Mineral Wool Fiber Mats, Method for Producing Same, and Use

Abstract

The invention relates to mineral wool fiber mats, which are stabilized by means of a binder made of polymers funtionalized with epoxy groups and/or with carboxyl groups and selected cross-linking agents. Said mats can be used as an insulating material and are characterized by low or no formaldehyde emissions.

Description

[0001] The present invention relates to mineral wool fiber mats impregnated with a selected binder. These mats are useful for example as insulants, for example for thermal insulation of roofs.

[0002] Aqueous polymeric dispersions for use as binders for mineral wool fiber mats are known per se. Mineral wool mats incorporating crosslinked polymers as binders form part of the subject matter of a wide variety of patent documents.

[0003] US-A-2008/0175997 describes binder compositions for glass mats that include an emulsion of a carboxyl-functionalized polymer and also a crosslinker having aziridine groups. Compared with conventional systems, a formaldehyde-free dispersion is concerned. It has comparable or even improved strength and flexibility compared with known systems. This document mentions further known binder systems for glass mats that derive from carboxyl-functionalized polymers and include specific crosslinkers, for example polyol compounds combined with phosphorus-containing accelerator, compounds containing active hydrogen, such as polyol, polyvinyl alcohol or polyacrylate, combined with fluoroborate accelerator, or crosslinkers which promote the esterification between COOH and OH groups in the polymer, or comprise epoxidized oils.

[0004] EP-A-1,018,523 discloses a polymer dispersion comprising a) dispersed addition polymer comprising 5-20% by weight interpolymerized carboxylic acid units, b) dissolved addition polymer comprising 60-100% by weight of interpolymerized carboxylic acid units, and c) selected alkoxylated long-chain amine as a crosslinker. This dispersion is useful as a binder for mineral wool mats for example.

[0005] DE-T-699 21 163 describes an insulating product based on mineral wool based on specific mineral fibers, the insulating product bearing a size based on a thermosetting resin admixed with a latex in order that mechanical strength after aging may be improved, The latex used comprises in particular polymers having hydrophilic groups, for example carboxyl, hydroxyl or carboxylic ester groups. Phenolic resin is mentioned as a thermosetting resin.

[0006] DE-A-197 38 771 and DE-A197 20 674 describe binders for mineral wool containing a) a thermoplastic polymer crosslinkable with phenolic resin, such as polyacrylate or polyvinyl ester, b) phenolic resin and c) flame retardant.

[0007] EP-A-1 164 163 discloses a binder for mineral wool, obtained by mixing a carboxylic acid and an alkanolamine under reactive conditions. An example of the carboxylic acid used is polyacrylic acid, polymethacrylic acid or a polymaleic acid.

[0008] WO-A-01/05,725 describes a binder for mineral wool, obtained by reacting a mixture which does not contain a polymer but includes an amine and also a first and a second anhydride. Typical representatives of the reaction mixture are diethanolamine, cyclic aliphatic anhydride, for example maleic anhydride succinic anhydride or hexahydrophthalic anhydride, and an aromatic anhydride, for example phthalic anhydride.

[0009] WO-A-2007/060,236 describes a formaldehyde-free binder for mineral wool comprising a) an aqueous dispersion of a polymeric polycarboxylic acid, b) a selected alkanolamine, for example ethanolamine, and c) an activated silane obtained by reacting a silane, for example alkoxysilane, with an enolizable ketone comprising at least one carboxyl group or with a ketone having at least one hydroxyl group, for example dihydroxyacetone or acetylacetone.

[0010] DE-A-100 14 399 discloses a mixture of two polymeric systems one of which bears mandatory carboxyl groups, while the second one contains interpolymerized functional groups capable of reacting with the carboxyl groups of the first polymeric system to form a covalent bond.

[0011] DE-A-26 04 544 discloses binders for consolidating glass fiber mats wherein a carboxyl-containing polymer is reacted with a crosslinker selected from the group of polyepoxides or capped isocyanates. The polymer basis for the binders used is restricted to polymers constructed from ethylenically unsaturated esters of acrylic or methacrylic acid.

[0012] JP-A-2006-089,906 describes a formaldehyde-free binder for mineral wool comprising a vinyl copolymer having hydroxyl groups and groups derived from an organic acid.

[0013] WO-A-2004/085,729 describes a formaldehyde-free binder for mineral wool comprising a) a compound having at least 2 cyclic ether groups and b) a copolymer having nucleophilic groups.

[0014] WO-A-2006/136,614 discloses a binder for mineral wool comprising a) phenol-formaldehyde binder and b) a hydroxylamine or an amino alcohol.

[0015] DE-A-40 24 727 discloses an agent for hydrophilicizing mineral wool fibers which comprises a) phenol-formaldehyde binder and, as hydrophilicizing agent, a mixture of b) water-soluble nitrogen-carbonyl compound, e.g., urea, c) acrylic resin and d) mixture of carboxyl-containing fatty acid condensation products with organic phosphoric esters.

[0016] There are also a number of documents already describing epoxy- or carboxyl-functionalized binders. Examples thereof are given in US-A-2008/0214716, US-A-2006/0258248, DE-C-199 56 420 and WO-A-03/104284. WO-A-03/104284 describes binder systems for producing glass fiber products in which low molecular weight epoxy compounds are crosslinked with functionalized polymeric compounds. US-A-2006/0258248 discloses epoxidized oils combined with multifunctionalized carboxylic acids or anhydrides as suitable crosslinking binders. US-A-2008/0214716 discloses binders for producing fiber weaves from a polymer based on ethylenically unsaturated monomers, a water-soluble polymer based on ethylenically unsaturated carboxylic acids and an alkoxylated or hydroxyalkylated crosslinker. DE-C-199 56 420 describes the use of water-soluble polymers based on ethylenically unsaturated carboxylic acids and certain amines in the presence of a crosslinking agent based on epoxy or acrylic resin for producing shaped articles.

[0017] There is increasing commercial demand for products which are formaldehyde-free in their formulations and emissions during application while retaining the current performance characteristics.

[0018] It is an object of the present invention to provide bound mineral wool fiber mats bonded together by formaldehyde-free binders and very useful as insulating materials. "Formaldehyde-free" is to be understood in the context of this description as meaning a composition having a formaldehyde content of less than 10 ppm.

