INSULATING COMPOSITION AND KIT COMPRISING SUCH COMPOSITION

Abstract

The present invention refers to an insulating composition, to a kit comprising such composition and a coating composition based on the Real Michael Addition chemistry, to its use, and to a method for the coating of a substrate employing such kit.

Claims

1. An insulating composition suitable for forming at least a layer of a multilayer coating composition, comprising at least one filming agent, at least one solvent and at least one silane or siloxane or their mixtures and, optionally, one or more amines, wherein the total amount of said at least one silane or siloxane or their mixtures and of the one or more optional amines varies from 2% to 30% by weight relative to the total weight of the insulating composition.

2. The insulating composition according to claim 1, wherein the film-forming agent is selected from the group consisting of vinyl acrylate, cellulose nitrate, polyvinyl alcohol, polyvinyl ether, polyvinyl ester, polyvinyl acetate, cellulose acetate butyrate, cellulose acetate propionate, polyvinyl pyrrolidone, acrylates, methacrylates, acrylamides, their copolymers and mixtures thereof.

3. The insulating composition according to claim 1, wherein the silane has the following general formula:
Si(R.sub.1X.sub.1)(R.sub.2X.sub.2)(R.sub.3X.sub.3)(R.sub.4X.sub.4)(I) wherein R.sub.1, R.sub.2, R.sub.3 and R.sub.4, are equal or different one from the other in any combination, and are selected from the group consisting of H or saturated or unsaturated, linear or branched alkyl, aryl, polyester, polyether, polycarbonate, polyurethane, polyacrylic, methacrylic and polysilyl chains with number of chain atoms between 1 and 18, and X.sub.1, X.sub.2, X.sub.3 and X.sub.4, are equal or different one from the other in any combination, present only when the correspondent R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is different from H, and are selected between H or a reactive group taken from the group consisting of cyano, isocyano, alcohol, carbonyl, carboxyl, epoxy, amine, amide, vinyl, acryl-, methacryl, chloride, bromide, iodide, nitride, phosphate, silane; and siloxane, and/or the siloxane has the following general formula:
X.sub.1R.sub.1Si(OR.sub.2X.sub.2)(OR.sub.3X.sub.3)(OR.sub.4X.sub.4)(II) where R.sub.1, R.sub.2, R.sub.3 and R.sub.4, are equal or different one from the other in any combination, and are selected from the group consisting of H or saturated or unsaturated, linear or branched alkyl, aryl, polyester, polyether, polycarbonate, polyurethane, polyacrylic, methacrylic and polysilyl chains, with number of chain atoms between 1 and 18, and X.sub.1, X.sub.2, X.sub.3 and X.sub.4, are equal or different one from the other in any combination, present only when the correspondent R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is different from H, and are selected from the group consisting of H or a reactive group taken from the group consisting of cyano, isocyano, alcohol, carbonyl, carboxyl, epoxy, amine, amide, vinyl, acryl, methacryl, chloride, bromide, iodide, nitride, phosphate, silane, siloxane, and the amine has the following general formula:
N(R.sub.1X.sub.1)(R.sub.2X.sub.2)(R.sub.3X.sub.3)(III) wherein R.sub.1, R.sub.2 and R.sub.3, are equal or different one from the other in any combination, and are selected from the group consisting of H or saturated or unsaturated, linear or branched alkyl, aryl, polyester, polyether, polycarbonate, polyurethane, polyacrylic, methacrylic and polysilyl chains with number of chain atoms between 1 and 18, and X.sub.1, X.sub.2 and X.sub.3, are equal or different one from the other in any combination, present only when the correspondent R.sub.1, R.sub.2 or R.sub.3 is different from H, and are selected from the group consisting of H or a reactive group selected from the group consisting of cyano, isocyano, alcohol, carbonyl, carboxyl, epoxy, amine, amide, vinyl, acryl, methacryl, chloride, bromide, iodide, nitride, phosphate, silane, and siloxane.

4. The insulating composition according to claim 1, wherein each of the said at least one silane or siloxane or their mixtures and of the one or more optional amines is present in an amount ranging of from 0.1% to 10% by weight, more preferably of from 0.5% to 5% by weight relative to the total weight of the insulating composition.

