JP2009242504A - Method for producing aqueous dispersion - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a resin aqueous dispersion of ethylene-unsaturated carboxylic acid copolymer with a small amount of unsaturated carboxylic acid content and low fluidity of melt (low melt flow rate) by using ammonia or an amine. <P>SOLUTION: This method for producing an aqueous dispersion comprises using as raw materials an ethylene-unsaturated carboxylic acid copolymer containing 1-15 mass% unsaturated carboxylic acid component having 0.5-200 g/10 min melt flow rate at 190°C and 21.2 N load, an organic solvent having ≥50 g/L solubility in water at 20°C and 30-250°C boiling point, ammonia and/or an organic amine compound, and water; and stirring these raw materials while heating at 80-280°C temperature. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a method for producing an aqueous dispersion, and more particularly to a method for producing an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer.

  Ethylene / unsaturated carboxylic acid copolymer, represented by ethylene / (meth) acrylic acid copolymer, is dispersed in water with metal compounds represented by amine, ammonia, alkali metal compounds, etc. Thereby obtaining a uniform and good aqueous dispersion. This has been known for a long time, and the obtained aqueous dispersions are widely used as adhesives and coating agents in various fields. However, this aqueous dispersion of the copolymer tends to become more difficult as the content of the unsaturated carboxylic acid component in the copolymer decreases and as the melt flow rate value of the copolymer decreases. Depending on the combination of the content of the unsaturated carboxylic acid component and the melt flow rate, it cannot be said unconditionally. Specifically, the content of the unsaturated carboxylic acid component is about 15% by mass or less, 190 ° C., 21. When the melt flow rate measured with a 2N (2160 g) load is about 300 g / 10 min or less, the particle size of the obtained aqueous dispersion is difficult even when aqueous dispersion is difficult or aqueous dispersion is possible. Is big.

  However, when the aqueous dispersion is performed using a metal compound typified by an alkali metal compound, the content of the unsaturated carboxylic acid component is smaller than when the aqueous dispersion is performed using ammonia or an amine, and Even a copolymer having a low melt flow rate value tends to facilitate aqueous dispersion. Utilizing this point, Patent Documents 1 and 2 show an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer using sodium or potassium. However, since the metal compound remains in the coating film of the aqueous dispersion obtained using such a metal compound after drying, there is a problem that peeling or whitening occurs when water is immersed in the coating film because of poor water resistance. Moreover, there exists a problem that alkali resistance and adhesiveness are scarce. Therefore, it cannot be used as it is in applications that require water resistance, alkali resistance, and high adhesion.

  On the other hand, an aqueous dispersion obtained using ammonia or amine can obtain a coating film excellent in water resistance. However, since aqueous dispersion is difficult, the content is limited to an aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer having a high content of an unsaturated carboxylic acid component and a high melt flow rate value. Therefore, the dry coating film of the obtained aqueous dispersion has a problem that it has a small surface hardness and rigidity, is easily peeled off, and is easily damaged. In order to solve these problems, using ammonia or amine, the method for aqueous dispersion of an ethylene / unsaturated carboxylic acid copolymer with a low content of unsaturated carboxylic acid component and a low melt flow rate value, Many studies have been made. For example, Patent Document 3 discloses an ethylene / unsaturated carboxylic acid in which a specific amount of ammonia is added, the content of the unsaturated carboxylic acid component is 15 to 35% by mass, and the melt flow rate is 50 to 2000 g / 10 min. A copolymer is shown. However, in Patent Document 3, there is actually only a specific example in which the content of the unsaturated carboxylic acid component is 20% by mass or more and the melt flow rate is 60 g / 10 min or more. For this reason, it is difficult to say that the content of the unsaturated carboxylic acid component is low. Furthermore, there are not a few gels and bumps in such an aqueous dispersion, and it cannot be said that the aqueous dispersion is sufficiently uniform.

  In Patent Document 4, a specific amine is used, an ethylene / unsaturated carboxylic acid copolymer 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. Coalescence is shown. However, in Patent Document 4, there are actually only specific examples in which the content of the unsaturated carboxylic acid component is 15% by mass or more and the melt flow rate is 60 g / 10 min or more. Furthermore, according to an experiment conducted by the present inventors, in the aqueous dispersion method using a specific amine as described in Patent Document 4, for example, the content of the unsaturated carboxylic acid component is 11% by mass, In addition, when an ethylene / unsaturated carboxylic acid copolymer having a melt flow rate of 100 g / 10 min is dispersed in water, a large amount of large-diameter undispersed particles are confirmed, and a completely uniform aqueous dispersion can be obtained. It is impossible (corresponding to Comparative Example 2 described later).

For aqueous dispersion of ethylene / unsaturated carboxylic acid copolymer with low content of unsaturated carboxylic acid component and low melt flow rate value using ammonia or amine, it is the only non-volatile such as surfactant. Only the method of adding an aqueous dispersion aid is known. For example, Patent Document 5 discloses the method. However, since the non-volatile aqueous dispersion aid remains after drying in the coating film of the aqueous dispersion obtained by this method, problems such as bleeding out and performance such as water resistance are significantly reduced. There is a problem.
Japanese Patent Laid-Open No. 51-62890 JP-A-10-298295 JP 2000-248141 A JP 2004-143293 A JP 2005-336277 A

  In order to solve the above-mentioned problems, the present invention uses ammonia or amine to reduce the content of unsaturated carboxylic acid components and have low flowability during melting (low melt flow rate value). An object of the present invention is to provide a production method capable of obtaining an aqueous resin dispersion of a saturated carboxylic acid copolymer.

  As a result of intensive studies to solve the above problems, the present inventors have found that ethylene / unsaturated carboxylic acid has a low content of unsaturated carboxylic acid component and low fluidity at melting (low melt flow rate value). Even if it is an acid copolymer, by adding a specific organic solvent and carrying out aqueous dispersion, it is aqueous-dispersed by ammonia and / or an organic amine compound, and contains a substantially non-volatile aqueous agent. The present inventors have found that an aqueous dispersion that has not been obtained can be obtained.

  That is, the gist of the present invention is as follows.

