Patent GB-401299-A (GB)
Title: Improvements in the manufacture of composite materials
IPC: C03C27/10
Filed: 1932-04-01
Abstract: 401,299. Compound glass ; compound sheet materials. BRITISH CELANESE, Ltd. and MOSS, W. H., 22, Hanover Square, London. April 1, 1932, No. 9382. [Class 140.] Laminated glass is made by uniting together a cellulose derivative sheet or sheets and sheets of glass by means of thin films of cellulose derivatives, low pressures of the order of 50 lbs. sq. in. or less being applied, for example in a press or by passing between rubber-faced rollers, while the films are in a softened condition due to the presence of a solvent or swelling agent. Atmospheric temperature, or a higher temperature (up to 100‹ C.) may be employed, and the pressed sheet may be maintained at a temperature up to 100‹ C. for several hours. Preformed films may be used, or films may be formed directly on the glass or reinforcing sheet or both from a suitable solution or plastic composition, in which case the assembly may be pressed before the films are quite dry. The same cellulose derivative may be used in the films as in the reinforcing sheet. The films and reinforcing sheet may contain cellulose esters such as the nitrate, formate, acetate, propionate, butyrate, stearate or palmitate, ethers such as methyl, ethyl, butyl or benzyl cellulose, mixed esters or ethers, or ester-ethers, resins such as manila, acaroid, kauri, dammar, rosin, shellac, phenol-formaldehyde, diphenylol propane-aldehyde, diphenylol propane-ketone, glyptal resins, polyvinyl resins such as polyvinyl acetate, plasticizers such as xylene &c. sulphonamides, sulphonanilides and other sulphonarylides, dimethyl, diethyl, dibutyl and other alkyl phthalates or tartrates, tricresyl or triphenyl phosphate, and mono-, di-, or triacetin. The adhesive film may be formed from a solution in, for example, acetone, methyl ethyl ketone, dioxane, and methylene ethylene ether, a mixture of ethylene or methylene dichloride with ethyl or methyl alcohol, and, if desired, medium or high-boiling solvents such as ethyl lactate, diacetone alcohol, acetyl carbinol, acetyl acetone, cyclopentanone, cyclobutanone, alkylated dioxanes, esters and ether-esters of olefine, polyolefine glycols or other polyhydric alcohols, for instance glycol monoacetate, or non-solvent liquids such as benzene, toluene. The solvent or swelling agent for the adhesive film may be acetone, acetic acid, ethylene or methylene dichloride with ethyl or methyl alcohol, together with, if desired, inert media such as benzene, toluene &c., hydrocarbons, a liquid having a solvent action at increased temperatures such as ethylene glycol, glycerin, benzene, toluene, &c., a plasticizer such as triacetin, or a latent solvent such as methyl, ethyl, propyl, isopropyl, &c. alcohol, preferably with a high boiling solvent or plasticizer. On cooling, the edge of the sheet may be sealed with a composition containing acaroid resin with, if desired. cellulose acetate. According to the Provisional Specification the process is suitable for uniting cellulose derivative sheets to sheets other than glass, heavy pressures may be used, and the softening of the films may be omitted.