JPH10298490A - Water-based primer coating composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water-based primer coating composition which is excellent in stability as a coating material and gives a coating film having sufficient adhesion to polyolefin materials and excellent water resistance. SOLUTION: This composition comprises 15-80 pts.wt. water-insoluble acrylic- modified chlorinated polyolefin resin which is composed of a chlorinated polyolefin part and an acrylic polymer chain part grafted onto the chlorinated polyolefin part and in which the glass transition temperature of the acrylic polymer chain part is 0-60 deg.C, 10-70 pts.wt. water-insoluble acrylic resin and/or water-insoluble urethane resin each of which has a glass transition temperature of -70 to 0 deg.C and 5-40 pts.wt. water-soluble acrylic resin and/or water-soluble urethane resin.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an improvement in an aqueous primer coating composition.

[0002]

2. Description of the Related Art Plastic materials used for automobile bumpers, moldings and the like generally have poor paint wettability and poor paintability. In particular, when the plastic material is a polyolefin resin molding material such as a polypropylene resin, since these resins have no polar group in the molecule and are chemically inert, the coating properties and adhesion of the top coat are extremely poor. Therefore, usually apply a primer before painting,
It is necessary to ensure adhesion to the material, and various solvent-based primers and aqueous primers have been proposed.

[0003] Solvent-based primers have problems in terms of flammability, solvent toxicity and the like, and aqueous primers have recently been developed. However, the water-based primer has lower paintability and adhesion than the solvent-based primer. In order to solve these problems of the aqueous primer, Japanese Patent Application Laid-Open
JP-A-214188 discloses an aqueous primer containing an unmodified chlorinated polyolefin. However, in the case of the unmodified chlorinated polyolefin, the cohesion is low, so that the improvement of the adhesion is not sufficient. JP-A-3-182534 discloses modifying a chlorinated polyolefin with an unsaturated polycarboxylic acid and / or an acid anhydride in order to further improve adhesion. However, modification with a highly water-soluble polycarboxylic acid and / or acid anhydride causes another problem that water resistance is reduced.

On the other hand, chlorinated polyolefins are themselves:
Since the strength of the coating film and the level of weather resistance are low, it has been considered to use an acrylic resin or the like in combination to improve this.
However, chlorinated polyolefins generally have poor compatibility with acrylic resins, and thus are difficult to use as they are. Therefore, Japanese Patent Application Laid-Open No. Hei 5-209006 proposes to solve the compatibility problem by modifying a chlorinated polyolefin with an acrylic resin. However, even with this water-based primer, further improvement in adhesion has not been realized, and although compatibility has been improved, there remains a problem in paint stability (storage stability).

[0005]

The problem to be solved by the present invention is to provide a water-based primer coating composition having sufficient adhesion to a polyolefin material, excellent water resistance and excellent coating stability. To provide.

[0006]

Means for Solving the Problems The inventors of the present invention have conducted various experiments to solve the above-mentioned problems. As a result, the glass transition of the acrylic polymer chain portion in the water-insoluble acrylic-modified chlorinated polyolefin resin has been found. If the temperature is selected within a specific range, it is possible to sufficiently improve the adhesiveness, and furthermore, it does not cause a problem of water resistance because the adhesiveness is improved without depending on acid modification. The compatibility problem can be prevented even by the combined use of the acrylic resin and / or the urethane resin. In addition, if the water-soluble acrylic resin and / or the urethane resin is blended, the paint stability can be improved. With these findings, the present inventors have achieved the present invention by devising the respective mixing ratios.

That is, the aqueous primer coating composition of the present invention comprises a chlorinated polyolefin portion and an acrylic polymer chain portion grafted on the chlorinated polyolefin portion, and the acrylic polymer chain portion has a glass transition temperature of 0.
15 to 80 parts by weight of a water-insoluble acrylic-modified chlorinated polyolefin resin having a glass transition temperature of -70 ° C.
It contains 10 to 70 parts by weight of a water-insoluble acrylic resin and / or a water-insoluble urethane resin, and 5 to 40 parts by weight of a water-soluble acrylic resin and / or a water-soluble urethane resin at ０0 ° C.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The aqueous primer coating composition of the present invention may be a water-insoluble acrylic-modified chlorinated polyolefin resin and a water-insoluble acrylic resin and / or a water-insoluble urethane resin (hereinafter sometimes referred to as a water-insoluble resin). )
And a water-soluble acrylic resin and / or a water-soluble urethane resin (hereinafter sometimes referred to as a water-soluble resin). Hereinafter, each component of the aqueous primer coating composition will be described in detail. Acrylic-modified chlorinated polyolefin resin The acrylic-modified chlorinated polyolefin resin used in the present invention comprises a chlorinated polyolefin portion and a glass transition temperature of 0 to 60 grafted to the chlorinated polyolefin portion.
It is a polyolefin containing an acrylic polymer chain portion at a temperature of ° C. and is water-insoluble. Since the acrylic-modified chlorinated polyolefin resin contains an acrylic polymer chain portion having a glass transition temperature of 0 to 60 ° C., it exhibits sufficient adhesion to the polyolefin material and has compatibility with a water-insoluble resin described later. Become better. In addition, the glass transition temperature in the present invention means a static glass transition temperature that can be measured using a differential calorimeter or a thermomechanical analyzer.

