US3617196A - Two-step cellulosic fabric modification under different reaction conditions - Google Patents

Abstract

Cellulosic fabrics are reacted in two steps with creaseproofing compounds having two or more functional groups which are activatable under different reaction conditions. The fabric may be formed into a garment between the reaction steps.

Description

United States Patent Continuation of application Ser. No. 691,650, Dec. 18, 1967, now abandoned.

TWO-STEP CELLULOSIC FABRIC MODIFICATION UNDER DIFFERENT REACTION CONDITIONS 6 Claims, No Drawings 11.8. CI 8/1 16.3, 8/115.7, 8/129, 8/120, 8/1 16.2, 38/144, 2/243 Int. Cl .,D06m 13/54, D06m 13/40, D06m 13/12 Field of Search 8/116.3,

[56] References Cited UNITED STATES PATENTS 2,837,511 6/1958 Mantell 8/116.3 X 3,102,773 9/1963 Needleman 8/116.2 3,138,802 6/1964 Getchell 8/1 16.3

OTHER REFERENCES Marsh, Crease Resisting Fabrics, Reinhold Publishing Corp. New York, 1962, pp. 172-178 Primary ExaminerGeorge F. Lesmes Axxismm Examiner-J. Cannon AlmrneysNorman C. Armitage and H. William Petry ABSTRACT: Cellulosic fabrics are reacted in two steps with creaseproofing compounds having two or more functional groups which are activatable under different reaction conditions. The fabric may be formed into a garment between the reaction steps.

TWO-STEP CELLULOSIC FABRIC MODIFICATION UNDER DIFFERENT REACTION CONDITIONS This application is a continuation of application, Ser. No. 691,650, filed Dec. 18, 1967 and now abandoned.

This invention relates to a novel process for developing durable creases in garments made of cellulosic material, preferably while simultaneously producing enhanced wet and dry resiliency properties in the garment.

In copending and coassigned US. Pat. applications Ser. No. 244,271 filed Dec. 13, 1962, now abandoned and Ser. No. 244,273 filed Dec. 13, 1962, now abandoned, there are disclosed various techniques for treating cellulosic materials to impart thereto a propensity for subsequent durable setting in garment form, while simultaneously producing enhanced wet and dry resiliency properties in the garment. All these desired properties, that is durable configurations and enhanced wet and dry resiliency properties, are developed under controlled moisture conditions on conventional pressing apparatus. The normal pressing time under best conditions runs about 30 seconds and can take as long as 5 minutes. Also, only a single garment can be treated at a time, so that production rates using the above processes have been only moderate. F urthermore, moisture control, where required, is particularly difficult on some equipment. It is essential, however, that garments produced from the presensitized fabric of the above patent applications be treated in a timely fashion in order to be acceptable to the cutter trade. It is also desirable to provide a process wherein moisture control, where necessary, is more readily provided.

It is, therefore, an object of this invention to provide a more readily controlled process for developing durable configurations in garments prepared from presensitized cellulosic materials, while simultaneously producing enhanced wet and dry resiliency properties in the garment.

A further object of this invention is to provide such a process whereby large numbers of such garments can be treated simultaneously thereby greatly increasing the production rate of garments produced in accordance with the inventions set forth in the above-identified patent applications.

Another object of this invention is to provide such a process wherein excellent sharp creases are produced in garments made of presensitized fabrics.

The objects of this invention are accomplished by hotpressing a cellulosic material characterized by one of the general formulas:

wherein Cell is the residue of a cellulose molecule and R and R,, are organic radicals reactive with hydroxy groups of cellulose under alkaline conditions at elevated temperatures, the hot-pressing procedure being conducted while the cellulosic material is folded to provide the desired configuration and impregnated with a catalyst which is alkaline and capable of initiating substantial reaction between Rand hydroxy groups of cellulose at elevated temperatures, preferably only at the elevated temperatures.

The hot-pressing is continued for a period of time sufficient only to set impermanent configurations in the presensitized cellulosic material. After this hot-pressing procedure, the stillpresensitized cellulosic material is exposed to steam, preferably containing less than about percent moisture, for a period of time sufficient to initiate substantial reaction between R and the hydroxy groups of the cellulosic material. In this manner additional cellulose ether cross-links are formed, rendering the impermanent configuration set in the fabric during hot-pressing substantially durable to wetting, simultaneously providing enhanced wet and dry resiliency properties in the cellulosic material.

The impermanently set cellulosic material must be maintained in its impermanent configuration during steaming and should be maintained at a moisture level not exceeding 20 percent by weight until after the impermanent configuration is rendered durable by the substantial cross-linking which occurs during steaming. If the impermanently set cellulosic material becomes excessively swollen as the result of the presence of large amounts of moisture, the impermanent configuration is destroyed so that the desired crease, for example, is not obtained, although improved flat-drying properties will be obtained. In a preferred embodiment of this invention, the moisture level in the fabric is maintained at less than about 10 percent, preferably below about 5 percent by weight.

