JP5154021B2 - Aqueous dispersion and laminate - Google Patents

Description

  The present invention has excellent adhesion to various substrates, and in particular, it is possible to form a film having boil resistance without aging or baking, but the trouble of mixing two liquids immediately before use, The present invention relates to an aqueous dispersion that is free from worries about pot life after mixing, and a laminate obtained by coating the aqueous dispersion.

Polyolefin resins are excellent in electrical properties, mechanical properties, chemical properties, formability, hygiene, recyclability, etc., and are therefore used in large quantities mainly in automobiles, electricity, packaging, and household goods. However, a polyolefin resin usually does not contain a polar group in the molecular chain, is difficult to coat or adhere, and a modified polyolefin resin modified with an acid or the like has been developed. In order to use the modified polyolefin resin for coating or adhesion, it is necessary to liquefy the resin. For example, a) the resin is used by melting, b) the resin is used by dissolving or dispersing in an organic solvent, c) A method in which a resin is dispersed in an aqueous medium is used. However, in a), there is a problem that the use is limited and it is difficult to reduce the thickness due to the balance with the melt viscosity of the resin. When b) and c) are compared, the use of organic solvents tends to be restricted from the standpoints of environmental protection, resource conservation, dangerous goods regulations by the Fire Service Act, and workplace environment improvement. Yes.

From the background as described above, studies on making the modified polyolefin resin aqueous have been actively conducted. For example, Patent Documents 1 to 5 describe the use of various surfactants as essential in order to stably disperse the modified polyolefin resin in an aqueous medium. However, in these methods, since a certain amount or more of the surfactant is used, the adhesion to various substrates and the heat sealability are insufficient. Further, the above surfactants are not preferable from the viewpoint of environment and hygiene because the water resistance of the coating film and the adhesion to the substrate are remarkably lowered and there is a possibility of bleeding out from the coating film. In addition, the performance may change over time.

As an example in which a modified polyolefin resin is used as an aqueous dispersion for coating or adhesion without using an emulsifier, a method disclosed in Patent Document 6 can be mentioned. Since an emulsifier such as a surfactant is not used, adhesion at room temperature is excellent, but further improvement has been demanded regarding the boil resistance of the coating film.

  As a technique for improving the heat resistance of a modified polyolefin resin coating film, a technique using a crosslinking reaction has been studied. Patent Document 7 discloses a polychloroprene two-component aqueous adhesive composition comprising a main component mainly composed of polychloroprene-based latex emulsion-polymerized with polyvinyl alcohol as an emulsifying / dispersing agent, and a curing agent mainly composed of isophorone diisocyanate. Things are disclosed. However, since an emulsifier is used, the adhesion to non-polar substrates is not sufficient, and a highly reactive crosslinking agent is used. there were.

In order to increase the heat resistance of the modified polyolefin resin coating film and to provide a long-term pot life, a technique in which a crosslinking agent that reacts with heat or the like is added to the aqueous resin dispersion is also disclosed. Patent Documents 8 and 9 show examples using a blocked isocyanate, but there is a problem that drying at a high temperature is required to dissociate the blocking agent.
JP-A-5-163420 Japanese Patent Laid-Open No. 6-80844 Japanese Patent Laid-Open No. 6-80845 JP-A-7-82423 JP-A-8-67726 JP 2003-119328 A JP 2004-352921 A JP-A-6-145286 Patent registration 29768841

  The present invention solves the above-mentioned problems, has adhesion to various substrates, and in particular, can form a film having boil resistance without aging or baking. An object of the present invention is to provide an aqueous dispersion that does not involve the trouble of mixing the two liquids immediately before use or the pot life after mixing.

  As a result of intensive studies to solve the above problems, the present inventors have obtained 1) a composition (C) obtained by reacting at least part of a specific polyolefin resin (A) and a specific compound (B), And, by using an aqueous dispersion containing a basic compound and substantially free of non-volatile aqueous additive, it has adhesion to various base materials without aging or baking. Despite being able to form a film having a boil resistance, it was found that it can be used without worrying about pot life, and the present invention was reached based on this finding.

That is, the gist of the present invention is as follows.
(1) A polyolefin resin (A) having a carboxyl group or an anhydride group thereof, and a compound (B) having at least two functional groups selected from an epoxy group, an oxazoline group, an isocyanate group, a carbodiimide group, and a silanol group The compound (C) in which at least a part of the compound is reacted and the content of the toluene insoluble matter is 5 to 85% by mass, and the basic compound, are substantially free of the non-volatile aqueous agent. Aqueous dispersion.
( 2 ) The aqueous dispersion according to (1) above, wherein the acid value in the polyolefin resin (A) is from 5 to 200 mgKOH / g.
( 3 ) The aqueous dispersion as described in (1) or (2) above, wherein the polyolefin resin (A) further contains a (meth) acrylic acid ester.
( 4 ) A film obtained by removing a solvent from the aqueous dispersion of any one of (1) to ( 3 ) above.
( 5 ) A laminate having the coating described in ( 4 ) above.

  In general, the two-component system is a process that requires aging or baking, but the aqueous dispersion of the present invention has excellent boil resistance without aging or baking because the reacted particles are dispersed. Despite being able to form a film, it has long-term stability and pot life. Moreover, since the aqueous dispersion of the present invention does not substantially contain a non-volatile aqueous additive, it is possible to form a film having excellent adhesion to various substrates. According to the aqueous dispersion of the present invention, a film excellent in adhesion and boil resistance to various substrates without deteriorating the working environment can be applied to various substrates in an economically and resource-saving manner. Can be granted.

Hereinafter, the present invention will be described in detail.
The aqueous dispersion of the present invention comprises a polyolefin resin (A) having a carboxyl group or an anhydride group thereof and at least a part of a compound (B) having at least two functional groups capable of reacting with a carboxyl group. Further, it contains a compound (C) having a toluene-insoluble content of 5 to 85% by mass and a basic compound , and substantially does not contain a nonvolatile aqueous agent.
Here, the “aqueous medium” is a liquid containing water as a main component and containing a water-soluble organic solvent and a basic compound described later. “Aqueous aid” is a drug or compound added for the purpose of promoting aqueousization or stabilizing the aqueous dispersion in the production of an aqueous dispersion. It means that it does not have a boiling point at pressure, or has a high boiling point (for example, 250 ° C. or higher) at normal pressure.
“Substantially no non-volatile aqueous solubilizing aid” means that no non-volatile aqueous solubilizing aid is actively added to the system, resulting in the absence of these. It is particularly preferable that the content of such a nonvolatile aqueous auxiliary agent is zero, but it may be contained in an amount of less than about 0.1% by mass with respect to the polyolefin resin component as long as the effects of the present invention are not impaired. Absent.

