EP1654322A2

EP1654322A2 - Composite materials comprising plastics and wood

Info

Publication number: EP1654322A2
Application number: EP04763532A
Authority: EP
Inventors: Manfred Rätzsch; Huong-Lan Nguyen; Uwe Müller; Harald ZÖBL
Original assignee: AMI Agrolinz Melamine International GmbH
Current assignee: AMI Agrolinz Melamine International GmbH
Priority date: 2003-07-22
Filing date: 2004-07-21
Publication date: 2006-05-10
Also published as: CN1906247A; KR20060037386A; US20070267609A1; CA2532955A1; WO2005009701A3; JP2006528089A; DE10333893A1; WO2005009701A2

Abstract

The invention relates to composite materials, comprising plastics and wood, with 55 to 90 mass % of wood in the form of sawdust, wood fibres, and/or wood chippings and 45 to 10 mass % of partly cross-linked melamine resin ethers or mixtures of partly cross-linked thermoplastics and cross-linked melamine resin ethers, whereby the plastics in the composite materials can be in the form of a foam. Said materials can be produced by homogenisation of the components in the extruder, pre-impregnation of wood with melamine resins in the screw mixer and subsequent homogenisation of the components in the extruder, or by a sinter method, each followed by a subsequent moulding to give the composite material. The composite materials are suitable for application in building and in sport and leisure applications.

Description

Composites containing plastics and wood

The invention relates to plastics and wood-containing composite materials and a method for their production.

Plastics and wood-containing composite materials are known.

Composites containing wood and thermoplastics are known. EP 1 172 404 A1 describes composites which consist of polypropylene, polyethylene or polystyrene with a wood fiber content of 20 to 80% by mass. The influence of elastomers such as ethylene-propylene-diene terpolymers on the impact resistance behavior of wood fiber filled polypropylene was investigated by Oksman (Int. Conf. Woodfiber-Plast. Compos. 4 ^th 1997, 144-145). JP 2001 121 654 A2 describes laminates made of polyolefin-wood powder blends which contain polyolefin / wood powder in a mixing ratio of 1: 2 in the inner and outer layer. Also known is the surface treatment of wood powder with diisocyanates in the production of wood-polypropylene compounds (KR 9 608 119 A2). A disadvantage of the thermoplastic and wood-containing composite materials is the limited strength and toughness as a result of the low compatibility of the apolar polyolefins with the wood component.

The use of wood powder as a filler in melamine molding compositions is described in JP 52 005 854 A2 and Ulimann's Encyclopedia of Industrial Chemistry (1987), Vol. A2, p. 134. A disadvantage of these composite materials is the complex production using the pressing technology and the low flexibility of the composite materials.

Also known is the impregnation of wood fiber-synthetic fiber mixtures with melamine resins in the production of composite panels (JP 27 25 228 B2) and the use of melamine-formaldehyde resins as an impregnation resin for wood products (SE 9 803 828 A, JP 2000 108 107 A ). The aim of the invention is plastics and wood-containing composite materials which can be produced by thermoplastic processing methods and which have improved material properties.

The object of the invention is achieved by plastics and wood-containing composite materials, the composite materials according to the invention having a proportion of wood which is particulate dispersed in the crosslinked plastics and the crosslinked plastics crosslinked melamine resin ethers or mixtures of 10 to 90% by mass of partially crosslinked thermoplastics and 90 are up to 10% by mass of crosslinked melamine resin ethers,

An advantageous example of a composite material according to the invention has the following composition:

A) 55 to 90% by mass of wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips, and B) 45 to 10% by mass of crosslinked plastics, the crosslinked plastics B1) crosslinked melamine resin ether, or B2) mixtures of - 10 to 90% by mass of partially crosslinked thermoplastics, and - 90 to 10% by mass of crosslinked melamine resin ethers, where the crosslinked melamine resin ethers and the partially crosslinked thermoplastics can be present in the composite materials in a foamed form, and the composite materials 3 to 10% by mass of flame retardants .0J to 2 mass% pigments, OJ to 5 mass% stabilizers and / or 0J to 5 mass%, each based on the sum of wood and Plastics, auxiliaries can contain. The parameters can all be met together or individually.

The composite materials are preferably sheets, profiles or injection molded parts.

The particulate wood, in particular in the form of wood flour, wood particles, wood fibers and / or wood chips in the composite materials, can consist of softwood and / or hardwood.

Wood flour with a mean particle diameter of 0.01 to 0.5 mm is suitable as wood flour in the composite materials. Suitable wood particles are wood particles with an average diameter of 0.5 to 5 mm. Suitable wood granules are granules which have an average particle diameter of 1 to 5 mm. Suitable wood fibers in the composite materials are wood fibers which have an average length of 0.05 to 1 mm and a length / thickness ratio of 2: 1 to 20: 1. Suitable wood chips are wood chips with a length of 1 to 5 mm and a thickness of 0.5 to 2 mm.

Composite materials consisting of 65 to 80% by mass of wood in the form of mixtures of wood fibers and wood chips in a ratio of 1:10 to 10: 1 and 35 to 20% by mass of crosslinked plastics are preferred.

In the crosslinked melamine resin ether, the molar ratio of aldehyde component / melamine component is preferably 1.5: 1 to 4: 1.

Preferred crosslinked melamine resin are cross-linked etherified melamine resin condensates are free from the triazine rings of the melamine resin condensate bound hydroxymethyleneamino and triazine rings linking -NH-CH ₂ -O-CH ₂ -NH- - groups, in which the non-crosslinked etherified melamine resin condensates by etherification Hydroxymethylamino groups of the non-crosslinked melamine resin condensates by CrC ₁₈ alcohols and / or polyols of the type diols, triols and / or tetrols with molecular weights from 62 to 20,000 has taken place, and in which the uncrosslinked etherified melamine resin condensates have been cured thermally and / or by acid generators.

The partially crosslinked thermoplastics are preferably partially crosslinked ethylene-vinyl acetate copolymers, partially crosslinked partially hydrolyzed ethylene-vinyl acetate copolymers, partially crosslinked thermoplastic polyurethanes, partially crosslinked high molecular weight aliphatic, aromatic aliphatic polyethers and / or partially crosslinked aliphatic and / or aromatic aliphatic polyesters, in particular partially crosslinked and / or unsaturated polycaprolactones Polyester.

Partially crosslinked copolymers which have a vinyl acetate content of 4 to 50% by mass are suitable as partially crosslinked ethylene-vinyl acetate copolymers in the composite materials.

Suitable partially crosslinked partially saponified ethylene-vinyl acetate copolymers in the composite materials are partially crosslinked copolymers which have a starting vinyl acetate content of 4 to 50% by mass and in which 5 to 50 mol% of the vinyl acetate groups are saponified to vinyl alcohol groups.

Another preferred composition of the composite materials consists of 65 to 80% by mass of wood in the form of mixtures of wood fibers and wood chips in a ratio of 1:10 to 10: 1 and 35 to 20% by mass of crosslinked plastics in the form of mixtures of partially crosslinked EVA copolymers with a vinyl acetate content of 25 to 40 mass% and crosslinked melamine resin in a mixing ratio of 2: 1 to 1: 5.

Examples of partially crosslinked polyurethanes that can be contained in the composite materials are partially crosslinked thermoplastic polyurethanes based on hexamethylene diisocyanate as the diisocyanate component and diol components such as butanediol, hexanediol, dodecanediol and / or polyalkylene glycols. If the plastics in the composite materials are in foamed form, the density of the composite materials is preferably 0.6 to 1.0 g / cm ³ .

