COMPRISING ALUMINIUM TRIHYDROXIDE

TECHNICAL FIELD

The present invention relates to a cross-linkable functional latex. The present invention relates in particular to an arrangement for producing a cured latex foam composition, which is suitable for the automotive sector.

PRIOR ART

Aqueous dispersions of polymers are also known as latex. A latex is used in coatings (for example latex paint) and adhesives because it hardens by coalescence of polymer particles while water evaporates and can therefore form films without releasing potentially toxic organic substances into the environment. Another application of latex involves the production of latex foams. Aqueous dispersions of hydroxy- or carboxy- functional polymers are widely known latex.

Within the automotive market, textile coverings (such as a seat, headlining, door panel) are always fitted with a layer of polyurethane foam compound. Different types of polyurethane foam can be used depending on the location in the car and the production process of the part. The bond between textile and foam is in most cases done with the flame lamination technique.

When flame laminating, the foam passes through a flame causing a melt to form in situ. Shortly thereafter, the fabric is placed on the melt. By cooling the melt, the textile will stick to the foam. This creates a bond between textile and foam. The reason why this has been a success to date is the cost price of the process. It is perfectly possible to make a bond using glue film or hot melt, but this is much more expensive and therefore less interesting for the automotive sector.

For curing latex to latex-based products, such as a latex film or latex foam, a cross linker is of great importance. Amino resins can be used to cross-link hydroxy- functional latex; adipine dihydrazide can be used to cross-link diacetone acrylamide latex. Latex compositions with hydroxy-functional polymers and amino resins or polyisocyanates as cross-linkers are known in the art, as illustrated in WO 2017/006298, EP 698 638 and US 6,592,944. WO 2017/006298 relates to a cross-linkable hydroxy-functional latex, wherein said latex comprises 10.0 to 65.0 wt% of hydroxy-functional latex; 0.1 to 25.0 wt% cross linker; 0.1 to 10.0 wt% of a surfactant; and at least 20.0 wt% of filler; supplemented with water up to 100.0 wt%. Examples of suitable cross-linkers include aminoplasts comprising methylol and/or methylol ether groups and polyisocyanates or carbamates. The cured latex compound from WO 2017/006298 is suitable for various carpets and upholstery. The cured latex compound can be used as a textile backing, the latex compound can be applied to the textile before drying and curing.

EP 0 698 638 describes for this purpose a cross-linkable water-based dispersion of a hydroxy-functional polydiene polymer composition, comprising : (a) 10 to 65 wt% of a hydroxy-functional polydiene polymer, (b) 0.2 to 25 wt% of a suitable amino resin, (c) 0.1 up to 10 wt% of a surfactant which is ionic or anionic and has a volatile cation, and (d) the remainder water. The technology of EP 0 698 638 also provides a water- continuous process and an inversion process for producing such dispersions.

The problem that US 6,592,944 seeks to solve relates to transparent cover layers suitable for multilayer coatings. There is a need for clear coating formulations with an excellent balance of performance characteristics after application, and this mainly with regard to the scratch resistance with a high amount of solids and a low application viscosity of the coating.

US 6,592,944 describes for this purpose a transparent coating composition which is suitable, among other things, for use as a transparent coating layer in, among other things, finishing layers in the automotive industry. The coating composition comprises polyisocyanate, polyester polyol and melamine components, with more than half of the total solid-based composition comprising the polyisocyanate and melamine components.

WO 02/26873 relates to a composition for preparing a latex foam. Such a composition comprises a latex, an epoxy silane as cross-linker and optionally various additives such as antioxidants and additives for improving resilience.

WO 2017/006298, EP 698 638 and US 6,592,944 present the problem that the compositions comprise an excess of expensive functional chemical agents. A more considered choice of the composition with attention to widely available components would reduce the dependence on suppliers and also mean a considerable cost saving. In addition, there remains a need for improved compositions for preparing latex foam which can be used directly in the automotive industry without the use of flame lamination techniques or similar cost, time and energy saving techniques.

There remains a need in the art for an improved, water-based and more environmentally friendly foam composition for technical textiles.

Styrene butadiene rubber is widely used in the automotive sector. However, normal vulcanisation with sulfur is preferably avoided for unpleasant odours and environmental problems Thus, there remains a need for a suitable replacement of styrene butadiene rubber by another more suitable polymer for the automotive industry.

It is an object of the present invention to find a solution to at least one of the aforementioned problems.

SUMMARY OF THE INVENTION

A first aspect of the invention relates to a cross-linkable functional latex, comprising :

10.0 to 55.0 wt% functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt% comprising at least one carboxy functional group in an amount of 0.05 wt% relative to the total weight of said latex;

optionally, up to 15.0 wt% cross-linker;

up to 15.0 wt% of a surfactant; and

40.0 to 70.0 wt% aluminium trihydroxide;

supplemented with water up to 100.0 wt%,

whereby the cross-linkable functional latex further comprises a functional monomer, said functional monomer being a hydroxy- or a carboxy-functional monomer or a mixture thereof.

The present invention relates to cross-linkable functional latex based on styrene and butadiene or similar monomers (90 to 99.5%). The term "similar monomers" as used herein refers to derivatives of styrene and butadiene or the monomers which can be polymerized in a similar way as styrene or butadiene itself. In should be understood by a skilled person that "polymerized in a similar way" means that the resulting polymer has similar physiochemical properties as the polymer obtained when styrene and butadiene are polymerized together. The wide variety of monomers which polymerize in a polymer of the similar physiochemical properties to the styrene- butadiene polymers can be used without departing from the scope of protection.

An overview of functional monomers used in the cross-linkable functional latex according to the first aspect of the invention and possible cross-linkers is shown as Table 1.

The present invention relates to an aqueous formulation developed on the basis of the hydroxy- and/or carboxy-functional latex and the cross-linking techniques with different cross-linkers. In a preferred embodiment, the present invention provides a cross-linkable carboxylated latex for the use of epoxy silanes as integrated, post additive cross-linkers. In a further preferred embodiment, even in the case of carboxylated latex, complex metal ions of the filler would also function as ionic cross linkers.

In another embodiment, the present invention provides a cross-linkable hydroxy- functional latex with amino resins, blocked isocyanate, carbamates, and other aminoplasts. In another embodiment, the present invention relates to a hybrid cross-linkable latex, with hydroxy and carboxy-functional monomers with in each case one or two or more suitable cross-linkers possibly dependent on the said functional monomers.

Aluminium trihydroxide has been added as a fire-retardant filler. In addition, this filler was used specifically for optimising the material properties. The said amount of aluminium trihydroxide of 40.0-70.0 wt% can be used to supplement the cross- linkable functional latex and thus provide the desired material properties, in particular a dimensional stability. Care must be taken that the finally cured latex retains a sufficiently high stability; that is, in which no failure of filler material or filler occurs.

The greatest advantage of the above-mentioned latex is that the textile manufacturer can apply the latex directly to the textile backing material. This results in no cutting waste and there is much less loss of raw materials. The burning off of residual material is completely eliminated, which means that we have a less toxic process that entails less loss of raw materials. In addition, the proposed latex is completely water-based and therefore more environmentally friendly.

A second aspect of the invention relates to a method wherein said latex foam composition, comprising a cross-linkable functional latex with a surfactant, aluminium trihydroxide in an amount between 40.0 to 70.0 wt% relative to the total weight of said latex foam composition, a thickening agent and optionally a cross-linker, a foam stabiliser and/or a foam booster, is applied directly to a textile backing, and then cured.

