CA1084209A - Fabric conditioning methods and articles - Google Patents

Abstract

FABRIC CONDITIONING METHODS AND ARTICLES

William T. Bedenk Paul J. Sagel ABSTRACT OF THE DISCLOSURE

A method for effectively imparting fabric condi-tioning agents to fabrics during the automatic drying step of the home laundering operation via friable microcapsules containing such agents. Fabric conditioning articles suitable fox carrying out this method are also provided.

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Description

BACRGROUND OF T}IE INVENTION ¦~ -~he present invention relat~s to the treatment of fabrics with conditioning agents (primarily perfume) ¦ -during the automatic drying stage of the home la~ndering operation. The invention herein utilizes friable microcap~es to carr~ the fabric conditioning agent to the fabric~ being treated. Capsules containing the conditioning agent are applied and to some extent attached to fabrics in the automatic dryer and are thereafter ruptured by manipulation of the fabrics to thereby release the cond-tioning agent.
The home laundering operation can provide an opportunity to treat fabrics being laundered wit~ a variety of materials which impart some desirable benefit .
or quality to the fabrics durin~ laundering. At each s,age of the laundering operation (presoaking, washing, .
rinsing, drying) fabrics are generally, to varying degrees, found in contact with water which can pr,ovide the medium for delivery of fabric conditioning agents.

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during the laundering operation is not, however, accomplished without certain difficulties. Surfactants are generally employed during the presoakin~ and washing steps fo~ the purpose of removing materials (soil) from the fabrics.
Simultaneous deposition onto fabrics of fabric condition-ing agents can, therefore, prove troublesome. While some of these problems can be overcome by conditioning fabrics in the automatic dryer (See, for example, Gaiser; U.S.
Patent 3,442,692; issued May 6, 1969), it is nevertheless exceptionally difficult to achieve efficient deposition in the dryer of those abric conditioning agents such as perfume which are volatile and therefore susceptible to rapid evaporation in the dryer heat.
Attempts have been made to improve the efficiency of conditioning agent fabric deposition during the laundering process. For example, the copending Canadian patent application of Haug et al, Serial No. 245,22S filed February 6, 1975 involves the use of particulate sorbitan ; 20 ester material as a fabric conditioning agent for use in home laundering. The copending Canadian patent application of Webb et al, Serial No. 237,530 filed October 14, 1975 involves the use of particulate starch material to deliver perfume to fabrics in the automatic dryer. In spite of these developments, there is a continuing need for methods and articles which are suitable for efficiently and effectively delivering conditioning agents to fabrics during the home laundering operation.
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Accordinyly, it is an object of the present inven-tion to provide an improved method for delivering fabric conditioning agents and especially volatile agents such as perfume to fabrics during the drying stage of the laundering process.
It is a further object of the presen-t invention to provide dryer-added articles of manufacture which can deliver effective amounts of fabric conditioning ayents to fabrics being laundered.
It has been surprisingly discovered that by utilizing particular types of conditioning agent~containing friable microcapsulesin combination with certain types of capsule transfer agents, the above-enumerated objec-tives can be ~ttained. Furthermore, methods and articles can be realized which are unexpectedly superior to similar methods and articles ~ of the prior art. Althouyh treatment of fabrics with -; mlcrocapsules is known (See, for examplet Ida et al; -U.S. Patent 3,870,542; issued March 11, 1975 and Pandell et al; U.S. Patent 3,632,296; issued January 4, 1972), such prior art fabric treatment has generally required utilization of large numbers of microcapsules ~or realization of effecti~ecapsule delivery. Furthermore, the prior art has not provided adequate methods or articles suitable , ~ 25 for microcapsule treatment of fabrics during treautoma-tic ~;` drying step of home laundering operations.
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~ SU~MARY OF TEIE INVENTION
t~ The present invention relates to a method of treating ~v~ fabrics with a fabric conditioning agent during the course of .i :~,...

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th~ auto~-ltic dryin~ step of tile ho~ launc~ring op~r~tio~l. A fa~ric treatment mixture containing water-insoluble, friable micro-capsules is applied to damp fabrics in the dryer, and the fabrics so treated a~e then manip-~a-ted so as to ruptuxe the mucrocapsules.
Microcapsules utilized comprise a liquid core containing fabric conditioning agent and a thin polymeric shell surrounding the liquid core. Micxocapsules utilized in the fabric treatment mixture vary in size between about 5 and 500 microns. Such capsules have an average shell thickness varying between about 0.1 and 50 microns.

- In addition to the microcapsules, the fabric : .
`~ treatment mixture additionally contains a substantially water-insoluble, fabric subsitanti~-e,capsule transfer agent which is present in contact with each microcapsule. The capsule transfer agent has a melting/sotening point between about 40C and 150C and is present to the extent that .. ~ .
the weight ratio of microcapsulesto capsule transfer agent within the fabric treatment mixture varies between about 0.002:1 and 2.0:1. The capsule transfer agent facilitates application and, to some extent, attachment ,...
of the individual microcapsules to the fabrics being treated.

Manipulation of the treated fabrics is carried out by any means which serves to rupture a significant number of applied microcapsules,thereby releasing the fabric conditioning agent.

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~ ,, In its clryer-aclded art.icle of m~nu~acture aspect, the present invention involves articles comprising an eEfectiv~ amoun-t o~ a Eabric treatment mixture and a dryer dispensing means for.such a mixture. The f~bric treatment mi~ture contains microcapsules and capsule transfer agent as described above. The dryer dispensing means provides for release of the capsule-containing fabric treatment mixture within the dryer under dryer operating conditions.
Thus, the method of the invention in its broadest aspect relates to a method for treating fabrics with a fabric conditioning agent, said method comprising A) applying to fabrics in an automatic laundry dryer an effective amount of a fabric treatment mixture, said mixture comprising i) water-insoluble, friable microcapsules.
varying in size from about 5 to 500 microns, ; each microcapsule consisting essentially of~ .
.~ a) a liquid core containing fabric condi- ;:
tioning agent; and ;
b) a solid thin polymeric shell completely :.
surrounding said core; said shell having an .`~ ~
average thickness ranging between about .
: 0.1 and 50 microns; and -~: ii) a substantially water-insoluble, fabric sub~
stantive capsule transfer agen.t having a melting/
softening point between about 40DC and 150C;
said capsule transfer agent contacting and completely surrounding or enveloping said micro-capsules within said fabric treatment mixture; the ' 4( - ~ - :
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wei~ht ratio of microcapsule~ to capsule transfer agent within said mixture varying between about 0.002:1 and 2:1;
said fabric treatment mixture being applied to said fabrics in a manner such that at least a portion of said microcapsules are at-tached to the ~' fabric being treated; and . B) manipulating said fabrics so as to rupture at least a portion of said microcapsules to thereby release the fabric conditioning agent.
: DESCRIPTION OF THE PREFERRED EMBO~IMENTS ~ :
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The present invention involves the home laundry application to fabrics of friable microcapsules containing fabric conditioning agent followed by manipulation of the treated fabrics so as to rupture the microcapsules. The microcapsu].es are in general applied to damp fabrics in a dryer via a fabric treatment mixture which contains the micro~
capsu~es and a capsule transfer agent co~tacti~g the ~crocapsules.
Each of these aspects of the present invention.as well as dryer-added articles suitable for carrying out the method of the present invention are discussed in detaiI as follows:

Microcapsules The microcapsules useful in the present invention comprise a liquid core containing one or more fabric condi~

