JP2012172099A - Aqueous dispersion of polyolefin resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an aqueous dispersion of a polyolefin resin, which has excellent dispersion stability and the excellent water resistance of a dry film.SOLUTION: The aqueous dispersion of a polyolefin resin includes a polyolefin resin (A) having a carboxyl group and water and does not contain any surfactant for dispersing the polyolefin resin (A). The acid value of the carboxyl group is preferably 5 to 300 and at least a part of the carboxyl group is preferably neutralized with at least one neutralizer selected from the group consisting of ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, and ethyldimethylamine.

Description

  The present invention relates to an aqueous polyolefin resin dispersion. More specifically, it is suitably used as a binder, primer, coating agent and adhesive for paints and inks used in various fields such as automobiles, electrical / electronic products, construction and packaging materials, and as a sizing agent for glass fibers. The present invention relates to an aqueous polyolefin resin dispersion.

Polyolefin resin aqueous dispersions are excellent in electrical properties, mechanical properties, chemical properties, recyclability, etc., so they are applied to adhesives, binders for paints and inks, primers, etc. in various fields such as automobiles and home appliances. It is expected that
For example, it is disclosed that an aqueous emulsion having a copolymer of ethylene, vinylcyclohexane and an unsaturated carboxylic acid as a dispersoid gives a film excellent in moldability, heat resistance, solvent resistance, mechanical properties and adhesion. (See Patent Document 1).
However, since the aqueous dispersion described in Patent Document 1 uses a surfactant for the purpose of improving the dispersion stability, there is a problem that the water resistance of the coating film decreases and the surfactant bleeds out from the coating film. was there.

JP 2005-320400 A

  The present invention has been made in view of the above problems, and an object of the present invention is to provide an aqueous polyolefin-based resin dispersion having excellent dispersion stability and water resistance of a dry film.

  The inventor of the present invention has arrived at the present invention as a result of intensive investigations to achieve the above object. That is, the present invention contains a polyolefin resin (A) having a carboxyl group and water, and does not contain a surfactant for dispersing the polyolefin resin (A). It is a dispersion.

  The aqueous polyolefin resin dispersion of the present invention is excellent in dispersion stability without using a surfactant to disperse the polyolefin resin, and excellent in water resistance of the dry film.

  The aqueous polyolefin resin dispersion of the present invention is obtained by dispersing a polyolefin resin (AP) having a carboxyl group and / or a carboxylic anhydride group in water by the method described below. When the polyolefin resin (AP) has a carboxylic acid anhydride group, the polyolefin resin (AP) is dispersed in water, whereby the carboxylic acid anhydride group is hydrolyzed to have a carboxyl group. It becomes.

  When the polyolefin resin (A) in the present invention has a carboxyl group, it has excellent dispersion stability without containing a surfactant for dispersing the polyolefin resin (AP), and is excellent in water resistance of the dry film. An aqueous dispersion can be obtained.

The polyolefin resin (AP) having a carboxyl group and / or a carboxylic anhydride group can be obtained, for example, by the following methods (1) to (3).
(1) A method of copolymerizing an olefin and an ethylenically unsaturated monomer (x) having a carboxyl group or an acid anhydride group.
(2) A method in which an ethylenically unsaturated monomer (x) having a carboxyl group or an acid anhydride group is graft-polymerized to an olefin (co) polymer in the presence of an organic peroxide or the like.
(3) A method of graft polymerizing an ethylenically unsaturated monomer (x) having a carboxyl group or an acid anhydride group in the presence of an organic peroxide or the like on a degradation product of an olefin (co) polymer.

