Aqueous hardener composition for hardening formaldehyde-based resins, respective resin compositions, impregnated substrates, methods and uses

Abstract

Described herein is an aqueous composition for impregnating absorptive, flexible, laminar substrates and an aqueous hardener composition for hardening a resin mixture comprising a formaldehyde-based resin. Moreover, it is described herein a method of making an aqueous resin composition for impregnating absorptive, flexible, laminar substrates and a method of making an impregnated, flexible, laminar substrate, as well as an impregnated, flexible, laminar substrate obtained or obtainable by said latter method. Furthermore, it is described a method of making a composite material and a composite material, obtained or obtainable by said method. In addition, it is described herein the use of an aqueous resin composition for impregnating an absorptive, flexible, laminar substrate and the use of an aqueous hardener composition for hardening a resin mixture comprising a formaldehyde- based resin.

Description

[0001] BASF SE

[0002] Carl-Bosch-StraBe 38, 67056 Ludwigshafen am Rhein Germany

[0003] Aqueous hardener composition for hardening formaldehyde-based resins, respective resin compositions, impregnated substrates, methods and uses

[0004] The present invention relates to an aqueous composition for impregnating absorptive, flexible, laminar substrates and to an aqueous hardener composition for hardening a resin mixture comprising a formaldehyde-based resin. Moreover, the present invention relates to a method of making an aqueous resin composition for impregnating absorptive, flexible, laminar substrates and to a method of making an impregnated, flexible, laminar substrate, as well as to an impregnated, flexible, laminar substrate obtained or obtainable by said latter method. Furthermore, the present invention relates to a method of making a composite material and to a composite material, obtained or obtainable by said method. In addition, the present invention pertains to the use of an aqueous resin composition for impregnating an absorptive, flexible, laminar substrate and to the use of an aqueous hardener composition for hardening a resin mixture comprising a formaldehyde-based resin.

[0005] Aqueous compositions based on sulfurous acid salts of alkanol amines have been used as hardeners for formaldehyde-based resins for some time. Such sulfurous acid salts have usually been prepared by reacting alkanol amines with gaseous sulfur dioxide. Examples thereof are e.g. described in document EP 2 905294 A1 . Formaldehyde-based resins hardened (cured) with such sulfurous acid salts of alkanol amines have found wide application in e.g. paper impregnation, due to the excellent properties regarding resistance against water vapour and acid, hardness, colour fastness and gloss level of papers impregnated with said formaldehyde-based resins hardened with sulfurous acid salts of alkanol amines.

[0006] Recently, safety aspects regarding the industrial use of gaseous sulfur dioxide and the role of gaseous sulfur dioxide as potentially harmful substance for the atmosphere have moved more into focus. For these and other reasons, alternatives are more and more considered | BASF SE | 240124 for replacing sulfur-dioxide based chemistry. One challenge in the search for such alternatives is to maintain or improve the favourable usage properties of chemical products that were previously manufactured using sulfur-dioxide based chemistry.

[0007] In the existing literature, a polymerization-enhancing composition for urea-formaldehyde resins is discussed in document WO 2006 / 015331 A1 .

[0008] Document WO 2006 / 040068 A1 (equivalent of US 2008 / 01 14097 A1 ) deals with an aqueous impregnating resin solution.

[0009] In document US 5,635,583, a catalytic composition and method for curing urea-formalde- hyde resins is described.

[0010] Document WO 2004 / 056899 A1 deals with synthetic material dispersions.

[0011] In the light of the existing prior art there is, however, still a need for a safe and sustainable method of hardening formaldehyde-based resins, in particular melamine-formaldehyde resins, and for related products, in particular for impregnating paper and similar absorptive, flexible, laminar substrates.

[0012] Correspondingly, it was a primary object of the present invention to provide a resin composition for impregnating paper and similar absorptive, flexible, laminar substrates, which resin composition can be hardened (cured) without the use of sulfurous acid salts, while showing at least similar favourable hardening properties when compared with known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines, and while resulting in impregnated paper and similar absorptive, flexible, laminar substrates which have at least similar or improved usage properties when compared with respective substrates made with known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines. “Alkanol amines” are also referred to herein as “amino alcohols” and both expressions are used herein synonymously.

[0013] It was a more specific object of the present invention to provide a hardener for resin compositions for impregnating paper and similar absorptive, flexible, laminar substrates, without the need of using of sulfurous acid salts, and to provide related methods of making and uses. | BASF SE | 240124

[0014] It has now been found that the primary object and other objects of the present invention can be accomplished by an aqueous resin composition for impregnating absorptive, flexible, laminar substrates, comprising or consisting of:

[0015] C1 ) a resin component, selected from the group consisting of a melamine-formaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-formalde- hyde resin mixture, preferably selected from a melamine-formaldehyde resin mixture and a urea-formaldehyde resin mixture; more preferably the resin component comprises or is a melamine-formaldehyde resin mixture;

[0016] C2) a hardener, comprising the following components:

[0017] C2-1 ) an ammonium salt, selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium bromide, ammonium nitrate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate and mixtures thereof; and

[0018] C2-2) one or more amino alcohols of general formula I

[0019] R2

[0020] N— R3l i

[0021] R(I), wherein

[0022] R1is a hydroxyalkyl group with 1 to 4 carbon atoms, and

[0023] R2and R3independently of each other are hydrogen, an alkyl group with 1 to 4 carbon atoms, or a hydroxyalkyl group with 1 to 4 carbon atoms, and

[0024] C3) water. BASF SE 240124

[0025] The invention as well as preferred variants and preferred combinations of parameters, properties and elements thereof are defined in the appended claims. Preferred aspects, details, modifications and advantages of the present invention are also defined and explained in the following description and in the examples stated below.

