WO2011026977A1

WO2011026977A1 - Composite molded part, in particular for furniture construction

Info

Publication number: WO2011026977A1
Application number: PCT/EP2010/063044
Authority: WO
Inventors: Klaus Hahn; Holger Ruckdaeschel; Ingo Bellin; Peter Merkel; Markus Hartenstein; Manfred Pawlowski
Original assignee: Basf Se
Priority date: 2009-09-07
Filing date: 2010-09-06
Publication date: 2011-03-10
Also published as: EP2475522A1

Abstract

The invention relates to a composite molded part, in particular for furniture construction, contains a core layer and one or more layers, wherein the core layer is designed as a closed-cell extrusion foam sheet having a cell count of 1-30 cells per mm and a density of 20-200 g/l and can be obtained by extrusion foaming a foamable melt, comprising (a) heating a polymer component P, which is composed of 85 to 100% by weight of component P', consisting of P1) 100 to 0% by weight (in relation to P') of one or more alpha-methyl styrene acrylonitrile copolymers (AMSAN), containing P11) 18 to 40% by weight (in relation to AMSAN) acrylonitrile embedded by polymerization, P12) 60 to 82% by weight (in relation to AMSAN) alpha-methyl styrene embedded by polymerization (P121) or a mixture, embedded by polymerization, of alpha-methyl styrene and styrene (P122), P13) 0 to 22% by weight (in relation to AMSAN) of at least one monomer embedded by polymerization from the group consisting of alkyl(meth)acrylates, (meth)acrylic acid, maleic acid anhydride and maleinimides, and P2) 0 to 100% by weight (in relation to P') of one or more styrene acrylonitrile copolymers (SAN), containing, preferably consisting of, P21) 18 to 40% by weight (in relation to SAN) acrylonitrile embedded by polymerization, P22) 60 to 82% by weight (in relation to SAN) styrene embedded by polymerization, and P23) 0 to 22% by weight (in relation to SAN) of at least one monomer embedded by polymerization from the group consisting of alkyl(meth)acrylates, (meth)acrylic acid, maleic acid anhydride and maleinimide, wherein the sum of the percentages by weight of P1 and P2 is 100% by weight, in relation to P', and P3) 0 to 15% by weight (in relation to P) of one or more thermoplastic polymers from the group consisting of styrene polymers and copolymers, polyolefins, polyacrylates, polycarbonates (PC), polyesters, polyamides, polyether sulfones (PES), polyether ketones (PEK) and polyether sulfides (PES), to form a polymer melt, (b) introducing 1 to 12% by weight (in relation to P) of a expanding agent component T, which preferably contains less than 0.2% by weight water (in relation to P), containing b1) 15 to 95% by weight (in relation to T) carbon dioxide and b2) 5 to 85% by weight (in relation to T) of one or more co-expanding agents selected from the group consisting of C₁-C₄ alcohols and C₁-C₄ carbonyl compounds, into the polymer melt to form a foamable melt, (c) extruding the foamable melt in a range of lower pressure to foam it into the extrusion foam, (d) optionally adding additives to the polymer component P in at least one of steps a), b) and/or c).

Description

The invention relates to a composite molding, in particular for furniture construction, comprising a core layer of an extruded foam and at least one further layer, a process for its preparation, and the use of the composite molding in furniture, the construction industry, in the automotive industry and in boat and shipbuilding.

Composite moldings for use in the furniture industry have long been known. They have, in addition to a core layer, further layers, for example cover layers, films or veneers, and optionally a stabilizing frame construction. If such composite moldings are to be used as lightweight components, it is desirable to have a core layer with the lowest possible density, which may, however, affect the further performance characteristics as little as possible.

German utility model DE 296 09 442 U1 describes a molded part, in particular for furniture or furniture parts, which contains a core layer of a paper honeycomb material, cover layers of, for example, chipboard or MDF (middle density fiber) sheets as cover layers and a frame construction. The disadvantage here is that the frame construction is imperative for stability reasons and that fittings are difficult to install, since the core layer is not solid. LU-A 80594 describes a sandwich element with an aluminum honeycomb panel. In addition to economic disadvantages due to the use of expensive aluminum fittings are difficult to install here.

In German utility model DE 202005012486 U1 door blanks are described from a lightweight board with polyurethane (PU) core. A disadvantage is besides the high price of polyurethane the difficult recyclability of this substance.

Lightweight panels with a core of expanded polystyrene (EPS) are marketed by SWL-Tischlerplatten-Betriebs-GmbH (Langenberg / Westfalen, Germany). These plates also require a frame construction.

In US 2007/0256379 a sandwich panel is described with a polymer foam as the core, whose cells have an anisotropic structure. Although good results have already been achieved with the known lightweight building panels for furniture construction, there is nevertheless a broad scope for improvement, in particular as regards a combination of low density with good processability and favorable application properties, such as heat resistance, compressive strength and flexural strength.

For example, in the manufacture of sandwich panels containing a core of foam material, there is still room for improvement in the adhesion of foam and cover layers.

Sandwich panels are usually offered by the manufacturers without edge coating, since these are applied individually in a further processing stage. For those companies where such edge coating is used, it is important that this can be done with common tools, adhesives and coating techniques that are also applicable to wood materials. Here also remains a wide room for improvement in the known materials.

It was therefore an object to provide a composite molding, in particular for furniture construction, which requires the least possible density without a frame construction and can be easily coated with conventional technologies, in particular at the edges.

Another object was to provide a composite molding, in particular for furniture construction, which has a high compressive and flexural strength at low density and, if desired, a high heat resistance.

It has been found that composite moldings having favorable performance properties are obtained when a layer is formed as a special extruded foam sheet.

Extruded foam boards with reduced thermal conductivity based on styrene polymerizates are known from EP-A 1 661 939. However, the document gives no indication as to how such panels would be improved with regard to use in composite moldings, in particular for furniture construction.

