JP2007262386A - Aqueous dispersion of (meth)acrylic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To impart, to a porous substrate or a laminate of hard substrates, satisfactory strength, hardness sufficient to restrain the generation of depressions, adhesion strength, heat resistance and the like, without diffusion of harmful substances such as formaldehyde. <P>SOLUTION: Use is made of an aqueous dispersion of a (meth)acrylic resin which is obtained by incorporating a polyisocyanate compound as a curing agent into a mixed dispersion containing a (meth)acrylic resin emulsion, a filler, starch and a water-soluble polymer other than starch. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention improves the surface hardness of various base materials and can reduce the occurrence of dents when a load is applied or a (meth) acrylic resin aqueous dispersion, and a surface treatment agent and an adhesive using the same. It relates to the agent.

  Base materials such as wood materials such as medium density fiberboard (MDF) and plywood, and porous inorganic base materials such as calcium silicate board and cement board are used for buildings such as houses, stores, public facilities and buildings. Used for interior wall surfaces such as wall coverings and flooring. When such a base material is used for flooring, for example, when a heavy object is placed for a long time, or when a load is repeatedly applied on a chair or the like, the surface of the flooring becomes concave and the trace remains. Can be detrimental to aesthetics.

  In addition, in the case of flooring etc. in which sheets etc. are laminated on a hard substrate, the surface of the flooring etc. is recessed when a heavy object is placed on it for a long time or when a load is repeatedly applied on a chair etc. In some cases, marks may remain or the surface sheet may peel off.

  In order to solve such a problem, a method of applying and impregnating a phenol resin or a melamine resin to a base material is widely used for the purpose of improving the surface hardness of the porous base material. However, in these methods, in some cases, harmful substances such as formaldehyde may be diffused from the treated substrate.

  Therefore, the present invention does not disperse harmful substances such as formaldehyde, and has sufficient strength, hardness to suppress the occurrence of dents, adhesive strength, heat resistance, etc. The task is to give to the body.

  This invention contains a water-soluble polymer other than (a) (meth) acrylic resin emulsion, (b) filler, (c) starches and (d) starches as (meth) acrylic resin aqueous dispersion This problem was solved by using (e) a compound containing a polyisocyanate compound as a curing agent in the mixed dispersion.

  Since the (meth) acrylic resin aqueous dispersion in which the (e) component is blended with the mixed dispersion containing the (a) component, the (b) component, the (c) component and the (d) component is used, formaldehyde is used. There is no need. In addition, by applying this (meth) acrylic resin aqueous dispersion to the surface of the base material, the surface of the base material can be sealed or the bonding process between the base material having pores on the surface and decorative paper can be simplified. And sufficient strength and surface strength can be imparted to the substrate surface. Furthermore, by using this (meth) acrylic resin aqueous dispersion as an adhesive, it exhibits sufficient adhesive strength and heat resistance, and the adhesive layer made of this adhesive provides sufficient strength and strength to the substrate. Can be granted.

The present invention will be described in detail below.
The aqueous (meth) acrylic resin dispersion according to the present invention comprises (a) (meth) acrylic resin emulsion (referred to as “(a) component”), (b) filler (referred to as “(b) component”). ), (C) starches (referred to as “component (c)”) and (d) water-soluble polymers other than starches (referred to as “component (d)”), (E) An aqueous dispersion containing a polyisocyanate compound as a curing agent (referred to as “(e) component”).

[(A) component]
The (meth) acrylic resin emulsion as the component (a) refers to an emulsion containing a homopolymer or copolymer of a monomer containing a (meth) acrylic monomer. Such (meth) acrylic monomers include (meth) acrylic acid ester monomers, hydroxyl group-containing (meth) acrylic monomers, amide group-containing (meth) acrylic monomers, methylol groups Containing (meth) acrylic monomer, alkoxymethyl group-containing (meth) acrylic monomer, epoxy group-containing (meth) acrylic monomer, polyfunctional (meth) acrylic monomer, (meth) Examples include acrylic acid and (meth) acrylonitrile.

  Examples of the (meth) acrylate monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, (meth ) Isobutyl acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, lauryl (meth) acrylate, benzyl (meth) acrylate, phenyl (meth) acrylate, etc. can give.

  Examples of the hydroxyl group-containing (meth) acrylic monomer include hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate. When the hydroxyl group-containing (meth) acrylic monomer is used as a monomer component, the resulting (meth) acrylic resin becomes a (meth) acrylic resin having a hydroxyl group, and polyisocyanate ((e ) Component)), it is effective in improving surface hardness and is preferred.

  Examples of the amide group-containing (meth) acrylic monomer include (meth) acrylamide, N, N-methylenebis (meth) acrylamide, diacetone (meth) acrylamide and the like. Examples of the methylol group-containing (meth) acrylic monomer include N-methylol (meth) acrylamide and dimethylol (meth) acrylamide.