[0026] It has been found in own experiments that the aqueous resin composition according to the present invention (or an aqueous resin composition according to the present invention as described herein as being preferred) can be hardened without the use of sulfurous acid salts, while showing at least similar favourable hardening properties when compared with known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines, and while resulting in impregnated paper and similar absorptive, flexible, laminar substrates which have at least similar or improved usage properties (e.g. resistance against water vapour and acid, hardness, colour fastness and gloss level) when compared with respective substrates made with known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines.

[0027] Moreover, the aqueous resin composition according to the present invention (or an aqueous resin composition according to the present invention as described herein as being preferred) allows the use of a reduced amount of alkanol amines, some of which are suspected to be water pollutants. Overall, the aqueous resin composition according to the present invention is assumed to have a reduced product carbon footprint when compared with known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines. It is further assumed that the use of the aqueous resin composition according to the present invention, when used for impregnating paper, causes less yellowing of the so impregnated paper than known resin compositions comprising hardeners based on sulfurous acid salts of alkanol amines.

[0028] The aqueous resin composition according to the present invention as defined above comprises a resin component C1 ), selected from the group consisting of a melamine-formalde- hyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-formaldehyde resin mixture.

[0029] As used herein and in accordance with the usual meaning in the technical field concerned, a “melamine-formaldehyde resin mixture” comprises a pre-condensates resulting from melamine and formaldehyde, i.e. it comprises oligomers and polymers which are formed (e.g. by partial polymerization) from melamine and formaldehyde monomers and which may be further hardened (by curing and / or further polymerization) to result in a hardened (or cured) melamine-formaldehyde resin. Such melamine-formaldehyde resin mixtures are usually BASF SE 240124 partially or fully water soluble. Melamine-formaldehyde resin mixtures which are suited as “resin component C1 )” in the aqueous resin composition according to the invention are known and may be commercially available. Examples of such melamine-formaldehyde resin mixtures (in the form of aqueous melamine-formaldehyde resin components, which can provide a resin component C1 ) in or for the aqueous resin composition of the present invention) are e.g. described in WO 2005 / 095514 A2 or WO 2006 / 040068 A1 .

[0030] As used herein and in accordance with the usual meaning in the technical field concerned, a “urea-formaldehyde resin mixture” comprises a pre-condensates resulting from urea and formaldehyde, i.e. it comprises oligomers and polymers which are formed (e.g. by partial polymerization) from urea and formaldehyde monomers and which may be further hardened (by curing and / or further polymerization) to result in a hardened (or cured) urea-formaldehyde resin. Such urea-formaldehyde resin mixtures are usually partially or fully water soluble. Urea-formaldehyde resin mixtures which are suited as “resin component C1 )” in the aqueous resin composition according to the invention are known and may be commercially available. Examples of such urea-formaldehyde resin mixtures (in the form of aqueous urea-formaldehyde resin components, which can provide a resin component C1 ) in or for the aqueous resin composition of the present invention) are e.g. described in EP 2407513 A1 .

[0031] As used herein and in accordance with the usual meaning in the technical field concerned, a “urea-melamine-formaldehyde resin mixture” comprises pre-condensates resulting from urea, melamine and formaldehyde, i.e. it comprises oligomers and polymers which are formed (e.g. by partial polymerization) from urea, melamine and formaldehyde monomers and which may be further hardened (by curing and / or further polymerization) to result in a hardened (or cured) urea-melamine-formaldehyde resin. Such urea-melamine-formalde- hyde resin mixtures are usually partially or fully water soluble. Urea-melamine-formalde- hyde resin mixtures which are suited as “resin component C1 )” in the aqueous resin composition according to the invention are known and may be commercially available.

[0032] Preferred is an aqueous resin composition according to the present invention as defined herein (or an aqueous resin composition according to the invention as described herein as being preferred), comprising: a total amount in the range of from > 40 to < 70 wt.-%, preferably of from > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of the resin component C1 ) (solids content) ; BASF SE 240124 and / or a total amount in the range of from > 0.03 to < 2.0 wt.-%, preferably of from > 0.04 to < 1 .0 wt.-%, more preferably of from > 0.05 to < 0.5 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2-1 ), the ammonium salt; and / or a total amount in the range of from > 0.3 x 10-3to < 0.04 wt.-%, preferably of from > 0.5 x 10-3to < 0.03 wt.-%, more preferably of from > 1 x 10-3to < 0.02 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2-2), the one or more amino alcohols of general formula I.

[0033] In many cases, the aqueous resin composition according to the present invention as described here above may comprise further additional constituents in amounts usually not exceeding 10 wt.-% individually (relative to the total weight of the aqueous resin composition) and usually not exceeding 30 wt.-% in combination (relative to the total weight of the aqueous resin composition).

[0034] Further preferred is therefore an aqueous resin composition according to the present invention as defined herein (or an aqueous resin composition according to the invention as described herein as being preferred), comprising: a total amount in the range of from > 40 to < 70 wt.-%, preferably > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of a melamine-formalde- hyde resin mixture as the resin component C1 ) (solids content), wherein preferably the resin component comprises or consists of melamine and formaldehyde; preferably wherein melamine and formaldehyde are present in a molar ratio of from > 1 :3 to < 1 :1 and preferably further comprising one, more than one, or all of the components selected from the group consisting of: one or more polyhydric alcohols with 2 to 12 carbon atoms, preferably in a total amount in the range of from > 1 to < 10 wt.-%, relative to the total weight of the aqueous resin composition, | BASF SE | 240124 caprolactam, preferably in a total amount in the range of from > 0 to < 8 wt.-%, relative to the total weight of the aqueous resin composition,

[0035] 2-(2-phenoxy-ethoxy)ethanol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition, and polyethylene glycol, preferably with an average molecular weight in the range of from > 200 to < 1500 g / mol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition.

