GB1054757A - - Google Patents

Abstract

1,054,757. Polysiloxane-unsaturated amide copolymer compositions. PITTSBURGH PLATE GLASS CO. March 26, 1964 [April 3, 1963], No. 13062/64. Headings C3P, C3R and C3T. A coating composition comprises (1) a copolymer of an unsaturated carboxylic acid amide having amide groups substituted by groups -CHR.OR 1 , where R is H or alkyl and R 1 is H or an organic radical, and (2) an organopolysiloxane of the average formula where R is an organic radical bound to silicon through a carbon atom, R<SP>1</SP> is hydrogen or an alkyl group of 1-20 carbon atoms, an aryl radical, or an acyl radical of 1-8 carbon atoms, n is 0À5-1À9, m is À01-2À5 and m+n is 0À51- 3À0. (1) is a copolymer with at least one other ethylenically unsaturated monomer. The composition preferably contains 1-40% of the polysiloxane and preferably also an alkyd resin, which preferably contains free hydroxy groups and constitutes 5-40% of the resin mixture, and which may be co-reacted with the polysiloxane. The alkylol groups in (1) are preferably at least 50% etherified. The resin (1) is obtained by reacting the unsaturated amide before or after polymerization with an aldehyde, and etherifying the alkylol groups so formed, if required. The ratio of aldehyde to amide group may be between 0À2 and 3À0 to 1, preferably about 2: 1, and the condensation catalyst may be e.g. maleic anhydride, oxalic, hydrochloric or sulphuric acid. Suitable amides are those of acrylic and methacrylic acids (preferred) and those of α-ethyl acrylic and crotonic acids, and the diamides of maleic, itaconic and fumaric acids, and maleuric acid and esters and N- carbamyl maleimide. Suitable aldehydes are formaldehyde (preferred), acetaldehyde, butyraldehyde and furfural. Suitable alcohols, for the etherification, are butanol (preferred) or any alkanol of up to 20 carbon atoms, benzyl alcohol, cyclohexanol, glycol monoethers and 3-chlorpropanol. Suitable ethylenic monomers include monoolefins, diolefins, halo-olefins, and unsaturated esters, acids and nitriles. Azo and peroxy catalysts for the polymerization include acetyl benzoyl peroxide, cyclohexanone peroxide, cyclohexyl hydroperoxide, cumene hydroperoxide, acetyl peroxide, lauroyl peroxide, benzoyl peroxide, methyl cyclohexyl hydroperoxide, di-t-butyl peroxide, peracetic acid, t-butyl permaleic acid and di-t-butyl diperphthalate, and p-methoxyphenyl diazothio-(2- naphthyl) ether and azobisisobutyronitrile. A chain modifying (" short stopping ' ) agent may be added, usually a mercaptan, possibly cyclopentadiene, allyl carbamate, or α-methylstyrene. In the organopolysiloxane, R may be an alkyl, cycloalkyl, aryl, aralkyl, alkaryl, alkenyl, cycloalkenyl, or alkenylaryl radical (examples given) or a halo, amino, hydroxy, cyano or sulphur-substituted hydrocarbon group, and R<SP>1</SP> may be an alkyl group of up to 20 carbon atoms or an aryl group, or an acyl group of 1-8 carbon atoms. The polysiloxane is produced by conventional methods. The alkyd resin may derive from e.g. phthalic, maleic, fumaric, isophthalic, succinic, adipic, azelaic and sebacic acids or their anhydrides, and e.g. glycrol, trimethylol ethane, pentaerythritol, sorbitol, mannitol, ethylene glycol, diethylene glycol and 2,3-butylene glycol. Suitable alkyd-modifying oils are soya, safflower, perilla, tung, oiticica, poppyseed, sunflower, coconut, babassu, tall, walnut and fish oils. Other materials which may be included in the composition are epoxy resins, e.g. polyglycidyl ethers of polyhydric compounds, epoxidized polyolefins and epoxidized aromatic compounds, phenol-aldehyde and aminoplast resins, nitrocellulose, solvents, plasticizers, anti-foaming agents, and anti-skinning agents. Pigments may be added, e.g. TiO 2 , carbon black, talc, barytes, chromates, Fe 2 O 3 , cadmium red and yellow, phthalocyanine blue and toluidine red. In examples, methylolated interpolymers of acrylamide, styrene, ethyl acrylate and optionally methacrylic acid are co-reacted with a polysiloxane, or mixed with a polysiloxane, or, in conjunction with an epoxy resin are mixed with polysiloxanes or polysiloxane-modified alkyd resins.