  Examples of the alkoxymethyl group-containing (meth) acrylic monomer include N-methoxymethyl (meth) acrylamide and N-butoxymethyl (meth) acrylamide. Examples of the epoxy group-containing (meth) acrylic monomer include glycidyl (meth) acrylate and methyl glycidyl (meth) acrylic acid.

  Examples of the polyfunctional (meth) acrylic monomer include polyoxyethylene di (meth) acrylate, polyoxypropylene di (meth) acrylate, butanediol di (meth) acrylate, trimethylolpropane tri (meth) acrylate, Examples include pentaerythritol tetra (meth) acrylate.

  As the monomer containing the (meth) acrylic monomer, in addition to the (meth) acrylic monomer, a vinyl monomer copolymerizable with the (meth) acrylic monomer is used. be able to. As this vinyl monomer, aromatic vinyl monomers, unsaturated carboxylic acids or esters other than the above (meth) acrylic monomers, amide group-containing monomers, epoxy group-containing monomers And other polyfunctional monomers, silyl group-containing monomers, monoesters or diesters of α, β-ethylenically unsaturated dicarboxylic acids, vinyl esters and the like.

  Examples of the aromatic vinyl monomer include styrene, vinylbenzene, vinyltoluene and the like. Examples of the unsaturated carboxylic acid other than (meth) acrylic acid include acidic esters of unsaturated polyvalent carboxylic acids such as maleic anhydride, maleic acid, fumaric acid, itaconic acid, or monoalkyl itaconate. Examples of the amide group-containing monomer other than the amide group-containing (meth) acrylic monomer include maleic acid amide, N-substituted or unsubstituted maleimide, and the like.

  Examples of the epoxy group-containing monomer other than the epoxy group-containing (meth) acrylic monomer include allyl glycidyl ether. Examples of the polyfunctional monomer other than the polyfunctional (meth) acrylic monomer include divinylbenzene. Examples of the silyl group-containing monomer include vinyltrichlorosilane, vinyltrimethoxysilane, vinyltriethoxysilane, tris-2-methoxyethoxyvinylsilane, γ-methacryloxypropyltrimethoxysilane, and γ-methacryloxypropylmethyldimethoxysilane. Can be given.

  Examples of the monoester or diester of the α, β-ethylenically unsaturated dicarboxylic acid include monobutyl maleate, dibutyl maleate, monooctyl fumarate, dioctyl fumarate and the like. Examples of the vinyl ester include vinyl acetate and vinyl propionate.

  Among these, a (meth) acrylic resin containing a hydroxyl group is preferable in terms of strength and surface strength. This (meth) acrylic resin containing a hydroxyl group is a resin containing the hydroxyl group-containing (meth) acrylic monomer as a monomer component. The content ratio of the hydroxyl group-containing (meth) acrylic monomer to the total monomers constituting this resin is preferably 0.5% by weight or more, and more preferably 1.0% by weight or more. If it is less than 0.5% by weight, crosslinking with isocyanate is insufficient, and sufficient strength and surface hardness may not be obtained. On the other hand, the upper limit of the content ratio is preferably 10% by weight, and preferably 5% by weight. If it exceeds 10% by weight, the polymerizability of the emulsion tends to deteriorate.

  Further, styrene- (meth) acrylic resin comprising styrene as an aromatic vinyl monomer and copolymerization thereof with one or more of the above (meth) acrylic monomers is water resistant. Is preferable. The styrene content in the styrene- (meth) acrylic resin is preferably 10 to 70% by weight, and more preferably 20 to 60% by weight. If it is less than 10% by weight, the water resistance tends to be insufficient. On the other hand, when it is more than 70% by weight, the glass transition temperature becomes high, the film forming property is lowered, and the adhesiveness may be deteriorated.

  The component (a) can be produced by subjecting each of the above monomers to a mixture as necessary, followed by emulsion polymerization. There is no restriction | limiting in particular regarding the method of emulsion polymerization, A conventionally well-known method can be used. For example, in an aqueous medium such as water, a dispersion system having the above-mentioned monomer, chain transfer agent, surfactant, radical polymerization initiator, and other additive components used as necessary as basic composition components. It can be obtained by polymerizing the monomer. In the polymerization, the composition of the monomer mixture to be supplied is made constant throughout the entire polymerization process, or the method of changing the composition of the particles produced by changing the polymerization process sequentially or continuously, as desired. Various methods are available.

  The surfactant refers to a substance having at least one hydrophilic group and one or more lipophilic groups in one molecule. Examples of the surfactant include anions such as aliphatic soap, rosin acid soap, alkyl sulfonate, dialkylaryl sulfonate, alkylsulfosuccinate, polyoxyethylene alkyl sulfate, and polyoxyethylene alkylaryl sulfate. Nonionic surfactants such as a reactive surfactant, polyoxyethylene alkyl ether, polyoxyethylene alkyl aryl ether, and polyoxyethylene oxypropylene block copolymer. In addition to these, a so-called reactive surfactant in which an ethylenic double bond is introduced into the chemical structural formula of a surfactant having a hydrophilic group and a lipophilic group may be used.