In particularly preferred embodiment, the invention relates to a method wherein said latex foam composition, comprising a cross-linkable functional latex comprising :

10.0 to 55.0 wt% functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt% comprising at least one carboxy functional group in an amount of 0.05 wt% relative to the total weight of said latex, whereby the cross- linkable functional latex further comprises a functional monomer, said functional monomer being a hydroxy- or a carboxy-functional monomer or a mixture thereof; optionally, up to 15.0 wt% cross-linker;

up to 15.0 wt% of a surfactant; and aluminium trihydroxide in an amount between 40.0 to 70.0 wt% relative to the total weight of said latex foam composition, a thickening agent, and optionally a foam stabiliser and/or a foam booster, is applied directly to a textile backing, and then cured. A third aspect of the invention relates to a method for producing a cured latex compound, comprising the steps of:

providing a cross-linkable functional latex polymer comprising at least a carboxy functional group in an amount of at least 0.05 wt% relative to the total weight of said latex;

mixing said cross-linkable functional latex with optionally a cross-linker, and further with a surfactant, a filler, a thickening agent and optionally a foam stabiliser and/or a foam booster, thereby obtaining a latex foam composition;

optionally, spreading said latex foam composition on a substrate; and

drying said latex foam composition, thereby obtaining a cured latex compound, wherein aluminium trihydroxide is mixed as a filler in an amount between 40.0 to 70.0 wt%, relative to the total weight of said latex foam composition.

In a particularly preferred embodiment, the present invention relates to a method for producing a cured latex compound, comprising the steps of:

providing 10.0 to 55.0 wt% cross-linkable functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt%, comprising at least one carboxy functional group in an amount of 0.05 wt% relative to the total weight of said latex, whereby the cross-linkable functional latex further comprises a functional monomer, said functional monomer being a hydroxy- or a carboxy-functional monomer or a mixture thereof;

mixing said cross-linkable functional latex with optionally up to 15.0 wt% of a cross-linker, and further with up to 15.0 wt% of a surfactant, a filler, a thickening agent and optionally a foam stabiliser and/or a foam booster, thereby obtaining a latex foam composition;

optionally, spreading said latex foam composition on a substrate; and drying said latex foam composition, thereby obtaining a cured latex compound, wherein aluminium trihydroxide is mixed as a filler in an amount between 40.0 to 70.0 wt%, relative to the total weight of said latex foam composition.

A fourth aspect of the invention relates to a cured latex compound obtainable according to a method according to the third aspect of the invention.

In a fifth aspect, the present invention provides an arrangement comprising a cured latex compound according to the third aspect of the invention, such as interior textile for the automotive industry, such as for car seat, car door and floor panel textiles. In a sixth aspect, the present invention provides a use of a cross-linkable functional latex according to the first aspect of the invention for producing a cured latex foam composition.

DETAILED DESCRIPTION

A first aspect of the invention provides a cross-linkable functional latex, comprising :

- 10.0 to 55.0 wt% functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt%, comprising at least a carboxy functional group in an amount of at least 0.05 wt% with respect to the total weight of said latex;

- optionally up to 15.0 wt% cross-linker;

- up to 15.0 wt% of a surfactant; and

- 40.0 to 70.0 wt% aluminium trihydroxide;

supplemented with water up to 100.0 wt%,

whereby the cross-linkable functional latex further comprises a functional monomer, said functional monomer being a hydroxy- or a carboxy-functional monomer or a mixture thereof.

Aluminium trihydroxide as a filler can be used to optimise the material properties of a composition. Said amount of filler in the cross-linkable functional latex of between 40.0 wt% to 70.0 wt%, preferably more than 45.0 wt%, more than 50.0 wt%, more than 55.0 wt%, and even more than 60.0 wt%; and less than 70.0 wt%, less than 67.0 wt%, and even less than 65.0 wt% of aluminium trihydroxide can be used to supplement the cross-linkable functional latex and thus to support the desired material properties.

It has unexpectedly been found that cross-linkable latex according to the present invention offers satisfactory properties and resilience even if no additional cross-linker was added to the mixture. Without being bound by mechanistic considerations, it is believed that this effect can be attributed to the use of aluminium trihydroxide by the formation of ionic bonds between aluminium and the free electron pairs specific to said latex, specifically with carboxylic acid functional groups present in said latex. Possibly Al ³⁺ ions are responsible for this cross-linking behaviour. Aluminium trihydroxide thus exhibits cross-linking properties. Moreover, it appears that aluminium hydroxide has better properties than other fillers known in the art, such as, for example, chalk (CaCCh). Aluminium trihydroxide is particularly suitable for the cross-linkable latex without conventional cross-linkers. It has unexpectedly been found that aluminium trihydroxide can act as a cross-linker in latex of the invention. Thus, the latex foam composition of the present invention has an improved characteristic, but a lower price, because it does not comprise additional cross-linkers in the composition. Aluminium hydroxide is non-carcinogenic, low toxic, halogen free and flame retardant. In addition to those properties, aluminium hydroxide can form gels in water. In fact, due to the formation of gels, aluminium hydroxide is occasionally used to purify waste water as the flocculating agent. Because gel has a strong adsorption capacity, suspended solids can be adsorbed and precipitated. The inventors realised that this property may be advantageous for cross-linking latex. Experiments indeed confirmed that aluminium has trihydroxide cross-linking properties, which contributes to good properties of the latex. The properties of the obtained latex are mainly advantageous for products in the automotive sector. Thereby care must be taken that the final cured latex foam composition retains a sufficiently high stability and is suitable for the textile manufacturers that can be applied directly to the textile; that is, in which no failure of filler material or filler occurs.

The percentages stated in this text are to be understood as percentages by weight and are abbreviated as 'wt%'.

A dispersion is a material comprising a plurality of phases in which at least one phase consists of finely divided phase domains, often in the colloidal size range, which is dispersed in a continuous phase. Dispersions include emulsions, suspensions, and smoke. An emulsion is a colloidal mixture of liquids, a suspension is a solid suspended in a liquid, and a smoke is a mixture of solid and/or liquid substances very finely distributed in a gas. The term 'aqueous dispersion' refers to a dispersion in which the continuous phase is water. The term 'aqueous emulsion' refers to an emulsion in which one of the liquids is water.

A cross-linkable latex is an aqueous dispersion or emulsion of one or more hydroxy- or carboxy-functional polymers or a mixture thereof. The hydroxy- or carboxy- functional polymers or a mixture thereof, are preferably polymerised in an aqueous emulsion with surfactants and regulators under specific time, temperature, pressure and agitation in accordance with the known principles of emulsion polymerisation, to form a latex. For the production of derived products of latex or cured latex compounds, it is important that the polymers of the latex are cross-linkable. The term 'cross- linkable' refers to a chemical compound that can be cross-linked. 'Cross-linking' refers to the interconnection of chemical compounds. Cross-linking a hydroxy- or carboxy- functional polymer according to the present invention will cause the latex to cure into a cured latex compound. In a preferred embodiment, the cross-linkable latex of the present invention comprises a functional monomer in an amount between 0.05 wt% to 10.0 wt%, preferably more than 1.5 wt%, and even more than 2.0 wt%; and less than 5.0 wt%, and even less than 4.0 wt% relative to the total weight of said cross-linkable latex.

In a preferred embodiment, the cross-linkable latex of the present invention comprises a polymer latex, said latex polymer comprising at least a carboxy-functional group in an amount of 0.05 wt% to 15.0 wt% relative to the total weight of said latex, preferably more than 0.1 wt% to 10.0 wt%, and less than 7.5 wt%, and even less than 5.0 wt% relative to the total weight of said latex. More preferably, said latex polymer comprises 0.10, 0.15, 0.20, 0.25, 0.30, 0.40, 0.50, 0.60, 0.70, 0.80, 0.90, 1.00, 1.25, 1.50, 1.75, 2.00, 2.50, 3.00, 3.50 or 4.00 wt% of a monomer with a carboxy-functional group, or any amount in between.

