CN111040601A

CN111040601A - Aqueous skin-feel bi-component woodenware coating and application thereof

Info

Publication number: CN111040601A
Application number: CN201911376130.4A
Authority: CN
Inventors: 马强华; 邓文根; 胡耀文
Original assignee: Shanghai Junzilan New Material Co ltd
Current assignee: Shanghai Junzilan New Material Co ltd
Priority date: 2019-12-27
Filing date: 2019-12-27
Publication date: 2020-04-21
Anticipated expiration: 2039-12-27
Also published as: CN111040601B

Abstract

The invention relates to the technical field of water-based paint, in particular to water-based skin-feel bi-component wood paint and application thereof. The preparation raw material of the wood coating consists of a component A and a component B; the applicant finds that the coating obtained by curing has good skin feel by adopting the two-component wood coating, compounding the two kinds of waterborne polyurethane in the component A and using the isocyanate action of the component B, and the coating rich in skin feel and elasticity can be further obtained by using a proper defoaming agent, a matting agent, polydimethylsiloxane and the like; in addition, through the combined action of the preparation raw materials of the component A and the component B, the coating obtained by curing has a certain self-repairing effect, can repair certain scratches, has good adhesion, water resistance and stain resistance, can be used for various wood furniture, such as wood artware, wood wallboard, wood sofa and the like, and provides protection, decoration and special hand feeling.

Description

Aqueous skin-feel bi-component woodenware coating and application thereof

Technical Field

The invention relates to the technical field of water-based paint, in particular to water-based skin-feel bi-component wood paint and application thereof.

Background

With the deep popularization of the environmental protection and low carbon concept, the application of the organic oil-soluble paint with high volatile organic compound VOC release is more and more restricted, and the environment-friendly water-based paint with low VOC release is more and more favored and becomes the mainstream trend of the development of the wood coatings. The water-based wood coating is an important component in the water-based coating, is mainly used for coating the surface of wood furniture, not only has the function of beautifying and decorating, but also can play a role of protecting the wood, thereby prolonging the service life of the wood furniture. As the main diluent is water, compared with the traditional solvent-based wood coating, the water-based wood coating has low VOC value, greatly reduces the harm to constructors or users, and belongs to environment-friendly coating.

Single-component water-based coatings for wood coatings have been developed greatly, and most of the single-component water-based coatings are focused on water-based acrylic acid and single-component water-based polyurethane systems. The water-based acrylic acid has the advantages of early market acceptance and low price, but has the defects of poor mechanical property and chemical resistance, poor hot-sticking and cold-brittleness, poor anti-sticking property and the like. The single-component water-based polyurethane coating can not be compared favorably with a solvent-based coating, both are not suitable for manufacturing high-quality woodenware coatings, and the double-component water-based polyurethane coating has high performance and multiple functions, such as high solid content, good wear resistance, flexibility, chemical resistance and durability, greatly reduces the release of VOC and can meet the requirements of high-grade coatings.

However, the existing two-component waterborne polyurethane coating has poor water resistance and stain resistance, is easy to scratch and influences use due to the fact that water is used as a solvent, and in addition, the existing two-component waterborne coating has few functions, so that the preparation of the waterborne coating with skin feel is important for research on the increase of the functions of the existing coating.

Disclosure of Invention

In order to solve the problems, the invention provides a water-based skin-feel double-component wood coating in a first aspect, wherein the wood coating is prepared from a raw material consisting of a component A and a component B;

the component A comprises, by weight, 70-90 parts of waterborne polyurethane, 0.1-1 part of a defoaming agent, 0.1-1 part of a wetting agent, 5-8 parts of a flatting agent and 8-15 parts of water;

the component B comprises 4-8 parts by weight of isocyanate and 1-3 parts by weight of solvent;

the isocyanate accounts for 5-10 wt% of the waterborne polyurethane.

As a preferable technical scheme of the invention, the flatting agent comprises silicon dioxide A with the particle size of 1-3 mu m and the oil absorption of 200-230 g/100 g.

As a preferable technical scheme, the delustering agent further comprises silicon dioxide B with the particle size of 4-6 mu m and the oil absorption of 350-400.

According to a preferable technical scheme of the invention, the weight ratio of the silicon dioxide A to the silicon dioxide B is (0.2-0.5): 1.

as a preferable technical scheme of the invention, the component A also comprises polydimethylsiloxane, and the viscosity of the polydimethylsiloxane at 25 ℃ is 200000-700000 cst.

In a preferred technical scheme of the invention, the weight ratio of the polydimethylsiloxane to the silicon dioxide B is (0.1-0.3): 1.

according to a preferable technical scheme of the invention, the silicon dioxide B comprises 10-20 wt% of modified silicon dioxide B, the preparation raw material of the modified silicon dioxide B comprises silicon dioxide B and a silane coupling agent, and the weight ratio of the silicon dioxide B to the silane coupling agent is 1: (0.2-0.4).