The chlorinated polyolefin portion is a portion forming the main skeleton of the acryl-modified chlorinated polyolefin resin, and is a portion composed of a polyolefin substituted with a chlorine atom. Examples of the polyolefin include polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-propylene-diene copolymer, polybutene, and water additives of copolymers such as styrene-butadiene-isoprene. Only the species may be used, or two or more species may be used in combination. Above all, it is preferable that the chlorinated polyolefin portion is a portion made of polypropylene substituted with a chlorine atom because it is easily available and has high adhesion.

[0010] The chlorine content and molecular weight of the chlorinated polyolefin portion are not particularly limited.
When the molecular weight of the chlorinated polyolefin portion is 8 to 30% by weight and the molecular weight of the chlorinated polyolefin portion is 20,000 to 150,000, the adhesion to the polyolefin material is further improved and the gasoline resistance is increased, so that the chlorine content is preferably 20 to 25% by weight. %, And the molecular weight of the chlorinated polyolefin portion is more preferably 50,000 to 120,000. When the chlorine content of the chlorinated polyolefin portion is less than 18% by weight, the compatibility with other resins decreases, and
High crystallinity makes it difficult to melt, resulting in poor film-forming properties. On the other hand, when the chlorine content exceeds 30% by weight, the adhesion to the polyolefin substrate is reduced. When the molecular weight of the chlorinated polyolefin portion is less than 20,000, the strength of the coating film obtained from the primer coating composition is low, and the water resistance and gasoline resistance are reduced. On the other hand, when the molecular weight exceeds 150,000, the wetting property decreases with respect to the polyolefin base material, and the adhesion decreases, and the compatibility with other resins decreases. The film may become cloudy.

In the present invention, it is also possible to use chlorinated polyolefins modified with carboxylic acids and / or acid anhydrides to such an extent that the water resistance is not reduced. Examples of the carboxylic acid and / or acid anhydride used for the modification include maleic acid, fumaric acid, maleic anhydride, citraconic acid, citraconic anhydride, itaconic acid, and itaconic anhydride. The amount of these modifications is determined in consideration of water resistance and the like, but generally 7% or less, preferably 5% or less, can be used as the chlorinated polyolefin portion.

The acrylic polymer chain portion is a polymer chain grafted on the chlorinated polyolefin portion. There is no particular limitation as long as the glass transition temperature of the acrylic polymer chain portion is in the range of 0 to 60 ° C. When the glass transition temperature is lower than 0 ° C., the adhesion to the polyolefin material is reduced. On the other hand,
If the glass transition temperature exceeds 60 ° C., the compatibility between the acrylic polymer chain portion and the chlorinated polyolefin portion is poor, and the flowability during heating is reduced. Furthermore, when it exceeds 60 ° C., the coating film obtained from the primer coating composition is not smooth,
Moreover, it is hard and poor in flexibility.

The acrylic polymer chain portion has a structural unit derived from an acrylic monomer as an essential component, but is a copolymer portion further containing a structural unit derived from another monomer as appropriate. Is also good. Examples of the acrylic monomer include acrylic acid and acrylic ester monomers such as a (meth) acrylic monomer described in the description of the water-insoluble resin described below, and only one type, or 2
More than one species may be used in combination.

Other monomers include, for example, styrene monomers such as styrene, vinyltoluene and α-methylstyrene; 4-hydroxybutyl vinyl ether;
A hydroxyl group-containing vinyl monomer such as hydroxystyrene;
Epoxy group-containing monomers such as allyl glycidyl ether and the like can be mentioned, and only one kind or two or more kinds may be used in combination.

The structural units derived from the acrylic monomer and other monomers are selected so that the glass transition temperature of the acrylic polymer chain portion is 0 to 60 ° C. in each case. As described above, the acrylic polymer chain portion satisfying the glass transition temperature condition includes, for example, a structural unit derived from butyl acrylate as a main component, and styrene, acrylic acid, methyl methacrylate, 2-hydroxyethyl, as appropriate. Those containing a structural unit derived from methacrylate or the like as an auxiliary component or a structural unit derived from cyclohexyl methacrylate as a main component, and styrene or 2
And those containing, as subcomponents, structural units derived from -ethylhexyl acrylate, 2-hydroxyethyl acrylate, and the like.

