 711.

sold by the American Cyanamide Company of Fairfield, OH) is added to the eucalyptus tube before its pump at a rate of 0.1% by weight of the dry fibers; and a 1% solution of the biodegradable chemical softening composition is added to the eucalyptus feed tube in front of the in-line mixer, at a rate of 0.2% by weight of the dry fibers. The eucalyptus slurry is diluted to about 0.2% consistency in the vane pump.

The treated mixture material of paper production (30% of NSK / 7O% '~ z ~ e'ulca'rýpCur) in ješmícháná of metal skřTnT ~~ ^- ^ ar seated and y ~ -

Fourdrinier sieve to form embryonic structure.

This strainer drains, which is assisted by a spray bar and vacuum boxes. The Fourdrinier screen is a 5 shed, satin weave configuration with 84 monofibers in the longitudinal direction and 76 monofibers in the transverse direction per inch (about 2.5 cm), respectively. The embryonic wet structure is converted from a photopolymer sieve, with a fiber consistency of about 15% at the transfer point. to a photopolymer fabric with 562 linear Idaho cells per square inch (i.e.

6.45 cm ² ). with a contact area (40% and 9 mils of Casi 0.022 cm) depth of the photopolymer. Further dewatering is achieved by vacuum dewatering until the structure has a fiber consistency of about 28%. The patterned structure is pre-dried by blowing air to a fiber consistency of about 65% by weight. Then, the structure is adhered to the surface of the Yankee dryer by means of non-sprayed creping adhesive. containing 0.25% aqueous solution of polyvinyl alcohol (CPVA). Fiber consistency is increased to an estimated 96%. before dry creping the structure with a scraper blade. which has a bevel angle of about 25 degrees and is positioned with respect to the Yankee dryer. to provide an angle of incidence of about 81 degrees: the Yankee is operated at about 800 feet per minute (about 244 meters per minute). The dry structure is formed into a roller at a rate of 700 feet per minute (214 meters per minute).

The two sub-layers of this structure are formed into multi-ply tissue products and laminated together using a layer bonding technique. The multilayer tissue paper has a basis weight of about 0.1123kg / m ² containing about 0.1% biodegradable chemical softening composition and about 0.2% dry strength resin. What is important is. that the resulting multilayer tissue paper is soft, absorbent, has good tear resistance and is suitable for use on cosmetic tissues and / or toilet paper.

Example 5

The purpose of this example is to illustrate a method of making traditional drying paper, to produce soft, absorbent and tear resistant toilet, multi-layered tissue paper, treated with a chemical softener mixture containing dimethylammonium chloride to touch hardened tallow diester diester (DEDTHTDMAC) and polyoxyethylene glycol 400 (PEG) ), a dry strength additive and a cationic polyacrylamide ₍ additive resin (Percol 175)) as a retention aid.

An experimental Fourdrinier paper machine was used in the working technique of the present invention. First. a chemical softener mixture is prepared according to the procedure of Example 1. wherein a homogeneous premixed mixture of DEDTHTDMAC and PEG-400 in the solid state is dispersed in a treated water tank (pH 3 3; temperature 6666 ° C) to form a dispersion of submicron bubbles. The particle size of the bubble dispersion is determined using an optical microscope technique. The particle size ranges from about 0.1 to 1.0 microns.

Second, a 3% by weight aqueous slurry of NSK is formed in a traditional pulper. The NSK slurry is refined and 2% resin solution with Acco ° 514 strength is added to the NSK batch tubes. Acco ° 711, sold by the American of Wayne, New Jersey) at a dose of 0.2% to dry (i.e.

Cyanamide company weighs dry fibers. The adsorption of resin with NSK fiber strength is increased by the in-line mixer.

in a vane pump diluted to about 0.2% consistency.

Third, in a traditional pulper, a 3% dry slurry is formed into the NSK slurry, the limestone aqueous slurry of eucyptic R-fiber fibers. "1% - the solution of the biodegradable chemical softening mixture is added to the eucalyptic feed tube upstream of its pump at a rate of 0.2% by weight of dry fibers: and a 0.05% Percol solution ° 175 is added to the eucalyptus layers upstream of the paddle pump at 0. 05% by weight of dry fibers. The adsorption of the biodegradable chemical softening composition to the eucalyptus fibers can be increased by an in-line mixer. The eucalyptus slurry is diluted to about 0.2% consistency in the vane pump.

