JP2009091426A - Aqueous dispersion, its manufacturing method and layered product - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an aqueous dispersion of ethylene-unsaturated-carboxylic-acid copolymer with little content of unsaturated-carboxylic-acid components and with low flowability at fusion (a small melt flow rate value), which was not able to be obtained as an aqueous dispersion in the past. <P>SOLUTION: This aqueous dispersion of ethylene-unsaturated-carboxylic-acid copolymer contains more than 1 mass% and less than 10 mass% of unsaturated-carboxylic-acid components, an aqueous dispersion of ethylene-unsaturated-carboxylic-acid copolymer with the melt flow rate of 0.5-100 g/10 minutes or unsaturated-carboxylic-acid components of 10-15 mass%, and ammonia and/or an organic amine component of the equivalent mole of 0.5-15 times in relation to the molar number of the carboxyl groups of the ethylene-unsaturated-carboxylic-acid copolymer, which is an aqueous dispersion of ethylene-unsaturated-carboxylic-acid copolymer of the melt flow rate of more than 0.5 g/10 minutes and less than 30 g/10 minutes, but does not substantially contain nonvolatile aqueous dispersion assistant. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  TECHNICAL FIELD The present invention relates to an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer having a low content of an unsaturated carboxylic acid component and low fluidity at the time of melting, a method for producing them, and a laminate to which these are applied. .

  An ethylene / unsaturated carboxylic acid copolymer represented by an ethylene / (meth) acrylic acid copolymer is dispersed in water (aqueous dispersion) with a metal compound represented by an amine, ammonia, an alkali metal compound, etc. It has been known for a long time that a uniform and good aqueous dispersion can be obtained, and it is widely used as an adhesive or a coating agent in various fields. However, aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer tends to become more difficult as the content of the unsaturated carboxylic acid component decreases and the melt flow rate value decreases. Depending on the combination of the melt flow rate and the melt flow rate, the melt flow rate (hereinafter simply referred to as the melt flow rate) measured when the unsaturated carboxylic acid component content is about 15% by mass or less or at 190 ° C. and 2160 g load is 300 g. In the case of about 10 minutes or less, aqueous dispersion tends to be difficult.

  The hardly water-dispersible ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid component content of 15% by mass or less or a melt flow rate of 300 g / 10 min or less is an alkali metal. When a metal compound such as a compound is used, aqueous dispersion tends to be relatively easy (Patent Documents 1 and 2). However, since the metal compound remains in the coating film of the aqueous dispersion obtained using the metal compound, the problem of peeling or whitening occurs when the coating film is dipped in water with poor water resistance. In addition, there is a problem that alkali resistance and adhesiveness are poor. Therefore, it cannot be used as it is in applications requiring water resistance, alkali resistance and high adhesion.

On the other hand, a method has also been proposed in which an ethylene / unsaturated carboxylic acid copolymer is dispersed in water using ammonia or an amine (Patent Documents 3 and 5).
In Patent Document 3, ammonia is used to make an ethylene / unsaturated carboxylic acid copolymer water-based with an unsaturated carboxylic acid component content of 15 to 35% by mass and a melt flow rate of 50 to 2000 g / 10 min. Proposed. However, Examples of Patent Document 3 only show that a copolymer having an unsaturated carboxylic acid component content of 20% by mass or more and a melt flow rate of 60 g / 10 min or more can be made aqueous. Therefore, it cannot be said that the effect when the content of the unsaturated carboxylic acid component is less than 20% by mass is shown. Further, in Patent Document 4 which is a subsequent application by the same applicant of Patent Document 3, it is described that there are not a few gels and blisters in such an aqueous dispersion, and even though it is a sufficiently uniform aqueous dispersion. There wasn't.

  Patent Document 5 discloses an ethylene / unsaturated carboxylic acid copolymer using a specific amine and having an unsaturated carboxylic acid component content of 10 to 30% by mass and a melt flow rate of 30 to 1500 g / 10 min. An aqueous dispersion of is shown. However, the examples of Patent Document 4 only illustrate those having an unsaturated carboxylic acid component content of 15% by mass or more and a melt flow rate of 60 g / 10 min or more. Furthermore, according to the verification by the present inventors, by the aqueous dispersion method described in Patent Document 4, the content of the unsaturated carboxylic acid component is 11% by mass and the melt flow rate is 100 g / 10 min. When the coalescence was dispersed in water, a large amount of undispersed particles having a large particle diameter were confirmed, and it was impossible to obtain a uniform aqueous dispersion at all (see Comparative Example 5 in the present specification).

A water-dispersible ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid component content of 15% by mass or less or a melt flow rate of 300 g / 10 min or less is converted to ammonia or an amine. As a method of carrying out aqueous dispersion using a surfactant, a method of adding a nonvolatile aqueous dispersion aid such as a surfactant is known (for example, Patent Document 6). However, since the non-volatile aqueous dispersion aid remains after drying in the coating film of the aqueous dispersion obtained by these methods, the problem of bleeding out and the performance such as water resistance are remarkably lowered. There was a problem.
Japanese Patent Laid-Open No. 51-62890 Japanese Patent No. 3617753 JP 2000-248141 A JP 2002-220498 A Japanese Patent No. 3813567 JP 2005-336277 A

  In order to solve the above-mentioned problems, the present invention uses ammonia or amine, has a low content of unsaturated carboxylic acid component, and has low fluidity at the time of melting (that is, low melt flow rate value). An object is to provide an aqueous resin dispersion of an unsaturated carboxylic acid copolymer and a method for producing them.

  As a result of intensive studies to solve the above problems, the present inventors have found that even if the content of the unsaturated carboxylic acid component is low and the ethylene / unsaturated carboxylic acid copolymer has low fluidity at the time of melting. Then, by adding a specific organic solvent and aqueous dispersion, an aqueous dispersion which is aqueous dispersed by ammonia and / or an organic amine compound and does not substantially contain a non-volatile aqueous solubilizer is found. The present invention has been reached.

