WO2008068180A1

WO2008068180A1 - Binder mixture comprising hyperbranched polymers or hyperbranched polymer amino resins

Info

Publication number: WO2008068180A1
Application number: PCT/EP2007/062976
Authority: WO
Inventors: Daniel SCHÖNFELDER; Eva RÜBA; Bernd Bruchmann; Günter Scherr; Stephan WEINKÖTZ; Maxim Peretolchin
Original assignee: Basf Se
Priority date: 2006-12-07
Filing date: 2007-11-29
Publication date: 2008-06-12

Abstract

The present invention provides a binder comprising A) 0.01% to 100% by weight, based on the binder mixture, of hyperbranched polymers, B) 0% to 99.99% by weight, based on the binder mixture, of amino resins, and C) 0% to 90% by weight, based on the binder mixture, of a solvent. The present invention further provides the preparation of the binder mixture, the woodbase materials produced therefrom, and their use for producing furniture or packaging materials or in house construction or in interior fitting-out.

Description

Binder mixture containing hyperbranched polymers or hyperbranched polymer-containing aminoplast resins

description

The present invention relates to a binder mixture containing

A) from 0.01 to 100% by weight, based on the binder mixture, of hyperbranched polymers,

B) 0 to 99.99 wt .-%, based on the binder mixture, aminoplast resins, and

C) 0 to 90 wt .-%, based on the binder mixture, of a solvent.

Furthermore, the present invention relates to the preparation of the binder mixture, the wood-based materials produced therefrom and their use for the production of furniture, of packaging materials, in house building or interior work.

Wood-based panels are a cost-effective and resource-saving alternative to solid wood and have gained great importance especially in furniture construction and as building materials. The starting materials are wood layers of different thicknesses, wood strips, wood shavings or wood fibers from different woods. Such wood parts or wood particles are usually pressed with natural and / or synthetic binders and optionally with the addition of further additives to plate or strand-shaped wood materials.

Formaldehyde-containing adhesives are frequently used as binders, for example urea-formaldehyde resins or melamine-containing urea-formaldehyde resins. The resins are produced by polycondensation of formaldehyde with urea or melamine. In order to obtain good adhesive properties, an excess of formaldehyde is generally used. This can lead to free formaldehyde in the finished wood material. By hydrolysis of the polycondensates additional formaldehyde can be released. The free formaldehyde contained in the wood material and the formaldehyde released by hydrolysis during the lifetime of the wood material can be released to the environment.

Even wood itself can release formaldehyde to the environment, especially after a heat treatment. Coated wood-based materials generally have lower emissions of formaldehyde than uncoated substrates ("wood as raw material", Volume 47, 1989, p. 227).

Formaldehyde may cause allergies, skin, respiratory or eye irritation above certain limits in humans. The reduction of formaldehyde emission in interior components is therefore an important concern. A lowering of the formaldehyde emission by reduced addition of formaldehyde in the production leads only to a limited extent to success, since the adhesive properties of the binder deteriorate with decreasing formaldehyde concentration, and the setting of the adhesive is markedly slowed down. This leads to extended production cycles (described in "Holzwerkstoffe und Leime", M. Dunky, P. Niemz, Springer Verlag Berlin-Heidelberg, 2002, pp. 251-302).

Another way to reduce the formaldehyde emission is the addition of formaldehyde scavengers such as di- or triamines, z. As urea, to the wood particles or the formaldehyde resin. A disadvantage of this method, however, is the slower setting rate of the resin, in addition, the mechanical properties of the products are adversely affected.

The formaldehyde emission can be further reduced by post-treatment of the wood materials. Examples for this are:

G. Myers (Forest Products Journal 1986, 36 (6), 41-51) gives an overview of possible methods. These range from the application of low molecular weight formaldehyde scavengers such as urea or ammonia in solid form (for example as ammonium bicarbonate), in aqueous solution (for example urea solution) or in gaseous form (NH3) until the application of a coating which acts as a physical barrier.

Technical importance have the fumigation of wood-based materials, in particular chipboard with ammonia (RY AB process, Verko method) and the spraying of the particle board with formaldehyde scavengers (Swedspan method) obtained (E. Roffael and H. Miertzsch, adhesion 1990, 4, 13 -19). In the Swedspan process (EP-B 0006486), the chipboard is sprayed while hot with aqueous solutions of urea or other solutions containing ammonia. A disadvantage is the poorer coatability of the chipboard treated in this way. When fumigating the wood materials with ammonia (RY AB method, Verko method) has proved to be disadvantageous that with increasing storage time, the formaldehyde release increases again (E. Roffael and H. Miertzsch, adhesion 1999, 4, 13-19).

WO 2004/085125 A2 describes a method for reducing the emissions of bonded wood materials, in which mixtures of aldehyde- and isocyanate-reactive substances are applied to the straightened edges lying perpendicular to the direction of adhesive bonding.

