JP2008095040A - Manufacturing process of aqueous resin dispersion and aqueous resin dispersion obtained by the process - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous resin dispersion containing a polyester with a low acid value which has conventionally been unavailable as a stable dispersion. <P>SOLUTION: The manufacturing process of the aqueous resin dispersion comprises a step (I) of obtaining (C) a mixed resin by kneading (A) a polyolefin resin containing 0.5-10 mass% of an unsaturated carboxylic acid component and (B) a polyester resin and an emulsifying step (II) of dispersing the mixed resin (C) in an aqueous medium. Preferably, the acid value of polyester resin (B) is not more than 10 mgKOH/g. An aqueous resin dispersion prepared by this process is also disclosed. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing an aqueous resin dispersion containing a polyolefin resin and a polyester resin, and an aqueous resin dispersion obtained therefrom.

Polyolefin resins and polyester resins are widely used in various fields such as automobiles, electricity, packaging, and the like. Furthermore, in recent years, research and development on coating agents for imparting high added value and high functionality to such materials have been actively conducted. Coating agents can be broadly classified into solvent-based and water-based, but water-based coating agents are desired from the standpoints of environmental protection, resource conservation, and dangerous goods regulations such as the Fire Service Act. Patent Document 1 can be exemplified as an aqueous dispersion, and Patent Document 2 can be illustrated as an aqueous dispersion of a polyester resin.
As a technology that makes use of the characteristics of both resins, Patent Document 3 discloses that the aqueous dispersion containing the polyolefin resin and the polyester resin in a specific ratio provides blocking resistance, adhesion to various substrates, and heat sealability. And a method for obtaining an aqueous resin dispersion by mixing an aqueous polyolefin resin dispersion and an aqueous polyester resin dispersion is described in detail.

JP 2003-119328 A JP 09-296100 A JP 2003-327756 A

  However, among polyester resins, those having a low acid value of about 10 mgKOH / g or less are difficult to disperse in water by themselves, and in the technique described in Patent Document 3, an aqueous dispersion containing such a polyester resin is difficult. It was sometimes difficult to manufacture the body.

  As a result of intensive studies to solve the above problems, the present inventors kneaded a low acid value polyester resin with a polyolefin resin containing 0.5 to 10% by mass of an unsaturated carboxylic acid component, and then The present inventors have found that a mixed resin aqueous dispersion containing a low acid value polyester resin, which has been difficult to disperse in water by itself, can be obtained by aqueous dispersion of the mixed resin, and the present invention has been achieved.

That is, the gist of the present invention is as follows.
(1) A polyolefin resin (A) containing 0.5 to 10% by mass of an unsaturated carboxylic acid component and a polyester resin (B) having an acid value of 10 mgKOH / g or less are kneaded to obtain a mixed resin (C). A method for producing an aqueous resin dispersion comprising the step (I) and an emulsification step (II) in which the mixed resin (C) is dispersed in an aqueous medium.
(2) The method for producing an aqueous resin dispersion according to (1), wherein the acid value of the polyester resin (B) is 1 mgKOH / g or less.
(3) The mass ratio (A) / (B) of the polyolefin resin (A) to the polyester resin (B) is 99.5 / 0.5 to 30/70 (1) or (2) ) A method for producing an aqueous resin dispersion.
(4) The method for producing an aqueous resin dispersion according to any one of (1) to (3), wherein the kneading method in the step (I) is melt kneading.
(5) The method for producing an aqueous resin dispersion according to any one of (1) to (4), wherein the non-volatile aqueous additive is not substantially used in step (II).
(6) An aqueous resin dispersion obtained by the production method according to any one of (1) to (5).

  According to the production method of the present invention, it is possible to easily obtain an aqueous resin dispersion containing a low acid value polyester, which has not been obtained as a stable aqueous dispersion, and the superiority of such a polyester resin. The characteristics can be utilized as an aqueous dispersion, which is also environmentally preferable. Moreover, since the aqueous dispersion obtained by this invention is excellent in the adhesiveness of an olefin base material and a polyester base material, and heat sealability, it can be utilized for various uses.

  Hereinafter, the present invention will be described in detail.

  The polyolefin resin (A) used in the present invention is a resin mainly composed of olefin components such as olefins having 2 to 6 carbon atoms such as ethylene, propylene, isobutylene, 1-butene, 1-pentene and 1-hexene. Yes, two or more of these monomers may be used. Among these, olefins having 2 to 4 carbon atoms such as ethylene, propylene, isobutylene and 1-butene are more preferable, and ethylene and propylene are particularly preferable.

  The polyolefin resin (A) contains an unsaturated carboxylic acid component in an amount of 0.5 to 10% by mass, preferably 1 to 8% by mass, and more preferably 2 to 7% by mass. If the unsaturated carboxylic acid component is less than 0.5% by mass, aqueous dispersion is difficult, and if it exceeds 10% by mass, aqueous dispersion becomes easier, but the polarity of the coating film obtained from the aqueous dispersion is high. Therefore, the adhesiveness to a substrate with low polarity such as polyolefin resin tends to be lowered.

