Modified polyolefin resin composition

Abstract

The object of the present invention is to provide a resin composition that exhibits excellent heat resistance and solution stability to poorly adhering substrates. [Solution] A resin composition comprising a modified polyolefin resin (A) having a melting point of 50 to 95°C measured at a heating rate of 10°C / min using a differential scanning calorimeter in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives, and a modified polyolefin resin (B) having an extrapolation melting onset temperature (Tim) of 120°C or higher measured at a heating rate of 10°C / min using a differential scanning calorimeter in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives, wherein the modified resin (B) is dispersed in the modified resin (A), and the average particle size of the modified resin (B) is 0.1 to 100 μm.

Description

Technical Field

[0001] The present invention relates to a resin composition containing a modified polyolefin obtained by modifying with an α,β-unsaturated carboxylic acid and / or its derivative.

Background Art

[0002] Polyolefin resins are excellent in mechanical properties such as tensile strength, tear strength, and impact strength, as well as water resistance and chemical resistance. They are also lightweight, inexpensive, and easy to mold, so they are used in various applications such as sheets, films, and molded articles. However, since polyolefin resins are non-polar and crystalline, different from polar base materials such as polyurethane resins, polyamide resins, acrylic resins, and polyester resins, painting and adhesion can be difficult in some cases.

[0003] In the automotive industry, a modified polyolefin resin modified with an α,β-unsaturated carboxylic acid or its derivative having high adhesion is used as an adhesion promoter for adhering a paint with poor adhesion to a polyolefin resin (in the automotive industry, a paint directly applied on a base material mainly composed of an adhesion promoter is particularly called a primer paint) (Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] It has been shown that when using modified polyolefin resins obtained by modifying polyolefin resins with relatively high melting points, excellent heat-resistant adhesion to poorly adhering substrates such as polyolefins can be achieved. However, such resins have the drawback of poor solution stability and poor handling.

[0006] The present invention aims to provide a resin composition that exhibits excellent heat resistance and solution stability to poorly adhering substrates. [Means for solving the problem]

[0007] The present invention provides the following: [1] A resin composition comprising a modified polyolefin resin (A) having a melting point of 50 to 95°C measured by differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives, and a modified polyolefin resin (B) having an extrapolation melting onset temperature (Tim) of 120°C or higher measured by differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives, wherein the modified resin (B) is dispersed in the modified resin (A), and the average particle size of the modified resin (B) is 0.1 to 100 μm. [2] The resin composition according to [1] above, wherein one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives contain a (meth)acrylic acid ester. [3] The resin composition according to [1] above, wherein the melting point of resin (B), measured by differential scanning calorimeter in accordance with JIS K7121-1987 at a heating rate of 10°C / min, is 140 to 200°C. [4] The resin composition according to [1] above, wherein the mass ratio of the modified resin (A) to the modified resin (B) is modified resin (A):modified resin (B) = 50:50 to 95:5. [5]Based on JIS K7121-1987, the difference (Tem - Tim) between the extrapolated melting end temperature (Tem) and the extrapolated melting start temperature (Tim) of the resin (B), measured by a differential scanning calorimeter at a heating rate of 10°C / min, is 25°C or less, and the resin composition according to the above [1]. [6]A primer, an adhesive, a paint, and an ink containing the resin composition according to the above [1].

Effect of the Invention

[0008] According to the present invention, it is possible to provide a resin composition that can exhibit excellent heat resistance adhesion and excellent solution stability to a hardly adherent substrate.

Modes for Carrying Out the Invention

[0009] In the following description, unless otherwise specified, the description of "AA to BB" means "AA or more and BB or less". Here, "AA" and "BB" each represent a numerical value, and AA < BB. The unit of "AA" is the same as the unit attached to "BB" unless otherwise specified.

[0010] In the following description, unless otherwise specified, the term "(meth)acrylic acid" includes "acrylic acid", "methacrylic acid", and combinations thereof, and the term "(meth)acrylate" includes "acrylate", "methacrylate", and combinations thereof.

[0011] The present invention provides a resin composition comprising a modified product obtained by modifying a polyolefin resin (A) having a melting point of 50 to 95°C or less with an α,β-unsaturated carboxylic acid and / or its derivative, and a modified product obtained by modifying a polyolefin resin (B) having an extrapolated melting start temperature (Tim) of 120°C or more with an α,β-unsaturated carboxylic acid and / or its derivative, wherein the modified product of the resin (B) is dispersed in the modified product of the resin (A), and the average particle diameter of the modified product of the resin (B) is 0.1 to 100 μm. Such a resin composition can exhibit excellent heat resistance adhesion and solution stability to a hardly adherent substrate. Hereafter, resin (A) will also be referred to simply as component (A), and resin (B) will also be referred to simply as component (B).