[0019] The present invention provides a mineral wool fiber mat bound with a binder containing an epoxy and/or carboxyl functionalized copolymer, more particularly containing an appropriately functionalized emulsion copolymer, preferably in dispersion form, and an amine and/or an amine derivative as crosslinker.

[0020] In a preferred embodiment of the present invention, the mineral wool fiber mats contain a biosoluble fiber material bonded by a formaldehyde-free binder applied in a pH range in which the fibers are not attacked. This range is ideally located above the neutral point. This pH range is preferably 7.5-10.

[0021] The mineral wool fiber mats of the present invention contain glass wool and/or rockwool and can in principle contain further aggregates known to a person skilled in the art and/or further fibers.

[0022] Glass wool can be produced using any of the foundation stocks known from the glass industry. Quartz sand, sodium carbonate and limestone are typically used; cullet can be admixed to these raw materials, for example at up to 70% by weight of cullet. The melt is fiberized in a conventional manner by centrifugal casting or jetting.

[0023] Rockwool can be produced in a similar manner to glass wool. Basalt, diabase, feldspar, dolomite, sand and limestone are typically used; these raw materials may likewise be admixed with cullet. The melt is fiberized in a conventional manner by centrifugal casting. In addition to the customary starting materials for producing rockwool, it is also possible to use slags generated as waste products in combustion or production processes, for example blast furnace slags. This form of rockwool known as slag wool is similarly known to a person skilled in the art.

[0024] The glass wool or rockwool used is preferably selected to have a high biosolubility. Biosolubility is to be understood as meaning the ability of the fibers to be dissolved and degraded in the body by endogenous substances.

[0025] The glass wool or rockwool fiber mats formed are additized with a binder to ensure their dimensional stability. The fiber mat is subsequently cured by heat treatment, for example in a hot air stream. Volatile constituents are additionally removed from the fiber mat in the course of the heat treatment. Web-forming processes of this type are described for example in US 200810175997 A1.

[0026] Alternatively, mineral wool fiber mats can also be produced by wet laying. To this end, fibers can be initially charged in an aqueous slurry together with the binder and be laid down on a moving support surface, for example a water-permeable conveyor belt, to form a fiber mat. After dewatering, the fiber mat is cured by heat treatment, for example in a hot air stream. Production processes for mineral wool mats of this type are described for example in DE 601 23 177 T2.

[0027] Mineral wool mats may also contain further customary added substances. Mineral oils are frequently added, for instance, to improve further processability and imbued the mineral wool mats with improved water-rejecting properties. In addition, such mats may be laminated with aluminum foil or fibrous nonwoven webs when used as an insulating material in particular.

[0028] The mineral wool fiber mats of the present invention are endowed with a specific binder which contains an epoxy and/or carboxyl functionalized copolymer.

[0029] The epoxy and/or carboxyl functionalized copolymers are preferably derived from one or more ethylenically unsaturated compounds, such that at least one of these monomers must have one or more epoxy groups and/or one or more carboxyl groups.

[0030] These embodiments comprise by way of reactive groups either only interpolymerized epoxy groups or only interpolymerized carboxyl groups or, in addition to the inter-polymerized epoxy groups, additionally interpolymerized carboxyl groups, for example from units derived from ethylenically unsaturated mono- or dicarboxylic acids. The selection of these embodiments depends inter alia on further additions to the binder formulation and/or on the reaction conditions prevailing at application (at the binding of the mineral wool in the binding process, for example).

[0031] In addition to these copolymers, it is also possible to use homo- or copolymers derived completely or overwhelmingly from carboxyl-containing ethylenically unsaturated monomers. Examples thereof are polyacrylic acid or salts thereof and also polymethacrylic acid or salts thereof, more particularly the alkali metal salts of these polymers.

[0032] The epoxy and/or carboxyl functionalized copolymers preferably comprise copolymers of vinyl esters and/or of esters of .alpha.,.beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids and/or of alkenyl aromatics, each polymerized with ethylenically unsaturated comonomers comprising epoxy groups and/or carboxyl groups or anhydrides thereof.

[0033] In addition to the epoxy-containing monomers and/or the carboxyl-containing monomers, it is mainly the following groups of monomers which are contemplated as a basis for the classes of polymer mentioned:

[0034] One group is formed by vinyl esters of monocarboxylic acids having one to eighteen carbon atoms, examples being vinyl formate, vinyl acetate, vinyl propionate, vinyl isobutyrate, vinyl valerate, vinyl valerate, vinyl pivalate, vinyl 2-ethylhexanoate, vinyl decanoate, isopropenyl acetate, vinyl esters of saturated branched monocarboxylic acids having 5 to 15 carbon atoms in the acid moiety, more particularly vinyl esters of Versatic.TM. acids, vinyl esters of relatively long-chain saturated or unsaturated fatty acids such as for example vinyl laurate, vinyl stearate and also vinyl esters of benzoic acid and of substituted derivatives of benzoic acid such as vinyl p-tert-butylbenzoate. Among these, however, vinyl acetate is particularly preferred for use as principal monomer.

[0035] A further group of monomers is formed by esters of .alpha.,.beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with preferably C.sub.1-C.sub.18-alkanols and more particularly C.sub.1-C.sub.8-alkanols or C.sub.5-C.sub.8-cycloalkanols. The esters of dicarboxylic acids may be monoesters, or preferably, diesters. Examples of suitable C.sub.1-C.sub.8-alkanols are methanol, ethanol, n-propanol, i-propanol, 1-butanol, 2-butanol, isobutanol, tert-butanol, n-hexanol and 2-ethylhexanol. Examples of suitable cycloalkanols are cyclopentanol or cyclohexanol. Examples are esters of acrylic acid, of methacrylic acid, of crotonic acid, of maleic acid, of itaconic acid, citraconic acid or of fumaric acid such as methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 1-hexyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, di-n-methyl maleate or fumarate, di-n-ethyl maleate or fumarate, di-n-propyl maleate or fumarate, di-n-butyl maleate or fumarate, diisobutyl maleate or fumarate, di-n-pentyl maleate or fumarate, di-n-hexyl maleate or fumarate, dicyclohexyl maleate or fumarate, di-n-heptyl maleate or fumarate, di-n-octyl maleate or fumarate, di-(2-ethylhexyl) maleate or fumarate, di-n-nonyl maleate or fumarate, di-n-decyl maleate or fumarate, di-n-undecyl maleate or fumarate, dilauryl maleate or fumarate, dimyristyl maleate or fumarate, dipalmitoyl maleate or fumarate, distearyl maleate or fumarate and diphenyl maleate or fumarate.