JP 2002-273145 A describes a method for reducing the Formaldehydabga- be of wood composites, in which several, each individually suitable for reducing the formaldehyde emission measures are combined. The described aqueous formaldehyde scavenger is composed of 20 to 50 wt .-% urea, and a Residual of a non-volatile amine, a means to increase the permeability of the wood so that the urea and the non-volatile amine can penetrate into the composite, and a film-forming solid which, upon drying, becomes a physical barrier to the formaldehyde on the wood composite.

WO 2006/104455 describes a method for reducing the aldehyde emission from wood-based materials comprising a plurality of layers, in which at least one surface of a layer is treated with one or more polymers comprising primary polyamines.

In the earlier European application with the file reference 06100479.2 a method for reducing the formaldehyde emission is described, wherein on the wood material, a mixture is applied, which contains at least one polyamine and optionally up to 20 wt .-% urea, based on the mixture. The term polyamine is understood to mean compounds which have a molecular weight of at least 500 g mol ^-1 and at least 6 primary or secondary amino groups.

The disadvantage of an aftertreatment to reduce the formaldehyde content is, on the one hand, that a further process step must be integrated into the process of producing wood-based materials by the after-treatment, and, on the other hand, some of the post-treated wood-based materials have inferior mechanical properties, in particular high swelling values and poor coatability, on.

Furthermore, formaldehyde-free binders are mentioned in the prior art:

DE 43 08 089 A1 describes a binder for wood bonding comprising a) a polyamine, b) 0.01 to 0.25 moles per mole of amino group of a) a sugar and c) 0.01 to 0.25 moles per mole of amino group of a ) one or more of the group consisting of dicarboxylic acid derivatives, aldehydes having two or more carbon atoms and epoxides. Polyamine is, for example, called polyethylenimine or N, N ', N "-tris- (6-aminohexyl) melamine The examples describe a formaldehyde emission of 0.04 to 0.1 mg HCHO / m ² h.

EP 1 192 223 B1 describes a fiberboard made of polyamines or polyamine-containing aminoplast resins as a binder. As a glue solution, inter alia, an aqueous solution of an aliphatic polyamine having at least three functional groups selected from the group of primary and secondary amino groups, which has a weight average molecular weight of 600 to 1,000,000 g mol ^"1 and apart from tertiary amino groups substantially is free of other functional groups It is described that polyethyleneimine or polyvinylamine is used as the preferred polyamine. Alternative binders such as polymeric diphenylmethane diisocyanate (PMDI), tannins or water glass are described in "Holzwerkstoffe und Leime", M. Dunky, P. Niemz, Springer Verlag Berlin-Heidelberg, 2002, pages 385-436 and the literature cited therein These binders are described in "alternative adhesives for solid wood panels" by A. Weber, D. Krug, Holz-Zentralblatt 2006, no. 31, page 894 (protein adhesives for solid wood panels), as well as in "alternative binders for wood-based panels" by D. Krug, E Kehr, Holz-Zentralblatt 2005, No. 72, page 957 (technical lignins, tannins and proteins for wood-based material production) and in "Adhesives in the wood industry" by M. Dunky, Handbook of Adhesive Technology (2nd Edition, Revised and Expanded) (2003), 887-956. Editor (s): Pizzi, A .; Mittal, KL Publisher: Marcel Dekker, Inc., New York, NY.

The disadvantage of the indicated binders is their low availability (eg PMDI, tannins), poorer processability, eg. As long press time or high pressing temperature / pressure (eg PMDI, acrylate dispersions), in ecological and health concerns (eg isocyanates), in poorer performance characteristics of the produced wood materials (proteins, tannins) and / or in a higher price (eg dispersions, PMDI).

The object of the present invention was therefore to overcome the disadvantages indicated in the prior art. In particular, formaldehyde-free binders or binders with a low formaldehyde emission should be demonstrated, which are based on cost-effective starting materials and furthermore lead to good mechanical properties of the wood-based materials. In addition, such a binder should be inexpensive to produce and easy to process. Furthermore, the binder should be ecologically safe.

The object was achieved by a binder mixture containing A) 0.01 to 100 wt .-%, based on the binder mixture, hyperbranched

polymers

B) 0 to 99.99 wt .-%, based on the binder mixture, aminoplast resins and

C) 0 to 90 wt .-%, based on the binder mixture, of a solvent.

The term "hyperbranched polymers" in the present invention means highly functional, highly branched and hyperbranched polymers, hyperbranched polymers (component A) in the sense of the invention are any highly functional, highly branched and hyperbranched polymers having a weight-average molecular weight of greater than 500 g moh ¹ , whose main chain is branched, and which have a degree of branching (DB) of greater than or equal to 0.05, preferably hyperbranched polymers having a weight-average molecular weight of greater than 1000 g moh ¹ , preferably greater 1,500 g mol ^"1 and in particular having a molecular weight of 1,500 to 200,000 g mol" ¹ , understood. The degree of branching is advantageously 0.1 and greater. The degree of branching of the hyperbranched polymers is preferably between 0.2 to 0.99, particularly preferably between 0.3 and 0.95 and in particular between 0.35 and 0.75. To define the degree of branching, see H. Frey et al., Acta Polym. 1997, 48, 30.

