Aqueous dispersion composition

Abstract

The present invention relates to an aqueous dispersion composition characterized by being aqueous and exhibiting high peel strength at low temperature (80 to 90°C) baking, high adhesion, and good water resistance to a difficultly adhering polyolefin base material, having a weight average molecular weight of 60,000 or more as measured using GPC, and being an aqueous dispersion composition containing a modified polyolefin (A) having a modification amount of less than 1.0 mass% modified with an α,β-unsaturated carboxylic acid and / or an acid anhydride thereof, a nitrogen-containing nonionic emulsifier (B), and an alkaline substance (C), the aqueous dispersion composition having a Z average particle diameter of 200 nm or less.

Description

TECHNICAL FIELD

[0001] The present application relates to an aqueous dispersion composition suitable for coating agents, primers, paints, inks, adhesives, and the like, which contains a polyolefin resin, a nitrogen-containing nonionic emulsifier, and a basic substance. BACKGROUND

[0002] Polyolefin-based resins such as polypropylene are used in large amounts for automobile parts, various films, various molded articles, and the like, because they are inexpensive and have excellent properties. However, since polyolefin-based resins are nonpolar, there are problems in that coating and adhesion are difficult. Therefore, in order to coat, print, or adhere polyolefin-based resins, modified polyolefins such as acid-modified polyolefins, acid-modified chlorinated polyolefins, and the like are being developed.

[0003] In addition, due to the rise of global environmental protection activities, measures to reduce CO2, which is a cause of global warming, by reducing VOCs in paints or reducing energy consumption in baking ovens are being actively taken in the entire paint industry, and the use of water-based or low-VOC paints for each layer is also increasing in automobile painting production lines.

[0004] Compared with water-based paints, solvent-based paints can be expected to have improved adhesion and good adhesion due to the penetration and diffusion effects of the solvent into the substrate or the swelling effect of the solvent on the substrate. In contrast, in water-based paints, the above effects cannot be expected, and there is a problem of reduced adhesion.

[0005] On the other hand, in recent years, due to changes in the composition of bumper substrates for the purpose of reducing material costs and thinning, bumper substrates that are more difficult to adhere paint to the substrate have appeared, and further improvement in the adhesion of water-based paints to difficult-to-adhere materials is required.

[0006] In addition, as a measure to reduce the amount of energy consumption, low-temperature baking of automobile painting production lines is also being studied, and from the viewpoint of adhesion, there is a problem of improving adhesion in low-temperature baking in water-based painting production lines.

[0007]

Prior Art Documents

[0008]

Patent Documents

[0009]

Patent Document 1

[0010]

Patent Document 2

[0011]

Problems to be Solved by the Invention

[0012] Patent Literature 1 discloses a film formation method characterized by coating an aqueous modified polyolefin resin composition on a substrate, and baking the dried film at 80 to 90°C, wherein the aqueous modified polyolefin resin composition has a melting point in a range of 19°C or more and 26°C or less lower than the drying temperature. However, there is a problem of insufficient adhesion strength. Further, Patent Literature 2 discloses an aqueous dispersion containing a high molecular weight polyolefin and a surfactant, but there is a problem of insufficient adhesion in low-temperature baking.

[0013] The present application has been made in view of the above, and provides an aqueous dispersion composition which is aqueous and exhibits high peel strength, high adhesion, and good water resistance in low-temperature (80 to 90°C) baking to a difficultly adhering polyolefin substrate.

[0014] <Means for solving the problems>

[0015] The present inventors have conducted intensive studies, and as a result, have found that an aqueous dispersion composition containing a specific modified polyolefin (A), a nonionic emulsifier containing nitrogen (B), and an alkaline substance (C), and having a Z-average particle diameter of the modified polyolefin (A) of 200 nm or less can solve the above problems, and have completed the present application.

[0016] That is, the gist of the present application is as described below.

[0017] That is, the present application is an aqueous dispersion composition characterized by containing a modified polyolefin (A) having a weight average molecular weight of 60,000 or more as measured by GPC and a modification amount of less than 1.0 mass%, a nonionic emulsifier containing nitrogen (B), and an alkaline substance (C), and having a Z-average particle diameter of the modified polyolefin (A) of 200 nm or less.

[0018] The melting point of the above modified polyolefin (A) is preferably 60°C to 85°C, and the modified polyolefin (A) is preferably free of chlorine.

[0019] The above nonionic emulsifier containing nitrogen (B) is preferably added in an amount of 10 to 45 parts by mass per 100 parts by mass of the modified polyolefin resin (A).

[0020] When the above water-soluble polymer containing an anionic group (D) is contained, the acid value of the water-soluble polymer containing an anionic group (D) is preferably 100 mg to 500 mg KOH / g-resin, and the content of the water-soluble polymer containing an anionic group (D) is preferably 0 to 2 parts by mass per 100 parts by mass of the above modified polyolefin (A).

[0021] The above acid-modified polyolefin (A) is preferably a propylene-α-olefin copolymer having a butene content of 2 to 35 mass% in the polyolefin component.

[0022] An adhesive and a coating containing the aqueous dispersion described in any one of the above. A coating film which is a coating film obtained by removing the aqueous medium from the aqueous dispersion described in any one of the above.

[0023] A laminate having a layer derived from the coating or adhesive described above.

[0024]

Effects of Invention

[0025] The aqueous dispersion composition according to the present application, when used as a primer for a polypropylene base material, is aqueous and can provide a coating film having high peel strength, high adhesion, and water resistance to a difficultly adhering polyolefin base material in low-temperature (80 to 90°C) baking, and can be suitably used for a coating or an adhesive, and is particularly suitable for use as a coating for automobiles. DETAILED DESCRIPTION

[0026] The following describes embodiments of the present application in detail.