[0036] Preferred principal monomers of this group are selected from the group of acrylates and methacrylates. Particular preference is given to methyl (meth)acrylate, ethyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, isobutyl (meth)acrylate, 1-hexyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate.

[0037] A further group of monomers is formed by alkenyl aromatics. The alkenyl aromatics in question are monoalkenyl aromatics. Examples thereof are styrene, vinyl toluene, vinyl xylene, .alpha.-methylstyrene or o-chlorostyrene. Styrene in particular must be mentioned as a preferred monomer in this group.

[0038] The monomers mentioned generally form the principal monomers which, in relation to the total amount of the monomers to be polymerized, normally account for a proportion of more than 50% by weight and preferably more than 75%.

[0039] A further group of monomers which can mainly be used together with vinyl esters and/or esters of .alpha.,.beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids and/or alkenyl aromatics is formed by aliphatic, monoolefinically or diolefinically unsaturated, optionally halogen-substituted hydrocarbons, such as ethene, propene, 1-butene, 2-butene, isobutene, conjugated C.sub.4-C.sub.8-dienes, such as 1,3-butadiene, isoprene, chloroprene, vinyl chloride, vinylidene chloride, vinyl fluoride or vinylidene fluoride.

[0040] The monomers are preferably to be selected so as to form an addition polymer or copolymer having good compatibility in common formaldehyde-free binder formulations which additionally has excellent binding properties in the production of mineral wool mats.

[0041] Preferably used binder polymers are derived from the following principal monomers or combinations thereof in addition to the epoxy-containing monomers and/or the carboxyl-containing monomers: [0042] copolymers based on one or more vinyl esters, more particularly vinyl acetate; [0043] copolymer based on esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono with C.sub.1-C.sub.8-alkanols, more particularly esters of (meth)acrylic acid; [0044] copolymers based on vinyl esters and esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with C.sub.1-C.sub.8-alkanols, more particularly esters of (meth)acrylic acid and maleic/or fumaric acid; [0045] copolymers based on vinyl esters, more particularly vinyl acetate, with ethylene; [0046] copolymer based on esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or [0047] dicarboxylic acids with C.sub.1-C.sub.8-alkanols, more particularly esters of (meth)acrylic acid and maleic/or fumaric acid, with ethylene; [0048] copolymers based on vinyl esters, ethylene and esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with C.sub.1-C.sub.8-alkanols, more particularly esters of (meth)acrylic acid and maleic/or fumaric acid; or [0049] copolymers based on styrene and esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with C.sub.1-C.sub.8-alkanols, more particularly esters of (meth)acrylic acid and optionally ethylene and/or butadiene.

[0050] The examples of preferred epoxy-containing monomers for copolymerization with the principal monomers are allyl glycidyl ether, methacryloyl glycidyl ether, butadiene monoepoxides, 1,2-epoxy-5-hexene, 1,2-epoxy-7-octene, 1,2-epoxy-9-decene, 8-hydroxy-6,7-epoxy-1-octene, 8-acetoxy-6,7-epoxy-1-octene, N-(2,3-epoxy)-propylacrylamide, N-(2,3-epoxy)-propylmethacrylamide, 4-acrylamidophenyl glycidyl ether, 3-acrylamidophenyl glycidyl ether, 4-methacrylamidophenyl glycidyl ether, 3-methacrylamidophenyl glycidyl ether, N-glycidoxymethylacrylamide, N-glycidoxypropylmethacrylamide, N-glycidoxyethylacrylamide, N-glycidoxyethyl-methacrylamide, N-glycidoxypropylacrylamide, N-glycidoxypropylmethacrylamide, N-glycidoxybutylacrylamide, N-glycidoxybutylmethacrylamide, 4-acrylamidomethyl-2,5-dimethylphenyl glycidyl ether, 4-methacrylamidomethyl-2,5-dimethylphenyl glycidyl ether, acrylamidopropyldimethyl-(2,3-epoxy)propylammonium chloride, meth-acrylamidopropyldimethyl-(2,3-epoxy)-propylammonium chloride and glycidyl methacrylate. Epoxy-containing monomers derived from glycidyl esters of ethylenically unsaturated mono- or dicarboxylic acids, such as glycidyl acrylate and glycidyl methacrylate for example, are particularly preferred.

[0051] The weight fraction contributed by the epoxy-containing monomers based on the total amount of the monomers to be polymerized is below 50% by weight, preferably between 0.1% and 20% by weight, more preferably between 1% and 10% by weight and most preferably between 2% and 5% by weight.

[0052] In addition to the abovementioned principal monomers, the binder polymers used according to the present invention may additionally contain at least structural units derived from carboxyl-containing monomers.

[0053] This group of monomers includes mainly .alpha.,.beta.-monoethylenically unsaturated mono- and dicarboxylic acids of 3 to 10 carbon atoms and their water-soluble salts, for example their sodium salts, and also their anhydrides. Preferred monomers from this group are ethylenically unsaturated C.sub.3-C.sub.8-carboxylic acids and C.sub.4-C.sub.8-dicarboxylic acids, e.g., maleic acid, fumaric acid, itaconic acid, crotonic acid, vinyl acetic acid, 2-carboxylethyl (meth)acrylate, acrylamidoglycolic acid and, more particularly, acrylic acid, methacrylic acid and also the monoesters of maleic and fumaric acids such as mono-2-ethylhexyl maleate and monoethyl maleate.

[0054] These carboxyl-containing monomers are normally interpolymerized in amounts of less than 50% by weight, preferably between 0.1% and 20% by weight, more preferably between 1% and 10% by weight and most preferably between 2% and 5% by weight, based on the total amount of the monomers to be polymerized.

[0055] Particularly preferred binders for mineral wool fiber mats contain an epoxy functionalized copolymer based on a polyvinyl ester, on a polyacrylate or on a polyalkenyl aromatic that includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated mono- or dicarboxylic acids, preferably from glycidyl esters of acrylic or methacrylic acid.

[0056] Particularly preferred binders for mineral wool fiber mats contain a carboxyl functionalized copolymer based on a polyvinyl ester, on a polyacrylate or on a polyalkenyl aromatic that includes interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, preferably from monoesters of fumaric or maleic acid or from acrylic or methacrylic acid.