  Among the monomer components constituting the polyolefin resin (A) having a carboxyl group used in the present invention, the content of unsaturated hydrocarbon is 50 to 98% by mass, preferably 60 to 98% by mass, more preferably 70 to 98%. % By mass, particularly preferably 75 to 95% by mass. If the unsaturated hydrocarbon content is less than 50% by mass, the adhesion to polyolefin materials such as polypropylene will decrease, or if it exceeds 98% by mass, the content of unsaturated carboxylic acid units will decrease relatively. , It may be difficult to make the resin water-based.

Among the monomer components constituting the carboxyl group-containing polyolefin resin (A) used in the present invention, the unsaturated hydrocarbon component includes ethylene, propylene, isobutene, 1-butene, 1-pentene, and 4-methyl-1-pentene. , Alkenes having 2 to 6 carbon atoms such as 3-methyl-1-pentene and 1-hexene, and dienes such as butadiene and isoprene, and a mixture thereof can also be used. Among these, alkenes having 2 to 6 carbon atoms such as ethylene, propylene, isobutene, 1-butene, etc. from the viewpoint of ease of production of the resin, ease of water treatment, adhesion to various materials, blocking properties, etc. More preferably, these may be used in combination, but it is particularly preferable that an ethylene component is included.
In the above-mentioned 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. Moreover, you may mix 2 or more types of polyolefin resin so that it may become the structural component ratio of this invention.

  The method for synthesizing the polyolefin resin used in the present invention is not particularly limited, but for the purpose of the present invention, it is preferable not to use an emulsifier or a protective colloid. Generally, it is obtained by high-pressure radical copolymerization of a monomer constituting the polyolefin resin in the presence of a radical generator. In addition, the unsaturated carboxylic acid or its anhydride may be graft copolymerized (grafted modification).

  The polyolefin resin (A) used in the present invention has a carboxyl group or an anhydride group thereof, and specific examples of the monomer component constituting such a functional group include acrylic acid, methacrylic acid, maleic acid, anhydrous In addition to maleic acid, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, fumaric acid, crotonic acid, citraconic acid, mesaconic acid, allyl succinic acid, etc., as well as unsaturated dicarboxylic acid half ester, half amide, etc. Mention may be made of compounds having at least one carboxyl group or acid anhydride group. Of these, maleic anhydride, acrylic acid, and methacrylic acid are preferable from the viewpoint of easy introduction into the polyolefin resin, and maleic anhydride is more preferable from the viewpoint of reactivity with the compound (B). In the present invention, 1 mol of an acid anhydride group in the resin is regarded as 2 mol of a carboxyl group.

  The unsaturated carboxylic acid only needs to be copolymerized in the polyolefin resin, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. For example, in the case of graft copolymerization, a method in which a polyolefin resin and an unsaturated carboxylic acid are heated and melted to a temperature higher than the melting point of the polyolefin resin in the presence of a radical generator, or after the polyolefin resin is dissolved in an organic solvent, Examples thereof include a method in which an unsaturated carboxylic acid unit is graft-copolymerized to a polyolefin resin by a method of reacting by heating and stirring in the presence of a generator.

  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 and used depending on the reaction temperature.

  The acid value of the polyolefin resin (A) having a carboxyl group used in the present invention is preferably 5 to 200 mgKOH / g, more preferably 10 to 100 mgKOH / g, and particularly preferably 15 to 70 mgKOH / g. If it is 5 mgKOH / g or less, it may be difficult to make the aqueous solution without containing the non-volatile aqueous agent. Further, at 200 mg KOH / g or more, when the reactivity of the compound (B) is low, many carboxyl groups remain, so that the adhesion to a nonpolar substrate and water resistance may deteriorate, and the compound (B When the reactivity of) is high, gelation may cause difficulty in making the aqueous solution, which is not preferable. The acid value can be determined according to JIS K 5407.

Furthermore, the polyolefin resin of the present invention may contain (meth) acrylic acid alkyl ester as a monomer unit in the structure of the polyolefin resin from the viewpoint of adhesion to various base materials and ease of aqueous formation. preferable. In this case, the content of the monomer unit is 0.1 to 25% by mass, and the (meth) acrylic acid ester includes an esterified product of (meth) acrylic acid and an alcohol having 1 to 30 carbon atoms.
The (meth) acrylic acid ester only needs to be copolymerized in the polyolefin resin, and the form thereof is not limited, and examples thereof include random copolymerization, block copolymerization, and graft copolymerization. For example, in the case of graft copolymerization, it can be performed by the same operation as the method in which the unsaturated carboxylic acid unit is introduced as described above.

In addition to the above components, other components may be contained in an amount of about 10% by mass or less of the total polyolefin resin. Examples of other components include alkenes having 6 or more carbon atoms such as 1-octene and norbornenes and dienes. , Cycloolefins, maleic esters such as dimethyl maleate, diethyl maleate, dibutyl maleate, alkyl methacrylates such as (meth) acrylic amides, methyl vinyl ether, ethyl vinyl ether, vinyl formate, vinyl acetate, Vinyl esters such as vinyl propionate, vinyl pivalate and vinyl versatate, and vinyl alcohol obtained by saponifying vinyl esters with basic compounds, 2-hydroxyethyl acrylate, glycidyl (meth) acrylate, (meth) acrylonitrile , Styrene, substitution Examples thereof include styrene, vinyl halides, halogenated vinylidenes, carbon monoxide, sulfur dioxide, and the like, and a mixture thereof can also be used.
Moreover, the polyolefin resin used for this invention may be chlorinated, and 5-50 mass% is suitable for the chlorination rate in that case. Chlorination improves adhesion to olefin resin substrates.

The method for chlorinating the polyolefin resin is not particularly limited, and a known method can be used. For example, it can be carried out by dissolving a resin to be chlorinated in a chlorine-based solvent such as chloroform and then blowing gaseous chlorine while irradiating with ultraviolet rays or in the presence of a radical generator.