The invention therefore relates to a composite molding, in particular for the furniture industry, comprising a first layer and one or more further layers connected to the first layer, the first layer being a closed-cell extrusion foam board having a cell count of 1 to 30 cells per mm and a density of 20-150 g / l, obtainable by (a) heating a polymer component P formed from

85 to 100 wt .-% of a component P \ consisting of

P1) 100 to 0 wt .-% (based on P ') of one or more alpha-methylstyrene-acrylonitrile copolymers (AMSAN) containing

P1 1) from 18 to 40% by weight (based on AMSAN) of copolymerized acrylonitrile, P12) from 60 to 82% by weight (based on AMSAN) of copolymerized α-methylstyrene (P121) or of a copolymerized mixture of α-methylstyrene and styrene ( P122)

P13) 0 to 22 wt .-% (based on AMSAN) of at least one copolymerized monomer selected from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimides.

P2) 0 to 100% by weight (based on P ') of one or more styrene-acrylonitrile copolymers (SAN), comprising, preferably consisting of,

P21) from 18 to 40% by weight (based on SAN) of copolymerized acrylonitrile, P22) from 60 to 82% by weight (based on SAN) of copolymerized styrene, and P23) from 0 to 22% by weight (based on SAN) at least a copolymerized monomer selected from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimide, the sum of the percentages by weight of P1 and P2 being 100% by weight, based on P ',

and

P3) 0 to 15 wt .-% (based on P) of one or more thermoplastic polymers selected from the group consisting of styrene polymers and copolymers, polyolefins, polyacrylates, polycarbonates (PC), polyesters, polyamides, polyether sulfones (PES). Polyether ketones (PEK) and polyether sulfides (PES), to form a polymer melt,

(b) incorporating from 1 to 12% by weight (based on P) of a blowing agent component T, which preferably contains less than 0.2% by weight of water (based on P), containing b1) 15 to 95 wt .-% (based on T) of carbon dioxide and

b2) from 5 to 85% by weight (based on T) of one or more co-blowing agents selected from the group consisting of C 1 -C ₄ alcohols and CC ₄ carbonyl compounds, in the polymer melt to form a foamable melt,

(c) extruding the foamable melt into a region of lower pressure with foaming to the extrusion foam,

(d) optionally adding additives to the polymer component P in at least one of the steps a), b) and / or c).

The invention likewise relates to a process for producing a composite molding according to the invention, comprising the steps of a) providing a polymer component (P) which is formed from

85 to 100 wt .-% of a component P ', consisting of P1) 100 to 0 wt .-% (based on P') of one or more alpha-methylstyrene-acrylonitrile copolymers (AMSAN) containing

P1 1) from 18 to 40% by weight (based on AMSAN) of copolymerized acrylonitrile, P12) from 60 to 82% by weight (based on AMSAN) of copolymerized α-methylstyrene (P121) or of a copolymerized mixture of alpha-

Methyl styrene and styrene (P122),

and

P2) 0 to 100 wt .-% (based on P ') of one or more styrene-acrylonitrile copolymers (SAN) containing, preferably consisting of, P21) 18 to 40 wt .-% (based on SAN) copolymerized acrylonitrile .

P22) 60 to 82 wt .-% (based on SAN) copolymerized styrene and

P23) 0 to 22% by weight (based on SAN) of at least one copolymerized monomer selected from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimide, wherein the sum of the weight percentages of (P1) and P1 is 100% by weight, based on

P \ is,

and

0 to 15 wt .-% (based on P) of one or more thermoplastic polymers selected from the group consisting of styrene polymers and copolymers, polyolefins; Polyacrylates, polycarbonates (PC), polyesters, polyamides, polyether sulfones (PES), polyether ketones (PEK) and polyether sulfides (PES), (b) heating the polymer component (P) to form a polymer melt,

(c) introducing from 1 to 12% by weight (based on P) of a blowing agent component T, which preferably contains less than 0.2% by weight of water (based on P), containing

b1) 15 to 95 wt .-% (based on T) of carbon dioxide and

b2) from 5 to 85% by weight (based on T) of one or more co-blowing agents selected from the group consisting of C 1 -C ₄ alcohols and CC ₄ carbonyl compounds; in the polymer melt to form a foamable melt,

(d) extruding the foamable melt into a lower pressure region with foaming to form a closed-cell extrusion foam sheet having a density in the range of 20 to 150 g / l and a cell count in the range of 1 to 30 cells per mm,

(e) optionally adding additives to the polymer component P in at least one of the steps a), b), c) and / or d)

(f) applying at least one further layer to the extrusion foam board obtained in step d). The invention further relates to the use of the composite molding according to the invention in furniture construction, in the construction industry, in exhibition construction, automotive engineering and in boat and shipbuilding.

The composite molding according to the invention is characterized by a combination of lower density, high compressive and flexural strength and increased heat resistance. In comparison to particle foams, the foam structure is more homogeneous and the mechanical properties can be adapted to the load direction required by the application by adjusting the cell orientation during foam extrusion. Due to their good heat resistance compared to materials such as XPS, the composite moldings according to the invention can be processed more easily, have a high compressive and flexural strength and require at densities between 50 and 100 g / l no frame construction. In particular composite moldings containing alpha-methylstyrene / acrylonitrile (AMSAN) show a high heat resistance. Sandwich panels containing the foam material according to the invention allow a coating of the edges according to customary methods in wood construction with conventional tools and coating techniques. The extrusion foam board used according to the invention for the core layer generally has a density of from 20 to 150 g / l, preferably from 50 to 130 g / l, particularly preferably from 60 to 120 g / l.

The extrusion foam according to the invention has a cell count in the range 1 to 30 cells per mm, preferably from 3 to 20 cells per mm, in particular from 3 to 25 cells per mm.

For the purposes of the invention, closed-cell extruded foam means that the cells, measured in accordance with DIN ISO 4590, are closed to at least 90%, in particular to 95-100%.

The AMSAN (P1), SAN (P2) and the thermoplastic polymers (P3) used according to the invention as polymer component P 'can be prepared by methods known to those skilled in the art, for example by free-radical, anionic or cationic polymerization in bulk, solution, dispersion or emulsion , In the case of P1 and P2, preference is given to preparation by free-radical polymerization.