  The unsaturated carboxylic acid component is a compound having at least one carboxyl group or acid anhydride group in the molecule, that is, in the monomer component, and specifically includes acrylic acid, methacrylic acid, maleic acid, maleic anhydride. In addition to acids, itaconic acid, itaconic anhydride, fumaric acid, crotonic acid, and the like, half esters and half amides of unsaturated dicarboxylic acids are exemplified. Of these, acrylic acid, methacrylic acid, maleic acid, and maleic anhydride are preferable, and acrylic acid and maleic anhydride are particularly preferable. Moreover, the unsaturated carboxylic acid component should just be copolymerized in polyolefin resin, The form is not limited, For example, random copolymerization, block copolymerization, graft copolymerization etc. are mentioned.

  In the polyolefin resin (A), monomers other than the olefin component and the unsaturated carboxylic acid component may be copolymerized. Examples of such monomers include methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, octyl (meth) acrylate, and lauryl (meth) acrylate. Vinyl ethers such as (meth) acrylic acid esters, methyl vinyl ether and ethyl vinyl ether; vinyl esters such as vinyl acetate and vinyl propionate; dienes; (meth) acrylonitrile; vinyl halides; vinylidene halides; Carbon; sulfur dioxide.

  Specific examples of the polyolefin resin (A) include ethylene-acrylic acid ester-maleic anhydride copolymer, ethylene-propylene-maleic anhydride copolymer, ethylene-butene-maleic anhydride copolymer, propylene-butene- Maleic anhydride copolymer, ethylene-propylene-butene-maleic anhydride copolymer, ethylene-propylene-acrylic ester-maleic anhydride copolymer, ethylene-butene-acrylic ester-maleic anhydride copolymer, Examples include propylene-butene-acrylic acid ester-maleic anhydride copolymer, ethylene-propylene-butene-acrylic acid ester-maleic anhydride copolymer, and the like.

  The polyolefin resin (A) preferably has a melt flow rate of 0.01 to 500 g / 10 min at 190 ° C. and a load of 2160 g, which is a measure of molecular weight, more preferably 0.1 to 400 g / 10 min, and 1 to 300 g. / 10 minutes is more preferable, and 5 to 200 g / 10 minutes is particularly preferable. When the melt flow rate of the polyolefin resin (A) is less than 0.01 g / 10 min, it may be difficult to make the resin water-based or heat sealability may be deteriorated. On the other hand, when the melt flow rate of the polyolefin resin (A) exceeds 500 g / 10 minutes, the resulting coating film tends to be hard and brittle, and the heat sealability tends to be lowered.

  The polyester resin (B) which is the other resin component used in the present invention is a polymer mainly composed of a polybasic acid component and a polyhydric alcohol component.

  Polybasic acid components constituting the polyester resin (B) include aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, phthalic acid, phthalic anhydride, naphthalenedicarboxylic acid, biphenyldicarboxylic acid; oxalic acid, succinic acid, succinic anhydride Saturated aliphatic dicarboxylic acids such as acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, hydrogenated dimer acid; fumaric acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, citraconic acid , Unsaturated aliphatic dicarboxylic acids such as citraconic anhydride and dimer acid; 1,4-cyclohexanedicarboxylic acid, 1,3-cyclohexanedicarboxylic acid, 1,2-cyclohexanedicarboxylic acid, 2,5-norbornene dicarboxylic acid and its anhydride Products, tetrahydrophthalic acid and anhydrides, etc. It is phosphate and the like.

  Trifunctional or higher acid components may be used in small amounts, such as trimellitic acid, pyromellitic acid, benzophenone tetracarboxylic acid, trimellitic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic acid anhydride, trimesic acid, Ethylene glycol bis (anhydro trimellitate), glycerol tris (anhydro trimellitate), 1,2,3,4-butanetetracarboxylic acid and the like can also be used.

  Examples of the polyhydric alcohol component constituting the polyester resin (B) include ethylene glycol, 1,2-propanediol, 1,3-propanediol, 1,4-butanediol, 2-methyl-1,3-propanediol, Aliphatic glycols such as 1,5-pentanediol, neopentyl glycol, 1,6-hexanediol, 3-methyl-1,5-pentanediol, 1,9-nonanediol, 2-ethyl-2-butylpropanediol Alicyclic glycols such as 1,4-cyclohexanedimethanol; glycols containing ether bonds such as diethylene glycol, triethylene glycol, dipropylene glycol, polytetramethylene glycol, polyethylene glycol, polypropylene glycol; 2,2-bis [4- (Hydroxyethoxy Phenyl] bisphenols such as propane (bisphenol A) and its ethylene oxide adduct, bis [4- (hydroxyethoxy) phenyl] bisphenols such as sulfone (bisphenol S, etc.) and its ethylene oxide adduct, and the like.

  Furthermore, the polyhydric alcohol more than trifunctional, for example, glycerol, a trimethylol ethane, a trimethylol propane, a pentaerythritol, etc. may be contained as a polyhydric alcohol component.

  The polyester resin (B) may be copolymerized with a monocarboxylic acid, monoalcohol, or hydroxycarboxylic acid, such as lauric acid, myristic acid, palmitic acid, stearic acid, oleic acid, linoleic acid, linolenic acid, Use of benzoic acid, p-tert-butylbenzoic acid, cyclohexane acid, 4-hydroxyphenyl stearic acid, stearyl alcohol, 2-phenoxyethanol, ε-caprolactone, lactic acid, β-hydroxybutyric acid, p-hydroxyethoxybenzoic acid, etc. it can.

