GB2097830A - Article and method for conditioning fabrics - Google Patents

Abstract

An article for fabric conditioning in a tumble drier is a sheet (10) of which one or both surfaces (12) are only partially occupied by fabric- conditioning agent (14), preferably applied by printing. The agent displays a visual contrast with the surface of the sheet. The partial occupation of the surfaces allows the article to pass air readily through it if as is preferred the material of the sheet is porous. <IMAGE>

Description

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GB 2 097 830 A 1

SPECIFICATION

Article and method for conditioning fabrics

The employment of fabric-conditioning articles to impart softening, antistatic, lubricating, bacteriostatic, mildew-proofing or other desirable fabric-conditioning effects has been described in the 5 art For example, U.S. Patent No. 3,442,692 to Gaiser (May 6, 1969) describes the conditioning of 5

fabrics in a laundry dryer by cotumbling the fabrics with a flexible substrate carrying a conditioning agent. The conditioning agent is removed to the tumbling fabrics to provide a fabric conditioning which otherwise might only inconveniently be effected by treatment — for example, during the rinsing cycle of a laundering operation. Similarly, U.S. Patent No. 3,686,025, issued August 22, 1972 to Morton 10 ar|d U.S. Patent No. 3,956,556 issued May 11,1968 and U.S. Patent No. 4,007,300 issued February 10 8, 1977 to McQueary, describe an article for conditioning fabrics in a laundry dryer. The articles comprise an absorptive substrate impregnated with a fabric-softening agent for the provision of fabric softening effects with minimal staining tendencies.

U.S. Patent No. 3,956,556, issued May 11,1976, and the divisional thereof, U.S. Patent No. 15 4,007,300, issued February 8, 1977, both to McQueary, addressed themselves to a further problem in 15 this particular art — namely, the tendency of an absorbed fabric conditioner substrate to adhere to the air outlet of the dryer which, if not rapidly unblocked, caused excessive heat build-up and possible burn-out of certain portions of the dryer. McQueary addresses this problem by providing a plurality of perforations in the substrate so as to permit at least 70% of the normal air flow through the dryer when 20 the coated substrate is used therein. A similar approach to the same end is set forth in another 20

McQueary patent, U.S. Patent No. 3,944,694, wherein the flexible substrate is provided with a plurality of slits in order to achieve the desired volume of air flow.

It should be noted that in the known prior art, which includes not only the above referenced patents but also those cited therein, the substrate which is preferably, but not solely, a non-woven 25 material is coated by a process of dipping the substrate in a solution or dispersion of the conditioning 25 agent. Indeed, McQueary, as in U.S. Patent No. 3,956,556, column 6, line 45 etseq, teaches that the manner of impregnating the substrate is not considered to be an important part of her invention.

The conditioning articles of the prior art, including in particular those made in accordance with the preferred or exemplified embodiments of the above identified patent, while operative, have two 30 disadvantages which it would be desirable to avoid. 30

The coating technique employed covers the entire substrate and, therefore, utilizes a great deal of fabric conditioning agent, which agent constitutes a substantial portion of the material cost of the article. It would, therefore, be desirable to provide an operative article utilizing a lesser amount of the conditioning agent.

35 The articles of the prior art have a tendency to crumple. Indeed, this quality is stated at 35

McQueary, U.S. Patent No. 3,956,556, column 7, lines 34 through 47, as being a desirable quality.

While the reasons for the desirability of crumpling are understood, they carry with them the concomitant disadvantage that an article which has the tendency to crumple equally has a tendency to fold, as is admitted in McQueary, and, thus, in the folded condition does not offer the same amount of 40 surface exposure to the clothing which it is intended to contact as would a softer and more flexible 40 material which did not possess the crumpling properties.

It would, therefore, be desirable to provide an article which has, in addition to the desirable qualities of the articles of prior art, the additional advantages of lower conditioning agent requirement together with a non-crumple quality, while at the same time, permitting the clearly desired volume of 45 air to continue to pass through the dryer even under those conditions where the conditioning article is 45 held up against the air exit vent of a dryer.

It should be noted that McQueary, U.S. Patent No. 3,956,556, at column 7, lines 66 through 68, mentions that the device disclosed and claimed in said patent possesses perforations which need not necessarily be cut into the substrate, but which could, it is alleged, be the result of the porosity or air 50 permeability of the particular substrate material employed in its manufacture. It should be noted, 50

however, that the method of manufacture of the article disclosed therein is such as to effectively negate the air permeability of the substrate unless a perforation of substantial size, say 1/8" or more, was inserted into the substrate prior to coating.

