JP2003313429A - Active energy beam-curable aqueous emulsion composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To obtain an active energy beam-curable aqueous emulsion composition capable of forming a coating film having an excellent moisture-proof property, high hardness and solvent resistance and to provide its application technology. <P>SOLUTION: The active energy beam-curable aqueous emulsion composition contains an active energy beam-curable hydrophobic compound and a water- swellable inorganic layered silicate having an average particle diameter of 1-100 μm. An active energy beam-curable aqueous emulsion composition in which the water-swellable inorganic layered silicate is a water-swellable synthetic fluorine mica having the ratio of numbers of the fluorine atoms to the silicon atoms being 0.25 or more is also provided. <P>COPYRIGHT: (C)2004,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an aqueous emulsion curable by irradiation with active energy rays such as electron beams or ultraviolet rays. The emulsion of the present invention is a coating material such as paint, coating agent and printing ink. ,
It is useful as a bonding agent for non-woven fabrics, adhesives, fillers, molding materials, resists, etc. Further, it is also useful as a covering material, especially for moisture-absorbing / water-absorbing substrates such as wood, inorganic materials, and paper. It is useful as a composition for use.

[0002]

2. Description of the Related Art Porous materials such as wood materials, paper, hydraulic inorganic materials, and gypsum board, and hygroscopic materials are deformed or deteriorated by moisture, so various moisture-proof measures have been taken.
A method of applying a water-based moisture-proof coating agent is also known. For example, a moisture-proof coating agent composition comprising a hydrophobic resin and a swelling fluoromica-based mineral is known (Japanese Patent Laid-Open No. 2002-2002).
-13094). However, the film obtained by applying the moisture-proof coating composition has a slightly low hardness,
The use may be restricted due to insufficient solvent resistance. Japanese Unexamined Patent Publication No. 2000-234044 discloses an aqueous emulsion containing an active energy ray-curable compound, but there is no description about moisture resistance and no specific description about a filler. In addition, JP-A-8-24
Japanese Patent No. 5927 discloses an ultraviolet-curable pressure-sensitive adhesive composition thickened with a smectite clay mineral.
There is no description about the moisture resistance of the coating film obtained from the composition.

[0003]

DISCLOSURE OF THE INVENTION The present invention provides an active energy ray-curable aqueous emulsion composition capable of forming a coating having excellent moisture resistance, high hardness and solvent resistance, and its application technique. To aim.

[0004]

In order to solve the above-mentioned problems, the active energy ray-curable aqueous emulsion composition of the invention according to claim 1 comprises an active energy ray-curable hydrophobic compound and an average particle size of 1 to 1. It contains a 100 μm water-swellable inorganic layered silicate. The active energy ray-curable aqueous emulsion composition according to claim 2 is the same as the invention according to claim 1, wherein the water-swellable inorganic layered silicate has a fluorine atom number of 1 when the silicon atom number is 1. It is a water-swellable synthetic fluoromica having a ratio of 0.25 or more. The active energy ray-curable aqueous emulsion composition according to claim 3 is the water-swellable inorganic layered silicic acid according to the invention according to claim 1 or 2, based on 100 parts by mass of the active energy ray-curable hydrophobic compound. It contains 2 to 50 parts by mass of salt. The active energy ray-curable aqueous emulsion composition of the invention described in claim 4 is the invention according to any one of claims 1 to 3,
Active energy ray curable hydrophobic compound has an average particle size of 1μ
It is dispersed as particles of m or less. The active energy ray-curable aqueous emulsion composition according to claim 5 is the one according to any one of claims 1 to 4, which also contains a water-soluble polymer having a weight average molecular weight of 1,000 to 500,000. is there. The active energy ray-curable coating composition for wood materials according to the invention of claim 6 is
It contains the active energy ray-curable aqueous emulsion composition according to any one of claims 1 to 5. The article of the invention according to claim 7 has a coating film formed by applying the active energy ray-curable aqueous emulsion composition according to any one of claims 1 to 5 to all or part of a substrate. It is a thing.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION In the present specification, acryl and methacryl are referred to as (meth) acryl, acryloyl and methacryloyl are referred to as (meth) acryloyl, and acrylates and methacrylates are referred to as (meth) acrylate. The active energy ray-curable aqueous emulsion composition of the present invention contains an active energy ray-curable hydrophobic compound and a water-swellable inorganic layered silicate having an average particle size of 1 to 100 μm.

The active energy ray-curable hydrophobic compound is a hydrophobic compound that can be cured by irradiation with active energy rays such as ultraviolet rays, electron beams, and X-rays, and is highly effective in coatings obtained by curing the composition. In addition to imparting hardness and solvent resistance, it also has the effect of improving moisture resistance. Hydrophobic means that the solubility in 100 g of water at 23 ° C. is 10 g or less. If the solubility in water exceeds 10 g, the resulting coating will have poor moisture resistance, which is not preferable. The compound may be a polymer compound.

Examples of the active energy ray-curable hydrophobic compound include acrylic monomers and oligomers. In particular, a hydrophobic compound having two or more (meth) acryloyl groups is desirable because it makes the curability of the composition and the moisture resistance, hardness, and solvent resistance of the resulting cured film excellent.

