NO744034L - - Google Patents

Description

"Procedure for producing

a washable finish on textiles".

The present invention relates to a method for the finish treatment of textiles. More particularly, the invention relates to an in situ method for giving a lasting finish to textiles by carrying out a free-radical polymerization and a condensation via aminoplast functionality on the textile, so that lasting properties such as e.g. flame retardant ability, stain resistance, grease resistance, water resistance and similar in the textile.

There has been a sharp increase in activity in the area of safety regulations for textiles, and consumers demand all-round application possibilities for textiles. This has put the textile industry to a serious test when it comes to the current textile finish technology, and the question is whether it is fully satisfactory.

Although textile treatment methods have been developed which are suitable for giving the textiles fire resistance, stain resistance, water resistance and the like, these treatment methods have generally been considered insufficient because they lack permanence. also a need for processes that give different lasting finishes to the textiles. Even the current imposed fire safety regulations that the textile industry meets, imply a clear and current need to use such methods.

Various pre-made polymers such as polyacrylates, polyvinyl chloride and the like have hitherto been used in textile finishing processes to give the textiles the above-mentioned properties. A problem which has been common to such finishing methods is that these polymers do not penetrate into the fibres, which e.g. are of cotton, rayon and the like, and therefore only cover the surface of the fibres. Under these circumstances, the polymer is removed by washing and/or wear during normal use of the textiles. Also when the polymer is a fairly stiff one, the "grip" (quality of the textile in terms of the feeling when feeling it with the hand) of the textile is adversely affected. Furthermore, the polymer, since it is on the surface of the fibers, causes fiber to fiber adhesion, which prevents the normal free movement of the fibers, thereby further affecting the grip and sometimes the strength of the textile.

Various methods have previously been used for the production of polymers in situ in fibers from non-polymeric reactants. These are referenced by Mark, Wooding and Atlas in "Chemical

Aftertreatment of Textiles", Wiley-Interscience, New York (1971). These methods fall into two main classes:

1) Free radical, in situ polymerization.

In these methods, a vinyl monomer is polymerized

like for example. acrylic acid or its derivatives on and if possible inside the fibers by means of a free radical catalyst to a vinyl polymer. Sometimes a grafting on the textile fibers follows such polymerization, especially if agents are used to form "grafting sites"

on the fibers. Such methods have found very little current application because they are expensive and it is difficult to induce a sufficient number of grafting sites on the fibers or to cause sufficient grafting polymers to form.

2) Aminoplast formation.

By these methods -NH- and -NCH(OR)-containing compounds such as e.g. urea formaldehyde, urea-glyoxal or melamine formaldehyde to form resins, usually of a cross-linked type, by means of acid catalysis which enables the formation of -NCH-N bonds and/or the attachment of NCH groups to the fiber

(where the fiber is reactive as in cases where the fibers have -0H-

or -NH groups which can form -NCH-N or -NCH-O bonds).

Generally, the methods described above are used

as two separate procedures or surgical procedures. For example, it is known to apply N-methylolacrylamide to cellulose textiles, where

when the amide is attached to the cellulose via acid-catalyzed aminoplast,

and then, as a separate operation, using high energy irradiation to induce free radical polymerization of the double bonds.

(See, e.g., W. Walsh, US-PS 3,434,161). This method has

not found commercial application, mainly because it involves special irradiation equipment.

It is also known in advance to attach a desired group,

like for example. (CH3O)2P(0)CH2CH2CONHCH2OH (as iDT-PS 1,495,383)

or a melamine resin (as in GB-PS 779,231) to a vinyl monomer group using aminoplast (acid catalyzed), and such mono-

more could presumably then be applied in a free-radical hardening step to the textile. But here too, two separate procedures (operations) are included.

It is also known (Kamogawa et al, JA-PS 363,142, reported by Mark et al, see above, p. 260) that N-methylolacrylamide can be both polymerized and condensed in cotton. However, this reaction core has not been used to bind a co-reactant to the textile to give the textile a large number of finish properties.