The acrylic-modified chlorinated polyolefin resin is prepared, for example, by dissolving a chlorinated polyolefin in a solvent and graft-polymerizing the acrylic monomer and other monomers in the presence of a peroxide. There are a method of phase inversion emulsification in an aqueous medium, a method of dispersing a solution of a chlorinated polyolefin raw material monomer and the like in water, and performing suspension polymerization with the acrylic monomer and other monomers.
The acryl-modified chlorinated polyolefin resin thus obtained is insoluble in water, and is usually dispersed in water to be handled as an emulsion that is easy to handle.

The weight ratio of the chlorinated polyolefin portion (a1) and the acrylic polymer chain portion (a2) in the acrylic-modified chlorinated polyolefin resin is not particularly limited, but preferably a1 / a2 = 80/20 to 10/90.
And more preferably a1 / a2 = 70 / 30-3.
0/70. When the weight ratio is less than 10/90, the weight ratio of the chlorinated polyolefin portion is low,
Adhesion to the polyolefin material is reduced. On the other hand,
When the weight ratio exceeds 80/20, the weight ratio of the acrylic polymer chain portion becomes low, and the compatibility with the water-insoluble resin described later and the water dispersibility may be reduced. Water-insoluble resin The water-insoluble resin used in the present invention is a water-insoluble acrylic resin and / or a water-insoluble urethane resin, and their glass transition temperatures are all in the range of -70 to 0 ° C.
Because the glass transition temperature of the water-insoluble resin is in the above range,
Excellent water resistance is imparted to the coating film obtained from the primer coating composition.

The glass transition temperature of the water-insoluble resin is from -70 to
The temperature is not particularly limited as long as it is in the range of 0 ° C, preferably -60 to -10 ° C, more preferably -50 to -30 ° C.
It is. When the glass transition temperature is less than -70 ° C, the coating film obtained from the primer coating composition is too soft and has low strength. On the other hand, when the glass transition temperature exceeds 0 ° C., it is difficult to obtain a uniform coating film from the primer coating composition, and the water resistance and the flexibility are reduced.

The water-insoluble resin used in the present invention is dispersed in water, and is handled as an emulsion which is easy to handle. The water-insoluble acrylic resin is obtained, for example, by emulsion polymerization, suspension polymerization or dispersion polymerization of a (meth) acrylic monomer in the presence of a dispersion stabilizer such as a surfactant, and is derived from the (meth) acrylic monomer. A water-insoluble acrylic resin containing a structural unit can be mentioned. The water-insoluble acrylic resin generally has an average particle size of 0.05
Acrylic resin in the form of fine particles of up to 5 μm, used in the form of an emulsion.

As the (meth) acrylic monomer, for example, methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, n-
Butyl (meth) acrylate, i-butyl (meth) acrylate, t-butyl (meth) acrylate, sec-
(Meth) having a hydrocarbon substituent such as butyl (meth) acrylate, n-pentyl (meth) acrylate, lauryl (meth) acrylate, dodecyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and cyclohexyl (meth) acrylate Acrylic esters; ethylenically unsaturated nitriles such as acrylonitrile and methacrylonitrile; N-alkoxy-substituted amides such as N-methoxymethylacrylamide, N-ethoxymethylacrylamide, N-butoxymethylacrylamide; dimethylaminoethyl (meth) ) Ethylenically unsaturated basic monomers such as acrylate and diethylaminoethyl (meth) acrylate; 2-hydroxyethyl (meth)
Acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate,
(Meth) acrylates having a hydroxyalkyl group such as 4-hydroxybutyl (meth) acrylate and 6-hydroxybutyl (meth) acrylate; ring-opening adduct of γ-butyrolactone to 2-hydroxyethyl methacrylate; 2-hydroxyethyl Ring-opening adduct of ε-caprolactone to acrylate; ring-opening adduct of ethylene oxide to methacrylic acid; ring-opening adduct of propylene oxide to methacrylic acid; glycidyl (meth) acrylate, methyl glycidyl (meth) acrylate, 3 , 4
-Epoxy group-containing monomers such as epoxycyclohexyl (meth) acrylate, etc.
Alternatively, two or more kinds may be used in combination.

Along with the above (meth) acrylic monomer,
Styrene monomers such as styrene, vinyltoluene and α-methylstyrene; hydroxyl-containing vinyl monomers such as 4-hydroxybutyl vinyl ether and p-hydroxystyrene; and epoxy group-containing monomers such as allyl glycidyl ether May be used in combination. further,
If necessary, a small amount of a polyfunctional monomer having two or more polymerizable unsaturated bonds in one molecule can be used in combination.

