NZ291136A

NZ291136A - Composite plate of coating of polymethyl methacrylate on a substrate of acrylonitrile-butadiene-styrene, for sanitary sink insert with coating a mixture of impact toughened and standard pmma

Info

Publication number: NZ291136A
Application number: NZ291136A
Authority: NZ
Inventors: Wilhelm Klepsch
Original assignee: Klepsch Senoplast
Priority date: 1994-09-06
Filing date: 1995-08-28
Publication date: 1997-12-19
Also published as: MY115981A; KR100241855B1; RU2137608C1; EP0781201A1; AU687605B2; MX9701691A; NO971014L; DE59501455D1; ES2114748T3; DK0781201T3; ATA170494A; SI0781201T1; IL115067A0; CN1075770C; PL318974A1; IL115067A; GR3026227T3; NO971014D0; EP0781201B2; CZ65297A3

Abstract

A composite panel may be deep drawn into sanitary inserts (bath tubs, shower tubs, sinks, lavabos). A coating (3) of polymethyl metacrylate (PMMA, acrylic glass) is arranged on a substrate made in particular of acrylonitrile-butadiene-styrene (ABS). The acrylic glass coating consists of a mixture of impact-resistant modified PMMA and standard PMMA.

Description

<div class="application article clearfix" id="description"> New Zealand No. 291136 International No. PCT/AT95/00171 TO BE ENTERED AFTER ACCEPTANCE AND PUBLICATION Priority dates: 06.09.1994; Complete Specification Filed: 28.08.1995 Classification:^) B32B27/30 Publication date: 19 December 1997 Journal No.: 1423 NEW ZEALAND PATENTS ACT 1953 COMPLETE SPECIFICATION Title of Invention: Composite panel Name, address and nationality of applicant(s) as in international application form: SENOPLAST KLEPSCH & CO. GMBH & CO. KG, A-5721 Piesendorf Nr. 444, Austria 29 1136 Ccrrposite plate The invention concerns a composite plate from which an insert for sanitary articles, in particular bath tubs, shower bases, flush bowls and wash basins can be produced by deep drawing, wherein a coating of polymethyl methacrylate (FM-IA, acrylic glass) is arranged on a support in 5 particular of acrylonitrile-butadiene-styrene (ABS). At the present time plastic plates comprising moulded acrylonitrile or co-extrusion plates of ABS/FM^A are used for various inserts for sanitary articles (bath tubs, flush bowls, shower bases and shower panels). 10 The European standard EN 263 precisely describes the requirements and testing methods that a plate of moulded acryl for bath tubs and shower bases must fulfil for domestic use. The requirements prescribed in EN 263 (besides the general requirements in terms of the moulded acryl plate in relation to the raw 15 material used) were hitherto only partially met by co-extruded plates of ABS with a coating of polymethyl methacrylate (FMdA). Hitherto the co-extruded ABS/FM*4A-plates were not capable with 100% certainty of complying with the requirement set forth in section 9 of the standard EN 263 'Resistance to hot water'. Added to this was the 20 experience that the prescribed test is not sufficiently close to reality insofar as it does not take account of the influence of the aggressive solvents, which in many countries are permitted as a constituent of cleaning agents, on the resistance of plastic materials to hot water. Therefore, in the development of co-extruded ABS/PfWA-plates for sanitary 25 articles, the applicants developed their own test which, in regard to testing of the co-extruded plates in accordance with the procedure of section 9 of the standard EN 263, additionally provides for a cleaning operation with commercially available aggressive cleaning agents, between the individual cycles. 291136 The present invention is based on the realisation that this test can only be passed when there is a sufficiently high level of chemical resistance and hot/cold water resistance in the case of the coating of polymethyl methacrylate. 5 It is further known that these requirements can be better met by the HtflA-covering layer if the molecular weight of the raw material used is as high as possible or if the melt flow index (MET) is as low as possible. The present applicants' EP-B1-225 500 describes composite plates of ABS and a coating of EM^A for the production of deep-drawn bath 10 tub inserts, which are co-extruded through a wide-slot nozzle and are characterised in that the acrylic glass forming the coating has a melt flow index MFI 230 C/3.8 (in accordance with German standard DIN 53735) of at most 2g/10'. It has been found that this is not sufficient in all cases to pass the above-indicated test. 15 Furthermore EP-Bl-304 679 describes a possible way of improving the hot-cold water resistance and the resistance to stress cracking in regard to composite plates of ABS and FMMA, wherein arranged on a support of ABS is a coating of FJMA provided with an additional covering layer which comprises 30 to 70 percent by weight of PVDF (polyvinylidene fluoride) 20 and the balance PNWA. With those plates, it was already possible substantially to comply with the requirements listed in EN 263 in respect of moulded acrylic plates for bath tubs and shower bases for domestic use. The stress crack resistance to alcohols, rrore especially methanol, 25 and in the test in accordance with section 9 of the standard EN 263, with an additional cleaning operation, was however adjudged to be still not adequate. The object of the present invention is to provide a composite plate of the general kind set forth in the opening part of this specification, 30 which is distinguished by an improved level of hot-cold water resistance as well as stress crack resistance to chemicals contained in cleaning agents, in particular alcohol. In accordance with the invention this is 291136 achieved in that the coating of acrylic glass comprises a mixture of impact toughness-modified PI<MA and standard FM«IA. The term standard FM4A is used to denote homo-polymethyl methacrylates. The term inpact toughness-modified FT*MA is used to denote in particular copolymers 5 (alloys) of methyl methacrylate with less than 30% (percent by mass), preferably less than 10%, of other acrylates (in particular butyl aery late, ethyl aery late or methyl aery late). It has been found from the applicants' investigations that the level of stress crack resistance, in particular in relation to alcohols, 10 in the case of IMVJA, is improved, the lower the modulus of elasticity (E-rrodulus) is and the lower the MET (melt flow index) is. In the general case this object can be very satisfactorily attained by inpact toughness-modified high-molecular types of PM4A (low flow melt indices generally below 2.0 g/10' at 230°C/3.8 in accordance with German standard DIN 15 53753 ). The disadvantage of these inpact toughness-modified types of EM-1A however is that they have a level of scratch resistance which is low in ccnparison with non-impact touchiness-modified EMMA and in the event of hot water storage for a prolonged period of time, a clouding effect or 20 'haze' occurs in the R*WA layer. For that reason, it was hitherto not possible to use high-molecular inpact toughness -modified types of FMtfA in co-extrusion plates of ABS with FMMA, for the subsequent production of bath tub and shower base inserts. Now, the basic idea of the invention is that of arriving at a 25 substantial improvement in the hot-cold water resistance and chemical stress crack resistance with at the same time undiminished scratch resistance, by specific deliberate mixing of high-molecular FMMA (low MFI) with high-molecular impact toughness -modified PMMA as a covering layer in the case of conposite plates with a coating of FM^A. 30 While a mixture of impact toughness-modified PINMA with standard PMMA can fundamentally improve the desired properties, investigations carried out by the applicants in relation to mixtures have shown that Z§^\lb 4 only a relatively small range of the possible mixtures satisfies highest requirements (in particular the standard EN 263 with additional cleaning by aggressive, cortmercially available cleaning agents), in regard to hot-cold water resistance and chemical stress crack resistance. That snail 5 range is best described by the melt flow index and/or the modulus of elasticity of the mixtures of inpact toughness-modified FftMA with standard H#1A, namely MFT below 0.8 and modulus of elasticity between 2500 and 2800 MPa. On the basis of the present results, very high hot-cold water 10 resistance and stress crack resistance (in particular in relation to alcohols) are achieved by mixtures of inpact toughness-modified PM4A with standard FMMA, which have an MFT 230°C/3.8 in accordance with German standard DIN 53753 of at most 0.8 and at the same time a modulus of elasticity (in accordance with ISO 527) of 2500 to 2800 MPa. 15 A composite plate according to the invention may for example comprise a supporting plate 1 which is several millimetres in thickness and which conprises ABS possibly mixed with PMMA. The next layer as indicated at 2 is a layer of ABS which is about 10 - 20% in thickness (relative to the overall thickness) and which forms the coloured support 20 for a coating 3 of acrylic glass (PNMA) of a thickness of 1 - 30% (with respect to the overall thickness). The composite plate can be produced for example by co-extrusion of the layers in a wide-slot nozzle. -U- U._. - 4 </div>