Examples of acrylic monomers having two or more (meth) acryloyl groups are alkylene glycol di (meth) acrylates such as ethylene glycol di (meth) acrylate and propylene glycol di (meth) acrylate; diethylene glycol di ( Low molecular weight polyalkylene glycol di (meth) s such as (meth) acrylate, dipropylene glycol di (meth) acrylate, tetraethylene glycol di (meth) acrylate and tripropylene glycol di (meth) acrylate
Acrylate or alkylene oxide modified product thereof; trimethylolpropane tri (meth) acrylate, pentaerythritol di-, tri- or tetra (meth) acrylate, and polyarlequin glycol poly (meth) acrylate such as dipentaerythritol penta- or hexaacrylate; poly. Examples include alkylene oxide modified products of allelequin glycol poly (meth) acrylate; and di- and tri (meth) acrylate modified products of isocyanuric acid alkylene oxide.

Examples of the acrylic oligomer having two or more (meth) acryloyl groups include urethane (meth) acrylate, polyester (meth) acrylate, epoxy (meth) acrylate and polyether polyol.

Examples of the urethane (meth) acrylate oligomer include a reaction product obtained by further reacting a polyol and an organic polyisocyanate reaction product with a hydroxyl group-containing (meth) acrylate. Here, examples of the polyol include low-molecular weight polyol, polyethylene glycol, polyester polyol, and the like, and examples of the low-molecular weight polyol include ethylene glycol, propylene glycol, cyclohexanedimethanol, and 3-methyl-1,5-pentanediol. Examples of the polyether polyol include polyethylene glycol and polypropylene glycol, and examples of the polyester polyol include these low molecular weight polyols and / or polyether polyols, adipic acid, succinic acid, phthalic acid, hexahydrophthalic acid and terephthalic acid. And a reaction product with an acid component such as a dibasic acid or an anhydride thereof. Examples of the organic polyisocyanate include tolylene diisocyanate, 4,4′-diphenylmethane diisocyanate, 4,4′-dicyclohexylmethane diisocyanate, hexamethylene diisocyanate and isophorone diisocyanate. Examples of the hydroxyl group-containing (meth) acrylate include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate.

Examples of the polyester (meth) acrylate oligomer include dehydration condensation products of polyester polyol and (meth) acrylic acid. As the polyester polyol, ethylene glycol, polyethylene glycol, cyclohexanedimethanol, 3-methyl-
Low molecular weight polyols such as 1,5-pentanediol, propylene glycol, polypropylene glycol, 1,6-hexanediol, and trimethylolpropane, and polyols such as alkylene oxide adducts thereof, adipic acid, succinic acid, phthalic acid, Examples thereof include a reaction product with a dibasic acid such as hexahydrophthalic acid and terephthalic acid, or an acid component such as an anhydride thereof.

The epoxy acrylate is obtained by addition-reacting an unsaturated carboxylic acid such as (meth) acrylic acid with an epoxy resin. The epoxy (meth) acrylate of the bisphenol A type epoxy resin, the epoxy of the phenol or the cresol novolac type epoxy resin is used. (Meth) acrylate and diglycidyl ether of polyether (meth)
Acrylate etc. are mentioned.

Examples of the polyether polyol include polyethylene glycol di (meth) acrylate and polypropylene glycol di (meth) acrylate, or alkylene oxide modified products thereof.

The compound having only one (meth) acryloyl group may be used mainly for the purpose of adjusting the curability of the composition and the adhesion and hardness of the cured product. Examples of such compounds include hydroxyalkyl (meth) acrylates such as 2-hydroxyethyl (meth) acrylate and 2-hydroxypropyl (meth) acrylate; alkylene oxide adducts of phenol such as phenoxyethyl (meth) acrylate (meth ) Acrylate, or a halogen nucleus substitution product thereof; ethylene glycol mono (meth) acrylate, methoxyethylene glycol mono (meth)
Acrylate, tetraethylene glycol mono (meth)
Acrylics and glycol mono (meth) acrylates such as tripropylene glycol mono (meth) acrylate; and N-vinyl compounds such as N-vinylpyrrolidone and N-vinylcaprolactam. A compound having only one (meth) acryloyl group reduces the hardness and moisture resistance of the obtained coating film if the proportion of use is too large, and therefore, it cannot be used as an active energy ray-curable hydrophobic compound.
It is preferable to keep it to 0% by mass or less, and more preferable to set it to 30% by mass or less.

The water-swellable inorganic layered silicate is an important component for making the film obtained by curing the composition excellent in moisture resistance, and also contributes to increase the hardness. The water-swelling property means that water is coordinated between layers to swell, and includes those that partially separate layers. Water swellability is a standard test method of Japan Bentonite Industry Association JBA
Measurement value obtained by a method according to S-104-77, that is, a method in which 2 g of a sample is added to 100 ml of ion-exchanged water, shaken well and allowed to stand and the sedimentation volume after 24 hours is measured (hereinafter, swelling degree Also called) 5 (5ml / 2g
Is also written. ) Means more than that. The degree of swelling is preferably 10 or more, more preferably 15 or more, even more preferably 20 or more.
When the degree of swelling is less than 5, the film obtained by curing the composition has insufficient moisture resistance.

The water-swellable inorganic layered silicate has an average particle size of 1 to
It should be 100 μm, preferably 3 to 30 μm, and more preferably 5 to 20 μm. If the average particle size is less than 1 μm, moisture resistance and hardness will be insufficient. If it exceeds 100 μm, the water-swellable inorganic layered silicate is easily damaged in the step of preparing a coating solution for applying the composition, and the workability of applying the composition is poor, and a good film can be obtained. There are problems such as difficulty.

