Classifications

• • 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
  • C08G18/00—Polymeric products of isocyanates or isothiocyanates
  • C08G18/06—Polymeric products of isocyanates or isothiocyanates with compounds having active hydrogen
  • C08G18/08—Processes
  • C08G18/10—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step
  • C08G18/12—Prepolymer processes involving reaction of isocyanates or isothiocyanates with compounds having active hydrogen in a first reaction step using two or more compounds having active hydrogen in the first polymerisation step

Definitions

• thermoplastic polyurethanes through the combined thermoplastic processing of a hydroxyl and an isocyanate polyurethane
• the present invention relates to a process for the production of thermoplastic polyurethanes, according to which a hydroxyl and an isocyanate polyurethane are processed together thermoplastically.
• the process products show very good properties within wide limits regardless of the mixing ratio.
• TPU Thermoplastic polyurethanes
• thermoplastics Because of the strong dependence of their molecular weights on dosing fluctuations in the manufacturing process, it is not easy to produce these thermoplastics with constant quality.
• the hydroxyl polyurethane and / or isocyanate polyurethane can be a TPU that was not obtained in accordance with the specification due to incorrect metering or thermal degradation, or it could also have been produced specifically for the two-component thermoplastic processing with corresponding functional groups
• both components must meet strict requirements with regard to their molecular weights, namely the average molecular weight ⁇ of the free isocyanate-containing component must be between 100,000 and 200,000, that of the hydroxyl-containing reaction partner is between 30,000 and 150,000 and Both components should be mixed in such a way that the resulting end product has a high molecular weight.
• thermoplastic polyurethanes which have been degraded thermally or by the action of water in the heat (hydrolysis) can also be used as the hydroxyl component, but this is to be regarded as difficult with regard to the mixing ratio because of their unknown, difficult to determine content of hydroxyl groups.
• the solution to this problem is a process for the two-component thermoplastic processing of polyurethanes and polyurethane ureas, which can be used much more universally and makes less precise dosing necessary.
• thermoplastic polyurethanes which are very easy to process outside the molecular weight limits of 100,000 to 200,000 and 30,000 to 150,000 mentioned in US Pat. No. 5,089,571, but also that these also have improved product properties, E.g.sp iel sw ei seb ei the f e sti gkeit, the solution, and the heat resistance.
• the present invention relates to a process for producing thermoplastic polyurethanes by joint thermoplastic processing:
• a molar ratio of the calculated isocyanate excess of component b) to the content of free hydroxyl groups and / or amino groups of at least 1.04: 1, very particularly preferably at least 1.05: 1, is maintained.
• thermoplastic processing of components a) and b) is preferably carried out by injection molding, extrusion or extrusion blow molding.
• both fully reacted polyurethanes and non-thermoplastic polyurethanes can advantageously be used as raw materials for components a) and b) can be used.
• waste polyurethane material or production waste can also be used as raw materials.
• Polythioethers polyesteramides, polycarbonates, polyacetals, vinyl polymers such as, for example, polybutadiene oils, polyhydroxyl compounds already containing urethane or urea groups, optionally modified natural polyols, and also other cerewitin-inactive groups such as compounds containing amino, carboxyl or thiol groups.
• These compounds correspond to the prior art and are described, for example, in DE-OS 23 02 564, 24 23 764 and 25 49 372 (US Pat. No. 3,963,679) and 24 02 840 (US Pat. No. 3,984,607) and in DE AS 24 57 387 (U.S. Patent 4,035,213) is described in detail.
• Preferred according to the invention are hydroxyl-containing polyesters of glycols and adipic acid, phthalic and / or terephthalic acid and also hydrogenation products, hydroxyl polycarbonates, polycaprolactones, - 5th