[0027] <Modified polyolefin (A)>

[0028] The modified polyolefin (A) used in the present application is a polyolefin obtained by acid-modifying a propylene-α-olefin copolymer.

[0029] As the acid component of the acid-modified polyolefin used in the present application, α,β-unsaturated carboxylic acids and / or acid anhydrides thereof can be cited. At least one of α,β-unsaturated carboxylic acids and acid anhydrides thereof is preferably grafted to a propylene-α-olefin copolymer.

[0030] The propylene-α-olefin copolymer is a copolymer containing propylene and α-olefin as copolymerization components, and a propylene-1-butene copolymer, or a copolymer in which propylene-1-butene is the main component and α-olefin is copolymerized, is preferable. As the α-olefin other than propylene and butene, one or a plurality of kinds of ethylene, isobutene, 1-pentene, 3-methyl-1-pentene, 1-hexene, 1-heptene, 1-octene, 4-methyl-1-pentene, vinyl acetate, and the like can be used. Of these α-olefins, ethylene is preferable.

[0031] The propylene-α-olefin copolymer preferably has a propylene component of 50% by mass or more, more preferably 60% by mass or more, and particularly preferably 65% by mass or more. By being within the above range, adhesion (adhesiveness) to polyolefin base materials typified by propylene base materials is good. Furthermore, the 1-butene component is preferably 2 to 35% by mass in the olefin component. More preferably, it is 3 to 33% by mass, and particularly preferably 5 to 31% by mass. By being within this range, a resin suitable for a coating film forming process dried at 80°C to 90°C can be formed.

[0032] As the at least one of α,β-unsaturated carboxylic acid and acid anhydride, for example, maleic acid, itaconic acid, citraconic acid, and acid anhydrides thereof can be exemplified. Among them, acid anhydrides are preferred, and maleic anhydride is more preferred. Specifically, maleic anhydride-modified propylene-butene copolymer, maleic anhydride-modified propylene-ethylene-butene copolymer, and the like can be exemplified, and these acid-modified polyolefins can be used alone or in combination of two or more.

[0033] As the method for producing the acid-modified polyolefin, there is no particular limitation, and for example, a radical grafting reaction (i.e., a reaction in which a radical species is produced in a polymer constituting a main chain, which radical species serves as a polymerization starting point, and an unsaturated carboxylic acid and an acid anhydride are subjected to graft polymerization) and the like can be exemplified.

[0034] As the radical initiator, there is no particular limitation, and organic peroxides, azonitriles can be exemplified, and the use of organic peroxides is preferred. As the organic peroxides, there is no particular limitation, and di-t-butyl perphthalate, t-butyl hydroperoxide, dicumyl peroxide, benzoyl peroxide, t-butyl peroxybenzoate, t-butyl peroxy-2-ethylhexanoate, t-butyl peroxyneopentanoate, methyl ethyl ketone peroxide, di-t-butyl peroxide, lauryl peroxide, and the like can be exemplified, and as the azonitriles, azobis isobutyronitrile, azobis isopropyl nitrile, and the like can be exemplified.

[0035] The acid-modification amount of the acid-modified polyolefin is preferably 0.1% by mass or more, and particularly preferably 0.3% by mass or more. Further, it is less than 1.0% by mass, preferably 0.9% by mass or less, and particularly preferably 0.8% by mass or less. By being 0.1% by mass or more, dispersibility in water easily becomes good, and by being less than 1.0% by mass, the peeling strength of the coating film with respect to the polyolefin base material and the water resistance are particularly improved.

[0036] The weight average molecular weight (Mw) of the modified polyolefin (A) is 60,000 or more, preferably 70,000 or more, and particularly preferably 80,000 or more. By being 60,000 or more, the cohesive force becomes strong, and the adhesion and the water resistance become good. Further, there is no particular limitation on the upper limit, but it is desirable to be 150,000 or less. The solubility becomes good, and the production of the aqueous dispersion composition tends to become easy. The weight average molecular weight in the present application refers to a value measured by GPC (gel permeation chromatography). As for the specific measurement conditions, they are described in the Examples described below.

[0037] The modified polyolefin (A) is preferably crystalline. By being crystalline, the cohesive force is strong compared to amorphous, and the adhesion, the water resistance, the heat resistance, and the chemical resistance are excellent, and thus it is advantageous.

[0038] The crystallinity in the present application means a substance showing a clear melting peak in a temperature rising process from -100°C to 250°C at 10°C / min using a differential scanning calorimeter (hereinafter, also referred to as DSC. Q-2000 manufactured by TA Instruments Japan). The melting point and the melting heat are measured based on the peak temperature and the area of the melting peak when the resin is melted at 10°C / min, cooled to solidify, and then melted again.

[0039] As for the melting point (Tm) of the modified polyolefin (A), it is desirable that the melting point of the modified polyolefin resin (A) is lower than the drying temperature by 20 to 5°C during the film formation process of drying at 80 to 90°C, and the melting point is preferably 60°C or higher. More preferably, it is 63°C or higher, and particularly preferably, it is 65°C or higher. Further, it is preferably 85°C or lower, more preferably 83°C or lower, and particularly preferably 80°C or lower. When it is 60°C or higher, the cohesion from the crystal becomes strong, and the peeling strength, the adhesion, the water resistance, the heat resistance, and the chemical resistance become more favorable. On the other hand, when it is 85°C or lower, the solubility is favorable, and it becomes easy to form an aqueous dispersion composition.

