HUT74119A - Multi-layered tissue paper web - 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

BACKGROUND OF THE INVENTION The present invention relates to multilayer silk crepe paper webs / rolls. More particularly, the present invention relates to biodegradable multi-layered silk crepe paper webs containing chemical softeners and binders. Treated silk crepe paper bands can be used to make soft, absorbent and lint-resistant paper products such as face wipes and toilet paper products.

Paper tapes or bands, sometimes referred to as "tissue" or "tissue", are widely used in modern society. These items, such as face wipes and toilet papers, are permanent articles of commerce. It has long been recognized that these products have four important physical properties, namely, strength, softness, absorbency, and in particular the ability to absorb aqueous systems ₍ and resistance to lint, especially when wet. Research and development efforts are being made to to hurt the rest, and to improve two or three qualities at the same time.

The strength of the products and webbing they are made of is its ability to retain its physical integrity and withstand tear, tear and tear under conditions of use, especially when wet.

Softness is the sensation of palpation perceived by the consumer when a man or woman wears a special product, wipes their skin or wrinkles it. This sense of touch is a combination of several physical attributes. One of the most important properties related to softness, according to experts, is the rigidity of the paper from which the product is made. On the other hand, stiffness is generally believed to be directly related to the dry tensile strength of the paper and the stiffness of the fibers from which the paper is made.

The absorbency of the products and webs they are made of is a measure of the amount of liquid they can absorb, especially aqueous solutions and dispersions. The overall absorbency, as perceived by the consumer, is generally a combination of the total amount of liquid absorbed by a particular mass of multilayer crepe paper to saturation and the rate at which this mass absorbs the liquid.

The ability of the fibrous product and the webs of which it is made to resist is the ability to withstand the conditions of use, particularly when wet. In other words, the higher the shear resistance, the less the paper is prone to shatter.

It is widely known to use wet strength resins to enhance the strength of the paper web. For example, Westfelt has described many of these materials and described their chemistry (Cellulose Chemistry and Technology, 13, 813-825 / 1979 / J). U.S. Patent No. 3,755,220 mentions that certain chemical additives, known as debonding agents, affect the bonding of natural fiber-a-fiber that occurs during papermaking in papermaking processes. This reduction in bonding results in softer or less coarse paper. The above patent discloses the use of wet strength resins in conjunction with the use of laxatives to eliminate undesirable properties of laxatives. Loosening agents reduce both dry and wet tensile strength.

U.S. Patent No. 3,821,068 also discloses that chemical loosening agents can be used to reduce stiffness and thereby enhance the softness of silk crepe paper webs.

Chemical release agents are mentioned in numerous publications, such as U.S. Patent 3,554,862. These materials include quaternary ammonium salts such as coconut alkyl trimethyl ammonium chloride, oleyl trimethyl ammonium chloride, di / hydrogenated / tallow alkyl dimethyl ammonium chloride and stearyl trimethyl ammonium chloride.

U.S. Patent No. 4,144,122 describes the use of complex quaternary ammonium compounds such as bis / phaloxy / 2-hydroxy / propylene / quaternary ammonium chlorides in paper webs. ··

- 5 soften. The authors also attempt to overcome the loss of absorbency caused by the use of laxatives by using ethylene oxide and propylene oxide adducts of nonionic surfactants such as aliphatic alcohols.

In Bulletin 76-17 of 1977, Armak Company, Chicago, Illinois, describes the use of dimethyl di / hydrogenated / tallow alkyl ammonium chloride in combination with fatty acid esters of polyoxyethylene glycols, which provide softness and absorbency to silk crepe paperbands.

For example, U.S. Patent No. 3,301,746 discloses the results of research into improved paper webs. Despite the high quality of the webs produced by the process described herein, and despite the commercial success of the products made from these webs, attempts have been made to produce improved products.

For example, U.S. Pat. No. 4,158,594 discloses a process that is claimed to produce strong, soft, fibrous germs. Specifically, it is reported that the web of silk crepe paper, which can be softened by the addition of chemical release agents, can be enhanced by bonding one surface of the paper web to a creping surface during manufacture, in a fine pattern, with a binder such as an acrylic latex resin or elastomeric binder / bonded to one side of the web and to the creping surface -

• · ·

- 6 in a fine print layout, and the web is creped from the creping surface to form a paper web.

Conventional quaternary ammonium compounds such as the well-known dialkyldimethylammonium salts include, for example, difaggyalalkyldimethylammonium chloride, difaggyalalkyldimethylammonium methylsulfate, di / hydrogenated / tallowalkyldimethylammonium chloride, and the like. However, these quaternary ammonium compounds are hydrophobic, non-biodegradable, and can adversely affect the absorbency of treated paper webs. It has been found that mixing a biodegradable quaternary ammonium compound with a polyhydroxy compound such as glycerol, sorbitol, polyglycerol or polyoxyethylene glycol improves both the softness and the rate of absorption of the fibrous cellulosic material.

Unfortunately, the use of biodegradable chemical softeners containing biodegradable quaternary ammonium compound and polyhydroxy compound can reduce the resistance of the treated paper webs to degradation. It has been found that the resistance to shear can be improved by using suitable binders known in the papermaking industry, such as wet and dry strength resins and retention aids.

The invention is applicable to silk crepe papers in general, but especially to the multi-ply silk crepe paper products disclosed in U.S. Patent No. 3,994,771.

It is an object of the present invention to provide a soft, absorbent and lint-resistant multilayer tissue paper product.

It is a further object of the present invention to provide a process for producing soft, absorbent, lint-resistant, multi-ply silk crepe paper products.

These and other objects are achieved by the use of the present invention as will become apparent from the following description.

BACKGROUND OF THE INVENTION The present invention relates to soft, absorbent, lint-resistant, multi-layered silk crepe paper products containing papermaking fibers, biodegradable emollients, and binders. Briefly, the biodegradable chemical softener composition is a mixture of the following: a / about 0.01 to about 3.0% of a biodegradable quaternary ammonium compound, preferably a compound of formula (1), (11) or (111), wherein R 6 is C 1-6 alkyl or hydroxyalkyl, benzyl or mixtures thereof; each R 1 substituent is a C 12 -C 22 hydrocarbon group or a substituted hydrocarbon group, or mixtures thereof; each R 1 substituent is C 11 -C 21 hydrocarbon or substituted hydrocarbyl or mixtures thereof; Y is -O-C / O / -, -C / O / -O-, -NH-C / O - or -C / O / -NH- or mixtures thereof; n = 1-4; and a suitable anion such as chloride, bromide,

- ·· ······ · · · · · ···· ** · ♦ *

- 8 methylsulfate, ethylsulfate, nitrate or the like; and b / about 0.01 to about 3.0% of a polyhydroxy compound, preferably glycerol, sorbitol, polyglycerols having an average weight of about 150 to about 800 or polyoxyethylene glycols or polyoxypropylene glycols having an average weight of about 200 to about 4000.

The weight ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound is preferably from about 1.0: 0.1 to about 1.0: 1.0. It has been found that a biodegradable chemical softener composition is more effective when the polyhydroxy compound is mixed with the biodegradable quaternary ammonium compound at a temperature at which the biodegradable quaternary ammonium compound and the polyhydroxy compound are mixed.

Preferred ester-function quaternary ammonium compounds useful in the present invention are, for example, the compounds of formula (IV), (V), (VI) or (VII), wherein each substituent is C 1-6 alkyl or hydroxyalkyl, benzyl or mixtures thereof; each substituent is a C12-C22 hydrocarbon group or a substituted hydrocarbon group, or mixtures thereof; and each substituent is a C 11 -C 21 hydrocarbon group or a substituted hydrocarbon group, or mixtures thereof.

These compounds may be mono or diester variants of the well-known dialkyldimethylammonium salts such as diester diphaggyalalkyldimethylammonium chloride, diesterdistearyldimethylammonium chloride, monoester diphaggyalkyldimethylammonium chloride. , diester di / hydrogenated / tallow alkyl dimethyl ammonium methyl sulfate, diester di / hydrogenated / tallow alkyl dimethyl ammonium chloride, monoester di / hydrogenated / tallow alkyl dimethyl ammonium chloride and mixtures thereof. Preferred diester variants are di / non-hydrogenated / tallowalkyldimethylammonium chloride, di / barely hydrogenated / tallowalkyldimethylammonium chloride / DEDTHTDMAC /, di / hydrogenated / tallowalkyldimethylammoniumDM / DED / DED and mixtures thereof. Depending on the desired characteristics of the product, the degree of saturation of the difaggyalkyl group can be controlled, from non-hydrogenated (soft) to barely, partially or fully hydrogenated / hard.

Without being bound in theory, it is believed that ester groups impart biodegradability to these compounds. It is important that the ester-function quaternary ammonium compounds used in the process of the present invention are more readily biodegradable than conventional dialkyldimethylammonium chemical plasticizers.