For the purposes of the invention, "molecular weights" are to be understood as meaning the weight-average molecular weights of the hyperbranched polymers which are to be determined by means of PMMA (poly-methyl methacrylate) -calcified GPC (gel permeation chromatography).

Advantageously, the hyperbranched polymers have at least four functional end groups, preferably at least eight functional end groups, in particular at least twenty functional end groups. The number of functional groups is in principle not limited above, but the hyperbranched polymers of the present invention advantageously have less than 500 functional end groups, preferably less than 300 functional end groups, especially less than 150 functional end groups.

The functional end groups as well as the functional groups of the polymer backbone are preferably able to react with the reactive groups contained in the wood strips, wood chips or wood fibers or to interact with the wood strips, wood chips or wood fibers.

The functional groups which are reactive towards wood strips, wood shavings or wood fibers are, for example, amino, urea, thiourea, carbamate, thiocarbamate, hydroxyl, mercapto, epoxy, carbonate, ester, carboxyl or acid anhydride groups, preferably amino, urea, carbamate, hydroxyl, carbonate, ester or carboxyl groups.

The functional groups that can interact with the wood strips, wood shavings, or wood fibers are entities that do not react covalently with the wood strips, wood shavings, or wood fibers, but interactions via positively or negatively charged groups, via electronic donor or acceptor bonds, hydrogen bonds, van der Waals bonds, or polymer entanglements.

For example, hydrogen-bonding or donor and acceptor bond forming moieties can include amino, urea, thiourea, carbamate, thiocarbamate, hydroxyl, mercapto, epoxy, carbonate, ester, carboxyl, acid anhydride , Carbonyl, and / or ether groups, olefinic double bonds, conjugated double bonds, Be triple bonds, activated double bonds, for example, (meth) acrylate groups or maleic or fumaric acid or their derivatives containing groups.

Van der Waals bonds or hydrophobic interaction-generating elements can be, for example, linear or branched alkyl, alkenyl or alkynyl radicals of the chain length Ci-C120 or aromatic systems having 1-10 ring systems which are also reactive with heteroatoms, such as nitrogen, phosphorus, Oxygen or sulfur can be substituted. Also suitable are linear or branched polyether elements based on ethylene oxide, propylene oxide, butylene oxide, styrene oxide or mixtures thereof, as well as polyethers based on tetrahydrofuran or butanediol.

As a rule, the hyperbranched polymers (A) have an end group number which can be determined by titration:

In the case of hyperbranched polymers containing acid groups, the acid number in accordance with DIN 53240, Part 2 can be determined. These acid numbers are generally in the range from 1 to 500, preferably from 1 to 300, particularly preferably from 2 to 250 and in particular from 5 to 200 mg KOH / g.

In the case of hyperbranched polymers containing amino groups, the amine number can be determined on the basis of DIN 53176. In this case, however, in contrast to the specified DIN specification titrated with a glacial acetic acid / Trifluormethansulfonsäuremischung and determines the equivalence point potentiometric. These amine numbers are generally in the range from 1 to 500, preferably from 10 to 400, particularly preferably from 20 to 350 and in particular from 50 to 350 mg KOH / g.

In the case of hyperbranched polymers containing hydroxyl groups, the hydroxyl number can be determined in accordance with DIN 53240, Part 2. These hydroxyl numbers are generally in the range from 1 to 500, preferably from 10 to 400, particularly preferably from 20 to 350 and in particular from 30 to 350 mg KOH / g.

Next hyperbranched polymers of the invention (a) generally have a glass transition temperature (measured by the method ASTM D3418 - 03 with DSC) -60 to 120 ⁰ C, preferably from -40 to 100 ⁰ C.

Advantageously used as hyperbranched polymers polycondensation and polyaddition onsprodukte, preferably polyureas, polyamides, polythioureas, polyurethanes, polyesters, polycarbonates, polyethers and all combinations of mixed forms with two or more of these functional groups, such as polyamidoureas and polyamidothioureas, polyurea (thiourea ), polyurea urethanes and polythiourea urethanes, polyester ureas and polyester thioureas, polyamino ureas and polyaminothioureas, polycarbonate ureas and polyureas. lycarbonate thioureas, polyether ureas and polytherthioureas, polyamidourethanes, polyamidoesters, polyamidoamines, polyamidocarbonates, polyamidoethers, polyesterurethanes, polyaminourethanes, polycarbonateurethanes, polyetherurethanes, polyaminoesters, polyesteramides, polycarbonate esters, polyester ethers, polyaminocarbonates, polyamino ethers, polycarbonate ethers or polyureaurethanamides, etc. Particular preference is given to used as hyperbranched polymers are polyureas, polythioureas, polyurethanes, polyureas, polyamides, polyesters, polyester amides, polycarbonates, polyamines and polyethers, in particular polyureas, polyurethanes, polyureas, polyamides and polylysines particularly preferred in the case of the polyamides. Such polymers and processes for their preparation are described, for example, in EP 1 141083, in DE 102 1 1 664, in WO 2000/56802, in WO 2003/062306, in WO 1996/19537, in WO 2003/54204, in WO 2003/93343 in WO 2005/037893, in WO 2004/020503, in DE 10 2004 026 904, in WO 1999/16810, in WO 2005/026234, in WO 2005/075541, in WO 2005/044897, in WO 2003/006702 and in the earlier German patent application with the file reference 102005056592.1 and the title "Preparation and use of highly functional, highly branched or hyperbranched polylysines" described.