The present invention, in its article aspects, is directed to a fabric conditioning article comprising 55 a substrate having a fabric conditioning agent applied to at least one surface thereof in a discontinuous 55 or substantially discontinuous manner. The term "discontinuous" as used herein means that certain portions of the substrate are coated with the conditioning agent and certain portions are not. Thus, if a line is drawn at random across the article in any manner other than along the axis of a straight line strip of conditioning material as applied to the substrate, said line will cross both coated and uncoated 60 portions of the article. 60

There is thus provided an article comprising a substrate partially coated with conditioning agents. The substrate chosen is a material which, due to its normal structure, permits a substantial flow of air therethrough. Non-woven fabrics well known in the art are especially suitable for this purpose. The conditioning agent is applied to the substrate suitably by printing in a predetermined pattern, the sole

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GB 2 097 830 A 2

criterion of the pattern being that it shall leave enough unoccupied area on the substrate to provide the necessary degree of airflow therethrough in operation in a conventional laundry dryer.

In its method aspect, the invention provides, in the conditioning of fabrics, the addition of softening agents thereto in the step of co-mingling the fabrics to be conditioned with a substrate 5 carrying the conditioning agent removable to the fabrics and having sufficient inherent interstices 5

therein to provide for a satisfactory volume of air flowing therethrough.

The fabric-conditioning article comprises a flexible web, such as paper or cloth, carrying a conditioning agent, such as a fabric softening agent, and is normally made up into a tubular roll or individual sheets. A desired length of the treated web is torn off the roll or a sheet removed from its 1 o package and placed into the clothes dryer wherein the fabrics to be treated have been loaded. The 10

dryer is then operated in customary fashion, and fabric conditioning occurs as the fabrics directly contact the treated web, whereby the conditioning agent is transferred from the web substrate to the fabric. Particularly when small fabric loads are tumbled and the probability of a tumbling fabric-conditioning article of making repeated, or prolonged, contact with a laundry dryer exhaust outlet is 15 enhanced the openings, in the treated web advantageously minimize the interruption of air flow 15

through the dryer. This is effected by passage of air through the natural interstices in the web on those portions of the web not coated with the conditioning agent.

In the accompanying drawings:—

Figure 1 is a side elevational view of an article of the present invention (not to scale: verticle scale 20 substantially expanded). 20

Figure 2 is a plan view of the article of Figure 1 viewed from 2—2.

Figure 3 is a plan view of a preferred embodiment of the invention.

Figure 4 is a plan view of an embodiment of the invention.

Figure 5 is a plan view of yet another embodiment of the invention showing fabric conditioner 25 printed on both sides. 25

Figure 6 is a side elevational view of the embodiment of Figure 5 viewed from 6—6 (not to scale: substantially expanded vertically).

Figure 7 is a side elevational view similar to Figure 6 showing two sheets of Figure 1 sealed to each other at either end.

30 The drawings show samples of possible embodiments of the invention. Three and four digit 30

numbers ending in a particular two digits signify the same type of member as the members carrying said two digits.

Figures 1 and 2 show a stripped embodiment in which an article 10 has strips of conditioner 14 printed on one side only of a substrate 12. In the illustrated embodiments substrate 12 is an "open 35 weave" non-woven fabric through which air may readily pass at those portions not carrying conditioner 35 14.

Figure 3 shows a substrate 112 carrying a plurality of dots 114.

Figure 4 shows a substrate 312 carrying a checker pattern 314.

Figures 5 and 6 show a substrate 212 carrying wavy pattern 214 on one side and wavy pattern 40 2214 on the other. 40

Figure 7 shows two sheets 112 with strips 14 on one surface sealed together with heat seals 16 at either end. An embodiment similar to this one, but using the dotted embodiment of Figure 3, is utilized in one of the comparative test procedures set forth in the Examples.

The fabric conditioning articles of the invention comprise a flexible web substrate carrying a 45 conditioning agent. Suitable substrate materials for carrying the conditioning agent include a variety of 45 natural or synthetic materials. Suitable substrates are those which have the ability to retain a fabric-conditioning agent in a form which is releasable to fabrics tumbled therewith, and which have a resistance to shredding or other tearing failures when tumbled with damp clothes in a dryer. Examples of suitable substrates include paper towelling, swatches of woven and non-woven cloth, papers, 50 sponges, plastics and felts. Fibrous materials can be natural or synthetic but are preferably cellulose. 50 Foam plastic web materials, such as the polyurethanes, can also be employed.

In one embodiment of the invention, a substrate which is relatively impermeable to the fabric-conditioning agent is employed so as to dispose the fabric-conditioning agent onto the substrate as a discrete surface coating. Wet strength papers, regenerated cellulose, rayon, nylon, polyester, 55 polyacrylonitrile, polyolefin and other synthetic woven or non-woven fibrous materials are suitable for 55 this purpose. Wet strength paper is suitably employed and can be treated with a waterproofing or sizing material such as a thermosetting resin, starch or other impregnant, having the effect of reducing water absorption by fibrous cellulosic products, and allowing the formation of a coating of conditioning agent. Waxy papers which carry coatings or impregnations of paraffin or microcrystalline or synthetic 60 wax can be used — for example, "butcher paper" or dry waxed paper — to the extent of reducing 60

moisture absorption but permitting adherent coating of the paper with conditioning agent. Wet strength papers, such as Kraft or bond paper, can be employed.