[0040] <Nonionic nitrogen-containing emulsifier (B)>

[0041] The emulsifier (B) contained in the aqueous dispersion of the present application is a nonionic nitrogen-containing emulsifier. By using this component, the water resistance of the coating film becomes favorable. As the nonionic nitrogen-containing surfactant, polyoxyethylene lauryl amine, polyoxyethylene stearyl amine, polyoxyethylene coco amine, polyoxyethylene tallow amine, and the like of the polyoxyalkyl alkyl amine type, polyoxyethylene polyoxypropylene monoamine and the like of the polyoxyalkyl amine type, polyoxyethylene oleoyl amide, polyoxyethylene coco fatty amide, polyoxyethylene lauryl amide, polyoxyethylene stearyl amide, polyoxyethylene tallow amide, polyoxyethylene coco fatty acid monoethanolamide, polyoxyethylene lauryl monoethanolamide, and the like of the polyoxyalkyl alkyl amide type, and the like can be exemplified. Among these nonionic nitrogen-containing emulsifiers, polyoxyethylene lauryl amine and polyoxyethylene coco amine are preferred because the bleeding is less and the peeling strength becomes favorable.

[0042] The nonionic nitrogen-containing emulsifier (B) is preferably in the range of 10 to 30, more preferably in the range of 12 to 25, in terms of the number of carbon atoms of the alkyl chain. By being 10 or more and 30 or less, the hydrophobic interaction becomes favorable, the stability with the olefin particles is improved, the water resistance is improved, and the peeling strength is improved.

[0043] The nonionic nitrogen-containing emulsifier (B) is preferably in the range of 8 to 30 in terms of the number of moles of ethylene oxide (EO) (the number of ethylene oxide units per 1 molecule). More preferably, it is in the range of 9 to 25, and particularly preferably, it is in the range of 10 to 20. By being in the range of 8 to 30, the water dispersibility at the time of emulsification becomes stable.

[0044] The nitrogen-containing nonionic emulsifier (B) is preferably 10 parts by mass or more, more preferably 13 parts by mass or more, further preferably 20 parts by mass or more, and particularly preferably 25 parts by mass or more, relative to 100 parts by mass of the modified polyolefin resin (A). In addition, it is preferably 45 parts by mass or less, further preferably 42 parts by mass or less, and particularly preferably 40 parts by mass or less. By being 15 parts by mass or more, the emulsifiability is improved, the particle size is reduced, and the film-forming property is improved, so the peel strength tends to be improved, and the water resistance of the coating film is easily made good at 45 parts by mass or less.

[0045] The compounding method of the nitrogen-containing nonionic emulsifier (B) is not particularly limited, and for example, it can be compounded without dilution in water or the like, or it can be compounded in the form of a 1 to 50 mass% aqueous solution. In order to be rapidly mixed in the aqueous dispersion composition, it is preferably compounded in the form of a 1 to 50 mass% aqueous solution. By compounding the emulsifier in the form of an aqueous solution in the aqueous dispersion composition, the emulsifier rapidly adsorbs to the particles, and the particle size can be reduced.

[0046] <Basic substance (C)>

[0047] The basic substance (C) used in the present application can neutralize the acidic group (carboxyl group) of the modified polyolefin (A) and improve the dispersibility of the modified polyolefin (A).

[0048] The basic substance (C) is not particularly limited, but a volatile basic substance is preferred, and among them, ammonia and amines are preferred. As the amines, there are no particular limitations, and monomethylamine, dimethylamine, trimethylamine, monoethylamine, mono-n-propylamine, dimethyl-n-propylamine, monoethanolamine, diethanolamine, triethanolamine, N-methylethanolamine, N-aminoethyl ethanolamine, N-methyldiethanolamine, mono-isopropanolamine, diisopropanolamine, triisopropanolamine, N,N-dimethylethanolamine, and N,N-dimethylpropanolamine, and the like can be mentioned, and triethylamine and N,N-dimethylethanolamine are particularly preferred. These volatile amines can be used alone or in combination of two or more.

[0049] The basic substance (C) is preferably 0.5 parts by mass or more, more preferably 1 part by mass or more, further preferably 2 parts by mass or more, and particularly preferably 3 parts by mass or more, relative to 100 parts by mass of the modified polyolefin (A). In addition, it is preferably 10 parts by mass or less, more preferably 9 parts by mass or less, further preferably 8 parts by mass or less, and particularly preferably 7 parts by mass or less. If it is too small, the particle size of the dispersed particles of the obtained aqueous dispersion composition is large, and the storage stability is sometimes reduced, and if it is too large, the water resistance of the coating film is sometimes reduced.

[0050] <Water-soluble polymer containing anionic group (D)>

[0051] The water-soluble polymer (D) containing an anionic group used in the present application can reduce the electric charge of the surface of the particles of the modified polyolefin (A) in the aqueous dispersion composition. Thus, the viscosity of the modified polyolefin in the aqueous dispersion composition at 30 mass% of the solid content can be kept constant in the range of 500 mPa-s or less.

[0052] Further, by using the water-soluble polymer (D) containing an anionic group, an excellent effect of not only reducing the viscosity of the aqueous dispersion composition but also not interfering with the effect of the viscosity modifier at the time of coating can be exerted. The viscosity modifier exhibits the target viscosity by hydration in the coating and association between the polar groups, but when a low-molecular compound such as an electrolyte is used as the charge reducing agent, the above-mentioned hydration and association between the polar groups are interfered with, and thus the viscosity modifier sometimes becomes unable to exert the function. On the other hand, it is considered that since the water-soluble polymer (D) containing an anionic group is a high-molecular compound, the flow in the coating is inhibited, and the interaction with the viscosity modifier is small, and the effect on the viscosity modifier is not affected. That is, when a coating, ink, sealant, primer, and adhesive, etc. are produced, various additives such as a viscosity modifier are compounded in addition to the aqueous dispersion composition, and liquid sagging at the time of coating is prevented. If the water-soluble polymer (D) containing an anionic group is used, since the effect of the viscosity modifier, etc. is not interfered with, liquid sagging at the time of coating does not occur, and a good coating, ink, sealant, primer, and adhesive, etc. can be obtained.

