MXPA99010814A - Compact sheet based on poliisocian poliadition products - Google Patents

Abstract

A compact sheet is based on a reaction mixture comprising: a) isocyanate, b) as compounds that are reactive to isocyanates, a mixture (b1), which comprises: b11) from 50 to 90% by weight, based on the weight of the mixture (b1), of a polyester polyol having an average functionality from 2 to 2.5 and a molecular weight of 500 to 4000, b12) from 0 to 20% by weight, based on the weight of the mixture (b1) ), of a bifunctional chain extender, b13) from 0 to 30% by weight, based on the weight of the mixture (b1) of polyether polyalcohols having a functionality of 1.5 and 5 and a molecular weight of 150 to 7000. C) catalysts and / or) auxiliary and / or additive

Description

COMPACT SHEET WITH BASE E? POLIADICIO PRODUCTS? DE POLIISOCIA? ATO The present invention relates to a compact sheet, based on a reaction mixture comprising: a) isocyanate, b) as compounds that are reactive towards isocyanates, a mixture (bl), comprising: bll) of 50 to 90% by weight, preferably 60 to 85% by weight, based on the weight of the mixture (bl), of a polyester polyol having an average functionality from 2 to 2.5 and a molecular weight from 500 to 4000 , bl2) from 0 to 20% by weight, preferably from 10 to 15% by weight, based on the weight of the mixture (bl), of a bifunctional chain extender, bl3) from 0 to 30% by weight, preferably from 5 to 25% by weight, based on the weight of the mixture (bl), of polyether polyalcohols having a functionality of 1.5 to 5 and a molecular weight of 150 to 7000, c) catalysts and / or d) auxiliaries and / or additives, wherein the sum of the percentages by weight of the components (bll), (b! 2) and (bl3) is preferably 100% by weight.

Furthermore, the invention relates to a process for producing molded parts comprising foamed polyisocyanate polyaddition products and a compact sheet according to the present invention as a surface layer that adheres, such as molded parts and their use. The polyisocyanate polyaddition products, usually polyurethanes and / or polyisocyanurates, which are obtained by reacting isocyanates with compounds which are reactive to isocyanates, are generally known. A particular embodiment of these products are molded parts having a synthetic surface layer based on these products laminated thereon. These molded parts are usually composite components comprising essentially this sheet, usually a flexible polyurethane foam and possibly a rigid support. These molded parts are used, among others, in automotive construction where they are used, for example, as seats, boards, consoles, compartments for gloves or glove boxes or as decorative pieces for the exterior or interior, but they are also used in boat construction and construction. vehicles to be used in the agricultural and construction sectors of houses and buildings.

These molded parts are generally produced by placing a thermoplastic film in the foam shell and subsequently subjecting this film to a deep-seated shell in the foam shell or by spraying a liquid polyurethane film with a thermo-curable component or with two curing components. cold on the appropriate mold and subsequently foaming the film back with a polyurethane foam in the presence of a rigid support, such that the foam provides a connection between the film and the support. Disadvantages of the use of the film subjected to deep drawing are the waste that results from the projecting parts of the film, the limitations imposed on the design by deep drawing and that surface characteristics such as graining, granulation or veining are changed, in the areas of stretched and the layer thickness determined by the film. The disadvantages of producing the sheet when spraying the liquid polyurethane systems as described for example in EP-A-275 009 and EP-A 303 305, are the relatively long cure time, the application problems in the case of forced notches , the layer thickness which is particularly difficult to set in the case of edges and formation errors by the reactive starting components at the work site. The application of a one-component polyurethane system as described in EP 0275009 it also has disadvantages such as an extremely high mold temperature and a comparatively small variation possible in terms of the mechanics and curing behavior of the surface layer. It is an object of the present invention to develop plates that have excellent optical and mechanical properties, for example a uniform structure, excellent touch feeling, high strength and / or high extensibility, together with great design freedom. These sheets should in particular be suitable for the economic production of molded parts, which preferably consist of a composite with flexible foams and, if desired, rigid supports and can be used, for example in automotive construction. In addition, the sheet and the foam made of the same material will be an advantage in terms of waste or future recycling. A further objective is to develop reaction mixtures that can be processed without the formation of aerosols to produce these sheets based on polyisocyanate polyaddition products. The reaction mixture should be possible to produce the sheet in a mold without a spraying step. We have found that this goal is achieved by the plates described at the beginning.