The above process is improved in another embodiment of this invention which enables the operator to raise the temperature of the fabric to the activating level in even a more efficient and rapid manner, while eliminating problems associated with moisture from steam condensing in the steam chamber and contributing to loss of the desired configuration. This is accomplished by preheating the chamber in which the steam operation is to be conducted to a temperature in excess of about C. This procedure aids in vaporizing some, if not all, of any moisture which may be present in the steam. This procedure greatly facilitates the accomplishment of the objectives of this treatment, that is, to maintain the garment in a substantially dry state, though containing enough moisture to provide enhanced wet resiliency properties, and to increase the temperature of the garment to the activating level at a rapid rate without destroying the impermanent configuration of the garment.

The process of this invention is adaptable to producing a wide variety of garments having durable configurations set therein along with enhanced wet and dry resiliency properties, for example, men's and women's slacks, shirts, suits, women's blouses, dresses and skirts and comparable children's wear. The process is particularly useful for producing mens slacks with permanent creases in the legs and in dress wear to provide permanent pleats.

The starting garments are formed of cellulosic fabrics which have been chemically treated to provide reactive radicals thereon which cross-link the cellulose molecules under conditions employed in the present process. Such chemically pretreated fabrics, when in the presence of a latent base-acting catalyst, may be referred to as presensitized fabrics. ln other words, they do not require the application of additional chemicals in order for the desired reaction to take place with the development of the desired properties therein.

The presensitized fabric forming the starting garments for the process of this invention preferably are those wherein the cellulosic molecules thereof have an average of at least 1.8 unsubstituted hydroxy groups and at least 0.05 hydroxy groups per anhydroglucose unit substituted through an ether linkage by a radical reactive under alkaline conditions at elevated temperatures in the presence of limited amounts of moisture or otherwise.

Such fabrics can be produced by chemically modifying, in accordance with the above-identified patent applications, natural cellulosic materials, for example, cotton, paper, linen, jute, flax and the like; synthetic cellulosic materials, for example, filament or staple viscose rayon, both unmodified and modified, for example, the Polynosic rayons.

In addition to the preferred number of free hydroxy groups and reactive radical-substituted hydroxy groups, the cellulosic material can have a minor proportion of hydroxy groups substituted with ether or ester groups, for example, lower hydrocarbon esters, including the acetate, propionate, butyrate, benzoate, sulfate, phosphate, aryl and alkyl sulfate esters; lower alkyl ethers, including methyl and ethyl; and hydroxy alkyl, including hydroxyethyl and carboxymethyl ethers and the other known cellulose esters and ethers.

The novel process of this invention is directed primarily, and preferably, to garments formed of woven fabric, but the advantages can also be achieved by treating nonwoven or knitted fabrics. The preferred cellulosic material is presensitized cotton fabric which is preferably woven and, more preferably, printcloth, broadcloth or sheeting. The configurations set in sheeting, for example, may be embossed if desired.

The cellulosic fabrics employed to form the garments treated in accordance with this invention consist substantially entirely of the cellulosic material, although blends with synthetic fiber components are entirely suitable if desired. For example, there may be treated blends with synthetic fibers including synthetic cellulosic fibers. For example, there may be used synthetic fibers, such as polyamides, e.g., poly (hexamethylene adipamide), poly e-caprolactam; polyesters, such as poly (ethylene terephthalate); acrylic fibers, such as polyacrylonitrile and copolymers containing at least 85 percent combined acrylonitrile.

As stated above, the preferred cellulosic fabric employed in the present process has an average of at least l.8 unsubstituted hydroxy groups per anhydroglucose unit. Such degree of unsubstitution enables the desired cross-linking reaction to take place to a satisfactory extent. Preferably, there are at least two unsubstituted and more preferably at least 2.5 unsubstituted hydroxy groups per anhydroglucose unit for the same reason. Of the remaining hydroxy groups, an average of at least 0.05 and more preferably at least 0.3, for example, up to 0.5 hydroxy groups per anhydroglucose unit, are substituted through an ether linkage by a radical reactive under alkaline conditions towards the hydroxy groups of cellulose at elevated temperatures, so as to form additional either linkages therewith. These substituted hydroxy groups can be represented by the formulas CellO-R or Cell-O as set forth above.

The etherified cellulose products Cell-O-R and Cell-O a CellO are preferably produced by impregnating a cellulosic material with a polyfunctional compound containing at least two groups reactive with hydroxy groups of cellulose, at least one of the groups being reactive with hydroxy groups of cellulose under conditions markedly different from the reactivity of at least one other of the groups. The diether product is prepared in a similar manner, except that the compound contains more than two reactive groups, at least two of which are similarly reactive, and at least one other being markedly different in reactivity. After impregnating the above cellulosic material with a catalyst for the reaction of only one class of the reactive groups with hydroxy groups of cellulose, the desired etherified cellulose product may be produced by exposing the cellulosic material to conditions, generally of elevated temperatures, whereby the catalyzed group reacts with hydroxy groups of cellulose and under which the other class of reactive groups is substantially nonreactive with hydroxy groups of cellulose. The presensitized material may then be produced by impregnating the cellulosic material with a latent base-acting catalyst, which catalyzes the reaction between the remaining class of reactive groups in cellulose at elevated temperatures under alkaline conditions, and drying the cellulosic material at temperatures sufficiently low that substantial reaction does not occur.