  The method of using the surfactant is not particularly limited, and for example, the entire amount may be used at the start of emulsion polymerization, or a necessary amount may be further added during and / or after emulsion polymerization.

  As the polymerization initiator, a radical is generated by heat or a reducing substance to initiate addition polymerization of the monomer, and any of an inorganic initiator and an organic initiator can be used. As such, water-soluble and oil-soluble polymerization initiators can be used. Examples of the water-soluble polymerization initiator include peroxodisulfate, various peroxides and peroxyesters, water-soluble azobis compounds, peroxide-reducing agent redox systems, and the like.

  Examples of the peroxodisulfate include potassium peroxodisulfate (KPS), sodium peroxodisulfate (NPS), and ammonium peroxodisulfate (APS). Examples of the peroxide include hydrogen peroxide, t-butyl hydroperoxide, t-butyl peroxymaleic acid, succinic acid peroxide, and benzoyl peroxide. Examples of peroxyls include t-butyl. Examples thereof include peroxyhybalate, di (2-ethylhexyl) peroxydicarbonate, t-cumyl peroxyneodecanoate, and the like.

  Further, examples of the water-soluble azobis compound include 2,2-azobis (N-hydroxyethylisobutyramide), 2,2-azobis (2-amidinopropane) dichloride, 4,4-azobis (4-cyanopentane). Acid) and the like. Furthermore, the redox system of the peroxide-reducing agent includes, for example, sodium sulfooxylate formaldehyde, sodium bisulfite, sodium thiosulfate, sodium hydroxymethanesulfinate, L-ascorbic acid, What combined reducing agents, such as a salt, cuprous salt, and ferrous salt, with the polymerization initiator is mentioned.

  The polymerization temperature in this emulsion polymerization is usually selected from the range of 60 to 100 ° C., but the polymerization may be carried out at a lower temperature by the redox polymerization method or the like. For example, when two-stage polymerization is used, the polymerization temperature in the first stage and the polymerization temperature in the second stage may be the same or different.

  The average particle size of the component (a) is preferably 100 to 400 nm. When the average particle size is 100 nm or more, there is no problem in pot life and the viscosity can be lowered. Furthermore, initial adhesiveness can be maintained by setting it as 400 nm or less. The average particle diameter is preferably 200 to 350 nm.

  The weight average molecular weight of the (meth) acrylic resin that is a resin component contained in the component (a) is preferably 100,000 to 800,000, and more preferably 300,000 to 600,000. If it is less than 100,000, the resulting coating film becomes soft, and for example, it may be peeled off if it is polished after surface treatment or used under conditions of friction. On the other hand, if it is larger than 800,000, the film forming property may be deteriorated.

  The glass transition temperature (Tg) of the (meth) acrylic resin that is a resin component contained in the component (a) is preferably 0 to 60 ° C, and more preferably 10 to 40 ° C. When the temperature is lower than 0 ° C., the formed film becomes soft, and may be peeled off when, for example, polishing is performed after the surface treatment or it is used under the condition of being subjected to friction. On the other hand, when the temperature is higher than 60 ° C., the film forming property may be deteriorated. The glass transition temperature can be measured by JIS K7121-1989 (plastic transition temperature measurement method) using a differential scanning calorimeter (DSC).

[Component (b)]
The filler which is said (b) component is used in order to provide the sealing and hardness of a base material. Examples of the filler include inorganic fillers and organic fillers. Examples of the inorganic filler include various metal oxides such as magnesium, calcium, zinc, barium, titanium, aluminum, antimony, and lead, hydroxide, sulfide, carbonate, sulfate, or silicate compound. Specific examples thereof include calcium carbonate, kaolin, talc, titanium dioxide, aluminum hydroxide, silica, gypsum, barite powder, alumina white, and satin white. Examples of the organic filler include solid polymer fine powder, and specific examples thereof include fine powder of polystyrene, polyethylene, polyvinyl chloride, polypropylene, poly (meth) acrylate resin, and the like.

  The average particle size of the component (b) is preferably 1 μm or more, and preferably 2 μm or more. If it is smaller than 1 μm, the viscosity of the aqueous (meth) acrylic resin dispersion according to the present invention tends to be high, and workability tends to deteriorate. On the other hand, the upper limit of the average particle diameter is preferably 40 μm, and preferably 30 μm. If it is larger than 40 μm, the surface after sealing becomes rough and the appearance tends to be inferior. This average particle diameter can be measured by, for example, a laser diffraction method.

  The content of the component (b) is preferably 70 parts by weight or more and preferably 100 parts by weight or more with respect to 100 parts by weight of the solid content of the component (a). If it is less than 70 parts by weight, the hardness of the produced coating film may be insufficient. On the other hand, the upper limit is preferably 200 parts by weight, and preferably 180 parts by weight. When it is more than 200 parts by weight, the film forming property may be deteriorated.

[Component (c)]
The starch as component (c) is intended to impart moisture retention to the surface treatment agent and adhesive comprising the (meth) acrylic resin aqueous dispersion according to the present invention, and to promote the isocyanate curing reaction efficiently. used. Examples of the starches include corn starch (corn starch).

