Resin composition and hot melt adhesive composition

Abstract

The purpose of the present invention is to provide a resin composition which exhibits excellent water vapor barrier properties, while maintaining the fluidity, adhesiveness, and thermal shock resistance of a resin with excellent low-pressure moldability. The resin composition comprises (A) a polyolefin resin, (B) an acid-modified polyolefin resin, (C) a styrene-isobutylene-styrene block copolymer, (D) an adhesion imparting agent, and (E) a filler, wherein: when the total content of the polyolefin resin (A), acid-modified polyolefin resin (B), styrene-isobutylene-styrene block copolymer (C), and adhesion imparting agent (D) is taken as 100 parts by mass, the content of the styrene-isobutylene-styrene block copolymer (C) is 8-32 parts by mass, the content of the adhesion imparting agent (D) is 8-27 parts by mass, and the content of the filler (E) is 1-13 parts by mass; and the filler (E) has a plate shape.

Description

Technical Field

[0001] The present invention relates to a resin composition. More specifically, it relates to a resin composition and a hot melt adhesive composition that are excellent in fluidity, water vapor barrier property, adhesiveness, and heat shock resistance.

Background Art

[0002] As insulating resins used for encapsulating electrical and electronic components used in automobiles, electrical appliances, etc., two-component curable epoxy resins and silicone resins have generally been used. However, since a long process is required and there is also a possibility of damaging the electrical and electronic components due to the shrinkage stress during curing, in recent years, encapsulation of electrical and electronic components by low-pressure molding using thermoplastic resins is known.

[0003] From the viewpoints of electrical insulation, water resistance, durability, and melt viscosity, polyester resins are used as suitable materials for encapsulating resins for electrical and electronic components. However, in low-temperature and low-pressure molding for reducing damage to electrical and electronic components, the adhesiveness between the electrical and electronic components and the encapsulating resin becomes insufficient, and the intended electrical insulation and waterproof properties are often not fully exhibited. Therefore, attempts to blend an adhesion promoter having a functional group, etc. have been actively studied from the viewpoint of improving adhesiveness (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In recent years, in addition to the above-mentioned required physical properties, advanced water vapor barrier properties have sometimes been required for electrical and electronic components. However, when using a thermoplastic resin blended with an adhesion-imparting agent as in Patent Document 1, although the adhesiveness is improved, there has been a problem that the water vapor barrier property cannot be ensured. In the conventional technology, a sealing resin composition capable of achieving both water vapor barrier properties while maintaining the fluidity, adhesiveness, and heat shock resistance of a resin excellent in low-pressure molding has not been proposed.

[0006] The present invention has been made in view of such problems of the conventional technology. That is, an object of the present invention is to provide a resin composition excellent in water vapor barrier properties while maintaining the fluidity, adhesiveness, and heat shock resistance of a resin excellent in low-pressure molding.

Means for Solving the Problems

[0007] As a result of intensive studies, the present inventors have found that the above problems can be solved by the means shown below and have reached the present invention. That is, the present invention has the following configuration. (1) A resin composition containing a polyolefin resin (A), an acid-modified polyolefin resin (B), a styrene-isobutylene-styrene block copolymer (C), an adhesion-imparting agent (D), and a filler (E), wherein when the total of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion-imparting agent (D) is 100 parts by mass, the content of the styrene-isobutylene-styrene block copolymer (C) is 8 to 32 parts by mass, the content of the adhesion-imparting agent (D) is 8 to 27 parts by mass, the content of the filler (E) is 1 to 13 parts by mass, and the filler (E) is plate-shaped. (2) The resin composition according to (1), wherein the polyolefin resin (A) includes a polypropylene resin and further includes at least one of an ethylene-α-olefin copolymer and a propylene-α-olefin copolymer. (3) The resin composition according to (1) or (2), wherein the melting point of the acid-modified polyolefin resin (B) is 100°C or higher. (4) The resin composition according to any one of (1) to (3), wherein the styrene content of the styrene-isobutylene-styrene block copolymer (C) is 10 to 30% by weight. (5) The resin composition according to any one of (1) to (4), wherein the hydroxyl value of the adhesion promoter (D) is 1 to 100 mgKOH / g. (6) When the total of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C) and the adhesion promoter (D) is 100 parts by mass, the content of the polyolefin resin (A) is 38 to 70 parts by mass, and the content of the acid-modified polyolefin resin (B) is 1 to 22 parts by mass. The resin composition according to any one of (1) to (5). (7) A hot melt adhesive composition containing the resin composition according to any one of (1) to (6).