Claims

CLAIMS 5 291136

1. A composite plate frcm which an insert for sanitary articles (bath tubs, shower bases, flush bowls and wash basins) can be produced by-deep drawing, wherein a coating of polymethyl methacrylate (H-MA, acrylic glass) is arranged on a support in particular of aerylonitrHe-butadiene -styrene (ABS), characterised in that the coating of acrylic glass comprises a mixture of inpact toughness-modified PM4A and standard EM4A.

2. A composite plate according to claim 1 characterised in that the MFI of the mixture 230°C/3.8 in accordance with German standard DIN 53735 is below 0.8 g/10'.

3. A composite plate according to claim 1 and claim 2 characterised in that the modulus of elasticity of the mixture used in the coating (3) is frcm 2500 to 2800 MPa.

4. A composite plate according to one of claims 1 to 3 characterised in that the inpact toughness-modified FM^IA is a copolymer of methyl methacrylate and less than 30% (percent by mass) and preferably less than 10% is aery late.

5. A composite plate according to claim 4 characterised in that butyl aery late, ethyl aery late or methyl aery late is used as the acrylate.

6. A composite plate, as claimed in any one of claims 1 to 5, substantially as herein described and with reference to the accompanying figure. END OF CLAIMS N PAT£MT OFFICE 14 OCT 1997