JP6362722B1 - Process for producing acid-modified polyolefin resin aqueous dispersion - Google Patents

Abstract

In an organic solvent contained in an aqueous dispersion of an acid-modified polyolefin resin, the solvent can be removed in a short time and the amount of scum generated in a treatment tank can be reduced. A method for producing a polyolefin resin aqueous dispersion is provided.
A process for producing an aqueous dispersion of an acid-modified polyolefin resin, comprising the following steps 1 and 2.
(1) Step 1 for obtaining a dispersion of an acid-modified polyolefin resin using an acid-modified polyolefin resin, an organic solvent, and water as raw materials
(2) Step 2 of removing the organic solvent in the presence of an additive comprising at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols, and a silica-containing compound.
[Selection figure] None

Description

  The present invention relates to a method for producing an aqueous dispersion of an acid-modified polyolefin resin.

  Polyolefin resins are excellent in electrical properties, mechanical properties, chemical properties, formability, hygiene, recyclability, etc., so they are widely used in various fields such as automobiles, electricity, electronics, packaging, and household goods. Is used. However, since a polyolefin resin usually does not contain a polar group in a molecular chain, coating and adhesion are difficult. So far, coating agents specialized for polyolefin resin substrate applications have been developed. In particular, from the standpoints of environmental protection, resource conservation, dangerous goods regulations under the Fire Service Act, and workplace environment improvement, the use of organic solvents has recently been restricted, and various aqueous coating agents have been developed. .

  For example, in order to modify a polyolefin resin and stably disperse the modified polyolefin resin in an aqueous medium, a method using various surfactants and liquid polyol as an essential component has been developed. On the other hand, the present applicant has found that an aqueous dispersion of a modified polyolefin resin is possible even without containing a non-volatile aqueous additive such as a surfactant, and has proposed an aqueous dispersion thereof ( Patent Documents 1 and 2).

  However, since this aqueous dispersion has a small amount of organic solvent added when the modified polyolefin resin is dispersed in water, the resulting aqueous dispersion is an organic solvent that volatilizes when used for coating or adhesion applications. Sometimes became a problem. Patent Document 2 describes that the organic solvent used to make the resin aqueous can be distilled out of the system by a solvent removal process called “stripping” to reduce the organic solvent.

JP 2003-119328 A International Publication No. 2004/104090

  However, in the solvent removal treatment, the dispersion foams during the treatment, and it takes a long time for the solvent removal treatment. In addition, the tank used for the solvent removal treatment has a dispersion soot (dry matter or agglomeration) called scum. Product) may occur. The generated scum becomes a foreign substance in the aqueous dispersion and sometimes deteriorates the appearance of the dried coating film obtained from the aqueous dispersion. In particular, in the electrical / electronic field, since it is required to improve the appearance of the coating film, it is essential to provide a step for removing scum. However, when the scum is filtered using a filter or the like, it adheres to the surface of the filter or the like and lowers the filterability. Therefore, the occurrence of scum has a problem of greatly reducing the productivity of the aqueous dispersion. .

  In the present invention, the present invention can remove the solvent in a short time in the desolvation treatment process of the organic solvent contained in the aqueous dispersion of the acid-modified polyolefin resin, and generate scum in the treatment tank. An object of the present invention is to provide a method for producing an acid-modified polyolefin resin aqueous dispersion capable of reducing the amount.

As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by adding a specific compound to the dispersion of the acid-modified polyolefin resin.
The gist of the present invention is as follows.

[1] A method for producing an aqueous dispersion of an acid-modified polyolefin resin having a solid content concentration of 10 to 45% by mass , comprising the following steps 1 and 2.
(1) Step 1 for obtaining a dispersion of an acid-modified polyolefin resin using an acid-modified polyolefin resin having a weight average molecular weight of 5,000 to 150,000 , an organic solvent, a basic compound, and water as raw materials
(2) Step 2 of removing the organic solvent in the presence of an additive comprising at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols, and a silica-containing compound.
[2] The method for producing an aqueous dispersion of an acid-modified polyolefin resin according to [1], wherein in step 1, an aqueous auxiliary agent having a boiling point of 185 ° C. or higher at normal pressure is not used as a raw material.
[3] The acid-modified polyolefin resin modified with an unsaturated carboxylic acid component and having an unsaturated carboxylic acid component content of 0.1 to 8% by mass is used. [1] or [2] A method for producing an aqueous dispersion of an acid-modified polyolefin resin.
[4] The method for producing an aqueous acid-modified polyolefin resin dispersion according to any one of [1] to [3], wherein a silica-containing compound whose surface is hydrophobically modified is used.
[5] The addition amount of at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols and the addition amount of the silica-containing compound are all based on 100 parts by mass of the acid-modified polyolefin resin. The method for producing an acid-modified polyolefin resin aqueous dispersion according to any one of [1] to [4], wherein the content is 3 parts by mass or less.
[6] The method for producing an acid-modified polyolefin resin aqueous dispersion as described in any one of [1] to [5], wherein an organic solvent having a boiling point of 10 to 200 ° C. is used.

  According to the present invention, the organic solvent contained in the dispersion of the acid-modified polyolefin resin can be removed in a short time, and the acid-modified polyolefin resin aqueous dispersion can be suppressed by suppressing the occurrence of scum in the solvent removal treatment tank. Furthermore, when the obtained acid-modified polyolefin resin aqueous dispersion is coated, a good coating film appearance can be obtained without causing unevenness or repellency.

Hereinafter, the present invention will be described in detail.
First, the acid-modified polyolefin resin will be described.
In the acid-modified polyolefin resin in the present invention, the content of the unsaturated hydrocarbon component is preferably 50 to 99% by mass, more preferably 60 to 99% by mass, and 70 to 98% by mass. More preferably, it is especially preferable that it is 80-98 mass%. If the content of the unsaturated hydrocarbon component is less than 50% by mass, the adhesiveness to a polyolefin material such as polypropylene is lowered. If it exceeds 98% by mass, the content of an unsaturated carboxylic acid component described later is relatively lowered. Therefore, it becomes difficult to make the resin water-based.