[0012] (1. Polyolefin resin) The resin composition of the present invention comprises a modified product obtained by modifying a polyolefin resin (A) having a melting point of 50 to 95°C with an α,β-unsaturated carboxylic acid and / or its derivative, and a modified product obtained by modifying a polyolefin resin (B) having an extracellular melting onset temperature (Tim) of 120°C or higher with an α,β-unsaturated carboxylic acid and / or its derivative.

[0013] Polyolefin resins are olefin (preferably α-olefin) polymers. Examples of α-olefins include ethylene, propylene, 1-butene, 1-pentene, 1-hexene, 1-heptene, and 1-octene.

[0014] The polyolefin resin may be a polymer of a single olefin (preferably α-olefin), or a copolymer of two or more olefins (preferably α-olefins). If the polyolefin resin is a copolymer, it may be a random copolymer or a block copolymer.

[0015] The mass ratio of the modified product of component (A) to the modified product of component (B) (modified product of component (A):modified product of component (B)) is preferably 40:60 to 95:5, more preferably 50:50 to 95:5, even more preferably 60:40 to 95:5, even more preferably 70:30 to 95:5, and particularly preferably 75:25 to 95:5.

[0016] (1-1. Component (A): Polyolefin resin with a melting point of 50-95°C or lower) From the viewpoint of exhibiting sufficient adhesion, the polyolefin resin of component (A) is preferably polypropylene (propylene homopolymer), propylene-ethylene copolymer, propylene-1-butene copolymer, ethylene-propylene-1-butene copolymer, or a mixture thereof.

[0017] Here, "polypropylene" represents a polymer whose constituent units are constituent units derived from propylene. "Propylene-ethylene copolymer" represents a copolymer containing a constituent unit derived from propylene and a constituent unit derived from ethylene as constituent units. "Propylene-1-butene copolymer" represents a copolymer containing a constituent unit derived from propylene and a constituent unit derived from 1-butene as constituent units. "Ethylene-propylene-1-butene copolymer" represents a copolymer containing a constituent unit derived from ethylene, a constituent unit derived from propylene, and a constituent unit derived from 1-butene as constituent units. As long as the amount does not significantly impair the original performance of the resin, these (co)polymers may contain a small amount of constituent units derived from other olefins as constituent units.

[0018] The polyolefin resin of component (A) preferably contains 15 mol% or more, more preferably 50 mol% or more, of the constituent units derived from propylene in 100 mol% of all constituent units. When the constituent units derived from propylene are contained within the above range, good adhesion can be maintained.

[0019] When the polyolefin resin of component (A) is a propylene-ethylene copolymer or a propylene-1-butene copolymer, preferably, in 100 mol% of all constituent units, the constituent units derived from ethylene or the constituent units derived from 1-butene are 3 to 85 mol% (more preferably 3 to 50 mol%), and the constituent units derived from propylene are 15 to 97 mol% (more preferably 50 to 97 mol%).

[0020] The lower limit of the melting point (Tm) of the polyolefin resin of component (A) is preferably 50°C or higher, more preferably 60°C or higher. The upper limit is preferably 95°C or lower, more preferably 90°C or lower. When the melting point of the polyolefin resin of component (A) is within the above range, when the resin composition is used in applications such as inks and paints, sufficient coating film strength can be exhibited. Therefore, sufficient adhesion to the substrate can be exerted. Also, the solution stability when the resin composition of the present invention is dissolved is excellent. The melting point (Tm) of the polyolefin resin of component (A) can be measured by a differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987.

[0021] The weight average molecular weight (Mw) of the polyolefin resin of component (A) is preferably 5,000 or more, more preferably 10,000 or more, still more preferably 30,000 or more, even more preferably 50,000 or more, particularly preferably 100,000 or more, and the upper limit is preferably 200,000 or less, more preferably 180,000 or less, still more preferably 170,000 or less, even more preferably 160,000 or less, particularly preferably 150,000 or less. The weight average molecular weight (Mw) can be measured by gel permeation chromatography (GPC) using polystyrene as a standard substance.

[0022] (1-2. Component (B): Polyolefin resin with an additional melting start temperature of 120°C or higher) The polyolefin resin of component (B) is preferably polypropylene (propylene homopolymer), propylene-ethylene copolymer, propylene-1-butene copolymer, ethylene-propylene-1-butene copolymer or a mixture thereof.

[0023] The lower limit of the melting point (Tm) of the polyolefin resin of component (B) is preferably 140°C or higher, more preferably 145°C or higher, even more preferably 150°C or higher, and particularly preferably 155°C or higher. The upper limit is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and particularly preferably 170°C or lower. The melting point (Tm) of the polyolefin resin of component (B) can be measured by a differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987.