Examples of suitable flame retardants which can be contained in the composite materials according to the invention are ammonium polyphosphate, melamine cyanurate, boron trioxide, boric acid, ammonium borate and zinc borate.

Examples of suitable pigments which can be contained in the composite materials according to the invention are iron oxide, ester group-containing isoindoline pigments, anthracene fluorescent dyes, carbazole dioxazine and delta indanthrone blue pigment.

The stabilizers contained in the composite materials are preferably UV absorbers and / or radical scavengers.

Examples of suitable UV absorbers that can be contained in the composite materials according to the invention are 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) benzotriazole, 2,4-dihydroxybenzophenone and sodium 3- (2H -benzo-triazol-2-yl) -5-sec.butyl-4-hydroxybenzenesulfate.

Examples of suitable radical scavengers which can be contained in the composite materials according to the invention are bis- [2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl] ester, bis (2,2,6, 6-tetramethyl-4-piperidinyl) sebacate, N, N'- (2-hydroxyphenyl) ethanediamide and N, N'-diformyl-N, N'-di- (1-oxyl radical-2,2,6,6-tetramethyl -4-piperidinyl) -1, 6-hexanediamine.

The auxiliaries contained in the composite materials are preferably lubricants of the zinc stearate, calcium stearate and / or magnesium stearate type, and / or talc, aluminum oxide, sodium carbonate, calcium carbonate, silica and / or polytetrafluoroethylene powder non-stick agents. A plastic and wood-containing composite material is produced according to a variant with an extruder process, in which in a first process step a melt mixture of melamine resin ether, wood or thermoplastics is produced in a first extruder segment, the melt mixture is degassed after homogenization, and in a second extruder segment in the melt mixture Hardeners, thermally decomposing radical formers and / or blowing agents are metered and homogenized in the melt mixture, and flame retardants, pigments, stabilizers and / or auxiliaries can be metered in the first and / or second extruder segment, and in a second process step the wood-containing melt mixture either in heated in a third extruder segment, discharged with crosslinking and optionally foaming through a molding tool and removed as a semi-finished product or discharged from the extruder, granulated and the granules in a third process step is processed in presses, extruders or injection molding machines with crosslinking and, if necessary, foaming to give semi-finished or molded materials.

An example of an advantageous embodiment of this method is given below.

Composites according to claim 1 are produced in the extruder process, the crosslinked melamine resin ethers and the partially crosslinked thermoplastics being able to be present in the composite materials in foamed form and the composite materials 3 to 10 mass% flame retardants, 0J to 2 mass% pigments, 0J to 5 mass% Stabilizers and / or 0J to 5% by mass, each based on the sum of wood and plastics, can contain auxiliaries, in which in the a) first stage of the process in extruders with a length of 30 to 60 D, with side-flow metering devices for solid and liquid media and vacuum degassing are equipped, in a first extruder segment, melt mixtures of melamine resin ether with molecular weight from 1500 to 200000 and a molar ratio of melamine / formaldehyde of 1: 1, 5 to 1: 4, wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips with a residual moisture of up to 10% by mass and possibly thermoplastics are produced at melt temperatures of 110 to 170 ° C, whereby the mixture components can be dosed together into the feed hopper or wood can be dosed into the plastic melt after melting the melamine resin ether and, if applicable, the thermoplastic into the plastic melt or wood after melting the thermoplastic into a side flow dosing device the thermoplastic melt is metered and then the melamine resin ether can be metered to the wood-containing thermoplastic melt via a side flow metering device, the melt mixture is degassed after homogenization and in the second extruder segment at melt temperatures of 100 to 150 ° C. into the melt mixture 0J to 2% by mass, based on the melamine resin ether, hardener, 0J to 2% by mass, based on the thermoplastics, thermally decomposing radical formers, and optionally 0.2 to 4% by mass, based on the sum of thermoplastic and melamine resin ether, blowing agent medium, metered and homogenized in the melt mixture, blowing agents, hardeners and / or thermally decomposing radical formers can be used as a masterbatch containing 60 to 90% by mass of thermoplastic, and wherein 3 to 10% by mass of flame retardants, 0J to 2% by mass Pigments, 0.1 to 5 mass% stabilizers and / or 0J to 5 mass% each based on the sum of melamine resin ether, wood and thermoplastic, auxiliaries in the first and / or second extruder segment can be metered into the extruder, and in which b) second stage of the process, the wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood shavings containing melt mixture either in a third extruder segment at temperatures from heated to 150 to 240 ° C, discharged with crosslinking and possibly foaming through a molding tool and removed as a semi-finished product is pulled or discharged from the extruder, granulated, and the molding compound granulate is processed in the c) third stage of the process at temperatures of 150 to 240 ° C. in presses, extruders or injection molding machines with crosslinking and optionally foaming to give semi-finished products or molding materials.

Twin-screw extruders or extruders with a plunger screw are preferably used as extruders in the extruder process.

Another advantageous method for producing plastics and wood-containing composite materials is that the composite material is produced by a pre-impregnation process, with wood in mixers containing solutions or dispersions of melamine resin condensates in water or mixtures of water and % impregnated and dried, the melamine resin condensates etherified melamine resin condensates and / or partially etherified with CC ^ alcohols melamine resin condensates with weight-average molar masses of 150 to 50,000 and a molar ratio of melamine / formaldehyde being 1: 1, 5 to 1: 4 and the melamine resin condensates optionally to 3% by mass hardener, based on the melamine resin condensates, and then the melt mixture in the first stage of the process is made from wood pre-impregnated with melamine resins and - melamine resin ether or - thermoplastics or mixtures of melamine resin ether and thermoplastics.

In the first stage of the process, for example, wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips with a residual moisture of up to 10% by mass in mixers at 80 to 102 ° C with solutions or dispersions of melamine resin condensates in water or mixtures of 10 to 90 mass% water and 90 to 10 mass% d ^ alcohols with a solids content of 20 to 80 mass% are impregnated and dried, the melamine Resin uptake by the wood substance is 2 to 20% by mass, based on the dry wood substance, the melamine resin condensates etherified melamine resin condensates and / or partially etherified with C 1 -C ₄ alcohols melamine resin condensates with molar mass weight means of 150 to 50,000 and a molar ratio of melamine / formaldehyde 1: 1.5 to 1: 4, - in the partially etherified melamine resin condensates the proportion of the hydroxy groups not etherified with CC ₄ alcohols is 5 to 75 mol%, based on the sum of hydroxyl groups and CrGralkoxy groups in the melamine resin precondensates partially etherified with CC alcohols, is, and - the melamine resin condensates can contain up to 3% by mass hardener, based on the melamine resin condensates, and in the second process stage in extruders with a length of 30 to 60 D, which are equipped with side flow metering devices for solid and liquid media and vacuum degassing .