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tioning agents and a thin polymeric shell completely surrounding ~ ~ the liquid core. By encapsulating the fabric conditioning :.~ agent (in liquid form), the fabric condi~ioning agent is :. protected during the laundering operation and is thus.p.reserved . for most efficient application to fabrics. Conditioning agent is .~ "

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act~lally ap~l1e~ e fabrics ~Jhen ~2 microcapsules ruptu~e. l'~is can occur either during the automatic drying step of the home laundering operation or can actually occur after the fabrics are launderea and wnile they are being used.
For purposes of the present învention a "fabric condi-tioning agent" is any substance which improves or modifies the chemical or physical characteristics of the fabric being treated therewith. Examples of suitable fabric conditioning agents include perfumes, elasticity improving agents, flame proofing agents, pleating agents, antistatic ag~nts, softening a~ents, soil proofing agents, water repellent agents, crease proofing agents, acid repellent agents, antishrinki~ agents, heat proofing agents, coloring material, brighteners and fluorescer~s. .
The most preferred fabric conditioning agent for use in the present invention is perfume. Perfume is an especially suitable fabric conditioning agent for use herein since its ~olatility generally creates special problems when it is used in dryer fabric treating situations.
The perfume which can be used in -the liquid cores of the microcapsulescan be any odoriferous material and ; will be selected according to the desires of the formulator. In general terms, such perfume materials are characterized by a vapor pressure below atmospheric pressure at ambient temperatures. The perfume ma-terials " .
employed herein will most often be liquid at ambient temperatures, but also can be solids such as the various camphoraceous per~umes kno~n in the art. A wide variety of chemicals are known for perfumery uses, including materials ~,., , ~L~8~2~3~

such as aldehydes, ke-~ones, esters, and the like. More commonly, naturally-occurring plant and animal oils and exudates com~risin~ complex mixtures of various che~ical components are known for use as perfumes, and such mate~ials can be used herein. The perumes herein can be relatively simple in their composition, or can comprise highly sophis-ticated, complex mixtures of natural and synthetic chemical components, all chosen to provide any desired odor.
Typical perfumes herein can comprise, for example, woody/earthy bases containing exotic materials such as sandalwood oil, civet, patchouli oil, and the like. The perfumes herein can be of a lightr floral fragrance, e.g., rose extract, violet extract, and the like. The perfumes herein can be ~ormulated to pro~ide desirable fruity odors, e.g., lime, lemon, o~nge, and the like. In short, -any m~terial which exudes a pleasant or otherwise desir-able odor can be used in the liquid microcapsule core to.
provide~a desLrable odor when applied to fabrics.

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Tlle fa~ric conditioning agent will frequently be in liquid form ~nd can be used as the sole material in the microcapsule core. Fabric conditioning agents which are normally solid can also be employed in the microcapsule core if they are admixed with a liqueying agent such as a solvent. Water or any other solvent can be used to liquify normally solid fabric conditioning agents for use in the microcapsule core provided such a solvent is chemically compatible with the microcapsule shell material described hereinafter.
The shell material surrounding the liquid, conditioning agent-containing core to form the microcapsule can be any suitable polymeric material which is impervious to the materials in the liquid core and the materials which may come in contact with the outer surface of the shell. The microcapsule shell wall can be composed of a wide variety of polymeric materials including polyurethane, polyolefin, polyamide, polyester, polysaccharide, silicone resins and epoxy resins. Many of these types of polymeric microcapsule shell materials are further described and exemplified in Ida et al, U.S. Patent 3,870,542 issued March ll, 1975.
Highly preferred materials Eor the microcapsule shell wall are the aminoplast polymers comprising the reactive products of urea and aldehyde, e.g. formaldehyde.
Such materials are those which are capable of acid condition polymerization from a water-soluble prepolymer state. Such prepolymers are made by reacting ~rea and formaldehyde in a formaldehyde~urea molar ratio of from about 1.2:1 to 2.6:1.
Thiourea, cyanuramide, guanidine, N-alkyl ureas, phenols, sulfonamides, anilines and amines can be included in small -~ - 8 - ~
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~8~Z~g amounts as modiEiers Eor the urea. Polymers formed from such prepolymer materials under acid conditions are water-insoluble and can provide the requisite capsule friability characteristics as described more fully hereinafter~
Microcapsules having the liquid cores and polymer shell walls as described above can be prepared by any conventional process which produces capsules of the requisite size, friability and water-insolubility. Generally, such methods as coacervation and interfacial polymerization can be employed in known manner to produce microcapsules of the desired characteristics. Such methods are described in Ida et al, U.S. Patent 3,870,542, issued March 11, 1975;
Powell et al, U.S. Patent 3,415,758, issued December 10, 1968 and Anthony, U.S. Patent 3,041,288, issued June 26, 1962.
Microcapsules made from the preferred urea-~ormal-dehyde shell materials can be made by an interfacial poly-merization process described more fully in Matson; U.S.
Patent 3,516,941; issued June 23~ 1970. By that process an aqueous solution of a urea-formaldehyde precondensate (methylol urea) is formed containing from about 3~ to 30%
by weight o the precondensate. Water-insoluble liquid core material (e.g., perfume) is dispersed throughout this solution in the form of microscopically-sized discrete droplets. While maintaining solution temperature between 20C and 90~C, acid is then added to catalyze polymerization of the dissolved urea-aldehyde precondensate. If the solution is rapidly agitated during this polymerization -~ step, shells of water-insoluble, urea-formaldehyde polymer form around and encapsulate the dispersed droplets of liquid core material. Preferred microcapsules for use in the present _ g _ ., .

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~8~ 3 invention are thereby produced.
No matter how the microcapsules utilized herein ar~ produced, it is essential that the microcapsules vary in size between about 5 microns and 500 microns, preferably between about 10 microns and 100 microns.
Furthermore it is essential that the capsules utilized in the present invention have an average shell thickness ranging from about 0.1 microns to 50 microns preferably from about 0.4 microns to 4 microns.
The microcapsules of the present invention must also be riable in nature. Friability refers to the propensity of the microcapsules to rupture or break open when subjected to direct external pressures or shear forces. For purposes of the present invention, the micro-; capsules utilized are "friable" if, after being "released"
in the laundry dryer, they can be ruptured by the forces encountered among the tumbling fabrics in an automatic ` laundry dryer or forces encountered when capsule-containing fabrics are manipulated by being worn or handled. Micro-capsules made with the above-disclosed shell materials will generally be "friable" if they fall within the essential capsule size and shell thickness limitations provided above.
Capsule Transfer Agent Application of the above-described microcapsules to the fabrics being treated therewith is facilitated by contacting the microcapsules with a particular type of ; ~ capsule transfer agent. Capsule transfer agents employed .. . .
~ in the present invention are those substantially water-- insoluble materials which are fabric substantive and which , . ~
',~ 30 have a melting/softening point within the range of from about 40C to 150C, preferably within the range of from about 49C