As unsaturated hydrocarbons, alkenes such as ethylene, propylene, 1-butene, isobutene, 1-pentene, 4-methyl-1-pentene, 3-methyl-1-pentene, 1-hexene, butadiene, isoprene, etc. Of the diene. Among these, ethylene, propylene, or butene (1-butene, isobutene, etc.) is preferred from the viewpoints of easy-to-manufacture of the resin, ease of aqueous formation, adhesion to various materials, and coating performance such as blocking properties. It is preferable that these can be used in combination.
A particularly preferred configuration as the acid-modified polyolefin resin in the present invention contains three components of propylene, butene, and ethylene, and the composition ratio of propylene is 8 to 8 when the total of these three components is 100 parts by mass. 90 parts by mass, 8 to 90 parts by mass of butene, and 2 to 50 parts by mass of ethylene.

  In the above acid-modified polyolefin resin, the copolymerization form of each component is not limited, and examples thereof include random copolymerization and block copolymerization. From the viewpoint of ease of polymerization, random copolymerization is preferable. . Two or more kinds of acid-modified polyolefin resins may be mixed so as to achieve the constituent component ratio of the present invention.

In addition to the above components, other components may be contained in an amount of about 20% by mass or less based on the entire acid-modified polyolefin resin. Other components include (meth) alkenes and dienes having 6 or more carbon atoms such as 1-octene and norbornenes, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate, and the like. Acrylic acid esters, maleic acid esters such as dimethyl maleate, diethyl maleate, and dibutyl maleate, alkyl vinyl ethers such as (meth) acrylic acid amides, methyl vinyl ether, ethyl vinyl ether, vinyl formate, vinyl acetate, propion Vinyl esters such as vinyl acid vinyl, vinyl pivalate, vinyl versatate, and vinyl alcohol obtained by saponifying vinyl esters with a basic compound, 2-hydroxyethyl acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile, Styrene, set Styrene, vinyl halides, halogenated fluoride acids, carbon monoxide, sulfur dioxide, and the like, can also be a mixture thereof.
Especially, it is preferable to contain (meth) acrylic acid ester from the point which becomes easy to make water-based and the adhesiveness with respect to various base materials improves. Specific examples of (meth) acrylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, hexyl (meth) acrylate, (meth) Examples include octyl acrylate, decyl (meth) acrylate, lauryl (meth) acrylate, octyl (meth) acrylate, dodecyl (meth) acrylate, stearyl (meth) acrylate, and the like.

The acid-modified polyolefin resin in the present invention preferably has 0.1 to 8% by mass of an unsaturated carboxylic acid component in its structure from the viewpoint of dispersibility. This component is more preferably 0.1 to 7% by mass, further preferably 0.2 to 6% by mass, particularly preferably 0.3 to 5% by mass, and 0.5 to 5%. Most preferably, it is mass%. When the unsaturated carboxylic acid component is less than 0.1% by mass, it tends to be difficult to make the resin water-based. On the other hand, when it exceeds 8% by mass, it becomes easy to make the resin water-based. There exists a tendency for the adhesiveness to polyolefin resin materials, such as a polypropylene, to fall.
The unsaturated carboxylic acid component is introduced by an unsaturated carboxylic acid or an anhydride thereof. Specific examples include acrylic acid, methacrylic acid, maleic acid, maleic anhydride, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, and allyl succinic acid. A compound having at least one carboxyl group or acid anhydride group in the molecule (in the monomer unit), such as an unsaturated dicarboxylic acid half ester or half amide, can also be used. Among these, maleic anhydride, acrylic acid, and methacrylic acid are preferable, and maleic anhydride is more preferable from the viewpoint of easy introduction into the polyolefin resin.
The unsaturated carboxylic acid component may be copolymerized in the acid-modified polyolefin resin, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. The acid anhydride component introduced into the polyolefin resin tends to take an acid anhydride structure in a dry state, and in an aqueous medium containing a basic compound described later, a part or all of the ring opens to form a carboxylic acid or a salt thereof. There is a tendency to become a structure.

The method for introducing the unsaturated carboxylic acid component into the polyolefin resin is not particularly limited. For example, in the presence of a radical generator, the polyolefin resin and the unsaturated carboxylic acid are heated and melted to a temperature equal to or higher than the melting point of the polyolefin resin. Examples thereof include a method of graft copolymerizing an unsaturated carboxylic acid component on a polyolefin resin by a method, a method of dissolving a polyolefin resin in an organic solvent, and then reacting by heating and stirring in the presence of a radical generator. The former method is preferable because the operation is simple.
Examples of the radical generator used for graft copolymerization include di-tert-butyl peroxide, dicumyl peroxide, tert-butyl hydroperoxide, tert-butyl cumyl peroxide, benzoyl peroxide, dilauryl peroxide, Examples thereof include organic peroxides such as cumene hydroperoxide, tert-butyl peroxybenzoate, ethyl ethyl ketone peroxide, and di-tert-butyl diperphthalate, and azonitriles such as azobisisobutyronitrile. These may be appropriately selected depending on the reaction temperature.

  The acid-modified polyolefin resin used in the present invention may be chlorinated, and the ratio of chlorination is not limited.

  The weight average molecular weight of the acid-modified polyolefin resin is preferably 5,000 to 150,000, more preferably 20,000 to 120,000, and further preferably 30,000 to 100,000. 35,000 to 90,000 is particularly preferable, and 40,000 to 80,000 is most preferable. When the weight average molecular weight is less than 5,000, there is a tendency that the adhesion to the substrate is lowered or the resulting coating film is hard and brittle. When the weight average molecular weight exceeds 150,000, it tends to be difficult to make the resin water-based. In addition, the weight average molecular weight of resin can be calculated | required on the basis of polystyrene resin using a gel permeation chromatography (GPC).