The polyolefin resin used in the present invention preferably has a melt flow rate of 0.01 to 500 g / 10 min at 190 ° C. and a load of 2160 g, which is a measure of molecular weight. More preferably, 0.1 to 300 g / 10 min, more preferably 1 to 100 g / 10 min can be used. When the melt flow rate of the polyolefin resin is less than 0.01 g / 10 min, it becomes difficult to make the resin water-based, and it may be difficult to obtain a good aqueous dispersion. On the other hand, when the melt flow rate of the polyolefin resin exceeds 500 g / 10 min, the film obtained from the aqueous dispersion becomes hard and brittle, and the mechanical strength may be reduced.
Next, the compound (B) having at least a divalent functional group used in the present invention has a functional group having reactivity with a carboxyl group such as an epoxy group, an oxazoline group, an isocyanate group, a carbodiimide group, or a silanol group. It is sufficient to have at least two of them in the inside, and these may be one kind or two kinds or more.
Among the compounds that can be used as the compound (B) in the present invention, examples of the compound having an epoxy group include bisphenol A, epichlorohydrin type epoxy resin, (poly) ethylene glycol diglycidyl ether, and (poly) propylene glycol diglycidyl. Glycidyl ethers such as ether, 1,6-hexanediol diglycidyl ether, polybutadiene diglycidyl ether, resorcinol diglycidyl ether, hydroquinone diglycidyl ether, glycerol polyglycidyl ether, sorbitol polyglycidyl ether, diglycidyl terephthalate, diglycidyl orthophthalate Glycidyl ester, diglycidyl aniline, diamine glycidyl amine, N, N, N ', N'-tetraglycidyl-m-xylylene And glycidylamines such as diamine and 1,3-bis (N, N′-diamineglycidylaminomethyl) cyclohexane.

  Examples of the catalyst for reacting the acid-modified polyolefin resin (A) with these epoxy group-containing compounds include dimethylethanolamine and diethylethanolamine. These are preferable because they can also be used as a basic compound described later, and are effective for facilitating the reaction and stabilizing the aqueous dispersion.

  Of the compounds that can be used as the compound (B) in the present invention, examples of the compound having an oxazoline group include 1,3-phenylenebis (2-oxazoline), 1,4-phenylenebis (2-oxazoline), 2, 2-bis (2-oxazoline), 2,2-bis (4-methyl-2-oxazoline), 2,2-bis (4,4-dimethyl-2-oxazoline), 2,2-bis (4-ethyl) -2-oxazoline), 2,2-bis (4,4-diethyl-2-oxazoline), 2,2-bis (4-propyl-2-oxazoline), 2,2-bis (4-butyl-2-) Oxazoline), 2,2-bis (4-hexyl-2-oxazoline), 2,2-bis (4-phenyl-2-oxazoline), 2,2-bis (4-cyclohexyl-2-oxazoline), 2 2-bis (4-benzyl-2-oxazoline), 2,2-ethylenebis (2-oxazoline), 2,2-tetramethylenebis (2-oxazoline), 2,2-hexamethylenebis (2-oxazoline) 2,2-octamethylenebis (2-oxazoline), 2,2-ethylenebis (4-ethyl-2-oxazoline), 2,2-tetraethylenebis (4-ethyl-2-oxazoline), 2,2 -A bisoxazoline compound such as cyclohexylenebis (4-ethyl-2-oxazoline), polyoxazoline, and the like can be mentioned, and 1,3-phenylenebis (2-oxazoline) is preferable.

  Among the compounds that can be used as the compound (B) in the present invention, the compounds having an isocyanate group include tolylene diisocyanate, diphenylmethane diisocyanate, triphenylmethane triisocyanate, polymethylene polyphenyl polyisocyanate, tolidine diisocyanate, naphthalene diisocyanate, Hexamethylene diisocyanate, isophorone diisocyanate, xylylene diisocyanate, tetramethylxylylene diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated diphenylmethane diisocyanate, dicyclohexylmethane diisocyanate, and / or their respective organic diisocyanate excess and polyhydric alcohol, low molecular weight polyester Additives with resin or water, or this Carbodiimide groups with polyisocyanates, uretdione, uretonimine groups, is modified product having a biuret group, or an isocyanurate group is used.

  In the present invention, among compounds that can be used as the compound (B), as the compound having a carbodiimide group, those derived from the isocyanate can be used, for example, having a structure obtained by decarboxylation from the isocyanate. Things can be used.

  In the present invention, among compounds that can be used as the compound (B), as a compound having a silanol group, a silane compound that is hydrolyzed to produce a silanol group can be used. Tetraethoxysilane (tetraethylorthosilicate, TEOS) ), And silicon alkoxides such as tetramethoxysilane (tetramethylorthosilicate, TMOS). In order to hydrolyze these silicon alkoxides to form silanol groups, it is preferably used in combination with basic catalysts such as ammonia, amines, ammonium compounds or pyridine, and triethylamine, ethylenediamine, trimethylamine, methylpiperidine, N-methylpyridine. , Ethylenediamine and the like are preferable.

  The addition amount of the compound (B) is preferably selected so as to be in the range of the gel fraction described later when reacted with the polyolefin resin (A) having a carboxyl group. When the molecular weight of the compound (B), the number of functional groups, and the ratio of the polyolefin resin (A) having a carboxyl group and the compound (B) are small when the number of functional groups of the compound (B) is large, the number of functional groups is small However, 0.01-100 parts by weight of the compound (B) is preferable with respect to 100 parts by weight of the polyolefin resin (A) having a carboxyl group. -50 parts by weight is more preferable, and 0.1-30 parts by weight is particularly preferable.

  Next, the composition (C) in the present invention will be described.

  The compound (C) in the present invention is a compound obtained by reacting at least part of the polyolefin resin (A) and the compound (B).

  The aqueous dispersion of the present invention comprises a polyolefin resin (A) having a carboxyl group or an anhydride group thereof, a compound (B) having at least two functional groups capable of reacting with a carboxyl group, and a polyolefin resin (A). And the compound (C) obtained by reacting at least a part of the compound (B), and a basic compound, as long as an aqueous dispersion can be produced, the olefin resin (A) and All of the compound (B) may be converted to the compound (C).