In a preferred embodiment of this invention, the starting cellulosic material is reacted initially on the acid side, i.e., under textile resin-curing conditions, with a polyfunctional compound containing at least one organic radical reactive with hydroxy groups of cellulose under acidic conditions and at least one other reactive group reactive with hydroxy groups of cellulose under alkaline conditions. The diether product is preferably similarly produced by reaction with a polyfunctional compound containing at least two acid-reactive groups and at least one base-reactive group.

The acid-reactive groups are generally those found in the textile resins presently employed in the resin treatment of cellulosic fabrics, e.g., methylol, epoxy, acetal, alkylated methylol, aldehyde,

where R is hydrogen or alkyl, -N=&O,-N=C =S and the like. These groups are characterized by their ability to combine with the hydroxy groups of the cellulose molecule under textile resin-curing conditions. The term textile resin" as used herein is in conformity with the generally accepted usage in the textile art; i.e., it defines a thermosetting reagent which is applied to a textile fabric and reacted therewith when the dry fabric is heated, usually in the presence of an acid-acting catalyst, at a temperature usually between about and about 200 C. These latter conditions are referred to herein as "textile resin-curing conditions. At these temperatures, the reagent, even by itself, will ordinarily resinify in the presence of an appropriate catalyst, thus probably contributing to the use of the term resin treatment." However, it is to be understood that the term as used in the textile art is a misnomer, in that in contradistinction to the generally accepted meaning of the term resin, "textile resins" are of relatively low molecular weights, are almost always water soluble and are often liquids.

Included in the e.g., of textile resins are the urea-formaldehydes and the melamine-formaldehydes, e.g., dimethylolurea and tetraand penta-methylol-melamines; the acroleinurea-formaldehyde resins; the cyclic ethylene urea-formaldehyde resins, e.g., dimethylol cyclic ethylene urea and dimethylol dihydroxy cyclic ethylene urea; trimethylol acetylene diurea and tetra-methylolacetylene diurea; the triazones, e.g., dimethylol-N-ethyl-triazone, dimethylol-N- hydroxyethyl-triazone and N,N'-ethylene-bis-dimethyloltriazone; and the urons, e.g., dimethylol uron.

These aminoplast textile resins exemplify the wide variety of structures which can be used to contribute to an acid-reactive group to the polyfunctional compounds employed in the process of this invention. Other nonnitrogen-containing textile resins can also be employed, e.g., the epoxy and acetal textile resins. It will be obvious to one skilled in the art that the choice of compound employed to contribute the base-reactive group will be influenced by the functional groups present in the compound contributing the acid-reactive group.

The base-reactive groups are those which have the capacity of reacting with the hydroxy groups of the cellulose molecule under alkaline conditions preferably only at elevated temperatures and include epoxy and halohydrin groups, and carbonyl, acetylenic, sulfone and sulfoxide activated groups, e.g., of the formula -CH Cl-l -AA' wherein A is a carbonyl, sulfone, sulfoxide or acetylenic group and A is sulfatoethyl, alkali-metal sulfatoethyl, phosphatoethyl, alkali-metal phosphatoethyl, thiosulfatoethyl, and alkali-metal thiosulfatoethyl, quaternary ammonium ethyl halides, e.g., pyridinium ethyl chloride, vinyl or substituted, e.g., lower alkyl vinyl, sulfonhalides, such as sulfonfluoride yethyl-triazone.

chloro-S-triazine and the like.

Both the acid-reactive and base-reactive groups can be epoxy if one of the epoxy groups has a.lower order of activity ,than the other under textile resin-curing conditions so that it does not, at that step, react with the cellulose, Employing a mild catalyst such as. for example, zinc chloride, magnesium chloride or an amine hydrochloride will facilitate such a preferential reaction.

Compounds which can be employed to contribute the basereactive group to the polyfunctional compounds employed in the process of this invention include polyhydroxy compounds, at least one hydroxy group of which is activated and esterified. Esters of activated hydroxy groups can be carried through the heating step under textile resin-curing conditions and will then be available to react with the cellulose molecule in*.;the presence of strong aqueous base. The unesterified hydroxy group is available to react with thecompound contributing the acid-reactive group, e.g., an aminoplast textile resin. thereby producing a polyfunctional compound having both acidand base-reactive groups. Within the above definition are included the monoesters of di-B-hydroxyethyl-sulfone and of di-B- hydroxyethyl-sulfoxide. The monoester can be the sulfate, phosphate or thiosulfate, preferably in the form oftheir alkalimetal salts, or an organic ester, e.g., lower alkanoate, orother alkyl, aryl, alkaryl, or arylalkyl ester, preferably hydrocarbon and containing from one to l2 carbon atoms.

Because of the activated character of the hydroxy'groups of the starting compounds, the monoesters thereof can readily be prepared by employing a mole of the esterifying reagent per mole of the starting dihydroxy compound. Only very mild esterification conditions are required. For example. the sulfate monoester can be prepared at room temperature with about two molar equivalents of concentrated sulfuric acid. The reaction product can be converted to an alkali-metal salt by pouring into ice water andthen carefully neutralizing to a pH of about 4 with, e.g., sodium carbonate.