[0024] The lower limit of the extrapolation melting onset temperature (Tim) of the polyolefin resin of component (B) is 120°C or higher, preferably 125°C or higher, more preferably 130°C or higher, even more preferably 135°C or higher, and particularly preferably 140°C or higher. The upper limit is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, and particularly preferably 170°C or lower. The extrapolation melting onset temperature (Tim) of the polyolefin resin of component (B) can be measured by a differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987.

[0025] The lower limit of the extrapolation melting termination temperature (Tem) of the polyolefin resin of component (B) is preferably 135°C or higher, more preferably 140°C or higher, even more preferably 145°C or higher, and particularly preferably 150°C or higher. The upper limit is preferably 210°C or lower, more preferably 200°C or lower, even more preferably 190°C or lower, and particularly preferably 180°C or lower. The extrapolation melting termination temperature (Tem) of the polyolefin resin of component (B) can be measured by a differential scanning calorimeter at a heating rate of 10°C / min in accordance with JIS K7121-1987.

[0026] The difference (Tem-Tim) between the extracellular melting completion temperature (Tem) and the extracellular melting start temperature (Tim) of the polyolefin resin of component (B) is preferably 25°C or less, more preferably 23°C or less, even more preferably 21°C or less, and particularly preferably 19°C or less.

[0027] The weight-average molecular weight (Mw) of the polyolefin resin of component (B) is preferably 5,000 or more, more preferably 10,000 or more, even more preferably 30,000 or more, even more preferably 40,000 or more, and particularly preferably 50,000 or more, with an upper limit of preferably 500,000 or less, more preferably 400,000 or less, even more preferably 300,000 or less, even more preferably 200,000 or less, and particularly preferably 180,000 or less.

[0028] (2. Modification with α,β-unsaturated carboxylic acids and / or their derivatives) The resin composition of the present invention is, for example, (1) A method comprising the step of simultaneously modifying component (A) and component (B) as a mixture with an α,β-unsaturated carboxylic acid and / or its derivative to obtain the resin composition of the present invention (hereinafter sometimes referred to as "simultaneous modification"), (2) A method comprising the steps of: modifying component (A) with an α,β-unsaturated carboxylic acid and / or a derivative thereof to obtain a modified product of component (A); modifying component (B) with an α,β-unsaturated carboxylic acid and / or a derivative thereof to obtain a modified product of component (B); and mixing the obtained modified product of component (A) and the obtained modified product of component (B) to obtain the resin composition of the present invention (hereinafter sometimes referred to as "individual modification"). It can be manufactured by [method].

[0029] Modification with α,β-unsaturated carboxylic acids and / or their derivatives can be carried out, for example, by graft copolymerization of an α,β-unsaturated carboxylic acid or its derivative onto the polyolefin chain of the raw material polyolefin resin. Modification with α,β-unsaturated carboxylic acids and / or their derivatives can also be carried out using a melting method.

[0030] Modification with α,β-unsaturated carboxylic acids and / or their derivatives is preferably carried out, for example, by heating and melting the polyolefin resin and reacting it with α,β-unsaturated carboxylic acids and / or their derivatives. The heating and melting temperature is particularly preferably above the melting point of the raw material polyolefin resin (or component (B) in the case of simultaneous modification).

[0031] Modification with α,β-unsaturated carboxylic acids and / or their derivatives can be carried out using equipment such as a Banbury mixer, kneader, or extruder, and it is preferable to carry it out using an extruder (by extrusion modification).

[0032] In the case of simultaneous modification, the extrusion modification method may include, for example, supplying a mixture of component (A) and component (B) as raw materials to the supply section of an extruder (e.g., a coaxial multi-screw extruder, a twin-screw extruder), mixing, melting, reacting, and defoliating the raw materials together with α,β-unsaturated carboxylic acid and / or its derivatives in the extruder at, for example, the above-mentioned heating and melting temperature, cooling, and further cooling the resin coming out of the tip die of the extruder (e.g., by immersion in a water bath) to obtain the resin composition of the present invention. The progress of the modification reaction and kneading can be adjusted by adjusting the temperature of each part of the extruder barrel and the screw rotation speed.

[0033] In the case of individual modification, the extrusion modification method may include, for example, the steps of: supplying component (A) as a raw material to the supply section of an extruder, mixing, melt-kneading, reacting, and deflorating the raw materials together with α,β-unsaturated carboxylic acid and / or its derivatives in the extruder, for example at the above-mentioned heating and melting temperature, cooling, and further cooling the resin coming out of the tip die of the extruder to obtain a modified product of component (A); supplying component (B) as a raw material to the supply section of an extruder, mixing, melt-kneading, reacting, and deflorating the raw materials together with α,β-unsaturated carboxylic acid and / or its derivatives in the extruder, for example at the above-mentioned heating and melting temperature, cooling, and further cooling the resin coming out of the tip die of the extruder to obtain a modified product of component (B); and supplying the obtained modified product of component (A) and the obtained modified product of component (B) to the supply section of an extruder, melt-kneading in the extruder, for example at the same temperature as the above-mentioned heating and melting temperature, cooling, and further cooling the resin coming out of the tip die of the extruder to obtain the resin composition of the present invention. The progression of the denaturation reaction and kneading can be controlled, as in the case of simultaneous denaturation, by adjusting the temperature of each part of the extruder barrel and the screw rotation speed.