  Examples of the method of reacting the polyolefin resin (A) having a carboxyl group and at least a part of the compound (B) include a method of reacting in a molten or solid phase, a method of reacting using a solvent, and the like.

  Examples of the method of melting or reacting in a solid phase include a method of heating and stirring the polyolefin resin (A) and the compound (B) in a container and a method of melt-kneading. When reacting in a container, it is preferable to react under reduced pressure or in an inert gas atmosphere in order to prevent deterioration of the resin. When melt-kneading, it can be kneaded using a general extruder, but it is preferable to use a multi-screw extruder in the sense of improving the kneading state.

  In this case, if the compound (B) used in the present invention is solid, there are a method of supplying it using a dry blend or a powder feeder, or a method of supplying it after dissolving or dispersing in a solvent to form a liquid. In the case of liquid, there is a method of injecting from the middle of the extruder using a pressure pump. However, in order to carry out the reaction more uniformly, a method of supplying after making it liquid is preferable. The solvent used here may be selected in a timely manner from the viewpoint of the affinity with the polyolefin (A) having a carboxyl group and the solubility or dispersibility of the compound (B), and is not particularly limited, but hydrocarbons such as toluene, xylene and cyclohexane And ethers such as ethylene glycol diethyl ether, ethylene glycol monoethyl ether acetate, cyclohexanone, dioxane, and tetrahydrofuran, esters, and ketones.

  The kneading temperature is preferably in the range of (resin melting point + 5 ° C.) to (resin melting point + 100 ° C.), and the kneading time is preferably 20 seconds to 30 minutes. If the temperature is lower or shorter than this range, kneading or reaction becomes insufficient, and if the temperature is higher or longer, the resin may be decomposed or colored.

  As a method of reacting using a solvent, the polyolefin resin (A) having a carboxyl group and the compound (B) may be reacted in a solvent, and the polyolefin resin (A) having a carboxyl group and the compound (B) are reacted. After mixing in a solvent, the reaction may be performed while heating and stirring to distill off the solvent and by-products. In order to make the reaction proceed uniformly, a method in which the polyolefin resin (A) and the compound (B) are separately dissolved in a solvent and then mixed and reacted is preferable.

  The solvent used in the above reaction is not particularly limited as long as it can dissolve, swell, and plasticize the polyolefin resin (A) having a carboxyl group, and is not particularly limited. Toluene, xylene, ethylbenzene, diethylbenzene, isopropylbenzene, amylbenzene, diamylbenzene , Aromatic hydrocarbons such as methylisopropylbenzene and naphthalene, alicyclic hydrocarbons such as cyclohexane, methylcyclohexane, decalin and menthane, ethers such as tetrahydrofuran and dioxane, ethylene glycol monomethyl ether acetate, ethylene glycol diethyl ether, ethylene Glycol monoethyl ether acetate, ethylene glycol monobutyl ether acetate, ethylene glycol dibutyl ether, propylene glycol monoethyl Esters or ethers of polyhydric alcohols such as ether acetate, propylene glycol dimethyl ether, propylene glycol diethyl ether, methyl ethyl ketone, methyl-n-butyl ketone, ethyl-n-butyl ketone, diisobutyl ketone, ketones such as cyclohexanone, methylcyclohexanone, acetic acid- n-butyl, n-butyl propionate, n-butyl butyrate, dimethyl oxalate, diethyl oxalate, dimethyl malonate, diethyl malonate, dimethyl succinate, diethyl succinate, dimethyl glutarate, diethyl glutarate, dimethyl adipate A solvent selected from esters such as diethyl adipate can be used alone or in admixture of two or more.

  The weight ratio between the carboxyl group-containing polyolefin resin (A) and the solvent may be appropriately selected so that the reaction occurs uniformly depending on the affinity between the carboxyl group-containing polyolefin resin (A) and the solvent and the viscosity of the solution. The range of the weight ratio is not particularly limited because it may react in a solvent or in some cases while the solvent is distilled off, but a typical range is 90/10 to 10/90% by weight at the stage of preparation. Can be mentioned.

  The reaction temperature is preferably 10 to 250 ° C., preferably 10 to 150 ° C., more preferably 10 to 100 ° C., because the reactivity of the compound (B) is high. When using a solvent at the time of reaction, you may make it react, recirculating | refluxing a solvent.

  The carboxyl group in the polyolefin resin (A) may be an acid anhydride group, but in that case, it may be contacted with moisture before the reaction and previously ring-opened. Since ring opening has active hydrogen, the reaction with the compound (B) may be advantageous. The method for ring opening is not particularly limited, and examples thereof include a method of contacting with water vapor, immersing the resin in water, and leaving it in a high humidity atmosphere. A method of contacting with water or steam higher than the melting point of the resin is preferable in terms of productivity because it can be opened in a short time, and a method of leaving it in a high humidity atmosphere is preferable because it does not cost.

  The compound (C) in the present invention is a compound obtained by reacting at least a part of the polyolefin resin (A) and the compound (B), and is confirmed by analyzing the presence of insoluble matter by the following toluene dissolution test. be able to.

  The toluene insoluble matter in the present invention represents the ratio of insoluble matter in toluene to the total solid content in the toluene dissolution test under conditions of a temperature of 70 ° C. and a concentration of 40 mg / ml. The toluene insoluble content is preferably 5 to 85 mass%, more preferably 10 to 65 mass%.

    When the toluene insoluble content is less than 5% by mass, the content of the compound (C) is small, so the effect of improving the heat-resistant adhesive property may be small. When the toluene insoluble content exceeds 85% by mass, the compound (C) There is a possibility that water content becomes difficult due to too much content.

  In the present invention, the polyolefin resin (A) having a carboxyl group or an anhydride group thereof, the compound (B) having at least two functional groups capable of reacting with the carboxyl group, and the polyolefin resin (A) and the compound (B) The acid value (mgKOH / g) of a resin composition (hereinafter abbreviated as a resin composition) composed of the compound (C) which is at least partially reacted can be measured according to JIS K5407. . The acid value of the resin composition is preferably 5 to 200 mgKOH / g, more preferably 10 to 100 mgKOH / g, still more preferably 15 to 70 mgKOH / g, and particularly preferably 15 to 45 mgKOH / g.

