JP3212696B2 - Water-dispersed composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to, for example,
The present invention relates to a water-dispersible composition which gives a coating film exhibiting good coating film performance in various coatings such as automobiles, home appliances and plastics, particularly in applications requiring weather resistance and durability.

[0002]

2. Description of the Related Art In recent years, in the field of paints and adhesives, from the viewpoint of pollution control or resource saving, a resin obtained by using an organic solvent or a resin using an organic solvent-containing resin is used. Conversion from paints and adhesives to paints and adhesives using water-soluble or water-dispersible resins has been attempted.

[0003] However, conventional water-dispersed resins are:
Manufactured by an emulsion polymerization method using an ionic or nonionic surfactant, and since there are no crosslinkable functional groups in the dispersed particles, they are strongly affected by the surfactant used for polymerization. In addition, the formed coating film has the drawback that the weather resistance, water resistance, and stain resistance are remarkably deteriorated, and the physical properties of the coating film are inferior to solvent-based coatings.

Various attempts have been made to improve this drawback. One of them is to use a water-soluble polymer compound such as a maleated polybutadiene, a maleated alkyd resin or a water-soluble acrylic resin as a dispersion stabilizer. A method of polymerizing in an aqueous medium, in order to improve water resistance and weather resistance, a vinyl monomer having a functional group capable of reacting with a silyl group in an aqueous solution of a water-soluble synthetic resin having a hydrolyzable silyl group. A method has been proposed in which a polymer is emulsion-polymerized (JP-A-2-178301). Also, in emulsion polymerization using an ionic or nonionic surfactant, in order to improve water resistance and weather resistance, other copolymerizable vinyl monomers having a hydrolyzable silyl group can be used. A method of emulsion copolymerization with a vinyl monomer (JP-A-63-254116) has been proposed.

[0005] However, the polymer emulsion obtained by these methods has a problem that the hydrolyzable silyl group present in the water-soluble resin or the water-dispersible resin contained therein has a trimethoxysilyl group or a triacetoxysilyl group. However, it has a drawback that it tends to gel during the synthesis or storage of a polymer emulsion and cannot be stably manufactured and stored.

[0006]

Means for Solving the Problems The inventors of the present invention have made intensive studies to solve these problems, and as a result, using a monomer containing a vinyl monomer having a specific silyl group. Emulsion polymerization enables stable emulsion polymerization, and a polymer emulsion (A) having a silyl group
The present inventors have found that silyl groups in the emulsion can be stabilized, and the storage stability of the obtained emulsion can be improved, thereby completing the present invention.

That is, the present invention relates to (A) a compound represented by the general formula (I):

[0008]

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(Wherein n is 6 to 15 and R ¹ is 1 to 10 carbon atoms)
A is an integer of 0 to 2, a is an integer of 0 to 2, and when R ¹ bonded to Si is 2 or more, they are the same group; And a different group). The present invention also relates to a water-dispersible composition comprising a polymer emulsion obtained by emulsion polymerization of a vinyl-containing monomer having a silyl group represented by the formula (I) and (B) a curing catalyst.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The polymer emulsion having a silyl group (A) used in the present invention comprises a vinyl monomer containing a silyl group, for example, a vinyl monomer having a silyl group (a) and And another vinyl-type monomer (b) copolymerizable with an ionic or non-ionic surfactant.

The vinyl monomer having a silyl group (silyl group-containing vinyl monomer) (a) has a polymerizable carbon-carbon double bond in one molecule and a compound represented by the following general formula (I):

[0012]

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This is a compound containing a group represented by the formula:

In the general formula (I), n is 6 to 15, and preferably 6 to 12. When n is from 6 to 15, emulsion polymerization can be carried out stably, and the storage stability and the like of the obtained emulsion can be improved.

R ¹ in the general formula (I) is a monovalent hydrocarbon group selected from an alkyl group having 1 to 10 carbon atoms, an aryl group and an aralkyl group, and is preferably an alkyl group, particularly a methyl group or an ethyl group. In the case of a group, it is preferable from the viewpoint of the balance between stability and curing reactivity.

Further, in the general formula (I), a is 0
It is an integer of ２2, but is preferably 0、1, and when R ¹ bonded to Si is two or more, they may be the same or different groups.

The silyl group-containing vinyl monomer is not particularly limited as long as it is a compound as described above.