[0053] The water-soluble polymer (D) containing an anionic group refers to a high-molecular compound which is dissolved in water and reduces the electric charge of the surface of the particles of the modified polyolefin (A). Specifically, an acrylic resin, a polyurethane resin, an epoxy resin, etc. containing a carboxyl group, a sulfonic acid group, a sulfate group, a phosphate group can be mentioned, and more specifically, a water-soluble polymer containing an anionic group in which polystyrene sulfonic acid, polyacrylic acid, a styrene-maleic anhydride copolymer, a styrene-acrylic acid monomer copolymer, a styrene-methacrylic acid ester monomer copolymer, etc. are used as the main component can be mentioned. These water-soluble polymers (D) containing an anionic group can be used alone or two or more kinds in combination.

[0054] The acid value of the water-soluble polymer (D) containing an anionic group is preferably 100 mgKOH / g-resin or more, more preferably 130 mgKOH / g-resin or more, further preferably 150 mgKOH / g-resin or more, particularly preferably 160 mgKOH / g-resin or more, still further preferably 170 mgKOH / g-resin or more, most preferably 180 mgKOH / g-resin or more. If it is less than 100 mgKOH / g-resin, the viscosity-reducing effect of the aqueous dispersion composition sometimes becomes small. In addition, it is preferably 500 mgKOH / g-resin or less, more preferably 490 mgKOH / g-resin or less, further preferably 480 mgKOH / g-resin or less, particularly preferably 470 mgKOH / g-resin or less, still further preferably 460 mgKOH / g-resin or less, most preferably 450 mgKOH / g-resin or less. If it is more than 500 mgKOH / g-resin, the water resistance of the coating film sometimes decreases, and in addition, the effect of the viscosity modifier at the time of coating sometimes is impaired. When it is within the above range, the viscosity of the aqueous dispersion composition and the physical properties of the coating film become good, and thus it is preferable. The acid value of the water-soluble polymer (D) containing an anionic group can be measured according to JIS K-0070-1992.

[0055] The weight average molecular weight (Mw) of the water-soluble polymer (D) containing an anionic group is preferably 1,500 or more, more preferably 2,000 or more, further preferably 3,000 or more, particularly preferably 5,000 or more, still further preferably 7,000 or more, most preferably 9,000 or more. If it is less than 1,500, the effect of the viscosity modifier at the time of coating is sometimes impaired. In addition, it is preferably 30,000 or less, more preferably 29,000 or less, further preferably 28,000 or less, particularly preferably 27,000 or less, still further preferably 26,000 or less, most preferably 25,000 or less. If it is more than 30,000, the solubility in water decreases, and the viscosity-reducing effect sometimes becomes small. If it is within the above range of 1,500 or more and 30,000 or less, the viscosity of the aqueous dispersion composition and the physical properties of the coating film become good, and thus it is preferable. The weight average molecular weight of the water-soluble polymer (D) containing an anionic group can be measured by GPC in an atmosphere of 40°C.

[0056] The solubility in water (20°C) of the water-soluble polymer (D) containing an anionic group is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 20% by mass or more, still further preferably 30% by mass or more. The upper limit is not particularly limited, and for practicality, it is 50% by mass or less.

[0057] The water-soluble polymer (D) containing an anionic group is preferably 0.1 parts by mass or more, more preferably 0.3 parts by mass or more, further preferably 0.5 parts by mass or more, and particularly preferably 0.8 parts by mass or more, relative to 100 parts by mass of the modified polyolefin (A). In addition, it is preferably 20 parts by mass or less, more preferably 19 parts by mass or less, further preferably 18 parts by mass or less, and particularly preferably 17 parts by mass or less. If it is too small, the viscosity-reducing effect is sometimes small, and if it is too large, the water resistance of the coating film is sometimes reduced, and in addition, the effect of the viscosity modifier at the time of coating is sometimes impaired.

[0058] The Z-average particle diameter in the aqueous dispersion containing the modified polyolefin (A) is 200 nm or less. It is preferably 150 nm or less, more preferably 120 nm or less, further preferably 100 nm or less, and particularly preferably 80 nm or less. By being 200 nm or less, it tends to be able to enter the gaps of the propylene base material, and adhesion (adhesion) due to a firm anchoring effect is obtained, and in addition, the fusion at the time of baking is improved, the film formation property is improved, and the peeling strength is improved. The lower limit is not particularly specified, but in order for the storage stability to be good, it is preferably 30 nm or more.

[0059] The viscosity of the aqueous dispersion composition containing the modified polyolefin (A) is preferably 5 mPa-s or more, and more preferably 10 mPa-s or more. In addition, it is preferably 300 mPa-s or less, and more preferably 250 mPa-s or less. The pH of the aqueous dispersion composition of the present application is preferably 5 or more, 10 or less, more preferably 7 or more, particularly preferably 8.3 or more, and further preferably 8.5 or more.

[0060] As the method for producing the aqueous dispersion composition, there is no particular limitation, and for example, the following production method can be cited. That is, it can be obtained by dissolving the modified polyolefin (A) and the emulsifier (B) in one or more solvents selected from an ether-based solvent, an alcohol-based solvent, and an aromatic-based solvent, and water, adding an alkaline substance, cooling, and removing the solvents.

[0061] From the viewpoint of the handling property of the aqueous dispersion, the solid content concentration of the aqueous dispersion of the resin composition in the present application is preferably 10 to 60% by mass, more preferably 20 to 50% by mass, and further preferably 25 to 45% by mass, relative to the total amount of the aqueous dispersion.

[0062] As the ether-based solvent, there is no particular limitation, and tetrahydrofuran (hereinafter, also referred to as THF), propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and the like can be cited, and these can be used alone or in combination with two or more.

