JP2002309111A - Curable composition and coating material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a curable composition which is flexible and has a high surface hardness and a passage closing effect. SOLUTION: The composition comprises an inorganic curable composition containing inorganic flaky particles having an aspect ratio (a length to thickness ratio) of 10 to 300, a specific surface of 300-800 m<2> /g, and such film-forming properties that the pencil hardness of a film obtained by applying a 15% dispersion of the particles in deionized water on a polyethylene terephthalate film to provide a coating weight of 25-30 g/m<2> and drying it is 2H or higher, and an organic polymer containing a bonding group selected from an ether linkage, an ester linkage, a urethane linkage, a urea linkage and an Si-O linkage in the main chain, or containing a polar group in the side chain, or its precursor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a curable composition, particularly to a curable composition suitable for forming a coating film.

[0002]

2. Description of the Related Art Conventionally, there has been a tendency that a material having a high surface strength is brittle and lacks flexibility, and a material having a soft and high flexibility has a low surface strength. On the other hand, plate-like powders have been known to have a maze effect that delays penetration of moisture and corrosive gas components when added to an organic polymer to form a cured product. There was a great demand for expecting. What has both performances was desired.

[0003]

Accordingly, an object of the present invention is to provide a curable composition which is flexible, has a high surface hardness, and has a closing effect.

[0004]

According to the present invention, there are provided an inorganic plate-like particle having an aspect ratio (ratio of a major axis to a thickness) of 10 to 300 and an average particle diameter of 2 μm or less; A curable composition comprising: a precursor;

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The inorganic plate-like particles used in the present invention have an aspect ratio (ratio of major axis to thickness) of 10 to 300.
It is necessary to be. When the aspect ratio is less than 10, sufficient interparticle bonding cannot be obtained, and it is difficult to obtain a closing effect. If the aspect ratio exceeds 300, mixing becomes difficult. Aspect ratio of 20 to 200, especially 20
The case of ~ 100 is more preferable.

The inorganic plate-like particles used in the present invention must have an average particle diameter of 3 μm or less. Average particle size is 3
If it exceeds μm, it is not suitable because a sufficient bonding force is not exhibited between the inorganic plate-like particles. It is preferable that the average particle diameter is 2 μm or less, because the bonding force is further increased.

The inorganic plate-like particles used in the present invention preferably have a specific surface area of 30 to 500 m ² / g. When the specific surface area is less than 30 m ² / g, sufficient interparticle bonding cannot be obtained, and it is difficult to obtain a closing effect. Specific surface area is 500m ²
/ G, mixing becomes difficult.

The inorganic plate-like particles used in the present invention preferably have a film-forming property defined as follows. That is, the solid content concentration of the particles is 15% (mass%, the same applies hereinafter).
It is preferable that the pencil hardness of a film obtained by applying and drying a dispersion liquid dispersed in ion-exchanged water on a polyethylene terephthalate film at a coating amount of 25 to 30 g / m ² is 2H or more. The pencil hardness of this film is a physical property that defines the film forming property of the inorganic plate-like particles themselves. If the pencil hardness is less than 2H, a flexible coating film may not be obtained, which is not preferable. The pencil hardness of this film is 3H
The case where the above is more preferable is more preferable.

It is preferable that the inorganic plate-like particles accounts for 1 to 90% of the solid content in the curable composition. 10 to 99% of an organic polymer or a precursor thereof (the organic polymer includes a precursor unless otherwise specified)
It is preferred to contain. When the amount of the inorganic plate-like particles is less than 1%, sufficient hardness and a closing effect cannot be obtained, which is not preferable. When the content of the inorganic plate-like particles exceeds 90%, the organic polymer cannot sufficiently fill the gaps between the plate-like powders, so that the closing effect cannot be obtained. More preferably, the content of the inorganic plate-like particles is 10 to 60%, particularly 20 to 50%. It is preferable that the total amount of the inorganic plate-like particles and the binder is 30% or more based on the solid content in the curable composition. A more preferred range is 50% or more, and a particularly preferred range is 70% or more.