[0057] Particularly preferred binders for mineral wool fiber mats contain an epoxy and carboxyl functionalized copolymer based on a polyvinyl ester, on a polyacrylate or on a polyalkenyl aromatic that includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated mono- or dicarboxylic acids, preferably from glycidyl esters of acrylic or methacrylic acid, and that includes interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, preferably from monoesters of fumaric or maleic acid or from acrylic acid or methacrylic acid.

[0058] A further particularly preferred embodiment of the binder is based on epoxy functionalized copolymers derived from alkenyl aromatics, preferably from styrene, or from esters of acrylic acid and/or methacrylic acid, and includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated mono- or dicarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid.

[0059] A further particularly preferred embodiment of the binder is based on epoxy functionalized copolymers derived from esters of .alpha.,.beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids and includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated monocarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid.

[0060] A further preferred embodiment of the binder is based on epoxy functionalized copolymers derived from one or more vinyl esters, more particularly vinyl acetate, and including interpolymerized units derived from glycidyl esters of ethylenically unsaturated monocarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid. The epoxy functionalized copolymers mentioned may contain further structural units derived from esters of .alpha.,.beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with C.sub.1-C.sub.8-alkanols, from .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids, e.g., acrylic acid, methacrylic acid or maleic acid or fumaric acid, from olefins, e.g., ethylene or butadiene, or from a combination of two or more of these monomers.

[0061] Selected epoxy and/or carboxyl functionalized copolymers are: copolymers derived from vinyl esters of saturated carboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids or from ethylenically unsaturated mono- or dicarboxylic acids, of copolymers derived from vinyl esters of saturated carboxylic acids, from esters of acrylic acid and/or methacrylic acid and/or fumaric acid and/or maleic acid with C.sub.1-C.sub.8-alkanols and from glycidyl esters of ethylenically unsaturated carboxylic acids or from ethylenically unsaturated mono- or dicarboxylic acids, of copolymers derived from vinyl esters of saturated carboxylic acids, from ethylene, from ethylenically unsaturated carboxylic acids and and from glycidyl esters of ethylenically unsaturated carboxylic acids or from ethylenically unsaturated mono- or dicarboxylic acids, of copolymers derived from vinyl esters, ethylene, esters of acrylic acid and/or methacrylic acid and/or fumaric acid and/or maleic acid with C.sub.1-C.sub.8-alkanols, from ethylenically unsaturated mono- or dicarboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from esters of acrylic acid and/or methacrylic acid, of ethylenically unsaturated mono- or dicarboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from styrene and optionally butadiene and/or from esters of acrylic acid and/or methacrylic acid with C.sub.1-C.sub.8-alkanols, from ethylenically unsaturated mono- or dicarboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids.

[0062] It will be appreciated that the polymerization may co-utilize further comonomers which modify the properties in a specific manner. Such auxiliary monomers are normally interpolymerized only as modifying monomers in amounts of less than 10% by weight, based on the total amount of the monomers to be polymerized.

[0063] These monomers can have different functions; for example, they can serve to stabilize polymer dispersions or they can improve film cohesion or other properties by crosslinking during the polymerization or during film formation, and/or react with the crosslinker via a suitable functionality.

[0064] Monomers useful for further stabilization are generally monomers which have an acid function and/or salts thereof. In addition to the abovementioned carboxyl-containing monomers, which likewise contribute to enhancing crosslink density in the binding process of the mineral wool fiber mats, further monomers having other acid functions, such as ethylenically unsaturated sulfonic acids, ethylenically unsaturated phosphonic acids or dihydrogen phosphates and water-soluble salts thereof, for example sodium salts thereof, can also be used. Preferred monomers from this group are vinylsulfonic acid and its alkali metal salts, acrylamidopropanesulfonic acid and its alkali metal salts, and also vinylphosphonic acid and its alkali metal salts.

[0065] Examples of crosslinking auxiliary monomers are monomers having two or more vinyl radicals, monomers having two or more vinylidene radicals, and also monomers having two or more alkenyl radicals. Of particular advantage are the diesters of dihydric alcohols with .alpha.,.beta.-monoethylenically unsaturated monocarboxylic acids, among which acrylic acid and methacrylic acid are preferred, the diesters of dibasic carboxylic acids with ethylenically unsaturated alcohols, other hydrocarbons having two ethylenically unsaturated groups, or the diamide of dihydric amines with .alpha.,.beta.-monoethylenically unsaturated monocarboxylic acids.

[0066] Examples of such monomers having two nonconjugated ethylenically unsaturated double bonds are alkylene glycol diacrylates and dimethacrylates, such as ethylene glycol diacrylate, 1,2-propylene glycol diacrylate, 1,3-propylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,4-butylene glycol diacrylates or methacrylates and ethylene glycol diacrylates or methacrylates, 1,2-propylene glycol dimethacrylate, 1,3-propylene glycol dimethacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butylene glycol dimethacrylates, hexanediol diacrylate, pentaerythritol diacrylate and also divinylbenzene, vinyl methacrylate, vinyl acrylate, vinyl crotonate, allyl methacrylate, allyl acrylate, diallyl maleate, diallyl fumarate, diallyl phthalate, methylene bisacrylamide, cyclopentadienyl acrylate, divinyl adipate or methylenebisacrylamide.

[0067] However, it is also possible to use monomers having more than two double bonds, for example tetraallyloxyethane, trimethylolpropane triacrylate or triallyl cyanurate.

[0068] A further group of auxiliary monomers is formed by auxiliary monomers which are self-crosslinking or can be crosslinked via carbonyl groups. Examples are diacetoneacrylamide, allyl acetoacetate, vinyl acetoacetate and also acetoacetoxy-ethyl acrylate or methacrylate.

