Patent GB-574425-A (GB)
Title: Improvements in or relating to the production of sheet wrapping materials
IPC: C08K5/42
Filed: 1943-10-26
Abstract: Sheets or films of organic material suitable for use as sheet wrapping material or light filters capable of affording substantially complete absorption of light rays in the region of the near ultra-violet and transparent to light rays of the visible spectrum are obtained by incorporating in the sheet or film a stilbene derivative or mixture of stilbene derivatives in finely-divided state having the formula <FORM:0574425/IV/1> wherein A and B represent mono-sulphonated benzene residues, and X, Y, W and Z represent benzene nuclei.  One or more of the benzene residues A, B, W, X, Y and Z may have their NH and CO connections in ortho, meta or para position, and may have one or more of the hydrogen atoms replaced by a halogen, alkyl or alkoxy group.  The sulphonic group, which may be free sulphonic acid, or a mono- or di-alkali-metal salt thereof, may be in the ortho or meta position to the ethylene residue of the stilbene residue. Specified stilbene derivatives are p : p1 - bis - [p - (p - amino - benzamido)benzamido - ]stilbene - o : o1 - disodium sulphonate, p : p1-bis-[m-(m-amino-benzamido-)benzamido-] stilbene-o : o1-disodium sulphonate, and p : p1-bis - [p - (m - amino - benzamido -)benzamido -] stilbene-o : o1-disodium sulphonate.  Coated or uncoated films or sheets of regenerated cellulose, or lowly substituted cellulose ethers, e.g. glycol cellulose, methyl and ethyl cellulose, or lowly substituted cellulose esters, e.g. lowly substituted acetylated cellulose, or lowly substituted cellulose ether-esters, e.g. acetyl-ethyl cellulose, or sheets of polyvinyl alcohol, or sheets of glassine paper, tissue or heavier paper may have the stilbene derivative dispersed therein.  Water-soluble stilbene derivatives may be dispersed in regenerated cellulose or other water-sensitive sheets by treating the formed or gelled sheets with an aqueous solution or dispersion of the derivative, to which may be added a softening agent, and the treated sheets are subsequently dried. Alternatively, the stilbene derivative may be dispersed in a coating composition which is applied to the base sheet, or in an anchoring composition between the base sheet and a coating composition.  Numerous examples are given in which (I) regenerated cellulose film in the gel condition is passed through an aqueous bath at 82 DEG  C. containing p : p1-bis-[p-(p-amino-benzamido)-benzamido]stilbene-o : o1-disodium sulphonate, glycerol and water, excess liquor removed, and the treated film dried; (V) regenerated cellulose film is passed through an aqueous bath containing glycerol, urea-formaldehyde isobutanol resin, citric acid, p : p1-bis-[p-(p-amino-benzamido - )benzamido - ] - stilbene - o : o1 - disodium sulphonate and water, excess liquor removed, and the sheet dried, rehumidified, and further coated with a moisture-proofing composition comprising cellulose nitrate, paraffin wax, dibutyl phthalate and dewaxed dammar resin. The sheet materials may be used as ultra-violet light protective wrappings for foodstuffs, fats, oils, or dyed fabrics, or as light filters in photographic filters or spectacles.  The stilbene derivatives may be prepared, for example, by treating the sodium salt of p-nitrotoluene-o-sulphonic acid with sodium hypochlorite to yield the sodium salt of p : p1-dinitrostilbene-o : o1-disulphonic acid which is then subjected to neutral reduction to yield the corresponding di-amino stilbene derivative. The diamino derivative is treated with p-nitrobenzoyl chloride to yield the di-nitrobenzoyl derivative of the diamino stilbene derivative which in turn is reduced to the diamino-benzoyl derivative.  A further nitrobenzoylation followed by another neutral reduction yields p : p1-bis-[p-(p-amino-benzamido)benzamido]-stilbene-o : o1-disodium sulphonate.  