  In the production method of the present invention, the desired aqueous resin dispersion can be obtained satisfactorily when the acid value of the polyester resin (B) is in the range of 10 mgKOH / g or less. Furthermore, the aqueous resin dispersion can be produced even in a low region where the acid value of the polyester resin (B) is as low as 5 mgKOH / g or less or 1 mgKOH / g or less. The adhesiveness and heat sealability of the coating film obtained from the aqueous resin dispersion thus produced are not particularly affected even when the acid value of the polyester resin (B) is lowered.

  The polyester resin (B) preferably has a hydroxyl value from the viewpoint of improving the adhesion between the polyester substrate and the polyolefin substrate and the heat sealability of the coating film obtained from the aqueous resin dispersion. The range of the hydroxyl value may be a range that does not impair the advantages of the polyester resin such as processability and adhesion to the substrate, and is preferably 10 to 100 mgKOH / g, and preferably 10 to 70 mgKOH / g. It is more preferable. When the hydroxyl value is lower than 10 mgKOH / g, the adhesion between the polyester substrate and the polyolefin substrate and the heat sealability tend to decrease. When the hydroxyl value exceeds 100 mgKOH / g, the physical properties of the polyester resin tend to decrease. .

  The number average molecular weight of the polyester resin (B) is not particularly limited, but is usually 500 to 50,000. Preferably it is 1,000-30,000. When the number average molecular weight is less than 500, the adhesion to the substrate and the heat sealability are lowered. On the other hand, when it exceeds 30,000, aqueous dispersion becomes difficult.

  Although the glass transition temperature of a polyester resin (B) is not specifically limited, -40-80 degreeC is preferable from the viewpoint with a favorable heat seal property of an adhesive agent, and 0-70 degreeC is more preferable from the point of an improvement in blocking resistance.

  The step (I) for obtaining the mixed resin (C) by kneading the polyolefin resin (A) and the polyester resin (B) will be described.

  The “kneading” as used in the present invention is not particularly limited as long as the two types of resins (A) and (B) are mixed well, and are dissolved and mixed in an organic solvent in which both resins can be dissolved. Alternatively, they may be mixed by melt kneading. In the former mixing method, a relatively large amount of organic solvent is required, and there are problems such as cost, natural environment, workplace environment, regulations by the Fire Service Act, etc., and the latter melt kneading method which is industrially simple is preferable. .

  In the case of obtaining a mixed resin by dissolving in an organic solvent, two or more kinds of organic solvents may be mixed or heated and stirred in order to enhance the solubility. After dissolution, all or a predetermined amount of the organic solvent is removed from the mixed resin (C) by heating, decompression, etc., and then dispersed in water according to the emulsification step (II) described later.

  When melt-kneading, a general extruder can be used, and it is preferable to use a twin-screw extruder for improving the kneading state. The polyolefin resin (A) and the polyester resin (B) may be supplied to the extruder by dry blending both resins in advance from one popper, or the respective resins are charged into two hoppers under the popper. You may use, quantifying with a screw etc. The melt kneading temperature is preferably equal to or higher than the higher melting point of the polyolefin resin (A) or the glass transition temperature of the polyester resin (B). Moreover, it is preferable that an upper limit is 350 degrees C or less, and it is more preferable that it is 300 degrees C or less. Furthermore, in order to make it easy to obtain a molten resin as a strand, the melting point of the polyolefin resin (A) or the glass transition temperature of the polyester resin (B) is preferably not lower than 250 ° C. or higher. When the kneading temperature is lower than the melting point of at least one of the resins, the effect of melt kneading may be reduced. When the temperature exceeds 350 ° C., the resin is oxidized or thermally decomposed, and the physical properties are likely to be lowered.

  When kneading, a cross-linking agent, pigment, heat stabilizer, antioxidant, weathering agent, flame retardant, plasticizer, lubricant, mold release agent, antistatic agent, filler, etc. are added depending on the purpose. Also good. Moreover, you may add a compatibilizing agent and a dispersing agent in order to improve the compatibility of polyolefin resin (A) and polyester resin (B) (to make a sea-island structure fine).

  The mass ratio (A) / (B) of the polyolefin resin (A) to the polyester resin (B) is preferably in the range of 99.5 / 0.5 to 30/70, and the aqueous dispersion yield is further increased. In addition, since adhesion to various substrates is enhanced, the range of 99.5 / 0.5 to 50/50 is more preferable, the range of 99/1 to 60/40 is further preferable, and (A) / (B ) = 99/1 to 70/30 is most preferable. When the content of the polyester resin (B) is less than 0.5% by mass, the adhesiveness to the polyester resin substrate tends to be lowered, and when it exceeds 30% by mass, the aqueous dispersion yield is low, Adhesiveness with the material may decrease.

  Next, the emulsification step (II) will be described.

  The mixed resin (C) obtained as described above can be dispersed in an aqueous medium by a known emulsification method, that is, aqueous dispersion. As the emulsification method, a method of heating and stirring the mixed resin (C) at a temperature of 80 to 250 ° C. with a basic compound, a water-soluble organic solvent, and water is preferable. In addition, an aqueous medium consists of water and a water-soluble organic solvent, and this is also included when a basic compound is water-soluble.

