US2073004A - Fireproof material - Google Patents

Description

Patented Mar. 9, 1937 UNITED STATES PATENT OFFICE FIREPROOF MATERIAL No Drawing. Application November 6, 1933, Serial No. 696,923. In Germany November 22,

3 Claims.

This invention relates to improvements in fireproofing of normally inflammable fibers of animal and vegetable origin; more particularly it relates to materials which are rendered fireproof 6 by a. treatment with a mixture of an uninfiammable wax and an uninfiammable lacquer-forming compound, and to a process of preparing such fireproof materials.

While no inflammable materials of organic 10 origin can be made wholly incombustible since all such materials will decompose and char when heated sufficiently, yet they can be made flameproof or flame-resisting, i. e. so that the flame does not spread when the impregnated material is heated for some time and that the flame will extinguish in a short time. This is the commercial sense of the word fireproof and is the one employed herein.

For fireproofing fibers by means of suitable uninfiammable wax-like compounds, such as chlorinated naphthalene or chlorinated diphenyl, the fibers must be pretreated with certain inorganic salts, such as diammonium phosphate and sodium sulfate. This manner of working is troublesome for it necessitates several working steps. The fibers areimpregnated in aqueous solution with the inorganic salts, then they are thoroughly dried, thereafter they are impregnated with the wax-like chlorinated hydrocarbon. It has also been proposed to impregnate the fibers with a. highly chlorinated naphthalene containing 68% of chlorine. The coating and impregnation made from this highly chlorinated naphthalene becomes however brittle and fissured on account of the crystalline structure of the chlorinated naphthalene containing 68% of chlorine, the coatings therefore do not adhere firmly.

In accordance with the present invention these difliculties are overcome by impregnating the fibers, such as wool, cotton, silk, paper, wood and materials made therefrom with a. mixture of can be added, or 15% of colophony, or 30% of residues from tar distillation without the mix ture becoming inflammable. As uninfiammable lacquer-forming compounds especially chlorinated rubber containing about 50 to 73% chlorine and polyvinylchloride come into consideration. To. the uninfiammable lacquer-forming compounds plastifiers and stabilizers may be added in the usual small amounts. The proportion of mixture of the compounds of the two groups changes according to the materials employed, in most cases a small addition of the uninfiammable lacquer-forming compound suffices to obtain the desired results. For instance, a mixture of about to 95 parts by Weight of the wax-like uninfiammable compound with 5 to 30 parts by weight of the lacquer-forming compound yields excellent results in fireproofing. By this manner of working the fibrous compound is not only fireproofed but it becomes also water-proof.

The invention is further illustrated by the following examples but it is not restricted thereto:

Example 1.--A copper wire covered with dry cotton or silk cross wound on a bobbin is immersed into a molten mixture having a temperature of to C. consisting of 95 parts by weight of a chlorinated naphthalene with a chlorine content of 50% and 5 parts by weight of chlorinated rubber with a chlorine content of 60%. As soon as the evolution of air bubbles has ceased the wire is rewound under intercalation of a wiper or stripper to remove the excess of the impregnating mixture. On a wire impregnated in such a manner a flame does not spread.

Example 2.A fabric is immersed into a melt as used in Example 1. After it has been thoroughly impregnated it is passed .over a heated calender or it is centrifuged to eliminate the adhering excess of impregnating material.

' Example 3.-A copper wire covered with paper and cross wound on a bobbin is treated in the same maner as indicated in Example 1 in a melt consisting of 90 parts by weight of a chlorinated naphthalene containing 60% of chlorine, 1 part by weight of. ozocerite or paraflin oil or colophony or a mixture of these additions and 10 parts by weight of chlorinated rubber containing 73% of chlorine and 0.5 to 1 part by Weight of tricresylphosphate and 0.01 to 0.1 part by weight of phenoxy propenoxide as a stabilizer. Also .on this wire the flame extinguishes near the ignition spot.

The terms wax-like chlorinated naphthalene and wax-like chlorinated diphenyl used in the claims are intended to comprise wax-like, resinlike and highly viscous chlorinated naphthalenes and diphenyls and such mixtures of these compounds with other-waxes, resins and the like,

which are uninfiammable in the commercial sense of the word.

I claim:

1. An organic fibrous material impregnated with a mixture of 70 to 95 parts of an uninflammable wax-like chlorinated naphthalene containing about to 60% of chlorine and 30 to 5 parts of a chlorinated rubber containing about to 73% of chlorine, said material being fireproof and waterproof.

2. An ,organic fibrous material impregnated with 90 parts by weight of a chlorinated naphthalene containing of chlorine, 1 part by weight RU'DOLF' ENGELHARDT.