That is, the gist of the present invention is as follows.
(1) Contains 1% by mass or more and less than 10% by mass of an unsaturated carboxylic acid component, and has a melt flow rate (hereinafter, simply referred to as a melt flow rate) of 0, measured at 190 ° C. and 2160 g load based on JIS K7210: 1999. An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer of 5 to 100 g / 10 min or containing 10 to 15% by mass of an unsaturated carboxylic acid component, and a melt flow rate of 0.5 g / 10 min or more and 30 g / An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer for less than 10 minutes, which is 0.5 to 15 times the molar equivalent of the number of carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer. An ethylene / unsaturated carboxylic acid copolymer characterized by containing ammonia and / or an organic amine compound and substantially free of non-volatile aqueous dispersion aids. Aqueous dispersion of polymer.
(2) An ethylene / unsaturated carboxylic acid copolymer or unsaturated carboxylic acid component containing 10 to 10% by weight of an unsaturated carboxylic acid component and having a melt flow rate of 0.5 to 100 g / 10 min. An ethylene / unsaturated carboxylic acid copolymer having a melt flow rate of 0.5 / 10 min or more and less than 30 g / 10 min, and a solubility in water at 20 ° C. of 50 g / L or more and 30 The method for producing an aqueous dispersion according to (1), wherein an organic solvent having a boiling point of ˜250 ° C., ammonia and / or an organic amine compound, and water are mixed at a temperature of 80 to 280 ° C.
(3) A coating film obtained from the aqueous dispersion described in (1).
(4) A laminate obtained by forming the coating film according to (3) on a substrate.

  According to the aqueous dispersion of the present invention, a coating film having water resistance, alkali resistance, adhesion, and solvent resistance can be obtained by applying and drying the dispersion. The provided laminated body can be used suitably for uses, such as a packaging material.

  Further, according to the method for producing an aqueous dispersion of the present invention, an ethylene / unsaturated carboxylic acid copolymer having a low content of unsaturated carboxylic acid component and a low melt flow rate value, which has been difficult in the past, is obtained. Aqueous dispersion can be easily performed without using a non-volatile aqueous auxiliary agent.

  Hereinafter, the present invention will be described in detail.

  In the ethylene / unsaturated carboxylic acid copolymer used in the present invention, the constituent unsaturated carboxylic acid includes acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, anhydrous Itaconic acid, monomethyl maleate, monoethyl maleate and the like can be mentioned, and a mixture thereof may be used. Among these, acrylic acid and / or methacrylic acid are preferable because of excellent polymerization reactivity with ethylene.

  The content of unsaturated carboxylic acid in the ethylene / unsaturated carboxylic acid copolymer is in the range of 1 to 15% by mass. Preferably it is 2-15 mass%, More preferably, it is 3-15 mass%, Most preferably, it is 4-15 mass%. When the content of the unsaturated carboxylic acid is less than 1% by mass, aqueous dispersion becomes difficult. On the other hand, when the content exceeds 15% by mass, performances such as water resistance and alkali resistance of the coating film tend to deteriorate.

  The melt flow rate of the ethylene / unsaturated carboxylic acid copolymer is 0.5 to 100 g / 10 min, preferably 1 to 100 g / 10 min, more preferably 2 to 100 g / 10 min. Most preferably, it is 3-100 g / 10min. When the melt flow rate is less than 0.5 g / 10 minutes, aqueous dispersion becomes difficult. On the other hand, when the melt flow rate exceeds 100 g / 10 minutes, the surface hardness and rigidity of the resulting coating film are small, and adhesion, alkali resistance, The solvent property also tends to deteriorate. In the present invention, the melt flow rate means a value at 190 ° C. and a load of 2160 g based on JIS K7210: 1999.

  Furthermore, the ethylene / unsaturated carboxylic acid copolymer used in the present invention comprises a specific combination of unsaturated carboxylic acid content and melt flow rate. That is, the content of the unsaturated carboxylic acid is 1% by mass or more and less than 10% by mass, and the melt flow rate is 0.5 to 100 g / 10 minutes, or the content of the unsaturated carboxylic acid content. Is an ethylene / unsaturated carboxylic acid copolymer satisfying any one of the above conditions, wherein the melt flow rate is from 10 to 15% by mass and the melt flow rate is 0.5 g / 10 min or more and less than 30 g / 10 min. It is characterized by the aqueous dispersion.

  In the ethylene / unsaturated carboxylic acid copolymer, when the content of the unsaturated carboxylic acid is 1% by mass or more and less than 10% by mass, the melt flow rate may be in the range of 0.5 to 100 g / 10 min. However, in the case where the content of unsaturated carboxylic acid content is 10 to 15% by mass, this value is less than 10% by mass, because the adhesiveness and solvent resistance tend to decrease. In order to maintain performance, a lower melt flow rate is required. For this reason, the melt flow rate needs to be 0.5 g / 10 min or more and less than 30 g / 10 min.

  Other monomers may be copolymerized with the ethylene / unsaturated carboxylic acid copolymer as long as the effects of the present invention are not impaired. As monomers, vinyl acetate, vinyl esters such as vinyl propionate, methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, nbutyl acrylate, isooctyl acrylate, 2-ethylhexyl acrylate, Mention may be made of unsaturated carboxylic acid esters such as methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate and diethyl maleate, carbon monoxide and sulfur dioxide. Content of these monomers should just be 0-30 mass% with respect to the whole resin.

  In the present invention, one type of ethylene / unsaturated carboxylic acid copolymer may be used as the ethylene / unsaturated carboxylic acid copolymer, or two or more types of ethylene / unsaturated carboxylic acid copolymers may be mixed. May be used. When mixing two or more kinds of ethylene / unsaturated carboxylic acid copolymers, the content of the unsaturated carboxylic acid and the melt flow rate value in the resin after mixing may be within the range specified in the present invention. Independently, a resin outside the range defined in the present invention may be mixed with another resin and used within the range defined in the present invention.

  When two or more types of ethylene / unsaturated carboxylic acid copolymers are used in combination, melt blending is preferable as a mixing method, but each resin pellet may be dry blended to be dispersed in water. . Note that the unsaturated carboxylic acid content and the melt flow rate in the melt blend having the same mixing ratio are used as the unsaturated carboxylic acid content and the melt flow rate in the dry blend.

  In the aqueous dispersion of the present invention, ammonia and / or an organic amine compound is used to neutralize the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer. As an organic amine compound, a thing with a boiling point of 0-250 degreeC is preferable. When the boiling point is less than 0 ° C., the rate of volatilization during aqueous dispersion increases and the progress of aqueous dispersion may be incomplete. When the boiling point exceeds 250 ° C., it becomes difficult to disperse the organic amine compound from the resin film by drying, and the water resistance of the film may deteriorate.

  Specific examples of the organic amine compound include dimethylamine, trimethylamine, monoethylamine, diethylamine, triethylamine, N, N-dimethylethanolamine, aminoethanolamine, N-methyl-N, N-diethanolamine, isopropylamine, iminobispropylamine. , 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, methylaminopropylamine, 3-methoxypropylamine, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, etc. , A mixture thereof, or a mixture of ammonia and these. Of these, diethylamine and triethylamine are preferably used.