  A basic compound neutralizes the carboxyl group in mixed resin (C), and produces | generates a carboxyl anion. Aggregation between the fine particles is prevented by the electric repulsion between the anions, and stability is imparted to the aqueous resin dispersion. As the basic compound, ammonia or an organic amine compound that volatilizes during the formation of the coating film is preferable from the viewpoint of water resistance of the coating film, and an organic amine compound having a boiling point of 30 to 250 ° C., more preferably 50 to 200 ° C. is particularly preferable. When the boiling point is less than 30 ° C., the rate of volatilization when the resin described later becomes aqueous may increase, and the aqueous formation may not proceed completely. When the boiling point exceeds 250 ° C., it becomes difficult to disperse the organic amine compound from the resin coating film by drying, and the water resistance of the coating film may deteriorate.

  Specific examples of the organic amine compound include triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine, ethylamine, diethylamine, and 3-ethoxypropylamine. , 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine and the like. The addition amount of the basic compound is preferably 0.5 to 3.0 times equivalent, more preferably 0.8 to 2.5 times equivalent to the carboxyl group in the polyolefin resin, and 1.01 to 2. A 0-fold equivalent is particularly preferred. If it is less than 0.5 times equivalent, the addition effect of a basic compound is not recognized, and if it exceeds 3.0 times equivalent, the drying time at the time of coating film formation may become long or the resin aqueous dispersion may be colored.

  The water-soluble organic solvent promotes aqueous dispersion of the mixed resin (C) and reduces the dispersed particle size. As the water-soluble organic solvent, those having a solubility in water at 20 ° C. of 10 g / L or more are preferably used, and more preferably 50 g / L or more. The amount of the water-soluble organic solvent to be used is preferably 40% by mass or less, more preferably 1 to 40% by mass, further preferably 2 to 35% by mass, and more preferably 3 to 30% of the total solvent contained in the aqueous resin dispersion. Mass% is particularly preferred. When the amount of the organic solvent exceeds 40% by mass, it cannot be regarded as an aqueous medium substantially, and not only deviates from one of the objects of the present invention (environmental protection), but depending on the organic solvent used, an aqueous resin dispersion The stability of the may decrease. The amount of the organic solvent in all the solvents can be appropriately reduced by a stripping operation.

  Specific examples of the water-soluble organic solvent used in the present invention include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec. -Alcohols such as amyl alcohol, tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, etc. Ketones, ethers such as tetrahydrofuran and dioxane, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-sec-butyl, acetic acid-3 Esters such as methoxybutyl, methyl propionate, ethyl propionate, diethyl carbonate, dimethyl carbonate, ethylene glycol, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether Glycols such as acetate, diethylene glycol, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, propylene glycol, propylene glycol monomethyl ether, propylene glycol monobutyl ether, propylene glycol methyl ether acetate Examples of the conductor include 3-methoxy-3-methylbutanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, and ethyl acetoacetate, and those having a boiling point of 30 to 250 ° C are preferable. 50 to 200 ° C. is particularly preferable. These organic solvents may be used in combination of two or more. When the boiling point of the organic solvent is less than 30 ° C., the rate of volatilization when the resin is emulsified increases, and the efficiency of aqueous dispersion may not be sufficiently increased. An organic solvent having a boiling point exceeding 250 ° C. is difficult to be scattered from the resin coating film by drying, and the water resistance of the coating film may be deteriorated.

  Among the above organic solvents, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone are highly effective in promoting aqueous dispersion of the mixed resin (C) and are easy to remove the organic solvent from the aqueous medium. , Cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, and ethylene glycol monobutyl ether are preferable, and ethanol, n-propanol, and isopropanol are particularly preferable from the viewpoint of low-temperature drying property.

  The shape of the mixed resin (C) used in the emulsification step (II) in the present invention is not particularly limited. However, from the viewpoint of increasing the aqueousization rate, the particle diameter is 1 cm or less, preferably 0.8 cm or less. It is preferable to use one.

  The addition amount of the mixed resin (C) is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, and further more preferably 5 to 50% by mass with respect to 100% by mass of the total of the aqueous medium and the mixed resin (C). Preferably, 5-45 mass% is especially preferable. When the addition amount is less than 1% by mass, the resin content of the resulting aqueous resin dispersion is too low to exhibit the performance of the coating film, and when it exceeds 60% by mass, aqueous dispersion tends to be difficult. is there.

  The container for aqueous dispersion is not particularly limited, and a known solid / liquid stirring device, emulsifier, autoclave, or the like can be used. It is preferable if pressurization of 0.1 MPa or more is possible. The stirring method and the rotational speed of stirring in the present invention are not particularly limited. Sufficient aqueous formation is achieved even with low-speed stirring that allows the resin to be in a floating state in an aqueous medium, and high-speed stirring (for example, 1000 rpm or more) is not essential, and an aqueous resin dispersion can be produced with a simple apparatus.

  The temperature when the aqueous dispersion of the mixed resin (C) is preferably 80 to 250 ° C. More preferably, it is 90-200 degreeC, More preferably, it is 100-190 degreeC. When the temperature in the tank is less than 80 ° C., aqueous dispersion of the polyolefin resin may be insufficient. When the temperature in a tank exceeds 250 degreeC, there exists a possibility that the molecular weight of polyolefin resin may fall.