A method ofproducing an alkali-metal salt directly involves mixing the starting dihydroxy compound with about a molecular equivalent of sodium or potassium bisulfate and then heating while .removing the water of reaction, usually with an azeotropic solvent. These monoesters can then be reacted with an aminoplast polymethylol textile resin either prior to applying the compounds to the selected textile-material or subsequent thereto.

Examples of compounds containing acid and basevreactivegroups which can be usedin the process of this invention are the reaction products of the sodium salt of the sulfato monoester of di-B-hydroxy-ethyl-sulfone with dimethylol urea, dimethylol-N-ethyl-triazonc dimethylol-N-hydroxdimethylol cyclic ethylene urea, or dimethylol-dihydroxy-cyclic ethylene urea, and thereaction products of the corresponding acetic acid monoester with each of the above textile resins.

While the above compounds are entirely suitable for usein accordance with this invention, preferred compounds include those characterized by the formulas:

whereinv R is selected from-hydrogen, lower alkyl, and the residue of a saturatedor unsaturated aldehyde; R is selected from hydrogen; lower alkyl; and

chlorine, bromine or iodine.

Additional suitable compounds include imides, such as and corresponding sulfoxamides.

Additional suitable compounds having reactive'groups of 'markedly.different orders of reactivity include anhydrides and the like; halotriazincs, such- 1X. 4 Y Z 'whercin'Z an organic radical such as and Y is halogen.

, -Additionalsuitable compounds include:

CH OR wherein R is selected from hydrogen. lower alkyl and -CH- ,OR; and .\=l--6. e .g.. N-methylokmethylene-bis-(acrylamide) and thelike;

eg. as derived from methylene-bis-acrylamide and glyoxal, and the like.

In any of these compounds, particularly those characterized by formulas I. ll, ill and IV above,

and sulfonium groups.

Additional compounds having reactive groups of markedly different orders of reactivity include anhydrides, such as and the like; halotriazones, such as an. N

wherein Z is an organic radical such as --NCIIg-CO2NL and the like such as B-hydroxyethyl vinyl sulfone: B-methoxyethyl vinyl sulfone and sodium sulfatoethyl -B-methoxyethylsulfone (as where R is also sulfatoethyl, alkali-metal sulfatoethyl, phosphatoethyl, alkali-metal phosphatoethyl. thiosulfatoethyl and alkali-metal thiosulfatoethyl and the like.

included in the above polyfunctional compounds are those wherein the methylol group is derived from aldehydes other than formaldehyde. such as those derived from saturated or unsaturated aldehydes, whereby R would be lower alkyl, e.g., acetaldehyde; vinyl, e.g., acrolein; acetyl, e.g,, pyruvaldehyde; CH CH=CH-, e.g., crotonaldehyde',

e.g., methacrolein; OCH(CH ),,-wherein n=-4, e.g., glyoxal (n=l OCH(CH CHOH-, e.g., hydroxy adipaldehyde and the like.

Preferred compounds characterized above are the methylol acrylamides and haloacetamides, e.g.,

HO CH:NHC-CH:CH2 (N-methylolacrylamide) H O CH N CH CCH=CH: (N-methylol'N-mcthylaery1amide) HOCHCH NII( ICH=CH (Nmethylmcthylolacrylamide) H0 CH NHC CH Cl (N-rnctliylolchloroacetamide) H H O CH -N CII3CCHQCI (N-rnethylol-N-methylchloroacetamidc) and the corresponding N,N-dimethylol derivatives thereof, the methylol groups of which are reactive with the hydroxy groups of cellulose under textile resin-curing conditions, as with an acid-acting catalyst at elevated temperatures,the CH2=CH- and -CH Cl groups being reactive with hydroxy groups of cellulose under alkaline conditions at elevated temperatures.

For example, when a cellulosic fabric impregnated with N- methylolacrylamide and an acid-acting catalyst is exposed to textile resin-curing conditions, the following cellulose ether is formed:

The fabric is then padded with catalyst which initiates substantial reaction between the ethylenically unsaturated group and hydroxy groups of cellulose only at elevated temperatures, e.g., NaHCO which forms strongly basic Na CO upon heating to temperatures in excess of about 65 C. After drying at lower temperatures, the fabric may be shipped to a garment manufacturer who can store the mildly alkaline fabric until ready for use, so long as activating conditions are not produced.

These garments can then be folded to provide the desired configuration therein, for example creases, and hot pressed on a conventional Hoffman press. The Hoffman press may be operated at conventional temperatures, for example, about C., but for a period of time sufficient only to impart impermanent creases and flat portions to the garment. By impermanent is meant that the configuration set therein, for example, a crease, is removed after immersion in water at F. for one-half hour while being agitated. It is possible that some slight degree of activation ofthe catalyst and some slight reaction between the base-reactive groups and hydroxy groups of cellulose occurs during hot-pressing. but the level of reaction is too low to produce durability in the configuration set.

This hot-pressing procedure generally requires no more than about 30 seconds but as little as 2 or 3. preferably 5 seconds, may be utilized with success. The garment is preferably exposed to steam, more preferably dry steam. during this procedure to facilitate placement of the impcrmanent configurations in the garment.