[0034] Examples of derivatives of α,β-unsaturated carboxylic acids include α,β-unsaturated carboxylic acid anhydrides, α,β-unsaturated carboxylic acid esters, α,β-unsaturated carboxylic acid amides, and α,β-unsaturated carboxylic acid imides. In the case of individual modification, the α,β-unsaturated carboxylic acid and its derivatives used to modify component (A) and the α,β-unsaturated carboxylic acid and its derivatives used to modify component (B) may be the same or different.

[0035] Examples of α,β-unsaturated carboxylic acids and their derivatives include maleic acid, maleic anhydride (maleic anhydride), fumaric acid, citraconic acid, citraconic anhydride, mesaconic acid, itaconic acid, itaconic anhydride, aconitic acid, aconitic anhydride, hymic anhydride, (meth)acrylic acid, and (meth)acrylic acid esters. It is preferable that the α,β-unsaturated carboxylic acids and their derivatives include one or more selected from maleic anhydride and (meth)acrylic acid esters.

[0036] In one embodiment, the α,β-unsaturated carboxylic acid and / or its derivative more preferably includes a (meth)acrylic acid ester. Preferred (meth)acrylic acid esters are alkyl (meth)acrylates such as methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, isopropyl (meth)acrylate, n-butyl (meth)acrylate, sec-butyl (meth)acrylate, tert-butyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, n-octyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, 2,4,6-trimethylheptyl (meth)acrylate, undecyl (meth)acrylate, lauryl (meth)acrylate, tridecyl (meth)acrylate, tetradecyl (meth)acrylate, and stearyl (meth)acrylate. In one embodiment, the number of carbon atoms in the alkyl group of the alkyl(meth)acrylate is preferably 1 to 30, more preferably 4 to 20, even more preferably 8 to 16, and particularly preferably 10 to 14. In one embodiment, the alkyl(meth)acrylate is most preferably lauryl(meth)acrylate.

[0037] In one embodiment, the α,β-unsaturated carboxylic acid and / or its derivative more preferably includes maleic anhydride. When the α,β-unsaturated carboxylic acid and / or its derivative includes maleic anhydride, the cyclic structure derived from maleic anhydride contained in the modified polyolefin resin may be partially hydrolyzed and ring-opened.

[0038] The content of maleic anhydride in α,β-unsaturated carboxylic acids and / or their derivatives is preferably 10% by mass or more, more preferably 30% by mass or more, even more preferably 40% by mass or more, and particularly preferably 50% by mass or more, when the total amount of α,β-unsaturated carboxylic acids and / or their derivatives is 100% by mass.

[0039] The amount of α,β-unsaturated carboxylic acid and / or its derivative used for modification with α,β-unsaturated carboxylic acid and / or its derivative is preferably 50% by weight or less, more preferably 30% by weight or less, even more preferably 20% by weight or less, and particularly preferably 10% by weight or less, relative to 100% by weight of the raw material polyolefin resin. The lower limit is not particularly limited, but is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, even more preferably 1% by weight or more, and particularly preferably 2% by weight or more.

[0040] Modification with α,β-unsaturated carboxylic acids and / or their derivatives is preferably carried out in the presence of a radical reaction initiator. Examples of radical reaction initiators include thermal polymerization initiators that generate free radicals when heated, such as organic peroxides and azonitriles. Examples of organic peroxides include di-tert-butyl peroxide, dicumyl peroxide, tert-butylcumyl peroxide, dibenzoyl peroxide, benzoyl m-tolyl peroxide, di(m-tolyl)benzoyl, dilauryl peroxide, 2,5-dimethyl-2,5-di(tert-butylperoxy)hexane, cumene hydroperoxide, tert-butyl hydroperoxide, 1,1-bis(tert-butylperoxy)-3,5,5-trimethylcyclohexane, 1,1-bis(tert-butylperoxy)-cyclohexane, cyclohexanone peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisobutyrate, tert-butyl peroxy-3,5,5-trimethylhexanoate, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxyisopropyl carbonate, and cumyl peroxyoctoate. Examples of azonitriles include 2,2-azobis(2-methylbutyronitrile), 2,2-azobisisobutyronitrile, 2,2-azobis(2,4-dimethylvaleronitrile), and 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile).