The processed paper manufacturing material mixture (30% of NSK / 70% of eucalyptus) is mixed in a headbox and deposited on a Fourdrinier screen. to form an embryonic structure. This strainer drains, which is assisted by a spray bar and vacuum boxes. The Fourdrinier sieve is a 5-mesh, satin weave configuration with 84 monofibers in the longitudinal direction and 76 monofibers in the transverse direction per inch (Cas1 2.5.cm), respectively. The embryonic wet structure is converted from a Fourdrinier sieve, with a fiber consistency of about 15% y conversion point, to a traditional felt. Further removal of water £ ¹ .dosahuje by vacuum assisted drainage until the web has a fiber consistency of _t 35%. Then this structure is adhered to the surface of the Yankee dryer. The fibrous consistency is increased to an estimated 96%, before dry creping, ρ of the structure using a scraper blade having a bevel angle of about it. 25 degrees and is positioned with respect to the Yankee to provide an angle of incidence of about 81 degrees: the Yankee is operated at about 800 feet per minute (about 244 meters per minute). The dry structure is formed into a roller at a rate

700 feet per minute (214 meters per minute).

The two sub-layers of this structure are formed into multi-ply tissue products and laminated together using a layer bonding technique. The multilayer tissue paper has a basis weight of about 0.1123 kg / m ² containing about 0.1% biodegradable chemical softening composition, about 0.1% dry strength resin and about 0.05% retention aid resin. Importantly, the resulting multilayer tissue paper is soft, absorbent, has good tear resistance, and is suitable for use on cosmetic tissues and / or toilet paper.

- 46 Example 6

The purpose of this example is to illustrate the use of blow-through drying and tissue paper manufacturing techniques to produce soft, absorbent, and tear-resistant cosmetic, multilayer tissue paper treated with a chemical softener mixture containing dimethylammonium chloride to touch hardened tallow diester diacids (DEDTHTDMAC) and polyoxyethylene glycol. 400), a permanent wet strength resin and a retention aid (Percol ° 175).

An experimental Fourdrinier paper machine was used in the working technique of the present invention. First, a chemical softener composition is prepared according to the procedure of Example 1, wherein the homogeneous premixed mixture of DEDTHTDMAC and solid polyhydroxy compounds is redissolved at about 66 ° C (150 ° F). This dissolved mixture is then dispersed in a treated water tank (pH 3 3, temperature 6666 ° C) to form a submicron bubble dispersion. The particle size of the bubble dispersion is determined using an optical microscope technique. The particle size ranges from about 0.1 to 1.0 microns.

Second, a 3% by weight aqueous slurry of NSK is formed in a traditional pulper. NSK slurry is softened

A 2% solution of the resin was added to the NSK batch tube at a constant wet strength (i.e., Kymene 557, sold by Hercules Incorporated of Vilmington, DE) at a rate of 1% by weight. dry fibers. Adsorption of temporary wet strength resin into NSK fibers is enhanced by the in-line mixer. The NSK slurry is diluted to about 0.2% consistency in the vane pump.

Third, a 3% by weight aqueous slurry of eucalyptus fibers is formed in a traditional pulper. A 1% biodegradable chemical softening solution solution is added to the eucalyptus feed tube in front of the in-line mixer at a dose of 0.2¾ dry weight of the fibers, and a 0.5¾ solution of Percol ° 175 is added to the eucalyptus layers upstream of the paddle pump at 0.05 The eucalyptus slurry is diluted to about 0.2¾ consistency in the vane pump.

Processed mixture of paper production material (30¾ from NSK /

70¾ of -eucalyptus) is mixed in a headbox and placed on a Fourdrinier screen to form an embryonic structure.

This strainer drains, which is assisted by a spray bar and vacuum boxes. The Fourdrinier screen is a 5 shed, satin weave configuration with 84 monofibers in the longitudinal direction and 76 monofibers in the transverse direction per inch (about 2.5 cm), respectively. The embryonic wet structure is converted from a photopolymer screen. with a fiber consistency of about 15¾ at the transfer point. to a 711 linear Idaho cell photopolymer fabric per square inch (i.e.

6.45 cm ² ), having a 40¾ knuckle area and 9 mils (about 0.022 cm) depth of the photopolymer. Further dewatering is achieved by vacuum dewatering until the structure has a fiber consistency of about 28¾. The patterned structure is pre-dried by blowing air to a fiber consistency of about 65¾ weight. Then this structure is adhered to the surface of the Yankee dryer by spraying a creping adhesive containing 0.25¾ aqueous polyvinyl alcohol (PVft) solution. Fiber consistency is increased to an estimated 96¾. before dry creping the structure with a scraper blade having a bevel angle of about 25 degrees and positioned with respect to the Yankee dryer to provide an angle of incidence of about 81 degrees; the Yankee dryer is operated at about 800 feet per minute (about 244 meters per minute). The dry structure is formed into a roller at a speed of 700 feet per minute (214 meters per minute).

This structure is refined into a tissue paper product with two partial, multiple layers. The multilayer tissue paper has a basis weight of about .01025kg / m ² containing about 1.0% stable wet strength resin, about 0.2% biodegradable chemical softening composition, and about 0.05% retention aid resin. Importantly, the resulting multilayer tissue paper is soft, absorbent, has good tear resistance and is suitable for use on cosmetic tissues and / or toilet paper.

