JP2018199788A - Aqueous resin dispersion and method for producing aqueous resin dispersion - Google Patents

Abstract

To provide an aqueous resin dispersion having excellent adhesion and water resistance with respect to a polyolefin base material such as a polypropylene base material and a method of producing the same.SOLUTION: The present invention provides an aqueous resin dispersion (C) made by polymerization of a radical-polymerizable monomer (B) in an aqueous resin dispersion (A) of an olefin polymer with an average particle size of 100 nm or less; and a method for producing an aqueous resin dispersion (C) by polymerization of a radical-polymerizable monomer (B) in an aqueous resin dispersion (A) of an olefin polymer with an average particle size of 100 nm or less.SELECTED DRAWING: None

Description

  The present invention relates to an aqueous resin dispersion and a method for producing an aqueous resin dispersion.

  Polyolefins such as propylene polymers and propylene-α-olefin copolymers are inexpensive and have excellent mechanical properties, heat resistance, chemical resistance, water resistance, and the like, and are therefore used in a wide range of industrial fields. However, since polyolefin has no polar group in the molecule and low polarity, it is often difficult to coat or adhere to a polyolefin substrate, and improvement in paintability and adhesiveness has been desired.

  As a method for modifying the surface of a polyolefin substrate, a method of chemically treating with a chemical or the like, a method of oxidizing the substrate surface by corona discharge treatment, plasma treatment, flame treatment or the like are known. However, these methods require not only a special device but also an effect of improving paintability and adhesiveness.

  As a method for modifying the surface of a polyolefin substrate, the surface of the substrate includes an olefin polymer or a graft copolymer in which a hydrophilic polymer is grafted to a modified polyolefin as a surface treatment agent, an adhesive, or a paint. A method of applying an aqueous resin dispersion is also known. As the modified polyolefin, chlorinated polypropylene, acid-modified propylene-α-olefin copolymer, acid-modified chlorinated polypropylene, or the like is used.

  In order to improve the performance and storage stability of the above-mentioned aqueous resin dispersion as a paint, a method of combining an olefin polymer or modified polyolefin with a polymer obtained by polymerizing a radical polymerizable monomer is also available. Proposed. For example, Patent Documents 1 and 2 disclose a method of emulsion polymerization of a vinyl monomer in an aqueous resin dispersion of a graft copolymer obtained by grafting a hydrophilic polymer or an unsaturated carboxylic acid to an olefin polymer. Is described. Patent Document 3 describes a method of polymerizing a vinyl monomer in a modified polyolefin aqueous resin dispersion. Patent Documents 4 and 5 describe a method in which an olefin polymer or a modified polyolefin is dispersed in water in the presence of a surfactant, followed by emulsion polymerization of a vinyl monomer.

JP 2011-46777 A JP 2006-36920 A JP 2004-91559 A JP 2002-308921 A JP2013-133417A

  However, in the methods described in Patent Documents 1 to 5, since the surfactant is contained in the aqueous resin dispersion in order to polymerize the radical polymerizable monomer, the paint using the obtained aqueous resin dispersion The adhesiveness and water resistance to a polypropylene substrate such as the above were not sufficient.

  This invention is made | formed in view of the said background, and provides the aqueous resin dispersion which has the outstanding adhesiveness and water resistance with respect to polyolefin base materials, such as a polypropylene base material, and its manufacturing method.

As a result of intensive studies, the inventors of the present invention have obtained an aqueous solution obtained by polymerizing the radical polymerizable monomer (B) in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less. The radically polymerizable monomer (B) in the resin dispersion (C) or the aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less and an acid value of 11 to 25 mgKOH / g It has been found that the above-mentioned problems can be solved by the aqueous resin dispersion (C) obtained by polymerizing (A).
That is, the present invention relates to the following.
[1] An aqueous resin dispersion (C) obtained by polymerizing a radical polymerizable monomer (B) in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less.
[2] The aqueous resin dispersion (C) according to [1], wherein the acid value of the aqueous resin dispersion (A) is 11 to 25 mg KOH / g.
[3] A method for producing an aqueous resin dispersion (C) in which the radical polymerizable monomer (B) is polymerized in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less.
[4] The aqueous resin according to [3], wherein the content of the surfactant in the aqueous resin dispersion (A) is 2 parts by mass or less with respect to 100 parts by mass of the radical polymerizable monomer (B). Production method of dispersion (C).

  According to the aqueous resin dispersion and the method for producing the same of the present invention, excellent adhesion and water resistance can be obtained even for a polyolefin substrate such as a polypropylene substrate.

  In the present invention, “dispersion” means a state in which solid particles are extremely small and exist as a single molecule in an aqueous medium, and is a concept including a state that can be said to be substantially dissolved.

[Aqueous resin dispersion (C)]
The aqueous resin dispersion (C) of the present invention (hereinafter also referred to as “aqueous resin dispersion (C)”) is a radical in the aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less. An aqueous resin dispersion obtained by polymerizing the polymerizable monomer (B). Hereinafter, with respect to the aqueous resin dispersion (C) of the present invention, “an aqueous resin dispersion of an olefin polymer (A)”, “radical polymerizable monomer (B)”, “aqueous resin dispersion (C)”. Will be described in the order.

≪Aqueous resin dispersion of olefin polymer (A) ≫
The olefin polymer aqueous resin dispersion (A) (hereinafter also referred to as “aqueous resin dispersion (A)”) refers to the olefin polymer (a1) (hereinafter also referred to as “polymer (a1)”). .) Means an aqueous resin dispersion dispersed in an aqueous medium.
The average particle diameter of the polymer (a1) dispersed in the aqueous resin dispersion (A) is 100 nm or less, and preferably 80 nm or less. When the average particle size is 100 nm or less, when polymerizing the radical polymerizable monomer (B) in the aqueous resin dispersion (A), cullet is generated due to destabilization of the aqueous resin dispersion (A). Tends to be reduced, and the adhesion to the polypropylene substrate tends to be less likely to be hindered. The lower limit of the average particle diameter is theoretically 0 and is not particularly limited. Incidentally, the average particle size means a cumulant average particle diameter measured by light scattering photometer (D _50).

  The acid value of the aqueous resin dispersion (A) is preferably 11 to 25 mgKOH / g, and more preferably 13 to 20 KOHmg / g. If the acid value is 11 mgKOH / g or more, the aqueous resin dispersion (A) and the radical polymerizable monomer (B) are compatible with each other, and cullet is formed even after polymerization of the radical polymerizable monomer (B). There is a tendency not to be generated. If the said acid value is 25 mgKOH / g or less, there exists a tendency for the adhesiveness with respect to the polypropylene base material of an aqueous resin dispersion (C) to be excellent.

