US2859136A

US2859136A - Process for the treatment of fabrics with resinous condensation products

Info

Publication number: US2859136A
Application number: US529774A
Authority: US
Inventors: Marsh John Thompson; Blease Ronald Arthur
Original assignee: Tootal Broadhurst Lee Co Ltd
Current assignee: Tootal Broadhurst Lee Co Ltd
Priority date: 1950-07-08
Filing date: 1955-08-22
Publication date: 1958-11-04
Anticipated expiration: 1975-11-04
Also published as: GB704143A; NL77270C; FR1131845A; BE504549A

Description

Nov. 4, 1958 J. T. MARSH ETAL 2,859,136

PROCESS FOR THE TREATMENT OF FABRICS WITH RESINOUS CONDENSATION PRODUCTS Fi led Aug. 22, 1955 2 Shee'is-Sheet 1 O Q I I I I Q I o. I x I I I I o I m I I I I I I I 3 x X I Q X I W J, I o\ X X I o l v I I I X g l X I I I o I m X I I I I o I I I I I l l I I I I0 O a 8 g g r Q 5 'o/wano ,wa us'no uvywsnqudrw 9/ 7 74 11 Inventors M flak, M Attorneys Nov. 4, 1958 J. T. MARSH ETAL 2,859,136

PROCESS FOR THE TREATMENT OF FABRICS WITH RESINOUS CONDENSATION PRODUCTS Filed Aug. 22, 1955 4 2 Sheets-Sheet 2 Inuenlors y 41%,; M M

Attorney]:

United States Patent Ofifice I 2,859,136 Patented Nov. 4, 1958 PROCESS FOR THE. TREATMENT OF FABRICS WITHRESINOUS CONDENSATION PRODUCTS John Thompson Marsh, Hale, and Ronald Arthur Blease, Ruislip, England, assignors to Tootal Broadhurst Lee Company Limited, -Manchester, England, a British company Application August 22, 1955, Serial No. 529,774

Claims priority, application Great Britain July*8,*19 50 9 Claims. (Cl. 117145) This invention which is a continuation-in-part of the now. abandoned applications Serial Nos. 235,015, filed July 3, 1951.; 295,361, filed June 24, 1952 and 295,362,

resin. When a urea-formaldehyde resin is insolubilised by heating in-the fibres of a textile fabric composed wholly or partly of cellulose, there is a loss in resistance to abrasion. Accordingly, when the treated fabric is subjected to rubbing, it-shows wear more readily than the untreated fabric. This loss in resistance to abrasion is particularly great in the-case of fabrics-which are composedwholly or mainly of regenerated cellulose. In the past this reduction in resistance to abrasion has had to be-tolerated but the fact that theresistanceto abrasion has been reduced has meant that large quantities of resin could not usefully be introduced into the fabrics.

the introduction-of quantities sufiicient to give crease-resistance causes a serious reduction in the resistance to abrasion. It has therefore been necessary in all casesto accept a compromise between the improvements effected by theresin and the loss in abrasion resistance. In cases where abrasion resistance was -a particularly important consideration small quantities of 'resin have had to be used'with consequent sacrifice of some of the desired improvements in physical properties.

It is accordingly an objeectof the present invention to give increased abrasion resistance to textile fabrics com:

posed wholly or mainly of regenerated cellulose, and having amino-formaldehyde resin insolubilised-inthe fibres thereof by heating. It is a further object of the invention to enable large quantities of amino-formaldehyde resin to-be insolubilised by heating in the fibres of a fabric composed wholly or mainly of regenerated cellulose, without undue loss in resistance to abrasion. It is a still fur-. ther object of the invention to give increased abrasion resistance to textile fabrics composed wholly or mainly of regenerated cellulose, and having insolubilised by hea ing in the fibres thereof, a melamine-formaldehyde resin ormixed melamine-formaldehyde urea-formaldehyde.

resin. These and other objects of the invention will be more apparent from the following description.

The customary method of insolubilising a thermohardening synthetic resin in the fibres of a textile fabric is to impregnate the fabric with an aqueous solution 'con-. taining theresin-forming ingredients or an intermediate condensation product thereof and an acidic catalyst and thereafter'to drythe impregnated fabric and heat it to Even.

a temperature of. l20l80 C. for a suflicient time-to insolubilise the resin, the time and temperature of suchheating being inter-related and being chosen in accordance with the activity of the particular acidic-catalyst em-- ployed. One proposal which has been made to reducethe loss in abrasion resistance is to omit the catalyst from the impregnatingmixture and then to supply the catalyst. as a steam-volatile organic acid by conducting the final heatingin a steambox containing an. excess of such steamvolatile organic acid.. We have found that this procedure: gives resins which .still havea substantial solubility in water i. e. the resin is not effectively insolubilised "in the fabric. Accordingly the effects produced by the resin are not fast to washing.