Component P1 consists of one or more alpha-methylstyrene-acrylonitrile copolymers (AMSAN) containing, preferably consisting of,

P1 1) from 18 to 40% by weight, preferably from 25 to 40% by weight, particularly preferably from 25 to 35% by weight (based on AMSAN) of copolymerized acrylonitrile,

P12) from 60 to 82% by weight, preferably from 60 to 75% by weight, particularly preferably from 65 to 75% by weight (based on AMSAN) of copolymerized α-methylstyrene (P121) or of a copolymerized mixture of alpha-

Methylstyrene and styrene (P122) and

P13) 0 to 30% by weight, preferably less than 20% by weight, particularly preferably less than 5% by weight (based on AMSAN), of at least one copolymerized monomer from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimides. In the context of the invention, alkyl (meth) acrylates are understood as meaning both alkyl acrylates and alkyl methacrylates. By (meth) acrylic acid is meant both acrylic acid and methacrylic acid.

Preferred alkyl (meth) acrylates are formed from (meth) acrylic acid and CrC ₆ - alcohols such as methanol, ethanol, 1-propanol, 2-propanol, n-butanol, sec-butanol, isobutanol, tert-butanol, 1 Pentanol and its isomers, 1-hexanol and its isomers and cyclohexanol.

Preferred maleimides are maleimide itself, N-alkyl-substituted maleimides (preferably with C 1 -C ₆ -alkyl) and N-phenyl-substituted maleimides.

In a preferred embodiment, component P1 contains no further (0 wt .-%) comonomers P13.

In a further embodiment, the component P1 contains 0.1 to 22 wt .-%, preferably 1 to 20 wt .-% of one or more comonomers (P13), preferably from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimides.

In a preferred embodiment, the component (P12) is alpha-methylstyrene (P121). In a further preferred embodiment, the component (P12) consists of a mixture of styrene and alpha-methylstyrene (P122).

In a particularly preferred embodiment, component P1 contains no comonomer (P13) and component (P12) consists of alpha-methylstyrene (P121).

In a further preferred embodiment, P1 consists of one or more, preferably one, copolymer with component (P121).

In another embodiment, P1 consists of one or more, preferably one, copolymers with component (P122). In another embodiment, P1 consists of one or more, preferably one, copolymer with component (P121) and one or more, preferably one, copolymer with component (P122).

Preferred as AMSAN (P1) with the component (P121) AMSAN types are available from (P1 1) 18 to 35 wt .-%, preferably 27 to 33 wt .-% (based on (P1)) of acrylonitrile and

(P121) 65 to 82 wt .-%, particularly preferably 67 to 73 wt .-% (based on

(P1)) alpha-methylstyrene.

Preferred as AMSAN (P1) with the component (P122) (alpha-methylstyrene / styrene / acrylonitrile terpolymers) are polymers obtainable from (P1221) from 61 to 81% by weight (based on (P1)) of alpha-methylstyrene,

(P1222) 1 to 15 wt .-% (based on (P1)) styrene and

(P1 1) 18 to 34 wt .-% (based on (P1)) acrylonitrile.

The SAN component (P2) generally contains from 18 to 40% by weight, preferably from 25 to 35% by weight and in particular from 30 to 35% by weight of copolymerized acrylonitrile and generally from 60 to 82% by weight, preferably from 65 to 75 wt .-% and particularly preferably 65 to 75 wt .-% of copolymerized styrene (in each case based on SAN). Preferably, the SAN consists of the components (P21) and (P22) and optionally (P23). The SAN (P2) may optionally contain 0 to 22% by weight of at least one copolymerized monomer from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimides (component P23). In a preferred embodiment, the SAN (P2) contains no monomer of the component (P23).

The SAN used in the invention (P2) generally have a melt volume rate MVR (220 ° C / 10 kg) according to ISO 1 13 in the range of 5 to 20 cm ^3/10 min.

Suitable types of SAN are, for example, polymers of BASF SE such as Luran 3380, Luran 33100 and Luran 2580. In a preferred embodiment, component (Ρ ') contains no (0 wt .-%) AMSAN (P1).

In a further preferred embodiment, the component (P) contains no (0 wt .-%) styrene-acrylonitrile copolymer (P2). In a further preferred embodiment, the component (Ρ ') contains one or more, preferably one, copolymer (P1), preferably in an amount of at least 5 wt .-%, and one or more, preferably a copolymer (P2), preferably in an amount of at least 5% by weight.

In a preferred embodiment, component (P) contains no (0 wt.%) Thermoplastic polymer (P3).

In a further preferred embodiment, the polymer component P (and thus also the extrusion foam) contains 0.1 to 15 wt .-%, particularly preferably 0.5 to 5 wt .-% of a thermoplastic polymer (P3) (in each case based on P).

Styrene polymers and copolymers, polyolefins, polyacrylates, polycarbonates (PC), polyesters, polyamides, polyethersulfones (PES), polyether ketones (PEK), polyethersulfides (PES) or mixtures thereof are optionally used as thermoplastic polymers (P3) of the polymer component P.

Suitable styrene copolymers (as component (P3)) are, for example, acrylonitrile-butadiene-styrene (ABS), styrene-maleic anhydride (SMA), acrylonitrile-styrene-acrylic ester (ASA) and styrene-methacrylic acid.

As component (P3) and polystyrene can be used. However, this is not preferred. Suitable polyolefins (as component (P3)) are, for example, polypropylene (PP) polyethylene (PE) and polybutadiene.

A suitable polyacrylate (as component (P3)) is, for example, polymethyl methacrylate (PMMA).

Suitable polyesters (as component (P3)) are, for example, polyethylene terephthalate (PET) and polybutylene terephthalate (PBT).

Suitable polyamides (as component (P3) are, for example, polyamide 6 (PA6), polyamide 6,6, polyamide 6, 1 and polyamide 6 / 6,6.