  The amount of ammonia and / or organic amine compound added is 0.5 to 15 times the equivalent mole of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer, and usually 0.8 to 3.0. A double equivalent mole is preferable, and a 1.0 to 2.5-fold equivalent mole is more preferable. However, when the content of the unsaturated carboxylic acid is 5% by mass or less, when the added amount is 3 to 15 times equivalent mol, there is a tendency that the aqueous dispersion is surprisingly easier. -12 times equivalent mol is preferable and 5-10 times equivalent mol is more preferable. When the addition amount is less than 0.5 times equivalent mole, the effect of addition is not recognized, and when it exceeds 15 times equivalent mole, the effect of addition does not change, and the drying time at the time of coating film formation becomes longer, There is a tendency for the dispersion to become heavily colored.

  The aqueous dispersion obtained in the present invention can be used to remove a part of ammonia and / or the organic amine compound by a solvent removal treatment to be described later. Alternatively, as described above, the content of the organic amine compound needs to be 0.5 equivalent mole or more with respect to the number of moles of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer. When it becomes less than 0.5 times equivalent, the resin particles in the aqueous dispersion tend to aggregate and storage stability tends to deteriorate. The content of ammonia and / or organic amine compound can be quantified by gas chromatography.

  There is no particular need to add a metal compound typified by an alkali metal compound or the like to the aqueous dispersion of the present invention, but if necessary for the purpose of use of the aqueous dispersion, the effect of the present invention is not impaired. They can be added.

  Next, the manufacturing method (aqueous dispersion) of the aqueous dispersion of the present invention will be described.

  The aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer in the present invention is an ethylene / unsaturated carboxylic acid copolymer, ammonia and / or an organic amine compound, and has a solubility in water at 20 ° C. of 50 g / L or more and A method of mixing an organic solvent having a boiling point of 30 to 250 ° C. and water at 80 to 280 ° C. can be employed.

  By the above method, the hardly water-dispersible ethylene / unsaturated carboxylic acid copolymer as defined in the present invention can be obtained without substantially adding a non-volatile aqueous dispersion aid such as an emulsifier component or a compound having a protective colloid effect. A good aqueous dispersion is obtained in which the polymer is uniformly dispersed in an aqueous medium. Here, the aqueous medium is a medium composed of water, ammonia and / or an organic amine compound and the organic solvent. A part of the aqueous medium in the aqueous dispersion may be removed by a solvent removal treatment described later.

  The aqueous dispersion aid refers to a drug or compound added for the purpose of promoting aqueous dispersion or stabilizing the aqueous dispersion in aqueous dispersion. The non-volatile aqueous dispersion aid remains after the coating film is formed, and plasticizes the coating film, thereby deteriorating the characteristics of the ethylene / unsaturated carboxylic acid copolymer, such as water resistance. Nonvolatile means that it does not have a boiling point at normal pressure or has a high boiling point (for example, 300 ° C. or higher) at normal pressure.

  Since the aqueous dispersion of the present invention does not substantially contain a nonvolatile aqueous dispersion aid, it is excellent in coating film characteristics, particularly water resistance. “Substantially no non-volatile aqueous dispersion aid” means that 100 parts by mass of the ethylene / unsaturated carboxylic acid copolymer component is not actively added to the system. In contrast, the content of the non-volatile aqueous dispersion aid is less than 0.1 parts by mass, and preferably the content is zero.

  Examples of the non-volatile aqueous dispersion aid used in the present invention include an emulsifier described later, a compound having a protective colloid effect, a modified wax, a high acid value acid-modified compound, a water-soluble polymer, and the like. 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 value, water-soluble polymers include polyvinyl alcohol, carboxyl group-modified polyvinyl alcohol, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, modified starch, polyvinylpyrrolidone 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 salt thereof, polyitaconic acid and salt thereof, water-soluble acrylic copolymer having amino group, gelatin, gum arabic, case Emissions, etc., generally compounds which are used as dispersion stabilizer of fine particles.

  The aqueous dispersion method of the present invention will be described in more detail.

  In the aqueous dispersion of the present invention, it is necessary to add an organic solvent having a solubility in water at 20 ° C. of 50 g / L or more and a boiling point of 30 to 250 ° C. The solubility of the organic solvent in water at 20 ° C. is more preferably 100 g / L or more. By using an organic solvent that satisfies the above conditions, it has been difficult to disperse in water in the past, the content of unsaturated carboxylic acid components is low, and the melt flow rate value is low. The aqueous dispersion of the coalescence is possible. When the solubility in water at 20 ° C. is less than 50 g / L, the effect of promoting aqueous dispersion is not observed.

  These organic solvents do not need to have high solubility with respect to the ethylene / unsaturated carboxylic acid copolymer defined in the present invention. For example, the ability to dissolve the copolymer is low. An organic solvent having a solubility of 0.5 g / L or less can also be used. The solubility can be evaluated by, for example, stirring a mixture of resin / organic solvent = 10/90 (mass ratio) at 80 ° C. for 2 hours.

  Furthermore, the organic solvent used in the aqueous dispersion method of the present invention needs to have a boiling point of 30 to 250 ° C. Specific examples of such organic solvents are methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert-amyl alcohol. , Alcohols such as 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, isophorone, tetrahydrofuran, dioxane, etc. Ethers, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, propion Esters such as methyl, 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 acetate, diethylene glycol, diethylene glycol Glycol derivatives such as 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, and 3-methoxy 3-methyl butanol, 3-methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate. Of these, those of 50 to 200 ° C. are more preferred.

  Two or more of the above organic solvents may be mixed and used. In addition, when the boiling point of the organic solvent is less than 30 ° C., the ratio of volatilization during aqueous dispersion 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 by drying from the coating film obtained from the aqueous dispersion, and the water resistance of the coating film may deteriorate. Moreover, the molecular weight of the organic solvent is not particularly limited, but those having a molecular weight of 90 or less are preferred. If the molecular weight exceeds 90, the resulting aqueous dispersion may gel.

  Among the above organic solvents, methanol, ethanol, n-propanol, and isopropanol are preferable because they are highly effective in promoting aqueous dispersion and are easily removed by a method called stripping described later.

  In the aqueous dispersion of the present invention, an aqueous medium and an ethylene / unsaturated carboxylic acid copolymer are added as an addition amount of an organic solvent having a solubility in water at 20 ° C. of 50 g / L or more and a boiling point of 30 to 250 ° C. Is preferably 5 to 60% by mass, more preferably 15 to 50% by mass, still more preferably 20 to 45% by mass, and particularly preferably 25 to 40% by mass. When the addition amount is less than 5% by mass, the effect of promoting aqueous dispersion is low, and when it exceeds 60% by mass, aqueous dispersion tends to be difficult or the resulting aqueous dispersion tends to gel.