- In a first extruder segment, wood pre-impregnated with melamine resins in the form of wood flour, wood particles, wood granules, wood fibers and / or wood shavings containing melt mixtures consisting of melamine resin ethers with molar mass weight average from 1500 to 200000 and a molar ratio melamine / formaldehyde of 1: 1, 5 to 1: 4, or mixtures of melamine resin ethers and thermoplastics, or thermoplastics, are produced at melt temperatures of 110 to 170 ° C, whereby the mixture components can be dosed together into the feed hopper, or pre-impregnated wood after melting the melamine resin ether and / or the thermoplastic via a side flow metering device can be dosed into the plastic melt, or pre-impregnated wood after melting the thermoplastic via a side flow metering device into the thermoplastic melt. and then the melamine resin ether can be metered via a side-flow metering device to the pre-impregnated wood-containing thermoplastic melt, the melt mixture is degassed after homogenization, and in the second extruder segment at melt temperatures of 100 to 150 ° C in the melt mixture 0J to 2 mass%, based on the melamine resin ether , Hardener, 0.1 to 2% by mass, based on the thermoplastics, thermally decomposing radical formers, and optionally 0.2 to 4% by mass, based on the sum of thermoplastic and melamine resin ether, blowing agent, metered and in the melt mixture are homogenized, blowing agents, hardeners and / or thermally decomposing radical formers can be used as masterbatch containing 60 to 90% by mass of thermoplastic,

and wherein 3 to 10% by mass of flame retardants, 0.1 to 2% by mass of pigments, 0J to 5% by mass of stabilizers and / or 0J to 5% by mass in each case based on the sum of melamine resin ether, wood and thermoplastic, auxiliaries in first and / or second extruder segment can be metered into the extruder, and in the third process stage the wood mixture in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips and melt mixture

either heated to temperatures of 150 to 240 ° C. in a third extruder segment, discharged with crosslinking and possibly foaming through a molding tool, and drawn off as a semi-finished product,

- Or discharged from the extruder, granulated, and the molding compound granulate is processed in a third process stage at temperatures of 150 to 240 ° C in presses, extruders or injection molding machines with curing and optionally foaming to give semi-finished products or molding materials. Examples of suitable mixers that can be used in the pre-impregnation process for impregnating wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips with aqueous solutions or dispersions of melamine resin condensates are paddle mixers, ploughshare mixers, centrifugal mixers and mixing devices with a mixing screw.

A third method for producing composite materials according to the invention is that they are produced by a sintering process, in a) first process stage mixtures of wood and plastics, which consist of melamine resin ether or mixtures of melamine resin ether and thermoplastics or thermoplastics, are sintered in high-speed mixers, which Sinter mixture is cooled and, after cooling, the sinter mixture, hardener, thermally decomposing radical formers and / or blowing agents, flame retardants, pigments, stabilizers and / or auxiliaries are tumbled, and in a b) second process step the sinter mixture containing wood, melamine resin ether and optionally thermoplastics in presses , Extruders or injection molding machines with crosslinking and possibly foaming to semi-finished or molded materials.

For example, in the first stage of the process, mixtures of wood in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips with a residual moisture of up to 10% by mass, which impregnates with 2 to 15% by mass, based on the dry wood substance, of melamine resins and plastics, which consist of melamine resin ethers with molar mass numbers from 1500 to 200000 and a molar ratio of melamine / formaldehyde of 1: 1, 5 to 1: 4, or mixtures of melamine resin ether and thermoplastics, or thermoplastics, in high-speed mixers with residence times of 3 to 30 min and final temperatures of 90 to 180 ° C are sintered, the sintered mixture is cooled to temperatures of 50 to 120 ° C, and after cooling to the sintered mixture 0.1 to 3 mass%, based on the melamine resin ether, hardener, 0J to 2 % By mass, based on the thermoplastics, thermally decomposing radical formers, and optionally 0.2 to 4% by mass, based on the sum of thermoplastic and melamine resin ether, blowing agent, 3 to 10% by mass, in each case based on the sum of melamine resin ether, Wood and thermoplastic, flame retardants, 0.1 to 2% by mass of pigments, 0J to 5% by mass of stabilizers and / or 0J to 5% by mass of auxiliaries, and in the second process stage the wood in the form of wood flour, wood particles, Wood granules, wood fibers or wood chips, melamine resin ethers and, if appropriate, a sintered mixture containing thermoplastics are processed at temperatures of 150 to 240 ° C. in presses, extruders or injection molding machines with crosslinking and, if appropriate, foaming to give semi-finished products or moldings.

In the sintering process, the heat input in the internal mixer takes place both through the friction heating and through the jacket heating.

Wood can be used in the process variants in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips with a residual moisture of up to 10% by mass. The residual moisture refers to the amount of water that is released within 24 hours when the wood dries at 103 ° C.

In the process variants according to the invention, wood is preferably used in the form of wood flour, wood particles, wood granules, wood fibers or wood chips which contains 3 to 10% by mass of sodium borate or sodium borate / boric acid mixtures in a mass ratio of 1: 9 to 9: 1.

The content of sodium borate or sodium borate / boric acid mixtures in the wood can be achieved by impregnation from aqueous solution and subsequent drying or by powdering.

Preferred are the melamine resin ethers used in the process variants for the production of composite materials, etherified melamine resin condensates, which are free of -NH-CH ₂ -O-CH ₂ -NH- groups linking hydroxymethylamino groups and triazine rings which are bonded to the triazine rings of the melamine resin condensate, and in which the etherification of the hydroxymethylamino groups by CC ₁₈ alcohols and / or diols of the HO-R-OH type with molecular weights from 62 to 20,000. The melamine resin ethers used for the production of the composite materials are preferred by etherification of melamine resin precondensates with CC ₄ alcohols, optionally with subsequent partial etherification with C ₄ -C ₁₈ alcohols, C ₂ -C ₈ diols, polyhydric alcohols of the glycerol type or Pentaerythritol, C ₅ -C ₁₈ amino alcohols, polyalkylene glycols, hydroxyl-terminated polyesters, siloxane polyesters, siloxane polyethers, melamine-alkylene oxide adducts and / or bipolar phenol-alkylene oxide adducts and subsequent thermal condensation of the melamine resin ethers in the melt in the continuous melt Temperatures of 140 to 220 ° C produced.

Weak inorganic acids such as boric acid and / or organic acids or acid formers can be used as hardeners for the melamine resin ethers in the process variants for producing the composite materials.

Preferred hardeners for the melamine resin ethers in the processes for the production of composite materials are aliphatic C ₄ -C ₁₈ carboxylic acids, aromatic C ₇ -C ₁₈ carboxylic acids, acid formers of the type blocked sulfonic acids, alkali metal salts or ammonium salts of phosphoric acid, C _r C ₁₂ alkyl esters or C ₂ -C ₈ - hydroxyalkyl esters of C ₇ -C ₁ aromatic carboxylic acids or inorganic acids, salts of melamine or guanamines with C ₁ -C ₁₈ aliphatic carboxylic acids, anhydrides, half esters or half amides of C -C ₂₀ dicarboxylic acids, half esters or Half-amides of copolymers of ethylenically unsaturated C ₄ -C ₂₀ dicarboxylic acid anhydrides and ethylenically unsaturated monomers of the type C ₂ -C ₂₀ olefins and / or C ₈ -C ₂₀ vinyl aromatics, and / or salts of C C ₂ alkylamines or alkanolamines with -CC ₈ -aliphatic, C ₇ -C ₁₄ -aromatic or alkylaromatic carboxylic acids or inorganic acids of the hydrochloric acid, sulfuric acid or phosphoric acid type, used. Examples of aliphatic C -C ₁₈ carboxylic acids as hardeners for the melamine resin ethers are butyric acid, caproic acid, palmitic acid, stearic acid and oleic acid.

Examples of aromatic C ₇ -C ₁₈ carboxylic acids as hardeners for the melamine resin ethers are benzoic acid, phthalic acid or naphthalenedicarboxylic acid.

Examples of blocked sulfonic acids as hardeners for the melamine resin ethers are benzilmonoxime tosylate, benzilmonoxime-p-dodecylbenzenesulfonate, 4-chloro-α-tri-fluoroacetophenonoxime-benzenesulfonate, and 2-pentafluorophenylsulfonyloxyimino-4-phenyl-but-3-uterol.