The polyhydroxy compounds useful in the present invention are glycerol, sorbitol, polyglycerols having a weight average molecular weight of about 150 to about 800, and polyoxyethylene glycols having a weight average molecular weight of about 200 to about 4000. Polyoxyethylene glycols preferably have a weighted average molecular weight average of about

200 to about 600.

The term binder refers to various wet and dry strength additives and retention agents known in the art. These materials improve the shear resistance of the silk crepe paper webs of the present invention and counteract the loss of tensile strength caused by biodegradable chemical softeners. Suitable binders are, for example, permanent wet strength resins (e.g., Kymene® 557H, available from Hercules Incorporated of Wilmington, DE), periodic wet strength resins (e.g., National starch 78-0030, sold by National Starch and Chemical Corporation). of New York, NY company distributes /, dry strength resins / as Acco ^{'O /} 514 and Acco' ^IY 711, by American Cyanamid company of Wayne, New Jersey under the trademark product of / and (r), retention aid resins / e.g. manufactured by Percol ^ 175, Allied Colloids of Sulfolk, Virginia.

Briefly, the process of the present invention for the production of multilayer webs of silk crepe paper comprises the steps of: forming a pulp for making multilayer paper from the above-mentioned components, layering a pulp for making multilayer paper on a perforated surface such as Fourdrinier from pulp.

Unless otherwise specified, all percentages, ratios, and proportions are by weight in this specification.

11 While the specification is a detailed description of the present invention, and it is expressly claimed, it will be understood that the invention will be more fully understood by reference to the following figures, which are to be read as follows:

Figure 1 is a schematic cross-sectional view of a single sheet of toilet paper comprising three layers of the invention;

Figure 2 is a schematic cross-sectional view of a two-layer face wiping paper according to the present invention comprising two layers.

The invention will be described in more detail below.

While the invention is described in more detail by the appended claims and clearly claims, it is believed that the invention will be better understood from the following detailed description and the accompanying examples.

As used herein, the term "shear resistance" is used to describe the fibrous products and webs that have the ability to withstand the conditions of use, particularly when wet. In other words, the higher the resistance to shredding, the less the tendency of the web to wrinkle.

The term binder as used herein refers to various wet and dry strength resins and retention aids known in the papermaking industry.

•••••••••••••••

- 12 The term "water soluble" as used herein refers to substances which are soluble in water at least 3% at 25 ° C.

As used herein, the term "crepe paper", "web", "ribbon", "papiriv" and "paper product" refers to all papermaking pulps obtained by preparing an aqueous papermaking pulp, by layering the pulp on a perforated surface such as Fourdrinier sieve and fibrous pulp. with or without water extraction, pressure or evaporation.

As used herein, the term aqueous papermaking pulp refers to an aqueous suspension of papermaking fibers and the chemicals described below.

Multilayer silk crepe tape, multilayer paper tape, multilayer paper, multilayer paper and multilayer paper product terms as used herein refer to two or more layers of long fibrous paper pulp, which are preferably different fibers. as they are used in the production of silk crepe papers. Preferably, the layers are formed by layering separate streams of hyg fiber suspensions on one or more endless perforated sieves. If the individual layers are initially formed on separate screens, the layers are then joined together in a wet state to form a composite composite tape.

· «Are formed.

The first step of the process according to the invention is the production of aqueous pulp for papermaking. The pulp contains papermaking fibers (sometimes referred to as wood pulp) and a mixture of at least one biodegradable quaternary ammonium compound, a polyhydroxy compound, and binders. All of the above materials will be described below.

It is anticipated that all variants of wood pulp will generally contain the papermaking fibers used in the process of the present invention. However, other cellulosic fibrous materials such as cotton, luggage, rayon and the like can be used, and are not excluded from the invention. The wood pulps that can be used in the present case are kraft, sulphite and sulphate pulps, as well as wood pulps such as wood chips, thermomechanical pulps and chemical thermomechanical pulps (CTMP). Celluloses from both deciduous and coniferous trees can be used.

Both hardwood cellulose and softwood cellulose as well as mixtures of the two can be used. Hardwood cellulose as used herein refers to fibrous cellulose derived from deciduous trees / angiosperms / woody material; ming softwood pulps are fibrous celluloses derived from coniferous / gymnosperms / woody material. Hardwood celluloses, such as eucalyptus, are particularly suitable for the outer layer of the multilayer silk crepe paper bands described below, while northern softwood kraft celluloses are preferred for the inner layer (s) or sheet (s). 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 binders, used to facilitate the production of the original paper may also be used in the present process.

Biodegradable chemical softeners

The compositions of the present invention comprise as an essential component a mixture of a biodegradable quaternary ammonium compound and a polyhydroxy compound. The ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound is about 1.0: 0.1 to 0.1: 1.0; the weight ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound is preferably about 1.0: 0.3 to 0.3: 1.0, the weight ratio of the biodegradable quaternary ammonium compound to the polyhydroxy compound being more preferably about 1.0: 0.7 - 0.7: 1.0, although this ratio will vary depending on the molecular weight of the particular polyhydroxy compound and / or biodegradable quaternary ammonium compound used.

All compounds of the above types are described in detail below.

A. Biodegradable quaternary ammonium compound

Biodegradable chemical softeners contain about tgC'.A- as a basic component.

-3.00% by weight, preferably about 0.01% to about 1.00% by weight of a biodegradable quaternary ammonium compound, preferably a biodegradable quaternary ammonium compound of the formula (1), (11) or (VII) wherein each R ₂ substituent is C 6 -alkyl or hydroxyalkyl, benzyl or mixtures thereof; each R 1 substituent is a C 12 -C 22 hydrocarbon group or a substituted hydrocarbon group, or mixtures thereof; each R 4 substituent is C 11 -C 21 hydrocarbon or substituted hydrocarbyl or mixtures thereof; Y is -O-C (O) -, -CF 10 -O-, -NH-C (O) - or -C (O) -NH- or mixtures thereof; n = 1-4; and X® is a suitable anion, such as chloride, bromide, methyl sulfate, ethyl sulfate, nitrate or the like.

As described by Swern / Ed. in Baily's Industrial Oil and Wood Products, Third Edition, John Wiley and Sons / New York 1964 / J is a naturally occurring, variable composition. Table 6.13 of the above publication illustrates that generally 78% or more of the fatty acids contain 16 or 18 carbon atoms.

Half of the fatty acids present in tallow are generally unsaturated, mainly in the form of oleic acid. Both synthetic and natural tallow fall within the scope of the invention. It is further known that, depending on the required characteristics of the product, the saturation level of the difaggyalkyl group ranges from non-hydrogenated / soft / slightly to partially hydrogenated / fully hydrogenated / hard. All levels of saturation described above are expressly contemplated by the present invention.

It should be noted that R 1, R ₂ and substituents may be optionally substituted with different groups, such as alkoxy or hydroxy, or branched, but these materials are not preferred in this case. Preferably, each R 1 substituent is C 12 -C 18 alkyl and / or alkenyl, most preferably each R 1 substituent is a straight-chain C 16 -C 18 alkyl and / or alkenyl group. Preferably each R ₂ substituent is methyl or hydroxyethyl. R 4 is preferably C 13 -C 17 alkyl and / or alkenyl; Furthermore, the ester functional quaternary ammonium compounds can optionally contain from about 10% mono- / hosszuláncu alkyl / derivatives, such as / R _2/2 - £ / CH _2/2 OHJ-f / _CH2 / OC / O / R ^ JX derivative than smaller amounts of components. These smaller amounts of components can act as emulsifiers and can be used in the present invention.

Ester-function quaternary ammonium compounds having the above structure and useful in the compositions of the present invention include, for example, well-known diester dialkyldimethylammonium salts such as diester difaggyalalkyldimethylammonium chloride, monoester difaggyalalkyldimethylammonium chloride, diester difaggyalkyldimethylammonium methyl · · ·

17-sulfate, diester di / hydrogenated / tallow alkyl dimethyl ammonium methyl sulfate, diester di / hydrogenated / tallow alkyl dimethyl ammonium chloride and mixtures thereof. Particularly preferred are diester difaggyalalkyldimethylammonium chloride and diester di / hydrogenated / tallowalkyldimethylammonium chloride. These specialty materials are commercially available from Sherex Chemical Company Inc. of Dublin, Ohio, under the trade name ADOGEN DDMC.

Diquaternary variants of ester-functional quaternary ammonium compounds can also be used and are within the scope of the invention. These compounds are of formula VIII wherein each R ₂ substituent is C 1 -C 6 alkyl or hydroxyalkyl, the R 2 substituent is C 11-C 21 hydrocarbon group, n = 2-4 and Χ ^{Θ is} a suitable anion. such as a nalogenide such as chloride or bromide or methyl sulfate ion. Preferably, each R 13 is C 13 -C 17 alkyl and / or alkenyl, most preferably R 14 is straight-chain C 15-17 alkyl and / or alkenyl and R 1 is methyl.