A 'carboxy-functional polymer' or carboxylated latex is a polymer with one or more functional carboxyl groups. The carboxylic acid monomers that can be used in the production of the polymers of this invention are the olefinically unsaturated carboxylic acids containing at least one active olefinic carbon-carbon double bond, and at least one carboxyl group, i.e. an acid containing an olefinic double bond that works well in polymerisation. Examples of these include low molecular weight carboxylic acids with a number average molecular weight of less than about 500 daltons, such as aliphatic, cycloaliphatic and aromatic acids, mainly acids with 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms. In a preferred embodiment, the present invention provides an acrylic or a metacrylic acid as a functional monomer in the cross-linkable functional latex of the present invention. Non-limiting examples comprise acrylic acid, methacrylic acid, ethacrylic acid, alpha-chloroacrylic acid, alpha-cyanoacrylic acid, beta-methyl-acrylic acid (crotonic acid), alpha-phenylacrylic acid, beta- acryloxypropionic acid, sorbic acid, alpha-chloro sorbic acid, cinnamic acid, p-chloro cinnamic acid, beta-styryl acrylic acid (l-carboxy-4-phenylbutadiene-l,3), itaconic acid, citraconic acid, mesaconic acid, glutaconic acid, aconitic acid, maleic acid, fumaric acid, tricarboxyethylene and the like.

A 'hydroxy-functional polymer' is a polymer with one or more functional hydroxy groups. Polymers with two functional hydroxy groups, i.e. diols, and polymers with more than two functional hydroxy groups are referred to as 'polyols' in this text. Examples of these comprise low molecular weight polyols with a number average molecular weight of less than about 500 daltons, such as aliphatic, cycloaliphatic and aromatic polyols, mainly diols with 2 to 20 carbon atoms, preferably 2 to 10 carbon atoms and 'macroglycols', i.e. polymeric polyols with molecular weights of at least 500 daltons, more typically about 1000 to 6000 daltons, or even 1000 to 10000 daltons. Examples of such macroglycols comprise polyester polyols comprising alkyd resins, polyether polyols, polycarbonate polyols, polyhydroxy polyester amides, hydroxy- containing polycaprolactones, hydroxy-containing acrylic polymers, hydroxy- containing epoxides, polyhydroxy polycarbonates, polyhydroxy polyacetals, polyhydroxy polythioethers, polysiloxane polyols, ethoxylated polysiloxane polyols, polybutadiene polyols and hydrogenated polybutadiene polyols, polyisobutylene polyols, polyacrylate polyols, halogenated polyesters and polyethers, and the like and mixtures thereof.

The latex may comprise an additional ethylenically unsaturated monomeric component or components such as butadiene derivatives which are polymerized with styrene. Specific examples of such ethylenically unsaturated compounds comprise methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, phenyl acrylate, acrylonitrile, methacrylonitrile, ethyl chloroacrylate, diethyl maleate, polyglycol maleate, vinyl chloride, vinyl bromide, vinylidene chloride, vinylidene bromide, vinyl methyl ketone, methyl isopropenyl ketone and vinyl ethyl ester. Derivatives thereof and/or mixtures thereof can be comprised.

Other acrylic or methacrylic acid derivatives are also suitable functional monomers according to the present invention. In one embodiment, amides such as acrylamide, methacrylamide, diacetone acrylamide and the like are defined as functional monomers.

In another embodiment, epoxides such as glycidyl methacrylate are used as functional polymers.

Hydroxy-functional polymers suitable within the scope of this invention are hydroxy- functional polydiene polymers. Hydroxy-functional polydiene polymers suitable for the present invention are monohydric alcohols, diols and polyols of hydrogenated and non- hydrogenated low molecular weight diene homopolymers and copolymers with more than one diene and/or a vinyl aromatic hydrocarbon. Such copolymers are usually random copolymers or tapered block copolymers because it is difficult to make low- molecular weight copolymers with a sharp separation between the blocks because the crossover reaction from one monomer to another is usually low compared to the propagation reaction. In a most suitable embodiment, said hydroxy-functional latex comprises a styrene-butadiene polymer. Suitable polymers comprise monohydric alcohols, diols and polyols of low molecular weight polybutadiene and polyisoprene and their copolymers with styrene, either hydrogenated or non-hydrogenated.

Hydrogenated polybutadiene diols are preferred for use in this invention because they can be easily prepared since they have a low glass transition temperature and excellent weather resistance. The diols, d i hydroxy lated polybutadienes, are synthesized by anionic polymerisation of conjugated diene hydrocarbons with lithium initiators. Monohydric alcohols and polyols can also be synthesized in the same way. This method is known and described, for example, in U.S. patent specifications with numbers US 4,039,593 and US RE 27,145.

According to the present invention, unsaturated linear or hydrogenated isoprene polymers with 1-2 terminal hydroxy groups per molecule and also such polymers with other hydroxy groups can also be used. Preferably, the isoprene polymers have more than 80% 1,4 addition of the isoprene and hydrogenation of at least 90% of the polymerised isoprene. Preferably, the polymers are prepared by anionic polymerisation in the absence of microstructure modifiers that increase 3,4 addition of the isoprene.

The hydroxy-functional polydiene polymers have suitable molecular weights from 1,000 to 3,000,000. Lower molecular weights require excessive cross-linking while higher molecular weights lead to very high viscosity, making processing difficult.