We have found that the loss in resistance to abrasion which accompanies the insolubilisation in a cellulosic fabric of an amino-formaldehyde resin canbe materially reduced, without corresponding sacrifice ofthe desirable properties conferred by the resin, ifthe final heating-to insolubilise the resin is effected in an atmosphere contain. ing a substantial proportion of superheated steam.

The use of small quantities of steam in the atmosphere used for heating textile fabrics containing resin-formingingredients is quite customary and has been recommended in processes for rendering cellulosic fabrics crease-resisting. In fact, the presence of steam can never be alto-- gether avoided since a very small amount of water is -liberated during the condensation of the resin. Such an amount of water is quite insignificant .and cannot produce in the heating chamber more than a very minute proportion of steam. Proposals have been made to introduce steam-into the heating chamber but the customary heatingcham bers are not capable, without modification, of maintaining, during the heating of-a textile fabric, an atmosphere having more than 20% of steam. It might havebeen' thought that when steam was passed into such a chamben at a sufiicient rate to be seen escaping from all the open ings such .heating chamber must contain an atmosphere; consisting substantially wholly of steam. Measurements which have been madeby the method and apparatus here-' inafter to be described show that this is not the case. They" show, in fact, that when a textile fabric is passed through a cloth baking machine of thetype normally used in the. crease-resisting process to which at the same time stean1{ is admitted from a supply at 40- lbs. per square inch pressure until steam is issuing from all'the openings in the baking chamber, the atmosphere in the chamber con tains much less than 20% of steam. The most careful precautions against steam losses must be taken to maintain in, a cloth baking machine of the type normally 11sed,-. for the crease-resisting process an atmosphere with asteam content of more than 20% We have found that, by tak ing such precautions, it is quite possible to maintain in a cloth. baking machine, an atmosphere containing over 50% of superheated steam.

To secure the objects of.the present invention, it is essentialthat the atmosphere in which the final heating to insolublise the resin is eifected shall contain at least 50%-;

of steam and that this steam be superheated steam.. By;

partial pressure of steam expressed as a percentage-off the total pressure of air and steam, measured at substantially the temperature of .the heating chamber.

The principle of the invention is illustrated in theaccompanying drawings in which Fig. 1 is a graphic representation of the comparison of the" results of theprocess with oven dry curing and i Fig. 2 isa vertical cross-sectional view of the testing apparatus ,used.

In order to measure the steam content of the chamber iniwhich the textile material is heated the following method may be employed; A sample of the atmosphere of the heating chamber (oven) is withdrawn, the steam condensed therefrom and the proportion of residual measured.

This can conveniently be done with the aid of the apparatus diagrammatically shown in Figure 2 of the accompanying drawing, as follows:

Theflask 1, the volume of which is small compared with. the oven, and which is surrounded by a removable heating jacket 2, is connected by a tube 3 having a valve 4 to the oven (not shown), by a tube 5 having a valve 6 to a vacuum pump (not shown) and by a tube 7 to a mercury manometer or to a Bourdon gauge (not shown). The flask 1 is provided with a thermometer 8. The flask 1 is exhaustedby the vacuum pump, the valve 6 being open and the valve 4 closed and then brought to the same temperature as the oven. When the flask 1 has been evacuated, as shown by the manometer or the Bourdon gauge, and is at the temperature of the oven, valve 6 is shut and the valve 4 opened for a few seconds to allow a sample of the. oven atmosphere to pass into the flask 1. As soon as the pressures are equalised, as shown by the manometer or the Bourdon gauge (the oven is at atmospheric pressure), the valve 4 is closed thus leaving the flask connected only to the manometer or the Boudon gauge.

The heating jacket 2 is then removed and the flask 1 cooled'down to room temperature. As a result of this cooling, the .water vapour condenses on the sides of the flask 1 and the cooling of the residual air also leads toa reduction in pressure. The final pressure in the flask 1 is read on on the manometer or the Bourdon gauge, and a knowledge of this and of the initial and final temperatures enables one to calculate the steam content as in the following calculation.

Atmospheric'pressure=760 mm.

Initial temperature of flask (equals temperature of oven) =150 C.

Final temperature of flask= C.

Final pressure diflerence recorded on mm. I

Final pressure in fiask=760500=260 mm.

Vapour pressure of water at 20 C.=l7 .5 mm.

