Patent GB-936055-A (GB)
Title: Improvements relating to reinforced synthetic resin products
IPC: C08F36/20
Filed: 1961-10-02
Abstract: 936,055. Lamiraies; agglutinated fibrous materials. ESSO RESEARCH & ENGINEERING CO. Oct. 2, 1961 [Oct. 11, 1960], No. 35506/61. Classes 42 (2) and 140. Laminates or resin-bonded fibrous layers are made from fibrous or fabric laminµ of glass, asbestos, cotton, linen, rayon, silk, hair, or nylon or other man-made fibres, or from mica or particulate rock, or iron, aluminium or copper films, which have been coated with an organic silane containing vinyl-, allyl-, methallyl- or other unsaturated groups, by coating the layers with a polyfunctional polymerizable material namely di- or tri-vinyl benzene, ethylene dimethylacrylate, triethylene dimethylacrylate, ethylene diacrylate, diallyl fumarate, triallyl cyanurate or trimethacrylato propane, applying a coating of a mix containing a thermosetting resinifiable polymer, and curing. The thermosetting resinifiable material may be a copolymer of styrene with a polyene such as divinyl benzene but preferably comprises a conjugated diolefin of 4-6 C atoms such as butadiene, isoprene, piperylene, n-hexadiene, dimethyl butadiene, or methyl pentadiene, or a mixture thereof with ethylenically unsaturated monomers such as styrene, acrylonitrile, methyl vinyl ketone, p-methyl styrene or dimethyl styrene, partially polymerized as with sodium catalyst. The thermosetting mix may contain, in addition to the above materials, crosslinking agents such as styrene, a vinyl toluene, dimethyl styrene, a halogenated styrene, e.g. 2,4-dichlorstyrene, butyl methacrylate, diethyl- or other alkyl-fumarate, di-allyl phthalate or other allyl ester, vinyl stearate or other ester, and an acrylate of a polyhydric alcohol; it may also contain a peroxidetype catalyst, a blocked phenol, such as 2,6-ditert.-butyl-p-cresol, as an oxidation inhibitor, natural or synthetic rubber, and a silane containing unsaturated groups. The polyfunctional coating may include a part of the monofunctional component of the resinifiable mix. Pipes may be made by winding coated material, preferably glass fibres, in helical layers on a mandrel before curing. In an example glass cloth coated with vinyl silane was coated with a solution in ethyl ether of divinyl benzene, or ethylene dimethylacrylate, and benzoyl peroxide, dried, and heated to 220‹ F. to effect partial reaction between the silane and the second coating material. The cloth was then impregnated with a composition comprising a copolymer (see below), styrene, divinyl benzene and t-butyl- and dicumyl-peroxides, and heated to 320‹ F., half of it then being post-cured at 350‹ F. The copolymer compound used comprised butadiene (80) and styrene (20) in a solvent, and finely divided sodium (1.5) with isopropanol (0.2), the mixture being polymerized at 50‹ C. to a molecular weight of about 8000, the catalyst destroyed, and the solvent removed. The products, particularly when post-cured, showed increased water resistance and retained a high pressure strength after boiling. In another example glass cloth layers, coated and impregnated as above, were superposed and cured in a mould.