Patent GB-386161-A (GB)
Title: Manufacture of shaped articles from polyvinyl alcohols
IPC: D04B11/32
Filed: 1932-03-09
Abstract: Artificial threads, cords, ribbons, tubes, and like articles are prepared by extruding an aqueous solution of a polymerized vinyl alcohol through suitably shaped orifices, for example, in the manner usual in the production of artificial silk.  The resistance to water of the products may be increased as desired by heat treatment, by the addition of substances having hydrophobic properties, by coating the surfaces with protective layers, or by chemical treatment of the surfaces as by means of the vapours of formaldehyde.  The products may be employed for textile purposes for example, they may be spun alone or in combination with silk, wool, cotton, or artificial silk. Fabrics woven from polyvinyl alcohol may be applied in the production of materials for dressing wounds, e.g. bandages.  A particularly useful application is in the preparation of materials for use in surgery for stitches and sutures, or tubes for joining nerves or draining wounds, and the capacity of these threads and the like of being resorbed can be controlled within wide limits by suitably choosing the polyvinyl alcohol.  The materials may be coloured in order to facilitate their observation before resorption.  In an example, an aqueous solution of polyvinyl alcohol in water is heated and forced through shaped orifices into hot air.  The Specification as open to inspection under Sect. 91 refers also to the use, as solvents or softening agents for the polyvinyl alcohol, of glycols, glycerol, formamide and also water together with alcohol or acetone to promote evaporation.  A polyvinyl alcohol of low degree of polymerization may be employed if there is added a substance capable of increasing its viscosity, e.g. borax or cane sugar.  By the use of similar additions it is possible to work with polyvinyl alcohols in lower concentrations. Fabrics woven from polyvinyl alcohol threads may be applied in the production of materials for dressing wounds, e.g. bandages, and in making the threads for this purpose there are added to the polyvinyl alcohol solution substances having therapeutic effects. An application of the polyvinyl alcohols is in the preparation of buttons for uniting parts of intestines.  The capacity of the threads and the like of being resorbed can be controlled within wide limits by variation of the solvents for the polyvinyl alcohol, or the addition of salts, gum, sugar, albumin, starch, or borax.  The therapeutic applicability of the product may be increased by incorporation of medicaments, for example disinfectants, substances promoting granulation, substances having a vaso-motor action, antitoxins, sera, and the like.  Thick medicinal threads may be subdivided into plugs, and articles having the form of a tube may be converted in capsules or hollow plugs or pills for containing other medicaments or solutions.  For special surgical purposes, the threads may contain a substance easily visible under Röntgen ray illumination, e.g. barium sulphate or a bismuth compound.  The following additional examples are given.  (1) Polyvinyl alcohol of high molecular weight is treated in an autoclave with water and alcohol, and after heating at 130 DEG  C. to complete dissolution, is extruded into hot air.  (2) The procedure is as in (1) but with the addition also of ethyl lactate.  (3) Polyvinyl alcohol of medium degree of polymerization is worked up as in (1) with the addition also of a small amount of iodoform.  (4) A paste made of polyvinyl alcohol of low degree of polymerization as in (1) is dyed with Mowilith Blue.  (5) Threads are made as in (1) from a polyvinyl alcohol of low degree of polymerization, there being added also barium sulphate.  (6) Polyvinyl alcohol of low degree of polymerization is worked as in (1) together with gelatine, albumin, gum, starch, or sugar.  (7) Polyvinyl alcohol of medium degree of polymerization is worked up as in (2) but at an extrusion temperature of 80 DEG  C.  (8) The threads made as in (1) are exposed to formaldehyde vapours.  (9) Threads made as in (1) are treated in a current of hot nitrogen.  (10) A highly viscous 30 per cent solution of polyvinyl alcohol is heated and poured into a container with perforated floor.  (11) A 10 per cent solution of polyvinyl alcohol in glycerine is extruded through a nozzle at 100 DEG  C.  