Patent GB-805313-A (GB)
Title: Laminates
Inventor: ALFORD MAITLAND WALTON
IPC: D06M17/00
Filed: 1956-05-23
Abstract: 805,313. Laminates. BRITISH CELANESE, Ltd. May 21, 1957 [May 23, 1956], No. 15934/56. Class 140. Films, or woven, knitted, felted or other fabrics, made of or containing cellulose acetate, particularly acetate of high acetyl value (59- 62.5 per cent), are laminated by heat and pressure to films or fabrics of cellulose, regenerated cellulose, cellulose acetate itself, or non-thermoplastic or high melting polymeric materials such as polyacrylonitrile, copolymers of acrylonitrile with other vinyl or vinylidene compounds, nylon 6 or 6,6 or polyethylene terephthalate, with the aid as bonding materials of cyclic amides of omega-amino paraffinic carboxylic acids such as epsilon-caprolactam, gammabutyro-lactam, zeta-heptolactam, or their mono- or di-methyl derivatives. The temperatures employed are 140-160‹ C. for acetone-soluble cellulose acetate and 180-210‹ C. for high acetyl value acetate ; at these temperatures the lactams are stated to soften and dissolve in the acetate. The lactams may be applied to either of the surfaces to be bonded as a powder, or as an aqueous or other solution and subsequently dried. Pressing may be carried out in a dry steam-heated press on dry or damp material, between heated rolls, or by a dry or steam iron or steaming press. Laminates comprising outer layers of woven fabric made of or containing high acetyl value cellulose acetate and an interlayer of cotton or regenerated cellulose may be used for making semi-stiff collars, shirt cuffs, lapels, belts, corsets, brassieres and book and instrument covers ; waterproof laminates, for example including one or more layers of waterproof film, may be used in making fuel tanks, hoses, and fabrics for collapsible dinghies and light aircraft. Film layers used are preferably perforated to assist removal of moisture. Mixed fabrics may be used, for example, for outer layers of a semi-stiff laminate, a woven fabric comprising interwoven threads of high acetyl value cellulose acetate and regenerated cellulose staple fibre or one or more of the non- thermoplastic or high melting polymers mentioned, or mixed yarns of these materials, and for interlayers, polymeric threads interwoven with cellulose acetate or mixed yarns of such materials. Examples: (1) Semi-stiff collars were made from outer layer blanks of fabric woven from cellulose acetate yarn of acetyl value 62 per cent and an interlayer cut from plain cotton fabric passed through a 50 per cent aqueous solution of epsilon caprolactam and dried at 50‹ C., the layers being pressed at 200‹ C. for 20 seconds under 200 lb./square inch in a steam-heated press. (2) Interlayer blanks of cotton were soaked in the aqueous caprolactam solution, centrifuged, and placed while damp between layers of cellulose acetate fabric, the three layers then being ironed at 180‹ C. for 30 seconds. (3) The interlayer in (1) was replaced by a cellulose acetate fabric (acetyl value 52-54 per cent) soaked in a 60 per cent alcoholic solution of the caprolactam and subsequently dried, bonding being effected at 160‹ C. and ¢ lb./square inch pressure.