The present invention differs from what is known and described above in that it uses both free-radical and acid-catalyzed condensation chemistry at the same time, i.e. a simple process step that uses a catalyst or combination of catalysts with both free-radical and acid catalysis properties, so that new polymeric textile finishes are formed. In the new textile finishes, the polymeric networks are always considered to be based on C-C bonds formed by free radical polymerization as well as bonds formed by acid-catalyzed condensation polymerization between the polymer chains and/or between polymer chains and the fiber and/or between polymer chains and useful side chains. Since the invention uses reactants with low molecular weights in contrast to the polymer from the previously known methods in the area indicated in 1) above, it is possible to achieve good fiber penetration and lasting finishes with good grip. Since the method according to the invention only requires one reaction step, it is economically advantageous compared to the two-step or multi-step methods previously used in the area.

It is therefore an object of the present invention to provide a method which gives textiles many different lasting finishes.

It is another object of the invention to provide an in-situ, one-step process for the finishing treatment of textiles where, by suitable choice of reactants, textiles can be given lasting finishes of many kinds.

These, as well as other objects, are achieved by the present invention which provides a method for producing a wash-resistant finish on textiles which comprises applying to the textiles an effective amount of at least one free radical polymerizable monomer with a functional group capable of undergoing an acid-catalyzed con- densa's ion reaction with at least one co-reactant with reactive methylol, hydroxy, alkoxy or amino groups capable of undergoing acid-catalyzed condensation with a reactive methylol group on said free radical polymerizable monomer, together with a free radical generating catalyst and an acid catalyst or a single catalyst with both free-radical and acid-catalyst character and subjecting said textile to curing conditions in order to simultaneously carry out free-radical polymerization and acid-catalyzed condensation reactions.

A solvent such as water, alcohol, perchlorethylene, methyl chloroform or the like can be used if desired, as a carrier for these reactants and catalysts.

Suitable free radical polymerizable monomers having functional groups capable of reacting under acid-catalyzed aminoplast-forming conditions with a co-reactant having reactive methylol, hydroxy, alkoxy or amino groups include acrylic-

amide, methacrylamide, N-methylolacrylamide, N-methylol methacrylamide, N-(Alkoxymethyl)acrylamide, diacetoneacrylamide, i.e.

CH2=CHCONHC(CH3)2CH2COCH3, the methylolated products of diacetoneacrylamide, and 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

The preferred monomer is, due to the advantageous combination of low price, low volatility and high activity, N-methylolacrylamide. Within the class of monomers suitable for use in the method according to the invention, two subclasses can be distinguished:

a) those that have the appropriate functionality to allow them

to react under acid-catalyzed conditions with an -OH-, O-alkyl or -NH group to form C-O or C-N bonds, and such functionality is encompassed by the term "reactive methylol compounds", exemplified by compounds such as have methylol groups or ethers or esters thereof (i.e. by -N(CH2OH)-, -N(CH2O-alkyloxy)-, -N(CH2~O-acyloxy)- and C(=0)C-CH2OH groups, and

b) those which are not in and of themselves reactive methylol compounds, but which contain -OH-, -O-alkyl- or -NH groups which

can undergo acid-catalyzed condensation reactions with reactive methylol compounds.

Subgroup a) is exemplified by N-methylol acrylamide, N-methylol methacrylamide, N-(Alkoxymethyl)acrylamide, N-(Alkoxymethyl) methacrylamide and the methylolation products of diacetonacryl-

amide, while subgroup b) is exemplified by acrylamide, methacrylamide, diacetonacrylamide, 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate.

An effective amount of the free radical polymerizable monomer will usually be in the range from 2 to 50%, and preferably

from 3 to 40%, calculated on the weight of the textile fabric.

Reactants capable of reacting together under acid-catalyzed condensation reaction conditions can likewise be divided into two subclasses: a) those having reactive -OH-, -O-alkyl- or -NH groups capable of acid-catalyzed condensation reaction with reactive methylol groups, but which are not in and of themselves reactive methylol compounds, and b) those which are in and of themselves reactive methylol compounds and which can react both with reactive methylol groups of the monomer

(or its polymer) or which can react with -OH or -NH groups in monomer units that do not have reactive methylol groups per se.