Preferred articles of the invention include those formed from a substrate having an absorption capacity in relation, for example, to fabric softening agents as to provide an impregnated article 65 capable of controllably releasing the softening agent to treated fabrics. Improved softeness or feel of 65

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GB 2 097 830 A 3

the treated fabrics is provided without overdosing or localized concentration of softener in the form of spots or stains. Suitable absorbent substrate materials are described in considerable detail in U.S.

Patent No. 3,686,025, issued August 22, 1972, to Morton.

While Morton teaches that an absorbant capacity of 5.5 through 12, as defined therein, is 5 desirable for practicing the invention disclosed by him, it has been our finding that, in the present 5

invention, substrates having absorbencies substantially lower than 5.5 are entirely satisfactory and,

indeed, constitute the preferred embodiment of the present invention.

While not limiting the invention thereto, the reason for this finding is that, while in the prior art it would appear that the conditioning agent is absorbed into the fiber of the substrate and held therein 10 and in the interstices between the fibers, in the articles of the present invention the conditioning agent 10 is, in effect, placed upon the substrate; so that the use of a finer denier fiber provides sufficient absorbency in the interstices only in that a very minimal amount of absorbency is adequate for the purposes of the present invention.

Preferred absorbent substrates are cellulosic materials such as multi-ply paper towel and non-15 woven cloth substrates. Preferred paper towel materials and their method of manufacture can be found 15 in U.S. Patent No. 3,414,459, issued December 3, 1968, to Wells, and incorporated herein by reference. Preferred non-woven cloth substrates can be generally defined as adhesively-bonded fibrous or filamentous products having a web structure, in which the fibers or filaments are distributed haphazardly, as in the "wet lay" processes, or with a degree of orientation, as in the "carding" process. 20 Such substrates exhibit desirable strength in all directions and are resistant to shredding or tearing 20 failures when tumbled with damp fabrics. The fibers or filaments of such non-woven cloth substrates can be natural (for example, wool, silk, jute, hemp, cotton, linen, sisal or ramie) or synthetic (for example, rayon, cellulose ester, polyvinyl derivatives, polyolefins, polyamides or polyesters) and bonded together with a polymetric binder resin such as polyvinyl acetate. While the invention is in no way 25 limited thereto, it has been found that the most satisfactory results are obtained using polyester fibers. 25 These fibers have the advantage, in the context of the present invention, of being softer, not as absorbent, and have the ability to be produced in a whiter — i.e., more hygenic appearing — form than those materials which are disclosed by the prior art and are presently to be found in the channels of commerce.

30 The factor of softness is advantageous as it tends to counter the crumpling and folding effects 30

which were present, and indeed believed to be desirable, in the articles of the prior art. The softer touch, as well as the whiter appearance of the polyester fiber, are considered to be specific advantages in a product closely related, in the mind of the consumer, with hygenic matters. The preferred, though not critical, range of absorbency of the materials used herein is between 100% and 500%. This lower 35 absorbency has the advantage of permitting the easier removal of the conditioning agent to the fabric 35 which it contacts in the dryer. This ratio of removability contributes to the efficiency of the present method since, inherently then, less material is required. Such substrates will normally have a void volume of from about 20% to about 80% to provide desirable airflow properties.

The conditioning agents employed herein include any of a variety of agents employed generally in 40 textile treating operations. Accordingly, fabric softening, antistatic, anti-mildew, germicidal, 40

mothproofing and anti-wrinkling agents, perfumes and the like can be employed. The most universal preference, however, is for agents which act to soften fabrics or otherwise improve their feel or "hand" Softening agents which also have antistatic properties and which reduce static charge or fabric cling are especially preferred.

45 Typically, the fabric softening agents that can be employed are compounds having a relatively- 45

long hydrocarbon group serving to provide hydrophobicity or lubricity. Among such groups are alkyl groups containing 8 or more carbon atoms and preferably from 12 to 22 carbon atoms. Suitable fabric softening agents include cationic, anionic, nonionic, or zwitterionic compounds. Cationic fabric-softening agents include the cationic nitrogen-containing compounds such as quaternary ammonium 50 compounds and amine which have one or two straight-chain organic groups of at least 8 carbon 50

atoms. Preferably, they have one or two such groups of from 12 to 22 carbon atoms. Preferred cation-active softener compounds include the quaternary ammonium softener compounds corresponding to the formula

R\ \

X

#1 "3_

55 wherein R is hydrogen or an aliphatic group of from 12 to 22 carbon atoms; R, is an aliphatic group 55 having from 12 to 22 carbon atoms; R2 and R3 are each alkyl groups of from 1 to 3 carbon atoms; and X is an anion selected from halogen, acetate phosphate, nitrite and methyl sulfate radicals.