[0069] A further group of auxiliary monomers are capable, under selected conditions, of undergoing a crosslinking reaction either by self-crosslinking or with a suitable monomeric reactant and/or with the crosslinkers present: [0070] this group includes monomers having N-functional groups, more particularly (meth)acrylamide, allyl carbamate, acrylonitrile, methacrylonitrile, N-methylol-(meth)acrylamide, N-methylolallyl carbamate and also the N-methylol esters, -alkyl ethers or Mannich bases of N-methylol(meth)acrylamide or of N-methylolallyl carbamate, acrylamidoglycolic acid, methyl acrylamidomethoxyacetate, N-(2,2-dimethoxy-1-hydroxyethyl)acrylamide, N-dimethylaminopropyl(meth)acrylamide, N-methyl(meth)acrylamide, N-butyl(meth)acrylamide, N-cyclohexyl(meth)acrylamide, N-dodecyl(meth)acrylamide, N-benzyl(meth)acrylamide, p-hydroxyphenyl-(meth)acrylamide, N-(3-hydroxy-2,2-dimethylpropyl)methacrylamide, ethyl-imidazolidone (meth)acrylate, N-(meth)acryloyloxyethylimidazolidin-1-one, N-(2-methacryloylamidoethyl)imidazolin-2-one, N-[3-allyloxy-2-hydroxypropyl]amino-ethyl]imidazolin-2-one, N-vinylformamide, N-vinylpyrrolidone or, N-vinylethyleneurea.

[0071] A further group of auxiliary monomers is formed by hydroxyl-functional monomers such as the C.sub.1-C.sub.9-hydroxyalkyl esters of methacrylic and acrylic acids, such as n-hydroxyethyl acrylate, n-hydroxyethyl methacrylate, n-hydroxypropyl acrylate, n-hydroxypropyl methacrylate, n-hydroxybutyl acrylate, n-hydroxybutyl methacrylate and also adducts thereof with ethylene oxide or propylene oxide.

[0072] A further group of auxiliary monomers consists of monomers comprising silane groups, e.g., vinyltrialkoxysilanes, such as vinyltrimethoxysilane, vinyltriethoxysilane, alkylvinyldialkoxysilanes or (meth)acryloyloxyalkyltrialkoxysilanes, e.g., (meth)-acryloyloxyethyltrimethoxysilane, or (meth)acryloyloxypropyltrimethoxysilane.

[0073] It is preferable in the context of the present invention to ideally not use any functional monomers comprising free or bound formaldehyde. If this is necessary as part of specific product optimizations, the rule is to also use a compound that acts as a formaldehyde scavenger. Pertinent examples thereof are N- or S-nucleophiles such as urea or sodium bisulfite and also other compounds described in the literature. The binders used according to the present invention are obtainable by any method of free-radical polymerization. Examples thereof are polymerization in bulk, in solution, in suspension or, more particularly, emulsion polymerization.

[0074] Preferably used binders contain aqueous polymeric dispersions comprising the epoxy- and/or carboxyl-containing copolymers described above. These dispersions are applied to the mineral wool fiber mats without a solvent or almost without a solvent.

[0075] In addition to the epoxy- and/or carboxyl-containing polymers, the dispersions preferably used according to the present invention contain protective colloids and/or emulsifiers.

[0076] Protective colloids are polymeric compounds which are present during the emulsion polymerization and which stabilize the dispersion.

[0077] Examples of suitable protective colloids are polyvinyl alcohols, polyalkylene glycols, cellulose derivatives, starch derivatives and gelatin derivatives or polymers derived from N-vinylpyrrolidone, N-vinylcaprolactam, N-vinylcarbazole, 1-vinylimidazole, 2-vinylimidazole, 2-vinylpyridine, 4-vinylpyridine, acrylamide, methacrylamide, amino-bearing acrylates, methacrylates, acrylamides and/or methacrylamides. A comprehensive description of further suitable protective colloids is given in Houben-Weyl, Methoden der organischen Chemie, Volume XIV/1, Macromolecular substances, Georg-Thieme-Verlag, Stuttgart, 1961, pages 411 to 420.

[0078] Emulsifiers are low molecular weight and surface-active compounds which are present during the emulsion polymerization and which stabilize the dispersion. The dispersions used according to the present invention may neutralize ionic and/or nonionic and/or amphoteric emulsifiers, most preferably nonionic emulsifiers or combinations of nonionic emulsifiers and anionic emulsifiers. A list of suitable emulsifiers is given in Houben-Weyl, Methoden der organischen Chemie, Volume XIV/I, Macromolecular substance, Georg-Thieme-Verlag, Stuttgart, 1961, pages 192-208).

[0079] The proportion of protective colloids can be up to 20% by weight, preferably in the range from 1% to 10% by weight and more particularly in the range from 2% to 8% by weight, all based on the dispersion.

[0080] The proportion of emulsifiers may likewise be up to 10% by weight, based on the dispersion, preferably in the range from 1% to 6% by weight.

[0081] The binders used according to the present invention contain at least one selected crosslinker from the group of amines, amine derivatives, including preferably hydrophobically modified amines, and amides, more particularly amidated amines. The amines or amine derivatives used as crosslinkers shall not be alkoxylated or hydroxyalkylated.

[0082] The crosslinkers used according to the present invention comprise for example mono- or polyamines, more particular diamines, preferably aliphatic mono- or diamines or aromatic mono- or diamines. The amino groups of the crosslinkers used according to the present invention can be primary, secondary and/or tertiary amino groups. Preferably, the crosslinkers contain one or more primary or secondary amino groups.

[0083] Preference for use as crosslinkers is given to amine derivatives in which some of the amino groups were converted into amide groups by reaction with hydrophobic acids. The amine derivatives may have one or more amide groups.

[0084] Particular preference is given to using polyaminoamides. Polyaminoamides are generally condensation products of unsaturated aliphatic acids with polyamines. Products of this kind are commercially available under the name of Versamid.RTM.. Examples of such compounds are given in EP-A-1,533,331.

[0085] Preferred crosslinkers from the group of amine derivatives having amidic structures are oligomeric or polymeric compounds derived from a carboxylic acid, more particularly derived from mono- or dicarboxylic acids or from a mixture of such carboxylic acids including ethylenically unsaturated carboxylic acids and from di-, oligo- or polyamines. The ethylenically unsaturated carboxylic acids may form multimers, preferably of 2 to 10 carboxylic acid units.

[0086] Particularly preferred crosslinking polymers are derived from unsaturated carboxylic acids and diamines or from dimers of ethylenically unsaturated carboxylic acids and di- or oligoamines.

[0087] Further preferred crosslinkers from polyaminoamides have an ASTM D 2073 amine number between 100 and 2000 mg of KOH/g of crosslinker and preferably between 250 and 1000 mg of KOH/g of crosslinker.

[0088] Particular preference is given to using crosslinkers of the Versamid.RTM. range (Cognis GmbH, Germany), e.g., Versamid.RTM. 150 or Versamid.RTM. 250.