[0063] As the alcohol-based solvent, there is no particular limitation, and aliphatic alcohols, aromatic alcohols, alicyclic alcohols, etc. having 1 to 7 carbon atoms can be cited, and these can be used alone or in combination of two or more.

[0064] As the aromatic-based solvent, benzene, toluene, xylene, ethylbenzene, cumene, solvent naphtha, etc. can be cited, and these can be used alone or in combination of two or more.

[0065] The amounts of the solvent and water can be arbitrarily selected, and it is preferable that the modified polyolefin (A) : water : solvent = 100 : 50 to 800 : 11 to 900 (mass ratio), and more preferable that 100 : 200 to 400 : 43 to 233 (mass ratio).

[0066] In addition, with respect to the aqueous dispersion composition of the present application, in order to further improve the water resistance, solvent resistance, etc., a curing agent can be compounded as necessary. As the curing agent, there is no particular limitation, and for example, an aqueous dispersion of a water-based multifunctional carbodiimide resin, a multifunctional isocyanate compound, a water-based multifunctional oxazoline-based resin, a water-soluble silane coupling agent containing a multifunctional silyl group, a water-based melamine compound, etc. can be cited. These curing agents are preferably compounded at 2 to 30 parts by mass with respect to 100 parts by mass of the resin in the aqueous dispersion composition of the present application.

[0067] Further, in a range not lowering the effects of the present application, with respect to the aqueous dispersion composition of the present application, various additives such as a filler, a pigment, a colorant, an antioxidant, etc. can be compounded. The compounding amount of these additives is preferably 150 parts by mass or less, more preferably 140 parts by mass or less, and further preferably 130 parts by mass or less, with respect to 100 parts by mass of the resin in the aqueous dispersion composition. It is further preferable to be 5 parts by mass or more, and more preferably 2 parts by mass or more. By being in the above range, the excellent effects of the present application can be exerted.

[0068] The aqueous dispersion composition of the present application can be used as an adhesive for various polyolefin-based materials represented by polypropylene. In addition, a paint can be obtained by mixing the aqueous dispersion of the present application and a pigment dispersion liquid, and can be used as a paint. A coating film obtained by removing the aqueous medium from the aqueous dispersion composition of the present application can be used as an adhesive layer, and a substrate can be adhered to each other to form a laminate. In addition, a coating film obtained by removing the aqueous medium from the aqueous dispersion composition of the present application can be used as a paint layer, and can be applied to a substrate to form a laminate. The aqueous dispersion composition of the present application is not limited to polyolefin-based materials, and for example, can be applied to other plastics, wood, metals, etc. As the polyolefin-based material, films, sheets, molded bodies, etc. can be cited. The application method is not particularly limited.

[0069] The present application is described in detail below by way of examples, but the present application is not limited to these examples. In the examples and comparative examples, the term "parts" means parts by mass. Furthermore, the measurement and evaluation methods employed in the present application are described below.

[0070] 1) Measurement of the solid content concentration of the aqueous dispersion composition

[0071] A sample of about 1 g of the aqueous dispersion was weighed in a 50-ml glass weighing bottle, and accurately weighed. The weighing bottle containing the sample was then dried in a hot air drier at 120°C for 2 hours, and the removed weighing bottle was placed in a desiccator, and left to stand, and cool for 30 minutes at room temperature. The weighing bottle was removed from the desiccator, and accurately weighed, and the mass % of the solid content concentration of the aqueous dispersion was calculated from the change in weight before and after hot air drying (the following equation).

[0072] Mass % of the solid content concentration of the aqueous dispersion = 100 - [(mass of the sample before hot air drying) - (mass of the sample after hot air drying)] / (mass of the sample before hot air drying) x 100

[0073] 2) Measurement of the viscosity of the aqueous dispersion composition

[0074] A sample of 0.6 g was measured using "Viscometer TV-22" (E-type viscometer) manufactured by Tokimec Inc., under the conditions of rotor No. 0.8° (= 48') x R24, H-type range, rotation speed 5 rpm, 25°C.

[0075] 3) Measurement of the pH of the aqueous dispersion composition

[0076] A value at 25°C was measured using "pH meter F-52" manufactured by Horiba Ltd. Furthermore, the calibration of the measuring device was performed using phthalate pH standard solution (pH: 4.01), neutral phosphate pH standard solution (pH: 6.86), and borate pH standard solution (pH 9.18) manufactured by Fuji Photo Film Co., Ltd. and Otsuka Pharmaceutical Co., Ltd., and three-point calibration was performed.

[0077] 4) Measurement of the average particle diameter (Z-average particle diameter) of the aqueous dispersion composition

[0078] The average particle diameter (Z-average particle diameter) based on the intensity distribution was measured using "Zetasizer Nano-ZS Model ZEN3600" manufactured by Malvern Instruments Ltd. by dynamic light scattering method. A sample in which the solid content of the aqueous dispersion composition was adjusted to a concentration of 0.05 g / L was measured three times at 25°C, and the average value was taken.

[0079] 5) Measurement of the acid modification amount

[0080] The acid modification amount in the case of acid modification with maleic anhydride was determined by FT-IR (Shimadzu Corporation, FT-IR 8200PC). First, a standard curve solution was prepared by dissolving maleic anhydride at an arbitrary concentration, and then FT-IR measurement of the standard curve solution was performed, and a standard curve was prepared from the absorbance of the stretching vibration peak (1780 cm -1 ) of the carbonyl (C=0) bond of maleic anhydride. The modified polyolefin (A) was dissolved in chloroform and subjected to FT-IR measurement, and the acid modification amount of maleic anhydride was determined from the absorbance of the stretching vibration peak (1780 cm -1 ) of the carbonyl bond of maleic anhydride based on the above standard curve.

