US3660009A - Method of manufacturing ready-to-wear crease-resistive garments - Google Patents

Abstract

Crease-resistant properties are imparted to wash-and-wear garments by impregnating cellulosic textile fabrics with a solution of a polymeric acetal obtained by reacting formaldehyde and a polyol, together with an acid catalyst, and thereafter drying and forming a garment from the fabric, and pressing the same, the pressed finished garment then being subjected to a prolonged cure which imparts crease resistance to the garment.

Description

O United States Patent [151 3,660,009

Sexsmith 51 May 2, 1972 [54] METHOD OF MANUFACTURING References Cited READY-TO-WEAR CREASE-RESISTIVE UNITED STATES PATENTS GARMENTS 2,785,948 3/1957 [72] Inventor: Frederick H. Sexsmith, Erie, Pa. 2,785,949 5 2,974,432 3/1961 173] Assignee. lrzligmaster Onyx Corporation, New York, 3,409,387 1 Hm I 22] Filed: Feb. 2, 1969 Primary Examiner-George F. Lesmes Assistant ExaminerJ. Cannon 1 l. N 21 2 [2 1 App 0 8 Att0rneyArthur A. Jacobs Related US. Application Data [63] Continuation-impart of Ser. No. 491,009, Sept. 28, [57] ABSTRACT 1965, abandoned. Crease-resistant properties are imparted to wash-and-wear garments by impregnating cellulosic textile fabrics with a solution of a polymeric acetal obtained by reacting formaldehyde 521 U.S. Cl ..8/116, 8/1 16.4, 8/120, and a P tOgether with an acid Catalyst, and thereafter 33/144 2/243 drying and forming a garment from the fabric, and pressing [51] Int. Cl ..D06m 15/10, D06m 15/44 the same. the pressed fin shed garment then being subjected to [58] Field of Search ..8/116.4, 1 16, 120; 38/ 144; a prolonged cure which imparts crease resistance to the gar- 2/243 ment.

8 Claims, No Drawings METHOD OF MANUFACTURING READY-TO-WEAR CREASE-RESISTIVE GARMENTS This is a continuation-in-part of co-pending application Ser. No. 491,009, filed Sept. 28, 1965, now abandoned.

This invention relates to the method of manufacturing ready-to-wear, crease-retentive garments. The method comprises treating a cellulosic fabric with a specific type of polymeric acetal, drying the fabric, forming a garment from such treated fabric, and then subjecting the garment to a prolonged cure, thereby imparting to the fabric a crease-recovery angle of at least about 260.

lt is known in the art that fabrics may be rendered substantially crease-retentive by applying a resinous prepolymer to the fabric, and then curing the fabric at an elevated temperature. Frequently, the resinous prepolymers which are used are urea-formaldehyde, melamine-formaldehyde, and the like.

These polymeric finishes, however, suffer from several serious defects. For example, they absorb chlorine from the bleachers which are commonly used in laundering. Accordingly, evolution of hypochlorous or hydrochloric acid occurs when the fabric is ironed, pressed, or otherwise subjected to heat treatment. The acid weakens the fabric and eventually disintegrates it. The polymeric finishes also frequently cause yellowing of the fabric.

Whether or not such treated fabrics are bleached, the finishes tend to decompose in part after laundering and ironing, thereby liberating substances with a pronounced offensive and persistent fish-like odor. These odors, as well as that of formaldehyde, are also encountered in the curing of the finish, and these odors constitute an industrial nuisance or hazard. While such odors are removed by ventilation during cooling, they very often reappear when the goods or fabrics have been stored for any length of time. Such goods meet with poor commercial acceptance.

In addition to wrinkle-resistance, it is often desirable to form a permanent crease in a garment, for example, the seams of trousers, or pleats, so that such garments will not require pressing after each laundering. A delayed cure method for forming permanent creases in garments is described in US. Pat. No. 2,974,432. Briefly, that process consists of impregnating a fabric with a solution of a polymerizable resin, partially drying the fabric below the curing temperature, making the fabric into a garment, ironing or pressing the garment to its final desired shape, and then applying heat to the garment to cure the thermosetting resin impregnated therein. The garment produced by this process is wrinkle-proof and retains the creases initially formed in it.