In a preferred embodiment, the polymer component P contains no (0% by weight) styrene copolymer (as component (P3)). In a further preferred embodiment, the polymer component P contains no (0 wt .-%) thermoplastic polymer (P3).

The components (P3) preferably contain no polystyrene.

In a preferred embodiment, component (P) consists of component (P1), this component (P1) preferably containing component (P121) and preferably no component (P13), more preferably component (P121) and none Component (P13).

In a further, particularly preferred embodiment, the component (P) consists of the component (P1) and the component (P2), wherein preferably the component (P1) contains the component (P121) and / or no component (P13), and / or the component (P2) contains no component (P23) and wherein particularly preferably the component (P1) contains the component (P121) and no component (P13) and the component (P2) contains no component (P23). In particular, in this embodiment, the two components (P1) and (P2) each consist of one (1) copolymer. It is furthermore particularly preferred in this embodiment if component (P) consists of from 20 to 98% by weight, and preferably from 50 to 97% by weight (P1), and the amount (P2) complementary to 100% by weight ,

In a further preferred embodiment, component P consists of component (P1) and component (P3), component (P1) preferably containing component (P121) and / or no component (P13) and / or component (P3 ) Is styrene-maleic anhydride (SMA) and / or acrylonitrile-styrene acrylic ester (ASA), and wherein component (P1) more preferably contains component (P121) and no component (P13) and component (P3) contains styrene-maleic anhydride (SMA) and / or acrylonitrile-styrene-acrylic ester (ASA). In particular, in this embodiment, the components (P1) and (P3) each consist of one (1) copolymer or polymer.

In a further preferred embodiment, the component P consists of the components (P1), (P2) and (P3), wherein the component (P1) preferably contains the component (P121) and / or no component (P13) and / or wherein the Component (P2) preferably contains no component (P23) and / or component (P3) is preferably styrene-maleic anhydride (SMA) and / or acrylonitrile-styrene-acrylic ester (ASA), and where component (P1) is particularly preferably component (P121) and no component (P13), component (P2) contains no component (P23) and component (P3) is styrene-maleic anhydride (SMA) and / or acrylonitrile-styrene-acrylic ester (ASA). In particular, in the case of this The components (P1), (P2) and (P3) are each made of a copolymer or polymer.

In a further preferred embodiment, the component P 'contains no component (P1) (100 wt .-% copolymer (P2)) and P2 contains no component (P23). Particularly preferred in this embodiment is (P) from the component (P2), i. the component (P3) does not exist.

The composition of the polymer component P can be selected according to the desired properties of the foam molding. With the copolymers used according to the invention, in particular when using AMSAN, the heat resistance is improved.

The blowing agent component (T) comprises (and preferably consists of)

(b1) 95-15% by weight, preferably 85-15% by weight, more preferably 75-15% by weight

%, (relative to (T)) C0 ₂ ,

(b2) 5-85% by weight, preferably 15-85% by weight, particularly preferably 25-85% by weight, based on T, of one or more, preferably one or two, in particular one, blowing agent from the group of -C ₄ alcohols and CC _4-carbonyl compounds, in particular C ₃ -C ₄ ketones and formates, and (b3) is preferably less than 0.2 wt .-% water, more preferably 0 to 0.18 wt %, more preferably 0 to 0.14 wt%, particularly preferably 0 to 0.1 wt%, particularly preferably 0 to 0.08 and most preferably 0 to 0.05 wt% of water ( in each case based on P).

It is preferred to use one or two, more preferably one co-propellant (b2).

Preferred alcohols are methanol, ethanol, 1-propanol, 2-propanol, 1-butanol, 2-butanol, 2-methylpropanol and tert-butanol. Particularly preferred are 2-propanol and ethanol. Particularly preferred is ethanol.

Ci-C _4- carbonyl compounds are ketones, aldehydes, carboxamides and Carbonsäureester 1 - 4 carbon atoms.

Suitable ketones are acetone and methyl ethyl ketone, preferred formates being methyl formate, ethyl formate, n-propyl formate and i-propyl formate. Preference is given to methyl formate and acetone. Especially preferred is acetone. Also preferred is a mixture of ethanol and acetone, in particular with an acetone content of at least 50 wt .-% (based on acetone and ethanol). The co-propellant (b2) and the carbon dioxide (b1) may contain water (b3). Water enters the blowing agent component T, especially by the use of technical alcohols and / or ketones. The water concentration is in the above ranges.

In a preferred embodiment, the blowing agent component is substantially anhydrous. Particularly preferred are mixtures of carbon dioxide and ethanol, carbon dioxide and acetone, carbon dioxide and methyl formate, carbon dioxide and mixtures of ethanol and acetone in the above mixing ratios.

The blowing agent component (T) is added to the polymer melt in a proportion of 1 to 12 wt .-%, preferably 1 to 8 and particularly preferably 1, 5 to 7% by weight (in each case based on P).

In a preferred embodiment, the blowing agent component (T) is added to the polymer melt in a proportion of 1 to 4.5% by weight (based on P).

A suitable composition of the blowing agent component (T) contains from 15 to 95% by weight of component (b1) and from 5 to 85% by weight of component (b2). Preferably, the proportion of component (b1) based on P at most 6 wt .-% and the proportion of component (b2) based on P at most 5 wt .-%, and the total content of components (b1) and (b2) based on P maximum 8 wt .-%. More preferably, the proportion of component (b1) based on P is at most 4.5 wt .-% and the proportion of component (b2) based on P at most 4 wt .-%.

In a particularly preferred embodiment, the blowing agent component (T) is added to the polymer melt in a proportion of from 1 to 4.5% by weight, based on P, and the blowing agent component contains from 15 to 40% by weight (based on (T) carbon dioxide - oxide (component b1)).

In a further particularly preferred embodiment, the blowing agent component (T) is added to the polymer melt in an amount of from 1 to 4.5% by weight, based on P, and the blowing agent component contains from 15 to 40% by weight (based on (T) Carbon dioxide (component (b1) and the extrusion foam has a density in the range from 50 to 130 g / l, preferably from 60 to 120 g / l.