Very particularly preferred are hyperbranched polyureas having 4 to 300 functional end groups, a degree of branching of 0.1 to 0.99 and a molecular weight of 1,500 to 200,000 g moh ¹ , in particular hyperbranched polyureas having 10 to 200 functional end groups, a degree of branching of 0 , 2 to 0.9 and a molecular weight of 2,000 to 150,000 g moh ^1, and particularly preferred are hyperbranched polyureas having 20 to 150 functional end groups, a degree of branching of 0.3 to 0.75 and a molecular weight of 2,500 to 100,000 g moh ¹ , in particular 5,000 to 60,000 g moh ¹ .

Furthermore, hyperbranched polyamides having from 4 to 300 functional end groups, a degree of branching of from 0.1 to 0.99 and a molecular weight of from 1,500 to 200,000 g moh ¹ , in particular hyperbranched polyamides having from 10 to 200 functional end groups, are very particularly preferably branched to a degree of branching 0.2 to 0.9 and a molecular weight from 2000 to 150,000 g moh ¹ and more preferably are hyperbranched polyamides having functional end groups from 20 to 150, a degree of branching from 0.3 to 0.75 and a molecular weight of from 2,500 to 100,000 g moh ¹ , in particular 2,500 to 60,000 g moh ¹ .

Furthermore, particularly preferred are hyperbranched polylysines having 4 to 300 functional end groups, a degree of branching of 0.1 to 0.99 and a molecular weight of 1,500 to 200,000 g moh ¹ , in particular hyperbranched polylysines having 10 to 200 functional end groups, a degree of branching of 0.2 to 0.9 and a molecular weight of 2,000 to 150,000 g moh ¹ and particularly preferred are hyperbranched polylysines having 20 to 150 functional end groups, a branching degree of from 0.3 to 0.75 and a molecular weight of from 2,500 to 100,000 g moM, in particular from 2500 to 60,000 g mol. ¹

The hyperbranched polymers can be prepared by all methods of preparation known to those skilled in the art.

1.) those monomers which already contain both groups required for the polycondensation or polyaddition reaction in one and the same monomer, so-called ABχ monomers, such as, for example, AB 2, such as, for example, lysine, are advantageously used for the preparation of the hyperbranched polymers AB3 monomers, or 2) those containing the reactive groups of different monomers, such as beipsielsweise A2 and B _x monomers, for example B3 or B4 monomers. In this case, groups of the type A are those groups which can react according to the same type of reaction, for example nucleophilic groups, but which need not necessarily be of the same chemical type. Thus, for example, an A _x molecule can contain both x identical amino groups and also consist of different types of amino groups (eg primary and secondary amino groups), the number of which gives x in total, or else contain different groups such as amino and alcohol groups Sum also gives x, which thus have different reactivities, but nevertheless all can react according to the same type of reaction, in this case as a nucleophile. In contrast to the pure A2 molecules, the latter molecules are often also referred to in the literature as AA ^* molecules (or generally as A _x A ^* _y molecules) in order to determine the different chemical nature or the different reactivity of the A groups To express. In the present specification, the term A _{x is} used synonymously for all these subgroups. The same applies to the B _x molecules. In the case of the B groups, the respective reaction type is of course complementary to the reaction type of the A groups. Thus, for example, electrophilic groups are to be selected as B groups if the corresponding A groups are nucleophilic. For the preparation of hyperbranched polymers according to the principle 2.) all difunctional monomers and / or their derivatives are formally combined into a group A2. These have the functionality fA = 2. In addition, all other monomers or their derivatives are combined into another group B _x . These are essentially monomers having a functionality greater than 2, but may also be those which have a functionality of less than 2 and thus function as chain terminators. However, the number-average functionality of the group B _x has to be greater than 2 overall for the preparation of hyperbranched polymers: f 2> 2. Advantageously, these two monomer mixtures A 2 (with functionality f A = 2) and B _x (with functionality f 2>) in a molar ratio of A2: B _x = f: 1 to 1: 2, preferably of A2: B _x = 3: 1 to 1: 2, more preferably of A2: B _x = 2.5: 1 to 1: 1, 5 and most preferably in the ratio of A2: B _x = 1, 8 to 2.2: 1 or in the ratio of 0.8 to 1, 2: 1, 0 polycondensed. Advantageously, the hyperbranched polyureas are prepared according to the synthesis processes described in WO 2005/075541, WO 2005/044897, WO 2003/066702, the hyperbranched polyamides according to the synthesis processes described in WO 2006/018125, the hyperbranched polylysines according to the methods described in the earlier German patent application internal reference 102005056592.1 and entitled "Preparation and Use of Highly Functional, High or Hyperbranched Polylysines".

