Classifications

• • D—TEXTILES; PAPER
  • D04—BRAIDING; LACE-MAKING; KNITTING; TRIMMINGS; NON-WOVEN FABRICS
  • D04H—MAKING TEXTILE FABRICS, e.g. FROM FIBRES OR FILAMENTARY MATERIAL; FABRICS MADE BY SUCH PROCESSES OR APPARATUS, e.g. FELTS, NON-WOVEN FABRICS; COTTON-WOOL; WADDING ; NON-WOVEN FABRICS FROM STAPLE FIBRES, FILAMENTS OR YARNS, BONDED WITH AT LEAST ONE WEB-LIKE MATERIAL DURING THEIR CONSOLIDATION
  • D04H1/00—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres
  • D04H1/40—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties
  • D04H1/58—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives
  • D04H1/587—Non-woven fabrics formed wholly or mainly of staple fibres or like relatively short fibres from fleeces or layers composed of fibres without existing or potential cohesive properties by applying, incorporating or activating chemical or thermoplastic bonding agents, e.g. adhesives characterised by the bonding agents used
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
  • C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
  • C08G63/88—Post-polymerisation treatment
  • C08G63/89—Recovery of the polymer
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J3/00—Processes of treating or compounding macromolecular substances
  • C08J3/12—Powdering or granulating
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J9/00—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof
  • C08J9/26—Working-up of macromolecular substances to porous or cellular articles or materials; After-treatment thereof by elimination of a solid phase from a macromolecular composition or article, e.g. leaching out
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
  • C08L67/00—Compositions of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Compositions of derivatives of such polymers
  • C08L67/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/10—Organic non-cellulose fibres
  • D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H13/24—Polyesters
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H13/00—Pulp or paper, comprising synthetic cellulose or non-cellulose fibres or web-forming material
  • D21H13/10—Organic non-cellulose fibres
  • D21H13/20—Organic non-cellulose fibres from macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H13/26—Polyamides; Polyimides
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H17/00—Non-fibrous material added to the pulp, characterised by its constitution; Paper-impregnating material characterised by its constitution
  • D21H17/20—Macromolecular organic compounds
  • D21H17/33—Synthetic macromolecular compounds
  • D21H17/46—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds
  • D21H17/54—Synthetic macromolecular compounds obtained otherwise than by reactions only involving carbon-to-carbon unsaturated bonds obtained by reactions forming in the main chain of the macromolecule a linkage containing nitrogen
  • D21H17/55—Polyamides; Polyaminoamides; Polyester-amides
• • D—TEXTILES; PAPER
  • D21—PAPER-MAKING; PRODUCTION OF CELLULOSE
  • D21H—PULP COMPOSITIONS; PREPARATION THEREOF NOT COVERED BY SUBCLASSES D21C OR D21D; IMPREGNATING OR COATING OF PAPER; TREATMENT OF FINISHED PAPER NOT COVERED BY CLASS B31 OR SUBCLASS D21G; PAPER NOT OTHERWISE PROVIDED FOR
  • D21H21/00—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties
  • D21H21/50—Non-fibrous material added to the pulp, characterised by its function, form or properties; Paper-impregnating or coating material, characterised by its function, form or properties characterised by form
  • D21H21/52—Additives of definite length or shape
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2367/00—Characterised by the use of polyesters obtained by reactions forming a carboxylic ester link in the main chain; Derivatives of such polymers
  • C08J2367/02—Polyesters derived from dicarboxylic acids and dihydroxy compounds
• • C—CHEMISTRY; METALLURGY
  • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
  • C08J—WORKING-UP; GENERAL PROCESSES OF COMPOUNDING; AFTER-TREATMENT NOT COVERED BY SUBCLASSES C08B, C08C, C08F, C08G or C08H
  • C08J2377/00—Characterised by the use of polyamides obtained by reactions forming a carboxylic amide link in the main chain; Derivatives of such polymers

