US2036195A - Plastic sheet compositions - Google Patents

Description

Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE No Drawing. Application July 7, 1934, Serial No. 734,238

6 Claims.

The present invention relates to a plastic composition, and it particularly relates to plastic compositions which are highly suitable for utilization in the manufacture of all building construction materials, such as wallboards, shingles and so forth.

It has been found most plastic compositions utilized for manufacturing shingles and wallboards are not altogether satisfactory because of expense, lack of durability, low heat insulating power, or low resistance to weather conditions normallyoccurring in the temperate zone regions of the United States of America.

Although a great many plastic wallboards and shingle wallboard compositions have been prepared from cellulosic materials with or without the addition of adhesive mixtures, many difficulties have been encountered and completely satisfactory material has not as yet been produced.

It has now been found if the character of the cellulosic material and if the character of the adhesive materials are most carefully controlled, that most satisfactory plastic compositions will be formed for the purpose above-described.

Among the most satisfactory materials which have been used are fibrous cellulosic materials, such as kapok, and sheet cellulose materials, preferably of a non-fibrous nature such as scrap Cellophane or other cellulose compound sheet material in divided condition. Cellophane refers to transparent sheets or films of regenerated cellulose, made by dissolving pure wood pulp or similar cellulose to produce an aqueous solution, the most common being viscose. The cellulose in this solution is then precipitated by means of acids to produce a very thin, non-fibrous sheet of regenerated cellulose, which after being purified and impregnated with a softener, such as glycerin, is dried. The finished material has a glass-clear transparency, is smooth and lustrous, gasproof, greaseproof, and as the result of special treatment is sometimes moisture-proof.

Kapok, strictly speaking, is the seed hair of Eriodendron anfractuosum, but the term is also applied to other vegetable downs. It is used as a stuffing for lifesaving appliances at sea, due to its power of resisting the penetration of water owing to the peculiar structure of the fiber. Kapok is a fibrous material in which the individual fibers are in the form of thin-walled tubes enclosing a relatively large volume of air. The cell wall represents on the average about one-fifth of the total diameter of the fiber.

These materials are preferably mixed with a proper adhesive such as casein glue, the casein glue acting to form substantially integral crystals or colloidal mass surrounding each of the kapok fibers and each of the said cellulose scraps. Although the kapok and the scrap sheet cellulose material may be utilized together it has also been found possible to use them separately or in combination with the casein glue.

In lieu of mixtures of scrap cellulose material and kapok, it is contemplated to use a mixture 10 of casein glue and kapok, or a mixture of casein glue and scrap cellulose material.

In preparing the composition of the present application, one part of kapok is thoroughly masticated with about an equal Weight of sheet cellulose scraps, preferably with the addition of water. When the kapok and the cellulose scraps have been thoroughly intermingled together, the moist mixture, from which most of the water is drained, is combined with half or an equal amount of casein glue and the resultant plastic composition is permitted to set either under pressure or in open vessels to form sheet materials of desired thickness and width.

Preferably the kapok and the sheet scrap cellu- 5 lose material when intermingled with the casein glue, should form a slurry or a cream which it is found may be readily poured and set. The resultant composition after setting and hardening, may be readily machined, cut to size or planed and it may be most desirably used for a material of construction. The preferred thickness is from one-eighth to one-quarter of an inch and in this thickness the material may be conveniently used for fireproofing, waterproofing, either in the form of wallboards or in the form of shingles.

The material is very cheap, has high insulating qualities and durability, is very strong and of light weight.

By the expression Cellophane in the accompanying claims is included scrap sheet regenerated cellulose materials, which may be sold under other and different trade-marks. The trade-mark Cellophane designates the product which has been. most widely sold and distributed upon the market.

What is claimed is:

1. A plastic composition for building material consisting of kapok fiber, pieces of relatively thin sheets of regenerated cellulose, and casein glue, said material being characterized by the fact that it is fireproof, waterproof and has a relatively low coefficient of heat-conductivity.

2. The process of making a plastic composition for building material which consists in masticating with water substantially equal parts by Weight of kapok fiber, and pieces of relatively thin sheets of regenerated cellulose, draining the resulting moist mixture of the greater part of the water and then adding casein glue, and permitting the resultant plastic composition to set to form sheet material.

3. A plastic composition for building material consisting of kapok fiber and casein glue, said material being characterized by the fact that it is fireproof, Waterproof, and has a relatively low coeflicient of heat conductivity.

4. The process of making a plastic composition for building material which consists in masticating kapok fiber with water to make a moist mixture, draining said mixture of the greater part of the water and then adding casein glue, and permitting the resultant plastic composition to set to form sheet material.

5. A plastic composition for building material consisting of pieces of relatively thin sheets of regenerated cellulose and casein glue, said material being characterized by the fact that it is fireproof, waterproof, and has a relatively low coefficient of heat conductivity.

6. The process of making a plastic composition for building material which consists in masticating with water pieces of relatively thin sheets of regenerated cellulose, draining the resulting moist mixture of the greater part of the water and then adding casein glue, and permitting the resultant plastic composition to set to form sheet material.

JOSEPH T. CASTLES, JR.