WO2020085263A1

WO2020085263A1 - Aqueous dispersion, production method for aqueous dispersion, and use for aqueous dispersion

Info

Publication number: WO2020085263A1
Application number: PCT/JP2019/041211
Authority: WO
Inventors: 匠伊藤; 白石　諭勲; 芳峰坂元; 謙太下道
Original assignee: 株式会社日本触媒
Priority date: 2018-10-22
Filing date: 2019-10-18
Publication date: 2020-04-30
Also published as: JPWO2020085263A1; JP7204773B2

Abstract

Provided are: an aqueous dispersion that demonstrates excellent adhesion to polyolefin substrates; and a production method for the aqueous dispersion. An aqueous dispersion that includes: a graft copolymer that is formed by graft polymerizing an acrylic polymer that includes a structural unit that is derived from a surfactant that has a polymerizable group onto a non-chlorinated polyolefin that has a carboxyl group; and an aqueous medium. Relative to the graft copolymer, the aqueous medium includes 1–10 mass% of the structural unit that is derived from a surfactant that has a polymerizable group.

Description

Aqueous dispersion, method for producing the same, and use thereof

The present invention relates to an aqueous dispersion, a method for producing the same, and its use.

Molded products of polyolefins such as polyethylene and polypropylene are used for parts such as vehicle bumpers, vehicle moldings, and home electric appliances. The surface is coated with a top coat paint, and in the coating, a primer is previously coated in order to improve the adhesion between the top coat film and the molded product. As such a primer, conventionally, a solvent-based primer containing a chlorinated polyolefin has been used, but in recent years, an aqueous paint that does not use an organic solvent and halogen has been developed in consideration of the environment (for example, Patent Document 1). 1-3).

Published Japanese patent application "JP-A-2011-46777" Japanese Patent Laid-Open Publication "Japanese Patent Application Laid-Open No. 2004-91559" Japanese Patent Laid-Open Publication "JP-A-2015-214600"

However, the above-mentioned conventional water-based paints that do not use organic solvents and halogens have not been sufficient in terms of adhesion to polyolefin substrates.

An aspect of the present invention is to provide an aqueous dispersion having excellent adhesion to a polyolefin substrate, and a method for producing the same.

The present inventors have conducted extensive studies to solve the above-mentioned problems, and as a result, a graft copolymer of an acrylic polymer containing a structural unit derived from a surfactant having a polymerizable group is attached to a non-chlorinated polyolefin having a carboxyl group. It was found that an aqueous dispersion having excellent adhesion to a polyolefin substrate can be realized by using a copolymer obtained by polymerization, and the present invention has been completed.

That is, the aqueous dispersion according to one embodiment of the present invention is obtained by graft-copolymerizing an acrylic polymer containing a structural unit derived from a surfactant having a polymerizable group onto a non-chlorinated polyolefin having a carboxyl group. The constitutional unit derived from the surfactant containing the graft copolymer and the aqueous medium and having the polymerizable group is contained in an amount of 2% by mass to 10% by mass with respect to the graft copolymer.

Further, the method for producing an aqueous dispersion according to one embodiment of the present invention is a graft copolymer of a non-chlorinated polyolefin having a carboxyl group with an acrylic polymer containing a constitutional unit derived from a surfactant having a polymerizable group. In the method for producing an aqueous dispersion, the constitutional unit derived from the surfactant having a polymerizable group and containing the graft copolymer obtained by the above is contained in an amount of 2% by mass to 10% by mass with respect to the graft copolymer. There is a step of emulsion-polymerizing an acrylic monomer in the presence of a polyolefin aqueous dispersion containing a non-chlorinated polyolefin having a carboxyl group, an aqueous medium, and a surfactant having a polymerizable group. Including.

According to one aspect of the present invention, an aqueous dispersion having excellent adhesion to a polyolefin substrate can be realized.

An embodiment of the present invention will be described below, but the present invention is not limited to this. The present invention is not limited to the respective configurations described below, and various modifications can be made within the scope shown in the claims, and the technical means disclosed in different embodiments or examples can be applied. Embodiments and examples obtained by appropriately combining them are also included in the technical scope of the present invention. Unless otherwise specified in this specification, “A to B” representing a numerical range means “A or more and B or less”.

[1. Aqueous dispersion)
The aqueous dispersion according to one embodiment of the present invention is a graft copolymer obtained by graft-copolymerizing an acrylic polymer containing a structural unit derived from a surfactant having a polymerizable group onto a non-chlorinated polyolefin having a carboxyl group. It includes a polymer and an aqueous medium.

[1.1 Non-chlorinated polyolefin having a carboxyl group]
The aqueous dispersion according to one embodiment of the present invention contains a copolymer obtained by graft-copolymerizing a non-chlorinated polyolefin having a carboxyl group with an acrylic polymer described below. Here, the non-chlorinated polyolefin having a carboxyl group may be a non-chlorinated polyolefin as long as it has a carboxyl group bonded thereto. Examples of the non-chlorinated polyolefin having a carboxyl group include acid-modified non-chlorinated polyolefin. The acid-modified non-chlorinated polyolefin is at least one selected from the group consisting of unsaturated carboxylic acids, acid anhydrides of unsaturated carboxylic acids, and derivatives of unsaturated carboxylic acids (hereinafter, in the present specification. It may be referred to as “unsaturated carboxylic acid etc.”), and non-chlorinated polyolefin acid-modified with (for example, unsaturated carboxylic acid is graft-copolymerized with unchlorinated polyolefin). The following copolymers can be used.

The above-mentioned polyolefin is not particularly limited as long as it is obtained by polymerizing an olefin compound. Examples of the olefin compound include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, 1-octene, 1-nonene, 4-methyl-1-pentene and the like. The polyolefin may be a homopolymer obtained by polymerizing one of these olefin compounds, or a copolymer obtained by copolymerizing two or more of these olefin compounds. Among them, the copolymer is More preferable. When the polyolefin is a copolymer, it may be a random copolymer, a block copolymer, or a graft copolymer. Above all, the olefin compound is more preferably ethylene or propylene.

More preferably, the polyolefin is polyethylene, polypropylene, or a propylene-α-olefin copolymer. Examples of the polyolefin include homopolymers such as polyethylene and polypropylene, and poly α-olefin copolymers obtained by copolymerizing a monomer containing α-olefin. As the poly α-olefin, for example, a propylene-α-olefin copolymer is more preferable. Here, the propylene-α-olefin copolymer is obtained by copolymerizing α-olefin with propylene as a main component. As the α-olefin, for example, ethylene, 1-butene, 1-heptene, 1-octene, 4-methyl-1-pentene and the like can be used alone or in combination of two or more. Of these, 1-butene is more preferable. Further, as the polyolefin, those containing propylene as a constitutional unit are preferable from the viewpoint of the adhesiveness of the formed coating film, and in this case, the content of the propylene unit in the polyolefin is the adhesiveness of the formed coating film or the like. From this viewpoint, it is preferably 50% by mass to 100% by mass, more preferably 70% by mass to 99% by mass.

More specific examples of the polyolefin include, for example, HARDREN (registered trademark) NZ-1004, NZ-1015 (manufactured by Toyobo Co., Ltd.); Arrow Base (registered trademark) DA, TD, SB, TC, SE, and YA. , DB and the like, or Arrowbase (registered trademark) SB-1200, SE-1200, SD-1200, DA-1010, DB-4010 and the like (manufactured by Unitika Ltd.).

The method for producing the polyolefin is not particularly limited, but for example, polyolefin polymerized by using a metallocene catalyst has uniform crystallinity and excellent solubility in a solvent, which is preferable. The melting point Tm of the polyolefin is 60 to 125 ° C., preferably 60 to 100 ° C., and more preferably 60 to 90 ° C. from the viewpoint of improving the adhesion of the formed coating film.

Examples of the unsaturated carboxylic acid include acrylic acid, methacrylic acid, maleic acid, fumaric acid, citraconic acid, mesaconic acid, itaconic acid, aconitic acid, and crotonic acid. Examples of the acid anhydride of the unsaturated carboxylic acid include maleic anhydride and itaconic anhydride. Examples of the acid anhydride derivatives of unsaturated carboxylic acids include half esters and half amides of unsaturated carboxylic acids. Among the unsaturated carboxylic acids and the like, it is more preferable to use acrylic acid, methacrylic acid, maleic acid, maleic anhydride, and itaconic acid.

The amount of graft polymerization with the unsaturated carboxylic acid or the like can be appropriately changed according to the physical properties desired for the formed coating film, but is preferably 0.1 based on the solid mass of the polyolefin having a carboxyl group. It is from 10% by mass to 10% by mass, more preferably from 1% by mass to 5% by mass. In order that the polyolefin can be stably dispersed in water, the amount of graft polymerization with a saturated carboxylic acid or the like, in other words, the content of the unsaturated carboxylic acid or the like is preferably 0.1% by mass or more and 10% by mass or less.

Examples of the method for graft-copolymerizing the unsaturated carboxylic acid or the like on the polyolefin include known methods such as a solution method and a melting method.

The solution method is, for example, as follows. That is, after dissolving at least one kind of the polyolefin in an aromatic organic solvent such as toluene at 100 to 180 ° C., at least one kind selected from the unsaturated carboxylic acid and the like is added, and a radical generator is further added. Add all at once or in divided portions to react.

The melting method is, for example, as follows. That is, at least one kind of the polyolefin is heated and melted to a temperature equal to or higher than the melting point, and then at least one kind selected from the unsaturated carboxylic acid and the like is added and reacted with a radical generator.

Examples of the radical generator include benzoyl peroxide, dicumyl peroxide, di-t-butyl peroxide and the like, which can be selected depending on the reaction temperature and the decomposition temperature.

The weight average molecular weight of the non-chlorinated polyolefin having a carboxyl group is preferably 5,000 to 200,000, more preferably 30,000 to 120,000. When the weight average molecular weight is 5000 or more, the final aqueous dispersion is excellent in adhesiveness, which is preferable. When the weight average molecular weight is 200,000 or less, dispersion in water is favorably performed, which is preferable. Here, in the present specification, the weight average molecular weight is a polystyrene-equivalent molecular weight measured by gel permeation chromatography (GPC).