The blowing agent component (T) may be incorporated into a molten polymer component P by any method known to those skilled in the art. For example, extruders or mixers (for example kneaders) are suitable. In a preferred embodiment, The blowing agent is mixed with the molten polymer component P under elevated pressure. The pressure must be high enough to substantially prevent foaming of the molten polymer material and to achieve homogeneous distribution of the blowing agent component (T) in the molten polymer component P. Suitable pressures are 50 to 500 bar (absolute), preferably 100 to 300 bar (absolute), more preferably 150 to 250 bar (absolute). The temperature in step (b) of the process according to the invention must be selected so that the polymeric material is in the molten state. For this it is necessary that the polymer component P is heated to a temperature above the melting or glass transition temperature. Suitable temperatures are generally at least 150 ° C, preferably 160 to 290 ° C, more preferably 180 to 250 ° C. Step (b) may be carried out continuously or batchwise, preferably step (b) is carried out continuously. The blowing agent can be added in the melt extruder (primary extruder) or in a downstream step.

In addition to the polymer (P) and blowing agent component (T), the extrusion foam board used according to the invention preferably contains an additive component (AK). Suitable additives are known to the person skilled in the art.

In a preferred embodiment, at least one nucleating agent is added to the polymer component P. Nucleating agents which may be used are finely divided, inorganic solids such as talc, metal oxides, silicates or polyethylene waxes in amounts of generally from 0.1 to 10% by weight, preferably from 0.1 to 3% by weight, particularly preferably from 0.1 to 1.5 % By weight, based on P, are used. The average particle diameter of the nucleating agent is generally in the range from 0.01 to 100 μm, preferably from 1 to 60 μm. A particularly preferred nucleating agent is talc, for example talc from Luzenac Pharma. The nucleating agent may be added by methods known to those skilled in the art.

If desired, further additives such as nucleating agents, fillers (for example mineral fillers such as glass fibers), plasticizers, flame retardants, IR absorbers such as carbon black or graphite, aluminum powder and titanium dioxide, soluble and insoluble dyes and pigments may be added. Preferred additives are graphite and carbon black.

Particularly preferably, graphite is added in amounts of generally 0.05 to 25 wt .-%, particularly preferably in amounts of 2 to 8 wt .-%, based on (P). Suitable particle sizes for the graphite used are in the range from 1 to 50 μm, preferably in the range from 2 to 10 μm.

Due to the fire protection regulations in various industries, one or more flame retardants are preferably added. Suitable flame retardants are, for example, tetrabromobisphenol A, brominated polystyrene oligomers, tetrabromobisphenol A diallyl ether, expandable graphite, red phosphorus, triphenyl phosphate and 9,10-dihydro-9-oxa-10-phosphaphenanthrene-10-oxide. Another suitable flame retardant is, for example, hexabromocyclododecane (HBCD), in particular the industrial products which essentially contain the o, ß and γ isomer and an addition of synergists such as dicumyl. Particularly preferred are brominated aromatics, such as tetrabromobisphenol A, and brominated styrene oligomers.

The total amount of additives is generally 0 to 30 wt .-%, preferably 0 to 20 wt .-%, based on the total weight of the extrusion foam.

In particular, the addition of graphite, carbon black, aluminum powder or an IR dye (for example indoaniline dyes, oxonol dyes or anthraquinone dyes) is preferred for thermal insulation.

In general, the dyes and pigments are added in amounts ranging from 0.01 to 30, preferably in the range of 1 to 5 wt .-% (based on P). For homogeneous and microdispersed distribution of the pigments in the polymer melt, it may be expedient in particular for polar pigments to use a dispersing assistant, for example organosilanes, polymers containing epoxy groups or maleic anhydride-grafted styrene polymers. Preferred plasticizers are fatty acid esters, fatty acid amides and phthalates, which can be used in amounts of from 0.05 to 10% by weight, based on the polymer component P. The preparation of the extrusion foam board used according to the invention can be carried out according to steps (a) to (e) of the process described above.

In step (b) of the process of the invention, the polymer component P is heated to obtain a polymer melt. In the context of the invention, the formation of a polymer melt is understood to mean a plasticization of the polymer component in a broader sense, ie the conversion of the solid constituents into a deformable or flowable state. For this it is necessary that the polymer component is heated to a temperature above the melting or glass transition temperature. Suitable temperatures are generally at least 150 ° C, preferably 160 to 280 ° C, more preferably 180 to 240 ° C. The heating of the polymer component can be accomplished by any means known in the art, such as by means of an extruder, a mixer (for example, a kneader). The use of melt extruders (primary extruders) is preferred. Step (b) may be carried out continuously or batchwise, with a continuous mode being preferred.

Step (c) of the process according to the invention comprises introducing the blowing agent component (T) into the polymer melt produced in step (b) to form a foamable melt.

The blowing agent component (T) is added to the polymer melt in a proportion of 1 to 12% by weight, preferably 1 to 4.5% by weight (in each case based on P). The blowing agent component (T) can be incorporated into the polymer melt (P) by any method known to those skilled in the art. For example, extruders or mixers (for example, kneaders) are suitable. In a preferred embodiment, the blowing agent is mixed with the molten polymer component under elevated pressure. The pressure must be so high that substantially prevents foaming of the molten polymer material and a homogeneous distribution of the blowing agent component is achieved in the molten polymer component. Suitable pressures are 50 to 500 bar (absolute), preferably 100 to 300 bar (absolute), more preferably 150 to 250 bar (absolute). The temperature in step (c) of the process according to the invention must be selected so that the polymeric material is present in the molten state. Therefore, step (c) is generally carried out at temperatures of at least 150 ° C, preferably 160 to 280 ° C, particularly preferably 180 to 240 ° C. Step (c) may be carried out continuously or batchwise, preferably, step (c) is carried out continuously. The blowing agent can be added in the melt extruder (primary extruder) or in a downstream step.