[0041] The amount of radical reaction initiator used for modification with α,β-unsaturated carboxylic acids and / or their derivatives is preferably 0.01% to 3% by weight, more preferably 0.1% to 2% by weight, based on 100% by weight of the raw material polyolefin resin.

[0042] The mass ratio (component (A):component (B)) of the amount of raw material component (A) to the amount of raw material component (B) required to obtain the resin composition of the present invention is preferably 40:60 to 95:5, more preferably 50:50 to 95:5, even more preferably 60:40 to 95:5, even more preferably 70:30 to 95:5, and particularly preferably 75:25 to 95:5. In the case of simultaneous modification, a mixture of component (A) and component (B) blended in the above mass ratio is used as a raw material to carry out modification and obtain the resin composition. In the case of individual modification, the above mass ratio is used as the mass ratio of the raw materials to be used to individually modify component (A) and component (B), and the resulting modified products are mixed to obtain the resin composition.

[0043] The total graft weight (degree of modification) of α,β-unsaturated carboxylic acids and / or their derivatives in the resin composition of the present invention is preferably 50% by weight or less, more preferably 30% by weight or less, even more preferably 20% by weight or less, and particularly preferably 10% by weight or less, when the total amount of the modified product of component (A) and the modified product of component (B) is taken as 100% by weight. The lower limit is not particularly limited, but is preferably 0.01% by weight or more, more preferably 0.1% by weight or more, and even more preferably 1% by weight or more. The graft weight (by weight) can be determined, for example, by alkaline titration, Fourier transform infrared spectroscopy, or 1 This can be determined by methods such as H-NMR.

[0044] (3. Resin composition) The resin composition of the present invention is in a form in which a modified product of component (B) is dispersed within a modified product of component (A). The modified product of component (B) may be in particulate form. The modified product of component (B) may also be in the form of particles in which the unmodified polyolefin resin of component (B) and the modified polyolefin resin of component (B) are unevenly mixed.

[0045] The resin composition of the present invention may contain a hydrophobic solvent. The resin composition of the present invention includes a solid form in which a modified solid particulate component (B) is dispersed within a modified solid component (A), a liquid form in which a modified solid particulate component (B) is dispersed in a solution in which a modified component (A) is dissolved, and so on.

[0046] When obtaining the resin composition of the present invention using an extrusion modification method, the resin composition obtained by cooling the resin coming out of the tip die of the extruder may be in a solid form in which a modified solid component (B) is dispersed within a modified solid component (A). The solid resin composition thus obtained can be mixed with a hydrophobic solvent to obtain a liquid form in which a modified solid component (B) is dispersed in a solution in which a modified solid component (A) is dissolved.

[0047] Examples of hydrophobic solvents include aromatic hydrocarbon solvents such as toluene and xylene; ester solvents such as methyl acetate, ethyl acetate, n-propyl acetate, isopropyl acetate, and butyl acetate; ketone solvents such as acetone, methyl ethyl ketone, and methyl butyl ketone; alicyclic hydrocarbon solvents such as cyclohexane, methylcyclohexane, and ethylcyclohexane; and aliphatic hydrocarbon solvents such as hexane, nonane, and decane.

[0048] The average particle size of the modified component (B) is 0.1 to 100 μm, and is not particularly limited, but is preferably 0.3 to 50 μm, more preferably 0.4 to 20 μm, and even more preferably 0.5 to 10 μm. The average particle size of the modified component (B) may be the volume-based median diameter Dv50 (the largest particle size below 50% of the sample volume). The average particle size of the modified component (B) can be measured and calculated, for example, as shown in Test Example 1 below.

[0049] The resin composition of the present invention can be used in primers, adhesives, paints, or inks. The primer, adhesive, paint, or ink may contain additives such as hydrophobic solvents, hydrophilic solvents, curing agents, adhesive components, basic substances, emulsifiers, crosslinking agents, diluents, light stabilizers, ultraviolet absorbers, pigments, dyes, and inorganic fillers, along with the resin composition of the present invention.

[0050] Examples of hydrophilic solvents include water; glycol-based solvents such as ethylene glycol; alcohol-based solvents such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, tert-butyl alcohol, and 2-ethylhexanol; and glycol monoether-based solvents such as ethyl cellosolve, butyl cellosolve, propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, propylene glycol monoisopropyl ether, and propylene glycol monobutyl ether. The solvent may be used alone or in combination of two or more types.

[0051] Examples of curing agents include polyisocyanate compounds, epoxy compounds, polyamine compounds, polyol compounds, or crosslinking agents in which their functional groups are blocked by protecting groups, or combinations of two or more of these. The content of the curing agent should be appropriately selected depending on the content of the modified polyolefin resin. When using a curing agent, catalysts such as organotin compounds and tertiary amine compounds may be used in combination depending on the purpose. The curing agent may be used alone or in combination of two or more types.