The non-chlorinated polyolefin having a carboxyl group may be used alone or in combination of two or more.

In an embodiment of the present invention, the non-chlorinated polyolefin having a carboxyl group may be graft-copolymerized with an acrylic polymer described below in the form of a polyolefin aqueous dispersion prepared by dispersing it in an aqueous medium. The polyolefin aqueous dispersion contains a non-chlorinated polyolefin having a carboxyl group and an aqueous medium. The polyolefin aqueous dispersion may contain a polyolefin other than the non-chlorinated polyolefin having a carboxyl group. Here, water is usually used as the aqueous medium in the present specification, but a hydrophilic organic solvent such as a lower alcohol such as methanol or ethanol may be used in combination, if necessary.

The content of the non-chlorinated polyolefin having a carboxyl group in the polyolefin aqueous dispersion may be appropriately adjusted depending on the finally obtained aqueous dispersion and the primer composition. On the other hand, it is 10% by mass to 50% by mass, preferably 15% by mass to 45% by mass, and more preferably 20% by mass to 40% by mass.

As the polyolefin aqueous dispersion, the reaction liquid obtained in the step of graft-copolymerizing the unsaturated carboxylic acid or the like with the polyolefin may be used as it is.

[1.2 Graft copolymer]
An aqueous dispersion according to an embodiment of the present invention is obtained by graft-copolymerizing an acrylic polymer containing a constitutional unit derived from a surfactant having a polymerizable group with the above-mentioned non-chlorinated polyolefin having a carboxyl group. Including a graft copolymer.

As the acrylic polymer, for example, an acrylic polymer containing a structural unit derived from a (meth) acrylic acid ester and a structural unit derived from a surfactant having a polymerizable group can be preferably used. In addition, in this specification, "(meth) acrylic" means "methacrylic" and "acrylic."

Preferable examples of the (meth) acrylic acid ester used as an acrylic monomer include, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-butyl (meth) acrylate. , Isobutyl (meth) acrylate, t-butyl (meth) acrylate, n-pentyl (meth) acrylate, n-hexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, tridecyl (meth) acrylate, n-octyl (meth ) Alkyl (meth) acrylates such as acrylates and n-lauryl (meth) acrylates; (meth) acrylates having a cycloalkyl group having 6 or more carbon atoms in the side chain such as cyclohexyl (meth) acrylate; benzyl (meth) acrylates; 2 -(Ace Acetoxy) ethyl (meth) acrylate; 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 4-hydroxybutyl (meth ) Hydroxyalkyl (meth) acrylates such as acrylates; having oxo groups such as ethylene glycol (meth) acrylate, ethylene glycol methoxy (meth) acrylate, diethylene glycol (meth) acrylate, and diethylene glycol methoxy (meth) acrylate ( (Meth) acrylic acid ester; (meth) acrylic acid ester having a polyoxyalkylene group and the like can be mentioned. These may be used alone or in combination of two or more. Among them, the (meth) acrylic acid ester is an alkyl (meth) acrylate whose alkyl group has 1 to 12 carbon atoms, from the viewpoint of the adhesion of the finally obtained aqueous dispersion to the polyolefin substrate. Is more preferable. From the same viewpoint, among alkyl (meth) acrylates having an alkyl group having 1 to 12 carbon atoms, methyl (meth) acrylate, cyclohexyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and butyl (meth) acrylate are also included. ) More preferably at least one selected from acrylates, and particularly preferably at least cyclohexyl (meth) acrylate is included.

“Acrylic polymer” refers to a polymer containing a structural unit derived from a (meth) acrylic acid ester, and a structure derived from a (meth) acrylic acid ester with respect to all the structural units derived from a monomer constituting the polymer. A polymer containing 20% by mass to 99% by mass of a unit. Among them, the structural unit derived from a (meth) acrylic acid ester is a structural unit derived from an alkyl (meth) acrylate in which the alkyl group has 1 to 12 carbon atoms, more preferably 1 to 8 and even more preferably 1 to 6 carbon atoms. It is more preferable to contain one or more kinds, and the number of carbon atoms of the alkyl group is 1 to 12, more preferably 1 to 8, and still more preferably 1 to 6 with respect to the total constitutional units derived from the monomers constituting the acrylic resin. The total amount of structural units derived from a certain alkyl (meth) acrylate is preferably 20% by mass or more, more preferably 50% by mass or more, further preferably 70% by mass, further preferably 90% by mass. Is particularly preferred. Further, among them, a copolymer containing a constitutional unit derived from 2-ethylhexyl (meth) acrylate and / or a constitutional unit derived from cyclohexyl (meth) acrylate is preferable, and a copolymer derived from a monomer constituting the acrylic copolymer is preferable. The total of structural units derived from these monomers is preferably contained in an amount of 20% by mass or more, more preferably 50% by mass or more, and further preferably 70% by mass or more, based on the entire structural units. , 90 mass% or more is particularly preferable.

The surfactant having a polymerizable group means a surfactant having an unsaturated double bond and capable of polymerizing with another monomer. More specifically, for example, a surfactant having a radically polymerizable double bond such as a vinyl group, a (meth) acryloyl group, an allyl group or a propenyl group in the molecule and functioning as an emulsifier is preferably used. be able to. If such a surfactant is used as an emulsifier during the production of the acrylic polymer, the emulsifier itself is incorporated into the acrylic polymer as a constituent unit of the acrylic polymer. Therefore, elution with time due to contact with water etc. after forming the coating film of the finally obtained aqueous dispersion is suppressed, and the water resistance of the coating film is improved as compared with the case of using an emulsifier having no polymerizable group. To do.

Examples of the surfactant having a polymerizable group include bis (polyoxyethylene polycyclic phenyl ether) methacrylated sulfonate salt (eg, Anox (registered trademark) MS-60 manufactured by Nippon Emulsifier Co., Ltd.), propenyl- Alkyl sulfosuccinate ester salt, (meth) acrylic acid polyoxyethylene sulfonate salt, (meth) acrylic acid polyoxyethylene phosphonate salt (for example, Sanyo Chemical Industry Co., Ltd., Eleminol (registered trademark) RS-30) , Polyoxyethylene alkylpropenyl phenyl ether sulfonate salt (for example, AQUALON (registered trademark) HS-10 manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), sulfonate salt of allyloxymethylalkyloxypolyoxyethylene (for example, Dai-ichi Kogyo) AQUARON (registered trademark) manufactured by Pharmaceutical Company H-10, etc.), a sulfonate salt of allyloxymethylnonylphenoxyethylhydroxypolyoxyethylene (for example, ADEKA CORPORATION, ADEKA REASOAP (registered trademark) SE-10, etc.), allyloxymethylalkoxyethylhydroxypolyoxyethylene sulfate. Ester salts (for example, ADEKA CORPORATION, ADEKA REASOAP (registered trademark) SR-10, SR-30, etc.), allyloxymethylalkoxyethyl hydroxypolyoxyethylene (for example, ADEKA CORPORATION, ADEKA rear soap (registered trademark) ) ER-20, etc.), polyoxyethylene alkylpropenyl phenyl ether (for example, Aqualon (registered trademark) RN-20, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.), allyloxymethylnonylphenoxyethyl hydroxypolyoxyethylene For example, ADEKA Co., Ltd., ADEKA RIASOAP (registered trademark) NE-10, etc.), polyoxyethylene styrenated propenyl phenyl ether sulfate ammonium salt (for example, manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd., Aqualon (registered trademark) AR-10 , AR-20, AR-30, etc.), polyoxyethylene styrenated propenyl phenyl ether (for example, Aqualon (registered trademark) AN-10, AN-20, AN-30, AN-5065, etc., manufactured by Dai-ichi Kogyo Seiyaku Co., Ltd.) ) And the like. These may be used alone or in combination of two or more. Particularly, when importance is attached to the environment, it is more preferable to use a non-nonylphenyl type surfactant.

The surfactant-derived constitutional unit having a polymerizable group is a non-chlorinated polyolefin having a carboxyl group, by graft copolymerizing an acrylic polymer containing a surfactant-derived constitutional unit having a polymerizable group. The content of the graft copolymer is preferably 2.0% by mass to 10% by mass, more preferably 2.5% by mass to 8.0% by mass, and further preferably 3.0% by mass to 7. It is more preferable that the content is 0% by mass. When the constituent unit derived from the surfactant is contained in an amount of 2.0% by mass or more, the polymerization stability is good. Therefore, the adhesion of the finally obtained aqueous dispersion can be improved. Further, when the constituent unit derived from the surfactant is 10% by mass or less, it is difficult to reduce the water resistance of the coating film formed using the finally obtained aqueous dispersion, which is preferable.

In addition, the structural unit derived from the surfactant having a polymerizable group may be contained in an amount of 2.0% by mass to 20% by mass based on the total structural units derived from the monomers constituting the acrylic polymer. It is more preferable that the content is 2.0% by mass to 10% by mass. When the constituent unit derived from the surfactant is contained in an amount of 2.0% by mass or more, the polymerization stability is good. Therefore, the adhesion of the finally obtained aqueous dispersion can be improved. Further, if the structural unit derived from the surfactant is 20% by mass or less, it is difficult to reduce the water resistance of the coating film formed using the finally obtained aqueous dispersion, which is preferable.

Moreover, in one embodiment of the present invention, the acrylic polymer may further include a structural unit derived from an unsaturated carboxylic acid. By further including a structural unit derived from an unsaturated carboxylic acid, the interaction between acrylic polymers can be enhanced. Therefore, it is possible to impart cohesive force to the coating film formed from the finally obtained aqueous dispersion, thereby improving the adhesiveness and the adhesiveness. Examples of the unsaturated carboxylic acid used as a monomer include (meth) acrylic acid, itaconic acid, crotonic acid, maleic anhydride, maleic acid, fumaric acid, citraconic acid, 2-acryloyloxyethylsuccinic acid, Examples thereof include 2-acryloyloxyethyl phthalic acid, 2-acryloyloxyethyl hexahydrophthalic acid, maleic acid monomethyl ester, maleic acid monobutyl ester, itaconic acid monomethyl ester, itaconic acid monobutyl ester, vinyl benzoic acid and the like. More preferably, the unsaturated carboxylic acid is (meth) acrylic acid.

