US3868349A - Permanent press fabric resin and processes therefor - Google Patents

Abstract

2,7-dioxo-4,5-dimethyl-decahydropyrimido-(4,5-d)-pyrimidine is reacted with glyoxal and the resulting adduct methylolated with formaldehyde to produce the corresponding methylolated derivative which exhibits very desirable properties as a permanent press resin for fabrics.

Description

Elite Powanda et a1.

PERMANENT PRESS FABRIC RESIN AND PROCESSES THEREFOR Assignee: Celanese Corporation, New York,

Filed: May 3, 1973 Appl. No.: 357,048

Related US. Application Data Division of Ser. No. 135,778, April 20, 1971, Pat. No. 3,753,648.

[15. Cl. 260/67.7, 260/29.4 R, 260/67.6 R, 260/256.4 F Int. Cl. C08g 9/26 Feb. 25, 1975 [58] Field of Search 260/67.5, 67.6 C, 67.6 R, 260/67.7

[56] References Cited UNlTED STATES PATENTS 3,734,879 5/1973 Von-a et a1. 260/67.6 C X 3,753,648 8/1973 Powanda ct al. 260/67.5 3,764,263 10/1973 Powanda et a1 260/69 R X Primary Examiner-Howard E. Schain Attorney, Agent, or FirmJohn A. Sheddcn [57] ABSTRACT 2,7-dioxo-4,5-dimethy1-decahydropyrimido-[4,5-d]- pyrimidine is reacted with glyoxal and the resulting adduct methylolated with formaldehyde to produce the corresponding methylolated derivative which exhibits very desirable properties as a permanent press resin for fabrics.

9 Claims, No Drawings PERMANENT PRESS FABRIC RESIN AND PROCESSES THEREFOR This is a division, of application Ser. No. 135,778, filed Apr. 20, 1971, now U.S. Pat. No. 3,753,648.

BACKGROUND OF THE INVENTION In the last decade permanent press fabrics have been a real boon to the textile industry. The future looks even brighter as consumers look for permanent press properties in other than casual wear, shirts and like apparel. It is anticipated, for instance, that use of permanent press resins in household white goods, e.g., sheets, pillowcases and tablecloths, will account for a substantial amount of the increased demand in the future. To meet this demand the resins must be able to impart permanent press properties without degrading the fiber from which the fabric is made. Typically, the fabric is cellulosic in nature, for example, cotton, cotton-polyester blends, regenerated cellulosic materials, such as rayon, and the like. Degradation can occur, for example, when the resin finish is applied and cured; it may also occur as a result of repeated washings of the treated fabric using the various popular bleaches and detergents.

The concept of permanent press is twofold: crease resistance and crease retention. Crease resistance is synonymous with wrinkle resistance and wrinkle recovery, viz., the ability of a treated fabric to resist wrinkling and to retain smoothness of shape and hand upon repeated wear and laundering. Crease retention is synonymous with durable press, viz., the ability of a treated fabric to drip-dry without loss of crease and to be worn without irnoning.

Clearly, the achievement of all of these desirable properties, and others such as resistance to soil redeposition, and the like, requires chemicals which are quite special.

Therefore, it is an object of the present invention to provide a novel composition of matter which, when applied to a fabric, particularly a cellulosic fabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a process for producing a novel composition of matter which, when applied to a fabric, particularly a cellulosic fabric, imparts a colorless, permanent press finish thereto.

Another object is to provide a permanent press fabric finish.

Yet another object is to provide a process for applying to a fabric, and particularly to a cellulosic fabric, a permanent press finish.

These and other objects of the present invention, as well as a fuller understanding of the advantages thereof, can be had by reference to the following detailed description and claims.

DETAILED DESCRIPTION OF THE INVENTION The above objects are achieved according to the present invention by the discovery of novel chemical compositions from which useful resins can be readily prepared, the latter exhibiting, as will be seen hereinafter, permanent press characteristics of the type intensely sought after by the textile industry and hereinbefore briefly described. The novel compounds of the present invention are prepared from 2,7-dioxo-4,5- dimethyl-decahydropyrimido-[4,5-d]-pyrimidine, (A), which has the following formula:

2 0H} CH3 HN NH (A) 0 N N o H H by reacting (A) with glyoxal to form the dihydroxyethyl-substituted adduct material, (B), which is repre-. sented by the following formulae:

H N gfcll HN 3 NH N N HO g and F (B) HO OH which in turn is treated with formaldehyde or source thereof to produce the corresponding methylolated material, (C), which is represented by the following formula NYN\ 0Y1: cu,

catalysed reaction between acetaldehyde and urea in aqueous menstruum. The ratio of the concentration of CH and 3 acetaldehyde to that of urea in the reaction system is and about 100C., with the atmospheric reflux temper ature of the reaction system being especially preferred.