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to 105~C. By "~ubstantially water-insoluble" herein is meant a water insolubility oE 1~ by weight, or less, at 30C.
Especially suitable capsule transfer agents are those cationic and nonionic organic materials which are generally employed as conventional fabric softening agents during the washing, rinsing or drying cycles of the house-hold laundry process. Materials of this type generally have the requisite fabric substantivity for use herein.
Suitable cationic capsule transfer agents include any of the cationic ~including imidazolinium) compounds listed in Morton, U.S. Patent 3,686,025, issued August 22, 1972. Such materials are well known in the art and include, for example, the quaternary ammonium salts having at least one, preferably two, C10-C20 fatty alkyl substituent groups;
alkyl imidazolinium salts wherein at least one alkyl group contains a C8-C25 carbon "chain"; the C12-C20 alkyl pyridinium salts, and the like.
Preferred cationic softeners herein include the quaternary ammonium salts of the general formula RlR2R3R4N+,X , wherein groups Rl, R2,R3 and R4 are, for '''' , ~- .
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- - ' , ex~mple, cllkyl, and X is ~n anion, e.g., halide, acetate, methyl-sulfate, ethylsul~ate and th~ like, with the chloride and methylsulfate salts being pre~erred. Especially preferred capsule transfer agents are those wherein Rl and R are each C12-C20 fatty alkyl and R3 and R4 are each Cl-C4 alkyl.
The fatty alkyl groups can be mixed, i.e., the mixed C14-Cl~ coconutalkyl and mixed C16-C18 tallowalkyl ~uat-ernary compounds. Alkyl groups R3 and R4 are preferably methyl.
Exemplary quaternary ammonium softeners herein include dital]owalkyldimethylammonium methylsulf2te, ditallowalkyldimethylammonium chloride, dicoconutalkyl-dimethylammonium methylsulfate, and dicoconutalkyl-dimethylammonium chloride.
- 15 Nonionlc capsule transfer agents include a wide variety of materials inc~uding sorbitan esters, fatty alcohols and their derivatives, diamine compounds and the like. One preferred type of nonionic capsule trans-fer agent comprises the esterified cyclic dehydration products of sorbitol, i.e., so~bitan ester. Sorbi~l, itself prepared by ~ `~
catalytic hydrogenation of glucose, can be dehydrated in well-known fashion to form mi~tures of cyclic 1,4-~; and 1,5-sorbitol anhydrides and small amounts of isosorbides. (See Brown; U.S. Patent -~
2,322,821; issued June 29, 1943) The resulting complex mixtures of cyclic anhydrides of sorbitol are collec-tively referred to herein as "sorbitan". It will be ; recogniz~d that this "sorbitan" mixture will also contain some free uncyclized sorbitol.

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Sorbitc~ ester capïule tr~nsfl~ acJents us~fu1 herein are prepar~d by esterifying the "sorbitan" miY~ture with a ~atty acyl group in standard fashion, e.g., by reaction with a fatty (C10-C24) acid or fatty acid halide. The esterification xeaction can occur a any of the available hydroxyl groups, and various mono-, di-, etc., esters can be prepared.
In fact, complex mixtures of mono-, di-, tri, and tetra-esters almost always result from such reactions, and the stoichiometricratios of the reactants can simply be adjusted to favor the desired reaction product. The sorbitan mono-esters and di-esters are preferred for use as the capsule transfer ayent in the present invention, but all such esters are useful.
The foregoing complex mixtures of ~sterified cyclic ~ 15 dehydration products of sorbitol (and small amounts of i~ esterified sorbitol) are collectively referred to herein . . , ~ i .
as "sorbitan esters". Sorbitan mono- and di~esters of lauric, myristic, palmitic, stearic and behenic acids 1. ., ~ .
~; are particularly useful herein for facilitating transfer $
of the microcapsules to fabrics being treated. Mixed , sorbitan esters, e.g., mixtures of the foregoing esters, !~ and mixtures prepared by esterifying sorbltan with fatty acid mixtures such as the mixed tallow and hydrogenated palm oil fatty acids, are useful herein and are economi-,, cally attractive. Unsaturated C10-Cl8 sorbitan esters, ~- e.g., sorbitan mono-oleate, usua]ly are present in such mixtures. It is to be recognized that all sorbitan esters, and mixtures thereof, which are essentially water-,, insoluble and which have fatty hydrocarbyl "tails'/, are useful capsule transfer agents in the context of the s; present invention.

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The preEerred alkyl sorbitan ester capsule transfer agents herein comprise sorbitan monolaurate, sorbitan mono-myristate, sorbit~n monopalmitate, sorbitan monostearate, sorbitan monobehenate, sorbitan dilaurate, sorbitan dimyri~-tate, sorbitan dipalmitate, sorbitan distearate, sorbitan dibehenate, and mixtures thereof, the mixed coconutalkyl sorbitan mono- and di-esters and the mixed tallowalkyl sorbitan mono~ and di-esters. The tri- and tetra~esters of sorbitan with lauric, myristic, palmitic, stearic and behenic acids, and mixtures thereof, are also useful herein.
Anot}ler useEul type of nonionic capsule transfer agent encompasses the substantially water-insoluble compounds chemically classified as fatty alcohols. Mono-ols, di-ols and poly-ols having the requisite melting points and water-insolubility properties set forth above are useful herein.
Such alcohol-type capsule transfer materials also include the l~
mono- and di-fatty glycerides which contain at least one "free" OH group.
All manner of water-insoluble, high melting alcohols ~including mono- and di-glycerides), are useful herein, inasmuch as all such materials are fabric substan-tive and tend to facilitate application of the micro-capsules herein to fabric surEaces. Of course, it is desirable to use those materials which are colorless, -.~` ' ' ''` ' ':
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so ~s not to alter the color of the fabrics being treated.
Toxicolo~ically acceptable materials which are safe for use in contact with skin should be chosen.
A preferred type of unesterified alcohol useful herein includes the higher melting members of the so-called fatty alcohol class. Although once limited to alcohols obtained from natural fats and oils, the term "fatty alcohols" has come to mean those alcohols which correspond to the alcohols obtainable from fats and oils, and all such alcohols can be made by synthetic processes.
Fatty alcohols prepared by the mild oxidation of petroleum products are useful herein.
Another type of material which can be classified as an alcohol and which can be employed as the capsule ~ .
transfer agent in the instant invention encompasses various esters of polyhydric alcohols~ Such "ester-alcohol" materials which have a melting point within the . . .
. range recited herein and which are substantially water-insoluble can be employed herein when they contain at Ieast one free hydroxyl group, i.e., when they can be classified chemically as alcohols.
The alcoholic di-esters of glycerol useful herein include both the 1,3-di-glycerides and the 1,2-di-;~ glycerides. In particular, di-glycerides containing two ; 25 C8-C20, preferably C10-Cl8, alkyl groups in the molecule ; are useful capsule transfer agents.
Non-limiting examples of ester-alcohols useful here}n include: glycerol-1,2-dilaurate; glycerol-1,3-dilaurate; glycerol-1,2-myristate; glycerol-1,3-dimyris-tate; glycerol-1,2-dipalmitate; glycerol-1,3-dipalmitate;

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.,' glycerol-~2-distearate and glycerol-1,3-distearate.
Mixed glycerides available from mixecl tallowalkyl fatty acids, i.e., l,2-ditallowalkyl glycerol and 1,3-ditallow-alkyl glycerol, are economically attractive for usP
herein. The foregoing ester-alcohols are preferred for use herein due to their ready availability from natural fats and oils.
Mono- and di-ether alcohols, especially the C10~
C18 di-ether alcohols having at least one free -OH group, also fall within the definition of alcohols useful as capsule~
transfer agents herein. The ether-alcohols can be prepared by the classic Williamson ether synthesis. As with the ester-- alcohols, the reaction conditions are chosen such that - at least one fr~e, unetherified -OH group remains in the molecule.
Ether-alcohols useful herein include glycerol-1,2 dilauryl ether; glycerol-1,3-distearyl ether; and butane -- tetra-ol-1,2,3-trioctanyl ether.
~; Yet another type of nonionic capsule transfer agent useful herein encompasses the substantially water-insoluble diamine compounds and diamine derivatives. The diamine capsuletransfer agents are selected from the group consisting of particular alkylated and acylated diamine compounds.
Useful diamine compounds have the general formula:
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wherein Rl is an alkyl or acyl yroup containing from about 12 to 20 carbon atoms; R2 and R3 are hydrogen or alkyl of fro~ about 1 to 20 carbon atoms and R4 is hydrogerl, Cl_20 alkyl or Cl2-20 acyl. At least two or R~, R3 and .R4 are hydrogen or alkyl containing 1 to