  (1) An ethylene / unsaturated carboxylic acid copolymer containing 1 to 15% by mass of an unsaturated carboxylic acid component and having a melt flow rate of 0.5 to 200 g / 10 min at 190 ° C. and a load of 21.2 N; , Using an organic solvent having a solubility in water at 20 ° C. of 50 g / L or more and having a boiling point of 30 to 250 ° C., ammonia and / or an organic amine compound, and water as raw materials. A method for producing an aqueous dispersion, comprising stirring while heating at a temperature of 280 ° C.

  (2) The method for producing an aqueous dispersion according to (1), wherein an ethylene / unsaturated carboxylic acid copolymer in which the unsaturated carboxylic acid component is acrylic acid and / or methacrylic acid is used as a raw material.

  (3) The method for producing an aqueous dispersion according to (1) or (2), wherein at least one of methanol, ethanol, npropanol, and isopropanol is used as the organic solvent.

  (4) The organic amine compound is used so as to be 0.5 to 15 times the equivalent number of moles of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer (1) to (3 ) Any one of the methods for producing an aqueous dispersion.

  (5) The method for producing an aqueous dispersion according to any one of (1) to (4), wherein the product is cooled so that it takes 30 minutes or more for the product temperature to drop from 120 ° C. to 80 ° C. .

  (6) The method for producing an aqueous dispersion according to any one of (1) to (5), wherein a non-volatile aqueous dispersion aid is not used.

  (7) After obtaining the aqueous dispersion by any one of the methods (1) to (6), the solvent is further removed to reduce the organic solvent content of the aqueous dispersion. A method for producing an aqueous dispersion.

  According to the present invention, an ethylene / unsaturated carboxylic acid copolymer that has conventionally been impossible to obtain as an aqueous dispersion due to a low content of unsaturated carboxylic acid components and a low melt flow rate value. It is possible to obtain an aqueous dispersion having a fine particle size. Furthermore, the aqueous dispersion obtained by the present invention can exhibit water resistance, alkali resistance, adhesiveness, and solvent resistance, which are superior to those of conventional coating films, due to the properties of the copolymer.

Hereinafter, the present invention will be described in detail.
The unsaturated carboxylic acid that is a constituent of the ethylene / unsaturated carboxylic acid copolymer used in the present invention includes acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, itaconic anhydride. An acid, monomethyl maleate, monoethyl maleate, etc. are mentioned. A mixture thereof may be used. Among these, acrylic acid and / or methacrylic acid are preferable.

  The unsaturated carboxylic acid content in the copolymer needs to be 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%. If the content of the unsaturated carboxylic acid is less than 1% by mass, aqueous dispersion becomes difficult. On the other hand, if it exceeds 15% by mass, the aqueous dispersion can be easily achieved without the present invention.

  The melt flow rate (JIS K7210: 1999) at 190 ° C. and 21.2N (2160 g) of the ethylene / unsaturated carboxylic acid copolymer used in the present invention is 0.5 to 200 g / 10 min. is necessary. Preferably it is 1-200 g / 10min, More preferably, it is 2-200g / 10min, Most preferably, it is 3-200g / 10min. When the melt flow rate is less than 0.5 g / 10 minutes, aqueous dispersion becomes difficult. On the other hand, when it exceeds 200 g / 10 minutes, it is possible to easily disperse in water without having the present invention, and the coating film of the obtained aqueous dispersion has small surface hardness and rigidity, and further has adhesiveness, The solvent resistance tends to deteriorate.

  Other monomers may be copolymerized in the ethylene / unsaturated carboxylic acid copolymer used in the present invention within a range not impairing the effects of the present invention. Such monomers include vinyl esters such as vinyl acetate and vinyl propionate; methyl acrylate, ethyl acrylate, isopropyl acrylate, isobutyl acrylate, nbutyl acrylate, isooctyl acrylate, acrylic acid-2 -Unsaturated carboxylic acid esters such as ethylhexyl, methyl methacrylate, ethyl methacrylate, isobutyl methacrylate, dimethyl maleate, diethyl maleate; carbon monoxide; sulfur dioxide and the like. Content of these monomers should just be 0-30 mass% with respect to the whole resin, and it is preferable that it is 0-20 mass%.

  In the present invention, as the ethylene / unsaturated carboxylic acid copolymer, it is of course possible to use only one kind of copolymer, but the content, type, and / or melt flow rate value of the unsaturated carboxylic acid. Two or more kinds of ethylene / unsaturated carboxylic acid copolymers different in the above may be mixed and used. In that case, what melt-blended two or more types of ethylene and unsaturated carboxylic acid copolymer is preferable. However, it may be dispersed in water as a dry blend. The content of the unsaturated carboxylic acid and the melt flow rate value for a mixture of two or more types of copolymers can be determined by actually measuring the melt blend. That is, even when dry blended, it is necessary to melt-blend a copolymer having the same mixing ratio and actually measure the resin. As long as the unsaturated carboxylic acid content of the copolymer and the actual measurement value of the melt flow rate value are within the scope of the present invention, the unsaturated carboxylic acid content and / or A melt flow rate value outside the range of the present invention may be used.

  The form of the ethylene / unsaturated carboxylic acid copolymer is not particularly limited, but is preferably in the form of particles or powder having a particle diameter of 1 cm or less, preferably 0.8 cm or less, from the viewpoint of increasing the speed of aqueous formation.

  The amount of the ethylene / unsaturated carboxylic acid copolymer added when the production method of the present invention is performed is 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. It is preferable that 5-30 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 aqueous dispersion obtained has too low a resin content, and when used as it is, the performance of the coating film is hardly exhibited. On the other hand, when it exceeds 40 mass%, aqueous dispersion tends to be difficult.

  In the method of the present invention, using an ethylene / unsaturated carboxylic acid copolymer, which is conventionally difficult to disperse in water, has a low content of unsaturated carboxylic acid component, and has a low melt flow rate value, In order to make the aqueous dispersion possible and to make the particle size of the aqueous dispersion finer, the solubility in water at 20 ° C. is 50 g / L or more and 30 It is necessary to add an organic solvent having a boiling point of ˜250 ° C. More preferably, the organic solvent has a solubility in water at 20 ° C. of 100 g / L or more. When the solubility in water at 20 ° C. is less than 50 g / L, the effect of promoting aqueous dispersion is not observed. The organic solvent is not particularly required to have high solubility in the ethylene / unsaturated carboxylic acid copolymer. For example, 10% by mass of the copolymer and 90% by mass of the organic solvent are used. Even if the mixture has a solubility of not more than 0.5 g / L when stirred at 80 ° C., it does not matter.