Polyurea is advantageously prepared in which one or more ureas are reacted with one or more amines having at least two primary and / or secondary amino groups, at least one amine having three primary and / or secondary amino groups (WO 2005/075541). Particularly suitable ureas are described in WO 2005/075541 on page 4, lines 3 to 37; Particularly suitable amines are described on page 4, line 39 to page 6, line 20. The preferred reaction of the ureas with the di- or polyamine is described on page 6, line 22 to page 7, line 17 in WO 2005/075541.

Polyureas based on carbonates and polyamines are advantageously prepared by reacting one or more carbonates with one or more amines having at least two primary and / or secondary amino groups, where at least one amine has three primary and / or secondary amino groups (WO 2005/044897). Particularly suitable carbonates are described in WO 2005/044897 on page 4, lines 9 to 31; Particularly suitable amines are described on page 4, line 33 to page 6, line 22. The preferred reaction of the carbonates with the di- or polyamine is described on page 6, line 24 to page 7, line 21 in WO 2005/044897.

Polyureas based on di- or polyisocyanates and di- or polyamines are advantageously prepared by reacting in step a) at least one difunctional blocked di- or polyisocyanate with at least one at least difunctional primary and / or secondary amine with elimination of the blocking agent and the reaction products from step a) in a step b) react by intermolecular conversion to a highly functional polyurea (WO 2003/066702). The process is described in more detail on page 4, line 21 to page 6, line 11 and on page 7, line 39 to page 15, line 18 in WO 2003/066702. Particularly suitable di- or polyisocyanates are described on page 6, line 36 to page 7, line 29 of WO 2003/066702; Particularly preferred amines are described on page 6, lines 13 to 34.

Polylysine is preferably prepared in which

- (A) a salt of lysine with at least one acid,

(B) optionally at least one amino acid other than lysine, - (C) optionally at least one di- or polycarboxylic acid or its copolyme-risersfähige derivatives and

- (D) if appropriate, at least one diamine or polyamine or their copolymerizable derivatives, - (E) optionally in at least one solvent at a temperature of 120 to 200 ⁰ C reacted

- in the presence of at least one catalyst (F) selected from the group consisting of

- (F1) tertiary amines and amidines, - (F2) basic alkali metal, alkaline earth metal or quaternary ammonium salts and

- (F3) alkoxides, alkanoates, chelates or organometallic compounds of the metals of groups INA to VIIIA or IB to VB in the Periodic Table of the Elements

(older German patent application with the internal file reference 102005056592.1). The synthesis process is described in more detail in the description of the earlier German patent application with the internal file reference 102005056592.1.

The term "aminoplast resins" in the present invention is understood as meaning all resins known to the person skilled in the art based on urea, formaldehyde, melamine, and / or phenol such aminoplast resins are generally known and are described, for example, in Ullmann's Encyclopedia of Industrial Chemistry, 1996 VCH Verlagsgesellschaft , Vol. A 2, chapter "Amino Resins" or "wood materials and glues", M. Dunky, P. Niemz, Springer Verlag Berlin-Heidelberg, 2002, page 249ff and the literature cited therein.

Advantageously, urea-formaldehyde resins, urea-melamine-formaldehyde resins, melamine-urea-phenol-formaldehyde and / or melamine-formaldehyde resins are used in the binder according to the invention.

The solids content of the aminoplast resins is advantageously from 50 to 70%.

The amino resins can be prepared by all known methods of preparation. For example, typical production methods of aminoplast resins are described in "Holzwerkstoffe und Leime" by M. Dunky, P. Niemz, Springer Verlag Berlin-Heidelberg, 2002, pages 249-385 or in WO 2005/1 13625. Water is advantageously used as the solvent.

The term conventional additives are to be understood as meaning all additives known to the person skilled in the art, for example waxes, paraffin emulsion, flame-retardant additives, wetting agents, salts.

Advantageously, the binder mixture according to the invention contains A) 0.01 to 60 wt .-%, preferably 1 to 50 wt .-%, in particular 5 to 30 wt .-%, based on the binder mixture, hyperbranched polymers,

B) 0.1 to 70 wt .-%, preferably 20 to 70 wt .-%, particularly preferably 30 to 60 wt .-%, in particular 40 to 50 wt .-%, based on the binder mixture, amino resins, and

C) 10 to 99.89 wt .-%, preferably 20 to 80 wt .-%, in particular 30 to 50 wt .-%, based on the binder mixture, solvent, preferably water.