5. The insulating composition according to claim 1, wherein the film-forming agent is present in an amount ranging of from 0.1% to 20% by weight relative to the total weight of the insulating composition.

6. Use of an insulating composition according to claim 1, for the coating of a substrate, optionally surfaced by impregnated paper or cellulosic material, or made from another material presenting acidic groups on its surface.

7. A kit comprising at least the following compositions suitable for the formation of a multilayer coating a) an insulating composition according to claim 1; and b) an RMA-based paint or varnish cross-linkable composition, and, optionally, c) at least one composition comprising a stain.

8. The kit according to claim 7, in which the RMA-based paint or varnish cross-linkable composition b) comprises: b1) at least one component with at least 2 acidic protons (CH donor groups) in activated methylene or methyne groups; b2) at least one component with at least 2 unsaturations (CC acceptor groups), where said CH donor groups of component b1) and said CC acceptor groups of component b2) can be present in the same molecule; b3) at least one base or latent base; b4) optionally, at least one component able to regulate the reactivity rates, such as a component comprising an XH group where X is N, P, O, S or where X is C in a methyl group, said component b4) having acidity, measured as pKa in water, lower by at least one unit than the acidity of the CH group in component b1), preferably said component b4) having pKa ranging from 7 to 13, and most preferably wherein component b4) is selected among substituted and unsubstituted 1,2,4 triazole and 1,2,3 triazole, succinimide, etosuccimide, 5, 5-dimethylhydantoin, benzotriazole, benzene sulfonamide, nitromethane, isatine, uracil, 4-nitro-2-methylimidazole, ethyl acetoacetate and phenol; b5) optionally, at least one solvent.

9. The kit according to claim 7, in which the solvent in the insulating composition a) and/or in the RMA-based paint or varnish cross-linkable composition b) is taken from the group consisting of water, benzene, toluene, xylene, aromatic solvents, aliphatic olefins, ethyl acetate, propyl acetate, butyl acetate, isobutyl acetate, acetates, acetone, methyl ethyl ketone, ketones, ethanol, propanol, isopropanol, alcohol, a glycol, a glycol ether, pyrrolidone, substituted pyrrolidones and mixtures thereof.

10. Use of the kit according to claim 7 for the coating of a substrate, optionally surfaced by impregnated paper or cellulosic material, or made from another material presenting acidic groups on its surface.

11. A method for coating a substrate, comprising the following steps: i. application to the substrate of at least one layer of the insulating composition a) according to claim 1; ii. drying of the insulating composition layer a) applied in step i., by keeping at ambient conditions or using drying methods; iii. application of at least one layer of the RMA-based paint or varnish composition b) to the parts of the substrate coated with the insulating composition a) dried in step ii.; iv. curing of the layer applied in step iii.

12. A three-dimensional object at least partially coated or a surface at least partially coated, obtained according to the method of claim 11.

13. The insulating composition of claim 1, wherein the total amount of said at least one silane or siloxane or their mixtures and of the one or more optional amines varies from 5% to 20% by weight relative to the total weight of the insulating composition.

14. The insulating composition according to claim 4, wherein each of the said at least one silane or siloxane or their mixtures and of the one or more optional amines is present in an amount ranging of from 0.5% to 5% by weight relative to the total weight of the insulating composition.

15. The insulating composition according to claim 5, wherein the film-forming agent is present in an amount ranging of from 0.2% to 19% by weight relative to the total weight of the insulating composition.

16. The insulating composition according to claim 5, wherein the film-forming agent is present in an amount ranging of from 0.5% to 5% by weight relative to the total weight of the insulating composition.

17. The use of an insulating composition according to claim 6, wherein the substrate is chosen from the group consisting of a surface and a three-dimensional object, optionally surfaced by impregnated paper or cellulosic material, or made from another material presenting acidic groups on its surface.

18. The use of an insulating composition according to claim 6, wherein the substrate is made of wood or wood-based material, optionally surfaced by impregnated paper or cellulosic material, or made from another material presenting acidic groups on its surface.

19. Use of the kit according to claim 10, wherein the substrate is a three-dimensional object, optionally surfaced by impregnated paper or cellulosic material, or made in other material presenting acidic groups on its surface.