In a preferred embodiment, styrene and butadiene in 90 to 99.5 wt% are used as monomers in the cross-linkable functional latex according to the first aspect of the invention. In another embodiment, styrene or butadiene may be replaced by any suitable derivative thereof or a similar monomer which could be polymerized instead of styrene or butadiene. It should be understood by a skilled person that any monomer which can be polymerized in a similar way as styrene or butadiene itself may be used without departing from the scope of the invention. In should be understood by a skilled person that "polymerized in a similar way" means that the resulting polymer has similar physiochemical properties as the polymer obtained when styrene and butadiene are polymerized together. The wide variety of monomers which polymerize in a polymer of the similar physiochemical properties to the styrene-butadiene polymers can be used without departing from the scope of protection. Some non limiting examples for the derivatives of styrene are alpha-methylstyrene, ethylstyrene, dimethylstyrene, t-butylstyrene, vinylnaphthalene, methoxystyrene, cyanostyrene, acetylstyrene, monochlorostyrene, dichlorostyrene, and other halostyrenes, and mixtures thereof. Alkenyl aromatic hydrocarbons that can be copolymerised comprise vinyl aryl compounds such as styrene, various alkyl-substituted styrenes, alkoxy- substituted styrenes, vinyl naphthalene, alkyl-substituted vinyl naphthalenes, and the like. Some non-limiting examples for the derivatives of butadiene are diolefins that can be polymerised anionically comprise those conjugated diolefins comprising 4 to 24 carbon atoms, such as 1,3-butadiene, isoprene, piperylene, methyl pentadiene, phenylbutadiene, 3,4-dimethyl-l,3-hexadiene, 4,5-diethyl-l,3-octadiene and the like. Isoprene and butadiene are the preferred conjugated diene monomers for use in the present invention because of their low cost and easy availability. The conjugated diolefins that can be used in the present invention comprise isoprene (2-methyl-l,3- butadiene), 2-ethyl-l, 3-butadiene, 2-propyl-l, 3-butadiene, 2-butyl-l, 3-butadiene, 2- pentyl-1, 3-butadiene (2-amyl-l, 3-butadiene), 2-hexyl-l, 3-butadiene, 2-heptyl-l,3- butadiene, 2-octyl-l, 3-butadiene, 2-nonyl-l, 3-butadiene, 2-decyl-l, 3-butadiene, 2- dodecyl-1, 3-butadiene, 2-tetradecyl-l, 3-butadiene, 2-hexadecyl-l, 3-butadiene, 2- isoamyl-1, 3-butadiene, 2-phenyl-l, 3-butadiene, 2-methyl-l,3-pentadiene, 2-methyl- 1,3-hexadiene, 2-methyl-l,3-heptadiene, 2-methyl-l,3-octadiene, 2-methyl-6- methylene-2,7-octadiene (myrcene), 2-methyl-l,3-nonyldiene, 2-methyl-l,3- decyldiene and 2-methyl-l,3-dodecyldiene, as well as 2-ethyl, 2-propyl, 2-butyl, 2- pentyl, 2-hexyl, 2-heptyl, 2-octyl, 2-nonyl, 2-decyl, 2-dodecyl, 2-tetradecyl, 2- hexadecyl, 2-isoamyl and 2-phenyl versions of all these dienes. Also included are 1,3- butadiene, piperylene, 4,5-diethyl-l,3-octadiene and the like. Disubstituted conjugated diolefins that can be used comprise 2,3-dialkyl-substituted conjugated diolefins, such as 2, 3-dimethyl-l, 3-butadiene, 2,3-diethyl-l,3-pentadiene, 2,3- dimethyl-l,3-hexadiene, 2,3-diethyl-l,3-heptadiene, 2, 3-dimethyl-l, 3-octadiene and the like and 2,3-fluoro-substituted conjugated diolefins such as 2,3-difluoro-l,3 - butadiene, 2,3-difluoro-l,3-pentadiene, 2,3-difluoro-l,3-hexadiene, 2,3-difluoro-l,3- heptadiene, 2, 3-fluoro-l, 3-octadiene, methyl methacrylate, ethyl acrylate, butyl acrylate, hexyl acrylate, 2-ethylhexyl acrylate, lauryl methacrylate, phenyl acrylate, acrylonitrile, methacrylonitrile, ethyl-chloroacrylate, diethyl maleate, polyglycol maleate, vinyl chloride, vinyl bromide, vinylidene chloride, vinylidene bromide, vinyl methyl ketone, methyl isopropenyl ketone, and vinyl ethyl ester and mixtures thereof.

In an embodiment, the present invention provides a hybrid functional latex. A hybrid functional latex comprises at least two functional monomers. In another embodiment, hybrid latex of the present invention comprises more than two functional monomers. In a preferred embodiment, the cross-linkable hybrid latex comprises a hydroxy- and a carboxy-functional monomer.

Preferably, the cross-linkable functional latex according to the first aspect of the invention comprises a hydroxy- and/or carboxyl-functional styrene / butadiene polymer, such as, for example, but not limited to, a carboxylated styrene-butadiene- styrene tri-block copolymer, a hydroxylated styrene-butadiene-styrene tri-block copolymer, a carboxylated styrene-butadiene random copolymer or a hydroxylated styrene-butadiene random copolymer. Both block copolymers and random or statistical copolymers are copolymers in which the mutual ratio of the monomer units changes along the polymer chain. With block copolymers, said mutual ratio changes abruptly, while with statistical or 'random' copolymers, said mutual ratio changes irregularly.

A latex as referred to in the present invention may also be a multimodal latex characterised by two or more latexes with different average particle size and/or particle size distribution; solids content and/or rheology parameters.

The term 'cross-linker' is to be understood as a synonym for the term 'curing means', 'curing agent', 'hardening means', 'hardening agent', 'hardener', 'cross-linking means' or 'cross-linking agent' and comprises substances or mixtures of substances which are added to a polymer compound to promote or control the curing reaction, i.e. the cross- linking. Preferably, the term 'cross-linker' refers to a reactive curing agent or hardener which is provided with at least two functional groups which can react with a functional groups of functional monomers or can make an ionic, coordinative or covalent chemical bond and is thus suitable for causing the curing of a polymer. A suitable cross-linker in the context of the present invention relates to a cross-linker with at least two functional groups that are reactive with hydroxy groups.

Examples of suitable cross-linkers include epoxy silanes as an integrated cross-linker in the carboxylated latex of the present invention. Various epoxy resins are suitable cross-linkers with carboxylated latex according to the present invention. Preferably, various complex metal ions such as, but not limited to, aluminium, magnesium, zinc, calcium lactate, Zn(NH3)4 ²⁺ (e.g., Puracal, Puramex AL Aluminium -L-lactate from Corbion) are suitable cross-linkers with carboxylated latex according to the present invention. Another example of suitable cross-linkers with carboxylated latex are carbodiimides (e.g., Desmodur xp 2802 from Bayer). Any mineral known in the art that is used as a filler or other purpose can represent a source of multivalent cations. In one embodiment, clay can be used as a source of multivalent cations. In another embodiment, hard water is used as a source of multivalent cations. In a preferred embodiment, the present invention provides that said cross-linkable latex is a carboxylated latex, wherein said carboxylated latex comprises ZnO as an ionic cross linker. Without being bound by mechanistic considerations, it is possible that ZnO in the presence of NH3 forms a multivalent, complex cation [Zn(NH3)4]2 ²⁺ .

Preferably, the hydroxy-functional cross-linkable latex comprises aminoplasts. These aminoplasts comprise methylol and/or methylol ether groups and polyisocyanates. Aminoplasts are obtained from the reaction of formaldehyde with an amine or amide. The most common amines or amides are melamine, urea or benzoguanamine, and are preferred. However, condensates with other amines or amides can be used; for example aldehyde condensates of glycoluril, which yield a high-melting crystalline product useful in powder coatings. Although the aldehyde used is mostly formaldehyde, other aldehydes such as acetaldehyde, crotonaldehyde and benzaldehyde can be used. Preferably, formaldehyde scavenger can be used to collect the released formaldehyde.

The aminoplast contains methylol groups and preferably at least a portion of these groups are etherified with an alcohol to modify the cure response. Any monohydric alcohol can be used for this purpose, including methanol, ethanol, butanol, isobutanol, and hexanol.

Preferably, the aminoplasts used are melamine, urea or benzoguanamine formaldehyde condensates etherified with an alcohol having one to four carbon atoms.

In an embodiment in which amides are used as functional monomers in the latex, amino resins are preferably used as cross-linkers.

In another embodiment, wherein diacetone acrylamide is used as a functional monomer in the latex of the invention, adipine dihydrazide is used as a cross-linker.

In another embodiment, wherein epoxide (e.g., gycidyl methacrylate) is used as a functional monomer in the latex of the invention, polyamine is used as a cross-linker. A surfactant is also referred to as a 'surface-active substance' or 'surface-active agent'. A surfactant normally comprises a hydrophobic and hydrophilic moiety. The hydrophobic moiety here comprises a chain length of 4 to 20 carbon atoms, preferably 6 to 19 carbon atoms and even more preferably 8 to 18 carbon atoms. Preferably, the surfactant used will be selected from the group of the anionic, cationic or non-ionic surfactants. Preferably, said cross-linkable functional latex comprises a surfactant in an amount of 0.1 to 15.0 wt%, relative to the total weight of the cross-linkable latex, and more preferably in an amount of 0.5 to 12.0 wt%, and still more preferably from 5.0 to 11.0 wt%. Most preferably, said aqueous composition comprises a surfactant in an amount of 5.0, 6.0, 7.0, 8.0, 9.0, 10.0 or 11.0 wt%, or any value in between.