Class a) includes alcohols, especially primary alcohols, primary and secondary amines and amides with -NH groups, aminoalkyl-substituted polysiloxanesilanols and alkoxysilanes which can hydrolyse to silanols.

Class b) includes methylolamides, methylolmelamines, methylolureas, methylolcarbonates, methylolguanidines, methylol dicyandiamides, glyoxalurea adducts and ethers and esters thereof, and quaternary alkylating agents of the type R" ^NC^NHCOR' (where R' and R" can both be alkyl or R^N may represent a pyridine ring).

An effective amount of the co-reactant will usually lie

in the range from 2 to 50, and more preferably from 3 to 40%, calculated on the weight of the textile fabric.

Free radical catalysts that can be used include organic and inorganic peroxy compounds and azo compounds, for example persulfates, perphosphate salts, t-butyl hydroperoxides, di-t-butyl peroxide, cumene hydroperoxide, methyl ethyl ketone peroxide, benzoyl peroxide, t-butyl peroxysuccinate, t-butyl perbenzoate, azobis-isobutyronitrile and azobis-isovaleronitrile. Preferred catalysts are, due to their water solubility and ability to also act as acid catalysts, the water-soluble persulphates, such as e.g. ammonium, sodium and potassium persulphate.

Acid catalysts that can be used include hydrochloric, sulphurous, fluoroboric, acetic, lactic, glycolic, citric, tartaric and oxalic acid, acid salts such as magnesium chloride, ammonium chloride, zinc chloride, magnesium nitrate, -fluoroborate or -fluorosilicate, zinc nitrate, -fluoroborate or -fluorosilicate, aminohydrochlorides, sodium bisulfate, potassium bisulfate, monoammonium phosphate and the like.

However, it is considered most advantageous to use a persulphate salt which simultaneously forms the acid as well as the free radical catalyst required by the process according to the invention.

An effective amount of catalyst is usually in the range from approx. 0.01 to 10% by weight of the reactants, and preferably between 0.05 and 5%.

Co-reactants of class a) above include primary alcohols containing phosphorus, such as e.g. pentavalent phosphorous esters containing primary alcohol groups as set forth in Applicant's US Application No. which was filed on the same date as this application, (HOCH2)3PO,(HOCH2)2P(0)CH2[0CH2P(0)(CH20H)CH2]OH, HO -alkylene-P0(OR)2 and the like, amines, e.g. NH2CH3~a(CH3)aP0(O-alkyl)2, phosphorus-containing amides, e.g. NH2C(0)CH2CH2P(0)(0CH3)2, (NH-[alkyl or H] 1 2p(°)(0-alkyl)2 PO(NH2)3, PO(NH-alkyl)3, [P(0 )(CH3)NHCH2CH2NH-]x, [P(0)(CH3)OCH2CH2NH]x, sulfonamides, e.g., NH2S02NH2, NH2S03H, and NH2S03NH4, and bromine-containing reactants such as HOCH2NHCOOCH2CHBrCH2Br or H0CH2C(CH2Br) 2CH2OH. Preferred examples due to commercial availability are PO(NHCH3)3, NH2SO3NH4, and (HOCH2CH2)2NCH2P(°) (°C2H5*2 *

The amounts required to provide flame retardant properties are such as to cause 0.5 to 5% phosphorus or sulfur to attach to the fabric.

Co-reactants of class b) above comprise hydroxy-methylated or alkoxy-methylated triazinylaminoalkylphosphonates such as e.g. those of applicant's US-PS 3,755,323 or of Tesoro's US-PS 3,551,422 (1970), methylolated amide phosphonates such as HOCH2NHCOCH2CH2P(0)(0CH3)2 or methylolated NH2C0-0-alkylene-P0(0-alkyl)2.