• Polyisocyanates to be used according to the invention are aliphatic, cycloaliphatic, araliphatic, aromatic and heterocyclic polyisocyanates, such as those e.g. by W. Siefken in Justus Liebigs Annalen der Chemie, 562, pages 75 to 136, for example those of the formula
• n 2 to 4 preferably 2
• Q is an aliphatic hydrocarbon residue of 2 to 18, preferably
• diisocyanates e.g. 2,4- and 2,6-tolylene diisocyanate and any mixtures of these isomers (“TDI”), dicyclohexylmethane diisocyanate and 4,4 '
• Chain extenders having groups which are reactive toward isocyanates are compounds of molecular weight 18 to 399 with a functionality of at least 1.8. Possible reactive groups are: hydroxyl, amino, carboxyl and thiol groups. Examples include difunctional low molecular weight compounds such as
• Dialcohols, diamines, amino alcohols, ether and ester alcohols and dicarboxylic acids such as e.g. Ethylene glycol, 1,4-butanediol and diethyltoluenediamine or its isomer mixture, but also water.
• Anti-aging agents flame retardants, dyes and pigments, plasticizers, thermoplastics, inert solvents, lubricants and other processing aids, release agents, catalysts, each of an inorganic and / or organic nature, as they correspond to the prior art.
• Components a) and b) for thermoplastic processing are produced in accordance with the methods of the prior art which are known per se, but in b) while maintaining the characteristic number of at least 110 in accordance with feature i).
• NCO excess is present in the product in whole or in part in the form of NCO groups, but it can e.g. also reacted to allophanate and / or biuret.
• the products to be processed according to the invention are largely independent of the storage. As with other polyurethanes, prolonged moisture storage of products a) and b) in the heat is not recommended.
• mixtures of linear polyols 1), isocyanates 2) and chain extenders 3) and auxiliaries and additives 4) can also be used for the process according to the invention.
• the products can also contain monofunctional compounds, which are often referred to as chain terminators.
• component a) to be used according to the invention with free hydroxyl groups and also for the construction of component b) produced with an excess of NCO.
• Components a) and b) can be constructed from the same or different raw materials.
• Components a) and b) to be used according to the invention are produced by processes known per se, such as e.g. produced in a screw reactor.
• This degradation process has the advantage over the degradation process described in US Pat. No. 5,089,571 that the molecular weight and functionality of the products to be used (in the process according to the invention) can be set in a targeted manner and easily determined if required.
• the degradation process described for the production of components a) and b) according to the invention also enables the reuse of non-thermoplastic, for example crosslinked, polyurethane waste, such as, for example, flexible foam or elastomers.
• non-thermoplastic for example crosslinked, polyurethane waste, such as, for example, flexible foam or elastomers.
• polyurethane waste such as, for example, flexible foam or elastomers.
• components a) and b) have approximately the same melt viscosities at the processing temperature. This can be achieved if e.g. the harder component a) with a large NCO deficit e.g. NCO: OH ratio of molar 0.8: 1 is produced.
• the method according to the invention also enables the reprocessing of polyurethanes and polyurethane ureas which have already been damaged by aging to give new products with good physical properties and good aging resistance.
• the processing of the two-component polyurethane mixture according to the invention can be carried out in conventional melt processing machines, such as injection molding machines, extruders, in blow molding plants, presses, by a sintering process or powder spraying process.
• melt processing machines such as injection molding machines, extruders, in blow molding plants, presses
• a sintering process or powder spraying process Of course, processing in solution, dispersion or emulsion is also possible in some cases.
• Components a) and b) can also have very different melting ranges, so that e.g. one component is dispersed or suspended in the other during shaping and is only melted and reacted by a later heat shock.