  In the aqueous dispersion, the addition amount of the ethylene / unsaturated carboxylic acid copolymer is preferably 3 to 40% by mass with respect to 100% by mass of the total of the aqueous medium and the ethylene / unsaturated carboxylic acid copolymer, 30 mass% is more preferable, 8-20 mass% is further more preferable, and 10-15 mass% is especially preferable. When the addition amount is less than 3% by mass, the resin content of the resulting aqueous resin dispersion is too low to use the film as it is, and when it exceeds 40% by mass, aqueous dispersion is not achieved. It tends to be difficult.

  The shape of the ethylene / unsaturated carboxylic acid copolymer is not particularly limited, but it is preferable to use a granular or powdery particle having a particle diameter of 1 cm or less, preferably 0.8 cm or less, from the viewpoint of increasing the aqueous conversion rate.

  Examples of the container for aqueous dispersion include a known solid / liquid stirring device and emulsifier that can mix raw materials under heating. A sealed container having a pressure resistance of 0.1 MPa (G) or more is preferable. In the production method of the present invention, the mixing means is not particularly limited and may be appropriately stirred. The stirring method and the rotation speed of stirring are not particularly limited, but sufficient aqueous dispersion can be achieved even with low-speed stirring at which the resin is suspended in an aqueous medium, and high-speed stirring (for example, 1000 rpm or more) is not essential. For this reason, the aqueous dispersion can be produced with a simple apparatus.

  After the raw materials are charged into the apparatus, it is preferable that the inside of the tank is first preliminarily stirred and mixed at a temperature of 40 ° C. or lower.

  Next, it is necessary to mix the temperature in the tank (product temperature) at 110 to 280 ° C. The temperature at this time is preferably 120 to 230 ° C, more preferably 150 to 200 ° C, and particularly preferably 160 to 180 ° C. When the temperature in the tank is lower than 80 ° C., aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer becomes difficult, and when it exceeds 280 ° C., the molecular weight of the ethylene / unsaturated carboxylic acid copolymer decreases. There is a fear. The time for maintaining the temperature at 110 to 280 ° C is not particularly limited, but a range of 5 to 120 minutes is appropriate.

  In the aqueous dispersion method of the present invention, surprisingly, there is a tendency for aqueous dispersion to proceed during subsequent cooling, and this tendency is particularly remarkable when the temperature is lowered from 110 to 80 ° C. Therefore, it is preferable to continue stirring during cooling. Further, in the conventional method for producing an aqueous dispersion, cooling was naturally performed in as short a time as possible in order to shorten the production time. On the contrary, in the present invention, 110 ° C. to 80 ° C. The temperature lowering time is preferably 30 minutes or more, more preferably 60 minutes or more. When the temperature lowering time is less than 30 minutes, the particle size of the aqueous dispersion may increase.

  Further, when the tank is stirred at a temperature of 110 to 280 ° C., the ethylene / unsaturated carboxylic acid copolymer in the container is preferably completely dispersed in water, but the ethylene / unsaturated carboxylic acid copolymer is preferable. Depending on the type, the undispersed resin may float as a lump in a molten state, or may be entangled with a stirring blade. Even in such a case, by setting the temperature lowering time from 110 ° C. to 80 ° C. to 30 minutes or more, the aqueous dispersion can be advanced and the yield can be improved.

  Cooling is preferably performed while stirring until the temperature in the tank finally reaches 40 ° C or lower. An aqueous dispersion can be obtained after cooling. After this, jet pulverization may be further performed as necessary. Jet pulverization is a process in which a fluid such as an aqueous dispersion is ejected from pores such as nozzles and slits under high pressure, causing resin particles to collide with each other and a collision plate. Is to further refine the resin particles. Specific examples of the apparatus for jet pulverization include a homogenizer manufactured by A.P.V.GAULIN, a microfluidizer M-110E / H manufactured by Mizuho Industries, Ltd., and the like.

  The aqueous dispersion thus obtained is distilled out of the system by a desolvation operation called stripping, or diluted with water so that the solid concentration or organic solvent concentration becomes a desired concentration. Can be adjusted. Even if the solid content concentration or the amount of the organic solvent is adjusted, there is no particular influence on the performance, and it can be used well for various applications.

  Examples of the stripping method include a method in which the aqueous dispersion is heated with stirring at normal pressure or reduced pressure to distill off the organic solvent. The organic solvent content can be quantified by gas chromatography. When the aqueous medium is distilled off and the solid content concentration is increased, the viscosity is increased and workability is deteriorated. In this case, the aqueous medium is diluted with water or water is added to the aqueous dispersion in advance. It is preferable.

  The content of the organic solvent in the aqueous dispersion may be adjusted to an arbitrary concentration depending on the purpose of use, but in order to ensure safety during use and storage, a smaller amount is preferable, and 1% by mass or less. More preferred.

  The solid concentration of the aqueous dispersion is preferably 5 to 40% by mass, more preferably 5 to 30% by mass, further preferably 10 to 25% by mass, and particularly preferably 15 to 20% by mass. When the content is less than 5% by mass, the solid content concentration is too low and the performance of the coating film is hardly exhibited, and when it exceeds 40% by mass, there is a tendency for remarkable thickening or gelation.

  The aqueous dispersion yield in the production of the aqueous dispersion can be known from the amount of coarse particles remaining in the obtained aqueous dispersion. Specifically, for example, the aqueous dispersion is subjected to pressure filtration (MAX 0.5 MPa (G)) with a 460 mesh stainless steel filter (wire diameter 0.035 mm, plain weave, mesh size 20 μm), and the resin remaining on the filter It can be determined by measuring the amount. Even when a sufficiently high aqueous yield is not obtained and coarse particles remain, if they are removed, they can be used as the aqueous dispersion of the present invention. From the viewpoint of manufacturing cost and filtration workability, the aqueous yield is preferably 60% or more, and more preferably 80% or more.

  In the aqueous dispersion of the present invention, an ethylene / unsaturated carboxylic acid copolymer is dispersed in an aqueous medium and is in a uniform liquid state. “Uniform liquid” means that, in terms of appearance, a portion where the solid content concentration is locally different from other portions such as precipitation, phase separation or skinning is not observed in the aqueous dispersion.

  The aqueous dispersion of the present invention has an excellent pot life and maintains a uniform liquid state even when allowed to stand at room temperature for 100 days.

  The number average particle diameter (hereinafter referred to as mn) of the ethylene / unsaturated carboxylic acid copolymer particles in the aqueous dispersion is preferably 1 μm or less from the viewpoint of improving the storage stability of the aqueous dispersion. From the viewpoint of film forming property, it is more preferably 0.5 μm or less, particularly preferably 0.2 μm or less, further preferably 0.1 μm or less, and most preferably less than 0.05 μm. Further, the volume average particle diameter (hereinafter referred to as mv) is preferably 3 μm or less. In addition, according to the manufacturing method of this invention mentioned above, said preferable number average particle diameter range is easily realizable.