It is desirable that the 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine be employed in a high state of purity, i.e., in crystalline form. In addition, it is preferred that this material be free of color bodies which become noticeable when the aminoplast (C) is applied to a fabric, or during the lifetime of the treated fabric.

The compound 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine suitable for use in the present invention is conveniently and preferably prepared according to the following procedure, it being understood, of course, that other methods of synthesis can be used without departing from the spirit of the invention. Thus, 5,285 parts by weight (120 moles) of acetaldehyde are charged to a suitable conventional reaction vessel and cooled to below 20C. Then a solution of 3,600 parts by weight (60 moles) of urea and 645 parts by weight of reagent grade sulfuric acid (98 percent) in 4,275 parts by weight of water are added dropwise with stirring to the acetaldehyde. During the addition, a suitable cooling means (e.g., an ice-bath) is applied to the reaction vessel, and the rate of addition is adjusted, if necessary, in order to maintain the reaction system at a temperature of about 20C. When the addition is complete, the reaction mixture is heated to atmospheric reflux temperature and maintained thereatfor 1 hour. Thereafter, the reaction mixture is cooled to ambient temperature, diluted with water, and filtered to isolate the crystalline product, (A). The product is washed with water, then with methanol, and finally recrystallized from water. After drying the recrystallized product at 70C., it weighs 1,467 parts (25 percent of the theroretical yield based on urea) and melts at 275-280C. Elemental analysis of the product corresponds to the formula C H N O The material with glyoxal, according to the present invention, as follows:

semi

cu, ca,

2,7-diox-4,5-dimethyldecahydropyrimido-[4,5-d]pyrimidine, (A), is reacted The glyoxal/2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine adduct, (B), is then further reacted, according to the present invention, by contacting and reacting the adduct with between about 1.0 and about 3.0 molar proportions of formaldehyde as illustrated in the following equation:

Eguation II ADDVCT (B) 71HCHo (agony, J"n

HO H

The exact nature of adduct (B) in Equation 1, above, is not known but is believed to be a mixture as shown in the equation; likewise, methylolation of the intermediate (B) of Equation I yield what is believed to be the 2,7-dioxo-4,5- dimethyl-decahydropyrimido-[4,5-d]- pyrimidine/Glyoxal/HCHO mixture (C) illustrated in Equation 11.

Intermediate (B) is best prepared by reacting equimolar proportions of glyoxal and (A) in a hydroxylic medium, preferably water, at elevated temperatures, e.g., in the range of about 40C. to about 75C, and then the reaction is completed by increasing the temperature to atmospheric reflux for a relatively short period of time. Usually, it is best to maintain the lower temperature for less than about an hour and then bring the reaction mixture to reflux for about 3 to about minutes. Of course, these temperatures may be varied considerably, depending upon concentrations of reactions, medium used, and other like factors. It should be understood that, in view of the fact that the reaction proceeds rather readily, a wide variety of temperatures, concentrations and pressures is permissible, the reaction conditions just mentioned being those best suited for equimolar proportions of reactants. Obviously, pressures above or below atmospheric require higher or lower temperatures, respectively; obviously, also, lean or excess concentrates, below or above stoichiometric, affect the temperature requirements for optimum results. In short, the reaction conditions are quite flexible, the stringencies being imposed by desired efficiencies.

Conversion of intermediate (B) to the composition (C) of Equation 11, above, likewise admits ofa wide variety of reaction conditions. Reaction is best carried out in a hydroxylic medium, usually water. Generally, between about 1.0 and about 3.0 molar proportions of formaldehyde, preferably between about 1.90 and about 2.10, is used based on adduct (B). Typical desirable formaldehyde sources are formalin, paraformaldehyde, and the like.

Admixture of adduct (B) with, say, an aqueous solution of formaldehyde give rise to an exotherm. When the exotherm subsides (about 40), the mixture of reactants is preferably heated for up to several hours, cooled and pH adjusted to about neutral. Broadly, a temperature above about 40C to about 105C is contemplated herein, the upper temperature being, preferably, no greater than about atmospheric reflux temperature.