<Polymer (a1)>
The polymer (a1) is preferably a propylene-based polymer containing a propylene-derived structural unit from the viewpoint of excellent adhesion to a polypropylene substrate.
The content of propylene-derived structural units in the propylene-based polymer is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more with respect to all the structural units.
The melting point (Tm) of the propylene-based polymer is preferably 125 ° C. or lower, more preferably 100 ° C. or lower, and further preferably 90 ° C. or lower. The melting point of the propylene polymer is preferably 60 ° C. or higher.

The polymer (a1) may be a homopolymer or a copolymer.
Examples of the polymer (a1) include an olefin polymer (a11) having no reactive group (hereinafter also referred to as “polymer (a11)”), and a modified olefin polymer (a12) having a reactive group. (Hereinafter also referred to as “polymer (a12)”).

(Polymer (a11))
The polymer (a11) is not particularly limited, and various known olefin homopolymers and olefin copolymers can be used. Specifically, the following polyolefin is mentioned, for example.
A homopolymer of ethylene or propylene; a copolymer of ethylene and propylene; a monomer copolymerizable with at least one of ethylene and propylene and ethylene and propylene (for example, butene-1, pentene-1, hexene-1, A copolymer with α-olefin having 4 or more carbon atoms such as heptene-1, octene-1, cyclopentene, cyclohexene, norbornene); from two or more selected from the group consisting of the α-olefin having 4 or more carbon atoms A copolymer of an α-olefin having 2 or more carbon atoms and a non-aromatic monomer other than an α-olefin such as vinyl acetate, acrylic acid ester or methacrylic acid ester; having 2 or more carbon atoms Copolymer of α-olefin and aromatic monomer such as aromatic vinyl monomer or hydrogenated product thereof; Conjugated diene block copolymer Body or hydrogenated product thereof.
The α-olefin having 2 or more carbon atoms is preferably an α-olefin having 2 to 4 carbon atoms. In addition, as a polymer (a11), you may use the chlorinated polyolefin which chlorinated the above-mentioned polyolefin. In this case, the chlorination degree of the chlorinated polyolefin is usually 5% by mass or more, preferably 10% by mass or more. Moreover, the chlorination degree of chlorinated polyolefin is 40 mass% or less normally, Preferably it is 30 mass% or less.
In addition, when it is simply referred to as “copolymer”, it may be a random copolymer or a block copolymer.

  Specific examples of the polymer (a11) include polyethylene, polypropylene, ethylene-butene copolymer, ethylene-propylene copolymer, propylene-butene copolymer, propylene-hexene copolymer, chlorinated polyethylene, and chlorinated polypropylene. , Chlorinated ethylene-propylene copolymer, chlorinated propylene-butene copolymer, ethylene-vinyl acetate copolymer, hydrogenated product of styrene-butadiene-styrene block copolymer (SEBS), styrene-isoprene-styrene block Examples thereof include a hydrogenated copolymer (SEPS). These polymers (a11) may be used individually by 1 type, and may be used in combination of 2 or more type. The polymer (a11) may be linear or branched.

As the polymer (a11), a propylene homopolymer or a copolymer of propylene and an α-olefin other than propylene is preferable, and a propylene homopolymer, an ethylene-propylene copolymer, and a propylene-butene copolymer are preferable. More preferred. These polymers (a11) may be chlorinated, but preferably contain few chlorine atoms, more preferably not chlorinated.
The most preferred embodiment of the polymer (a11) is a propylene homopolymer containing no chlorine atom, an ethylene-propylene copolymer containing no chlorine atom, a propylene-butene copolymer containing no chlorine atom, and no chlorine atom. It is an ethylene-propylene-butene copolymer.
These polymers (a11) may be used individually by 1 type, and may be used in combination of 2 or more type.

  As the polymer (a11), a propylene-based polymer containing a propylene-derived structural unit is preferable. The content of propylene-derived structural units in the propylene-based polymer is preferably 50 mol% or more, more preferably 60 mol% or more, and even more preferably 70 mol% or more with respect to all the structural units. As the content rate of the structural unit derived from propylene is higher, the adhesion to the polypropylene substrate tends to increase.

The weight average molecular weight (Mw) of the polymer (a11) is preferably 5,000 to 500,000. The lower limit of Mw of the polymer (a11) is more preferably 10,000, further preferably 20,000, and particularly preferably 30,000. As for the upper limit of Mw of a polymer (a11), 300,000 is more preferable. If Mw of a polymer (a11) is 5,000 or more, the stickiness degree of a coating film will become small and there exists a tendency for the adhesiveness to a polypropylene base material to increase. If the Mw of the polymer (a11) is 500,000 or less, the viscosity of the aqueous powdered resin dispersion is further reduced, and thus the aqueous powdered resin dispersion tends to be easily prepared.
In addition, Mw is the value converted into the calibration curve obtained by measuring each polymer with a known molecular weight using GPC (Gel Permeation Chromatography). GPC measurement is performed by a conventionally known method using a commercially available apparatus using orthodichlorobenzene or the like as a solvent.

The melting point (Tm) of the polymer (a11) is preferably 125 ° C. or lower. If the melting point of the polymer (a11) is 125 ° C. or lower, it is preferable because a high temperature is not required for drying and baking after the application of the obtained aqueous resin dispersion (C). The upper limit of the melting point of the polymer (a11) is more preferably 100 ° C, and further preferably 90 ° C.
The Tm of the polymer (a11) is preferably 60 ° C. or higher. When the melting point of the polymer (a11) is 60 ° C. or higher, the polymer (a11) is less likely to be sticky, and handling is easy when the aqueous resin dispersion (C) is used as a paint.

  The manufacturing method of a polymer (a11) will not be specifically limited if the polymer which satisfy | fills the requirements of this invention can be manufactured, For example, radical polymerization, cationic polymerization, anionic polymerization, coordination polymerization etc. are mentioned. These may be living polymerizing.

In the case of coordination polymerization, for example, a method of polymerizing with a Ziegler-Natta catalyst or a method of polymerizing with a single site catalyst can be mentioned, and a method of polymerizing with a single site catalyst is preferred. This is because the single-site catalyst can sharpen the molecular weight distribution and stereoregularity distribution by the ligand design.
As the single site catalyst, for example, a metallocene catalyst or a Brookhart catalyst can be used. As the metallocene catalyst, those having a symmetric type such as a C1 symmetric type, a C2 symmetric type, a C2V symmetric type, and a CS symmetric type are known. In the present invention, an appropriate symmetric metallocene catalyst may be selected and used according to the stereoregularity of the target olefin polymer.

  The polymerization may be any polymerization form such as solution polymerization, slurry polymerization, bulk polymerization, gas phase polymerization and the like. In the case of solution polymerization or slurry polymerization, examples of the solvent include aromatic hydrocarbons such as toluene and xylene; aliphatic hydrocarbons such as hexane, heptane and octane; alicyclic hydrocarbons such as cyclohexane and methylcyclohexane; Examples include hydrogen; esters; ketones; ethers and the like. Among these, aromatic hydrocarbons, aliphatic hydrocarbons, and alicyclic hydrocarbons are preferable, and toluene, xylene, heptane, and cyclohexane are more preferable. These solvent may be used individually by 1 type, and may be used in combination of 2 or more type.