The method for producing the acid-modified polyolefin resin aqueous dispersion of the present invention comprises:
(1) Step 1 of obtaining a dispersion of an acid-modified polyolefin resin using an acid-modified polyolefin resin, an organic solvent, and water as raw materials;
(2) including a step 2 of removing the organic solvent in the presence of an additive containing at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols, and a silica-containing compound. is necessary.

  In the present invention, when the acid-modified polyolefin resin is dispersed in the step 1, it is necessary to use an organic solvent as a raw material in order to promote the aqueous formation of the acid-modified polyolefin resin and reduce the dispersed particle size. . The amount of the organic solvent to be used is preferably 50% by mass or less in the aqueous medium, more preferably 1 to 45% by mass, further preferably 2 to 40% by mass, and 3 to 35% by mass. It is particularly preferred that When the amount of the organic solvent exceeds 50% by mass, not only does it depart from one of the objects of the present invention (environmental protection), but the stability of the aqueous dispersion may decrease depending on the organic solvent used. .

As the organic solvent, those having a solubility in water at 20 ° C. of 10 g / L or more are preferably used from the viewpoint of obtaining a good aqueous dispersion. More preferably, it is 20 g / L or more, Most preferably, it is 50 g / L or more.
As the organic solvent, those having a boiling point of 10 to 200 ° C. at atmospheric pressure are preferred, and those having a temperature of 20 to 180 ° C. are particularly preferred from the viewpoint of easy removal from the coating film. An organic solvent having a boiling point of 200 ° C. or higher is difficult to be scattered from the resin coating film by drying, and the water resistance of the coating film at the time of low-temperature drying, adhesion to the substrate, and the like may be lowered.

Specific examples of the organic solvent used include, for example, methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, sec-butanol, tert-butanol, n-amyl alcohol, isoamyl alcohol, sec-amyl alcohol. , Alcohols such as tert-amyl alcohol, 1-ethyl-1-propanol, 2-methyl-1-butanol, n-hexanol, cyclohexanol, ketones such as methyl ethyl ketone, methyl isobutyl ketone, ethyl butyl ketone, cyclohexanone, tetrahydrofuran , Ethers such as dioxane, ethyl acetate, n-propyl acetate, isopropyl acetate, n-butyl acetate, isobutyl acetate, sec-butyl acetate, 3-methoxybutyl acetate, propylene Esters such as methyl acetate, ethyl propionate, diethyl carbonate, dimethyl carbonate, glycol derivatives such as ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol monopropyl ether, ethylene glycol monobutyl ether, ethylene glycol ethyl ether acetate, Furthermore, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile, dimethylformamide, dimethylacetamide, diacetone alcohol, ethyl acetoacetate, 1
, 2-dimethylglycerin, 1,3-dimethylglycerin, trimethylglycerin and the like. These organic solvents may be used in combination of two or more.
Among the above organic solvents, ethanol, n-propanol, isopropanol, n-butanol, methyl ethyl ketone, cyclohexanone, tetrahydrofuran, dioxane, ethylene glycol monoethyl ether, ethylene glycol monopropyl are effective because they are highly effective in promoting aqueous formation of resins. Ether, ethylene glycol monobutyl ether, and diethylene glycol monomethyl ether are preferable. Among these, an organic solvent having one hydroxyl group in the molecule is more preferable, and ethylene glycol alkyl ethers are more preferable from the viewpoint that the resin can be made aqueous with a small amount of addition.

  In step 1 of the method for producing an aqueous dispersion of the present invention, it is preferable to use a basic compound as a raw material together with the organic solvent. By this basic compound, some or all of the carboxyl groups in the acid-modified polyolefin resin are neutralized, and the electric repulsive force between the generated carboxyl anions prevents aggregation between the fine particles and stabilizes the aqueous dispersion. Sex is imparted.

  The boiling point of such a basic compound at normal pressure is preferably less than 185 ° C. from the viewpoint of water resistance, drying property and the like. When the boiling point is 185 ° C. or more, it is difficult to disperse from the resin coating film by drying, and particularly the water resistance of the coating film at low temperature drying and the adhesion to the substrate may decrease.

  The basic compound having a boiling point of less than 185 ° C. is not particularly limited, and specific examples include ammonia, triethylamine, N, N-dimethylethanolamine, isopropylamine, aminoethanol, dimethylaminoethanol, diethylaminoethanol, ethylamine, diethylamine. , Isobutylamine, dipropylamine, 3-ethoxypropylamine, 3-diethylaminopropylamine, sec-butylamine, propylamine, n-butylamine, 2-methoxyethylamine, 3-methoxypropylamine, 2,2-dimethoxyethylamine, mono Examples include ethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, pyrrole, and pyridine.

  The amount of the basic compound used is preferably 0.5 to 3.0 times equivalent to the carboxyl group in the acid-modified polyolefin resin, more preferably 0.8 to 2.5 times equivalent, It is particularly preferably 0.9 to 2.0 times equivalent. When the amount is less than 0.5 times equivalent, the addition effect of the basic compound is not recognized, and when the amount exceeds 3.0 times equivalent, the drying time at the time of coating film formation becomes longer or the stability of the aqueous dispersion decreases. There is.

