Process for producing a laminate from wood and a hardenable composition

Abstract

The present invention relates to a method for producing a laminate, characterized in that - a wood body is provided, - a hardening composition in liquid state is applied to it, - the composition hardens, the composition containing at least one organic binder and at least 80% by weight, based on the total composition, of inorganic fillers. The method allows a permanent bond between the wood body and the composition based on organic binders and having a high content of inorganic fillers. The laminate obtained from the method is relatively light, stable, strong and particularly suitable as a permanent component for building structures, in particular as a ceiling element.

Description

[Technical field]

[0001] The present invention relates to a method for producing a laminate, to the laminate and to its use as a component in building construction. [Background technology]

[0002] Wood, a renewable raw material, has been used as a building material since time immemorial and has the additional advantages of durability over mineral building materials such as concrete, in particular high tensile strength in addition to low density and attractive appearance. The disadvantages of wood as a building material are mainly its poor fire resistance and sound conductivity (which makes it difficult to achieve fire and sound insulation) and its swelling and shrinking properties under the influence of moisture. The combination of wood and mineral building materials as a hybrid system can combine the mutual advantages of the two building materials, since wood absorbs tensile forces and mineral building materials can absorb compressive forces. This can be used, for example, for roof structures that have a relatively low specific weight and low overall height as well as high load-bearing capacity and bending stiffness, and therefore, in addition to good fire and sound insulation properties, can also be used for large spans. To achieve such properties, it is important to bond wood and mineral building materials, which are fundamentally different materials, with maximum shear resistance and durability by suitable bonding methods, which has been attempted in various ways in the prior art.

[0003] A typical course of action in the bonding of wood to mineral building materials such as concrete is to bond the hardened concrete body to the wood by means of metallic fastening systems such as screws, bolts, clamps or anchors. Although such bonds are stable and durable, they are often complex to manufacture and visually unpleasing. A further option is to establish a mechanically stable interdigitation with the concrete, for example by means of notches or slots in the wood, since the liquid concrete hardens in contact with the wood body. However, such bonds often have insufficient stability and durability, due to, among other things, movements of the wood as a result of shrinkage or expansion due to increased humidity or mechanical stress.

[0004] Bonding of wood to hardened concrete is also known, however, typically requires complex pre-treatment of the concrete surface in which the cement skin on the concrete surface is mechanically removed to avoid inhibiting the curing of the adhesive and to ensure a stable and durable bond.

[0005] WO 99 / 02796 and M. Brunner et al., Materials and Structures (2007) 40:119-126, describe the bonding of wood to concrete with adhesives in a wet-on-wet process and the problems that arise. The laminates thus obtained often break under mechanical stress or at the adhesive interface as a result of the swelling and shrinking properties of wood with changes in humidity. Furthermore, the curing reaction of the adhesive is often inhibited by the fresh concrete, which results in insufficient bond strength and thus a non-durable and / or permanent bond. Summary of the Invention [Problem to be solved by the invention]

[0006] It is an object of the present invention to provide a hybrid system comprising wood and mineral building materials that is easily manufacturable and suitable as a building element in building structures, overcoming the drawbacks of the prior art. [Means for solving the problem]

[0007] This object is surprisingly achieved by a method for producing a laminate as claimed in claim 1. This comprises laminating a wooden body with a curable composition applied in liquid form, which contains at least one organic binder, preferably based on an epoxy resin or a polyisocyanate, and at least 80% by weight of an inorganic filler.

[0008] The method of the invention can be carried out easily and quickly. The composition applied in liquid form hardens quickly, shows almost no shrinkage, can be exposed to initial stresses and does not release moisture or dampness like mineral building materials incorporated in cementitious form. The result is excellent adhesion of the hardened composition on the wood body, even without complex pretreatment of the wood surface. The resulting laminate is mechanically durable and impact resistant. It has high compressive strength and high vibration stiffness, even when the layer thickness of the applied composition is small and there is no steel, textile or fiber reinforcement. In addition, it shows a low coefficient of thermal expansion, good thermal insulation properties, is not susceptible to corrosion and is particularly insensitive to the action of moisture or frost due to the effective impregnation of the wood body with the impermeable hardened composition.

[0009] The method of the present invention allows the production of laminates with excellent suitability as permanent components in building structures, especially as roof elements, which have high demands in terms of appearance, sound insulation, strength and stability. Furthermore, the method of the present invention allows the use of hardwood in the construction sector, which is often not possible due to its high tendency to absorb water compared to softwood, especially in combination with ready-mix concrete. The composition used in the method of the present invention also acts as a moisture barrier, protecting the wood side of the laminate from water penetration from above. The laminates obtained from the method are relatively light, stable and durable, making them particularly suitable as permanent components in building structures, especially as roof elements.

[0010] Further aspects of the invention are the subject matter of further independent claims. Particularly preferred embodiments of the invention are the subject matter of the dependent claims.

[0011] Methods of carrying out the invention The present invention relates to a method for producing a laminate, the method comprising the steps of: -Wood body is provided, a curable composition in liquid form is applied thereto, - The composition hardens, The composition is characterized in that it contains at least one organic binder and at least 80% by weight, based on the total composition, of an inorganic filler.

[0012] "Inorganic filler" refers to powdered or granular inorganic materials.

[0013] "Slag" refers to a material that solidifies in a vitreous or crystalline form and is formed as a by-product, especially in the recovery of metals in ore smelting, in metal recycling or incineration of waste materials, and is suitable in ground form as an inorganic filler. It is a mixture of substances having as its main components CaO, SiO2, Al2O3, MgO and FeO.

[0014] Substance names beginning with "poly", such as polyamine or polyol, formally refer to substances that contain more than one of the functional groups present in their name per molecule.