[0089] The crosslinkers used according to the present invention are typically present in amounts of 0.1% to 10% by weight, based on the binder.

[0090] Preferred crosslinker concentrations are between 1-10% by weight and more particularly between 2-7% by weight.

[0091] When carbonyl-containing auxiliary monomers are present in a copolymer of the binder, crosslinking via these groups may also take place in addition. Crosslinkers useful for this purpose include compounds selected from the group of bis- or polyoxazolines, bis- or polyiminooxazolidines, carbodiimides, bis- or polyepoxides or blocked isocyanates (as described in EP-A-206,059 for example).

[0092] It is further possible to use compounds having an at least divalent metal ion for further crosslinking. The compounds in question are capable of forming complexes or coordinative bonds with the carboxyl groups of the binder polymer. This group typically includes salts of Al.sup.3+, Zn.sup.2+, Sn.sup.2+, Sn.sup.4+, Ti.sup.4+, TiO.sup.2+, Hf.sup.4+, HfO.sup.2+Zr.sup.4+, ZrO.sup.2+ and further polyvalent ions. Ideally, these ions may recruit further components of the binder into the crosslinking and thereby increase crosslink density. The poly(vinylalcohol) frequently used as a protective colloid is an example.

[0093] The binders used according to the present invention may contain further customary additives. These include, for example, film-forming auxiliaries to depress the minimum filming temperature ("MFT") presence, plasticizers, buffers, pH control agents, dispersants, defoamers, fillers, dyes, pigments, silane coupling agents, thickeners, viscosity regulators, solvents and/or preservatives.

[0094] The binder used according to the present invention shall be used in a formulation adjusted to a pH in an optimum range for suitable reactivity of the functional groups of the polymeric binder with the groups of the crosslinker. This pH range is preferably located above the neutral point. Preferably, this pH range is 7.5-10.

[0095] A suitable pH may already be obtained after the emulsion polymerization for preparing the polymer dispersion or after addition of the crosslinker, the amidated amine for example, or it may be set subsequently in the formulation by adding pH control agents.

[0096] The polymer dispersions particularly preferably used are prepared under the customary continuous or batch procedures of free-radical emulsion polymerization.

[0097] The conduct of a free-radically initiated aqueous emulsion polymerization of ethylenically unsaturated monomers has been extensively described and therefore is well-known to a person skilled in the art [cf. for example Encyclopedia of Polymer Science and Engineering, Vol. 8, pages 659 to 677, John Wiley & Sons, Inc., 1987; D. C. Blackley, Emulsion Polymerisation, pages 155 to 465, Applied Science Publishers, Ltd., Essex, 1975; D. C. Blackley, Polymer Latices, 2.sup.nd Edition, Vol. I, pages 33 to 415, Chapman & Hall, 1997; H. Warson, The Applications of Synthetic Resin Emulsions, pages 49 to 244, Ernest Bonn. Ltd. London, 1972; D. Diederich, Chemie in unserer Zeit 1990, 24, pages 135 to 142, Verlag Chemie, Weinheim; J. Piirma, Emulsion Polymerisation, pages 1 to 287, Academic Press, 1982; F. Holscher, Dispersionen synthetischer Hochpolymerer, pages 1 to 160. Springer-Verlag, Berlin, 1969 and patent document DE-A 40 03 422]. Typically, the ethylenically unsaturated monomers are dispersed in an aqueous medium, frequently with the aid of dispersant auxiliaries, and are polymerized using at least one free-radical polymerization initiator at least.

[0098] Water-soluble and/or oil-soluble initiator systems such as peroxodisulfates, azo compounds, hydrogen peroxide, organic hydroperoxides or dibenzoyl peroxide are used. They can be used either on their own or combined with reducing compounds such as Fe(II) salts, sodium pyrosulfite, sodium hydrogensulfite, sodium sulfite, sodium dithionite, sodium formaldehydesulfoxylate, 2-hydroxyphenylhydroxymethyl-sulfonic acid or its sodium salt, 4-methoxyphenylhydroxymethylsulfinic acid or its sodium salt, 2-hydroxy-2-sulfinatoacetic acid or its disodium or zinc salt and 2-hydroxy-2-sulfinatopropionic acid or its disodium salt, or ascorbic acid or its salts or isoascorbic acid or its salts, as redox catalyst system.

[0099] Polymeric protective colloids and/or emulsifiers can be added before or during the polymerization. An additional subsequent addition of polymeric stabilizers and/or of emulsifiers is likewise possible. This dispersion is then optionally further admixed with the additives envisioned for the desired application.

[0100] The binders of the present invention can be formulated in the apparatuses known by a person skilled in the art for this purpose, for example stirred tanks and/or suitable mixers.

[0101] After the binder has been prepared, it is generally applied directly to mineral wool fibers to produce the mineral woof fiber mats. This can be done using relevant application methods known to a person skilled in the art, for example spraying the fibers with the dispersion. After application and thermal treatment of the moist fibrous nonwoven web raw material, the reactive binder cures and consolidates and thereby stabilizes the mineral wool fiber mat. The curing reaction is preferably induced by raising the temperature. The rate of curing, as will be known to a person skilled in the art, can be influenced through further measures via the formulation. Typical curing temperatures are preferably 70.degree. C.-250.degree. C. and more particular 130.degree. C.-180.degree. C.

[0102] The invention also provides a process for producing the above-defined mineral wool fiber mat comprising the steps of [0103] i) applying a crosslinkable composition containing an epoxy and/or carboxyl-containing copolymer and a crosslinker selected from the group of amines or amine derivatives to an unbound mineral wool fiber mat, and [0104] j) consolidating the mineral wool fibers to form a bound mineral wool fiber mat by crosslinking the binder.

[0105] The mineral wool fiber mats of the present invention combine comparable mechanical strengths and application properties with very low and preferably no formaldehyde emissions.

[0106] The mineral wool fiber mats of the present invention are particularly useful as an insulating material, more particularly for insulating, more particularly thermally insulating built structures and structural objects of any kind.

[0107] The examples which follow serve to illustrate the invention. Parts and percentages in the examples are by weight, unless otherwise stated.