Anionic surfactants comprise saponified fatty acids and derivatives of fatty acids with carboxyl groups such as sodium lauryl sulfate, sodium dodecyl benzene sulfonate, sulfates and sulfonates, and abietic acid. Examples of anionic surfactants are also: carboxylates, sulfonates, sulfo fatty acids, methyl esters, sulfates, phosphates. The anionic surfactants are preferably added as a salt. Salts are, for example, alkali metal salts, such as sodium, potassium, lithium, ammonium, hydroxyethyl ammonium, di(hydroxyethyl) ammonium and tri(hydroxyethyl) ammonium salts or alkanolamine salts. Most preferably, said surfactants comprise sodium dicyclohexyl sulfosuccinate, diarium mono- and diodecyl diphenyl oxid sulfones, and sodium alkyl benzene sulfonate or a combination of the foregoing. Non-limiting examples are Eurovet CH® (EOC Surfactant), Aerrosol DPOS-45® (CYTEC), Marlon A 375 (SASOL). Mixtures of disodium mono- and didodecyl diphenyl oxide sulfone and Sodium alkyl benzene sulfonate are preferred as these ingredients do not contribute to the total VOCs of the coating.

Cationic surfactants comprise dialkyl benzene alkyl ammonium chloride, alkylbenzyl methyl ammonium chloride, alkyl benzyl dimethyl ammonium bromide, benzalkonium chloride, cetyl pyridinium bromide, C12, C15, of C17 trimethyl ammonium bromides, halide salts of quaternised polyoxyethylalkylamines, dodecyl benzyl triethyl ammonium chloride and benzalkonium chloride. Examples of cationic surfactants are also: quaternary ammonium compounds. A quaternary ammonium compound is a compound which comprises at least one R4N ⁺ group in its molecule.

A betaine surfactant is a compound which, under conditions of use, comprises at least one positive charge and at least one negative charge. An alkyl betaine is a betaine surfactant, which comprises at least one alkyl unit per molecule. Non-ionic surfactants comprise polyvinyl alcohol, poly-acrylic acid, methalose, methyl cellulose, ethyl cellulose, propyl cellulose, hydroxy ethyl cellulose, carboxymethyl cellulose, natural gums, polyoxyethylene cetyl ether, polyoxyethylene lauryl ether, polyoxyethylene octyl ether, polyoxyethylene octylphenyl ether, polyoxyethylene oleyl ether, polyoxyethylene sorbitan monolaurate, polyoxyethylene stearyl ether, polyoxyethylene nonylphenyl ether and dialkylphenoxy poly (ethyleneoxy) ethanol.

Non-ionic surfactants have a neutral, polar and hydrophilic head, which makes non ionic surfactants water-soluble. Such surfactants adsorb to surfaces and aggregate to micelles above a critical micelle concentration. According to the nature of the head, different surfactants can be distinguished, such as (oligo)oxyalkylene groups, and in particular (oligo)oxyethylene groups, (polyethylene)glycol groups and carbohydrate groups, such as alkyl polyglucosides and fatty acid N-methyl glucamides.

Alcohol phenol alkoxylates are surfactants which can be produced by addition of alkylene oxide, preferably ethylene oxide to alkyl phenols. Non-limiting examples are: Norfox® OP-102, Surfonic® OP-120, T-Det® 0-12.

Fatty acid ethoxylates are fatty acid ester surfactants that have been treated with different amounts of ethylene oxide. Triglycerides are esters of glycerols (glycerides), in which all three hydroxyl groups are esterified with fatty acids. These can be modified with alkylene oxides. Fatty acid alcohol amides comprise at least one amide group with an alkyl group and one or two alkoxyl groups. Alkyl polyglycosides are mixtures of alkyl monoglucosides (alkyl-a-D and -b-D-glucopyranoside with a small amount of -glucofuranoside), alkyldiglucosides (isomaltosides, maltosides and others) and alkyl oligoglucosides (maltotriosides, tetraosides, tetraosides). Alkyl polyglycosides can be synthesised non-limitingly by an acid-catalysed reaction (Fisher reaction) of glucose (or starch) or n-butyl glycosides with fatty acid alcohols. Furthermore, alkyl polyglycosides can also be used as a non-ionic surfactant. A non-limiting example is Lutensol® GD70. In addition, non-ionic N-alkylated, preferably N-methylated, fatty acid amides can also be used as surfactant.

Alcohol alkoxylates comprises a hydrophobic moiety with a chain length of 4 to 20 C atoms, preferably 6 to 19 C atoms and more preferably 8 to 18 C atoms, wherein the alcohol can occur linearly or branched, and a hydrophilic moiety which can contain alkoxylate units, such as ethylene oxide, propylene oxide and/or butylene oxide, with 2 to 30 repeat units. Non-limiting examples are: Lutensol® XP, Lutensol® XL, Lutensol® ON, Lutensol® AT, Lutensol® A, Lutensol® AO, Lutensol® TO.

It has been found that the incorporation of a surfactant can improve the working life of the curable or cross-linkable functional latex of the present invention.

By the term 'filler' as used herein is meant a component that can improve the material properties of a composition by, for example, improving its texture or structure, by providing dimensional stability and reduced elasticity, by providing fire resistance properties and/or by reducing the total cost of the composition. These functional characteristics of a filler indicate the advantage of using a certain amount of filler in the cross-linkable functional latex according to the present invention.

Aluminium trihydroxide is used as a filler in an amount of between 40.0 wt% to 70.0 wt%, preferably more than 45.0 wt%, more than 50.0 wt%, more than 55.0 wt%, and even more than 60.0 wt%; and less than 70.0 wt%, less than 67.0 wt%, and even less than 65.0 wt% aluminium trihydroxide. According to a preferred embodiment, further fillers can be used. Examples of fillers comprise, but are not limited to, chalk, talc, limestone, barium sulfate, kaolin, silica, aluminium trioxide, magnesium hydroxide, clay, melamine, or a combination of the foregoing. According to a preferred embodiment, chalk and melamine are used as additional fillers. The filler can be recycled from any source and can be in any physical form that makes it possible to be diffused or mixed with the other components of a composition.

As mentioned above, a filler is a component that can improve the material properties of a composition by, for example, improving its texture or structure, by providing dimensional stability and reduced elasticity, by providing fire resistance properties and/or by reducing the overall cost of the composition. The said amount of aluminium trihydroxide in the cross-linkable functional latex of at least 40.0 wt% can be used to obtain a cross-linkable functional latex with desired, improved and advantageous material properties obtained by applying a filler.

In a preferred embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein said filler is comprised in an amount of 40.0 to 85.0 wt%. Excessive amounts of filler in a cross-linkable functional latex according to the present invention cause negative effects, including failure problems of filler in curing the cross- linkable functional latex, excessively reduced elasticity, non-optimal compression properties, and a non-optimal wear resistance of a cured product. 'Failure' of filler refers to a portion of filler that is not bonded with the rest of the cross-linkable functional latex upon curing. Too low an amount of a filler also leads to a more expensive product, requires a producer to add other more expensive and less available components in larger quantities, and leads to an inefficient use of the aforementioned improved properties that can be obtained through a filler.

It has been unexpectedly found that the high content of filler and in particular aluminium trihydroxide as filler contributes to an improved fire resistance of the latex of the present invention.

The stated amount of filler in the cross-linkable functional latex of from 40.0 to 85.0 wt% gives rise to a cross-linkable functional latex with highly desirable, improved and advantageous properties obtained by using a filler, while avoiding negative effects due to a too high filler content.

In a preferred embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein aluminium trihydroxide is comprised in an amount of between 40.0 wt% to 70.0 wt%, preferably more than 45.0 wt%, more than 50.0 wt%, more than 55.0 wt%, and even more than 60.0 wt%; and less than 70.0 wt%, less than 67.0 wt%, and even less than 65.0 wt% of aluminium trihydroxide relative to the total weight of the latex foam composition of the present invention. The said amount of aluminium trihydroxide in the cross-linkable functional latex gives rise to a cross-linkable functional latex with the most desirable, improved and advantageous properties obtained by using a filler, while avoiding negative effects due to a too high filler content.