3 carbon atoms, and n i5 from 2 to 5.
Nonlimiting examples of such alkylated diamine compounds include:

16 33 N(CH3) ~ (CH2)3-N(CH3)2 18 37 N(cH3)-(cH2)2-N(c2~I5)2 - C12H25-N(CH3)-(cH2~3 ~N C12 25 ~. . 12H25 N(c2Hs)-(cH2)3-N(C3H7)2 ; Tallow NH (cH2)3-N(c2H5)2 ~.; 20 41 N(C~3)-(CH2)2-N(CH3)2 ! 15H31 N(C2H5)-(CH2)3-NH2 ,~ ,~ , .
~; C18H37 NH (C 2)3 3 r C16H33-NH-(CH2)3-HN C16H33 :~ Tallow N(CH3)~(C~2)3~N(C2H5)2 ;
~ 16H33N(CH3)-tc~2)5-N~c2H5)2 12 25N(C2H5)-(CH2)2-N(C3H7)2 and 14 29N(CH3) (C~2)3-cH3)N-c~Hl7 :, ,i Wherein in the above formulas RTallow derived from rallow fatty acid.
:s -.,1, ;- Other ex~amples of suitabl.e alkylated diamine com-- ~ 25 pounds include N-tetradecyl, N'-propyl-1,3-propane-diamine;
.: N-eicosyl,N,N',N'-triethyl-1,2-ethane-diamine and N-octa-: decyl,N,N',N'-tripro~y~1,3-propane-diamine.
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Exami~les o~ suit~ble acylated diamine capsule transfer acJents include C13 20 amido amine deriva-tives such as those marXeted under the tradename Chemical Base 6532 by Sandoz Colors and Chemicals.
The capsule transfer agents of the present inven-tion can and preferably do comprise mixtures of the above-described types of substantially water-insoluble, fabric substantive fatty compounds. Such especially preferred mixtures of cationic and nonionic materials include, for example, mixtures of cationic quaternary a~monium compounds and various sorbitan ester compounds which are especially suitable when fabrics are treated with microcapsules during the drying cycle o~ the laundering operation.`
Such preferred capsule transfer agent mixtures are aescribed more fully hereinafter.

capsule Application to Fabrics in Dryer The above described microcapsules are in general applied to fahrics in the dryer via a fabric treatment ; mixture which contains the microcapsules and the capsule transfer agent or agents. Within such a fabric ~reatment mixture, the weight ratio of microcapsules to capsule transfer agent generally varies between about 0.002:1 and 2:1, preferably betwe~ about 0.01:1 and 0.2:1. The fabric treatment mixture can contain other optional ingredients dependiny upon ~he method of applying the fabric treatment mixture to the fabrics being treated in the dryer.

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Within ~he fabric trea-tment mixture, the microcap-sules an~ c~sule transfer agent should be in contact with each other. Preîerably, th2 capsule trans~er agent ~letely surrounds or envelops the individual microcapsules. This is generally accomplished by throughly admixing the microcapsules with the capsule transfer agent in ~ome form of liquid medium.
: Thus, for example, the water-insoluble capsule transer ayent can be dispersed in an agitated aqueous liquid to which the water-insoluble microcapsules are added. The capsule:transfer agent thus tends to surround the individual microcapsules within the dispersion.
Alternati~ely, the capsule transfer agent can be melted to form a liquid and the microcapsules added with agitation to the liquid melt. Upon cooling and hardening, a fabric treatment mixture is formed having ; the microcapsules imbedded in the surrounding capsule transfer agent.
If the fabric treatment mixture is to be in granu-lar form, the microcapsules can be pretreated wi-th the capsule transfer agent so as to coat the microcapsules.
Any conventional coating technique can be utilized inclu-ding spray-on processes (Maurumerization) or fluidized bed coating methods.
The fabric treatment mixture, in any suitable form, can be applied by any suitable means to the fabrics in the automatic laundry dryer. The fabric ' treatment mixture can simply be sprinkled in either granular or liquid form onto the fabrics in the dryer.
, 30 The fabric treatment mixture can be dispensed in the dryer by means of any suitable dryer dispensing device or .:
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tech~ique known in the art. Preferred articles for carrying out such dryer dispensing or the fabric treat-ment mixture are described more ully hereinafter.
When the fabric treatment mixture containiny S microcapsules and capsule transfer agent is applied to fabrics in the dryer, it has been surpxisingly discovered that at least some of the microcapsules migrate to the fabrics in the dryer and attach themselves to the fabrics being treated. It is believed that the fabric substan-tive capsule transfer agent helps deliver the micro-capsules to the fabric surfaces and can also serve as an "adhesive" which fastens at least a portion of the individual microcapsules to the fabrics.

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By utilizin~ the capsule transfer agent contacting~and ~-~ 15 preferably completely surrounding the microcapsules, it is possible to ~' ; deliver satisfactory nu~bers of microcapsules to fabric surfaces without utilizing extremely large numbers of capsules.
Generally the amount of microcapsules employed in the instant invention constitutes only from about 0.0002% to 0.2% by weight of the fabricsbeing treated therewith.
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.5 :~ Fabric Manipulation Once microcapsules containing fabric conditioning , agent have been applied to fabrics being treated, it ; is, of co~rse, necessary to manipulate the treated fabrics in a manner sufficient to rupture the microcapsules and ; ~ thereby release the conditioning agent. Microcapsules ~ ~ .
of the type u~ilized herein have friability characteris-tics such that the ordinary fabric manipulation encountered ... . .
in the home is sufficient to rupture at least a portion of the attached microcapsules.

. .

2~3g Fabric manipulation can, for example, take the form of tumbling the fabrics in an automatic laundry dryer. Generally, microcapsules which have been applied during the automatic dryer stage of the laundering oper-ation are easily ruptured by the tumbling actionof the dryer. It is believ~ that microcapsules applied in the dryer axe not very deeply embedded in fabrie inter-stices. The dryer tumbling action is, therefore, generally suffieient to rupture a significan~ number of dryer-applied mieroeapsules.
Microcapsules ean also be selected so as to survive intact the tumbling aetion of the dryer. Microcapsules of this stronger type can be ruptured by fabrie manipulation which occurs when the treated fabri~s axe worn or used.
A significant number of attached microcapsules which survive the dryer can then be broken bv the normal forces encountered when treated garments are worn. For fabric articles which are not worn, the normal household handling operations sueh as ironing, folding, crumpling, etc. can serve as fabrie manipulation sufIieient to rupture the attached microcapsules.