    When this acid value exceeds 200 mgKOH / g, the particle size of the fine particles produced in the water dispersion step becomes too small, and it becomes difficult to ensure storage stability, and the water resistance of the formed film may be poor. On the other hand, when the acid value is less than 5 mgKOH / g, the amount of carboxyl groups contributing to hydrophilicity is not sufficient, and a good aqueous dispersion may not be obtained.

  In addition, since the resin composition in this invention at least one part of the polyolefin resin (A) and compound (B) which have a carboxyl group has reacted, all may not necessarily melt | dissolve in a solvent. In this case, in the present invention, the acid value is measured without removing the insoluble matter.

  Next, the basic compound in the present invention will be described.

  The aqueous dispersion of the present invention needs to contain a basic compound. The basic compound neutralizes the carboxyl group in the polyolefin resin, and the carboxyl anion generated by the neutralization prevents aggregation between the resin fine particles by its electric repulsive force, thereby imparting stability to the aqueous dispersion. The basic compound contained in the aqueous dispersion may be any compound that can neutralize the carboxyl group. In order not to impair the effects of the present invention, it is preferable to use a basic compound that is volatile (for example, a boiling point of 250 ° C. or lower).

  As the basic compound in the present invention, ammonia which volatilizes during film formation or an organic amine compound having a boiling point of 30 to 250 ° C. is preferable from the viewpoint of water resistance of the film, and an organic amine compound of 50 to 200 ° C. is more preferable. When the boiling point is less than 30 ° C., the rate of volatilization when the resin is made aqueous increases, and the aqueous formation may not proceed completely. When the boiling point exceeds 250 ° C., it becomes difficult to disperse the organic amine compound from the resin film by drying, and the water resistance of the film may deteriorate.

  The addition amount of the basic compound is preferably 0.5 to 3.0 times equivalent to the carboxyl group in the polyolefin resin, more preferably 0.8 to 2.5 times equivalent, and 0.9 to A 2.0-fold equivalent is particularly preferred. If it is less than 0.5 times equivalent, the addition effect of a basic compound is not recognized, and if it exceeds 3.0 times equivalent, the drying time at the time of coating film formation becomes long, or the stability of the aqueous dispersion deteriorates. There is a case.

  Specific examples of the organic amine compound include 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, monoethanolamine, morpholine, N-methylmorpholine, N-ethylmorpholine, Examples include pyrrole and pyridine.

  In the production of the aqueous dispersion of the present invention, as will be described later, it is preferable to use an organic solvent in order to promote the aqueous formation of the polyolefin resin and reduce the dispersed particle size, and the resulting aqueous dispersion May include these. If the organic solvent is volatile (for example, a boiling point of less than 300 ° C.), even if it is contained in the aqueous dispersion, it does not remain in the coating during use, so there is almost no influence on the physical properties. Further, as described later, by performing a stripping operation in a part of the production process, substantially all of the organic solvent used can be removed to obtain an aqueous dispersion containing no organic solvent.

  When an organic solvent is used in the production of the aqueous dispersion of the present invention, the amount of addition thereof is not particularly limited, but the organic solvent contained in the finally obtained aqueous dispersion is 50% by mass or less in the aqueous medium. Preferably, the content is 1 to 45% by mass, more preferably 2 to 40% by mass, and particularly preferably 3 to 35% by mass. When the amount of the organic solvent exceeds 50% by mass, it cannot be regarded as an aqueous medium substantially, and not only deviates from environmental protection, which is one of the objects of the present invention, but depending on the organic solvent used, Stability may be reduced.

  As the organic solvent, those having a solubility in water at 20 ° C. of 10 g / L or more are preferably used, more preferably 20 g / L or more, and particularly preferably 50 g / L or more from the viewpoint of obtaining a good aqueous dispersion. is there.

  The organic solvent preferably has a boiling point of 250 ° C. or less, more preferably 50 to 200 ° C., and particularly preferably 50 to 185 ° C. in view of easy removal from the coating film. An organic solvent having a boiling point exceeding 250 ° C. is difficult to be scattered from the resin coating film by drying, and the water resistance of the coating film at low temperature drying, adhesion to the substrate, etc. may be deteriorated.

  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, Diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, diethylene glycol ethyl ether acetate, 1-methoxy-2-propanol, 1-ethoxy-2-propanol, 3-methoxy-3-methyl-1-butanol, methoxybutanol, acetonitrile , Dimethylformamide, dimethylacetamide, diacetone alcohol Ethyl acetoacetate, 1,2-dimethyl glycerin, 1,3-dimethyl glycerin, trimethyl glycerin. 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 preferred, and among these, organic solvents or ethers having one hydroxyl group in the molecule are more preferred. Among these, ethylene glycol alkyl ethers are more preferable from the viewpoint that the resin can be made aqueous with a small amount of addition, and n-propanol, isopropanol, and tetrahydrofuran are more preferable from the viewpoint of easy stripping described later.

  As a method for obtaining the aqueous polyolefin resin dispersion of the present invention, a resin composition, a basic compound, an organic solvent, and an aqueous medium are charged all at once or in stages, and then heated in a container that can be sealed. A method of stirring and a method of adding a basic compound and an aqueous medium to an organic solvent containing a resin composition and heating and stirring can be preferably used. When adding the basic compound and the aqueous medium to the organic solvent containing the resin composition, it is preferable to add the basic compound and the aqueous medium after the resin composition is dissolved or dispersed to such an extent that particles cannot be visually confirmed. Although a basic compound and an aqueous medium may be added simultaneously, it is preferable to add an aqueous medium after adding a basic compound first from the point of work efficiency.

  As the container, a solid / liquid stirring device or an emulsifier can be used, and it is preferable to use a device capable of refluxing or a device capable of pressurization of 0.1 MPa or more.

  When the resin composition, the basic compound, the aqueous medium, and the organic solvent are charged all at once and then made aqueous, the raw materials are put into the above-mentioned apparatus, and the mixture is preferably stirred and mixed at a temperature of 40 ° C. or lower. Next, while maintaining the temperature in the tank at 60 to 220 ° C., preferably 100 to 180 ° C., preferably the resin composition is sufficiently obtained by continuing stirring until there are no coarse particles (for example, 5 to 120 minutes). By making it aqueous, an aqueous dispersion can be obtained. Thereafter, further jet processing may be performed as necessary.