Examples of alkali metal salts or ammonium salts of phosphoric acid as hardeners for the melamine resin ethers are ammonium hydrogen phosphate, sodium polyphosphate and potassium hydrogen phosphate.

Examples of CC ₁₂ alkyl esters or C ₂ -C ₈ hydroxyalkyl esters of C ₇ -C ₁₄ aromatic carboxylic acids as hardeners for the melamine resin ethers are dibutyl phthalate, phthalic acid diglycol ester and / or trimellitic acid glycol ester.

Examples of salts of melamine or guanamines with dC _t β-aliphatic carboxylic acids as hardeners for the melamine resin ethers are melamine formate, melamine citrate, melamine maleate, melamine fumarate and / or acetoguanamine butyrate.

Examples of anhydrides, half esters or half amides of C ₄ -C ₂₀ dicarboxylic acids as hardeners for the melamine resin ethers are maleic anhydride, succinic anhydride, phthalic anhydride, mono-CrCtβ-alkyl maleates, maleic acid monoamide or maleic acid mono-C ₁₈ alkylamides. Examples of mono-C Ci ₈ -alkyl maleates as hardeners for the melamine resin ethers are maleic acid monobutyl ester, maleic acid monoethylhexyl ester or monostearyl maleate.

Examples of maleic acid mono -CC ₁₈ alkyl amides as hardeners for the melamine resin ethers are maleic acid monoethylamide, maleic acid monooctylamide or maleic acid monostearylamide.

Examples of half esters or half amides of copolymers of ethylenically unsaturated C ₄ -C ₂₀ dicarboxylic acid anhydrides and ethylenically unsaturated monomers of the type C ₂ -C ₂₀ olefins and / or C ₈ -C ₂₀ vinyl aromatics as hardeners for the melamine resin ethers are half esters or half amides of Copolymers of maleic anhydride and C ₃ -C ₈ -α-olefins of the isobutene, diisobutene and / or 4-methylpentene and / or styrene type with a molar ratio of maleic anhydride / C ₃ - C ₈ -α-olefin or styrene or corresponding monomer mixtures of 1: 1 to 1: 5.

Examples of salts of C 1 -C ₁₂ -alkylamines or alkanolamines with CrC ₈ - aliphatic, C ₇ -C ₁₂ -aromatic or alkylaromatic carboxylic acids or inorganic acids of the hydrochloric acid, sulfuric acid or phosphoric acid type as hardeners for the melamine resin ethers are ethanolammmonium chloride, triethy- lammonium maleate, diethanolammonium phosphate and / or isopropylammonium p-toluenesulfonate.

Preferred in the process variants for producing the composite materials as thermoplastics are ethylene-vinyl acetate copolymers, partially saponified ethylene-vinyl acetate copolymers, thermoplastic polyurethanes, high-molecular aliphatic and / or aromatic aliphatic polyethers and / or aliphatic and / or aromatic aliphatic polyesters, preferably polycaprolactones and / or unsaturated polyester. Copolymers which have a vinyl acetate content of 4 to 50% by mass and melt indices in the range from 0.5 to 400 g / 10 min at 190 ° C./2.16 kp are suitable as ethylene-vinyl acetate copolymers in the production of the composite materials.

Suitable partially saponified ethylene-vinyl acetate copolymers in the production of the composite materials are copolymers which have a starting vinyl acetate content of 4 to 50% by mass and melt indices in the range from 0.5 to 400 g / 10 min at 190 ° C./2J6 kp, and in which 5 to 50 mol% of the vinyl acetate groups are saponified to vinyl alcohol groups.

For better meterability, ethylene copolymers with a high vinyl acetate content can be used as talc powdered granules.

Examples of thermoplastic polyurethanes that can be used in the process variants for producing the composite materials are polyurethanes based on tolylene diisocyanate, diphenylmethane diisocyanate, butane diisocyanate and / or hexane diisocyanate as diisocyanate components and butane diol, hexane diol and / or polyalkylene glycols as diol components with molar masses from 2000 to 30000.

Examples of polyethers which can be used in the process variants for producing the composite materials are preferably polyalkylene glycols with molecular weights from 20,000 to 70,000.

Examples of suitable polycaprolactones that can be used in the process variants for producing the composite materials are polycaprolactones with densities of 1.05 to 1.15 g / cm ³ at 60 ° C., viscosities in the range from 500 to 5000 Pas at 100 ° C. and melt indices in the range of 2 to 80 g / 10 min at 160 ° C / 2.16 kp. The polycaprolactones can also be ethylene oxide adducts with polycaprolactone. Radical formers, the thermal decomposition of which is below 210 ° C., of the acyl peroxide, alkyl peroxide, hydroperoxide, peroxycarbonate and / or perester type are preferably used as thermally decomposing radical formers for crosslinking the thermoplastic component in the process for producing composite materials.

Examples of suitable acyl peroxides which can be used as thermally decomposing radical formers in the production of composite materials are benzoyl peroxide, 4-chlorobenzoyl peroxide, 3-methoxybenzoyl peroxide and methylbenzoyl peroxide.

Examples of suitable alkyl peroxides which can be used as thermally decomposing radical formers in the production of composite materials are allyl tert-butyl peroxide, 1 J-bis (tert-butyl peroxy) -3,3,5-trimethyl-cyclohexane, di- (tert.-butylperoxyisopropyl) benzene, diethylaminomethyl-tert.butylperoxide, tert.butylcumylperoxide and tert.butylperoxide.

Examples of suitable peresters and peroxycarbonates which can be used as thermally decomposing radical formers in the production of composite materials are butyl peracetate, cumyl peracetate, cumyl perpropionate, cyclohexyl peracetate, di-tert.butylperadipat, tert.butylcyclobutane percarboxylate, tert.-butyl-2-butyl-2-propyl -2-oat, tert-butyl-1-methylcypropyl percarboxylate and tert-butyl perpropionate.

If ethylene-vinyl acetate copolymers and / or partially saponified ethylene-vinyl acetate copolymers are used as thermoplastics in the production process for composite materials, the necessary crosslinking can also be achieved by adding alkali metal alkoxylates such as sodium methylate, potassium methylate or sodium tert-butoxide.

In the process variants for the production of composite materials, gas-releasing propellants, in particular sodium hy- bicarbonate, azodicarbonamide, citric acid / bicarbonate propellant systems and / or acid hydrazides such as cyanuric acid hydrazide, toluenesulfonic acid hydrazide or oxo-bis-sulfonic acid hydrazide.

If the production of foamed semi-finished products or molding materials takes place in the extruder process or the pre-impregnation process in an immediately downstream process step, the foaming can also take place with the metering in of C ₃ -C ₆ -hydrocarbons such as isobutane or pentane or with metering in of inert gases as physical blowing agents. These blowing agents can also be used if the semi-finished products or molded materials are produced from the molding compound by extrusion.

The composite materials according to the invention are preferably used in the construction industry, in particular for the production of windows, doors, cladding elements and roof elements in the outdoor area, and in the sports and leisure sector for garden furniture, outdoor seating and for playground design.

The invention is illustrated by the following examples:

The theological characterization of the processing behavior in the production of the composite material in the examples was carried out with a high-pressure capillary rheometer, the evaluation of the measurement data was carried out by temperature-invariant representation of the viscosity curves after the Carreau approach:

viscosity measurement

The viscosity measurements were carried out on a high-pressure capillary rheometer, type Rheograph 2002, manufacturer Göttfert Werkstoff-Prüfmaschinen GmbH, Buchen, Germany, in accordance with DIN 53014 or ISO 11443.