The weight data refer to the pure, undiluted substances or to the solid.

Optionally, adjust the pH of the hyperbranched polymer to the aminoplast resin system. For example, the pH is adjusted to 5 to 11, preferably 6 to 10, especially 7 to 9.

Furthermore, the aminoplast-containing binder mixtures according to the invention immediately before processing to shorten the curing times with a hardener, z. As a carboxylic acid such as formic acid or an ammonium salt.

Furthermore, from 0 to 20% by weight, preferably from 0 to 5% by weight, in particular from 0 to 1% by weight, based on the binder mixture, of customary additives known to the person skilled in the art may be added to the binder mixture according to the invention.

The binder preferably contains

1 to 40 wt .-%, based on the binder, polyureas, having 10 to 200 functional groups and a molecular weight of 2000 to 150 000 g mol "¹; 20 to 70 wt .-%, based on the binder, urea-formaldehyde resins with a weight ratio of urea to formaldehyde of 1.5: 1 to 2.5: 1, furthermore preferred are resins which, in addition to formaldehyde and urea, contain up to 15% of methylamine and 20 to 80% by weight on the binder, water.

Preferably, the binder contains 5 to 60 wt .-%, based on the binder, polylysines having 20 to 150 functional groups and a molecular weight of 2500 to 100 000 g moM; 20 to 70 wt .-%, based on the binder, urea-formaldehyde resins having a weight ratio of urea to formaldehyde of 1, 5: 1 to 2.5: 1, furthermore resins are preferred, in addition to formaldehyde and urea up to 15 Contain% methylamine, and

20 to 80 wt .-%, based on the binder, water. Furthermore, aminoplast resin-free binders are preferred, in particular those having from 1 to 99% by weight, preferably from 5 to 80% by weight, in particular from 10 to 60% by weight, based on the binder mixture according to the invention, of hyperbranched polymers.

Furthermore, the present invention relates to a process for preparing the binder mixture according to the invention, in which the hyperbranched polymers, optionally amino resins, water and other additives are mixed at a temperature of 15 to 90 ⁰ C. If appropriate, the pH of the hyperbranched polymers is adjusted before mixing or the pH of the binder mixture is adjusted.

Optionally, the hyperbranched polymers can already be partially or completely present during the preparation of the amino resins.

Furthermore, the present invention relates to a method for producing the binder mixture according to the invention, in which the hyperbranched polymers and the aminoplast resin are applied separately to the wood chips or fibers.

The present invention furthermore relates to wood-based materials containing wood fibers and / or wood chips glued to the binder mixture according to the invention. Consequently, the present invention relates to the use of hyperbranched polymers for the production of binders for wood-based materials.

The binder mixture according to the invention is applied by conventional methods to the cellulose-containing wood fibers and / or wood chips. When gluing the binder mixture according to the invention is used in such amount that for 100 g atro fibers or chips in the case of an aminoplastfreien binder advantageously 0.1 to 500 g, preferably 0.1 to 30 g, more preferably 0.5 to 15 g and in particular 1 to 10 g of binder, in the case of an aminoplast resin-containing binder advantageously 0.1 to 500 g, preferably 0.5 to 30 g, more preferably 2 to 25 g and especially 5 to 15 g of binder used.

Finally, the glued cellulosic fibers, chips, veneers or strands are pressed by a conventional method to wood-based materials. For this purpose, usual cherweise generated by scattering the glued cellulosic fibers or chips to a substrate, a fiber / chips mat and this is pressed at temperatures of from 80 ⁰ C to 250 ° C and at pressures from 5 to 50 to wood-based materials ( "Handbook of Chipboard Technology "H.-J. Deppe, K. Ernst, 4th ed., 2000, DRW - Verlag Weinbrenner GmbH & Co., Leinfelden-Echterdingen, page 232 - 254." MDF - Medium Density Fiberboard "H.-J. Deppe, K. Ernst, 1996, DRW - Verlag Weinbrenner GmbH & Co., Leinfelden-Echterdingen, page 93 - 104). Wood-based materials are all materials which are made of wood strips, such as veneer boards or plywood boards, wood-based panels made of wood chips, for example chipboards or OSB boards, and wood-fiber materials such as LDF, MDF and HDF boards. These wood-based materials are produced from the corresponding wood particles with the addition of natural and / or synthetic binders by hot pressing. Advantageously, wood-based materials containing formaldehyde or formaldehyde-free binders are produced by the process according to the invention. Preference is given to OSB, wood fiber and chipboard.

Furthermore, the present invention relates to the use of the invention

Wood-based materials for the production of furniture, packaging materials, in building construction, in drywall or interior work, for example as a laminate, insulation material, wall or ceiling element.

Further embodiments of the present invention can be taken from the claims, the description and the examples.