[0015] "Amine hydrogen" refers to the hydrogen atoms of primary and secondary amino groups.

[0016] "Molecular weight" refers to the molar mass (in grams per mole) of a molecule. "Average molecular weight" refers to the number average M n which is typically determined by gel permeation chromatography (GPC) against polystyrene as a standard.

[0017] A "storage-stable" composition is one that can be stored at room temperature in a suitable container for an extended period of time, typically at least three months and up to six months or more, without the storage resulting in changes to an extent that is relevant to the use of the composition.

[0018] The "pot life" of a hardenable composition refers to the maximum period between mixing of the components and application during which the mixed composition is in a sufficiently fluid state and has good ability to wet the wood surface.

[0019] "Room temperature" refers to a temperature of 23°C.

[0020] All industry standards and conventions referred to herein refer to the versions in effect as of the original filing date unless otherwise specified.

[0021] Weight percentage (wt %) refers to the proportion by mass of a component in a composition based on the entire composition, unless otherwise specified. The terms "mass" and "weight" are used interchangeably herein.

[0022] The wooden body preferably consists of hard or soft wood, preferably beech or spruce, as these types of wood are mechanically durable and are widely used in the building industry.

[0023] In particular, the wooden body is made of beechwood, which is widely available and is particularly hard and durable, but which has so far been relatively rarely used as a building material due to its high tendency to swell under the influence of moisture.

[0024] Suitable wooden bodies are any kind of moldings made of wood. Preference is given to moldings having at least one flat surface.

[0025] The wooden body is preferably provided with the horizontal plane facing upwards, which is hereinafter also referred to as the "upper side".

[0026] The wooden body preferably has the shape of a cube or a rectangular prism, in particular a rectangular prism. In the case of a rectangular prism, it is preferably arranged so that one of its widest faces is at the top and thus forms the upper side. The side perpendicular to the upper side is hereinafter also referred to as the "thickness".

[0027] The wooden body preferably has a thickness in the range of 10 to 300 mm, preferably 20 to 200 mm. The thickness of the wooden body (H) is shown as an example in FIG. H is displayed.

[0028] The upper side of the wooden body preferably has a length in the range of 0.3 to 20 m, particularly preferably 1 to 10 m. The length of the wooden body (H) is shown by way of example in FIG.

[0029] The upper side of the wooden body preferably has a width in the range of 50-2000 mm, preferably 150-1500 mm, in particular 150-1000 mm. The width of the wooden body (H) is shown by way of example in FIG.

[0030] The wooden body preferably has a rectangular parallelepiped shape, the length being greater than the width which is greater than the thickness. Such a wooden body may also be called a board, beam or rod.

[0031] The wood body may be made of unglued hardwood.

[0032] The wooden bodies preferably consist of laminated wood pieces, preferably consisting of lamellae or prisms, glued and / or interlocked, which allows for wooden bodies with high mechanical durability and dimensional stability, in particular wooden bodies with lengths of more than 1 m and widths of more than 150 mm.

[0033] The wood is preferably in dry storage conditions typical for use as a building material.

[0034] The wooden body may be pre-treated prior to application of the hardenable composition. The wooden body is preferably cleaned of dust.

[0035] Mechanical pretreatment in the form of roughening or machining of grooves or slits is possible but is not necessary for good bonding and is therefore not preferred.

[0036] Pretreatment with an activator or primer is possible, however, particularly in the case of epoxy resin-based curable compositions, pretreatment with an activator or primer is not necessary for good adhesion.

[0037] Preferably, the wooden body during application of the liquid hardening composition is provided with a formwork element on the outside, for example in the extension of the outer edge, so that the composition remains on the wooden body after application and cannot flow out. In FIG. 1, the thickness D of the wooden body (H) is H are evident by way of example. The formwork elements are preferably H and projecting upwards to such an extent as to form a complete form in the case of complete filling of the volume to be formed by the liquid composition. The height of the form element preferably corresponds to the thickness D of the laminate, as shown by way of example in FIG.

[0038] Suitable formwork elements are plates or other devices that are removed after the hardenable composition has hardened, as is customary in concrete construction.

[0039] Preferably, the hardenable composition comprises at least two separately packaged components that are mixed prior to or during application of the liquid composition.

[0040] The hardenable composition is preferably cement-free.

[0041] The liquid composition upon application preferably has a generally self-leveling, easily castable consistency to adequately wet the surface of the wood body.

[0042] During application, the attached formwork elements preferably prevent the applied composition from flowing out. Together with the upper side of the wooden body, the formwork elements preferably form a mold on which the upper side of the wooden body is based. The formwork elements preferably protrude above the upper side of the wooden body to such an extent that the depth of the mold corresponds to the desired layer thickness of the hardenable composition.

[0043] Preferably, the curable composition is applied in a layer thickness ranging from 10 to 300 mm, preferably from 20 to 200 mm, in particular from 30 to 100 mm. The layer thickness of the curable composition (Z) is shown by way of example in FIG. Z is displayed.

[0044] The curable composition is preferably applied to form a level surface. Optionally, the surface composition is smoothed towards the end of application, for example with a spatula or brick trowel. In addition, it is possible to use a spiked roller to collapse and thus eliminate any air bubbles present in the surface.

[0045] The curable composition is preferably applied within its pot life.

[0046] This is then preferably followed by curing of the applied curable composition.

[0047] The composition is preferably cured at ambient temperature, optionally under the action of moisture. The organic binder crosslinks here by chemical reaction of the reactive groups present. The duration of the curing process depends on the ambient conditions and on the components used in the curable composition. Typically, the existing formwork elements are removed after about 12 to 24 hours and the laminate reaches its final strength after several days or weeks at room temperature.