  Examples of the olefin in the above methods (1) to (3) include aliphatic unsaturated hydrocarbons having 2 to 18 carbon atoms or more [for example, ethylene, propylene, (iso) butene, pentene, 4-methyl-1-pentene. , Alkenes such as heptene, diisobutylene, octene, dodecene and octadecene, and alkadienes such as butadiene, isoprene, 1,4-pentadiene, 1,6-hexadiene, 1,7-octadiene and 1,11-dodecadiene]; 18 or more cycloaliphatic unsaturated hydrocarbons [eg cyclohexene, (di) cyclopentadiene, pinene, limonene, indene, vinylcyclohexene and ethylidenebicycloheptene]; aromatic unsaturated hydrocarbons having 8 to 20 carbon atoms [For example, α-methylstyrene, 2,4-dimethylstyrene, Styrene, isopropyl styrene, butyl styrene, phenyl styrene, cyclohexyl styrene, benzyl styrene, vinyl toluene, crotyl benzene, vinyl naphthalene and polyvinyl unsaturated hydrocarbons (divinyl benzene, divinyl toluene, divinyl xylene, trivinyl benzene, etc.) etc.]; Etc.

Examples of the ethylenically unsaturated monomer (x) having a carboxyl group or an acid anhydride group include unsaturated carboxylic acids having 3 to 10 carbon atoms (for example, acrylic acid, methacrylic acid, maleic acid, fumaric acid, itaconic acid, citraconic acid and Cyclohexene dicarboxylic acid) and unsaturated carboxylic anhydrides having 4 to 10 carbon atoms (for example, maleic anhydride, itaconic anhydride, citraconic anhydride, cyclohexenedicarboxylic anhydride and aconitic acid).
Of these (x), unsaturated dicarboxylic acid anhydrides, more preferably maleic anhydride.

  As the olefin (co) polymer in the above method (2) or (3), the above olefin is prepared by a conventional method (for example, as described in JP-A-59-206409, JP-A-55-135102, etc.). Homopolymerized or copolymerized by the method).

  Examples of the organic peroxide in the above method (2) or (3) include benzoyl peroxide, di-t-butyl peroxide, lauroyl peroxide, dicumyl peroxide, 2,2-bis (4,4- Di-t-butylperoxycyclohexyl) propane, 1,1-bis (t-butylperoxy) 3,3,5-trimethylcyclohexane, di-t-butylperoxyhexahydroterephthalate, diallyl peroxydicarbonate and t -Butyl peroxyallyl carbonate is mentioned.

  As the degradation product of the olefin (co) polymer in the method of (3) above, the olefin homopolymerized or copolymerized by a usual method is thermally, chemically or mechanically degraded. Examples of the degradation products obtained include thermal degradation, because many double bonds are generated at the end or inside of the polyolefin resin, and graft polymerization due to (x) is likely to occur. The degradation product obtained in this way is particularly preferred.

  The number average molecular weight (hereinafter abbreviated as Mn) of the above olefin homopolymerized or copolymerized by a conventional method used in the degradation method is 1,000 from the viewpoint of ease of graft polymerization by (x). ˜500,000, more preferably 1,500 to 300,000, particularly preferably 2,000 to 100,000. The number average molecular weight in the present invention is measured by gel permeation chromatography at 135 ° C. using o-dichlorobenzene as a solvent and based on standard polystyrene.

  The number of double bonds per 1,000 carbons in the degradation product of the olefin (co) polymer is preferably 0.2 to 10, more preferably, from the viewpoint of ease of graft polymerization by (x). Is 0.3 to 6, particularly preferably 0.5 to 5. Further, the number of double bonds can be calculated from a peak derived from a double bond between 4.5 and 6.0 ppm in a spectrum obtained by 1H-NMR (nuclear magnetic resonance).

  In the thermal degradation method, the above-mentioned olefin homopolymerized or copolymerized by a conventional method is continuously introduced for 0.5 to 10 hours at 300 to 450 ° C. in the absence of an organic peroxide under nitrogen flow. And a method of continuously heat degrading at 180 to 300 ° C. for 0.5 to 10 hours in the presence of an organic peroxide. Among these, the former method is preferable because the amount of double bonds in the degradation product is large and graft polymerization by (x) is likely to occur.