When a higher closing effect is required, the inorganic plate-like powder must have a particle size of 50 to make the plate-like particles more interact with each other and to have a non-porous body.
~ 60% is desirable.

In the curable composition, the solid content is 3 to 50.
%. If the solids content is less than 3%
It is not preferable because it is difficult to increase the film thickness. 50% solids
When the viscosity exceeds the above range, the viscosity of the curable composition becomes high and it becomes difficult to form a coating film, which is not preferable. A more preferred range of the solid content is 5 to 30%.

What is contained as a component other than the solid content in the curable composition is a so-called solvent, and the solvent is preferably a polar solvent, more preferably water, alcohol, ketone or ester, and particularly preferably water. The curable composition contains a dispersion medium as a component other than the solid content. As the dispersion medium, a polar liquid is preferable, water, alcohol, ketone, and ester are more preferable, and water is particularly preferable.

As the inorganic plate-like particles, specifically, it is preferable to use a layered polysilicic acid such as silica-X, silica-Y, magazinite, and kanemite. The above silica-X
Examples thereof include flaky silica described in Japanese Patent Application No. 11-351182. In addition, talc, mica, and glass flake can also be used. In the case of talc, mica, and glass flakes, it is preferable to perform a surface treatment by, for example, contacting with an aqueous alkali solution because a high closing effect can be obtained.

The organic polymer contained in the curable composition includes a main chain containing a bonding group selected from an ether bond, an ester bond, a urethane bond, a urea bond, and a Si—O bond, or a side chain containing Those containing a polar group are preferred because of their high affinity with the inorganic plate-like particles. Examples of such an organic polymer include a urethane resin, an epoxy resin, an acrylic resin, an acrylic urethane resin, a silicone resin, an acrylic silicone resin, and a melamine resin. These organic polymers may be used alone or in combination of two or more. The organic polymer precursor is a raw material that forms an organic polymer by a chemical reaction, and includes not only a monomer but also a partially polymerized product.

As the urethane resin contained in the curable composition of the present invention, either a thermoplastic type or a curable type can be used. As the thermoplastic type, it is suitable to be mixed with the curable composition as a urethane emulsion. Examples of the curing type include a polyol curing type obtained by a reaction between an isocyanate compound and a polyol, and a moisture curing type in which the isocyanate compound is cured by moisture in the atmosphere. For the moisture-curing type, it is preferable to use an amine-based curing catalyst.

Examples of the polyisocyanate compound used in the urethane resin include tolylene diisocyanate, diphenylmethane diisocyanate, lysine diisocyanate methyl ester, dicyclohexyl methane diisocyanate, isophorone diisocyanate, xylylene diisocyanate, hexamethylene diisocyanate, diphenylmethane-4,4'-diisocyanate, hexane Examples thereof include a hydrotrimer of methylene diisocyanate (for example, Desmodur, trade name, manufactured by Bayer AG). Furthermore, adducts or blocks of these isocyanate compounds can also be used.

The polyol used for the urethane resin includes polyether polyol, polyester polyol, acrylic polyol, epoxy polyol and the like. The molecular weight of the polyol is 300 to 300
00 is preferred.

The epoxy resin contained in the curable composition of the present invention includes, for example, polyglycidyl ether of polyphenol produced by reacting polyphenol with epichlorohydrin in the presence of an alkali. As the polyphenol, for example, 2,2
-Bis (4-hydroxyphenyl) propane, dihydroxybenzophenone, 1,1-bis (4-hydroxyphenyl) ethane, bis (2-hydroxynaphthyl) methane, 1,5-dihydroxynaphthalene, and the like. Further, an epoxy resin obtained by reacting diglycidyl ether with the above-mentioned polyphenol and further reacting a reaction product with shrimp chlorohydrin can also be used.