Such a process has not been entirely successful, however, because the thermosetting resins employed therein frequently possess the undesirable qualities described above, that is, they tend to retain chlorine when the fabric is bleached. They tend to cure permaturely while they are stored and they tend to give off unpleasant odors. Moreover, after the fabric is impregnated with the thermosetting resin, it is necessary to maintain a certain amount of moisture in the fabric when it is dried so as to avoid premature curing. Therefore, when the fabric is dried, it is essential that the drying process be carried out under very carefully controlled conditions so as to avoid overdrying and pre-curing. Usually about 2-8 percent of moisture must be retained.

it is also known in the an that a wide variety of acetal re agents can be used to impregnate cellulosic fabrics so as to impart dimensional stability to the fabric. It is equally well known from US Pat. No. 2,785,947, that such treatment of cellulosic fabrics with acetals improves the crease-resistance of the fabric. Special surface effects, such as embossing, may be achieved in such acetal-treated textile materials. Such a process has not been employed in the production of washwear fabrics, however, because of the unsatisfactory wrinkle recovery of the fabric, and the undesirable yellowing of the fabric. In many instances, and with many acetals, either the expense is prohibitive or too many problems are encountered because of volatilization of the acetal.

It has now been found, however, that wash-wear garments, and the like, exhibiting excellent properties of wrinkle-resistance and crease-retention, can be prepared by treating cellulosic or partly cellulosic fabrics with specific polymeric acetal reagents, drying the fabric, preparing garments from the treated fabrics, pressing or ironing the garments so they are creased as desired, and then subjecting the garments to prolonged cure at elevated temperatures so as to achieve a crease-recovery angle of at least about 260, as measured by the standard wrinkle-recovery tester method employed in the textile industry. This method is the Tentative Test Method 55-1959T, as appears in the Technical Manual of the American Association of Textile Chemists and Colorists, (1964), Part ll, pp. Bl43-4. The wrinkle-recovery property of a fabric is measured in terms of its crease-recovery angle.

This wrinkle-recovery tester method measures the wrinkle recovery of a fabric quite accurately. Briefly described, test specimens of the size of 1.5 X 4 cm. are cut from a fabric to be tested. The long dimension corresponds to the direction of the test. These specimens are prepared by cutting in both the warp and filling directions. Generally, six specimens of each are used to obtain an average value. The specimens are maintained for at least 24 hours in an atmosphere having a relative humidity of 65 percent and a temperature of 70 F. The fabric is creased under a weight of 500 grams for 5 minutes. Five minutes after the weight is removed, the angle of recovery is measured. The maximum angle of recovery is 180. The angle of recovery of a specimen cut in the warp direction is added to the angle of recovery of a specimen cut in the filling direction in order to arrive at the final angle of recovery value for the fabric. A high angle of recovery indicates good wrinkle recovery.

The process of this invention completely avoids the aforementioned drawbacks encountered in the use of urea-formaldehyde, melamine-formaldehyde, etc., as wrinkle-proofing agents, both in the manufacture and in the use of garments treated with such reagents. Moreover, it has been found to be of considerable benefit that the polymeric acetals employed according to the present invention are not adversely affected if the fabric is over-dried. Accordingly, the complicated controls that are ordinarily required with the usual impregnating compounds, to prevent over-drying and pre-curing, can be avoided.

The polymeric acetal reagents which are used according to this invention are prepared by reacting formaldehyde with a Water-soluble polyol in the presence of an acid catalyst according to well-known methods. These polyacetals are watersoluble and have a boiling point of at least about 300 F. For the purposes of this invention, the term for-rnaldehyde" includes the common formaldehyde derivatives, namely, paraformaldehyde, trioxymethylene, methylal, and the like. The water-soluble polyols which may be used include ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, sorbitol, glycerine, mannnitol, glycol monoethers, partial esters of polyhydric alcohols, and the like.

Blends of polymeric acetals may be used as well as single polymeric acetals. The acetals may be employed in combination with carbamates, as for example, with dimethylolmethyl carbamate or dimethylol-hydroxyethyl carbamate, or with triazone resins, or with melamine-formaldehyde resins, or with polyvinyl alcohol, or with hydroxyethyl cellulose. When used in relatively small amounts, in the order of about 10 percent by weight of the acetal, there is neither chlorine retention damage nor odor formation with either the melamine, or carbamate derivatives. It has been found to be particularly advantageous to employ up to about 10-15 percent by weight of polyethylene or a self-crosslinking acrylic resin along with the polymeric acetals. Unusually high crease recovery values are thereby achieved.

