US2602018A - Monomethylol dimethyl hydantoin and dimethylol urea to shrinkproof and creaseproof cellulose fabrics - Google Patents

Description

Patented July 1 1952 2,602,018 7 MONOMETHYLOL DIMETHYL HYDANTOIN AND DIMETHYLOL UREA TO SHRINK- PROOF AND CREASEPROOF CELLULOSE FABRICS Leo Beer, Montreal, Quebec, Canada No Drawing. Application January 3, 1950,'Serial No. 136,661. In Canada December 22, 1949 INTRODUCTION This invention relates to a process of imparting I to cellulosic textile fabrics crease-resistance of improved permanence against washing combined with permanent boil-fast shrink-proofness. This application is a continuation-in-partof application S. N. 130,609 filed December 1,1949.

This process is applicable to textile fabrics selected from the group COIlSiStlIlg. of natural cellulose, regenerated cellulose, mixtures of a plurality of the foregoing types in any proportion, and mixtures of one or more of the said types with up to about 50% of a cellulose ester of an organic acid, for example, cellulose acetate.

PRIOR ART Fabrics made from these cellulosic materials not only have the tendency to shrink in washing but also to deteriorate rapidly in appearance and to lose their freshness when crushed, twisted, or otherwise subjected to localized physical force. Therefore, these fabrics are often subjected to processes attempting to render them creaseproof so as to maintain their freshness in appearance. For crease-proofing,,the textile materials are generally treated with watery solutions of ureaformaldehyde or melamine-formaldehyde precondensates under specific conditions. If such processes are carried-out under tensionless working conditions, it might sometimes be expected that the treated material would in addition to being crease-proofed, be stabilized againstshrinkage when washed.

For example, according to U. S. Patent 2,088,227 Tootal Broadhurst Lee 00., a resin precondensate is prepared having a mol ratio of 1:1.6 of urea to formaldehyde. The patent states that such solutions consist mainly of a monomethylol urea or mixtures thereof with dimethylol urea The aqueous solutions of monomethylol urea or mix;

tures of monomethylol ureaand dimethylol urea are very sensitive to acid conditions. vBy-adding a dilute mineral acid or even by adding a solution of a weak organic acid as for example, acetic acid, to a watery solution of monomethylol urea or mixtures of monomethylol urea with dimethylol urea, a fioeculent amorphous'precipitate will be formed almost instantly, whereas dimethylol urea in aqueous solution will give a white amorphous precipitate only on standing for several hours if dilute mineral or organic acids are added. Therefore, the patentees assert that in such solutions it is found that free acid and particularly strong acid causes precipitation of a further condensation product whereas if the acid is replaced 2 Claims. (Cl. 8-1163) by the correspondingammonium salt a relative stability of the solution is obtained. The patent warns that the impregnating solution must not be too fully condensed, otherwise the molecular weight of the partial condensatewill' be so large that it cannot --penetrate within the fibres.- Claim 2 of this U. S. patent reads:

Process of improying-, the crease resistance of textile materials which consists in'impregnating the material with a solution of a partially condensed resin components-which is unstable in acid solution and which solution contains a potentially acid ammonium saltandheating the impregnated material ,toinsolubilize the-resi and produce a crease resisting product. 1

According to these patents, the treating solution has to be acidified with an organic acid to a pH of 4.5 or, for instance, if diammonium phosphate or another potentially acid substance of the amino type is used asa catalyst, the acidity of the impregnated, dried textile material should also show a pH of 4.5.,

But, the crease-proof effect or the reduced tendency towards shrinkage achieved by 'the method of the patent is only effective for a limited time if the goods are washed atelevated temperatures in aqueous soap solution. This is because the resin formed within the fibres by repeated washing operations leaches out, and both the creaserproofingeffect and the initial stabilizing effect is continuously diminished by these successive washings. This is a serious defeet of which users of the process have always complained. In addition, a comparativelyhigh concentration of the formed urea formaldehyde resin is necessary to produce a satisfactory anticrease effect. Asa general rule from about 12 to about 15% resin based on the weight of the dry fabric treated has to be. formed within the fibers to achieve-the desiredv effect. v.But, in all cases. due to the high resin-concentration necessary to produce the desired anti-crease effect it is a very well known fact that rayon :fabrics treated for this purpose have a highly diminished resistance to. abrasion compared with untreated material.

