EP0920470B1 - Multilayered, flat shaped part with a visible side and a support layer - Google Patents

Abstract

PCT No. PCT/EP97/04301 Sec. 371 Date Feb. 12, 1999 Sec. 102(e) Date Feb. 12, 1999 PCT Filed Aug. 7, 1997 PCT Pub. No. WO98/07774 PCT Pub. Date Feb. 26, 1998A multilayer flat molding with a visible side and a supporting layer, for example bathtubs or shower fittings, is described, the visible side consisting of a polyurethane surface coating layer and the supporting layer consisting of a reinforced polyurethane layer.

Description

The present invention relates to a multi-layer, flat molded part a visible side and a base course, in particular in the form of sanitary facilities like bathtubs or shower trays. According to the invention, multilayered, flat molded parts as inner and outer cladding e.g. of caravans, used in boat building and the like.

According to DE-A 4 223 993 it is known that the visible and usage side of Bathtubs and shower trays made of deep-drawn thermoplastic material, in particular Polymethyl methacrylate, form and on the back with a load-bearing To provide polyurethane layer, the deep-drawn molded part as lost Mold is used for the polyurethane layer. The advantage of such sanitary articles is seen in their recyclability by the thermoplastic layer can be removed from the polyurethane layer simply by increasing the temperature can.

According to the invention, it is now proposed to use such multilayer, two-dimensional Molded parts with a visible and if necessary use side and a base layer Made entirely from polyurethane by essentially one solvent-free polyurethane lacquer layer first applied to a negative mold and on the not yet hardened polyurethane lacquer layer Polyurethane base layer is applied.

a1) Lackpolyisocyanate auf Basis 1,6-Diisocyanatohexan und/oder Isophorondiisocyanat mit einer Viskosität von 100 bis 10 000 mPas und einem NCO-Gehalt von 5 bis 30 Gew.-%,

b1) Polyester und/oder Polyether mit einer Viskosität von 200 bis 5 000 mPas und einem OH-Gruppen-Gehalt entsprechend einer OH-Zahl von 33 bis 1 000,

c1) gegebenenfalls üblichen Pigmenten, Füllstoffen, Additiven und Katalysatoren sowie

d1) gegebenenfalls Lösungsmittel in Mengen von maximal 5 Gew.-%,

erhalten wurde,
und die Tragschicht aus einer Polyurethan-Schicht, die durch Aushärten einer zweiten Mischung, enthaltend

a2) Semiprepolymere auf Basis Diphenylmethandiisocyanat und Polyetherpolyol mit einem NCO-Gehalt von 20 bis 30 Gew.-%,

b2) Polyetherpolyole mit einer OH-Zahl von 250 bis 400 und

c2) 10 bis 60 Gew.-%, bezogen auf die Mischung, verstärkende Füllstoffe und/oder Fasern,

erhalten wurde.The present invention accordingly relates to a multi-layer flat molded part with a visible side and a base layer, the visible side consisting of a polyurethane layer, which comprises curing a first mixture

a1) lacquer polyisocyanates based on 1,6-diisocyanatohexane and / or isophorone diisocyanate with a viscosity of 100 to 10,000 mPas and an NCO content of 5 to 30% by weight,

b1) polyester and / or polyether with a viscosity of 200 to 5,000 mPas and an OH group content corresponding to an OH number of 33 to 1,000,

c1) optionally customary pigments, fillers, additives and catalysts and

d1) optionally solvents in amounts of at most 5% by weight,

was obtained
and the base layer made of a polyurethane layer, which is obtained by curing a second mixture

a2) semiprepolymers based on diphenylmethane diisocyanate and polyether polyol with an NCO content of 20 to 30% by weight,

b2) polyether polyols with an OH number of 250 to 400 and

c2) 10 to 60% by weight, based on the mixture, of reinforcing fillers and / or fibers,

was obtained.