[0048] Suitable organic binders of the curable composition are all kinds of organic binders, in particular those based on epoxy resins, polyisocyanates, polymers which crosslink via silane groups, unsaturated polyester resins, acrylic resins or further polymers which have crosslinkable reactive groups.

[0049] The organic binder is preferably divided into at least two separately packaged storage-stable components before application, and the inorganic filler can be present at least partially as an additional separately packaged component. Alternatively, it is possible for the organic binder to be present in only one separately packaged component, in particular where some of the reactive groups of the organic binder are in blocked form and are released, for example by hydrolysis under the action of moisture, during and after application, and / or where the reactive groups of the organic binder undergo crosslinking under the action of moisture, as is the case especially for polyisocyanates.

[0050] Preferably, the organic binder of the curable composition is selected from a) epoxy resins and curing agents for epoxy resins and b) polyisocyanates and crosslinking agents for polyisocyanates. Such compositions allow fast curing, high bond strength in wood bodies and good mechanical properties of the resulting laminates without deformation of the wood bodies as a result of shrinkage or incompatibility.

[0051] In a particularly preferred embodiment of the present invention, the organic binder in the curable composition comprises at least one epoxy resin and at least one hardener for the epoxy resin. Such a composition allows for excellent adhesion of the cured composition on the wood body without the need for pretreatment of the wood surface with an activator or primer, which means that the method of the present invention can be carried out in a particularly simple manner. Moreover, such a composition in carrying out the method is particularly insensitive to moisture, for example in the form of high air humidity or high water content of the wood body. This also simplifies the carrying out of the method.

[0052] Such a curable composition preferably comprises: a first component comprising at least one epoxy resin, in particular chosen from bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and phenol novolac glycidyl ether, having an average functionality of between 2.3 and 3, and a second component comprising a hardener for epoxy resins, the hardener containing at least one polyamine having aliphatically bound amino groups and at least three amine hydrogens. Including, The inorganic filler is present as a constituent of the first and / or second component and / or as a further component.

[0053] Suitable epoxy resins are in particular liquid epoxy resins. These are technical grade epoxy resins that are fluid at room temperature and have a glass transition temperature of less than 25° C. They are obtained in known manner from the glycidylation of compounds having at least two active hydrogen atoms, more particularly polyphenols, polyols or amines, more particularly by reaction with epichlorohydrin.

[0054] Suitable epoxy resins are in particular aromatic liquid epoxy resins, in particular the glycidyl ethers of: bisphenol A, bisphenol F or bisphenol A / F, where A represents acetone and F represents formaldehyde used as reactant for the production of these bisphenols. In the case of bisphenol F, positional isomers may also be present, more particularly those derived from 2,4'- or 2,2'-hydroxyphenylmethane. - dihydroxybenzene derivatives, for example resorcinol, hydroquinone or catechol; further bisphenols or polyphenols, for example bis(4-hydroxy-3-methylphenyl)methane, 2,2-bis(4-hydroxy-3-methylphenyl)propane (bisphenol C), bis(3,5-dimethyl-4-hydroxyphenyl)methane, 2,2-bis(3,5-dimethyl-4-hydroxyphenyl)propane, 2,2-bis(3,5-dibromo-4-hydroxyphenyl)propane, 2,2-bis(4-hydroxy-3-tert-butylphenyl)propane, 2,2-bis(4-hydroxyphenyl)butane (bisphenol B), 3,3-bis(4-hydroxyphenyl)pentane, 3,4-bis(4-hydroxyphenyl)hexane, 4,4-bis(4-hydroxyphenyl)heptane, 2,4-bis(4-hydroxyphenyl)-2-methylbutane, 2,4-bis(3,5-dimethyl-4-hydroxyphenyl)-2-methylbutane, 1,1-bis(4-hydroxyphenyl)-2-methylbutane, bis(4-hydroxyphenyl)cyclohexane (bisphenol Z), 1,1-bis(4-hydroxyphenyl)-3,3,5-trimethylcyclohexane (bisphenol TMC), 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,4-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol P), 1,3-bis[2-(4-hydroxyphenyl)-2-propyl]benzene (bisphenol M), 4,4'-dihydroxydiphenyl (DOD), 4,4'-dihydroxybenzophenone, bis(2-hydroxynaphthal-1-yl)methane, bis(4-hydroxynaphthalene-1-yl)methane, 1,5-dihydroxynaphthalene, tris(4-hydroxyphenyl)methane, 1,1,2,2-tetrakis(4-hydroxyphenyl)ethane, bis(4-hydroxyphenyl)ether or bis(4-hydroxyphenyl)sulfone; novolaks which are in particular condensation products of phenols or cresols with formaldehyde or paraformaldehyde or acetaldehyde or crotonaldehyde or isobutyraldehyde or 2-ethylhexanal or benzaldehyde or furfural; aromatic amines, such as aniline, toluidine, 4-aminophenol, 4,4'-methylenediphenyldiamine, 4,4'-methylenediphenyldi(N-methyl)amine, 4,4'-[1,4-phenylenebis(1-methylethylidene)]bisaniline (bisaniline P) or 4,4'-[1,3-phenylenebis(1-methylethylidene)]bisaniline (bisaniline M).

[0055] Further possible epoxy resins are aliphatic or cycloaliphatic polyepoxides, in particular - saturated or unsaturated, branched or unbranched, cyclic or open chain difunctional, trifunctional or tetrafunctional C2-C 30 alcohols, in particular ethylene glycol, propylene glycol, butylene glycol, hexanediol, octanediol, polypropylene glycol, dimethylolcyclohexane, neopentyl glycol, dibromoneopentyl glycol, castor oil, trimethylolpropane, trimethylolethane, pentaerythritol, sorbitol or glycerol, or glycidyl ethers of alkoxylated glycerol or alkoxylated trimethylolpropane; - hydrogenated bisphenol A, F or A / F liquid resins or glycidylation products of hydrogenated bisphenol A, F or A / F; - N-glycidyl derivatives of amides or heterocyclic nitrogen bases, for example triglycidyl cyanurate or triglycidyl isocyanurate, or reaction products of epichlorohydrin with hydantoins It is.