Next, in Step 1 of the method for producing an acid-modified polyolefin resin aqueous dispersion of the present invention, a method for obtaining a dispersion of an acid-modified polyolefin resin using the acid-modified polyolefin resin, organic solvent, base compound, and water as raw materials will be described. To do.
In step 1, the method for obtaining the dispersion of the acid-modified polyolefin resin is not particularly limited, but the method includes heating and stirring the acid-modified polyolefin resin, the organic solvent, the basic compound, and water in a sealable container. This method is most preferred. According to this method, it is not necessary to add an aqueous auxiliary agent having a boiling point of 185 ° C. or higher, which will be described later.
As the container, an apparatus widely known to those skilled in the art as a solid / liquid stirring apparatus or an emulsifier can be used, and an apparatus capable of pressurization of 0.1 MPa or more is preferably used. The stirring method and the rotation speed of stirring are not particularly limited, but may be stirring at a low speed such that the resin is in a floating state in the aqueous medium. Therefore, high-speed stirring (for example, 1,000 rpm or more) is not essential, and an aqueous dispersion can be produced with a simple apparatus.
Raw materials such as acid-modified polyolefin resin and water are put into the above-mentioned apparatus, and preferably stirred and mixed at a temperature of 40 ° C. or lower. Next, while keeping the temperature in the tank at 60 to 220 ° C., preferably 80 to 200 ° C., more preferably 100 to 190 ° C., particularly preferably 100 to 180 ° C., preferably until coarse particles disappear (for example, 5 to 5 ° C. By continuing stirring for 120 minutes, the acid-modified polyolefin resin is made sufficiently aqueous, and then the dispersion is preferably obtained by cooling to 40 ° C. or lower, preferably with stirring. When the temperature in the tank is lower than 60 ° C., it becomes difficult to disperse the acid-modified polyolefin resin. When the temperature in a tank exceeds 220 degreeC, there exists a possibility that the molecular weight of acid-modified polyolefin resin may fall.

  Thereafter, a jet pulverization process may be further performed as necessary. Jet pulverization is a process in which a dispersion is ejected from pores such as nozzles and slits under high pressure, resin particles or resin particles collide with a collision plate, etc. It is to make it fine. Specific examples of the apparatus for that purpose include A.I. P. V. Examples thereof include a homogenizer manufactured by GAULIN, and a microfluidizer M-110E / H manufactured by Mizuho Industrial Co., Ltd.

In the above step 1, the amount of the aqueous auxiliary agent having a boiling point of 185 ° C. or higher at normal pressure is preferably 3 parts by mass or less, preferably 1 part by mass or less with respect to 100 parts by mass of the acid-modified polyolefin resin. More preferably, it is more preferably 0.1 parts by mass or less, particularly preferably 0.01 parts by mass or less, and most preferably not added. “At normal pressure” means at atmospheric pressure. The boiling point as used in the present specification means all boiling points at normal pressure. In addition, the hydration aid having no boiling point at normal pressure corresponds to the hydration aid having a boiling point of 185 ° C. or higher in the present invention.
Here, the “aqueous auxiliary” is a drug or compound added for the purpose of promoting aqueous formation or stabilizing the aqueous dispersion in the production of an aqueous dispersion.
From the viewpoint of the water resistance of the resulting coating film, it is preferable not to use, as a raw material, an aqueous auxiliary agent having a boiling point of 185 ° C. or higher at normal pressure in Step 1 of the present invention.

  Examples of the aqueous auxiliary agent having a boiling point at normal pressure of 185 ° C. or higher in the present invention include, for example, a surfactant, a compound having a protective colloid action, a modified wax, a high acid value acid-modified compound, and a water-soluble compound. Examples thereof include polymers and polyols.

  Examples of surfactants include cationic surfactants, anionic surfactants, nonionic (nonionic) surfactants, amphoteric surfactants, fluorosurfactants, and reactive surfactants. In addition to those used for emulsion polymerization, emulsifiers are also included. For example, anionic surfactants include sulfate esters of higher alcohols, higher alkyl sulfonic acids and salts thereof, higher carboxylic acids such as oleic acid, stearic acid, and palmitic acid and salts thereof, alkylbenzene sulfonic acids and salts thereof, Examples thereof include oxyethylene alkyl sulfate salts, polyoxyethylene alkyl phenyl ether sulfate salts, and vinyl sulfosuccinates. Nonionic surfactants 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 copolymer, etc. And a sorbitan derivative such as a polyoxyethylene sorbitan fatty acid ester. Examples of amphoteric surfactants include lauryl betaine and lauryl dimethylamine oxide. Examples of reactive surfactants include alkylpropenylphenol polyethylene oxide adducts and their sulfate esters, allyl alkylphenol polyethylene oxide adducts and their sulfate esters, allyl dialkylphenol polyethylene oxide adducts and their sulfate esters, etc. And compounds having a reactive double bond.

Compounds having protective colloid action, modified waxes, high acid value acid-modified compounds, 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 other acid-modified polyolefin waxes having a weight average molecular weight of usually 5,000 or less and salts thereof , Acrylic acid-maleic anhydride copolymer and salts thereof, styrene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid copolymer, isobutylene-free A carboxyl group-containing polymer having an unsaturated carboxylic acid content of 20% by mass or more, such as an alternating maleic acid copolymer, a (meth) acrylic acid- (meth) acrylic acid ester copolymer, and a polyitaconic acid and a salt thereof; Examples thereof include water-soluble acrylic copolymers having amino groups, gelatin, gum arabic, and casein, which are generally used as fine particle dispersion stabilizers.
Examples of the polyol having a boiling point of 185 ° C. or higher include diols, polyoxyalkylene diols, polyhydric alcohols, polyester polyols, acrylic polyols and polyurethane polyols. Specific examples include ethylene glycol, diethylene glycol, triethylene glycol, propylene glycol, butanediol, glycerin and the like.

  In step 2 of the method for producing an acid-modified polyolefin resin aqueous dispersion of the present invention, the organic solvent used in the step of obtaining the dispersion of step 1 or a part thereof is removed by a solvent removal treatment generally called “stripping”. Distill off to reduce the amount of organic solvent. By stripping, the content of the organic solvent in the aqueous dispersion can be 10% by mass or less, and if it is 5% by mass or less, it is environmentally preferable. In the stripping process, substantially all of the organic solvent used for dispersion can be distilled off, but this requires increasing the pressure reduction of the apparatus or extending the operation time. The lower limit of the amount of the organic solvent considering productivity is about 0.01% by mass. However, even if it is about 0.01% by mass, there is no particular influence on performance, and the resin can be used satisfactorily.