B. Polyhydroxy Compounds

The biodegradable chemical softener composition contains from about 0.01% to about 3.00% by weight, preferably from about 0.01% to about 1.00% by weight, of the polyhydroxy compound as an essential component.

Polyhydroxy compounds useful in the present invention include glycerol, sorbitol, polyglycene with a weight average molecular weight of about 150 to about 800.

and polyoxyethylene glycols and polyoxypropylene glycols having a weight average molecular weight of about 200 to about 4000, more preferably about 200 to about 1000, most preferably about 200 to about 600. Polyoxyethylene glycols having a weight average molecular weight of about 200 to about 600 are particularly preferred. Mixtures of the polyhydroxy compounds described above can also be used. For example, mixtures of glycerol and polyoxyethylene glycols having a weight average molecular weight of from about 200 to about 1000, more preferably from about 200 to about 600, may be used in the process of the invention. The weight ratio of glycerol to polyoxyethylene is preferably from about 10: 1 to 1:10.

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

The biodegradable chemical softener composition described above, i.e., a mixture of a biodegradable quaternary ammonium compound and a polyhydroxy compound, is preferably diluted to the desired concentration to form a dispersion of the quaternary compound and the polyhydroxy compound before adding to the papermaking composition. , in the wet section of the papermaking machine, at a convenient point before the Fourdrinier screen or the sheet forming section. However, the use of the biodegradable chemical softener composition described above, after the wet web has been formed and before the web has completely dried, provides significant benefits in terms of softness, absorbency and wet strength, and is also specifically within the scope of the invention.

It has been found that a biodegradable chemical softener composition is more effective when the biodegradable quaternary ammonium compound and the polyhydroxy compound are premixed before being added to the pulp of paper making. A preferred process, which will be described in more detail in Example 1, is to first heat the polyhydroxy compound to about 66 ° C, then add the biodegradable quaternary ammonium compound to the hot polyhydroxy compound to form a homogeneous liquid. . The weight ratio of the quaternary ammonium compound to the polyhydroxy compound is 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, More preferably from about 1.0: 0.7 to about 0.7: 1.0, but this ratio depends on the specific polyhydroxy compound used and / or the molecular weight of a biodegradable quaternary ammonium compound.

Surprisingly, it has been found that the absorption of the polyhydroxy compound on the paper is significantly increased when the polyhydroxy compound is absorbed on the paper. It is premixed with the biodegradable quaternary ammonium compound and added to the paper by the above procedure. At least 20% of the polyhydroxy compound and the biodegradable quaternary ammonium compound added to the fibrous cellulose remain; the retention amount of the biodegradable quaternary ammonium compound and the polyhydroxy compound is preferably about 50 to about 90% of the administered amount.

It is important that the absorption occurs at a concentration and for a period which is practically appropriate for use in paper making. In order to better understand the surprisingly high retention rate of the polyhydroxy compound on the paper, a solution of a diester / di-hardened / tallow alkyl alkyldimethylammonium chloride / DEDTHTDMAC / polyoxyethylene glycol 400 melt solution and aqueous dispersion was studied.

Without wishing to be bound in theory or otherwise limited to the present invention, the following description is offered to explain how the ester-functional quaternary compound promotes the absorption of the polyhydroxy compound on paper.

The £ DEDTHTDMAC the diester di / barely hardened / tallow dimethyl ammonium chlorides such as liquid kristáIa $ i + ^j - t ic.

lyos ^ There is a equilibrium mixture of Tazis. X-ray data show that commercial DEDTHTDMAC is in fact a liquid crystalline phase that does not give crystalline states.

«V ··« · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · r & r & led

- 21 Mixtures of DEDTHTDMAC and PEG-400

Phase studies of these two materials, using the gradual dilution method, show that their physical behavior is similar to di / hydrogenated / tallow alkyl dimethyl ammonium chloride. These compounds are miscible over a wide temperature range (from 50 ° C), indicating that these mixtures can be dispersed in similar temperature ranges. There is no upper temperature limit for mixing. X-ray data show that a mixture of crystalline and liquid phases exists in DEDTHTDMAC / PEG-400 mixtures.

Mixtures of DEDTHTDMAC and glycerol

From direct observations and X-ray data, a 1: 1 weight ratio of DEDTHTDMAC to glycerol appears to be in the liquid phase. Although glycerol, in combination with other surfactants, can form liquid crystalline phases, it appears to be present in this formulation but not in this system.

Mixtures of DEDHTDMAC and PEG-400

Phase studies of these two substances, using the gradual dilution method, show that their physical behavior is similar to that of DEDTHTDMAC. These two compounds are miscible over a wide temperature range (> 67 ° C), indicating that dispersions can be made from these mixtures at similar temperature ranges. There is no upper limit for mixing.

· · · · · ··· · · · · · · · · · · · · · · · · · · · · · · ·

- 22 Physical state of quaternary and polyhydroxy compounds and water mixtures

Dispersions of any of the above materials can be prepared by diluting a mixture at water temperature which maintains the polyhydroxy compound with the ester-functional quaternary ammonium salt. Neither DEDTHTDMAC nor DEDHTDMAC are soluble in water, so that when diluting any solid phase with water, the ester-functional quaternary ammonium compound precipitates in the form of small particles. The polyhydroxy compound is soluble in water in all ratios so that it does not precipitate.

When mixed with about equal parts of DEDTHTDMAC and polyhydroxy compounds such as glycerol, PEG-400, etc., to form a mixture containing about 1% DEDTHTDMAC, DEDTHTDMAC precipitates. The DEDTHTDMAC phase becomes a lamellar liquid crystal / crystalline liquid at about room temperature.

Colloidal structure of the dispersions

The liquid crystalline phase is present in the diluted mixtures in the form of vesicles, which are mostly closed and spherical. The formation of these dispersions is probably the result of the high osmotic pressure gradients that currently exist during the process. The source of these pressure gradients is the spatial gradients in the composition (and thermodynamic activity) of the water that are generated. Because DEDTHTDMAC / glycerol blends · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

The liquid phase of 23 may exist over a wide range of temperatures so that dispersions can be made over a wide range of temperatures.

Cryo-electron microscopy shows that the particles present are about 0.1 to 1.0 micrometers in size and are highly variable in structure. Some are sheets (curved or flat), while others are closed vesicles. The membranes of each particle are bilayer in molecular dimensions, where the head groups are directed towards the water and the back portions are together. Presumably, PEG is attached to these particles. Using the dispersions prepared in this way on paper, the result is that the ester-functional quaternary ammonium ion is attached to the paper, strongly promoting the absorption of the polyhydroxy compound on the paper, and providing the desired modification of softness and retention of wettability.

Status of dispersions

If the above-mentioned dispersions are cooled, partial crystallization of the material in the colloidal particles may occur. However, achieving equilibrium is likely to take a long time (possibly months), with disordered particles having membranes in a liquid crystalline or disordered crystal phase interacting with the paper. The biodegradable chemical softening compositions described are preferably used before the equilibrium state is reached.

· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

- 24 It is likely that the biodegradable quaternary and vesicles containing polyhydroxy compounds such as glycerol, PEG-400at, etc. will break when the fibrous cellulosic material is dried. Once the vesicle is broken, most of the PEG component can penetrate inside the cellulosic fibers, where it improves the flexibility of the fiber. Importantly, a portion of the PEG remains on the surface of the fiber, where it enhances the absorption rate of the cellulosic fibers. Due to ionic interactions, the cationic portion of the biodegradable quaternary compounds remains on the surface of the cellulosic fiber, whereby it improves the surface feel and softness of the paper product.

binder

The compositions of the present invention contain from about 0.01% to about 3.0%, preferably from about 0.01% to about 1%, by weight of a binder, such as permanent wet strength resin, periodic wet strength resin, dry strength resin, retention aids or mixtures thereof. The binder acts to reduce degradation and to counteract any reduction in biodegradable chemical plasticizers that may be present in tensile strength.

If permanent wet strength is required, the binder may be selected from the group consisting of polyamide-epichlorohydrin or polyacrylamide resins, styrene-butadiene latexes, rendered insoluble, · · · · · · · · · · · · · · · · · · · · · · · ··· ··

- 25 polyvinyl alcohol, urea formaldehyde, polyethyleneimine, chitosan polymers and mixtures thereof. The polyamide-epichlorohydrin resins are cationic wet strength resins which have proven to be extremely useful. Suitable types of such resins are disclosed in U.S. Patent Nos. 3,700,623 and 3,772,076. One commercial source of usable polyamide-epichlorohydrin resins is Hercules, Inc. of Wilmington, Delaware, which markets these resins under the trade name Kymeme ^ 557H.