  Specific examples of such organic solvents include methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol, tert. Alcohols such as amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol and cyclohexanol; ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone and isophorone; tetrahydrofuran Ethers such as dioxane, ethyl acetate, acetic acid-n-propyl, isopropyl acetate, acetic acid-n-butyl, isobutyl acetate, acetic acid-sec-butyl, acetic acid-3-methoxybutyl, Esters such as methyl pionate, 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 , Glycol derivatives such as 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; Methoxy-3-methylbutanol; 3-methoxy butanol; acetonitrile; dimethylformamide; dimethylacetamide; diacetone alcohol; ethyl acetoacetate, and the like.

  The organic solvent needs to have a boiling point of 30 to 250 ° C., particularly preferably 50 to 200. These organic solvents may be used as a mixture of two or more. In addition, when the boiling point of the organic solvent is less than 30 ° C., the rate of volatilization during aqueous dispersion increases and the efficiency of aqueous dispersion is not 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 thus the water resistance of the coating film is deteriorated. 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 production method of the present invention, the addition amount of the organic solvent is preferably 5 to 60 parts by mass with respect to 100 parts by mass of the total of the aqueous medium and the ethylene / unsaturated carboxylic acid copolymer, and 15 to 50 parts by mass. Is more preferable, 20-45 mass parts is further more preferable, and 25-40 mass parts is especially preferable. When the addition amount is less than 5 parts by mass, the effect of promoting aqueous dispersion is low. Conversely, when it exceeds 60 parts by mass, aqueous dispersion tends to be difficult or the resulting aqueous dispersion tends to gel. There is.

  As ammonia and the organic amine compound used in the production method of the present invention, those which volatilize during the formation of the coating film are preferable from the viewpoint of the water resistance of the coating film, and an organic amine compound having a boiling point of 0 to 250 ° C. is particularly preferable. When the boiling point is less than 0 ° C., the rate of volatilization during aqueous dispersion described later increases, and thus aqueous dispersion may not proceed completely. When the boiling point exceeds 250 ° C., it becomes difficult to scatter 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. Can do. A mixture thereof, or a mixture of ammonia and these may be used. Of these, diethylamine and triethylamine are preferable.

  The amount of ammonia and / or organic amine compound added in the production method of the present invention is an amount that is 0.5 to 15 times the equivalent mol of the number of moles of carboxyl groups in the ethylene / unsaturated carboxylic acid copolymer. It is preferable that the amount is usually 0.8 to 3.0 times equivalent mol, and more preferably 1.0 to 2.5 times equivalent mol. In the case where the content of unsaturated carboxylic acid is small (for example, 5% by mass or less), when these addition amounts are 3 to 15 times equivalent mol, surprisingly, aqueous dispersion tends to be easier. There is. In this case, the addition amount is more preferably 4 to 12 times equivalent mol, and further preferably 5 to 10 times equivalent mol. When the addition amount is less than 0.5 equivalent mole, the effect of addition is hardly recognized. On the other hand, when the amount exceeds 15 times the equivalent mole, the effect of addition does not change, and the drying time at the time of forming the coating film tends to be long, and the aqueous dispersion tends to be intensely colored.

  In the production method of the present invention, it is not particularly necessary to add a metal compound typified by an alkali metal compound. However, if necessary for the purpose of use of the aqueous dispersion, they may be added within a range not impairing the effects of the present invention.

Next, an actual method for producing an aqueous dispersion of the present invention, that is, an actual aqueous dispersion method will be described.
The aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer in the production method of the present invention has an ethylene / unsaturated carboxylic acid copolymer and water solubility at 20 ° C. of 50 g / L or more and 30 to 250. It is necessary to stir while heating an organic solvent having a boiling point of ° C., ammonia and / or an organic amine compound, and water at a temperature of 80 to 280 ° C.

  By the above method, the ethylene / unsaturated carboxylic acid copolymer is uniformly dispersed in the aqueous medium, and a good aqueous dispersion is obtained. Here, the aqueous medium refers to a medium composed of a liquid mainly composed of water other than the resin solid content in the aqueous dispersion. The aqueous medium may be obtained by reducing or completely removing the organic solvent contained therein by a method called stripping described later.

  According to the aqueous dispersion method of the present invention, an ethylene / unsaturated carboxylic acid copolymer 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. Can be made into an aqueous dispersion. That is, the method for producing an aqueous dispersion of the present invention can avoid using a non-volatile aqueous dispersion aid. Even if these are not used, the ethylene / unsaturated carboxylic acid copolymer can be stably maintained in an aqueous medium having a number average particle diameter of 1 μm or less. The non-volatile aqueous dispersion aid remains after the formation of the coating film, and plasticizes the coating film, thereby deteriorating the characteristics of the ethylene / unsaturated carboxylic acid copolymer, such as water resistance. In the present invention, since the non-volatile aqueous dispersion aid is not used, the produced aqueous dispersion does not substantially contain the non-volatile aqueous dispersion aid. Excellent in properties.

  Here, 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. “Non-volatile” means having no boiling point at normal pressure or having a high boiling point (eg, 300 ° C. or higher) at normal pressure. “Substantially free of non-volatile aqueous dispersion aid” means that the aqueous dispersion produced by adding no non-volatile aqueous dispersion aid actively to the system results in It means not containing. That is, the nonvolatile aqueous dispersion aid is particularly preferably zero in content, but within a range not impairing the effects of the present invention, it is 0.1% relative to the ethylene / unsaturated carboxylic acid copolymer component. If it is less than mass%, it may be included.

  Non-volatile aqueous dispersion aids that are not used in the present invention include, for example, emulsifiers described later, compounds having a protective colloid effect, modified waxes, acid-modified compounds having a high acid value, and water-soluble polymers.

  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. And the like. Nonionic emulsifiers include polyoxyethylene alkyl ethers, polyoxyethylene alkylphenyl ethers, polyethylene glycol fatty acid esters, ethylene oxide propylene oxide block copolymers, polyoxyethylene fatty acid amides, ethylene oxide-propylene oxide copolymers, and the like. Examples thereof include compounds having an oxyethylene structure and sorbitan derivatives such as polyoxyethylene sorbitan fatty acid esters. Examples of amphoteric emulsifiers include lauryl betaine and lauryl dimethylamine oxide.