Particularly suitable as coating polyisocyanates based on HDI 1,6-diisocyanatohexane Allophanate, biuret, isocyanurate, oxadiazine, uretdione and / or Derivatives of HDI containing urethane groups of the type known per se with the understand the aforementioned characteristics. Thus, for example, are suitable Polyisocyanates containing uretdione and / or isocyanurate groups in EP-A-0 010 589, -0 089 297, -0 173 252, -0 178 520, -0 330 966, -0 337 116, -0 377 177, -0456062 and -0495307 or DE-OSen 32 19 608 and 38 10 908 mentioned type; Polyisocyanates containing biuret groups of those in EP-A-0 150 769 and -0 320 703, U.S. Pen 3,903,127, 3,976,622 and 4,028,392 or the DE-OSen 28 08 801, 30 30 655 and 31 33 865 mentioned type; Allophanate and optionally isocyanurate polyisocyanates that in EP-A-0 000 194, -0 496 208, -0 524 500, -0 524 501 and -0 566 037 mentioned type; Polyisocyanates containing oxadiazine groups in DE-OS 16 70 666 mentioned type or any mixtures of such polyisocyanates.

Lacquer polyisocyanates with uretdione or allophanate and / or are preferred Isocyanurate structure that has a viscosity of 100 to 1500 mPas and at 23 ° C have an isocyanate group content of 17 to 24% by weight and one Monomeric HDI content of less than 0.5% by weight.

Lacquer polyisocyanates containing allophanate or isocyanurate groups are also suitable based on isophorone diisocyanate (IPDI) containing isocyanate groups from 10 to 25% by weight and containing monomeric diisocyanates less than 0.5% by weight.

The production of such isocyanurate groups containing polyisocyanates The basis of IPDI is known and is described, for example, in EP-A-0 003 765, -0 017 998 or - 0 193 828 or described in DE-OSes 19 34 763 and 26 44 684.

Lacquer polyisocyanates are preferably used, which between 10 and Contain 60% by weight of a biuret based on 1,6-diisocyanatohexane. Hereby processing viscosity is reduced and processing time is extended, on the other hand, the curing accelerates at higher temperatures. The Mixture of lacquer polyisocyanates to be used according to the invention has a viscosity of 100 to 10,000, particularly preferably from 200 to 5,000 mPas.

As a polyol component b1) or as a component of the polyol component b1) Suitable are the known polyhydroxyl compounds of polyester and Polyether type.

The polyester polyols can be reacted in a manner known per se of polyhydric alcohols with insufficient amounts of polyhydric Carboxylic acids, corresponding carboxylic anhydrides, corresponding polycarboxylic esters of lower alcohols or lactones.

Suitable polyhydric alcohols for the preparation of these polyester polyols are in particular those of the molecular weight range 62 to 400, such as. B. 1,2-ethanediol, 1,2- and 1,3-propanediol, the isomeric butanediols, pentanediols, hexanediols, Heptanediols and octanediols, 1,2- and 1,4-cyclohexanediol, 1,4-cyclohexanedimethanol, 4,4 '- (1-methylethylidene) biscyclohexanol, 1,2,3-propanetriol, 1,1,1-trimethylolethane, 1,2,6-hexanetriol, 1,1,1-trimethylolpropane, 2,2-bis (hydroxymethyl) -1,3-propanediol or 1,3,5-tris (2-hydroxyethyl) isocyanurate.

The acids or acid derivatives used to produce the polyester polyols can be aliphatic, cycloaliphatic and / or heteroaromatic in nature and optionally, e.g. B. by halogen atoms, substituted and / or unsaturated his. Examples of suitable acids are, for example, polyvalent carboxylic acids of the molecular weight range 118 to 300 or their derivatives, such as Succinic acid, adipic acid, sebacic acid, phthalic acid, isophthalic acid, trimellitic acid, Phthalic anhydride, tetrahydrophthalic acid, maleic acid, maleic anhydride, dimeric and trimeric fatty acids, dimethyl terephthalate and Terephthalic acid bis-glycol ester.