As in the case of the Equation 1 reaction described hereinbefore, reaction conditions for the Equation 11 reaction are very flexible, the stringencies also generally being dictated be desired efficiencies. If pressures above or below atmospheric are used, proportionately higher or lower temperatures, respectively, are usually indicated; likewise, lean or excess concentrations of formaldehyde with respect to adduct (B) could affect the temperature requirements for optimum results, as would of course, the amount of water or other hydroxylic medium used relative to the reactants.

Fabric treatment is carried out in a conventional pad bath in an aqueous medium containing the resinforming material (C) and a curing catalyst as the principal ingredients. Generally, small amounts of surfactant and softener are present to enhance transfer of aminoplast material (C) to the fabric being treated.

The catalyst functions to catalyze the curing process which takes between about 5 seconds and about 30 minutes, preferably between about 3 minutes and about 15 minutes, at temperatures in the range of about 275F to about 425F, preferably between about 300F and about 350F. Substances suitable for catalysing the curing process include any conventional acidic catalysts or like catalysts heretofore known to be useful in catalysing the curing of conventional aminoplast materials. Such acid catalysts are employed in conventional amounts, e.g., at a concentration of between about 1 percent and about 50 percent by weight, based on the weight of aminoplast material. Typical catalysts contemplated herein are the water-soluble inorganic salts which behave as so-called latent acid catalysts, e.g., ammonium chloride, magnesium chloride, zinc nitrate, and the like.

According to a preferred mode of carrying out the fabric treatment process of the present invention, the aqueous reaction mixture containing the novel composition of matter (C) dissolved therein is cooled to ambient temperature, brought to a pH of about 7.0, and filtered to remove any insolubles which may be present. Then it is diluted with water to the desired concentration, mixed with a conventional amount of an acidic curing catalyst, and the fabric to be treated is immersed therein. The amount of resin pickup experienced by the substrate fabric is determined in large measure by the concentration of the resin-forming material, (C), in the aqueous pad bath solution. Generally, the concentration of (C) in the pad bath solution (which can be determined gravimetrically) ranges between about 2 percent or less and about 65 percent by weight or more, for cellulosic fabrics. Preferably, a pad bath concentration of between about 5 percent and about 45 percent is used, with a concentration of between 10 percent and about 25 percent being especially preferred. Percentages are based upon the total weight of the pad bath solution. The particular desired concentration of resin-forming substance in any given instance can be conveniently achieved by appropriate adjustment of the concentrations of reactants (i.e., (A)/- glyoxal/HCHO) or by the judicious addition of water to an initially relatively highly concentrated solution of resin-forming compound (C).

After saturating the fabric with the pad bath solution, the treated fabric is withdrawn from the bath, wrung between rollers made of an inert material (e.g., metal, ceramic, rubber, and the like), preferably rubber rollers or adjacent, cooperatively-functioning stainless steel/rubber rollers, dried and simultaneously or subsequently heat cured at a temperature within the aforementioned range. The heat curing step can, if desired be conducted by contacting the fabric with heated metal rollers, preferably heated stainless steel rollers.

In the present invention, the percent pickup of the (A)/Glyoxal/HCHO composition is measured as: Wet Pickup, after immersion in the pad bath solution; Dry Pickup, after curing; Dry Pickup, after I wash; and Dry Pickup, after 21 washes.

As will be seen hereinafter, all tests are comparative tests using commercial resins as controls and comparing these resins with the novel composition (C) of the instant discovery. The tests recorded herein, other than resin pickup characteristics, are intended to illustrate the effectiveness of compound (C) with respect to 7 wrinkle recovery, hand, deterioration of fabric, soil redeposition, and the like. Obviously, permanent press resins are not attractive if they deleteriously affect fiber strength, if wrinkle recovery is poor, etc.

Fabrics, particularly cellulosic fabrics, treated with aminoplast material (C) according to the present invention exhibit as will be seen hereinafter, very desirable and valuable permanent press properties. The examples which follow teach the novel adducts (B) and (C) of the instant discovery and processes for preparing same. In addition, treatment of fabrics with resinforming compound (C) is fully disclosed, as well as a number of tests comparing the latters efficacy with that of the following commerically popular resinforming compounds:

some --m uca es PERMAFRESH*113B (dimethyloldihydroxyethyleneurea) DMDHEU a 2 m H Cit pfl Z. R hydr oxyalkyl or alkyl] AEROTEX" 8 2 (carbamate) *Trademark for permanent press compound sold by Sun Chemical Co., Wood River Junction. R.l.

"Trademark for permanent press compound sold by American Cyauamid Co.. Bound Brook, NJ.