This subject-matter does not appear in the Specification as accepted.ALSO:Artificial threads, cords, ribbons, tubes, and like articles are prepared by extruding an aqueous solution of a polymerized vinyl alcohol through suitably shaped orifices, for example, in the manner usual in the production of artificial silk. The resistance to water of the products may be increased as desired by heat treatment, by the addition of substances having hydrophobic properties, by coating the surfaces with protective layers, or by chemical treatment of the surfaces as by means of the vapours of formaldehyde.  The Specification as open to inspection under Sect. 91 refers also to the use, as solvents or softening agents for the polyvinyl alcohol, of glycols, glycerol, formamide and also water, together with alcohol or acetone to promote evaporation.  A polyvinyl alcohol of low degree of polymerization may be employed if there is added a substance capable of increasing its viscosity, e.g. borax or cane sugar.  By the use of similar additions it is possible to work with polyvinyl alcohols in lower concentrations. The following additional examples are given: (1) Polyvinyl alcohol of high molecular weight is treated in an autoclave with water and alcohol, and after heating at 130 DEG  C. to complete dissolution, is extruded into hot air.  (2) The procedure is as in (1) but with the addition also of ethyl lactate.  (3) Polyvinyl alcohol of low degree of polymerization is worked as in (1) together with gelatine, albumin, gum, starch, or sugar.  (4) A 10 per cent solution of polyvinyl alcohol in glycerine is extruded through a nozzle at 100 DEG  C. This subject-matter does not appear in the Specification as accepted.ALSO:Artificial threads, cords, ribbons, tubes, and like articles are prepared by extruding an aqueous solution of a polymerized vinyl alcohol through suitably shaped orifices, for example, in the manner usual in the production of artificial silk. The resistance to water of the products may be increased as desired by heat treatment, by the addition of substances having hydrophobic properties, by coating the surfaces with protective layers, or by chemical treatment of the surfaces as by means of the vapours of formaldehyde.  Fabrics woven from polyvinyl alcohol may be applied in the production of materials for dressing wounds, e.g. bandages. Another application is in the preparation of materials for use in surgery for stitches and sutures, or tubes for joining nerves or draining wounds, and the capacity of these threads and the like of being resorbed can be controlled within wide limits by suitably choosing the polyvinyl alcohol.  The materials may be coloured in order to facilitate their observation before resorption.  In an example, an aqueous solution of polyvinyl alcohol in water is heated and forced through shaped orifices into hot air.  The Specification as open to inspection under Sect. 91 refers also to the use of various specific solvents or softening agents for the polyvinyl alcohol.  Polyvinyl alcohol of low degree of polymerization or in low concentrations may be employed if suitable specified substances are added.  Fabrics woven from polyvinyl alcohol threads may be employed in the production of materials for dressing wounds, e.g. bandages, and in making the threads for this purpose there are added to the polyvinyl alcohol solution substances having therapeutic effects.  An application of the polyvinyl alcohols is in the preparation of buttons for uniting parts of intestines.  The capacity of the threads and the like of being resorbed can be controlled within wide limits by variation of the solvents for the polyvinyl alcohol, or the addition of salts, gum, sugar, albumin, starch, or borax.  The therapeutic applicability of the product may be increased by incorporation of medicaments, for example disinfectants, substances promoting granulation, substances having a vaso-motor action, antitoxins, sera, and the like.  Thick medicinal threads may be sub-divided into plugs, and articles having the form of a tube may be converted in capsules or hollow plugs or pills for containing other medicaments or solutions.  For special surgical purposes, the threads may contain a substance easily visible under Röntgen ray illumination, e.g. barium sulphate or a bismuth compound.  Numerous examples are given relating, inter alia to preparations containing glycerine, iodoform, Mowilith Blue, gelatine and other additional ingredients.  This subject-matter does not appear in the Specification as accepted.