~ Dr er-Added Fabric Conditioning Articles .. ; Y ' , As noted, fabrie applieation o~ the microcapsule-containing fabric treatment mixture takes place during the automatic drying step of the home laundering operation.
Particular dryer-added articles of manufacture can be realized which are especially useful for carrying out the dryer capsule application step of the instant fabrie . . .
, ~
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treatment me~hod ~ccordingly, such articles of manu-facturè for use in ~he automatic dryer also form part of of the inven-tion herein.
Dryer-added articles of manufacture herein com-prise an effective amount of a microcapsule-containing fabric treatme~t mixture and a dispensing means which provides for the release of this fabric treatment mixture within an automatic laundry dryer under dryer operating conditions.
The fabric treatment mixture utilized in dryer-added articles of manufacture containsthe same type and . .
concentration of water-insoluble friable microcapsules and the same type and concentra~i~of substantially water-insoluble, fabric substantive capsule transfer agent as described above. The capsule transfer agent component serves to facilitate delivery of the microcapsules to fabric surfaces within the Iaundry dryer. The capsule transfer agent material can also function as a fabric sotener which is applied to the fabrics tumbling within the dryer.
.
As noted above, especially preferred capsule :~; transfer agents for use in dryer-added articles include mixtures of cationic quaternary ammonium compounds and nonionic sorbitan ester compounds. More preferably the capsule transfer agent component for dryer-added articles containsfrom about 15% to 75% by weight of the capsule trans'er agent of di-C14 18 alkyl,dimethyl -` ammonium methylsulfate and from about 25% to 85% by weight of the capsule transfer agent of C10-C26 alkyl ~ sorbitan mono- and di-esters.

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It is essential that the microcapsules within the fabric treatment mixture be in contact with and preferably oompletely surro-~ded by the capsule transfer agent. For mixtures suitable for dryer-added articles, this can be accomplished by melting the capsule transfer agen~ and adding the micro capsules to the melted liquid under agitation.
The fabric treatment mixture can optionally contain a variety of conventional fabric treating adjuncts and/or processing aids in addition to the requisite microcapsulesand capsule transfer agent component.
Such optional abric treatment mixture components include inorganic softening/antistatic agents, e.g., impalpable smectite and/or hectorite clay materials; perfume; solvents;
emulsifier~ dyes; germicides, coloring agents and the . .
like.
The dryer-added articles of the present invention utilize a dispensing means which effec-.. ~ .
tively releases the capsule-containing fabric treatment mix~ure under conditions encoun~ered in an op~rating autcmatic clothes dryer. Such dispensing means can be designed for single usage or for multiple uses.
One such article comprises a spongematerial releasably enclosing enough fabric treatment mixture to e fectively treat fabrics during several cycles of ~! 25 clothes. This multi-use article can be made by filling a hollow sponge with about 20 grams of the fabric treat-. ., ment mixture. In use, the capsule transfer agent melts -~ and leaches out through the pores of the sponge carrying ~ capsules and transfer agent to the fabrics. Such a ,, ~ .

, . . .

.

2~9 filled sponcJe can be used to treat several loads of fabrics in conventional dryers and has the advantage that it can remain in the dryer after use and is not likely to be misplaced or lost.
Another article comprises a cloth or paper bag releasably enclosiny the fabric treatment mixture and sealed with the hardened capsule transfer agent. The action and heat of the dryer opens the bag and releases the mixture to perform its various functions.
Still ano-ther article comprises an aerosol cannister containing the above-described fabric treatment mixture under pressure. The mixture can be dispensed from this aerosol article onto the fabrics or onto the dryer drum in the manner more fully described in Rudy et al, U.S. Patent 3,650,816, issued March 21, 1972.
Other devices and articles suitable for di~pensing the fabric treatment mixture into automatic dryers include those described in Dillarstone, U.S. Patent 3,736,668 issued June 5, 1973; Compa et al, U.S. Patent 3,701,202 issued October 31, 1972; Furgal, U.S. Patent 3,634,947 issued January 18, 1972; Hoeflin, U.S. Patent 3,633,538 issued January 11, 1972 and Rumsey, U.S. Patent 3,435,537 issued April 1, 1969.
A highly preferred article herein comprises the -- fabric treatment mixture releasably affixed to a sheet of paper or woven or non-woven cloth substrate. When ; such an article is placed in an automatic laundry dryer, the heat and tumbling action of the dryer ~;

~i8~9 remove the mi~iure from the substrate and deposit it on the fab~ics.
The sheet conformation has several advantages.
For example, effective amounts of the fabric treatment S mixture for use in conventional dryers can be easily : sorbed onto and into the sheet.substrate by a simple .
- dippin~ or padding process. ~hus, the user need not measure the amount of mixture necessary. Aadi~ionaIly,~ ~ ~
the flat configuration of the sheet provides a large surface area which results in efficient release of the ~` mixture onto fabrics by the tumbling action of the dryer.
... The water-insoluble paper, or woven or non-woven :j - . substrates used as the .dryer dispensing means in the ^; articles herein can have a dense, or more~preferably, 1: `'- _ ~ : _ ~ _ ___, __,,, ___._, _ ,, .. __.. .. _ .. .

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open or porous str~lcture. Examples of suitable materials which can be used ~s snbstrates herein include paper, woven cloth, and non-woven cloth. The term "cloth" herein means a woven or non-woven substrate for the articles of manufac-ture, as distin~uished Erom the term "fabric" which encQmpasses the items (clothing, etc.) being dried and conditioned in an automatic dryer.
Highly preerred paper, woven or non-woven '1absorbent"
substrates useful herein are fully disclosed in Morton, U.S.
Patent 3,686,025 issued August 22, 1972. It is known that most substances are able to absorb a liquid substance to some degree; however, the term "absorbent" as used herein, is intended to mean a substance with an absorbent capacity (i.e., a parameter representing a substrate's ability to take up and retain a liquid) from 4 to 12, preferably 5 to 7, times it weight of water.
Determination of absorbent capacity values is made by using the capacity testing procedures described in U.S. ~ederal Specifications UU-T-595b, modified as follows:
(1) tap water is used instead of distilled water;
; (2) the specimen is immersed for 30 seconds instead of 3 minutes;
(3) draining time is 15 seconds instead of 1 minute; and

(4) the specimen is immediately weighed on a torsion balance having a pan with turned-up edges.
Absorbent capacity values are then calculated in accordance with the formula given in said Specification. Based , - 27 -.~ ~
, :' , ,'' ' : ~ ;' ' ' ':

on this test, one-ply, dense bl~ached paper ~e.g., kraft or bond having a basis weight of about 32 pounds per 3,000 square feet) has an absorbent capacity of 3.5 to 4; commercially available household one-ply toweling S paper has a value of 5 to 5; and commercially available two-ply household toweling paper has a value of 7 to - about 9.5.
Using a substrate with an absorbent capacity of less than 4 tends to cause too rapid release of the fabric treatment mixture from the substrate resulting in several disadvantages~ one of which is uneven treat-ment of the fabrics. Using a substrate with an absorbent capacity over 12 is undesirable, inasmuch as too little of the treatment mixture is releas~dto treat the fabrics in optimal fashion during a normal drying cycle.
As noted above, suitable materials which can be used as a substrate in the articles herain include, ; among others, sponges, paper, and woven and non-woven cloth, all having the necessary absorbency requirments defined above. The preferred substrates herein are ~
cellulosic, particularly non-woven cloth. `
The preferred non-woven cloth substrates used in the articles herein can generally be defined as adhesively bonded fibrous or filamentous products having a web or carded fiber structure (where the fiber strength is su't~ble to allow carding), or comprising fibrous mats_ in which the fibers or filaments are distributed haphazardly or in random array (i.e., an array of fibers in a carded web wherein partial orientation of tne fibers is frequently present, as well as a completely ,;