[0018]

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However, the present invention is not limited to these.

These silyl group-containing vinyl monomers include:
They may be used alone or in combination of two or more. Also,
The copolymer is preferably copolymerized so that the ratio in the obtained polymer is 1 to 50% (% by weight, the same applies hereinafter), and more preferably 2 to 20%. If the copolymerization ratio is less than 1%, the water resistance and weather resistance are inferior, and if it exceeds 50%, the stability of the emulsion tends to decrease.

The other vinyl monomer (b) copolymerizable with the silyl group-containing vinyl monomer is not particularly limited. For example, methyl (meth) acrylate, ethyl (meth) acrylate, butyl ( Vinyl monomers such as (meth) acrylate, isobutyl (meth) acrylate, benzyl (meth) acrylate, and cyclohexyl (meth) acrylate; trifluoroethyl (meth)
Fluorine-containing vinyl monomers such as acrylate, pentafluoropropyl (meth) acrylate, perfluorocyclohexyl (meth) acrylate, 2,2,3,3-tetrafluoropropyl methacrylate, and β- (perfluorooctyl) ethyl (meth) acrylate Aromatic vinyl monomers such as styrene, α-methylstyrene, chlorostyrene, 4-hydroxystyrene and vinyltoluene; acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid and itaconic anhydride acid,
An acid having a polymerizable carbon-carbon double bond such as α, β-ethylenically unsaturated carboxylic acid such as crotonic acid, fumaric acid and citraconic acid, styrene sulfonic acid and vinyl sulfonic acid; the polymerizable carbon-carbon Salts of acids having a double bond (alkali metal salts, ammonium salts, amine salts, etc.); acid anhydrides such as maleic anhydride or half esters thereof with linear or branched alcohols having 1 to 20 carbon atoms; dimethyl Aminoethyl (meth) acrylate,
(Meth) acrylates having an amino group such as dimethylaminopropyl (meth) acrylate and diethylaminoethyl (meth) acrylate; (meth) acrylamide, α-ethyl (meth) acrylamide, N-butoxymethyl (meth) acrylamide, N, N -Dimethyl acrylamide, N-methyl acrylamide, acryloyl morpholine or their hydrochlorides and acetates; vinyl esters and allyl compounds such as vinyl acetate, vinyl propionate and diallyl phthalate; vinyl monomers containing nitrile groups such as (meth) acrylonitrile Body; an epoxy group-containing vinyl monomer such as glycidyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate;
-Hydroxypropyl (meth) acrylate, 2-hydroxyethyl vinyl ether, N-methylol (meth)
Acrylamide, hydroxystyrene, Aronix 57
00 (manufactured by Toa Gosei Chemical Co., Ltd.), Placel FA
-1, Placel FA-4, Placel F
M-1, Placel FM-4 (all manufactured by Daicel Chemical Industries, Ltd.), HE-10, HE-20, HP-1
0, HP-20 (manufactured by Nippon Shokubai Chemical Industry Co., Ltd.),
Blemmer PP series, Blemmer PE series, Blemmer PEP series, Blemmer AP-400, Blemmer AE-350, Blemmer NKH-5050,
Hydroxyl group-containing vinyl monomers such as Blemmer GLM (manufactured by NOF Corporation), hydroxyl group-containing vinyl-modified hydroxyalkyl vinyl monomers; α, β-ethylene such as hydroxyalkyl esters of (meth) acrylic acid Hydroxyalkyl esters of unsaturated unsaturated carboxylic acids and vinyl compounds having a phosphate group or vinyl compounds such as (meth) acrylates containing urethane bonds or siloxane bonds; AS-macro, a macromonomer manufactured by Toa Gosei Chemical Industry Co., Ltd. 6, AN-6, AA-6, AB-
Compounds such as 6, AK-5; and other vinyl monomers such as vinyl methyl ether, vinyl chloride, vinylidene chloride, chloroprene, propylene, butadiene, N-vinyl imidazole, and vinyl sulfonic acid.

When a fluorine-containing vinyl monomer or a siloxane-containing vinyl monomer is used as the copolymerizable vinyl monomer, water repellency is improved, and water resistance and durability are improved. When a hydrophilic monomer such as a hydroxyl group-containing vinyl monomer or polypropylene glycol methacrylate or polyethylene glycol monomethacrylate is used, the stability of the emulsion is improved. In addition, a monomer having two or more polymerizable unsaturated bonds, such as polyethylene glycol dimethacrylate, ethylene glycol diacrylate, and triallyl cyanurate, is used in addition to the above, and the resulting polymer has a crosslinked structure. It is also possible to have.

