Patent GB-476869-A (GB)
Title: Improvements in or relating to the hardening of protein materials
IPC: C08L89/00
Filed: 1936-06-11
Abstract: In processes involving the treatment of proteins by means of hardening or insolubilizing agents such as tannins, aldehydes, aluminium and chromium salts, fatty-acid amides (particularly formamide, but also including other water soluble fatty-acid amides) are added to the materials to inhibit or delay the hardening action. The processes to which the invention is applicable include the coating of porous materials, e.g. paper, for waterproofing, the making of plastic compositions, films, adhesives, printers' ink, leather manufacture and embalming.  The acid amide may be added to the protein or to the hardening agent or to both in mixture. Sufficient amide may be added to protein and hardening agent to prevent coagulation until the preparation is dried or heated.  In the case of leather manufacture, the tanning effect is only partial in a bath containing formamide and is completed on removing the hides and drying.  According to examples: (1) paper &c. is coated with a preparation comprising casein, formamide, ammonia, and formaldehyde polymer in aqueous solution, and dried; (2) aqueous solutions containing gelatine, formamide and formaldehyde solution or oak extract remain uncoagulated but form water insoluble films when dried; (3) and (4) coating compositions are prepared containing casein, formamide, formaldehyde or a polymer and ground quartz; (5) acetamide is used instead of formamide with either formaldehyde, a polymer thereof or tannic acid as hardening agent; (6) solutions containing casein, formamide and ammonia give a precipitate when larger quantities of formaldehyde are added which redissolve on standing; resistant films are obtained on drying; (7) a mixture of propionamide and butyramide is used to inhibit precipitation of casein by formaldehyde; the coagulum first formed redissolves; (8) films are prepared from solutions containing in one case glue, kaolin, ferric, oxide, formamide, and in another the same ingredients with the addition of chromic sulphate.  Coating &c. compositions according to the invention are particularly suitable for preparing coated or waterproofed paper and for this purpose various protein substances may be used, e.g. gelatine, casein, soya bean meal and vegetable proteins.  Substances which evolve aldehydes under the conditions, such as para - formaldehyde and hexamethylene tetramine, may be used instead of aldehydes themselves especially when using inorganic pigments.  Example 9 describes the coating of paper with mixtures containing kaolin, a green aniline dye supported on barium sulphate and glue and varying proportions of formaldehyde and formamide and example 10, the use of the same ingredients with ferric hydrate substituted for green pigment and para-formaldehyde for the formaldehyde.ALSO:In processes involving the treatment of proteins by means of hardening or insolubilizing agents such as tannins, aldehydes, aluminium and chromium salts, fatty-acid amides (particularly formamide but also including other water-soluble fatty-acid amides) are added to the materials to inhibit or delay the hardening action.  The processes to which the invention is applicable include the coating of porous materials, e.g. paper, for waterproofing, and the making of plastic compositions, films, adhesives, and printers' ink.  The acid amide may be added to the protein or to the hardening agent or to both in mixture. Sufficient amide may be added to protein and hardening agent to prevent coagulation until the preparation is dried or heated. According to examples: (1) paper &c. is coated with a preparation comprising casein, formamide, ammonia, and formaldehyde polymer in aqueous solution, and dried; (2) aqueous solutions containing gelatine, formamide and formaldehyde solution or oak extract remain uncoagulated but form water-insoluble films when dried; (3) and (4) coating - compositions are prepared containing casein, formamide, formaldehyde or a polymer and ground quartz; (5) acetamide is used instead of formamide with either formaldehyde, a polymer thereof or tannic acid as hardening agent; (6) solutions containing casein, formamide and ammonia give a precipitate when larger quantities of formaldehyde are added which redissolves on standing; resistant films are obtained on drying; (7) a mixture of propionamide and butyramide is used to inhibit precipitation of casein by formaldehyde; the coagulum first formed redissolves; (8) films are prepared from solutions containing in one case glue, kaolin, ferric oxide, formamide, and in another the same ingredients with the addition of chromic sulphate.  Coating &c. compositions according to the invention are particularly suitable for preparing coated or waterproofed paper and for this purpose various protein substances may be used, e.g. gelatine, casein, soya bean meal and vegetable proteins.  Substances which evolve aldehydes under the conditions, such as paraformaldehyde and hexamethylenetetramine, may be used instead of aldehydes themselves, especially when using inorganic pigments.  Example 9 describes the coating of paper with mixtures containing kaolin, a green aniline dye supported on barium sulphate and glue and varying proportions of formaldehyde and formamide, and example 10 the use of the same ingredients with ferric hydrate substituted for green pigment and paraformaldehyde for the formaldehyde.ALSO:In processes involving the treatment of proteins by means of hardening or insolubilizing agents such as tannin, aldehydes, aluminium and chromium salts, fatty-acid amides (particularly formamide but also including other water soluble fatty-acid amides) are added to the materials to inhibit or delay the hardening action.  The processes to which the invention is applicable include the coating of porous materials, e.g. paper, for waterproofing, the making of plastic compositions, films, adhesives, printers' ink, leather manufacture and embalming.  The acid amide may be added to the protein or to the hardening agent or to both in mixture.  Sufficient amide may be added to protein and hardening agent to prevent coagulation until the preparation is dried or heated.  In the case of leather manufacture the tanning effect is only partial in a bath containing formamide and is completed on removing the hides and drying.  According to examples: (1) paper &c. is coated with a preparation comprising casein, formamide, ammonia, and formaldehyde polymer in aqueous solution, and dried; (2) aqueous solutions containing gelatine, formamide and formaldehyde solution or oak extract remain uncoagulated but form water insoluble films when dried; (3) and (4) coating compositions are prepared containing casein, formamide, formaldehyde or a polymer and ground quartz; (5) acetamide is used instead of formamide with either formaldehyde, a polymer thereof or tannic acid as hardening agent; (6) solutions containing casein, formamide and ammonia give a precipitate when larger quantities of formaldehyde are added which redissolve on standing; resistant films are obtained on drying; (7) a mixture of propionamide and butyramide is used to inhibit precipitation of casein by formaldehyde; the coagulum first formed redissolves; (8) films are prepared from solutions containing in one case glue, kaolin, ferric oxide, formamide, and in another the same ingredients with the addition of chromic sulphate.  Coating &c. compositions according to the invention are particularly suitable for preparing coated or waterproofed paper and for this purpose various protein substances may be used, e.g. gelatine, casein, soya bean meal and vegetable proteins.  Substances which involve aldehydes under the conditions, such as paraformaldehyde and hexamethylene tetramine, may be used instead of aldehydes themselves especially when using inorganic pigments.  Example 9 describes the coating of paper with mixtures containing kaolin, a green aniline dye supported on barium sulphate and glue and varying proportions of formaldehyde and formamide and example 10 the use of the same ingredients with ferric hydrate substituted for green pigment and paraformaldehyde for the formaldehyde.ALSO:In processes involving the treatment of proteins by means of hardening or insolubilizing agents such as tannins, aldehydes, aluminium and chromium salts, fatty-acid amides (particularly, formamide but also including other water-soluble fatty-acid amides) are added to the materials to inhibit or delay the hardening action.  The processes to which the invention is applicable include the coating of porous materials, e.g. paper for water-proofing, the making of plastic compositions, films, adhesives, printers' ink, leather manufacture and embalming.  The acid amide may be added to the protein or to the hardening agent or to both in mixture.  Sufficient amide may be added to protein and hardening agent to prevent coagulation until the preparation is dried or heated.