[0036] Examples of aqueous melamine-formaldehyde resin mixtures which are suited to provide component C1 ) in the above-defined preferred aqueous resin composition according to the invention are e.g. described in WO 2005 / 095514 A2 or in WO 2006 / 040068 A1 .

[0037] Particularly preferred is an aqueous resin composition according to the present invention as defined herein (or an aqueous resin composition according to the invention as described herein as being preferred), consisting of a total amount in the range of from > 40 to < 70 wt.-%, preferably > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of a melamine-formaldehyde resin mixture as the resin component C1 ) (solids content); preferably wherein melamine and formaldehyde are present in a molar ratio of from > 1 :3 to < 1 :1 a total amount in the range of from > 0.03 to < 2.0 wt.-%, preferably of from > 0.04 to < 1 .0 wt.-%, more preferably of from > 0.05 to < 0.5 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2-1 ), the ammonium salt; a total amount in the range of from > 0.3 x 103to < 0.04 wt.-%, preferably of from > 0.5 x 10-3to < 0.03 wt.-%, more preferably of from > 1 x 10-3to < 0.02 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2-2), the one or more amino alcohols of general formula I; optionally one or more polyhydric alcohols with 2 to 12 carbon atoms, preferably in a total amount in the range of from > 1 to < 10 wt.-%, relative to the total weight of the aqueous resin composition, BASF SE 240124 optionally caprolactam, in a total amount in the range of from > 0 to < 8 wt.-%, relative to the total weight of the aqueous resin composition, optionally 2-(2-phenoxy-ethoxy)ethanol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition, and optionally polyethylene glycol, preferably with an average molecular weight in the range of from > 200 to < 1500 g / mol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition.

[0038] In a further variant is preferred an aqueous resin composition according to the present invention as defined herein (or an aqueous resin composition according to the invention as described herein as being preferred), comprising a total amount in the range of from > 40 to < 70 wt.-%, preferably > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of a urea-formaldehyde resin mixture as the resin component C1 ) (solids content), wherein preferably the resin component comprises or consists of urea and formaldehyde; preferably wherein urea and formaldehyde are present in a molar ratio of from > 1 :1 .3 to < 1 :2.0, and preferably further comprising one, more than one, or all of the components selected from the group consisting of: one or more polyhydric alcohols with 2 to 12 carbon atoms, preferably in a total amount in the range of from > 1 to < 8 wt.-%, relative to the total weight of the aqueous resin composition, caprolactam, preferably in a total amount in the range of from > 0 to < 4 wt.-%, relative to the total weight of the aqueous resin composition, polyethylene glycol, preferably with an average molecular weight in the range of from > 200 to < 1500 g / mol, preferably in a total amount in the range of from > 1 to < 5 wt.-%, relative to the total weight of the aqueous resin composition. BASF SE 240124

[0039] Examples of aqueous urea-formaldehyde resin mixtures which are suited to provide component C1 ) in the above-defined preferred aqueous resin composition according to the invention are e.g. described in EP 2407513 A1 .

[0040] As used herein, the “one or more polyhydric alcohols with 2 to 12 carbon atoms” which may be present in the above-defined preferred aqueous resin compositions according to the present invention (or which may be added to receive the above-defined preferred aqueous resin compositions according to the present invention) preferably comprise respective carbohydrates (as falling under the respective definition, e.g. glucose or saccharose), glycerine (also known as “glycerol”) and diethylene glycol.

[0041] For the purposes of the present invention, the average molecular weight of the polyethylene glycol which may be present in the above-defined preferred aqueous resin compositions according to the present invention (or which may be added to receive the above-defined preferred aqueous resin compositions according to the present invention) is preferably determined by gel chromatography. Respective methods for measuring the average molecular weight of polyethylene glycol by gel chromatography are known in the technical field concerned.

[0042] Also preferred is an aqueous resin composition according to the present invention as defined herein (or an aqueous resin composition according to the invention as described herein as being preferred), wherein the hardener component C2-1 ) is selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium phosphate and mixtures thereof, preferably wherein the hardener component C2-1 ) comprises or is ammonium sulfate; and / or the hardener component C2-2) is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N-methyl-ethanolamine, N,N-dimethyl-ethan- olamine, N-ethyl-ethanolamine, N,N-diethyl-ethanolamine and mixtures thereof, preferably wherein the hardener component C2-2) comprises or is monoethanolamine; and / or BASF SE 240124 the aqueous resin composition has a pH in the range of from > 7 to < 1 1 , preferably of from > 8 to < 10.

[0043] In the aqueous resin composition according to the present invention, the hardener components C2-1 ) and C2-2) may act as pH regulators or together may act as buffer system, so that, by adjusting the ratios of the (more acidic) component C2-1 ) and the (more basic) component C2-2), the pH of the aqueous resin composition may be adjusted as desired.

[0044] The present invention also pertains to an aqueous hardener composition for hardening a resin mixture selected from the group consisting of a melamine-formaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-formaldehyde resin mixture (preferably for hardening a melamine-formaldehyde resin mixture), comprising the following components:

[0045] C2-1 ) an ammonium salt, selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium bromide, ammonium nitrate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate and mixtures thereof, preferably selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium phosphate and mixtures thereof, more preferably wherein the hardener component C2-1 ) comprises or is ammonium sulfate; and

[0046] C2-2) one or more amino alcohols of general formula I

[0047] R2

[0048] N— R3l i

[0049] R(I), wherein

[0050] R1is a hydroxyalkyl group with 1 to 4 carbon atoms, and

[0051] R2and R3independently of each other are hydrogen, an alkyl group with 1 to 4 carbon atoms, or a hydroxyalkyl group with 1 to 4 carbon atoms, BASF SE 240124 wherein preferably the hardener component C2-2) is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N-methyl-ethanola- mine, N,N-dimethyl-ethanolamine, N-ethyl-ethanolamine, N,N-diethyl-ethanolamine and mixtures thereof, more preferably wherein the hardener component C2-2) comprises or is monoethanolamine; and further comprising water.