[0052] Examples of adhesive components include known adhesive components such as polyester adhesives, polyurethane adhesives, and acrylic adhesives. The adhesive components may be used individually or in combination of two or more types.

[0053] When using a solvent such as water, alcohol-based solvent, glycol-based solvent, ketone-based solvent, or ester-based solvent, it is preferable that the resin composition contains a basic substance. This allows for appropriate adjustment of the pH and further enhances the dispersibility of the resin in the solvent and its storage stability. Examples of basic substances include sodium hydroxide, potassium hydroxide, ammonia, methylamine, propylamine, hexylamine, octylamine, ethanolamine, propanolamine, diethanolamine, N-methyldiethanolamine, dimethylamine, diethylamine, triethylamine, N,N-dimethylethanolamine, 2-dimethylamino-2-methyl-1-propanol, 2-amino-2-methyl-1-propanol, morpholine, dimethylethanolamine, and 2-amino-2-ethyl-1,3-propanediol. Preferably, ammonia, triethylamine, 2-amino-2-methyl-1-propanol, morpholine, dimethylethanolamine, and 2-amino-2-ethyl-1,3-propanediol are used. Basic substances may be used individually or in combination of two or more.

[0054] When using a hydrophobic solvent as the solvent, the resin composition preferably contains a diluent. This can improve storage stability. Examples of diluents include alcohols and propylene glycol ethers. Examples of alcohols include methanol, ethanol, propanol, isopropanol, and butanol. Examples of propylene glycol ethers include propylene glycol methyl ether, propylene glycol ethyl ether, and propylene glycol tert-butyl ether. The diluent may be used alone or in combination of two or more types.

[0055] When a hydrophobic solvent is used as the solvent, the resin composition preferably contains a crosslinking agent. The crosslinking agent may be a compound that reacts with groups such as hydroxyl groups, carboxyl groups, and amino groups present in the resin composition to form a crosslinked structure, and may be, for example, a water-soluble crosslinking agent or an aqueous dispersion of the crosslinking agent (a crosslinking agent dispersed in water by some means). Examples of crosslinking agents include blocked isocyanate compounds, aliphatic or aromatic epoxy compounds, amine compounds, and amino resins. The crosslinking agent may be used alone or in combination of two or more types.

[0056] When a hydrophilic solvent is used as the solvent, the resin composition preferably contains an emulsifier. Examples of emulsifiers include surfactants such as nonionic surfactants and anionic surfactants, with nonionic surfactants being preferred.

[0057] Examples of nonionic surfactants include polyoxyethylene alkyl ethers, polyoxyethylene polyoxypropylene alkyl ethers, polyoxyethylene derivatives, polyoxyethylene fatty acid esters, polyoxyethylene polyhydric alcohol fatty acid esters, polyoxyethylene polyoxypropylene polyols, sorbitan fatty acid esters, polyoxyethylene hydrogenated castor oil, polyoxyalkylene polycyclic phenyl ethers, polyoxyethylene alkylamines, alkyl alkanolamides, and polyalkylene glycol (meth)acrylates. Preferably, polyoxyethylene alkyl ethers, polyoxyethylene fatty acid esters, polyoxyethylene sorbitan fatty acid esters, and polyoxyethylene alkylamines are used.

[0058] Examples of anionic surfactants include alkyl sulfates, polyoxyethylene alkyl ether sulfates, alkylbenzene sulfons, α-olefin sulfons, methyl tauryl salts, sulfosuccinates, ether sulfons, ether carboxylates, fatty acid salts, naphthalene sulfonic acid formalin condensates, alkylamine salts, quaternary ammonium salts, alkyl betaines, and alkylamine oxides. Preferably, polyoxyethylene alkyl ether sulfates and sulfosuccinates are used. The emulsifier may be used alone or in combination of two or more types. [Examples]

[0059] The present invention will be described in detail below using examples, but the present invention is not limited to these examples. In the following, the unit "parts" means "parts by weight". Unless otherwise specified, "%" refers to weight percentage. In the following explanation, unless a specific temperature condition is specified, the temperature condition is room temperature (25°C), and unless a specific pressure condition is specified, the pressure condition is normal pressure (760 mmHg).

[0060] <Example 1> 80 parts of propylene-ethylene copolymer (Tm=61°C) as component (A), 20 parts of polyolefin-based thermoplastic elastomer (Tm=166°C, Tim=152°C, Tem=169°C) as component (B), 4 parts of maleic anhydride, 4 parts of lauryl methacrylate, and 1.5 parts of di-tert-butyl peroxide were mixed in a twin-screw extruder set to a reaction temperature of 170°C and reacted. Vacuum defloration was performed in the extruder to remove any remaining unreacted material. After the reaction, the mixture was cooled to room temperature to obtain a modified polyolefin resin composition. The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.3% by weight, with the total amount of modified polyolefin resin being 100% by weight. The total graft weight of maleic anhydride was measured by alkaline titration. The same procedure was followed for subsequent steps.