The ionic or nonionic surfactant can be used without any particular limitation as long as it is used for ordinary emulsion polymerization. Examples of the ionic surfactant include, for example, sodium lauryl sulfonate,
Sulfonates such as sodium dodecylbenzenesulfonate, sodium isooctylbenzenesulfonate and sodium polyoxyethylene nonylphenyl ether sulfonate; ammonium salts such as imidaline laurate and ammonium hydroxide; examples of nonionic surfactants Typical examples thereof include polyoxyethylenes such as polyoxyethylene nonylphenyl ether and polyoxyethylene lauryl ether.

The polymer emulsion (A) used in the present invention
A method for producing a compound by an emulsion polymerization method will be described.

As the emulsion polymerization method, a batch polymerization method,
Emulsion polymerization means such as a monomer drop polymerization method and an emulsion monomer drop polymerization method can be appropriately selected. In particular, a monomer drop polymerization method and an emulsion monomer drop polymerization method are preferable from the viewpoint of securing stability during production.

Normally, during the emulsion polymerization, the silyl group undergoes a hydrolysis reaction or a condensation reaction. Therefore, it is preferable to suppress the hydrolysis reaction and the like as much as possible. 40-60 ° C
The polymerization is carried out at a temperature of
It is preferable to adjust the number to 8, and more preferably to 6 to 7.
Furthermore, when an alkali metal compound, an alkaline earth metal compound, a transition metal compound and / or an alcohol are added during or after polymerization, the hydrolyzable silyl group is stabilized.

As described above, it is preferable to use a redox catalyst for the emulsion polymerization. Examples of such a redox catalyst include potassium persulfate, a combination of ammonium persulfate and sodium acid sulfite, Rongalite, and peroxide. A combination of hydrogen and ascorbic acid, a combination of organic peroxides such as t-butyl hydroperoxide, benzoyl peroxide, cumene hydroperoxide, p-menthane hydroperoxide and sodium acid sulfite, Rongalite, etc. are used. Can be In particular, a combination of an organic peroxide and a reducing agent is preferred. Further, in order to stably obtain a catalytic activity, a compound containing a divalent iron ion such as iron sulfate and a chelating agent such as disodium ethylenediaminetetraacetate may be used in combination.

The amount of the initiator used is 0.01 to 10%, preferably 0.05 to 5%, based on the weight of the monomer.

A monomer and a solvent for emulsion polymerization of the monomer,
There is no particular limitation on the ratio of the solvent to the emulsifier, etc., but the amount of the solvent used is 50 to 300 parts per 100 parts (parts by weight, the same applies hereinafter) of the monomer, and 70 to 200 parts of the aqueous dispersion composition Of stability, viscosity, economy, etc.,
The amount of the emulsifier to be used is preferably 0.1 to 10 parts, more preferably 0.5 to 5 parts in view of polymerization stability, emulsion stability, water resistance of the coating film, weather resistance and the like.

As the solvent, water is usually used. If necessary, a solvent may be used in the polymer emulsion, for example, in an amount of about 0.1 to 15%, preferably about 0.5 to 10%. The film-forming properties of the water-dispersed composition may be improved.

Specific examples of such a solvent include, for example, a linear and / or branched alcoholic solvent having 1 to 10 carbon atoms,

[0032]

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[0033] represented by (poly) ethylene glycol monoalkyl ether (R ² is an alkyl group having straight chain and (or) branched having 1 to 10 carbon atoms, n represents an integer of 1 to 5),

[0034]

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[0035] represented by (poly) ethylene glycol ether esters (R ^2, R ³ is an alkyl group having straight chain and (or) branched having 1 to 10 carbon atoms, alkyl groups at both ends can be the same Good or different, n
Is an integer of 1 to 5),

[0036]

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(R ² is a linear and / or branched alkyl group having 1 to 10 carbon atoms, n is an integer of 1 to 5) (poly) propylene glycol monoalkyl ether,

[0038]