In a preferred embodiment, the preparation of the foamable polymer melt is carried out in XPS extruders known to the person skilled in the art, for example via a tandem structure consisting of a melting extruder (primary extruder) and a cooling extruder (secondary extruder). The process can be carried out continuously and discontinuously, wherein the polymer component (P) is melted in the primary extruder (step (b)) and the addition of the blowing agent (step (c)) to form a foamable melt also takes place in the primary extruder. Thereafter, the foamable melt provided with blowing agent in the secondary extruder to a suitable temperature for foaming of 50-180 ° C, preferably to a temperature of 80-150 ° C, cooled. Step (d) of the process of the invention comprises foaming the foamable polymer melt to obtain an extrusion foam.

The melt is to promote by a suitable device, such as a nozzle plate. The nozzle plate is heated at least to the temperature of the blowing agent-containing polymer melt. Preferably, the temperature of the nozzle plate is 60 to 200 ° C. Particularly preferably, the temperature of the nozzle plate is 1 10 to 180 ° C.

The blowing agent-containing polymer melt is transferred through the nozzle plate in a region in which a lower pressure prevails than in the region in which the foamable melt is held prior to extrusion through the nozzle plate. The lower pressure may be superatmospheric or subatmospheric. Preferably, the extrusion is in a region of atmospheric pressure. Step (d) is also conducted at a temperature at which the polymeric material to be foamed is in a molten state. In general at temperatures of 50 to 170 ° C, preferably at 90 to 150 ° C, more preferably at 1 10 to 140 ° C. Characterized in that the blowing agent-containing polymer melt is transferred in step (c) in a region in which a lower pressure prevails, the blowing agent is converted into the gaseous state. Due to the large volume increase, the polymer melt is expanded and foamed.

Optionally, one or more additives are added to the polymer component P in at least one of the steps a), b), c) and d) (step e)).

The geometric shape of the cross section of the extruded foams obtainable by the process according to the invention is essentially determined by the choice of the nozzle plate and, if appropriate, by suitable downstream devices such as plate calibrations, roller conveyor prints or tape strips, is freely selectable and can be adapted to the requirements for the composite molded article.

The extruded foams obtainable by the process according to the invention preferably have a rectangular cross-section. The thickness of the extrusion foams is determined by the height of the nozzle plate slot. The width of the extrusion foams is determined by the width of the nozzle plate slot. The The length of the extruded foam parts is determined in a subsequent working step by known methods familiar to the person skilled in the art, such as gluing, welding, sawing and cutting. Particularly preferred are extruded foam parts with a plate-shaped geometry. Plate-shaped means that the dimension of the thickness (height) is small in comparison with the dimension of the width and the dimension of the length of the molding.

In step f), at least one further layer is applied to the extrusion foam board obtained in step d) by known methods known to the person skilled in the art.

In addition to a first layer of the described extrusion foam board, the composite molded parts according to the invention contain at least one further layer. The first layer is preferably connected to at least two surfaces with one or more further layers. Further preferably, the first layer is on at least two surfaces (in the case of a rectangular cross-section top and bottom), also preferably all surfaces are connected to one or more further layers.

In one embodiment of the invention, the structure of the composite molding consists of one or more core layers, one or more cover layers and a surface layer.

In a further embodiment of the invention, the structure of the composite molding consists of a core layer and a surface layer. For example, aminoplast resin films, in particular melamine films, PVC (polyvinyl chloride), glass fiber reinforced plastic (GRP), for example a composite of polyester resin, epoxy resin, or polyamide and glass fibers, prepregs, films, laminates, for example HPL ( high pressure laminates) and CPL (continuous pressure laminates), veneers, and metal, especially aluminum or lead coatings suitable. Also suitable are fabrics and nonwovens, in particular of natural and / or synthetic fibers.

Furthermore come for a planking of the moldings (s) according to the invention all materials into consideration, which are made of wood strips, wood fibers, wood chips, wood, wood veneers, glued woods, veneers or a combination of the corresponding manufacturing processes, such as veneer or plywood panels, wood chips produced wood-based materials, for example particleboard or OSB (Oriented Strand Boards) and wood fiber materials such as LDF, MDF and HDF boards. These wood materials are made from the corresponding wood particles made with the addition of natural and / or synthetic binders by hot pressing.

Also preferred is a planking of the moldings (s) according to the invention with OSB, chipboard, HDF (high-density fiberboard) or MDF (medium-density fiberboard), in particular thin chipboard, HDF and MDF with a thickness of 2 to 10 mm.

Particularly preferred are chipboard or MDF / HDF, which are optionally surface-coated on one side, i. by painting, veneering, an applied film (melamine film) or laminate.

The planking takes place according to known, familiar to the expert methods.

The surface layer is pressed, for example, by methods known to those skilled in the art with the molded parts (s) according to the invention.

For example, in the case of an MDF board, the sizing liquor can be applied to the core layer according to the invention, the board can be laid on and pressed under temperature and pressure.

The pressing pressure is typically below 100 bar, the pressing time is usually up to 15 minutes and the pressing temperature is usually at a maximum of 100 ° C.

Adhesives may include conventional materials, for example dispersion adhesives, for example white glue, epoxy resins, formaldehyde condensation resins, such as phenolic resins, urea-formaldehyde resins, melamine-formaldehyde resins, melamine-urea-formaldehyde resins, resorcinol and phenolic resorcinol resins, isocyanate adhesives, polyurethane adhesives and Hot melt adhesive can be used.

If one or more layers of the composite molding are made of materials capable of emitting formaldehyde, it is advantageous to subject the corresponding layer or composite molding to a polyamine treatment as described in WO 2007/082837.

The composite molding according to the invention can be finished after the application of the surface layer, for example by cutting to the plate format and calibrating.

In a preferred embodiment, the composite molded part is designed as a sandwich panel, in particular for furniture construction. Such a plate, in which at least one side length is a multiple of the height, contains one or more core layers, at least one of which consists of the extrusion foam according to the invention, optionally one or more intermediate or functional layers and one or more cover layers which cover the upper and lower surfaces of the plate. Likewise, one or more edges of the sandwich panel can also be coated.