Conventional pressing apparatus can be utilized for the hotpressing step and include such apparatus as the Hoffman press, heated platens, and the like. The temperature utilized during this hot-pressing step is not particularly critical. the objective being to place a sharp crease or other configuration in the fabric in the least time possible. This is generally facilitated by increased temperature. for example. temperatures up to about 400 F. and the use of steam, preferably steam containing less than about 10 percent moisture, or equivalentswelling agent.

After this short hot-pressing step. during which imper manent configurations are set in the garment, the garments are then loosely arranged in a steam chamber along with a multiplicity of similar garments, hot-pressed in a similar manner. Any conventional steam box may be utilized, but preferably a steam box which is equipped with apparatus for heating the sidewalls thereof is utilized. e.g.. as with heat jackets or electrical resistance wires. The multiplicity of garments is then exposed to steam containing less than about 10 percent moisture for a period oftimc sufficient to permit substantial reaction to occur between the base-reactive groups and the hydroxy groups of cellulose. By forming an ether linkage with another hydroxy group of cellulose through the basereactive group, a cross-linked stable configuration is set into the garment and enhanced wet and dry resiliency properties are obtained.

It is an objective during the steaming operation to raise the temperature of the garment above the activating temperature of the catalyst, whereby substantial reaction can be effected at as rapid a rate as possible. This can be greatly facilitated by preheating the walls of the steam chamber r'ir'n 'eraiir'e'in excess of 100 C. before and/or after, or both, the garments are placed therein.

In conducting this press-curing operation, it should be noted that the fabric should not be moistened at any time after the impermanent crease is set therein to a level exceeding 10 percent in excess of the moisture regain level of the fabric, in that the swelling so induced would remove the impermanent creases therefrom, so that permanent sharp creases could not be obtained by any curing technique.

When only difunctional presensitizing agents are utilized, the moisture content at the time of setting is also critical for the production of both wet and dry resiliency properties. For example, both properties are provided to the optimum extent only at fairly low moisture levels, of less than 10 percent total moisture in the garment. On the other hand, the dry resiliency properties imparted during the acid cure when trifunctional compounds, i.e., those with at least two acid-reactive groups, is permanent and both wet and dry resiliency properties are obtained after the basic cure regardless of moisture level, provided even small amounts of moisture are present.

Preferably, the total moisture level in a cotton fabric, or similar natural cellulosic, does not exceed 12 percent at any time after hot-pressing and before permanent setting. The corresponding value for viscose rayon fibers is a little higher because of the higher regain values for these fibers, and should be no more than about 16 percent by weight.

The textile resin catalysts employed during textile resin curing are a well-known class of compounds and include the acid-acting" compounds, i.e., those compounds which are acidic in character under the curing conditions. The most common are the metal salts, e.g., magnesium chloride, zinc nitrate, and zinc fluoroborate, and the amino salts, e.g., monoethanolamine hydrochloride and 2-amino-2-methylpropanol nitrate. The amounts of catalyst to be employed are the same as those employed when using the usual textile resins, e.g., up to about 20 percent by weight of the acid-reacting compound employed, with the preferred range being from about 0.5 percent to about 10 percent.

While any acid-acting catalyst may be utilized, it may be preferable in some instances to use a mild or strong catalyst depending on the polyfunctional compound. For example, if both the acid-reactive and base-reactive groups are epoxides, it is preferred to use a mild acid-acting catalyst to induce the required preferential reaction. On the other hand, when utilizing N-methylol acrylamides, it is often preferred to utilize a strong acid-acting catalyst, such as zinc nitrate and the like, in that improved properties, such as less chlorine retention, are obtained using these stronger acid catalysts. In this regard, compounds like zinc nitrate, which produce relatively low pH values in fabric during curing, are considered strongly acidic, whereas compounds like magnesium chloride are considered mildly acidic.

Selection of the base-acting catalyst is particularly critical for the production of a presensitized" fabric which will withstand normal storage. The base-acting catalyst is a compound which does not initiate substantial reaction between the base-reactive group and hydroxy groups of cellulose under normal conditions, but does initiate substantial reaction under prescribed conditions, such as elevated temperature or some other activating means, as by use of another chemical compound. For example, an alkali-metal sulfite can be padded onto the fabric can be decomposed into strongly basic alkalimetal hydroxide by including small amounts of formaldehyde in the steam used for curing.

The latent base-acting catalyst utilized herein, however, preferably comprises alkaline-earth salts, such as alkali-metal carbonates like sodium bicarbonate, which is neutral to mildly alkaline, e.g., pH of about 8.5, on the fabric, but decomposes at temperatures of about 65 C. to form the stronger base, sodium carbonate, which will initiate the reaction at the elevated temperatures utilized during press curing. Sodium carbonate may be utilized ifdesired, since the pH of 9.5 in the fabric produced by this compound under normal conditions, is generally insufficient to initiate the desired degree of reaction to any appreciable extent under normal temperature conditions. Fabrics at pH level above about 10, however, gradually degrade during storage and essentially neutral or mildly alkaline catalysts are preferred where optimum storage properties are desired.