Therefore, pressure of residual air at 20 C.=260

The importance of employing at least 50% of superheated steam in the atmosphere in which the heating to insolubilise the resin is efiected is illustrated by the following Table I and the graph shown in Figure 1 of the accompanying drawing. Table I shows the result of a series'of tests in which diflferent portions of the same fabric composed wholly of viscose spun rayon were immanometer 500 t wear was measured on the ringwear testing machine described in the Journal of the Textile Institute,-l935, 26, 93P.

Table I Percent Percent Improve- Improve= Percent Steam nient in Percent Steam men in Ringwear Ringwe'ar over dry over dry cure cure 9. 5 68. 5 --l. 0 38. 5 3. 0 74. 0 2. 0 81. 0 2. 5 70.0 -7. O 46. 5 13.0 58.0 46. 5 51.0 92. 0 86.0 19.0 96. O 52. 0 61.0 65.0 66. 0 37. 0 89. 0

The figures shown in Table I are represented as crosses band gives a representation of the improvement in abra sion resistance resulting from increasing the proportion of superheated steam in the atmosphere used for heating.

It will be seen that the improvement is particularly strik-n. ing when the atmosphere contains at least 50% of steam.

' and that in no case where the proportion of steam exceeded was the improvement less than 38.5%. p Accordingly, the objects of the present invention are secured by a process which comprises impregnating the textile fabric with an aqueous solution of water-soluble amino-formaldehyde resin-forming ingredients containing) an acidic catalyst for the resin-formation, drying the fabric and heating it to produce water-insoluble thermoy resin from, said resin-forming containing at least 50% hardened synthetic ingredients in an atmosphere of superheated steam.

The thermohardening syntheticresins employed in our.

invention are selected from the group which-consists of urea-formaldehyde resin, melamine-formaldehyde resin pregnated with the same aqueous solution Qfurea-formand mixed melamine-formaldehyde urea formaldehyde.

resin.

The term melamine includes substituted rnelamincs, such as alkylated melamine.

When the textile materialtreated in accordance with the present invention does not consist wholly of regenw erated cellulose, it preferably contains more than about by weight of regenerated cellulose. The regenerated cellulose is, preferably, viscose rayon. The inven:

tion is of particular value when the regenerated cellulose is spun viscose rayon.

It is well known that the insolubilisation substantially,

within and not between the fibres of a regenerated cellu-, lose fabric without undue loss of resistance to abrasion, of a suflicient proportion of urea-formaldehyde resin, melamine-formaldehyde resin or mixed melamineformaldehyde urea-formaldehyde resin will give creaseresistance, and even a degree of recovery from creasing1 comparable with that of high grade wool fabrics. In the case of urea-formaldehyde resin, an amount of, for

example, 12 to 18% by weight of resin calculated upon the weight of dry fabric before treatment is suitable for this purpose in the case of most types of regenerated cellulose fabrics. Substantially 15%, for example, is a convenient amount. In the case of melamine-formalde-a:

hyde resins comparableresults are obtained with considerably less resin, 7% for example being a convenient amount.

yseful effects can be obtained with smaller proportions v of. any'ofthe resins'employed, i. e. stabilisation with reduced loss of resistance to abrasion.

'It has been*known that higher-"proportions of these resins would confer upon regenerated cellulose fabrics an .evenbetter crease-resistance, but because of the loss inthe" resistance of the fabric to abrasionwhich accompanies the treatment withsuchresins, the proportion that couldusefully be insolubilised within the fibres has hitherto been limited,-in commercial practice.

We have now found-that much larger percentages of these-resins can be insolubilised Within the fibres'of a "textilefabric composedwholly or mainly'of regenerated cellulose and thus theproperties further improved, while maintaining satisfactory resistance to abrasion, or even obtaining a resistance'to abrasion slightly better than that hithertoconsidered tobesatisfactory, by carrying out tl1e insolubilisation of the resin in the presence of '-not '-less than 50% of superheated steam. By eifecting the insolubilisation in this way, 'it is possible, by correct choice ofconditions, to obtain improved physical properties due to the larger percentage of resin,as wellas improved resistance to abrasion compared with a fabric *s'imilarlytreate'dbut heated without added steam. By

larger percentages of resin we'mean over 20% by "weight in thecase of urea-formaldehyde resins and'over 8% :by weight in'the case of melamine-formaldehyde resins 'or' of mixed melamine-formaldehyde urea-form- 1 aldehyde resins, calculated upon 5 the weight of thedry =,p0rtion .of formaldehyde, although it is'fast to washing, and-although the crease recoveryproperties of the fabric are greaterthanthose -of a-fabric' treated with resin I formed from urea and formaldehyde in the proportions of about 1.6 to l,the'f'abric is'-so tendered that it: may

have no commercial value. We have found that by using for the insolubilisation:byiheating an atmosphere containing at least 50% of superheated steam,-in accordance with our invention, we may employ aqueous solutions of the urea-formaldehyde resin-forming ingredients wherein the molecular proportion of formaldehyde is at least 2 to 1, for example from 2 /2 to l to 4 to l and still obtain a fabric having a satisfactory resistance to abrasion.