[0056] In particular, aromatic liquid epoxy resins having an average epoxy equivalent in the range of 156 to 210 g / eq are preferred.

[0057] The epoxy resins are preferably selected from bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and phenol novolac glycidyl ether, having an average functionality of 2.3 to 3. These have easily manageable viscosities, enabling the curable compositions to have good processability and high strength and durability after curing.

[0058] Further preferred are epoxy resins based at least in part on renewable raw materials, in particular epoxy resins from the reaction of biobased hydroxy-functional compounds with biobased epichlorohydrin.Vanillin-based epoxy resins, such as in particular vanillin alcohol diglycidyl ether or the glycidyl ethers of bisvanillin derivatives, and glycerol-based epoxy resins, such as in particular the glycidyl ethers of glycerol or polyglycerol, are particularly preferred.Such epoxy resins allow for particularly long-lasting laminates.

[0059] The first component in this embodiment preferably comprises at least one reactive diluent containing an epoxy group, such as, in particular, butanediol diglycidyl ether, hexanediol diglycidyl ether, trimethylolpropane di- or triglycidyl ether, phenyl glycidyl ether, cresyl glycidyl ether, guaiacol glycidyl ether, 4-methoxyphenyl glycidyl ether, p-n-butylphenyl glycidyl ether, p-tert-butylphenyl glycidyl ether, 4-nonylphenyl glycidyl ether, 4-dodecylphenyl glycidyl ether, cardanol glycidyl ether, benzyl glycidyl ether, allyl glycidyl ether, butyl glycidyl ether, hexyl glycidyl ether, 2-ethylhexyl glycidyl ether, or glycidyl ethers of natural alcohols, such as, in particular, C8-C 10 Or C 12 ~C 14 Or C 13 ~C 15 Contains alkyl glycidyl ether.

[0060] Butanediol diglycidyl ether, Hexanediol diglycidyl ether, C 12 ~C 14 Alkyl glycidyl ethers or combinations of these reactive diluents are preferred.

[0061] The second component in this embodiment, which contains a hardener for the epoxy resin, contains at least one polyamine having aliphatically bound amino groups and at least three amine hydrogens.

[0062] Suitable polyamines of this type are, in particular, N-benzylethane-1,2-diamine, N-benzylpropane-1,2-diamine, N-benzyl-1,3-bis(aminomethyl)benzene, N-(2-ethylhexyl)-1,3-bis(aminomethyl)benzene, 2,2-dimethylpropane-1,3-diamine, pentane-1,3-diamine (DAMP), pentane-1,5-diamine, 1,5-diamino-2- Methylpentane (MPMD), 2-butyl-2-ethylpentane-1,5-diamine (C11-neodiamine), hexane-1,6-diamine, 2,5-dimethylhexane-1,6-diamine, 2,2(4),4-trimethylhexane-1,6-diamine (TMD), heptane-1,7-diamine, octane-1,8-diamine, nonane-1,9-diamine, decane-1,10-diamine, undecane-1, 11-diamine, dodecane-1,12-diamine, 1,2-, 1,3- or 1,4-diaminocyclohexane, 1,3-bis(aminomethyl)cyclohexane, 1,4-bis(aminomethyl)cyclohexane, bis(4-aminocyclohexyl)methane, bis(4-amino-3-methylcyclohexyl)methane, bis(4-amino-3-ethylcyclohexyl)methane, bis(4-amino-3,5-dimethylcyclohexyl)methane, bis(4-amino-3-ethyl-5-methylcyclohexyl)methane, 1-amino-3-aminomethyl-3,5,5-trimethylcyclohexane (IPDA), 2(4)-methyl-1,3-diaminocyclohexane, 2,5(2,6)-bis(aminomethyl)bicyclo[2.2.1]heptane (NBDA), 3(4),8(9)-bis(aminomethyl)tricyclo[5.2.1.0 2,6]decane, 1,4-diamino-2,2,6-trimethylcyclohexane (TMCDA), menthane-1,8-diamine, 3,9-bis(3-aminopropyl)-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3-bis(aminomethyl)benzene (MXDA), 1,4-bis(aminomethyl)benzene, bis(2-aminoethyl)ether, 3,6-dioxaoctane-1,8-diamine, 4,7-dioxadecane-1,10-diamine, 4,7-dioxadecane-2,9-diamine, 4,9-dioxadodecane-1,12 -diamines, 5,8-dioxadodecane-3,10-diamine, 4,7,10-trioxatridecane-1,13-diamine or higher oligomers of these diamines, bis(3-aminopropyl)polytetrahydrofuran or other polytetrahydrofuran diamines, polyoxyalkylene di- or -triamines, in particular polyoxypropylene diamines or polyoxypropylene triamines, such as Jeffamine® D-230, Jeffamine® D-400 or Jeffamine® T- 403 (all from Huntsman), furan-based amines such as 2,5-bis(aminomethyl)furan, 2,5-bis(aminomethyl)tetrahydrofuran, bis(5-aminomethylfuran-2-yl)methane, bis(5-aminomethyltetrahydrofuran-2-yl)methane, 2,2-bis(5-aminomethylfuran-2-yl)propane or 2,2-bis(5-aminomethyltetrahydrofuran-2-yl)propane, or diethylenetriamine (DETA), triethylenetetramine (TETA), tetraethylenepentamine (TPE), EPA), pentaethylenehexamine (PEHA), dipropylenetriamine (DPTA), N-(2-aminoethyl)propane-1,3-diamine (N3 amine), N,N'-bis(3-aminopropyl)ethylenediamine (N4 amine), N,N'-bis(3-aminopropyl)-1,4-diaminobutane, N5-(3-aminopropyl)-2-methylpentane-1,5-diamine, N3-(3-aminopentyl)pentane-1,3-diamine, N5-(3-amino-1-ethylpropyl)-2-methylpentane-1,5-diamine, N,N'-bis(3-amino-1-ethylpropyl)-2-methylpentane-1,5-diamine, 3-(2-aminoethyl)aminopropylamine, bis(hexamethylene)triamine (BHMT), N-aminoethylpiperazine, 3-dimethylaminopropylamine (DMAPA), 3-(3-(dimethylamino)propylamino)propylamine (DMAPAPA), amine-functional adducts of the amines mentioned with the epoxides, phenalkamines (which are reaction products of cardanol with aldehydes, in particular formaldehyde), and polyamines, polyamidoamines, such as, in particular, reaction products of dimeric fatty acids with a stoichiometric excess of polyamines, such as, in particular, DETA, TETA or TEPA.