(Polymer (a12))
As the polymer (a12), a copolymer (a121) obtained by copolymerizing an olefin and an unsaturated compound having a reactive group, or a radically polymerizable unsaturated compound having a reactive group is grafted to the olefin polymer. Examples thereof include a polymerized graft polymer (a122).

  The content of the reactive group in the polymer (a12) is preferably 0.01 to 1 mmol, that is, 0.01 to 1 mmol / g, per 1 g of the olefin polymer used for the polymer (a12). The lower limit of the content of the reactive group in the polymer (a12) is more preferably 0.05 mmol / g, further preferably 0.1 mmol / g. The upper limit of the content of the reactive group in the polymer (a12) is preferably 0.5 mmol / g, more preferably 0.3 mmol / g. If the content of the reactive group is 0.01 mmol / g or more, the acid value of the aqueous resin dispersion (A) increases, and the polymerizability of the radical polymerizable monomer (B) described later tends to improve. is there. Moreover, if the upper limit of content of a reactive group is 1 mmol / g or less, it exists in the tendency for the adhesiveness with respect to a polypropylene-type base material to increase.

When the reactive group in the polymer (a12) is an acidic group such as a carboxyl group or its anhydride or a sulfonyl group, the acid value of the aqueous resin dispersion (A) is increased by increasing the content of the acidic group. Can give.
Moreover, it exists in the tendency for the mechanical stability of the aqueous resin dispersion (C) of this invention to become favorable by neutralizing this acidic group with a basic compound.
Basic substances include inorganic bases such as sodium hydroxide, potassium hydroxide and ammonia; triethylamine, diethylamine, ethanolamine, dimethylethanolamine, 2-methyl-2-amino-propanol, triethanolamine, morpholine, pyridine, etc. Of the organic base.
The neutralization rate of the polymer (a12) with the basic compound is not particularly limited in the range of 1 to 100 mol% as long as dispersibility in water is obtained, and is preferably 50 mol% or more. As the neutralization rate is higher, the dispersibility of the polymer (a12) in water tends to be improved.

The copolymer (a121) is a copolymer obtained by copolymerizing an olefin and an unsaturated compound having a reactive group, and having a structural unit derived from the unsaturated compound having a reactive group inserted in the main chain. It is.
Examples of the olefin used for the copolymer (a121) include α-olefins such as ethylene, propylene, and butene. One olefin may be used alone, or two or more olefins may be used in combination.
Examples of the unsaturated compound having a reactive group used for the copolymer (a121) include α, β-unsaturated carboxylic acids or anhydrides such as acrylic acid and maleic anhydride. The unsaturated compound which has a reactive group may be used individually by 1 type, and may be used in combination of 2 or more type.

Specific examples of the copolymer (a121) include an ethylene-acrylic acid copolymer, an ethylene-acrylic acid ester-maleic anhydride copolymer, and the like. A copolymer (a121) may be used individually by 1 type, and may be used in combination of 2 or more type.
It can apply to the manufacturing method of a copolymer (a121) similarly to the method described as a manufacturing method of a polymer (a11).

The graft polymer (a122) can be obtained by graft polymerization of a radical polymerizable unsaturated compound having a reactive group to an olefin polymer. As the olefin polymer, the above-mentioned polymer (a11) can be used.
Examples of the reactive group include a carboxyl group, an amino group, an epoxy group, an isocyanato group, a sulfonyl group, and a hydroxyl group. Among these, a carboxyl group and its anhydride are preferable. Examples of the radical polymerizable unsaturated compound having a reactive group include (meth) acrylic acid, fumaric acid, maleic acid or its anhydride, itaconic acid or its anhydride, crotonic acid, and the like. These may be used individually by 1 type and may be used in combination of 2 or more type.
“(Meth) acrylic acid” is a general term for acrylic acid and methacrylic acid, and other compounds are also equivalent thereto.

  Specific examples of the graft polymer (a122) include maleic anhydride-modified polypropylene and its chlorinated product, maleic anhydride-modified ethylene-propylene copolymer and its chlorinated product, maleic anhydride-modified propylene-butene copolymer, acrylic acid Examples thereof include modified polypropylene and chlorinated products thereof, acrylic acid-modified ethylene-propylene copolymers and chlorinated products thereof, and acrylic acid-modified propylene-butene copolymers. These may be used individually by 1 type and may be used in combination of 2 or more type.

  The manufacturing method of a graft polymer (a122) will not be specifically limited if the polymer which satisfy | fills the requirements of this invention can be manufactured, What kind of manufacturing method may be sufficient. As a manufacturing method, the method of manufacturing by heating and stirring in a solution, the method of manufacturing by melting and heating without solvent, the method of manufacturing by heating and kneading with an extruder, etc. are mentioned. As a solvent in the case of manufacturing in a solution, the solvent illustrated as a manufacturing method of a polymer (a11) can be used similarly.

The radical polymerization initiator used for the graft polymerization can be appropriately selected from ordinary radical polymerization initiators, and examples thereof include organic peroxides and azonitriles.
Examples of organic peroxides include peroxyketals such as di (t-butylperoxy) cyclohexane; hydroperoxides such as cumene hydroperoxide; dialkyl peroxides such as di (t-butyl) peroxide; benzoylperoxide And diacyl peroxides such as oxide; and peroxyesters such as t-butyl peroxyisopropyl monocarbonate. These may be used individually by 1 type and may be used in combination of 2 or more type.
Examples of the azonitrile include azobisbutyronitrile and azobisisopropylnitrile. These may be used individually by 1 type and may be used in combination of 2 or more type.
As the radical polymerization initiator, benzoyl peroxide and t-butylperoxyisopropyl monocarbonate are preferable.

The use ratio of the radical polymerization initiator and the graft copolymer unit of the graft polymer (a122) is preferably radical polymerization initiator: graft copolymer unit = 1: 100 to 2: 1 (molar ratio), and 1:20 to 1: 1 is more preferred.
The reaction temperature of graft polymerization is usually 50 ° C. or higher, preferably in the range of 80 to 200 ° C. The reaction time for graft polymerization is usually about 2 to 20 hours.