Similarly, in using melamine-formaldehyde resin it has generally been considered necessary that the molecular .proportion of formaldehyde to melamine should not exceed 3 to 1. -It has beenfound that if the resinis made with substantially more than this proportion of formaldehyde, although it is fast to washing and 'the crease recovery properties of the treated fabric are greater than those of a fabric treated with resin made from melamine and formaldehyde in the molecular proportion 3 to l, the fabric is so tendered that it may have no commercial value. We have found that by using for the insolubilisation by heating at atmosphere containing at least 50% of superheated steam in accordance with our invention, we may employ aqueous solutions of melamine-formaldehyde resin-forming ingredients wherein the molecular proportion of formaldehyde is greater than 7 three to one, for example from 4 to 1 we to 1 and still obtain a fabric having a satisfactory resistance to abrasubsequently renderedpermanent by the insolubilisation of the 'urea fQImaIdehyde resinffor example, "it isipossible to calender, to schreiner, to emboss or to produce glazed effects by friction or to pleat.

The temperature and time of heating to insolubilise the resin, when employing an atmosphere, containing'at least 50% of superheated steam according to'the present invention,may be the same as that which'wouldbe employed without added steam or with'the smallproportions of steam which have hitherto been customary. This, as is known, exceeds C. and preferably "exceeds C. Thus, temperatures between ."and 180 C. are suitable, for example "C. Therondensation may be carried out in theipresence of. the'customary catalysts and in particular we may use apotentially acid catalyst, e. g. an ammoniumsalt or an'amine salt.

In practicing the present invention, 'it'isipreferredto impregnate the textile material in'the form of a'fabric with an aqeuous solution'containing'a water-soluble crystalloidal intermediate condensation product of'the aminoformaldehyde resin and containing also an acidic catalyst, remove excess solution from the fabric, 'dry"the fabric and then heat it in 'an atmosphere containing at least 50% of superheated steam to complete the condensation, i. e. to insolubilise the resin.

The acidic catalyst maybe an acid, a mixture of acids, a mixture of'an acid and a salt, or, preferably, a potentially acid substance i. e. one which is capable of becoming acid (or more acid, e. g. a mixture of calcium chloride and boric acid) or of liberating acid during the treatment, for example aluminum chloride .or, most 'suitably, an'ammonium salt or an amine salt such as ammonium thiocyanate or ammonium dihydrogen phosand a urea-formaldehyde intermediate condensationproduct are prepared, mixed and suitablycatalysed; oralternatively melamineand urea are mixed and then partially condensed with formaldehyde before catalysing. "The general technique of preparing a urea-formaldehyde intermediate condensation product may be'in accordance'with our British Patent No. 449,243.

The present invention-'m-ay be "carried out with mixtures of any melamine-formaldehyde and urea-formaldehy'cle intermediate condensation products capable of being insolubilised withinthe fibres by heating; for example methylol melamine and methylol urea, alkylated methylol melamine andmethylol urea, methylol -melam;ine and alkylated methylol urea, or alkylated methylol melamine and alkylatedmethylol urea maybe used.

"The invention will be illustrated by but is not limited to the following examples.

Example '1.'100 gms. urea 'and'200 cc. of neutral 40% formaldehyde were mixed together and 9 cc. ammonium hydroxide (specific gravity 0.88) added.- This mixture was then refluxed for 3 minutes and cooled to room temperature.

To 30 cc. of'this refluxed mixture were added 10 cc. of a 10% solution of ammonium dihydrogen phosphate and thevolume made up to'lOO cc. with water.

Two samples of spun viscose rayon fabric were-impregnated in this solution, squeezed so as to contain about their own weight of liquor and dried at about 40 C.

One sample "wastlien heated "at atmospheric pressure for. 2 minutes at 150 added steam. The other .was heated at atmospheric pressure for 2 minutes at 150 C. ina hotair chamber concotton count spun'rayon weft.

e se-18 C. in a hot 'air chamber without taining a mixture of 16"pa'rts of air and 84 parts of steam. The two samples were then washed for 2 minutes at 90 C. in an aqueous washing medium containing 0.25% soap and 0.25 soda ash. They were then rinsed, dried and conditioned to normal moisture content.