Because of their excellent softening efficacy and ready availability, preferred cationic softener compounds of the invention are the dialkyl dimethyl ammonium chlorides, wherein the alkyl groups 60 have from 12 to 22 carbon atoms and are derived from long-chain fatty acids such as hydrogenated 60

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GB 2 097 830 A 4

10

15

20

tallow. As employed herein, alkyl is intended as including unsaturated compounds such as are present in alkyl groups derived from naturally occurring fatty oils. The term "tallow" refers to fatty alkyl groups derived from tallow fatty acids. Such fatty acids give rise to quaternary softener compounds wherein R and Rn have predominantly from 16 to 18 carbon atoms. The term "coconut" refers to fatty acid groups from coconut oil fatty acids. The coconut-alkyl R and R, groups have from about 8 to about 18 carbon atoms and predominate in C12 to C14 alkyl groups. Representative examples of quaternary softeners of the invention include tallow trimethyl ammonium chloride; ditallow dimethyl ammonium chloride; ditallow dimethyl ammonium methyl sulfate; dihexadecyl dimethyl ammonium chloride; di(hydrogenated tallow)dimethyl ammonium chloride; dioctadecyl dimethyl ammonium chloride; dieicosyl dimethyl ammonium chloride; didocosyl dimethyl ammonium chloride; di(hydrogenated tallow)dimethyl ammonium methyl sulfate; dihexadecyl diethyl ammonium chloride; dihexadecyl diethyl ammonium chloride; dihexadecyl dimethyl ammonium acetate; ditallow dipropyl ammonium phosphate; ditallow dimethyl ammonium nitrite; di(coconut-alkyl)dimethyl ammonium chloride.

Suitable cation-active amine softener compounds are the primary, secondary and tertiary amine compounds having at least one straight-chain organic group of from 12 to 22 carbon atoms and 1,3-propylene diamine compounds having a straight-chain organic group of from 12 to 22 carbon atoms. Examples of such softener actives include primary tallow amine; primary hydrogenated-tallow amine; tallow 1,3-propylene diamine; oleyl 1,3-propylene diamine; coconut 1,3-propylene diamine; soya 1,3-propylene diamine; and the like.

Other suitable cation-active softener compounds herein are the quaternary imidazolinium salts. Preferred salts are those conforming to the formula

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H H

I I

H-C—C-H

0

10

15

20

N N—C2 fy—N —C—R7

V\ 1

| r6 R5

r8

wherein R6 is an alkyl containing from 1 to 4, preferably from 1 to 2, carbon atoms; R7 is an alkyl containing from 1 to 4 carbon atoms or a hydrogen radical; R8 is an alkyl containing from 8 to 22, preferably at least 15, carbon atoms; R5 is hydrogen or an alkyl containing from 9 to 22, preferably at least 15, carbon atoms; and X is an anion, preferably methyl sulfate or chloride ions. Other suitable anions include those disclosed with reference to the cationic quaternaryammonium fabric softeners described hereinbefore. Particularly preferred are those imidazolinium compounds in which both R5 and R8 are alkyls of from 12 to 22 carbon atoms — for example, 2-heptadecyl-1,1-methyl[(2-stearoylamide)ethyl]imidazolinium methyl sulfate.

Other cationic quaternary ammonium fabric softeners which are useful herein include, for example, alkyl(C12 to C22)-pyridinium chlorides, alkyl(C12 to C22) (C, to C3)-morpholinium chlorides, and quaternary derivatives of amino acids and amino esters.

The anionic conditioning agents can include any of the various surface-active anionic fabric-softening and anti-static agents such as alkali metal or ammonium salts of higher fatty alcohol sulfates, higher fatty alcohol ether sulfates, higher fatty alcohol sulfonates, the linear higher alkyl benzene sulfonates, the higher fatty acyl taurides and isothionates. Generally, the cation of such compounds will be an alkali metal or other water-solubilizing radical. The hydrophobic moiety of such compounds will normally contain from 10 to 22 carbon atoms. Alkali metal and ammonium soaps of fatty acids of from 10 to 22 carbon atoms can also be employed and include the sodium or potassium coconut or tallow soaps.

Suitable nonionic fabric softeners and anti-static agents that can be employed are the polyoxyalkylene glycols and the higher fatty alcohol esters of polyoxyalkylene glycols.

Also suitable are the ethoxyiates of long-chain alcohols of from 8 to 22 carbon atoms such as the ethoxylates of tallow alcohol with, for example, 10 to 40 moles of ethylene oxide. Other nonionics include the amides such as the alkanolamides — for example, the higher fatty amides and higher fatty acid mono- and di-lower alkanolamides, wherein the long-chain hydrophobic groups have from about 10 to 22 carbon atoms.