The measurements were carried out with a slot nozzle with a gap height H of 2.5 mm and a gap width B of 10 mm. The diameter of the feed cylinder was 15 mm. A cross-sectional view of the test chamber of the high-pressure capillary rheometer with the slot nozzle used is shown in Fig. 1.

The pressure was measured at 4 measuring points along the flow channel

(p, / p ₂ / p ₄ / p ₅ = 27.5 / 42.5 / 72.5 / 87.5 mm from the start of the slot nozzle).

The temperature was measured at 3 measuring points along the flow channel in

Distance of 1mm from the surface of the flow channel (T,, T ₃ and T ₅ ).

evaluation

The rheological measurements give the pressures P ₁ to P _{5 of} the respective

Pressure sensor at a given stamp speed (see Figure 1). First, the wall shear stress τ _{w is} calculated from the nozzle geometry and the pressure difference between two pressure transducers. The pressure difference Δp is formed from the pressures P ₂ and P _{4 in} order to rule out any interfering effects caused by the nozzle inlet and the nozzle end.

Δp = P ₂ - P ₄ (1)

The wall shear stress, taking into account the lateral wall surfaces, results from Eq. (2) _ Δp - (B - H) ^{τw _} 2 - L - (B ₊ H) ⁽²⁾ with B - gap width, H - gap height, L - measuring gap length.

The volume throughput V is calculated from the stamp speed v _Ko , _ben .

D ² π ^{v = v} κoiben - - ^ - (3)

with D - punch diameter.

With purely wall adhesion, taking into account the finite width of the slot channel, the corrected volume throughput results _{H, k} or _r = _H - - (4)

Since the F _p factor assumes values <1, taking into account the finite

Width of the slot channel is associated with an increase in the shear rate. The viscosity is determined with the corrected volume throughput. The apparent shear rate γ _s in the rectangular gap results from Eq. (5)

The Weißenberg-Rabinowitsch correction gives the true shear rate γ _w . γ _w = ^ 3 + s) (6) 4 where s applies: s = d (iogγ _s ) (7) d (logτ _w )

The true viscosity η is η = (8) w

The viscosity at any temperature and any shear rate results when using the Ostwald-deWaele power approach

with: Φ - fluidity, m - flow index, where m <1, a _τ - temperature shift factor,

and when using the Carreau approach too

with: A, B, C - Carreau constants, where A denotes the zero viscosity.

The Arrhenius temperature _{shift factor} a _τ is used for semi-crystalline thermoplastics and is defined as

with: ΔU - activation energy at constant wall shear stress in kJ / mol, R - universal gas constant (= 8.314 kJ / mol K), T ₀ - reference temperature in K.

example 1

1 J Manufacture of thermoplastically processable melamine resin ethers

A melamine dispersion is prepared in a 30 l stirred autoclave by introducing 4.0 kg melamine in 14.2 kg methanol at 95 ° C., and after setting a pH value of 5.9 with 10% HCl in the stirred autoclave, 7.7 kg a 37% formaldehyde solution, which has been preheated to 60 ° C., is metered in under pressure, and the reaction mixture is reacted at a reaction temperature of 95 ° C. and a reaction time of 20 min.

After cooling to 30 ° C., a pH of 9 is set by adding 10% sodium hydroxide solution, and the etherified melamine resin condensate dissolved in the water-methanol mixture is transferred to a first vacuum evaporator after adding 2.5 kg of butanol which the solution of the etherified melamine resin condensate is concentrated at 82 ° C. to a highly concentrated melamine resin solution which has a solids content of 76% by mass and a butanol content of 8% by mass.

The highly concentrated solution of the etherified melamine resin is then transferred to a second vacuum evaporator and concentrated at 90 ° C. to a syrupy melt which has a solids content of 96% by mass and a butanol content of 2% by mass.

The syrupy melt is mixed in a mixing section with 2.27 kg of polyethylene glycol (molecular weight 1,000), into the feed hopper of a laboratory extruder GL 27 D44 (temperature profile 150/200/200/230/230/230/230/230/230/130/130 ° C, extruder speed 150 min ^'1 ) with vacuum degassing zones after the feed zone and after the reaction zone before the product is discharged, the reaction mixture is degassed at 800 mbar, and after a residence time in the reaction zone of 3J min, the volatile components are degassed at 900 mbar, and the emerging strand is cut in a granulator. To improve the meterability, the granules are powdered with 0.3% by mass of talc. The etherified melamine resin condensate has a weight-average molecular weight (GPC) of 24,000 and a proportion of butoxy groups of 0.3% by mass. To the Triazine rings of the melamine resin condensate-bonded hydroxymethylene amino groups and triazine rings linking -NH-CH ₂ -O-CH ₂ -NH- - groups are not detectable in the IR spectrum.

The thermoplastic melamine resin ethers listed in Table 2 were synthesized in an analogous manner according to the above working procedure. Table 2 shows an overview of batch sizes and molar mass weight average of the melamine resin ethers obtained.

1.2 Production of the composite material

In a Werner & Pfleiderer extruder ZSK 30, LD = 48, with sidestream dosing for solid and liquid media, vacuum degassing and plate tool (4.0 x 100.0 mm), the etherified melamine resin condensate 1 according to 1.1 is fed into the feed hopper at 1.86 kg / h , with 0.8 kg / h an ethylene-vinyl acetate copolymer (vinyl acetate content 28% by mass, melt index 25 g / 10 min at 190 ° C / 2J6 kg), which as a crosslinking agent 0.5% by mass di- ( contains tert-butylperoxyisopropyl) benzene, and metered in at 0.54 kg / h borax and melted at 130 ° C. and homogenized. A sidestream metering with 7.5 kg / h of wood in the form of wood fibers (average length 1 mm, average diameter 0.2 mm, residual moisture 1 mass%) and with 0.54 kg / h polyethylene glycol (molecular weight 35000 ) dosed, and the melt containing wood fibers and polyethylene glycol homogenized at a melt temperature of 130 ° C and degassed at 880 mbar. After degassing, the melt is discharged through a plate tool at 180 ° C and drawn off as a cross-linked web.

Punched out test specimens from the wood fiber composite panel have a density of 1, 22 g / cm ³ and a tensile modulus of elasticity of 3.1 GPa.

The non-crosslinked wood / melamine resin / additive compound homogenized at 130 ° can be determined by the viscosity values shown in Table 3 and by The temperature-invariant representation of the viscosity curves shown in Fig. 2 (Carrea approach, A = 1, 38 * 10 ⁵ Pa ^* s; B = 2.19 ^* 10- ¹ s; C = 9.1 ^* 10 ^_1 ; T ₀ = 125 ° C; ΔUτ = 60.8 KJ / mol) can be characterized theologically.

In an analogous manner, the composite materials listed in Table 4 were produced from the melamine resin ethers described under 1.1 in accordance with the above working instructions.

Example 2

2.1 Production of the thermoplastically processable plastic

A melamine dispersion is prepared in a 30 l stirred autoclave by introducing 4.0 kg of melamine in 14.2 kg of methanol at 95 ° C., and after setting a pH of 5.9 with p-toluenesulfonic acid in the stirred autoclave, 7.7 kg a 37% formaldehyde solution, which is preheated to 60 ° C, metered in under pressure, and the reaction mixture is reacted at a reaction temperature of 95 ° C and a reaction time of 20 min.