Co-reactants of type a) which can be used to provide water-repellent and softening properties, include long-chain (C§~ C22^ ~ primary alcohols or amines, such as, for example, octyl, dodecyl, hexadecyl and eicosyl alcohol, long-chain amides such as caproamide or stearamide, fatty acid diethanolamides, monoglycerides, polyfluoroalkyl alcohols or amines, amides of polyfluorinated fatty acids, polyfluorinated alkylsulfonamides, or silanols or alkoxysilanes which hydrolyze to silanols or aminoalkyl-substituted polysiloxanes.

Co-reactants of type b) which can be used to provide water-repellent and softening properties include N-methylolated, long-chain fatty acid amides, also N-methylolated, long-chain alkylureas, etherified methylolmelamines containing at least one long chain, quaternary, ammoniomethylated , long-chain fatty acid amides such as N-(stearamidomethyl)pyridinium salts, quaternary, ammoniomethylated, long-chain alcohols such as e.g. N-(octadecyloxymethyl)-pyridinium salts, 3,6-dioxatetracosyloxymethylenepyridinium salts or stearate ethoxymethylpyridinium salts. These quaternary salts are water-soluble equivalents of the corresponding methylol compounds.

Anti-stain properties can be achieved by using as co-reactants carboxymethyl cellulose, hydroxyethyl cellulose, hydroxy-terminated poly(alkylene amides), glycolic acid, polyfluoroalkylamines, polyfluoroalkanols or polyfluoroalkanamides.

Antistatic properties can be achieved by using as co-reactants hydroxy-terminated poly(alkylene oxide), polyethoxylated alkylphenols and polyethoxylated glycerides.

Cross-linking, which gives wrinkle resistance or lasting pressure properties, can be achieved by using as co-reactants in the method according to the invention such reactive methylol compounds as e.g. methylolated ureas, cyclic ureas, urones, triazones, melamines, dicyandiamides and urethanes or ethers or esters thereof. Examples are dimethylolurea, dimethylolethyleneurea, dimethylolpropyleneurea, dimethylolmethyluron, dimethoxymethylethylene urea, methylolmelamine, dimethylolmelamine, trimethylolmelamine, pentamethylolmelamine, hexamethylolmelamine (or the partially or fully etherified derivatives thereof such as pentamethoxymethylmelamine), dimethylolmethylcarbamate, dimethylisobutylcarbamate, tris( N-methylol-2-carbamoylethyl)amine, trimethylolglyoxaldiurein, dimethyloldihydroxyethyleneurea and dimethyloldicyandiamide.

When the monomer that can be cured by free radical catalysis is one that has reactive methylol groups, such as, for example, N-methylolacrylamide or hydroxymethylated diacetoneacrylamide, the co-reactant can be of the above-mentioned type or can be of the type a) such as, for example an unmethylolated urea, ethyleneurea, propyleneurea or another cyclic urea, melamine, dicyandiamide, cyanamide, urethane or lactamide.

When used together with phosphorus or sulfur containing flame retardant co-reactants, these nitrogen containing co-reactants synergize the flame retardant effect of phosphorus or sulfur.

Synergistic flame retardant properties are also achieved by

to use silanols or hydroxysiloxanes which can be hydrolysed

to silanols as co-reactants that can undergo acid-catalyzed co-reaction with monomer units of methylol reagent character.

Particularly effective are silanols or silicones with primary alcohol groups, amino or amido groups.

When the co-reacting methylol compound has two types of functional groups that differ in the degree of acid-catalyzed reactivity, the method according to the invention can be used as the first step in a method for producing permanent pressure. By, for example, using N-methylolacrylamide and dimethyloldihydroxyethyleneurea as monomer and co-reactant and using a sufficiently low temperature to avoid complete reaction of the functional groups of dimethyloldihydroxyethyleneurea, a finish is obtained that allows the material to be cut and pressed and then subjected to a final, stronger hardening which then gives a permanent press finish.

The method according to the invention can be carried out by

to use the reactants in any of the methods known in the textile finishing treatment field, such as e.g. stopping, spraying, aerosol spraying, application with a "kissing roller" or by pressing.