For the purposes of the present invention, the term "sheets" refers to compact sheet-like bodies, which usually have a thickness from 0.1 to 5 mm. Veneers that are generally known as (synthetic) skins, usually serve as cover layers for molded parts. In accordance with the present invention, preference is given to molded parts comprising polyisocyanate foamed polyaddition products, in particular flexible polyurethane foams and a sheet according to the present invention as a skin adhering to it. Particularly preferably molded parts also comprise rigid supports, for example compact reinforcement elements or building elements, for example based on steel, aluminum or conventional plastics such as polyurethane. These molded parts according to the present invention are used, among others, as seats, boards, consoles, glove boxes or interior or exterior decorative finishes for example in the construction of automobiles. These products comprising the molded parts of the present invention have the following advantages: * high design freedom * uniform grain * excellent mechanical properties * excellent touch feeling * few production wastes * can be produced without problems products with light fastness and color * water impermeability With respect to the starting components present in the reaction mixture according to the present invention, the following can be set, with examples given for the components (a), (c) and (d) which also apply to the polyisocyanate polyaddition products, particularly preferably flexible polyurethane foams, also preferably present in the molded parts: As isocyanates (a), it is It is possible to use generally known (cyclo) aliphatic and / or aromatic polyisocyanates. Particularly convenient isocyanates for producing the composite elements of the present invention are aromatic diisocyanates, preferably diphenylmethane diisocyanate (MDI) and / or tolylene diisocyanate (TDI) and / or polyisocyanates such as polyphenyl polymethylene polyisocyanates. The isocyanates can be used in the form of the pure compound, in mixtures and / or in modified form, for example in the form of uretdiones, isocyanurates, allophanates or biurets, preferably in the form of reaction products, known as isocyanate prepolymers, containing urethane and isocyanate groups.

