Patent GB-681121-A (GB)
Title: Improvements in making gas-expanded organic plastics
IPC: C08J9/10
Filed: 1950-10-20
Abstract: Gas expanded organo plastic material is obtained by mixing hydrazine, hydrazine hydrate, or a salt of hydrazine with an organo plastic material such as rubbery copolymers of butadiene with styrene, or acrylonitrile, or of isobutylene with butadiene or isoprene, or polychloroprene, polyacrylonitrile, polystyrene, polyvinyl chloride, copolymers of vinyl chloride and vinyl acetate, alkyd resins, urea formaldehyde, cellulose acetate or ethyl cellulose, which is normally solid and has sufficient consistency and tensile strength at the blowing temperature to retain the expanded structure, and heating the mixture thus effecting expansion of the mixture.  The hydrazine salt may be formed from the following acids:-formic, acetic, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, malic, tartaric, citric, benzoic, salicylic, acetyl-salicylic, phthalic, linoleic, linolenic, undecylenic, oleic, ricinoleic, and elaeostearic acids, and inorganic acids such as sulphuric, hydrochloric and phosphoric acids.  In addition hydrazine salts of non-carboxylic acids such as hydrazinium dithiocarbazate, hydrazine benzene sulphonate, hydrazine toluene sulphonate and hydrazine carbazate may be used. In an example (No. 31), a mix consisting of polyvinyl chloride, lead stearate, mono-hydrazine oxalate and tri-octyl phosphate was heated in a press at 330-350 DEG  F. for 12 minutes.ALSO:Gas expanded organo plastic material is obtained by mixing hydrazine, hydrazine hydrate, or a salt of hydrazine with an organo plastic material such as rubber, which is normally solid and has sufficient consistency and tensile strength at the blowing temperature to retain the expanded structure, and heating the mixture thus effecting expansion of the mixture.  The hydrazine salt may be formed from the following acids: formic, acetic, propionic, butyric, valeric, caproic, caprylic, capric, lauric, myristic, palmitic, stearic, oxalic, malonic, succinic, glutaric, adipic, pimelic, suberic, azelaic, sebacic, malic, tartaric, citric, benzoic, salicylic, acetyl-salicylic, phthalic, linoleic, linolenic, undecylenic, oleic, ricinoleic, and elaeostearic acids, and inorganic acids such as sulphuric, hydrochloric and phosphoric acids.  In addition hydrazine salts of noncarboxylic acids such as hydrazinium dithiocarbazate, hydrazine benzene sulphonate, hydrazine toluene sulphonate and hydrazine carbazate may be used.  In examples the effects produced by the action of various hydrazine compounds were demonstrated on master batches consisting of: (1)-(14), pale cr<\>zepe rubber, limestone, zinc oxide, zinc diethyl dithiocarbamate, benzothiazyl disulphide and paraffin oil, (15) flat bark rubber, whiting, zinc oxide, black pigment, oleic acid, retarder, benzothiazyl disulphide, paraffin oil, sulphur, sodium bicarbonate, (16)-(30) pale crepe, zinc oxide, calcium carbonate, lithopone, zinc salt of cocoanut fatty acids, petrolatum, sulphur bis(benzothiazole) disulphide.