Patent GB-410770-A (GB)
Title: Improvements in or relating to moulding compositions
IPC: C08K5/098
Filed: 1932-08-12
Abstract: Compositions suitable for moulding contain at least one resinous reaction product of a partially or completely hydrolysed polyvinyl ester with an aldehyde, together with an ester wax, e.g. carnauba wax, candellilla wax, or montan wax, or a metallic stearate as lubricant.  The compositions may also contain fillers, e.g. clay, such as "Melosil," or precipitated silica, pigments, natural resins, e.g. shellac, rosin or copal, other artificial resins, stearates of aliphatic alcohols or the usual plasticizers. Two or more vinyl resins may be employed having different softening points and different characteristics of toughness or hardness or flexibility or viscosity or any combination of these and mixed in proportions varying through a wide range.  The percentage of resin in the compositions may vary from about 25 per cent to about 93 per cent. The compositions may be employed for the manufacture of sound records, either of the usual rigid variety or in a thin and flexible form, with or without a backing such as paper.  Resins from high viscosity polymers, especially those with high hydrolysis require plasticizers for ordinary moulding methods, but preformed sheets are mouldable without plasticizers.  In the intermediate hydrolysis and viscosity range fillers are not essential.  The first three resins (A. B and C) described in Specification 405,986 are described as suitable for use in the compositions.  In examples: (1) resin (A), clay, bone black, carbon black and carnauba wax are mixed and worked on hot rolls, and the material is formed into sheets and pressed to produce records of the usual thickness, e.g. \ba1/8\be inch; (2) the resin in (1) is replaced by a mixture of resins (B) and (C) or of either or both of these with resin (A), and the composition is employed for the manufacture of records 0.025--0.04 inch thick; (3) half the clay filler of (1) or (2) is replaced by additional amounts of the resins; (4) all the clay filler of (2) is similarly replaced, or replaced by a single resin; (5) two resins, made by 70 per cent hydrolysis and reaction with acetaldehyde of polyvinyl esters of different viscosities are mixed with clay and pigments and lubricant as in (2) and the composition is employed for the manufacture of records of \ba1/16\be to \ba3/32\be inch thickness; (6) a resin produced by 95 per cent hydrolysis and reaction with acetaldehyde of a vinyl ester polymer, or a mixture thereof with resin (B), is mixed with clay and pigments and lubricant as in (1); (7) the resin of (6) is replaced by a resin of 30 per cent hydrolysis; (8) mixtures as in (2) are applied in a thin film to suitable backing such as hard paper, either by heat or pressure sufficient to spread the resin or by applying a solution thereof, and impressed with sound grooves; (9) resin (B) and carnauba wax are mixed and worked on hot rolls with addition of dibutyl phthalate towards the end of the rolling and the material is passed through calender rolls to produce a sheet of 0.025--0.035 inch thickness which is pressed to form a record; (10) records are made as in previous examples from mixtures of resin (B), carnauba wax, tricresyl phosphate, carbon black and nigrosine or silica flour; (11) resins (B) and (C), shallac, bone black, carbon black, copal, rosin, amyl stearate, zinc stearate and a filler of the Melosil clay type are mised and heated on rolls and the material is calendered into sheets, portions of which of suitable size are softened on a hot table and formed into a ball which is pressed to produce records of about 0.04 inch thickness; (12) resin (B), shellac, amyl stearate, bone black, carbon black, copal, rosin, a filler of the Melosil clay type, nigrosine and carnauba wax are employed as in (5), or the material is fed in tablet form to an extrusion machine which ejects the appropriate quantity of softened material, records of 0.05 inch thickness being made therefrom; (13) a mixture of resins (B) and (C), benzyl cellulose, bone black, carbon black, manilla copal, rosin (which may be replaced by more manilla copal), a filler of the Melosil clay type and carnauba wax is employed in the manufacture of records in a similar manner to that of (12); (14) a mixture of resin (C), benzyl cellulose, carnauba wax, zinc stearate, rosin, carbon black and superfloss (diatomaceous earth) is employed in the manufacture of records in a similar manner to that of (11).  The pigments in the examples may be replaced by other pigments or omitted, whilst other plasticizers may be used. Moulded articles other than sound records may be manufactured from the compositions.  Specifications 383,045 and 387,353 also are referred to.ALSO:Compositions suitable for moulding contain at least one resinous reaction product of a partially or completely hydrolysed polyvinyl ester with an aldehyde, together with an ester wax, e.g. carnauba wax, candellilla wax or montan wax, or a metallic stearate as lubricant.  The compositions may also contain fillers, e.g. clay, such as "Melosil," or precipitated silica, pigments, natural resins, e.g. shellac, rosin or copal, other artificial resins, stearates of aliphatic alcohols or the usual plasticizers. Two or more vinyl resins may be employed having different softening points and different characteristics of toughness or hardness or flexibility or viscosity or any combination of these and mixed in proportions varying through a wide range.  The percentage of resin in the compositions may vary from about 25 per cent to about 93 per cent. In examples, one or more vinyl resins of the type specified are mixed with: (1) to (8) clay (part or the whole of which may be replaced by a further quantity of the resin or resins), bone black, carbon black and carnauba wax; (9) carnauba wax and dibutyl phthalate; (10) carnauba wax, tricresyl phosphate, carbon black and nigrosine or silica flour; (11) shellac, bone black, carbon black, copal, rosin, amyl stearate, zinc stearate and a filler of the Melosil clay type; (12) shellac, amyl stearate, bone black, carbon black, copal, rosin, a filler of the Melosil clay type, nigrosine and carnauba wax; (13) benzyl cellulose, bone black, carbon black, manilla copal, rosin (which may be replaced by more manilla copal), a filler of the Melosil clay type, and carnauba wax; (14) benzyl cellulose carnauba wax, zinc stearate, rosin, carbon black and Superfloss (diatomaceous earth).  The pigments in the examples may be replaced by other pigments or omitted, whilst other plasticizers may be used. Specifications 383,045, and 387,353, [Group IV], are referred to.