In one embodiment of the present invention, the structural unit derived from the unsaturated carboxylic acid is 0.4% by mass to 8.0% by mass based on the total structural units derived from the monomers constituting the acrylic polymer. The content is more preferably contained, further preferably 0.6 mass% to 7.0 mass%, further preferably 1.0 mass% to 6.0 mass%. When the content of the structural unit derived from the unsaturated carboxylic acid is 0.4% by mass or more, the adhesiveness and the adhesiveness are improved, which is preferable. Further, it is preferable that the constitutional unit derived from the unsaturated carboxylic acid is 8.0% by mass or less because the water resistance is improved.

In one embodiment of the present invention, the acrylic polymer preferably contains a constitutional unit derived from a nitrogen atom-containing monomer. Examples of the nitrogen atom-containing monomer include 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine , 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine, 4- (meth) acryloyl-1-methoxy-2,2,6,6-tetramethylpiperidine, 4-cyano- Piperidine groups such as 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine, 1- (meth) acryloyl-4- (meth) acryloylamino-2,2,6,6-tetramethylpiperidine Monomers included: (meth) acrylamide, diacetone (meth) acrylamide, N-monomethyl (meth) acrylamide, N-monoethyl (meth) a Rylamide, N, N-dimethyl (meth) acrylamide, Nn-propyl (meth) acrylamide, N-isopropyl (meth) acrylamide, methylenebis (meth) acrylamide, N-methylol (meth) acrylamide, N-butoxymethyl (meth ) (Meth) acrylamide compounds such as acrylamide, dimethylaminoethyl (meth) acrylamide, N, N-dimethylaminopropyl (meth) acrylamide, diacetone (meth) acrylamide; dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate And nitrogen atom-containing (meth) acrylate compounds; N-vinylpyrrolidone; (meth) acrylonitrile and the like. These nitrogen atom-containing monomers may be used alone or in combination of two or more.

Among these nitrogen atom-containing monomers, a (meth) acrylamide compound, (meth) acrylonitrile, and a piperidine group-containing monomer are preferable from the viewpoint of forming a coating film having excellent cohesive force, and (meth) acrylamide, Acrylonitrile, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine (LA-87), and 4- (meth) acryloyloxy-1,2,2,6,6-pentamethylpiperidine ( LA-82) is more preferable, and acrylamide, acrylonitrile, 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine (LA-87), and 4- (meth) acryloyloxy-1,2, 2,6,6-Pentamethylpiperidine (LA-82) is more preferred.

The constituent unit derived from the nitrogen atom-containing monomer is more preferably contained in an amount of 0.1% by mass to 20% by mass, based on the total constituent units derived from the monomer forming the acrylic polymer. It is more preferable that the content is 0.1% by mass to 15% by mass, and particularly preferably 0.1% by mass to 10% by mass. When the constituent unit derived from the nitrogen atom-containing monomer is contained in an amount of 0.1% by mass to 20% by mass, a coating film having excellent cohesive force can be formed, which is preferable.

In one embodiment of the present invention, it is preferable that the acrylic polymer contains a structural unit derived from a hydroxyl group-containing monomer from the viewpoint of improving peel strength and adhesion. Examples of the hydroxyl group-containing monomer include 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 3-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, and 4-hydroxy. Examples thereof include hydroxyalkyl (meth) acrylates such as butyl (meth) acrylate. These hydroxyl group-containing monomers may be used alone or in combination of two or more.

It is more preferable that the structural unit derived from the hydroxyl group-containing monomer is contained in an amount of 0.1% by mass to 20% by mass, based on the total structural units derived from the monomers constituting the acrylic polymer. It is more preferable that the content is 0.1% by mass to 15% by mass, and particularly preferably 0.1% by mass to 10% by mass. It is preferable that the structural unit derived from the hydroxyl group-containing monomer is contained in an amount of 0.1% by mass to 20% by mass, because a coating film excellent in peel strength and improvement in adhesion can be formed.

In one embodiment of the present invention, the acrylic polymer preferably contains a structural unit derived from an alkoxyalkyl group-containing monomer from the viewpoint of improving peel strength and adhesiveness. Examples of the alkoxyalkyl group-containing monomer include alkoxyalkyl (meth) acrylates such as methoxyethyl (meth) acrylate, methoxybutyl (meth) acrylate, ethoxybutyl (meth) acrylate, and trimethylolpropane tripropoxy (meth) acrylate. And the like. These alkoxyalkyl group-containing monomers may be used alone or in combination of two or more.

It is more preferable that the structural unit derived from the alkoxyalkyl group-containing monomer is contained in an amount of 0.1% by mass to 20% by mass based on the total structural units derived from the monomer forming the acrylic polymer, The content is more preferably 0.1 to 15% by mass, and particularly preferably 0.1 to 10% by mass. It is preferable that the constituent unit derived from the alkoxyalkyl group-containing monomer is contained in an amount of 0.1% by mass to 20% by mass, because a coating film excellent in peel strength and adhesion can be formed.

In one embodiment of the present invention, the acrylic polymer may react with a cross-linking agent and / or a polyfunctional compound having a reactive functional group β described below to form a cross-linked structure between particles of the aqueous dispersion. It is preferable to contain the functional group α. Examples of the reactive functional group α include alkoxycarbonyl group, cyclocarbonate group, epoxy group, isocyanate group, blocked isocyanate group, oxazoline group, oxazolidine group, acetoacetoxy group, hydrazino group, carbonyl group, and carboxyl group. However, the present invention is not limited to such examples. These reactive functional groups may be used alone or in combination of two or more kinds. Among these reactive functional groups, an epoxy group, an isocyanate group, an oxazoline group, a hydrazino group, a carbonyl group and a carboxyl group are preferable, an oxazoline group, a hydrazino group and a carbonyl group are more preferable, and a carbonyl group is further preferable. The acrylic polymer containing the reactive functional group α can be obtained, for example, by copolymerizing a monomer containing the reactive functional group α as a monomer.

In one embodiment of the present invention, the monomer having a carbonyl group as the reactive functional group α is a monomer having a group represented by the formula: ═C═O, and the carbonyl group has 2 A monomer having a hydrogen atom or an alkyl group bonded to one of the two bonds and a group having a polymerizable unsaturated double bond at the end such as a vinyl group bonded to the other bond. means.

Examples of the carbonyl group-containing monomer (hereinafter, may be referred to as "carbonyl group-containing monomer") include, for example, acrylolein, methacrolein, formyl styrene, vinyl ethyl ketone, acryloxyalkylpropenal, Methacryloxyalkyl propenal, acetonyl acrylate, acetonyl methacrylate, diacetone acrylate, diacetone methacrylate, diacetone acrylamide, diacetone methacrylamide, 2-hydroxypropyl acrylate acetyl acetate, 2-hydroxypropyl methacrylate acetyl acetate, butanediol- 1,4-acrylate acetyl acetate, 2- (acetoacetoxy) ethyl acrylate, 2- (acetoacetoxy) ethyl methacrylate And the like can be given. These carbonyl group-containing monomers may be used alone or in combination of two or more.

Among the carbonyl group-containing monomers, from the viewpoint of forming a coating film having comprehensively excellent water whitening resistance, water crack resistance, water deformation resistance, weather resistance and long-term hydrophilicity, (meth) acryloline, formyl Styrole, vinyl ethyl ketone, (meth) acryloxyalkyl propenal, acetonyl (meth) acrylate, diacetone (meth) acrylate, and diacetone (meth) acrylamide are preferable, and (meth) acrylorain, formyl styrene, acetonyl (meth) ) Acrylate, diacetone (meth) acrylate, and diacetone (meth) acrylamide are more preferable, (meth) acryloline, acetonyl (meth) acrylate, diacetone (meth) acrylate, and diacetone (meth) acrylamide. More preferably, diacetone (meth) acrylate, and diacetone (meth) acrylamide is even more preferred.

The constitutional unit derived from the monomer containing the reactive functional group α is contained in an amount of 0.1% by mass to 20% by mass based on the entire constitutional unit derived from the monomer forming the acrylic polymer. Is more preferable, 0.1 mass% to 15 mass% is more preferable, and 0.1 mass% to 10 mass% is particularly preferable. For example, when the structural unit derived from the carbonyl group-containing monomer is contained in an amount of 0.1% by mass to 20% by mass, the water whitening resistance, the water crack resistance, the water deformation resistance, the weather resistance and the long-term hydrophilicity are comprehensively obtained. It is preferable because an excellent coating film can be formed.

In one embodiment of the present invention, the acrylic polymer preferably contains a structural unit derived from a silane group-containing monomer.

Examples of the silane group-containing monomer include vinyltrimethoxysilane, vinyltriethoxysilane, vinyltri (methoxyethoxy) silane, γ- (meth) acryloyloxypropyltrimethoxysilane, 2-styrylethyltrimethoxysilane, and vinyl. Examples thereof include trichlorosilane, γ- (meth) acryloyloxypropylhydroxysilane, and γ- (meth) acryloyloxypropylmethylhydroxysilane. These silane group-containing monomers may be used alone or in combination of two or more. Among these silane group-containing monomers, γ- (meth) acryloyloxypropyltrimethoxysilane is preferable from the viewpoint of forming a coating film excellent in water resistance, blister resistance and adhesion to a substrate. -Methacryloyloxypropyltrimethoxysilane is more preferred.

The constituent unit derived from the silane group-containing monomer is preferably contained in an amount of 0.01% by mass to 10% by mass, based on the total constituent units derived from the monomer constituting the acrylic polymer. The content is more preferably 0.05 to 10% by mass, and particularly preferably 0.1 to 10% by mass. When the constituent unit derived from the silane group-containing monomer is contained in an amount of 0.01% by mass to 10% by mass, it is possible to form a coating film excellent in water resistance, blister resistance and adhesion to a substrate. preferable.