[0052] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention as defined herein apply mutatis mutandis to the aqueous hardener composition according to the present invention as defined herein, and vice versa.

[0053] It has been found in own experiments that the aqueous hardener composition according to the present invention (or an aqueous hardener composition according to the present invention as described herein as being preferred) can be beneficially used for hardening formaldehyde-based aqueous resin compositions and can in particular replace sulfurous acid salts in this role. It has further been found in own experiments that using the aqueous hardener composition according to the present invention (or an aqueous hardener composition according to the present invention as described herein as being preferred) in combination with formaldehyde-based aqueous resin compositions results in at least similar favourable hardening properties of said formaldehyde-based aqueous resin compositions when compared with known formaldehyde-based aqueous resin compositions which were hardened with hardeners based on sulfurous acid salts of alkanol amines. In addition, the use of the aqueous hardener composition according to the present invention (or of an aqueous hardener composition according to the present invention as described herein as being preferred) in combination with formaldehyde-based aqueous resin compositions results in impregnated paper and similar absorptive, flexible, laminar substrates which have at least similar or improved usage properties (e.g. resistance against water vapour and acid, hardness, colour fastness and gloss level) when compared with respective substrates made with known formaldehyde-based aqueous resin compositions hardened with hardeners based on sulfurous acid salts of alkanol amines.

[0054] Preferred is an aqueous hardener composition according to the present invention as defined herein (or an aqueous hardener composition according to the invention as described herein as being preferred), comprising a total amount of from > 10 to < 45 wt.-%, preferably of from > 12 to < 40 wt.-%, more preferably of from > 12 to < 35 wt.-%, relative to the total BASF SE 240124 weight of the aqueous hardener composition, of hardener component C2-1 ), the ammonium salt.

[0055] Furthermore is preferred an aqueous hardener composition according to the present invention as defined herein (or an aqueous hardener composition according to the invention as described herein as being preferred), comprising the hardener component C2-2), the one or more amino alcohols of general formula I, in a total amount of from > 0.03 to < 2.0 wt.-%, preferably of > 0.05 to < 2.0 wt.-%, more preferably of > 0.1 to < 1 .5 wt.-% and even more preferably of > 0.2 to < 1 .2 wt.-%, relative to the total weight of the aqueous hardener composition; and / or in an amount sufficient to adjust in the aqueous hardener composition a pH value in the range of from > 3 to < 10, preferably of from > 5 to < 9.

[0056] In the aqueous hardener composition according to the present invention, the hardener components C2-1 ) and C2-2) may act as pH regulators or together may act as buffer system, so that, by adjusting the ratios of the (more acidic) component C2-1 ) and the (more basic) component C2-2), the pH of the aqueous hardener composition may be adjusted as desired.

[0057] The present invention then further also pertains to a method of making an aqueous resin composition for impregnating absorptive, flexible, laminar substrates, comprising the steps

[0058] A1 ) providing or preparing an aqueous resin component, comprising a resin component selected from the group consisting of a melamineformaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-mela- mine-formaldehyde resin mixture, as defined above (or as described herein as being preferred), in a total amount in the range of from > 40 to < 70 wt.-%, preferably of from > 45 to < 65 wt.-%, relative to the aqueous resin composition;

[0059] A2) providing or preparing an aqueous hardener composition as defined above (or an aqueous hardener composition described above as being preferred), preferably in a BASF SE 240124 total amount in the range of from > 0.2 to < 1 .0 wt.-%, preferably of from > 0.3 to < 1 .0 wt.-%, relative to the total weight of the aqueous resin component of step A1 ), and

[0060] A3) mixing the aqueous hardener composition from step A2) with the aqueous resin component from step A1 ) and optionally with additional water, to receive an aqueous resin composition for impregnating absorptive, flexible, laminar substrates.

[0061] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention and of the aqueous hardener composition according to the present invention as defined herein, apply mutatis mutandis to the method of making an aqueous resin composition according to the present invention as defined herein, and vice versa.

[0062] The present invention still further also pertains to a method of making an impregnated, flexible, laminar substrate, comprising the steps:

[0063] 51 ) providing or preparing an absorptive, flexible, laminar substrate, preferably selected from the group consisting of a paper web, a paper sheet and a nonwoven fabric,

[0064] 52) providing or preparing an aqueous resin composition as defined above (or an aqueous resin composition described above as being preferred), or an aqueous dilution thereof,

[0065] 53) applying the aqueous resin composition, or the aqueous dilution thereof, from step S2) to the absorptive, flexible, laminar substrate from step S1 ), to receive a restated, flexible, laminar substrate, and

[0066] 54) drying the resinated, flexible, laminar substrate as received in step S3), preferably at a temperature in the range of from > 60 to < 150 °C, more preferably of from > 80 to < 130 °C, to receive an impregnated, flexible, laminar substrate. BASF SE 240124

[0067] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention and of the method of making an aqueous resin composition according to the present invention as defined herein, apply mutatis mutandis to the method of making an impregnated, flexible, laminar substrate according to the present invention as defined herein, and vice versa.

[0068] Moreover, the present invention also pertains to an impregnated, flexible, laminar substrate obtained or obtainable by a method of making an impregnated, flexible, laminar substrate according to the present invention as defined herein.