After cooling to 30 ° C., a pH of 9 is set by adding 10% sodium hydroxide solution. 1.2 kg of polyethylene glycol (molar mass 1000) are then added to the etherified melamine resin condensate dissolved in the water-methanol mixture. After the diol has been dissolved, the aqueous methanolic solution is transferred to a first vacuum evaporator, in which the etherified melamine resin condensate solution is concentrated at 82 ° C. to a highly concentrated melamine resin solution which has a solids content of 78% by mass.

The highly concentrated solution of the etherified melamine resin is subsequently transferred to a second vacuum evaporator and concentrated at 90 ° C. to a syrupy melt which has a solids content of 97% by mass. The syrupy melt of the melamine resin mixed with polyethylene glycol is fed into the feed hopper of a laboratory extruder GL 27 D44 (temperature profile 195/195/195/195/250/250/250/250/135/130/130 ° C, extruder speed 250) at 11 kg / h min ^"1 ) with vacuum degassing zones after the feed zone and after the reaction zone, metered and degassed at 800 mbar. In zone 9, a masterbatch based on an ethylene-vinyl acetate is added to the melamine resin melt by means of a side stream metering at 4.7 kg / h. Copolymer (vinyl acetate content 28% by mass, melt index 25 g / 10 min at 190 ° C / 2.16 kg), which as a crosslinking agent benzene 0.5% by mass di- (tert-butylperoxyisopropyl) and 5% by mass Nat - rium-3- (2H-benzotriazol-2-yl) -5-sec-butyl-4-hydroxybenzenesulfate contains, metered, and the resulting melt of the melamine resin ether / ethylene-vinyl acetate copolymer - blends at a melt temperature of 130 ° C homogenized and the emerging strand is cut in a granulator. The etherified melamine resin cond ensat has a weight average molecular weight (GPC) of 22,000. Hydroxymethylene amino groups bound to the triazine rings of the melamine resin condensate and -NH-CH ₂ -0-CH ₂ - NH- groups linking triazine rings cannot be detected in the IR spectrum. In an analogous manner, the thermoplastic melamine resin ethers listed in Table 5 were homogenized with ethylene-vinyl acetate copolymers or partially saponified ethylene-vinyl acetate copolymers to give thermoplastically processable plastic mixtures in accordance with the above procedure.

2.2 Manufacture of the composite material

In a Werner & Pfleiderer extruder ZSK 30, LD = 48, with side flow metering for solid and liquid media, vacuum degassing and plate tool 4.0 x 100, the blend of the etherified melamine resin condensate (blend A after 2J ) dosed and melted at 130 ° C. A side stream metering with 11 kg / h of wood in the form of wood fibers (average length 1.5 mm, average diameter 0.2 mm, residual moisture 0.5% by mass) and as additives with 0.8 add to the melt of the melamine resin ether kg / h polyethylene lenglycol (molecular weight 35000) and dosed with 0.8 kg / h disodium tetraborate and degassed at 880 mbar. After degassing, the melt is homogenized at 130 ° C, discharged through a 4 x 100 mm plate tool at 180 ° C, and drawn off as a crosslinked web.

Punched out test specimens from the wood fiber composite board have a density of 1, 22 g / cm ³ and a tensile modulus of elasticity of 3.2 GPa.

The composite materials listed in Table 6 were produced in an analogous manner from the melamine resin ether blends in accordance with the above working instructions.

Example 3

3J Preparation of the melamine resin impregnation solution

A melamine resin dispersion is prepared in a 30 I stirred autoclave by introducing 1.0 kg of melamine in 13.9 kg of methanol at 95 ° C., and after setting a pH of 6.0 with 10% HCl in the stirred autoclave, 2.25 kg 37% formaldehyde solution, which is preheated to 60 ° C, metered in under pressure, and the reaction mixture is reacted at a reaction temperature of 90 ° C and a reaction time of 15 min.

After cooling to 65 ° C., a pH of 9 is adjusted by adding 10% NaOH. The melamine resin condensate dissolved in water-methanol mixture, the main component of which is 2,4-dimethoxymethyl-6-hydroxymethylmelamine, is transferred to a vacuum evaporator and concentrated there to a solids content of approximately 50%.

3.2 Production of the composite material

In a screw mixer (length 2200 mm, screw diameter 35 mm) with dosing nozzle for liquid media at L / D = 6 and degassing nozzle at L / D = 40 and 50, temperature gradient from entry to the degassing nozzle 80 to 102 ° C, with 4, 9 kg / h of spruce wood chips (average length 2.8 mm, average diameter 0.9 mm, residual moisture 0.5% by mass). A melamine resin impregnation solution is sprayed over the chips at 0.9 kg / h after 3J and the chips impregnated with the melamine resin solution are discharged after degassing and drying.

In the feed hopper of a Werner & Pfleiderer twin screw extruder ZSK 30, UD 48, a 7: 3 mixture of the thermoplastically processable melamine resin ether 1 according to 1.1 and a granulate based on an ethylene-vinyl acetate copolymer (vinyl acetate content 28% by mass, melt index 150 g / 10 min at 190 ° C / 2J6 kg) dosed at 4.5 kg / h and melted at a melt temperature of 130 ° C. The spruce wood chips impregnated with the melamine resin solution and 0.5 kg / h of polyethylene glycol (molecular weight 35,000) are metered into the melt via a side-stream metering at 10 kg / h, homogeneously distributed in the melt at 130 ° C., and the mixture is vacuum degassed at 850 mbar subjected. After degassing, an EVA masterbatch containing 5% by mass of phthalic anhydride, 20% by mass of azodicarbonamide and 2.5% by mass is introduced into the melt at a melt temperature of 125 ° C. with 0.8 kg / h ammonium polyphosphate, with 1 kg / h -% contains di-tert-butyl peroxide, metered, and the melt containing wood chips discharged and granulated. The molding compound containing wood chips is melted in an extruder with a U-profile tool at 140 ° C, discharged through the U-profile tool at 180 ° C and removed as a cross-linked profile.

Punched out test specimens from the wood fiber composite panel have a density of 0.95 g / cm ³ and a tensile modulus of elasticity of 2.9 GPa. Example 4

In a Leistritz Micro 27, LD = 44 extruder with side-flow metering for solid and liquid media, vacuum degassing and plate tool (4.0 x 100.0 mm), an ethylene-vinyl acetate copolymer is loaded into the feed hopper at 3.0 kg / h (Vinyl acetate content 20% by mass, melt index 25 g / 10 min at 190 ° C / 2J6 kp) melted at 130 ° C. A side stream metering with 7.5 kg / h of wood in the form of wood fibers (average length 1 mm, average diameter 0.2 mm, residual moisture 8 mass%) and then the etherified melamine resin at 0.9 kg / h are introduced into the melt 7 (cf. 1.1), and the wood fiber-containing melt of ethylene-vinyl acetate copolymer and melamine resin ether was homogenized at a melt temperature of 130 ° C. and degassed at 850 mbar. After degassing, the wood fiber-containing melt of ethylene-vinyl acetate copolymer and melamine resin ether at a melt temperature of 150 ° C. with 0.84 kg / h of ammonium polyphosphate and at 0.84 kg / h is a polyethylene wax masterbatch containing 5 masses -% Sodium methylate, 20 mass% 2- (2-hydroxy-3-tert-butyl-5-methylphenyl) benzotriazole, 15 mass% monostearyl maleate and 10 mass% zinc stearate contains, metered, at a melt temperature of 175 ° C homogenized, discharged through a 4 x 100 mm plate tool, and drawn off as a cross-linked web.