In a preferred embodiment of the present invention, the silane coupling agent is selected from one or more of aminosilane coupling agents, epoxy silane coupling agents, and anhydride silane coupling agents.

The second aspect of the invention provides a preparation method of the aqueous skin-feel bi-component woodenware coating, which comprises the following steps:

and mixing the preparation raw materials of the component A, standing for 20-30 h, adding the preparation raw materials of the component B, and mixing to obtain the wood ware coating.

The third aspect of the invention provides an application of the aqueous skin-feel bi-component wood coating in wood furniture.

Compared with the prior art, the invention has the following beneficial effects: the applicant finds that the coating obtained by curing by adopting the two-component woodware coating and using two kinds of waterborne polyurethane to compound in the component A and using the isocyanate action of the component B has good skin feel, and the coating rich in skin feel and elasticity can be further obtained by using a proper defoaming agent, a matting agent, polydimethylsiloxane and the like; in addition, through the combined action of the preparation raw materials of the component A and the component B, the coating obtained by curing has a certain self-repairing effect, can repair certain scratches, has good adhesion, water resistance and stain resistance, can be used for various wood furniture, such as wood artware, wood wallboard, wood sofa and the like, and provides protection, decoration and special hand feeling.

Detailed Description

The disclosure may be understood more readily by reference to the following detailed description of preferred embodiments of the invention and the examples included therein. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. In case of conflict, the present specification, including definitions, will control.

The term "prepared from …" as used herein is synonymous with "comprising". The terms "comprises," "comprising," "includes," "including," "has," "having," "contains," "containing," or any other variation thereof, as used herein, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises a list of elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

The conjunction "consisting of …" excludes any unspecified elements, steps or components. If used in a claim, the phrase is intended to claim as closed, meaning that it does not contain materials other than those described, except for the conventional impurities associated therewith. When the phrase "consisting of …" appears in a clause of the subject matter of the claims rather than immediately after the subject matter, it defines only the elements described in the clause; other elements are not excluded from the claims as a whole.

When an amount, concentration, or other value or parameter is expressed as a range, preferred range, or as a range of values, with a range of upper preferable values and lower preferable values, this is to be understood as specifically disclosing all ranges formed from any pair of any upper range limit or preferred value and any lower range limit or preferred value, regardless of whether ranges are separately disclosed. For example, when the range "1 to 5" is disclosed, the described range should be construed as including the ranges "1 to 4", "1 to 3", "1 to 2 and 4 to 5", "1 to 3 and 5", and the like. When a range of values is described herein, unless otherwise stated, the range is intended to include the endpoints thereof and all integers and fractions within the range.

The singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. "optional" or "any" means that the subsequently described event or events may or may not occur, and that the description includes instances where the event occurs and instances where it does not.

Approximating language, as used herein in the specification and claims, is intended to modify a quantity, such that the invention is not limited to the specific quantity, but includes equivalents thereof that are acceptable without resulting in a change in the basic function to which it is related. Accordingly, the use of "about" to modify a numerical value means that the invention is not limited to the precise value. In some instances, the approximating language may correspond to the precision of an instrument for measuring the value. In the description and claims of this application, range limitations may be combined and/or interchanged, including all sub-ranges contained therein if not otherwise stated.

In addition, the indefinite articles "a" and "an" preceding an element or component of the invention are not intended to limit the number requirement (i.e., the number of occurrences) of the element or component. Thus, "a" or "an" should be read to include one or at least one, and the singular form of an element or component also includes the plural unless the number clearly indicates the singular.

The present invention is illustrated by the following specific embodiments, but is not limited to the specific examples given below.

The first aspect of the invention provides a water-based skin-feel bi-component woodware coating, wherein the preparation raw material of the woodware coating consists of a component A and a component B;

the isocyanate accounts for 5-10 wt% of the waterborne polyurethane.

In a preferred embodiment, the raw materials for preparing the wood coating comprise a component A and a component B;

the component A comprises 80 parts of waterborne polyurethane, 0.5 part of defoaming agent, 0.4 part of wetting agent, 6.5 parts of flatting agent and 11.6 parts of water in parts by weight;

the component B comprises 6 parts of isocyanate and 2 parts of solvent in parts by weight;

the isocyanate accounted for 7.5 wt% of the aqueous polyurethane.

[ A component ]

Aqueous polyurethane

Polyurethane is the general name of high molecular polymer containing repeated carbamate groups (-NHCOO-) in the molecular structure, and has the advantages of wide adjustable range of hardness, low temperature resistance, good flexibility, strong adhesion and the like. The waterborne polyurethane disclosed by the invention comprises, but is not limited to, Changxing ETERANE 8928-2A, ETERANE 8911A, ETERANE 8916A, ETERANE 8918, ETERANE 8925, ETERANE 8933BA, ETERANE 8962BA, ETERANE 89641BA, ETERANE 82421 and ETERANE 89120.