Additional base-acting catalysts include potassium bicarbonate, potassium carbonate, sodium silicate, alkali-metal phosphates, such as sodium or potassium phosphates; barium carbonate; quaternary ammonium hydroxides and carbonates, e.g., lauryl trimethylammonium hydroxide and carbonate, and the like.

These bases are usually employed as about 0.2 percent to about 16 percent solutions, preferably about 2 percent to about 16 percent. The exact concentration, while not critical, will affect the results obtained. The concentration which gives the optimum result will depend, in part, on the percent pickup of the base by the textile material, the temperature at which the reaction is conducted, and the amount of base consumed in the reaction. If a highly acidic group is released during the reaction, the amount of base applied to the textile material should be at least the amount that will be consumed by that group. Generally, a 3 to 10 percent aqueous solution of base is preferred when the pickup is between about 30 to I30 percent, calculated on the weight of the dry textile material.

In carrying out the initial heating step of the process of this invention the cellulosic material, uniformly impregnated with a polyfunctional organic compound having at least one acidreactive group and at least one base-reactive group, is heated under textile resin-curing conditions in the presence of an acidic catalyst. As stated before, this acid and base-reactive compound can be that which is initially applied to the textile material or can be the product of an in situ reaction of an acidreactive group-containing compound and a base-reactive group-containing compound. Under ordinary conditions, this step employs conditions identical to that of a conventional resin treatment. For example, the selected reagents can be applied to the textile material by padding, spraying, or applicator roll and then passing through squeeze rolls, if necessary, to achieve the desired pickup of the reagents. As these reagents are ordinarily applied as aqueous solutions, the textile material is dried and then heated to the appropriate temperature, e.g., about to 200 C., preferably about to C., to chemically affix the compound to the textile material through the acid-reactive group. When employing fabric, these steps of drying and curing are conducted while the fabric is free from extraneous wrinkles, usually in a smooth, open width condition.

Conventional curing equipment is suitable for this opera tion. For example, when employing a fabric, the reagents can be applied with the usual equipment and then passed through squeeze rolls and dried, e.g., at room temperature or while the fabric passes through a hot-air oven or over heated cans. In production, it is preferred to conduct the heating operations in a tenter frame to maintain the desired dimensions.

The thus-treated textile material is then ordinarily given a thorough wash to remove the catalyst and any unreacted reagents. lf sufficient reagents are employed in this step, the textile material will be found to possess a high degree of dry resiliency at this stage.

The step of contacting the textile material with the desired base-acting catalyst employs conditions generally employed in the textile trade, and the necessary techniques will be apparent to those skilled in the art. For example, impregnating the textile material with flie se lected catalyst can be accomplished in a manner similar to those employed in the previous step. The material can be moistened by dipping in an aqueous solution of the selected base, and squeezed through rollers to achieve the desired pickup of the base.

The fabric is then dried under conditions insufficient for the base-acting catalyst to cause substantial reaction between the base-reactive group and hydroxy groups of cellulose. The fabric containing the latent catalyst is then shipped to garment manufacturers for production of garments which can be subsequently pressed to obtain both wet and dry resiliency properties, in addition to sharp, durable creases or pleats.

The following examples illustrate preferred embodiments of this invention.

EXAMPLE 1 An aqueous solution containing 28.4 percent by weight of N-methylolchloroacetamide is padded onto 80x80 bleached and mercerized cotton print cloth in the following manner. The print cloth is padded through a solution comprising 10 percent solids N-methylolchloroacetamide, a zinc nitrate catalyst (1 percent of Zn(NO (H O), 6 percent of a polyethylene softener (Moropol 700and one-third percent of the surfactant (Surfonic N-95). The wet fabric is then squeezed through nip rolls at 60 lbs. per square inch pressure to provide a pickup of about 75 percent based on the weight of the dry fabric. The fabric is dried over hot cans and then cured by passing through a curing oven about 175 C. for 90 seconds.

The cured fabric is then washed to remove all unreacted chemicals, air dried and padded and squeezed to 75 percent pickup with percent aqueous sodium bicarbonate. The fabrics are then air dried to give the presensitized cotton fabric.

Five dozen men's trousers are prepared trousers the presensitized fabric and they are then pressed while steaming on a Hoffman press set at 135 C. for 5 seconds. The impermanently sharp-creased trousers are then hung on hangers and mounted onto a rollable carriage. The carriage is rolled into a steam autoclave adapted thereto. The vessel is a conventional steam autoclave capable of withstanding up to about 50 p.s.i. pressure and having electrical resistance heating elements located around its outer periphery for heating the sidewalls. In this example, the sidewalls are preheated to 105 C. before the carriage is placed in the autoclave and maintained at that temperature throughout the treatment.

Steam at 130 C. is then admitted to the autoclave through a preheated pipe (electrical resistance wires) and a moisture trap. After exposure to the steam for 10 minutes, the carriage is removed. The sharp creases produced in this manner remain in the trousers after washing in water containing 0.1 percent detergent at 120 F. for 1 hour. After drying, the trousers exhibit excellent flat-drying properties as shown by their neat appearance.