The acrylic polymer is a structural unit derived from the aforementioned (meth) acrylic acid ester, a structural unit derived from a surfactant having a polymerizable group, and, if necessary, a structural unit derived from an unsaturated carboxylic acid, a nitrogen atom. Constitutional unit derived from the containing monomer, constitutional unit derived from the monomer containing the hydroxyl group, constitutional unit derived from the monomer containing the reactive functional group α, and / or constitution derived from the silane group-containing monomer In addition to the units, structural units derived from other monomers may be contained within a range that does not adversely affect the effects of the present invention. Examples of the other monomer include styrene. The constituent unit derived from the other monomer may be contained in the range of 0 to 20 mass% with respect to the entire constituent unit derived from the monomer constituting the acrylic polymer.

Further, the glass transition temperature Tg of the acrylic polymer when it is assumed that the acrylic polymer is not graft-copolymerized with the non-chlorinated polyolefin having a carboxyl group and exists as an acrylic polymer (hereinafter, simply referred to as “ Tg "may be referred to as" Tg ") is 0 ° C to 60 ° C, preferably 10 ° C to 40 ° C. Here, Tg can be calculated by the following method.

The glass transition temperature Tg of the acrylic polymer can be obtained from the calculated Tg (K) calculated from the following Fox equation.
1 / Tg = Σ (Wn / Tgn) / 100
Here, Wn represents the content rate (mass%) of the monomer n, and Tgn represents the Tg (K: absolute temperature) of the homopolymer composed of the monomer n.

It is preferable that the acrylic polymer has a Tg of 0 ° C. or higher because the adhesion of the formed coating film is improved. Further, when the temperature is 60 ° C. or lower, the low temperature film-forming property is good, which is preferable. Here, the low-temperature film-forming property means that a film can be formed without cracks and cracks in the coating film even when the coating material is applied at a temperature of room temperature (23 ° C.) or lower. The low-temperature film-forming property can be determined by measuring the minimum film-forming temperature (MFT) by a thermal gradient tester described later, and a coating film in which cracks do not occur even when MFT is 0 ° C. has good low-temperature film-forming property. An aqueous dispersion of a graft copolymer according to an embodiment of the present invention is a copolymer obtained by grafting an acrylic polymer having a Tg of 0 ° C or higher onto a non-chlorinated polyolefin having a carboxyl group having a melting point Tm of 60 ° C or higher. Despite being a polymer, it has good low-temperature film-forming properties. Further, if the Tg of the acrylic polymer is 10 ° C. or higher, it is more preferable from the viewpoint of improving the peel strength of the formed coating film.

In one embodiment of the present invention, a graft copolymer is produced by graft-copolymerizing an acrylic polymer having a constitutional unit derived from a surfactant having a polymerizable group with a non-chlorinated polyolefin having a carboxyl group. The method for, but not limited to, a non-chlorinated polyolefin having a carboxyl group, an aqueous medium, a polyolefin aqueous dispersion containing, in the presence of a surfactant having a polymerizable group. A method of emulsion polymerizing an acrylic monomer can be mentioned. Here, the acrylic monomer means the (meth) acrylic acid ester described above, and optionally the unsaturated carboxylic acid, the nitrogen atom-containing monomer, the hydroxyl group-containing monomer, and the reaction. It is intended to include a monomer containing a functional group α, a silane group-containing monomer, and / or another monomer. For example, the (meth) acrylic acid ester, and optionally the unsaturated carboxylic acid, the nitrogen atom-containing monomer, the hydroxyl group-containing monomer, and the monomer containing the reactive functional group α. , A silane group-containing monomer, and / or another monomer as a monomer, in the presence of the polyolefin aqueous dispersion and the polymerizable group-containing surfactant functioning as an emulsifier. The method of carrying out emulsion polymerization can be preferably used. By emulsion polymerization, an aqueous dispersion of the graft copolymer (also referred to as an aqueous dispersion of graft copolymer particles or a graft copolymer emulsion) is produced.

The emulsion polymerization carried out here is not particularly limited, and it can be carried out by using a conventionally known method such as a multistage feed method or a power feed method. Specifically, the following methods (1) and (2) can be used. At this time, the above-mentioned surfactant having a polymerizable group is used as an emulsifier.

(1) The polyolefin aqueous dispersion and an emulsifier are dissolved in an aqueous medium, and the mixture is heated and stirred with the (meth) acrylic acid ester, and if necessary, the unsaturated carboxylic acid and the nitrogen atom-containing monomer. A method of dropping the polymerization initiator with the hydroxyl group-containing monomer, the reactive functional group α-containing monomer, the silane group-containing monomer, and / or another monomer.

(2) Non-chlorinated polyolefin having a carboxyl group, the (meth) acrylic acid ester, and, if necessary, the unsaturated carboxylic acid and the nitrogen atom-containing monoemulsified previously emulsified with an emulsifier and an aqueous medium. The monomer, the hydroxyl group-containing monomer, the reactive functional group α-containing monomer, the silane group-containing monomer, and / or another monomer, and the polymerization initiator are heated and stirred. Below, a method of dropping into an aqueous medium.

The amount of the surfactant having a polymerizable group, the adhesion of the finally obtained aqueous dispersion, and from the viewpoint of water resistance, the non-chlorinated polyolefin having a carboxyl group, the interface having a polymerizable group. The amount is preferably 2.0% by mass to 10% by mass, more preferably 2.5% by mass, based on the graft copolymer obtained by graft copolymerizing an acrylic polymer containing a constitutional unit derived from an activator. To 8.0 mass%, and more preferably 3.0 to 7.0 mass%.

The polymerization initiator is not particularly limited, but examples thereof include azo compounds such as 2,2-azobis (2-diaminopropane) hydrochloride; persulfates such as potassium persulfate; peroxides such as hydrogen peroxide; Etc. Specifically, for example, azo oily compounds (eg, azobisisobutyronitrile, 2,2-azobis (2-methylbutyronitrile), 2,2-azobis (2,4-dimethylvaleronitrile)) Etc.), aqueous compounds (eg, anionic 4,4-azobis (4-cyanovaleric acid), cationic 2,2-azobis (2-methylpropionamidine)); redox oily peroxides (eg, , Benzoyl peroxide, parachlorobenzoyl peroxide, lauroyl peroxide, t-butyl perbenzoate, etc.), aqueous peroxide (eg potassium persulfate, ammonium peroxide, etc.); and the like. The polymerization initiator may be used alone or in combination of two or more.

The amount of the polymerization initiator used is not particularly limited, but is preferably 0.05% by mass to 1% by mass, more preferably 0.1% by mass to 0%, based on the total monomer components. It is preferable to set it to 0.5% by mass. When the amount of the polymerization initiator used is 0.05% by mass or more, a suitable polymerization rate can be obtained, so that the monomer hardly remains, and when the amount is 1% by mass or less, the water resistance of the coating film formed is Good.

The method of adding the polymerization initiator is not particularly limited, and may be, for example, batch charging, divided charging, continuous dropping, or the like. Furthermore, in order to accelerate the completion of the polymerization, a part of the polymerization initiator may be added before or after the dropping of the final polymerizable monomer component.

In the emulsion polymerization, a reducing agent such as sodium hydrogen sulfite and / or a transition metal salt such as ferrous sulfate may be added for the purpose of promoting the decomposition of the polymerization initiator. In the emulsion polymerization, known additives such as a pH buffering agent, a chelating agent, a chain transfer agent, and a film forming aid may be added, if necessary. Examples of the chain transfer agent include compounds having a thiol group such as t-dodecyl mercaptan. The amount of the chain transfer agent and the regulator used is not particularly limited, but is, for example, 0.01% by mass to 5% by mass, more preferably 0.1% by mass to 3% by mass, based on the total monomer components. Good to do.

The polymerization temperature in the graft copolymerization step is not particularly limited and is preferably 0 ° C to 100 ° C, more preferably 40 ° C to 95 ° C. The polymerization temperature may be constant or may be changed during the polymerization or in each step. The polymerization time is also not particularly limited and may be appropriately set according to the progress of the reaction, but for example, it is preferably in the range of 2 hours to 8 hours from the start to the end of the polymerization. Regarding the atmosphere during the polymerization, it is preferable to carry out under an atmosphere of an inert gas such as nitrogen in order to enhance the efficiency of the polymerization initiator.

Further, as an emulsifier used in the emulsion polymerization, in addition to the above-mentioned surfactant having a polymerizable group, a surfactant not having a polymerizable group may be used in combination. Examples of the surfactant having no polymerizable group include anionic surfactants having no polymerizable group, anionic surfactants, nonionic surfactants, cationic surfactants, amphoteric surfactants, and polymeric surfactants. Can be used. These surfactants may be used alone or in combination of two or more.

Examples of the anionic surfactant having no polymerizable group include, for example, alkyl sulfate salts such as ammonium dodecyl sulfate and sodium dodecyl sulfate; alkyl sulfonate salts such as ammonium dodecyl sulfonate and sodium dodecyl sulfonate; Alkyl aryl sulfonate salts such as ammonium dodecyl benzene sulfonate and sodium dodecyl naphthalene sulfonate; polyoxyethylene alkyl sulphate salts; polyoxyethylene alkyl aryl sulphate salts; dialkyl sulfosuccinates; aryl sulfonic acid formalin condensates; ammonium Fatty acid salts such as laurylate and sodium stearate; and the like. Examples of the nonionic surfactant having no polymerizable group include polyoxyethylene alkyl ether; polyoxyethylene alkylaryl ether; condensate of polyethylene glycol and polypropylene glycol; sorbitan fatty acid ester; polyoxyethylene sorbitan fatty acid ester. Fatty acid monoglyceride; polyamide; condensation product of ethylene oxide and aliphatic amine; and the like. Examples of the cationic surfactant having no polymerizable group include alkylammonium salts such as dodecylammonium chloride; and the like. Examples of the amphoteric surfactant having no polymerizable group include betaine ester type emulsifiers and the like. Examples of the polymer surfactant having no polymerizable group include poly (meth) acrylic acid salts such as sodium polyacrylate; polyvinyl alcohol; polyvinylpyrrolidone; polyhydroxyalkyl (meth) such as polyhydroxyethyl acrylate. Acrylate; or a copolymer having one or more of the polymerizable monomers constituting these polymers as a copolymerization component; and the like.