  The Mn of the thermally degraded product is preferably 500 to 40,000, more preferably 800 to 30,000, particularly preferably 1,000 to 20,000, from the viewpoint of ease of graft polymerization by (x). is there.

  In the above methods (1) to (3), the bonding form of the olefin copolymer moiety may be random or block, or a combination thereof. In addition, when (co) polymerizing olefins, alkyl (meth) acrylate (1 to 30 carbon atoms) ester or vinyl acetate may be used in combination as monomers.

  A polyolefin-based resin (AP) having a carboxyl group and / or a carboxylic acid anhydride group from the degradation product of an olefin (co) polymer or an olefin (co) polymer by the method of (2) or (3) above. As a specific production method, for example, an olefin (co) polymer or a degradation product of an olefin (co) polymer and an ethylenically unsaturated monomer (x) having a carboxyl group or an acid anhydride group are used. Heat melting, or organic solvent (s) [C3-18, eg hydrocarbons (eg hexane, toluene and xylene), halogenated hydrocarbons (eg di, tri or tetrachloroethane and dichlorobutane), ketones (eg acetone and Methyl ethyl ketone) and ether (eg ethyl-n-propyl ether, diisopropyl ether and dioxane)] If necessary, a solution in which the radical initiator (d) or (d) is dissolved in the organic solvent (s), a chain transfer agent (t), and a polymerization inhibitor (u) are added and stirred as necessary. Examples thereof include a melting method, a suspension method, and a solution method, and a melting method and a solution method are preferable.

  The reaction temperature in the melting method may be a temperature at which the degradation product of the olefin (co) polymer or olefin (co) polymer is melted, and the olefin (co) polymer or olefin (co) heavy weight. From the viewpoint of the reactivity between the degradation product of the coalescence and (x) and the decomposition temperature of the obtained (AP), it is preferably 120 to 260 ° C, more preferably 130 to 240 ° C.

  The reaction temperature in the solution method may be a temperature at which the olefin (co) polymer or the degradation product of the olefin (co) polymer is dissolved in the solvent, and the olefin (co) polymer or olefin (copolymer). ) From the viewpoint of the reactivity between the polymer degradation product and (x) and the decomposition temperature of the obtained (AP), it is preferably 50 to 220 ° C, more preferably 110 to 210 ° C, particularly preferably 120 to 180 ° C. It is.

  Examples of the chain transfer agent (t) include hydrocarbons [having 6 to 24 carbon atoms, such as aromatic hydrocarbons (for example, toluene, xylene, ethylbenzene and isopropylbenzene) and unsaturated aliphatic hydrocarbons (for example, 1- or 2-butene). , 1- or 2-hexene, 1-dodecene and 1-tetradecene)]; halogenated hydrocarbons (C1-C24, such as dichloromethane, chloroform, carbon tetrachloride and benzyl chloride); alcohols (C1-C24, For example, methanol, ethanol, 1-propanol and allyl alcohol); thiols (C1-C24 such as methyl riol, ethyl thiol, propyl thiol and 1-dodecyl thiol); ketones (C3-C24 such as acetone, methyl ethyl ketone and Ethyl butyl ketone); aldehyde (carbon) 2-18, such as 2-methyl-2-propylaldehyde and 1-octylaldehyde); phenol (6-36 carbons, such as phenol, m-, p- or o-cresol); quinone (6-24 carbons, For example hydroquinone); amines (3-24 carbons such as diethylmethylamine, triethylamine and diphenylamine); and disulfides (2-24 carbons such as diethyl disulfide, di-1-propyl disulfide and di-1-octyl disulfide). Can be mentioned. Of these, hydrocarbons and halogenated hydrocarbons are preferable from the viewpoint of compatibility with olefin (co) polymers or olefin (co) polymer degradation products, and hydrocarbons are more preferable. Preference is given to unsaturated aliphatic hydrocarbons. The amount of (t) used is usually 40% by weight or less based on the weight of (x), the reactivity of (x) with an olefin (co) polymer or an olefin (co) polymer degradation product and From the viewpoint of compatibility with an olefin (co) polymer or a degradation product of an olefin (co) polymer, the amount is preferably 0.05 to 20% by weight.