The average particle size of the water-swellable inorganic layered silicate can be measured by the diffraction / scattering method, the dynamic light scattering method, the electric resistance change method, or the image processing after taking a picture in a liquid microscope. Although the method and the like are possible, the average particle diameter in the present invention is one measured by the diffraction / scattering method. Particle size distribution and average particle size measurement by the diffractive / scattering method is performed by measuring the diffractive / scattering pattern obtained when light is transmitted to a dispersion liquid in which swelled and cleaved inorganic layered silicate is dispersed in pure water. This is done by calculating the particle size distribution that is most consistent with the pattern using scattering theory or the like. As a commercially available device capable of performing the above measurement, a particle size measuring device by a laser diffraction / light scattering method (LS230 Coulter, Inc.), a laser diffraction type particle size distribution measuring device (SALD) is used.
3000, manufactured by Shimadzu Corporation, laser diffraction / scattering type particle size distribution measuring device (LA910, LA700, LA500,
Horiba, Microtrack SPA, Nikkiso) and the like.

Examples of the water-swellable inorganic layered silicates include clay minerals belonging to the genus Smectite, montmorillonite, synthetic mica, hectorite, synthetic hectorite, saponite, synthetic saponite, beidellite and synthetic teniolite. The water-swellable inorganic layered silicate may be naturally produced or artificially synthesized or modified. In the present invention, preferred water-swellable inorganic layered silicates include water-swellable synthetic fluoromica. Examples of the water-swellable synthetic fluoromica include those represented by the chemical formula shown in the following formula (1).

W _j Y _k Si _m O ₁₀ F _n (1)

In the formula (1), W is Na (sodium) or Li (lithium), Y is Mg (magnesium) or a part of Mg substituted with Li,
j is 0.33 to 1.5, k is 2.0 to 3.5, m is 3.0 to 5.0, and n is 1.25 to 3.0. Needless to say, S
i, O and F are silicon, oxygen and fluorine, respectively. Specific examples of the water-swellable synthetic fluoromica represented by the chemical formula shown in the above formula (1) include Na tetrasilylic mica [NaMg2.5 (Si4 O10) F2], Na or Li teniolite [(Na or Li). Mg2 Li (Si
4 O10) F2], montmorillonite Na or Li hectorite [(Na or Li) 1/3 Mg 2/5 Li 1/8
(Si4 O10) F2] and the like, which may be used alone or in admixture of two or more.
Ratio of the number of fluorine atoms in the water-swellable inorganic layered silicate, where the number of silicon atoms is 1, (hereinafter, also referred to as F / Si).
Is more preferably 0.25 or more water-swellable synthetic fluoromica. Those having F / Si of 0.30 or more are more preferable, and those having 0.30 to 0.50 are particularly preferable. F / S in water-swellable synthetic fluoromica
If i is too small, the resulting cured film may have insufficient moisture resistance. Note that F / Si can be obtained by a fluorescent X-ray analysis method.

The water-swellable synthetic fluoromica can be synthesized by the method described below. For example,
There is a method in which talc is used as a starting material and alkali metal ions are intercalated into the talc to obtain a swelling fluoromica mineral. Temperature 70
A swellable fluoromica-based mineral is obtained by heat treatment at 0 to 1200 ° C for a short time. Further, silicon oxide, magnesium oxide, and various fluorides are mixed, and the mixture is heated in an electric furnace or a gas furnace at a temperature of 1400 to 1500 ° C.
There is a so-called melting method in which the fluorinated mica-based mineral is crystallized in the reaction vessel during the cooling process. The melting method is a preferable method because it facilitates the production of a water-swellable synthetic fluoromica having F / Si of 0.25 or more, and is described in detail in, for example, JP-A-5-270815.

The water-swellable inorganic layered silicate used in the present invention, for example, the water-swellable synthetic fluoromica, is a tabular grain before swelling by immersing in water (as a model, the thickness of the grain is several μm, the grain size is Has an aspect ratio (particle size / thickness) of around 10. The aggregate or agglomeration of the following ultra-thin film-like particles swells in water to form an ultra-thin film-like particle in whole or in part. (As a model, the particle thickness is 0.001 to 0.005 μm, and the particle size is 1 to several tens μ
m, aspect ratio (particle size / thickness) is 200 to 3000
0 or so. ) Is dissociated. This is considered to have an important meaning in improving the moisture resistance. What is generally called simply mica does not have such a property.

The active energy ray-curable aqueous emulsion composition of the present invention contains an active energy ray-curable hydrophobic compound and a water-swellable inorganic layered silicate having an average particle size of 1 to 100 μm. The proportion of the water-swellable inorganic layered silicate based on 100 parts by mass of the active energy ray-curable hydrophobic compound is preferably 2 to 50 parts by mass, more preferably 5 to 50 parts by mass. If the proportion of the water-swellable inorganic layered silicate is too low, the moisture resistance of the cured film may be low and the hardness may not be sufficient. If it is too high, the active energy curability and the hardness of the cured film will be reduced and the moisture resistance will be low. May not improve. The total amount of the active energy ray-curable hydrophobic compound and the water-swellable inorganic layered silicate based on 100 parts by weight of the active energy ray-curable aqueous emulsion composition is preferably 10 to 60% by mass, and 20 to 50% by mass.
Is more preferable. If this ratio is too small, it may be difficult to adjust the film thickness, it may take time to dry after coating the base material, or the drying may be insufficient.If it is too large, the emulsion becomes unstable. May become.