The amount of the surfactant having no polymerizable group to be used is not particularly limited, but from the viewpoint of not reducing both the water resistance and the polymerization stability of the coating film, it is 0 to 5 mass% based on all the monomer components. %, More preferably 0 to 3% by mass, further preferably 0 to 1% by mass, and most preferably substantially 0% by mass. Therefore, when the reaction liquid obtained by the emulsion polymerization in which a surfactant having no polymerizable group is used in combination, as it is, is used in an aqueous dispersion, the aqueous dispersion contains a surfactant having no polymerizable group. The amount may be preferably 0 to 5% by mass, more preferably 0 to 3% by mass, and further preferably 0 to 1% by mass, based on the total amount of the graft copolymerized acrylic polymer. It may be substantially 0% by mass.

The content ratio of the carboxyl group-containing non-chlorinated polyolefin and the acrylic polymer in the graft copolymer is preferably 10:90 to 70:30 on a mass basis, and more preferably 20: 80 to 60:40. When the content ratio is within the above range, an aqueous dispersion having excellent adhesion to a polyolefin substrate can be realized.

The weight average molecular weight of the graft copolymer is not limited to this, but is preferably 100,000 to 5,000,000, more preferably 300,000 to 5,000,000 from the viewpoint of the adhesiveness of the formed coating film. is there.

The average particle size of the graft copolymer particles present in the aqueous dispersion is preferably 40 nm to 300 nm, more preferably 50 nm to 200 nm. In the present specification, the average particle size means the average particle size measured by the method described in Examples.

In one embodiment of the present invention, a graft copolymer obtained by graft-copolymerizing the acrylic polymer with a non-chlorinated polyolefin having a carboxyl group is a cross-linking agent having a reactive functional group β described below and / or It is preferable to include a constituent unit derived from a monomer having a reactive functional group α, which can react with a polyfunctional compound to form a crosslinked structure between particles of the aqueous dispersion. As the reactive functional group α, for example, a carboxyl group derived from the unsaturated carboxylic acid or the like contained in a non-chlorinated polyolefin having a carboxyl group; a carboxyl group derived from the acrylic monomer constituting an acrylic polymer, The above-mentioned reactive functional groups such as a hydroxyl group and a carbonyl group can be mentioned. Among them, the reactive functional group α is more preferably an epoxy group, an isocyanate group, an oxazoline group, a hydrazino group, a carbonyl group, a carboxyl group or the like.

[1.3 Crosslinking agent]
The aqueous dispersion according to one embodiment of the present invention may further include a crosslinking agent having a reactive functional group β capable of reacting with the reactive functional group α, which is included in the graft copolymer. This is preferable because the adhesiveness of the obtained aqueous dispersion can be further improved.

When the reactive functional group α is, for example, a carboxyl group, examples of the crosslinking agent include a crosslinking agent having an oxazoline group, a carbodiimide group, an epoxy group or the like as the reactive functional group β.

When the reactive functional group α is, for example, a hydroxyl group, examples of the crosslinking agent include a crosslinking agent having an isocyanate group or the like as the reactive functional group β.

When the reactive functional group α is, for example, a carbonyl group, examples of the crosslinking agent include a crosslinking agent having a hydrazide group or the like as the reactive functional group β.

The aqueous dispersion according to one embodiment of the present invention may more preferably contain a crosslinking agent capable of reacting with a carboxyl group. Examples of such a cross-linking agent include an oxazoline group-containing compound, a carbodiimide group-containing compound, and an epoxy group-containing compound, and a plurality of them may be mixed and used as necessary. Among them, it is more preferable to add an oxazoline group-containing compound, a carbodiimide group-containing compound, an isocyanate group-containing compound, and an epoxy group-containing compound from the viewpoint of easy handling. These may be used alone or in combination of two or more.

The oxazoline group-containing compound is not particularly limited as long as it has at least two or more oxazoline groups in the molecule. For example, 2,2'-bis (2-oxazoline), 2,2'-ethylene-bis (4,4'-dimethyl-2-oxazoline), 2,2'-p-phenylene-bis (2-oxazoline) , Bis (2-oxazolinylcyclohexane) sulfide and other compounds having an oxazoline group, and oxazoline group-containing polymers. These 1 type (s) or 2 or more types can be used. Among these, an oxazoline group-containing polymer is preferable because it is easy to handle.

The oxazoline group-containing polymer is generally obtained by polymerizing an addition-polymerizable oxazoline such as 2-vinyl-2-oxazoline, 2-vinyl-4-methyl-2-oxazoline, 2-isopropenyl-2-oxazoline. If necessary, the oxazoline group-containing polymer may be copolymerized with another monomer. The method for polymerizing the oxazoline group-containing polymer is not particularly limited, and a known polymerization method can be adopted.

Commercially available oxazoline group-containing polymers include Epocros (registered trademark) series manufactured by Nippon Shokubai Co., Ltd., for example, water-soluble types “WS-500” and “WS-700”; emulsion type “K-1010E”. , "K-1020E", "K-1030E", "K-2010E", "K-2020E", "K-2030E" and the like.

The carbodiimide group-containing compound is not particularly limited as long as it has at least two carbodiimide groups in the molecule. Compounds having a carbodiimide group such as p-phenylene-bis (2,6-xylylcarbodiimide), tetramethylene-bis (t-butylcarbodiimide), cyclohexane-1,4-bis (methylene-t-butylcarbodiimide) , And polycarbodiimide, which is a polymer having a carbodiimide group. These 1 type (s) or 2 or more types can be used. Among these, polycarbodiimide is preferable because it is easy to handle.

Commercially available products of polycarbodiimide include the carbodilite (registered trademark) series manufactured by Nisshinbo. Specific products include, for example, water-soluble type "SV-02", "V-02", "V-02-L2", "V-04"; emulsion type "E-01", "E" -02 "; organic solution type" V-01 "," V-03 "," V-07 "," V09 "; solventless type" V-05 "and the like.

The epoxy group-containing compound is not particularly limited as long as it has at least two epoxy groups in the molecule. For example, bisphenol A diglycidyl ether, bisphenol A β-dimethylglycidyl ether, bisphenol F diglycidyl ether, tetrahydroxyphenylmethane tetraglycidyl ether, resorcinol diglycidyl ether, brominated bisphenol A diglycidyl ether, chlorinated bisphenol A diglycidyl ether, Glycidyl ether type such as hydrogenated bisphenol A diglycidyl ether, diglycidyl ether of bisphenol A alkylene oxide adduct, novolac glycidyl ether, polyalkylene glycol diglycidyl ether, glycerin triglycidyl ether, pentaerythritol diglycidyl ether, epoxy urethane resin; p-Hydroxybenzoic acid glycidyl ether D Glycidyl ether / ester type such as ter; glycidyl ester type such as phthalic acid diglycidyl ester, tetrahydrophthalic acid diglycidyl ester, hexahydrophthalic acid diglycidyl ester, acrylic acid diglycidyl ester, dimer acid diglycidyl ester; glycidyl aniline , Glycidyl amine type such as tetraglycidyl diaminodiphenylmethane, triglycidyl isocyanurate and triglycidyl aminophenol; linear aliphatic epoxy resin such as epoxidized polybutadiene and epoxidized soybean oil; 3,4-epoxy-6 methylcyclohexylmethyl-3 , 4-epoxy-6-methylcyclohexanecarboxylate, 3,4-epoxycyclohexylmethyl (3,4-epoxycyclohexane) carboxylate, bis (3 , 4-epoxy-6-methylcyclohexylmethyl) adipate, vinylcyclohexene diepoxide, dicyclopentadiene oxide, bis (2,3-epoxycyclopentyl) ether, alicyclic epoxy resin such as limonenedioxide, and the like. These 1 type (s) or 2 or more types can be used.

Examples of commercially available epoxy compounds include water-based epoxy compounds suitable for the present invention, for example, Denasel (registered trademark) series (EM-150, EM-101, etc.) manufactured by Nagase Chemtech, and ADEKA Resin (registered trademark) manufactured by ADEKA Corporation. ) Series, etc., and Adeka Resin (registered trademark) EM-0517, EM-0526, EM-11-50B manufactured by ADEKA Co., Ltd., which is a polyfunctional epoxy resin emulsion from the viewpoint of improving UV ink adhesion and scratch resistance. EM-051R and the like are preferable.

The aqueous dispersion according to another embodiment of the present invention may include a crosslinking agent capable of reacting with a hydroxyl group. Examples of the crosslinking agent in the other embodiment include isocyanate group-containing compounds. The isocyanate group-containing compound is not particularly limited as long as it has at least two isocyanate groups in the molecule. Preferred examples of the isocyanate group-containing compound include diisocyanates such as aromatic diisocyanates, alicyclic diisocyanates, and aliphatic diisocyanates; adduct polyisocyanate compounds; burette polyisocyanate compounds; polyisocyanate compounds having an isocyanurate ring.

Examples of the aromatic diisocyanate include tolylene diisocyanate (TDI), 4,4′-diphenylmethane diisocyanate (MDI), xylylene diisocyanate, polymethylene polyphenyl isocyanate and the like.

Specific examples of the aliphatic diisocyanate include butane diisocyanate, pentane diisocyanate, hexamethylene diisocyanate (HDI), trimethylhexamethylene diisocyanate, lysine diisocyanate, butylene diisocyanate, and the like.

Examples of the alicyclic diisocyanate include hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, 1,4-cyclohexane diisocyanate, cyclopentylene diisocyanate, and isophorone diisocyanate.

Examples of the adduct polyisocyanate compound include “Sumijour L” (manufactured by Sumitomo Bayer Urethane Co.); “Coronate L” and “Coronate HL” (both manufactured by Nippon Polyurethane Co.).

Examples of the burette polyisocyanate compound include “Sumijour N” (manufactured by Sumitomo Bayer Urethane Co.).

Examples of the polyisocyanate compound having an isocyanurate ring include "Desmodur IL" and "Desmodur HL" (all manufactured by Bayer AG); "Coronate EH" and "Coronate HX" (any. Also manufactured by Nippon Polyurethane Industry Co., Ltd.); “Takenate D110N” and “Takenate D120N” (both manufactured by Mitsui Chemicals, Inc.) and the like.

These can be used alone or in combination of two or more. Further, a so-called blocked isocyanate in which the isocyanate group of these compounds is inactivated by reacting with a masking agent having active hydrogen can also be used.