' The loss amounts intheaverage, to about 30%.

In co-pending application Serial Number 130,609 filed Decemberll, 19.49, theapplicant has disclosed the use, in shrinkage control of textile fabrics, of an aldehyde donor compound which is soluble in water and is capable ofsplitting oif aldehyde under both acid andalkaline conditions. Such a compound selected from the group consisting of monomethylol dimethyl hydantoin and dimethyl hydantoin formaldehyde is capable of forming with the fibres, under ,acid conditions,

ent inventlonds IIltOlflOl'llB thYlOlidilflCthYl hydantoin.

The applicant has now found that this type of shrinkage control can be successfully combinedwith crease-proofing. The treated fabric-ex hibits no loss of wearing qualitiesand practically no loss of abrasion resistance: :Th'is is done in"- accordance with the present invention by subjecting the textile fabric to the action of a solution containing the aldehyde donor'compound; and also a dimethylol ureanprecondensatemadei from urea and formaldehyde inaimolratiofrom 1 urea to at least 2 formaldehyde. The. solution contains a selected non-volatile organic" or mor ganic acid to obtain a pH- from about 2 to about 2.5; Because of: thiswcombinedtreatment with the aldehyde donor of the type described and dimethylol'ureaiin mostcases comparatively small amounts only 'of the latter; for example, from about 3 "tdabout 10% 011 the fweight'ofthe fabric (100% pick-up) need be employed to achieve satisfactory crease-proofing. The amounts of dimethylol :urea will "Yary w'ithfthe construction of the fabric. The fact that such low amounts can beused eflectively apparently'flows from the reduced' swelling capacity of f the fibre resulting from" the action f the aldehyde donor. The above amountswill; of course. vary as the pick-up departs from 100'% which is the preferred condition.

Broadly speaking; the process of the present invention employs-the aqueous solution of the aldehyde do'nor which solutionis nearly neutral 4 to about 7.5% (preferably from about 1 to about 5%) based upon the weight of the treating solution. The amount of the stabilizing compound or compounds employed should be equivalent to an amountveifective to furnishfrjoml about 2% to about 1.5% (preferablyfrom-- about 12% to about 1.0%) of active available formaldehyde based on the weight of the aqueous solution (at 100% pick-upbasedon the dry Weight of the oods): and-in addition a certain amount of dimethylolurea depending on the construction of the wovene t'org knitted textile material to be treated.

Fabrics of' viscose rayon or cuprammonium =-yarnsso processediare'further improved as borne out by the'faict that they show less tendency to H fuzz during washing as compared to an untreated material similarly washed.

It should also be explained that if solutions containing monomethylol urea or mixtures of this compound with dimethylol urea are mixed with a-solution; plus anacid catalyst effective to give a 'pH from about 2 to about 2.5, polymerization takes place within the "solution almost immediby 'dimethylol' ure'a'aloneQthe solutions are sufiland diinethylol urea andcontains a water-soluble I non volatile organic orinorgamc acid or a mixture of organic and-inorganic acids, a catalyst, capable of giving the solution 'apI-I from about 2 toabout 2.5. Suitable organic' acids" are; for example, oxalic acid, lactica'cid', citric acid, tartaric acid;'and other non-volatile organic acids or mixtures thereof' 'strong-enough"to catalyze the reaction: Siiitableinor'ganidacids are, for example, boric' acid-and phosphoric acid. According to the inventiomtextil materials of the type described are-thoroughly wetted i. e. impregnated With' the'solutioncontaining the aldehyde donor, dimethylorurea, and the acid-catalyst. V The solution mayor may "not contain a wetting agent. The solution mayor may' not contain a small amount of sodium sulphate," as for example, taught in co-pendihg applications; N; 130,609. The solutions --'described are satisfactorily stable fo'r'a'period-bf time for-practi'cal application according --to* the inventi'on The surplus of the impregnating liquor is mechanically removed, for in'stancef by squeezing "or'other means allowing a pick-up of a" predetermined percentage, for ex: ample a '100%*liquid retentionon the basis of the dry weight of the goods." They are thentension less dried preferably at "200 F5" to 240 F. and finally'cure'd or" baked "from about 2 to about 5 minutes at 212* Ffor higher; After curin the fabrics are =neutrali'zed with an alkali, for example, soda' ash; eventually soaped; rinsed, hydroextracted andf'dried without tension before putting into industrial-channels of trade or before making the physical fneasurements referred to in the comparative tests below. I