<Aqueous medium>
The aqueous medium contains water and may contain a solvent other than water.
The content of the solvent other than water in the aqueous resin dispersion (A) is preferably 50% by mass or less, more preferably 20% by mass or less, and still more preferably 10% by mass or less with respect to the aqueous resin dispersion (A). 1% by mass or less is most preferable.
A solvent other than water is preferably a solvent that dissolves 1% by mass or more, more preferably a solvent that dissolves 5% by mass or more with respect to water. Examples of solvents other than water include ketones such as methyl ethyl ketone and cyclohexanone; alcohols such as n-propanol, isopropanol, n-butanol, isobutanol, t-butanol and cyclohexanol; ethers such as tetrahydrofuran; 2-methoxyethanol, 2-ethoxy Examples include glycol ethers such as ethanol, 2-butoxyethanol, 2-methoxypropanol, and 2-ethoxypropanol. These may be used individually by 1 type and may be used in combination of 2 or more type.

<Optional component>
The aqueous resin dispersion (A) may contain optional components other than the polymer (a1) and the aqueous medium. For example, a surfactant may be added to the aqueous resin dispersion (A) for the purpose of improving the storage stability of the aqueous resin dispersion (C) of the present invention. In addition, since the coating film obtained from the aqueous resin dispersion (C) has high water resistance, and there is little bleeding out and excellent stability, a hydrophilic polymer such as polyether resin may be added.

As the optional surfactant, various anionic, cationic, or nonionic surfactants or polymer surfactants can be used. In addition, so-called reactive surfactants having an ethylenically unsaturated bond in the surfactant component can also be used. Among these, it is preferable to use an anionic surfactant from the viewpoint of improving the storage stability of the aqueous resin dispersion (C) of the present invention.
The anionic surfactant is not particularly limited. For example, the reactive surfactant, ADEKA rear soap SR (trade name, manufactured by ADEKA Co., Ltd.) and the non-reactive surfactant Neocor SW-C ( Trade name, manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) can be used.

  The content of the surfactant in the aqueous resin dispersion (A) is preferably 2 parts by mass or less, more preferably 1 part by mass or less, and not contained with respect to 100 parts by mass of the radical polymerizable monomer (B). Is more preferable. If content of the said surfactant is 2 mass parts or less, the stability at the time of paint formulation can be maintained, without impairing water resistance.

  The details of the optional hydrophilic polymer and preferred embodiments thereof are described in the section “Method for producing aqueous resin dispersion (A)” in “Method for producing aqueous resin dispersion (C)” of the present invention described later. explain.

  The aqueous resin dispersion (A) described above is changed to the aqueous resin dispersion (C) of the present invention by polymerizing the radical polymerizable monomer (B) described later in the aqueous resin dispersion. That is, the aqueous resin dispersion (A) is a raw material of the aqueous resin dispersion (C) of the present invention.

≪Radically polymerizable monomer (B) ≫
The radical polymerizable monomer (B) is preferably a vinyl monomer since it is excellent in polymerizability. Examples of vinyl monomers include (meth) acrylic monomers such as (meth) acrylic acid and (meth) acrylic acid esters; aromatic monomers such as styrene and α-methylstyrene; (meth) acrylamide Amide monomers such as dimethyl (meth) acrylamide; (meth) acrylonitrile, vinyl acetate, vinyl propionate, vinyl versatate and the like. These may be used individually by 1 type and may be used in combination of 2 or more type. Among these, (meth) acrylic monomers and aromatic monomers are preferable in terms of weather resistance and solvent resistance.

Specific examples of the (meth) acrylic monomer include methyl (meth) acrylate, ethyl (meth) acrylate, (meth) acrylate-n-propyl, isopropyl (meth) acrylate, and (meth) acrylic acid. -N-butyl, isobutyl (meth) acrylate, (t-butyl) (meth) acrylate, hexyl (meth) acrylate, cyclohexyl (meth) acrylate, octyl (meth) acrylate, (meth) acrylic acid-2 -Ethylhexyl, nonyl (meth) acrylate, lauryl (meth) acrylate, stearyl (meth) acrylate, or the like or (meth) acrylic acid ester having an aryl group or aralkyl group having 6 to 12 carbon atoms (for example, (meth) Benzyl acrylate), dimethylaminoethyl (meth) acrylate, diethylaminoethyl (meth) acrylate , (Meth) acrylic acid-2-aminoethyl, (meth) acrylic acid glycidyl, (meth) acrylic acid-2-methoxyethyl, (meth) acrylic acid-3-methoxypropyl, (meth) acrylic acid and polyethylene oxide (Meth) acrylic acid esters having a fluoroalkyl group having 1 to 20 carbon atoms (for example, trifluoromethylmethyl (meth) acrylate, 2-trifluoromethylethyl (meth) acrylate, (meth ) Acrylic acid-2-perfluoroethylethyl) and the like.
Specific examples of the aromatic monomer include styrene and α-methylstyrene.

The radical polymerizable monomer (B) improves the coating film performance of a coating composition obtained by mixing the aqueous resin dispersion (C) with a crosslinking agent such as melamine resin and isocyanate. It is preferable to use a combination of at least one or more kinds of monomers.
Examples of the hydroxyl group-containing vinyl monomer include (meth) acrylic acid-2-hydroxyethyl, (meth) acrylic acid-2-hydroxypropyl, (meth) acrylic acid-4-hydroxybutyl, and the like. The amount of the hydroxyl group-containing vinyl monomer used for the polymerization is preferably 5 to 30 parts by mass with respect to the vinyl monomer in the mixture of the radical polymerizable monomer (B).

  The radical polymerizable monomer (B) is polymerized in the above-described aqueous resin dispersion (A) to thereby form a polymer (b1) (hereinafter referred to as a component containing a structural unit derived from the radical polymerizable monomer (B)). (Also referred to as “polymer (b1)”). That is, the radical polymerizable monomer (B) is a raw material for the polymer (b1) and a raw material for the aqueous resin dispersion (C) of the present invention. For details of the polymerization of the radical polymerizable monomer (B) and preferred embodiments thereof, the “polymerization of the radical polymerizable monomer (B)” in the “method for producing an aqueous resin dispersion (C)” of the present invention described later will be described. This will be described in detail in the section.

≪Aqueous resin dispersion (C) ≫
The aqueous resin dispersion (C) is an aqueous resin dispersion in which the polymer (a1) and the polymer (b1) are dispersed in an aqueous medium. In addition, about the detail of a polymer (a1) and a polymer (b1), and its preferable aspect, in the "aqueous resin dispersion (C)" of the above-mentioned this invention, "the aqueous resin dispersion (A) of an olefin polymer" ”And“ Radically polymerizable monomer (B) ”.

  In the aqueous resin dispersion (C) of the present invention, the polymer (a1) and the polymer (b1) may be dispersed as separate particles, and the polymer (a1) and the polymer (b1) It may be dispersed as composite particles. From the viewpoint of the stability of the aqueous resin dispersion (C), it is preferable to include composite particles of the polymer (a1) and the polymer (b1).