[0069] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention, of the method of making an aqueous resin composition according to the present invention and of the method of making an impregnated, flexible, laminar substrate according to the present invention as defined herein, apply mutatis mutandis to the impregnated, flexible, laminar substrate according to the present invention as defined herein, and vice versa.

[0070] Preferred impregnated, flexible, laminar substrates according to the present invention are selected from the group consisting of an impregnated paper web, an impregnated paper sheet and an impregnated non-woven fabric.

[0071] Under a further aspect, the present invention also pertains to a method of making a composite material, comprising the steps

[0072] C1 ) providing an impregnated, flexible, laminar substrate according to the present invention as defined above (or an impregnated, flexible, laminar substrate according to the present invention as described above as being preferred), preferably selected from the group consisting of an impregnated paper web, an impregnated paper sheet and an impregnated nonwoven fabric, or preparing an impregnated, flexible, laminar substrate by a method according to the present invention as defined above (or according to a method of making an impregnated, flexible, laminar substrate according to the present invention as described above as being preferred), BASF SE 240124

[0073] C2) providing or preparing a carrier material, preferably comprising or consisting of a material comprising cellulosic fibers, bound by an organic binder,

[0074] C3) applying the impregnated, flexible, laminar substrate from step C1 ) to the carrier material from step C2), and

[0075] C4) applying heat, preferably in the range of from > 180 to < 240 °C, more preferably of from > 180 to < 220 °C, and / or pressure to the impregnated, flexible, laminar substrate on the carrier material from step C3), to receive a composite material.

[0076] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention, of the method of making an aqueous resin composition according to the present invention, of the method of making an impregnated, flexible, laminar substrate according to the present invention and of the impregnated, flexible, laminar substrate according to the present invention as defined herein, apply mutatis mutandis to the method of making a composite material according to the present invention as defined herein, and vice versa.

[0077] In step C2) of the method of making a composite material according to the present invention as defined above, a carrier material is provided or prepared. Particularly suitable as carrier materials for this purpose are selected from the group consisting of fiberboards of varying densities (including high density fiberboards, HDF, and medium density fiberboards, MDF) and wood particle boards.

[0078] In step C4) of the method of making a composite material according to the present invention as defined above, heat and / or pressure is applied to the impregnated, flexible, laminar substrate on the carrier material from step C3). Where heat is applied, this means preferably heat of a temperature in the range of from from > 180 to < 240 °C, preferably of from > 180 to < 220 °C when applied via (or measured at) the heating / pressing tool. When measured at the object (i.e. the impregnated, flexible, laminar substrate on the carrier material from step C3)), the temperature is preferably in the range of from > 130 to < 180 °C and more preferably in the range of from > 135 to < 170 °C . BASF SE 240124

[0079] The present invention then furthermore also pertains to a composite material, obtained or obtainable by a method of making a composite material according to the present invention as defined above.

[0080] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention, of the method of making an aqueous resin composition according to the present invention, of the method of making an impregnated, flexible, laminar substrate according to the present invention, of the impregnated, flexible, laminar substrate according to the present invention and of the method of making a composite material according to the present invention as defined herein apply mutatis mutandis io the composite material, obtained or obtainable by a method of making a composite material according to the present invention as defined herein, and vice versa.

[0081] Still further, the present invention pertains to the use of an aqueous resin composition according to the present invention as defined above (or of an aqueous resin composition according to the present invention as described herein as being preferred), or an aqueous dilution thereof, for impregnating an absorptive, flexible, laminar substrate, preferably selected from the group consisting of a paper web, a paper sheet and a nonwoven fabric.

[0082] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention, of the method of making an aqueous resin composition, of the method of making an impregnated, flexible, laminar substrate according to the present invention, of the impregnated, flexible, laminar substrate according to the present invention, of the method of making a composite material according to the present invention and of the composite material, obtained or obtainable by a method of making a composite material according to the present invention as defined herein apply mutatis mutandis to the use of the aqueous resin composition for impregnating an absorptive, flexible, laminar substrate according to the present invention as defined herein, and vice versa.

[0083] In a still further variant, the present invention also pertains to the use of an aqueous hardener composition according to the present invention as defined above (or of an aqueous hardener composition according to the present invention as described herein as being preferred), for hardening a resin mixture selected from the group consisting of a melamineformaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-for- maldehyde resin mixture, or for hardening an aqueous resin composition comprising a resin BASF SE 240124 mixture selected from the group consisting of a melamine-formaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-formaldehyde resin mixture.

[0084] Generally, all aspects of the present invention discussed herein in the context of the aqueous resin composition according to the present invention, of the aqueous hardener composition according to the present invention, of the method of making an aqueous resin composition, of the method of making an impregnated, flexible, laminar substrate according to the present invention, of the impregnated, flexible, laminar substrate according to the present invention, of the method of making a composite material according to the present invention, of the composite material obtained or obtainable by a method of making a composite material according to the present invention and of the use of the aqueous resin composition for impregnating an absorptive, flexible, laminar substrate according to the present invention as defined herein apply mutatis mutandis to the use of an aqueous hardener composition for hardening a resin mixture according to the present invention as defined herein, and vice versa.

[0085] Examples

[0086] The following examples are meant to further explain and illustrate the present invention, without limiting its scope.