  The content of the component (c) is preferably 20 parts by weight or more and preferably 30 parts by weight or more with respect to 100 parts by weight of the solid content of the component (a). If it is less than 20 parts by weight, curing may be delayed. On the other hand, the upper limit is preferably 100 parts by weight, and preferably 80 parts by weight. If it is more than 100 parts by weight, the adhesion and hardness may be insufficient.

[Component (d)]
The water-soluble polymer other than the starch as the component (d), like the component (c), imparts moisture retention to the surface treatment agent or adhesive composed of the (meth) acrylic resin aqueous dispersion, Used to efficiently perform the curing reaction. Examples of such water-soluble polymers include polyvinyl alcohols, cellulose resins, chitin, chitosan, polyethylene glycol, polypropylene glycol, water-soluble polymers containing hydroxyl groups such as cyclodextrins, amino acids such as gelatin and caseins. Examples thereof include water-soluble polymers containing groups, polyvinyl ether, and aqueous nitrified cotton.

  Examples of the polyvinyl alcohols include polyvinyl alcohol (PVA), ethylenic polyvinyl alcohol (EVOH), silanol-modified polyvinyl alcohol and the like. This polyvinyl alcohol (PVA) may be either completely saponified or partially saponified. Examples of the cellulose resin include methyl cellulose, ethyl cellulose, hydroxypropyl cellulose, carboxymethyl cellulose and the like.

  The content of the component (d) is preferably 10 parts by weight or more and preferably 15 parts by weight or more with respect to 100 parts by weight of the solid content of the component (a). When the amount is less than 10 parts by weight, the curing reaction becomes slow and the hardness tends to decrease. On the other hand, the upper limit is preferably 50 parts by weight, and preferably 40 parts by weight. When the amount is more than 50 parts by weight, the water resistance tends to decrease.

[(E) component]
In the mixed dispersion obtained by mixing the components (a) to (d), the curing agent as the component (e) is blended to form the aqueous (meth) acrylic resin dispersion of the present invention. (E) By mix | blending a component with the said mixed dispersion, a (meth) acrylic-type resin aqueous dispersion is bridge | crosslinked after application | coating and a highly rigid film is formed.

  A polyisocyanate compound is used as the component (e). This polyisocyanate compound contains two or more isocyanate groups in one molecule, and aliphatic polyisocyanate, alicyclic polyisocyanate, or derivatives thereof can be used.

  Examples of the aliphatic polyisocyanate include trimethylene diisocyanate, tetramethylene diisocyanate, 1,6-diisocyanatohexane (hexamethylene diisocyanate, HDI), pentamethylene diisocyanate, 1,2-propylene diisocyanate, 1,2-butylene diisocyanate, 2,3-butylene diisocyanate, 1,3-butylene diisocyanate, 2,4,4- or 2,2,4-trimethylhexamethylene diisocyanate, 2,6-diisocyanate methyl captroate, lysine ester triisocyanate, 1,4 , 8-triisocyanate octane, 1,6,11-triisocyanate undecane, 1,8-diisocyanate-4-isocyanate methyloctane, 1,3,6-triisocyanate Hexane, 2,5,7-trimethyl-1,8-diisocyanate-5-isocyanatomethyl octane, and the like.

  Examples of the alicyclic polyisocyanate include 1,3-cyclopentane diisocyanate, 1,3-cyclopentene diisocyanate, 1,4-cyclohexane diisocyanate, 1,3-cyclohexane diisocyanate, 1-isocyanato-3,3,5- Trimethyl-5-isocyanatomethyl-cyclohexane (isophorodiisocyanate, IPDI), 4,4'-2,4'- or 2,2'-methylenebis (cyclohexyl isocyanate) or mixtures thereof (hydrogenated MDI), methyl-2 , 4-cyclohexane diisocyanate, methyl-2,6-cyclohexane diisocyanate, 1,3- or 1,4-bis (isocyanatomethyl) cyclohexane or mixtures thereof (hydrogenated XDI), 1,3,5-triisocyanate cyclohexane, , 3,5-trimethylisocyanatocyclohexane, 2- (3-isocyanatopropyl) -2,5-di (isocyanatomethyl) -bicyclo (2.2.1) heptane, 2- (3-isocyanatopropyl) -2,6 -Di (isocyanatemethyl) -bicyclo (2.2.1) heptane, 3- (3-isocyanatopropyl) -2,5-di (isocyanatemethyl) -bicyclo (2.2.1) heptane, 5- (2 -Isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) -bicyclo (2.2.1) heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-3- (3-isocyanatopropyl) ) -Bicyclo (2.2.1) heptane, 5- (2-isocyanatoethyl) -2-isocyanate Methyl-2- (3-isocyanatopropyl) -bicyclo (2.2.1) -heptane, 6- (2-isocyanatoethyl) -2-isocyanatomethyl-2- (3-isocyanatopropyl) -bicyclo (2.2 .1) Heptane and the like.