  By using the method of the present invention, the mixed resin (C) can be finely and stably dispersed in an aqueous medium, and the number average particle diameter (hereinafter, mn) of the resin can be 3 μm or less. mn is preferably 1 μm or less, more preferably 0.5 μm or less, and still more preferably 0.3 μm or less from the viewpoint of storage stability and low-temperature film-forming properties. Further, the weight average particle diameter (hereinafter, mw) can be 3 μm or less, preferably 1 μm or less, and more preferably 0.5 μm or less.

  In the emulsification step (II) of the present invention, the use amount of the non-volatile aqueous auxiliary agent such as an emulsifier, a protective colloid, and a high acid value wax is 100 masses of the mixed resin (C) in terms of coating properties such as water resistance The amount is preferably 10 parts by mass or less, more preferably 5 parts by mass or less, still more preferably 0.1 parts by mass or less, and most preferably not used. “Aqueous aid” refers to a drug or compound added for the purpose of promoting aqueousization or stabilizing the aqueous resin dispersion in the production of an aqueous resin dispersion. It means that it does not have a boiling point at pressure, or has a high boiling point (for example, 300 ° C. or higher) at normal pressure.

  Examples of the non-volatile auxiliary agent used in the present invention include an emulsifier, a compound having a protective colloid effect, a high acid value wax, a high acid value acid-modified compound, and a water-soluble polymer.

  Examples of the emulsifier include a cationic emulsifier, an anionic emulsifier, a nonionic emulsifier, and an amphoteric emulsifier. In addition to those generally used for emulsion polymerization, surfactants are also included. For example, anionic emulsifiers include higher alcohol sulfates, higher alkyl sulfonates, higher carboxylates, alkyl benzene sulfonates, polyoxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, vinyl sulfosuccinates. Nonionic emulsifiers include polyoxyethylene alkyl ether, polyoxyethylene alkyl phenyl ether, polyethylene glycol fatty acid ester, ethylene oxide propylene oxide block copolymer, polyoxyethylene fatty acid amide, ethylene oxide-propylene oxide. Compounds having a polyoxyethylene structure such as copolymers and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid esters And examples of the amphoteric emulsifiers, lauryl betaine, lauryl dimethyl amine oxide, and the like. Compounds having protective colloid action, modified waxes, acid-modified compounds with high acid values, water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethyl cellulose, hydroxyethyl cellulose, hydroxypropyl cellulose, modified starch, polyvinyl pyrrolidone Polyacrylic acid and salts thereof, carboxyl group-containing polyethylene wax, carboxyl group-containing polypropylene wax, carboxyl group-containing polyethylene-propylene wax and the like, and acid-modified polyolefin waxes having a number average molecular weight of usually 5000 or less and salts thereof, acrylic acid- Maleic anhydride copolymer and salts thereof, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-maleic anhydride male A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 15% by mass or more such as an acid alternating copolymer, a (meth) acrylic acid- (meth) acrylic ester copolymer, and a polyitaconic acid and a salt thereof; Examples thereof include water-soluble acrylic copolymers having amino groups, gelatin, gum arabic, and casein, which are generally used as fine particle dispersion stabilizers.

  The aqueous resin dispersion thus obtained may be appropriately distilled off the aqueous medium or diluted with water and / or an organic solvent so as to obtain a desired viscosity and resin content. The resin content in the aqueous resin dispersion can be appropriately selected depending on the film forming conditions, the desired thickness and performance of the resin coating film, and is not particularly limited, but keeps the viscosity of the coating composition moderately, and 1-60 mass% is preferable with respect to 100 mass% of resin aqueous dispersion at the point which expresses favorable film formation ability, 3-55 mass% is more preferable, 5-50 mass% is further more preferable, 5-45 Mass% is particularly preferred.

  In order to further improve various coating film performances such as water resistance and solvent resistance, the aqueous resin dispersion of the present invention contains 0% by weight of the crosslinking agent with respect to 100% by mass of the mixed resin (C) in the aqueous resin dispersion. 0.01 to 50% by mass, preferably 0.1 to 40% by mass can be added. As the crosslinking agent, a crosslinking agent having self-crosslinking property, a compound having a plurality of functional groups that react with a carboxyl group or a hydroxyl group in the molecule, a metal complex having a polyvalent coordination site, and the like can be used. Preferred are isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium salt compounds, phenol resins, silane coupling agents, and the like. Moreover, you may use combining these crosslinking agents.

  In the aqueous resin dispersion of the present invention, various agents such as leveling agents, antifoaming agents, anti-waxing agents, pigment dispersants, UV absorbers, pigments such as titanium oxide, zinc white, carbon black, etc. A dye may be added.

  The aqueous resin dispersion of the present invention is excellent in adhesiveness to various substrates such as various thermoplastic resin film substrates, metal substrates, glass substrates, paper, and synthetic paper.

  As thermoplastic resin films, polyamide resins such as nylon 6, nylon 66, nylon 46, polyethylene terephthalate, polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polylactic acid, etc. A film made of a polyester resin, a polyolefin resin such as polypropylene or polyethylene, a polyimide resin, a polyarylate resin, or a mixture thereof, or a laminate of these films. The thermoplastic resin film may be an unstretched film or a stretched film, and the production method is not limited. Although the thickness of a thermoplastic resin film is not specifically limited, Usually, what is necessary is just 1-500 micrometers. Especially, the resin aqueous dispersion of this invention is excellent in the adhesiveness to the thermoplastic resin film which consists of a polyester resin or polyolefin resin.