It has been found that polyacrylamide resins can also be used as wet strength resins or retention agents. These resins are disclosed in U.S. Patent Nos. 3,556,932 and 3,556,933. One commercial source of polyacrylamide resins is the American Cyanamid Co. of Stanford, Connecticut, which markets these resins under the trade name Parez ^ 631 NC. Other commercial sources of cationic polyacrylamide resins are Allied Colloids of Sulfolk, Virginia and Hercules, Inc. of Wilmington, Delaware, which market these resins under the trade names Percol (R) 175 and Rethene (R) 1232.

Other water-soluble cationic resins useful in the compositions of the present invention include urea-formaldehyde and melamine-formaldehyde resins. The most common functional groups of these polyfunctional resins are nitrogen-containing groups, such as amino groups and amino acids, and the like. ··· ··

- methylol groups bound to 26 nitrogen atoms. Polyethyleneimine-type resins can also be used in the compositions of the invention.

If periodic wet strength is required, binders can be selected from the group consisting of starch based periodic wet strength resins: cationic dialdehyde starch based resins, such as Caldas, manufactured by Japan Cary, or Cobond 1000, National Starch product; dialdehyde starch; and / or the resin described in U.S. Patent 4,981,557.

If dry strength is required, the binders may be selected from the group consisting of polyacrylamide, such as combinations of Cypro 514 and Accostrength 711, as described in American Cyanamid of Wayne, N.J. manufactured by /; starches (such as corn starch and potato starch); polyvinyl alcohol (such as Airvol 540, manufactured by Air Products Inc. of Allentown, PA); guar gum and locust bean gum; polyacrylate latexes; and / or carboxymethylcellulose (such as Aqualon CMC-T, Aqualon Co., Wilmington, DE). Suitable starches for use in the present invention are characterized by water solubility and hydrophilicity. Such suitable starches include, but are not limited to, corn starch and potato starch; and is particularly suitable for waxy corn starch, which is known in the industry as amyloid starch. Amioca starch differs from common corn starch in that:

- Contains 27 wholly amylopectin, while common corn starch contains both amylopectin and amylose. The various unique properties of amyloid starch are described in p'Amioca - The Starch from Waxy Corn, H.H. Schopmeyer, Food Industries, December 1945, p. 106-108 / Vol. pp. 1476-1478 / J. The starch may be in granular or dispersed form, but granular form is preferred. Preferably, the starch is cooked sufficiently to cause the granules to swell. More preferably, the starch granules are swollen by cooking just before the starch granules are dispersed. These highly swollen starch granules are referred to as fully cooked starch granules. The dispersion conditions will generally vary depending on the size of the starch granules, the degree of crystallinity of the granules, and the amount of amylose present. For example, fully cooked amo starch can be prepared by heating an aqueous slurry of a starch granule having a density of about 4x for about 30 to about 40 minutes at about 88 ° C. Other starches which may be used, such as modified cationic starches, such as those containing nitrogen-containing groups such as amino groups and nitrogen-linked methylol groups, are available from National Starch and Chemical Company of Bridwater, New Jersey. These modified starches are mainly used as pulp additives,

- 28 for wet and / or dry strength. Considering that these modified starches are more expensive than non-modified starches, the latter are preferred.

The methods of application are the same as those described for the use of other chemical additives, preferably wet application, spraying and less preferably printing. The binder may be applied to the silk crepe paper either alone or at the same time as, before or after the plasticizer, absorbent and / or aesthetic additives. Preferably, at least an effective amount of a binder, preferably starch, is added to the paper sheet, which reduces shrinkage and, at the same time, increases its strength after drying, as compared to an untreated but otherwise identical sheet. Preferably, about 0.01% to about 3.0% of binder, based on the weight of dry fiber, remains in the dried curve; and more preferably from about 0.1% to about 1.0%, preferably starch based binder.

In the process of the present invention, the second step for layering the multilayer paper is to lay the pulp onto an apertured surface using the chemical softener composition and binders described above, and the third step is to remove water from the layered pulp. The methods and equipment that can be used to perform these two operations are well known to those skilled in the art of papermaking. A preferred embodiment of the present invention is the following: ···············································································································

The 29-ply silk crepe papers contain from about 0.01% to about 3.0%, more preferably from about 0.1% to about 1.0%, by weight of the biodegradable chemical softener composition and binders described above, based on the dry fiber.

The method of the invention is applicable to multilayer silk crepe papers in general, including traditionally felt-pressed multilayer crepe papers; high specific volume, patterned compacted multi-ply tissue paper and high-specific, non-pressed multi-ply tissue paper. Multi-ply silk crepe paper products made from these may consist of a single-ply or multi-ply structure. Paper structures made of laminated webs are described in U.S. Patent No. 3,994,771. Wet-layered, multi-part, soft, low-density, and absorbent paper structures are generally made of two or more fiber layers, preferably consisting of different types of fibers. Preferably, the layers are formed by layering separate streams of dilute fiber suspensions on one or more endless sieves, the fibers being relatively long soft fibers and relatively short hard fibers commonly used in the production of multilayer silk crepe papers. If the individual layers are initially formed on separate sieves, the layers are subsequently combined in a wet state to form a laminated composite web. Then, the laminated web is a mesh-like web.

It is attached to the surface of a dryer / printer screen by exerting a fluid pressure on the paper web, and thereafter pre-dried therewith as part of a low density paper manufacturing process. The laminated paper web may be made into layers according to the fiber type, or the fiber content of each layer may be substantially the same. The multilayer silk 2 crepe paper preferably has a basis weight of 10 g / m 2 to about 65 g / m 2 and a density of about 0.60 g / ml or less. Preferably, the basis weight is less than or equal to about 35 g / m 2; and a density of about 0.30 g / ml or less. Most preferably, the density is between 0.04 g / ml and 0.20 g / ml.

The multilayer silk crepe paper webs of the present invention comprise at least two superimposed layers, a first layer and at least one second layer contacting the first layer. The multilayer silk crepe papers preferably comprise three superimposed layers, an inner or middle layer and two outer layers; the inner layer is located between the two outer layers. Preferably, the primary fibrous component of the two outer layers is about 60 weight percent or more of relatively short papermaking fibers having an average fiber length of about 0.2 to about 1.5 mm. These short papermaking fibers are typically hard fibers, preferably eucalyptus fibers. We can also use inexpensive sources of shorter fiber, such as sulfite fibers, thermomechanical cellulosic fibers, chemo-thermomechanical cellulosic fibers, recycled fibers.

- 31 fibers including fiber fractionated from recycled fibers and mixtures thereof. They may be used in one or both outer layers or, if desired, mixed in the inner layer. Preferably, the primary fibrous component of the inner layer is about 60% by weight or more of relatively long papermaking fibers having an average fiber length of at least about 2.0 mm. These long papermaking fibers are typically soft fibers, preferably northern softwood kraft fibers.

Figure 1 is a schematic cross-sectional view of a three-ply, single-sheet toilet paper according to the invention. Referring to Fig. 1, the web of three-layer sheet paper 10 consists of three superimposed layers, the inner layer 12 and the two outer layers 11. The outer layers 11 consist primarily of short papermaking fibers 16, while the inner layers 12 consist primarily of long papermaking fibers 17.

In another preferred embodiment of the process of the invention, multi-ply silk crepe paper products are formed by placing at least two multi-ply silk crepe paper webs together. For example, a crepe paper product consisting of two sheets of paper may be made, consisting of a first double-ply web and a second double-ply web stacked side by side. In this example, each sheet layer is a two-layer silk crepe iv with a first and a second layer. The first layer preferably comprises short hard fibers and the second layer preferably contains short hard fibers.

- 32 layers of long softwood fibers. The two sheet layers are combined so that the short hard fibers of each sheet face outward and the layers containing the long soft fibers inward.

Figure 2 is a schematic cross-sectional view of two facial wiping paper according to the present invention consisting of two double-layer sheets. Referring to Fig. 2, the paper web consisting of two double-layered sheets 20 comprises two adjacent sheets of sheet 15. Each sheet layer 15 comprises an inner layer 19 and an outer layer 18. The outer layers 18 consist primarily of short papermaking fibers 16, while the inner layers 19 consist primarily of long papermaking fibers 17. Likewise, silk crepe paper products consisting of three sheets may be prepared by placing three layers of silk crepe paper side by side.

It is not to be understood from the foregoing description that the present invention is limited to three-layer, single-sheet or two-ply, and so on. tissue-paper products. Silk crepe paper products comprising three or more sheets, each of which consists of one or more layers, are also within the scope of the present invention.

Most of the biodegradable quaternary ammonium compound and the polyhydroxy compound of the multi-layer silk crepe paper web according to the invention are present in the present invention.