  The viscosity of the aqueous dispersion is preferably 1 to 50000 mPa · s / 20 ° C, more preferably 5 to 5000 mPa · s / 20 ° C. The pH is preferably 9.0 to 13, and more preferably 9.5 to 12.

  In the present invention, two or more types of aqueous dispersions of ethylene / unsaturated carboxylic acid copolymers may be mixed to form the aqueous dispersion of the present invention.

  An additive can be mix | blended with the aqueous dispersion of this invention. Examples of additives include polyhydric alcohols such as glycerin, ethylene glycol, polyethylene glycol, and polypropylene glycol, water-soluble epoxy compounds, lower alcohols such as methanol, ethanol, isopropyl alcohol, and n-propyl alcohol, ethylene glycol monomethyl ether, and ethylene glycol mono Ethers such as ethyl ether, propylene glycol monomethyl ether, propylene glycol diethyl ether, diethylene glycol monoethyl ether, dipropylene glycol monomethyl ether, esters such as ethylene glycol monoacetate and propylene glycol monoacetate, and aqueous dispersions of other polymers , Inorganic particles, crosslinking agents, leveling agents, antifoaming agents, foaming agents, anti-waxing agents, antioxidants, weather resistance Agents, ultraviolet absorbers, light stabilizers, antistatic agents, plasticizers, pigments, pigment dispersants, dyes, antibacterial agents, lubricants, antiblocking agents, rust inhibitors, adhesives, writability improvers, inorganic fillers, Examples thereof include pigments or dyes such as titanium oxide, zinc white, and carbon black. In addition, organic or inorganic compounds other than those described above can be added to the aqueous dispersion as long as the stability of the aqueous dispersion is not impaired. Two or more kinds of the additives may be used.

  The aqueous dispersion of the other polymer is not particularly limited. For example, ethylene / (meth) acrylic acid ester / maleic anhydride terpolymer, polyvinyl acetate, ethylene / vinyl acetate copolymer, polychlorinated Vinyl, polyvinylidene chloride, styrene / maleic acid resin, styrene / butadiene resin, butadiene resin, acrylonitrile / butadiene resin, poly (meth) acrylonitrile resin, (meth) acrylamide resin, chlorinated polyethylene resin, chlorinated polypropylene resin, polyester resin And aqueous dispersions such as modified nylon resins, urethane resins, phenol resins, silicone resins, and epoxy resins. You may use these in mixture of 2 or more types.

  The inorganic particles are not particularly limited, and particles such as magnesium oxide, zinc oxide and tin oxide, calcium carbonate, silica and other particles, vermiculite, montmorillonite, hectorite, synthetic mica and other water-swellable materials. Examples thereof include particles of a layered inorganic compound. The average particle diameter of these inorganic particles is preferably 0.005 to 10 μm, more preferably 0.005 to 5 μm from the viewpoint of the stability of the aqueous dispersion. Two or more inorganic particles may be mixed and used.

  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 in the molecule, a metal complex having a polyvalent coordination site, and the like can be used. Compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium salt compounds, silane coupling agents and the like are preferable. These crosslinking agents may be used in combination. The addition amount of a preferable crosslinking agent for further improving various coating film performances such as cohesive force and water resistance is 0.01 to 100 parts by mass, more preferably 0 with respect to 100 parts by mass of the resin in the aqueous dispersion. .1 to 60 parts by mass.

  The coating film obtained from the aqueous dispersion of the present invention has excellent adhesion to various base materials, and therefore is provided on various base materials for various purposes such as adhesives, heat sealability-imparting agents, surface protection, and paints. To form a laminate. Examples of the substrate include plastic, metal, glass, paper, and the like. More specifically, high, medium and low density polyethylene, ethylene / α-olefin copolymer, ethylene / vinyl acetate copolymer, ethylene・ (Meth) acrylic acid ester copolymer, ethylene / (meth) acrylic acid copolymer or its ionomer, ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or its ionomer, polypropylene, poly- Olefin polymer or copolymer such as 1-butene, poly-4-methyl-1-pentene, styrene such as polystyrene, high impact polystyrene, ABS type resin, styrene / butadiene block copolymer or hydrogenated product thereof Such as polyethylene resin, polyethylene terephthalate, polybutylene terephthalate Thermoplastic polymers such as reesters, polyamides such as nylon 6 and nylon 66, polycarbonates, polyvinyl chloride and mixtures of these in any proportion, rubber materials such as natural rubber and synthetic rubber, heats such as phenolic resins and polyurethanes Examples thereof include curable resins, metals such as iron, copper, aluminum and stainless steel, natural materials such as glass, ceramics, wood, paper, rayon and leather. The thermoplastic polymer can be applied to various molded products such as films, sheets, hollow molded products, injection molded products, woven fabrics, nonwoven fabrics, and synthetic leathers. By using a flat substrate such as a film, sheet, woven fabric, nonwoven fabric, synthetic leather, or paper as the substrate, a laminate in which a heat seal layer is formed on the substrate can be easily obtained. The aqueous dispersion of the present invention is excellent in wettability not only with polar materials but also with hydrophobic materials such as olefin polymers and styrene polymers, so that the aqueous dispersion has good coatability. The body can be applied. For example, a film obtained by applying and drying the aqueous dispersion of the present invention to a polyolefin film typified by an OPP film has low moisture permeability and good heat sealing performance, and is suitably used as various packaging materials. can do. In addition, the laminate obtained by applying the aqueous dispersion of the present invention to a metal material and drying is excellent in rust resistance, in particular moisture and rust resistance, and should be used suitably for applications requiring rust prevention. Can do. Furthermore, the laminate obtained by applying and drying the aqueous dispersion of the present invention on glass has excellent coating film adhesion, and can be used in the fields of adhesives for glass, inks for glass, and the like.

  Known methods can be used to form the coating film, 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. Uniform coating on the surface of the base material, setting it near room temperature as necessary, and then subjecting it to heat treatment for drying or drying and baking to form a uniform resin film in close contact with the surface of the base material Can do. 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 heating temperature and the heating time are appropriately selected depending on the characteristics of the base material to be coated, the type of the curing agent described later, the blending amount, and the like, but considering the economy, the temperature is 30 to 250 ° C. Preferably, 60 to 230 ° C is more preferable, 80 to 210 ° C is particularly preferable, and the time is preferably 1 second to 20 minutes, more preferably 5 seconds to 15 minutes, and particularly preferably 5 seconds to 10 minutes. The temperature and time when the crosslinking agent is added are appropriately selected according to the reactivity of the resin component and the crosslinking agent.