In one embodiment, the waterborne polyurethane disclosed by the invention comprises ETERANE 82421 and ETERANE89120 in a weight ratio of (3-5): (3-5); further, the weight ratio of ETERANE 82421 and ETERANE89120 is 1: 1.

applicants have found that by formulating two aqueous polyurethanes, particularly ETERANE 82421 and ETERANE89120, and controlling the weight ratio to isocyanate, the skin feel of the resulting coating is increased, possibly due to the interaction of the hydroxyl and like functional groups of the two aqueous polyurethanes ETERANE 82421 and ETERANE89120 with the isocyanate to form an interconnected training network, and due to the different structural interactions of ETERANE 82421 and ETERANE89120, the elasticity and skin feel of the coating is increased, and applicants have found that when only one of ETERANE 82421 and ETERANE89120 is used, the skin feel is poor.

Defoaming agent

Defoamers are substances that reduce the surface tension of water, solutions, suspensions, etc., prevent the formation of foam, or reduce or eliminate the original foam. The defoaming agent is not limited to, non-silicon type defoaming agents, polyether type defoaming agents, silicone defoaming agents.

As examples of the non-silicon type defoaming agent, there are included, but not limited to, alcohol type defoaming agents, carboxylate type defoaming agents, phosphate ester type defoaming agents, mineral oil type defoaming agents, amide type defoaming agents; as the amide defoaming agent, monoamide, bisamide, and the like, trialkyl melamine, cyanuric chloride melamine, aliphatic amine; the phosphate defoaming agent may include, for example, monoalkyl phosphate ester, dialkyl phosphate ester, fluorinated alkyl phosphate ester; the carboxylate may be exemplified by fatty acids such as lauric acid, palmitic acid, fatty acid esters such as fatty glyceride, animal and vegetable oils, etc., fatty acid soaps such as calcium, aluminum, magnesium soaps of stearic acid and palmitic acid; the alcohol antifoaming agent includes, but is not limited to, fatty alcohol, ether.

Examples of the polyether type defoaming agent include, but are not limited to, GP type polyether type defoaming agent, GPE type polyether type defoaming agent, GPEs type polyether type defoaming agent.

Examples of silicone defoamers include, but are not limited to, BYK-series defoamers of Bik chemical Germany, BYK-051, BYK-052, BYK-053, BYK-055, BYK-057, BYK-020, BYK-065, BYK-066N, BYK-067-A, BYK-070, BYK-085, BYK-088, BYK-141, BYK-019, BYK-021, BYK-022, BYK-023, BYK-024, BYK-025, BYK-028, BYK-011, BYK-031, BYK-033, BYK-034, BYK-035, BYK-036, BYK-037, BYK-045, BYK-A530, BYK-A500, BYK-A506, BYK-032, BYK-A-032, BYK-03, BYK-060, BYK-018, BYK-044, BYK-094, BYK-1790 and BYK-093.

Preferably, the defoamer of the present invention is BYK-024 of Pico Germany.

Wetting agent

Wetting agents are substances that make solid materials more susceptible to wetting by water. The solid material is wetted by reducing its surface tension or interfacial tension, allowing water to spread on or penetrate the surface of the solid material. The wetting agent of the present invention includes, but is not limited to, anionic wetting agents, nonionic wetting agents, silicone wetting agents.

Examples of anionic wetting agents include, but are not limited to, alkyl sulfates, sulfonates, fatty acid or fatty acid ester sulfates, carboxylic acid soaps, phosphate esters.

Examples of nonionic wetting agents include, but are not limited to, polyoxyethylene alkylphenol ethers, polyoxyethylene fatty alcohol ethers, polyoxyethylene polyoxypropylene block copolymers.

Examples of silicone wetting agents include, but are not limited to, BYK series wetting agents of Bick chemistry, Germany, such as BYK-310, BYK-320, BYK-322, BYK-323, BYK-325, BYK-330, BYK-331, BYK-333, BYK-335, BYK-337, BYK-341, BYK-344, BYK-346, BYK-348, BYK-349, BYK-354, BYK-356, BYK-358n, BYK-uv3510, BYK-361n, BYK-370, BYK-371, BYK-377, BYK-390, BYK-392.

Preferably, the wetting agent of the present invention is BYK-349.

Matting agent

The flatting agent is a flatting auxiliary agent, and the flatting agent comprises but is not limited to silicon dioxide, talc powder and polyethylene wax powder.

In one embodiment, the matting agent of the invention is silica.

Examples of the silica include, but are not limited to, titanium dioxide of the ACEMATT series of Degussa, and HK125, HK400, HK440, OP278, HK450, HK460, OK412 (particle size of 3 μm, oil absorption of 230g/100g), OK412LC, OK500 (particle size of 3 μm, oil absorption of 260g/100g), OK520, OK607 (particle size of 2 μm, oil absorption of 220g/100g), 3600, TS100 (particle size of 4 μm, oil absorption of 360g/100g), TS100/20, 3300 are listed.