[0063] The curing agent preferably contains a combination of two or more such polyamines.

[0064] Preferred polyamines have an average molecular weight M in the range of 200 to 500 g / mol. n where R is an integer from 1 to 3; and R is an integer from 1 to 3. In particular, R is an integer from 1 to 3, and R is an integer from 1 to 3.

[0065] The epoxy resin-based curable compositions preferably contain further components, in particular fillers such as benzyl alcohol or catalysts such as calcium nitrate, sulfonic acids or amines containing phenolic groups, such as, in particular, 2,4,6-tris(dimethylaminomethyl)phenol, or other substances which are customarily used in epoxy resin compositions.

[0066] Preferably, neither the epoxy resin nor the curing agent is water-based. Such curable compositions preferably contain a low water content, preferably less than 5% by weight, in particular less than 1% by weight, based on the total composition. Such compositions are particularly stable after curing.

[0067] The components of such epoxy resin-based compositions are preferably mixed in such a ratio that the molar ratio of amine hydrogen to epoxy groups is in the range of 0.5 to 1.5, in particular 0.7 to 1.2, and such compositions cure quickly without destruction.

[0068] In a further preferred embodiment of the present invention, the organic binder in the curable composition comprises at least one polyisocyanate and at least one crosslinker for the polyisocyanate. Such compositions cure particularly quickly, which allows for a particularly efficient process.

[0069] Such a curable composition preferably comprises: a first component comprising a crosslinker for polyisocyanates, which contains at least one polyol having an average molecular weight of 250 to 2000 g / mol and an average OH functionality of 1.7 to 6, and a second component comprising at least one polyisocyanate. Including, The inorganic filler is present as a constituent of the first and / or second component and / or as a further component.

[0070] Polyols that are liquid at room temperature are preferred.

[0071] Conventional polyols such as those typically used for polyurethane compositions are preferred, particularly polyether polyols, polyester polyols, polycarbonate polyols, polyacrylate polyols, especially polyols derived from natural fats and oils such as castor oil or the reaction products of castor oil with ketone resins, polyhydrocarbon polyols such as polybutadiene polyols, and combinations of such polyols.

[0072] Polyols having an average molecular weight of 250 to 1000 g / mol are preferred.

[0073] Polyols with an average OH functionality of 1.8 to 4 are preferred.

[0074] The first component preferably comprises at least one further crosslinker, such as, in particular, ethane-1,2-diol, propane-1,3-diol, 2-methylpropane-1,3-diol, butane-1,4-diol, pentane-1,5-diol, neopentyl glycol, hexane-1,6-diol, 3-methylpentane-1,5-diol, heptane-1,7-diol, octane-1,8-diol, cyclohexane-1,3-dimethanol, cyclohexane-1,4-dimethanol, diethylene glycol or triethylene glycol, or further di- or polyfunctional alcohols, such as, in particular, ethoxylated bisphenol A, propoxylated bisphenol A, cyclohexanediol, hydrogenated bisphenol A, dimeric fatty acid alcohols, 1,1,1-trimethylolethane, 1,1,1-trimethylolpropane, glycerol, pentaerythritol, sugar alcohols, such as, in particular, xylitol, sorbitol or mannitol, or sugars, such as, in particular, sucrose, or alkoxylated derivatives of the alcohols mentioned or mixtures of the alcohols mentioned.

[0075] Furthermore, the first component may in particular contain further crosslinkers such as compounds containing amine groups or di- or polyfunctional aldimines or ketimines.

[0076] Suitable polyisocyanates are, in particular, diisocyanates, oligomers or polymers or derivatives of diisocyanates, isocyanate-containing reaction products of diisocyanates with polyols, or combinations thereof.

[0077] Suitable diisocyanates are in particular toluene diisocyanate (TDI), diphenylmethane diisocyanate (MDI), mixtures of MDI and MDI homologues (polymeric MDI or PMDI), hexane 1,6-diisocyanate (HDI), 2,2(4),4-trimethylhexane 1,6-diisocyanate (TMDI), 1-methyl-2,4(6)-diisocyanatocyclohexane (H6TDI), isophorone diisocyanate (IPDI) or perhydro(diphenylmethane diisocyanate) (H 12 MDI).

[0078] The polyisocyanates are preferably in the form of NDI that is liquid at room temperature, in particular polymeric MDI, partially carbodiimidized MDI or MDI qualities with a high 2,4'-MDI content. These polyisocyanates are easily processable and / or allow for particularly high strength.

[0079] The polyisocyanate-based curable compositions preferably contain further components, in particular solvents or diluents, catalysts for the crosslinking reaction, drying agents such as molecular sieves, adhesion promoters, in particular silanes or titanates, or other substances which are customarily used in polyurethane compositions.