In a preferred embodiment, the edges are not coated, since this coating is individualized for the desired later application and takes place at a later point in time than the production of the sandwich plate.

The cover layer (s) are preferably selected from the materials listed above.

By way of example, the sandwich panel may contain, in addition to the core layer (s), functional layers which facilitate further processing, for example the attachment / insertion of fastening elements.

The extrusion layer according to the invention is light, homogeneous, hydrophobic, heat-resistant, pressure-insensitive in all directions and has a coefficient of expansion which is the same in the longitudinal and in the transverse direction. It can be firmly connected with standard glues and adhesives.

The composite moldings according to the invention show a combination of:

homogeneity

- high compressive strength in all directions (no pressing problems with usual pressures in the surface compression, no marking on surfaces of webs, voids, etc., maintenance of usual top pressure in edge banding machines, the foam density allows proper start-up and operation of the aggregates of edge banding machines (flush milling , Profiling, grinding, caps) - networked structure (tear-free format saw cut with standard machines and tools)

heat-resistant (edge can be coated with hot-melt adhesive in the standard temperature range of 180-210 ° C, for example 190 ° C),

suitable for surface coating with non-absorbent materials in a hot-melt system.

This represents a considerable advantage in a standard lightweight panel component, for example a shelf with the dimensions 1 mx 0.40 mx 40 mm, in which the core is coated with 2 x 4 mm HDF. In contrast, the plates with hollow chamber webs / honeycombs of the prior art do not provide closed edge surfaces. Only the two top surfaces, which usually consist of 4-8 mm chip or MDF / HDF (and the few intermediate webs in web plates), provide glue surfaces. Furthermore, the adhesion is very limited, it can only edges from min. 1, 5 mm thickness are processed. The hollow surfaces are characterized even with these strengths, the edges sound hollow and it can not be attached to commercially available fittings.

A particular advantage is that the new materials make it much easier to machine the edges, which is of great advantage since the fact that the edges are coated often does not have the plate manufacturers' special techniques and equipment.

The advantages mentioned facilitate both the coating of the edges and the attachment of connecting and fastening elements.

The composite molding according to the invention preferably has a density in the range from 50 to 300 g / l, particularly preferably 50 to 150 g / l, in particular 50 to 100 g / l. The composite molding according to the invention preferably contains no frame construction.

The composite molding according to the invention is preferably used for the production of furniture, door, room, wall, ceiling, separating or floor elements, for example in building, drywall or interior work, for example as a laminate, insulation, plate or packaging material. Preference is also given to an application in exhibition construction, automotive engineering, for example for motorhomes, boat building, yacht building and shipbuilding

The invention is explained in more detail by the examples without wishing to be limited thereby.

Examples:

Starting materials: Luran HH120 AMSAN with an acrylonitrile content of 29.5% by weight and a viscosity number of 57 ml / g (commercial product of BASF SE) Luran 3360 SAN with an acrylonitrile content of 33% by weight and a viscosity number of 60 ml / g (Commercial product of BASF SE)

Luran 3380 SAN with an acrylonitrile content of 33% by weight and a viscosity number of 80 ml / g (commercial product of BASF SE) Luran 33100 SAN with an acrylonitrile content of 33% by weight and a viscosity number of 100 ml / g (commercial product of BASF SE)

Luran 2580 SAN with an acrylonitrile content of 25% by weight and a viscosity number of 80 ml / g (commercial product of BASF SE)

Talc Talum IT Extra, Luzenac Pharma

158 K polystyrene having a viscosity number of 93-98 ml / g (commercial product of BASF SE)

Examples 1 to 17 (extruded foam boards used according to the invention)

The polymers used were continuously fed together with talc to a melt-down extruder. The total throughput of the polymers was 60 kg / h. The propellants (C0 ₂ , ethanol, acetone) were fed continuously through an injection opening introduced into the melting extruder. The blowing agent-containing melt was cooled in a subsequent cooling extruder and extruded through a slot die. The intumescent melt was calibrated with a plate calibrator and continuously withdrawn through a roller belt.

Table 1 shows inventive extrusion foams (B1-B17) in which SAN types of different molecular weights were used.

Table 1

* phr = weight fraction

Tables 1 and 3 show extruded foams B9-B17 according to the invention, in which AMSAN and SAN / AMSAN mixtures with different blowing agent components were used. Table 2

Table 3

Example 18 Production of a composite molding made of foam board, formica and veneer layer

Extruded foam boards according to Example B2 and B6 were coated with a Resopalplatte and a wood veneer. A Kauritleim was used as adhesive, the pressing conditions were 90 to 95 C and 100 atü.

In the panels obtained conventional dowels (for example HUD-1 or HLD 2 of Hilti Germany GmbH or HM Fischwerke GmbH & Co KG) could be used. In addition, the plates could be cut by means of a circular saw.

Example 19 Production of a composite molding made of foam board and beech veneer on both sides

A 20 x 20 cm ² large and 0.5 cm thick foam sheet according to Example 5 with a density of 70 g / l was pasted on both sides with a 1, 5 mm thick beech veneer (glue application 200 g / m ² white glue, screw press, pressing time 120 min . at room temperature). The resulting composite moldings meet the requirements z. B. be placed on chipboard. Example 20 Production of a composite molding made of foam board and one-sided book veneer

A 20 x 20 cm ² large and 0.5 cm thick foam sheet according to Example 18 with a density of 70 g / l was stuck on one side with a 1, 5 mm thick beech veneer (glue application 170 g / m ² white glue, screw press, pressing time 120 min . at room temperature).

EXAMPLE 21 Production of a Composite Formed Part of Foam Sheet and Double-Sided Medium-Density Fiberboard (MDF)

A 20 x 20 cm ² large and 0.5 cm thick foam sheet according to Example 18 with a density of 70 g / l was covered on both sides with 3.5 mm thick MDF boards (Homanit GmbH & Co KG, Herzberg am Harz, Germany) (Glue application 200 g / m ² white glue, screw press, pressing time 120 min at room temperature).