Advantages of the Invention

[0008] The resin composition of the present invention exhibits excellent resin fluidity, adhesiveness and heat shock resistance in low-pressure molding, and further has excellent water vapor barrier properties. Therefore, by using it as a sealing material for products that require high waterproofing, it is possible to manufacture products that satisfy the water vapor barrier properties. In particular, the resin composition of the present invention can be used as a hot melt adhesive, and is particularly suitable for sealing applications of electric and electronic components.

Brief Description of the Drawings

[0009]

Figure 1

Embodiments for Carrying Out the Invention

[0010] Hereinafter, the present invention will be described in detail.

[0011] <Polyolefin Resin (A)> The resin composition of the present invention contains a polyolefin resin (A). By containing the polyolefin resin (A), good water vapor barrier properties can be imparted to the resin composition. The polyolefin resin (A) used in the present invention is not particularly limited, but a polypropylene resin is preferred from the viewpoint of water vapor barrier properties. Also, an ethylene-α-olefin copolymer or a propylene-α-olefin copolymer is preferred from the viewpoint of adhesion to metals and films. In order to highly balance water vapor barrier properties and adhesiveness, a polypropylene resin can be used in combination with an ethylene-α-olefin copolymer or a propylene-α-olefin copolymer. Here, the polypropylene resin is a so-called homopolypropylene mainly composed of propylene units, which does not contain a copolymerization component such as an α-olefin other than propylene, or even if it contains, it is only a very small amount of about 1 mol%. Also, the polyolefin resin (A) does not correspond to the acid-modified polyolefin resin (B) described later, and refers to a non-acid-modified one.

[0012] When a polypropylene resin and an ethylene-α-olefin copolymer and / or a propylene-α-olefin copolymer (hereinafter collectively referred to as an olefin copolymer) are used in combination as the polyolefin resin (A), the preferred blending ratio of the polypropylene resin / olefin copolymer is 20 / 80 to 80 / 20 by mass ratio, more preferably 30 / 70 to 70 / 30, and even more preferably 40 / 60 to 60 / 40. By setting it within the above range, it is possible to highly balance water vapor barrier properties and adhesiveness in particular.

[0013] The polyolefin resin (A) used in the present invention preferably has a melt mass flow rate (hereinafter sometimes abbreviated as MFR) measured according to JIS K 7210-1:2014 (test temperature 190°C, nominal load 2.16 kg) of 10 to 70 g / 10 min. By setting it to be equal to or higher than the lower limit value, the fluidity of the resin is appropriately maintained and the moldability becomes good. Further, by setting it to be equal to or lower than the upper limit value, extreme softening as a resin composition due to a decrease in viscosity is prevented, and the mechanical properties become good. When the polyolefin resin (A) contains a plurality of types of polyolefin resins, it is preferable that each polyolefin resin is within the above range.

[0014] When the resin composition of the present invention is used as a hot melt adhesive, in order to mold it without causing thermal degradation of the resin as much as possible, rapid melting at 210 to 240°C is required. Therefore, the upper limit of the melting point of the polyolefin resin (A) is preferably 210°C. Preferably, it is 200°C or lower, more preferably 190°C or lower. The lower limit is preferably 90°C or higher, more preferably 100°C or higher, still more preferably 110°C or higher, and particularly preferably 120°C or higher. It is good to set it 5 to 10°C or higher than the heat resistance temperature required for the corresponding application. When the polyolefin resin (A) contains a plurality of types of polyolefin resins, it is preferable that each polyolefin resin is within the above range.

[0015] When the total of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion promoter (D) is 100 parts by mass, the content of the polyolefin resin (A) in the resin composition of the present invention is preferably 38 parts by mass or more, more preferably 40 parts by mass or more, still more preferably 42 parts by mass or more, and particularly preferably 48 parts by mass or more. Also, it is preferably 70 parts by mass or less, more preferably 68 parts by mass or less, and still more preferably 63 parts by mass or less. When the content ratio of the polyolefin resin (A) is equal to or higher than the lower limit value, particularly good water vapor barrier properties can be imparted to the resin composition. Further, when it is equal to or lower than the upper limit value, the heat shock resistance of the resin composition becomes good.