[0087] Example 1 : Preparation of aqueous hardener compositions according to the present invention, as described herein

[0088] 140 g of ammonium sulfate are dissolved in 860 mL de-ionized water to yield a 14 % wt. / wt. aqueous ammonium sulfate solution. To this solution, 10 g monoethanolamine (1 % wt. / wt., relative to the total weight of the aqueous hardener composition) were added under stirring at a temperature of 20 to 30 °C, to receive an aqueous hardener composition named IAHC- 1 (of 14 wt.-% ammonium salt / 1 wt.-% alkanol amine)

[0089] The following further aqueous hardener compositions as summarized in table 1 here below were prepared according to the above-mentioned manufacturing instructions, or according to methods analogous to these instructions. | BASF SE 240124

[0090] Table 1 : Further aqueous hardener compositions according to the present invention relative to the total weight of the aqueous hardener composition

[0091] MEA: monoethanolamine

[0092] Similar aqueous hardener compositions according to the present invention were prepared with diethanol amine as amino alcohol (hardener component C2-2) and with diethyl ethanolamine as amino alcohol (hardener component C2-2).

[0093] Example 2: Preparation of aqueous hardener compositions according to the prior art

[0094] Aqueous solutions of sulfurous acid salts of (about 80 % wt. / wt.) were prepared (as aqueous hardener compositions according to the prior art, for comparison) according to the method described in EP 2905294 A, p. 4, “Beispiel A”, as shown in table 2 here below.

[0095] Table 2: Aqueous hardener compositions according to the prior art relative to the total weight of the aqueous hardener composition

[0096] MeEA: methyl ethanolamine

[0097] MEA: monoethanolamine Example 3: Preparation of aqueous resin compositions according to the present invention, as described herein

[0098] For the preparation of an aqueous resin composition according to the present invention, a 60 wt.-% (solids content) liquid Kauramin® impregnating resin 799 (aqueous melamine- BASF SE 240124 formaldehyde resin component, commercially available from BASF SE; according to “Technisches Merkblatt Tl-M 6383d, “KAURAMIN® Trankharz 799 fliissig” of December 2018) with a molar ratio of formaldehyde : melamine of 1 .6 : 1 was mixed with the amounts of aqueous hardener compositions according to the present invention (for preparation see example 1 above) as shown in table 3 below, and the turbidity times were determined in each case as a measure of the aqueous resin composition’s reactivity.

[0099] For determining the turbidity time of an aqueous resin composition, 100 g of the impregnating resin (here: liquid Kauramin® impregnating resin 799, 60 wt.-%) were mixed with the amounts of aqueous hardener compositions as shown in table 3 below. A 20 mL sample of a so received, homogenous solution was then filled into a glass test tube (diameter 18 mm) and the glass test tube was put into a heating bath thermostatted at 100 °C. The sample was left in the thermostatted heat bath until the contents of the test tube (sample) showed a continuous white colouration and the respective time (in seconds) was recorded and is shown in table 3 here below:

[0100] Table 3: Aqueous resin compositions according to the present invention relative to the total weight of the aqueous hardener composition

[0101] Similar results in examples 3 and 4 can be obtained when other but similar aqueous resin components are used instead of liquid Kauramin® impregnating resin 799, e.g. aqueous melamine-formaldehyde resin components prepared according to “Komponente (A)” in the example section of WO 2006 / 040068 A1 , or aqueous melamine-formaldehyde resin components prepared according to the examples section of WO 2005 / 095514 A2, in particular the aqueous melamine-formaldehyde resin components prepared according to examples 1 to 3 “ErfindungsgemaR”, or according to examples 1 and 3 “Vergleich”. Similar results can also be obtained when aqueous urea-formaldehyde resin components prepared according to the examples section of EP 2407513 A1 , in particular the aqueous urea-formal- dehyde resin components prepared according to “wassrige Harnstoffharzmischung Nr. 1 a” BASF SE 240124 or according to “wassrige Harnstoffharzmischung Nr. 1 b” are used instead of liquid Kau- ramin® impregnating resin 799.

[0102] Similar aqueous resin compositions according to the present invention were prepared with aqueous hardener compositions comprising diethanol amine as amino alcohol (hardener component C2-2) and with diethyl ethanolamine as amino alcohol (hardener component C2-2), with similar results.

[0103] Example 4: Preparation of aqueous resin compositions according to the prior art

[0104] For the preparation of an aqueous resin composition according to the present invention, a 60 wt.-% (solids content) liquid Kauramin® impregnating resin 799 (aqueous melamineformaldehyde resin component, see above) with a molar ratio of formaldehyde : melamine of 1 .6 : 1 was mixed with the amounts of aqueous hardener compositions according to the prior art (for preparation see example 2 above) as shown in table 4 below, and the turbidity times were determined in each case as a measure of the aqueous resin composition’s reactivity, as explained in example 3 above.

[0105] Table 4: Aqueous resin compositions according to the prior art relative to the total weight of the aqueous hardener composition

[0106] From a comparison of the data shown in table 3 and in table 4 it can be seen that the aqueous resin compositions according to the present invention (cf. data in table 4) showed similar hardening reactivities as the aqueous resin compositions according to the prior art and that the hardening kinetics of the aqueous resin compositions according to the present invention can be easily adjusted to conform with the hardening kinetics of the aqueous resin compositions according to the prior art. BASF SE 240124

[0107] Example 5: Preparation of papers impregnated with aqueous resin compositions according to the present invention

[0108] Commercial overlay papers having a basis weight of 25 g / m2were saturated with aqueous resin composition IARC-1 (0.3 wt.-%, 0.5 wt.-% or 0.8 wt.-%) according to the present invention, and excess resin composition was removed with a doctor blade. The resinated papers were then dried in a convection oven for 2 to 3 min. at 120 °C. This treatment was repeated once.

[0109] The resin coats so obtained were between 400 and 500% of the paper basis weight, i.e. the resulting impregnated papers (an impregnated, flexible, laminar substrate in the sense of the present invention) had a mass per unit area of between 125 and 150 g / m2(resin application 100 g to receive an impregnated paper with mass per unit area of 125 g / m2; 100 g resin applied on paper having basis weight of 25 g / m2=> resin coat is 400 % of paper basis weight).