Alternatively, the sodium salt of di-m-amino-benzoyl-diamino-stilbene disulphonic acid referred to in Specification 436,891 is treated with p-nitrobenzoyl chloride to yield the di-nitro benzoyl derivative which is then reduced to the corresponding bis-[(amino-benzamido-)benzamido]-stilbene disodium sulphonate.  Specification 211,446, [Class 2 (ii)], also is referred to.  The Specification as open to inspection under Sect. 91 states that the stilbene derivatives may be dispersed in sheets or films of cellulose substitution products soluble in organic solvents, e.g. cellulose nitrate, acetate, acetate-butyrate, or ethyl, propyl, benzyl and methyl-benzyl cellulose, or in sheets or films of rubber-like material, e.g. rubber hydrohalides, halogenated rubber, isomerized rubber and phenol modified rubber: or in sheets of polyvinyl resins, nylon or polythene.  This subject-matter does not appear in the Specification as accepted.ALSO:Sheets or films of organic material suitable for use as sheet wrapping material for foodstuffs, particularly fats and oils, capable of affording substantially complete absorption of light rays in the region of the near ultra-violet and transparent to light rays of the visible spectrum are obtained by incorporating in the sheet or film a stilbene derivative or mixture of stilbene derivatives in finely divided state having the formula H-C-A-NH-CO-X-NH-CO-W-NH2 H-C-B-NH-CO-Y-NH-CO-Z-NH2 wherein A and B represent mono-sulphonated benzene residues, and X, Y, W and Z represent benzene nuclei. Specified stilbene derivatives are p:p1-bis- [p-(p-amido-benzamido) benzamido-] stilbene-o: o1-disodium sulphonate, p:p1-bis- [m-(m-amino-benzamido-) benzamido-] stilbene-o:o1-disodium sulphonate, and p:p1-bis- [p- (m-amino-benzanido-) benzamido-] stilbeneo:o1 disodium sulphonate, Coated or uncoated films or sheets of regenerated cellulose, or slowly substituted cellulose ethers, e.g. glycol cellulose, methyl and ethyl cellulose, or lowly substituted cellulose esters e.g. lowly substituted acetylated cellulose, or lowly substituted cellulose ether-esters, e.g., acetyl-ethyl cellulose, or sheets of polyvinyl alcohol or sheets of glassine paper, tissue or heavier paper may have the stilbene derivative dispersed therein.  Water soluble stilbene derivatives may be dispersed in regenerated cellulose or other water sensitive sheets by treating the formed or gelled sheets with an aqueous solution or dispersion of the derivatives, to which may be added a softening agent, and the treated sheets are subsequently dried.  Alternatively, the stilbene derivative may be dispersed in a coating composition, which is applied to the base sheet, or in an anchoring composition between the base sheet and a coating composition.  Numerous examples are given in which regenerated cellulose film in the gel condition is passed through an aqueous bath at 82 DEG  C. containing p:p1-bis- [p-(p-amino benzamido) benzamido] stilbene-o:o1-disodium sulphonate, glycerol and water, excess liquor removed, and the treated film dried or regenerated cellulose film is passed through an aqueous bath containing glycerol, urea-formaldehyde isobutanol resin, citric acid, p:p1-bis- [p-(p-amino-benzamido-) benzamido-] stilbeneo:o1-disodium sulphonate and water, excess liquor removed, and the sheet dried, rehumidified, and further coated with a moisture proofing composition comprising cellulose nitrate, paraffin wax, dibutyl phthalate and dewaxed dammar resin. Specifications 211,446, [Class 2 (ii)], and 436,891 are referred to.  The Specification as open to inspection under Sect. 91 states that the stilbene derivatives may be dispersed in sheets or films of cellulose substitution products soluble in organic solvents e.g. cellulose nitrate, acetate, acetate-butyrate, or ethyl, propyl benzyl and methyl-benzyl cellulose, or in sheets or films of rubber-like material e.g. rubber hydrohalides, halogenated rubber, isomerised rubber and phenol modified rubber, or in sheets of polyvinyl resins, nylon or polythene.  This subject matter does not appear in the Specification as accepted.