Example 22

To a 1 x 0.6 m x 40 mm chipboard according to Example 18 ABS and veneer edges are glued from the roll with a Schmelzschmelzklebeaggregat at a conventional melt adhesion temperature.

Result:

Heat resistance: no deformation

Glue application: full-surface hot melt application

Liability: very good and full surface

- Demolition test: only with sharp tool could be driven under the edge.

The edge broke only in fragments, tearing out core pieces of the foam. This results in an excellent adhesion from core to edge over the hotmelt adhesive as well as a clean and smooth edge course. In the plate commercially available connections and fittings can be introduced, as shown by the example of a large dowel that can be easily and without damage to the plate introduced.

Claims

claims

Composite molding, in particular for furniture construction, comprising a first layer and one or more further layers connected to the first layer, the first layer being a closed-cell extrusion foam board having a cell count of 1 to 30 cells per mm and a density of 20 to 150 g / l is made available by

(a) heating a polymer component P formed from 85 to 100% by weight of a component P 'consisting of

P1 1) from 18 to 40% by weight (based on AMSAN) of copolymerized acrylonitrile,

P12) from 60 to 82% by weight (based on AMSAN) of copolymerized α-methylstyrene (P121) or a copolymerized mixture of α-methylstyrene and styrene (P122),

P13) 0 to 22% by weight (based on AMSAN) of at least one copolymerized monomer from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimides.

and

P2) 0 to 100% by weight (based on P ') of one or more styrene

Acrylonitrile copolymers (SAN) containing, preferably consisting of, P21) from 18 to 40% by weight (based on SAN) of copolymerized acrylonitrile,

P22) from 60 to 82% by weight (based on SAN) of copolymerized styrene, and

P23) 0 to 22 wt .-% (based on SAN) of at least one copolymerized monomer selected from the group consisting of alkyl (meth) acrylates, (meth) acrylic acid, maleic anhydride and maleimide, wherein the sum of the weight percent of (P1) and (P2 ) 100% by weight, based on P ',

and P3) 0 to 15% by weight (based on P) of one or more thermoplastic polymers selected from the group consisting of styrene polymers and copolymers; Polyolefins, polyacrylates, polycarbonates (PC), polyesters, polyamides, polyether sulfones (PES), polyether ketones (PEK) and polyether sulfides (PES), to form a polymer melt,

(b) introducing from 1 to 12% by weight (based on P) of a blowing agent component T containing

b1) 15 to 95% by weight (based on T) carbon dioxide and b2) 5 to 85% by weight (based on T) of one or more co-blowing agents selected from the group consisting of C 1 -C ₄ alcohols and C 1 -C ₄ Carbonyl compounds in the polymer melt to form a foamable melt,

2. Composite molding according to claim 1, wherein the component P 'consists of the component (P1).

3. Composite molding according to claim 1, wherein the component P 'consists of the component (P2).

4. Composite molding according to claim 1, wherein the component P 'consists of one or more copolymers (P1) and one or more copolymers (P2).

5. The composite molding according to any one of claims 1 to 4, wherein the blowing agent component (b2) of the extrusion foam sheet is ethanol.

6. The composite molding according to any one of claims 1 to 4, wherein the blowing agent component (T2) of the extrusion foam sheet is acetone.

The composite molding according to any one of claims 1 to 4, wherein the blowing agent component (T2) of the extrusion foam sheet is methyl formate.

8. Composite molding according to one of claims 1 to 7, wherein the blowing agent component (T) of the extrusion foam sheet has a water content (T3) of at most 0.2

Wt .-% (based on (P)).

9. Composite molding according to one of claims 1 to 8, wherein the extrusion foam sheet has a density of 50 to 120 g / l.

10. Composite molding according to one of claims 1 to 9, wherein the extrusion foam board contains as additive component (AK) at least one nucleating agent.

1 1. Composite molding according to one of claims 1 to 10, wherein at least one further layer of aluminum, high pressure laminates, wood veneer, GRP, synthetic resin or PVC.

12. A method for producing a composite molding according to any one of claims 1 to 1 1, comprising the steps a) providing a polymer component (P), which is formed from

85 to 100 wt .-% of a component P ', consisting of

P1 1) from 18 to 40% by weight (based on AMSAN) of copolymerized acrylonitrile,

and P2) 0 to 100% by weight (based on P ') of one or more styrene-acrylonitrile copolymers (SAN), comprising, preferably consisting of,

P21) from 18 to 40% by weight (based on SAN) of copolymerized acrylonitrile,

P22) from 60 to 82% by weight (based on SAN) of copolymerized styrene, and P23) from 0 to 22% by weight (based on SAN) of at least one copolymerized monomer from the group consisting of alkyl (meth) acrylates, ( Meth) acrylic acid, maleic anhydride and maleimide, the sum of the percentages by weight of (P1) and P1 being 100% by weight, based on P ',

and

P3) 0 to 15% by weight (based on P) of one or more thermoplastic polymers selected from the group consisting of styrene polymers and copolymers, polyolefins, polyacrylates, polycarbonates (PC), polyesters,

Polyamides, polyether sulfones (PES), polyether ketones (PEK) and polyether sulfides (PES),

Heating the polymer component (P) to form a polymer melt,

Introducing from 1 to 12% by weight (based on P) of a blowing agent component T containing

b1) from 15 to 95% by weight (based on T) of carbon dioxide and b2) from 5 to 85% by weight (based on T) of one or more co-blowing agents selected from the group consisting of C 1 -C ₄ alcohols and C -C ₄ carbonyl links; in the polymer melt to form a foamable melt,

(d) extruding the foamable melt into a lower pressure region with foaming to form a closed-cell extrusion foam sheet having a density in the range of 20 to 150 g / l and a cell count in the range of 1 to 30 cells per mm, (e) optionally adding additives to the polymer component P in at least one of the steps a), b), c) and / or d)

(f) applying at least one further layer to the extrusion foam board obtained in step d).

13. Use of a composite molding according to one of claims 1 to 1 1 in furniture, in the construction industry, in exhibition construction, in the automotive industry and in boat and shipbuilding.