The water-insoluble acrylic resin can be obtained by subjecting a (meth) acrylic monomer to a polymerization reaction by a known method or the like. The water-insoluble acrylic resin is prepared, for example, by dissolving a dispersion stabilizer (emulsifier) and a water-soluble polymerization initiator in water, and then adding the above-mentioned (meth) acrylic monomer or the like at a predetermined temperature required for polymerization, Obtained. Also, a mixture of a dispersion stabilizer (suspension stabilizer), a water-insoluble polymerization initiator, and the above-mentioned (meth) acrylic monomer is suspended in water by stirring or the like, and then the mixture is polymerized at a predetermined temperature. A water-insoluble acrylic resin may be obtained.

The water-insoluble urethane resin is prepared by subjecting a polyisocyanate, a polyol and a dialkanolcarboxylic acid to an addition reaction to synthesize a urethane resin A, and then neutralizing a carboxyl group in the urethane resin A with an amine compound and / or ammonia. Obtained by dispersing in water. In the above addition reaction, a chain extender and / or a reaction terminator may be used in combination, if necessary. In addition, urethane resin A is reacted by a multi-step method to synthesize a urethane prepolymer, and then the prepolymer is mixed with water while neutralizing with an amine compound, and a water elongation reaction is performed to simultaneously disperse in water. In this case, viscosity adjustment and solvent evaporation are easy, which is preferable in production. In this way, the urethane resin in the form of fine particles having an average particle diameter of 0.01 to 1 μm is used in the form of an emulsion.

The polyisocyanate is not particularly limited as long as it is a compound having two or more isocyanate groups in one molecule, and examples thereof include aliphatic polyisocyanates such as hexamethylene diisocyanate and 2,2,4-trimethylhexane diisocyanate. 1,4-cyclohexane diisocyanate, isophorone diisocyanate,
Alicyclic polyisocyanate such as 4,4'-dicyclohexylmethane diisocyanate; aromatic polyisocyanate such as xylylene diisocyanate; burette of the polyisocyanate; modified isocyanurate of the polyisocyanate; Or two or more of them may be used in combination.

The polyol is not particularly limited as long as it is a compound having two or more hydroxyl groups in one molecule. Examples thereof include polyether polyols such as polyethylene glycol, polypropylene glycol and polytetramethylene ether glycol; Polyester polyols such as condensates with molecular diols; polycarbonate polyols such as polyhexamethylene carbonate diol; and the like, and only one kind or two or more kinds may be used in combination.

The dialkanolcarboxylic acid is a component for introducing an anionic hydrophilic group for stably dispersing the urethane resin in water, and examples thereof include dimethylolacetic acid and dimethylolpropionic acid. Only one kind or two or more kinds may be used in combination.
By neutralizing these carboxylic acids with an amine compound and / or ammonia, they can be dispersed in water.

Examples of the chain extender include polyols and polyamines, and one type may be used alone, or two or more types may be used in combination. Further, examples of the reaction terminator include monoalcohols and monoamines, and only one kind or two or more kinds may be used in combination. In addition, a chain extender and a reaction terminator are used as needed.

The acid value of a water-insoluble urethane resin is an important property that determines the state of water dispersibility.
/ G is preferred. Acid value of water-insoluble resin is 5mgK
If it is less than OH / g, the coating stability of the primer coating composition will decrease. On the other hand, when the acid value exceeds 50 mgKOH / g, the hydrophilicity increases, the water becomes insoluble, and the water resistance of the coating film obtained from the primer coating composition may decrease. Water-Soluble Resin The water-soluble resin used in the present invention is a water-soluble acrylic resin and / or a water-soluble urethane resin, which prevents the above-mentioned water-insoluble resin from agglomerating, and is excellent in a primer coating composition. It is used for imparting stability and pigment dispersibility.

As the water-soluble acrylic resin, for example,
A water-soluble acrylic resin containing a structural unit derived from a hydrophilic (meth) acrylic monomer can be used. Examples of the hydrophilic (meth) acrylic monomer include (meth) acrylic monomers containing a carboxyl group such as acrylic acid, methacrylic acid, crotonic acid, and itaconic acid;
Hydroxyl-containing (meth) acrylic monomers such as hydroxylethyl (meth) acrylate, hydroxylpropyl (meth) acrylate, and ring-opened adducts obtained by reacting these (meth) acrylates with caprolactone, ethylene oxide, etc .; dimethylaminoethyl (meth) acrylate, etc. (Meth) acrylic monomers containing amino group; (meth) such as acrylamide, N-methoxymethylacrylamide, etc.
An acrylamide monomer and the like can be mentioned, and only one kind or two or more kinds may be used in combination.