  When a basic compound and an aqueous medium are added to the organic solvent containing the resin composition, the temperature is not particularly limited, but the higher the temperature, the lower the viscosity of the organic solvent containing the resin composition, so uniform aqueous dispersion It is preferable because it is easy to obtain a body. However, from the viewpoint of economy, working environment, and working efficiency, it is preferable to stir and mix under reflux of the organic solvent or below the boiling point. An aqueous dispersion can be obtained by adding the basic compound and the aqueous medium while stirring the organic solvent containing the resin composition. Thereafter, further jet processing may be performed as necessary.

  When the above organic solvent is used in the production of the aqueous dispersion, after the resin is made aqueous, a part thereof is distilled out of the system by a solvent removal process generally called “stripping”, and the amount of the organic solvent Can be reduced.

  The number average particle diameter of the polyolefin resin particles dispersed in the aqueous dispersion of the present invention is 1 μm or less. Further, from the viewpoint of low-temperature film-forming properties, it is preferably 0.5 μm or less, more preferably 0.3 μm or less, and further preferably 0.2 μm or less. When the number average particle diameter exceeds 1 μm, the low-temperature film-forming property is remarkably deteriorated, and the storage stability of the aqueous dispersion is lowered. The volume average particle diameter is also preferably 2 μm or less, more preferably 1 μm or less, further preferably 0.5 μm or less, and particularly preferably 0.3 μm or less from the viewpoint of low-temperature film-forming properties and storage stability. A preferable lower limit of the number average particle size and the volume average particle size is 0.01 μm. When the particle diameter is less than 0.01 μm, the viscosity may increase when the solid content concentration of the aqueous dispersion is increased.

  The resin content in the aqueous dispersion of the present invention can be appropriately selected depending on the film forming conditions, the desired thickness and performance of the resin coating film, and is not particularly limited, but the viscosity of the coating composition is appropriately set. It is preferably 1 to 60% by mass, more preferably 3 to 55% by mass, further preferably 5 to 50% by mass, and particularly preferably 10 to 45% by mass in terms of maintaining and exhibiting good coating film forming ability.

  In order to further improve the performance, an aqueous dispersion of another polymer, a tackifier, inorganic particles, a crosslinking agent, a pigment, a dye, and the like can be added to the aqueous dispersion of the present invention.

  The aqueous dispersion of other polymer is not particularly limited. For example, polyvinyl acetate, ethylene-vinyl acetate copolymer, polyvinyl chloride, polyvinylidene chloride, ethylene- (meth) acrylic acid copolymer, ethylene- (meth) acrylic acid ester-maleic anhydride copolymer, 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 And an aqueous dispersion such as a tackifier resin such as rosin, a phenol resin, a silicone resin, and an epoxy resin. You may use these in mixture of 2 or more types.

  As inorganic particles, metal oxides such as magnesium oxide, zinc oxide and tin oxide, inorganic particles such as calcium carbonate and silica, and layered inorganic compounds such as vermiculite, montmorillonite, hectorite, hydrotalcite and synthetic mica are added. be able to. 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. In addition, you may use an inorganic particle in mixture of 2 or more types. Zinc oxide can be used for ultraviolet shielding and tin oxide can be used for antistatic purposes.

  When a crosslinking agent is added to the aqueous dispersion of the present invention, various coating film performances such as water resistance and solvent resistance can be further improved. The addition amount of the crosslinking agent is 0.01 to 80 parts by mass, preferably 0.1 to 50 parts by mass, and more preferably 0.5 to 30 parts by mass with respect to 100 parts by mass of the resin in the aqueous dispersion. When the addition amount of the crosslinking agent is less than 0.01 parts by mass, the degree of improvement of the coating film performance is small, and when it exceeds 80 parts by mass, the performance such as workability may be deteriorated.

  As the crosslinking agent, there can be used 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 having a polyvalent coordination site, etc., of which an isocyanate compound, 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.

  Examples of the pigment / dye include titanium oxide, zinc white, and carbon black.

  In the aqueous dispersion of the present invention, various kinds of leveling agents, antifoaming agents, anti-waxing agents, pigment dispersants, ultraviolet absorbers, thickeners, weathering agents, flame retardants, antistatic agents, etc. It is also possible to add drugs.

  Next, a method for using the aqueous polyolefin resin dispersion of the present invention will be described.

  The resin composition obtained from the aqueous dispersion of the present invention is excellent in adhesiveness to various substrates, for example, metal, glass, plastic moldings, films, synthetic paper, paper, etc. It is suitable as a coating agent, paint, ink and adhesive.

  The aqueous dispersion of the present invention can form a coating film by removing the liquid medium after coating on various substrates. Since the coating film has excellent adhesion to various materials and heat sealability, it can be used for various coating agents, primers, adhesives, heat sealants, paint and ink binders, etc. Suitable as heat sealant and primer.

  Usable base materials include paper, synthetic paper, thermoplastic resin film, plastic products, steel sheets, metal foil such as aluminum foil, coating on wood, woven fabric, knitted fabric, non-woven fabric, gypsum board, wood board, etc. Can be used for impregnation. Especially, it is preferable to use for aluminum foil, paper, synthetic paper, and a thermoplastic resin film.

  Examples of the thermoplastic resin film include polyethylene terephthalate (hereinafter referred to as PET), polyethylene naphthalate, polytrimethylene terephthalate, polytrimethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate and other polyester resins, polyglycolic acid, polylactic acid, etc. Biodegradable resins typified by aliphatic polyester resins such as polyhydroxycarboxylic acid, polyethylene succinate, polybutylene succinate, polyamide resins such as nylon 6, nylon 66, nylon 46, polypropylene, polyethylene, ethylene-vinyl acetate Examples include films made of thermoplastic resins such as polyolefin resins such as copolymers, polyvinyl chloride, polyimide resins, polyarylate resins, or mixtures thereof, and laminates thereof. That is, inter alia, polyester resin, polyamide resin, polyethylene, ethylene - vinyl acetate copolymer, consisting of PP film can be suitably used. These base films may be unstretched films or stretched films, and the production method is not limited. Moreover, although the thickness of a base film is not specifically limited, Usually, what is necessary is just to be the range of 1-500 micrometers. Furthermore, you may perform what is called in-line coating which apply | coats the aqueous dispersion of this invention to an unstretched film, and extends | stretches the coat film.