In the aqueous impregnating solution; the sug-f gested range -*-of: concentration of the mono-- methylo'l 'dimethylhydantoin" is from about 1 ciently stable fora suitable period of time to allow their technicaliapplication' and if at the same time the amount of dimethylol urea is sufficient they. WilL i mpart the' desired crease-proofing effect.

Treated with'thesolution of an aldehyde donor of the type described and'the necessary amount of dimethylol urea, the crease-proof effect is excellent andrremainsnearly unchanged after several "washings even at :the' boil. Especially.

I ShOW 7 in: addition to. the permanent boil-fast shrink-proofingefie'ct "of 1 my prior application Serial Number ',609, excellent crease proofing characteristics withstanding repeated washing at temperatures even up to the boiling point.

Before treatmentfalhtraces of starch, gums, glue or natural resins and other sizing agents should first be removed from the fabric inorder to permit the aqueous treating solution to penetrate the fibrous material and enter the heart of the fibres; Y

If desired; the hand or body of the goods treated can be modified-in the direction of either softness or a stiffer atwillby the'introduction tothe impregnating baths of suitable agents such as cation softeners for the former (elect or such"'vegetable'-or animal colloids as starches, gums, glues; 'gelatin'es'mod-ifid starches,- or solutions or dispersionsof polyvinyl" alcohol; etc, for the latter effect p This 'invention will' more clearly be understood by reference tothe following examples. It is to be understdodfhoweventhat these *examples are merelyillustrative of the process and that the invention :not limited thereto, but rather is defined in the appended claims. In the examples, theterm"check" has the meaning-of untreated or original material'.'-

EXAMPLE 2 ing combined with shrink-proofing by treating with aqueous solutions of the following compos1t1ons. The check was not treated.

Monomethylol dimethyl hydantoin, g.-. 20 30 30 25 Dimethylol urea 100%, g 40 40 60 80 Oxalic Acid, 2 6 3 Lactic Acid 50%, g 120 70 60 NA SO; Anhydrous, g 4 4 4 4 Igepal CTA Extra" (Wetting agent non-ionic) g l 1 l 1 Water to make l l 1 1 l l 1 1 Warp Shrinkage and Percentages 1 hour wash test Sam 1e Identificap tion scoured Total 1st 2nd 3rd Shrinkage A. WARP TENSILE STRENGTH (LBS. GRAB TEST) B. ABRASION (TABER CYCLES) (Th PPI 56 300 #1 56 250 #2 55% 350 #3 56 320 #4 55 280 The treated samples had a full soft hand and a very satisfactory degree of crease-proofing was obtained which practically appeared undiminished after 3 wash tests at the boil. The achieved stabilization is good as can be seen from the above figures, with practically no change in tensile strength or abrasion resistance. Very good crease-proof eifect was achieved with high permanency. No discoloration had taken place due to the treatment.