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haphazard clistributional orientation), or substantially aligned. The fibers or fila~en~s can be natural ~e.g., wool, silk, jute, hemp, cotton, linen, sisal, or ramie) or synthetic (e.y., rayon, cellulose ester, polyvinyl derivatives, poly-olefins, polyamides, o~
polyesters).
Me~hods of making non-woven cloths are not a part of this invention and, beinq well known in the art, are not described in detail herein. Generally, however, such cloths are made by air- or water-laying processes in which the fibers or filaments are first cut to desired lengths from long strands, pdssea into a water or air stream, and then deposited onto a screen through which the fiber-laden air or water is passed. The lS deposited fibers or filaments are then adhesively bonded together, dried, cured, and otherwise treated as desired to form the non-woven cloth. Non-woven cloths made of poly~sters, polyamides, vinyl resins, and other thermo-plastic fibers can be span-bonded, i.e., the fibers are spun out onto a flat surface and bonded (melted) together by heat or by chemical reactions.
~;` The absorbentproperties preferred herein are particularly easy to obtain with non-woven cloths and ; are pro~ided merely by building up the thicknes~ of the cloth, i.e., by superimposing a plurality of carded webs or mats to a thickness adequate to obtain the necessary absorbent properties, or by allowing a sufficient ~; thickness of the fibers to deposit on the screen. Any ,. ~
diameter or denier of the fiber (generally up to about ~ 30 10 denier) can be used, inasmuch as it is the free space ,~.
~. ~
., :

, -29~ , between each fiber that mak~s the thickness of the cloth directly related to the absorbent capacity of the cloth, and which, further, makes the non-woven cloth especially suitable for impregnation with fabric treatment mixture by means of intersectional of capillary action. Thus, any thickness necessary to obtain the required absorbent capacity can be used.
The choice of binder-resins used in the manufac-ture of non-woven cloths can provide substrates possessing a variety of desirable traits. For example, the absor-bent capacity of the cloth can be increased, decreased, or regulated by respectively using a hydrophilic binder-resin, a hydrophobic binder-resin, or a mixture thereof, in the fiber bonding step. Moreover, the hydrophobic binder-resin, when used singly or as the predominant compound of a hydrophobic-hydrophilic mixture, provides ; non-woven cloths which are especially useful as substrates when the dryer-added articles herein are used with damp ~ fabrics in an automatic dryer.
- 20 When the substrate for the articles herein is ~ a non-woven cloth made from fibers deposited haphazardly - or in random array on the screen, the articles exhibit : excellentstrength in all directions and are not prone ~ to tear or separate when used in the automatic clotnes - 25 dryer.
Preferably, the non-woven cloth is water-laid or air-laid and is made from cellulosic fibers, parti-,, ~
cularly from regenerated cellulose or rayon. Such non-woven cloth can be lubricated with any standard r ~ ~

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~ -30-., ~'' . .

textile lubric~nt. Pref~r~bly, the Eibers ~re from 3/16" to 2" in length and are from 1.5 to 5 denier.
Preferably, the fibers are at least partially oriented haphazardly, particularly substantially haphazardly, and are adhesively bonded tocJether with a hydrophobic or substantially hydrophobic binder-resin, particularly with a nonionic self-crosslinkiny acrylic polymer or polymers. Preferably, the cloth comprises about 70~
by weight fiber and 30~ by weig~ binder-resin polymer and has a basis weight of from about 18 to 24 grams per square yard.
The preferred 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, heat and drying air may be omitted for part or all of the cycle.
Generally, however, heated air will be employed and such air will be circulated frequently in the dryer.
Normally, there are from about 5 to 50 volume changes of air :in the dryer drum per minute and the air moves atab~ut 125 to 175 cubic feet per minute. These changing volumes of air create a drawing or suction ' ~ 25 effect which can, especially with small fabric loads, .
cause an item such as a sock, handkerchief or the like, or a fabric c~nditioning article, to be dispQsed on the ~- surface of the air outlet of the dryer. A usual load - of fabrics of from about 4 to 12 pounds dry weight will fill from about 10% to 70% of the volume of most dryers .
, :

~ -31-z~g and will normally pose little difflculty. 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. In the event, however, a fabric conditioning article is caused to be disposed in relation to the air exhaust outlet in such a manner as to cause blockage of passing air, undesir-able temperature increases can result. In the case of fabric conditioning articles prepared from the normally solid or waxy capsule transfer agents such as the quaternary ammonium materials and/or sorbitan esters which soften or melt under conditions of heat, the article may tend to adhere to an exhaust outlet.
The problem of blockage can be solved by providing openings in the article in the manner described in Canadian ; Patents 1,033,916 and 1,033,917 of A.R. McQueary. More specifically, slits or holes are cut through the substrate to allow free passage of air.
~- The slit openings are provided in the preferred -~ 20 fabric conditioning articles of this invention for two principal purposes. Importantly~ the slits permit passage of air in the event the article is placed in a blocking relationship to the air exhaust outlet.
Moreover, the slit openings provide a degree of flexi-bility or resiliency which causes the article to crumple or pucker. The effect of such crumpling is that only a portion of the air exhaust outlet will be coveFed hy ' ~ ~ - 32 -S,: , ~."
!-Z~
the conditionin~ article in the ~vent it is carriedby the moving air stream to thP exhaust outlet. More-over, the crum~led article is more readily removed by tumbling fabrics than ~ould be the case if -the article were placed in a flat relationship to the exhaust outl~t.
The type and number slit openings can vary considerably and will depend upon the nature of the substrate material, its inherent flexibility or rigidity, the nature of the ahric treatment mixture carried therein or thereon, and the extent to which increased passage of air therethrough is desired. The -preferred articles of this invention can comprise a large number of small slits of various types or configur-ations, or fewer larger slits. For example a single rectilinear or wavy slit, or a plurality thereof, confin~ to within the area of a sheet and extending clos~ to opposite edges of the article, can be employed.
By maintaining a border around all edges of the condi-tioning article, a desired degree of flexibility andsurface area availability to tumbling fabrics can be maintained. While, for example, rectilinear slits can be cut into a conditioning article completely to the edges of the article, confinement of the slits to -;25 within the area of the article will be preferred where the convenience of packaging the conditioning article in roll form is desired.
According to one preferred embodiment of the -invention, a sheet of fabric-conditioning article is ~30 provided with a plurality of rectilinear slits extending ,- ~.

2~

in on~ direction, e.y., the machine direction of the w~b substrate, and in a substantially parallel relation-ship. The slits can be aligned or in a staggered relationship. A preferred embodiment will co~tain from

5 to 9 of such slits which will extend to within about 2 inches and preferably 1 inch from the edge of the web material which is, for example, a 9" x 11" sheet.
The slit openings in the softening articles of the invention can be in a variety of configurations and `` 1~ sizes, as can be readily appreciated. In some instances, it may be desirable to provide slit openings as C-, U-- or V-shaped slits. Such slits arranged in a continuous or regular or irregular pattern are desirable from the standpoint of permitting gate-like or flat structures which permit the passage of air therethrough.
As an alternative to slits, the flexible substrate article can be provided with One or more openings having a diameter of from about 0.02 inch to about 4 inches, from about 5~ to about 40% of the surface area of the article com-prising said openings. The openings can be disposed inany convenient relationship to one another but it is simplest, from a manufacturing standpoint, to punch the ::
openings through the substrate in evenly spaced rows.
Openings, in fact, need not be punched in the substrate i 25 but rather can be provided simply by the use of porous substrates.
~i As noted, the articles herein comprise fabric ~ treatment mixture in combination with any dispensing means 'f suitable for releasing the mixture under conditions encoun-:~ .
;~ 30 tered in automatic laundry dryers. However, preferred .~. .