The epoxy resin preferably has a number average molecular weight of 350 or more, particularly preferably from 350 to 5,000. Epoxy equivalent is 150-4000, especially 1
90-2000 is preferred. Such epoxy resins include, for example, Epicoat 828, 1001, 100
Specific examples include those commercially available under trade names such as 2, 1004 and 1007 (manufactured by Shell Chemical Company).
As a curing agent for the epoxy resin, polyamine, polyamide, or the like is used. The compounding amount is adjusted according to the epoxy equivalent of the main agent and the amine value of the curing agent, respectively.

The acrylic resin contained in the curable composition of the present invention includes acrylic acid or methacrylic acid (hereinafter collectively referred to as (meth) acrylic acid) or (meth) acrylic acid such as (meth) acrylic acid ester. At least one derivative (hereinafter collectively referred to as acrylic monomer)
Is obtained by polymerizing the polymer, and a thermoplastic type is preferable. If necessary, those obtained by adding a crosslinking agent (melamine resin, polyisocyanate, alkoxysilane compound, etc.) can be used.

As the (meth) acrylate,
Methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, isopropyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) acrylic acid-2- C1-C1 of (meth) acrylic acid such as ethylhexyl, octyl (meth) acrylate, lauryl (meth) acrylate
6 alkyl esters; glycidyl (meth) acrylate; methoxyethyl (meth) acrylate, ethoxybutyl (meth) acrylate, methoxybutyl (meth) acrylate, alkoxy having 1 to 18 carbon atoms of (meth) acrylic acid C2 to C3 alkenyl ester of (meth) acrylic acid such as allyl (meth) acrylate; carbon of (meth) acrylic acid such as hydroxyethyl (meth) acrylate and hydroxypropyl (meth) acrylate Hydroxyalkyl esters of the formulas 2 to 6;
Examples thereof include aminoalkyl esters of (meth) acrylic acid such as dimethylaminoethyl (meth) acrylate and diethylaminoethyl (meth) acrylate; and epoxy group-containing substances such as glycidyl (meth) acrylate. Other (meth) acrylic acid derivatives include (meth) acrylamide and (meth) acrylonitrile.

As the acrylic urethane resin contained in the curable composition, a resin obtained from a hydroxyl group-containing acrylic resin and a polyisocyanate is preferable, and any of a thermoplastic type and a curable type can be used.

Examples of the hydroxyl group-containing acrylic resin include copolymers composed of the same acrylic monomer and a hydroxyl group-containing polymerizable monomer as described above. Further, it can be copolymerized with another polymerizable monomer. The OH group equivalent of the hydroxyl group-containing acrylic resin is preferably from 5 to 300 mgKOH / g resin.

Examples of the hydroxyl group-containing polymerizable monomer include hydroxyethyl (meth) acrylate, hydroxypropyl (meth) acrylate and (meth) acrylic acid-4.
-Hydroxybutyl, polycaprolactone modified (meth)
Hydroxyethyl acrylate can be used.

Other polymerizable monomers used for the hydroxyl group-containing acrylic resin include olefins such as ethylene; aromatic polymerizable monomers such as styrene, α-methylstyrene, vinyltoluene and p-methylstyrene; vinyl acetate Vinyl ester such as acrylonitrile; and carboxyl group-containing polymerizable monomers such as crotonic acid, maleic acid, fumaric acid, monoalkyl maleate and monoalkyl fumarate. One or more selected from the group can be used.

Examples of the polyisocyanate used for the acrylic urethane resin include hexamethylene diisocyanate, isophorone diisocyanate, 1,3-bis (isocyanatomethyl) cyclohexane and dicyclohexylmethane-4,4'-diisocyanate, which are non-yellowing type isocyanates. Can be used alone or as a mixture of two or more, and adducts, blocks, and the like thereof can also be used.

The hydroxyl group-containing acrylic resin and polyisocyanate used for the acrylic urethane resin are preferably blended so that the equivalent ratio of hydroxyl group / isocyanate group becomes 0.6 to 1.2. If it is less than 0.6, the unreacted polyisocyanate may reduce the water resistance and mechanical properties of the cured product obtained from the curable composition, and if it exceeds 1.2, the crosslinking density is reduced, and the water resistance, Mechanical properties decrease.