[0110] Example 6: Preparation of papers impregnated with aqueous resin compositions not according to the present invention

[0111] Commercial overlay papers having a basis weight of 25 g / m2are saturated with aqueous resin composition CARC-1 (0.5 wt.-% or 0.8 wt.-%) according to the prior art, and excess resin composition is removed with a doctor blade.

[0112] Commercial overlay papers having a basis weight of 25 g / m2are saturated with aqueous resin composition CARC-2 (0.3 wt.-% or 0.5 wt.-%) according to the prior art, and excess resin composition is removed with a doctor blade.

[0113] The resinated papers so obtained are dried in a convection oven for 2 to 3 min. at 120 °C. The resin coats so obtained are between 400 and 500 % of the paper basis weight, i.e. the resulting impregnated papers have a mass per unit area of between 125 and 150 g / m2. | BASF SE | 240124

[0114] Example 7: Preparation of a composite material with a paper impregnated with aqueous resin composition according to the present invention

[0115] The impregnated papers produced according to example 5 above (coated with aqueous resin composition IARC-1 , 0.3 wt.-%) were pressed under a pressure of 20 bar (2 MPa) at a temperature of 200 °C (measured at the press) and for a pressing time of 40 sec. onto conventional laminatable fiber boards, to result in a composite material according to the present invention.

[0116] Example 8: Comparison of impregnated papers according to the present invention vs. according to the prior art The impregnated papers according to the present invention produced according to example 5 above and the impregnated papers according to the prior art produced according to example 6 above are analysed for their following technical properties for comparison:

[0117] (1 ) Resistance against diluted acid (acid resistance), indication with rhodamine;

[0118] (2) Resistance against water vapour (according to DIN 53 799); (3) Gloss level measurement (analogously to DIN EN 14323:2022-02).

[0119] As a result of the analyses, no noteworthy differences are found between the technical properties of the impregnated papers according to the present invention vs. the impregnated papers according to the prior art.

Claims

BASF SE240124Claims:1 . Aqueous resin composition for impregnating absorptive, flexible, laminar substrates, comprising:C1 ) a resin component, selected from the group consisting of a melamine-formal- dehyde resin mixture, a urea-formaldehyde resin mixture and a urea-mela- mine-formaldehyde resin mixture,C2) a hardener, comprising the following components:C2-1 ) an ammonium salt, selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium bromide, ammonium nitrate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate and mixtures thereof; andC2-2) one or more amino alcohols of general formula IR2N— R3l iR(I), whereinR1is a hydroxyalkyl group with 1 to 4 carbon atoms, andR2and R3independently of each other are hydrogen, an alkyl group with 1 to 4 carbon atoms, or a hydroxyalkyl group with 1 to 4 carbon atoms, andC3) water.BASF SE2401242. Aqueous resin composition according to claim 1 , comprising: a total amount in the range of from > 40 to < 70 wt.-%, preferably of from > 45 to < 65 wt.-%, relative to the aqueous resin composition, of the resin component C1 ); and / or a total amount in the range of from > 0.03 to < 2.0 wt.-%, preferably of from > 0.04 to < 1 .0 wt.-%, more preferably of from > 0.05 to < 0.5 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2- 1 ), the ammonium salt; and / or a total amount in the range of from > 0.3 x 103to < 0.04 wt.-%, preferably of from > 0.5 x 10-3to < 0.03 wt.-%, more preferably of from > 1 x 10-3to < 0.02 wt.-%, relative to the total weight of the aqueous resin composition, of the hardener component C2-2), the one or more amino alcohols of general formula I.

3. Aqueous resin composition according to any of the preceding claims, comprising a total amount in the range of from > 40 to < 70 wt.-%, preferably > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of a mela- mine-formaldehyde resin mixture as the resin component C1 ), wherein preferably the resin component comprises or consists of melamine and formaldehyde; preferably wherein melamine and formaldehyde are present in a molar ratio of from > 1 :3 to < 1 :1 and preferably further comprising one, more than one, or all of the components selected from the group consisting of: one or more polyhydric alcohols with 2 to 12 carbon atoms, preferably in a total amount in the range of from > 1 to < 10 wt.-%, relative to the total weight of the aqueous resin composition,BASF SE240124caprolactam, preferably in a total amount in the range of from > 0 to < 8 wt.- %, relative to the total weight of the aqueous resin composition,2-(2-phenoxy-ethoxy)ethanol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition, and polyethylene glycol, preferably with an average molecular weight in the range of from > 200 to < 1500 g / mol, preferably in a total amount in the range of from > 0.5 to < 10 wt.-%, relative to the total weight of the aqueous resin composition.