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(R ² and R ³ are a straight-chain and / or branched alkyl group having 1 to 10 carbon atoms, and the alkyl groups at both terminals may be the same or different. Is an integer of 1 to 5). Specifically, for example, methyl alcohol, ethyl alcohol, propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, hexyl alcohol,
Alcohols such as octyl alcohol; cellosolve,
Ethyl cellosolve, butyl cellosolve, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, propylene glycol monoethyl ether, propylene glycol monobutyl ether, propylene glycol monoisobutyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, dipropylene glycol isobutyl ether, Ethers such as tripropylene glycol monoethyl ether, tripropylene glycol monobutyl ether and tripropylene glycol monoisobutyl ether; butyl cellosolve acetate, diethylene glycol monobutyl ether acetate, dipropylene glycol monobutyl ether acetate, tripropylene glycol Over mono butyl ether acetate, glycol ether esters, such as tripropylene glycol mono isobutyl ether acetate.

These solvents may be added during the polymerization of the polymer emulsion (A) or after the polymerization.

The polymer emulsion thus obtained usually has a solid content of 20 to 70%, preferably 30 to 60%.
%, Having an average particle size of 0.02 to 0.1 μm. If the solid content exceeds 70%, the viscosity of the system will increase significantly, making it difficult to remove the heat generated by the polymerization reaction,
Inconveniences such as taking a long time to take out from the polymerization machine are likely to occur. When the solid content concentration is less than 20%, there is no problem in terms of polymerization operation, but the amount of polymer produced by one polymerization operation is small. In addition, if the concentration is less than 20% in view of application requirements, the thickness of the coating film becomes thin, resulting in deterioration in performance and disadvantageous in terms of coating workability. Further, the average particle size of the polymer emulsion is 0.
Since it is composed of ultrafine particles having a particle size of 02 to 0.1 μm, it has excellent film-forming ability even when it is made into an aqueous dispersion composition.

The obtained polymer emulsion (A)
The polymer inside usually has a molecular weight of about 50,000 to 500,000,
Therefore, the number of silyl groups represented by the general formula (I) contained in one molecule is about 2 to 1,000, and the silyl group represented by the general formula (I) is not substantially hydrolyzed.

The water-dispersed resin composition of the present invention is produced from the polymer emulsion (A) as described above and a curing catalyst (B) which is a catalyst for curing the silyl group-containing polymer in the emulsion.

Specific examples of the curing catalyst (B) include, for example, dibutyltin dilaurate, dibutyltin malate,
Organic tin compounds such as dioctyltin dilaurate, dioctyltin malate, tin octylate; phosphoric acid, monomethyl phosphate, monoethyl phosphate, monobutyl phosphate, monooctyl phosphate, monodecyl phosphate, dimethyl phosphate, diethyl phosphate, dibutyl phosphate, dioctyl phosphate ,
Phosphoric acid or phosphoric acid esters such as didecyl phosphate; propylene oxide, butylene oxide, cyclohexene oxide, glycidyl methacrylate,
Glycidol, acrylic glycidyl ether, γ-glycidoxypropyltrimethoxysilane, γ-glycidoxypropyltriethoxysilane, γ-glycidoxypropylmethyldimethoxysilane, (3,4-epoxycyclohexyl) ethyltrimethoxysilane, oil Shell Epoxy Co., Ltd. Cardura (E), Epicoat 82
8, an addition reaction product of an epoxy compound such as Epicoat 1001 with phosphoric acid and / or acidic monophosphate; an organic titanate compound; an organic aluminum compound;
Organic zirconium compounds; maleic acid, adipic acid, azelaic acid, sebacic acid, itaconic acid, citric acid, succinic acid, trimellitic acid, pyromellitic acid, their acid anhydrides, acidic compounds such as paratoluenesulfonic acid; hexylamine , Di-2-ethylhexylamine, N, N-
Amines such as dimethyldodecylamine and dodecylamine; mixtures or reactants of these amines with acidic phosphate esters; and alkaline compounds such as sodium hydroxide and potassium hydroxide.

Among these curing catalysts (B), organotin compounds, mixtures or reactants of acidic phosphate esters and amines, saturated or unsaturated polycarboxylic acids or anhydrides thereof, reactive silicon compounds, organic titanate compounds ,
An organoaluminum compound or a mixture thereof is preferred because of its high activity. More preferred are organotin compounds, acidic phosphates, and mixtures or reactants of acidic phosphates and amines.