In a most preferred embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein aluminium trihydroxide is comprised in an amount of at least 60.0 wt% to 65.0 wt% relative to the total weight of the latex foam composition according to the present invention.

In an embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein said additional fillers are preferably chalk and melamine. Chalk, or chalk stone, is a sedimentary rock that consists almost entirely of the calcareous skeletons of algae and other fauna, the so- called coccolites. It is a limestone, and therefore consists of CaCCh. Chalk is widely available and is not harmful to the environment. In addition, chalk is known as a cheap filler. These properties illustrate why chalk is preferred as filler in the cross-linkable functional latex of the present invention.

Use of one or more of these additional fillers in the cross-linkable functional latex according to the present invention allows a large freedom of choice of fillers depending on technical considerations. For example, types and quantities of fillers can be selected to obtain or optimise desired material properties, such as texture and fire resistance.

In a preferred embodiment, the present invention provides a cross-linkable carboxylated latex according to the first aspect of the invention, wherein the cross linker is an epoxy silane cross-linker.

An epoxy silane cross-linker is an integrated, functional cross-linker that can be used for cross-linking. Use of epoxy silane functional cross-linkers in a cross-linkable functional latex according to the present invention offers the advantage that cured products obtained from the cross-linkable latex exhibit highly desirable hardness properties as well as highly desirable acid, base, solvent, and detergent resistance properties.

The epoxy silanes used as integrated cross-linkers in the latex of the invention can generally be described as silanes with epoxy seal. These compounds are well known in the literature and are available commercially. These compounds have polymerisable (preferably terminal) epoxy groups and terminal, polymerisable silane groups. The epoxy and silane groups may be linked by non-hydrolysable aliphatic, aromatic or aliphatic and aromatic divalent hydrocarbon bonds wherein linkages may have nitrogen and/or oxygen atoms in the divalent group. The oxygen atoms are, for example, preferably in the chain as ether bonds. These connecting chains may be generally substituted as is widely known in the art because these substituents on the chain do not greatly affect the reactivity of the epoxy terminated silanes. Representative examples of such substituents comprise -NO2, alkyl, alkoxy, halogen,

(H,C-CH-R-)..... _ra Si(OR ^, _m

\ /

etc. A representative representation of said epoxy silanes is: ^

wherein R is a divalent hydrocarbon group with fewer than 20 carbon atoms that may comprise one or more substituents (e.g., two or more ether bonds); R' is an aliphatic hydrocarbon radical with less than 10 carbon atoms or a hydrocarbon radical of formula (CH ₂ CH ₂ 0) _k Z where k is an integer of at least 1 and Z is an aliphatic hydrocarbon radical, where m is 1, 2 or 3 and characteristically being 3. Another

representative formula is: wherein R, R' and m are as described above, and wherein R" and R'" together form a cyclic structure such as a six-membered hydrocarbon ring. In these formulas, R may be, for example, divalent hydrocarbon radicals such as methylene, ethylene, decalene, phenylene, cyclohexylene, cyclopentylene, methylcyclohexylene, 2-ethylbutylene and alone or an ether radical such as -CH2-CH2-O-CH2-CH2-, -(CH2-CH2-0)2-CH ₂ -CH ₂ -, -X-O-CH2-CH2- and -CH ₂ 0-(CH ₂ ) ₃ - wherein X is a divalent cyclohexane unit. R' can be any aliphatic hydrocarbon radical with less than 10 carbon atoms, such as methyl, ethyl, isopropyl, butyl, vinyl, alkyl or any acyl radical with fewer than 10 carbon atoms, such as formyl, acetyl, propionyl or any radical of the formula (ChhCHhC _k Z where k is an integer of at least 1, for example 2, 5 and 8 and Z is hydrogen or an aliphatic hydrocarbon radical with less than 10 carbon atoms, such as methyl, ethyl, isopropyl, butyl, vinyl and allyl. Epoxy-functional silane oligomers are particularly suitable for use as a coupling agent, adhesion promoter and cross-linker for water-based coatings with acrylic, styrene- acrylic, vinyl-acrylic, polyurethane dispersions, epoxy dispersions and other anionic or cationic binders. Epoxysilane oligomers comprise a polyfunctional structure that carries gamma glycidoxy groups, which has a reduced methanol emission upon hydrolysis of the material as compared to typical monomeric epoxy silanes. Said epoxy-functional silane oligomers lead to improved wear and scrub resistance, improved adhesion to concrete, glass, textiles and metals, improved chemical and corrosion resistance, improved hardness and the like. Representative examples of epoxy silanes currently commercially available include the Silquest™ epoxy silanes and CoatOsil epoxy silane such as CoatOsil 2287 and CoatOsil MP200 available from Momentive Performance Materials. According to a preferred embodiment, Coatosil MP200 is used if it has more epoxide rings on a molecule and this increases the cross- linking efficiency with a carboxyl latex. Another advantage is that with Coatosil MP200 less alcohol is also released through the hydrolysis reaction of the alcoxy-silane groups.

In a preferred embodiment, the present invention provides a cross-linkable carboxylated latex according to the first aspect of the invention where a cross-linker is not used. It should be clear to a person skilled in the art that complex metal ions of filler or other added additives can function as cross-linkers in carboxylated latex. In a further preferred embodiment, carboxylated latex is cross-linked with zinc oxide as an ionic cross-linker.

According to another embodiment of the present invention, nitrogen-functional cross linkers are cross-linkable with hydroxy-functional latex. Non-limiting examples of said cross-linkers are amines, preferably compounds comprising two nitrogen groups for cross-linking, such as diamines. Examples of suitable cross-linkers include various maleimides, various diisocyanates such as toluene diisocyanate, various isocyanate- terminated polyester prepolymers, melamine formaldehyde resins, polyisocyanates, blocked polyisocyanates, and various polyamines such as methylenedianiline. In addition, various epoxides such as the diglycidyl ether of bisphenol-A, etc. can be used.

The term 'blocked' used in combination with a polymer, as used in this text with blocked polyisocyanates, refers to a polymer whose one or more terminal functional groups are blocked with one or more chemical compounds that act as blocking agents.

In a preferred embodiment, the present invention provides a hybrid cross-linkable hydroxy and carboxy functional latex according to the first aspect of the invention, wherein said hybrid latex is cross-linked with epoxy silanes, epoxy resins, complex metal ions, carbodiimides, amino resins or any combination thereof.

In a preferred embodiment, the present invention provides a cross-linkable hydroxy- functional latex according to the first aspect of the invention, wherein the nitrogen- functional cross-linker is a melamine formaldehyde resin.

In a preferred embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein the cross-linkable functional latex comprises one or more additives selected from the group comprising salts, catalysts, water softeners, antioxidants, antimicrobial agents, hydrophobic additives, oleophobic additives, ammonia, agents that can bind volatile organic compounds such as aldehyde-binding agents or oxygen-binding agents, or a combination thereof.

In this text, 'catalysts' specifically refers to catalysts that can catalyse or accelerate the curing of the cross-linkable functional latex. Said agents that can bind volatile organic compounds are also called 'scavengers'. Aldehyde-binding agents or aldehyde scavengers can be chosen from the group comprising tetraethylene-pentamine, propionamide, caprolactam, ammonium hydroxide, sodium bisulphate, sodium metabisulphite, ammonium phosphate, diammonium phosphate, a combination of ammonium phosphate and diammonium phosphate, a combination of ammonium phosphate, ammonium diphosphate and a sulphite, a polyvinyl alcohol; adipic acid dihydrazide and a combination of a polyvinyl alcohol and adipic acid dihydrazide.