  The mass ratio (b1) / (a1) (solid content) of the polymer (b1) to the polymer (a1) contained in the aqueous resin dispersion (C) is preferably 0.5 to 2. The larger the mass ratio (b1) / (a1) is within the above range, the easier it is to produce the aqueous resin dispersion stably, and the storage stability of the aqueous resin dispersion is improved. Moreover, the smaller the mass ratio (b1) / (a1) is within the above range, the better the initial adhesion of the coating film to a polyolefin substrate such as a polypropylene substrate.

<Aqueous medium and optional component in aqueous resin dispersion (C)>
The aqueous medium and optional components in the aqueous resin dispersion (C) are water-based materials described in the section “Aqueous resin dispersion (A) of olefin polymer” in the above-mentioned “aqueous resin dispersion (C) of the present invention”. The same kind of aqueous medium and optional component as the medium and optional component may be included.

(Use)
The aqueous resin dispersion (C) of the present invention can be used as a primer, a paint, an adhesive, an ink binder, a compatibilizing agent for a different material from polyolefin, and particularly suitable for a composition such as a paint, an ink, and an adhesive. Can be used. The paint can be used for automobile paints for interior and exterior of automobiles, paints for home appliances such as mobile phones and personal computers, paints for building materials, heat sealants and the like.
The aqueous resin dispersion (C) of the present invention can be particularly suitably used as a primer for a plastic substrate, particularly a polypropylene substrate, and a coating for an automobile interior 1 coat.

(Function and effect)
As described above, the aqueous resin dispersion (C) of the present invention is obtained by polymerizing the radical polymerizable monomer (B) in the aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less. This is an aqueous resin dispersion (C). When the average particle diameter of the olefin polymer dispersed in the aqueous resin dispersion (A) is 100 nm or less, the radical polymerizable monomer (B) is polymerized in the aqueous resin dispersion (A). Since the formation of cullet due to destabilization of the aqueous resin dispersion (A) is reduced, particle stability is improved as a coating material, and excellent adhesion and water resistance to polyolefin substrates such as polypropylene substrates Is obtained.

[Method for producing aqueous resin dispersion (C)]
The method for producing an aqueous resin dispersion (C) of the present invention is an aqueous resin in which a radical polymerizable monomer (B) is polymerized in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less. It is a manufacturing method of a dispersion (C).
Hereinafter, the production method of the aqueous resin dispersion (C) of the present invention will be described in the order of “production method of aqueous resin dispersion (A)” and “polymerization of radical polymerizable monomer (B)”. The details of the aqueous resin dispersion (A) and the radical polymerizable monomer (B) and preferred embodiments thereof are the same as the contents described in the respective sections of the “aqueous resin dispersion (C)” of the present invention described above. It is the same.

≪Method for producing aqueous resin dispersion (A) ≫
The method for producing the aqueous resin dispersion (A) is not particularly limited. For example, after preparing a mixture of the polymer (a1) and an aqueous medium (water and a solvent other than water), a solvent other than water is prepared from the mixture. A method for removing the polymer to make a dispersion of the polymer (a1), adding a solvent other than water to the polymer (a1), heating and dissolving as necessary, and then adding water to the polymer (a1) And the like.

  The method of dispersing the polymer (a1) in the aqueous medium may be a method of blending and dispersing a surfactant, and a graft copolymer obtained by grafting a hydrophilic polymer to the polymer (a1). A method of dispersing the surfactant without blending it may be used, but is not particularly limited. The latter method is preferred because the coating film obtained from the aqueous resin dispersion (C) of the present invention has high water resistance, low bleed-out, etc. and excellent stability.

  The hydrophilic polymer graft-bonded to the polymer (a1) is a polymer having an insoluble content of less than 1% by mass when dissolved in water at 25 ° C. at a concentration of 10% by mass. As the hydrophilic polymer, various polymers such as a synthetic polymer, a semi-synthetic polymer, and a natural polymer can be used without particular limitation as long as the effects of the present invention are not significantly impaired. Since the aqueous resin dispersion (A) is excellent in mechanical stability, the number average molecular weight Mn is preferably 300 or more.

  Synthetic polymers that can be used as hydrophilic polymers include, but are not limited to, polyether resins, polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and the like. Examples of natural polymers that can be used as hydrophilic polymers include, but are not limited to, starch, gum arabic, tragacanth gum, casein, gelatin, and dextrin. Examples of the semisynthetic polymer that can be used as the hydrophilic polymer include, but are not limited to, carboxylated starch, cationized starch, dextrin, ethyl cellulose, carboxylated methyl cellulose, hydroxyethyl cellulose, and cationized cellulose.

Among the hydrophilic polymers, synthetic polymers are preferable, and polyvinyl alcohol resins, polyvinyl pyrrolidone resins, and polyether resins are more preferable because the degree of hydrophilicity can be easily controlled and the characteristics are stable. In order to control the average particle diameter of the aqueous resin dispersion (A) of the olefin polymer (a1), these may be used singly or in combination of two or more. Among these, a highly hydrophilic polyether resin is preferable.
The polyether resin is usually produced by ring-opening polymerization of cyclic alkylene oxide or cyclic alkylene imine. The polyether resin may be contained in the aqueous resin dispersion (A), and the polymer (a1) and the polyether resin may be chemically bonded. The latter is preferred because the polyether resin does not bleed out.

  As the polyether resin, a hydrophobic polyether resin may be used in combination in order to adjust the HLB or to control the average particle diameter of the aqueous resin dispersion (A). Here, the hydrophobic polymer means a polymer having an insoluble content of 1% by mass or more when dissolved in water at 25 ° C. at a concentration of 10% by mass.

  The structural unit of the polyether resin is preferably composed of polyethylene oxide or polyethyleneimine exhibiting hydrophilicity and polypropylene oxide or polypropyleneimine exhibiting hydrophobicity. More preferably, it is composed of polyethylene oxide and polypropylene oxide. The HLB of the polyether resin can be adjusted by the number of repeating units of polyethylene oxide and polypropylene oxide.

  The polyether resin preferably has a weight average molecular weight (Mw) of 200 to 200,000 as measured by GPC and converted using a polystyrene calibration curve. A more preferable value of the lower limit value of Mw is 300, and a more preferable value is 500. A more preferable value of the upper limit value of Mw is 100,000, a more preferable value is 10,000, and a further preferable value is 3,000. As Mw is higher than the lower limit, the surface energy of the aqueous resin dispersion is lowered and the wettability tends to be improved. Moreover, it exists in the tendency for a viscosity to become low and to prepare a resin dispersion easily, so that Mw is lower than the said upper limit. The GPC measurement is performed by a conventionally known method using a commercially available apparatus using tetrahydrofuran or the like as a solvent.