EXAMPLE [I Impermanent creases which remain sharp until the steamcuring step are also imparted to the fabric of example 1 when pressed on the Hoffman press for 2 seconds under steam, 10 seconds under steam, seconds without steam and by pressing with a platten press at 200 C. for 5 seconds under 10 pounds per square inch pressure. The fabric during platten pressing contains 5-10 percent moisture as its moisture regain level.

EXAMPLE 111 swatches impregnated with sodium carbonate are dried over hot cans, heated to 1 10 C. Under these conditions, the fabric does not reach the temperature of the hot cans so that the reaction between the acetyl halide groups and hydroxy groups of cellulose does not occur to a degree sufficient to destroy the fabrics propensity for subsequent durable setting. Upon pressing on a Hoffman press for 5 seconds under steam and steaming in an autoclave as in example [,trousers havingsharp creases substantially durable to laundering are obtained, with good wet and dry resiliency properties.

EXAMPLE 1V Samples of the same starting fabric as that described in example are padded in the manner described therein with a solution comprising 15 percent of a 60 percent aqueous solution of N-methylolacrylamide (obtained from the American Cyanamid Company), 2 percent catalyst AC (a solution of 2- amino-Z-methyl-l-propanol hydrochloride), 6 percent of a polyethylene softener (Moropol 700) and one-third percent of a surfactant (Surfonic N-95). The fabrics are dried over hot cans, then cured by passing through a curing oven at 182 C. for seconds. After washing and drying, the fabrics exhibit a tensile strength of 27.6 lb. a tear strength of 456 gm., crease recovery angles (warp and fill) of 210 (dry) and 230 (wet), and spin and tumble ratings of 1.7 and 2.8, respectively.

The fabric samples are further padded to a pickup of approximately 85 percent, with 4 percent aqueous sodium bicarbonate or 2 percent aqueous sodium carbonate and air dried to give the presensitized cotton fabrics.

The presensitized fabrics yield creases durable to laundering when hot-pressed and steamed in the autoclave as in example 1. The creases have a good appearance irrespective of whether the fabrics are spun dried following by line drying, or tumble dried. The sodium carbonate catalyst gives slightly better creases than the sodium bicarbonate.

EXAMPLE V Samples of the starting fabric of example 1 are padded as described therein with a solution comprising N- methylolacrylamide (15 or 25 percent of a 60 percent solution, being equivalent to 9 and 15 percent solids, respectively), 3 percent catalyst AC, 6 percent Moropol 700 polyethylene softener and one-third percent Surfonic N- surfactant. After drying over hot cans, the fabrics are cured at 182 C. for 90 seconds, washed and dried.

These hot-pressing are then padded to a pickup of about 85 percent with aqueous solutions containing 4 percent sodium bicarbonate and 3 percent sodium carbonate together with one-third percent sodium borohydride and air dried. Durable pleats are provided in the fabric samples by hot-pressing for 10 seconds in the presence of steam in the Hoffman press and then dry-steamed in an autoclave as in example 1 for 15 minutes. The presence of the sodium borohydride completely eliminated any tendency of the fabrics to yellow during the pressing operation. However, the pressing time for production ofa good durable crease is now only 30-60 seconds.

It may be noted that the fabrics impregnated with sodium bicarbonate solutions must be dried at less than 65 C. to avoid conversion of the bicarbonate to carbonate. The fabrics impregnated with sodium carbonate solutions may be dried over hot cans at temperatures up to 1 10 C., since the fabric apparently does not reach a sufficiently high temperature to cause substantial reaction of the vinyl group with the cellulose.

Good durable creases are also produced by pressing the samples in the presence of steam on the Hoffman press for 5 seconds, followed by setting in dry air in an oven at C. for 2 minutes. The bicarbonate catalyzed samples have 4.0X4.0 spin and tumble ratings after this latter press-curing operation.

EXAMPLE V1 The examples thus far enumerated have involved the production of presensitized fabrics by the acid-catalyzed reaction, with the cellulose hydroxy groups, of one functional group in a difunctional reagent. The second functional group is then subsequently reacted under conditions of basecatalysts. It is also possible to reverse this procedure as the present example will show.

The procedure of example I is repeated except that the starting fabric is padded with solutions comprising N- methylolacrylamide (9 or l8 percent solids) and 3 percent sodium hydroxide. After aging overnight at room temperature, the fabrics are washed and dried, and at this point exhibit spin and tumble ratings both equal to 1.0. The fabricsare then padded to about 85 percent pickupwith a magnesium chloride catalyst (catalyst MX; 2 or 3 percent) and air dried. The presensitized fabrics thereby obtained are given impermanent creases by hot-pressing on a Platen press at l77 C. for 5 seconds. Durable creases are obtained by. steaming in an autoclave as in example l'but for 30 minutes. No yellowing of the fabrics occurs. Similar results are obtained with catalyst AC.

EXAMPLE VIl This example illustrates the use of a difunctional presensitizing agent where advantage is taken of the very different reactivities of the two epoxide groups contained therein. In this case, both steps in the process involve acid catalysts.

The starting fabric of example [is padded as described therein with a solution containing 20 percent of vinylcyclohexene diepoxide and 2 percent zinc fluoroborate (Zn(BF,) and dried at a temperature of l40 C. The fabric is washed, dried, repaglded to about 85 percent pickup with 1.5 percent Zn(BE and dried, to yield the presensitized fabric.