All types of textiles can be treated using the method according to the invention to give them lasting finishes. In this way, textiles obtained from natural fibers such as e.g. cotton, wool, silk, sisal, jute, hemp and linen, and from synthetic fibers including nylon and other polyamides, polyolefins such as polypropylene, polyesters such as polyethylene terephthalate, cellulose fibers such as rayon, cellulose acetate and triacetate, glass fibers, acrylic and modacrylic fibers, i.e. fibers based on acrylonitrile copolymers, saran fibers, i.e. fibers based on vinylidene chloride copolymers, nytril fibers, i.e. fibers based on vinylidene dinitrile copolymers, rubber-based fibers, spandex- fibers, i.e. fibers based on segmented polyurethane, vinyl fibers, i.e. fibers based on vinyl alcohol copolymers, vinylon fibers, i.e. fibers based on vinyl chloride copolymers, and metallic fibers. Textiles obtained from mixtures of any of the above natural and/or synthetic

fibres, can also be treated using the method according to the invention.

As used herein, the term "textile" or "textiles" means woven or knitted fabrics as well as non-woven fabrics consisting of continuous and/or discontinuous fibers joined together to form a fabric by mechanical winding, thermal inter-fiber bonding or when using glue or binding substances.

It should also be noted at this point that in addition to being used to provide durable finishes to textiles, the finishing method according to the invention can be used to provide durable finishes to various substrates such as e.g. cellulose in the form of paper, wood, veneer, chipboard, jute, "batting" and the like, urethane foam, rebonded urethane coatings, elastomers and the like.

Curing can be carried out by any treatment that starts both free-radical and acid-catalysed reactions. Usually this will take place by applying heat in the range from 50 to 200°C. Lower temperatures can be used, but the problem with too long curing times if a highly reactive catalyst is used is that the stability of the treatment solutions can be poor. Higher temperatures can cause damage to the materials. Curing times of from a few seconds at higher temperatures to a few days at lower temperatures are used. The person skilled in the art will understand that the required time can easily be determined by routine testing in any given equipment, where the time is varied upwards until it is found that adequate curing has been achieved, which is shown by the washing fastness of the finish. The appropriate time will be a function of catalyst selection and amount, fabric type, heat transfer characteristics of the equipment, presence of dyes and other ingredients on the fabric or in the finish, moisture content of the fabric, and other variables well known in the art.

The simultaneous radical-acid-catalyzed curing can also be produced by using a catalyst activator, such as e.g. sulfur dioxide which produces a "redox" reaction with the peroxide type free radical initiator and also produces an acidic reaction by means of sulfuric acid and sulfuric acid being formed on the substance.

When heat is the agent used, it can be added

by irradiation (such as by heat lamps), convection (such as in an oven), conduction (such as by heating rollers) or by vaporization or application of another heated gas to or through the substance. The free radical part of the reaction can be promoted by simultaneous application

of actinic radiation such as by ultraviolet light, corona discharge, electron radiation or gamma radiation.

To further illustrate the invention, the following examples are given - These examples are only illustrative and should not be understood as a limitation of the invention. Unless otherwise stated, all percentages and weights are given by weight.

Example 1

This example illustrates the production of a water repellency and fabric softening finish in situ on cotton.

A preparation is made with the following composition:

Cotton fabric is soaked to 70% moisture absorption and dried at 60 to 70°C, then heated to 150°C for 5 minutes to effect curing.'The resulting fabric exhibits durable water-repellent properties and a soft grip.

Example 2

This example illustrates the provision of a permanent press finish in cotton fabric by a delayed cure.

An aqueous preparation with the following composition is prepared:

A broad cotton fabric is moistened to 75% moisture absorption and then heated to 120°C for 2 minutes to effect drying and some curing, but very little cross-linking (which is shown by the fabric being easy to cut and sew). The fabric is then cut and sewn into clothes that are pressed at 145 to 150°C. Curing is then completed to effect crosslinking at 165 to 170°C for 3 minutes. The finished article retains its pressure and wrinkle resistance with normal use and washing.

Example 3

This example illustrates the production of a flame retardant finish in situ on cotton.