Zinc oxide is a non-limiting example of a suitable catalyst. Antimicrobial agents are agents that act against microorganisms. Examples of antimicrobial agents are bactericides and fungicides. One or more of the listed additives may be selected as part of the cross-linkable latex depending on desired functionalisation of products obtained through curing the cross-linkable functional latex according to the present invention.

An adjustment of the pH of the mixture of the reactive latex and the co-reactive material can be made, if desired, by the addition of conventional acidifying or alkalising agents such as, for example, acetic acid, citric acid, dilute mineral acids, ammonium hydroxide and dilute aqueous solutions of alkali metal hydroxides.

In a preferred embodiment of the present invention, ammonium hydroxide is used to adjust a pH of the latex composition.

In a preferred embodiment, the present invention provides a cross-linkable latex according to the first aspect of the invention, wherein the cross-linkable latex comprises a foam booster and/or a foam stabiliser.

Foaming of the cross-linkable latex of the present invention can be carried out in any suitable or conventional manner according to the prior art. A foam can be produced by methods well known in the art, for example by releasing a non-coagulating gas such as nitrogen, or by causing the decomposition of a gas-releasing chemical compound after chemical reaction with an ingredient in the mixture in which a non- coagulable gas is released as a reaction product. When foaming the cross-linkable latex, the use of foam boosters and/or foam stabilisers is desirable. Known foaming aids or foam boosters, such as sodium lauryl sulfate or foam stabilisers, such as potassium oleate, sulfosuccinamate soaps such as - but not limited to - disodium tallow sulfosuccinamate soap can be added if desired. Preferably, such added substances should be relatively non-reactive with the reactive group in the hydroxy or carboxy-functional polymer or optionally in the co-reactive material, and therefore the preferred composition may vary depending on the composition of the mixture. As an alternative to disodium tallow sulfosuccinamate, betaine soap, sodium silicate and ethyl vinyl acetate latex can also be used. However, other soaps, emulsifiers, wetting agents, and/or surfactants can be used, although they may be reactive to a limited extent.

In a preferred embodiment, the present invention provides a cross-linkable functional latex according to the first aspect of the invention, wherein the cross-linkable functional latex comprises a thickening agent.

A thickening agent, also called a thickener or thickening means, refers to a substance that is added to a liquid composition to thicken it and reduce its flowing properties. The use of a thickener in the cross-linkable latex composition of the present invention is advantageous for the foam stability of a foamed product obtained from this cross- linkable latex.

Other additives known to those skilled in the art for use in latex synthesis, such as radical initiators, chain transfer agents, seed latexes and the like, can be used in the synthesis of the latex without departing from the scope of the invention.

A second aspect of the invention relates to a method wherein said latex foam composition comprising a cross-linkable latex with a surfactant, aluminium trihydroxide in an amount between 40.0 wt% to 70.0 wt%, preferably more than 45.0 wt%, more than 50.0 wt%, more than 55.0 wt%, and even more than 60.0 wt%; and less than 70.0 wt%, less than 67.0 wt%, and even less than 65.0 wt% of aluminium trihydroxide relative to the total weight of said latex foam composition, a thickener and optionally a cross-linker, a foam stabiliser and/or a foam booster, is applied directly to a textile backing, and then cured.

In particularly preferred embodiment, the invention relates to a method wherein said latex foam composition, comprising a cross-linkable functional latex comprising :

10.0 to 55.0 wt% functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt%, comprising at least one carboxy functional group in an amount of 0.05 wt% relative to the total weight of said latex;

optionally, up to 15.0 wt% cross-linker; up to 15.0 wt% of a surfactant; and aluminium trihydroxide in an amount between 40.0 to 70.0 wt% relative to the total weight of said latex foam composition, a thickening agent, and optionally a foam stabiliser and/or a foam booster, is applied directly to a textile backing, and then cured.

In a particularly preferred embodiment according to the second aspect of the invention, said functional latex polymer further comprises a hydroxy- or a carboxy- functional monomer or a mixture thereof.

A third aspect of the invention relates to a method wherein said latex foam composition, comprising a cross-linkable latex with a surfactant, aluminium trihydroxide in an amount between 40.0 to 70.0 wt% relative to the total weight of said latex foam composition, a thickening agent and optionally a cross-linker, a foam stabiliser and/or a foam booster, is applied directly to a textile backing, and then cured. It is clear to those skilled in the art that any of the additional components mentioned in the first aspect of the present invention can be used as components of the present latex composition. The non-limiting examples of the above-mentioned additives are: salts, catalysts, water softeners, antioxidants, antimicrobial agents, hydrophobic additives, ammonia, oleophobic additives, agents that can bind volatile organic compounds such as aldehyde-binding agents or oxygen-binding agents, or a combination thereof. Components such as radical initiators, chain transfer agents, seed latexes and the like can also be added to the latex composition without departing from the scope of the invention.

A third aspect of the invention relates to a method for producing a cured latex compound, comprising the steps of:

providing a cross-linkable latex polymer comprising at least a carboxy functional group in an amount of at least 0.05 wt% relative to the total weight of said latex; mixing said cross-linkable latex with optionally a cross-linker, furthermore a surfactant, a filler, a thickener and optionally a foam stabiliser and/or a foam booster, thereby obtaining a latex foam composition;

optionally, spreading said latex foam composition on a substrate; and

drying said latex compound, thereby obtaining a cured latex compound, wherein aluminium trihydroxide is mixed as a filler in an amount of 40.0 to 70.0 wt%, relative to the total weight of said latex foam composition.

In a particularly preferred embodiment, the present invention relates to a method for producing a cured latex compound, comprising the steps of: providing 10.0 to 55.0 wt% cross-linkable functional latex polymer based on styrene and butadiene or similar monomers in 90 to 99.5 wt%, comprising at least one carboxy functional group in an amount of 0.05 wt% relative to the total weight of said latex;

mixing said cross-linkable functional latex with optionally up to 15.0 wt% of a cross-linker, and further with a up to 15.0 wt% of a surfactant, a filler, a thickening agent and optionally a foam stabiliser and/or a foam booster, thereby obtaining a latex foam composition;

optionally, spreading said latex foam composition on a substrate; and drying said latex foam composition, thereby obtaining a cured latex compound, wherein aluminium trihydroxide is mixed as a filler in an amount between 40.0 to 70.0 wt%, relative to the total weight of said latex foam composition.

In a particularly preferred embodiment according to the third aspect of the invention, said cross-linkable functional latex polymer further comprises a hydroxy- or a carboxy- functional monomer or a mixture thereof

The use of a well-considered amount of aluminium trihydroxide as a filler as part of a cross-linkable functional latex for the production of a cured latex foam composition is extremely suitable for improving the material properties, such as texture and fire resistance, of the resulting cured latex compound and particularly suitable for textile in the automobile industry.

The mixing of the composition in the method according to the third aspect of the invention can be done with the aid of means as are known in the art. The drying can be done at any suitable temperature above ambient temperature for a specific residence time.

The residence time is variable and depends on factors such as temperature, layer thickness, foam density, the water content and the components of the curable composition. The typical residence time is between 1 and 20 minutes, preferably between 1 and 10 minutes. Drying can be carried out in an air circulation oven. The internal temperature of the oven is preferably maintained at or above 120°C. It should be understood by those skilled in the art that any type of oven commonly used for curing/drying latex compositions can be used herein without departing from the scope of the invention; In a preferred embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, comprising the step of mixing said crosslinkable latex or latex compound with one or more additives selected from the group comprising : salts, catalysts, water softeners, antioxidants, antimicrobial agents, hydrophobic additives, ammonia, oleophobic additives, agents that can bind volatile organic compounds such as aldehyde-binding agents or oxygen-binding agents, or a combination thereof.