33 preferably comprises at least one outer layer. More preferably, most of the biodegradable quaternary ammonium compound and the polyhydroxy compound are present on both outer layers. It has been found that the biodegradable chemical softener composition is most effective when added to the outer layers or sheets of crepe paper products. Here, the biodegradable quaternary compound and the polyhydroxy compound act to improve the softness and absorbency of the multi-ply silk crepe paper products of the present invention. Referring to Figures 1 and 2, a biodegradable chemical softener composition comprising a mixture of a biodegradable quaternary ammonium compound and a polyhydroxy compound is schematically represented by black circles 14. It can be seen from Figures 1 and 2 that most of the biodegradable chemical softener composition 14 is contained in outer layers 11 and 18, respectively.

However, it has also been found that the shear resistance of multilayer silk crepe paper products is reduced by the addition of the biodegradable quaternary ammonium compound and the polyhydroxy compound. Therefore, binders are used to reduce friction and increase tensile strength. Preferably, the binder is comprised of an inner layer and at least one outer layer of the multilayer silk crepe paper webs of the present invention. More preferably, the binder is contained within the entire multilayer product, i.e., both the inner and outer layers. Figures 1 and 2 hi ·· ·

- 34 binders, the binders are schematically represented by the 13 white circles. It can be seen in Figures 1 and 2 that most of the binders 13 are contained in the inner layers 12 and 19, respectively. In another preferred embodiment (not shown) most of the binder is contained in at least one outer layer, more preferably both outer layers, of the multilayer product.

Combining a biodegradable quaternary ammonium compound and a biodegradable chemical plasticizer composition comprising a polyhydroxy compound with a binder results in a softer, better absorbency, and resistance to fibrillation. Effectiveness is enhanced when the bulk of the biodegradable chemical softener composition is selectively added to the outer layers or sheets of the crepe paper. Binders are generally dispersed throughout the paper to reduce littering. However, like the biodegradable plasticizer composition, binders can be selectively introduced where they are most needed.

Conventionally pressed multi-ply silk crepe papers and methods for making such papers are known in the art. Such papers are generally prepared by layering paper pulp onto a perforated sheet forming screen. This sheet forming screen is often referred to in the art as the Fourdrinier screen. Once the pulp has been deposited on a forming screen, then

- 35 we call it paper tape. The web is dewatered by applying to a dewatering felt, the web is squeezed and dried at a higher temperature.

The specific processes and typical equipment for producing paper webs by the process described herein are well known to those skilled in the art. In a typical process, low-density cellulosic pulp is prepared in a high-pressure overhead cabinet. The overhead cabinet has an opening through which a thin layer of cellulosic pulp is passed to the Fourdrinier sieve and forms a wet web there. Thereafter, the web is generally dewatered to about 7% to about 25% of the total web weight / fiber density by vacuum dewatering and further dewatered when pressed under pressure from opposite mechanical members, such as rollers.

The dewatered web is then pressed further as it passes and dried in a flow drum dryer known in the art as a Yankee dryer. The Yankee dryer can be pressurized by mechanical means, thereby clamping an opposed cylindrical drum against the web. Vacuum can also be applied to the web as it is pressed onto the Yankee dryer surface. Multiple Yankee dryers can be used to create additional pressure between the drums, if necessary. The fabricated multilayer silk crepe paper structures are referred to as conventional pre-fabricated fabric.

Reference is made to 36 multi-ply silk crepe paper structures. These spurs are compressed as the paper web is subjected to significant mechanical compression forces while the fibers are still wet and then dried in a compressed state.

Patterned multi-ply silk crepe papers are characterized by having a relatively low fiber density, high specific volume zone, and a pattern consisting of relatively high fiber density compressed zones. High specific volume zones are called pillow regions. Compressed zones are regions of knuckles. Compressed zones may be located separately in the high specific volume field or in the high specific volume field, or they may be fully interconnected. Preferred methods for making patterned crepe paper webs are disclosed in U.S. Patent Nos. 3,301,746, 3,974,025, 4,191,609 and 4,637,859.

Patterned compacted webs are generally preferably prepared by layering the papermaking pulp onto a perforated forming screen, such as a Fourdrinier screen, to form a wet web, and then placing the web alongside a patterned substrate. The web is pressed against the pattern substrate to form compacted zones within the web that locally correspond to the points of contact between the pattern substrate and the wet web.

- 37 The remainder of the paper web that was not compressed during this operation is the high specific volume field. This high specific volume field can be further relaxed using a hydrostatic pressure such as a vacuum type device or a flow dryer. The paper web is dewatered and optionally pre-dried in such a way as to substantially avoid compressing the high specific volume field. This is preferably done by means of a hydrostatic pressure, such as a vacuum type device or a blow dryer, or by mechanically pressing the paper web against a patterned carrier so that the high specific volume zone is not compressed. The dewatering, possible pre-drying and compaction zones operations may be combined or partially combined, thus reducing the total number of process operations performed. After forming the compacted zones, dewatering and possibly pre-drying, the paper web is completely dried, preferably also avoiding mechanical pressing. Preferably, about 8 to about 55% of the surface of the crepe paper comprises compacted screen knots having a relative density of at least 125% of the density of the high specific volume field.

The patterned carrier is preferably a printer transfer screen with a patterned location of the screen knots, which acts as a pattern carrier that facilitates the formation of compacted zones by applying pressure. The pattern of the screen knots forms the pattern arrangement of said substrate. Printer transfer screens are described in 3,301,746, · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

U.S. Patent Nos. 38,382,068, 3,974,025, 3,573,164, 3,473,576, 4,239,065, and 4,528,239.

Preferably, the pulp is first formed into a wet paper web on a perforated forming screen, such as a Fourdrinier screen. By dehydrating the paper web and transferring it to a printer screen, it is also possible to initially lay the pulp onto a perforated substrate, which also functions as a printer screen. The formed wet web is dewatered and preferably thermally pre-dried to a fiber density of about 40% to about 80%. Dewatering can be done with suction cupboards or other vacuum devices or with blow dryers. The print screen printout of the screen sieve is pressed into the web as described above before the web is completely dried. One way to do this is to use mechanical pressing. This can be done, for example, by pressing the roller provided with the printer screen against the drying surface of the dryer drum, such as the Yankee dryer, while the paper web is located between the feed roller and the drum dryer.

Preferably, the paper web is pressed against the printer screen before it is completely dried using hydrostatic pressure, a vacuum device such as a suction cup or a blow dryer. Hydrostatic pressure can be applied to induce pressure in compacted zones during initial dewatering, after 39 -

sowing, in a separate process operation or in combination.

Non-pressed, non-pattern compacted silk crepe paper structures are disclosed in U.S. Patent Nos. 3,812,000 and 4,208,459. Non-pressed, non-pattern compacted silk crepe paper structures are generally made by layering the pulp to a perforated forming screen, such as a Fourdrinier screen, to form a wet paper web, to remove water from the web and to remove any residue. the web having a fiber density of at least 80% and then creping the web. Water from the web is removed by vacuum dewatering and drying by thermal post. The structure thus obtained is soft but weak, having a high specific volume of iv which consists of relatively uncompressed fibers. Preferably, a binder is added to the portions of the web before creping.

The multilayer webs of the present invention can be used in any application where soft, absorbent, multi-ply webs are required. The multilayer tissue paper webs of the present invention are particularly advantageous for use in toilet paper and facial tissue products. For example, two multi-ply webs of silk crepe paper according to the present invention can be pasted together into two sheets of face wipes or toilet paper products.

Determination of molecular weight

A. Introduction

A key distinguishing feature of polymeric materials is their molecular size. The properties which enabled the polymers to be used in a variety of applications are almost exclusively due to their macromolecular nature. In order to fully characterize these materials, it is essential that we have methods for the definition and determination of their molecular weights and molecular weights. It is preferable to use the term relative molecular weight rather than molecular weight, although the latter is more commonly used in polymer technology. It is not always practical to determine molecular weight distributions. However, the use of chromatographic techniques is gaining ground. Rather, molecular size is expressed as molecular weight averages.

B. Molecular Weight Averages

Assuming a simple molecular weight distribution representing the mass fraction of molecules having a relative molecular weight M 2, some useful average values can be defined. The averaging is the number of specific mass molecules M / N. / based on average molecular weight:

An important consequence of this definition is that the average molecular weight in grams gives the Avogadro number of molecules. This definition of molecular weight refers to monodisperse species, i.e., molecules of the same molecular weight. More Relevant • · ·

41 is the recognition that if the number of molecules in a given mass of a polydisperse polymer can be determined in some way, then M can be easily calculated. This is the basis for measuring colligative property.

Averaging based on the weight fraction of molecules in a given mass leads to the definition of weighted molecular weight averages.

W. N. <N.M.

_ * -11 * -11

J.M.

≤ 1-11 is much more useful for expressing polymer molecular weights than M _n since it more accurately reflects certain properties such as melt viscosity and the mechanical properties of polymers and is therefore used in the present invention.

Analytical and test procedures

Quantitative analysis of the biodegradable chemicals used in the process or retained on the webs of silk crepe paper can be performed by any method known in the art.