  The aqueous resin dispersion of the present invention can be applied by a known coating method. As a coating method, various substrate surfaces can be formed by known film forming methods such as gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc. It is possible to form a uniform resin coating in close contact with the surface of various substrates by coating it uniformly and setting it at around room temperature as necessary, followed by heat treatment for drying or drying and baking. it can. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used.

  In addition, the thickness of the resin coating film formed using the aqueous resin dispersion of the present invention is appropriately selected depending on the application, but is preferably 0.01 to 30 μm, preferably 0.02 to 10 μm. More preferably, 0.03 to 9 μm is more preferable, and 0.05 to 8 μm is particularly preferable. When the thickness of the resin coating film is less than 0.01 μm, the heat sealability deteriorates. In addition, since the resin aqueous dispersion of this invention expresses various outstanding performances including heat-sealability at a thickness of several μm or less, there is no need to apply more than 10 μm unless there is a special reason. In order to adjust the thickness of the resin coating film, an apparatus used for coating and its use conditions are appropriately selected, or an aqueous resin dispersion having an appropriate concentration is used.

EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited thereto. Various characteristics were measured or evaluated by the following methods.
1. Characteristics of resin (1) Composition of polyolefin resin
^It calculated | required from < ¹ > H-NMR analysis (The product made by Varian, 300MHz). The polyolefin resin was measured at 120 ° C. using orthodichlorobenzene (d ₄ ) as a solvent.
(2) Acid value of polyester resin 0.5 g of polyester resin was dissolved in 50 ml of water / dioxane = 10/1 (volume ratio), titrated with KOH using cresol red as an indicator, and the amount of KOH consumed for neutralization. The acid value (mgKOH / g) in the polyester resin was determined from the mg number.
(3) Hydroxyl value of the polyester resin 3 g of the polyester resin is precisely weighed, added with 0.6 ml of acetic anhydride and 50 ml of pyridine, stirred at room temperature for 48 hours, and then reacted with 5 ml of distilled water. By further stirring for 6 hours at room temperature, all acetic anhydride that was not used in the above reaction was changed to acetic acid. Add 50 ml of dioxane to this solution, titrate with KOH using cresol red and thymol blue as indicators, and the amount of KOH consumed for neutralization (W1) and the initial amount of acetic anhydride reacted with the polyester resin. The difference (W0-W1) was determined in terms of mg of KOH from the amount of KOH required for neutralization (calculated value: W0). The value divided by the number was defined as the hydroxyl value.
(4) Melting point of resin, glass transition temperature (Tg)
Using 10 mg of the resin as a sample, a DSC (Differential Scanning Calorimetry) apparatus (DSC7 manufactured by Perkin Elmer Co., Ltd.) was used for measurement at a temperature rising rate of 10 ° C./min, and the melting point was determined from the obtained temperature rising curve. Moreover, the intermediate value of the temperature of two bending points originating in the glass transition in the obtained temperature rising curve was calculated | required, and this was made into Tg.
(5) Melt flow rate of polyolefin resin It measured by the method of JIS6730 description (190 degreeC, 2160g load).
(6) Number average molecular weight of polyester resin The number average molecular weight is measured by GPC analysis (liquid feeding unit LC-10ADvp type and UV-visible spectrophotometer SPD-6AV type manufactured by Shimadzu Corporation), detection wavelength: 254 nm, solvent: tetrahydrofuran , Polystyrene conversion).

2. Characteristics of Aqueous Resin Dispersion (1) Aqueous Dispersion Yield The aqueous resin dispersion after aqueous dispersion was subjected to pressure filtration with a 300 mesh stainless steel filter (plain weave, wire diameter 35 μm, filtration area 133 cm ² ). After 2 MPa (G)), the resin remaining on the filter was dried by vacuum drying at 80 ° C. for 1 hour, the resin weight was measured, and the yield was calculated from the charged resin weight. When the entire amount could not be filtered at one time, the filter was replaced. In that case, the total residual resin amount was evaluated. From the viewpoint of evaluating / utilizing the aqueous dispersion, the aqueous yield is preferably at least 5% or more.
(2) Appearance of aqueous resin dispersion The color tone was observed visually.
(3) Solid content concentration of aqueous resin dispersion An appropriate amount of the aqueous resin dispersion was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight to determine the solid content concentration.
(4) Average particle diameter of resin aqueous dispersion The number average particle diameter and the weight average particle diameter were calculated | required using the Nikkiso Co., Ltd. make and Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method). Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50.

3. Characteristics of coating film In the following evaluation, as a base material, a biaxially stretched polyethylene terephthalate (PET) film (Embret PET12 manufactured by Unitika, thickness 12 μm), a stretched polypropylene (OPP) film (manufactured by Tosero, thickness 50 μm), A stretched polyethylene (PE) film (manufactured by Tosero Co., Ltd., thickness 50 μm) was used.

(1) Adhesion (tape peeling test)
After applying the resin aqueous dispersion to a corona-treated surface of a stretched OPP film, a stretched PE film, and a biaxially stretched PET film using a Meyer bar so that the film thickness after drying becomes 1 μm, at 100 ° C. for 2 minutes, Dried. The obtained laminated film was evaluated after standing at room temperature for 1 day. A cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was attached to the adhesive surface, and the degree of peeling when the tape was peeled at once was visually evaluated according to the following criteria.