20. Use of the kit according to claim 10, wherein the substrate is made of wood or wood-based material, optionally surfaced by impregnated paper or cellulosic material, or made in other material presenting acidic groups on its surface.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0110] The attached drawings are intended to better illustrate the present invention without limiting the invention in any manner whatsoever.

[0111] FIG. 1A is an illustration of an oak sample coated without an insulating layer, pursuant to Example 1 of Table 1.

[0112] FIG. 1B is an illustration of an oak sample without a coating.

[0113] FIG. 1C is an illustration of an oak sample coated using the insulating composition of the invention, pursuant to Example 4 of Table 1.

[0114] FIG. 2A is an illustration of an oak sample stained and coated without an insulating layer, pursuant to Example 5 of Table 1.

[0115] FIG. 2B is an illustration of an oak sample stained and coated using the insulating composition of the invention, pursuant to Example 6 of Table 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0116] The following examples are provided to illustrate some embodiments of the invention, without limiting in any way its scope.

[0117] All the example coating formulations were applied on oak, a type of wood showing clearly defined, open pores and containing a significant amount of mobile chemical species, particularly tannins

[0118] The general scheme of the coating compositions used in the examples (where examples 1-3, 5 and 7 are comparative, and examples 4 and 6 are according to the invention), and the application sequence of the coating compositions, are as follows

TABLE-US-00001 TABLE 1 example coating cycles and relative esthetic evaluation RMA-based example stain Insulating layer(s) composition esthetic evaluation 1 no None 2 layers as DARKENING 2 no WB (insulating described in text DARKENING waterborne) 3 no NCO-based insulating NATURAL COLOR composition 4 no Insulating composition NATURAL COLOR according to the invention 5 yes None GRAYING 6 yes Insulating composition ORIGINAL STAIN COLOR according to the invention 7 yes Insulating composition First RMA-based layer is with the components of removed when the second RMA- the invention but below layer is applied the concentration limits of the invention

[0119] The compositions of the coating products of the examples are given below; concentrations are always given in weight percentages relative to total composition weight.

[0120] The stain, when used, was applied by rag, that is by dabbing with pressure a rag soaked in the stain onto the substrate, letting the composition penetrate the substrate, and removing any excess liquid. The overcoats were then applied after 4 hours, to allow for complete drying and evaporation of the solvent.

[0121] The stain of the examples is a normal commercial formulation of the Milesi CIT series, comprised of the following components: [0122] 8% pigments [0123] 88% glycol ether solvents [0124] 3% polyester binders [0125] 1% dispersants and rheological agents.

[0126] The insulating compositions were all applied by spray coating in an amount of 100 g/m.sup.2. Before the application of the overcoats, a sufficient time was always allowed for drying and filming, specifically 2 hours after the application of the WB composition (example 2) and after the application of the NCO-based composition (example 3). Advantageously, the overcoats can be applied just 1 hour after the application of the inventive composition (examples 4 and 6).

[0127] The WB insulating composition comprises: [0128] 60% Neocryl XK30 from DSM, a stain locking resin based on acrylic copolymer emulsion [0129] 4% Texanol from Eastman Chemical (isobutyrric acid ester with 2,2,4-trimethyl-1,3-pentandiol), cosolvent and coalescent [0130] water to 100% [0131] pH adjusted to 7 with mono ethanolamine

[0132] The NCO-based insulating composition was also a commercially available product, Ilva TF23, a 2K solvent borne PU product. It comprises [0133] 14% polyisocyanate binders based on TDI, toluene diisocyanate [0134] 9% hydroxylated polyester binders based on phthalic anhydride and trimethylol propane with fatty acids [0135] 77% solvents

[0136] The insulating composition according to the present invention of examples 4 and 6 comprises [0137] 92% butyl acetate solvent [0138] 4% cellulose acetate butyrate [0139] 4% gamma-aminopropyl triethoxysilane

[0140] The insulating composition of example 7 comprises [0141] 95.6% butyl acetate solvent [0142] 4% cellulose acetate butyrate [0143] 0.4% gamma-aminopropyl triethoxysilane

[0144] The RMA-based composition employed in the examples was modeled on the formulation of example 9 of cited patent EP2556108B1. A formulation with a solid content of 75% was prepared by sequential mixing of [0145] 100 g of a solution of polyesters comprising malonates [0146] 30 g of Dowanol PMA (1-methoxy-2-propanol) [0147] 6 g of tetrabutylammonium bicarbonate [0148] 50 g of TMPTA (trimethylolpropane triacrylate).