Preferably, the flatting agent comprises silicon dioxide A with the particle size of 1-3 mu m and the oil absorption of 200-230 g/100 g.

The particle size is the size of the particles. For testing according to methods well known to those skilled in the art, such as laser methods, sedimentation methods, photon cross-correlation spectroscopy, sieving methods, microscopy, ultrasonic particle size analysis, X-ray small angle diffraction methods.

Oil absorption is the minimum amount of oil required to wet the surface of the particles and fill the interstices between the particles. The specific quantification method is the lowest amount of pure linseed oil absorbed per 100g of pigment, namely the oil absorption. The test may be performed according to methods well known in the art.

Examples of silica a include, but are not limited to, OK607, OK 412.

More preferably, the matting agent a of the present invention is OK 607.

Further preferably, the flatting agent also comprises silicon dioxide B with the particle size of 4-6 mu m and the oil absorption of 350-400; further, the silica B of the present invention is TS 100.

More preferably, the weight ratio of silica a to silica B in the present invention is (0.2 to 0.5): 1; further, the weight ratio of the silicon dioxide A to the silicon dioxide B is 0.3: 1.

the applicant finds that when the defoaming agent is added, although the defoaming agent can promote the elimination of bubbles in the preparation process of the wood coating, the phenomenon of recesses and shrinkage cavities is easy to occur due to the excessively low surface tension of the defoaming agent, and in addition, local shrinkage and generation of holes are easy to occur in the curing process of the waterborne polyurethane, so that the coating and the skin feeling and smoothness of the wood coating are affected.

The applicant has unexpectedly found that when silica is used as a matting agent, particularly when silica having different particle sizes and oil absorption amounts is used, it is possible to prevent the occurrence of cavities and shrinkage cavities, to promote skin feel, and to contribute to water resistance, probably because more water-based polyurethane molecules are adsorbed around the silica, silica near the bubbles tends to fill up the bubbles during defoaming, and because of the oil absorption of silica, it is also advantageous to drive the polyurethane molecules to move, further avoiding cavities and shrinkage cavities during defoaming, and silica is also advantageous to fill up the micropores generated by curing shrinkage during polyurethane curing, but the applicant has unexpectedly found that when the oil absorption of silica is too high, it is easy to cause the reduction of flowable polyurethane molecules near the silica, and is disadvantageous to fill up the micropores of silica, so the present invention combines silica having different particle sizes and oil absorption amounts, the content of polyurethane adsorbed on the surface of the silicon dioxide and the fluidity of the polyurethane are adjusted, and the silicon dioxide with different particle sizes is adopted, so that the sink and the shrinkage cavity can be more fully filled, and a smoother coating can be obtained; in addition, with the curing of the wood coating, the silicon dioxide can migrate to the surface of the coating, and the silicon dioxide with different grain diameters generates microscopic roughness, so that the skin feel can be better shown, and the silicon dioxide can be used as a physical crosslinking point, so that the compactness of the coating is improved, and the water resistance is improved.

However, the applicant has unexpectedly found that although the use of silica as a matting agent is advantageous in increasing the water resistance, the stain resistance is slightly reduced, probably because contaminants such as tea water, coffee, and organic molecules such as fats and oils, tea polyphenols, and caffeine contained in cosmetics in a large amount are easily adsorbed by the silica particles, resulting in the residue of contaminants on the coating layer.

In a preferred embodiment, the silica B comprises 10-20 wt% of modified silica B, and the modified silica B is prepared from silica B and a silane coupling agent in a weight ratio of 1: (0.2 to 0.4); further, the silicon dioxide B comprises 20 wt% of modified silicon dioxide B; further, the raw materials for preparing the modified silica B comprise silica B and a silane coupling agent, wherein the weight ratio of the silica B to the silane coupling agent is 1: 0.3.

in a more preferred embodiment, the silane coupling agent of the present invention is selected from one or more of aminosilane coupling agents, epoxysilane coupling agents, and anhydride silane coupling agents.

Examples of aminosilane coupling agents include, but are not limited to, gamma-aminopropyltrimethoxysilane, 3-aminopropyltriethoxysilane, gamma-diethylenetriaminopropylmethyldimethoxysilane, N-2-aminoethyl-3-aminopropyltrimethoxysilane, N-2-aminoethyl-3-aminopropylmethyldimethoxysilane, gamma-aminopropylmethyldiethoxysilane.

Examples of the epoxysilane coupling agent include, but are not limited to, 3-glycidoxypropyltrimethoxysilane, 3- (2, 3-glycidoxy) propyltriethoxysilane, 3- (2, 3-glycidoxy) propylmethyldimethoxysilane.

Examples of the acid anhydride silane coupling agent include, but are not limited to, 3- (trimethoxysilyl) propylsuccinic anhydride (CAS number: 156088-53-8), 3- (triethoxysilyl) propylsuccinic anhydride (CAS number: 93642-68-3).

In a further preferred embodiment, the silane coupling agent of the present invention is an anhydride silane coupling agent.