The active energy ray-curable aqueous emulsion composition can be obtained by mixing the above components with a homomixer, a homogenizer, ultrasonic waves or the like. As a specific example of the preparation method, an aqueous dispersion of a water-swellable inorganic layered silicate that has been swollen and dispersed in water in advance, and an aqueous dispersion of an active energy ray-curable hydrophobic compound are mixed. After the active energy ray-curable hydrophobic compound is dispersed in water, a water-swellable inorganic layered silicate is added thereto, and the silicate is swollen and dispersed at the same time. An active energy ray-curable hydrophobic compound and a surfactant are added to and dispersed in an aqueous dispersion of a water-swellable inorganic layered silicate that has been swollen and dispersed in water in advance. A method is possible in which the water-swellable inorganic layered silicate and the active energy curable hydrophobic compound are mixed in advance, and then water is further mixed to simultaneously swell and disperse the silicate in water. The method or is more preferable in that the operation is simple, the water-swellable inorganic layered silicate is sufficiently swelled, and higher moisture resistance is obtained.

In mixing the aqueous dispersion of the swellable fluoromica and the active energy curable compound, it is preferable to adjust the pH of the emulsion to 7 or more, more preferably the pH, from the viewpoint that a film having excellent moisture resistance can be easily obtained. Is 8-12
Is an aqueous resin dispersion. For adjusting the pH, for example, ammonia can be preferably used. pH
The adjustment method may be adjusted at the stage of the aqueous dispersion of the active energy curable compound or after all the ingredients are blended. In the active energy ray-curable aqueous emulsion composition, it is preferable that the active energy ray-curable hydrophobic compound is dispersed as particles having an average particle diameter of 1 μm or less, because the resulting coating has particularly excellent moisture resistance. . It is more preferably 0.5 μm or less, still more preferably 0.2 μm or less, most preferably 0.1 μm or less.

In order to stably disperse the active energy ray-curable hydrophobic compound in water, it is preferable to use a surfactant. As the surfactant, an anionic surfactant, a nonionic surfactant, a polymer surfactant, or a so-called reactive emulsifier having a reactive group such as a vinyl group can also be used. Examples of the anionic surfactant include alkyl or alkyl allyl sulfate, alkyl or alkyl allyl sulfonate, polyoxyethylene alkyl or alkyl allyl ether sulfate, sulfonated paraffin alkali metal salt, sulfonated paraffin ammonium salt, and dialkyl. Examples thereof include sulfosuccinate, sodium laurate, triethanolamine oleate, and triethanolamine abietate. As the nonionic surfactant, polyoxyethylene alkylphenyl ether, polyoxyethylene alkyl ether, polyoxyethylene carboxylic acid ester, polyoxyethylene polyoxypropylene copolymer, ethylene oxide and an aliphatic amine, an amide or an acid Examples include condensation products.

Examples of the polymer surfactant include polyvinyl alcohol, sodium poly (meth) acrylate, potassium poly (meth) acrylate, ammonium polymethacrylate, polyhydroxyethyl (meth) acrylate, polyhydroxypropyl (meth). 2 of acrylate or polymerizable monomer which is a constitutional unit of these polymers
Examples include copolymers of at least one kind and copolymers of a hydrophobic monomer and a hydrophilic monomer described in JP-A No. 2000-234044. In particular, paints for wood and the like have the function of emulsifying a polymerizable monomer and the function of crosslinking by light without adding a photoinitiator.
Those having a cyclic imide structure as exemplified by 34044 in the skeleton thereof are preferable in terms of less coloring and odor which are harmful effects of the low molecular weight photoinitiator.

The reactive surfactant may have a hydrophobic and copolymerizable vinyl group, for example, styrene sulfonate, isoprene sulfonate, allyl alkyl sulfonate, allyl alkyl sulfosuccinic acid. salt,
In addition to polyoxyethylene alkyl (or polyoxyethylene alkylaryl) allyl glycerin ether sulfate ester salt, etc., trade name Latemur S-180A (manufactured by Kao Corporation), Eleminol JS-2 (manufactured by Sanyo Kasei Co., Ltd.), Aqualon HS -10, RS-20 (manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), ADEKA REASOAP SE-10N, N
E-20 (Asahi Denka Kogyo Co., Ltd.), ANTOX MS
-60 (manufactured by Nippon Emulsifier Co., Ltd.) can be mentioned. Among these, polymer surfactants and reactive surfactants are preferable, and polymer surfactants neutralized with ammonia or an organic amine are more preferable, from the viewpoint that moisture resistance can be increased.

The amount of the surfactant used when the active energy ray-curable hydrophobic compound is dispersed in water is determined according to the properties required for the composition and the film. Generally, it is desirable to use a large amount of a surfactant for the purpose of improving the polymerization stability and the mechanical and chemical stability of the emulsion. On the contrary, in order to improve the water resistance of the dry film, The smaller the amount used, the better. Usually, about 0.1 to 15 parts by mass in the case of anionic surfactant, nonionic surfactant or reactive emulsifier, based on 100 parts by mass of the total amount of active energy ray-curable hydrophobic compound, polymer surface activity In the case of an agent, the amount used is determined within the range of about 0.1 to 100 parts by mass according to the purpose.