In the present invention, in the solvent removal treatment in Step 2, the dispersion is performed in the presence of an additive containing at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols, and a silica-containing compound. It is necessary to remove the organic solvent from the body.
If these compounds are present in the solvent removal treatment step, the organic solvent can be distilled off in a short time without foaming, and no scum is generated in the treatment tank. Further, when the obtained acid-modified polyolefin resin aqueous dispersion subjected to solvent removal treatment is coated, it is possible to obtain a coating film in which unevenness and repellency do not occur.
If the additive containing at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols and a silica-containing compound is contained in the aqueous dispersion when the organic solvent is removed, Good. The additive may be added in the step 1 for obtaining the dispersion of the acid-modified polyolefin resin, or may be added until the organic solvent in the step 2 is removed after the dispersion of the acid-modified polyolefin resin is obtained. . In order to improve the additive effect of the additive, the latter addition is preferable.
Moreover, the compound which comprises may be added simultaneously, may be added in a divided manner, and the same compound may be added in divided portions.

Examples of fatty acid amides include stearic acid amide, oleic acid amide, erucic acid amide fatty acid amide, methylene bis stearic acid amide, ethylene bis stearic acid amide alkylene fatty acid amide, etc., methylene bis stearic acid amide, ethylene Bistearic acid amide is preferred.
Polyether is a polymer compound containing an ether bond in the molecule, and examples thereof include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, fatty acid esters and fatty acid amides, and ethylene oxide-propylene oxide copolymers. An ethylene oxide-propylene oxide copolymer is preferable.
Acetylene glycol is a compound having an acetylene glycol structure.
The silica-containing compound is a compound composed of silicon dioxide (SiO ₂ ), and the surface is preferably modified to be hydrophobic.

The amount of fatty acid amide added is preferably 3 parts by mass or less, more preferably 1 part by mass or less, and 0.00001 to 1 part by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. More preferably, it is 0.00001-0.1 mass part, and it is most preferable that it is 0.00001-0.01 mass part.
The addition amount of the polyether and the acetylene glycol compound is preferably 3 parts by mass or less, more preferably 1 part by mass or less, and more preferably 0.0001 to 1 part by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. More preferably, it is 0.001-0.1 mass part.
Fatty acid amides, polyethers, and acetylene glycols may be used in combination. In that case, the total amount is preferably 3 parts by mass or less, based on 100 parts by mass of the acid-modified polyolefin resin. More preferably, it is 0.0001-0.1 mass part.
The addition amount of the silica-containing compound is preferably 3 parts by mass or less, more preferably 1 part by mass or less, and 0.001 to 1 part by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. Is more preferable, and it is especially preferable that it is 0.001-0.1 mass part.
When the addition amount is 0.00001 parts by mass or less, the effect of suppressing the occurrence of scum is small, and when the addition amount exceeds 3 parts by mass, the coating film appearance is inferior and the adhesiveness tends to be lowered.

  The additive containing at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols and a silica-containing compound may further contain mineral oil.

  Examples of the stripping method include a method in which the dispersion is heated with stirring at normal pressure or reduced pressure to distill off the organic solvent. Since the solid content concentration is increased by distilling off the aqueous medium, for example, when the viscosity increases and the workability decreases, water may be added to the dispersion in advance.

In the aqueous dispersion produced by the method of the present invention, the number average particle diameter of the dispersed acid-modified polyolefin resin particles is preferably 1 μm or less, and 0 from the viewpoint of low-temperature film-forming property and coating color tone. More preferably, it is 0.5 micrometer or less, It is further more preferable that it is 0.005-0.3 micrometer, It is especially preferable that it is 0.005-0.2 micrometer. When the number average particle diameter exceeds 1 μm, the low-temperature film-forming property is remarkably lowered, or the storage stability of the aqueous dispersion is lowered. Regarding the weight average particle size, from the viewpoint of low-temperature film-forming properties and storage stability, it is preferably 2 μm or less, more preferably 1 μm or less, and further preferably 0.005 to 0.5 μm, It is especially preferable that it is 0.01-0.3 micrometer. By reducing the particle size, adhesion, film-forming property at low temperature, and color tone of the coating film are improved.
The number average particle diameter and the weight average particle diameter of the acid-modified polyolefin resin are measured by a dynamic light scattering method that is generally used for measuring the particle diameter of a fine particle substance.

In the aqueous dispersion produced by the method of the present invention, the solid content concentration can be appropriately selected depending on the film forming conditions, the desired thickness and performance of the resin coating film, and is not particularly limited. However, it is preferably 1 to 60% by mass, more preferably 3 to 55% by mass in terms of maintaining the viscosity of the coating composition moderately and expressing good coating film forming ability. It is more preferable that it is 50 mass%, and it is especially preferable that it is 10-45 mass%.
Examples of the method for adjusting the solid content concentration include a method in which the aqueous medium is further distilled off or diluted with water.

  By adopting the above production method, the acid-modified polyolefin resin is dispersed or dissolved in an aqueous medium to prepare a uniform liquid. 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 or skinning is not found in the aqueous dispersion. Say.

  The aqueous dispersion obtained in the present invention further includes the above surfactants, aqueous dispersions of other polymers, metal ions, inorganic particles, crosslinking agents, leveling agents, antifoaming agents, anti-waxing agents, pigment dispersions. One or more additives such as an agent, an ultraviolet absorber, a pigment or a dye may be contained.

Hereinafter, the present invention will be described specifically by way of examples. In addition, this invention is not limited only to these Examples.
Various properties described below were measured or evaluated by the following methods.

(1) Content of unsaturated carboxylic acid component The acid value of the acid-modified polyolefin resin was measured according to JIS K5407, and the content of unsaturated carboxylic acid was determined from the value.

(2) Composition of resin other than unsaturated carboxylic acid component In orthodichlorobenzene (d ₄ ), ¹ H-NMR and ¹³ C-NMR analysis (manufactured by Varian, 300 MHz) was performed at 120 ° C. ^{In 13} C-NMR analysis, measurement was performed using a gated decoupling method in consideration of quantitativeness.

(3) Weight average molecular weight of resin Using GPC analysis (HLC-8020 manufactured by Tosoh Corporation, column is TSK-GEL), the sample was dissolved in tetrahydrofuran, measured at 40 ° C., and from a calibration curve prepared with a polystyrene standard sample The weight average molecular weight was determined. Ortho-dichlorobenzene was used when it was difficult to dissolve in tetrahydrofuran.

