Patent GB-1111603-A (GB)
Title: Reinforced poly(alkyl methacrylate) compositions
IPC: C07F7/18
Filed: 1966-01-06
Abstract: Reinforced polymeric compositions comprise an alkyl methacrylate polymer, an inorganic reinforcing agent (having a solubility in water of less than 0.15 g/l. and having, or acquiring on treatment with a base, an alkaline surface), and residues, derived from a coupling agent, linking polymer molecules to the reinforcing agent, said coupling agent being of the formula <FORM:1111603/C3/1> where R is H or alkyl, X is a hydrolysable radical (e.g. halogen or an alkyl carboxylate, alkoxycarbonyl, alkoxy or hydroxy group), Y is a hydrocarbon group, Z is C7-C20 alkylene, a is 1, 2 or 3, b is 0, 1 or 2, c is 1, 2 or 3, and a + b + c = 4.  The compositions are prepared by polymerizing an alkyl methacrylate in the presence of the reinforcing and coupling agents; the latter two agents may first be pre-reacted to form a so-called "adduct".  The alkyl methacrylate may be homopolymerized, or copolymerized with other alkyl methacrylates or with different comonomers, e.g. alkyl acrylates, styrene and its derivatives, acrylonitrile, methacrylonitrile, hydroxyalkyl methacrylates, maleic anhydride, biallyl, dimethacrylates and trimethacrylates. Specified reinforcing agents are alumina, feldspar, wollastonite, asbestos, crocidolite, quartz, silica gel, ground glass, glass fibres, cristobalite, various metals of Groups II to VIII and oxides thereof, heavy metal phosphates, sulphides and sulphates in gel form, spodumene, mullite, mica, montmorillonite, kaolinite, bentonite, hectorite, beidellite, attapulgite, graphite, chrysolite, garnet, saponite and hercynite.  The viscosity of the polymerizable mixture can be reduced, if necessary, by adding a surface-active agent, e.g. zinc stearate, long chain alkyl trimethyl ammonium halides and alkylene oxide condensates of long chain carbon compounds.  The pre-reacted "adduct" can be obtained by bringing the coupling and reinforcing agents together, preferably at 40-150 DEG C., in an inert liquid dispersion medium, e.g. water, alcohol or dioxan, which product is then preferably dried before being used in the polymerization mixture; alternatively, said agents may be prereacted in the monomer, and the mixture dried to remove volatile reaction products.  The polymerization is initiated by means of a free-radical catalyst, of which many examples are listed, preferably a peroxy compound; an activator may also be used, e.g. a boron hydride or borane (optionally complexed with various basic compounds, such as amines or triphenylphosphine, or with tetrahydrofuran) or a redox reducing component.  The polymerization is generally effected using a casting process so as to obtain shaped products.  The coupling agents of the above formula wherein X represents a hydroxy, hydrocarbyloxy or alkyl carboxylate group can be prepared by reacting a compound R1OH (where R1 is H, hydrocarbyl or alkyl carbonyl) with a halosilyalkyl alkanoate of the formula <FORM:1111603/C3/2> where X1 is halogen and Alk is alkyl, and then reacting the product with (alk)acrylic acid or an ester thereof.  The halosilyl compound can itself be obtained by reacting an alkenyl alkanoate with an appropriate halogenated silane, preferably in the presence of a catalyst consisting of or containing a metal of the platinum or palladium series.  The coupling agents can also be used in reinforcing other polymer systems, e.g. polystyrenes, polyesters, acrylonitrile-butadiene-styrene copolymers and styrene-acrylonitrile copolymers.  They are also suitable for rendering hydrophilic substances water-repellant and for use as monomers in the preparation of polysiloxane resins.  Examples illustrate the polymerization of methyl methacrylate using benzoyl peroxide catalyst and of ethyl methacrylate using a cumene hydro-peroxide-triethylborane-pyridine catalyst system dissolved in an onyl phenol-ethylene oxide condensate; using a reinforcing adduct of wollastonite / 11 - trimethoxysilylundecyl methacrylate, feldspar / 18 - trichlorosilyloctadecyl acrylate or wollastonite/18-acrylato-octadecyl-triacetoxysilane. Examples also illustrate the preparation of 11 - (trimethoxysilyl)undecyl methacrylate by reacting undecenyl acetate with trichlorosilane in the presence of chloroplatinic acid to form trichlorosilylundecyl acetate which is then reacted with methacrylic acid to give the desired compound; and the analogous preparation of 18-acrylato-octadecyl triacetoxysilane starting from 17-octadecenyl propionate.