Any mixtures of these can also be used to prepare the polyester polyols starting compounds mentioned as examples.

However, preferred polyester polyols are those known per se Way from lactones and simple polyhydric alcohols, such as. B. the above exemplified, can be produced as starter molecules with ring opening. Suitable Lactones for the production of these polyester polyols are, for example, β-propiolactone, γ-butyrolactone, γ- and δ-valerolactone, ε-caprolactone, 3,5,5- and 3,3,5-trimethylcaprolactone or any mixture of such lactones.

The preparation is generally carried out in the presence of catalysts, such as, for example Lewis or Brönstedt acids, organic tin or titanium compounds, at temperatures of 20 to 200 ° C, preferably 50 to 160 ° C.

The polyether polyols can be alkoxylated in a manner known per se produce suitable starter molecules. For the production of these polyether polyols can be any polyhydric alcohols, for example those in the molecular weight range 62 to 400, as described above in the production of polyester polyols have been described, are used as starter molecules.

Alkylene oxides suitable for the alkoxylation reaction are, in particular, ethylene oxide and propylene oxide added in any order or in a mixture the alkoxylation reaction can be used.

The alkylene oxide units of the polyether polyols preferably consist of at least 80%, but particularly preferably exclusively, from propylene oxide units.

The mixture for producing the visible side can, in addition to the two-component mentioned Binding agents common in coating technology and Contain additives c1), such as fillers, pigments, curing catalysts, UV protection agents, antioxidants, microbicides, algicides, water scavengers, Thixotropy carriers, wetting agents, flow control agents, matting agents, anti-slip agents, Deaerator or extender. The auxiliaries and additives c1) are depending on the requirements of the application of the coating solving problems and their compatibility mixed into the a1) and b1) components.

Suitable fillers are, for example, heavy spar, talc, stone or plastic granules, Glass balls, sand or cork, possibly in amounts of up to to 200 wt .-%, based on that consisting of the individual components a1) and b1) Binder mixture can be used.

Suitable pigments are, for example, heavy spar, talc, titanium dioxide, zinc oxide, Iron oxides, chromium oxides or soot. A detailed overview of Pigments for paints are given in the "Textbook of paints and coatings, Volume II, Pigments, Fillers, Dyes ", Kittel, publisher W.A. Colomb in the Heenemann GmbH, Berlin-Oberschwandorf, 1974, pp. 17-265. The exemplary the pigments mentioned, if at all, in amounts of up to 100% by weight, based on the binder mixture consisting of the individual components a1) and b1), be used.

Catalysts from polyurethane chemistry per se can also be used known type may be included. These include, for example, the well-known lead or bismuth compounds, preferably those known in this connection Tin compounds and tertiary amines, such as those found in "Plastic Handbuch 7, Polyurethane "Carl-Hanser-Verlag, Munich - Vienna, 1984, pp. 97-98, are described in more detail. Such catalysts can, if at all, in Quantities of up to 2% by weight, based on the weight of the individual components a1) and b1) existing binder can be used.

Other auxiliaries and additives that may be used are, for example UV protection agents, antioxidants, microbicides, algicides, water scavengers, thixotropy carriers, Wetting agents, leveling agents, matting agents, anti-slip agents, deaerating agents or extenders. Such auxiliaries and additives are for example in "Textbook of paints and coatings, volume III., Solvents, plasticizers, Additives, intermediate products ", H. Kittel, publisher W.A. Colomb in the Heenemann GmbH, Berlin-Oberschwandorf, 1976, pp. 237-398. As a water catcher acting desiccants are described, for example, in "Kunststoff Handbuch 7, Polyurethane", Carl-Hanser-Verlag, Munich - Vienna, 1983, p. 545 described in more detail. The total amount of such other auxiliaries and additives is generally 0 to 25% by weight, based on that from the individual components a1) and b1) existing binders.