In a further preferred embodiment, the process for the preparation of the modified silica B according to the invention comprises the following steps:

adding the silicon dioxide B into toluene, dispersing for 20-40 min, adding a silane coupling agent, reacting for 5-6 h at 70-80 ℃, centrifuging, and drying to obtain the modified silicon dioxide.

In one embodiment, the a component of the present invention further comprises polydimethylsiloxane.

Polydimethylsiloxane

The polydimethylsiloxane is colorless or light yellow liquid, is tasteless, has high transparency, heat resistance, cold resistance, small viscosity change along with temperature, water resistance and surface tension, has physiological inertia and good chemical stability. Good electric insulation, weather resistance and hydrophobicity, and high shear resistance. The composite material has excellent physical characteristics, can be directly used for damp-proof insulation, damping, shock absorption, defoaming, lubrication, polishing and the like, and can be widely used as insulation lubrication, shock prevention, oil dust prevention, dielectric fluid and heat carriers.

In one embodiment, the polydimethylsiloxane of the invention has a viscosity of 200000 to 700000cst at 25 ℃.

The viscosity of the invention is kinematic viscosity, namely the ratio of the dynamic viscosity of a liquid to the density rho of the fluid at the same temperature. Can be tested according to methods well known in the art.

Preferably, the weight ratio of the polydimethylsiloxane to the silicon dioxide B is (0.1-0.3): 1; further, the weight ratio of the polydimethylsiloxane to the silicon dioxide B is 0.2: 1.

more preferably, the polydimethylsiloxane is DC-51 (viscosity at 25 ℃ is 200000-700000 cst) of Dow Corning.

The applicant finds that the addition of the polydimethylsiloxane with ultrahigh viscosity, namely ultrahigh molecular weight is beneficial to improving the stain resistance, generating certain self-repairing capability and promoting the skin feel of the coating, and the reason is that the polydimethylsiloxane with ultrahigh molecular weight is easily added to form an interpenetrating network with polyurethane in the curing process of the wood coating, so that the flexibility of a polyurethane network system is increased, the skin feel of the coating obtained by curing is improved, and the polydimethylsiloxane with ultrahigh viscosity is easily enriched on the surface of the coating due to the low surface tension of the polydimethylsiloxane, so that the surface tension of the coating is further reduced, and the polydimethylsiloxane and the silica matting agent have good compatibility and are also beneficial to the migration of the silica and the polydimethylsiloxane to the surface of the coating together, when exposed to contaminants, the polydimethylsiloxane, in the vicinity of the silica, increases the density of the crosslinked network on the surface of the coating, and reduces the adsorption and permeation of contaminants.

In addition, applicants have unexpectedly found that when a lower viscosity polydimethylsiloxane is used, the stain resistance and sink improvement is not good, probably because the shorter backbone of the lower viscosity polydimethylsiloxane causes maldistribution of the polydimethylsiloxane concentrated on the surface of the coating, which also tends to affect the performance development of the silica matting agent. However, applicants have found that the addition of ultra-high viscosity polydimethylsiloxane to the A component tends to affect compatibility with the B component, particularly when the B component contains an aromatic isocyanate.

The applicant has unexpectedly found that when modified silica B, in particular an anhydride silane coupling agent, is added, it is advantageous to increase the compatibility of the ultra-high viscosity polydimethylsiloxane with the B component and to provide a certain self-healing capability to the cured coating, probably because by grafting an anhydride silane coupling agent onto the surface of silica B, the anhydride bonds on the surface of silica B can interact with the isocyanate when B component is added, and it is advantageous to promote the compatibility of the isocyanate with the polydimethylsiloxane due to the compatibility of the silica with the polydimethylsiloxane itself, and that the silica serves as a bridge connecting the isocyanate with the polydimethylsiloxane, and the isocyanate reacts with the functional groups of the aqueous polyurethane, such as hydroxyl groups, to provide isocyanate, aqueous polyurethane, self-healing coating, and the like, The raw materials for preparing the silicon dioxide matting agent and the polydimethylsiloxane are connected with each other to form a network system with tighter connection. And because of the conformation active surface and flexibility of the polydimethylsiloxane, when scratches exist on the coating, the polydimethylsiloxane can be acted together with polar groups such as ester groups, amino groups and the like with high polarity in the polyurethane, so that the polydimethylsiloxane has certain repair capability on the scratches.

[ B component ]

Isocyanates

In one embodiment, the isocyanate of the present invention comprises an aliphatic isocyanate.

Examples of aliphatic isocyanates include, but are not limited to, Hexamethylene Diisocyanate (HDI), isophorone diisocyanate (IPDI), diisocyanatocyclohexylmethane (HMDI), Butylidene Diisocyanate (BDI), 2, 4-trimethylhexamethylene diisocyanate, diisocyanatomethylcyclohexane, diisocyanatomethyltricyclodecane.

Preferably, the aliphatic isocyanate of the present invention is hexamethylene diisocyanate.