  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 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. As a container for aqueous dispersion, a tank into which a liquid can be charged is provided, and a mixture of an aqueous medium and copolymer powder or granular material charged in the tank. Can be appropriately stirred and heated, and a sealed container having a pressure resistance of 0.1 MPa (G) or more is preferable for the rusting. As such a device, a device widely known to those skilled in the art as a solid / liquid stirring device or an emulsifier can be used. The stirring method and the rotational speed of stirring in the present invention are not particularly limited, but sufficient aqueous dispersion can be achieved even with low-speed stirring that causes the resin to float in an aqueous medium. ) Is not required. For this reason, the aqueous dispersion can be produced with a simple apparatus.

  In the tank of this apparatus, an aqueous medium comprising ammonia and / or an organic amine compound, 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., and water. At the same time, granular or powdered ethylene / unsaturated carboxylic acid copolymer is charged. And it stirs and mixes preferably at the temperature of 40 degrees C or less. Subsequently, stirring is continued for 5 to 120 minutes while keeping the temperature (article temperature) in the tank at 80 to 280 ° C, preferably 120 to 230 ° C, more preferably 150 to 200 ° C, particularly preferably 160 to 180 ° C. Is preferred. When the temperature in the tank is lower than 80 ° C., aqueous dispersion of the ethylene / unsaturated carboxylic acid copolymer becomes difficult. On the other hand, when it exceeds 280 ° C., the molecular weight of the ethylene / unsaturated carboxylic acid copolymer may decrease. The heating and cooling method in the tank is not particularly limited, but for example, a jacket is provided on the outer wall of the tank, or a coiled tube is provided in the tank, and control is performed using oil, steam, water, etc. as a heating medium. Or by attaching a heater to the tank.

  At this time, that is, when the temperature in the tank is 80 to 280 ° C., the ethylene / unsaturated carboxylic acid copolymer in the container does not necessarily need to be completely dispersed, and floats as a lump in the molten state. There is no problem even if it is entangled with a stirring blade or the like. Surprisingly, in the aqueous dispersion method of the present invention, there is a tendency that aqueous dispersion proceeds during subsequent cooling, and this tendency becomes remarkable when the temperature is lowered from 120 ° C to 80 ° C. Therefore, it is preferable to continue stirring during cooling. Further, in the conventional method for producing an aqueous dispersion, it has become natural that cooling is performed as quickly as possible in order to shorten the production time, but in the method of the present invention, the temperature drop from 120 ° C. to 80 ° C. takes 30 minutes or more. Slow cooling is preferred, and more preferably 60 minutes or more. If the temperature lowering time is less than 30 minutes, the particle size of the aqueous dispersion may increase, or a large amount of undispersed resin may remain, resulting in a decrease in aqueous dispersion yield.

  Cooling is preferably performed with stirring until the temperature finally reaches 40 ° C. or lower. After cooling, an aqueous dispersion can be obtained. After this, jet pulverization may be further performed as necessary. Jet pulverization here refers to an aqueous dispersion of a fluid-like ethylene / unsaturated carboxylic acid copolymer that is ejected from pores such as nozzles and slits under high pressure to cause resin particles to collide with each other. It means that the resin particles are further refined by mechanical energy by causing the resin particles to collide with a collision plate or the like. Specific examples of the apparatus for that purpose include a homogenizer manufactured by APV GAULIN, M-110E / H, which is a microfluidizer manufactured by Mizuho Industries, Ltd., and the like.

  The aqueous dispersion thus obtained is subjected to a desolvation operation called stripping so that the solid content concentration, the organic solvent concentration, and the amine and / or organic amine compound concentration become the desired concentration. It can be adjusted by distilling out of the system or diluting with water. Specifically, a method of distilling off the organic solvent by heating the aqueous dispersion under normal pressure or reduced pressure can be mentioned. The content of the organic solvent can be quantified by gas chromatography. Further, since the solid content concentration is increased by distilling off the aqueous medium, for example, when the viscosity is increased and the workability is deteriorated, the aqueous medium is diluted with water, or the aqueous dispersion is previously mixed with water. Or the like is preferably added.

  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 the content is 1% by mass or less. More preferably.

  It is not preferable that ammonia and / or the organic amine compound be completely distilled off by such a solvent removal operation. The content of ammonia and / or organic amine compound is preferably 0.5 times equivalent mole or more, and 0.7 times equivalent mole relative to the number of moles of carboxyl groups in the ethylene / unsaturated carboxylic acid copolymer. The above is more preferable, and 1.0 equivalent mole or more is more preferable. When the content is less than 0.5 times equivalent, the resin particles in the aqueous dispersion aggregate and the storage stability tends to deteriorate. The content of ammonia and / or organic amine compound can be quantified by gas chromatography.

  The solid content concentration of the aqueous dispersion is preferably 5 to 40% by mass, more preferably 5 to 30% by mass with respect to 100% by mass of the total of the aqueous medium and the ethylene / unsaturated carboxylic acid copolymer, 10-25 mass% is further more preferable, and 15-20 mass% is especially preferable. In the case of less than 5% by mass, the solid content concentration is too low and the performance of the coating film is hardly exhibited. When it exceeds 40 mass%, there exists a tendency for remarkable thickening and gelatinization to arise.

  The aqueous dispersion obtained by the production method of the present invention is not particularly affected in terms of performance even if the solid content concentration or the amount of organic solvent is adjusted by stripping as described above. can do.

  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 amount of resin remaining on the filter It is possible to determine the aqueous dispersion yield by measuring. Even if there is some residual resin and the yield is low, it is possible to use it as an aqueous dispersion in the subsequent steps by removing the coarse particles by performing the above filtration during the production process. However, from the viewpoint of production cost and filtration workability, the aqueous dispersion yield is preferably 60% or more, and more preferably 80% or more.

  In the aqueous dispersion obtained as described above, the ethylene / unsaturated carboxylic acid copolymer is dispersed in an aqueous medium and is in a state of being prepared in a uniform liquid state. Furthermore, it has an excellent pot life and maintains a uniform liquid state even when left at room temperature for 100 days. Here, the uniform liquid state means that, in terms of appearance, a portion where the solid content concentration is locally different from other portions such as precipitation, phase separation and skinning is not found in the aqueous dispersion. Say.

