Patent GB-348083-A (GB)
Title: Improvements in or relating to the manufacture of laminated glass and of materials for use therein
IPC: C03C27/10
Filed: 1929-10-28
Abstract: Laminated glass includes a strengthening layer having a basis of cellulose nitrate possessing a nitrogen content of 10,5 to 11,5 per cent.  A mixture containing the cellulose nitrate may be kneaded with a volatile solvent, a plasticizer, a stabilizer, and a colouring matter opposed to yellowness, the mass being then block-pressed and cut into sheets which are dried, seasoned and pressed between polished plates.  In an example 100 parts of cellulose nitrate of 10,5-11,5 per cent nitrogen content is made into a paste with 35-50 parts of camphor (plasticizer) and a mixture of equal parts of ethyl and methyl alcohols.  In some cases 20-30 parts of methyl alcohol and 30-40 of ethyl alcohol to 100 parts of cellulose nitrate may be used or either alcohol may be used singly.  Methyl alcohol containing 1-4 per cent of acetone may also be employed.  1-1 1/2 parts of urea to 100 parts of cellulose nitrate may be used as the stabilizer and a combination of blue and red pigments, lakes and/or dyes may be used for tinting.  Milori (blue) and Diazine (red) are suitable colourings. Filtering operations are carried out to remove impurities.  After kneading, the plastic is rolled, solidified by heat and pressure and cut into sheets of 10, 15 or 20 thousandths of an inch thickness.  The sheets are then dried, preferably at a temperature slightly above normal, and rendered glossy by pressing between hot polished nickel-surfaced plates.  Before assembly with adhesive coated glass the sheets are freed from dust, soaked in water from 1-5 hours or until 5-10 per cent of moisture is absorbed and surface dried.  A 2 1/2 per cent aqueous gelatine solution may be sprayed on to the glass sheets to form the adhesive layer, a preservative such as mercury bichloride mercury cyanide or phenol to an amount of 1 part in 5000 being preferably added.  The cellulose nitrate sheet is inserted between the coated glass faces and a number of assemblies pressed between padded surfaces in a multiple press.  A temperature of 225-250 DEG  F. and a pressure of 150-300 lbs. per square inch are preferably applied for about 3-20 minutes.  The edges of the glass may be sealed if necessary.ALSO:Laminated glass includes a strengthening layer having a basis of cellulose nitrate possessing a nitrogen content of 10,5 to 11,5 per cent.  A mixture containing the cellulose nitrate may be kneaded with a volatile solvent, a plasticizer, a stabilizer, and a colouring matter opposed to yellowness, the mass being then block pressed and cut into sheets which are dried, seasoned and pressed between polished plates.  In an example 100 parts of cellulose nitrate of 10,5-11,5 per cent nitrogen content, is made into a paste with 35-50 parts of camphor (plasticizers) and a mixture of equal parts of ethyl and methyl alcohols.  In some cases 20-30 parts of methyl alcohol and 30-40 of ethyl alcohol to 100 parts of cellulose nitrate may be used or either alcohol may be used singly.  Methyl alcohol containing 1-4 per cent. of acetone may also be employed.  1-1 1/2 parts of urea to 100 parts of cellulose nitrate may be used as the stabilizer and a combination of blue and red pigments, lakes and/or dyes may be used for tinting. Milori (blue) and Diazine (red) are suitable colourings.  Filtering operations are carried out to remove impurities.  After kneading, the plastic is rolled, solidified by heat and pressure and cut into sheets of 10, 15 or 20 thousandths of an inch thickness.  The sheets are then dried, preferably at a temperature slightly above normal and rendered glossy by pressing between hot polished nickel-surfaced plates.