The content of the cross-linking agent is preferably 0.1% by mass to 5% by mass based on the graft copolymer obtained by graft-copolymerizing the acrylic polymer with the carboxyl group-containing non-chlorinated polyolefin. , And more preferably 0.5% by mass to 2% by mass. When the content of the crosslinking agent is 0.1% by mass to 5% by mass, the adhesion of the formed coating film is improved, which is preferable.

Alternatively, the aqueous dispersion according to one embodiment of the present invention preferably contains a polyfunctional compound as a crosslinking agent capable of reacting with the reactive functional group α. The polyfunctional compound preferably contains a hydrazino group-containing crosslinking agent containing two or more of at least one of a carboxyl group, a hydrazino group, an oxazoline group and an epoxy group, and preferably has two or more hydrazino groups.

Examples of the hydrazino group-containing cross-linking agent include oxalic acid dihydrazide, malonic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, and itaconic acid dihydrazide. 2 to 10 dicarboxylic acid dihydrazides, ethylene-1,2-dihydrazine, propylene-1,3-dihydrazine, butylene-1,4-dihydrazine, and other aliphatic water-soluble dihydrazines having 2 to 4 carbon atoms, etc. Can be mentioned. These hydrazino group-containing compounds may be used alone or in combination of two or more kinds. Among these hydrazino group-containing cross-linking agents, from the viewpoint of the adhesiveness of the coating film formed, adipic acid dihydrazide, sebacic acid dihydrazide, maleic acid dihydrazide, fumaric acid dihydrazide, itaconic acid dihydrazide, succinic acid dihydrazide, glutaric acid dihydrazide, etc. A dicarboxylic acid dihydrazide having 4 to 6 carbon atoms is preferable, and adipic acid dihydrazide is more preferable.

The content of the polyfunctional compound such as the hydrazino group-containing cross-linking agent, based on the solid content of the aqueous dispersion, more preferably in the non-chlorinated polyolefin having the carboxyl group contained in the aqueous dispersion, polymerizable. Based on the solid content of the graft copolymer obtained by graft-copolymerizing an acrylic polymer containing a structural unit derived from a surfactant having a group, preferably 0.1% by mass to 5% by mass, more preferably It is 0.5% by mass to 2% by mass. When the content of the crosslinking agent is 0.1% by mass to 5% by mass, the adhesion of the formed coating film is improved, which is preferable.

Among them, the hydrazino group-containing cross-linking agent is a cross-linking agent capable of reacting with a carbonyl group, and more preferably used in combination with an acrylic resin containing a constitutional unit derived from a carbonyl group-containing monomer.

In addition, the aqueous dispersion according to one embodiment of the present invention may further contain an acid catalyst, for example, paratoluenesulfonic acid, phosphoric acid, hydrochloric acid, ammonium chloride, etc., in order to further promote crosslinking, if necessary. . The content of the crosslinking accelerator is 10% by mass to 50% by mass with respect to the crosslinking agent.

[1.4 Aqueous dispersion]
Aqueous dispersion according to an embodiment of the present invention, the non-chlorinated polyolefin having a carboxyl group, by graft copolymerizing an acrylic polymer containing a specific amount of a surfactant-derived structural unit having a polymerizable group. And a water-based medium.

The lower the chlorine content in the carboxyl group-containing chlorinated poly (propylene) -based random copolymer, the better the adhesion to the olefin substrate, but if it is too low, the softening point and melting point of the resin will increase, so that low-temperature baking will occur. Adhesion is reduced. Thus, by replacing the aqueous dispersion of chlorinated polyolefin with the aqueous dispersion of non-chlorinated polyolefin, it has been a conventional problem that the adhesiveness is lowered during low temperature baking. A graft copolymer obtained by graft-copolymerizing an acrylic polymer containing a specific amount of a constitutional unit derived from a surfactant having a polymerizable group onto a non-chlorinated polyolefin having a carboxyl group according to an embodiment of the present invention. According to the aqueous dispersion containing the above and the aqueous medium, such a problem can be solved.

In one embodiment of the present invention, the aqueous dispersion is obtained by graft-copolymerizing an acrylic polymer having a specific amount of a surfactant-containing constitutional unit having a polymerizable group on the non-chlorinated polyolefin having the carboxyl group. It suffices to include the graft copolymer thus obtained and an aqueous medium, but it may further include the above-mentioned crosslinking agent, if necessary.

In addition, the aqueous dispersion may be, for example, a thickener, a pigment, a pigment dispersant, an antifoaming agent, an inorganic filler, a surfactant, a neutralizing agent, a stabilizer, a thickener, or a surface adjusting agent, if necessary. Agents, leveling agents, ultraviolet absorbers, antioxidants, conductive carbon, conductive fillers, conductive fillers such as metal powders, organic modifiers, and plasticizers.

The content of the graft copolymer in the aqueous dispersion is preferably 10% by mass to 60% by mass, more preferably 20% by mass to 50% by mass, based on the aqueous dispersion.

The solid content of the aqueous dispersion is preferably 10% by mass to 60% by mass, more preferably 20% by mass to 40% by mass. In the present specification, the solid content means the solid content measured by the method described in Examples below. The solid content of the aqueous dispersion according to one embodiment of the present invention includes a graft copolymer, a polyolefin remaining ungrafted, and an acrylic copolymer. The content of the graft copolymer is 70 mass% or more, more preferably 80 mass% or more, particularly preferably 90 mass% or more, and most preferably substantially 100 mass% with respect to the solid content.

The pH of the aqueous dispersion is preferably 5 to 10, more preferably 6 to 9.5, and further preferably 7 to 9.5, from the viewpoint of improving the stability of the dispersion. If the pH is less than 5, the stability and mechanical stability of the aqueous dispersion may decrease. When the pH exceeds 10, there is a possibility that there is a problem in practical use such as deterioration of water resistance and generation of odor.

Any suitable pH adjuster may be used to adjust the pH of the aqueous dispersion to the above range. Specific examples of such pH adjusters include alkali metal compounds such as sodium hydroxide and potassium hydroxide; alkaline earth metal compounds such as calcium hydroxide and calcium carbonate; ammonia; dimethylaminoethanol, monomethylamine, dimethylamine , Water-soluble organic amines such as trimethylamine, monoethylamine, diethylamine, triethylamine, monopropylamine, dimethylpropylamine, monoethanolamine, diethanolamine, triethanolamine, ethylenediamine and diethylenetriamine. These pH adjusters may be used alone or in combination of two or more.

[2. Use of aqueous dispersion]
The aqueous dispersion according to one embodiment of the present invention has excellent adhesion to a polyolefin substrate, and thus can be used as an aqueous primer composition for a polyolefin substrate. Therefore, the present invention also includes an aqueous primer composition containing the aforementioned aqueous dispersion.

The aqueous primer composition according to one embodiment of the present invention is applied to a polyolefin base material such as polyethylene, polypropylene, TPO (thermoplastic olefin; thermoplastic olefin resin), and dried to form a flyer on the polyolefin base material. A layer is formed. The drying temperature is not particularly limited, but when the aqueous primer composition contains a cross-linking agent, the cross-linking reaction proceeds during heating and drying, so the drying is performed at a temperature at which the cross-linking reaction rapidly proceeds depending on the type of the cross-linking agent. It is preferable. For forming the film, use a conventionally known method, for example, gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, and brush coating method. You can

The molded product according to one embodiment of the present invention is preferably a molded product having a polyolefin base material or a polyolefin molded product, the primer layer, and one or more overcoat layers on the primer layer.

Examples of the above-mentioned topcoat layer include coating films obtained by applying a one-component melamine baking coating, a two-component urethane coating, a one-component lacquer coating, a glitter coating, a high solid clear coating and the like. When the top coat film has a multilayer structure of two or more layers, for example, a multilayer structure including a base coating film and a clear coating film can be mentioned.

Examples of the above-mentioned polyolefin molded products include bumpers for vehicles, moldings, fender mirrors, grills, members of home appliances, and the like.

[3. Method for producing aqueous dispersion]
A method for producing an aqueous dispersion according to an embodiment of the present invention, a non-chlorinated polyolefin having a carboxyl group, by graft copolymerizing an acrylic polymer containing a structural unit derived from a surfactant having a polymerizable group. 2% by mass to 10% by mass of the structural unit derived from the surfactant having a polymerizable group and containing the graft copolymer A method for producing an aqueous dispersion, comprising a non-chlorinated polyolefin having a carboxyl group, an aqueous medium containing a polyolefin aqueous dispersion, and a surfactant having a polymerizable group in the presence of an acrylic resin. The process of emulsion-polymerizing a monomer is included. The emulsion polymerization process is the same as described in [1.2], and thus the description thereof is omitted here.

In one embodiment of the present invention, the reaction liquid obtained in the emulsion polymerization may be used as it is as the aqueous dispersion.

Alternatively, the reaction solution obtained in the emulsion polymerization may further include a step of mixing at least one selected from an aqueous medium, a crosslinking agent, and other additives.

Further, in another embodiment, a step of separating the graft copolymer obtained in the emulsion polymerization and adding an aqueous medium may be included.

An embodiment of the present invention may have the following configuration.

[1] A graft copolymer obtained by graft-copolymerizing an acrylic polymer having a constitutional unit derived from a surfactant having a polymerizable group with a non-chlorinated polyolefin having a carboxyl group, and an aqueous medium. The aqueous dispersion, wherein the constitutional unit derived from the surfactant having a polymerizable group is contained in an amount of 2% by mass to 10% by mass based on the graft copolymer.

[2] The aqueous dispersion according to [1], which contains a surfactant having no polymerizable group in an amount of 0 to 5 mass% with respect to the total amount of the graft copolymerized acrylic polymer.

[3] The aqueous dispersion according to [1] or [2], wherein the acrylic polymer contains a structural unit derived from (meth) acrylate having a cycloalkyl group having 6 or more carbon atoms in its side chain.

[4] The aqueous dispersion according to any one of [1] to [3], wherein the acrylic polymer contains a constituent unit derived from 2-ethylhexyl acrylate.

[5] The aqueous dispersion according to any one of [1] to [4], wherein the acrylic polymer further contains a structural unit derived from an unsaturated carboxylic acid.