  The number average particle diameter (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 safety, 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 (mv) is preferably 3 μm or less.

  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.

  The aqueous dispersion obtained by the method of the present invention contains two or more kinds of ethylene / unsaturated carboxylic acid copolymers having different contents, types, and / or melt flow rate values of unsaturated carboxylic acids. The aqueous dispersion may be mixed at an arbitrary ratio. Examples thereof include a mixture of an aqueous dispersion of an ethylene / methacrylic acid copolymer and an aqueous dispersion of an ethylene / acrylic acid copolymer.

  The aqueous dispersion obtained by the present invention can optionally contain various additives. Examples of such 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 Ethers such as ether, ethylene glycol monoethyl ether, propylene glycol monomethyl ether, propylene glycol diethyl ether, diethylene glycol monoethyl ether and dipropylene glycol monomethyl ether; esters such as ethylene glycol monoacetate and propylene glycol monoacetate; Aqueous dispersion of coalescence; inorganic particles; crosslinking agent; leveling agent; antifoaming agent; foaming agent; Antistatic agent; Antistatic agent; Plasticizer; Pigment; Pigment dispersant; Dye; Antibacterial agent; Lubricant; Antiblocking agent; Rust preventive agent; Adhesive writability improver; Examples include various agents such as inorganic fillers, and pigments or dyes such as titanium oxide, zinc white, and carbon black. By adding these additives, the aqueous dispersion obtained by the method of the present invention can be used as a coating agent or a paint. Moreover, it is also possible to add organic or inorganic compounds other than those described above within a range not impairing the stability of the aqueous dispersion. Moreover, you may use the additive shown above in combination of 2 or more types.

  Among the above, the aqueous dispersion of another polymer is not particularly limited. For example, ethylene / (meth) acrylic acid ester / carboxylic anhydride terpolymer, polyvinyl acetate, ethylene / vinyl acetate copolymer, polyvinyl chloride, polyvinyl 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, modified nylon resin, urethane resin, phenol resin, silicone resin, epoxy resin An aqueous dispersion such as You may use these in mixture of 2 or more types.

  Among these, examples of the inorganic particles include metal oxides such as magnesium oxide, zinc oxide and tin oxide; particles such as calcium carbonate and silica. In addition, a water-swellable layered inorganic compound such as vermiculite, montmorillonite, hectorite, or synthetic mica can be added. 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. Inorganic particles may be used as a mixture of two or more.

  In order to further improve various coating film performances such as cohesive strength and water resistance, the crosslinking agent is added in an amount of 0.01 to 100% by mass, preferably 0.1 to 60% with respect to 100% by mass of the resin in the aqueous dispersion. Mass% can be added. When the addition amount of the crosslinking agent is less than 0.01% by mass, the degree of improvement of the coating film performance is small, and when it exceeds 100% by mass, the performance such as workability is deteriorated.

  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, or the like can be used. Of these, isocyanate compounds, melamine compounds, urea compounds, epoxy compounds, carbodiimide compounds, oxazoline group-containing compounds, zirconium salt compounds, silane coupling agents, and the like are preferable. Moreover, you may use combining these crosslinking agents.

  The aqueous dispersion obtained by the production method of the present invention, or the resin composition obtained from the aqueous dispersion is excellent in adhesiveness to various substrates, and therefore various adhesives, heat sealability-imparting agents, rust preventive coatings, etc. For this purpose, it can be applied to various substrates and dried, and a laminate having these functions can be obtained. 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 an ionomer thereof, an ethylene / (meth) acrylic acid / (meth) acrylic acid ester copolymer or an ionomer thereof, an olefin polymer such as polypropylene, poly-1-butene, poly-4-methyl-1-pentene, or Copolymer: Styrenic resin such as polystyrene, high impact polystyrene, ABS type resin, styrene-butadiene block copolymer or hydrogenated product thereof; Polyester such as polyethylene terephthalate and polybutylene terephthalate; Nylon 6 and Nylon 66 Such as polyamide; Thermoplastic polymers such as bonates, polyvinyl chloride and mixtures of these in any proportion; rubber materials such as natural rubber and synthetic rubber; thermosetting resins such as phenolic resins and polyurethanes; iron, copper, aluminum and stainless steel Examples of such a metal; glass; ceramics; natural materials such as 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 produced by the method of the present invention has excellent wettability not only for polar materials but also for hydrophobic materials such as olefin polymers and styrene polymers. It can be applied with good coatability.

  For example, a film obtained by applying the aqueous dispersion of the present invention to a polyolefin film, typically a stretched polypropylene film, and drying, has low moisture permeability and good heat seal performance, and is suitable as various packaging materials. Can be used for 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.

  A known method can be used as a film forming method on these substrates. For example, gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dip coating, brush coating, etc., uniformly coat the surface of various substrates, and at room temperature as required After setting in the vicinity, a uniform resin film can be formed in close contact with the surfaces of various substrates by subjecting it to drying or heat treatment for drying and baking. As a heating device at this time, a normal hot air circulation type oven, an infrared heater, or the like may be used. The heating temperature and heating time at that time are appropriately selected according to the characteristics of the substrate to be coated, the kind of the curing agent to be added, the blending amount, and the like. However, in consideration of economy, the heating temperature is preferably 30 to 250 ° C, more preferably 60 to 230 ° C, and particularly preferably 80 to 210 ° C. The heating time is preferably 1 second to 20 minutes, more preferably 5 seconds to 15 minutes, and particularly preferably 5 seconds to 10 minutes. In addition, when a crosslinking agent is added, in order to sufficiently advance the reaction between the carboxyl group in the polyolefin and the crosslinking agent, it is desirable to appropriately select the heating temperature and time depending on the type of the crosslinking agent.

  The thickness of the resin film formed using the aqueous dispersion obtained by the method of the present invention is appropriately selected depending on the application, but is preferably 0.01 to 100 μm, ˜50 μm is more preferable, and 0.2 to 30 μm is particularly preferable. When the film is formed so that the thickness of the resin film falls within the above range, a resin film having excellent uniformity can be obtained. In order to adjust the thickness of the resin film, in addition to appropriately selecting an apparatus used for coating and its use conditions, an aqueous dispersion having a concentration suitable for the desired thickness of the resin film may be used. preferable. The concentration at this time can be adjusted by the charged composition at the time of preparation. Moreover, you may adjust so that the aqueous dispersion once prepared may be diluted or concentrated suitably.