A. Quantitative Analysis of the Ester Functional Quaternary Ammonium Compound and the Polyhydroxy Compound

An ester-function quaternary ammonium compound retained by silk crepe paper, such as diester di / hydrogenated / tallow alkyl dimethyl ammonium chloride

0,, _,, / DEDHTDMAC, that is, ADOGEN DDMC / determines the amount · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

For example, the DEDHTDMAC is extracted with an organic solvent and the extract is subjected to anionic / cationic titration using a dimethyl bromide indicator. The amount of the polyhydroxy compound, such as PEG-4OO, may be determined by extraction with an aqueous solvent, such as water, and then the amount of PEG-400 in the extract determined by gas chromatography or colorimetry. These methods are exemplary only and do not exclude the use of other methods that can be used to determine the amount of special components retained by the tissue paper.

B. Hydrophilicity / Absorption /

The hydrophilicity of multilayer silk crepe paper generally indicates the tendency of the paper to wet with water. The hydrophilicity of the multilayer crepe paper can be quantified by quantifying the time required for the dry multilayer crepe paper to be completely moistened with water. This period is wetting! called time. In order to provide a suitable and repeatable test of the wetting time, the following procedure may be used to determine the wetting time: first, a conditioned unit sample of about 11.1 x 12 cm is prepared from the multilayer silk crepe paper structure / 23 + 1 ° C and 50 + 2% relative humidity as required by TAPPI Method T4O2 /; Second, drink four one · ·

- folded into 43 adjacent quarters and folded into scoops of about 1.9 cm to about 2.5 cm in diameter; third, placing the scooped drink on the surface of a distilled body of water at 23 + 1 ° C and simultaneously triggering a control clock; fourth, the clock is stopped and read when the dampening of the IV drip is complete. Total wetting is determined visually.

Of course, the hydrophilicity properties of the multilayer silk crepe papers of the present invention can be determined immediately after manufacture. However, there may be a significant increase in hydrophobicity within the first two weeks after the production of multi-ply silk crepe paper, that is, after two weeks of production. Therefore, the wetting! times are preferably measured at the end of the two-week period. Wetting at room temperature at the end of the two-week aging period! times are called two-week wetting times.

C. Biodegradability

Suitable, essentially anhydrous, self-emulsifying chemical plasticizers suitable for use in the present invention are biodegradable. As used herein, the term biodegradable refers to the complete degradation of a substance by microorganisms, carbon dioxide, water, biomass, and inorganic materials. The biodegradation efficiency can be estimated by measuring the evolution of carbon dioxide and the removal of dissolved organic carbon from a medium that is the test substance. as the sole source of carbon and energy, and a hig bacterial inoculum obtained from the supernatant of homogenized activated sludge. Larson, Estimation of Biodegradation Potential of Xenobiotic Organic Chemicals, Applied and Environmental Microbiology, 38, 1153-61 / 1979 / J. This publication describes a suitable method for the estimation of biodegradability. Using this method, a substance is said to be readily biodegradable if the evolution of carbon dioxide is greater than 70% and more than 90% of the dissolved organic carbon can be removed within 28 days. The plasticizers used in the present invention meet these requirements.

D. Density

The density of multi-ply silk crepe paper, as used in this description, is the average density calculated by dividing the basis weight of the paper by the caliper / appropriate unit conversions. Caliper is the thickness of multilayer silk crepe paper that is obtained when the paper is subjected to a weight of 15.5 g / cm.

E. Fossil

Dry littering / dusting /

The dry littering / dusting / measurable one

Sutherland Rub Tester, one piece of black felt, using four pounds / 1.8 kg / weight and one Hunter Color meter. Powered by Sutherland tester motor,

which can hit a measured sample back and forth with a standing sample. Black felt is attached to four important weights. The tester then rubs or moves the measured felt with five strokes over a standing pattern. The Hunter Color L value of the black felt is determined before and after rubbing. The difference between the two Hunter Color readings is the degree of dry litter. Other methods known in the art for measuring dry litter may also be used.

Wet litter

A suitable method for measuring the wet shear properties of silk crepe papers is described in U.S. Patent No. 4,950,545. The process essentially involves passing a sample of crepe paper between two steel rolls, one of which is partially immersed in a water bath. From the crepe paper sample, the paper scraps are transferred to the steel roller which is moistened by the water bath. Continuous rotation of the steel cylinder puts shreds in the water bath. The fragments are collected and evaluated, cf. column 5, line 45 to column 6, line 27 of the above-mentioned patent specification. Other methods known in the art for measuring wet decay can also be used.

Possible components

Other chemicals commonly used in papermaking may be added to the biodegradable chemical softener formulation described above or to the pulp used in papermaking provided that they do not have a significant effect on the papermaking pulp. · · · ·· · ·

46 and adversely affect the softness and absorbency of the fibrous material and enhance the effects of the biodegradable chemical softener composition.

For example, surfactants may be used to treat the multilayer silk crepe paper webs of the present invention. If a surfactant is used, it will preferably be present in an amount of about 0.01 to about 2.0% by weight based on the dry fiber weight of the multi-ply tissue paper. The surfactants preferably have alkyl chains of eight or more carbon atoms. Suitable anionic surfactants include, for example, linear alkyl sulfonates and alkyl benzene sulfonates. Nonionic surfactants include, for example, alkyl glycosides, including alkyl glycoside esters such as Crodesta SL-40, product of Croda, Inc., New York, NY; alkyl glycoside ethers disclosed in U.S. Patent 4,011,389; alkyl polyethoxylated esters such as Pegosperse 200 ML, from Glyco Chemicals, Inc., Greenwich, CT, and IGEPAL RC-520, available from Rhone Poulenc Corporation / Cranbury, N.J.

The above list of possible chemical additives is provided by way of example only and is not intended to limit the scope of the invention.

The practice of the process of the invention is illustrated by the following examples, without limiting the scope of the invention.

1x_2glda

The purpose of this example is to illustrate a process for the preparation of a substantially anhydrous, self-emulsifying, biodegradable chemical composition comprising a mixture of diester di / barely hardened / tallow alkyl dimethylammonium chloride (DEDTHTDMAC) and polyoxyethylene glycol 400 / PEG-400 /. .

An anhydrous, self-emulsifying, biodegradable chemical softener composition is prepared by the following process: 1. Equivalent amounts of DEDTHTDMAC and PEG-400 are weighed separately; 2. heating the PEG to about 66 ° C; 3. DEDTHTDMAC is dissolved in PEG to form a melt solution at 66 ° C; 4. forming a homogeneous mixture of DEDTHTDMAC and PEG, providing proper mixing; 5) cooling the homogeneous mixture of 4 to room temperature to solidify.

The substantially anhydrous, self-emulsifying, biodegradable chemical plasticizer composition of claim 5 is illustrated in claims 1-5. may be premixed in a chemical apparatus (e.g., the Sherex Company of Dublin, Ohio) and then delivered economically to end users of the biodegradable chemical softener composition, where it can be diluted to the desired concentration.

Example 2 ^

The purpose of this example is to illustrate a process which is a substantially anhydrous, self-emulsifying, biodegradable mixture of a mixture of diester di / barely hardened / tallow alkyl di • · * · · · methyl ammonium chloride (DEDTHTDMAC) and glycerol / PEG-400. for use in the preparation of a degradable chemical softener composition.

A substantially anhydrous, self-emulsifying, biodegradable chemical plasticizer composition is prepared by the following process: 1. mixing glycerol and PEG-400 in a ratio of about 75:25 by weight; 2) measuring separately the equivalent amounts of DEDTHTDMAC and the mixture of 1; 3.

about 66 ° C; 4th

heating the mixture of s and heating the DEDTHTDMAC to form a melt solution at 66 ° C; 5. ensuring proper mixing between DEDTHTDMAC and

3) forming a homogeneous mixture; 6. the homogeneous mixture of 5 is cooled to room temperature to give a solid.

The substantially anhydrous, self-emulsifying, biodegradable chemical plasticizer composition of claim 6 is shown in claims 1-6. may be premixed in a chemical apparatus (e.g., the Sherex Company of Dublin, Ohio) and then delivered economically to end users of the biodegradable chemical softener composition, where it may be diluted to the desired concentration.

.._ 2élda

The purpose of this example is to illustrate a process using drying and layering paper processes that are fluffy, absorbent, and resistant to linting ·································································································· · ··

- 49 stationary multi-layered toilet paper with a chemical softener composition comprising diester di / barely hardened tallow alkyl dimethyl ammonium chloride / DEDTHTDMAC / and polyoxyethylene glycol 400 / PEG-400 and a periodic wet strength resin.

In the practice of the invention, a half-size Fourdrinier papermaking machine is used.

First, the chemical softener composition was prepared as in Example 1. The homogeneous premix of DEDTHTDMAC and polyhydroxy compound was re-thawed at about 66 ° C from solid state. The thawed mixture is then dispersed in a conditioned water tank / pH 2 → 3; a temperature of ~ 66 ° C / s thus forming a submicron vesicle dispersion. The particle size of the vesicle dispersion was determined using an optical microscope. The particle size is about 0.1 to 1.0 microns.