Examples

1 Preparation of hyperbranched polymers

1.1 List of the used educts or their abbreviations in the tables (in brackets)

1 a: urea, urea (U)

1 b: diethyl carbonate (DEC)

2: tris (2-aminoethyl) amine (TAEA)

3: Lysine (Lys)

1.2 Analysis of the hyperbranched polymers used according to the invention

The hyperbranched polymers were analyzed by gel permeation chromatography with a refractometer as detector. Hexafluoroisopropanol (HFiP) was used as the mobile phase in the case of polyureas; polymethyl methacrylate (PMMA) was used as the standard for determining the molecular weight.

The determination of the amine number was carried out in accordance with DIN 53176. Here, however, in contrast to the specified DIN specification titrated with a glacial acetic acid / trifluoromethanesulfonic acid and the equivalence point determined potentiometrically.

The characterization of the polylysine is listed in the corresponding experimental specification. 1.3 Preparation of hyperbranched polyureas

1.3.1 Synthesis of hyperbranched polyureas containing predominantly amino end groups in addition to urea end groups.

Examples PoIyI - Poly3:

1 equivalent of urea (1 a) and 1 equivalent of a trifunctional amine 2 were added

Room temperature in a round bottom flask of appropriate size, equipped with a stirrer, reflux condenser, internal thermometer and gas discharge tube, initially charged and heated to about 100 ⁰ C with stirring. The resulting ammonia was introduced via the gas discharge tube connected to a gassing frit in a scrubber with hydrochloric acid, aqueous solution (CHCI = 30 wt .-%). In this case, in the scrubber, an appropriate amount of hydrochloric acid, added with a few drops of an indicator solution (eg Bromophenol Blue), submitted, which has met the target conversion (50 - 100%) formed amount of ammonia. In the course of the reaction, the temperature was increased stepwise (about 10 ⁰ C temperature increase per 1 h reaction time, maximum temperature: 220 ⁰ C) until a color change of the indicator was detected in the scrubber. Thereafter, the product was cooled, diluted with water and analyzed.

Overview of synthesized hyperbranched polyureas:

Eg starting material 1 starting material 2 water M _n Mw

[% By weight] [g moi- ¹ ] [g moi- ¹ ]

PoIyI M 1 a (U) 2 (TAEA) 50 6,200 21,000

Poly2 1 a (U) 2 (TAEA) 50 7,300 29,200

Poly3 1 a (U) 2 (TAEA) 50 9,300 57,000

1.3.2 Synthesis of hyperbranched polyureas containing predominantly amino end groups in addition to carbamate end groups (urethane groups).

Example Poly4:

1 equivalent of diethyl carbonate (1 b) and 1 equivalent of a trifunctional amine 2 were placed at room temperature in a round bottom flask of appropriate size, equipped with a stirrer, reflux condenser and internal thermometer and heated with stirring to about 130 ⁰ C. In this case, due to the formation of the elimination product ethanol in the course of the reaction, the boiling point decreased to about 100 - 120 ⁰ C. Subsequently, the apparatus was equipped with a descending condenser and a distillation receiver instead of the reflux condenser and the resulting ethanol was distilled off. Ethanol was removed until the respective target conversion (50 - 100%) was achieved. In the course of this reaction section, the temperature for this purpose was increased stepwise (about 10 ⁰ C temperature increase per 1 h reaction time, ma- Maximum temperature: 160 ⁰ C) until the desired amount of ethanol was distilled off. Thereafter, the product was cooled and analyzed.

Overview of the synthesized hyperbranched polyurea:

Eg starting material 1 starting material 2 water M _n Mw [wt .-%] [g moi- ¹ ] [g mol ^"1 ]

Poly4 I b (DEC) 2 (TAEA) 0 2,800 6,700

1.4 Synthesis of hyperbranched polyamides (polylysines)

Example Poly5:

In a 4L four-necked flask equipped with stirrer, internal thermometer, gas inlet tube and descending condenser with vacuum port and receiver were added 1000 g of L-lysine hydrochloride, 218 g of sodium hydroxide, 100 g of water and 0.3 g of dibutyltin dilaurate and the mixture heated with stirring to an internal temperature of 150 ⁰ C. After 5 hours of reaction time, water was distilled off under reduced pressure (200 mbar), after passing the largest amount of water, the temperature slowly increased to 180 ⁰ C and the pressure was reduced to 10 mbar. After 8 hours, 240 g of water were collected as distillate. The high-viscosity polymer was discharged hot, poured onto a cooling plate and then finely ground in a mortar. For further processing for the binder systems, the product was dissolved in water to give a 50 wt% solution. To determine the molecular weight distribution, the aqueous solution was filtered and measured by GPC. The GPC analysis was carried out by column combination of OHpak SB-803 HQ and SB-804 HQ (Shodex) in aqueous solution with the addition of 0.1 mol / L sodium bicarbonate at 30 ⁰ C at a flow rate of 0.5 mL / min and polyethylene oxide as standard. For detection, a UV detector was used, which worked at a wavelength of 230 nm.