The active energy ray-curable aqueous emulsion composition preferably contains a photopolymerization initiator when the coating film to be obtained is cured by ultraviolet rays. When curing with an electron beam, a photopolymerization initiator is unnecessary. Examples of the photopolymerization initiator include benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, and other benzoins and their alkyl ethers; acetophenone, 2,2-dimethoxy-2-phenylacetophenone, 2,2-diethoxy-
2-phenylacetophenone, 1,1-dichloroacetophenone, 1-hydroxyacetophenone, 1-hydroxycyclohexylphenylketone and 2-methyl-1.
Acetophenones such as-[4- (methylthio) phenyl] -2-morpholino-propan-1-one; 2-methylanthraquinone, 2-ethylanthraquinone, 2-tert-butylanthraquinone, 1-chloroanthraquinone and 2-amylanthraquinone Anthraquinone; 2,4-dimethylthioxanthone, 2,4-diethylthioxanthone, 2-chlorothioxanthone and 2,
Thioxanthones such as 4-diisopyrthioxanthone; ketals such as acetophenone dimethyl ketal and benzyl dimethyl ketal; benzophenones such as benzophenone; and xanthones. These photopolymerization initiators can be used alone or in combination with a benzoic acid-based or amine-based photopolymerization initiation accelerator. The photopolymerization initiator is 0.1 based on 100 parts by mass of the active energy ray-curable aqueous emulsion composition.
It is preferable to add 10 to 10 parts by mass. The addition method when adding a photopolymerization initiator to the emulsion composition of the present invention, a method of adding a photopolymerization initiator to the active energy ray-curable hydrophobic compound, to the aqueous dispersion of the active energy ray-curable hydrophobic compound There are a method of adding and a method of directly adding to the emulsion composition. In the case of a photopolymerization initiator that is a solid and has a small solubility in water, a method of adding it to an active energy ray-curable hydrophobic compound in advance and dissolving it is
It is preferable because the photopolymerization initiator is easily dispersed uniformly.

In the active energy ray-curable aqueous emulsion composition, when the water-soluble polymer having a specific weight average molecular weight is added in a specific amount, the resulting coating is more excellent in moisture resistance. Is preferred. The weight average molecular weight of the water-soluble polymer is 1,000 to 500,000.
0 is preferable, 1000 to 50,000 is more preferable, and 1000 to 20,000 is further preferable. If the weight average molecular weight is too large, the viscosity of the emulsion composition may increase and the moisture resistance of the resulting coating may decrease, which is not preferable. If the weight average molecular weight is too small, it is difficult to improve the moisture resistance. The preferable mixing ratio of the water-soluble polymer is
Based on 100 parts by weight of the water-swellable inorganic layered silicate,
The amount is preferably 0.01 to 50 parts by mass, more preferably 0.1 to 10 parts by mass, still more preferably 0.2 to 5 parts by mass.
If the blending ratio of the water-soluble polymer is too small, the moisture-proof property improving effect is difficult to be exhibited, and if it is too large, the moisture-proof property is lowered, which is not preferable.

The water-soluble polymer means a polymer having a solubility in pure water of 1% by mass or more at room temperature, and a hydroxyl group, amino group, thiol group, carboxyl group, sulfonic acid group, phosphoric acid group, oxazoline group. , Amide group, carboxylate group,
Sulfonate ion group, phosphate ion group, ammonium group,
A phosphonium group added to the polymer main chain,
Ether bond (-O-), ester bond (-CO.O)
-), Urethane bond (-NH.CO.O-), amide bond (-NH.CO-), urea bond (-NH.CO.NH)
-), A buret bond, an alphanate bond, etc., whose main chain is made of a water-soluble polymer.

Examples of the water-soluble polymer include modified starch and its derivatives, cellulose derivatives, saponified products of polyvinyl acetate and its derivatives, polymers containing sulfonic acid groups or salts thereof, and (meth) acrylic acid. Polymers and copolymers and salts thereof, polymers and copolymers of acrylamide, polyethylene glycol, polymers in which oxazoline groups are pendant or ring-opening polymerized, hydrophilic polyurethane, and polyvinylpyrrolidone compound groups may be mentioned as representatives. It is possible to use one or more water-soluble polymers selected from those compounds. Specific examples of these compound groups include, for example, polyvinyl alcohol (PVA), ethylene vinyl alcohol copolymer, polyethylene glycol, cellulose derivative, oxazoline-based polymer, polyvinylpyrrolidone, water-soluble polyester, polyacrylic acid, polymethacrylic acid. And polyacrylamide. Of these, polyvinyl alcohol, cellulose derivatives, polyvinylpyrrolidone, polyoxazoline, oxazoline-containing polymers and polyethylene glycol are particularly preferable. As a method for adding the water-soluble polymer to the emulsion composition, the water-soluble polymer may be added to the final preparation liquid, or may be added in the form of an aqueous solution or as it is. As a specific method, it is previously mixed with an aqueous dispersion of a water-swellable inorganic layered silicate.
The aqueous dispersion of the active energy ray-curable hydrophobic compound and the water-soluble polymer are mixed and then mixed with the inorganic layered silicate.
A water-soluble polymer alone or in combination with a surfactant is used to disperse an active energy ray-curable hydrophobic compound in water, and then mixed with a layered silicate compound for preparation. Etc. are possible.
The method or is preferable because the operation is simple and the effect of improving the moisture resistance is large.