Claims (9)

PA TENT CLAIMS What is claimed is: 1. A multilayer tissue paper structure. comprising at least two superimposed layers, a first layer and at least one second layer adjacent to the first layer, wherein the multilayer structure comprises: (a) paper-making fibers: from 0.01% to 3.0% by weight of a biodegradable quaternary ammonium compound having the formula: Rz <CH) n - Y - R ₃ N ⁺ xRz CCH ₂ > _n - Y - R ₃ or R 2 < CH ₂ ) n -Y-R ₃ N * R 2 R 1 or R ₃ -Y-ch ₂ CH - CH ₂ - N ⁺ - _{(R2) 3} X- R ₃ -Y hydrocarbyl alkyl C 16 -C 18 hydrocarbyl hydrocarbyl or wherein each R 2 is C 1-10 alkyl or hydroxyalkyl, benzyl or mixtures thereof, preferably methyl; each R 1 is a C 12 -C 22 hydrocarbyl group, or a substituted group or mixtures thereof, preferably or alkenyl; each R 3 is C 11 -C 21, or substituted with mixtures thereof; Y is -O-CCO) - or - CCO5 - O - or - NH - CCO - or CCO - NH - or mixtures thereof; n is 1 to 4 and X ^- is a suitable anion, preferably chloride or methyl sulfate ·; Cc) from 0.1¾ to 3.0¾ a water-soluble polyhydroxy compound, preferably selected from glycerols, sorbitols, polyglycerol of an average molecular weight of from 150 to 800, polyoxyethylene glycols and polyoxypropylene glycol of an average molecular weight of from 200 to 4,000, preferably from 200 to 1,000, most preferably from 200 to 600, and mixtures thereof; and λ Cd) from 0.01¾ to 3.0¾ of a binder material, preferably selected from permanent wet strength resins, preferably polyamideepichlorohydrin and polyacrylamide permanent strength resins and mixtures thereof, from temporary wet strength resins, preferably starch based resins with temporary wet strength, dry strength resins, retention aids and mixtures thereof. The multilayer tissue paper structure of claim 1, wherein the multilayer structure comprises three superimposed layers, an inner layer and two outer layers, the inner layer being disposed between the two outer layers, the multilayer structure preferably comprising a single thickness in which each one or more of said layers of said multilayer structure comprising a biodegradable quaternary ammonium compound, a water-soluble polyhydroxy compound, and a binder material. Multilayer tissue paper structure according to claim 2, wherein the majority of the biodegradable quaternary ammonium compound and the polyhydroxy compound are contained in at least one of the outer layers, preferably both. The multilayer tissue paper structure of claim 2 or 3, wherein most of the binder material is contained in the inner layer. The multilayer tissue paper structure according to any one of claims 2-4, wherein the inner layer comprises relatively long fiber-forming paper, preferably softwood fibers, most preferably northern softwood fibers, said long fiber-forming paper having an average length of at least 2.0 mm and wherein each of the two outer layers comprises relatively short fiber-forming paper, preferably hardwood fibers. most preferably eucalyptus fibers, the short fiber forming paper having an average length between 0.2 and 1.5 mm. The multilayer tissue paper structure according to claim 5, wherein the inner layer comprises a sweep of softwood fibers and cost fiber fibers and at least one of the outer layers comprises low cost fibers or mixtures of hardwood fibers and low cost fibers selected from thermomechanical pulp. fibers. in which the sulfite fibers are fibers of chemothermomechanical pulp fibers. recycled fibers, and mixtures thereof. The multilayer structure of claims 1Y6. wherein the tissue paper of any one of the above is a biodegradable quaternary ammonium compound dimethylammonium chloride to the touch. tallow diester diacids or dimethyl methyl sulphate for contacting the hardened tallow diester acids. Multilayer tissue paper structure according to any one of claims 1-7. wherein the weight ratio of quaternary ammonium to polyhydroxy compound is in the range from 1.0 = 0.3 to 0.3 = 1.0, preferably from 1.0 = 0.7 to 0.7 = 1.0. A multi-ply tissue paper product comprising at least two multilayered multi-ply tissue paper structures according to claim 1, wherein the multi-ply tissue paper product preferably comprises two sub-layers, each of said sub-layers preferably comprising two superimposed layers. and wherein the binder materials are permanent wet strength resins or temporary wet strength resins and in which most of the biodegradable quaternary ammonium compound and polyhydroxy compound are contained in at least one of the outer layers and wherein the majority of the binder material is contained in the inner layer. ÍO. The multi-ply tissue paper structure of any one of claims 1-9. in which the tissue paper structure is a cosmetic napkin or toilet paper.