[0016] <Acid-modified polyolefin resin (B)> The resin composition of the present invention contains an acid-modified polyolefin resin (B). By containing the acid-modified polyolefin resin (B), good dispersibility with the polyolefin resin (A), styrene-isobutylene-styrene block copolymer (C), adhesion promoter (D), and filler (E) can be imparted. As a result, appropriate adhesiveness, heat shock resistance, and water vapor barrier properties can be imparted to the resin composition. The acid-modified polyolefin resin (B) is not particularly limited as long as it is a resin having a polyolefin segment and a carboxylic acid segment. For example, ethylene-unsaturated carboxylic acid copolymers such as ethylene-vinyl acetate-maleic anhydride terpolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, etc., unsaturated carboxylic acid graft-modified polyolefin resins such as maleic anhydride graft-modified polypropylene, maleic anhydride graft-modified propylene-α-olefin copolymer, etc. are included. Among them, unsaturated carboxylic acid graft-modified polyolefin resins are preferred, and maleic anhydride is more preferred as the unsaturated carboxylic acid used for graft modification.

[0017] The melting point of the acid-modified polyolefin resin (B) used in the present invention is preferably 100°C or higher, more preferably 110°C or higher, and even more preferably 120°C or higher. Also, it is preferably 160°C or lower, more preferably 150°C or lower. If the melting point of the acid-modified polyolefin resin (B) is at or above the lower limit value, the heat resistance of the resin composition is good, and if it is at or below the upper limit value, the fluidity during molding of the resin composition is good.

[0018] In the resin composition of the present invention, the content of the acid-modified polyolefin resin (B) is preferably 1 part by mass or more, more preferably 3 parts by mass or more, and even more preferably 5 parts by mass or more when the total of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion promoter (D) is 100 parts by mass. Further, it is preferably 22 parts by mass or less, more preferably 20 parts by mass or less, even more preferably 15 parts by mass or less, and particularly preferably 10 parts by mass or less. When the content ratio of the acid-modified polyolefin resin (B) is equal to or higher than the lower limit value, the dispersibility with the polyolefin resin (A), the styrene-isobutylene-styrene block copolymer (C), the adhesion promoter (D), and the filler (E) becomes good. Further, when the content ratio of the acid-modified polyolefin resin (B) is equal to or lower than the upper limit value, the mechanical properties become good.

[0019] <Styrene-isobutylene-styrene block copolymer (C)> The resin composition of the present invention contains a styrene-isobutylene-styrene block copolymer (C). By containing the styrene-isobutylene-styrene block copolymer (C), appropriate heat shock resistance can be imparted to the resin composition. The styrene-isobutylene-styrene block copolymer (C) used in the present invention is not particularly limited, but a triblock structure is preferable from the viewpoints of water vapor barrier properties and heat shock resistance.

[0020] The styrene content of the styrene-isobutylene-styrene block copolymer (C) used in the present invention is preferably 10% by weight or more, more preferably 13% by weight or more, and even more preferably 15% by weight or more. Further, it is preferably 30% by weight or less, more preferably 25% by weight or less, and even more preferably 20% by weight or less. When the styrene content of the styrene-isobutylene-styrene block copolymer (C) is equal to or higher than the lower limit value, the heat resistance becomes good. Further, when the styrene content of the styrene-isobutylene-styrene block copolymer (C) is equal to or lower than the upper limit value, the flexibility increases and the heat shock resistance becomes good.

[0021] In the resin composition of the present invention, when the total amount of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion promoter (D) is 100 parts by mass, the content of the styrene-isobutylene-styrene block copolymer (C) needs to be 8 parts by mass or more. Preferably it is 10 parts by mass or more, more preferably 12 parts by mass or more, still more preferably 15 parts by mass or more, and particularly preferably 18 parts by mass or more. Also, it needs to be 32 parts by mass or less. Preferably it is 30 parts by mass or less, more preferably 28 parts by mass or less, still more preferably 25 parts by mass or less, and particularly preferably 22 parts by mass or less. When the content ratio of the styrene-isobutylene-styrene block copolymer (C) is at least the above lower limit value, the thermal shock resistance becomes good. Also, when the content ratio of the styrene-isobutylene-styrene block copolymer (C) is at most the above upper limit value, the fluidity of the resin becomes high and the moldability becomes good.

[0022] <Adhesion promoter (D)> The resin composition of the present invention contains an adhesion promoter (D). By containing the adhesion promoter (D), when the resin composition is used as a sealing agent, good adhesiveness can be imparted, and in addition, the fluidity of the resin composition can be appropriately improved. The adhesion promoter (D) used in the present invention is not particularly limited, and phenolic compounds, xylene-modified phenolic resins, terpene-modified phenolic resins, hydrogenated terpene-modified phenolic resins obtained by hydrogenating terpene-modified phenolic resins, etc. can be used. In particular, from the viewpoint of compatibility with the polyolefin resin (A), xylene-modified phenolic resins and terpene-modified phenolic resins are preferred.