  In the polymer (a1), from the viewpoint of the polymerizability of the radical polymerizable monomer (B), the polymer (a1) and the polyether resin are polymer (a1): polyether resin = 100: 1 to 100. : The thing couple | bonded in the ratio of 100 (mass ratio) is preferable. This mass ratio is more preferably 100: 5 to 100: 70, and still more preferably 100: 10 to 100: 50. The larger the mass ratio of the polyether resin, the smaller the particle size of the polymer (a1). Further, the smaller the mass ratio of the polyether resin is, the higher the acid value of the aqueous resin dispersion (A) is, and the adhesiveness to the polypropylene substrate tends to be improved.

  The mode of bonding between the polymer (a1) and the polyether resin is not particularly limited. For example, a method of ring-opening polymerization of a cyclic alkylene oxide in the polymer (a12), a polyether polyol obtained by ring-opening polymerization, etc. Examples thereof include a method of reacting a reactive group such as polyetheramine with a reactive group of the polymer (a12).

The polyether polyol has hydroxyl groups as reactive groups at both ends of a resin having a polyether skeleton.
Polyetheramine has a primary amino group as a reactive group at one or both ends of a resin having a polyether skeleton. As the polyether resin to be bonded, polyetheramine is preferable. Examples of the polyetheramine include “Jeffamine” M series, D series, ED series, “Surphonamine” L series, etc., manufactured by Huntsman.

  The polyether resin preferably has at least one reactive group capable of reacting with the polymer (a12) before being bonded to the polymer (a12). Examples of the reactive group include a carboxyl group, a dicarboxylic acid anhydride group, a dicarboxylic acid anhydride monoester group, a hydroxyl group, an amino group, an epoxy group, an isocyanate group, and the like, and preferably has at least an amino group. Since the amino group is highly reactive with various reactive groups such as a carboxylic acid group, a carboxylic anhydride group, a glycidyl group, and an isocyanate group, it is easy to bond the polymer (a12) and the polyether resin. The amino group may be primary, secondary, or tertiary, but more preferably is a primary amino group.

  There may be one or more reactive groups in the polyether resin, but a more preferable number of reactive groups is one. When there are two or more reactive groups, there is a possibility that a three-dimensional network structure will be formed when the polymer (a12) is bonded, resulting in gelation. However, even if it has a plurality of reactive groups, it may not gel, such as in the case of a polyether resin having only one reactive group higher than the others. Examples of such polyether resins include polyether resins having one or more hydroxyl groups and one amino group having a higher reactivity. Here, the reactivity is the reactivity with the reactive group of the polymer (a12).

  As a method of obtaining a water-based resin dispersion (A) by dispersing a graft copolymer obtained by grafting a hydrophilic polymer to the polymer (a1) in water, a solvent other than water is added, and if necessary For example, there may be mentioned a method of adding water after heating and dissolving.

  If a method of adding water after adding a solvent other than water and heating and dissolving as necessary is required, it becomes somewhat easy to produce an aqueous resin dispersion (A) having a fine particle size. The temperature at the time of dissolution in a solvent other than water or at the time of addition of water is usually 30 to 150 ° C, preferably 50 ° C to 100 ° C. Moreover, when dissolving once in solvents other than water, after adding water, you may distill a solvent off.

  Although it does not specifically limit as an apparatus used with the manufacturing method of the aqueous resin dispersion (A) which adds water after making it melt | dissolve in a solvent, For example, a reaction kettle with a stirring apparatus, a uniaxial or biaxial kneader etc. are used. it can. The stirring speed at that time varies slightly depending on the selection of the apparatus, but is usually in the range of 10 to 1000 rpm. When the stirring speed is higher than the lower limit value, the particle size of the aqueous resin dispersion (A) tends to increase.

≪Polymerization of radical polymerizable monomer (B) ≫
As the method for producing the aqueous resin dispersion (C) of the present invention, after obtaining the aqueous resin dispersion (A), the radical polymerizable monomer (B) is polymerized in the aqueous resin dispersion (A). Examples of the method include (1), a method (2) in which the olefin polymer (a1) and the radical polymerizable monomer (B) are dispersed in an aqueous medium and then polymerized, but are not limited thereto. From the viewpoint of polymerizability of the radical polymerizable monomer (B), the method (1) is preferable.

In the polymerization of the radical polymerizable monomer (B), any one of batch polymerization and dropwise polymerization can be used as long as the effects of the present invention are not impaired. Here, collective polymerization is a method in which the entire amount of the radical polymerizable monomer (B) is charged and polymerized at once. When batch polymerization is adopted in the method (1), for example, the water-soluble initiator or organic peroxide is mixed with the aqueous resin dispersion (A) after the entire amount of the radical polymerizable monomer (B) is mixed. Polymerization is carried out by adding a redox initiator containing a reducing agent such as sodium thiosulfate. Moreover, dripping polymerization is a method of polymerizing while dropping monomers little by little. When employing drop polymerization in the method (1), for example, polymerization is performed while dropping the radical polymerizable monomer (B) into the aqueous resin dispersion (A).
From the viewpoint of polymerization stability and adhesion to a polyolefin substrate such as a propylene substrate, it is preferable to employ batch polymerization for the method (1). More preferably, the radically polymerizable monomer (B) containing 80 to 100% by mass of the vinyl monomer is supplied in a batch with respect to the total amount of the monomer (B) and polymerized.

  As the initiator used for the polymerization, those generally used for radical polymerization can be used. Specific examples include persulfates such as potassium persulfate, sodium persulfate, and ammonium persulfate; azobisisobutyronitrile, 2,2′-azobis (2-methylbutyronitrile), 2,2′-azobis ( 2,4-dimethylvaleronitrile), 2,2′-azobis (4-methoxy-2,4-dimethylvaleronitrile), oil-soluble azo compounds such as 2-phenylazo-4-methoxy-2,4-dimethylvaleronitrile 2,2′-azobis {2-methyl-N- [1,1-bis (hydroxymethyl) -2-hydroxyethyl] propionamide}, 2,2′-azobis {2-methyl-N- [2 -(1-hydroxyethyl)] propionamide}, 2,2′-azobis {2-methyl-N- [2- (1-hydroxybutyl)] propionamide}, 2,2 ′ Azobis [2- (5-methyl-2-imidazolin-2-yl) propane] and salts thereof; 2,2′-azobis [2- (2-imidazolin-2-yl) propane] and salts thereof; 2,2 '-Azobis {2- [1- (2-hydroxyethyl) -2-imidazolin-2-yl] propane} and salts thereof; 2,2'-azobis (2-methylpropyneamidine) and salts thereof; Water-soluble azo compounds such as 2′-azobis [N- (2-carboxyethyl) -2-methylpropionamidine]; benzoyl peroxide, cumene hydroperoxide, t-butyl hydroperoxide, t-butyl peroxy-2 -Organic peroxides such as ethyl hexanoate and t-butyl peroxyisobutyrate. These initiators may be used individually by 1 type, and may be used in combination of 2 or more type.