○: No peeling at all △: Some peeling off ×: All peeling off

(2) Heat seal strength The aqueous resin dispersion was applied to the corona-treated surface of a biaxially stretched PET film so that the film thickness after drying was 2 μm, and dried at 90 ° C. for 2 minutes. The coated layer of the obtained laminated film and the corona-treated surface of the stretched OPP film were bonded together and pressed at 100 ° C. with a heat press machine (seal pressure 0.2 MPa / cm 2 for 6.5 seconds). The sample was cut out with a width of 15 mm, and one day later, the peel strength of the coating film was measured at a tensile speed of 200 mm / min and a tensile angle of 180 degrees using a tensile tester (Intesco Precision Universal Material Tester Model 2020 manufactured by Intesco Corporation). The measurement was performed at n = 5, and the measured value was the average value. Similarly, the heat seal strength in bonding of the corona-treated surface of the biaxially stretched PET film to the corona-treated surface of the stretched PE film and the biaxially stretched PET film was also measured.

  As the polyolefin resin (A), commercially available Bondine HX8290 (manufactured by Arkema, hereinafter referred to as HX8290) and the following resin A-1 were used.

(Production of Resin A-1)
2.8 kg of propylene-butene-ethylene terpolymer (manufactured by Huls Japan Co., Ltd., Bestplast 708, propylene / butene / ethylene = 64.8 / 23.9 / 11.3 mass%) was charged into the autoclave, and nitrogen After being melted by heating in an atmosphere, 120 g of maleic anhydride as an unsaturated carboxylic acid and 40 g of dicumyl peroxide as a radical generator were added over 1 hour while maintaining the system temperature at 170 ° C. and stirring. Reacted for hours. After completion of the reaction, it was pelletized with a cutter and poured into a large amount of acetone to precipitate the resin. This resin was further washed several times with acetone to remove unreacted maleic anhydride, and then dried under reduced pressure in a vacuum dryer to obtain polyolefin resin A-1.

  The properties of the polyolefin resin (A) used are summarized in Table 1.

  As the polyester resin (B), commercially available Elitel UE3200 (manufactured by Unitika, hereinafter referred to as UE3200), Elitel UE3210 (manufactured by Unitika, hereinafter referred to as UE3210), Elitel UE3380 (manufactured by Unitika Ltd., hereinafter referred to as UE3380) Elitel UE3320 (manufactured by Unitika Ltd., hereinafter referred to as UE3320) and resin B-1 shown below were used.

(Production of resin B-1)
1.0 kg of UE3200 was charged into the autoclave, and the temperature inside the autoclave was increased and stirred in a nitrogen gas atmosphere to melt the resin. When the temperature reached 270 ° C., 14.5 g of trimellitic acid was added, and the mixture was stirred at 250 ° C. for 1 hour to perform a depolymerization reaction. Thereafter, the resin was discharged in a sheet while being pressurized with nitrogen gas. And after fully cooling to room temperature, this was grind | pulverized with the crusher and the fraction of 1-6 mm of openings was extract | collected using the sieve, and it obtained as granular polyester resin B-1.

  The properties of the polyester resin (B) used are summarized in Table 2.

[Example 1]
A polyolefin resin “HX8290” and a polyester resin “UE3200” are dry blended at a mass ratio of “HX8290” / “UE3200” = 99/1, and this is a biaxial kneader at a temperature of 160 ° C. (PCM-30 manufactured by Ikegai, The mixture was melt kneaded at a screw rotation of 180 rpm and a discharge rate of 100 g / min, and pelletized with a cutter to obtain a mixed resin.

  Next, using a stirrer equipped with a heat-resistant 1 L glass container with a heater, 100.0 g of melt-kneaded mixed resin, 100.0 g of 2-propanol, 4.6 g of triethylamine and 295.4 g of distillation When water was charged into a glass container and stirred at a rotation speed of 400 rpm, no resin granular precipitates were observed at the bottom of the container, confirming that it was in a floating state. Therefore, while maintaining this state, the heater was turned on, the system temperature was set to 120 ° C., and the mixture was further stirred for 60 minutes. Thereafter, the mixture was cooled to about 40 ° C. while stirring with air cooling at a rotational speed of 400 rpm, and then filtered through a 300 mesh stainless steel filter to obtain an aqueous resin dispersion.

[Examples 2 to 11]
As shown in Table 3, the same operation as in Example 1 was performed except that the types and mixing ratios of the polyolefin resin and the polyester resin were changed to obtain an aqueous resin dispersion.

[Example 12]
A polyolefin resin “A-1” and a polyester resin “UE3200” are dry blended at a mass ratio of “A-1” / “HX8290” = 95/5, and this is a biaxial kneader (manufactured by Ikegai, 160 ° C.). PCM-30, screw rotation 180 rpm, discharge rate 100 g / min) and melt-kneaded, and pelletized with a cutter to obtain a mixed resin.