EXAMPLES

Dispersion A

[0108] In a stirred glass tank equipped with stirring apparatus, anchor stirrer, feed means and electronic temperature control, 2.97 parts of .RTM.Emulsogen EPN 287 nonionic emulsifier (from Clariant), 0.5 part of .RTM.Emulsogen LS anionic emulsifier (from Clariant), 0.25 parts of sodium acetate, 0.51 part of sodium vinylsulfonate, 0.04 part of sodium metabisulfite and 0.00023 part of ammoniumiron(II) sulfate (as 1% solution) were dissolved in 60 parts of deionized water to form the initial charge.

[0109] Under agitation, 5 parts of vinyl acetate were emulsified into the initial charge. Thereafter, the initial charge was heated to 65.degree. C. with a solution of 0.22 part of sodium persulfate in 1.77 parts of deionized water being added at 40.degree. C. to start the polymerization reaction.

[0110] Once the internal temperature of 65.degree. C. was reached, the metered addition was commenced of 95 parts of vinyl acetate and 3 parts of glycidyl methacrylate and continued for 240 minutes. During the reaction, the internal temperature was maintained at 65.degree. C. 30 minutes before completion of the metered addition of monomer the temperature was raised from 65.degree. C. to 85.degree. C. in the course of 30 minutes and, concurrently, a solution of 0.11 part of sodium persulfate in 1.77 parts of deionized water was added over 30 minutes.

[0111] On completion of the metered addition of monomer the batch was maintained at 85.degree. C. for 60 minutes and then cooled down.

[0112] Solids content: 60.7%

[0113] Brookfield viscosity RVT (23.degree. C.), spindle 2, 20 rpm: 780 mPas

[0114] pH: 4.2.

Dispersions B

[0115] In a stirred glass tank equipped with stirring apparatus, anchor stirrer, feed means and electronic temperature control, 0.25 part of .RTM.Disponil A 3065 nonionic emulsifier (from Cognis) was dissolved in 31.5 parts of deionized water at the start to prepare the initial charge.

[0116] Concurrently, in a separate vessel, 2.72 parts of .RTM.Disponil A 3065 and 2 parts .RTM.Disponil FES 77 anionic emulsifier (from Cognis) were dissolved in 55.6 parts of deionized water. Under vigorous agitation, a monomer mixture of 30 parts of methyl methacrylate, 10 parts of butyl acrylate, 60 parts of styrene, 1.5 parts of glycidyl methacrylate, 2 parts of methacrylic acid and 1 part of acrylic acid was emulsified into this solution to prepare the monomer emulsion.

[0117] Furthermore, solutions were prepared of 0.195 part of sodium persulfate in 2.92 parts of deionized water (=oxidant solution) and 0.1 part of sodium metabisulfite in 0.91 part of water (=reductant solution).

[0118] The initial charge was heated to 80.degree. C. Subsequently, 2.85% (by weight) of the monoemulsion and also 22.8% (by weight) of the reductant solution were added dropwise to the initial charge. After 5 minutes, 33.3% of the oxidant solution were added to this mixture to initiate the polymerization reaction. After a further 15 minutes the metered addition was commenced of monoemulsion and initiator system (oxidant and reductant solutions), and continued for 240 minutes in the case of the monoemulsion and for 225 minutes in the case of the concurrent edition of the two solutions of the initiator system. During reaction initiation and metering, the internal temperature of the reactor was maintained at 80.degree. C.

[0119] On completion of the metered addition of monomer a solution of 0.023 part of .RTM.Tego Foamex 805 defoamer (from Evonik) in 0.13 part of deionized water was added during 5 minutes. Immediately thereafter, 1 part of methyl methacrylate was added dropwise to the polymer during 10 minutes. Following rapid addition of a solution of 0.065 part of sodium persulfate and 0.21 part of deionized water, the temperature rose to 85.degree. C. and was maintained at 85.degree. C. for 90 minutes. Then, the internal temperature was lowered to 65.degree. C. and a solution of 0.11 part of .RTM.Trigonox AW 70 (70% aqueous solution of tert-butyl hydroperoxide from Akzo) in 0.42 part of deionized water was added. After 15 minutes a solution of 0.11 part of sodium metabisulfite in 0.42 part of deionized water was added, followed by a delay time of 15 minutes. This operation was repeated immediately thereafter. Following addition of 0.033 part of ammonia (as 25% solution) in 0.13 part of deionized water the internal temperature was brought below 40.degree. C. and the dilute ammonia solution was used to set a pH of 4.5.

[0120] Solids content: 53.1%

[0121] Brookfield viscosity RVT (23.degree. C.), spindle 1, 20 rpm: 120 mPas

[0122] pH: 4.5.

Determination of Crosslink Density in Mixtures of Glycidyl-Functionalized Dispersions and Amidated Amines as Crosslinkers

[0123] Producing mineral wool fibers according to the prior art utilizes primarily phenol-formaldehyde resins which cure to form close-meshed three-dimensional networks. The high crosslink density is responsible for a plastic of very thermoset character being formed. The combination of glycidyl-functionalized polymeric dispersions and suitable crosslinkers, for example amidated amines, which is described in this invention likewise cures to form highly crosslinked polymeric systems having thermoset properties. Therefore, crosslink density is hereinafter used as a measure of the effectivity of the binding system.

[0124] Crosslink density was determined by determining insoluble constituents in thermally treated thin films formed from mixtures of dispersion and crosslinker. The method used is analogous to that described in US-A-2008/0175997. The film thickness of the substrates applied to planar-ground glass plates was 250 pm in all cases, and N-dimethylformamide (DMF) was used as solvent. A Mathis Labdryer LTE-S oven was used to heat-condition the films. The heat-conditioning time was 10 minutes for the examples listed hereinbelow. The temperatures to which the dried films were exposed for this period were varied. The corresponding temperatures are apparent from the table below, in which the investigated examples according to the invention are shown.

[0125] The samples were prepared as follows before the films were drawn down: the dispersions were admixed with 3% by weight and 6% by weight (reckoned on the solids content of the dispersion) of the appropriate crosslinker. The .RTM.Versamid 150 product from Cognis was used in the examples listed herein. The amidated amine was used as-supplied, and incorporated into the dispersion by slow stirring for 5 minutes. Subsequently, the pH of the mixture was determined, and found to be between 8 and 9.5 depending on the dispersion used and the crosslinker quantity.