[0061] The melting points (Tm) of component (A) and (B), as well as the extrapolation start temperature (Tim) and extrapolation end temperature (Tem), were measured using a differential scanning calorimeter at a heating rate of 10°C / min, in accordance with JIS K7121-1987.

[0062] <Example 2> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that 20 parts of propylene-butene copolymer (Tm=77°C) were used instead of 80 parts of propylene-ethylene copolymer (Tm=61°C). The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.1% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0063] <Example 3> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that 20 parts of propylene-butene copolymer (Tm=86°C) were used instead of 80 parts of propylene-ethylene copolymer (Tm=61°C). The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.4% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0064] <Comparative Example 1> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that the amount of propylene-ethylene copolymer (Tm=61°C) used was changed from 80 parts to 100 parts, and polyolefin-based thermoplastic elastomer (Tm=166°C, Tim=152°C, Tem=169°C) was not used. The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.1% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0065] <Comparative Example 2> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that 100 parts of propylene-butene copolymer (Tm=77°C) were used instead of 80 parts of propylene-ethylene copolymer (Tm=61°C), and polyolefin-based thermoplastic elastomer (Tm=166°C, Tim=152°C, Tem=169°C) was not used. The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.0% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0066] <Comparative Example 3> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that 100 parts of propylene-butene copolymer (Tm=86°C) were used instead of 80 parts of propylene-ethylene copolymer (Tm=61°C), and polyolefin-based thermoplastic elastomer (Tm=166°C, Tim=152°C, Tem=169°C) was not used. The total graft weight of maleic anhydride in the modified polyolefin resin composition was 3.0% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0067] <Comparative Example 4> A modified polyolefin resin composition was obtained in the same manner as in Example 1, except that 80 parts of propylene-butene copolymer (Tm=97°C) were used instead of 80 parts of propylene-ethylene copolymer (Tm=61°C). The total graft weight of maleic anhydride in the modified polyolefin resin composition was 2.9% by weight, with the total amount of modified polyolefin resin being 100% by weight.

[0068] <Test Example 1: Measurement and Calculation of the Average Particle Size of Modified Component (B)> The volume-based particle size distribution was measured using a Malvern Mastersizer 3000, and the average particle size was calculated using the volume-based median diameter Dv50 (the largest particle size below 50% of the sample volume). For the measurement sample, a solution sample of the modified polyolefin resin composition obtained in the examples and comparative examples (solid content: 15% by weight, solvent composition: methylcyclohexane / MEK = 80 / 20 (w / w)) was added to the dispersion solvent (solvent composition: methylcyclohexane / methyl ethyl ketone (MEK) = 80 / 20 (w / w)) so that the laser scattering intensity was approximately 12%.

[0069] In the measurement samples used to measure the particle size distribution, it was confirmed, using the following procedure, that the modified resin (A) was completely dissolved, while the modified resin (B) remained undissolved and existed as particles. 50 g of a solution sample of the modified polyolefin resin composition obtained in the example (solid content: 15% by weight, solvent composition: methylcyclohexane / MEK = 80 / 20 (w / w)) was taken into a centrifuge tube (250 cc) and centrifuged at 10,000 rpm (centrifugal force 15,600 × g) at 15°C for 3 hours. After drying the obtained supernatant and precipitate, differential scanning calorimetry (DSC) was performed. A melting point peak for resin (A) was observed from the solid obtained from the supernatant, and a melting point peak for resin (B) was observed from the solid obtained from the precipitate (i.e., the material that existed as particles without dissolving). Furthermore, when Fourier transform infrared (FT-IR) spectroscopy (ATR method) was measured for both the supernatant and the precipitate obtained in the same manner, peaks originating from the carbonyl group of the α,β-unsaturated carboxylic acid anhydride were observed in both the solid obtained from the supernatant and the solid obtained from the precipitate. This confirmed that the dissolved resin was a modified form of resin (A), and the resin that remained undissolved as particles was a modified form of resin (B). The details of the melting point measurement using DSC are as follows. In accordance with JIS K7121 (1987), approximately 5 mg of the sample is heated to 150°C for 10 minutes and held in a molten state using a DSC measuring device (e.g., "DISCOVERY DSC2500," manufactured by T.A. Instrument Japan). Then, the temperature is lowered at a rate of 10°C / min and held stably at -50°C for 5 minutes. After that, the temperature is raised to 150°C at a rate of 10°C / min, and the peak melting temperature is measured and defined as the melting point. Further details regarding the FT-IR (ATR method) measurement are as follows: Using an FT-IR measuring device (e.g., "FT / IR-4100", manufactured by JASCO Corporation), the measurement was performed at 400-4000 cm⁻¹. -1 The infrared absorption spectrum was observed. Analysis was performed using the accompanying software ("Spectro Manager," JASCO Corporation). Wavenumber 1700–1750 cm⁻¹ -1 The peak appearing in this region is attributed to the carbonyl group of the ring-opened α,β-unsaturated carboxylic acid anhydride, at wavenumbers 1750-1820 cm⁻¹. -1 The peaks observed were attributed to the carbonyl group of the unopened α,β-unsaturated carboxylic acid anhydride.