  As the polymerization inhibitor (u), inorganic compounds [for example, oxygen, sulfur and metal salts (for example, ferric chloride)] and organic compounds [catechol (having 6 to 36 carbon atoms, for example, 2-methyl-2-propylcatechol), Quinones (6 to 24 carbon atoms such as p-benzoquinone and duroquinone), hydrazine (2 to 36 carbon atoms such as 1,1-diphenyl-2-picrylhydrazine), ferrazine (5 to 36 carbon atoms such as 1,3 carbon atoms) , 5-triphenylferdazine), nitro compounds (3 to 24 carbon atoms such as nitrobenzene) and stable radicals {5 to 36 carbon atoms such as 1,1-diphenyl-2-picrylhydrazyl (DPPH), 2, 2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) and 1,3,5-triphenylferdazyl}]The amount of (u) used is usually 5% by weight or less based on the weight of (x), the reactivity between (x) and the olefin (co) polymer or olefin (co) polymer degradation product and From the viewpoint of the compatibility between the olefin (co) polymer or the degradation product of the olefin (co) polymer and (x), the content is preferably 0.01 to 0.5% by weight.

  As for the usage-amount of the ethylenically unsaturated monomer (x) which has a carboxyl group or an acid anhydride group, 3 to 20 weight% is preferable with respect to the weight of polyolefin resin (AP).

  Among the methods (1) to (3), the method (3) is preferable from the viewpoint of ease of graft polymerization by (x).

  The content of carboxyl groups and carboxylic anhydride groups in the polyolefin resin (AP) can be quantified by measuring the acid value of the resin. From the viewpoint of dispersibility, the acid value of the polyolefin resin (AP) is preferably 5 to 300, more preferably 10 to 280, and particularly preferably 20 to 260.

  Mn of the polyolefin resin (AP) in the present invention is preferably 1,000 to 2,000,000 or more, more preferably 1,500 to 500,000, particularly preferably 2,000 to 100,000. is there.

  The apparatus for producing the polyolefin resin (AP) is not particularly limited as long as it can be stirred or kneaded, and a Kolben, a simple pressure reactor (autoclave), a uniaxial or biaxial kneader, or the like can be used. However, a uniaxial or biaxial kneader is preferred from the viewpoints of kneading strength, hermeticity, and heating ability. Examples of the uniaxial or biaxial kneader include a kneader ["KRC Kneader" manufactured by Kurimoto Seiko Co., Ltd.], a uniaxial kneader and a twin screw extruder ["PCM-30" manufactured by Ikegai Co., Ltd.], and the like. It is done.

  In the production of the polyolefin resin (AP), additives such as a catalyst, an antioxidant, an anti-coloring agent, a retarder and a plasticizer can be used in combination.

  The aqueous polyolefin resin dispersion of the present invention comprises the polyolefin resin (A), water, and, if necessary, the organic solvent (s) and other additives as constituent components. By dispersing the polyolefin resin (AP) in water, the polyolefin resin (A) is obtained. When (AP) has a carboxylic acid anhydride group, the carboxylic acid anhydride group becomes a carboxyl group by hydrolysis.

  The content of the carboxyl group of the polyolefin resin (A) in the aqueous polyolefin resin dispersion can be quantified by measuring the acid value of the resin. The acid value of (A) is preferably 5 to 300, more preferably 10 to 280, and particularly preferably 20 to 260 from the viewpoint of dispersibility.

  Mn of the polyolefin resin (A) in the present invention is preferably 1,000 to 2,000,000 or more, more preferably 1,500 to 500,000, particularly preferably 2,000 to 100,000. is there.