[0126] The dependence of the degree of crosslinking on the temperature was determined for dispersions A and B in the experiments. In the case of dispersion A, the dependence of the degree of crosslinking on the amount of crosslinker was additionally determined. The degree of crosslinking can be influenced positively by higher temperature, longer heat-conditioning times and an optimized concentration of crosslinker. The amount of insoluble constituents from a film of dispersion A and B without added crosslinker served as a comparative example.

TABLE-US-00001 TABLE Amount of Insoluble Versamid 150 in Temperature constituents Example Dispersion % by weight in .degree. C. in % V1 A 0 210 7 V2 B 0 180 6 1 A 3 120 17 2 A 3 150 26 3 A 3 180 57 4 A 6 120 21 5 A 6 150 47 6 A 6 180 69 7 B 3 120 30 8 B 3 150 81 9 B 3 180 87

It is apparent from the table that using the suitable crosslinker in the inventive examples as compared with the comparative examples V1 and V2 (each without added crosslinker) increases the fraction of insoluble constituents and hence the crosslink density as a function of the amount of crosslinker added and of the temperature. It is further apparent that the presence of the carboxyl groups in dispersion B serves to enhance crosslink density as evidenced by the increase in the percentage of insoluble constituents, particularly clearly from a comparison of test 5 with test 8.

Claims

1. A mineral wool fiber mat bound with a binder containing an epoxy and/or carboxyl functionalized emulsion copolymer and an amine and/or an amine derivative as crosslinker.

2. The mineral wool fiber mat according to claim 1 wherein the epoxy and/or carboxyl functionalized emulsion copolymer is a polyvinyl ester, a polyacrylate or a polyalkenyl aromatic including interpolymerized units derived from glycidyl esters of ethylenically unsaturated mono- or dicarboxylic acids, and/or including interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, salts or anhydrides.

3. The mineral wool fiber mat according to claim 2 wherein the epoxy and/or carboxyl functionalized emulsion copolymer derives from alkenyl aromatics, preferably from styrene, and/or from esters of acrylic acid and/or methacrylic acid and includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated monocarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid, and/or includes interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, salts or anhydrides.

4. The mineral wool fiber mat according to claim 2 wherein the epoxy and/or carboxyl functionalized emulsion copolymer derives from esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids and includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated monocarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid, and/or includes interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, salts or anhydrides.

5. The mineral wool fiber mat according to claim 2 wherein the epoxy and/or carboxyl functionalized emulsion copolymer derives from one or more vinyl esters and includes interpolymerized units derived from glycidyl esters of ethylenically unsaturated monocarboxylic acids, preferably from glycidyl esters of acrylic acid and/or methacrylic acid, and/or includes interpolymerized units from ethylenically unsaturated mono- or dicarboxylic acids, salts or anhydrides, and/or includes interpolymerized units derived from ethylenically unsaturated mono- or dicarboxylic acids, salts or anhydrides.

6. The mineral wool fiber mat according to claim 5 wherein the epoxy functionalized emulsion copolymer in addition to the structural units derived from one or more vinyl esters contains further structural units derived from esters of .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids with C.sub.1-C.sub.8 alkanols, from .alpha., .beta.-ethylenically unsaturated C.sub.3-C.sub.8-mono- or dicarboxylic acids, from olefins or from a combination of two or more of these monomers.

7. The mineral wool fiber mat according to claim 2 wherein the epoxy functionalized emulsion copolymer is selected from the group of copolymers derived from vinyl esters of saturated carboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from vinyl esters of saturated carboxylic acids, from esters of acrylic acid and/or methacrylic acid and/or fumaric acid and/or maleic acid with C.sub.1-C.sub.8-alkanols and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from vinyl esters of saturated carboxylic acids, from ethylene, from ethylenically unsaturated carboxylic acids and and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from vinyl esters, ethylene, esters of acrylic acid and/or methacrylic acid and/or fumaric acid and/or maleic acid with C.sub.1-C.sub.8-alkanols, from ethylenically unsaturated carboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from esters of acrylic acid and/or methacrylic acid, of ethylenically unsaturated carboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids, of copolymers derived from styrene with butadiene and/or from esters of acrylic acid and/or methacrylic acid with C.sub.1-C.sub.8-alkanols, from ethylenically unsaturated carboxylic acids and from glycidyl esters of ethylenically unsaturated carboxylic acids.

8. The mineral wool fiber mat according to claim 7 wherein the polymer is an epoxy functionalized polyvinyl ester containing at least 50% by weight of vinyl acetate monomer units.

9. The mineral wool fiber mat according to at least one of claim 1 wherein the binder is introduced in the form of an aqueous dispersion of the polymer.

10. The mineral wool fiber mat according to at least one of claim 1 wherein the binder content is in the range from 0.1% to 10% by weight and preferably in the range from 0.5% to 5% by weight.

11. The mineral wool fiber mat according to at least one of claim 1 wherein the crosslinker is selected from the group of mono- or polyamines, preferably aliphatic mono- or diamines or aromatic mono- or diamines.

12. The mineral wool fiber mat according to at least one of claim 1 wherein the crosslinker is selected from the group of amides having one or more amide groups, more particularly polyaminoamides and very particularly preferably the condensation products of unsaturated aliphatic acids with polyamines.

13. The mineral wool fiber mat according to claim 12 wherein the crosslinker is selected from the group of polyaminoamides having an ASTM D 2073 amine number between 100 and 2000 mg of KOH/g of crosslinker, preferably between 250 and 1000 mg of KOH/g of crosslinker.

14. The mineral wool fiber mat according to claim 12 wherein the crosslinker used is neither alkoxylated nor hydroxyalkylated.

15. The mineral wool fiber mat according to at least one of claim 1 wherein the crosslinker is used in amounts ranging from 0.1% to 10% by weight, based on the binder, preferably between 1-10% by weight and more particularly between 2-7% by weight.

16. A process for producing the mineral wool fiber mat according to claim 1 comprising the steps of i) applying a crosslinkable composition containing an epoxy and/or carboxylfunctionalized emulsion copolymer and a crosslinker selected from the group of amines or amine derivatives to mineral wool fibers, and ii) consolidating the mineral wool fibers to form a bound mineral wool fiber mat by crosslinking the binder.

17. The process according to claim 16 wherein the crosslinkable composition is applied in the form of an aqueous dispersion.

18. The use of the mineral wool fiber mat according to any one of claim 1 as an insulating material, more particular more particularly for insulating, more particularly thermally insulating built structures and structural objects of any kind, preferably for insulating roofs.