(4) Content of fatty acid amide, polyether, and acetylene glycol The content of fatty acid amide, polyether, and acetylene glycol in the acid-modified polyolefin resin aqueous dispersion is a mixed solvent of chloroform / methanol = 9/1 (volume ratio). It extracted, and analyzed and measured by LC / MS (Agilent 6100LC-MS system). LC / MS analysis was performed under the following conditions.
<LC>
Column: ZORBAX SB-C18 φ2.1 × 50mm, 1.8μm
Oven temperature: 35 ° C
Mobile phase: 10 mM CH ₃ COONH ₄ methanol solution flow rate: 0.5 mL / min
<MS>
Ionization method: ESI
Drying _Gas: N 2, 12L / min
Drying gas temperature: 300 ° C
Mass range: Low 100-700

(5) Content of silica-containing compound 5 mL of the acid-modified polyolefin dispersion was weighed and dried at 100 ° C. for 5 hours to obtain a coating film. The obtained coating film was dissolved in 3 mL of nitric acid and 1 mL of hydrofluoric acid, and then diluted to 50 mL of water. And measured.

(6) Scum amount In the examples and comparative examples, the scum remaining on the filter when the aqueous dispersion was filtered with a filter was thoroughly washed with water, collected and dried, and its mass was measured.

(7) Solid content concentration of aqueous dispersion An appropriate amount of the acid-modified polyolefin dispersion is weighed and heated at 150 ° C. until the mass of the residue (solid content) reaches a constant weight to determine the acid-modified polyolefin resin solid content concentration. It was.

(8) Content of organic solvent in aqueous dispersion Gas chromatograph GC-8A manufactured by Shimadzu Corporation [using FID detector, carrier gas: nitrogen, column packing material (manufactured by GL Sciences): PEG-HT (5%) -Uniport HP (60/80 mesh), column size: diameter 3 mm × 3 m, sample charging temperature (injection temperature): 180 ° C., column temperature: 80 ° C., internal standard substance: n-butanol] What was diluted with water as needed was directly put into the apparatus, and the content of the organic solvent was determined. The detection limit was 0.01% by mass.

(9) Number average particle diameter of acid-modified polyolefin resin particles The number average particle diameter (mn) was determined using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340) manufactured by Nikkiso Co., Ltd. The refractive index of the resin was 1.5.

(10) Pot life The appearance when the aqueous dispersion was allowed to stand at room temperature for 180 days was evaluated in the following three stages.
○: No change in appearance.
Δ: Thickening is observed.
X: Solidification, aggregation and precipitation are observed.

(11) Water resistance of coating film An aqueous dispersion is coated on an untreated surface of a stretched polypropylene (PP) film (manufactured by Tosero Co., Ltd., OP U-1, thickness 20 μm), and the coating amount after drying becomes about 2 g / m ² And coated with a Mayer bar and dried at 100 ° C. for 2 minutes. The coated film thus prepared was immersed in 40 ° C. warm water for 1 day, and then the state of the coated surface was visually evaluated.
○: No change in appearance.
(Triangle | delta): A coating film whitens.
X: The coat layer is dissolved or peeled off.

(12) Adhesive A coating solution containing an aqueous dispersion is formed on a plasma treated surface of a stretched PP film (manufactured by Tosero, OP U-1, thickness 20 μm), on an aluminum foil (manufactured by Mitsubishi Aluminum, thickness 15 μm), and A4. Each size fine paper (made by Daishowa Paper Co., Ltd.) was coated with a Mayer bar so that the coating amount after drying was about 5 g / m ² and dried at 100 ° C. for 2 minutes. Next, the other PP film and the coated surface to the above-mentioned stretched PP film, the other PP film and the coated surface to the aluminum foil, and the other PP film and the coated surface to the high-quality paper are in contact with each other. The sample was pressed at a seal pressure of 3 kg / cm ² and a seal temperature of 110 ° C. for 5 seconds to obtain a sample. This sample was cut out with a width of 15 mm, and after one day from the press, the peel strength of the coating film was measured using a tensile tester (precision universal material tester type 2020 manufactured by Intesco) at a pulling speed of 200 mm / min and a pulling angle of 180 degrees. Was measured to evaluate the adhesiveness.

(13) Appearance of coating film (1)
The obtained aqueous dispersion was coated on an aluminum foil so that the coating thickness after drying was 2 μm, and then dried at 100 ° C. About the coating surface of 30 cm in length and breadth, the surface state of the coating film was observed visually, and the following evaluation criteria evaluated.
○: No unevenness or repellency is confirmed.
Δ: Unevenness is confirmed, but no repelling is confirmed.
X: Unevenness is confirmed, and 1 to 5 repels are confirmed.
XX: Unevenness is confirmed, and 6 or more repellencies are confirmed.

(14) Appearance of coating film (2)
To the obtained aqueous dispersion, 20 parts by mass of titanium oxide (manufactured by Ishihara Sangyo Co., Ltd., TYPEPEC CR-50) was added to 100 parts by mass of the resin of the aqueous dispersion to prepare a white paint. The obtained white paint was coated on an aluminum foil so that the coating thickness after drying was 2 μm, and then dried at 100 ° C. About the coating surface of 30 cm in length and breadth, the surface state of the coating film was observed visually, and the following evaluation criteria evaluated.
○: No unevenness or repellency is confirmed.
Δ: Unevenness is confirmed, but no repelling is confirmed.
X: Unevenness is confirmed, and 1 to 5 repels are confirmed.
XX: Unevenness is confirmed, and 6 or more repellencies are confirmed.