Secondly, in a conventional reconstituting agent, a 3 wt% aqueous NSK suspension is prepared fNSK = northern softwood kraft pulp = northern softwood kraft pulp. The NSK slurry is slightly purified / refined and a 2% solution of a temporary wet strength resin (National starch 78-0080) from the National Starch and Chemical Corporation of New York, NY, is added to the dry to about 0.75% by weight. The absorption of the intermittent wet strength resin onto NSK fibers is promoted by a paper machine mixer. The NSK slurry was diluted to a density of about 0.2% using a propeller pump.

• · ·

Third, a 3 wt% aqueous suspension of eucalyptus fibers is prepared in a conventional pulping agent. A periodic wet strength resin / National Starch 78-0080, a product of the National Starch and Chemical Corporation of New York, NY, is injected into the eucalyptus slurry pipeline prior to the material pump with a 0.1% w / w solution of dry fibers. %; then a 1% solution of the biodegradable chemical softener mixture is introduced into the eucalyptus suspension material line, in front of the papermaking mixer, at a dry weight of 0.2%. The eucalyptus suspension is diluted with a propeller pump to a density of about 0.2%.

The so treated pulp mixture / 30% NSK / 70% eucalyptus / overhead is mixed and layered on a Fourdrinier sieve to form an initial web. Dewatering is done through the Fourdrinier sieve and is assisted by a baffle and suction cups. The Fourdrinier sieve has a 5 shed fineness satin fabric configuration, containing 84 machine direction and 76 transverse monofilament yarns per inch. The initial strip of paper from the Fourdrinier sieve, at the transfer point, was transferred to a photopolymer sieve containing 562 linear Idaho cells per square inch, 40% screen knot area, and 9 µm photopolymer depth. Further dewatering is performed by vacuum assisted water extraction until the web has a fiber density of about 28%. The patterned paper tape is airborne · · · · · · · · · · · · · · · · · ·

- pre-dried through 51 passes to a fiber density of about 65% by weight. The web is then glued to a drying surface of a Yankee by spraying a creping adhesive consisting of 0.25% aqueous polyvinyl alcohol solution. The fiber density is increased to about 96%, and the web is creped dry with a scraper knife. The scraper blade has an incline of about 25 ° and is positioned relative to the Yankee dryer with an inlet angle of about 81 °. The Yankee dryer is operated at a speed of approximately 244 meters / minute. The dry web is rolled at a speed of 214 meters per minute.

The web is processed into a multi-ply, single-ply silk crepe paper product. The multilayer paper has a basis weight of about 18 µM / ft, about 0.2% biodegradable chemical softener blend, and about 0.3% periodic wet strength resin. It is important that the multi-layered silk crepe paper so prepared is soft, absorbent, has good resistance to abrasion and corresponds to facial tissue and / or toilet paper.

4 _r _example

The purpose of this example is to illustrate a process using a permeable drying papermaking process to produce soft, absorbent and lint-resistant multi-ply toilet paper which is diester / barely hardened / tallow alkyl dimethyl ammonium DID / compound mixture / glycerin / ·····

- treated with a chemical softener composition containing 52 PEG-400 / and dry strength resin.

In the practice of the invention, a half-size Fourdrinier papermaking machine is used.

First, the chemical softener composition is prepared by the method described in Example 2. The homogeneous solid premix of DEDTHTDMAC and polyhydroxy compounds was thawed at about 66 ° C. The thawed mixture is then in a conditioned water tank / pH ^ -3; the temperature is dispersed at 6666 ° to form a submicron vesicle dispersion. The particle size of the vesicle dispersion was determined using an optical microscope. The particle size range is about 0.1 to 1.0 microns.

Second, a 3% w / w aqueous suspension of NSK is prepared in a conventional pulverizer. The NSK slurry was slightly refined and a 2% solution of dry strength resin / Acco ⁰ 514 or Acco ^ 711, manufactured by the American Cyanamid Company of Fairfield, OH, was introduced into the NSK conduit, about 0.2% on dry fibers. by weight. The absorption of the dry strength resin onto NSK fibers is promoted by a paper machine mixer. The NSK slurry was diluted with a propeller pump to a density of about 0.2%.

Third, a conventional eucalyptus fiber suspension is prepared in a conventional pulp paste by weight of 3%. The eucalyptus conduit, before the material pump, is dry · ········································································································

A 2% solution of 53 strength resin / Accc > 514 or Acco &^lt; / RTI &gt; and introducing a 1% solution of the biodegradable chemical softener composition into the eucalyptus conduit prior to the papermaking mixer at a dry weight ratio of 0.2%. The eucalyptus suspension is diluted with a propeller pump to a density of about 0.2%.

The treated pulp mixture / 30% NSK / 70% eucalyptus / overhead was mixed and layered on a Fourdrinier sieve to form an initial paper web. Dewatering is done through the Fourdrinier sieve and is assisted by a baffle and suction cups. The Fourdrinier sieve has a 5 shed fineness satin fabric configuration, containing 84 machine direction and 76 transverse monofilament yarns per inch. The initial paper strip from the Fourdrinier sieve, at the transfer point, was transferred to a photopolymer sieve containing 562 linear Idaho cells per square inch and 40% screen knot area and 9 µm photopolymer depth. Further dewatering is performed by vacuum assisted water extraction until the web has a fiber density of about 28%. The sample web is pre-dried by air blowing to a fiber density of about 65% by weight. The web is then glued to a drying surface of a Yankee by spraying with a creping adhesive consisting of 0.25% aqueous polyvinyl alcohol solution. Increase the fiber density to about 96%, then dry the paper strip with a scraper blade • ·

- 54 crepe. The scraper blade has an incline of about 25 ° and is positioned relative to the Yankee dryer with an inlet angle of about 81 °. The Yankee dryer is operated at a speed of approximately 244 meters / minute. The dry web is rolled at a speed of 214 meters per minute.

Multilayer silk crepe paper products are made from two sheets of paper web and laminated by a sheet bonding process. The multilayer silk crepe paper has a basis weight of about 23 µM (929.23 '' cm), about 0.1% biodegradable chemical softener blend and about 0.2% dry strength resin. It is important that the multi-ply silk crepe paper produced is soft, absorbent, has good resistance to abrasion, and is suitable for use with face wipes and toilet paper.

5._gélda

The purpose of this example is to illustrate a process using a conventional drying papermaking process to produce a soft, absorbent and lint-resistant multi-ply toilet paper which is diester di / barely hardened / tallow alkyl alkyl dimethylammonium chloride / DEDTHTDM / D 400 /, a dry strength additive and a retention agent, a cationic polyacrylamide resin (Percol. 175).

The process of the present invention is carried out using a semi-industrial Fourdrinier paper making machine.

• · ···· · · · · · · · · · · · · · · · · · · · · · · · · ·

First, the chemical softener composition is prepared according to the procedure described in Example 1. A homogeneous premix of DEDTHTDMAC and PEG-400 in a conditioned water tank / pH ^ -3; the temperature is dispersed at r * 66 [deg.] C. to form a submicron vesicle dispersion. The particle size of the vesicle dispersion was determined using an optical microscope. The particle size ranges from about 0.1 to about 1.0 microns.

Second, a 3% w / w aqueous suspension of NSK is prepared in a conventional pulverizer. The NSK slurry is slightly refined and a dry strength resin / Acco ^< ®514, Acco ^ 711, supplied by the NSK slurry inlet, is supplied by a 2% solution of the American Cyanamid Company of Wayne, New Jersey, based on the dry fiber. , 2 weight? ratio. The absorption of the dry strength resin onto NSK fibers is promoted by a paper machine mixer. The NSK slurry was diluted with a propeller pump to a density of about 0.2%.

Third, a 3 wt% aqueous suspension of Eucalyptus fibers is prepared in a conventional pulp blower. A 1% solution of the biodegradable chemical softener mixture is introduced into the material line of the eucalyptus slurry prior to the material pump, 0.2 weight percent of dry fiber? ratio; and to the eucalyptus layers is added 0.05% Percol 175 solution before the propeller pump, 0.05% by weight on dry fibers? ratio. The absorption of the biodegradable chemical softener blend into the eucalyptus fibers can be assisted by a paper machine mixer · ·································································································

- 56 forward. The eucalyptus suspension is diluted with a propeller pump to a density of about 0.2%.