  The volume average particle diameter of the polyolefin resin (A) in the aqueous polyolefin resin dispersion of the present invention is preferably from 0.01 to 5 μm, more preferably from the viewpoint of improving dispersion stability. ˜4 μm, particularly preferably 0.02 to 2 μm, most preferably 0.03 to 0.8 μm. The volume average particle diameter can be controlled by the amount of the carboxyl group (A), the amount of the organic solvent (s) used if necessary, and the like.

  The volume average particle size in the present invention is determined using a laser diffraction particle size distribution measuring device [for example, LA-750 (manufactured by Horiba Seisakusho)] or a light scattering particle size distribution measuring device [for example, ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.)]. Can be measured.

  By neutralizing the carboxyl group of the polyolefin resin (A) in the aqueous polyolefin resin dispersion with a neutralizing agent, the dispersion stability of the resin particles is further improved.

Examples of the neutralizing agent include ammonia, amine compounds having 1 to 10 carbon atoms, and alkali metal (sodium, potassium, lithium, and the like) hydroxides.
Examples of the amine compound having 1 to 10 carbon atoms include primary amines such as monomethylamine, monoethylamine, monobutylamine and monoethanolamine, secondary amines such as dimethylamine, diethylamine, dibutylamine and diethanolamine, and trimethylamine, triethylamine and dimethylethylamine. And tertiary amines such as triethanolamine.

  As the neutralizing agent for the carboxyl group, a compound having a high vapor pressure at 25 ° C. is preferable from the viewpoint of the drying property of the aqueous dispersion of the polyolefin resin (A) to be produced and the water resistance after drying. From such a viewpoint, ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine and ethyldimethylamine are preferable, and ammonia, monoethylamine, dimethylamine and diethylamine are more preferable, and ammonia is particularly preferable. .

  The use amount of the neutralizing agent is preferably 0.1 to 3 equivalents with respect to 1 equivalent of the carboxyl group in the polyolefin resin (A) from the viewpoint of dispersion stability of the aqueous polyolefin resin dispersion, Preferably it is 0.5-1 equivalent.

  By using the organic solvent (s) when the polyolefin resin (A) is dispersed in water, the dispersibility of the polyolefin resin (A) can be further improved.

  When the organic solvent (s) is used, the amount used is usually 50% by weight or less, preferably 20% by weight or less. In addition, when the organic solvent (s) is used, including the production of the above-mentioned polyolefin resin (AP), this is preferably 1000 ppm or less, more preferably after production of the aqueous polyolefin dispersion from the viewpoint of environmental pollution. Is preferably distilled off to 500 ppm or less, particularly preferably 100 ppm or less, most preferably without using the organic solvent (s) and substantially free of the organic solvent.

  Examples of other additives include pH adjusters, foam breakers, foam suppressors, defoamers, antioxidants, anti-coloring agents, plasticizers and mold release agents.

  The solid content concentration of the aqueous polyolefin resin dispersion of the present invention is preferably 10 to 65% by weight, more preferably 20 to 55% by weight, from the viewpoint of dispersion stability and transportation cost.

The aqueous polyolefin resin dispersion of the present invention can be produced by neutralizing the polyolefin resin (A) with a neutralizing agent as necessary and dispersing it in water. Specifically, a method of dispersing in water at a temperature lower than the melting temperature of the polyolefin-based resin (A) using a rotary dispersion mixing apparatus as the dispersion mixing apparatus can be mentioned. By using the above method, it is possible to obtain an aqueous polyolefin resin dispersion having further excellent dispersion stability without using a surfactant for dispersing the polyolefin resin.
In the production, the organic solvent (s), which is an optional component, and other additives are used in combination as necessary.

  When using a neutralizing agent, it may be added before the water dispersion step, during the water dispersion step or after the water dispersion, but from the viewpoint of dispersion stability of the polyolefin resin (A), the water dispersion It is preferable to add it before the process or during the water dispersion process.

  In the case of using the above method, the shape of the polyolefin resin (AP) is preferably 0.2 to 50 mm in the form of granules or blocks from the viewpoint of easy supply to the rotary dispersion mixing apparatus, and the size is more preferable. Is 0.5 to 30 mm, particularly preferably 1 to 10 mm.