More preferably, the isocyanate further comprises aromatic isocyanate, wherein the aromatic isocyanate accounts for 10-30 wt% of the aliphatic isocyanate; further, the aromatic isocyanate of the present invention accounts for 20 wt% of the aliphatic isocyanate.

As examples of the aromatic isocyanate, there may be mentioned, but not limited to, aromatic diisocyanates such as diphenylmethane diisocyanate (MDI), tetramethylm-xylylene diisocyanate, xylylene diisocyanate; polyaromatic isocyanates, which may be enumerated by polymeric MDI; the modified aromatic isocyanate may be exemplified by carbodiimide-modified MDI.

Further preferably, the aromatic isocyanate has an NCO content of 25-35% and a viscosity of 10-30 cst at 25 ℃; furthermore, the aromatic isocyanate has an NCO content of 25-30% and a viscosity of 20-30 cst at 25 ℃; further, the aromatic isocyanate of the present invention has an NCO content of 229.7% and a viscosity at 25 ℃ of 25 cst.

The NCO content is the isocyanate group in the chemical material and the value is the mass of isocyanate (-NCO) groups contained in a 100g sample, which can be measured according to methods known in the art, such as DIN EN ISO 11909.

Still more preferably, the aromatic isocyanate according to the present invention is carbodiimide-modified MDI.

In a preferred embodiment, the carbodiimide modified MDI of the invention is Suprasec4102 from Hensman (NCO content 29.7%, viscosity 25cst at 25 ℃).

The applicant has found that when an aromatic isocyanate, particularly a modified aromatic isocyanate having a certain NCO content and viscosity, is added to the raw material for preparing the B component simultaneously with the addition of an aliphatic isocyanate, it is advantageous to increase the self-healing effect, and that compatibility with the a component and promotion of skin feel are possible because, by adding a modified aromatic isocyanate, particularly a carbodiimide-modified aromatic isocyanate, both carbodiimide groups and isocyanate groups on the isocyanate can react with an acid anhydride in the modified silica B to further promote compatibility, and by controlling the NCO content and viscosity of the isocyanate, the crosslinking density around the aromatic isocyanate is promoted, the influence of an excessively high NCO content on the elasticity of the coating is avoided, the skin feel of the coating is increased, and the presence of crosslinking points of aliphatic and aromatic isocyanates in the coating obtained by curing, when the coating is scratched, the conjugated benzene ring in the aromatic isocyanate and the residual carbodiimide group promote the non-covalent bond interaction with the polar group on the polyurethane and the polydimethylsiloxane, so that the scratch is recovered.

The applicant finds that when the aromatic isocyanate is added into the component B, the compatibility between the aromatic isocyanate and the silica A and between the aromatic isocyanate and the unmodified silica B is poor due to the larger volume of the aromatic isocyanate, but when the carbodiimide modified aromatic isocyanate is added, the compatibility can be improved, probably because the organic group of the carbodiimide is favorable for adsorption with the silica, so that the cured coating contains more uniform aliphatic and aromatic isocyanate crosslinking points nearby the silica, and the interaction between the rigid aromatic group and the flexible aliphatic group is also favorable for increasing the layering of the coating and improving the skin feel; in addition, when the pollution is received, the long-distance conjugated structure of the aromatic group and the carbodiimide group near the silicon dioxide is also beneficial to reducing the penetration of the pollution and increasing the pollution-resistant effect.

Solvent(s)

In one embodiment, the solvent of the present invention is selected from one or more of ethylene glycol butyl ether, propylene glycol methyl ether, propylene glycol ethyl ether, propylene glycol butyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monopropyl ether, dipropylene glycol monobutyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, propylene glycol methyl ether acetate; further, the solvent is propylene glycol methyl ether acetate.

The third aspect of the invention provides an application of the aqueous skin-feel bi-component woodware coating in woodware furniture.

The water-based skin-feel bi-component wood coating provided by the invention is coated in various wood furniture and baked and cured, wherein the thickness of the coated wet film is 100-120 mu m, the baking temperature is 38-45 ℃, and the baking time is 4-6 h, so that a cured coating can be obtained, the coating has good elasticity and skin feel, has certain self-repairing capability, can gradually recover small scratches, has good stain resistance and water resistance, can be used for various wood furniture, such as wood artware, wooden wallboard, wooden sofa and the like, and provides protection, decoration and special hand feeling.

Examples

The present invention will be specifically described below by way of examples. It should be noted that the following examples are only for illustrating the present invention and should not be construed as limiting the scope of the present invention, and that the insubstantial modifications and adaptations of the present invention by those skilled in the art based on the above disclosure are still within the scope of the present invention.

C1: aqueous polyurethane

The aqueous polyurethane is Changxing ETERANE 82421.

C2: aqueous polyurethane

The aqueous polyurethane is Changxing ETERANE 89120.

C3: aqueous polyurethane

The water-based polyurethane is Changxing ETERANE 8928-2A.