  The polymerization temperature is preferably 50 ° C. or higher from the viewpoint of the polymerization rate of the obtained aqueous resin dispersion (C). In this case, it is preferable to use a reducing agent such as sodium bisulfite, ferrous sulfate, isoascorbate or Rongalite as an initiator in combination with a water-soluble polymerization catalyst.

  The polymerization time is preferably 30 minutes or longer. When the polymerization time is 30 minutes or longer, the radical polymerizable monomer (B) is sufficiently polymerized and the polymerization rate tends to be excellent. The polymerization time is preferably 3 hours or less. When the polymerization time is 3 hours or less, cullet is hardly generated during the polymerization, and the production stability tends to be excellent.

  When performing the polymerization, a known chain transfer agent such as n-dodecyl mercaptan, t-dodecyl mercaptan, α-methylstyrene dimer may be used as a molecular weight adjusting agent.

  After the polymerization reaction is completed, when cooling and taking out the aqueous resin dispersion (C), it is preferable to perform a filtration operation in order to prevent contamination of foreign matters and cullet. As the filtration method, a known method can be used. For example, nylon mesh, bag filter, filter paper, metal mesh, etc. can be used.

(Use)
The aqueous resin dispersion (C) obtained by the production method of the present invention is a primer, a paint, an adhesive, an ink binder, as described above in the section “Application” of the aqueous resin dispersion (C). It can be used as a compatibilizing agent for different materials from polyolefin, and can be suitably used particularly for paints, inks and adhesives.

(Coating composition)
The aqueous resin dispersion (C) of the present invention can be used for a coating composition. Constituent components of the coating composition include, in addition to the aqueous resin dispersion (C), inorganic fillers, resin beads, film-forming aids, base material wetting agents, base material wetting agents, acrylic resins, urethane resins, and polyester resins. Various additives such as a colorant, an antifoaming agent, and a thickener may be included as necessary. Known additives can be used as these additives.

  An organic solvent can be used as a film-forming auxiliary compounded for the purpose of increasing the drying speed or obtaining a surface with a good finish feeling. Examples of the organic solvent include alcohols such as methanol, ethanol and isopropanol; ketones such as acetone; glycols such as ethylene glycol, propylene glycol, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether and propylene glycol monomethyl ether, and ethers thereof.

(Function and effect)
As described above, the method for producing the aqueous resin dispersion (C) of the present invention is based on the radical polymerizable monomer (B) in the aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less. Is a method for producing an aqueous resin dispersion (C). When the average particle diameter of the olefin polymer dispersed in the aqueous resin dispersion (A) is 100 nm or less, the radical polymerizable monomer (B) is polymerized in the aqueous resin dispersion (A). The production of cullet due to destabilization of the aqueous resin dispersion (A) is reduced. Furthermore, since it is not necessary to use a surfactant at the time of polymerization of the radical polymerizable monomer, particle stability is improved as a paint, and excellent adhesion and water resistance to polyolefin substrates such as polypropylene substrates. Sex is obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited by the following description. In the examples, “parts” and “%” represent “parts by mass” and “% by mass”, respectively.

[Properties of aqueous resin dispersion (A)]
1. Average particle diameter The average particle diameter of the aqueous resin dispersion (A) is a cumulant average particle diameter (D ₅₀ ) measured with a light scattering photometer “Dense particle size analyzer FPAR-1000” (trade name, manufactured by Otsuka Electronics Co., Ltd.). Was used.

2. Acid value Aqueous resin dispersion (A) was dissolved in toluene / ethanol, and the value obtained by titration with 0.1N KOH ethanol solution using phenolphthalein as an indicator was used as the solid value of aqueous resin dispersion (A). Calculated by dividing by minutes.

[Evaluation of aqueous resin dispersion (C)]
1. Polymerization rate of radical polymerizable monomer From the solid content of the aqueous resin dispersion obtained after polymerization of the radical polymerizable monomer, the polymerization rate (% by mass) at the time of polymerization of the radical polymerizable monomer was calculated by the following formula (1). .
Polymerization rate (mass%) = (total solid content−olefin polymer solid content) / (charge amount of radical polymerizable monomer) (1)
○: The polymerization rate is 96% by mass or more. Δ: The polymerization rate is 90% by mass or more and less than 96% by mass.

2. Initial adhesiveness 3 parts by mass of TEGO WET KL-245 (manufactured by EVONIK) as a substrate wetting agent was added to the solid content of the aqueous resin dispersion, and the mixture was stirred with a homodisper stirrer (Polytron PT-3100) at 700 rpm for 5 minutes. A water-based paint was left for one day at room temperature and filtered through 300 mesh.

  A 3 mm thick substrate surface molded from a polypropylene resin (manufactured by Nippon Polypro Co., Ltd.) “TSOP-6” was wiped with isopropyl alcohol. The aqueous paint obtained on this substrate was spray-coated to a dry film thickness of 20μ, set at room temperature for 10 minutes, then dried in an atmosphere of 80 ° C. for 30 minutes in a safe ben dryer to form a coating film, This was left still at room temperature for 1 day, and the test piece was obtained.

On the coating surface of the prepared test piece, 11 incisions were made at intervals of 1 mm in length and breadth so as to reach the base material, and 100 grids were made. The state of the coating film after having been peeled off rapidly was observed, and the number of cells remaining on the coating film surface without peeling was confirmed. The initial adhesion of the coating film to the substrate was evaluated based on the following evaluation criteria.
○: In 100 squares, 91 to 100 squares remain on the coating surface.
Δ: Of 100 squares, 81 to 90 squares remain on the coating surface.
X: Less than 80 squares remain in the coating film surface in 100 squares.

3. Water Resistance Adhesive After obtaining a test piece in the same manner as the “initial adhesion” evaluation method, the test piece was immersed in warm water at 60 ° C. for 1 day. Subsequently, the test piece was taken out from the warm water and dried.
Next, on the coating surface of the test piece, 11 cuts were made at intervals of 1 mm in length and breadth so as to reach the base material, 100 grids were made, and a cellophane adhesive tape was applied thereon, and then the adhesive tape The state of the coating film after having been peeled off rapidly was observed, and the number of cells remaining on the coating film surface without peeling was confirmed. The water-resistant adhesion was evaluated based on the same evaluation criteria as the initial adhesion.