[0149] The catalyst concentration was 0,029 meq/g of solids.

[0150] A first layer was spray coated with a laydown of 80 g/m.sup.2; after 1 hour light sanding was effected with 320 grit sand paper, followed by application of a second layer, spray coated again at 80 g/m.sup.2. The overall applied composition was as follows [0151] 34% malonate polyester [0152] 19% trimethylol propane triacrylate [0153] 1% tetrabutylammonium bicarbonate [0154] 35% butyl acetate [0155] 11% primary alcohol.

[0156] In the attached figures, one can see examples of wood not coated, coated in accordance to the present invention, and coated as in the state of the art, and specifically:

[0157] FIG. 1: oak: 1A) area coated without insulating layer (example 1 of Table 1), 1B) area not coated and 1C) area coated using the insulating composition of the invention (example 4 in Table 1);

[0158] FIG. 2: oak: 2A) area stained and coated without insulating layer (example 5 of Table 1) and 2B) area stained and coated using the insulating composition of the invention (example 6 in Table 1).

[0159] The effect of the interaction between wood-contained tannins and the RMA-based coatings is evidenced in FIG. 1 showing an oak-veneered panel coated on one side (1A) with cycle of example 1 of Table 1, on the other side (1C) with cycle of example 4 of Table 1, whereas the central band (1B) was not coated in order to provide a comparative sample.

[0160] Therefore, the left (1A) and right (1C) ends have been coated with identical cycles not including a stain, differing only in that the cycle of example 1 on the left (1A) is without insulating composition, whereas the cycle of example 4 on the right (1C) includes the insulating composition according to the present invention.

[0161] It can be clearly noticed how the area (1A) coated with cycle of example 1 is much darker than the area (1C) coated with cycle of example 4, that preserves the natural color of the wood with a good enlivening.

[0162] These results show that the use of the insulating composition according to the present invention makes it possible to keep wood color chromatically unchanged by coating.

[0163] Overall the esthetic results of the coating cycles of the example are summarized in the fifth column of Table 1. It can be seen that the insulating composition according to the present invention achieves the same insulating efficacy of the state-of-the art NCO-based insulating composition without, of course, having to include isocyanates or polyisocyanates, and, therefore, making it possible to fully enjoy the health and safety improvements of RMA-based coatings.

[0164] The effect of the interaction between wood-contained tannins and the RMA-based cross-linkable coatings in the presence of a stain is evidenced in FIG. 2 showing an oak-veneered panel coated on one side (2A) with cycle of example 5 of Table 1 (comparative), on the other side (2B) with cycle of example 6 of Table 1 (according to the present invention). Therefore, the left (2A) and right (2B) halves are coated with identical cycles including the optional stain, differing only in that the cycle of example 5 (on the left, 2A) is without insulating composition, whereas the example of example 6 (on the right, 2B) includes the insulating composition according to the present invention.

[0165] It can be clearly noticed how the area (2A) coated with cycle of example 5 is much grayer and dull than the area (2B) coated with cycle of example 6, for the presence of a grey or black component that makes the color more neutral, than the area (2B) coated with cycle of example 6: in this case, the reaction between tannins and RMA-based composition led to an evident shift in stain color.

[0166] Finally, when an insulating composition contains the same components of the insulating composition according to the present invention but contains the silane/siloxane and optional amine in concentrations lower than those indicated in the composition according to the present invention, is applied over a stain as in example 7, a strange phenomenon is observed.

[0167] Indeed, even though the first layer of RMA-based composition appears to adhere and cross-link perfectly, when a second layer of RMA-based composition is applied, the adhesion of the first layer gets lost. Such phenomenon becomes apparent as an esthetic defect, especially tactile (the surface becoming rough to the touch), randomly diffused over the coated surface or piece.

[0168] Such phenomenon makes diluted insulating compositions absolutely unsuitable for industrial use.