The latex foam composition can be cast in moulds, spread on a flat plate or tape, or coated on substrates. For the purposes of this specification, the term 'substrate' is defined as any material such as fabric, leather, wood, glass or metal or any form of support such as for carpet and shoe soles, wall coverings, to which the latex compound will stick when applied and after it has cured.

In an embodiment of this invention in which the cured latex foam composition is used as a textile backing, the latex compound can be applied to the textile before drying and curing. A typical latex foam, formed from the latex compound as a cured latex foam composition, has a density in the range of about 100 to 1000 grams per litre in the wet state, preferably 100 to 600 grams per litre, and more preferably 120, 130, 140, 150, 160, 170, 180, 190, 200, 210, 220 or 230 grams per litre or any value in between. The latex foam can be applied to the substrate with the help of a squeegee.

In a preferred embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, wherein said latex compound is dried by heating to a temperature between 50°C and 200°C.

Preferably, said latex foam composition is dried at a temperature between 60°C and 180°C, more preferably at a temperature between 125°C and 160°C.

In a preferred embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, wherein said latex compound is treated with the aid of an infrared lamp.

In another preferred embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, wherein said latex compound is dried in a hot-air oven. For this purpose, the temperature of the hot-air oven is preferably set at 50°C to 80°C. In a preferred embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, wherein said cured latex foam composition is mechanically post-treated, such as, for example, by compressing, printing or pressing.

In another embodiment, the present invention provides a method for producing a cured latex foam composition according to the third aspect of the invention, wherein said cured latex compound is thermally post-treated, such as, for example, by curing at a temperature between 100°C and 200°C.

Preferably, said cured latex foam composition is thermally post-treated in an oven at a temperature between 125°C and 180°C, more preferably at a temperature between 125°C and 160°C.

A fourth aspect of the invention relates to a cured latex foam composition obtainable according to a method according to the third aspect of the invention.

In a fifth aspect, the present invention provides an arrangement comprising a cured latex foam composition according to the third aspect of the invention, such as, for example, an interior textile for the automotive industry, such as for car seat, car door and floor panel textile. In another preferred embodiment, a cured latex foam composition is used as a covering for technical textile, especially as a mattress cover, duvets, curtain fabric, and the like. The cured latex foam composition according to the third aspect of the invention can be used as an anti-slip coating, a tufted carpet, a woven carpet, artificial grass, a carpet for the automotive sector, a needle felt carpet, tiles, needle felts, rubber granulate, upholstery, a carpet for household use as for example in a lounge or bathroom, a carpet for stairs, a carpet for use in hospitals, furniture, mattresses, car tyres, shoe soles and for use in medical or hygienic applications, such as for example in surgical gloves.

In a sixth aspect, the present invention provides a use of a cross-linkable latex according to the first aspect of the invention for producing a cured latex foam composition. EXAMPLES

The examples described below relate to a preparation of a cured latex compound and more particularly to a latex foam, and the composition of cross-linkable latex to obtain this latex foam.

The general methods for preparing a cross-linkable latex and for producing a latex foam are described below, after which the various examples of obtained cross-linkable latex compositions are illustrated in Example 1 and Example 2.

A first step is to mix the ingredients of a cross-linkable functional latex, water (A) and optionally a cross-linker (B) to obtain a composition (A+B). Also, a filler such as aluminium trihydroxide, or the mixture of aluminium trihydroxide with chalk and melamine (C) in the aforementioned composition (A+B) is mixed at room temperature. A cross-linkable latex compound (A+B+C) is thus obtained. In addition, other substances are mixed with the aforementioned cross-linkable latex, such as additives and a foam booster and stabiliser. Optionally, a thickener is added as the last addition. In a second step, the cross-linkable latex is intensively mixed to obtain an aqueous latex foam.

When the aqueous latex foam has obtained good foam quality, it is applied to a substrate. The substrate can for example be the back of a carpet. A good contact between the aqueous latex foam and the substrate is thereby ensured, for example by pressing down by means of drum rolling.

Subsequently, in a third step, the aqueous latex foam is treated by means of an infrared lamp to a temperature of 120°C. Alternatively, the aqueous latex foam can be heated in a hot-air oven at a temperature of 80°C.

In a final step, the at least partially dried latex foam is cured and further dried. In this way, the cross-linking of the cross-linkable latex is achieved. This thermal treatment is optionally followed by a mechanical treatment, such as for example pressing, and a thermal after-treatment for curing in an oven at a temperature of approximately 150°C.

The various cross-linkable functional latex compositions of Examples 1-3 are shown respectively with reference to Table 2-4. In Table 6, a latex foam composition of the invention is shown, using the latex obtained in Examples 1-3.

Table 2: Composition of a carboxylated latex according to Example 1 of the present invention.

Material function Material Dry parts

Monomers Styrene 40.0

Butadiene 54.45

Itaconic acid 0.55

Acrylic acid 3

Acrylonitrile 2

Add water to a dry matter of 50-55 wt%

Cross-linker (in post-addition) Epoxy silanes variable, from 0.1 to 5.0% dry to wet weight percentage latex (optimum concentration is 1 to 3.0%)

Table 3: Composition of a hydroxy-functional latex according to Example 2 of the present invention.

Material function Material Dry parts

Monomers Styrene 52.45

Butadiene 42.0

Itaconic acid 0.55

Hydro xylethyl acrylate 3

Acrylonitrile 2

Add water to a dry matter of 50-55 wt%

Cross-linker (in post- Blocked polyisocyanate or other variable, from 0.1 addition) suitable cross-linker* that is to 10.0%, reactive towards hydroxyl groups optimum

concentration is 4 to 6.0%)

* other suitable cross-linkers are shown in Table 1.

Table 4: Composition of a hybrid hydroxy and carboxy-functional latex according to Example 3 of the present invention. Material function Material Dry parts

Monomers Styrene 52.0

Butadiene 41.45

Itaconic acid 0.55

Hydro xylethyl acrylate 2

Acrylic acid 3

Acrylonitrile 2

Add water to a dry matter of 50-55 wt%

Cross-linker Suitable cross-linker* variable

(in post-addition)

*Cross-linkers suitable for this latex are those that can react with hydroxyl groups (blocked isocyanates, amino resins, etc.) or that can react with carboxyl groups (epoxy silanes, etc.) or a combination of both types of cross-linkers.

Table 5: A list of polymerisation surfactants that were used

polymerisation Surfactant Quantity of surfactant dry / 100 dry polymer

Sodium dicyclohexyl sulfosuccinate 1

Mixture of disodium mono- and didodecyl 1

diphenyl oxide sulfone

Sodium alkyl benzene sulfonate 1

Remark: Mixtures of disodium mono- and didodecyl diphenyl oxide sulfone and Sodium alkyl benzene sulfonate are preferred as these ingredients do not contribute to the total VOCs of the coating.

Table 6: The latex foam composition of the present invention.

Ingredient Din dr

Latex of Example 1, 2 or 3 100.0

Sodium hexametaphosphate 1.0

Tetra potassium pyrophosphate 2.0

Sodium lauryl sulfate 1.5

Sulfosuccinamate soap 6.0

Antioxidant (Wingstay L) 1.5

Zinc oxide 2.0 Ammonia 0.25

Aluminium trihydroxide 210.0

Water up to a dry matter of 60-80%

Thickener (Polyacrylate, CMC, etc.) to the required viscosity, e.g. Brookfield

RVF3/4= 10-30