[0023] The adhesion promoter (D) used in the present invention preferably has a hydroxyl group. When the adhesion promoter (D) has a hydroxyl group, it can exhibit the effect of improving the wettability to the substrate, improving the adhesiveness to the substrate, and improving the insulation. The hydroxyl value of the adhesion promoter (D) is preferably 1 mgKOH / g or more, more preferably 30 mgKOH / g or more, and even more preferably 50 mgKOH / g or more. Also, it is preferably 100 mgKOH / g or less, more preferably 90 mgKOH / g or less, even more preferably 80 mgKOH / g or less, and particularly preferably 70 mgKOH / g or less. When the hydroxyl value is below the above upper limit value, the adhesiveness can be improved while appropriately maintaining the moisture permeability.

[0024] The value of the hydroxyl value can be measured, for example, by the potentiometric titration method defined in JIS K 0070:1992.

[0025] When the total amount of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion promoter (D) in the resin composition of the present invention is 100 parts by mass, the content of the adhesion promoter (D) needs to be 8 parts by mass or more. Preferably it is 10 parts by mass or more, more preferably 13 parts by mass or more, and even more preferably 15 parts by mass or more. Also, it needs to be 27 parts by mass or less, preferably 25 parts by mass or less, more preferably 22 parts by mass or less, and even more preferably 20 parts by mass or less. When the content of the adhesion promoter (D) is within the above range, particularly good adhesiveness can be exhibited. Also, a decrease in the flexibility of the resin composition and a decrease in adhesiveness due to embrittlement are suppressed.

[0026] <Filler (E)> The resin composition of the present invention contains a filler (E). By containing the filler (E), good water vapor barrier properties can be imparted to the resin composition. The filler (E) used in the present invention is not particularly limited, and glass beads, calcium carbonate, kaolin, talc, glass fiber, carbon fiber, clay, etc. can be used. The filler (E) used in the present invention is plate-shaped. By making the filler (E) plate-shaped, the water vapor barrier properties are particularly improved. Here, being plate-shaped means a shape like a plate with an extremely small height compared to the width and depth of the filler. The aspect ratio of the filler (E), that is, the ratio of the minor axis to the major axis of the filler (E) (major axis / minor axis) is preferably from 3 to 500. The aspect ratio of the filler (E) may be 5 or more, 10 or more, 20 or more, 50 or more, 100 or more, and also 450 or less, 400 or less, 350 or less, 300 or less, 200 or less. The aspect ratio of the filler (E) can be determined by a method such as automatic area measurement of an image obtained by observing the filler (E) with an electron microscope. If the aspect ratio of the filler (E) is too low, the water vapor barrier properties will deteriorate, and if the aspect ratio is too high, the dispersibility will deteriorate and the mechanical properties may decrease.

[0027] When the total of the polyolefin resin (A), acid-modified polyolefin resin (B), styrene-isobutylene-styrene block copolymer (C) and adhesion promoter (D) is 100 parts by mass, the content of the filler (E) in the resin composition of the present invention needs to be 1 part by mass or more, preferably 2 parts by mass or more, more preferably 4 parts by mass or more. When the content of the filler (E) is at or above the lower limit value, the water vapor barrier properties are good. Also, the mechanical properties of the resin composition are good, and the shear adhesion strength may be improved. Also, the content of the filler (E) needs to be 13 parts by mass or less, preferably 10 parts by mass or less, more preferably 8 parts by mass or less. If the content of the filler (E) is at or below the upper limit value, the adhesiveness is good.

[0028] The particle size (D50) of the filler (D) in the resin composition of the present invention may be, for example, 1 to 50 μm. The particle size (D50) can be measured by, for example, the laser diffraction method or the dynamic light scattering method.

[0029] <Resin composition> The resin composition of the present invention contains at least the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), the adhesion promoter (D), and the filler (E). Further, various additives such as antioxidants may be contained as necessary.