The so-treated fiber pulp mixture / 30% NSK / 70% eucalyptus / overhead is mixed and layered on a Fourdrinier sieve to form an initial paper web. Dewatering is done through the Fourdrinier sieve and is assisted by a baffle and suction cups. The Fourdrinier sieve has a 5 shed fineness satin fabric configuration, containing 84 machine direction and 76 transverse monofilament yarns per inch. The initial wet web is transferred from the Fourdrinier screen to a conventional felt with a fiber density of about 15% at the transfer point. Further dewatering is performed by vacuum assisted water extraction until the web has a fiber density of about 35%. The paper tape is then glued to the surface of a Yankee dryer. The fiber density is increased to about 96%, and the web is creped dry with a scraper knife. The scraper blade has an incline of about 25 ° and is positioned relative to the Yankee dryer with an inlet angle of about 81 °. The Yankee dryer is operated at a speed of approximately 244 meters / minute. The dry web is rolled at a speed of 214 meters per minute.

Multilayer silk crepe paper products are made from two sheets of paper web and laminated by a sheet bonding process. Multilayer Silk Crepe Paper has a basis weight of about 23 # / 3M square feet • ·

- 572 / 929.03 cm /, and contains about 0.1% biodegradable chemical plasticizer mixture, about 0.1% dry strength resin and about 0.05% retention aid. It is important that the tissue paper produced is soft, absorbent, resistant to lint, and suitable for use with face wipes and / or toilet paper.

6 ₂ __example

The purpose of this example is to illustrate a process using dry drying and a layered papermaking process to produce a soft, absorbent and lint-resistant multilayer facial tissue made of diester di / barely hardened / tallow alkyl alkyl dimethyl ammonium DID / PEG-400, a permanent wet strength resin and a retention agent (Percol. 175).

The process of the present invention is carried out using a semi-industrial Fourdrinier paper making machine.

First, the chemical softener composition is prepared according to the procedure described in Example 1. The homogeneous solid premix of DEDTHTDMAC and polyhydroxy compound was thawed at about 66 ° C. The thawed mixture is then dispersed in a conditioned water tank (pH ^ v3, temperature 66 ° C) to form a submicron vesicle dispersion. The vesicle dispersion · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·

The particle size of 58 is determined using optical microscopy. The particle size ranges from about 0.1 to about 1.0 microns.

Second, a 3% by weight aqueous NSK slurry is prepared in a conventional re-pulverizer. The NSK slurry was slightly refined and a 2% solution of permanent wet wet strength resin (e.g., Kymene ^w 557H, manufactured by Hercules Incorporated of Wilmington, DE) was introduced into the NSK conduit at a ratio of about 1% by weight of dry fiber. The absorption of the permanent wet strength resin onto NSK fibers is promoted by a paper machine mixer. The NSK slurry was diluted with a propeller pump to a density of about 0.2%.

Thirdly, a conventional eucalyptus fiber suspension is prepared in a conventional pulp paste by weight of 3%. A 1% solution of the biodegradable chemical softener composition is added to the eucalyptus conduit prior to the papermaking mixer at a dry weight of 0.2%; and adding to the eucalyptus layers a 0.5% solution of Percol ⁰ 175 prior to the propeller pump, to the dry fibers

0.05% by weight. The eucalyptus suspension is diluted with a propeller pump to a density of about 0.2%.

The pulp mixture treated in the above manner / 50% NSK / 50% eucalyptus / overhead is mixed and layered on a Fourdrinier sieve to form an initial paper web. Dewatering is done through a Fourdrinier sieve and is assisted by a baffle and suction cups. THE • ·

- 59 Fourdrinier screens with 5 shed fine satin fabric configurations, 84 machine direction and 76 transverse monofilament yarns per inch / 2.54 cm /. The initial wet paper strip from the Fourdrinier sieve is transferred to a photopolymer sieve containing 711 linear Idaho cells per square inch, 40% sieve area, and a photopolymer depth of 9 ml, at a transfer density of approximately 15%. Further dewatering is performed by vacuum assisted water extraction until the fiber density of the paper web reaches 28%. The sample web is pre-dried by air blowing to a fiber density of about 65% by weight. The web is then glued to the drying surface of a Yankee with a sprayed creping adhesive consisting of 0.25% aqueous polyvinyl alcohol solution. The fiber density is increased to about 96%, and the web is creped dry with a scraper knife. The scraper blade has an incline of about 25 ° and is positioned relative to the Yankee dryer with an inlet angle of about 81 °. The Yankee dryer is operated at approximately 244 meters / minute. The dry web is rolled at a speed of 214 meters per minute.

The web is made of two multi-layer face wipes. Multilayer Silk Crepe Paper has a basis weight of about 214 / 3M square feet (929.03 cm), about 1% permanent wet strength resin, about 0.2% biodegradable chemical softener blend and about 0.05% retention • · ··· · · · · · · · · · · · · · · · · · · · · · · ·

- Contains 60 assisting resins. It is important that the multi-layered silk crepe paper produced is soft, absorbent, has good resistance to abrasion and corresponds to facial tissue.

Claims (10)

Claims A multilayer web of silk crepe paper, characterized in that it comprises at least two superimposed layers, a first layer and at least one second layer contacting the first layer; the multilayer paper web comprises: a / papermaking fibers; b / 0.01 to 3.0% by weight of a biodegradable quaternary ammonium compound, preferably a compound of the formula (1), (11) or (111) wherein each R 2 is C 1-6 alkyl or hydroxyalkyl, benzyl or mixtures thereof, preferably methyl; each R 1 substituent is a C 12 -C 22 hydrocarbon group or a substituted hydrocarbon group, or mixtures thereof, preferably a C 16 -C 13 alkyl or alkenyl group; each R 1 substituent is C 11 -C 21 hydrocarbon or substituted hydrocarbyl or mixtures thereof, preferably C 15 -C 17 alkyl or alkenyl; Y is -O-C / O / -, -C / O / -O-, -NH-C / O - or -C / O / -NH- or mixtures thereof; n = 1-4; and a suitable anion, preferably chloride or methyl sulfate; c / 0.01-3.0% water soluble polyhydroxy compound; preferably, the polyhydroxy compound is glycerol, sorbitol, polyglycerols having a weight average molecular weight of 150-800 or polyoxyethylene glycols or polyoxypropylene glycols having a weight average molecular weight of 200-800; 4000, preferably 200-1000, most preferably 200-600 or mixtures thereof; and d / 0.01% to 3.0% of a binder, which is preferably a permanent wet strength resin, preferably a polyamide-epichlorohydrin or polyacrylamide permanent wet strength resin, or mixtures thereof; a periodic wet strength resin, preferably a starch based periodic wet strength resin; dry strength resin; a retention aid; or mixtures thereof. The multilayer web of silk crepe paper according to claim 1, comprising three superposed layers, an inner layer and two outer layers, the inner layer being located between the two outer layers; preferably, the multilayer paper web consists of a single sheet layer comprising each of the biodegradable quaternary ammonium compound, the water soluble polyhydroxy compound, and the binder in one or more layers of the multilayer paper web. The multilayer web of silk crepe paper according to claim 2, wherein most of the biodegradable quaternary ammonium compound and the polyhydroxy compound are present in at least one outer layer, preferably both outer layers. • · · « The multilayer web of silk crepe paper according to claim 2 or 3, wherein most of the binder is contained in the inner layer. 5. The multilayer silk crepe paper web as claimed in any one of claims 1 to 4, wherein the inner layer comprises relatively long papermaking fibers, preferably softwood fibers, most preferably northern softwood fibers, and the average length of these long papermaking fibers is at least 2.0 mm; and both outer layers comprise relatively short papermaking fibers, preferably hardwood fibers, most preferably eucalyptus fibers, and the average length of these short papermaking fibers is between 0.2 and 1.5 mm. The multilayer web of silk crepe paper according to claim 5, wherein the inner layer comprises a mixture of soft fibers and cheap fibers and at least one of the outer layers comprises cheap fibers or mixtures of hardwood fibers and cheap fibers, wherein the cheap fibers are sulfite, thermomechanical cellulose thermomechanical cellulosic fibers, recycled fibers or mixtures thereof. 7. The multilayer silk crepe paper web as claimed in any one of claims 1 to 4, wherein the biodegradable quaternary ammonium compound is diester / di-hardened / tallow alkyl alkyl dimethylammonium chloride or diester 64 - - - - - - - - - - - - - - * ·· t «« ·· ·· * ·· di-barely hardened dimethyl methyl sulfate. 8. The multilayer silk crepe paper belt according to any one of claims 1 to 3, wherein the weight ratio of the quaternary ammonium compound to the polyhydroxy compound is 1.0: 0.3 to 0.3: 1.0, preferably 1.0: 0.7 to 0.7: 1.0 . A multi-ply tissue paper product comprising at least two stacked multi-ply tissue paper webs according to claim 1, the multi-ply tissue product preferably comprising two sheets, and each sheet preferably comprising two superposed layers; and the binder in the product is a permanent wet strength resin or a temporary wet strength resin; and most of the biodegradable quaternary ammonium compound and the polyhydroxy compound are contained in at least one outer layer and most of the binder is contained in the inner layer. 10. A multilayer tissue paper web as claimed in any one of claims 1 to 4, which is toilet paper or facial tissue.