  Although the thickness of the coating film formed using the aqueous dispersion of the present invention is appropriately selected depending on the application, 0.01 to 100 μm is preferable, 0.1 to 50 μm is more preferable, and 0.2 to 30 μm is preferable. Particularly preferred. In order to adjust the thickness of the coating film, it is preferable to use an aqueous dispersion having a solid content concentration suitable for the target thickness as well as selection of a coating apparatus and use conditions.

  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 Ethylene / Unsaturated Carboxylic Acid Copolymer (1) Content of Unsaturated Carboxylic Acid Component Measured by FT-IR method.
(2) Melt flow rate It measured by the method of JISK7210: 1999 description (190 degreeC, 2160g load).

2. Characteristics of Aqueous Dispersion (1) Aqueous Dispersion Yield Pressurized filtration of aqueous resin dispersion after aqueous dispersion with a 460 mesh stainless steel filter (wire diameter 35 μm, plain weave, mesh opening 20 μm, filtration area 133 cm ² ) After (MAX 0.5 MPa (G)), the resin remaining on the filter was dried at 110 ° C. under vacuum for 1 hour, the resin weight was measured, and the yield was calculated from the charged resin weight.
(2) Solid Content Concentration of Aqueous Dispersion An appropriate amount of the aqueous dispersion after 460 mesh filtration 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. .
(3) Average particle diameter of aqueous dispersion Using Nikkiso Co., Ltd., Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method), number average particle diameter of aqueous resin dispersion after 460 mesh filtration Asked. Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50.
(4) Pot life The aqueous dispersion after 460 mesh filtration was placed in a transparent glass container and visually observed for 100 days, and evaluated in the following three stages.
○: No change in appearance.
Δ: Thickening is observed.
X: Solidification, aggregation and precipitation are observed.
(5) Viscosity The rotational dispersion at a temperature of 20 ° C. was measured for the aqueous dispersion after 460 mesh filtration using a B type viscometer (DVL-BII type digital viscometer manufactured by Tokimec Co., Ltd.).
(6) pH
The pH of the aqueous dispersion after 460 mesh filtration was measured at a temperature of 20 ° C. using a pH meter (Horiba, Ltd., F-52).

3. Characteristics of the coating film In the following test, using a resin aqueous dispersion after filtration at 460 mesh, a stretched polyethylene (PE) film (manufactured by Tosero Co., Ltd., thickness 50 μm), aluminum (AL) foil (manufactured by Mitsui Chemicals, Inc., thickness 12 μm) ), Stretched polypropylene (OPP) film (manufactured by Tosero Co., Ltd., thickness 50 μm), and glass plate (thickness 1.5 mm).
(1) Adhesion (tape peeling test)
A resin aqueous dispersion was applied to a stretched PE film, an AL foil, an OPP film, and a glass plate using a Meyer bar, and then dried at 90 ° C. for 2 minutes to obtain a laminate having a coating film having a thickness of 1 μm. . The obtained laminate was allowed to stand at room temperature for 1 day and then evaluated. 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.
Δ: A part was peeled off.
X: Most peeled off.
(2) Adhesiveness After applying the aqueous dispersion to the corona surface of the stretched PE film and the non-glossy surface of the AL foil using a Meyer bar, it was dried at 90 ° C. for 2 minutes, and a coating film having a thickness of 1.5 μm A laminated body having was obtained. The coated surfaces of the obtained laminate were bonded together and pressed with a heat press machine (sealing pressure 0.2 MPa / cm ² for 10 seconds). The press temperature was 110 ° C. for PE / PE and PE / AL bonding, and 140 ° C. for AL / AL bonding. The sample thus obtained was cut out at a width of 15 mm, and one day later, it was peeled off at a tensile speed of 200 mm / min and a tensile angle of 90 degrees using a tensile tester (Intesco Precision Universal Material Tester Model 2020 manufactured by Intesco Corporation). The strength was measured. The measurement was performed at n = 5, and the measured value was the average value.
(3) Water resistance test A glass plate was coated with an aqueous dispersion with a Mayer bar and dried at 150 ° C for 2 minutes to form a coating film having a thickness of 10 µm. The glass plate was immersed in tap water and allowed to stand at room temperature for 24 hours, and then the degree of solubility and peeling state of the coating film was visually evaluated according to the following criteria.
○: No change in appearance.
(Triangle | delta): Whitening of a coating film, swelling, and partial peeling are seen.
X: The coating film cannot be confirmed due to dissolution or peeling of the coating film.
(4) Alkali resistance test A glass plate on which a coating film has been formed in the same manner as in (3) is immersed in a 0.2 mass% NaOH aqueous solution and allowed to stand at room temperature for 24 hours. Was visually evaluated according to the following criteria.
○: No change in appearance.
(Triangle | delta): Whitening of a coating film, swelling, and partial peeling are seen.
X: The coating film cannot be confirmed due to dissolution or peeling of the coating film.
(5) Solvent resistance test The glass plate on which the coating film was formed in the same manner as in (3) was immersed in tetrahydrofuran (THF) and allowed to stand at room temperature for 24 hours. The visual evaluation was performed based on the criteria.
○: No change in appearance.
(Triangle | delta): Whitening of a coating film, swelling, and partial peeling are seen.
X: The coating film cannot be confirmed due to dissolution or peeling of the coating film.

  As the raw material, ethylene / unsaturated carboxylic acid copolymer, commercially available products such as Nucrel (Mitsui / Dupont Polychemical Co., Ltd., ethylene / methacrylic acid polymer), Lexpearl EAA (Nippon Polyethylene Co., Ltd., ethylene / acrylic) Various brands of acid polymer) and Primacol (produced by Dow Chemical Co., ethylene / acrylic acid polymer) were used. The characteristics of the ethylene / unsaturated carboxylic acid copolymer used in the test are summarized in Table 1.

[Example 1]
In a sealable 1 L pressure-resistant glass container equipped with a stirrer and a heater, 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of n-propanol (hereinafter referred to as NPA), triethylamine as raw materials (Hereinafter TEA) 17.6 g (2.5 equivalents / COOH) and distilled water 257.4 g were charged, sealed, and stirred and mixed at a rotational speed of the stirring blade of 400 rpm. No precipitation was observed, confirming that it was in a floating state. Therefore, the entire glass container was covered with a heat insulating material, the heater was turned on, the system temperature was set to 170 ° C., and the mixture was further stirred for 60 minutes. Thereafter, the heater was turned off and cooled to 80 ° C. by natural cooling while stirring at a rotational speed of 400 rpm. At this time, the time required to lower the system temperature from 120 ° C. to 80 ° C. was 1 hour. Then, the heat insulating material of the glass container was removed, and the lower half of the glass container was immersed in water and cooled with water. When the system internal temperature became 35 ° C. or lower, stirring was stopped, and the contents in the glass container were filtered with a 460 mesh stainless steel filter to obtain an aqueous dispersion. Various characteristics of the aqueous dispersion are shown in Table 2.