The acetals employed in the process of this invention may be prepared by methods well known in the art. For example, a glycol and paraforrnaldehyde may be heated together in the v n r A up presence of a trace of an acid catalyst, such as sulfuric acid, methane sulfonic acid, paratoluene sulfonic acid, and the like, the dihydric alcohol and the aldehyde being in molar proportions. An azeotropic vehicle, such as benzene, toluene, xylene, ethyl benzene, is employed. By the use of azeotropic distillation, one mol of water is removed and the reaction proceeds essentially to completion in good yield. After neutralizing the acid catalyst with dilute caustic, and stripping 013' the toluene or other solvent under reduced pressure, the product may be recovered as a viscous liquid, often with a tendency to crystallize.

Pad baths must contain, in addition to an appropriate acetal composition, a suitable curing catalyst, such as magnesium chloride, zinc sulfate, zinc nitrate, ammonium chloride, 2- amino-methyl propanol hydrochloride, oxalic acid, citric acid, and the like. These catalysts are preferably salts of strong acids and weak bases, or Lewis acids. The acid catalyst is advantageously present in an amount of from about 5-400 percent by weight of the acetal content in the bath, and the acetal content is from about 5 to about 40 percent by weight of the bath. Certain antioxidants, reducing agents, or oxidizing agents, sequestrants, and other auxiliaries, may also be incorporated into the finishing bath in order to minimize thermal discoloration of the cellulose.

After the cellulosic fabric has been impregnated with the pad bath containing the polymeric acetal, the fabric is dried. The drying may be complete or a small amount of moisture may be present, up to about 7-10 percent, for example. Generally, this treated fabric is stored or shipped to garment manufactures, and during this period of storage, the treated fabric does not tend to pre-cure to any undesirable extent. After the fabric has been cut and sewn so as to form the desired garment, the garment is pressed into a suitable shape, such as by forming creases or pleats. The garment is then subjected to a prolonged cure, that is, to a temperature between about 320 F. and 400 F. for a sufiicient period of time so as to achieve a crease-recovery angle in the fabric of at least about 260. The prolonged heating, therefore, is at a higher temperature and for a longer period of time than ordinarily would be expected. After the polymeric acetal has apparently completely cured, the prolonged curing produces a further increase in the crease-recovery angle of the treated fabric to a value over about 260, thereby permitting the garment to be commercially suitable for press-free wash-wear use. If a temperature as low as 320 F, is employed, generally at least about minutes of cure time is required to produce a creaserecovery angle of 260 in the fabric.

The cellulosic textile material which can be used includes natural cellulose or regenerated cellulose, such as hydrolyzed cellulose acetate, viscose rayon, or any suitable fabric blend having a major portion of cellulosic material therein.

The following examples illustrate the process of the invention, but are not intended to limit it.

EXAMPLE 1 TABLE I Crease Recovery Sample No. Curing Time Angle (W F) l 1.5 minutes 244 2 10.0 minutes 261 Generally, 1.5 minutes of curing time at 340 F. is sufficient to cure the acetal. Further curing, however, substantially increased the crease-recovery angle. Based on experience, it is generally known to the art that a minimum wrinkle recovery of about 260 is necessary for adequate wash-wear and pressfree performance.

EXAMPLE 2 A polymeric acetal was prepared by reacting ethylene glycol with paraformaldehyde as described above. Finishing baths were prepared containing the acetal, magnesium chloride hexahydrate catalyst, and a 30 percent polyethylene fabric softener.

Standard weight shirting broadcloth, scoured, bleached and mercerized, was padded through the bath to 60-70 percent wet pickup, framed, dried l is minutes at 280 F stored for 1 week, and then cured for 10 minutes at 340 F. Sample swatches were tested for chlorine retention damage by the standard test methods according to the method described in the Technical Manual of the American Association of Textile Chemists and Colorists (1964) Damage By Chlorine Retained Standard Test Method No. 92-1962. The following results were obtained.

TABLE II Crease Chlorine Recovery Retention Sample Acetal MgCl, (W F) Damage It was noted that the finishing bath was essentially free of disagreeable chemical odors. Very slight amounts of formaldehyde were detected when the treated fabric was dried and again when the same sample was cured. The finished fabric was found to have no objectionable odors. The chlorine retention damage was negligible.

EXAMPLE 3 A bath was prepared containing the diethylene glycol acetal of Example 1, 3 percent of magnesium chloride hexahydrate, 2 percent of a 30 percent polyethylene fabric softener, and 2.7 percent of a 45 percent reactive polyacrylate emulsion, The broadcloth of Example 2 was padded to 60-70 percent wet pickup, framed, dried for l i minutes at 280 F., stored for l week and cured for 10 minutes at 340 F., with the following results;

TABLE III Crease Recovery Sample No. Acetal Angle (W F) The crease recovery was noted to be quite high.