When tested on the ringwear testing machine the sample heated without added steam wore through at 1148 cycles but the sample heated in the above-mentioned mixtureflof steam and air wore through only at 2162 cycles,

an improvement of 88.3%

Example 2.The.following Table H shows the effect of treating two fabrics according to'the method described in Example 1 but using substantially 100% of superheated steam (steam) a compared with fabrics similarly treated but in which the resin was insolubilised without added steami(dry), Fabric 1 was a viscose rayon fabric made from 75 denier filament warp and 30s Fabric 2 was a 100% viscose spun rayon fabric made from yarn spun to 30s cotton count.

Table II Percent Ringwear Resin Content Fabric Steam Untreated Dry Steam Dry Steam Example 3.The following Table III show that the improved wear resistance effect obtained by treating two fabrics according to the method described in Example 1 but using about 90% of superheated steam is substantially unaffected by washing.

litres of-% neutral formaldehyde and 1.5 litres of. ammonia (0.88 .specific gravity) added. This was mixed and allowed to stand overnight at room temperature, its .final viscosity being 6.5 centipoises. n

This, concentrated reaction mixture was diluted with water until .it contained 70% by volume of the concen- 'trated reaction mixture and 3% of ammonium dihydrogen phosphate (calculated on the weight of the concentrated reactionmixture) added. A 100% viscose spun rayon fabric and also a fabric composed of a blend of viscose and wool were each impregnated so aszto retain 76% of its weight of the liquor, partially dried on steam heated cylinders and passed on to a stenter where it was dried to 36 inches wide. The fabrics were then each divided into two parts; one part was heated at atmospheric pressure for 2.75 minutes at 160. C. without added steam and the other part was heated at atmospheric pressure for 2.75 minutes at 160 C. in the presence of 90% steam. Both parts were then washedin open width in soda ash at 90 C. for 10 seconds, then in water at 90 C. for 10 seconds, then in water at20 C. for 10 seconds, and then passed through a bath containing 1% of a sulphated fatty alcohol as a softener and dried on a stenter to 36 inches wide.

Other portions of the same fabrics were similarly prepared using diluted reaction mixtures containing 27.5%,

%. and 70% of the concentrated reaction mixture. The resin content (based on the weight of dry cellulose), resistance to abrasion and dry recovery are shown in the following Tables V and VI. These tables also show that the recovery from creasing of fabrics in which the resin ha been insolubilised in presence of superheated steam is substantially equal to that of fabrics in which Tabl? HI 1 the resin has been insolubilised in the absence of added steam. Percent Improve- T bl V mgnt in Ringdviear gure over y 100 PU Fabric Percent Percent insolubilisation s N VISOOSE RAYON FABRIC Steam Resin R Before After 45 esm, percent Rmgwear Recovery from creasing Washing 10 washes Strength of mixturi, D st D Dry Steam n 92 9 8 1 10 94 119N611 ry eam ry Steam 4 g 90 72 93 Warp Weft Warp Weft Fabric 3 was a 100% viscose spun rayon dress fabric, 2.: 942 1, 754 3.0 2.8 2.9 2.7 the warp being. made of staple viscose rayon fibres spun 21:1 282 32. 2:1 33 3;? 5;? to 15s cotton count withalternate yarns of S and Z twist and the weft being made of staple viscose rayon Table VI fibres spun to 15s cotton count; Fabric 4 was a dress fabric made of a blend of 16% by weight of wool and 84% by weight of viscose spun rayon.

Exizmple 4.--The following Table IV shows that there is less loss of resin on washing fabrics treated according 5 to the method described in Example 1 but using atmospheres containing 90% of superheated steam and over, in which to'insolubilise the 'resin (steam), as compared with fabrics in which the atmosphere used to insolubilise the resin contained no added steam (dry).

Table 1 IV Percentage loss on Steam washing of resin 7 Fabric content originally present I of oven,

percent Dry Steam FABRIC MADE FROM A BLEND OF 16% BY WEIGHT OF Example 6.--100% viscose spun rayon and viscose spun rayon and wool mixture-fabrics were treated as in Example 5 but with repeated impregnation with diluted reaction mixtures containing 50%, 60%, and 70% of the concentrated reaction mixture so as to obtain fabrics having higher resin contents than in Example 5... The resin content (based on the weight of dry fabric not containing resin), resistance to abrasion and dry recovery are shown in the following tables VII and VIII.