[0081] 6) Measurement of melting point

[0082] The melting point and the heat of fusion in the present application were determined based on the peak temperature of the melting peak when the resin was melted and resolidified by raising the temperature at a rate of 10°C / min using a differential scanning calorimeter (hereinafter, DSC, Q-2000, manufactured by TA Instruments Japan), and then the temperature was raised again to melt the resin.

[0083] 7) Measurement of glass transition temperature

[0084] The glass transition temperature (Tg) (°C) of the resin was determined by DSC under the same conditions as in the measurement of the melting point, by taking the temperature at which a straight line at an equal distance from the extension lines of each baseline during the raising temperature process intersects with the curve of the glass transition stage change portion in the vertical axis direction.

[0085] 8) Weight average molecular weight of modified polyolefin (A)

[0086] The weight average molecular weight of the modified polyolefin (A) was determined by gel permeation chromatography Alliancee2695 (hereinafter, GPC, manufactured by Waters Corporation, Japan, standard substance: polystyrene resin, mobile phase: tetrahydrofuran, chromatographic column: Shodex KF-806+KF-803, column temperature: 40°C, flow rate: 1.0 ml / min, detector: photodiode array detector (wavelength 254 nm = ultraviolet light)).

[0087] Production Example 1

[0088] To a 1 L autoclave were added 100 parts by mass of a propylene-butene copolymer (propylene / butene = 69 / 31 mass%), 300 parts by mass of toluene, and 10 parts by mass of maleic anhydride, and after warming to 120°C, 1 part by mass of di-t-butyl peroxide was added, and stirring was performed for 1 hour. Then, after the resulting reaction liquid was allowed to cool, it was poured into a container filled with a large amount of methyl ethyl ketone, and the resin was allowed to precipitate. Then, the liquid containing the resin was separated by centrifugation, and the maleic anhydride graft-polymerized acid-modified propylene-butene copolymer was separated from the ungrafted maleic anhydride and low-molecular-weight substances and refined. Then, by drying this under reduced pressure at 70°C for 5 hours, a maleic anhydride-modified propylene-butene copolymer (PO-1, melting point 72°C, modified amount of maleic anhydride 0.6 mass%, weight average molecular weight 80,000) was obtained.

[0089] Production Example 2

[0090] To a 1 L autoclave were added 100 parts by mass of a propylene-butene copolymer (propylene / butene = 75 / 25 mass%), 300 parts by mass of toluene, and 10 parts by mass of maleic anhydride, and after warming to 120°C, 2 parts by mass of di-t-butyl peroxide was added, and stirring was performed for 1 hour. Then, after the resulting reaction liquid was allowed to cool, it was poured into a container filled with a large amount of methyl ethyl ketone, and the resin was allowed to precipitate. Then, the liquid containing the resin was separated by centrifugation, and the maleic anhydride graft-polymerized acid-modified propylene-butene copolymer was separated from the ungrafted maleic anhydride and low-molecular-weight substances and refined. Then, by drying this under reduced pressure at 70°C for 5 hours, a maleic anhydride-modified propylene-butene copolymer (PO-2, melting point 80°C, modified amount of maleic anhydride 0.6 mass%, weight average molecular weight 80,000) was obtained.

[0091] Production Example 3

[0092] By using the same method as in Production Example 1, except that the amount of maleic anhydride added was changed to 20 parts by mass and di-t-butyl peroxide was changed to 5 parts by mass, a maleic anhydride-modified propylene-butene copolymer (PO-3, melting point 72°C, modified amount of maleic anhydride 2.0 mass%, weight average molecular weight 50,000) was obtained.

[0093] Production Example 4

[0094] To a 1 L autoclave equipped with a stirrer, 100 parts by mass of a propylene-ethylene copolymer (MFR = 5 g / 10 minutes in an atmosphere at 2300C), 150 parts by mass of toluene, and 10 parts by mass of maleic anhydride, 1 part by mass of di-t-butyl peroxide were added, and after warming to 1400C, further stirring was performed for 3 hours. Then, after allowing the resulting reaction liquid to cool, it was poured into a container filled with a large amount of methyl ethyl ketone, and the resin was allowed to precipitate. Then, the maleic anhydride-grafted acid-modified propylene-ethylene copolymer was separated from the (poly)maleic anhydride and low-molecular-weight substances by centrifugal separation of the liquid containing the resin, and was refined. Then, by drying it at a reduced pressure at 70°C for 5 hours, a maleic anhydride-modified propylene-ethylene copolymer was obtained. Then, 100 parts by mass of the maleic anhydride-modified propylene-ethylene copolymer, 1700 parts by mass of chloroform were added to a 2 L glass-lined reaction kettle, and were sealed. While stirring and dispersing the liquid in the kettle, warming was performed, and dissolution was performed in the kettle at a temperature of 1200C for 1 hour. After allowing the temperature in the kettle to cool to 1100C, 0.5 parts by mass of t-butyl peroxy-2-ethylhexanoate was added, and 70 parts by mass of chlorine was introduced. After allowing the temperature in the kettle to cool to 600C, 1400 parts by mass of chloroform was distilled off, and 4 parts by mass of p-t-butylphenyl glycidyl ether was added as a stabilizer. Then, by drying, a maleic anhydride-modified chlorinated propylene-ethylene copolymer (CPO-1, melting point 75°C, modification amount of maleic anhydride 0.8 mass%, chlorine content 20 mass%, weight average molecular weight 103,000) was obtained.

[0095] Production Example 5

[0096] A maleic anhydride-modified chlorinated propylene-ethylene copolymer (CPO-2, melting point 75°C, modification amount of maleic anhydride 2.5 mass%, chlorine content 20 mass%, weight average molecular weight 83,500) was obtained by the same method as in Production Example 4, except that the amount of maleic anhydride added was changed to 20 parts by mass, and the amount of di-t-butyl peroxide added was changed to 5 parts by mass.