The water-soluble acrylic resin contains, as an essential component, a structural unit derived from a hydrophilic (meth) acrylic monomer, and optionally a structural unit derived from another (meth) acrylic monomer or a structural unit derived from a styrene-based monomer. May be included. The water-soluble acrylic resin is obtained by polymerizing the above hydrophilic (meth) acrylic monomer. If necessary, the water-soluble acrylic resin may be copolymerized with another (meth) acrylic monomer or a styrene-based monomer, or may be water-soluble with an acid or alkali. It may be obtained by sexualizing. Regarding the water-solubility, for example, when the hydrophilic (meth) acrylic monomer is a carboxyl group-containing (meth) acrylic monomer, the water-soluble can be neutralized with an amine or ammonia. Similarly, when the hydrophilic (meth) acrylic monomer is an amino group-containing (meth) acrylic monomer, it can be made water-soluble by neutralization using an organic acid or the like.

The water-soluble urethane resin can be obtained, for example, by the same raw material or production method as the above-mentioned water-insoluble urethane resin, but the amount of dialkanolcarboxylic acid and the amine compound used for neutralization are converted to hydrophilic compounds such as alkanolamine. It is obtained by changing to a water-soluble amine and making it water-soluble. The acid value of the water-soluble urethane resin is an important property that determines the state of water dispersibility, and is preferably 10 to 200 mgKOH / g. If the acid value of the water-soluble resin is less than 10 mgKOH / g, water-solubilization becomes insufficient, and the coating stability of the primer coating composition is reduced. On the other hand, the acid value is 200 mgK
If it exceeds OH / g, the hydrophilicity will be high, the water will not be insoluble, and the water resistance of the coating film obtained from the primer coating composition may decrease. Other Components The water-based primer coating composition of the present invention contains water as an essential component in addition to the components described above, and is appropriately blended with a pigment or the like. As the pigment, for example, titanium oxide,
Inorganic pigments such as carbon black, iron oxide, chromium oxide and navy blue; organic pigments such as azo, anthraquinone, perylene, quinacridone, indigo, phthalocyanine, etc .; More than one species may be used in combination.

The aqueous primer coating composition of the present invention may contain, if necessary, auxiliary additives such as inorganic fillers, organic modifiers, stabilizers, plasticizers and additives; alkyd resins, polyester resins, melamine resins, A resin such as an epoxy resin, a vinyl resin, and a cellulose resin may be blended. When an inorganic filler such as talc or silica is blended, the adhesiveness and workability are improved. In order to give conductivity to the primer coating,
Conductive carbon, conductive filler, metal powder, and the like may be blended. Furthermore, a small amount of an organic solvent can be added to improve the pigment dispersion stability, workability, and the like. Aqueous primer coating composition The aqueous primer coating composition of the present invention comprises the water-insoluble acrylic-modified chlorinated polyolefin resin (A), water-insoluble resin (B), and water-soluble resin (C) described in detail above. , Water and, if necessary, other components such as pigments.

The weight ratio (solid content weight ratio) of the three components (A) to (C) constituting the aqueous primer coating composition of the present invention is A: B: C = 15 to 80:10 to 70: 5. ~ 4
0 (however, A + B + C = 100), preferably 40 to 70:20 to 40:10 to 30. The weight ratio of acrylic-modified chlorinated polyolefin resin is 15
If it is less than 30, sufficient adhesion to the polyolefin material cannot be obtained. On the other hand, if the weight ratio exceeds 80, it becomes difficult to obtain a coating film from the primer paint (poor film forming property), and even if it is obtained, the coating film is hard and brittle.

When the weight ratio of the water-insoluble resin is less than 10, the film-forming property is deteriorated, and the water resistance and the like are reduced. On the other hand, if the weight ratio is more than 70, the coating film is too soft, so that adhesion of dust and the like is likely to occur, and the amount of the acryl-modified chlorinated polyolefin resin relatively decreases, so that the adhesion to the polyolefin material is reduced. . If the weight ratio of the water-soluble resin is less than 5, paint stability is reduced, especially if the primer paint contains a pigment, it cannot be stably dispersed,
Sedimentation may occur over time. On the other hand, when the weight ratio exceeds 40, water resistance, solvent resistance, and the like deteriorate.