[0080] The polyisocyanate-based curable composition may contain a small amount of water, in particular 0.005% to 0.1% by weight of water based on the total composition. This may achieve a certain degree of foaming of the composition during the curing process, which may have a positive effect on the properties of the laminate. Water may be present as a constituent of the first component or may be added in another form during the mixing of the components.

[0081] The components of such polyisocyanate-based compositions are preferably mixed in a ratio such that the molar ratio of hydroxyl groups and any other isocyanate-reactive groups present to isocyanate groups ranges from 0.7 to 1.1, preferably from 0.8 to 1.0.Such compositions cure rapidly without destruction.

[0082] The hardenable compositions in all embodiments contain at least 80% by weight of inorganic fillers. These may take the form of separate components, which may be mixed with the remainder of the composition during or after application, and / or they may be in a pre-blended form with further components of the composition.

[0083] In the case of the above-mentioned epoxy resin-based or polyisocyanate-based compositions comprising a first component and a second component, the inorganic filler is present as a constituent of the first and / or second component and / or further components.

[0084] Preferably, at least a portion of the inorganic filler is present as a separate third component, and optionally also as a further fourth component.

[0085] The curable composition preferably contains at least 85% by weight of inorganic filler, based on the total composition, which allows a particularly low amount of heat release during curing and a particularly low shrinkage during curing, which prevents warping of the laminate.

[0086] Suitable inorganic fillers are, in particular, crushed quartz, quartz sand, crushed limestone sand, river sand, aggregates, slag, calcium carbonate, chalk, barite, dolomite, wollastonite, talc, titanium dioxide, iron oxide, calcined gravel, clay minerals, pumice, perlite, limestone, crushed limestone, silica dust, aluminum oxide, cement, fly ash, metakaolin, silica fume, calcium sulfate or combinations thereof. Shape and size can vary from finely ground material or sand particles or gravel to large rocks.

[0087] When the settable compositions contain hydraulic binders, such as cements, these take the form of fillers and the compositions set without them.

[0088] The hardenable composition is preferably cement-free.

[0089] The inorganic filler is preferably quartz and / or slag.

[0090] The curable composition preferably contains at least 50% by weight, based on the total composition, of an inorganic filler selected from quartz and slag. Such compositions have good processability and allow particularly high strength.

[0091] The curable composition may further comprise further components, in particular fibres, in particular glass, carbon, metal, ceramic or polymer fibres, such as polyamide or polyethylene fibres; rheology modifiers, in particular thickeners, surface-active additives, in particular antifoaming, degassing, wetting, dispersing or levelling agents, or - Stabilizer against oxidation, heat, light or UV rays or biocides may contain

[0092] In a preferred embodiment of the present invention, at least a portion of the inorganic filler is coated with at least one dispersing agent, in particular with a polycarboxylate ether, which allows particularly good flowability of the curable composition even in the case of a high content of inorganic filler, and thus particularly low heat generation during curing and particularly high strength of the cured composition.

[0093] The polycarboxylate ethers are preferably present in the form of comb polymers containing carboxylic acid groups and / or their salts and poly(oxyalkylene) side chains. Such polycarboxylate ethers are known as plasticizers for mortars and are commercially available, for example, under the trademark Viscocrete® (Sika).

[0094] In the case of coating of inorganic fillers, the dispersion can be sprayed or it can be mixed, optionally in diluted form, with the inorganic fillers.

[0095] The present invention further provides a laminate obtainable from the process of the present invention.

[0096] The laminate comprises a wood layer and a layer of the hardened composition as described. In particular, the laminate comprises a) a wood layer and b) a layer of the hardened composition.

[0097] The laminate preferably has a rectangular parallelepiped shape. [Brief description of the drawings]

[0098] [Figure 1] For the sake of illustration only, the described laminate is shown, which comprises a wood layer (H) and a layer (Z) of the described composition. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0099] The bottom side of the cuboid is preferably formed by the wood side, and the upper side of the cuboid is formed by the hardened composition. The thickness of the wood layer is preferably equal to or greater than the thickness of the composition. FIG. 1 shows, by way of example, the thickness (D H ) and the thickness (D Z ) is shown.

[0100] The dimensions of the laminate are preferably such that the wood layer, in the absence of support, strengthening or reinforcement, is capable of supporting the layer of composition applied thereto without bending significantly under its weight.

[0101] The laminate preferably has a load-bearing capacity of at least 100 kN, preferably at least 120 kN, determined on a laminate of dimensions 5200 x 320 x 180 mm composed of wood and hardened composition by four-point bending with two pressure cylinders (the distance between the pressure cylinders before the sample is placed is 1680 mm, respectively, and the distance between the pressure cylinders is 1640 mm) with a test span of 5000 mm, where the wood layer has dimensions 5200 x 320 x 120 mm and the hardened composition has dimensions 5200 x 320 x 60 mm.

[0102] The maximum deformation is preferably in the range of 70 to 250 mm, in particular 100 to 200 mm.

[0103] The stiffness of the composite section is preferably at least 10 9 N / mm 2 , especially, 10 11 N / mm 2 It is.

[0104] The laminate is stable and durable. It can be transported freely in space, in particular without permanent bending. It can be laminated and can be in contact with heat, moisture or ultraviolet light without significant loss of stability.

[0105] The laminate may also be referred to as a plate, beam, rod or sandwich element.

[0106] Laminates are different from bonded articles. In the laminates of the present invention, the hardened composition is in contact with the area of ​​the wood layer on only one side. In the case of articles bonded with the hardened composition, in contrast, the composition is placed between at least two substrates that are in contact with and bonded by the composition.