It is essential that the first mixture forming the visible side is as possible has low solvent content, since otherwise with a greater layer thickness and especially after application of the second mixture forming the base layer Bubbles may appear during curing. Small amounts of solvent but can pigment wetting when using pigments and fillers promote.

The components a1) and b1) are in such a ratio according to usual methods of polyurethane chemistry mixed that the index 90 to Is 130.

To prepare the second mixture, polyether polyols with an OH number are used from 250 to 400, preferably a mixture of polyether polyols, the mixture having an average OH number of 250 to 400. Especially the polyether polyol preferably consists of a component with an OH number from 350 to 550 and a second component with an OH number of 30 to 50.

The isocyanate component is based in the form of a semi-prepolymer Diphenylmethane-4,4'-diisocyanate (MDI) and polyether polyols with an NCO content from 20 to 30 wt .-% used. Furthermore, the second mixture in minor amounts (below 3% by weight, preferably below 1% by weight) Chain extenders, e.g. low molecular weight diamines, condensation catalysts, e.g. Diaza-dicyclo-octane, defoaming agents, e.g. Polyether siloxanes and other modifiers are added. The ratio of Polyether polyols and isocyanate components are preferred in such Ratio chosen that the key figure is 90 to 130.

Mineral fillers are particularly suitable as reinforcing fillers. However, fibers, in particular short glass fibers, from 3 to 15 µm in diameter and 0.3 to 3 mm in length.

The mixtures are produced using the processes customary in polyurethane chemistry continuously produced in mixing units and through to a negative form Spray or pour applied. First, the one that forms the visible side applied first mixture and, before it has hardened, the second mixture applied for the base course. The joint curing of both layers takes place at 20 to 120 ° C, preferably 40 to 100 ° C, over a period of 15 Minutes to 24 hours, depending on the curing temperature.

The layer forming the visible side preferably has a thickness of 0.2 to 0.7 mm. The base layer can, depending on the application of the multilayer flat molded part have a thickness between 2 and 10 mm. Possibly the thickness of the base layer can be variable, so that more stressed areas are thicker. Furthermore, the base layer can be in the form of a sandwich unfoamed and foamed polyurethane can be formed by the second mixture is applied in multiple layers, with a middle layer a blowing agent is added.

Claims (5)

1. Multilayer, flat moulding with a visible side and a supporting layer,
   the visible side consisting of a polyurethane layer that has been obtained by curing a first mixture containing

   a1) surface coating polyisocyanates based on 1,6-diisocyanatohexane and/or isophorone diisocyanate having a viscosity of 100 to 10 000 mPa.s and a NCO content of 5 to 30 wt.%,

   b1) a polyester and/or polyether having a viscosity of 200 to 5000 mPa.s and an OH group content corresponding to an OH number of 33 to 1000,

   c1) optionally conventional pigments, fillers, additives and catalysts, as well as

   d1) optionally solvents in amounts of at most 5 wt.%,

   and the supporting layer consisting of a polyurethane layer that has been obtained by curing a second mixture containing

   a2) semi-prepolymers based on diphenylmethane diisocyanate and a polyether polyol having an NCO content of 20 to 30 wt.%,

   b2) polyether polyols having an OH number of 250 to 400, and

   c2) 10 to 60 wt.%, referred to the mixture, of reinforcing fillers and/or fibres.
2. Moulding according to claim 1, wherein the component a1) contains a biuret based on 1,6-diisocyanatohexane in an amount of 10 to 60 wt.% referred to the component a1).
3. Moulding according to claim 1 or 2, in the form of a shower fitting or bathtub.
4. Moulding according to one of claims 1 to 3, wherein the layer forming the visible side is 0.2 to 0.7 mm thick.
5. Process for producing mouldings according to one of claims 1 to 4, characterised in that the first mixture is first of all applied to a mould forming the visible side of the moulding, and the second mixture is then applied to the not yet cured first mixture.