The acid-modified polyolefin resin was produced by the following method.
(1) Acid-modified polyolefin resin “P-1”
100 kg of propylene-butene-ethylene terpolymer “P-0” (propylene / butene / ethylene = 64.8 / 23.9 / 11.3% by mass) and 500 kg of toluene are put into a 2000 L sealed reaction vessel. And heated and melted in a nitrogen atmosphere. Thereafter, the system temperature was maintained at 110 ° C., and a 20 kg solution of 1 kg of dicumyl peroxide as a radical generator was added over 1 hour with stirring. Then, 10 kg of heptane in 7 kg of maleic anhydride as an unsaturated carboxylic acid was added dropwise over 1 hour, followed by reaction for 30 minutes. After completion of the reaction, the reaction mixture was cooled to room temperature, and then the obtained reaction product was put into a large amount of acetone to precipitate a resin. This resin was further washed several times with acetone to remove unreacted substances, and then dried under reduced pressure in a vacuum dryer to obtain an acid-modified polyolefin resin “P-1”. The properties of the obtained resin are shown in Table 1.

(2) Acid-modified polyolefin resin “P-2”
The acid-modified polyolefin resin “P-” was prepared in the same manner as in the production method of the acid-modified polyolefin resin “P-1” except that a propylene-butene copolymer (propylene / butene = 80/20% by mass) was used as the copolymer. 2 "was obtained. The properties of the obtained resin are shown in Table 1.

(3) Acid-modified polyolefin resin “P-3”
As the acid-modified polyolefin resin P-3, a commercially available acid-modified polyolefin resin (Bondaine HX8290 manufactured by Arkema Co.) was used. The resin properties are shown in Table 1. Since the resin was not stably dissolved in tetrahydrofuran or orthodichlorobenzene, GPC could not be measured.

(4) Acid-modified polyolefin resin “P-4”
As acid-modified polyolefin resin P-4, ethylene-acrylic acid copolymer resin (Primacol 5980I manufactured by Dow Chemical Co., Ltd., 20% by mass acrylic acid copolymer) was used.

  The resin properties of the acid-modified polyolefin resins “P-1” to “P-4” are shown in Table 1.

Example 1
[Step 1]
Using a stirrer equipped with a heatable and sealable pressure-resistant 1000 L reaction vessel, 60 kg of acid-modified polyolefin resin “P-1”, 70 kg of tetrahydrofuran (boiling point 66 ° C.), 7 kg of N, N-dimethylethanolamine (boiling point) 134 ° C.) and 103 kg of distilled water were charged into the reaction vessel. While stirring, the heater was turned on and heated. Then, the system temperature was maintained at 140 ° C. and further stirred for 2 hours. Then, it cooled to 40 degreeC with water cooling, stirring.
[Step 2]
To the obtained aqueous dispersion, 100 kg of distilled water and 60 g of an additive containing ethylene bis stearamide and modified silica (AGITAN 350 manufactured by MUNZING) were added. 100 kg of an aqueous medium containing tetrahydrofuran was distilled off under reduced pressure (absolute pressure 100 kPa) while observing foaming while heating. It took 1.2 hours to distill off 100 kg of aqueous medium.
Thereafter, it was cooled with water until the internal temperature reached about 25 ° C., and filtered using a polypropylene wind cartridge filter (manufactured by Advantech) having a pore size of 25 μm to obtain an aqueous dispersion “E-1”. It was possible to filter without changing the filter. The scum amount was 18 g.

Examples 2 and 4
The aqueous dispersion “E” was prepared in the same manner as in Example 1 except that the acid-modified polyolefin resin “P-2” was used in Example 2, and the acid-modified polyolefin resin “P-4” was used in Example 4. -2 "and" E-4 "were obtained. The solvent removal time was 1 hour and 3 hours, respectively, and filter exchange was 0 times and 2 times, respectively. The scum amounts were 20 g and 70 g, respectively.

Example 3
[Step 1]
Using a stirrer equipped with a heatable and sealable pressure-resistant 1000 L reaction vessel, 60 kg of acid-modified polyolefin resin “P-3”, 60 kg of isopropanol (boiling point 83 ° C.), 5 kg of N, N-dimethylethanolamine and 115 kg Of distilled water was charged into the reaction vessel. While stirring, the heater was turned on and heated. Then, the system temperature was maintained at 130 ° C. and further stirred for 2 hours. Then, it cooled to 40 degreeC with water cooling, stirring.
[Step 2]
To the obtained aqueous dispersion, 100 kg of distilled water and 60 g of an additive containing ethylene bis stearamide and modified silica (AGITAN 350 manufactured by MUNZING) were added. 100 kg of an aqueous medium containing isopropanol was distilled off under reduced pressure (absolute pressure 100 kPa) while observing foaming while heating. It took 1.5 hours to distill off 100 kg of aqueous medium.
Thereafter, it was cooled with water until the internal temperature reached about 25 ° C., and filtered using a polypropylene wind cartridge filter having a pore size of 25 μm (manufactured by Advantech) to obtain an aqueous dispersion “E-3”. It was possible to filter without changing the filter. The scum amount was 15 g.

Examples 5 and 6
Instead of the additive in Example 1, in Example 5, an additive containing a polyether compound and silica (SN deformer 180 manufactured by San Nopco), and in Example 6, an additive containing an acetylene glycol compound and silica. Aqueous dispersions “E-5” and “E-6” were obtained in the same manner as in Example 1 except that (Olfin AF-103 manufactured by Nissin Chemical Industry Co., Ltd.) was used.
The solvent removal time was 1.2 hours and 1.3 hours, respectively, and neither filter was replaced. The scum amounts were 20 g and 25 g, respectively.

Examples 7-9
In Example 7, the aqueous dispersion “E-7” was prepared in the same manner as in Example 1, except that the amount of additive (AGITAN 350) was changed to 6 g, Example 8 was changed to 600 g, and Example 9 was changed to 3 kg. “E-8” and “E-9” were obtained.
The solvent removal times were 1.8 hours, 1.1 hours, and 1.5 hours, respectively, and the filter was changed once, 0 times, and 1 time, respectively. The scum amounts were 68 g, 20 g, and 35 g, respectively.