  The method of applying the aqueous dispersion of the present invention to a substrate is not particularly limited, but gravure roll coating, reverse roll coating, wire bar coating, lip coating, air knife coating, curtain flow coating, spray coating, dipping Coating, brushing, etc. can be employed.

  What is necessary is just to determine suitably the application quantity of an aqueous dispersion with a base material. In the case where the substrate is a thermoplastic resin film, the thickness of the coating film is preferably at least 0.1 μm, more preferably 0.1 to 10 μm, in order to sufficiently enhance the heat sealability. 2-8 micrometers is further more preferable and 0.3-7 micrometers is especially preferable.

  The drying temperature of the aqueous dispersion of the present invention is not particularly limited and may be appropriately determined depending on the heat-resistant temperature of the base material, etc., but is usually 50 to 240 ° C., more preferably 60 to 210 ° C., 70-200 degreeC is further more preferable. When the drying temperature is less than 50 ° C., the aqueous medium cannot be volatilized sufficiently, or it takes time to volatilize, and it becomes difficult to develop good adhesive performance. On the other hand, when the drying temperature exceeds 240 ° C., the adhesion performance tends to decrease. 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 resin and the crosslinking agent, it is desirable to appropriately select the heating temperature and time depending on the type of the crosslinking agent.

  In addition, since the coating film obtained from the aqueous dispersion of the present invention is excellent in heat sealability, it is possible to thermally bond another substrate on the coating film provided on the substrate. it can. Thus, a laminated body laminated through the coating film is obtained. As the base material that can be combined, the above-mentioned thermoplastic resin film, paper, synthetic paper, wood, woven fabric, knitted fabric, nonwoven fabric, metal foil such as aluminum foil, etc., can be appropriately selected and used. Or different ones. Among them, at least one is preferably a polyolefin resin material such as PP, and is used for lamination of polyolefin resin materials, lamination of polyolefin resin material and paper or synthetic paper, and lamination of polyolefin resin material and aluminum foil. Further preferred.

EXAMPLES Hereinafter, the present invention will be specifically described with reference to examples, but the present invention is not limited thereto. Various characteristics were measured or evaluated by the following methods.

1. Characteristics of Aqueous Dispersion (1) Acid Value of Polyolefin Resin The acid value (mgKOH / g) of the polyolefin resin was measured according to JIS K5407.
(2) Constitution of Resins Other than Unsaturated Carboxylic Acid Units Obtained by performing ¹ H-NMR and ¹³ C-NMR analysis (manufactured by Varian, 300 MHz) in orthodichlorobenzene (d ₄ ) at 120 ° C. ^{In 13} C-NMR analysis, measurement was performed using a gated decoupling method in consideration of quantitativeness.

2. Characteristics of Aqueous Dispersion (3) Solid Concentration of Aqueous Dispersion A suitable amount of the aqueous dispersion was weighed and heated at 150 ° C. until the mass of the residue (solid content) reached a constant weight to determine the solid concentration. .
(4) Viscosity of aqueous dispersion The rotational viscosity of the aqueous dispersion at a temperature of 20 ° C. was measured using a DVL-BII type digital viscometer (B type viscometer) manufactured by Tokimec.
(5) Average particle diameter of aqueous dispersion The number average particle diameter and the volume average particle diameter were determined using a Microtrac particle size distribution analyzer UPA150 (MODEL No. 9340, dynamic light scattering method) manufactured by Nikkiso Co., Ltd. Here, the refractive index of the resin used for calculating the particle diameter was set to 1.50. (6) Pot life of aqueous dispersion The appearance of the aqueous dispersion after the aqueous dispersion was allowed to stand at room temperature for 30 days was evaluated in the following three stages.
○: No change in appearance.
Δ: Thickening is observed.
X: Solidification, aggregation and precipitation are observed.
3. Coating properties

In the following evaluation, as a thermoplastic resin film, a biaxially stretched PET film (Embret PET12 made by Unitika, thickness 12 μm), a biaxially stretched nylon 6 film (Emblem made by Unitika, thickness 15 μm), a stretched polypropylene film (East Cello) (Made by company, thickness 50 micrometers) was used.
(7) Adhesion Evaluation: Tape Peeling Test After coating the aqueous dispersion of the present invention on the corona-treated surface of various thermoplastic resin films using a Mayer bar so that the coating thickness after drying becomes 2 μm, 60 ° C. For 1 minute. The obtained coated film was evaluated after standing at room temperature for 1 day. Cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) was applied to the coated surface, and the degree of peeling when the tape was peeled off at a stretch was visually evaluated.
○: No peeling at all, Δ: Partial peeling off, x: All peeling off (8) Boil resistance evaluation method Coating thickness after drying the aqueous dispersion of the present invention on the corona-treated surface of a biaxially stretched PET film Was coated with a Mayer bar so that the thickness of the film became 1 μm, and then dried at 60 ° C. for 1 minute. The obtained coated film was allowed to stand at room temperature for 1 day, and then the appearance and adhesion (tape peeling test) of the coating film after the sample was immersed in warm water at 90 ° C. for 2 hours were evaluated. Regarding the adhesion after boiling, after drying the sample after boiling at 60 ° C. for 2 hours, the cellophane tape (TF-12 manufactured by Nichiban Co., Ltd.) is applied to the coated surface, and the degree of peeling when the tape is peeled off at once. Visually evaluated.
Appearance; ○: No change, X: Whitening of coating film or peel adhesion; ○: No peeling, Δ: Partially peeled, x: All peeled (9) Heat sealability evaluation method Various thermoplastic resins The aqueous dispersion of the present invention was dried on the corona-treated surface of the film at 60 ° C. for 1 minute so that the coating thickness after drying was 2 μm. The laminate film thus obtained was pressed at 120 ° C. with a heat press (sealing pressure of 0.3 MPa for 2 seconds) so that the coating film was in contact therewith. This sample is cut out at a width of 15 mm, and one day later, the peel strength of the coating film is measured at a tensile speed of 200 mm / min and a tensile angle of 180 degrees using a tensile tester (Intesco Precision Universal Material Tester 2020, manufactured by Intesco Corporation). The heat seal strength was evaluated.