1 Table X 100% vrsoosn SPUN'RAYON FABRIC FABRIC MADE FROM A BLEND OF 16% BY WEIGHT OF WOOLAND 84% BY WEIGHT OF VISOOSE STAPLE FIBRE PercentResin Ringwear 7 Recovery from creasing Strength of I mixture, Dry Steam percent Dry Steam Dry Steam Warp Weft Warp Weft Example 7.A ten percent solution in water of trimethylol-melamine intermediate condensation product (ET 314 sold by'Beetle Products Co. Ltd.) was prepared and catalysed with five percent of ammonium dihydrogen phosphate on the weight of solid RT 314. This was used to treat different samples of a fabric of standard width made from a blend of 16% by weight of wool and 84% by weight of spun rayon. Each sample was impregnated so as to retain about 100 percent of its weight of the liquid, dried at a low temperature, and then heated at atmospheric pressure in an atmosphere containing superheated steam for 4 minutes at 145 C. The samples were then washed for 2 minutes in 4% soap and soda ash solution at 90 C., rinsed in cold water and finally dried at the standard width. One sample, for com .parison, treated in a similar way but was heated for 4 minutes at 145 C. in an atmosphere not containing steam. The effect on abrasion resistance (as measured by the ringwear testing machine) of increasing the proportion of isuperheated steam is shown in the following Table IX.

Table IX Steam content, percent It can be seen that as with fabrics treated=with ureaformaldehyde resin, the abrasion resistance of fabrics treated with melamine-formaldehyde resin is improved by increasing the proportion of superheated steam in the atmosphere in which the resin is insolubilised.

Example 8.Samples of a 100% viscosespun rayon fabric were treated as in Example 7 but each sample-was impregnated so as to retain 80% instead of 100% of its weight of the liquid. In different samples the resin was insolubilised in atmospheres containing different proportions of superheated steam.

Table XI shows that in fabrics containing more than 8% of melamine formaldehyde resin the resistance to abrasion, as measured by the ringwear testing machine, is improved by insolubilising the resinin atmospheres containing increasing proportions of superheated steam, and 'that' recovery from creasing is unaltered.

Recoveryfrom Percent V Greasing PercentSteam Resin Ringwear Warp Wait Example 9.-Four concentrated reaction mixtures having different molecular proportions of formaldehyde to urea (referred to hereinafter as .formaldehyde ratios) were prepared by dissolving the urea in a 40% aqueous solutionof formaldehyde, adding an aqueous solution of ammonia (specific gravity 0.88), mixing,'and'allowing to stand overnight at room temperature.

The amounts of the various ingredients in the mixtures were as follows:

Table XI Form- 0.88 S. G. Formaldehyde Ratio Urea, Kg. aldehyde Ammonia solution (Litres) (Litres) In addition, amixture containing formaldehyde and 'urea in the molecular proportions-of 1.6 to 1 was prepared as described in British Patent No. 449,243.

These concentrated reaction mixtures were diluted with water, catalysedby adding 5% of-ammonium 'dihydrogen phosphate, calculated on the weight of dissolved urea and formaldehyde, and were used to impregnate samples of 100% viscose spun rayon fabrics as follows:

"Each sample offabric was impregnated with one of the above diluted and catalysedireaction mixtures so as to retain about 80% or its weight of the liquid, partially dried on steam heatedicylinders andvthen passed on ma stenter where it was'dried to the standard-width. Some samples were heated at atmospheric pressure for "2% minutes at 160 C. in an atmosphere not containing added steam (hereinafter indicated in the tables by D after the formaldehyde ratio) and some samples were heated at atmospheric pressure for.2% minutes at 160 C. in an atmosphere containing 8590% of superheated steam (hereinafter indicated in the tables by S after the formaldehyde ratio). All samples were then washedin open width first in 2% sodium carbonate at 90 C. for 10 secs., then in water at 90 C. for 10 secs. and then in water at 20 C. for 10 secs.

They were then passed through. a bath containing 1% of a sulphated fatty alcohol as a softener, and dried on a stenter tothe standard width.

The effects obtained by treating these samples vare shown in the following tables. The 'laundry shrinkage referred to in some of the tables was measured as follows:

The samples to be laundered were first measured and weighed. 40-litres of water-at 40C. and 75 .gms. of soap were put into a -washin'g machine using this quantity 'of water; the samples were then washed in the washing machine with agitation for 20- minutes. After centrifugingthe samples-were separated, rinsed in 40litres of waterat 40 C. for 5 minutes, and recentrifuged. The samples were then shaken gently and pressed with a *hot; iron i.-'e. the iron'isi placed on'the cloth for a few seconds :withouti there being any horizontal movement .of

"7 5 the iron. After conditioning for approximately one hour,

- the Laundry shrinkage? coluinnfin'dicates that an extension hasoccurred.

