GB1132261A - Reinforced polymeric compositions - Google Patents

Abstract

1,132,261. Polymerizing alkyl methacrylates. MONSANTO CO. 6 Jan., 1966 [6 Jan., 1965], No. 654/66. Headings C3G and C3P. A reinforced composition comprises an alkyl methacrylate polymer, a maximum of 20% by weight based on the total polymeric composition of a rubbery polymer dispersed through the said methacrylate polymer, a coupling agent and a reinforcing agent, the latter agent being adherently bound to the methacrylate polymer through the former agent. The composition may be formed by interpolymerizing the alkyl methacrylate, optionally with other monomers, with the rubbery polymer which is dissolved in the monomer system, the interpolymerization taking place in the presence of a product formed by reaction of the coupling agent with the reinforcing agent. The alkyl methacrylate e.g. a C 1 to C 4 -alkyl methacrylate is used in combination with another methacrylate, an alkyl acrylate, styrene or a ring substituted styrene, (meth) acrylonitrile or maleic anhydride or with a cross-linking monomer. Specified rubbery polymers are polybutadiene, polyisoprene, styrene-butadiene, acrylonitrile-butadiene, butadiene-vinyl pyridine, butadiene-styrene-vinyl pyridine, polychloroprene, isobutylene-isoprene, ethylene-vinyl acetate, ethylene-propylene and ethylene-propylene-conjugated diene rubbers and natural rubber. Examples of the preferred mineral, metal, metal oxide, metal aluminate and cellulose reinforcing agents are given. In one embodiment alkyl methacrylate-rubber slurries are cast and polymerized on to wooden, concrete or urethane foam surfaces previously treated with a coupling agent. Specified couplers contain an ethylenically unsaturated group and at least one hydrolysable group X attached to a silicon atom e.g. agents of formula wherein Z is a radical copolymerizable with the alkyl methacrylate, or reactive with a polyalkyl methacrylate molecule e.g. a vinyl, allyl or (meth)acryloxy radical, Y is a hydrocarbyl radical, X is a radical capable of reaction with the surface of the reinforcing agent e.g. halogen, alkoxy, cycloalkoxy, aryloxy, alkoxycarbonyl, aryloxycarbonyl, alkyl carboxylate, aryl carboxylate or hydroxyl, n is 1 to 20, a is 1 to 3, b is 0 to 2, c is 1 to 3 and a + b + c is 4. Examples are vinyl triethoxysilane, vinyl methyldichlorosilane, di-(3-methacryloxypropyl) dipropoxy silane and 6-acryloxyhexyl tricyclohexylsilane. Other couplers specified are phosphorus compounds containing X, Y and Z groups and co-ordinated Cr complexes containing Z and X groups. In most of the examples, wollastonite previously treated with 2-methacryloxyethyl trimethoxysilane is combined with (a) polybutadiene and methyl methacrylate, (b) butadiene-acrylonitrile rubber and methyl methacrylate alone or together with lauryl methacrylate and ethyl acrylate or (c) butadiene-styrene rubber and methyl methacrylate alone or together with acrylonitrile, trimethylol propane trimethacrylate or polyethylene glycol dimethacrylate and the resulting slurry is polymerized in a mould and post-cured in some cases. This procedure is modified in Examples 15 and 16, in which the wollastonite is treated with 3-(trimethoxysilyl)propyl methacrylate, in Examples 17 and 18, in which a mixture of wollastonite treated with 11-trimethoxysilylundecyl methacrylate and mullite treated with trimethoxysilylpropyl methacrylate is used, and in Example 34 in which wollastonite treated as in Example 17 is used. The polymerization catalyst employed comprises at least one peroxide or hydroperoxide, used in some cases in combination with a triethyl borane/pyridine complex accelerator. In Examples 24 and 25 wollastonite treated with trimethoxysilyl propyl methacrylate is combined with methyl methacrylate, a saturated acrylate rubber, cumene hydroperoxide and the said complex accelerator and moulded to yield a product in which no interpolymerization of the methacrylate and the rubber occurs.