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articles herein are those wherein the fabric tre~tment mixture is impregnated into or coated onto an absorbent substrate. The impregnation or coating can be accomplished in any convenient manner, and many metho~ are ~nown in the axt. For example, the ~abric treatment mixture, in liquid for~, can simply be sprayed onto a substrate.
The flexible sub~trate dispensing device can either be "coa~ed" or "impregnated" with the fabr~c treabment - - -mixture. ~he term "coati~g" connotes the adjoining of one substance to the external surface of ano~her~
n impregnating" is intended to mean the permeation of the entire substrate structure, internally as well as externally.
One factor affecting a given substrate's absorbent capacity ~-~ is its free space. Accordingly, when a.softening o~asition is ,, j - ` .

. ... . .
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appLied to an absorhent substrate, it pene-trates into the free space; hence, the substrate is deemed impre~-nated. The free space in a substrate of low absorbency, such as a one-ply kraft or bond paper, is very limited;
such a substrate is, therefore, termed "dense". Thus, while a small portion of the fabric treatment mixture penetrates into the limited free space available in a dense substrate, a rather substantial balance of the mixture does not penetrate and remains on the surface of the substrate so that it is deem~ a coating. The difference between coating and impregnation is believed to explain why the impregnated sheet substrates o~ -the invention herein can eliminate or substantially reduce the staining of fabrics observed when a coated dense substrate is utilized.
In one method of making the preferred impregnated absorbent sheet substrate, a fabric treatment mixture containing microcapsules, capsule transfer agent and - optional additives is applied to absorbentpaper or non-:
woven cloth by a method generally known as padding.
~; The mixture is preferably applied in liquid form to the substrate. Thus, the fabric treatment mixtures which are normally solid at room temperature should first be melted and/or solvent treated. Methods of melting the fabric treatment mixture and/or for treating the mixture with a solvent are known and can easily be done to ; provide a satisfactorily treated substrate.
In another preferred method, the fabric treatment mixture in liquified form is placed in a pan or trough which can be heated to maintain the mixture in liquid form.
~ The liquid fabric treat~;ent m~ture contains the microcapsules and any ', :, , -36-,. .
., z~

of the d~;ired optional additiv~s. ~ roll of absorbent paper (or cloth) is then set up on an apparatus so that it can unroll freely. As the paper or cloth unrolls, it travels do~mwardly and, submersed, passes through the pan or trough containing the liquid fabric trea-tment mixture 3t a slow enough speed to allo~ suf~icient impregnation. The absorbent paper or cloth then travels upwardly and through a pair of rollers which remove excess bath liquid and provide the absorbent paper or cloth with about 1 to about 12 grams of the fabric treat-ment mixture per 100 in.~ to 150 in.2 of substrate sheet.
The impregnated paper or cloth is then cooled to room temperature, after which it can be folded, cut or perforated at uniform lengths, and subsequently packaged and/or used.
In applying the fabric treatment mixture to the absorbent substrate, the amount of mixture impregnated into or coated onto the absorbent substrate is conven-iently in the weight ratio range of from about 10:1 to -0.5:1 based on the ratio of total fabric treatment mixture - to dry, untreated substrate (fiber plus hinder). Pre-ferably, the weight ratio of fabric treatment mixture to substrate ranges from about 5:1 to about l:lj pre-ferably from about 3:1 to 1:1.

Following application of the liquified fabric treatment mixture, the articles are held at room tempera-ture until the mixture solidifies. The resulting dry articles, prepared at the mixture: substrate ratios set ~ ; forth above, remain flexible; the sheet articles are : ~ ~37~

. ~ .

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suitable for packaging in rolls. The sheet articles can optionalLy be slit~ed or p~nched as described above at any convenient time during the manufacturing process.
S The methods and articles of the present invention are illus~rated by the ~ollowing examples;
.

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EXA~lPLE I

A dryer-added fabric conditioning article in sheet configuration i5 prepared by impregnating a flexible non-woven substrate with a liquefied capsule-containing fabric treatment mix~ure. The flexible substrate utilized : ` is non-woven and made of rayon fiber (~70%) and polyvinyl acetate binder (~30~). Fiber utilized is approximately 1-9~16 inches in lengtk and denier of 3. The substrate .has an abi~orbe~ capacity ~f about 6.5 and is provid~d in - -a roll containing detachable sheets whîch are 9 inches :~ ~y 11 inches in size.

. The ~lexible substrate is impregnated with a ... . . , ... - . . ..... . . ...
- : fabric treatment mixture which contains friable perfume-: -:`` containing microcapsules and cationic and nonlonic - ~ -15 ~capsule transfer agentsO The microcapsules utilized in this~mixture are prepared by:the interfacial polymer-ization procedure outlined in Matson: U.S. Patent 3,516,~41; issued Jun~ 23, 1970. These capsules comprise - a liquid core (80%~of the capsule) containing citrus 20 ~:per ume and a urea-formaldehyde shell (20%~of the cap-sule):surrounding the liquid~core. The capsule shell ~ :

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wall has an av~ra~e thickness of about 1.5 microns.
The water-insoluble microcapsules have ~n ~verage diameter of about ~ microns.
The cationic o~nent of the fcibric treatment mixture is ditallow-alkyl, dimethyl ammonium methyl sulfate ~94~
active) obtained as a commercial product from Ashland Chemical Company.
The nonionic component of the fabric treat~ent mix~ure comprises the C16 and C18 alkyl mono, di, tri, and tetra estersof sorbitan, isosorbide and small amounts of sorbitol (collectively 1l sorbitan esters") and is obtained as a commercial product under the tradename - Glycomul~ . This sorbitan ester component comprises about 31% of the tallowalkyl monoester of 1,4-sorbitan, about 35% of the tallowalkyl diester of 1,4-sorbitan, about 12% of the tallowalkyl tri and tetra esters of 1,4-sorbitan and about 15% of isosorbide.
The cationic and nonionic components of the fabric treatment mixture are liquefied by heating, and the microcapsules are blended into the liquid mixture. The substrate roll is then fed through the liquid mixture such that the mixture is allowed to permeate the absor-bent substrate material. The substrate material is then cocled such that the fabric treatment mixture hardens, thereby formin~ a roll of impregnated substrate $ material. The substrate roll is 9 inches wide and is perforated in lines at 11 inch intervals to provide detachable sheets. Each sheet is cut with a set of , . . .

, .,, , ~

~nives to provide six parallel slots in the sheet 1 3/16 inches apart. Such slits average in length from 5 to 7 inches.
Each 9" x 11l' sheet of the impregnated substrate S has the following approximate composition:
Substrate 1.50 Grams Total Fabric Treatment Mixture 2.95 Grams Cationic Component 1.9 grams Nonionic Component 0.8 grams Microcapsules 0.25 grams Mixture/Substrate ~eight Ratio - 1.97 1 pn impregnated sheet such as described above can ,. ..... . .
be utilized in the laundry dryer to simultaneously soften - and impart perfume odor to fabrics ~eing tumbled therewith. A significant number of microcapsules from ~ , . . . . .
the substrate are transferred to the tumbling fabrics ;~ where they can then be ruptured by the tumbling ac-tion of the fabrics in the dryer.
A substantially similar dryer-added article is realized i in the Example I article the fabric treatment mixture contains about 1.9 grams of the nonionic component and about 0.8 grams of the cationic ;~ component.
- A substantia]ly similar dryer-added article is realized if in the Example I article the cationic and ; nonionic components of the fabric treatment mixture are replaced wiih about 2.6 grams of the nonionic component alone.
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A substantially similar dryer-added article is realized if in the Example I article the fabric treat-ment mixture additionally contains about 0.2 grams of a smectite clay (Gelwhite GP).