Other suitable softening agents include the zwitterionic compounds of the formula

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50

Rs—N+—CH,—Rn—CH2SO^

50

5

GB 2 097 830 A 5

wherein Rg and R10 are each methyl, ethyl, n-propyl, isopropyl, 2-hydroxyethyl or 2-hydroxypropyl; Rs is a 12 to 22 carbon atom alkyl or alkenyl and wherein said alkyl or alkenyl contains from 0 to 2 hydroxyl substituents, from 0 to 5 ether linkages, and from 0 to 1 amide linkage; and R,, is an alkylene group containing from 1 to 4 carbon atoms with from 0 to 1 hydroxyl substituents; particularly preferred are 5 compounds wherein Ra is a carbon chain containing from 14 to 18 carbon atoms selected from the 5 group consisting of alkyls and alkenyl and wherein said alkyls and alkenyls contain 0 to 2 hydroxyl substituents. Specific examples of the particularly preferred compounds of this class include the following: 3-(N-hexadecyl-N,N-dimethylammonio)-2-hydroxypropane-1-sulfonate; and 3-(N-octadecyl-N,N-dimethylammonio)-propane-1-sulfonate.

10 Other examples of conditioning agents suitable for the articles herein are described in detail in 10

U.S. Patent No. 3,686,025 at column 5, line 51, to column 14, line 6, which disclosure is incorporated herein by reference.

The amount of conditioning agent carried by the substrate is an amount sufficient to provide the desired conditioning effect without substantial excess. The amount will vary in any given case and will 15 depend, for example, upon the nature of the particular conditioning agent or substrate material and the 15 type of conditioning effect desired. When the conditioning agent is a fabric softening agent, such agent will preferably be employed in a weight ratio of agent to untreated substrate from 0.5:1 to 4:1 or more. Generally, the amount of softener will range from about 40 mg to about 1.2 grams per centimeter length of a substrate no more than 28 cm wide, with small amounts of softener being used on 20 lightweight substrates, such as non-woven cloths, and large amounts on heavy substrates, such as 20 multi-ply paper.

The manner of applying the fabric conditioning agent to the substrate in such a manner as to provide a discontinuous pattern in at least one direction, is not critical. It has been found most convenient, however, to apply the conditioning agent by a printing process which will permit a ready 25 repetition of the predetermined discontinuous pattern, as well as a means for applying the conditioning 25 agent on one, or both, principal surfaces of the substrate in a predetermined amount.

The sole criterion of the pattern of fabric conditioner applied is that it shall leave an adequate amount of free space upon the substrate, preferably upon a non-woven substrate, to allow a sufficient amount of air to pass through the substrate that the air outlet of a typical domestic dryer should not be 30 blocked thereby. While the preferred embodiments of the present application contemplate the use of 30 non-woven fabrics which, because of the nature of their construction, possess a substantial number of interstices between the fibers thereof through which air may pass, the scope of the invention does not exclude the use of woven fabrics, or other flexible substrates in which perforations have been placed in the manner of McQueary, U.S. Patent No. 3,956,556. Provided that the important criterion of air 35 permeability is maintained, the pattern carrying the fabric conditioner is purely a matter of economic 35 and aesthetic convenience. As specifically exemplified herein, a pattern of dots has been employed.

There may also be employed patterns including strips running with the length of the substrate, strips running diagonally across the width of the substrate, and strips running straight across the width of the substrate. The strips may be straight, they may be curved, they may be sinusoidal, or they may be 40 totally random. There may be included checkerboard patterns, aesthetic, repeating designs, printed text 40 having meaning and not having meaning, and so forth. It is also contemplated within the scope of the invention to utilize a fabric conditioner having a different color from the substrate. Because of the need to be able to employ the articles of the present invention with colored and non-colored fabrics, it would be preferred to utilize a non-colored or white conditioner upon a substrate of a different shade or color. 45 This latter type of patterning goes solely to the appearance of the goods rather than their basic 45 function which is to transfer fabric conditioner to fabrics without the disadvantages possessed by certain prior art fabric conditioning articles.

In order to comply with the principal criterion of the pattern set forth above, however, the pattern selected should be one which does not involve large areas of fabric conditioner located in one portion 50 of the article since such large areas of conditioner tend to block air flow and tend to permit adhesion of 50 the article to the airflow outlet. The more open the applied pattern of fabric conditioner, the better.

The fabric conditioning articles of the present invention are structured to be compatible with conventional laundry dryer designs. While it is preferred to employ the articles of the present invention in an automatic laundry dryer, other equivalent machines can be employed and, in some instances,

55 heat and drying air may be omitted for part or all of the cycle. Generally, however, heated air will be 55 employed and such air will be circulated frequently in the dryer. Normally, there are from about five to fifty volume changes of drying gas in the dryer drum per minute and the air moves at about 125 to 175 cubic feet per minute. These changing volumes of air create a drawing or suction effect which can,

especially in small loads, cause a fabric, such as a sock, handkerchief or the like, or a fabric-60 conditioning article, to be disposed on the surface of the air outlet of the dryer. A usual load of fabrics 60 of from about four to twelve pounds dry weight will fill from about 10% to 70% of the volume of most dryers and will normally pose little difficulty. A sufficient number of tumbling items will normally be present to prevent any item from being drawn to the exhaust outlet or to cause it to be removed from the outlet.