[Example 2]
As raw materials, 50.0 g (10% by mass) of Nucrel N1108C, 175.0 g (35% by mass) of NPA, 16.2 g (2.5 times equivalent / COOH) of TEA, and 258.8 g of distilled water were used. Except for the above, the same operation as in Example 1 was performed to obtain an aqueous dispersion. Various characteristics of the aqueous dispersion are shown in Table 2.

[Example 3]
The raw materials were 50.0 g (10% by mass) of Nucrel N0903HC, 175.0 g (35% by mass) of NPA, 13.2 g (2.5 times equivalent / COOH) of TEA, and 261.8 g of distilled water. Except for the above, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 4]
As raw materials, 50.0 g (10% by mass) of Nucrel AN42115C, 175.0 g (35% by mass) of NPA, 14.9 g (7 times equivalent / COOH) of diethylamine (hereinafter referred to as DEA), and 260. of distilled water. Except for 1 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 5]
As raw materials, except that 50.0 g (10% by mass) of Nucrel AN4225C, 175.0 g (35% by mass) of NPA, 21.2 g (10 times equivalent / COOH) of DEA, and 253.8 g of distilled water were used. The same operations as in Example 1 were performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 6]
As raw materials, 50.0 g (10% by mass) of Lexpearl EAA, A221M, 175.0 g (35% by mass) of NPA, 14.9 g of TEA (2.5 times equivalent / COOH), and 260. distilled water. Except for 1 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 7]
As raw materials, 50.0 g (10% by mass) of Lexpearl EAA, A210K, 175.0 g (35% by mass) of NPA, 12.3 g (2.5 times equivalent / COOH) of TEA, and 262. of distilled water. Except for 7 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 8]
As raw materials, except that 50.0 g (10% by mass) of Primacol 3150, 175.0 g (35% by mass) of NPA, 7.6 g (5 times equivalent / COOH) of DEA, and 267.4 g of distilled water were used. Were the same operations as in Example 1 to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 9]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of NPA, 12.7 g of 28% aqueous ammonia (3 times equivalent / COOH), and 262.3 g of distilled water Except that, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 2.

[Example 10]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of isopropanol (hereinafter referred to as IPA), 17.6 g (2.5 times equivalent / COOH) of TEA, and distilled water Except for 257.4 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 2.

[Example 11]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of ethanol (hereinafter EtOH), 17.6 g of TEA (2.5 times equivalent / COOH), and distilled water Except for 257.4 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 2.

[Example 12]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of methanol (hereinafter, MeOH), 17.6 g (2.5 times equivalent / COOH) of TEA, and distilled water Except for 257.4 g, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 2.

[Example 13]
As raw materials, Nucrel N0903HC was 75.0 g (15 mass%), NPA was 175.0 g (35 mass%), TEA was 19.8 g (2.5 times equivalent / COOH), and distilled water was 230.2 g. Except for the above, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 14]
As raw materials, 50.0 g (10% by mass) of Nucrel AN42115C, 175.0 g (35% by mass) of NPA, 5.3 g (2.5 times equivalent / COOH) of DEA, and 269.7 g of distilled water were used. Except for the above, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Example 15]
In a 1 L pressure-resistant glass container equipped with a stirrer and a heater, as raw materials, 50.0 g (10% by mass) of Nucrel N0903HC, 175.0 g (35% by mass) of NPA, and 13.2 g (2 of TEA) .5 times equivalent / COOH) and 261.8 g of distilled water were charged, sealed, and stirred and mixed at a rotation speed of the stirring blade of 400 rpm. It was confirmed that Therefore, the entire glass container was covered with a heat insulating material, the heater was turned on, the system temperature was set to 170 ° C., and the mixture was further stirred for 60 minutes. Thereafter, all of the heat insulating material covering the glass container was removed, the heater was turned off, and the system was cooled to a temperature of 35 ° C. or lower while stirring at a rotational speed of 400 rpm. At this time, the time required for the system internal temperature to drop from 120 ° C. to 80 ° C. was about 15 minutes. When the system internal temperature became 35 ° C. or lower, stirring was stopped, and the content in the glass container was filtered with a 460 mesh stainless steel filter to obtain an aqueous dispersion. Various properties of the aqueous resin dispersion are shown in Table 2.

[Comparative Example 1]
The same operation as in Example 1 was performed except that 50.0 g (10% by mass) of Nucrel N1214, 17.6 g of TEA (2.5 times equivalent / COOH), and 432.4 g of distilled water were used as raw materials. As a result, almost all of the raw material resin was recovered in the filtration step, and almost no aqueous dispersion was obtained.

[Comparative Example 2]
The same operation as in Example 1 was performed except that 50.0 g (10% by mass) of Nucrel N1108C, 16.2 g (2.5 times equivalent / COOH) of TEA, and 433.8 g of distilled water were used as raw materials. As a result, all the raw material resins were recovered in the filtration step, and no aqueous dispersion was obtained.

[Comparative Example 3]
The same as Example 1, except that 50.0 g (10% by mass) of Lexpearl EAA A221M, 14.9 g of TEA (2.5 times equivalent / COOH), and 435.1 g of distilled water were used as raw materials. As a result of the operation, all raw material resins were recovered in the filtration step, and no aqueous dispersion was obtained.

[Comparative Example 4]
The same operation as in Example 1 was carried out except that 50.0 g (10% by mass) of Primacol 3150, 7.6 g of DEA (5 times equivalent / COOH), and 442.4 g of distilled water were used as raw materials. As a result, all the raw resin was recovered in the filtration step, and no aqueous dispersion was obtained.

[Comparative Example 5]
The same operation as in Example 1 was performed except that 50.0 g (10% by mass) of Nucrel N1110H, 14.0 g of DEA (3 times equivalent / COOH), and 436.0 g of distilled water were used as raw materials. However, most of the raw material resin was recovered in the filtration step, and no good aqueous dispersion that could be evaluated was obtained.