As compounds (b) which are reactive to isocyanates, the novel mixture (bl) described at the beginning is used according to the present invention. • As component (bll), it is possible to use polyester polyols generally known to have the characteristics specified in accordance with the present invention. These compounds are usually prepared by known methods for the esterification of known aliphatic, cycloaliphatic, araliphatic and / or aromatic carboxylic acids, which generally contain 2 to 3 carboxyl groups with known aliphatic, cycloaliphatic, araliphatic and / or aromatic alcohols which usually have from 2 to 4 hydroxyl groups. Preference is given to using polyester alcohols based on adipic acid such as carboxylic acid and butanediol, pentanediol and / or hexanediol. Examples of bifunctional chain extenders (bl2) are diols and / or amines, for example, ethanediol, propanediol, butanediol, pentanediol, hexanediol or 4-hydroxymethylbenzyl alcohol. Polyether polyalcohols suitable as component (bl3) are usually polyether polyalcohols which are prepared, for example, by generally known alkoxylation of bifunctional initiator substances or of higher functionality, for example ethylene glycol, propylene glycol, N, N'- bis (3-aminopropyl) ethylenediamine, 2- (diethylamino) ethylamine, diethylamino-4-aminopentane, diethylamino-propylamine, trimethylolpropane, glycerol, triethanolamine, dimethylaminopropylamine, pentaerythritol, sucrose, sorbitol, ethylenediamine, propandiamine and / or N, N'-bis (3-aminopropyl) ethylenediamine and / or dimethylaminopropylamine, using known alkylene oxides, for example ethylene oxide, propylene oxide and / or butylene oxide. The alkylene oxides may be added in the initiating substance or substances as a mixture or as blocks. For example, the component (bl3) can be terminated to the extreme with ethylene oxide. In order to produce the foamed polyisocyanate polyaddition products which are preferably present in the molded parts in addition to the sheets of the present invention, the isocyanate reactive compounds (b) used can generally be known substances such as polyalcohols, for example polycarbonate diols, polyesterols and / or polyetherols, with the polyetherols particularly preferred due to their superior hydrolysis stability and / or polyamines. These polyalcohols usually have a functionality from 1.5 to 5, in particular from 1.5 to 3 and a molecular weight from 500 to 10,000, in particular from 500 to 7,000. It is also possible to use chain extenders and / or interlayers as (b) The chain extenders are predominantly 2-functional alcohols having molecular weights from 60 to 499, for example ethylene glycol, propylene glycol, 1,4-butanediol or 1,5-pentadiol. The crosslinkers are compounds having molecular weights of 60 to 499 and 3 or more active H atoms, preferably amines and particularly preferably alcohols, for example glycerol, trimethylolpropane and / or pentaerythritol. The proportion by weight of chain extenders and / or interleavers is usually from 0 to 20% by weight, based on the total weight of component (b). The reaction for producing the sheet and the polyaddition products of foamed polyisocyanate is preferably carried out in the presence of catalysts. As catalysts (c), it is possible to use conventional compounds which, for example, strongly accelerate the reaction of component (a) with component (b). Examples of suitable catalysts are strongly basic amines, for example amidines, tertiary amines, for example 1,4-diazabicyclo- [2.2.2] octane and / or organic metal compounds, for example iron (III) acetylacetonate and / or in particular tin compounds. The reaction to produce the foamed polyisocyanate polyaddition products and the sheets can be carried out in the presence or absence of (d) auxiliaries and / or additives such as dyes, fillers, cell regulators, surfactant compounds and / or stabilizers against oxidation, thermal or microbial degradation or aging. The polyisocyanate foamed polyaddition products which are present in the molded parts according to the present invention in addition to the sheets of the present invention, are produced in the presence of blowing agents (e). As blowing agents (e), it is possible to use compounds of known chemical or physical action. As chemical blowing agents, preference is given to using water that forms carbon dioxide by reacting with the isocyanate groups. Examples of physical blowing agents, ie inert compounds which evaporate under the conditions of polyurethane formation, are for example (cyclo) aliphatic hydrocarbons, preferably those having 4 to 8, particularly preferably 4 to 6 and in particular carbon atoms, partially halogenated hydrocarbons or ethers, ketones or acetates. The amount of blowing agents used depends on the desired density of the foams. The various blowing agents can be used individually or in any mixtures with each other. To generate the products according to the present invention, the isocyanates (a) and the compounds Isocyanate reagents (b) or (bl) can be reacted in amounts such that the ratio of equivalence of the NCO groups of (a) to the sum of the reactive hydrogen atoms of (b) or (bl) is preferably 0.95- 1.3: 1, particularly preferably 1-1.2: 1 and especially 1-1.15: 1. If the product will contain at least some linked isocyanate groups, it is usual to employ a ratio of ?CO groups to the sum of the reactive hydrogen atoms of 1.5-60: 1, preferably 1.5-8: 1. The products are usually made by the method of a known filler or the processes of known prepolymers. In the known and preferred prepolymer process, it is usual to prepare a prepolymer containing isocyanate groups of (a) and a deficiency of (b) in a first step and then react this prepolymer with additional (b) to form the desired products. The starting components, for example the reaction mixture according to the present invention, usually depending on the application, are mixed from 0 to 100 ° C, preferably from 20 to 80 ° C, and introduced, for example into the mold . As already indicated, the mixing can be carried out mechanically by a stirrer or a stirring spindle or in a conventional high-pressure mixing head.