Durable creases are imparted to this fabric by hotpressing for seconds and pressure steaming for minutes in an.autoclave, as in example 1 except that the autoclave is not preheated.

EXAMPL-E VIII The reaction product of glyoxal with two molar equivalents of acrylamide is also employed as a presensitizing agent. 285 grams of 40 percent glyoxal (2 moles) and 95 gm. water are adjusted to a pH of 8.0 with 1.0 N-sodium hydroxide solution. 284 gm. of acrylamide and 3 gm. of methylhydroquinone inhibitor are added and the mixture is heated at 50 .C. for 1.5 hours and cooled. The starting fabric of example I is padded as described-therein with a solution comprising 20 percent of; the above solution, an acid catalyst (l percent Zn(NO '6H O), .or 2 percent catalyst MX), 6 percent Moropol 700 polyethylene softener and one-third percent Surfonic bl-95 surfactant. After drying over hot cans, the fabrics are cured at l77 C. for 90 seconds, washed and dried.

These fabrics are padded to approximately 100 percent pickup with a solution comprising 4 percent sodium bicarbonate and 0.2 percent sodium borohydride, and air dried to give the presensitized fabrics. Ten seconds pressing in the presence of steam .on the Hoffman press is sufficient to impart sharp, but impermanent, creases to the presensitized fabrics. These fabrics are then placed in a nonpressurized steam box for 20 minutes in the presence of dry steam to render the sharp creases permanent. Less sharp, though satisfactory creases, are obtained when no effort is made to provide dry steam. It is believed the moisture level in the fabric reached 8.0 percent during steaming.

EXAMPLE IX The procedure of example VIII is repeated except that the 14 reaction product of 1 mole acrolein and 3 moles acrylamide, condensed at pH 2 by heating at 60 C. for 30 minutes, is utilized as the presensitizing agent. The fabric is padded with a 50 percent solution (adjusted to pH 9) of the reaction product containing 3 moles formaldehyde. Substantially similar results are obtained.

EXAMPLE X The procedure of example I is repeated except that an aqueous solution containing 10 percent of the sodium salt of the sulfato monoester of di-B-hydroxy-ethyl-sulfone, 10 percent dimethylol urea along with the same catalystQsoftener and surfactant is utilized. Substantially similar results are obtained.

EXAMPLE XI wherein R is selected from hydrogen and lower alkyl; R is selected from hydrogen and lower alkyl; R is selected from hydrogen and methyl; Ris selected from hydrogen and lower ,alkyl; R5 :is-selected from -CI-IR, -CH CH X is selected from sulfur and oxygen and Y is a halogen, and an acid-actingcatalyst which is capable of promoting the reaction between ce'llulose hydroxyl groups and the methylo'l or alkylated methylol group or groups of said creaseproofing compound without functioning as a catalyst for the reaction between cellulose hydroxyl groups and .the remaining functional group of said compound; I

b. reacting said fabric with said creaseproofing compound;

c. thereafter impregnating said fabric with an alkaline-acting catalyst which is capable of catalyzing the reaction between cellulose hydroxyl groups and the remaining functional group of said creaseproof ng compound and which is m-ildlyalkaline on the textile fabric but which is .convertable ;to a stronger base at temperatures in excess of ou C;

d. drying said fabric at a temperature sufficiently below about 60 C. to avoid significant reaction between the remaining functional group of said creaseproofing compound .an d the hydroxy groups of the cellulose;

e. forming a -garment from said fabric;

f. arrangingsaid garment to provide a desired configuration;

g. hot-pressing said garment for a period of time only sufficient to set impermanent configurations in said garment;

h. steaming said impermanently set garment for a period of time sufficient to initiate substantial reaction between said unreacted second type of functional group and hydroxy groups of the cellulose to form an ether linkage therebetween by activation of the catalyst of step (c). while the moisture level in said garment is maintained below about20 percent by weight in excess of moisture regain to render durable the impermanent configurations in said garment.

ture above about C.

5 The process as defined in claim 1 wherein the polyfunctional organic creaseproofing compound is selected from the group consisting of N-methylol acrylamide and N-methylol chloroacetamide.

6. The process as defined in claim 1 wherein the moisture level of the garment during steaming is maintained below about 10 percent by weightin excess ofmoisture regain.

Claims (4)

1. 2. The process as defined in claim 1 wherein the alkaline catalyst is an alkali-metal bicarbonate.
2. 3. The process as defined in claim 1 wherein the cellulosic textile fabric is selected from the group consisting of cotton fabric, regenerated cellulose fabric and a synthetic/cotton blend fabric.
3. 4. The process as defined in claim 1 wherein the steaming is conducted in a chamber that has been preheated to a temperature above about 100* C. 5 The process as defined in claim 1 wherein the polyfunctional organic creaseproofing compound is selected from the group consisting of N-methylol acrylamide and N-methylol chloroacetamide.
4. 6. The process as defined in claim 1 wherein the moisture level of the garment during steaming is maintained below about 10 percent by weight in excess of moisture regain.