65 Preferably, a fabric conditioning article of the invention will contain a sufficient number of 65

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GB 2 097 830 A 6

perforations as to permit the passage of at least about 75% of the normal volume of airflow of the laundry dryer. This permits fabrics to be dried efficiently without undesirable temperature build-up or alternate on/off cycling of the heater and resulting rise and fall of dryer temperature. Normal operating temperatures are adhered to and extended drying times are thereby avoided. Preferably, an article will have a sufficient number of perforations as to allow at least 85% of the volume of air to pass through 5 the dryer.

The fabric.conditioning articles of the invention are simple to employ and normally will be employed in a laundry dryer which is operated at a temperature, for example, of from 75°F to 210°F and for a drying period of from about five to sixty minutes. A load of fabrics to be dried is placed into the dryer and a sheet, such as may be detached by tearing from a perforated roll, is simply added to the 10 dryer which is operated in usual fashion. The treated fabrics are then removed and handled in customary fashion.

The following Examples illustrate certain preferred embodiments of the invention and are not intended as limiting the invention. The quaternary ammonium fabric softening agent of Examples I—III was di tallow dimethyl ammonium chloride. Other of the various fabric conditioning agents described ^ 5 hereinbefore in detail can be employed to advantage.

Example I

There is utilized as a substrate a non-woven fabric cut to a desired size (7.6x22.8 centimeters). The substrate consists of 100% airlaid polyester fiber bonded with a hydrophobic binder, has a thickness of 280 microns, weighs 24 grams per square meter, and has an absorbency of 4 (400%).

The fabric conditioning formulation consists of 100% Arquad 2HT-75 (a di tallow dimethyl ammonium chloride manufactured by Armak Co., Chicago, Illinois). (Arquad is a Registered Trade Mark of the manufacturer).

A nickel sheet, 127 microns in thickness, perforated with dot shaped perforations at a rate of 26 perforations per square centimeter, each perforation having a diameter of 0.7 millimeters diameter, is placed on top of the substrate sheet. The softening formulation is warmed to a temperature of approximately 40°C, and squeegeed through the perforated sheet onto the substrate. The foregoing procedure provides substrate application at the rate of 30 grams per square meter.

Example II

The procedure of Example I was repeated utilizing, however, in place of the substrate of Example 30 I, a 100% rayon fiber non-woven substrate bonded with an acrylic binder (Sterns & Foster, Style F-3387, a material similar to that utilized in commercially available fabric softeners produced under the trademark Bounce, a product of Proctor & Gamble). The substrate has a thickness of 254 microns,

weighs 24 grams per square meter, and has an absorbency of 6.5 (650%).

Example III

Comparison of Example I and II products

Four samples produced in accordance with each of the foregoing Examples were, at separate times, placed in a commercially available home-size clothes dryer (Frigidaire Model LCT-120,

manufactured by General Motors, "Frigidaire" is a Registered Trade Mark) together with six spin dried but damp terrycloth towels, and dried in the dryer for 120 minutes. Examination of the samples after use showed that the substrates of Example I (absorbency 4.0) released over 60% of the fabric conditioning agent and those of Example II (absorbency 6.5) released less than 40% of the fabric conditioning agent.

Example IV

Pairs of sheets, produced in accordance with Example I, are heat sealed together at two opposite 45 ends yielding a two-layer sample containing 38 grams of fabric conditioning agent per square metre.

Example V

Samples were prepared in accordance with the procedure of Example I but, in place of utilizing a sheet having 26 dots per square centimeter of 0.7 millimeter diameter, there is utilized a masking sheet having 15 dots per square centimeter of 1.4 millimeters in diameter. The resulting sheets carry 50 38 grams of fabric conditioning agent per square meter. The resultant sheets are then joined together in accordance with the procedure of Example IV.

Example VI

Comparison of Example IV and V products

The samples compared in accordance with Examples IV and V were tested in accordance with the 55 test procedures utilized for the products of Examples I and II and showed that the product of Example IV released 20% more fabric conditioning agent than the product of Example V.

Example VII

Samples were prepared in accordance with Example IV, except that the fabric conditioning

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GB 2 097 830 A 7

formulation utilized consisted of Arquad 2HT-75 and EthomeenT/12 (4:1). Ethomeen T/12 is a Bis-2-hydroxyethyl tallow amine manufactured by Armak Co., Chicago, Illinois. (Ethomeen is the Registered Trade Mark of the manufacturer). The sheets utilized were 7.6x24.76 centimeters, and the weight of fabric softening agent is 57 grams per square meter.