D: defoaming agent

The defoamer was BYK-024 from Pick, Germany.

E: wetting agent

The wetting agent is BYK-349 from Pico Germany.

F1: matting agent

The matting agent is OK607 of degussa.

F2: matting agent

The matting agent is OK500 of degussa.

F3: matting agent

The matting agent is TS100 of degussa.

F4: matting agent

The flatting agent is modified silicon dioxide, and the preparation raw materials of the modified silicon dioxide comprise TS100 and 3- (trimethoxysilyl) propyl succinic anhydride in a weight ratio of 1: 0.3.

The preparation method of the modified silicon dioxide comprises the following steps:

and adding TS100 into toluene, dispersing for 20-40 min, adding 3- (trimethoxysilyl) propyl succinic anhydride, reacting for 5-6 h at 70-80 ℃, centrifuging, and drying to obtain the modified silicon dioxide.

F5: matting agent

The matting agent is modified silicon dioxide, and the preparation raw materials of the modified silicon dioxide comprise TS100 and gamma-aminopropyl trimethoxy silane in a weight ratio of 1: 0.3.

and adding TS100 into toluene, dispersing for 20-40 min, adding gamma-aminopropyltrimethoxysilane, reacting for 5-6 h at 70-80 ℃, centrifuging, and drying to obtain the modified silicon dioxide.

G1: polydimethylsiloxane

The polydimethylsiloxane is DC-51 of Dow Corning.

G2: polydimethylsiloxane

The polydimethylsiloxane was Dow Corning PMX-200 (viscosity 50000cst at 25 ℃).

H: water (W)

I1: isocyanates

The isocyanate is hexamethylene diisocyanate.

I2: isocyanates

The isocyanate was MDI, available from Hensmei as Suprasec3051(NCO content 33.5%, viscosity at 25 ℃ C. 12 cst).

I3: isocyanates

The isocyanate was carbodiimide modified MDI, available from Hounsfield as Suprasec4102(NCO content 29.7%, viscosity 25cst at 25 ℃).

I4: isocyanates

The isocyanate was carbodiimide modified MDI, available from Hounsfield as Suprasec2020 (29.5% NCO content, 40cst viscosity at 25 ℃).

J: solvent(s)

The solvent is propylene glycol methyl ether acetate.

TABLE 1

Attached table 1

Embodiments 1-18 provide an aqueous skin-feel bi-component wood coating, the formulation of which is shown in table 1, the formulation amounts being in parts by weight.

Embodiments 1-18 provide a method for preparing an aqueous skin-feel bi-component wood coating, comprising the steps of:

and mixing the preparation raw materials of the component A, standing for 24 hours, adding the preparation raw materials of the component B, and mixing to obtain the wood ware coating.

Evaluation of Performance

The woodware paint provided in the example was coated on woodware, wherein the coated wet film thickness was 110 μm, the baking temperature was 40 ℃, and the baking time was 5 hours, to obtain a cured coating sample, and the following tests were performed.

1. Skin feel test: selecting 20 volunteers aged 20-40 years, evaluating the touch sense of the coating sample, and rating the touch sense to be 1-4 grade, wherein the grade 1 is rich in elasticity and fine and smooth in surface; grade 2 is that the elasticity of the coating is general; level 3 is that the coating is hard and the surface has a little granular feeling; the grade 4 is that the coating is relatively corresponding and has relatively obvious granular feel; the most numerous ratings were assigned to the coating samples and the percentage of the total number of ratings was recorded and the results are shown in table 2.

2. And (3) visual and sensory testing: selecting 20 volunteers of 20-40 years old, evaluating the appearance of a coating sample, and rating the coating sample to be 1-5 grade, wherein the coating surface is smooth on the 1 grade; level 2 is that the coating has a little recess and shrinkage cavity; the 3-grade coating has more small recesses and shrinkage cavities; the 4-level coating has more small recesses, shrinkage cavities and larger recesses; rating 5, where the larger pockets of coating were evident, was used to locate the rating for the coating sample for the most number and the percentage of the total number of ratings was recorded and the results are shown in table 2.

3. Self-repairing: the coated sample was scratched until a shallow scratch was left but not scratched, and whether the scratch disappeared after one week was observed with naked eyes, wherein the scratch disappeared in level 1, the scratch was not apparent in level 2, the scratch partially disappeared in level 3, and the scratch did not disappear and became apparent in level 4, and the results are shown in table 3.

4. Water resistance: and (3) carrying out a normal temperature water resistance test on the coating sample according to GB/T23999-.