EXANIPLE 4 TABLE IV Crease Sample Recovery Angle No. Cloth Acetal (W F) 1 Cotton 6.5% 275 2 Cotton 10.0% 282 In the above Examples l-4, where the crease-recovery angle was measured as 260 and over, the fabric tested was capable of maintaining a pressed crease put into it before the curing operation even after repeated washings. Garments made from such fabric are ideally suitable for press-free, crease-retentive, wash-wear use. It was also noted in the above examples that the impregnated fabric could be substantially completely dried, i.e., to a moisture content of less than 2 percent, prior to the curing step without any undesirable pre-curing of the polymeric acetals.

The invention claimed is:

1. A method of making wash-wear, press-free garments having crease-retention properties which comprises impregnating a cellulosic textile fabric with an aqueous solution of (a) a water-soluble polymeric acetal of formaldehyde and a polyol, said acetal having a boiling point of at least about 300 F., and being present in an amount of from about 5 to 40 percent by weight of said solution, and said polyol being a member of the group consisting of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, sorbitol, glycerine, mannitol, glycol monoethers, and partial esters of polyhydric alcohols, and (b) an acid catalyst present in an amount of from about 5 to 400 percent by weight of the acetal, drying the fabric, forming a garment from the fabric and pressing at least one crease into the garment, and

then heating the garment at a temperature between about 320 F. and 400 F. for a sufi'icient period of time to impart to the fabric a crease-recovery angle of at least about 260.

2. A method of making wash-wear, press-free garments having crease-retention properties which comprises impregnating a cellulosic textile fabric with an aqueous solution of (a) a water-soluble polymeric acetal of formaldehyde and a polyol, said acetal having a boiling point of at least about 300 F., and being present in an amount of from about 5 to 40 percent by weight of said solution, and said polyol being a member of the group consisting of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, sorbitol, glycerine, mannitol, glycol monethers, and partial esters of polyhydric alcohols, (b) an acid catalyst present in an amount of from about 5 to 400 percent by weight of the acetal, and (c) from about 1-15 percent, by weight of said solution, of a self-crosslinking polyacrylate resin, drying the fabric, forming a garment from the fabric and pressing at least one crease into the garment, and then heating the garment at a temperature between about 320 F. and 400 F. for a sufficient period of time to impart to the fabric a creaserecovery angle of at least about 260.

3. The method of claim 1 wherein said polyol is ethylene glycol.

4. The method of claim 1 in which the impregnated fabric is dried to a moisture content of less than about 2 percent prior to the curing of the treated fabric.

5. The method of claim 2 in which a water-soluble polymeric acetal of formaldehyde and ethylene glycol is employed as the acetal.

6. A garment produced in accordance with the method of claim 1.

7. A garment produced in accordance with the method of claim 2.

8. A garment produced in accordance with the method of claim 3.

Claims (7)

1. 2. A method of making wash-wear, press-free garments having crease-retention properties which comprises impregnating a cellulosic textile fabric with an aqueous solution of (a) a water-soluble polymeric acetal of formaldehyde and a polyol, said acetal having a boiling point of at least about 300* F., and being present in an amount of from about 5 to 40 percent by weight of said solution, and said polyol being a member of the group consisting of ethylene glycol, propylene glycol, butylene glycol, diethylene glycol, dipropylene glycol, dibutylene glycol, sorbitol, glycerine, mannitol, glycol monethers, and partial esters of polyhydric alcohols, (b) an acid catalyst present in an amount of from about 5 to 400 percent by weight of the acetal, and (c) from about 1-15 percent, by weight of said solution, of a self-crosslinking polyacrylate resin, drying the fabric, forming a garment from the fabric and pressing at least one crease into the garment, and then heating the garment at a temperature between about 320* F. and 400* F. for a sufficient period of time to impart to the fabric a crease-recovery angle of at least about 260*.
2. 3. The method of claim 1 wherein said polyol is ethylene glycol.
3. 4. The method of claim 1 in which the impregnated fabric is dried to a moisture content of less than about 2 percent prior to the curing of the treated fabric.
4. 5. The method of claim 2 in which a water-soluble polymeric acetal of formaldehyde and ethylene glycol is employed as the acetal.
5. 6. A garment produced in accordance with the method of claim 1.
6. 7. A garment produced in accordance with the method of claim 2.
7. 8. A garment produced in accordance with the method of claim 3.