5 Example VIII 5

Comparison of Example VII product with a commercial sheet

A sample of Example VII is evaluated in the home dryers previously described. The dryer load consisted of two cotton terrycloth dishcloths, four cotton terrycloth dish towels, four blue polyester pillow cases, and four velour terrycloth bath towels, all spin dried but damp. The quantitative and 10 qualitative results are set forth below. 1 q

Example #VII Commercial sheet

Density 57 gm/sq. m. 32.45 gm/sq. m.

applied weight 1.073 gram 2.072 gram amount transferred 0.651 1.184

15 % transferred 60.7% 57.2% 15

A panel often women judged the fabrics treated with Example VII product to be superior in perceived softness to similar goods treated using the commercial material even though the actual amount of fabric conditioning agent transferred to the fabric by the commercial softener is almost twice the amount transferred by the Example VII product.

20 Example IX 20

Samples were prepared in accordance with Example I with the following variants. The samples were 28x22.8 centimeters in size (full commercial size). The fabric conditioning agent utilized was Arquad 2HT-75 and Carbowax (9:1) (Carbowax is a polyethylene glycol, molecular weight range 190—210, manufactured by Union Carbide Corporation, New York, New York. Carbowax is a 25 Registered Trade Mark of the manufacturer). The conditioner is applied in various weight per unit area 25 ranges — i.e. 29, 24, and 12 grams per square meter. (Commercial sheet density is 39.5 grams per square meter).

Example X

Comparison of Example IX product with commercial sheet

30 The procedures relating to the evaluation of Example VII material (comparison No. 3) were 30

repeated utilizing samples prepared according to Example VIII with commercial sheets. (Quantitative and Qualitative Tests).

Quantitative tests

35 applied wt. 1.859 1.541 0.761 2.526 35

A

B

C

Commercial sheet applied wt.

1.859

1.541

0.761

2.526

density

29

24

12

39.5

amount agent

1.044

0.970

0.516

0.933

transferred

% transferred

56.2%

63%

67.8%

37%

40 Qualitative tests 40

A panel often women judged the clothes being treated for perceived softness. The women were asked to evaluate the treated clothing by rating each lot from 1 to 5 with 1 being the highest degree of softness and 5 being the least degree of softness. The results are tabulated with the lowest score being rated as the highest degree of softness. For purposes of the panel test a control, Column E, was 45 included. This control was dryed under normal conditions and not treated with softening agents. The 45 panel test appears below.

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GB 2 097 830 A 8

Commercial sheet

A

B

C

D

E

Woman #1

1

5

2

3

4

Woman #2

2

1

3

4

5

Woman #3

3

1

2

4

5

Woman #4

1

2

4

3

5

Woman #5

2

1

4

3

5

Woman #6

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The foregoing tests show that, utilizing commercial size sheets, approximately twice as much softening agent is released by products produced in accordance with the present invention than from products presently commercially available. It is further shown that the least satisfactory product produced in accordance with the present invention compares favorably with the commercial product, but requires a conditioning agent load of approximately 1/3 of the amount utilized in the commercial product.

Example XI (Comparative)

400 grams of a softening formulation consisting of 90 parts Arquad 2HT-75, 10 parts polyethylene glycol 200, and 300 parts water was prepared by placing said materials in a container and immersing the container in a water bath heated at 44°C. A non-woven substrate of the type described in Example I was prepared. The softening agent was applied by immersing the substrate in the softening agent, completely saturating the substrate, and removing the excess with a spatula. The polyester material is dried in an oven for five minutes at 104°C to remove excess moisture. A dried coating weight of approximately 0.8 grams per 175 centimeters squared sheet (i.e., 4.6 mg/cm2) is achieved.

Example XII (Comparative)

Example XI is repeated but a non-woven substrate of the type described in Example II is substituted. A coating weight of 0.75 grams per 175 square centimeters (4.3 mg/cm2) is achieved.

Example XIII (Comparative)

Evaluation of samples from Examples XI and XII

The treated samples were evaluated by testing them under actual drying conditions. Four samples from Example XI were placed in a home dryer. Sears Model Kenmore 77656100, along with six damp terry towels and dried for thirty minutes.

It was found that Example XI using a fabric of 100% polyester fiber with an absorbency of 400%, there was released over 60% of the softening agents.

It was noted that the finished coated polyester material was stiff, waxy and had an objectionable feel and hand.

Using a 100% rayon fiber fabric of Example XII substrate with 650% absorbency, there was released under 45% of the softening agent.