DESCRlPTION OF PREFERRED EMBODIMENTS The following examples are merely intended to be illustrative of certain of the preferred embodiments within the spirit and scope of the present invention and,

therefore, are not to be interpreted too restrictively;

parts and percentages given in the examples are by weight, unless otherwise indicated:

EXAMPLE 1 To a reaction vessel is fed 538 grams of 2,7-dioxo- 4,5-dimethyl-decahydropyrimido-[4,5-d]-pyrimidine, 395 grams of 40% glyoxal aqueous solution and water, thus providing a 2,7-dioxo-4,5-dimethyldecahydropyrimido-[4,5-d]-pyrimidine: glyoxal molar ratio of 1:1. Sufficient water is introduced to obtain good stirring (approximately 165 grams). The mixture of reactants is heated to 60C held at that temperature for 45 minutes, and then slowly heated to atmospheric reflux (103C) and held at that temperature for 5 minutes before cooling the reaction mixture to ambient temperature and then filtering to remove unreacted 2,- 7-dioxo-4,5-dimethyl-decahydropyrimido- [4,5-d]-pyrimidine (147 grams). The filtrate (1,055 grams) therefore contains 395 grams (approximately 2 moles) of reacted (A), i.e., the adduct (B), described hereinabove in Equation I, in solution.

EXAMPLE 2 TABLE 1 7vfree Compound Solids pH HCHO Aerotex 82 4812* 6.5 3.2 Permafresh 113B 45i2* 5.9 O (Al/Glyoxal/HCHO 39 7 O 1.5

Published values EXAMPLE 3 The product (A)/Glyoxal/l-1Cl-1O composition (C) of Example 2, above, is used to treat plain weave white 50/50 cotton-polyester (PE) cloth, of the type used in shirts or household goods (e.g., sheets and pillowcases). The test procedure is as follows:

Bath: compound tested (dry weight basis) Surfactant (Triton*X-100) Softener (Lubritron**KN) Catalyst-KMMgCl solution)*** Water x rw OCOONO Standard Pad Bath 8(l'71 Wet Pickup Dry at 220F for 12 minutes Cure at 325T for 12 minutes 7-97r Dry Pickup After wash Half of the test swatches are laundered through 20 cycles Wrinkle Recovery Stiffness Tearing Strength Abrasion Resistance (ASTM D-1175-64T) *Triton X- is a trademark for an alkylaryl polyethcr alcohol surfactant sold by Rohm & Haas Co. Philadelphia. Pa.

Lubriton KN is a trademark for a softener comprised of a nonionie emulsion of a high density olefin sold by Chas. S. Tanner Co.. Warwick, R1

*"Catalyst-KR is a magnesium chloride-based catalyst solution sold by Sun Chemical Co, Wood River Junction, R.l.

Procedure:

Tests:

The following table shows the pickup properties of each of the controls as compared with compound (C), the product of Example 2, above:

Wrinkle recovery characteristics of the fabric of Example 3, above, treated with the compounds of Table 9 II is determined by a well-known method: ASTM D- l 2- 95-67-Warp direction only. The results of these tests follow:

TABLE III WRINKLE RECOVERY Recovery in Degrees After 20 lnitial Wash Cycles Blank (Untreated 50/50 PEzCotton) 107 120 Aerotex 82 142 142 CONTROLS Permafresh l l3B 145 144 (Al/Glyoxal/HCHO 140 140 Cantilever stiffness of the fabric of Example 3 using the compounds of Table ll is determined using the method: ASTM Dl388-64-Warp direction only. The results are as follows:

Tearing strength of the fabric of Example 3, above, using the compounds of Table ll is determined by the method: ASTM D226l-64T-Warp direction only. The results are as follows:

TABLE V TEARING STRENGTH BY THE TONGUE (SlNGLE RIP) METHOD 4 Break Load (in pounds) After 20 Initial Wash Cycles Blank (Untreated 50/50 PEzCotton) 3.14 4.08 Aerotex 3.62 3.69 CONTROLS Permafresh llflB 3.75 4.]3 (AHGIyoxal/HCHO 3.02 2.97