These curing catalysts (B) may be used alone or in combination of two or more.

The amount of the curing catalyst (B) used is not particularly limited, but is based on 100 parts of the solid content of the polymer emulsion.
It is usually 0.01 to 20 parts, preferably 0.1 to 10 parts. If the amount used exceeds 20 parts, the appearance of the coating film tends to decrease.

Additive (C) is added to the obtained water-dispersed composition.
If necessary, pigments (white pigments such as titanium dioxide, calcium carbonate, barium carbonate, and kaolin, and colored pigments such as carbon, red iron, and cyanine blue) commonly used in paints, plasticizers, solvents, dispersants, You may mix and use the additive used as a normal coating composition, such as a thickener, a defoamer, a preservative, and an ultraviolet absorber.

It is also possible to blend with commercially available water-based paints, such as acrylic paints, thermosetting acrylic paints such as acrylic melamine paints, alkyd paints, epoxy paints and the like. Is raised. Blending can improve the weather resistance, acid resistance, solvent resistance, and the like of these paints.

It is also possible to add a melamine resin and an isocyanate compound as a cross-linking agent to make the composition quick-curing.

The composition of the present invention may be cured at room temperature or may be cured by heating at 60 to 200 ° C.

Next, the composition of the present invention will be described based on examples.

Production Examples 1 to 4 (Synthesis of Polymer Emulsion) 120 parts of deionized water and sodium dodecylbenzenesulfonate were placed in a reaction vessel equipped with a stirrer, thermometer, reflux condenser, nitrogen gas introduction pipe and dropping funnel. 2 parts were charged, and 0.5 parts of Rongalite as a polymerization catalyst, 0.04 part of iron (II) sulfate,
Add 0.05 parts of disodium ethylenediaminetetraacetate,
After the temperature was raised to 60 ° C. while introducing nitrogen gas, a mixture having a composition shown in Table 1 was dropped at a constant rate over 3 hours using a dropping funnel. At this time, the pH of the polymerization reaction solution was maintained at 7 by adding a 5% aqueous ammonia solution. After completion of dropping of the mixture, the mixture was aged at 60 ° C. for 2 hours, cooled, and adjusted to a solid concentration of 40% by adding deionized water to the aqueous dispersion.

[0054]

[Table 1]

Examples 1 and 2 and Comparative Examples 1 and 2 100 parts of the polymer emulsion obtained in Production Examples 1 to 4
One part of dibutyltin malate was added as a curing catalyst, and the mixture was coated on a slate plate and a sheet coated with an epoxy primer so as to have a thickness of 50 μm, and dried at room temperature for 2 weeks. Table 2 shows the results of the curability and the water resistance test of the obtained coating film and the results of the storage stability test of the emulsion (aqueous dispersion type composition).

[0056]

[Table 2]

[0057]

The water-dispersible composition of the present invention comprises a polymer emulsion obtained by emulsion polymerization of a vinyl-containing monomer having a silyl group represented by the general formula (I) and a curing catalyst. The composition has cross-linking reactivity and is excellent in storage stability. Moreover, the curability is excellent, and the cured product is excellent in water resistance, and the performance is greatly improved as compared with the conventional water-based paint.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) C08L 43/04 C08F 2/22

Claims (3)

(57) [Claims] (A) General formula (I): (In the formula, n is 6 to 15, R ¹ is a monovalent hydrocarbon group selected from an alkyl group, an aryl group, and an aralkyl group having 1 to 10 carbon atoms, a is an integer of 0 to 2, and is bonded to Si. When R ¹ is two or more, they may be the same or different groups), and are obtained by emulsion polymerization of a vinyl-containing monomer having a silyl group represented by the following formula: An aqueous dispersion composition comprising a polymer emulsion and (B) a curing catalyst. 2. The emulsion according to claim 1, wherein the emulsion comprises at least one vinyl monomer having a silyl group represented by the general formula (I) and at least one vinyl monomer copolymerizable therewith. 2. The aqueous dispersion composition according to claim 1, which is an emulsion obtained by emulsion polymerization of the monomer in an aqueous medium. 3. The emulsion according to claim 1, wherein said emulsion has a pH during polymerization of a vinyl monomer having a silyl group represented by the general formula (I).
2. The aqueous dispersion composition according to claim 1, which is an emulsion obtained by adjusting the pH of the emulsion to 5 to 8.