I claim:

1. A process of imparting improved creaseresistance against washing and boil-fast shrinkage control of a cellulosic textile fabric selected from the group consisting of natural cellulose, regenerated cellulose and their mixtures with up to 50% of cellulose acetate, the steps of impregnating said fabric with an aqueous solution of monomethylol dimethyl hydantoin, said aldehyde donor being present in a concentration ranging from 1 to 7% by weight of the aqueous solution which, upon baking, decomposes to form from 0.2 to 1.5% of available active formaldehyde and from about 3 to 10% by weight of the fabric of dimethylol urea comprising 1 mol of urea and 2 mols of formaldehyde, and a water-soluble nonvolatile acid in a concentration such as to give to the solution a pH of from about 2' to about 2.5, removing the surplus liquid from the material,

drying the material at a temperature'of from to 240 F., baking the dried fabric at a temperature, of from 212 to 310 F. for a time s'uflicient to effect reaction between liberated formaldehyde and the textile fabric, and neutralizing and washing the fabric to remove acid and reaction byproducts thereby to provide a fabric which is crease-resistant and shrinkage-controlled and which has substantially retained its original tensile strength and color.

2. The process of claim 1, wherein the acid is selected from the group consisting of oxalic acid, lactic acid, citric acid, tartaric acid, boric acid, and phosphoric acid.

LEO BEER.

REFERENCES CITED The following references are of record in the file of this-patent:

UNITED STATES PATENTS Number Name Date 2,108,520 Wolf et a1. Feb. 15, 1938 2,159,743 Latham et a1 May 23, 1939 2,347,024 Beer Apr. 18, 1944 2,412,832 Pfefler et a1 Dec. 1'7, 1946 2,441,859 'Weisberg et al. May 18, 1948 FOREIGN PATENTS Number Country Date 547,846 Great Britain Sept. 15, 1942 880,185 France Dec. 18, 1942 OTHER REFERENCES Chemical and Engineering News, Nov. 3, 1947, page 3243, and Feb. 9, 1948, page 415.

Claims (1)

1. A PROCESS OF IMPARTING IMPROVED CREASERESISTANCE AGAINST WASHING AND BOIL-FAST SHRINKAGE CONTROL OF A CELLULOSIC TEXTILE FABRIC SELECTED FROM THE GROUP CONSISTING OF NATURAL CELLULOSE, REGENERATED CELLULOSE AND THEIR MIXTURES WITH UP TO 50% OF CELLULOSE ACETATE, THE STEPS OF IMPREGNATING SAID FABRIC WITH AN AQUEOUS SOLUTION OF MONOMETHYLOL DIMETHYL HYDANTOIN, SAID ALDEHYDE DONOR BEING PRESENT IN A CONCENTRATION RANGING FROM 1 TO 7% BY WEIGHT OF THE AQUEOUS SOLUTION WHICH, UPON BAKING, DECOMPOSES TO FORM FROM 0.2 TO 1.5% OF AVAILABLE ACTIVE FORMALDEHYDE AND FROM ABOUT 3 TO 10% BY WEIGHT OF THE FABRIC OF DIMETHYLOL UREA COMPRISING 1 MOL OF UREA AND 2 MOLS OF FORMALDEHYDE, AND A WATER-SOLUBLE NONVOLATILE ACID IN A CONCENTRATION SUCH AS TO GIVE TO THE SOLUTION A PH OF FROM ABOUT 1 TO ABOUT 2.5, REMOVING THE SURPLUS LIQUID FROM THE MATERIAL, DRYING THE MATERIAL AT A TEMPERATURE OF FROM 180* TO 240* F., BAKING THE DRIED FABRIC AT A TEMPERATURE OF FROM 212* TO 310* F. FOR A TIME SUFFICIENT TO EFFECT REACTION BETWEEN LIBERATED FORMALDEHYDE AND THE TEXTILE FABRIC, AND NEUTRALIZING AND WASHING THE FABRIC TO REMOVE ACID AND REACTION BYPRODUCTS THEREBY TO PROVIDE A FABRIC WHICH IS CREASE-RESISTANT AND SHRINKAGE-CONTROLLED AND WHICH HAS SUBSTANTIALLY RETAINED ITS ORIGINAL TENSILE STRENGTH AND COLOR.