Furthermore, as a derivative of a polyisocyanate compound, a multimer of the above polyisocyanate (dimer, trimer (isocyanurate group-containing polyisocyanate), pentamer, heptamer, etc.),
Biuret group-containing polyisocyanate (biuret-modified polyisocyanate produced by reaction of the polyisocyanate compound with water), urethane group-containing polyisocyanate (the polyisocyanate compound or a part of the isocyanate group in the multimer is monool or polyol) Modified or reacted urethane-modified polyisocyanate, etc.), urea group-containing polyisocyanate (such as urea-modified polyisocyanate produced by reaction of the above polyisocyanate compound and diamine), oxadiazine trione group-containing polyisocyanate (with the above polyisocyanate compound) Oxadiazine trione-modified polyisocyanate produced by reaction with carbon dioxide gas, etc.).

  These polyisocyanate compounds can be used alone or in combination of two or more. For example, a polyisocyanate derivative and an aliphatic and / or alicyclic polyisocyanate may be used in combination.

  The amount of the component (e) used is preferably 2% by weight or more based on the total amount of the solid content of the component (a), the component (b), the component (c) and the component (d), and 5% by weight. The above is preferable. If it is less than 2% by weight, the hardness may be insufficient. On the other hand, the upper limit is preferably 30% by weight, and preferably 20% by weight. When it is more than 30% by weight, the pot life tends to be shortened.

  In addition, when the (meth) acrylic resin of the component (a) has a carboxyl group, when a polyoxazoline compound, a polycarbodiimide compound, or the like is used in combination, a film with higher hardness is formed. preferable.

[Other additives]
The aqueous dispersion of (meth) acrylic resin according to the present invention includes, in addition to the above-mentioned components, water-soluble resins, solvents, plasticizers, antifoams other than the above components within the range not impairing the object of the present invention. Agents, thickeners, leveling agents, dispersants, colorants, water resistance agents, lubricants, pH adjusters, preservatives, surfactants, polyvalent metal compounds, and the like may be blended.

[Usage]
When the surface treatment agent containing the (meth) acrylic resin aqueous dispersion according to the present invention is applied to the surface of various substrates, for example, when evaluated by “pencil hardness” (JIS method), the hardness The surface hardness of the base material can be improved so that the hardness of the base material of “H” is “2H” to “4H”.

  Moreover, since the said (meth) acrylic-type resin aqueous dispersion has adhesiveness, the agent containing this (meth) acrylic-type resin aqueous dispersion can be used as an adhesive agent. That is, as shown in FIG. 1 (a), a base material 1 and a sheet 3 such as decorative paper are bonded together using this adhesive, so that the layer (adhesive layer) 2 made of this adhesive is interposed. Thus, a laminate in which the substrate 1 and the sheet 3 are laminated can be obtained. Furthermore, as shown in FIG.1 (b), you may manufacture a laminated body by interposing the other adhesive bond layer 4 between the said adhesive bond layer 2 and the sheet | seat 3 as needed.

  The laminate as shown in FIG. 1 (a) or FIG. 1 (b) has the adhesive layer 2 as an intermediate layer, so that the hardness of the adhesive layer 2 is increased, and the layer laminated on the surface thereof Since it becomes difficult to produce a dent, there exists a tendency for a dent to become difficult to produce as the whole laminated body.

  The base material to which the (meth) acrylic resin aqueous dispersion of the present invention can be applied includes a porous base material having a large number of pores on its surface, such as a medium density fiberboard (MDF), a wood base material such as plywood, a silica Examples thereof include inorganic base materials such as calcium acid plates and cement plates. Moreover, glass etc. can be illustrated as a hard base material.

  Furthermore, as a method for applying this aqueous (meth) acrylic resin dispersion to a substrate, methods such as coating, dipping and spraying can be employed. Furthermore, when further laminating sheets such as the decorative paper, design, embossing and the like may be applied to this sheet. As a material for such a sheet, any base material such as resins such as polyolefin, polyvinyl alcohol, polyester, polyvinyl chloride, and paper can be used.

  When the (meth) acrylic resin aqueous dispersion of the present invention is applied to the substrate 1 and the sheet 3 is laminated with the other adhesive layer 4 interposed on the surface, a laminate is produced. The adhesive strength between the material 1 and the sheet 3 is improved by 1.2 to 1.5 times compared to the case where the (meth) acrylic resin aqueous dispersion of the present invention is not applied to the substrate 1. Also, heat resistant creep tends to improve.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely using an Example, this invention is not limited by a following example. First, the evaluation method will be described.

(Evaluation methods)
<Viscosity>
It measured on 25 degreeC and 10 rpm conditions using the BH type | mold viscosity meter.

<Measurement of solid content>
The measurement was performed according to the method described in JIS K6833.

<Glass transition temperature (Tg)>
According to JIS K7121-1989, it measured with the differential scanning calorimeter (DSC).