  As means for adjusting the polyolefin resin (AP) into particles, means such as cutting, pelletizing, granulating or pulverizing can be used. This adjustment to the particulate form can be carried out in water or in the absence of water. For example, there is a method in which a polyolefin resin (AP) rolled into a sheet is formed into particles with a square pellet machine (manufactured by Horai Co., Ltd.).

  The polyolefin-based resin (AP) adjusted into particles is introduced into a rotary dispersion mixing apparatus together with water and the like. The main dispersion principle of this apparatus is to apply shearing force to the particles from the outside by rotation of the drive unit or the like. The principle is to pulverize and disperse. The apparatus can be operated at normal pressure or under pressure.

  Examples of the rotary dispersion mixing apparatus include TK homomixer [manufactured by Primics Co., Ltd.], Claremix [manufactured by Mtechnics Co., Ltd.], Philmix [manufactured by Primix Co., Ltd.], Ultra Turrax [manufactured by IKA Corporation] ], Ebara Milder [manufactured by Ebara Manufacturing Co., Ltd.], Cavitron (manufactured by Eurotech) and biomixer [manufactured by Nippon Seiki Co., Ltd.], and these two or more types of apparatuses may be used in combination. .

  The temperature of the dispersion when the polyolefin resin (AP) is dispersed and mixed using a rotary dispersion mixer is selected from the viewpoint of preventing decomposition and deterioration of the polyolefin resin (AP) as a dispersion. Dispersion efficiency and decomposition are less than the melting temperature of the resin (AP), preferably 5 ° C. or more lower than the melting temperature and room temperature or higher, more preferably 10 to 120 ° C. lower than the melting temperature. -It is preferable from the viewpoint of suppressing deterioration.

  The residence time of the polyolefin resin (AP) and water in the rotary dispersion mixing apparatus is preferably from 0.1 to 60 minutes, more preferably from 10 to 30 minutes, from the viewpoint of suppressing decomposition and deterioration.

  EXAMPLES Hereinafter, although an Example demonstrates this invention concretely, this invention is not limited to these. Hereinafter, the part means part by weight.

<Example 1>
100 parts of polyolefin (Mn = 70,000) having propylene 80 mol% and 1-butene 20 mol% as structural units are introduced into a KRC kneader of a twin-screw kneader in a nitrogen atmosphere, and nitrogen is passed through the gas phase portion. The mixture was melted by heating and kneaded at 360 ° C. for 5 minutes to obtain a thermally degraded product. The number of double bonds per 1,000 carbon atoms of this thermally degraded product was 2, and Mn was 1,1000. In a separate reaction vessel, 55 parts of the above thermal degradation product, 45 parts of maleic anhydride and 100 parts of xylene were charged. After purging with nitrogen, the mixture was heated to 130 ° C. under nitrogen flow and dissolved uniformly. A solution prepared by dissolving 0.5 part of dicumyl peroxide in 10 parts of xylene was added dropwise thereto, and then the temperature was raised to xylene reflux temperature and stirring was continued for 3 hours. Thereafter, xylene and unreacted maleic anhydride are distilled off under reduced pressure (1.5 kPa) to have 18 acid anhydride groups per molecule and acid anhydride modified polyolefin having Mn of 12,500. Got. 100 parts of this acid anhydride-modified polyolefin resin is rolled with a pressure press heated to 300 ° C., cut with a square pelletizer [manufactured by Horai Co., Ltd.], and then placed in a pressure-controllable container with temperature control in ion-exchanged water 221. And an aqueous dispersion of polyolefin of the present invention were obtained by carrying out a dispersion treatment at 180 ° C. for 40 minutes using a TK homomixer [manufactured by Primix Co., Ltd.].