Examples 10 and 11
In Step 1 of Example 1, a surfactant (Neugen EA-190D manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) was added in the same manner as in Example 1 except that 2 kg was added in Example 10 and 0.4 kg was added in Example 11. Aqueous dispersions “E-10” and “E-11” were obtained.
The solvent removal time was 4 hours and 2.5 hours, the filter was changed once and 0 times, respectively, and the scum amounts were 65 g and 27 g, respectively.

Example 12
[Step 1]
Using a stirrer equipped with a heatable and sealable pressure-resistant 1000 L reaction vessel, 60 kg of acid-modified polyolefin resin “P-1”, 70 kg of tetrahydrofuran, 7 kg of N, N-dimethylethanolamine, 60 g of additive (AGITAN) 350) and 103 kg of distilled water were charged into the reaction vessel. While stirring, the heater was turned on and heated. Then, the system temperature was maintained at 140 ° C. and further stirred for 2 hours. Then, it cooled to 40 degreeC with water cooling, stirring.
[Step 2]
100 kg of an aqueous medium containing tetrahydrofuran was distilled off under reduced pressure (absolute pressure of 100 kPa) while heating the obtained aqueous dispersion while observing foaming. It took 2.2 hours to distill off 100 kg of aqueous medium.
Thereafter, it was cooled with water until the internal temperature reached about 25 ° C., and filtered using a polypropylene wind cartridge filter (manufactured by Advantech) having a pore size of 25 μm to obtain an aqueous dispersion “E-12”. It was possible to filter without changing the filter. The scum amount was 42 g.

Example 13
In Step 2 of Example 12, 60 g of the additive (AGITAN 350) was added, and then 100 kg of the aqueous medium containing tetrahydrofuran was distilled off to obtain an aqueous dispersion “E-13” in the same manner as in Example 12. It was. It took 1 hour to distill off 100 kg of aqueous medium. It was possible to filter without changing the filter. The scum amount was 19 g.

Comparative Example 1
An aqueous dispersion (H-1) was obtained in the same manner as in Example 1 except that the additive (AGITAN 350) was not added in Example 1.
The solvent removal time was 5 hours, and filter replacement was performed 6 times. The scum amount was 250 g.

Comparative Examples 2 and 3
In Examples 2 and 3, aqueous dispersions (H-2 and H-3) were obtained in the same manner as in Examples 2 and 3, except that the additive (AGITAN 350) was not added.
The solvent removal time was 5.2 hours and 6 hours, respectively, and the filter was changed 5 times and 6 times, respectively. The scum amounts were 212 g and 244 g, respectively.

Comparative Example 4
Step 1 of Example 1 using propylene-butene-ethylene terpolymer “P-0” (propylene / butene / ethylene = 64.8 / 23.9 / 11.3 mass%) which is not acid-modified. I tried to disperse in the same way. However, dispersion of this resin did not proceed at all.

  Table 2 shows the evaluation results of the acid-modified polyolefin dispersions produced by the production methods of Examples 1 to 13 and Comparative Examples 1 to 3.

The method for producing an aqueous dispersion of an embodiment including the two steps defined by the present invention can remove the solvent in a short time and can reduce the amount of scum generated after the removal of the solvent. Therefore, productivity was good. Among these, in the production methods of Examples 1 to 3 and 5 to 8 in which the additive is added in a preferable addition amount in Step 2 using an acid-modified polyolefin resin having an acid modification amount in a preferable range, the obtained aqueous dispersion The surface state of the coating film coated with the body was good, the coating film was excellent in water resistance, and the adhesion to various substrates was also good.
In Example 10, since the addition amount of the surfactant exceeded the preferable range in Step 1, the obtained coating film had a tendency to decrease the water resistance and the adhesiveness was significantly decreased. It was a usable level.
In Example 12, since the additive was added in the step of obtaining the acid-modified polyolefin resin dispersion in Step 1, the amount of scum generated slightly increased and the appearance also tended to be inferior.

On the other hand, in the production method of Comparative Examples 1 to 3, since the additive is not present in the organic solvent removal step, the solvent removal time is longer than those of Examples 1 to 3, respectively. Regardless of the type, the amount of scum generated increased significantly, resulting in frequent filter clogging and a significant decrease in productivity. Moreover, the obtained coating film was also inferior in surface shape.
In Comparative Example 4, since the polyolefin resin not acid-modified was used as the resin, the resin could not be dispersed in water.

Claims (6)

The manufacturing method of the acid-modified polyolefin resin aqueous dispersion whose solid content concentration is 10-45 mass% characterized by including the following process 1 and process 2.
(1) Step 1 for obtaining a dispersion of an acid-modified polyolefin resin using an acid-modified polyolefin resin having a weight average molecular weight of 5,000 to 150,000 , an organic solvent, a basic compound, and water as raw materials
(2) Step 2 of removing the organic solvent in the presence of an additive comprising at least one compound selected from the group consisting of fatty acid amides, polyethers, and acetylene glycols, and a silica-containing compound.   The process for producing an acid-modified polyolefin resin aqueous dispersion according to claim 1, wherein, in step 1, an aqueous auxiliary agent having a boiling point of 185 ° C or higher at normal pressure is not used as a raw material.   The acid-modified polyolefin resin aqueous solution according to claim 1 or 2, wherein an acid-modified polyolefin resin modified with an unsaturated carboxylic acid component and having an unsaturated carboxylic acid component content of 0.1 to 8% by mass is used. A method for producing a dispersion.   The method for producing an aqueous dispersion of an acid-modified polyolefin resin according to any one of claims 1 to 3, wherein a silica-containing compound whose surface is hydrophobically modified is used.   The addition amount of at least one compound selected from the group consisting of fatty acid amide, polyether, and acetylene glycol and the addition amount of the silica-containing compound are each 3 parts by mass with respect to 100 parts by mass of the acid-modified polyolefin resin. It is set as follows, The manufacturing method of the acid-modified polyolefin resin aqueous dispersion in any one of Claims 1-4 characterized by the above-mentioned.   The method for producing an acid-modified polyolefin resin aqueous dispersion according to any one of claims 1 to 5, wherein an organic solvent having a boiling point of 10 to 200 ° C is used.