4. Aqueous resin composition according to any of claims 1 or 2, comprising a total amount in the range of from > 40 to < 70 wt.-%, preferably > 45 to < 65 wt.-%, relative to the total weight of the aqueous resin composition, of a ureaformaldehyde resin mixture as the resin component C1 ), wherein preferably the resin component comprises or consists of urea and formaldehyde; preferably wherein urea and formaldehyde are present in a molar ratio of from > 1 :1 .3 to < 1 :2.0, and preferably further comprising one, more than one, or all of the components selected from the group consisting of: one or more polyhydric alcohols with 2 to 12 carbon atoms, preferably in a total amount in the range of from > 1 to < 8 wt.-%, relative to the total weight of the aqueous resin composition, caprolactam, preferably in a total amount in the range of from > 0 to < 4 wt.- %, relative to the total weight of the aqueous resin composition, polyethylene glycol, preferably with an average molecular weight in the range of from > 200 to < 1500 g / mol, preferably in a total amount in the range of from > 1 to < 5 wt.-%, relative to the total weight of the aqueous resin composition.BASF SE2401245. Aqueous resin composition according to any of the preceding claims, wherein the hardener component C2-1 ) is selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium phosphate and mixtures thereof, preferably wherein the hardener component C2-1 ) comprises or is ammonium sulfate; and / or the hardener component C2-2) is selected from the group consisting of monoethanolamine, diethanolamine, triethanolamine, N-methyl-ethanolamine, N,N-dime- thyl-ethanolamine, N-ethyl-ethanolamine, N,N-diethyl-ethanolamine and mixtures thereof, preferably wherein the hardener component C2-2) comprises or is monoethanolamine; and / or the aqueous resin composition has a pH in the range of from > 7 to < 1 1 , preferably of from > 8 to < 10.

6. Aqueous hardener composition for hardening a resin mixture selected from the group consisting of a melamine-formaldehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-formaldehyde resin mixture, comprising the following components:C2-1 ) an ammonium salt, selected from the group consisting of ammonium sulfate, ammonium chloride, ammonium bromide, ammonium nitrate, ammonium phosphate, diammonium hydrogen phosphate, ammonium dihydrogen phosphate, ammonium polyphosphate and mixtures thereof; andC2-2) one or more amino alcohols of general formula IBASF SE240124R2N— R311R(I), whereinR1is a hydroxyalkyl group with 1 to 4 carbon atoms, andR2and R3independently of each other are hydrogen, an alkyl group with 1 to 4 carbon atoms, or a hydroxyalkyl group with 1 to 4 carbon atoms, and further comprising water.

7. Aqueous hardener composition according to claim 6, comprising a total amount of from > 10 to < 45 wt.-%, preferably of from > 12 to < 40 wt.-%, more preferably of from > 12 to < 35 wt.-%, relative to the total weight of the aqueous hardener composition, of hardener component C2-1 ), the ammonium salt.

8. Aqueous hardener composition according to any of claims 6 or 7, comprising the hardener component C2-2), the one or more amino alcohols of general formula I, in a total amount of from > 0.03 to < 2.0 wt.-%, preferably of > 0.05 to < 2.0 wt.- %, more preferably of > 0.1 to < 1 .5 wt.-% and even more preferably of > 0.2 to < 1 .2 wt.-%, relative to the total weight of the aqueous hardener composition; and / or in an amount sufficient to adjust in the aqueous hardener composition a pH value in the range of from > 3 to < 10, preferably of from > 5 to < 9.

9. Method of making an aqueous resin composition for impregnating absorptive, flexible, laminar substrates, comprising the stepsA1 ) providing or preparing an aqueous resin component, comprising a resin component selected from the group consisting of a mela- mine-formaldehyde resin mixture, a urea-formaldehyde resin mixture and aBASF SE240124urea-melamine-formaldehyde resin mixture, as defined in any of claims 1 to 4, in a total amount in the range of from > 40 to < 70 wt.-%, preferably of from > 45 to < 65 wt.-%, relative to the aqueous resin composition;A2) providing or preparing an aqueous hardener composition as defined in any of claims 6 to 8, preferably in a total amount in the range of from > 0.2 to < 1 .0 wt.-%, preferably of from > 0.3 to < 1 .0 wt.-%, relative to the total weight of the aqueous resin component of step A1 ), andA3) mixing the aqueous hardener composition from step A2) with the resin component from step A1 ) and optionally with additional water, to receive an aqueous resin composition for impregnating absorptive, flexible, laminar substrates.

10. Method of making an impregnated, flexible, laminar substrate, comprising the steps:51 ) providing or preparing an absorptive, flexible, laminar substrate, preferably selected from the group consisting of a paper web, a paper sheet and a nonwoven fabric,52) providing or preparing an aqueous resin composition according to any of claims 1 to 5, or an aqueous dilution thereof,53) applying the aqueous resin composition, or the aqueous dilution thereof, from step S2) to the absorptive, flexible, laminar substrate from step S1 ), to receive a resinated, flexible, laminar substrate, and54) drying the resinated, flexible, laminar substrate as received in step S3), preferably at a temperature in the range of from > 60 to < 150 °C, more preferably of from > 80 to < 130 °C, to receive an impregnated, flexible, laminar substrate.11 . Impregnated, flexible, laminar substrate obtained or obtainable by a method according to claim 10.BASF SE24012412. Method of making a composite material, comprising the stepsC1 ) providing an impregnated, flexible, laminar substrate according to claim 1 1 , or preparing an impregnated, flexible, laminar substrate by a method according to claim 10,C2) providing or preparing a carrier material, preferably comprising or consisting of a material comprising cellulosic fibers, bound by an organic binder,C3) applying the impregnated, flexible, laminar substrate from step C1 ) to the carrier material from step C2), andC4) applying heat, preferably in the range of from > 180 to < 240 °C, more preferably of from > 180 to < 220 °C, and / or pressure to the impregnated, flexible, laminar substrate on the carrier material from step C3), to receive a composite material.

13. Composite material, obtained or obtainable by a method according to claim 12.

14. Use of an aqueous resin composition as defined in any of claims 1 to 5, or an aqueous dilution thereof, for impregnating an absorptive, flexible, laminar substrate, preferably selected from the group consisting of a paper web, a paper sheet and a nonwoven fabric.

15. Use of an aqueous hardener composition as defined in any of claims 6 to 8, for hardening a resin mixture selected from the group consisting of a melamine-formal- dehyde resin mixture, a urea-formaldehyde resin mixture and a urea-melamine-for- maldehyde resin mixture.

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