<Pot life of mixed dispersion>
After blending an aqueous dispersion of (meth) acrylic resin (including component (e)), the time until the viscosity doubled was measured under the condition of standing at 25 ° C., and evaluated according to the following criteria. .
○: More than 2 hours Δ: 30 minutes or more and 2 hours or less ×: Less than 30 minutes

<Creation of specimen>
In order to perform the following evaluations, first, test pieces were prepared.
[Production Method 1 (When Using Porous Material as Base Material)]
The production atmosphere was the following two conditions.
(1) 23 ° C., 50% RH
(2) 5 ° C, 50% RH
As the base material, plywood (Okura Wood Co., Ltd .: ordinary plywood, F ☆☆☆☆ type) or medium density fiberboard (MDF) (Hokushin Co., Ltd., F ☆☆☆☆ type) is used. As the adherend, a polypropylene film having a thickness of 0.15 mm (adhesive surface primer treatment) was used.
First, about 80 g / m ² (8.0 g / scale ² ) of the aqueous dispersion produced in the following Examples and Comparative Examples was applied to a substrate with a roll coater. Next, an adherend (polyolefin sheet (manufactured by Toppan Printing Co., Ltd .: Eco sheet (trade name), thickness 0.16 mm, wetting index: 34 mN / m)) is applied on the substrate coated with the above aqueous dispersion. After deaeration using a laminator, bonding was performed and cold pressing was performed at 0.2 MPa for 30 minutes. After curing for 3 days in an atmosphere of 23 ° C. and 50%, the obtained product was cut to a width of 25 mm to obtain a test piece.
In addition, if necessary, other adhesives (manufactured by Chuo Rika Kogyo Co., Ltd .: BA-10L are used as curing agents on the surface of the layer (adhesive layer) made of an aqueous dispersion, BA: After applying about 72 g / m ² (7.2 g / scale ² ) of -11B (polyisocyanate 2.5% by weight)), the adherend was laminated under the above conditions.

[Production method 2 (when a hard material is used as a base material)]
On the glass plate, the aqueous dispersions produced in the following Examples and Comparative Examples were applied with an applicator so as to have a thickness of 0.1 mm. And after preliminary drying (23 degreeC x 10 minutes), it processed at 80 degreeC x 24 hours, and was set as the test piece.

<Surface treatment evaluation test>
[Surface hardness 1 (pencil hardness)]
The test was conducted according to JIS 5600-5-4 (scratch hardness (pencil method)). In addition, what was manufactured with the preparation method 2 was used for the test piece of a measuring object.
The test was conducted from a soft pencil, and the hardness of the scratched pencil was shown for the first time.

[Surface hardness 2 (JIS hard tester measurement)]
Using the test piece produced by the production method 2, it was measured using a JIS HARDNESS TESTER manufactured by Shimadzu Corporation according to the spring type hardness test of JIS K6301.

<Simple indentation test>
A 500 g weight was placed upside down on the test piece obtained in Production Method 1, and a load of about 7.3 kg / cm ² was applied. The depression after 2 days at 23 ° C. was observed, and the diameter of the depression was measured.

<Adhesion performance evaluation test>
[Adhesive strength]
(Normal strength)
As a test piece, the test piece produced in the production atmosphere of production method 1 (1) was used, and the peel strength of this test piece was measured. That is, in an atmosphere of 23 ° C. and 50% RH, the 180 ° angular tensile adhesive force of the adherend was measured at a pulling rate of 200 mm / min using an Toyo Baldwin tensile tester: Tensilon rheometer to determine the peel strength. It was.

(Heat resistant creep)
As a test piece, a test piece produced in the production atmosphere of production method 1 (1) was used. A part of this test piece was peeled off, a static load of 4.9 N was applied to the peeled surface in the 90-degree angle direction, and the test piece was left to stand for 24 hours in a hot air circulating drier set at 70 ° C. The length of peeling of the adherend after 24 hours was measured.

(JAS1 immersion peeling test)
As a test piece, a test piece produced in the production atmosphere of production method 1 (1) and cut into 75 mm × 75 mm was used. This test piece was immersed in boiling water for 4 hours. Then, it dried at 60 degreeC +/- 3 degreeC for 20 hours. Subsequently, after being immersed again in boiling water for 4 hours, it was dried at 60 ° C. ± 3 ° C. for 3 hours. The treated specimen was visually evaluated according to the following criteria.
○: The length of the non-peeled portion is 50 mm or more on all side surfaces. X: The length of the non-peeled portion is less than 50 mm on any side surface.

(Cold resistant)
As a test piece, a test piece produced in the production atmosphere of production method 1 (1) was used. This test piece was allowed to stand at −20 ° C. for 24 hours, and then the adherend was instantaneously peeled by hand in an atmosphere at −20 ° C. At that time, the fracture state of the peeled portion was visually observed and evaluated in the following three stages.
○: The base material was destroyed.
Δ: Cohesive failure occurred.
X: Interfacial destruction was caused.