Punched out test specimens from the wood fiber composite panel have a density of 1.2 g / cm ³ and a tensile modulus of elasticity of 5.0 GPa.

Test specimens made from the plate showed fire behavior B1 (flame retardant) in accordance with DIN 4102.

Example 5

1.0 kg of oak wood particles (residual moisture 2% by mass, average diameter 2.5 mm) and 0.3 kg of granules based on an ethylene-vinyl acetate copolymer (vinyl acetate content) are placed in a high-speed mixer (internal volume 10 l, jacket heating 55 ° C.) 28 mass%, melt index 150 g / 10 min at 190 ° C / 2J6 kg) and mixed at 3500 min ^"1 . When the melt temperature of 135 ° C is reached, the speed is reduced to 1200 min ^'1 , and after cooling to a melt temperature of 110 ° C, 0.4 kg of the thermoplastic melamine resin 5 (see 1.1) are metered into the mixture.

After a further 5 minutes, 40 g of dihydroxybenzophenone, 130 g of zinc borate, 30 g of magnesium stearate, 5 g of phthalic anhydride, 5 g of tert-butyl perbenzoate and 25 g of cyanuric trihydrazide are tumbled onto the whirled sintered mixture at 85 ° C., and the sintered mixture is discharged.

The sintered mixture containing oak wood particles is melted in a plate tool with a movable die at 155 ° C / 80 bar and foamed after the pressure has been reduced to 2 bar. The foamed cross-linked composite plate has a density of 0.82 g / cm ³ . Test specimens made from the plate showed fire behavior B1 (flame retardant) in accordance with DIN 4102.

Example 6

0.9 kg of spruce wood shavings (average length 2.8 mm, average diameter 0.9 mm, residual moisture 0.5% by mass), 0.4 kg of spruce wood fibers (average Length 0.4 mm, average diameter 0.15 mm, residual moisture 4 mass%), 0.35 kg of granules based on an ethylene-vinyl acetate copolymer (vinyl acetate content 18 mass%, melt index 150 g / 10 min at 190 ° C / 2.16 kg) and 0.10 kg polypropylene glycol (molecular weight 8000) and whirled at 3500 min ^"1. When a melt temperature of 145 ° C is reached, the speed is reduced to 1200 min ^'1 , and then Cooling to a melt temperature of 110 ° C., 0.3 kg of the thermoplastic melamine resin 1 according to 1.1 are metered onto the whirled sinter mixture.

After a further 4 min, 45 g sebacic acid bis [2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyi] ester, 170 g melamine cyanurate, 30 g zinc stearate, 5 g maleic anhydride are added to the sintered mixture and 5 g of dicumyl peroxide, and the sintered mixture was discharged. The sintered mixture containing spruce wood chips and spruce wood fibers is processed in a Ferromatic Millacron FM 60 injection molding machine (three-zone screw, L = 22 D) at a melt temperature of 185 ° C and a mold temperature of 50 ° C to form cross-linked standard test bars. The standard test rods have a density of 0.98 g / cm ³ and a tensile modulus of elasticity of 3.5 GPa and, in accordance with DIN 4102, show fire behavior B1 (flame-retardant).

Example 7

1.0 kg of spruce wood shavings (average length 2.8 mm, average diameter 0.9 mm, residual moisture 0.5 mass%), 0.5 kg of spruce wood fibers (average Length 0.4 mm, average diameter 0J5 mm, residual moisture 4% by mass), 0.25 kg of granules based on a partially saponified ethylene-vinyl acetate copolymer (starting vinyl acetate content 22% by mass, degree of saponification 30 mol%, melt index 60 g / 10 min at 190 ° C / 2.16 kg) and 0.2 kg of a thermoplastic polyurethane based on hexamethylene diisocyanate and dodecanediol and whirled at 4000 min ^"1 .

When the melt temperature of 180 ° C is reached, the speed is reduced to 1200 min ^"1 , and after cooling to a melt temperature of 120 ° C, 250 g of the melamine resin 4 according to 1.1 are metered onto the whirled sintered mixture.

After a further 4 min, 45 g of sebacic acid bis [2,2,6,6-tetramethyl-1- (octyloxy) -4-piperidinyl] ester, 200 g of disodium tetraboate, 30 g of zinc stearate, 5 g of phthalic anhydride and 5 g of di-tert-butyl peroxide are tumbled on, and the sintered mixture is discharged.

The sinter mixture containing spruce wood chips and spruce wood fibers is processed in a Ferromatic Millacron FM 60 injection molding machine (three-zone screw, L = 22 D) at a melt temperature of 200 ° C and a mold temperature of 60 ° C to form cross-linked standard test bars. The standard test rods have a density of 0.90 g / cm ³ and a tensile modulus of elasticity of 2.8 GPa and, in accordance with DIN 4102, show fire behavior B1 (flame-retardant). tables

Table 1: Flow correction factor - F _D with different ratios of nozzle widths to nozzle heights.

Table 2: batch size (in kg) and temperature profile (in ° C) for the production of thermoplastic melamine resins and the molar mass weight average (GPC) of the products obtained

^a bisphenol A oligoethylene glycol ether; Polyester of ε-caprolactone with hexanediol 1, 6; ^c Polyester of ε-caprolactone with pentaerythritol

Table 3: Viscosity values of the uncrosslinked compound shown in 1.2 (Compound I, see Tab. 4) at three melt temperatures and a nozzle gap of 2.5 mm

Table 4: Composition (in kg / h), homogenization temperature (T _h0 mo in ° C), take-off temperature (T _ab in ° C) and mechanical properties of the composite materials produced according to Example 1.2 (density in g / cm ³ , tensile E- Module in GPa) and the viscosity of the uncrosslinked compounds (ηc _o mp at 130 ° C in Pa * s).

Table 5: Composition and homogenization _temperature (Th _0mo in ° C) of the thermoplastically processable plastics produced according to Example 2Λ (resin type and batch sizes see Table 2),

Table 6: Composition (in kg / h), homogenization temperature (T _hom o in ° C), take-off temperature (T _ab in ° C) and mechanical properties of the composite materials (density in g / cm ³ , tensile modulus in GPa) , and the viscosity of the uncrosslinked compound (η _c omp at 130 ° C in Pa * s).

Claims

claims

1.Composite material with a proportion of wood and a proportion of cross-linked plastics, characterized in that the proportion of wood is particulate dispersed in the cross-linked plastics and the cross-linked plastics cross-linked melamine resin ether or mixtures of 10 to 90% by mass of partially cross-linked thermoplastics and 90 are up to 10% by mass of crosslinked melamine resin ethers,

2. Composite material according to claim 1, characterized by a proportion of wood of 55 to 90 mass% and the proportion of crosslinked. Plastics 45 to 10 mass%.

3. Composite material according to claim 1 and 2, characterized by the fact that the proportion of wood is in the form of wood flour, wood particles, wood granules, wood fibers and / or wood chips.

4. Composite material according to at least one of the preceding claims, characterized in that the proportion of wood, in particular in the form of mixtures of wood fibers and wood chips, in a ratio of 1:10 to 10: 1 65 to 80% by mass and the proportion cross-linked plastics is 35 to 20 mass%.

5. The composite material according to at least one of the preceding claims, characterized in that the crosslinked plastics are mixtures of partially crosslinked EVA copolymers with a vinyl acetate content of 25 to 40% by mass and crosslinked melamine resin ether in a mixing ratio of 2: 1 to 1: 5.