[0107] The invention further provides for the use of the laminate as a component in a building structure, in particular as a roofing element, which is in particular installed as a roofing element, with the wood side forming the ceiling visible from the inside and the side of the hardened composition facing towards the roof or upper floor.

[0108] The laminate from the method of the invention allows the installation of load-bearing timber ceilings which are particularly sound- and thermally insulating, are stable, do not require hydraulic binders and only require low levels of admixture and are therefore particularly durable. EXAMPLES

[0109] Examples are now given, which are intended to further illustrate the invention described. It will be clear that the invention is not limited to these described examples.

[0110] "Standard Climatic Conditions" ("SCC") refers to a temperature of 23±1°C and a relative air humidity of 50±5%.

[0111] The beech wood bodies used were prismatic laminated beech wood and were obtained from Fagus Suisse SA.

[0112] The curable composition used: Composition Z1 (based on epoxy resin): Sikadur® 42 LE Plus component A (from Sika), a reactive thinning epoxy resin based on bisphenol A / F diglycidyl ether. Sikadur® 42 LE Plus component B (from Sika), a hardener for epoxy resins, containing isophorone diamine, polyether amine, triethylene tetramine and benzyl alcohol. Sikadur® 42 LE Plus component C (from Sika), a mixture of inorganic fillers containing approximately 75% by weight quartz.

[0113] For application, liquid components A and B and powder component C were mixed in a weight ratio of A:B:C=3:1:32 and processed within 60 minutes.

[0114] Composition Z2 (based on epoxy resin): Sikadur® 42 LE Plus component A (from Sika), a reactive thinning epoxy resin based on bisphenol A / F diglycidyl ether. Sikadur® 42 LE Plus component B (from Sika), a hardener for epoxy resins, containing isophorone diamine, polyether amine, triethylene tetramine and benzyl alcohol. Sikadur® 42 LE Plus component C (from Sika), a mixture of inorganic fillers containing approximately 75% by weight quartz. 2.0-3.2mm quartz sand, abbreviated as "QS".

[0115] For application, liquid components A and B, powder component C and quartz sand QS were mixed in the weight ratio A:B:C:QS=3:1:22:11 and processed within 60 minutes.

[0116] Composition Z3 (polyisocyanate based): Sika Biresin® F50 component A (from Sika), a polyol mixture with about 25% by weight aluminum hydroxide and about 5% by weight molecular sieves. SikaBiresin® F50 Component B (manufactured by Sika), liquid MDI. Sikadur® 514 Plus Component C (from Sika), a mixture of mineral fillers containing about 70% by weight quartz and about 15% by weight Portland cement.

[0117] For application, liquid components A and B and powder component C were mixed in a weight ratio of A:B:C=2:1:20 and processed within 30 minutes.

[0118] Composition Z4 (polyisocyanate based): Sika Biresin® F50 component A (from Sika), a polyol mixture with about 25% by weight aluminum hydroxide and about 5% by weight molecular sieves. SikaBiresin® F50 Component B (manufactured by Sika), liquid MDI. Sikadur® 514 Plus Component C (from Sika), a mixture of mineral fillers containing about 70% by weight quartz and about 15% by weight Portland cement. 2.0-3.2mm quartz sand, abbreviated as "QS".

[0119] For application, liquid components A and B, powder component C and quartz sand QS were mixed in the weight ratio A:B:C:QS=2:1:14:7 and processed within 30 minutes.

[0120] Laminate manufacturing: Example 1: Several laminates were produced under standard climatic conditions by placing each 40x50x30 mm wooden body made of beech on a horizontal base with an area of ​​40x50 mm facing upwards and a thickness of 30 mm. The surface was cleaned of dust by means of a brush.

[0121] The wooden body thus provided was then fixed in a formwork mould which seamlessly surrounded the outside of the wooden body and projected 30 mm above the surface of the wooden body so as to form a mould for the hardenable composition 30 mm deep.

[0122] The freshly mixed composition Z1 was then poured into a mould with a layer thickness of 30 mm so that it was completely filled, and the surface was smoothed with a brick trowel. The mould was removed after 12 hours under standard climatic conditions. This resulted in a laminate of 40x50x60 mm.

[0123] Some such laminates were stored under standard climatic conditions for 28 days and then subjected to a compressive shear strength test. The compressive shear strength was determined according to DIN EN 392 at a test speed of 1 mm / s on a bond shear area of ​​50×40 mm.

[0124] Further laminates of this type were stored under standard climatic conditions for 28 days and then in water at room temperature for 24 hours and likewise subjected to compressive shear strength tests in the wet state.

[0125] Example 1 showed a compressive shear strength of 18 MPa (average of 5 laminates) after storage under standard climatic conditions for 28 days, with spalling mainly in the wood layers.

[0126] After storage in water for 24 hours, each wood layer was noticeably swollen (volume increase of about 30%), but the laminate was otherwise intact. The compressive shear strength of the wet laminate was 7 MPa (average of five laminates), each with spalling at the interface between composition Z1 and the wood.

[0127] Examples 2 and 3: Several laminates were produced under standard climatic conditions by placing each 1020 x 60 x 30 mm wooden body made of beech on a horizontal base with the 1020 x 60 mm area facing upwards and a thickness of 30 mm.

[0128] In Example 2, the dust on the wood surface was removed using a brush, then freshly mixed composition Z1 was placed in a mold with a layer thickness of 30 mm so that it was completely filled, and the surface was smoothed using a brick trowel.

[0129] In Example 3, the wood surface was pretreated with Sika® Primer MR Fast (a water-based two-component epoxy primer from Sika). After a flash-off time of 24 hours, the freshly mixed composition Z3 was placed in a mold with a layer thickness of 30 mm so that it was completely filled, and the surface was smoothed with a brick trowel.