The active energy ray-curable aqueous emulsion composition contains a filler other than water-swellable inorganic layered silicate such as barium sulfate, silicon oxide, talc, clay and calcium carbonate, phthalocyanine blue, phthalocyanine. Coloring pigments such as green, titanium oxide and carbon black, and various additives such as an adhesion promoter and a leveling agent may be added. When these are added, the blending ratio is based on 100 parts by mass of the active energy ray-curable hydrophobic compound (the active energy ray-curable aqueous emulsion composition is a polymer emulsifier or a water-soluble polymer added. In this case, it is preferably 100 parts by mass or less) (based on the total amount of 100 parts by mass of the active energy ray-curable hydrophobic compound, the polymeric emulsifier and the water-soluble polymer). If it exceeds 100 parts by mass, the denseness of the film is lowered and the moisture resistance is lowered, which is not preferable.

The active energy ray-curable aqueous emulsion composition may be added with a polymerization inhibitor such as hydroquinone, hydroquinone monomethyl ether, phenothiazine and N-nitrosophenylhydroxylamine aluminum salt. When the polymerization inhibitor is added, the mixing ratio is 0.001 to 100% by mass based on 100% by mass of the active energy ray-curable aqueous emulsion composition.
It is preferably 2% by mass.

The active energy ray-curable aqueous emulsion composition of the present invention has various uses such as coating materials for coating materials, coating agents and printing inks, binders for non-woven fabrics, adhesives, fillers, molding materials and resists. Can be used as a coating material, can be preferably used as a coating material, and can be more preferably used in OPV and wood paint.

The active energy ray-curable aqueous emulsion composition may be used according to a conventional method. For example, the composition is applied to a substrate, heated and dried, and then the active energy ray is irradiated. Is mentioned. As a coating method, a conventionally known method such as a roll coater, a flow coater, spraying, dipping or brush coating may be used. The composition of the present invention can have a low viscosity, and is particularly suitable as a coating composition for a flow coater, spray and dipping. It is preferable that the coating film applied to the substrate is sufficiently dried by heating, because the cured coating film has excellent strength, moisture resistance and transparency. The irradiation method of the active energy ray may be a conventional method. The coating amount of the active energy ray-curable aqueous emulsion composition is preferably 5 to 100 g / m ^{2 in} terms of solid content. If the coating amount is too small, the surface of the substrate to be coated cannot be covered sufficiently and pinholes are generated, so that the moisture resistance may be extremely reduced. If the coating amount is too large, the obtained moisture resistance may be wasted because the moisture resistance is only slightly improved as the coating amount increases.

Examples of the active energy ray used for curing the coating film obtained by applying the active energy ray-curable aqueous emulsion composition include ultraviolet rays, X-rays and electron rays, and a relatively inexpensive apparatus is used. The method using ultraviolet rays is preferable because it can be used. As the light source for curing with ultraviolet rays, various light sources can be used, and examples thereof include a high pressure mercury lamp, a metal halide lamp, a xenon lamp, an electrodeless discharge lamp and a carbon arc lamp.

The active energy ray-curable aqueous emulsion composition can be suitably used as a coating composition. In this case, if necessary, the composition is a synthetic resin such as an acrylic resin, a ketone resin and a petroleum resin, an inorganic or organic extender pigment, a matting agent, a filler such as a sanding aid, a leveling agent, a pigment dispersant, Various additives such as a gloss imparting agent, a slip agent, and a thixotropic agent may be added.

The above-mentioned coating composition comprises wood such as natural wood and synthetic wood, molded resin processed products (plastic) such as polycarbonate, polymethylmethacrylate and polyvinyl chloride, fibers such as paper, cloth and non-woven fabric, iron, It can be suitably used as a paint for metals such as aluminum, glass, concrete, lightweight concrete, lightweight cellular concrete, mortar, calcium silicate board, slate, gypsum board, decorative board, wallpaper and other building materials. The above-mentioned coating composition is particularly suitable as a coating material for wood materials because it has excellent moisture-proof property and also excellent adhesion, and has the effect of being able to be imparted with dimensional stability by being coated on a hygroscopic substrate such as wood. Used for.

The reason why the coating film obtained from the active energy ray-curable aqueous emulsion composition of the present invention exhibits excellent moisture resistance is that the water-swellable inorganic layered silicate having a specific particle diameter swells in water. , By dissociating (cleaving) into a large number of ultra-thin film-like particles that do not have water permeability, and by closely arranging the film-like particles in parallel with the surface of the substrate, water is prevented from passing through the coating film. Presumed to be. Further, the present invention is particularly excellent by using an active energy ray-curable hydrophobic compound as a binder component that supports the water-swellable inorganic layered silicate, that is, a component that becomes a matrix in a film state, rather than a simple polymer material. They have found that moisture resistance is exhibited. In addition, since the thin flakes of a hard inorganic silicate having crystallinity are dispersed in the cured resin layer having relatively flexibility in the order of nanometers, it is possible to express a high hardness that could not be realized by the conventional technique. Guessed.

[0042]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. "Parts" and "%" mean parts by mass and% by mass, respectively. The abbreviations of the monomers and photopolymerization initiators used have the following meanings.