6. Composite material according to at least one of claims 1 to 5, characterized by the fact that 3 to 10% by mass of flame retardants, 0.1 to 2% by mass of pigments, OJ to 5% by mass of stabilizers and / or 0J to 5 % By mass, each based on the sum of wood and plastics, auxiliaries are included.

7. The composite material according to claim 6, characterized in that the stabilizers are UV absorbers and / or radical scavengers.

8. Composites according to claim 6 or 7, characterized by the fact that the auxiliaries are lubricants of the zinc stearate type, calcium stearate and / or magnesium stearate, and / or non-stick agents of the talcum type, aluminum oxide, sodium carbonate, calcium carbonate, silica and / or polytetrafluoroethylene powder ,

9. The composite material according to at least one of the preceding claims, characterized in that the crosslinked melamine resin ethers and the partially crosslinked thermoplastics are in foamed form.

10. The composite material according to at least one of the preceding claims, characterized in that it is present as a plate, profile or injection molded part.

11. Composite material according to at least one of the preceding claims, characterized in that the crosslinked melamine resin ethers are crosslinked etherified melamine resin condensates which are free of -NH-CH ₂ -O-CH ₂ - linking hydroxymethylamine groups and triazine rings which are bonded to the triazine rings of the meiamine resin condensate. NH - are groups in which the uncrosslinked etherified melamine resin condensates are formed by etherification of the hydroxymethylamino groups of the non- Rethered melamine resin condensates by C ^ C ^ alcohols and / or polyols of the type diols, triols and / or tetrols with molar masses from 62 to 20,000, and in which the uncrosslinked etherified melamine resin condensates have been cured thermally and / or by acid generators.

12. The composite material according to at least one of the preceding claims, characterized in that the partially crosslinked thermoplastics are partially crosslinked ethylene-vinyl acetate copolymers, partially crosslinked partially hydrolyzed ethylene-vinyl acetate copolymers, partially crosslinked thermoplastic polyurethanes, partially crosslinked high molecular weight aliphatic and / or aromatic aliphatic polyethers and / or partially crosslinked aliphatic and / or aromatic aliphatic polyesters, preferably partially crosslinked polycaprolactones and / or unsaturated polyesters.

13. A method for producing a composite material according to claim 1, characterized by the fact that the composite material is produced by an extruder process, a melt mixture of melamine resin ether, wood and optionally thermoplastics being produced in a) first process step in a first extruder segment The melt mixture is degassed after homogenization, and in a second extruder segment, hardener, thermally decomposing radical formers and / or blowing agents are metered into the melt mixture and homogenized in the melt mixture, and wherein flame retardants, pigments, stabilizers and / or auxiliaries are metered into the first and / or second extruder segment and in a b) second process step, the wood-containing melt mixture is either heated in a third extruder segment, with crosslinking and if necessary, foaming is carried out by means of a mold and withdrawn as a semifinished product or discharged from the extruder, granulated, and the granulate is processed in a c) third process stage in presses, extruders or injection molding machines with crosslinking and optionally foaming to give semifinished products or moldings.

14. The method according to claim 13, characterized in that the extruders have a length of 30 to 60 D, the melt mixture is produced in the first extruder segment at melt temperatures of 110 to 170 ° C, the metering in the second extruder segment at melt temperatures of 100 to 150 ° C, heating in the third extruder segment to 150 to 240 ° C and processing in the third stage of the process at temperatures of 150 to 240 ° C.

15. The method according to claim 13 or 14, characterized in that the melt mixture in the first process stage from melamine resin with molar mass weight means of 1500 to 200000 and a molar ratio of melamine / formaldehyde of 1: 1, 5 to 1: 4 is produced.

16. The method according to claim 13 or 14, characterized in that before the first process stage wood in mixers with solutions or dispersions of melamine resin condensates in water or mixtures of water and dC ^ Alcohols% is impregnated and dried, the melamine resin condensates etherified melamine resin condensates and / or melamine resin condensates partially etherified with dC ₄ alcohols with molar mass weight averages of 150 to 50,000 and a molar ratio of melamine / formaldehyde of 1: 1.5 to 1: 4 and the melamine resin condensates optionally contain up to 3% by mass hardener, based on the melamine resin condensates, and then the melt mixture in the first stage of the process, wood is pre-impregnated with melamine resins and - melamine resin ethers or - thermoplastics or mixtures of melamine resin ethers and thermoplastics.

17. The method according to claim 16, characterized by the fact that the solutions or dispersions have a solids content of 20 to 80% by mass, the impregnation takes place at 80 to 102 ° C, the extruders have a length of 30 to 60 D, Melt mixtures are produced in the first extruder segment at melt temperatures of 110 to 170 ° C, the dosing in the second extruder segment at melt temperatures of 100 to 150 ° C, the heating in the third extruder segment to temperatures of 150 to 240 ° C and processing in the third process stage Temperatures of 150 to 240 ° C takes place.

18. A method for producing a composite material according to claim 1, characterized in that the composite material is produced by a sintering process, wherein in a) first process step mixtures of wood and plastics consisting of melamine resin ether or mixtures of melamine resin ether and thermoplastics or thermoplastics, in Rapid mixers are sintered, the sintered mixture is cooled and, after cooling, the sintered mixture, hardener, thermally decomposing radical formers and / or blowing agents, flame retardants, pigments, stabilizers and / or auxiliaries are tumbled, and in a b) second process step the wood, melamine resin ether and optionally Sinter mixture containing thermoplastics in presses, extruders or injection molding machines with crosslinking and possibly foaming to semi-finished or molded materials.

19. The method according to claim 18, characterized in that the sintering in the first process stage in high-speed mixers with residence times of 3 to 30 min and final temperatures of 90 to 180 ° C, the cooling of the sintered mixture to temperatures of 50 to 120 ° C and the Processing of the sintered mixture takes place in the second process stage at temperatures of 150 to 240 ° C.

20. The method according to at least one of claims 13 to 19, characterized by the fact that the wood used is in the form of wood flour, wood particles, wood granules, wood fibers or wood chips and 3 to 10% by mass of sodium borate or sodium borate / boric acid mixtures in a mass ratio 1: 9 to 9: 1 contains.

21. The method according to at least one of claims 13 to 20, characterized in that aliphatic C -C ₁₈ carboxylic acids, aromatic C ₇ -C ₁₈ carboxylic acids, acid formers of the blocked sulfonic acid type, alkali metal salts or ammonium salts of phosphoric acid are used as hardeners, CτCι - alkyl esters or C ₂ -C ₈ hydroxyalkyl esters of C ₇ -C ₁₄ aromatic carboxylic acids or inorganic acids, salts of melamine or guanamines with CrCiβ aliphatic carboxylic acids, anhydrides, half esters or half amides of C ₄ -C ₂₀ dicarboxylic acids, half esters or half-amides of copolymers of ethylenically unsaturated C -C ₂₀ dicarboxylic acid anhydrides and ethylenically unsaturated monomers of the type C ₂ -C ₂₀ olefins and / or C ₈ -C ₂₀ vinyl aromatics, and / or salts of C C ₂ alkylamines or alkanolamines with CC ₁₈ -aliphatic, C ₇ -C ₁₄ - aromatic or alkylaromatic carboxylic acids or inorganic acids of the hydrochloric acid, sulfuric acid or phosphoric acid type n.

2. Use of composite materials according to at least one of claims 1 to 12 in the construction industry, in particular for the production of windows, doors, cladding elements and roof elements in the outdoor area, and in the sports and leisure sector for garden furniture, outdoor seating and for playground design.