Definitions

• This invention relates to the production of fine particles of synthetic polymers, and to the products obtained.
• Synthetic fibres may be added to the usual cellulose pulps in order to increase the strength of the papers obtained. Papers of entirely synthetic nature have also been made, but in this case it is necessary to use bonding agents of varying kinds to ensure cohesion of the fibres. For this purpose there have been proposed more especially solutions of mineral salts, dispersions of fusible synthetic resins, in particular of N-alkoxy-alkyl polyamides, and thermoplastic fibres which melt or soften at temperatures at which the base fibres undergo no deterioration.
• the cohesion of the fibres in the paper has been ensured during calendering, which was effected in the first case at a temperature at which the mineral salt solutions swell and locally plasticise the synthetic fibres, thus ensuring their mutual adhesion, and in the other two cases at a temperature above the melting or softening point of the bonding agent.
• the process of the invention comprises incorporating in a gel of a synthetic linear polymer a solid compound which is soluble in an aqueous medium, so as to obtain an intimate mixture of consistency between that of a pulp and that of a powder, dispersing the mixture in an aqueous medium which dissolves or solubilises the incorporated solid compound, and separating the fine particles thus formed from the liquid.
• gel is employed in the normal way to denote solid or semi-solid two-phase systems in which the two phases are continuous.
• polyamide gels in particular, their appearance ranges from that of hard products having a waxy appearance and handle with the maximum polymer content, to that of products which become increasingly rubbery in proportion as the solvent content increases.
• the solid compound may be added to a solution of the polymer, which is thereafter allowed to gel. This procedure gives a particularly homogeneous mixture.
• the solid compounds employed may advantageously be mineral salts such as sodium chloride or sodium sulphate.
• the choice of a particular salt is generally a question of cost.
• the salt may be recovered, if necessary, by evaporation of the mother liquor after separation of the precipitated particles. It may be desirable, in order to favour the formation of very fine particles, to use a carbonate as the compound to be added to the polymer gel, and then to disperse the mixture in acidified water.
• the brisk effervescence produced by the evolution of carbon dioxide facilitates the bursting of the polymer particles.
• a water-soluble organic colloid may be used, for example gelatine, carboxymethylcellulosc, an alginate, etc. Mixtures of the required consistency are obtained when the polymer gel is mixed with at least an equal weight of such a salt or of a gel of such a watersoluble colloid.
• interpolymer which is soluble in solvents which are more readily accessible than are most solvents for the corresponding homopolymers.
• interpolyamides for example the binary copolymers derived from hexamethylene diammonium adipate and caprolactam and the ternary copolymers derived from these two compounds and hexamethylene diammonium sebacate
• interpolyesters for example interpolyesters derived from terephthalic acid, ethylene glycol and tetra methylene glycol, or from ethylene glycol and terephthalic and isophthalic acids (or sebacic or hexahydroterephthalic acid, etc.).
• the polymer gels which are treated preferably contain from 10% to 50% of polymer.
• the necessary quantity of soluble salt or colloid in relation to the amount of the gel varies with the nature of the polymer and with the nature of the added salt. It must be sufficient for the mixture of the salt or colloid with the polymer gel to possess a consistency between that of a pulp and that of a powder.
• the particles precipitated and separated from the mother liquor containing the soluble salt or colloid in solution may be used as such after washing and straining, or may first be dried under moderate conditions which do not cause any substantial modification of their physical structure. They can readily be re-dispersed in water, for example in aqueous suspensions of synthetic or other fibres intended for the production of paper, non-woven fibrous sheets, etc. These products can be made by forming a felt, e.g. a paper, from the suspension in the known way, i.e. by deposition on a wire or the like followed by drying, and subsequently heating it at least to the melting temperature of the particles, so causing them to bond the fibres together. Naturally, the felt should not be heated to a temperature at which either the fibres or the bonding particles decompose.
• Example I 10 g. of an aqueous alcoholic gel containing 28% of an interpolyamide derived from 60% of hexamethylene diammonium adipate and 40% of caprolactam is introduced into a motar. There are slowly added to this gel, with crushing by means of a pestle, g. of sodium chloride capable of passing through a screen having a mesh size of 0.149 mm. There is finally obtained a very finely divided powder which is dry to the touch and which does not stick to the walls of the mortar or to the pestle.
• This powder is thrown into 500 cc. of water at 13 C., whereupon it forms extremely tenuous flakes. These flakes, whose dimensions are between and 60 have considerable water-retaining power; they retain about 25 times their weight of water after straining. They are rinsed with one litre of Water at 13 C. Until completely free from the salt.
• the dispersion When the dispersion is homogeneous, it is introduced onto a laboratory mould having a 100 mesh (U.S.A. system) screen, i.e. a mesh aperture of 0.149 mm.