Monomers and chain transfer agents for producing high molecular weight emulsifiers: MMA: methyl methacrylate, BA: butyl acrylate, MAA: methacrylic acid, MPA: mercaptopropionic acid, imide acrylate: structural formula shown in the following formula (2). Compound represented by

[0044]

[Chemical 1]

○ Active energy ray-curable hydrophobic compound and photoinitiator ・ DPHA: dipentaerythritol hexaacrylate [Aronix M400 manufactured by Toagosei Co., Ltd.] ・ PETA: pentaerythritol triacrylate [Aronix M305 manufactured by Toagosei Co., Ltd.] ・ TMP (EO) TA: trimethylolpropane ethylene oxide 3 mol modified triacrylate [Aronix M350 manufactured by Toagosei Co., Ltd.]-BDK: benzyl dimethyl ketal [Aronix MC-101 manufactured by Toagosei Co., Ltd.]

O Water-swellable layered silicate and comparative filler a. DMA350: Sodium tetrasilicic mica (manufactured by Topy Industries, Ltd.) Swelling degree 30 ml / 2 g, average particle size 15 μm, F / Si
Molar ratio = 0.40 b. DM Clean A: Sodium Tetrasilicic Mica (manufactured by Topy Industries, Ltd.) Swelling degree 30 ml / 2 g, average particle size 10 μm, F / Si
Molar ratio = 0.40 c. NTS5: Sodium tetrasilicic mica swelling degree 30 ml / 2 g, average particle diameter 4 μm, F / Si molar ratio = 0.33 d. ME-100: Sodium tetrasilicic mica (made by Corp Chemical) Swelling degree 30 ml / 2 g, average particle diameter 6 μm, F / Si molar ratio = 0.22 e. Mica A21: muscovite (manufactured by Yamaguchi Mica Co., Ltd.) Swelling degree 5 ml / 2 g or less (non-swelling), average particle size 21
μm F / Si molar ratio = 0.0 f. Kunipia F: Montmorillonite (manufactured by Kunimine Industries) Swelling degree 60 ml / 2 g, average particle diameter 0.2 μm, F / S
i molar ratio = 0.0 g. Smectite SWF: Synthetic smectite (made by Corp Chemical) Swelling degree 100 ml / 2 g, average particle diameter 0.1 μm, F /
Si molar ratio = 0.17

○ F / Si molar ratio measurement It was determined by fluorescent X-ray analysis. A Rigaku 3270 type fluorescent X-ray analyzer was used, and the analysis conditions were a rhodium target X-ray acceleration voltage of 50 KV and a tube current of 30 mA.

Production Examples 1-2 (Production of Polymeric Surfactant) 57 parts of water and lauryl sulfate were placed in a reactor equipped with an emulsifier stirrer, a thermometer, a cooler, a nitrogen introducing tube and two dropping funnels. 0.7 part of sodium was charged and the temperature was raised to 85 ° C., and 2.4 parts and 11 parts of 13% ammonium persulfate aqueous solution were added thereto.
% 3.3% aqueous sodium carbonate solution was added. To 100 parts of the monomer mixture having the composition shown in Table 1, 0.7 part of sodium lauryl sulfate and 40 parts of water were added and emulsified. The obtained aqueous emulsion was continuously dropped into the reactor through the dropping funnel over 3 hours, and emulsion polymerization was carried out at 85 ° C. After the dropwise addition was completed, the mixture was stirred for 1 hour at 85 ° C., after which the system was cooled to complete the polymerization. 2 in the aqueous dispersion of the obtained copolymer
The pH was adjusted to 9.6 by adding 5% aqueous ammonia.
Table 1 shows various physical properties of the obtained aqueous dispersions A-1 and A-2.

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[Table 1]

Production Examples 3 to 10 (Production of Active Energy Ray-Curable Hydrophobic Compound Aqueous Dispersion) The active energy ray-curable hydrophobic compound was sequentially mixed into the mixture of the surfactant and water in the proportions shown in Table 2. , And homogenizers to obtain water dispersions A-3 to A-10. Table 2 shows the average particle size of the obtained water dispersion.

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[Table 2]

Example 1 Synthetic fluoromica DMA350 as a water-swellable layered silicate
Was dispersed in ion-exchanged water so as to have a solid content of 5%, further heated to 80 ° C., and then stirred with a homogenizer for 1 hour,
A dispersion of the synthetic fluoromica was obtained. 10% PVA for this
102 (Kuraray's polyvinyl alcohol, degree of polymerization 20
0) An aqueous solution and an aqueous dispersion A-3 of an active energy ray-curable hydrophobic compound were sequentially added, so that the water-swellable layered silicate / A-3 / PVA102 = 10/100 / 0.5 in terms of solid content ratio. Was mixed with the mixture to obtain an active energy ray-curable aqueous emulsion composition.

Examples 2 to 11 Table 3 shows the type and number of parts of the water-swellable layered silicate, the type and part of the aqueous dispersion of the active energy ray-curable hydrophobic compound, and the type and part of the water-soluble polymer. Example 1 except that
An active energy ray-curable aqueous emulsion composition was prepared in the same manner as in.