5. Stain resistance: subjecting the samples to tea-, coffee-and cosmetic-resistance tests

(1) Tea resistance test: adding 250mL of boiling water into 2g of green tea, standing at room temperature for 5min to obtain tea water, putting the coating sample into the tea water for 24h, taking out, wiping with water by using a cloth, and observing;

(2) coffee resistance test: adding 250mL of boiling water into 2g of coffee powder, standing at room temperature for 5min to obtain caffeine, putting the coating sample into tea water for 24h, taking out, wiping with water, and observing;

(3) cosmetic resistance test: uniformly mixing 2g of hand cream, 2g of sun-screening oil and 1g of spacer fluid, uniformly coating the mixture on a sample, standing for 24 hours, taking out the sample, wiping the sample with water by using cloth, and observing the sample;

the surface of the sample is graded and rated as 1-4, wherein the grade 1 is that the surface of the sample has no stain and residual color stain, the grade 2 is that the surface of the sample has slight color stain and residual stain, the grade 3 is that the stain and residual color stain on the surface of the sample are general, and the grade 4 is that the stain and residual color stain on the surface of the sample are obvious, and the result is shown in the table 3.

6. Other tests: pencil hardness, gloss and adhesion tests were carried out on the coating samples of example 5 according to GB/T23999-.

Table 2 characterization test of properties

Table 3 performance characterization test

Examples	Self-repairing	Water resistance	Tea for resisting diseases	Coffee-resistant coffee	Cosmetic product
						1	4 stage	X	Grade 3	Grade 3	4 stage
2	4 stage	X	Grade 3	4 stage	4 stage
						3	Grade 3	O	Stage 2	Stage 2	Stage 2
4	Grade 3	O	Stage 2	Stage 2	Grade 3
						5	Grade 3	O	Stage 2	Stage 2	Stage 2
6	Stage 2	O	Stage 2	Level 1	Level 1
						7	Grade 3	O	Stage 2	Grade 3	Stage 2
8	Stage 2	O	Level 1	Level 1	Stage 2
						9	Level 1	O	Level 1	Level 1	Level 1
10	4 stage	X	4 stage	4 stage	4 stage
						13	4 stage		Stage 2	Grade 3	Grade 3
14	Grade 3		Grade 3	Grade 3	Grade 3
						15	Grade 3		Grade 3	Stage 2	Grade 3
17	Stage 2		Level 1	Stage 2	Stage 2
						18	Grade 3		Grade 3	Grade 3	Grade 3

Table 4 characterization test of properties

Hardness (mitsubishi pencil):	HB
		gloss (20 °/6)0°)：	1.2/2.4

The test results in tables 2 to 3 show that the aqueous skin-feel dual-component wood coating provided by the invention has good skin feel, smooth surface and no recess or shrinkage cavity, in addition, the water resistance, the stain resistance, the adhesive force and the like can be improved by controlling each preparation raw material of the wood coating, and the aqueous skin-feel dual-component wood coating has certain self-repairing capability, and can disappear after a period of time for some shallow scratches.

The foregoing examples are merely illustrative and serve to explain some of the features of the method of the present invention. The appended claims are intended to claim as broad a scope as is contemplated, and the examples presented herein are merely illustrative of selected implementations in accordance with all possible combinations of examples. Accordingly, it is applicants' intention that the appended claims are not to be limited by the choice of examples illustrating features of the invention. Where numerical ranges are used in the claims, also included are sub-ranges within them, and variations in these ranges are also to be construed as being covered by the appended claims where possible.

Claims

1. The water-based skin-feel double-component woodware coating is characterized in that the woodware coating is prepared from a raw material A and a raw material B;

the isocyanate accounts for 5-10 wt% of the waterborne polyurethane.

2. The aqueous skin-feel two-component wood coating of claim 1, wherein the matting agent comprises silica A having a particle size of 1 to 3 μm and an oil absorption of 200 to 230g/100 g.

3. The aqueous skin-feel two-component wood coating of claim 2, wherein the matting agent further comprises silica B having a particle size of 4 to 6 μm and an oil absorption of 350 to 400.

4. The aqueous skin-feel two-component wood coating as claimed in claim 3, wherein the weight ratio of the silica A to the silica B is (0.2-0.5): 1.

5. the aqueous skin-feel two-component wood coating of claim 3, wherein the A component further comprises polydimethylsiloxane, and the viscosity of the polydimethylsiloxane at 25 ℃ is 200000 to 700000 cst.

6. The aqueous skin-feel two-component wood coating as claimed in claim 5, wherein the weight ratio of the polydimethylsiloxane to the silica B is (0.1-0.3): 1.

7. the aqueous skin-feel dual-component woodenware coating as claimed in any one of claims 3 to 6, wherein the silica B comprises 10 to 20 wt% of modified silica B, the modified silica B is prepared from silica B and a silane coupling agent in a weight ratio of 1: (0.2-0.4).

8. The aqueous skin-feel two-component wood coating of claim 1, wherein the silane coupling agent is selected from one or more of an aminosilane coupling agent, an epoxy silane coupling agent, and an anhydride silane coupling agent.

9. The preparation method of the aqueous skin-feel two-component wood coating according to any one of claims 1 to 8, characterized by comprising the following steps:

10. The use of the aqueous skin-feel bicomponent wood coating of any one of claims 1 to 8 in wood furniture.