The aqueous primer coating composition of the present invention is used, for example, for coating polyolefin materials such as bumpers for automobiles. A coating film (primer coating film) is formed on the polyolefin material by applying the aqueous primer coating composition to the polyolefin material and drying. The method of applying the water-based primer coating composition to the polyolefin material is not particularly limited, and may be applied by air spray coating or airless spray coating.
The coating amount of the aqueous primer coating composition is, for example, such that the dry film thickness is 2 to 30 μm, preferably 5 to 20 μm. If the dry film thickness is less than 2 μm, a continuous uniform film may not be obtained because it is too thin. On the other hand, if the dry film thickness exceeds 30 μm, the water resistance, weather resistance, and the like may decrease. After coating on the polyolefin material surface, the coating film is dried. This drying may be performed at room temperature, but is preferably 60 to 140 ° C. in order to improve workability and physical properties.
And heat drying. In the case of drying by heating, the drying temperature must be selected in a range that does not cause thermal deformation of the material in consideration of the heat resistance of the material.

The coating of the polyolefin material is performed by further applying a top coat to the primer coating film. Although there is no particular limitation on the top coating, for example, a one-pack melamine baking coating, a two-pack urethane coating, a one-pack lacquer coating, or the like can be used. The aqueous primer coating composition of the present invention is particularly suitable for coating a polypropylene material among polyolefin materials. The aqueous primer coating composition can be used for general plastic materials other than the polyolefin material.

[0037]

EXAMPLES Specific examples and comparative examples of the present invention will be shown below, but the present invention is not limited to the following examples. Hereinafter, "parts" represents "parts by weight". [Production Example 1] (Production of acrylic-modified chlorinated polyolefin resin emulsion A) A reactor equipped with a stirring blade, a thermometer, a temperature control rod and a cooling pipe was charged with Supercron 822 (manufactured by Nippon Paper Industries Co., Ltd. After charging 500 parts of 20%, a chlorine content of 26%, and a molecular weight of 80,000) and 60 parts of toluene, the temperature was raised to 80 ° C. Further, a mixed solution of 15 parts of styrene, 20 parts of methyl methacrylate, 40 parts of n-butyl acrylate, 16 parts of acrylic acid, 9 parts of 2-hydroxyethyl methacrylate and 2 parts of benzoyl peroxide was added dropwise to the reactor over 2 hours, 3 at 80 ° C
After continuing stirring for a time, a solution of 2 parts of Parkadox 16 (manufactured by Kayaku Akzo) and 25 parts of methyl ethyl ketone was added, and
Stirring was continued at 80 ° C. for 2 hours to complete the reaction. After completion of the reaction, the solvent was distilled off under reduced pressure to obtain an acrylic-modified chlorinated polyolefin resin having a nonvolatile solid content of 60% and a resin acid value of 52.

After adding 65 parts of methyl ethyl ketone and 100 parts of n-butanol to the acrylic-modified chlorinated polyolefin resin thus obtained, dimethylethanolamine 2 was stirred under a homogenizer at 8000 rpm.
An aqueous solution of 0 parts and 500 parts of ion-exchanged water was gradually added dropwise to obtain an acrylic-modified chlorinated polyolefin resin emulsion A. Emulsion A has a nonvolatile solids content of 20.2
%, The average particle size is 1.1 μm, and the Tg (glass transition temperature) of the acrylic resin portion measured by a differential calorimeter is 24 ° C.
Met.

[Production Example 2] (Production of Acrylic-Modified Chlorinated Polyolefin Resin Emulsion B) In a reactor equipped with a stirring blade, a thermometer, a temperature control rod and a cooling pipe, a hardlen 14LWP (manufactured by Toyo Kasei Kogyo Co., Ltd.) Non-volatile solid content 100%, chlorine content 27
%, Molecular weight 60,000) 125 parts, methyl methacrylate 65 parts, 2-ethylhexyl methacrylate 35
After charging 50 parts of Emulgen 920 (a nonionic emulsifier manufactured by Kao Corporation) and 50 parts of toluene, 100 parts
C. and stirred for 30 minutes to form a homogeneous solution. After cooling to 50 ° C., a solution of 1.5 parts of AIBN and 10 parts of methyl methacrylate was added. Further, while stirring at 1000 rpm, 600 parts of ion-exchanged water was added dropwise over 30 minutes to prepare a suspension. The temperature of the suspension was raised to 85 ° C again,
The reaction was performed at 150 rpm for 3 hours. After cooling, a toluene removal operation was performed under reduced pressure to obtain an acrylic-modified chlorinated polyolefin resin emulsion B. Emulsion B had a nonvolatile solids content of 30.8% and an average particle size of 0.34μ, and the Tg of the acrylic resin portion measured by a differential calorimeter was 52 ° C.