[0130] The formwork was removed after 12 hours under standard climatic conditions, resulting in a 1020x60x60 mm laminate made of beech wood and hardened composition.

[0131] Some such laminates were stored for 28 days under standard climatic conditions and then subjected to a three-point bending test according to DIN 512186 with a span width of 900 mm, an initial load of 5 N and a test speed of 5 mm / min for the determination of the bending strength and maximum deformation. To determine the elastic modulus, further laminates of this type were subjected to an identical test, except that the test speed was 2 mm / min and the load range was 100-3200 N.

[0132] The results are reported in Table 1.

[0133] As a comparison (control), an uncoated beech wood body of dimensions 1020×60×60 mm was subjected to the same tests, the results of which are likewise reported in Table 1.

[0134] [Table 1]

[0135] Examples 4 and 5: Several stacks were produced under standard climatic conditions by placing a rectangular laminated timber beam of dimensions 5200 x 320 x 120 mm, made of glued square beech timber (approximately 2000 x 40 x 40 mm), on a horizontal base, with the 5200 x 320 mm area facing upwards and a thickness of 120 mm. A formwork mould was fitted around the timber beam to provide a mould 60 mm deep on the surface.

[0136] In Example 4, the dust on the wood surface was removed using a brush, then freshly mixed composition Z2 was placed into a mold with a layer thickness of 60 mm so that it was completely filled, and the surface was smoothed using a brick trowel.

[0137] In Example 5, the wood surface was pretreated with Sika® Primer MR Fast (a water-based two-component epoxy primer from Sika). After a flash-off time of 24 hours, freshly mixed composition Z4 was placed into a mold with a layer thickness of 60 mm so that it was completely filled, and the surface was smoothed with a brick trowel.

[0138] The formwork was removed after 12 hours under standard climatic conditions. A 5200x320x180 mm laminate of beech wood and hardened composition was obtained without distortion in length, width or height. In particular, the laminate showed neither shrinkage cracks and shrinkage warping, also called "keying", in the hardenable composition, nor peeling of the composition from the wood surface after hardening.

[0139] Several such laminates were subjected to four-point bending with two pressure cylinders (where the distance between the pressure cylinders before the sample was placed was 1680 mm and the distance between the pressure cylinders was 1640 mm, respectively) with a test span of 5000 mm after storage for 28 days under standard climatic conditions. The force-deformation relationship measured at the middle of the carrier was used to determine the bending strength (stiffness), the load-bearing capacity and the maximum deformation at fracture (averaged over two laminates) of the composite section.

[0140] The results are reported in Table 2.

[0141] [Table 2]

Claims

1. 1. A method for manufacturing a laminate, comprising: - providing a wooden body, - applying thereto a curable composition in liquid form, and curing the composition, The method of claim 1, wherein the composition comprises at least one organic binder and at least 80% by weight of an inorganic filler, based on the total composition.

2. 10. The method of claim 1, wherein the curable composition comprises at least two separately packaged components that are mixed before or during the application of the liquid composition.

3. 3. The method of claim 1 or 2, wherein the hardenable component does not include cement.

4. 3. The method according to claim 1 or 2, characterized in that the wooden body consists of laminated wood made of thin layers or prisms, glued and / or interlocked.

5. A method according to claim 1 or 2, characterized in that the wooden body has a thickness in the range of 10 to 300 mm, preferably 20 to 200 mm.

6. 3. The method according to claim 1 or 2, characterized in that the wooden body has, on the outside, formwork elements during the application of the liquid hardenable composition, so that the composition remains on the wooden body after the application and cannot flow out.

7. 3. The method according to claim 1 or 2, characterized in that the curable composition is applied in a layer thickness in the range of from 10 to 300 mm, preferably from 20 to 200 mm, in particular from 30 to 100 mm.

8. 3. A method according to claim 1 or 2, characterized in that the composition is cured at ambient temperature, optionally under the action of moisture.

9. 3. The method of claim 1 or 2, characterized in that the organic binder of the curable composition is selected from (a) epoxy resins and curing agents for epoxy resins and (b) polyisocyanates and crosslinking agents for polyisocyanates.

10. The curable composition is a first component comprising at least one epoxy resin, in particular at least one epoxy resin chosen from bisphenol A diglycidyl ether, bisphenol F diglycidyl ether and phenol novolac glycidyl ether, having an average functionality of from 2.3 to 3; and a second component comprising a curing agent for the epoxy resin, the second component containing at least one polyamine having aliphatically bound amino groups and at least three amine hydrogens. Including, 3. The method according to claim 2, characterized in that the inorganic filler is present as a constituent of the first and / or second component and / or as a further component.

11. The curable composition is a first component comprising a crosslinker for polyisocyanates, which contains at least one polyol having an average molecular weight of 250 to 2000 g / mol and an average OH functionality of 1.7 to 6; and a second component comprising at least one polyisocyanate. Including, 3. The method according to claim 2, characterized in that the inorganic filler is present as a constituent of the first and / or second component and / or as a further component.

12. 3. The method of claim 1 or 2, characterized in that the curable composition contains at least 50% by weight, based on the total composition, of an inorganic filler selected from quartz and slag.

13. A laminate obtained from the method of claim 1 or 2.

14. 14. A laminate according to claim 13, characterized in that it has a load-bearing capacity of at least 100 kN, determined in a laminate of dimensions 5200 x 320 x 180 mm composed of wood and the hardened composition, by four-point bending using two pressure cylinders with a test span of 5000 mm, the distance between the pressure cylinders being 1680 mm before the sample is placed and 1640 mm between the pressure cylinders, respectively, wherein the wood layer has dimensions 5200 x 320 x 120 mm and the hardened composition has dimensions 5200 x 320 x 60 mm.

15. 14. Use of a laminate according to claim 13 as a component in a building construction, in particular as a roof element.

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