• the process products are suitable for the production of solid and foamed moldings, coatings, foils, bonds.
• the procedure is as described in Example 2, but 45.3 parts by weight of 4,4'-diphenylmethane diisocyanate are used.
• Waste of a polyurethane obtained by reaction casting consisting of 100 parts by weight of polyethanediol adipate with an average molecular weight of 2000, 4.5 parts by weight of butanediol (1,4), 0.3 part by weight of trimethylolpropane and 24 parts by weight of naphthylene ( 1,5) -diisocyanate are reacted in a twin-screw reactor with 0.82 part by weight of butanediol- (1,4) per 100 parts waste at about 230 ° C. - 1 1 -
• thermoplastic polyurethane (7) with a Shore D hardness of 52.
• thermoplastic polyurethane is produced as described in Comparative Example 1.
• 38.6 parts by weight of 4,4'-diphenylmethane diisocyanate are used, which corresponds to an NCO: OH ratio of 1.02.
• Injection molded articles are produced from the granules (product 8A) and are stored in water at 80 ° C. for 14 days. After drying in air and then in a vacuum desiccator, the injection molded articles have a tensile strength of about 5 MPa as a result of the hydrolytic action. The dried spray bodies are granulated.
• 1655 parts by weight of a propylene-ethylene oxide mixed polyether started on glycerol with the OH number 56 and polypropylene oxide started on trimethylolpropane with the OH number 56 are in 140 parts by weight of hexanediol (1.6) at 230 ° C. (Polyether ratio 100: 3.5) and tolylene diisocyanate (proportion of the 2,4-isomer 80%, remainder: 2,6-isomer) as main components of the standard hot-molded foam produced are stirred under nitrogen until a homogeneous solution is obtained. Polyurethane (11) with a theoretical OH number of 74 is formed.
• the product (11) is mixed with product (3) so that there is a theoretical NCO: OH ratio of 1.00.
• This mixture (12A) is sprayed off in an injection molding machine to give test specimens which have a tensile strength of 15.5 MPa and an elongation at break of 435% with a hardness of 78 Shore A.
• Example 12A The procedure is as described in Example 12A, but components (3) and (11) are mixed in such a way that a theoretical NCO: OH ratio of 1.05 results.
• the injection molded bodies (12B) have a tensile strength of 18.6 MPa.
• Example 13A The procedure is as described in Example 13A, but an NCOOH ratio of 1.01 is chosen and, under the same conditions, a solution viscosity of 79,000 mPa.s is measured for the product (13B).
• Example 13A The procedure is as described in Example 13A, but an NCOOH ratio of 1.30 is chosen.
• the product (13C) melts at about 214 ° C. It is not soluble in the solvent mixture mentioned in Example 13 A under the conditions mentioned but only swells.
• Example 13 A The granules from Examples 13 A and C are mixed in a weight ratio of 1: 2.3, so that there is a theoretical NCO: OH ratio of 1.2, and then sprayed into test specimens which are stored at 80 ° C. overnight (Product (13D)).
• the test specimens are not soluble in the solvent mixture mentioned in Example 13 A and have a tensile strength of 27.8 MPa.
• Example 14A The procedure is as described in Example 14A, but an NCO: OH ratio of 1.06 is selected as in Example 3B of US Pat. No. 5,089,571 (product (14B)).

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• Chemical & Material Sciences (AREA)
• Health & Medical Sciences (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Medicinal Chemistry (AREA)
• Polymers & Plastics (AREA)
• Organic Chemistry (AREA)
• Polyurethanes Or Polyureas (AREA)
• Compositions Of Macromolecular Compounds (AREA)

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• 1994
  • 1994-11-14 PL PL31458694A patent/PL314586A1/xx unknown
  • 1994-11-14 EP EP95901379A patent/EP0730614A1/de not_active Withdrawn
  • 1994-11-14 CZ CZ961520A patent/CZ152096A3/cs unknown
  • 1994-11-14 JP JP7507810A patent/JPH09505325A/ja not_active Ceased
  • 1994-11-14 WO PCT/EP1994/003774 patent/WO1995014723A1/de not_active Application Discontinuation
  • 1994-11-14 HU HU9601417A patent/HUT74769A/hu unknown
  • 1994-11-14 CA CA 2177168 patent/CA2177168A1/en not_active Abandoned

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