  Next, using a stirrer equipped with a heat-resistant 1 L glass container with a heater, 100.0 g of mixed resin, 150.0 g of tetrahydrofuran, 8.3 g of N, N-dimethylethanolamine and 241.7 g of Distilled water was charged into a glass container and stirred at a rotation speed of the stirring blade of 400 rpm. As a result, no precipitation of resin particles was observed at the bottom of the container, and it was confirmed that the container was floating. Therefore, while maintaining this state, the heater was turned on, the system temperature was set to 120 ° C., and the mixture was further stirred for 60 minutes. Thereafter, the mixture was cooled to about 40 ° C. while stirring with air cooling at a rotational speed of 400 rpm, and then filtered through a 300 mesh stainless steel filter to obtain an aqueous resin dispersion.

  Table 3 shows the characteristics of the aqueous resin dispersions obtained in Examples 1 to 12.

[Comparative Example 1]
Using the polyolefin resin “HX8290” alone, an operation similar to the aqueous dispersion method described in Example 1 was performed to obtain an aqueous resin dispersion “E-1”.

[Comparative Examples 2 to 5]
The polyester resin “UE3200”, “UE3210”, “UE3380”, “UE3320” was used alone, and the resin aqueous dispersion was made by the same operation as the aqueous dispersion method of Example 1. An aqueous resin dispersion was not obtained and all the resin remained on the filter.

[Comparative Example 6]
An aqueous dispersion of the polyester resin “B-1” alone was produced and evaluated. Using a stirrer equipped with a hermetic pressure-resistant 1 L glass container with a heater, 100.0 g of resin B-1, 100.0 g of 1-propanol, 3.5 g of triethylamine, and 296.5 g of distilled water are made into glass. When charged in the container and stirred at a rotation speed of the stirring blade of 400 rpm, no sedimentation of resin particles was observed at the bottom of the container, and it was confirmed that the container was in a floating state. Therefore, while maintaining this state, the heater was turned on, the system temperature was set to 80 ° C., and the mixture was further stirred for 60 minutes. Thereafter, the mixture was cooled to about 40 ° C. while stirring with air cooling at a rotational speed of 400 rpm, and then filtered through a 300-mesh stainless steel filter to obtain an aqueous resin dispersion “E-2”.

[Comparative Example 7]
The aqueous dispersion “E-1” obtained in Comparative Example 1 and the aqueous dispersion “E-2” obtained in Comparative Example 6 were mixed at a solid mass ratio of “E-1” and “E-2” of 95. The mixture was mixed so as to be / 5 and homogenized with stirring.

  Table 4 shows the characteristics of the aqueous resin dispersions obtained in Comparative Examples 1 to 7.

  From the results of Examples 1 to 7, even a low acid value polyester resin could be made aqueous by mixing with a polyolefin resin. In particular, when the mixing ratio in the resin was 30% by mass or less, the aqueous dispersion yield was 100%. From the results of Examples 5 to 7, the aqueous dispersion yield tended to decrease as the mixing ratio of the polyester resin increased. It was possible to do. When the mixing ratio of the polyester resin is 30% by mass or less, the heat seal strength of the coating film is improved from the result of HX8290 alone (Comparative Example 1) in the bonding of all films, and the mixing ratio of the polyester resin is 70% by mass. Even if it was% or more, it improved from the result (comparative example 1) of HX8290 in the bonding of PET.

  From the comparison between Examples 2 and 8 and Examples 9 and 10, when the hydroxyl value of the polyester resin is 10 mgKOH / g or more, the heat seal strength tends to be higher than that of the low hydroxyl value less than 10 mgKOH / g. It was.

  From the results of Example 11, when the acid value of the polyester resin was 10 mgKOH / g or more, the heat seal strength was slightly lowered as compared with the low acid value product.

  From the comparison between Examples 2 and 11 and Comparative Example 7, when an aqueous dispersion was obtained after melt-kneading the polyolefin resin and the polyester resin, the heat seal strength was higher than that obtained by blending the aqueous dispersions without kneading. Tended to be higher.

  From the results of Example 12, even when the polyolefin resin was a polypropylene copolymer, it was possible to disperse in water with a yield of 100%, and the performance of the coating film was excellent.

  As in Comparative Examples 2 to 5, when the polyester resin had a low acid value of 10 mgKOH / g or less, the aqueous dispersion of the polyester resin alone could not be performed.

In Comparative Example 6, since the acid value of the polyester resin exceeded 10 mgKOH / g, it was possible to disperse in water alone, but the performance of the coating film was inferior.

Claims (6)

A step of obtaining a mixed resin (C) by kneading a polyolefin resin (A) containing an unsaturated carboxylic acid component of 0.5 to 10% by mass and a polyester resin (B) having an acid value of 10 mgKOH / g or less (I) And an emulsifying step (II) in which the mixed resin (C) is dispersed in an aqueous medium. The method for producing an aqueous resin dispersion according to claim 1, wherein the acid value of the polyester resin (B) is 1 mgKOH / g or less. The resin aqueous solution according to claim 1 or 2, wherein the mass ratio (A) / (B) of the polyolefin resin (A) to the polyester resin (B) is 99.5 / 0.5 to 30/70. A method for producing a dispersion. The method for producing an aqueous resin dispersion according to any one of claims 1 to 3, wherein the kneading method in the step (I) is melt kneading. The method for producing an aqueous resin dispersion according to any one of claims 1 to 4, wherein a non-volatile aqueous additive is not used in step (II). The resin aqueous dispersion obtained by the manufacturing method in any one of Claims 1-5.