It has been found to be advantageous that the components for the generation of polyisocyanate polyaddition products compact, for example the sheets of the present invention, are degassed before and during the processing by application of vacuum (1-759 torr) in order to obtain bubble-free moldings. The reaction to form the product can be carried out for example by manual molding, by high pressure or low pressure machines, or by RIM (reaction injection molding) methods, usually in open or preferably closed molds. Suitable PU processing machines are commercially available (for example Fa.Elastogran, Isotherm, Hennecke, Kraus Maffei, etc.). The reaction of the mixture is advantageously carried out in conventional molds, preferably that can be heated and closed. Particularly, in the production of very smooth products, the molds used are preferably those whose surface is very smooth or ornamented in a defined form and preferably do not have heterogeneities, fissures, scratches or contamination. The surface of this mold can be treated, for example by polishing. As molds for the products, it is possible to use usual and commercially available molds whose The surface comprises, for example, steel, aluminum, enamel, Teflon, epoxy resin or other polymeric material, with the surface capable of, if desired, being chromium plated, for example hard chromium plating or provided with other electrodeposited coatings. The molds are preferably heated in such a way that preferred temperatures can be established, which are closed and preferably equipped to apply a pressure to the product. The sheets of the present invention can be produced, for example by emptying the starting components for example the reaction mixture in an open mold or by injection in a closed mold.The reaction mixture comprising the starting components, is preferably It is uniformly distributed in the mold in such a way that sheets having a substantially uniform thickness can be obtained.This can be achieved, for example by emptying the reaction mixture in a mold and subsequent rotation of the mold to distribute the reaction mixture, preferably from uniformly on the inside surface of the mold or manually distribute the reaction mixture in the mold, for example by means of a brush.The disadvantages usually caused by spraying the reactive components as a result of spray from above or from above or sprayed on the edges of seal of the mold, in this way can be avoided.