<Comparative Example 1>

100 parts of propylene-butene-ethylene terpolymer (“Best Plast 708” manufactured by Huls Japan Co., Ltd .: propylene / butene / ethylene weight ratio = 64.8: 23.9: 11.3) in 200 parts of toluene The dissolved solution and a solution obtained by dissolving 5 g of sodium polyoxyethylene lauryl ether sulfate in 420 g of ion-exchanged water were mixed and stirred for 10 minutes at a rotational speed of 12000 rpm using a homomixer to obtain an aqueous dispersion. After heating this aqueous dispersion to 60 ° C., toluene was distilled off under reduced pressure to obtain a comparative polyolefin resin aqueous dispersion.

  Table 1 shows the results of measuring the acid values of the polyolefin resins obtained in Example 1 and Comparative Example 1 by the following method. Table 1 shows the results of measuring or evaluating the solid content concentration, volume average particle diameter, and water resistance of the polyolefin resin film in the aqueous dispersions obtained in Example 1 and Comparative Example 1 by the following methods. Shown in

<Resin acid value>
The method for measuring the acid value (mgKOH / g) of the polyolefin resin in the present invention is as follows.
(1) Xylene is added to a polyolefin-based resin, heated and dissolved, and then titrated with an N / 10 potassium hydroxide methanol solution.
(2) The acid value is determined using the following formula.
Acid value (mgKOH / g) = (A × f × 5.61) / S
However, A is the mL number of the 0.1 mol / L potassium hydroxide titration solution, f is the titer of the 0.1 mol / L potassium hydroxide titration solution, and S is the sampled amount (g).

<Concentration of solid content>
About 1 g of an aqueous polyolefin resin dispersion was thinly spread on a Petri dish and weighed accurately. Then, the weight after heating at 130 ° C. for 45 minutes using a circulating constant temperature dryer was precisely weighed, and the weight before heating was measured. It can be obtained by calculating the ratio (percentage) of the remaining weight after heating.

<Volume average particle diameter>
After diluting the polyolefin resin aqueous dispersion with ion-exchanged water so that the solid content of the polyolefin resin becomes 0.01% by weight, a light scattering particle size distribution analyzer [ELS-8000 (manufactured by Otsuka Electronics Co., Ltd.)] Use to measure.

<Water resistance of film>
Pour an amount of polyolefin resin aqueous dispersion into a 10 cm x 20 cm x 1 cm polypropylene mold so that the film thickness after drying is 0.2 ± 0.1 mm, dry at room temperature for 12 hours, and further dry at 120 ° C for 2 hours Then, the obtained film was immersed in ion-exchanged water for 24 hours, and then the state of the taken-out film was visually evaluated. If there is no change at all, ◯, and if whitening is observed, X.

  The aqueous polyolefin-based resin dispersion of the present invention can provide a coating with excellent water resistance, so it can be used for paints and inks used in various fields such as automobiles, electrical / electronic products, construction and packaging materials. It can be suitably used as a binder, primer, coating agent and adhesive, and as a sizing agent for glass fibers.

Claims (6)

  A polyolefin resin aqueous dispersion comprising a polyolefin resin (A) having a carboxyl group and water, and containing no surfactant for dispersing the polyolefin resin (A).   The aqueous polyolefin resin dispersion according to claim 1, wherein the polyolefin resin (A) has an acid value of 5 to 300.   The aqueous polyolefin-based resin dispersion according to claim 1 or 2, wherein at least a part of the carboxyl group is neutralized with a neutralizing agent.   The polyolefin resin aqueous solution according to claim 3, wherein the neutralizing agent is at least one neutralizing agent selected from the group consisting of ammonia, monomethylamine, monoethylamine, dimethylamine, diethylamine, trimethylamine, triethylamine, and ethyldimethylamine. Dispersion.   Content of organic solvent is 1000 ppm or less, The polyolefin resin aqueous dispersion in any one of Claims 1-4.   The polyolefin resin aqueous dispersion according to any one of claims 1 to 5, wherein the polyolefin resin (A) has a volume average particle diameter of 0.01 to 5 µm.