[Production of maleic anhydride-modified propylene copolymer]
“Tafmer XM-7070” which is a propylene-butene copolymer polymerized by a metallocene catalyst (Mitsui Chemicals, melting point 75 ° C., propylene content 74 mol%, weight average molecular weight (Mw) 250,000 (polypropylene conversion) 200 kg of molecular weight distribution (Mw / Mn) 2.2) and 5 kg of maleic anhydride were dry blended with a supermixer, and then propylene-butene copolymer using a twin screw extruder (“TEX54αII” manufactured by Nippon Steel Co., Ltd.) While feeding t-butyl peroxyisopropyl monocarbonate (“Perbutyl I” manufactured by NOF Corporation) halfway with a liquid pump so that the amount becomes 1 part by mass with respect to 100 parts by mass of the coalescence, the cylinder temperature of the kneading part is 200 Kneading under the conditions of ℃, screw rotation speed 125rpm, discharge rate 80kg / hour, Jo maleic anhydride-modified propylene - to give a butene copolymer.
The maleic anhydride group content (graft ratio) of the maleic anhydride-modified propylene-butene copolymer thus obtained was 1.0% by mass (0.1 mmol / g as maleic anhydride group, carboxylic acid group 0.2 mmol / g). Moreover, the weight average molecular weight (polystyrene conversion) (Mw) was 156,000, and the number average molecular weight (Mn) was 84,000.

[Production Example 1: Production of aqueous resin dispersion (A1)]
In a glass flask equipped with a reflux condenser, a thermometer, and a stirrer, 100 g of the maleic anhydride-modified propylene-butene copolymer obtained in Production Example 1 and 50 g of toluene were placed, and the inside of the container was replaced with nitrogen gas. The temperature was raised to ° C. After raising the temperature, 2.0 g of maleic anhydride was added, 1 g of t-butyl peroxyisopropyl monocarbonate (“Perbutyl I” manufactured by NOF Corporation) was added, and the reaction was continued for 7 hours at the same temperature.
The maleic anhydride group content (graft ratio) of the resulting maleic anhydride-modified propylene-butene copolymer was 2.0% by mass (0.2 mmol / g as the maleic anhydride group, 0.4 mmol as the carboxylic acid group) / G).
After completion of the reaction, the system was cooled to around room temperature, 70 g of toluene was added, and then 20 g of “Jefamine M-2005” dissolved in 90 g of 2-propanol (HLB3 number average molecular weight 2000 maleic anhydride modified propylene-butene copolymer) (It corresponds to 20 parts by mass with respect to 100 parts by mass of the union), and the mixture was reacted at 70 ° C for 1 hour. Thereafter, 10 g of “Jefamine M-1000” dissolved in 90 g of 2-propanol (corresponding to 10 parts by mass with respect to 100 parts by mass of HLB17 number average molecular weight 1000 maleic anhydride-modified propylene-butene copolymer) was added at 70 ° C. For 1 hour.
Thereafter, 2 g of dimethylethanolamine and 54 g of water were added to neutralize the system. Maintaining the temperature of the obtained reaction liquid at 45 ° C., heating and stirring, adding 300 g of water dropwise, lowering the degree of vacuum in the system and reducing toluene and 2-propanol to a polymer concentration of 30% by mass under reduced pressure. Thus, a milky white aqueous resin dispersion (A1) having an average particle diameter of 70 nm was obtained. In addition, the surfactant is not added to the aqueous resin dispersion (A1).

[Production Example 2: Production of aqueous resin dispersion (A2)]
In order to adjust the particle size of Production Example 2 to 90 nm, an aqueous resin dispersion (A2) was obtained in the same manner as Production Example 1 except that the stirring speed was lowered.

[Production Examples 3 to 5: Production of aqueous resin dispersions (A3) to (A5)]
Aqueous resin dispersions (A3) to (A5) were prepared in the same manner as in Production Example 2 except that the maleic anhydride of Production Example 1 and Jeffamine M-2005 and M-1000 were changed as shown in Table 1. Obtained.

[Example 1]
A flask equipped with a stirrer, a reflux condenser, and a temperature controller was charged with 333 parts of the aqueous resin dispersion (A1) (100 parts in solid content) and 119.6 parts of deionized water, and stored at 30 ° C.
Next, as a vinyl monomer, 10.4 parts of 4-hydroxybutyl acrylate (4HBA), 44.8 parts of butyl acrylate (BA), 44.8 parts of isobutyl methacrylate (iBMA) are put at 50 ° C. Stored for 1 hour.
0.02 part of perbutyl H69 (manufactured by NOF Corporation) as an initiator, 1.0 part of deionized water, 0.002 part of iron sulfate heptahydrate, 0.00027 part of ethylenediaminetetraacetic acid, sodium erythorbate 08 parts were charged to initiate polymerization.
After detecting the exothermic peak of polymerization, 0.03 part of perbutyl H69 and 10.0 part of deionized water were added dropwise over 15 minutes.
After completion of dropping, the mixture was aged at 60 ° C. for 30 minutes to obtain an aqueous resin dispersion (C) having an average particle size of 80 nm.

[Examples 2 to 5]
An aqueous resin dispersion (C) was obtained in the same manner as in Example 1 except that the aqueous resin dispersion (A1) was changed as shown in Table 1 in Example 1.

[Comparative Examples 1 and 2]
Emulsions of Comparative Examples 1 and 2 in the same manner as in Example 1 except that the aqueous resin dispersion (A1) in Example 1 was changed to APTLOCK BW-5550 manufactured by Mitsubishi Chemical Corporation and Hardlen NZ-1015 manufactured by Toyobo Co., Ltd. Got. The evaluation results of the obtained emulsion are shown in Table 2.

As shown in Table 2, aqueous resin dispersions of Examples 1 to 5 obtained by polymerizing vinyl monomers in aqueous resin dispersions (A1) to (A5) having an average particle size of 100 nm or less ( C) was superior in water-resistant adhesion as compared with the emulsion of Comparative Example 1 using an aqueous resin dispersion having an average particle size of 105 nm.
When a vinyl monomer was polymerized in hardene NZ-1015 having an average particle size of 165 nm, the dispersibility of the reaction product was poor and evaluation was impossible.

  As explained in the above examples, the method for producing an aqueous resin dispersion (C) is a radical polymerizable monomer (A) in an aqueous olefin polymer dispersion (A) having an average particle size of 100 nm or less. B) is a method of polymerizing, and since the aqueous resin dispersion (A) does not contain a surfactant, the aqueous resin dispersion excellent in initial adhesion and water-resistant adhesion to a polypropylene substrate I was able to provide a body.

Claims (4)

  An aqueous resin dispersion (C) obtained by polymerizing a radical polymerizable monomer (B) in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less.   The aqueous resin dispersion (C) according to claim 1, wherein the acid value of the aqueous resin dispersion (A) is 11 to 25 mg KOH / g.   A method for producing an aqueous resin dispersion (C) in which a radical polymerizable monomer (B) is polymerized in an aqueous resin dispersion (A) of an olefin polymer having an average particle size of 100 nm or less.   4. The aqueous resin dispersion according to claim 3, wherein the content of the surfactant in the aqueous resin dispersion (A) is 2 parts by mass or less with respect to 100 parts by mass of the radical polymerizable monomer (B). C) Production method.