The silicone resin contained in the curable composition is preferably of a thermoplastic type. Specific examples of the silicone resin include pure silicone resins such as dimethylpolysiloxane, methylphenylpolysiloxane, and diphenylpolysiloxane, and pure silicone resins reacted with modifying resins such as alkyd resins, polyester resins, acrylic resins, and epoxy resins. Modified silicone resins are exemplified.

As the acrylic silicone resin contained in the curable composition, any of a thermoplastic type and a thermosetting type can be preferably used. Acrylic resin and silicone resin similar to those described above, which are composited by block copolymerization or the like, those in which the other component is crosslinked with any of the above components,
Silicone partially modified with acrylic,
Those obtained by crosslinking the components with another crosslinking agent can be used.

Such an acrylic silicone resin can be produced, for example, as follows. In other words, in the polymerization of the acrylic resin, allyl (meth) acrylate or the like is radically copolymerized, whereby an acrylic copolymer having a carbon-carbon double bond introduced therein is obtained. Further, the carbon-carbon double of the acrylic copolymer is obtained. For bonding, a metal complex catalyst such as platinum is used, and HSi (OR ¹ ) _3-n R is used as a silane component.
² _n (n is 0 or 1, R ^1, R ² each an alkyl group.) Was hydrosilylation by reacting a hydrosilane compound such as this, for example, by molecular weight 1,000 to
A target silyl group-containing acrylic resin of 0000 can be obtained.

The organic polymer contained in the curable composition of the present invention is preferably in the form of an aqueous emulsion because it can be easily mixed with the inorganic plate-like particles.

The curable composition of the present invention may contain an inorganic or organic filler in addition to the plate-like particles. In that case, the content is preferably 20% or less. If the content exceeds 20%, the film-forming properties of the plate-like particles may be impaired, which is not preferred. The curable composition of the present invention may further contain the following additives. The content is preferably 10% or less. Examples of the additives include a plasticizer, a leveling agent, an ultraviolet absorber, a light stabilizer, a dye, and a pigment.

The curable composition of the present invention is excellent as a coating material such as a paint, a top coat and a wax. It is also useful as a sheet-like molded product, an adhesive, a primer and the like.

[0034]

EXAMPLES The following formulations were applied to glass plates, respectively cured, and subjected to a pencil hardness test, a cross cut test, and a cellophane adhesive tape peel test in accordance with JIS-K5400. Furthermore, JIS-L for each formulation
Flexibility was measured by the 45 ° cantilever method according to 1096.

Examples 1 to 12 As the inorganic plate-like particles, silica-X described in Japanese Patent Application No. 11-351182 (manufactured by Dokai Chemical Industry Co., Ltd., trade name: Sun Lovely LFS, aspect ratio 50, average particle diameter) 1.5 μm, specific surface area 70 m ² /
g, the above-mentioned film forming property 3H) was used. The particles have the content shown in Table 1, and the balance has a solid content of an organic polymer of the following A to F. A coating solution having a solid content concentration of 15% is coated on a substrate at 20 g / m ² . About the film obtained by applying the coating amount,
Table 1 shows the results of the pencil hardness, cross cut test, and flexibility test.

(Organic polymer composition) A: Urethane prepolymer (bifunctional, molecular weight 3000)
A mixture of 100 parts and 10 parts of diisopropylamine, curing conditions: 60 ° C, 1 day. B: Water-dilutable epoxy resin (epoxy equivalent 200) 10
Mixture of 0 parts and 20 parts of polyaminoamide, curing conditions: 1
00 ° C., 60% RH, 1 hour. C: acrylic emulsion (number average molecular weight 2000
0), curing conditions: 150 ° C., 30 minutes. D: acrylic urethane emulsion (average molecular weight 150
00), curing conditions: 120 ° C., 30 minutes. E: dimethylpolysiloxane (average molecular weight 4000, hydroxyl equivalent 1500), curing conditions: 60 ° C., 60% RH,
3 hours. F: acrylic silicone (styrene equivalent molecular weight 2000
0), curing conditions: 50 ° C., 60% RH, 30 minutes.