[Production Example 3] (Production of acrylic-modified chlorinated polyolefin resin emulsion C) In the above-mentioned Production Example 2, the monomers constituting the acrylic resin part were changed to 35 parts of methyl methacrylate, n-
An acrylic-modified chlorinated polyolefin resin emulsion C was obtained in the same manner as in Production Example 2 except that the amount was changed to 39 parts of butyl acrylate and 26 parts of 2-ethylhexyl methacrylate. Emulsion C has a non-volatile solids content of 31.0
%, The average particle size was 0.28 μm, and the Tg of the acrylic resin portion measured by a differential calorimeter was −31 ° C.

[Production Example 4] (Production of acrylic-modified chlorinated polyolefin resin emulsion D) In the above-mentioned Production Example 2, the monomer constituting the acrylic resin portion was changed to cyclohexyl methacrylate 55
Parts, 42 parts of methyl methacrylate and 3 parts of n-butyl acrylate in the same manner as in Production Example 2, except that
Acrylic modified chlorinated polyolefin resin emulsion D
I got Emulsion D had a nonvolatile solid content of 30.3% and an average particle size of 0.30 μm, and the Tg of the acrylic resin portion measured by a differential calorimeter was 74 ° C.

Example 1 Water-soluble acrylic resin (Nippon Paint Co., Ltd., nonvolatile solid content 32%, resin acid value 50 m)
gKOH / g), 60 parts of carbon black, 2 parts of titanium oxide, 35 parts of titanium oxide, 1 part of defoamer and 2 parts of butycelo were premixed, and then a pigment paste was prepared using a sand grinder mill.

The pigment paste 25 thus obtained is
52 parts of the emulsion A prepared in Production Example 1 (including 50 parts of the non-volatile solid content of the emulsion A as 100 parts of the resin component) (including 100 parts of the resin component and 23 parts of the non-volatile solid content of the water-soluble acrylic resin) And 20 parts of an acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content 28%, Tg-60 ° C)
(Including 27 parts of a nonvolatile solid content of an acrylic resin emulsion as 00 parts), and then 2 parts of a surface conditioner and 1 part of a thickener were mixed to prepare an aqueous primer (1).

Example 2 An aqueous primer (2) was prepared in the same manner as in Example 1 except that the components shown in Table 1 were used. [Example 3] Water-soluble acrylic resin (Nippon Paint Co., Ltd.)
32% non-volatile solid content, resin acid value 50mgKOH /
g) 38 parts, carbon black 3 parts, titanium oxide 35
Parts, 5 parts of silica, 1 part of an antifoaming agent and 18 parts of N-methylpyrrolidone were preliminarily mixed, and a pigment paste was prepared using a sand grinder mill.

The thus obtained pigment paste 30
47 parts of the emulsion B prepared in Production Example 2 (including 61 parts of the nonvolatile solids of the emulsion B as 100 parts of the resin components) in parts (including 15 parts of the nonvolatile solids of the water-soluble acrylic resin as a total of 100 parts of the resin components) And 20 parts of an acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content 28%, Tg-60 ° C)
(Including 24 parts of a nonvolatile solid content of an acrylic resin emulsion as 00 parts), and then 2 parts of a surface conditioner and 1 part of a thickener were mixed to prepare an aqueous primer (3).

Examples 4 to 6 Aqueous primer (4) was prepared in the same manner as in Example 3 except that the components shown in Table 1 were used.
To (6). [Comparative Examples 1 to 4] Comparative aqueous primers (1) to (4) in the same manner as in Example 3 except that the components shown in Table 2 were used.
Was prepared.

Comparative Example 5 18 parts of a water-soluble acrylic resin (manufactured by Arakawa Chemical Industries, Ltd., nonvolatile solid content: 30%), 4 parts of carbon black, 49 parts of titanium oxide, 5 parts of silica, 1 part of a defoaming agent and After premixing 23 parts of N-methylpyrrolidone, a pigment paste was prepared using a sand grinder mill.

The pigment paste 15 thus obtained is
50 parts of the emulsion B prepared in Production Example 2 (including 60 parts of the non-volatile solid content of the emulsion B as 100 parts of the resin component in total). And 32 parts of an acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content 30%, Tg-38 ° C.) (resin component total 10
Non-volatile solid content of acrylic resin emulsion as 0 parts 3
7 parts), 2 parts of the surface conditioner and 1 part of the thickener 1
And Comparative Example 2 to prepare a comparative aqueous primer (5).

Comparative Example 6 60 parts of a water-soluble urethane resin (manufactured by Sanyo Chemical Industries, Ltd., nonvolatile solids content: 35%), 2 parts of carbon black, 35 parts of titanium oxide, 5 parts of silica, 1 part of defoamer and After premixing 23 parts of N-methylpyrrolidone, a pigment paste was prepared using a sand grinder mill.