Claims (8)

Claims

1. An article suitable for conditioning fabrics in a laundry dryer, said article comprising a flexible woven or non-woven web in sheet form having disposed thereon a fabric conditioning composition, wherein the fabric conditioning composition is unevenly distributed on the substrate in areas of high concentration of fabric conditioning composition per unit area of substrate and areas of low concentration of fabric conditioning composition per unit area of substrate so as produce visual contrast between said high concentration and low concentration areas, wherein the ratio of weight per unit area of composition in the high concentration areas to the weight per unit area of composition in the low concentration areas is infinity, and wherein the total weight ratio of fabric conditioning composition to substrate is from 0.5:1 to 4:1.

2. The article of Claim 2, wherein the fabric conditioning agent is a methylsulfate salt.

3. The article of Claim 2 or Claim 3, wherein the substrate has a porosity and areas of low concentration sufficient in size and number to reduce restriction by said articles of the flow of air through a laundry dryer.

4. An article suitable for conditioning fabrics in a laundry dryer, said article comprising a flexible

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GB 2 097 830 A 9

woven or non-woven web in sheet form having disposed thereon a fabric conditioning composition wherein the fabric conditioning composition is unevenly distributed on the substrate in areas of high concentration of fabric conditioning composition per unit area of substrate and areas of low concentration of fabric conditioning composition per unit area of substrate so as to produce a visual 5 contrast between said high concentration and low concentration areas, wherein the fabric conditioning composition in the area of high concentration differs in colour from the article in the areas of low concentration, wherein the ratio of the weight per unit area of composition in the high concentration areas to the weight per unit area of composition in the low concentration areas is infinity, and wherein the total weight ratio of fabric conditioning composition to substrate is from 0.5:1 to 4:1.

10 5. The article of Claim 4, wherein the fabric conditioning agent is a methylsulfate salt.

6. The article of Claim 4 or Claim 5, wherein the substrate has a porosity and areas of low concentration sufficient in size and number to reduce restriction by said article of the flow of air through a laundry dryer.

7. The article of any of Claims 1 to 6, wherein the areas of high concentration of fabric

15 conditioning composition occupy from 10% to 25% of the total substrate area while the remaining portion of the total substrate consists of areas of low concentration of fabric conditioning composition.

8. A method of manufacturing dryer-added fabric conditioning articles in sheet form wherein said

50 articles comprise a flexible woven or non-woven web substrate having a fabric conditioning agent disposed unevenly on said substrate so as to produce a visual contrast between areas having fabric conditioning composition and areas without fabric conditioning composition which includes printing the agent onto one or two surfaces of the substrate so as to give a total weight ratio of fabric conditioning composition to substrate of from 0.5:1 to 4:1.

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Printed for Her Majesty's Stationery Office by the Courier Press, Leamington Spa, 1982. Published by the Patent Office, 25 Southampton Buildings, London, WC2A 1 AY, from which copies may be obtained.

8. A method of manufacturing dryer-added fabric conditioning articles in sheet form wherein said articles comprise a flexible woven or non-woven web substrate having a fabric conditioning agent disposed unevenly on said substrate so as to produce a visual contrast between areas of relatively high

20 concentration of fabric conditioning composition and areas of relatively low concentration of fabric conditioning composition which includes printing the agent onto one or two surfaces of the substrate.

New Claims or Amendments to Claims filed on 18th June 1982.

Superseded Claims 1—8.

New or Amended Claims:—

25 1. An article suitable for conditioning fabrics in a laundry dryer, said article comprising a flexible woven or non-woven web in sheet form having disposed thereon a fabric conditioning composition, wherein the fabric conditioning composition is unevenly distributed on the substrate in areas having fabric conditioning composition and areas without fabric conditioning composition so as to produce visual contrast between said areas, wherein the total weight ratio of fabric conditioning composition to

30 substrate is from 0.5:1 to 4:1.

2. The article of claim 1, wherein the fabric conditioning agent is a methylsulfate salt.

3. The article of claim 1 or claim 2, wherein the substrate has a porosity and areas without fabric conditioning composition sufficient in size and number to reduce restriction by said articles of the flow of air through a laundry dryer.

35 4. An article suitable for conditioning fabrics in a laundry dryer, said article comprising a flexible woven or non-woven web in sheet form having disposed thereon a fabric conditioning composition wherein the fabric conditioning composition is unevenly distributed on the substrate in areas having fabric conditioning composition and areas without fabric conditioning composition so as to produce a visual contrast between said areas, wherein the fabric conditioning composition differs in colour from

40 the article in the areas without fabric conditioning composition, and wherein the total weight ratio of fabric conditioning composition to substrate is from 0.5:1 to 4:1.

5. The article of claim 4, wherein the fabric conditioning agent is a methylsulfate salt.

6. The article of claim 4 or claim 5, wherein the substrate has a porosity and areas without fabric conditioning composition sufficient in size and number to reduce restriction by said article of the flow

45 of air through a laundry dryer.

7. The article of any one of claims 1 to 6, wherein the areas having fabric conditioning composition occupy from 10% to 25% of the total substrate area while the remaining portion of the total substrate consists of areas without fabric conditioning composition.