Patent GB-1059073-A (GB)
Title: Improvements in or relating to drafting film
Inventor: ABBOTT TERENCE ARNOLD
IPC: C08J7/046
Filed: 1964-03-20
Abstract: Coating compositions comprise:  (A) mixed terephthalic - isophthalic polyesters, polyester amides containing the ester or amide units of one or more dicarboxylic acids including at least either isophthalic acid or terephthalic acid, or a polyester oxazoline containing the ester units of one or more dicarboxylic acids including at least either isophthalic or terephthalic acid, the polyester, polyester amide or polyester oxazoline being soluble in methylene chloride, in organic solvent media.  The polyester may be formed from one or more alkylene glycols and may have 25 to 90% of the ester groups derived from isophthalic acid. Polyester amides may be formed from one or two dicarboxylic acids, including isophthalic or terephthalic, combined with one or two alkylene glycols and an alkylene diamine, the latter comprising 5 to 30% of the total molar amount of glycols and diamine. Polyester oxazolines may be formed from one or more dicarboxylic acids including isophthalic, terephthalic, combined with one or two alkylene glycols and either 4,4-dihydroxymethyl 2-substituted oxazoline-2 or N-aroyl or N-acyl tris-(hydroxymethyl)-amino-methane, the oxazoline-2 derivative or the derivative of tris(hydroxymethyl)-aminomethane comprising 5 to 30% of the total molar amount of the glycol and oxazoline constituents.  The polyester amides, oxazolines may have acid radicals derived from isophthalic, terephthalic acid or both, and one or more of phthalic, sebacic, adipic, succinic acid.  The composition may include a cross-linking agent, e.g. a tetraalkoxy titanium or zirconium.  (B) A film-forming material containing only carbon, hydrogen, oxygen and optionally nitrogen and which is soluble in a hydrocarbon, chlorinated hydrocarbon, ketone, alcohol, ester or mixtures thereof, finely divided particles of an inorganic translucence producing toothing agent(s) in organic solvent media.  The film-forming material may be one or more of a cellulose ester, acrylic or methacrylic acid or ester polymer or copolymer with other ethylenically unsaturated monomers, urea-, melamine-formaldehyde resin, alkyd resin, a polyvinyl acetal, a curable epoxy resin, a polyamide resin.  Toothing agents may be silica, silicates, ground glass, chalk, talc, diatomaceous earth, magnesium carbonate, zinc oxide, titanium oxide or mixtures thereof.  Other materials effecting cure, flexibility when used as a coating, antistatic properties, may be present. Coating compositions disclosed include:  in Example 1, a lacquer comprising cellulose nitrate, a castor oil alkyd, a modified urea-formaldehyde resin, a silica, rutile titanium oxide, zinc chloride, industrial methylated spirits, methyl ethyl ketone, methyl "Cellosolve" (Registered Trade Mark), xylene; in Example 2, a copolyesteramide derived from 15 mole per cent terephthalic, 35 mole per cent isophthalic acid, 45 mole per cent ethylene glycol, 5 mol per cent hexamethylene diamine, tetraisopropyl titanate, methlene chloride; in Example 3, a polyesteroxazoline derived from 15 mole per cent terephthalic acid, 35 mole per cent isophthalic acid, 40 mole per cent ethylene glycol, 10 mole per cent 4, 4-dihydroxymethyl 2-methyl oxazoline-2, tetraisopropyl titanate, methylene chloride; in Example 7, cellulose nitrate, a drying oil alkyd modified with a polymethacrlic ester, a castor oil alkyd, a silica, industrial methylated spirits, methyl ethyl ketone, xylene; in Example 8, cellulose nitrate, a melamine resin, a castor oil alkyd, a silica, industrial methylated spirits, methyl ethyl ketone, xylene; in Example 9, a copolyvinyl formal containing 40 to 50% polyvinyl acetate and 5 to 6.5% polyvinyl alcohol, a silica, toluene, ethanol; in Example 10, a lacquer comprising a copolymer derived from methylmethacrylate, lauryl methacrylate, N-hydroxy-methylacrylamide.ALSO:A translucent, polyester film material which is receptive to clear and legible marking with pencil or ink, comprises a film base of syntheic, linear polyester having superimposed thereon, on at least one surface, in order: (a) a directly adherent layer consisting of an organic solvent-soluble, mixed terephthalic-isophthalic polyester, a polyester amide containing the ester or amide units of one or more dicorboxylic acids including at least either isophthalic acid or terephathalic acid, or a polyester oxazoline containing the ester units of one or more dicarboxylic acids including at least either isophthalic acid or terephthalic acid, the said polyester, polyester amide or polyester oxazoline being soluble in an organic solvent medium comprising methylene chloride, and (b) an adherent layer of a film-forming, material containing carbon, hydrogen, oxygen and optionally nitrogen but no other elements, and which is soluble in a hydrocarbon, chlorinated hydrocarbon, ketone, alcohol, ester or mixtures thereof containing finely divided, discrete particles of an inorganic, translucence producing toothing agent(s).  The film base may be formed from polyethylene terephthalate, and it may be molecularly oriented by stretching in one or two directions at right angles. Polyester for layer A may be formed from one or more alkylene glycols and may have 25 to 90% of the ester groups derived from isophthalic acid.  Polyester amides for layer A may be formed from one or two dicarboxylic acid, including isophthalic or terephthalic, combined with one or two alkylene glycols, and an alkylene diamine, the latter comprising 5 to 30% of the total molar amount of glycols and diamine. Polyester oxazolines for layer A may be formed from one or more dicarboxylic acids, including isophthalic or terephthalic, combined with one or two alkylene glycols and either 4,4-dihydroxy-methyl-substituted oxazoline-2 or a N-aroyl or N-acyl tris-(hydroxymethyl)-amino-methane the oxazoline-2 derivative or the derivative of tris-(hydroxymethyl)-aminomethane comprising 5 to 30% of the total molar amount of the glycol and oxazoline constituents. The polyesteramides or polyester oxazolines for A may have acid radicals derived from isophthalic acid, terephthalic acid or both and one or more other dicarboxylic acids, e.g. phthalic, sebocic, adipic and succinic acids.  Layer A may include a cross-linking agent e.g. a tetra-alkoxy titanium or tetra-alkoxy zirconium, and is dried under conditions effecting partial cross-linking or cure e.g. by heating at 60 DEG C.  Materials for layer (B) may be one or more of: a cellulose ester; an acrylic or methacrylic acid or ester polymer or copolymer with other ethylenically unsaturated monomers; urea-formaldehyde or melamine-formaldehyde resin; an alkyd resin; a polyvinyl acetal; a curable epoxy resin; a polyamide resin.  Toothing agents may be silica, silicates, ground glass, chalk, talc, diatomaceous earth, magnesium carbonate, zinc oxide, titanium oxide or mixtures of these. Layers (B) can be baked at 100 to 120 DEG C. to effect cure of partially polymerised constituents.  Other constituents in (B) may be materials effecting cure and flexibility of the coating and to reduce static electricity pick-up.  An intermediate layer or layers of a film forming material may be applied between (A) and (B) to improve adhesion.  Layers A and B may be applied from volatile, organic solvent media by e.g. bead coaters, dip or reverse roll coaters.  The toothing agent may be dispersed in a concentrate with some of the lacquer constituents by ball milling or attritor milling, and the dispersion incorporated in the final lacquer by stirring.  The product is stated to be suitable for use in drawing offices, for tracing or photographic reproduction purposes.