Patent GB-628150-A (GB)
Title: New polymerisable materials and polymers thereof
IPC: C04B26/06
Filed: 1947-02-10
Abstract: Polymerizable products are obtained by reacting, under conditions such that polymerization is inhibited, one or more monohydroxy acrylic, including methacrylic and a -haloacrylic, esters with one or more compounds containing 3 or more methylol or alkoxymethyl groups attached ortho and/or para in a hydroxy and/or amino-substituted aromatic ring or to a nitrogen atom attached to a >CO, >CS or >C=N- group or an aromatic nucleus. Polymerization inhibitors which may be present include copper salts, and anhydrous metal halides as described in Specification 456,147.  Suitable polymethylol compounds include trimethylol phenol and aniline, hexamethylol melamine, polymethylol polyamides, and their methyl to butyl ethers.  The monohydroxy acrylic esters may be prepared from suitable molecular proportions of an acrylic acid or a lower ester, anhydride or acid chloride thereof, and a di- or poly-hydric alcohol or from a salt of the acid and a hydroxychloride, e.g. ethylene chlorhydrin.  Alcohols of not more than 4 hydroxy groups, e.g. ethylene glycol, glycerol, pentaerythritol, trimethylene, propylene, and polyethylene glycols are suitable.  Polymerization inhibitors, especially polyhydric phenol sulphonic acids as described in Specification 606,685, [Group IV (b)], or mixtures of copper salts or antimony pentachloride together with strong acids as esterification catalysts, may be present.  Preferred polymers are obtained from the products if, based on the weight of reactants less their weight of acrylic groups and the weight of by-products, the weight of hydroxyl groups equivalent to acrylic groups is less than 25, preferably less than 17 per cent, and greater than 1.25, preferably greater than 3.5 per cent.  The products have the general formula X.(CH2.O.R.(O.A)q)x, where X is an acryl group having hydroxyl and/or amino substituents in ortho and/or para positions or is nitrogen attached to >CO, >CS, >C=N- or an aromatic nucleus, R is an alkyl group, A an acrylic group, q is 1, 2 or 3, and x an integer above 2.  Polymerization may be effected in one or more stages, if desired with other compounds having a C=C linkage such as di-(allyl glycollyl) succinate, glycol dimethacrylate, methyl or butyl methacrylate, vinyl chloride or acetate, styrene, maleic anhydride, polyesters of maleic or fumaric acid and dihydric alcohols, dyes, pigments, fillers and the like being present.  Low molecular weight compounds may be added to the polymerizable products to give an average molecular weight of 200-500.  The products may be used to bond fibrous materials, particularly glass cloth, to give laminated sheets.  In an example, hexamethylol melamine is added to b -hydroxyethyl methacrylate and nitric acid, finally heating to 40 DEG  C. and neutralizing.  The product freed from volatiles is heated to 100 DEG  C. with a solution of benzoyl peroxide in butyl methacrylate, giving a hard resin.ALSO:Polymerizable products are obtained by reacting under conditions such that polymerization is inhibited, one or more monohydroxy acrylic, including methacrylic and a -haloacrylic, esters with one or more compounds containing 3 or more methylol or alkoxymethyl groups attached ortho and/or para in a hydroxy and/or amino-substituted aromatic ring or to a nitrogen atom attached to a >CO, >CS or >C=N- group or an aromatic nucleus. Polymerization inhibitors which may be present include copper salts, and anhydrous metal halides as described in Specification 456,147.  Suitable polymethylol compounds include trimethylol phenol and aniline, hexamethylol melamine, polymethylol polyamides, and their methyl to butyl ethers.  The monohydroxy acrylic esters may be prepared from suitable molecular proportions of an acrylic acid or a lower ester, anhydride or acid chloride thereof, and a di- or poly-hydric alcohol or from a salt of the acid and a hydroxychloride, e.g. ethylene chlorhydrin.  Alcohols of not more than 4 hydroxy groups, e.g. ethylene glycol, glycerol, pentaerythritol, trimethylene, propylene, and polyethylene glycols, are suitable.  Water or alcohol liberated may be removed from the reaction mixture by azeotroping. Polymerization inhibitors, especially polyhydric phenol sulphonic acids as described in Specification 606,685, or mixtures of copper salts or antimony pentachloride, together with strong acids as esterification catalysts, may be present.  Preferred polymers are obtained from the products if, based on the weight of reactants less their weight of acrylic groups and the weight of by-products, the weight of hydroxyl groups equivalent to acrylic groups is less than 25, preferably less than 17 per cent and greater than 1.25, preferably greater than 3.5 per cent.  The products have the general formula X.(CH2.O.R.(O.A)q)x, where X is an aryl group having hydroxyl and/or amino substituents in ortho and/or para positions or is nitrogen attached to >CO, >CS, >C=N-or an aromatic nucleus, R is an alkyl group, A an acrylic group, q is 1, 2 or 3, and x an integer above 2.  Polymerization may be effected in one or more stages, if desired with other compounds having a C=C linkage such as di-(allyl glycollyl) succinate, glycol dimethacrylate, methyl or butyl methacrylate, vinyl chloride or acetate, styrene, maleic anhydride, polyesters of maleic or fumaric acid and dihydric alcohols, dyes, pigments, fillers, and the like being present.  Low molecular weight compounds may be added to the polymerizable products to give an average molecular weight of 200-500.  The products may be used to bond fibrous materials, particularly glass cloth, to give laminated sheets.  In an example, hexamethylol melamine is added to b -hydroxyethyl methacrylate and nitric acid, finally heating to 40 DEG C. and neutralizing.  The product freed from volatiles, is heated to 100 DEG  C. with a solution of benzoyl peroxide in butyl methacrylate, giving a hard resin.