[0037]

[Table 1]

In the organic polymer compositions A to F, those containing the inorganic plate-like particles and those not containing the inorganic plate-like particles were compared. The compound containing the compound showed high characteristics.

Examples 13 to 20 Coatings were formed from the same inorganic plate-like particles used in Examples 1 to 12 and the above-mentioned organic polymer composition F. The inorganic plate-like particles 2 were contained in an amount described in the column of content in Table 2. In Examples 17 to 21, 0.33% of those shown in the column of additives in Table 2 were added. Example 15 is the same coating film as Example 5.

[0040]

[Table 2]

As can be seen from Examples 13 to 16, the pencil hardness and flexibility tend to increase as the content of the inorganic plate-like particles increases, and high results can be obtained in the cross-cut test within this range. Understand.

[Examples 22 to 24] Instead of the inorganic plate-like particles used in Example 6, a coating film was formed from 50 parts of an inorganic pigment shown in Table 3 and 50 parts of the above organic polymer composition F.

[0043]

[Table 3]

Example 18 A sheet-shaped cured product sample was prepared using the components used in Example 14 among the formulations. This sample was measured for water vapor transmission rate according to JIS-K5400, and found to be 3.1 g / m ² · H × 10 ^-2 . For comparison, a sheet-like cured product sample was prepared using the composition shown in Example 25 of Table 3 among the formulations. This sample was measured for water vapor transmission rate according to JIS-K5400, and was found to be 1.5 g / m ² · H × 10 ^-2 .

[0045]

According to the present invention, in a cured organic polymer,
Since the plate-like particles capable of interacting with the organic polymer are oriented, the surface hardness can be increased while maintaining the inherent elongation and flexibility of the resin. Further, interaction between the plate-like particles occurs in the cured product, preventing the penetration of moisture and corrosive gas components, and a closing effect one step further than the maze effect can be obtained.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 7/12 C09D 7/12 201/00 201/00 F term (Reference) 4J002 AA011 AA021 BG001 BG051 BG061 BG071 BG091 BG121 CC181 CD001 CD041 CK021 CK031 CK041 CP031 CP171 DJ006 DJ016 FA016 GH01 4J038 CG031 CG141 CH031 CH041 CH171 CH221 DB061 DG111 DG131 DG161 DG191 DG271 DG281 DG301 DL031 DL061 DL101 HA436 KA08 MA10

Claims (8)

[Claims] 1. A curing method comprising: an inorganic plate-like particle having an aspect ratio (ratio of a major axis to a thickness) of 10 to 300 and an average particle diameter of 3 μm or less; and an organic polymer or a precursor thereof. Composition. ^2. A film obtained by applying and drying a 15% dispersion of particles of said inorganic plate-like particles in ion-exchanged water on a polyethylene terephthalate film at a coating amount of 25 to 30 g / m ^2. 2. A pencil hardness of 2H or more.
3. The curable composition according to item 1. 3. The inorganic plate-like particles have a specific surface area of 30 to 500 m.
The curable composition according to claim 1 or ² / g. 4. The curable composition according to claim 1, wherein said inorganic plate-like particles are layered polysilicic acid. 5. The method according to claim 4, wherein said layered polysilicic acid is silica-X, silica-Y, magazinite or kanemite.
3. The curable composition according to item 1. 6. The organic polymer according to claim 1, wherein the main chain has an ether bond,
The curable composition according to any one of claims 1 to 5, wherein the curable composition is one containing a bonding group selected from an ester bond, a urethane bond, a urea bond, and a Si-O bond, or one containing a polar group in a side chain. . 7. The organic polymer according to claim 1, wherein said organic polymer is selected from the group consisting of urethane resins, epoxy resins, acrylic resins, acrylic urethane resins, silicone resins, acrylic silicone resins and melamine resins. 3. The curable composition according to item 1. 8. A paint comprising the curable composition according to claim 1 as a main component.