(Low temperature adhesion)
As the test piece, the test piece produced in the production atmosphere of production method 1 (2) was used. The adherend was instantaneously peeled off by hand from the test piece in an atmosphere of 5 ° C. At that time, the fracture state of the peeled portion was visually observed and evaluated in the following three stages.
○: The base material was destroyed.
Δ: Cohesive failure occurred.
X: Interfacial destruction was caused.

(raw materials)
[(A) component]
1) Monomer / butyl acrylate: Wako Pure Chemical Industries, Ltd .: Special grade (hereinafter abbreviated as “BA”)
・ Hydroxyethyl methacrylate: Wako Pure Chemical Industries, Ltd .: Grade 1 (hereinafter abbreviated as “HEMA”)
Acrylic acid: Wako Pure Chemical Industries, Ltd .: Special grade (hereinafter abbreviated as “AA”)
・ Methacrylic acid: Wako Pure Chemical Industries, Ltd .: Special grade (hereinafter abbreviated as “MAA”)
Acrylamide: Wako Pure Chemical Industries, Ltd .: Grade 1 (hereinafter abbreviated as “AAm”)
Styrene monomer: Wako Pure Chemical Industries, Ltd .: Special grade (hereinafter abbreviated as “SM”)
-2-ethylhexyl acrylate: Wako Pure Chemical Industries, Ltd .: 1st grade (hereinafter abbreviated as “2EHA”)
Vinyl acetate: Wako Pure Chemical Industries, Ltd .: Special grade (hereinafter abbreviated as “VAc”)

1 ′) Polymer / ethylene-vinyl acetate polymer: Sumitomo Chemical Co., Ltd .: Sumikaflex S-305 (hereinafter abbreviated as “EVA”)

2) Emulsifier, Eleminol ES-70 ... manufactured by Sanyo Chemical Industries (hereinafter abbreviated as "ES70")
Polyvinyl alcohol (PVA): manufactured by Nippon Synthetic Chemical Co., Ltd .: Gohsenol GH-17 (trade name) (hereinafter abbreviated as “GH-17”)
* Emulgen 1118S-70 ... manufactured by Kao Corporation (hereinafter abbreviated as "S70")

3) Polymerization initiator / potassium persulfate: Tokai Denka Co., Ltd .: KPS (hereinafter abbreviated as “KPS”)
-Anhydrous sodium bisulfite ... (To) Chemicals of Togawa: SBS (hereinafter abbreviated as "SBS")

[Component (b)]
Calcium carbonate: Nitto Flour Industries Co., Ltd .: NS-100 (hereinafter abbreviated as “NS100”)

[Component (c)]
Starch: J-Oil Mills Co., Ltd .: Corn starch Y (hereinafter abbreviated as “corn starch”)

[Component (d)]
Polyvinyl alcohol: Kuraray Co., Ltd .: Kuraray Poval PVA217 (trade name) (hereinafter abbreviated as “PVA217”)

[(E) component]
Polyisocyanate: manufactured by Nippon Polyurethane Industry Co., Ltd .: Millionate MR-400 (hereinafter abbreviated as “MR400”)

[Porous substrate]
MDF: manufactured by Hokushin Co., Ltd .: Starwood STLI (Standard: F ☆☆☆☆, hereinafter abbreviated as “MDF”)
Plywood: Okura Wood Co., Ltd .: JAS1 class plywood (Standard: F ☆☆☆☆, hereinafter abbreviated as “plywood”)

(Examples 1-7, Comparative Example 1)
[Production of resin emulsion]
Each monomer component, emulsifier, and water shown in the column of the component (a) in Table 1 were mixed at a ratio shown in Table 1 to prepare a pre-emulsion.
After stirring, a quantity of ion-exchanged water and ES70 shown in Table 1 were put in a reaction vessel equipped with a reflux condenser, a thermometer and a dropping funnel, and heated to 75 ° C. The amounts of polymerization initiators KPS and SBS shown in Table 1 were each dissolved in ion-exchanged water and added to the reaction vessel. Subsequently, the said pre-emulsion was continuously dripped over 3 hours, and the polymerization reaction was performed. Further, after the completion of the dropwise addition, the temperature was raised to 80 ° C., and 0.5 parts by weight of KPS dissolved in water was added and aged for 3 hours. After completion of aging, the mixture was cooled to obtain a resin emulsion (EM1 or EM2).

[Production and evaluation of aqueous dispersion]
The components (a) to (e) shown in Table 2 are mixed in the amounts shown in the same table to produce an aqueous dispersion, and test pieces are prepared according to the preparation methods described in Table 2, and the above evaluations are made. Went. The results are shown in Table 2. In addition, the pot life test was done about the aqueous dispersion liquid containing (e) component.

(Comparative Examples 2 and 3)
Each of the above evaluations was performed using only plywood and MDF without using an aqueous dispersion. The results are shown in Table 2.