[0054]

[Table 3]

○ Evaluation (Solvent Resistance) The active energy ray-curable aqueous emulsion composition was bonded to a Bonderite steel plate PB-14 using a bar coater # 10.
4 [made by Nippon Test Panel Co., Ltd.]
Water was removed from the coating film by heating for 5 minutes in the drier.
Then, under the following conditions, the above coating material was repeatedly passed under an ultraviolet lamp four times. Ultraviolet irradiation conditions Lamp: 120 W / cm condensing type high pressure mercury lamp Lamp height: 10 cm Conveyor speed: 5 m / min About the obtained cured film, using a cotton swab impregnated with acetone, a load of 500 g, 1 reciprocation per second The surface of the cured film obtained under the conditions was rubbed, and the number of times until abnormalities such as whitening or peeling occurred on the surface of the cured film was evaluated according to the following three grades. ○: No abnormality in cured film after 20 reciprocations △: Abnormality in cured film after 10 reciprocations and less than 20 reciprocations ×: Abnormality in cured film after less than 10 reciprocations

○ Evaluation (pencil hardness) For the same cured film as that used for solvent resistance evaluation, J
The evaluation was performed according to IS "hand-shaking method K5400". ○ Evaluation (moisture proof, unit: g / m ² · 24 h) Except that coated paper is used as the base material instead of the Bonderite steel plate and the coating amount is 15 g / m ² as the solid content by the Meyer bar. It was cured under the same conditions as in Examples 1 to 9 above. The coated paper having the obtained coating is J
It was measured by IS Z0208 (cup method) B method with the moisture-proof coated surface facing outward. 100 as the standard for the lithographic water vapor transmission rate
If it is less than g / m ² · 24 h, it is practical. The evaluation results are shown in Table 3.

Comparative Examples 1 to 7 Example 1 except that the types and amounts of raw materials shown in Table 3 were used
An emulsion composition was produced in the same manner as in. The obtained emulsion composition was evaluated in the same manner as in the examples. The results are shown in Table 3. However, in Comparative Examples 1 and 3, since the composition did not have active energy ray curability, ultraviolet irradiation was not performed, and the coating film after drying the emulsion was evaluated.

○ Examples 12 to 13 and Comparative Example 8 (coating test on wood-based materials) The emulsion compositions of Examples 1 and 3 and Comparative Example 2 contained 10 parts.
A coating composition for wood materials was manufactured by adding 1 part of a fluorine-based leveling agent to 0 part. The obtained coating composition for wood materials was evaluated according to the following. The results are shown in Table 4.
Shown in.

○ Evaluation (Dimensional stability test) A coating composition for wood materials was spray-coated on both sides of a 2.5 mm thick, 120 mm wide, 1800 mm long lauan plywood to a solid content of 30 g / m ^2. Apply with
After leaving it at room temperature for 2 hours, leave it in a hot air dryer at 70 ° C for 20 hours.
Dry for minutes. The treated plywood thus obtained was placed in a constant temperature and high humidity chamber and (I) left at 15 ° C. and 70% RH (relative humidity) for 4 days, and then the lengthwise dimension was measured. Next, this is 40 ℃, 9
The size in the length direction was measured after 4 days under the condition of 8% RH, and the amount of size change due to environmental change was calculated. (II) Similarly 40 ° C, 98% RH to 40 ° C, 30%
The dimensional change when placed under the condition of RH was measured. (III) Similarly, 40 ° C., 30% RH, 40 ° C. again,
The dimensional change when placed under the condition of 98% RH was measured.

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[Table 4]

[0061]

EFFECT OF THE INVENTION An active energy ray-curable aqueous emulsion composition capable of forming a film having excellent moisture resistance, high hardness and solvent resistance was obtained. The composition can be applied to the surface of a hygroscopic substrate to exert an excellent moisture-proof effect.

─────────────────────────────────────────────────── ─── Continuation of front page (51) Int.Cl. ⁷ Identification code FI theme code (reference) C09D 5/02 C09D 5/02 7/12 7/12 201/00 201/00 C09J 4/02 C09J 4 / 02 201/00 201/00 F-term (reference) 4J002 AA00W AB01X BE02X BE03X BG01X BG04W BG13X BJ00X CD19W CF27W CH02X CH11W DJ056 FD206 HA07 4J038 CG141 CH121 CH141 CJ251 C07251 C07251 JA03 LA06 LA07 PA32

Claims (7)

[Claims] 1. An active energy ray-curable aqueous emulsion composition containing an active energy ray-curable hydrophobic compound and a water-swellable inorganic layered silicate having an average particle size of 1 to 100 μm. 2. The active energy according to claim 1, wherein the water-swellable inorganic layered silicate is a water-swellable synthetic fluoromica having a ratio of the number of fluorine atoms when the number of silicon atoms is 1, which is 0.25 or more. Ray-curable aqueous emulsion composition. 3. An active energy ray-curable hydrophobic compound 10
Water-swellable inorganic layered silicate 2-5 based on 0 parts by weight
The active energy ray-curable aqueous emulsion composition according to claim 1, which contains 0 part by mass. 4. An active energy ray-curable hydrophobic compound,
The active energy ray-curable aqueous emulsion composition according to claim 1, which is dispersed as particles having an average particle diameter of 1 μm or less. 5. A weight average molecular weight of 1,000 to 500,000.
The active energy ray-curable aqueous emulsion composition according to any one of claims 1 to 4, containing the water-soluble polymer. 6. An active energy ray-curable coating composition for a wood material containing the active energy ray-curable aqueous emulsion composition according to claim 1. 7. An article having a coating formed by applying the active energy ray-curable aqueous emulsion composition according to any one of claims 1 to 5 to all or part of a substrate.