• the sheet obtained when suction-dried on a Buchner filter and then removed, possesses good wet strength similar to that of sheets obtained from mechanical pulps which have undergone a small degree of beating. It is dried for 30 seconds between a plate heated at 180 C. and a felt, and then subjected for 40 seconds to a pressure of 25 kg./cm. between two chromium-plated plates polished and coated with silicones, and heated at 180 C. The melting of the bonding agent binds the fibres together. There is obtained after cooling a sheet having a weight of 98 g./m. and possessing the following characteristics:
• Tearing index 571 (this index is obtained by dividing by the weight of the paper, in g./m. the value given in kg. by the Lhome and Argy ED 1 apparatus).
• Bursting index 30.5 (this index is obtained by dividing by the weight of the paper, in g./m. the value given in g./cm. by the Miillen paper tester).
• the sheet obtained when suction-dried on a Buchner filter and then removed, possesses good wet strength. It is dried for 30 seconds between a plate heated at 150 C. and a felt. It is then pressed for 40 seconds under 25 kg./cm. between two chromium-plated, polished and silicone-coated plates at a temperature of C. The melting of the bonding agent binds the fibres together. There is obtained on cooling a sheet having a weight of 99 g./m. and possessing the following characteristics:
• Sheets are prepared by the method of Example I, mixing with these flakes polyhexamethylene adipamide fibres having a count of 1.5 denier and a length of 4 mm.
• Example IV In a colour grinder having a capacity of 2 litres are mixed 20 g. of calcium carbonate of coarse grain size and 10 g. of an aqueous alcoholic gel containing 10% by weight of an interpolyamide identical to that of Example II. A homogeneous pulp is obtained, which is poured into a litre vat filled with water acidified with 10% of hydrochloric acid. As a result of the action of the acid on the calcium carbonate, carbon dioxide is evolved, which divides the interpolyamide into a multitude of very spongy flakes possessing a high water retaining power.
• Sheets are prepared by the procedure of Example II from polyhexamethylene adipamide fibres having a count of 1.5 denier and a length of 4 mm., and the flakes of this example have characteristics very similar to those of the sheets of Example II.
• Example V 75 her, in which it gels.
• the pulp obtained is fractionated with a spatula so as to divide the coarser fragments, and it is then thrown into water at 20 C.
• solution of the salt in the water flakes are formed, which are separated from the mother liquor and then washed with pure water.
• These flakes possess a high water retaining power (at least times their weight) and can readily be re-dispersed, for example in the presence of polyamide fibres.
• Sheets are prepared with them and by the method of Example II, with polyhexamethylene adipamide fibres having a count of 1.5 denier and a length of 4 mm., so that the sheet obtained contains as bonding agent 0% of the flakes.
• Example VI By a procedure similar to that of Examples I and II, 80 g. of sodium chloride passing through a screen having a mesh aperture of 0.149 mm. are mixed with 10 g. of a gel containing, in methylene chloride, about 210% of an interpolyester derived from ethylene glycol and a mixture of hexahydroterephthalic acid and terephthalic acid, in molecular proportions of 25/75.
• a finely divided powder is obtained, which is thrown into 500 cc. of water at ambient temperature. Very fine flakes are obtained, Whose dimensions are of the order of 50 1. When strained, they possess a Water retaining power of about times their weight. They are rinsed until completely free from salt.
• Sheets are prepared by the method of Example I, mixing with these flakes polyethylene terephthalate fibres having a count of 1.5 denier and a length of 4 mm., so that the proportion of flakes employed as bonding agent is of the total weight of their mixture with the fibre.
• a powder is obtained, which is poured into a 1 litre vat filled with water acidified with 10% of hydrochloric acid, as in Example IV.
• the flakes obtained, when strained and rinsed, can readily be re-dispersed in water, for example in the presence of polyethylene terephthalate fibres.
• Sheets are prepared from these flakes in the manner indicated in Example VI, the pressing temperature being 180 C.
• the sheets obtained possess characteristics similar to those mentioned in that example.

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• Chemical & Material Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Health & Medical Sciences (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Engineering & Computer Science (AREA)
• Materials Engineering (AREA)
• Textile Engineering (AREA)
• Paper (AREA)
• Processes Of Treating Macromolecular Substances (AREA)
• Compositions Of Macromolecular Compounds (AREA)
• Polyesters Or Polycarbonates (AREA)

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Cited By (6)

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Citations (6)

• 0
  • BE BE618128D patent/BE618128A/xx unknown
  • NL NL124229D patent/NL124229C/xx active
  • NL NL277863D patent/NL277863A/xx unknown
• 1961
  • 1961-05-30 FR FR863326A patent/FR1301835A/fr not_active Expired
• 1962
  • 1962-03-27 GB GB11720/62A patent/GB959743A/en not_active Expired
  • 1962-04-06 ES ES276223A patent/ES276223A1/es not_active Expired
  • 1962-05-23 US US196903A patent/US3334070A/en not_active Expired - Lifetime
  • 1962-05-29 CH CH650362A patent/CH407545A/fr unknown

Patent Citations (6)

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