[Comparative Example 6]
As raw materials, 50.0 g (10% by mass) of Nucrel N1110H, 100.0 g (20% by mass) of NPA, 16.2 g (2.5 times equivalent / COOH) of TEA, and 333.8 g of distilled water were used. Except for the above, the same operation as in Example 1 was performed to obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Example 7]
The same operation as in Example 1 was conducted except that 50.0 g (10% by mass) of Nucrel N1050H, 17.6 g (3.0 times equivalent / COOH) of TEA, and 432.4 g of distilled water were used as raw materials. To obtain an aqueous resin dispersion. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Example 8]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 125.0 g (25% by mass) of NPA, 3.9 g (1.0 times equivalent / COOH) of potassium chloride (hereinafter referred to as KOH), and distilled water A resin aqueous dispersion was obtained in the same manner as in Example 1 except that 321.1 g was used. Various characteristics of the aqueous resin dispersion are shown in Table 3.

[Comparative Example 9]
Example 1 except that 50.0 g (10% by mass) of Nucrel N1214, 175 g of toluene, 17.6 g of TEA (2.5 times equivalent / COOH), and 257.4 g of distilled water were used as raw materials. When the same operation was performed, most of the raw material resin was recovered in the filtration step, and a good aqueous dispersion that could be evaluated was not obtained at all.

[Comparative Example 10]
As raw materials, 50.0 g (10% by mass) of Nucrel N1214, 175 g of methylcyclohexane (hereinafter, MCH), 17.6 g of TEA (2.5 times equivalent / COOH), and 257.4 g of distilled water were used. When the same operation as in Example 1 was performed, most of the raw material resin was recovered in the filtration step, and a good aqueous dispersion that could be evaluated was not obtained at all.

  The results of Examples 1 to 15 show that the water-dispersible ethylene / unsaturated carboxylic acid copolymer that could not be dispersed in water without a non-volatile aqueous dispersion aid in the past was the aqueous solution of the present invention. It shows that it can be made aqueous by the dispersion method. Further, the obtained aqueous dispersion had excellent pot life, particle size and viscosity. Furthermore, the coating film obtained from this aqueous dispersion was excellent in adhesion to various substrates, adhesion, water resistance, alkali resistance, and solvent resistance.

  From the comparison between Examples 14 and 4, it can be seen that when the amount of the organic amine compound is increased, the aqueous dispersion yield is improved. In addition, it can be seen from the comparison between Examples 15 and 3 that the aqueous dispersion yield is improved by increasing the time required for cooling.

  Comparative Examples 1 to 4 show that the ethylene / unsaturated carboxylic acid copolymer defined in the present invention cannot be dispersed in water without using an organic solvent suitable in the present invention. In Comparative Example 5, an ethylene / unsaturated carboxylic acid copolymer having an unsaturated carboxylic acid component content of 11% by mass and a melt flow rate of 100 g / 10 min was attempted to be aqueous by the method described in Patent Document 4. However, a sufficient aqueous dispersion yield was not obtained.

  Further, from the results of Comparative Examples 1 to 5, a resin having a low content of unsaturated carboxylic acid or a low melt flow rate value compared to the ethylene / unsaturated carboxylic acid copolymer used in these Comparative Examples. That is, N0903HC, AN42115C, AN4225C, and A210K are more difficult to disperse in water, and it is easily assumed that an aqueous dispersion cannot be obtained without the use of an organic solvent, as in Comparative Examples 1-5. .

  In Comparative Example 7, the carboxylic acid component or melt flow rate of the ethylene / acrylic acid copolymer used deviated from the provisions of the present invention, and the resin could be made aqueous without using an organic solvent. However, although the obtained coating film had good water resistance, it was inferior in alkali resistance and solvent resistance.

  From the results of Comparative Examples 9 and 10, when the organic solvent added at the time of aqueous dispersion was one having a solubility in water at 20 ° C. of less than 50 g / L, the effect of promoting aqueous dispersion could not be confirmed.

  Comparative Example 8 is an example in which an aqueous dispersion was performed using a metal compound instead of an organic amine compound, but the aqueous coating was possible, but the resulting coating film was inferior in water resistance and alkali resistance. It was.

From comparison between Examples 1 to 15 and Comparative Examples 6 to 7, it can be seen that Examples 1 to 15 are superior in adhesion, alkali resistance, and solvent resistance to various substrates. The excellent adhesiveness is thought to be due to the increased strength of the adhesive layer due to the low melt flow rate value of the raw resin, and the excellent alkali resistance is softened by alkali because the content of unsaturated carboxylic acid in the raw resin is low. It is considered that the solvent resistance is excellent because the melt flow rate value of the raw material resin is low.

Claims (10)

The melt flow rate (hereinafter simply referred to as “melt flow rate”) measured at 190 ° C. and 2160 g load based on JIS K7210: 1999 is 0. An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer of 5 to 100 g / 10 minutes or an unsaturated carboxylic acid component of 10 to 15% by mass, and a melt flow rate of 0.5 g / 10 minutes or more and 30 g / An aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer for less than 10 minutes, which is 0.5 to 15 times the molar equivalent of ammonia relative to the number of moles of carboxyl groups of the ethylene / unsaturated carboxylic acid copolymer And / or an organic amine compound and is substantially free of non-volatile aqueous dispersion aids. Aqueous dispersion of the polymer. The aqueous dispersion according to claim 1, wherein the unsaturated carboxylic acid component is acrylic acid and / or methacrylic acid. An unsaturated carboxylic acid component is contained in an amount of 1% by mass or more and less than 10% by mass, and an ethylene / unsaturated carboxylic acid copolymer or an unsaturated carboxylic acid component is melted at a flow rate of 0.5 to 100 g / 10 min. %, The melt flow rate of 0.5 / 10 min or more and less than 30 g / 10 min ethylene / unsaturated carboxylic acid copolymer, water solubility at 20 ° C. is 50 g / L or more and 30 to 250 ° C. The method for producing an aqueous dispersion according to claim 1 or 2, wherein an organic solvent having a boiling point of, ammonia and / or an organic amine compound, and water are mixed at a temperature of 110 to 280 ° C. The aqueous dispersion according to claim 3, wherein the organic solvent having a water solubility at 20 ° C of 50 g / L or more and a boiling point of 30 to 250 ° C is methanol, ethanol, n-propanol, or isopropanol. Manufacturing method. 5. The aqueous dispersion according to claim 3, wherein the content of the organic amine compound is 3 to 15 times equivalent moles relative to the number of moles of carboxyl groups in the ethylene / unsaturated carboxylic acid copolymer. Production method. 6. The method for producing an aqueous dispersion according to claim 3, wherein after the heating, the container is cooled for 30 minutes or more to lower the temperature from 110 ° C. to 80 ° C. 6. The method according to any one of claims 3 to 6, wherein the aqueous dispersion is further subjected to a solvent removal treatment. A coating film obtained from the aqueous dispersion according to claim 1. The laminated body formed by forming the coating film of Claim 8 on a base material. The laminate according to claim 9, wherein the substrate is metal, glass, plastic, or paper.