US1697077A - Process of treating fibrous material - Google Patents

Description

Patented 'Jan. 1-, 1929.

UNITED. STATES PATENT OFFICE.

JAMES MCIN'IOSH, OF vNORRISCllOVVN, PENNSYLVANIA, ASSIGNOR TO DIAMOND STATE FIBRE COMPANY, F BRIDGEPORT, PENNSYLVANIA-7., A CORPORATION OF DELA WARE.

PROCESS TREATING FIBROUS"MATER IAL.

N0 Drawing.

One object of my invention is to prepare a fibrous material which wil be water-resistant. and mechanically strong and will have a hard,'s1 nooth, lustrous surface.

5 Another object is to provide a means of covering a fibrous material with a transparent, colorless and highly polished coatit further object of my invention is to make a laminated material which willbe water-proof, mechanically strong, hard, compact, and relatively inexpensive to make.

Anotherobject of my invention is to provide a novel means for preparing the above product.

The product comprising my invention broadly comprises fibrous material, which has been impregnated with a solution of acellulose ester and subsequently subjected to heat and pressure.

The fibrous sheets may be made of any of the large class of substances which, when passed through a bath of the cellulose ester, will absorb the solution Paper, textile fabrics, fibre board, and asbestos sheets have proved to be satisfactory.

The term cellulose ester embraces that class of compounds which are formed by the action of; acids on cellulose, and includes the cellulose acetates and cellulose nitrates. Due to the non-inflammable nature of cellulose acetate, I prefer to use this compound. It may be dissolved in any solvent desired, such as alcohol, acetone, acetic acid, chloroform, acetylenetetrachloride.

The fibrous material to be impregnated is passed through the bath of the cellulose ester in the solvent, whereupon the solution is absorbed. The solvent is then usually evaporated by passing the sheets overheating coils at a temperature sufliciently high to volatilize the solvent but not high enough to cause the cellulose acetate to fuse. a

Theimpregnated fibrous material is then ready to be vulcanized, that 1'sto be subjected to heat and pressure. .The single sheets, if they are of the desired thickness", are vulcanized per se, or a laminated product is built up bv superimposing one sheet upon another until the requisite thickness is obtained. In

either case. the vulcanization is accom-' plished inthe same manner.

Thesheets are placed between the heated Application filed January 30, 192 6. Serial No. 85,021.

platens of a suitable press whereby they are subjected to pressure such as one thousand pounds per square inch at a temperature of one hundred and twenty-five pounds of steam.

This heat and pressure are maintained for a time sufficient to cause the cellulose ester to fuse throughout the fibrous mass and to flow completely over the surface forming a continuous. coating. If the platens are highly polished, there will result a smooth, uniform and highly the surface of the fibrous material.

Since the cellulose ester is colorless and transparent, suitable designs may be printed upon the uppermost sheet which designs will be clearly visible through the coating of the cellulose ester. -This gives a simple and eifective means ofimitating the grain of wood.

'A very desirable product will be made if a natural or synthetic resin such as bakelite is added to the bath. The process is carriedlout in exactly the same manner as described above for the phenol or other condensation product is converted to the hard, infusible, insoluble compound at the same time that the cellulose acetate is fused under the heat and pressure. The amount of phenol con- .densation product that may beadded varies and I have found that as high a ratio as fifty parts of phenol condensation product to fifty parts of cellulose acetate is satisfactory.

Modifying agents such as starch, glue, oils, camphor or naphthalene, and filling materials such as zinc oxide, soapstone orcarbon 1 black maybe added to the bath'and thus be incorporated in the laminated product. I havealso found that the addition of suitable ester will result in the coloring of the product as desired.

,90 dyes to the solvent containing the cellulose The above described material is available for a wide variety of uses, such as a raw materialfrom which machine elements such as gears, pulleys, or the like may be formed or machined and also asan electrical insulator, especially in the construction of switchboards for radio apparatus, a material for making.

containers, or other structures which it is desirable shallbe unaffected by moisture, oil

or other liquids. -It is also applicable for the surface veneering of wood or cardbpard.

It will be understood-that the above described products may be built up, molded,

machined or otherwise formedin'to any ,de-

sired shapes, slnce its nature 1s such as to lend itself with peculiar facility to these operations.

. I claim:

1. The process of making laminated material which comprises passing fibrous sheets through a solution of cellulose ester, thereafter evaporating the solvent and dryin the sheet and then superimposing the ried sheets one upon the other to obtain the thickness desired, and thereafter heating the sam under ressure.

2. e process of makinglaminated mate- -rial which comprises passing fibrous sheets ness desired, and thereafter heating the same 20 under pressure.

\ JAMES MCINT OSHU