12 aldehyde ratio and in which the resin is insolubilised in an atmosphere containing no added steam. It will also be seen that under the same conditions the laundry shrink-v age is reduced.

Table XIV shows theeifect on the laundry shrinkage Table XII shows the efiect on the recovery from creasing abrasion resistance (as shown by the ringwear test resulting from repeated washings when the "fabric" is ing machine) and laundry shrinkage, of treating fabric treated according to the method described above, and with resin according to the method described above and using a reaction mixture having at least 2 molecular prousing a reaction mixture having at least 2 molecular proportions of formaldehydeto l of urea and insolubilising portions of formaldehyde to 1 of urea and insolubilising the resin in an atmosphere containing superheated steam. the resin by heating in an atmosphere containing no added L Steam 1 Table XIV T bl X1 100% vrsoosn SPUN RAYON FABRIC 100% VISCOSE SPUN RAYON FABRIC Number of washings Reco fr Formal- Per- 7 Percent cr si ng om hyde cent 2 4 7 9 Formaldehyde Ratio Resin Ringwear B81510 esm Warp Weft Warp Weft Warp Weft Warp Weft Warp Weft Untreated fabric 2.5 2.4 V 1, s70 1.0/1 S-- 13.7 2.0 1.1 2.4 1.7 3.4 2.1 3.4 1.5 1.6/1 11.7 3.0 2.9 632 I18 12.1 0.5 0.6 1.2 1.3 1.5 1.5 1.2 1.0

3:; 3:; 23 It will be seen that with fabric in which the resin is 25 insolubilised in presence of superheated steam. the It will be seen that the crease-resistance is improved but z g gsizg g g ifg f g 222 2 i 6 that the abrasion resistance is drastically reduced by using Table XV shows the efiect to I ag i i gg i g f g th f (as measured by the Ringwear testing machine) of treata e S 9 ee cc on erecovqy mm ing the fabric accordingto the method described above apraslon reslstance (as.shown by the i i tesqng and using a reaction mixture having a formaldehyde maFhme) laundry shrmkage f.treatmg fabncs i ratio of 3 to l and which has been diluted to 40% and; resin apcording to the.methd descnbed above and u.smg insolubilising the resin by heating in an atmosphere cona reactlon mlxmre havmg at least i propomoils taining increasing proportions of superheated steam. of formaldehyde to 1 of urea and lnsolubihsing the resin Y by heating in an atmosphere containing superheated Table XV Steam- 100% SPUN vrscosn RAYON FABRIC Table XIII 100% vrscosn SPUN RAYON-FIRST FABRIC Percent provemen 0 40 Steam Content, percent Ringwear: Recovery from Laundry over. dry- Formaldehyde Percent creasing Ring Shrinkage cured fabric Ratio Resin Wear r Warp Weft Warp Weft 100% vIsoosE SPUN RAYON-SECOND FABRIC FABRIC CONSISTING OF 84% VISCOSE SPUN RAYON WITH 16% WOOL It will be seen that increases in the formaldehyde ratio improve the recovery from creasing obtained by a given amount of resin and that when the resin is insolubilised in an atmosphere containing superheated steam the resistance to abrasion is substantially maintained as compared with the fabric treated with resin of 1.6/1 fol'm- It will be seen that, as with fabric treated with resin having a formaldehyde ratio of 1.6 to l, the resistance to abrasion is improved by insolubilising the resin in atmospheres containing high proportions of superheated steam when the formaldehyde ratio is 3 to l. 1

1. A process of'giving increased abrasion resistancet'o a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating,- a resinselected from the group consisting of urea-formaldehyde wherein the molecular ratio of formaldehyde to urea is from. 2:1 to 4:1, melamine-formaldehyde wherein the molecular ratio of formaldehyde to melamine-is greater than 3:1 and up to 6:1, and a mixture ofsaid urea-formaldehyde melamine-formaldehyde resins, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation-drying the fabric and heating it to produce said water-insoluble resin from said resin-forming ingredients in an atmos- 13 phere wherein at least 50% of said atmosphere is superheated steam.

2. A process of giving increased abrasion resistance to a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating, a urea-formaldehyde resin wherein the molecular ratio of formaldehyde to urea is from 2:1 to 4:1, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation, drying the fabric and heating it to produce said water-insoluble urea-formaldehyde resin from said resin-forming ingredients in an atmosphere wherein at least 50% of said atmosphere is superheated steam.

3. A process of giving increased abrasion resistance to a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating, a urea-formaldehyde resin wherein the molecular ratio of formaldehyde to urea is 3:1, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation, drying the fabric and heating it to produce said water-insoluble urea-formaldehyde resin from said resin-forming ingredients in an atmosphere wherein at least 50% of said atmosphere is superheated steam.