Example 1
A three-neck separable flask equipped with a Dimroth cooler and a stirrer is 100 parts by weight of Bondine HX8290 (ethylene-acrylic acid ester-maleic anhydride terpolymer) manufactured by Sumitomo Chemical Co., Ltd. as polyolefin resin A-1 and 400 weight of tetrahydrofuran. Part was added and heated to reflux with stirring to dissolve the resin. Table 1 shows the physical properties of the polyolefin resin A-1.

  Next, 40 parts by weight of a 10% by weight tetrahydrofuran solution of BASONAT HW100 (water-dispersible polyisocyanate) manufactured by BASF as a compound B-1 (solid weight ratio is A-1 / B-1 = 100/4) is stirred. Then, stirring was continued for 2 hours to obtain a tetrahydrofuran solution of the resin composition containing the compound (C-1). The toluene insoluble content of the obtained resin composition was 50% by mass (the toluene insoluble content of the polyolefin resin (A-1) was 3% by mass or less).

Next, the heating was stopped, 2.4 times equivalent of triethylamine (hereinafter referred to as TEA) and 200 parts by weight of water were added to the carboxyl group of maleic anhydride in the resin before the reaction to prepare a suspension solution. Then, the solvent was distilled off using the evaporator and the aqueous dispersion (E-1) was obtained. Table 2 shows the results of various evaluations using this aqueous dispersion.

Example 2
An aqueous dispersion was obtained and evaluated in the same manner as in Example 1 except that the polyolefin resin A-1 and the compound B-1 were mixed so that the resin components had a mass ratio shown in Table 2.
Examples 3-6
An aqueous dispersion was obtained and evaluated in the same manner as in Example 1 except that the type of the compound (B) was changed as shown in Table 2.
Example 7
Hulls Japan Co., Ltd., Bestplast 708 (propylene-butene-ethylene terpolymer) 100 g and toluene 500 g were heated and melted under a nitrogen atmosphere in a four-necked flask equipped with a stirrer, condenser, and dropping funnel. Thereafter, a solution of 1.0 g of dicumyl peroxide as a radical generator in 20 g of heptane was added over 1 hour with stirring while maintaining the system temperature at 110 ° C., and then 7.0 g of maleic anhydride as an unsaturated carboxylic acid. A solution of 10.0 g of octyl acrylate and 10 g of heptane containing 0.5 g of dicumyl peroxide 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 polyolefin resin A-2. The weight average molecular weight in terms of styrene measured by GPC of A-2 was 50,000, the acid value was 48 mgKOH / g, and the content of octyl acrylate in the resin was 6.5% by mass. Table 1 shows the physical properties of A-2.

The obtained polyolefin resin A-2 and compound B-1 were mixed such that the resin components had a mass ratio shown in Table 2 to obtain an aqueous dispersion E-7. Evaluation was performed in the same manner as in Example 1 except that this aqueous dispersion was used.
Example 8
As the polyolefin resin A-3, Nucleel N1050H (ethylene-methacrylic acid copolymer) manufactured by Mitsui DuPont Chemical Co., Ltd. is used, and the resin component of the polyolefin resin A-3 and the compound B-1 has a mass ratio shown in Table 1. An aqueous dispersion E-8 was obtained in the same manner as in Example 1 except that the mixture was mixed as described above. The same evaluation as in Example 1 was performed except that this aqueous dispersion was used. The physical properties of A-3 are shown in Table 1, and the evaluation results of the obtained aqueous dispersion are shown in Table 2.

  Table 1 shows the physical properties of the polyolefin resin (A) used in Examples 1 to 8, and Table 2 shows the coating performance evaluation results of the prepared aqueous dispersions.

Comparative Example 1
In the preparation of the aqueous dispersion of Example 1, an aqueous dispersion H-1 was prepared using only A-1 without using the compound (B), and various evaluations were performed using this aqueous dispersion.
Comparative Example 2
In the preparation of the aqueous dispersion of Example 1, an aqueous dispersion H-1 was prepared using only A-1 without using the compound (B). Separately, BASONAT HW100 manufactured by BASF was dispersed in water so that the solid content was 1 wt%, and an aqueous dispersion H-2 mixed with H-1 at room temperature was prepared. Various evaluations were performed using this aqueous dispersion.
Comparative Example 3
An aqueous dispersion H-3 was prepared in the same manner as in Example 1 except that Denacol EX121 (2-ethylhexyl glycidyl ether) manufactured by Nagase ChemteX Corporation was used as the compound (B). Various evaluations were performed using this aqueous dispersion.

  Table 2 shows the coating performance evaluation results of the aqueous dispersions prepared in Comparative Examples 1 to 3.

  The aqueous dispersions of Examples 1 to 8 have an excellent pot life, and the coating film obtained from the aqueous dispersion is transparent even at low temperature drying, and is excellent in boil resistance, adhesion, and heat sealability. It was. When the content of the cross-linking agent used as the compound (B) was increased, the viscosity was slightly increased with time, but the heat sealability was improved.

On the other hand, since Comparative Example 1 did not contain a cross-linking agent having a functional group that reacts with a carboxyl group, the boil resistance was insufficient. Comparative Example 2 is a simple mixture of an aqueous dispersion of a polyolefin resin and a crosslinking agent having a functional group that reacts with a carboxyl group, and in the initial stage of preparation of the aqueous dispersion, adhesion and boil resistance are good. However, during storage for a long time, the crosslinking agent was deactivated and the boil resistance deteriorated. In Comparative Example 3, since the number of functional groups of Denacol EX121 used as the compound (B) was small, the boil resistance was insufficient.

Claims (5)

At least one of a polyolefin resin (A) having a carboxyl group or an anhydride group thereof and a compound (B) having at least two functional groups selected from an epoxy group, an oxazoline group, an isocyanate group, a carbodiimide group, and a silanol group. An aqueous dispersion containing a compound (C) having a toluene content of 5 to 85% by mass and a basic compound, and substantially free of non-volatile aqueous auxiliary agent. . The aqueous dispersion according to claim 1 , wherein the polyolefin resin (A) has an acid value of 5 to 200 mgKOH / g. The aqueous dispersion according to claim 1 or 2 , wherein the polyolefin resin (A) further contains a (meth) acrylic acid ester. A film formed by removing a solvent from the aqueous dispersion according to any one of claims 1 to 3 . A laminate having the coating according to claim 4 .