[0070] <Test Example 2: Measurement of Adhesion Strength (Heat Resistance) by Tensilon Peel Test> To the solution samples (solids content: 15%, solvent composition: methylcyclohexane / MEK=80 / 20 (w / w)) of the modified polyolefin resin compositions obtained in the examples and comparative examples, 0.52 g of HDI isocyanurate (solids content 100%, NCO content 20%) was added as a curing agent and mixed. This mixture was then applied to aluminum foil using a #16 Meyer bar to achieve a resin dry film thickness of 3 μm. The coating was then dried in a constant temperature dryer set to 100°C. The coated aluminum foil was then laminated to an unoriented polypropylene (CPP) sheet and heat-pressed at 200°C, 0.1 MPa, and 1 second. After that, aging was performed for 3 days in a constant temperature dryer set to 60°C. Test specimens were cut to a width of 15 mm, and the laminate adhesive strength was measured under conditions of a peel angle of 180°C, a peel speed of 100 mm / min, and a 120°C atmosphere.

[0071] <Test Example 3: Evaluation of Solution Stability> 10 g of solution samples (solid content: 15%, solvent composition: methylcyclohexane / MEK=80 / 20(w / w)) of the modified polyolefin resin compositions obtained in the examples and comparative examples were placed in screw-cap tubes and left to stand at 5°C. The change in the solution state after 5 days was observed. The evaluation criteria were as follows: samples that maintained fluidity after 5 days were marked with "○", and samples that were gel-like or solidified were marked with "×".

[0072] Table 1 below summarizes the melting points, extracellular melting start temperatures, and extracellular melting end temperatures of the raw materials used in Examples 1-3 and Comparative Examples 1-4, as well as the evaluation and measurement results for Test Examples 1-3.

[0073] The abbreviations in Table 1 have the following meanings. Tim: Extramelting initiation temperature Tem: Extramelting termination temperature Adhesion strength: Tensilon peel test adhesion strength

[0074] [Table 1]

[0075] From the above results, it can be seen that the resin composition of the present invention, which comprises a modified product obtained by modifying a polyolefin resin (A) having a melting point of 50 to 95°C or lower with an α,β-unsaturated carboxylic acid and / or its derivative, and a modified product obtained by modifying a polyolefin resin (B) having an extracellular melting initiation temperature (Tim) of 120°C or higher with an α,β-unsaturated carboxylic acid and / or its derivative, wherein the modified product of component (B) is dispersed in the modified product of component (A), and the average particle size of the modified product of component (B) is 0.1 to 100 μm, can exhibit excellent heat resistance and adhesion to difficult-to-adhere substrates and excellent solution stability.

Claims

1. A resin composition comprising: a modified polyolefin resin (A) having a melting point of 50 to 95°C measured at a heating rate of 10°C / min using a differential scanning calorimeter in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives; and a modified polyolefin resin (B) having an extracellular melting onset temperature (Tim) of 120°C or higher measured at a heating rate of 10°C / min using a differential scanning calorimeter in accordance with JIS K7121-1987, modified with one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives, wherein the modified resin (B) is dispersed within the modified resin (A), and the average particle size of the modified resin (B) is 0.1 to 100 μm.

2. The resin composition according to claim 1, wherein one or more compounds selected from the group consisting of α,β-unsaturated carboxylic acids and their derivatives contain a (meth)acrylic acid ester.

3. The resin composition according to claim 1, wherein the melting point of resin (B), measured by differential scanning calorimeter in accordance with JIS K7121-1987 at a heating rate of 10°C / min, is 140 to 200°C.

4. The resin composition according to claim 1, wherein the mass ratio of the modified resin (A) to the modified resin (B) is modified resin (A):modified resin (B) = 50:50 to 95:

5.

5. The resin composition according to claim 1, wherein the difference (Tem-Tim) between the extrapolation melting termination temperature (Tem) and the extrapolation melting start temperature (Tim) of resin (B), measured by differential scanning calorimeter in accordance with JIS K7121-1987 at a heating rate of 10°C / min, is 25°C or less.

6. A primer, adhesive, paint, or ink comprising the resin composition described in claim 1.

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