  Hereinafter, the present invention will be described specifically by way of examples. However, the present invention is not limited by these. 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 IR method.

(2) Melt flow rate It measured by the method (190 degreeC, 21.2N (2160g) load) as described in JISK7210: 1999.

2. Characteristics of aqueous resin dispersion (1) Yield of aqueous dispersion The aqueous resin dispersion after aqueous dispersion was added with a 460 mesh stainless steel filter (wire diameter 35 μm, plain weave, mesh opening 20 μm, filtration area 133 cm ² ). Pressure filtration was performed (MAX 0.5 MPa (G)). Thereafter, the resin remaining on the filter was dried by vacuum drying at 110 ° C. for 1 hour, the resin mass was measured, and the yield was calculated using the measured mass and the charged resin mass.

(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. Asked.

(3) Average particle size of aqueous dispersion The number average particle size of aqueous resin dispersion after 460 mesh filtration using Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. mn). The refractive index of the resin used for calculating the particle diameter was 1.50.

(4) Pot life The aqueous dispersion after 460 mesh filtration was put in a transparent glass container and allowed to stand at room temperature for 100 days, and its appearance was evaluated by the following three stages by visual observation.

○: No change in appearance △: Thickening is observed ×: Solidification, aggregation and generation of precipitates are observed

(5) Viscosity About the aqueous dispersion after 460 mesh filtration, rotational viscosity at a temperature of 20 ° C. was measured using a B-type viscometer (DVL-BII type digital viscometer manufactured by Tokimec Co., Ltd.).

(6) pH
About the aqueous dispersion after 460 mesh filtration, pH at a temperature of 20 ° C. was measured using a pH meter (Horiba, Ltd., F-52).

3. Characteristics of coating film (1) Adhesion (tape peeling test)
Stretched polyethylene (PE) film (manufactured by Tosero, thickness 50 μm), aluminum (AL) foil (manufactured by Mitsui Chemicals Fabro, thickness 12 μm), stretched polypropylene (OPP) film (manufactured by Tosero, thickness 50 μm), glass plate (thickness) 1.5 mm), the aqueous resin dispersion after 460 mesh filtration was applied using a Mayer bar so that the film thickness after drying was 1 μm, and then dried at 90 ° C. for 2 minutes. The obtained laminate was allowed to stand at room temperature for 1 day and then evaluated.

Specifically, 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 a stretch was visually evaluated according to the following criteria.
○: No peeling at all △: Some peeling off ×: Most peeling off

(2) Adhesiveness 460 mesh filtration on each of the corona surface of stretched polyethylene (PE) film (manufactured by Tosero, 50 μm thick) and the non-glossy surface of aluminum (AL) foil (manufactured by Mitsui Chemicals Fabro, 12 μm thick) The subsequent aqueous dispersion was applied using a Mayer bar so that the film thickness after drying was 1.5 μm, and then dried at 90 ° C. for 2 minutes to obtain a laminate. The coated surfaces of the obtained laminate were bonded together and pressed with a heat press (sealing pressure 0.2 MPa) for 10 seconds. The pressing 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 with a width of 15 mm, and one day later, using a tensile tester (manufactured by Intesco, Intesco Precision Universal Material Tester 2020), peel strength at a tensile speed of 200 mm / min and a tensile angle of 90 degrees. Was measured. The measurement was performed with the number of samples n = 5, and the measured value was the average value.

(3) Water resistance A glass plate (thickness: 1.5 mm) is coated with a 460 mesh filtered aqueous dispersion with a Mayer bar so that the thickness of the coating layer after drying is 10 μm, and dried at 150 ° C. for 2 minutes. did. The glass plate thus obtained was immersed in tap water and allowed to stand at room temperature for 24 hours. Thereafter, the degree of solubility and peeling state of the coating layer was visually evaluated according to the following criteria.

○: No change in appearance Δ: Whitening, swelling, and partial peeling of the coating layer are observed ×: The coating layer cannot be confirmed due to dissolution or peeling of the coating layer

(4) Alkali resistance A glass plate (thickness: 1.5 mm) is coated with the aqueous resin dispersion after filtration at 460 mesh with a Mayer bar so that the thickness of the coating layer after drying is 10 μm, and at 150 ° C. for 2 minutes. Dried. The glass plate thus obtained was immersed in a 0.2 mass% NaOH aqueous solution and allowed to stand at room temperature for 24 hours. Thereafter, the degree of solubility and peeling state of the coating layer was visually evaluated according to the following criteria.

○: No change in appearance Δ: Whitening, swelling, and partial peeling of the coating layer are observed ×: The coating layer cannot be confirmed due to dissolution or peeling of the coating layer

(5) Solvent resistance A glass plate (thickness: 1.5 mm) was coated with a resin aqueous dispersion after filtration at 460 mesh with a Mayer bar so that the thickness of the coating layer after drying was 10 μm. Dried for minutes. The glass plate thus obtained was immersed in tetrahydrofuran (THF) and allowed to stand at room temperature for 24 hours. Thereafter, the degree of solubility and peeling state of the coating layer was visually evaluated according to the following criteria.

○: No change in appearance Δ: Whitening, swelling, and partial peeling of the coating layer are observed ×: The coating layer cannot be confirmed due to dissolution or peeling of the coating layer

[material]
As the ethylene / unsaturated carboxylic acid copolymer as a raw material, a commercially available product was used. That is, Nukurel (Mitsui / Dupont Polychemical Co., ethylene / methacrylic acid polymer), Lexpearl EAA (Nippon Polyethylene Co., ethylene / acrylic acid polymer), Primacol (Dow Chemical Co., ethylene / acrylic acid heavy polymer) Combined) was 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 npropanol (NPA), and 17 of triethylamine (TEA) .6 g (2.5 equivalents / COOH) and 257.4 g of distilled water were charged, and the glass container was sealed and stirred at a rotation speed of the stirring blade of 400 rpm. Was not observed and it was confirmed that it was floating. Therefore, the whole 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 stirred for 60 minutes. Thereafter, the heater was turned off and cooled to about 80 ° C. by natural cooling while stirring at a rotational speed of 400 rpm. At this time, the time required for the system temperature to drop from 120 ° C. to 80 ° C. was about 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 temperature became 35 ° C. or lower, the 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 obtained aqueous resin dispersion are shown in Table 2.