Overview of the synthesized hyperbranched polylysine:

Example educt Water M _n Mw [% by weight] [g moi- ¹ ] [g mol ^"1 ]

Poly δ 4 (Lys) 50 2.330 1 1. 050

2 Formaldehyde-free binders 2.1 Preparation of formaldehyde-free binders

The formaldehyde-free binders were prepared by mixing the hyperbranched polymers compiled in Table 1 with water at room temperature. Table 1 :

2.2 Production of the wood-based materials according to the invention with the aid of the binders according to 2.1

An MDF plate (30 × 30 cm) having a density of 750 kg / m ³ and a thickness of 8 mm was prepared using the binder according to Table 1, the binder being in a solid amount g per 100 g fiber fibers as indicated in Table 2 was used. The pressing was carried out at a pressure of 4 N / mm ² , a pressing temperature of 200 ⁰ C and a pressing time of 120 s.

Table 2:

2.3 Analysis of the wood-based materials produced according to 2.2

The transverse tensile strength was determined according to EN 319. The swelling values were determined in accordance with EN 317. The results are summarized in Table 3.

Table 3:

3. Binder containing hyperbranched polymer and urea-formaldehyde condensation resin

3.1 Preparation of the binder containing hyperbranched polymer and urea-formaldehyde condensation resin

A 50% hyperbranched polymer solution adjusted to pH 7 with formic acid was mixed with a urea-formaldehyde condensation resin (Kaurit® glue 340, 68% solid resin content) at room temperature with stirring. Water was added to obtain a 50% solution. The hyperbranched polymers used and the proportions in the binder mixture are summarized in Table 4.

Table 4:

3.2 Production of MDF boards using the binders according to 3.1

An MDF plate (30 × 30 cm) having a density of 750 kg / m ³ and a thickness of 8 mm was prepared using the binders listed in Table 4, the binder being in an amount of 9 g solid per 100 g of atro fibers was used. The pressing was carried out at a pressure of 4 N / mm ² , a pressing temperature of 200 ⁰ C and a pressing time of 120 s. The conditions of the individual experiments are summarized in Table 5.

Table 5:

3.3 Analysis of the wood materials produced according to 3.2

The transverse tensile strength was determined according to EN 319. The determination of the swelling values was carried out in accordance with EN 317.

The formaldehyde emission was determined by desiccator method (JIS A 5908). Each desiccator measurement was carried out with 10 test specimens.

The formaldehyde emission was carried out by perforator method EN 120. The results are summarized in Table 6.

Table 6:

3.4 Production of particle boards using the binders according to 3.1

A chipboard (30 × 30 cm) having a density of 650 kg / m ³ and a thickness of 19 mm was produced using the binders summarized in Table 4, the binder being 9 g Solid per 100 g of atro fibers was used. The pressing was carried out at a pressure of 4 N / mm ² , a pressing temperature of 200 ⁰ C and a pressing time of 120 s.

The conditions of the individual experiments are summarized in Table 7. Table 7:

3.5 Analysis of the wood-based materials produced according to 3.4

The transverse tensile strength was determined according to EN 319.

The determination of the swelling values was carried out according to EN 317.

The formaldehyde emission was determined by desiccator method (JIS A 5908).

Each desiccator measurement was carried out with 10 test specimens.

The formaldehyde emission was carried out by perforator method EN 120.

The results are summarized in Table 8.

Table 8:

Claims

claims

1. containing binder mixture

B) 0 to 99.99 wt .-%, based on the binder mixture, aminoplast resins, and

C) 0 to 90 wt .-%, based on the binder mixture, of a solvent.

2. A binder according to claim 1, wherein the hyperbranched polymers have at least four functional groups.

3. A binder according to claim 1 or 2, wherein the hyperbranched polymers have at least one degree of branching greater than or equal to 0.05.

4. A binder according to claims 1 to 3, wherein the hyperbranched polymers have a molecular weight of greater than 500 g Moh ¹ .

5. Binder according to claims 1 to 4, wherein the hyperbranched polymers of amino, urea, thiourea, carbamate, thiocarbamate, hydroxyl, mercapto, epoxy, carbonate, ester, carboxyl and / or or acid anhydride groups as functional groups.

6. The binder according to claims 1 to 4, wherein polyureas, polyamides, polythioureas, polyurethanes, polyesters, polyamines, polycarbonates, polyethers and combinations thereof are used as the hyperbranched polymers.

7. A binder according to claims 1 to 4, wherein as hyperbranched polymers polyureas, polyamides and / or polylysines are used.

8. A binder according to claims 1 to 7, comprising

5 to 30 wt .-%, based on the binder, hyperbranched polymers, 40 to 50 wt .-%, based on the binder, aminoplast resins and 30 to 50 wt .-%, based on the binder, water.

9. Use of hyperbranched polymers for the production of binders for wood-based materials.

10. wood material comprising glued with a binder according to claim 1 wood fibers and / or wood chips.

1. Use of the wood-based material according to claim 10 for the production of furniture, packaging materials, in construction, drywall or interior work.