Three finish solutions are made as follows:

Cotton (129 g/m<2>flannel) is moistened to 101-102% moisture absorption, dried for 1.5 minutes at 121°C and cured for 1 minute at 177°C. After washing with water, the substance was found to pass the Federal Vertical Flammability Test DOC FF-3-71 with 7.5-10 cm burn length.

After ten washings with detergent, only the laundry treated with preparations A and C passed the test, which indicated the necessity of the free radical polymerization catalyst.

Similar results are obtained by replacing N-methylolacrylamide with methylolated diacetoneacrylamide (Lubrizol Corp. "HMDAA") and potassium persulfate with ammonium persulfate.

Example 4

This example will further illustrate the preparation

of a flame retardant finish on cotton.

An aqueous preparation is prepared as follows:

Cotton fabric is moistened in this solution and dried at 121°C for 1.5 minutes and then cured at 177°C for 1 minute. Flammability is determined by the limiting oxygen index (LOI) method (ASTM D-2863). See also for application to textiles Tesoro and Meiser, Text Res. J. 40 430-436 (1970). • Original LOI for treated cloth is 30.78%.

LOI for untreated cloth is 17.8%. After ten washes with detergent, the LOI for the treated laundry was 27.25%, and this indicates

that the main part of the flame-retardant finish was preserved.

A similar experiment using a product obtained by acid-catalyzed, dehydrative oligomerization of tris(hydroxymethyl)phosphine oxide instead of tris(hydroxymethyl)phosphine oxide shows an even greater degree of durability, both on cotton and on a cotton-polyester blend.

Example 5

This example further illustrates the preparation of a flame retardant finish on cotton flannel.

Aqueous preparations are prepared as follows:

Cotton flannel (129 g/m 2 ) is moistened, dried and hardened as in the previous examples. Both fabrics show original values above 31 and retain most of their flame retardancy after heavy washing with a commercial phosphate-based detergent.

Claims (12)

1. Method for producing a wash-resistant finish on a textile, characterized in that it includes applying convey to the textile an effective amount of: a) at least one free radical polymerisable monomer with a functional group that can undergo an acid-catalyzed reaction with b) at least one co-reactant with a reactive methylol, hydroxy, alkoxy or amino group which can undergo acid-catalyzed condensation with a reactive methylol group on said free radical polymerizable monomer, c) at least one free radical generating catalyst and at least one acidic catalyst, or at least one catalyst with both free radical generating and acidic properties, and d) subjecting said textile to curing conditions in order to simultaneously carry out free radical polymerization and acid-catalyzed condensation reactions. 2. Method according to claim 1, characterized in that the curing is carried out by heating the textile to 50-200°C. 3. Method according to claim 1, characterized in that the free radical polymerizable monomer used is N-methylolacrylamide. 4. Process according to claim 1, characterized in that HOCH2 NHCOCH2 CH2 PO(OCH3 )2 , <NH>2 COCH2 CH2 PO(OCH3 )2 , (<CH>3 NH)3 PO, (HOCH^ PO and oligomeric products from dehydration of (HOCH2 )3 PO. 5. Method according to claim 1, characterized in that a water-soluble persulphate salt is used as catalyst. 6. Method according to claim 1, characterized in that a free radical polymerisable monomer is used in amounts in the range from 2 to 50% by weight, based on the weight of the textile. 7. Method according to claim 1, characterized in that an amount of co-reactant is used in the range from 2 to 50% by weight based on the weight of the textile. 8. Method according to claim 1, characterized in that a catalyst is used in an amount of from 0.01 to 10% by weight of the reactant. 9. Method according to claim 1, characterized in that a phosphorous or sulphur-containing co-reactant is used to provide a flame retardant finish to the textile in a sufficient quantity to provide from 0.5 to 5% phosphorous or sulfur to the fabric. 10. Method according to claim 1, characterized in that N-methylolacrylamide and dimethyloldihydroxyethylene urea are applied to a textile which is first partially cured on the textile, said textile is cut and/or pressed and said reactant is then cured almost completely to give permanent pressure to the textile. 11. Method according to claim 1, characterized in that a catalyst activator is further used. 12. Method according to claim 1, characterized in that sulfur dioxide is used as catalyst activator.