[Example 2]
The raw materials for the aqueous dispersion were 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. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 3]
The raw materials for the aqueous dispersion were 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. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 4]
The raw materials for the aqueous dispersion 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. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 5]
The raw materials for aqueous dispersion were 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 (DEA), and 260 of distilled water. 0.1 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 6]
The raw materials for aqueous dispersion were 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. did. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 7]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1560, 175.0 g (35% by mass) of NPA, 13.2 g (1.5 times equivalent / COOH) of TEA, and 261. 8 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 8]
The raw materials for aqueous dispersion are 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, distilled water Was 262.7 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Various characteristics of the obtained aqueous resin dispersion are shown in Table 2.

[Example 9]
As raw materials for aqueous dispersion, 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 It was. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 10]
The raw materials for the aqueous dispersion were 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 of distilled water. .3 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 11]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of isopropanol (IPA), 17.6 g (2.5 times equivalent / COOH) of TEA, distilled water Was 257.4 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 12]
The raw materials for aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of ethanol (EtOH), 17.6 g (2.5 times equivalent / COOH) of TEA, distilled water Was 257.4 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 13]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 175.0 g (35% by mass) of methanol (MeOH), 17.6 g (2.5 times equivalent / COOH) of TEA, distilled water Was 257.4 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 14]
The raw materials for aqueous dispersion were 75.0 g (15% by mass) of Nucrel N0903HC, 175.0 g (35% by mass) of NPA, 19.8 g (2.5 times equivalent / COOH) of TEA, and 230. distilled water. 2 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 15]
The raw materials for the aqueous dispersion were 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. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Example 16]
The glass container was heated by the same raw materials and method as in Example 4, the system temperature was set to 170 ° C., and the mixture was further stirred for 60 minutes. Thereafter, all the heat insulating material covering the glass container is removed, the heater is turned off, the lower half of the glass container is immersed in water, and the system temperature is 35 ° C. or lower while stirring at a rotational speed of 400 rpm. Until cooled. At this time, the time required for the temperature inside the system to drop from 120 ° C. to 80 ° C. was about 15 minutes. When the temperature inside the system 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. Table 3 shows various properties of the obtained aqueous resin dispersion.

[Comparative Example 1]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 17.6 g (2.5 times equivalent / COOH) of TEA, and 432.4 g of distilled water. That is, no organic solvent was used. Otherwise, the same operation as in Example 1 was performed. As a result, almost all of the raw material resin was recovered in the filtration step, and no aqueous dispersion was obtained. The results are shown in Table 4.

[Comparative Example 2]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1110H, 16.2 g (2.5 times equivalent / COOH) of TEA, and 433.8 g of distilled water. That is, as in Comparative Example 1, no organic solvent was used. Otherwise, the same operation as in Example 1 was performed. As a result, 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 are shown in Table 4.

[Comparative Example 3]
The raw materials for aqueous dispersion were 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. That is, the organic solvent was not used as in Comparative Examples 1 and 2. Otherwise, the same operation as in Example 1 was carried out. As a result, all raw material resins were recovered in the filtration step, and no aqueous dispersion was obtained. The results are shown in Table 4.

[Comparative Example 4]
The raw materials for aqueous dispersion were 50.0 g (10% by mass) of Lexpearl EAA A210K, 12.3 g (2.5 times equivalent / COOH) of TEA, and 437.7 g of distilled water. That is, the organic solvent was not used like Comparative Examples 1-3. Otherwise, the same operation as in Example 1 was carried out. As a result, all raw material resins were recovered in the filtration step, and no aqueous dispersion was obtained. The results are shown in Table 4.

[Comparative Example 5]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Primacol 3150, 7.6 g (5 times equivalent / COOH) of DEA, and 442.4 g of distilled water. That is, the organic solvent was not used similarly to Comparative Examples 1-4. Otherwise, the same operation as in Example 1 was carried out. As a result, all raw material resins were recovered in the filtration step, and no aqueous dispersion was obtained. The results are shown in Table 4.

[Comparative Example 6]
The raw materials for aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1560, 13.2 g (1.5 times equivalent / COOH) of TEA, and 436.8 g of distilled water. That is, the organic solvent was not used similarly to Comparative Examples 1-5. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 4 shows various characteristics of the obtained aqueous resin dispersion.

[Comparative Example 7]
The raw material for aqueous dispersion has an unsaturated carboxylic acid component content of 10% by mass within the scope of the present invention, but a melt flow rate of 500 g / 10 min, 50.0 g of Nucrel N1050H exceeding the scope of the present invention. (10% by mass), 6.2 g (1.2 times equivalent / COOH) of N, N-dimethylethanolamine (DMEA), and 443.8 g of distilled water. That is, the organic solvent was not used similarly. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 4 shows various characteristics of the obtained aqueous resin dispersion.

[Comparative Example 8]
The raw material for the aqueous dispersion had an unsaturated carboxylic acid component content of 20% by mass and a melt flow rate of 300 g / 10 min, both 50.0 g (10% by mass) of Primacol 5980I exceeding the scope of the present invention. ), 21.1 g (1.5 times equivalent / COOH) of TEA, and 428.9 g of distilled water. That is, the organic solvent was not used similarly. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 4 shows various characteristics of the obtained aqueous resin dispersion.

[Comparative Example 9]
As raw materials for aqueous dispersion, 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 (KOH), distilled Water was 321.1 g. Otherwise by performing the same operations as in Example 1, an aqueous resin dispersion was obtained. Table 4 shows various characteristics of the obtained aqueous resin dispersion.

[Comparative Example 10]
The raw materials for aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 175 g (35% by mass) of toluene substantially insoluble in water at 20 ° C., and 17.6 g (2.5% of TEA). Double equivalent / COOH) and 257.4 g of distilled water. Otherwise, the same operation as in Example 1 was performed. As a result, 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 are shown in Table 4.

