Patent GB-1178714-A (GB)
Title: Sealing Agent of One-Component Type containing an Acrylate Polymer as Binder
Inventor: FURENDAL ALLAN RICKARD BENJAMI
IPC: C09J133/06
Filed: 1967-02-14
Abstract: 1,178,714. Sealing agents containing acrylate polymer binders. BOFORS AB. 14 Feb., 1967 [14 Feb., 1966], No. 7106/67. Heading C3P. Sealing agents of the one-component type comprise (1) a binder which is a polymer having a Tg value not greater than +10‹ C. and such a molecular weight that its relative viscosity is between 1-05 and 18 (in 1,2-dichloroethane solvent), the polymer comprising at least 30% by weight of units of one or more acrylate esters of a C 4 -C 12  alcohol, and optionally containing a plasticizer in an amount of not more than 40% based on the total weight of polymer and plasticizer; (2) a filler which consists of one or more pulverized or fibrous materials present in an amount of 75-30% based on the total weight of binder and filler; and (3) an organic solvent present in an amount not greater than 50% based on the total weight of binder and filler. Suitable acrylates for the binder include n-alkyl acrylates, alkyl acrylates with a single branch chain, alkoxyalkyl acrylates, cyclic acrylates, e.g. cyclohexyl, benzyl, phenoxyethyl or tetrahydrofurfuryl acrylate, and acrylates with at least two side branch chains, e.g. 4-methyl-amyl- (2) acrylate. The acrylate ester may be copolymerized with a monomer which promotes hardening (i.e. its homopolymer has a Tg> +10‹ C.), e.g. n-butyl methacrylate, n-propyl rnethacrylate, ethyl methacrylate, isobutyl methacrylate, methyl methacrylate, vinyl acetate, vinyl chloride, acrylonitrile or styrene; or with an adhesion-promoting monomer, e.g. acrylic acid, methacrylic acid, itaconic acid, acrylamide, methacrylamide, 2-hydroxyethyl acrylate or methacrylate, diethylaminoethyl acrylate or methacrylate, or glycidyl acrylate or methacrylate. Suitable plasticizers which can be used include dibutyl or dioctyl phthalate or sebacate, butyl benzyl phthalate, butoxyethyl phosphate and self-extinguishing plasticizers such as tris-(2,3-dibromopropyl) or tris-(2,3- diehloropropyl) phosphate. Specified as fillers are chalk, talc, titanium dioxide, zinc oxide, antimony trioxide, pulverized polyvinyl chloride, colloidal silicic acid, zinc stearate, calcium stearate, aluminium stearate, and fibres of asbestos, glass, nylon, polyester or cellulose. Specified solvents are toluene, xylene, cyclohexane, hexane, heptane, petroleum ether, ligroin, white spirit, ethanol, propanol, butanol, ethyl acetate, butyl acetate, acetone, methyl ethyl ketone and trichloroethylene. The compositions may also contain a liquid additive to prevent the sealant from running or to improve adhesion, e.g. amines containing a C 8 -C 18  alkyl radical, polyamines, surfactants, silicones and silanes. Examples describe the solution polymerization of (a) n-butyl acrylate and methyl methacrvlate, (b) n-butyl acrylate and acrylonitrile, (c) n-butyl acrylate and n-butyl methacrylate, (d) n-butyl acrylate and cyclohexyl acrylate and (e) n-butyl acrylate, methyl methacrylate and acrylic acid, in the presence of azodiisobutyronitrile (and in some cases also in the presence of monothioglycerol), the monomers and catalyst being added to the reaction mixture in 3-7 distinct stages.