4. A process of giving increased abrasion resistance to a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating, a melamine-formaldehyde resin wherein the molecular ratio of formaldehyde to melamine is greater than 3:1 and up to 6:1, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation, drying the fabric and heating it to produce said water-insoluble melamine-formaldehyde resin from said resin-forming ingredients in an atmosphere wherein at least 50% of said atmosphere is superheated steam.

5. A process of giving increased abrasion resistance to .a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating, a melamine formaldehyde resin wherein the molecular ratio of formaldehyde to melamine is 4:1, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation, drying the fabric and heating it to produce said waterinsoluble melamine-formaldehyde resin from said resinforming ingredients in an atmosphere wherein at least 50% of said atmosphere is superheated steam.

6. A process of giving increased abrasion resistancev to a spun viscose rayon textile fabric by insolubilising in the fibers of said fabric, by heating, a resin selected from the group consisting of urea-formaldehyde wherein the molecular ratio of formaldehyde to urea is from 2:1 to 4:1, melamine-formaldehyde wherein the molecular ratio of formaldehyde to melamine is greater than 3:1 and up to 6: 1, and a mixture of said urea-formaldehyde melamine-formaldehyde resins, which process comprises the step of impregnating said fabric with an aqueous solution containing a water-soluble crystalloidal intermediate condensation product of said resin, said solution also containing an acid catalyst for the resin forma tion, drying the fabric and heating it to produce said water-insoluble resin from said intermediate condensation product in an atmosphere wherein at least 50% of said atmosphere is superheated steam.

7. The process as defined in claim 2 wherein said urea-formaldehyde resin insolubilised in the fiber is at least 12%, calculated uponthe weight of dry fabric before treatment.

8. The process as defined in claim 4 wherein the melamine-formaldehyde resin insolubilised in the fiber'is at least 8%, calculated upon the weight of dry fabric before treatment.

9. A process of giving increased abrasion resistance to a textile fabric containing at least 50% of regenerated cellulose by insolubilising in the fibers thereof, by heating, a resin selected from the group consisting of ureaformaldehyde wherein the molecular ratio of formaldehyde to urea is from 2:1 to 4:1, melamineformaldehyde wherein the molecular ratio of formaldehyde to melamine is greater than 3:1 and up to 6:1, and a mixture of said urea-formaldehyde mela-.

mine-formaldehyde resins, which process comprises the steps of impregnating said fabric with an aqueous solution containing water-soluble ingredients for forming said resin, said solution also containing an acid catalyst for the resin formation, drying the fabric and heating it to produce said water-insoluble resin from said resinforming ingredients in an atmosphere consisting substantially wholly of superheated steam.

References Cited in the file of this patent UNITED STATES PATENTS 2,088,227 Battye July 27, 1937 2,093,651 Widmer Sept. 21, 1937 2,190,672 Meharg Feb. 20, 1940 2,299,786 Battye Oct. 27, 1942 2,484,598 Weisberg Oct. 11, 1949 2,512,195 Bener June 20, 1950 2,590,850 Dungler Apr. 1, 1952

Claims

1. A PROCESS OF GIVING INCREASED ABRASION RESISTANCE TO A TEXTILE FABRIC CONTAINING AT LEAST 50% OF REGENERATED CELLULOSE BY INSOLUBILISING IN THE FIBERS THEREOF, BY HEATING, A RESIN SELECTED FROM THE GROUP CONSISTING OF UREA-FORMALDEHYDE WHEREIN THE MOLECULAR RATIO OF FORMALDEHYDE TO UREA IS FROM 2:1 TO 4:1, MELAMINE-FORMALDEHYDE WHEREIN THE MOLECULAR RATIO OF FORMALDEHYDE TO MELAMINE IS GREATER THAN 3:1 AND UP TO 6:1, AND A MIXTURE OF SAID UREA-FORMALDEHYDE MELAMINE-FORMALDEHYDE RESINS, WHICH PROCESS COMPRISES THE STEPS OF IMPREGNATING SAID FABRIC WITH AN AQUEOUS SOLUTION CONTAINING WATER-SOLUBLE INGREDIENTS FOR FORMING SAID RESIN, SAID SOLUTION ALSO CONTAINING AN ACID CATALYST FOR THE RESIN FORMATION, DRYING THE FABRIC AND HEATING IT TO PRODUCE SAID WATER-INSOLUBLE RESIN FROM SAID RESIN-FORMING INGREDIENTS IN AN ATMOSPHERE WHEREIN AT LEAST 50% OF SAID ATMOSPHERE IS SUPERHEATED STEAM.