US2597163A

US2597163A - Heat-resistant nylon cloth produced by reaction with quinones

Info

Publication number: US2597163A
Application number: US129526A
Authority: US
Inventors: Edwin B Michaels; Machlis Samuel
Original assignee: Individual
Current assignee: Individual
Priority date: 1949-11-25
Filing date: 1949-11-25
Publication date: 1952-05-20
Anticipated expiration: 1969-05-20

Description

Patented May 20, 1952 HEAT-RESISTANT I NYLON CLOTH PRO- DUCED BY REACTION WITH QUINONES Edwin B. Michaels, Stamford, Conn., and Samuel Machlis, New Rochelle, N. Y.

No Drawing. Application November 25, 1949, Serial No. 129,526

3 Claims. 1

This invention relates to new and useful improvements in the treatment of nylon and especially nylon cloth to make it heat resistant and adapted for use as a pressing cloth cover for steam heated laundry presses.

This invention is applicable to nylon cloth whether the fill and warp are formed entirely of monofilament threads or whether the fill is formed of spun staple nylon, and the warp threads are formed of monofilament threads.

Woven nylon cloth'has a very high tenacity and abrasion resistance. It has been found that cloth woven from nylon thread where the fill is spun from staple nylon and the warp from monofilaments, has tougher abrasion resistance than cloth consisting of warp and fill formed of monofilament threads even when they are of high denier. This adapts the nylon cloth for use as a cover for laundry presses. However, in spite of very desirable initial qualities, this cloth has been found to rapidly disintegrate at temperature above 300 F. and particularly when the clothing being treated contain starch.

It is known that untreated nylon cloth may lose as much as 70% of its strength in five hours when subjected to an ironing temperature of 180 C. (356 F.). The same cloth in hours may lose over 90% of its original tensile strength. It has been found that the heat deterioration of nylon is dependent largely upon an oxidation reaction accelerated by high temperatures. The main object of the present invention is to block this oxidation reaction and thereby check or reverse this degenerative characteristic of nylon under heat.

It has been found that spun nylon yarn deteriorates much more rapidly than monofilament yarn. However, when treated in accordance with this invention, these finer filaments no longer experience rapid deterioration and this makes possible the production of resistant fabrics woven from spun yarns. This is of great importance because spun yarns have a significantly higher abrasion resistance than the monofilament yarn.

A further object is to provide a very simple and eificient method for the relatively inexpensive treatment of nylon cloth to produce in it such a resistance to heat as will greatly increase its utility for any use in which it may be subjected to temperatures above 300 F., but not exceeding the melting point of the nylon.

It has been found that this improved condition of the cloth or material can be achieved by combining with the nylon certain quinones of which benzoquinone is an example. Another quinone which may be used is anthraquinone. This treatment is most'readily and efliciently accomplished by immersing the cloth in an aqueous solution of benzoquinone. The immersion may be made of various samples of cloth in solution of 0.5% to 5%, and pH below '7, for periods of time ranging from 12 seconds to 24 hours, and at temperatures ranging from 15 to 100 C. The percentage of solution, the time period and the temperatures employed would depend upon the characteristics of the material being treated. It has been found further that the most effective treatment as a whole has been effected by use of 1% solutions of benzoquinone in water at room temperatures for about 15 hours.

As an example, 15 yards of 44 inch nylon cloth (Whitehouse Leather Products #8,400 monofilament warp and spun fill), is immersed in a bath prepared by dissolving 160 grams of benzoquinone in 16 liters of water. The cloth is emerged for 15 hours at F., and after treatment, is rinsed free of the quinone and dried ready for use. Cloth so treated may lose about 25% of its tensile strength when heated for 15 hours at 350 F., whereas the untreated cloth will lose 70% of its strength in five hours at the same temperature and of its strength in 15 hours at the same temperature.

The process may be considerably speeded up by the use of increased temperatures and in commercial production for example, pounds of nylon fabric treated in a solution consisting of approximately 5 pounds of benzoquinone in 200 gallons of water at F. for two hours under agitation, produces a satisfactory product with an increase of tensile strength of about 10% or better. In this process, the cloth can be kept moving in the water to prevent a settling of the benzoquinone in the solution. In preparing the solution, it has been found that a more stable solution can be secured if the benzoquinone is first dissolved in acetone or di-acetone and the water added. However, this method while producing a more stable solution has certain disadvantages in that gas having an unpleasant odor, is released and for this reason, it has been found more satisfactory to prepare the solution by adding steam or boiling water to the powdered chemical.

It has been found that a cloth so treated is impervious to any degenerative effects from starch in the clothing being pressed thereon. Any untreated nylon will gradually coat with starch when used as an ironing cloth, as it is adhesive to the starch. Nylon processed in accordance with the present invention, is non-adhesive to starch and will not coat. It has also been found that other quinonoid bodies such as the oxidation products of pyrogallic acid, may be used and will result in a marked increase of the resistance of the nylon cloth to heat degradation.

It is, of course, expressly understood that the nylon cloth impregnated in accordance with the invention is a water insoluble nylon cloth formed of a polyamide having the general formula (.NH.(CH2) .NH.CO. (CH2) yCO.NH. (CH2) 1:.

where a: and y are integers greater than 1.

While the invention has been described in detail, it is not to be limited to such details and forms since many changes and modifications may be made in the invention without departing from the spirit and scope of the invention in its broadest aspects. Hence, it is intended to cover any and all forms and modifications of the invention which may come within the language or scope of any one or more of the appended claims.

What we claim as our invention is:

1. A heat resistant polyamide fabric produced at the process of impregnating a Water insoluble polyamide woven cloth in which the polyamide has the formula [.NH. (CH2) m.NH.CO. (CH2) y-CO.NH.(CH2) r.

where :r and y are integers greater than 1, with a 0.5 %-5% aqueous solution of a quinone of the class consisting of benzoquinone, and anthraquinone having a pH of less than '7 at a temperature ranging from 15 C. to 100C. for a period of time ranging from 12 seconds to 24 hours.

2. A heat resistant polyamide fabric produced by the process of impregnating a water insoluble polyamide woven cloth in which the polyamide has the formula [.NH. (CH2) w.NH.CO. (CH2) .CO.NI-I.(CH2) I. .l

where a: and y are integers greater than 1, with a 0.5 %-5% aqueous solution of benzoquinone having a pH of less than 7 at a temperature ranging from 15 C. to C. for a period of time 7 ranging from 12 seconds to 24 hours.

3. A heat resistant fabric produced by the process of impregnatingv a water insoluble woven cloth in which the polyamide has the formula REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,265,119 Coolidge Dec. 2, 1941 2,312,469 Freund Mar. 2, 1943 2,484,529 Roedel Oct. 11, 1949

Claims

1. A HEAT RESISTANT POLYAMIDE FABRIC PRODUCED AT THE PROCESS OF IMPREGNATING A WATER INSOLUBLE POLYAMIDE WOVEN CLOTH IN WHICH THE POLYAMIDE HAS THE FORMULA