[Comparative Example 11]
The raw materials for the aqueous dispersion were 50.0 g (10% by mass) of Nucrel N1214, 175 g (35% by mass) of methylcyclohexane (MCH) that is substantially insoluble in water at 20 ° C., and 17.6 g of TEA. (2.5 times equivalent / COOH) and distilled water were 257.4 g. Otherwise, the same operation as in Example 1 was performed. As a result, 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.

  In Comparative Examples 1 to 5 in which no organic solvent was used corresponding to the conventional aqueous dispersion method, the aqueous dispersion could not be achieved, whereas in Examples 1 to 6 and 8 to 16, the unsaturated carboxylic acid was not used. Even an ethylene / unsaturated carboxylic acid copolymer having a low acid component content and a low melt flow rate value could be dispersed in water by adding a specific organic solvent. The obtained aqueous dispersion was excellent in terms of pot life, particle diameter, and viscosity. In addition, from the results of Comparative Examples 1 to 5, resins (N0903HC, AN42115C, AN4225C) having a low content of unsaturated carboxylic acid or a low melt flow rate value of an ethylene / unsaturated carboxylic acid copolymer are assumed to be conventional. If this aqueous dispersion method is applied, it is easily estimated that aqueous dispersion becomes more difficult and an aqueous dispersion cannot be obtained.

  When Example 7 is compared with Comparative Example 6, the content of the unsaturated carboxylic acid component is 15% by mass and the melt flow rate is 60 g / 10 min. For an ethylene / unsaturated carboxylic acid copolymer (N1560). It was possible to obtain an aqueous dispersion even with the conventional aqueous dispersion method (Comparative Example 6). However, by adding NPA during the aqueous dispersion (Example 7), it was possible to remarkably reduce the number average particle size.

  As in Examples 1 to 9, by using NPA as an organic solvent, aqueous dispersion was possible for many types of ethylene / unsaturated carboxylic acid copolymers. Moreover, even when ammonia was added as in Example 10, aqueous dispersion was possible. Further, as in Examples 11 to 13, even when IPA, EtOH, or MeOH was used, aqueous dispersion was possible as in the case of NPA.

Even in the case where the solid content concentration was increased as in Example 14, aqueous dispersion was possible in the same manner.
Even if it is an ethylene / unsaturated carboxylic acid copolymer (AN42115) in which the content of the unsaturated carboxylic acid component is less than 5% by mass as compared with Examples 5 and 15, the organic amine compound is used as in Example 5. By adding excessively, there was an effect of further improving the aqueous dispersion yield.

Compared with Examples 4 and 16, there was an effect of further improving the aqueous dispersion yield by increasing the cooling time as in Example 4, that is, by gradually cooling.
Even when the content of the unsaturated carboxylic acid component in the ethylene / unsaturated carboxylic acid copolymer (N1050H) is a little as 10% by mass as in Comparative Example 7, the melt flow rate is 500 g / 10 min. When the value was high, aqueous dispersion could be achieved by the conventional method. However, the adhesiveness was lower than that of the example. Further, as in Comparative Example 8, even when the resin is an ethylene / acrylic acid copolymer, similarly, when the content of the unsaturated carboxylic acid component is large and the melt flow rate value is high, the conventional method is also water-based. Dispersion was possible. However, the adhesiveness was lower than that of the example.

  As in Comparative Examples 10 and 11, when an organic solvent added at the time of aqueous dispersion used a solvent having a solubility in water at 20 ° C. of less than 50 g / L, the effect of promoting aqueous dispersion could not be confirmed. .

From the comparison between Example 1 and Comparative Example 9, when the aqueous dispersion was performed using a metal compound instead of the organic amine compound, the water resistance of the obtained aqueous dispersion was significantly deteriorated.
When Examples 1, 3-6, 8, and 9 were compared with Comparative Examples 6-8, Examples 1, 3-6, 8, and 9 were superior in adhesion to various substrates. The reason why such good adhesion performance was expressed is considered that the strength of the adhesive layer was increased because the melt flow rate value of the raw material resin was low.

  When Examples 3-6, 8, and 9 were compared with Comparative Examples 6-8, Examples 3-6, 8, and 9 were superior in alkali resistance. The reason why such good alkali resistance performance was expressed is that the content of unsaturated carboxylic acid in the raw material resin is low, so it is difficult to be softened by alkali, and the melt flow rate value is low, so the strength of the coating film This is thought to be due to the high price.

  When Examples 1, 3-6, 8, and 9 were compared with Comparative Examples 6-8, Examples 1, 3-6, 8, and 9 were superior in solvent resistance. It is considered that the reason why such good solvent resistance was exhibited was that the solubility of the coating film in the solvent was lowered because the melt flow rate value of the raw material resin was low.

Claims (7)

  An ethylene / unsaturated carboxylic acid copolymer containing 1 to 15% by mass of an unsaturated carboxylic acid component and having a melt flow rate of 0.5 to 200 g / 10 min at 190 ° C. and 21.2 N load, and 20 ° C. The organic solvent having a water solubility of 50 g / L or more and a boiling point of 30 to 250 ° C., ammonia and / or an organic amine compound, and water are used as raw materials, and these raw materials are 80 to 280 ° C. A method for producing an aqueous dispersion, comprising stirring while heating at a temperature.   2. The method for producing an aqueous dispersion according to claim 1, wherein an ethylene / unsaturated carboxylic acid copolymer in which the unsaturated carboxylic acid component is acrylic acid and / or methacrylic acid is used as a raw material.   The method for producing an aqueous dispersion according to claim 1 or 2, wherein at least one of methanol, ethanol, npropanol, and isopropanol is used as the organic solvent.   The organic amine compound is used so that the molar amount of the carboxyl group in the ethylene / unsaturated carboxylic acid copolymer is 0.5 to 15 times equivalent mol. A process for producing the aqueous dispersion according to claim 1.   The method for producing an aqueous dispersion according to any one of claims 1 to 4, wherein after the heating, the product is cooled so that it takes 30 minutes or more to lower the temperature from 120 ° C to 80 ° C.   The method for producing an aqueous dispersion according to any one of claims 1 to 5, wherein a non-volatile aqueous dispersion aid is not used.   An aqueous dispersion obtained by obtaining an aqueous dispersion by the method according to any one of claims 1 to 6, and further performing a solvent removal treatment to reduce the organic solvent content of the aqueous dispersion. Body manufacturing method.