The pigment paste 57 thus obtained was obtained.
8 parts of the emulsion B prepared in Production Example 2 (including 10 parts of the non-volatile solid content of the emulsion B as 100 parts of the resin component) (including 50 parts of the non-volatile solid content of the water-soluble urethane resin as a total of 100 parts of the resin component) And 32 parts of an acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content 30%, Tg-38 ° C.) (resin component total 10
Non-volatile solid content of acrylic resin emulsion as 0 part 4
0 parts), 2 parts of the surface conditioner and 1 part of the thickener 1
And Comparative Aqueous Primer (6).

The aqueous primers (1) to (6) and the comparative aqueous primers (1) to (6) obtained as described above.
The performance of (6) was evaluated by the following evaluation methods, and the evaluation results are shown in Tables 1 and 2. Evaluation method 10 μm thick polypropylene material washed with a neutral detergent
m was spray-coated and dried at 120 ° C. for 15 minutes. After cooling, a solvent-based metallic base (manufactured by Nippon Bee Chemical Co., Ltd.) was spray-coated to a dry film thickness of 15 μm, and then a solvent-based clear (manufactured by Nippon Bee Chemical Co., Ltd.) was spray-coated to a dry film thickness of 30 μm. And dried at 120 ° C. for 30 minutes to produce a test piece.

The test piece was peeled off from a cross cut tape to evaluate the adhesion. Water resistance, moisture resistance, high temperature water resistance and gasoline resistance were evaluated by secondary adhesion (cross-cut tape peeling) after each condition shown in the table. The evaluation criteria are as follows. ：: 0/100 (no peeling) Δ: 1/100 to 50/100 (50% or less peeling) ×: 51/100 to 100/100 (50% or more peeling) Note that the paint stability is 500 ml flat bottom. 400 ml of paint is collected in a transparent beaker and the rotation speed is 200 rpm with a Teflon-coated magnetic stirrer.
After stirring at room temperature for 24 hours, the separation and sedimentation of the pigment were examined and evaluated.

[0053]

[Table 1]

[0054]

[Table 2]

In the above table, Tg is the Tg of the acrylic resin (part).
g. The numerical values of the examples and the comparative examples represent the respective blending amounts (parts by weight) with the total of the components listed in the table being 100 parts by weight. * 1 Acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content: 28%).

* 2 Acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content: 30%). * 3 Acrylic resin emulsion (Zeon Corporation)
, 30% non-volatile solids). * 4 Urethane resin emulsion (Zeneca Corporation, nonvolatile solid content 35%).

* 5 Acrylic resin emulsion (manufactured by Nippon Bee Chemical Co., Ltd., nonvolatile solid content: 30%). * 6 Acrylic resin emulsion (Nippon B Chemical Co., Ltd., nonvolatile solid content 30%). * 7 Acrylic resin emulsion (Zeon Corporation)
, 30% non-volatile solids).

* 8 Water-soluble acrylic resin (Nippon Paint Co., Ltd., nonvolatile solid content 32%). * 9 Water-soluble urethane resin (manufactured by Sanyo Chemical Industries, Ltd., nonvolatile solid content: 35%). * 10 Water-soluble acrylic resin (Arakawa Chemical Industries, Ltd., nonvolatile solid content 30%).

[0059]

The aqueous primer coating composition of the present invention comprises:
It has sufficient adhesion to the polyolefin material, is excellent in water resistance and paint stability, and balances these properties. Therefore, it is particularly excellent for use in coating polyolefin materials such as automobile bumpers and moldings.

──────────────────────────────────────────────────続 き Continuing on the front page (51) Int.Cl. ⁶ Identification symbol FI C09D 175/04 C09D 175/04 (72) Inventor Katsumi Mizuguchi 2-14-1, Odani Otani, Hirakata-shi, Osaka Japan B.C. Inside (72) Inventor Tsuyoshi Nakasuka 2-14-1, Otani, Hirakata-shi, Osaka Japan B-Chemical Co., Ltd.

Claims (2)

[Claims] 1. A water-insoluble acrylic-modified chlorine containing a chlorinated polyolefin portion and an acrylic polymer chain portion grafted to the chlorinated polyolefin portion, wherein the acrylic polymer chain portion has a glass transition temperature of 0 to 60 ° C. 15 to 80 parts by weight of a fluorinated polyolefin resin, 10 to 70 parts by weight of a water-insoluble acrylic resin and / or a water-insoluble urethane resin having a glass transition temperature of −70 to 0 ° C., and a water-soluble acrylic resin and / or a water-soluble urethane resin 5 To 40 parts by weight of an aqueous primer coating composition. 2. The aqueous primer coating composition according to claim 1, wherein the chlorinated polyolefin portion has a chlorine content of 18 to 30% by weight and a molecular weight of 20,000 to 150,000.