Patent GB-347646-A (GB)
Title: Improvements in or relating to the manufacture of compound glass
IPC: C09J161/22
Filed: 1929-10-21
Abstract: In making laminated glass, a layer of reinforcing material having a basis of cellulose derivative is secured between sheets of glass by means of an adhesive comprising a synthetic resin. The resin may be formed by the condensation of a phenol or cresol or other aromatic compound containing a hydroxyl group, a ketone or with an aldehyde, such as formaldehyde, paraformaldehyde or acetaldehyde in the presence of phosphoric acid or an acid phosphate.  The resin may also be formed by the condensation of diphenylol propane and an aldehyde such as formaldehyde, or by the condensation of diphenylol propane with a ketone such as acetone. Other suitable resins may be obtained by the condensation of an aromatic sulphonamide such as toluene, benzene, or xylene sulphonamide with an aldehyde such as formaldehyde, paraformaldehyde, and acetaldehyde.  Alkyl toluene sulphonamides such as methyl paratoluene sulphonamide and ethyl paratoluene sulphonamide with an aldehyde may also be used for producing the resin.  The adhesive may be a mixture of these resins and may also contain other resins, natural or synthetic, a derivative of cellulose, preferably of low viscosity, plasticizers, softening agents and dyes or stabilizers.  The cellulose derivative used in the adhesive may be either an inorganic derivative such as cellulose nitrate, or an organic derivative such as cellulose esters, including cellulose acetate formate, propionate or butyrate, or cellulose ethers such as ethyl, methyl or benzyl cellulose.  The reinforcing layer and the adhesive may contain such plasticizers as camphor, triacetin, diethyl tartrate, dibutyl tartrate, diethyl phthalate &c., and also pigments and/or dyes particularly of violet tint. Stabilizers such as urea may be added to the derivatives of cellulose.  The cellulose derivative is preferably purified by filtration, or treated either in solid form or in solution with oxidizing agents such as nitric acid or hydrogen peroxide.  The adhesive may be applied to the glass or strengthening layer or to both by flowing, spraying, dipping or brushing.  In some cases a number of coats may be employed, the first coat preferably having a larger proportion of synthetic resin and succeeding coats having less resin and more cellulose derivative and/or plasticizer. Alternatively the glass may be coated with an adhesive as described above and the reinforcing layer built up by applying further coats comprising a synthetic resin and cellulose derivative.  The adhesive coating may be dried at 50-100 DEG  C. for 15-60 minutes.  Where synthetic resin is the sole solid constituent, suitable solutions are:-  (a) Synthetic resin 10 parts by weight, acetone 20 parts by weight.  or (b) Synthetic resin 10 parts by weight, benzene 20 parts by weight.  or (c) Phenol-aldehyde resin 10 parts by weight, ethyl alcohol 20 parts by weight.  The following examples give proportions by weight of solutions containing a high boiling solvent:-  (a) Cellulose acetate 8 parts, phenol-aldehyde resin 12 parts, acetone 50 parts, benzene 25 parts, ethyl lactate 20 parts.  (b) Cellulose acetate 8 parts, toluene sulphonamide aldehyde resin 12 parts, acetone 50 parts, ethyl alcohol 25 parts, benzene 25 parts, ethyl lactate 5 parts.  For a mixture of cellulose acetate and synthetic resin the solution may consist of cellulose acetate 10 parts, synthetic resin 10 parts, acetone 100 parts.  The following examples give solutions containing one or more plasticizers:-  (a) Synthetic resin 10 parts, monomethylxylene sulphonamide 4 parts, acetone 30 parts.  or (b) Ethyl toluene sulphonamide resin 10 parts, ethyl toluene sulphonamide 5 parts, acetone 20 parts.  or (c) Lactic acid resin 10 parts, diethyl phthalate 4 parts, acetone 30 parts.  or (d) Lactic acid resin 10 parts, triacetin 4 parts, acetone 20 parts.  or (e) Phenol-aldehyde resin 15 parts, cellulose acetate 6 parts, triacetin 8 parts, acetone 50 parts, ethyl alcohol 25 parts, benzene 25 parts, benzyl alcohol 5 parts.  or (f) Lactic acid resin 6 parts, cellulose acetate 15 parts, triacetin 3 parts, acetone 50 parts, ethyl alcohol 25 parts, benzene 25 parts, diacetone alcohol 10 parts. or (g) Phenol aldehyde resin 20 parts, cellulose acetate 5 parts, diethyl phthalate 5 parts, triacetin 3 parts, acetone 100 parts.  The following examples contain more than one synthetic resin.  (a) Toluene sulphonamide formaldehyde resin 10 parts, ethyl toluene sulphonamide-formaldehyde resin 10 parts, acetone 20 parts.  (b) Ethyl toluene sulphonamide formaldehyde resin 8 parts, toluene sulphonamide formaldehyde resin 12 parts, acetone 50 parts, ethyl alcohol 25 parts, benzene 25 parts, ethyl lactate.  The resins in the last example may be replaced by lactic acid resin 8 parts, diphenylol propane formaldehyde resin 10 parts.  In the following example cellulose nitrate is included.  Synthetic resin 15 parts, cellulose nitrate 11 parts, camphor 4 parts, benzene 40 parts, ethyl alcohol 20 parts, butyl alcohol 40 parts, butyl acetate 40 parts, ethyl acetate 60 parts.