[6] The aqueous dispersion according to any one of [1] to [5], wherein the graft copolymer contains a constitutional unit derived from a monomer having a reactive functional group α.

[7] The aqueous dispersion according to [6], which contains a crosslinking agent having a reactive functional group β capable of reacting with the reactive functional group α.

[8] An aqueous primer composition used for a polyolefin substrate, which comprises the aqueous dispersion according to any one of [1] to [7].

A molded article containing the aqueous primer composition described in [9] and [8].

[10] A graft copolymer obtained by graft-copolymerizing an acrylic polymer having a structural unit derived from a surfactant having a polymerizable group onto a non-chlorinated polyolefin having a carboxyl group, A method for producing an aqueous dispersion, wherein the constituent unit derived from a surfactant is contained in an amount of 2% by mass to 10% by mass with respect to the graft copolymer, wherein the non-chlorinated polyolefin having a carboxyl group and an aqueous medium are used. A production method, which comprises a step of emulsion-polymerizing an acrylic monomer in the presence of a polyolefin aqueous dispersion containing: and a surfactant having a polymerizable group.

Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the following examples, "part" means "part by mass".

〔Measuring method〕
The melting point of the polyolefin used in Examples and Comparative Examples, the Tg of the acrylic polymer, and the solid content, pH, and the average particle size of all particles contained in the aqueous dispersions obtained in Examples and Comparative Examples are It was measured by the following method.

(1) Average Particle Size The volume average particle size was measured using a particle size distribution analyzer (“FPAR-1000” manufactured by Otsuka Electronics Co., Ltd.) by the dynamic light scattering method.

(2) Tg
It was calculated from the monomer composition using the Fox equation described above.

(3) Melting point The melting point is 20 ° C./min using a differential scanning calorimeter (hereinafter, also referred to as “DSC”, manufactured by TA Instruments Japan, “Q-2000”). It is a value measured from the top temperature and the area of the melting peak when the temperature rise melting is performed, the resin is cooled to form a resin, and then the temperature rise melting is performed again.

(4) Solid content 1 g of each aqueous dispersion was weighed and dried at 110 ° C. for 1 hour with a hot air drier, and the remaining dry amount was calculated as the solid content, and the ratio to the mass before drying was calculated in mass%.

(5) pH
The value at 25 ° C. was measured with a pH meter (“F-23” manufactured by Horiba Ltd.).

〔Evaluation methods〕
The aqueous dispersions obtained in Examples and Comparative Examples were evaluated by the following methods.

(Preparation of paint for evaluation)
To 100 parts of each aqueous dispersion, 4 parts of dipropylene glycol n-butyl ether (manufactured by Dow Chemical Co., product number: Dowanol (registered trademark) DPnB) as a film forming aid, and a wetting agent (manufactured by Nisshin Chemical Co., Ltd., trade name) : Orfin (registered trademark) EXP.4200) (1 part) was added, and the coating material for evaluation was prepared by stirring for 10 minutes using a homodisper at a rotation speed of 1500 rpm.

(Preparation of coating film for evaluation)
The coating material for evaluation was applied onto a polypropylene plate (manufactured by Nippon Test Panel Co., Ltd., length: 70 mm, width: 150 mm, thickness: 2 mm) using a bar coater (No. 14). The coated coating composition for evaluation is dried in a jet oven at a wind speed of 3 m and 80 ° C. for 15 minutes to prepare a test plate in which a coating film for evaluation having a film thickness of 10 ± 2 μm is formed on the polypropylene plate. did.

(1) Initial adhesion evaluation (cross-cut test)
(Test method)
Using the test plate on which the coating film for evaluation was formed, a cross-cut test was conducted according to JIS K5600-5-6.

Specifically, a 25 mm (vertical: 5 squares, horizontal: 5 squares) incision was made in a 2 mm square grid pattern with a sharp blade on the evaluation coating film. Then, a 25 mm-wide cellophane adhesive tape (Nichiban CT-24) was rubbed with a finger to be closely attached to the portion in which the cross-cuts were made. Then, the coating film for evaluation was allowed to stand in the atmosphere at 25 ° C. for 5 minutes, and then the cellophane adhesive tape was peeled off. The number of peeled squares was counted from the 25 squares produced, and the initial adhesion to the polyolefin substrate was evaluated based on the following evaluation criteria.

(Evaluation criteria)
◯: The number of peeled squares is 0 to 4.
Δ: The number of peeled squares is 5 to 14.
X: The number of peeled squares is 15 or more.

(2) Water resistance evaluation (test method)
The test plate on which the coating film for evaluation was formed was immersed in warm water kept at 40 ° C. for 10 days. After 10 days, the test plate was pulled up and dried, and then a cross-cut test was conducted in the same procedure as the cross-cut test of the initial adhesion evaluation, the number of peeled squares was counted, and based on the following evaluation criteria: Water resistance was evaluated.

(3) Adhesion evaluation (peeling strength test)
Gum tape (manufactured by Nichiban Co., Ltd., trade name: cloth adhesive tape 102N) was attached to the coating film for evaluation of the test plate on which the coating film for evaluation was formed, and allowed to stand at 23 ° C. and 65% RH for one day. . Then, in order to create a trigger for the coating film to peel from the substrate, a 10 mm wide cut was made in the evaluation tape from above the gum tape. Next, using a tensile tester (manufactured by Shimadzu Corporation, trade name: Autograph AGS-100D), the film with the gum tape and the coating film integrated in a 180 ° direction at a tensile speed of 50 mm / min. The peel strength when pulled was measured, and the peel strength was calculated per 1 m to calculate the peel strength.

(4) Evaluation of low-temperature film-forming property (test method)
Each aqueous dispersion was applied to a polyethylene terephthalate (PET) film placed on a thermal gradient tester (MFT tester LT type manufactured by Tester Sangyo Co., Ltd.) using an applicator with a gap adjusted to 0.2 mm. . Then, the coating film was dried, and it was observed whether cracks were formed in the obtained coating film. The temperature at the time of coating was changed from 30 ° C. to 1 ° C. on the low temperature side, and the same observation was performed. The temperature at which cracks were formed in the obtained coating film was defined as the minimum film formation temperature (MFT).

[Example 1]
100 parts of deionized water in a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser, and a surfactant (manufactured by ADEKA Co., Ltd., trade name: ADEKA rear soap (registered trademark) SR 10 parts of a 25% aqueous solution of (-10) (2.5 parts as a surfactant) and 250 parts of an aqueous polyolefin dispersion (manufactured by Toyobo Co., Ltd., trade name: HARDREN NZ-1004: 100 parts of polypropylene with an unsaturated carboxylic acid) An aqueous dispersion of a modified polyolefin modified with 2 parts of maleic anhydride and 75 parts as a resin component) were mixed, and the temperature was raised to 80 ° C. while gently blowing nitrogen gas.

In a dropping funnel, 28 parts of deionized water, 20 parts of a 25% aqueous solution of a surfactant (manufactured by ADEKA, trade name: ADEKA REASOAP (registered trademark) SR-10) (5 parts as a surfactant), and 2 -Prepare a dropping pre-emulsion consisting of 21.5 parts of ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA), and add 3 parts of ammonium persulfate to the dropping buret. 13 parts of a 0.5% aqueous solution was prepared, and each was uniformly added dropwise into the flask for 90 minutes to initiate polymerization.

After the completion of dropping, the contents of the flask were kept at 80 ° C for 60 minutes. Then, 25% ammonia water was added to the contents of the flask to adjust the pH to 8 to complete the polymerization reaction.

The obtained reaction solution was cooled to room temperature and then filtered through a 300 mesh (JIS mesh, the same applies hereinafter) wire mesh to obtain an aqueous dispersion having a solid content of 30 mass%. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 1 and 2.

[Example 2]
An aqueous dispersion was produced in the same manner as in Example 1 except that 2-ethylhexyl acrylate was changed to 17.5 parts and methyl methacrylate 52.0 parts was changed to cyclohexyl methacrylate (CHMA) 56.0 parts. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 1 and 2.

[Example 3]
Solid content 100 parts in the aqueous dispersion obtained in Example 1 (total mass of the graft copolymer, the polyolefin remaining ungrafted and the acrylic copolymer, substantially 100 mass % Of the graft copolymer), and 2 parts of a crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500, containing 0.8 part of a water-soluble polymer containing an oxazoline group), and homogenized. The mixture was stirred with a disper at a rotation speed of 500 times / minute for 30 minutes. As a result, an aqueous dispersion containing a crosslinking agent that reacts with a carboxyl group was obtained. Table 2 shows the composition, evaluation results, etc. of the obtained aqueous dispersion.

[Example 4]
Solid content 100 parts in the aqueous dispersion obtained in Example 2 (total mass of the graft copolymer, the polyolefin remaining ungrafted and the acrylic copolymer, substantially 100 mass % Of the graft copolymer), and 2 parts of a crosslinking agent (manufactured by Nippon Shokubai Co., Ltd., trade name: Epocros WS-500, containing 0.8 part of a water-soluble polymer containing an oxazoline group), and homogenized. The mixture was stirred with a disper at a rotation speed of 500 times / minute for 30 minutes. As a result, an aqueous dispersion containing a crosslinking agent that reacts with a carboxyl group was obtained. Table 2 shows the composition, evaluation results, etc. of the obtained aqueous dispersion.

[Example 5]
96 parts of 100 parts of deionized water mixed with 250 parts of polyolefin aqueous dispersion, 6 parts of 10 parts of 25% aqueous solution of a surfactant (made by ADEKA, trade name: ADEKA REASORP SR-10) (surfactant The content was changed to 1.5 parts as an agent, and in the preparation of the pre-emulsion for dropping, 28 parts of deionized water was changed to 33 parts, and a surfactant (manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SR) An aqueous dispersion was produced in the same manner as in Example 1 except that 20 parts of the 25% aqueous solution of -10) was changed to 12 parts (containing 3 parts as a surfactant). The composition and evaluation results of the obtained aqueous dispersion are shown in Tables 1 and 2.

[Comparative Example 1]
The polyolefin aqueous dispersion used in Example 1 was used as an aqueous dispersion. Table 2 shows the composition, evaluation results and the like of this aqueous dispersion.