(Examples 8-12, Comparative Examples 4-6)
[Production of resin emulsion (EM3, EM4)]
Each monomer component, emulsifier, and water shown in Table 3 were mixed in the ratio shown in Table 3 to prepare a pre-emulsion.
After stirring, a quantity of ion-exchanged water and ES70 shown in Table 3 were placed in a reaction vessel equipped with a reflux condenser, a thermometer and a dropping funnel, and heated to 75 ° C. The amounts of polymerization initiators KPS and SBS shown in Table 3 were each dissolved in ion-exchanged water and added to the reaction vessel. Subsequently, the said pre-emulsion was continuously dripped over 3 hours, and the polymerization reaction was performed. Further, after the completion of the dropwise addition, the temperature was raised to 80 ° C., and 0.5 parts by weight of KPS dissolved in water was added and aged for 3 hours. After completion of aging, the mixture was cooled to obtain resin emulsions (EM3, EM4).

[Production of resin emulsion (EM5)]
Each monomer component, emulsifier, and water shown in Table 3 were mixed in the ratio shown in Table 3 to prepare a pre-emulsion.
After stirring, the amounts of GH-17, S70 and ion-exchanged water shown in Table 3 were placed in a reaction vessel equipped with a reflux condenser, a thermometer and a dropping funnel, and heated to 70 ° C. The amount of polymerization initiator KPS shown in Table 3 was dissolved in ion exchange water and added to the reaction vessel. Subsequently, the said pre-emulsion was continuously dripped over 3 hours, and the polymerization reaction was performed. Further, after the completion of the dropwise addition, the temperature was raised to 80 ° C., and 0.5 parts by weight of KPS dissolved in water was added and aged for 3 hours. After completion of aging, the mixture was cooled to obtain a resin emulsion (EM5).

[Resin emulsion (EM6)]
As the resin emulsion (EM6), an ethylene-vinyl acetate resin emulsion (EVA) (manufactured by Sumitomo Chemical Co., Ltd .: Sumikaflex S-305 (trade name)) was used.

[Production of resin emulsion (EM7)]
100 parts by weight of an ethylene-vinyl acetate copolymer emulsion (manufactured by Sumitomo Chemical Co., Ltd .: Sumikaflex S-455HQ (trade name)) is used as a polyurethane emulsion (manufactured by Sumitomo Bayer Urethane Co., Ltd .: Desco Pearl U-53). 30 parts by weight of (trade name)) and 5 parts by weight of MR400 as component (e) were mixed and dispersed to obtain a resin emulsion (EM7).

[Production and evaluation of aqueous dispersion]
Components (a) to (e) shown in Table 4 were mixed in the amounts shown in the same table to produce an aqueous dispersion, and test pieces were prepared according to the preparation methods described in Table 4, and each of the above evaluations Went. The results are shown in Table 4. In addition, the pot life test was done about the aqueous dispersion liquid containing (e) component.

(A) (b) Sectional drawing which showed the example of the laminated body using the (meth) acrylic-type resin aqueous dispersion concerning this invention

Explanation of symbols

1 Base material 2 Adhesive layer 3 Sheet 4 Other adhesive layer

Claims (11)

  (E) (is) a polyisocyanate compound as a curing agent in a mixed dispersion containing (meth) acrylic resin emulsion, (b) filler, (c) starches and (d) water-soluble polymers other than starches (Meth) acrylic resin aqueous dispersion containing   The (meth) acrylic resin aqueous dispersion according to claim 1, wherein the (meth) acrylic resin contained in the (a) (meth) acrylic resin emulsion is a styrene- (meth) acrylic resin.   The (meth) acrylic resin aqueous dispersion according to claim 1 or 2, wherein a glass transition temperature of the (meth) acrylic resin contained in the (a) (meth) acrylic resin emulsion is 0 to 60 ° C.   The (meth) acrylic resin according to any one of claims 1 to 3, wherein the (meth) acrylic resin contained in the (a) (meth) acrylic resin emulsion is a (meth) acrylic resin having a hydroxyl group. Resin aqueous dispersion.   The (meth) acrylic resin aqueous dispersion according to any one of claims 1 to 4, wherein the (b) filler is at least one selected from an inorganic filler and an organic filler.   The (meth) acrylic resin aqueous dispersion according to any one of claims 1 to 5, wherein the water-soluble polymer other than (d) starch is a water-soluble polymer having a hydroxyl group.   70 to 200 parts by weight of the component (b), 20 to 100 parts by weight of the component (c), and 10 to 50 parts by weight of the component (d) with respect to 100 parts by weight of the solid content of the component (a) The aqueous (meth) acrylic resin dispersion according to any one of claims 1 to 6.   The (meta) component according to claim 7 containing 2 to 30% by weight of the component (e) with respect to the total amount of the solid content of the component (a), the component (b), the component (c) and the component (d). ) Acrylic resin aqueous dispersion.   A surface treatment agent comprising the (meth) acrylic resin aqueous dispersion according to any one of claims 1 to 8.   An adhesive comprising the (meth) acrylic resin aqueous dispersion according to any one of claims 1 to 8.   The laminated body which bonded together the base material and the sheet | seat using the adhesive agent of Claim 10.

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