CAPSULE T~NSFER EVALUATION
.
Dryer-added fabric conditioning articles of the present invention are evaluated for their ability to deliver pexfume-containing micxocapsules to fa~rics being tumbled in the dryer therewith.
Articles substantially similar to those o-E
Example, I above containing varying amounts of encap-, sulatéd perfume are compared with similar articles .
~ containing equivalent levels of unencapsulated perfume -~ with respect to theix ability to impart perfume odor , -- 15 to fabxics being treated. For this evaluation, terxy-, cloth swatches are washed and xinsed in conventional manner and placed in Kenmore automatic dxyers along with ~' the flexi~le substrate fabric conditioning articles being tested. Dryers are operated fox 45 minutes after ,~
which time the dry test fabrics are xemoved, folded in ,, quarters and wrapped in aluminum foil to prevent odor ,~, contamination. Test swatches are then graded for odox ,, by at leas~ three expert gradexs. Each swatch is graded 5 ' immediately after being dried and again at one or ~wo ~--' 25 day intervals thereafter. Grades are assigned on a '~ scale of 0 to 10 with 0 corresponding to no detectable ,,~ ,........................................................................ .
,' fabric ordor and 10 corresponding to overwhelming fabric :,' odor, , . -Average odor grading values for these articles ,~ 3~ are shown in TABLE I.

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~'' ~ ' ' ~ '" . , , The above T~sLE I data demonstrate that articles employing the microencapsulated perfume are generally more effective at imparting perfume odor to treated fabrics tnan are similar articles wherein no perfume microcapsules are used.
When the swatches treated with microcapsule-containing articles are rubbed together, graders can detect an increase in perfume odor intensity. It can be concluded, therefore, that at least some friable microcapsules are trans~ered to fabrics in the dryer from the articles of the present invention.

WHAT IS CLAIMED IS:
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Claims (19)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A method for treating fabrics with a fabric conditioning agent, said method comprising A) applying to fabrics in an automatic laundry dryer an effective amount of a fabric treatment mixture, said mixture com-prising i) water-insoluble, friable microcapsules varying in size from about 5 to 500 microns, each microcapsule consisting essentially of a) a liquid core containing fabric condi-tioning agent;and b) a solid thin polymeric shell completely surrounding said core; said shell having an average thickness ranging between about 0.1 and 50 microns; and ii) a substantially water-insoluble,fabric sub-stantive capsule transfer agent having a melting/softening point between about 40°C and 150°C; said capsule transfer agent contacting and completely surrounding or enveloping said micro-capsules within said fabric treatment mixture; the weight ratio of microcapsules to capsule transfer agent within said mixture varying between about 0.002:1 and 2:1;
said fabric treatment mixture being applied to said fabrics in a manner such that at least a portion of said microcapsules are attached to the fabric being treated; and B) manipulating said fabrics so as to rupture at least a portion of said mocrocapsules to thereby releasre the fabric conditioning agent.

2. A method in accordance with Claim 1 wherein the amount of fabric treatment mixture utilized provides a microcapsule concentration of from about 0.0002% to 0.2%
by weight of the fabrics being treated.

3. A method in accordance with Claim 2 wherein a) the fabric conditioning agent utilized is a perfume compound;
b) the microcapsule shell wall material is selected from the group consisting of poly-urethanes, polyolefins, polyamides, polyesters, polysaccharides, silicone resins, epoxy resins, and aminoplast polymers derived from urea and aldehydes; and c) the capsule transfer agent is selected from the group consisting of cationic and nonionic organic materials and mixtures thereof.

4. A method in accordance with Claim 3 wherein the capsule transfer agent is selected from the group consis-ting of quaternary ammonium salts, C10_24 alkyl sorbitan esters, fatty monoalcohols, C8-20 alkyl diesters of glycerol C10-18 alkyl glycerol mono and di esters, and C12-20 alkylated and acylated diamine compounds.

5. A method in accordance with Claim 4 wherein the microcapsule shell wall material is a urea-formaldehyde polymer having an average shell thickness of from about 0.4 to 4.0 microns.

6. A method in accordance with Claim 5 wherein the capsule transfer agent is selected from the group consisting of quaternary ammonium salts, C10-24 alkyl sorbitan esters, and mixtures thereof.

7. A method in accordance with Claim 6 wherein A) the microcapsules vary in size between about 10 and 100 microns; and B) the weight ratio of microcapsules to capsule transfer agent varies between about 0.1:1 and 0.2:1.

8. An article of manufacture adapted for providing fabric conditioning within an automatic laundry dryer, said article comprising:
A) an effective amount of a fabric treatment mixture comprising i) water-insoluble, friable microcapsules varying in size from about 5 to 500 microns, each microcapsule consisting essentially of a) a liquid core containing fabric condi-tioning agent; and b) a solid thin polymeric shell completely surrounding said core; said shell.
having an average thickness ranging between about 0.1 and 50 microns; and ii) a substantially water-insoluble, fabric substantive capsule transfer agent having a melting/softening point between about 40°C and 150°C; said capsule transfer agent contacting and completely surrounding or enveloping each of said microcapsules within said fabric treatment mixture; the weight ratio of microcapsules to capsule transfer agent within said mixture varying between about 0.002:1 and 2:1; and B) a dispensing means which provides for release of the fabric treatment mixture within an automatic laundry dryer under dryer operating conditions.

9. An article in accordance with Claim 8 wherein A) the dryer dispensing means is an absorbent substrate having an absorbent capacity of from about 4 to 12; and B) the fabric treatment mixture is present to the extent that the weight ratio of mixture to dry substrate varies between about 5:1 and 1:1.

10. An article in accordance with Claim 9 wherein a) the fabric conditioning agent utilized is a perfume compound;
b) the microcapsule shell wall material is selected from the group consisting of poly-urethanes, polyolefins, polyamides, polyesters, polysaccharides, silicone resins, epoxy resins, and aminoplast polymers derived from urea and aldehydes; and c) the capsule transfer agent is selected from the group consisting of cationic and nonionic organic materials and mixtures thereof.

11. An article in accordance with Claim 10 wherein the absorbent substrate is in sheet configuration and has the fabric treatment mixture impregnated therein such that the weight ratio of mixture to dry substrate varies between about 3:1 and 1:1.

12. An article in accordance with Claim 11 wherein the capsule transfer agent is selected from the group consisting of cationic quaternary ammonium compounds, nonionic sorbitan ester compounds and mixtures of said cationic and anionic compounds.

13. An article in accordance with Claim 12 wherein the microcapsule shell wall material is a urea-formal-dehyde polymer having an average shell thickness of from about 0.4 to 4 microns.

14. An article in accordance with Claim 13 wherein the absorbent substrate is a flexible nonwoven cloth comprising cellulosic fibers, said fibers having a length of from 3/16 inch to 2 inches and a denier of from 1.5 to 5 and wherein said substrate is adhesively bonded together with a binder resin.

15. An article in accordance with Claim 14 wherein the capsule transfer agent comprises from about 15% to 75% by weight of di-C14-18 alkyl dimethyl ammonium methyl sulfate and from about 25% to 85% by weight of C10-26 alkyl sorbitan mono- and di-esters.

16. An article in accordance with Claim 15 wherein the flexible substrate has openings sufficient in size and number to reduce restriction by said article of the flow of air through an automatic dryer.

17. An article in accordance with Claim 16 wherein A) the microcapsules vary in size between about 10 and 100 microns; and B) the weight ratio of microcapsules to capsule transfer agent varies between about 0.1:1 and 0.2:1.

18. An article in accordance with Claim 12 wherein the fabric treatment mixture additionally contains an effective amount of an adjunct selected from the group consisting of smectite and hectorite clay materials.

19. An article in accordance with Claim 9 wherein the dryer dispensing means is an aerosol spray device.