[Comparative Example 2]
1000 parts of deionized water was charged into a flask equipped with a dropping funnel, a stirrer, a nitrogen introducing tube, a thermometer and a reflux condenser.

To the dropping funnel, 249 parts of deionized water, 120 parts of a 25% aqueous solution of a surfactant (manufactured by ADEKA, trade name: Adecaria Soap SR-10) (containing 30 parts as a surfactant), 172 parts of 2-ethylhexyl acrylate. , 416 parts of methyl methacrylate, and 12 parts of acrylic acid were prepared as a pre-emulsion for dropping. 95 parts of it was added to the flask, and the temperature was raised to 80 ° C. while slowly blowing nitrogen gas. Then, 36 parts of a 5% aqueous solution of ammonium persulfate was added into the flask to initiate polymerization.

Next, the rest of the pre-emulsion for dropping was uniformly dropped into the flask over 120 minutes. After the dropping was completed, the content in the flask was maintained at 80 ° C. for 60 minutes, and 25% aqueous ammonia was added to adjust the pH to 9, thereby completing the polymerization reaction.

After cooling the obtained reaction solution to room temperature, it was filtered through a 300-mesh wire net to obtain an aqueous dispersion having a solid content of 30% by mass. The emulsion particles contained in the obtained aqueous dispersion had an average particle diameter of 100 nm and the glass transition temperature of the entire emulsion particles was 30 ° C. The composition and evaluation results of this aqueous dispersion are shown in Tables 1 and 2.

[Comparative Example 3]
An aqueous dispersion was produced in the same manner as in Comparative Example 2 except that 172 parts of 2-ethylhexyl acrylate was changed to 139 parts, and 416 parts of methyl methacrylate was changed to 449 parts of cyclohexyl methacrylate. The composition and evaluation results of this aqueous dispersion are shown in Tables 1 and 2.

[Comparative Example 4]
10 parts of a 25% aqueous solution of a surfactant (manufactured by ADEKA, trade name: ADEKA REASORP SR-10) mixed with 250 parts of an aqueous polyolefin dispersion is a surfactant having no polymerizable group (Nippon Emulsifier Co., Ltd.). Manufactured by trade name: Newcol 707-SF) to 8 parts of a 30% aqueous solution (contains 2.4 parts as a surfactant), and further, in the preparation of the pre-emulsion for dropping, 28 parts of deionized water 31 parts To 20 parts of a 25% aqueous solution of a surfactant (manufactured by ADEKA Co., Ltd., trade name: ADEKA rear soap SR-10), and a surfactant having no polymerizable group (manufactured by Nippon Emulsifier Co., Ltd., trade name: An aqueous dispersion was produced in the same manner as in Example 1 except that 17 parts of a 30% aqueous solution (Newcol 707-SF) (containing 5.1 parts as a surfactant) was used. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 1 and 2.

[Comparative Example 5]
93 parts of 100 parts of deionized water mixed with 250 parts of polyolefin aqueous dispersion, 2 parts of 10 parts of 25% aqueous solution of a surfactant (made by ADEKA, trade name: ADEKA RIASORP SR-10) (surfactant) 0.5 parts as an agent), and in the preparation of the pre-emulsion for dropping, 28 parts of deionized water was changed to 38 parts, and a surfactant (manufactured by ADEKA Co., Ltd., trade name: Adecaria Soap SR) An aqueous dispersion was produced in the same manner as in Example 1 except that 20 parts of a 25% aqueous solution of -10) was changed to 4 parts (containing 1 part as a surfactant). A lot of aggregates were floating in the obtained reaction solution. The composition and evaluation results of this aqueous dispersion are shown in Tables 1 and 2.

From Examples 1 to 5, an aqueous dispersion containing a graft copolymer obtained by graft-copolymerizing an acrylic polymer containing a constitutional unit derived from a surfactant having a polymerizable group onto a non-chlorinated polyolefin having a carboxyl group. The body was excellent in initial adhesion and water resistance, and the low temperature film forming temperature was 0 ° C or lower.

Although not shown in the table, the peel strengths of the aqueous dispersions obtained in Examples 2 to 5 were superior to those of the aqueous dispersions obtained in Example 1.

From Comparative Example 1, it can be seen that the aqueous dispersion produced using only the olefin aqueous dispersion has poor adhesion to the olefin base material and the low temperature film forming temperature is 30 ° C to 50 ° C. Further, from Comparative Example 4, an aqueous dispersion containing a graft copolymer obtained by graft-copolymerizing an acrylic polymer with a non-chlorinated polyolefin having a carboxyl group using a surfactant having no polymerizable group. It can be seen that the body has poor initial adhesion and water resistance.

Furthermore, in the aqueous dispersions obtained in Examples 1 and 5 in which the contents of the polymerizable surfactant were 5.0% by mass and 3.0% by mass, respectively, the content of the polymerizable surfactant was 1. It can be seen that the initial adhesion and the water resistance are excellent as compared with Comparative Example 5 which is 0% by mass.

[Example 6]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 54.6 parts, acrylic acid (AA) 1.5 parts, and acrylamide (AAm) 1.5 parts were used, but the same as in Example 1. The operation was performed to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 7]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 54.6 parts, acrylic acid (AA) 1.5 parts and diacetone acrylamide (DAAM, manufactured by Mitsubishi Chemical Corporation) 1.5 parts were used. Other than that, the same operation as in Example 1 was performed to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 8]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 54.6 parts, acrylic acid (AA) 1.5 parts, and 4- (meth) acryloyloxy-2,2,6,6-tetramethylpiperidine ( The same operation as in Example 1 was carried out except that 1.5 parts of LA-87) was used to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 9]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 54.6 parts, acrylic acid (AA) 1.5 parts, and acrylonitrile (AN) 1.5 parts were used in the same manner as in Example 1. The operation was performed to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 10]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 54.6 parts, acrylic acid (AA) 1.5 parts, and 2-hydroxyethyl methacrylate (HEMA) 1.5 parts The same operation as in 1 was performed to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 11]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 55.4 parts, acrylic acid (AA) 1.5 parts and 3-methacryloxypropyltriethoxysilane (KBE-503) 0.8 parts. The same operation as in Example 1 was carried out except that it was obtained to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 12]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 17.4 parts, cyclohexyl methacrylate (CHMA) 53.1 parts, acrylic acid (AA) 1.5 parts, acrylonitrile (AN) 1.5 parts, and 2-hydroxyethyl methacrylate (HEMA) 1. The same operation as in Example 1 was carried out except that 5 parts were used to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

[Example 13]
In the preparation of the pre-emulsion for dropping, 21.5 parts of 2-ethylhexyl acrylate (2EHA), 52.0 parts of methyl methacrylate (MMA) and 1.5 parts of acrylic acid (AA) were replaced with 2-ethylhexyl acrylate ( 2EHA) 21.5 parts, methyl methacrylate (MMA) 49.1 parts, acrylic acid (AA) 1.5 parts, acrylonitrile (AN) 1.5 parts, and 2-hydroxyethyl methacrylate (HEMA) 1. The same operation as in Example 1 was carried out except that 5 parts were used to obtain an aqueous dispersion having a solid content of 30% by mass. The compositions and evaluation results of the obtained aqueous dispersion are shown in Tables 3 and 4.

Also from Examples 6 to 13, an aqueous solution containing a graft copolymer obtained by graft-copolymerizing an acrylic polymer containing a constitutional unit derived from a surfactant having a polymerizable group with a non-chlorinated polyolefin having a carboxyl group. It can be seen that the dispersion has excellent initial adhesion and water resistance, and the low temperature film forming temperature is 0 ° C. or lower.

Furthermore, Examples 6 to 6 in which an acrylic polymer containing a nitrogen atom-containing monomer, a hydroxyl group-containing monomer, a carbonyl group-containing monomer, or a silane group-containing monomer as a monomer component was graft-copolymerized In No. 13, although not shown in the table, the peel strength was superior to those of the aqueous dispersions obtained in Examples 2 to 5.

The present invention can be used for a water-based primer used for a molded product of polyolefin, for example, a member for a vehicle bumper, a molding for a vehicle, a member for home electric appliances and the like.

Claims

A non-chlorinated polyolefin having a carboxyl group, a graft copolymer obtained by graft copolymerizing an acrylic polymer containing a constitutional unit derived from a surfactant having a polymerizable group, and an aqueous medium,
The aqueous dispersion in which the structural unit derived from the surfactant having a polymerizable group is contained in an amount of 2% by mass to 10% by mass based on the graft copolymer.
The aqueous dispersion according to claim 1, wherein the surfactant having no polymerizable group is contained in an amount of 0 to 5 mass% with respect to the total amount of the graft-copolymerized acrylic polymer.
The aqueous dispersion according to claim 1 or 2, wherein the acrylic polymer contains a structural unit derived from (meth) acrylate having a cycloalkyl group having 6 or more carbon atoms in a side chain.
The aqueous dispersion according to any one of claims 1 to 3, wherein the acrylic polymer contains a constituent unit derived from 2-ethylhexyl acrylate.
The aqueous dispersion according to any one of claims 1 to 4, wherein the acrylic polymer further contains a structural unit derived from an unsaturated carboxylic acid.
The aqueous dispersion according to any one of claims 1 to 5, wherein the graft copolymer contains a constitutional unit derived from a monomer having a reactive functional group α.
The aqueous dispersion according to claim 6, comprising a crosslinking agent having a reactive functional group β capable of reacting with the reactive functional group α.
An aqueous primer composition used for a polyolefin substrate, which comprises the aqueous dispersion according to any one of claims 1 to 7.
A molded article containing the aqueous primer composition according to claim 8.
Non-chlorinated polyolefin having a carboxyl group, a graft copolymer obtained by graft copolymerizing an acrylic polymer containing a structural unit derived from a surfactant having a polymerizable group, the surfactant having a polymerizable group A method for producing an aqueous dispersion, wherein the constitutional unit derived from the agent is contained in an amount of 2% by mass to 10% by mass with respect to the graft copolymer,
A non-chlorinated polyolefin having a carboxyl group, an aqueous medium, a polyolefin aqueous dispersion containing an aqueous medium, in the presence of a surfactant having a polymerizable group, including a step of emulsion polymerizing an acrylic monomer, production Method.