[0097] The composition of the aqueous dispersion used in the following examples and comparative examples is shown in Table 1.

[0098] [Table 1]

[0099]

[0100] [Example 1]

[0101] To a flask equipped with a stirrer, 100 parts by mass of the modified polyolefin (PO-1), 10 parts by mass of polyoxyethylene laurylamine (B-1) having an EO addition mole number of 10 as an emulsifier, 300 parts by mass of ion exchange water, 30 parts by mass of tetrahydrofuran, and 50 parts by mass of toluene were added, warmed to 90°C, and then heated to dissolve at the same temperature for 1 hour. Then, 3.5 parts by mass of N,N-dimethylethanolamine was added, and stirred at the same temperature for 1 hour. Then, after slowly cooling to 40°C over 1 hour, the organic solvent was distilled off under a reduced pressure of 91 kPa, and 1.0 parts by mass of ARUFON UC-3920 was added, to obtain an aqueous dispersion having properties as shown in Table 1.

[0102] Examples 2 to 7

[0103] An aqueous dispersion composition was obtained in the same manner as in Example 1, using the modified polyolefin (A) shown in Table 1, except that the amount of addition of polyoxyethylene laurylamine (B-1) having an EO addition mole number of 10 as an emulsifier was changed. The properties are shown in Table 1.

[0104] Comparative Examples 1 and 2

[0105] An aqueous dispersion composition having properties as shown in Table 1 was obtained in the same manner as in Example 1, except that 15 parts by mass and 35 parts by mass of polyoxyethylene oleyl cetyl ether (B-2) having an EO addition mole number of 15 were used as an emulsifier, as shown in Table 1.

[0106] Comparative Examples 3 and 4

[0107] An aqueous dispersion composition having the composition shown in Table 1 was obtained in the same manner as in Example 1, except that the modified polyolefin (PO-3) was changed to 100 parts by mass, and the amount of addition of polyoxyethylene laurylamine (B-1) having an EO addition mole number of 10 was changed to 25 parts by mass and 45 parts by mass, respectively.

[0108] Comparative Example 5

[0109] An aqueous dispersion composition having the composition shown in Table 1 was obtained in the same manner as in Example 1, except that the modified polyolefin (CPO-2) was changed to 100 parts by mass, and the amount of addition of polyoxyethylene laurylamine (B-1) having an EO addition mole number of 10 was changed to 35 parts by mass.

[0110] Comparative Example 6

[0111] An aqueous dispersion composition shown in Table 1 was obtained in the same manner as in Example 1, except that polyoxyethylene laurylamine (B-1) having an EO addition mole number of 10 as an emulsifier was changed to 5 parts by mass, and N,N-dimethylethanolamine was changed to 0.4 parts by mass.

[0112] <Dispersed liquid of pigment>

[0113] 4 parts by mass of a water-soluble acrylic resin, 2 parts by mass of an electrically conductive carbon black, 36 parts by mass of a rutile titanium oxide, and 70 parts by mass of ion exchange water were added, stirred for 30 minutes, and then dispersed for 30 minutes using a bead mill. Then, 5 parts by mass of a polyurethane associative thickener and 2 parts by mass of a leveling agent were added to obtain a pigment dispersion liquid.

[0114] <Preparation of a coating composition>

[0115] To 20 parts by weight of the aqueous dispersion obtained above, 38 parts by mass of the pigment dispersion liquid, 16 parts by mass of a polyester polyurethane dispersion (Sanyo Chemical Industries, UXA-310, solid content 38%), were added, and stirred for 10 minutes using a dispersion stirrer. Then, 1.0 parts by mass of BYK-349 as a leveling agent and 2 parts by weight of an alkali-swellable thickener (Rohm & Haas, ASE-60) were added dropwise, and stirred for 15 minutes to obtain a coating composition. The following evaluations were performed on the coating composition. The results are shown in Table 2.

[0116] (Evaluation of peel strength)

[0117] A bumper polypropylene substrate (TYC-1175P-G01, Standard Plaque Co., Ltd., 150 mm x 1000 mm x 3 mm) was coated with the coating composition prepared above using an airbrush to a dry film thickness of 10 μm, and heated and dried at 80°C for 10 minutes. Then, a commercially available water-based base paint (RETAN PG WB ECO, Kansai Paint) was coated using an airbrush to a dry film thickness of 150 μm. Then, the test piece was left to stand for 15 minutes after painting in an environment at 23°C, and then taken out after heating and drying in a drying oven at 80°C for 30 minutes. Then, the peel strength of the test piece was measured at 25°C using a TENSILON RTM-100 (A & T Co., Ltd.) at a tensile speed of 50 mm / minute after leaving to stand for 72 hours in an environment at 23°C.

[0118] Evaluation criteria

[0119] A: When the value of the peel strength is 1000 gf / cm or more

[0120] B: When the value of the peel strength is 700 or more and less than 1000 gf / cm

[0121] C: When the value of the peel strength is 500 or more and less than 700 gf / cm

[0122] D: When the value of the peel strength is less than 500 gf / cm

[0123] (Evaluation of adhesion of the coating film)

[0124] On a polypropylene substrate for a bumper (TYC-1175P-G01 Standard Plaque, manufactured by the company, 150 mm x 1000 mm x 3 mm), the paint composition prepared above was applied with an airbrush to a dry film thickness of 10 μm, and heated and dried at 80°C for 10 minutes. Then, a commercially available water-based base paint (RETAN PG WB ECO, manufactured by Kansai Paint) was applied with an airbrush to a dry film thickness of 35 μm. Then, the test piece was taken out after being baked and dried in a drying oven at 80°C for 30 minutes after being left to stand for 15 minutes after application in an environment at 23°C.