Conventional soil redeposition tests showed the product of Example 2, i.e., compound (C), to be superior to Permafresh 113B (DMDHEU). Using a small amount of anti-soil-redposition agent for polyester/cotton blends when subjecting the fabric of Example 3, treated as taught in the same Example, to an otherwise conventional soil redeposition test showed the fabric treated with (A)/Gyloxal/HCHO compound (C) performed as well as the Aerotex 82 treated fabric and better than the Permafresh ll3B-treated fabric under the same conditions. In other words, the Aerotex 82- treated fabric and the compound (C)-treated fabric both remained almost completely white. The anti-soilredeposition agent used is a water-soluble methyl cellulose derivative (4,000 cps) bearing the trademark ME- THOCEL90-HG and sold by Dow Chemical Corp., Midland, Michigan. A concentration of 1%, by weight, of Methocel-HG is added to the conventional soil redeposition test soiling bath alluded to hereinabove; the concentration, viz., 1% by weight, is based on the total weight of the soil bath. The use of methyl cellulose derivatives (Methocel) is claimed in copending application Ser. No. 22,140 filed Mar. 2, 1970, by A. S. Forschirm et al. and entitled Anti-Soiling Polyester Textile Material.

As is evident from Table III and IV, above, the wrinkle recovery and stiffness performance of compound (C) compares very favorably with the performance of the commercial resins, even after multiple launderings. This indicates, in the case of wrinkle recovery, good bonding of the compound (C) resin to the fabric. Tear strength data reported Table V, above, showed compound (C), like the commerical controls, produced no significant deterioration in fiber strength. Abrasion resistance tests (ASTM D-ll75-64T) not tabulated hereinabove, likewise indicated no significant deterioration in fiber strength.

Pursuant to statutory requirements, there are described above the invention and what are now considered its best embodiments. It should be understood, however, that the invention can be practiced otherwise than as specifically described, within the scope of the appended claims.

What is claimed is:

1. A method which comprises reacting 2,7-dioxo-4,5- dimethyl-decahydro-pyrimido-[4,5-d]-pyrimidine (A) with glyoxal in a hydroxylic medium to form a dihydroxyethylene-substituted adduct (B), and reacting adduct (B) with between about 1.0 and about 3.0 molar proportions of formaldehyde, the resulting methylolated derivative composition (C) being useful as an aminoplast material for imparting permanent press properties to fabrics.

2. The method of claim 1 wherein the hydroxylic medium is water.

3. The method ofclaim 2 wherein reaction is carried out at elevated temperatures.

4. The method of claim 3 wherein the reaction temperature, for the most part at a temperature in the range of about 40C to about 75C. is ultimately increased to atmospheric reflux temperature to complete the reaction.

5. The method of claim 1 wherein adduct (B) and formaldehyde are reacted in a hydroxylic medium.

6. The method of claim 5 wherein the hydroxylic mey l 1 l2 8. The method of claim 1 wherein the adduct (B) re- 9. A methylolated (A)/glyoxal/HCHO derivative of action product, without first being separated from its the formulae (C):

' 1 -(cu, we), Hz i ar n o ,N so

CH3 no lg and reaction medium, is reacted with formaldehyde to prowherein n is an integer from 1 to 2, inclusive. duce the methylolated derivative compound (C).

Claims (9)

1. A METHOD WHICH COMPRISES REACTING 2,7-DIOXO-4,5DIMETHYL-DECAHYDRO-PYRIMIDO-(4,5-D)-PYRIMIDINE (A) WITH GLYXOAL IN A HYDROXYLIC MEDIUM TO FORM A DIHYDROXYETHYLENESUBSTITUTED ADDUCT (B), AND REACTING ADDUCT (B) WITH BETWEEN ABOUT 1.0 AND ABOUT 3.0 MOLAR PROPORTIONS OF FORMALDEHYDE, THE RESULTING METHYLOLATED DERIVATIVE COMPOSITION (C) BEING USEFUL AS AN AMINOPLAST MATERIAL FOR IMPARTING PERMANENT PRESS PROPERTIES TO FABRICS.

2. The method of claim 1 wherein the hydroxylic medium is water.

3. The method of claim 2 wherein reaction is carried out at elevated temperatures.

4. The method of claim 3 wherein the reaction temperature, for the most part at a temperature in the range of about 40*C to about 75*C, is ultimately increased to atmospheric reflux temperature to complete the reaction.

5. The method of claim 1 wherein adduct (B) and formaldehyde are reacted in a hydroxylic medium.

6. The method of claim 5 wherein the hydroxylic medium is water.

7. The method of claim 6 wherein reaction is made to take place at a temperature in the range of above about 40*C to about atmospheric reflux.

8. The method of claim 1 wherein the adduct (B) reaction product, without first being separated from its reaction medium, is reacted with formaldehyde to produce the methylolated derivative compound (C).

9. A methylolated (A)/glyoxal/HCHO derivative of the formulae (C):