Preferential reaction is not introduced into the mold by spraying. The reaction for forming the polyisocyanate polyaddition products is usually carried out at a mold temperature, preferably also at a temperature of the starting components, from 20 to 220 ° C, preferably from 40 to 120 ° C, particularly preferably from 50 to 100 ° C, for a time of usually 0.2 to 30 minutes, preferably from 0.3 to 5 minutes. The sheets of the present invention can be processed to produce the moldings described above. This is usually carried out by producing the sheet of the present invention in a first step in a mold and subsequently producing a polyisocyanate polyaddition product foamed by reaction of a reaction mixture comprising (a) isocyanates, (b) compounds which are reactive to isocyanates, (e) blowing agents and, if desired, (c) catalysts, (d) auxiliaries and / or additives in contact with the surface of the sheet in a mold, preferably in the same mold. For the second reaction, the sheet can be transferred in an additional mold or in another way can also be processed in the same mold, for example when replacing the lid of the mold. The foaming in the opposite direction of the sheet, preferably takes place in the presence of support rigid, for example reinforcement elements or "construction elements." The foam produced in accordance with this by usual surface coating methods. The invention is illustrated by the following examples. Example 1 560 g of 4,4 '-MDI and 60 g of 4,4' -MDI modified with uretdione (Lupranat MM MM 103 from BASF Aktiengesellschaft) were heated to 60 ° C with stirring. 380 g of a bifunctional polyadipate having an average molecular weight of 2000 g / mol (Lupraphen ™ VP 9143 from BASF Aktienges llschaft) are subsequently added and the reaction mixture is heated to 80 ° C with stirring. After this temperature has been reached, the mixture is stirred for another 90 minutes. The resulting prepolymer had an NCO content of 18.8% by weight and a viscosity at 25 ° C, determined in accordance with DIN 53018, of 1100 mPas. To produce the molded skin, the prepolymer was added with a mixture of 86% by weight of Lupraphen ™ VP 9143 having a molecular weight of 2000, 13.5% by weight of 1,4-butanediol and 0. 5% by weight of a Lupragen ™ N 201 amine catalyst from BASF Aktiengesellschaft (concentration 10% in dipropylene glycol) at 50 ° C in an equimolar weight ratio of polyol component: isocyanate component using a high pressure machine. The mechanical properties of the resulting molding elastomer are illustrated in the table. Example 2 560 g of 4, 4'-MDI and 60 g of uretdione-modified 4,4'-MDI (Lupranat MM MM 103 from BASF Aktiengesellschaft) were heated at 60 ° C with stirring. 380 g of a bifunctional polyadipate having an average molecular weight of 2000 g / mol (Lupraphen ™ VP 9143 from BASF Aktiengesellschaft) are subsequently added and the reaction mixture is heated to 80 ° C with stirring. After this temperature is reached, the mixture is stirred for another 90 minutes. The resulting prepolymer had an NCO content of 18.8% by weight and a viscosity at 25 ° C, determined in accordance with DIN 53018, of 1100 mPas. To produce the molded skin, the prepolymer is added with a mixture of 86% by weight of Lupraphen ™ VP 9143 having a molecular weight of 2000, 9.5% by weight of 1,4-butanediol, 4% by weight of trifunctional polypropylene glycol which has an average molecular weight of approximately 200 g / mol (Lupranol ^ 3901 from BASF Aktiengesellschaft) and 0.5% by weight of amine catalyst Lupragen ™ N 201 from BASF Aktiengesellschaft (10% concentration in dipropylene glycol) at 50 ° C in an equimolar proportion by weight of polyol component: isocyanate component using a high pressure machine. The mechanical properties of the resulting molding elastomer are illustrated in the table. Table: Property Example 1 Example 2 Shore hardness [A] 75 75 Traction Resistance [MPa] 25 21 Elongation at break [%] 450 400 Tear propagation resistance [N / mm] 30 12 These products according to the present invention have the following advantages. * high design freedom * uniform grain * excellent mechanical properties * excellent feel to the touch * little production waste * water impermeability

Claims (5)

1. CLAIMS 1. A compact sheet based on a reaction mixture comprising: a) isocyanate, b) as compounds that are reactive towards isocyanates, a mixture (bl), comprising: bll) of 50 to 90% by weight, preferably from 60 to 85% by weight, based on the weight of the mixture (bl), of a polyester polyol having an average functionality from 2 to 2.5 and a molecular weight from 500 to 4000, bl2) from 0 to 20 % by weight, preferably from 10 to 15% by weight, based on the weight of the mixture (bl), of a bifunctional chain extender, bl3) from 0 to 30% by weight, preferably from 5 to 25% by weight, based on the weight of the mixture (bl), of polyether polyalcohols having a functionality of 1.5 to 5 and a molecular weight of 150 to 7000, c) catalysts and / or d) auxiliaries and / or additives.
2. 2. A process for producing compact sheets, comprising reacting a reaction mixture according to claim 1, in a mold.
3. 3. A molding piece comprising polyaddition polyisocyanate foamed products and a compact sheet according to claim 1, as a skin that adheres to it.
4. 4. A method for producing molded parts according to claim 3, characterized in that it comprises producing a sheet in a mold according to claim 2, in a first step and subsequently produce in contact with the surface of the sheet, a polyisocyanate polyaddition product foamed upon reaction of a reaction mixture comprising (a) isocyanates, (b) compounds that are reactive to isocyanates, (e) blowing agents and if desired (c) catalysts, (d) auxiliaries and / or additives. 5. The use of molded parts according to claim 3, such as seats, panels, consoles, glove boxes or interior or exterior decorative finishes of automobiles and also in boat construction and construction of vehicles for the agricultural and home construction sectors and buildings 6. A car seat, dashboard, console, glove compartment or interior or exterior decorative finish according to claim
5. 5.