[0125] After being left to stand for 36 hours in an atmosphere at 25°C, 100 grids were drawn on the applied surface with a cutter knife at intervals of 2 mm, and a glass paper tape was peeled off at an angle of 60°. Using a new glass paper tape, the peeling was repeated 10 times. In the case where the applied surface did not change even after 10 times, 10 points were given, and the evaluation was A. In the case where peeling occurred at the 10th time, 9 points were given, and the evaluation was B. Below that, 8, 7, and 6 points were given, and in the case where peeling occurred at the 1st time, 0 point was given, and the evaluation was C.

[0126] (Evaluation of Water Resistance of the Paint Film)

[0127] The test piece prepared under the same conditions as in the evaluation of adhesion of the paint film was immersed in warm water at 40°C for 10 days after being left to stand for 36 hours in an atmosphere at 25°C. After confirming the change in the paint film, the evaluation of adhesion of the paint film described above was performed. In the case where the paint film did not change and the evaluation of adhesion was 10 points, it was good, and was A. In the case where the paint film did not change and the evaluation of adhesion was 9 points, it was B. In the case where the paint film had bubbles and the evaluation of adhesion was 8 points or less, it was poor, and was C.

[0128] (Storage Stability)

[0129] 200 g of the paint composition prepared above was sealed in a polypropylene container, and stored at 40°C for 10 days. Then, the viscosity after storage was measured with a rotational viscometer (TVB-10M, manufactured by Tokimec). The change rate in the viscosity before and after storage was measured.

[0130] Evaluation Criteria

[0131] A: Change rate in the viscosity before and after storage was less than 5%

[0132] B: Change rate in the viscosity before and after storage was 5% or more and less than 10%

[0133] C: Change rate in the viscosity before and after storage was 11% or more and less than 20%

[0134] D: Change rate in the viscosity before and after storage was 20% or more

[0135] [Table 2]

[0136]

[0137] [Consideration of results of Table 2]

[0138] The aqueous dispersion composition obtained in Examples 1 to 7 showed good peeling strength, good adhesion, and good water resistance with respect to a polypropylene base material for a bumper. On the other hand, since the nonionic emulsifier (B) containing nitrogen was not used in Comparative Examples 1 and 2, inferior results were obtained in terms of water resistance and peeling strength. Further, since the weight average molecular weight of the modified polyolefin (A) was 60,000 or less in Comparative Examples 3 and 4, inferior results were obtained in terms of water resistance and peeling strength. Furthermore, since the modified polyolefin (A) in which the modification amount of the α,β-unsaturated carboxylic acid and / or anhydride thereof was less than 1.0 mass% was not used in Comparative Example 5, inferior results were obtained in terms of water resistance and peeling strength. Further, since the Z average particle diameter of the modified polyolefin (A) was greater than 200 nm in Comparative Example 6, inferior results were obtained in terms of water resistance and peeling strength.

[0139] [Industrial applicability]

[0140] The aqueous dispersion composition of the present application can provide a coating film that shows high peeling strength, high adhesion, and good water resistance at low temperature (80 to 90°C) baking with respect to a difficultly adhering polyolefin base material. Therefore, it can contribute to reduction of coating failure in an aqueous coating system, reduction of VOC, or reduction of CO2 that is a cause of global warming due to energy consumption in a baking drying oven.

Claims

1. An aqueous dispersion composition characterized in that, which is an aqueous dispersion composition containing a modified polyolefin A, a nitrogen-containing nonionic emulsifier B, and an alkaline substance C; the modified polyolefin A has a weight average molecular weight of 60,000 or more as determined by GPC, and a modification amount of less than 1.0 mass% with an α,β-unsaturated carboxylic acid and / or an acid anhydride thereof, the aqueous dispersion composition has a Z average particle diameter of 200 nm or less, the modified polyolefin A does not contain chlorine, the nitrogen-containing nonionic emulsifier B is a polyoxyethylene laurylamine, a polyoxyethylene cocoylamine, a polyoxyethylene tallow amine, a polyoxyethylene coconut fatty amide, a polyoxyethylene lauryl amide, a polyoxyethylene stearyl amide, a polyoxyethylene tallow amide, a polyoxyethylene coconut fatty acid monoethanolamide, or a polyoxyethylene lauryl monoethanolamide, the number of ethylene oxide units in each molecule of the nitrogen-containing nonionic emulsifier B is in the range of 8 to 30.

2. The aqueous dispersion composition of claim 1, wherein, the modified polyolefin A has a melting point of 60°C to 85°C.

3. The aqueous dispersion composition of claim 1, wherein, the nitrogen-containing nonionic emulsifier B is added in an amount of 10 to 45 parts by mass per 100 parts by mass of the modified polyolefin A.

4. The aqueous dispersion composition of claim 1, wherein, further contains a water-soluble polymer D containing an anionic group, the water-soluble polymer D containing an anionic group has an acid value of 100 mg to 500 mg KOH / g-resin, and the content of the water-soluble polymer D containing an anionic group is 0.1 to 20 parts by mass per 100 parts by mass of the modified polyolefin A.

5. The aqueous dispersion composition of claim 1, wherein, the modified polyolefin A is a propylene-α-olefin copolymer having a butene content of 2 to 35 mass% in a polyolefin component.

6. A coating characterized by, which contains the aqueous dispersion composition according to any one of claims 1 to 5.

7. An adhesive characterized by, which contains the aqueous dispersion composition according to any one of claims 1 to 5.

8. A coated film characterized by which is a coating film obtained by removing an aqueous medium from the aqueous dispersion composition according to any one of claims 1 to 5.

9. A laminate characterized by comprising: which has a layer derived from the paint according to claim 6.

10. A laminate characterized by comprising: which has a layer derived from the adhesive according to claim 7.

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