[0030] The resin composition of the present invention preferably has a melt viscosity at 240°C of 5 to 1500 dPa·s. The melt viscosity of the resin composition can be achieved by appropriately adjusting the types and blending ratios of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), the adhesion promoter (D), and the filler (E). Here, the melt viscosity at 240°C is a value measured as follows. That is, the resin composition is dried to a moisture content of 0.1% or less, and then the resin composition stabilized at 240°C is passed through a die having a pore diameter of 1.0 mm and a thickness of 10 mm at a pressure of 98 N / cm 2 by a flow tester (model number CFT-500C) manufactured by Shimadzu Corporation, and it is the measured value of the viscosity. By using a resin composition having a melt viscosity of 1500 dPa·s or less, preferably 1000 dPa·s or less, a product excellent in electrical insulation can be obtained at a relatively low injection pressure of 0.1 to 20 MPa without sacrificing the properties. Also, from the viewpoint of the resin composition injection operation, it is preferable that the melt viscosity at 230°C is lower, but considering the adhesiveness and cohesive force of the resin composition, the lower limit is preferably 5 dPa·s or more, more preferably 10 dPa·s or more, still more preferably 30 dPa·s or more, and most preferably 50 dPa·s or more.

[0031] The resin composition of the present invention may further contain an antioxidant. The antioxidant used in the present invention is not particularly limited as long as it can prevent the oxidation of the polyolefin resin (A), and hindered phenol antioxidants, phosphorus antioxidants, thioether antioxidants, etc. can be used. For example, as hindered phenols, 1,3,5-tris(3,5-di-t-butyl-4-hydroxybenzyl)isocyanurate, 1,1,3-tri(4-hydroxy-2-methyl-5-t-butylphenyl)butane, 1,1-bis(3-t-butyl-6-methyl-4-hydroxyphenyl)butane, 3,5-bis(1,1-dimethylethyl)-4-hydroxy-benzenepropanoic acid, pentaerythrityl tetrakis(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 3-(1,1-dimethylethyl)-4-hydroxy-5-methyl-benzenepropanoic acid, 3,9-bis[1,1-dimethyl-2-[(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3,5-trimethyl-2,4,6-tris(3’,5’-di-t-butyl-4’-hydroxybenzyl)benzene; as phosphorus compounds, 3,9-bis(p-nonylphenoxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5]undecane, 3,9-bis(octadecyloxy)-2,4,8,10-tetraoxa-3,9-diphosphaspiro[5.5] Undecane, tris(monononylphenyl) phosphite, triphenoxyphosphine, isodecyl phosphite, isodecyl phenyl phosphite, diphenyl 2-ethylhexyl phosphite, dinonyl phenyl bis(nonylphenyl) ester phosphoric acid, 1,1,3-tris(2-methyl-4-ditridecyl phosphite-5-t-butylphenyl) butane, tris(2,4-di-t-butylphenyl) phosphite, pentaerythritol bis(2,4-di-t-butylphenyl phosphite), 2,2'-methylenebis(4,6-di-t-butylphenyl) 2-ethylhexyl phosphite, bis(2,6-di-t-butyl-4-methylphenyl) pentaerythritol diphosphite, as a thioether type, 4,4'-thiobis[2-t-butyl-5-methylphenol] bis[3-(dodecylthio)propionate], thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene] bis[3-(tetradecylthio)-propionate], pentaerythritol tetrakis(3-n-dodecylthiopropionate), bis(tridecyl) thiodipropionate can be mentioned, and these can be used alone or in combination.

[0032] The content of the antioxidant is preferably 0.1 part by mass or more, more preferably 0.2 part by mass or more, and still more preferably 0.3 part by mass or more with respect to 100 parts by mass in total of the polyolefin resin (A), acid-modified polyolefin resin (B), styrene-isobutylene-styrene block copolymer (C) and adhesion promoter (D). If the content is too small, it may have an adverse effect on the long-term durability at high temperatures. Also, it is preferably 5 parts by mass or less, more preferably 3 parts by mass or less, and still more preferably 1 part by mass or less. If the content is too large, it may have an adverse effect on adhesiveness and the like.

[0033] The resin composition of the present invention may contain, within a range that does not impair the effects of the present invention, other resins such as polyamide, polycarbonate, acrylic, ethylene vinyl acetate, etc., isocyanate compounds, curing agents such as melamine, pigments such as carbon black, titanium oxide, etc., and flame retardants such as antimony trioxide, brominated polystyrene, etc., which do not fall under any of the polyolefin resin (A), acid-modified polyolefin resin (B), styrene-isobutylene-styrene block copolymer (C), adhesion promoter (D), and filler (E). By blending these components, adhesiveness, flexibility, durability, etc. may be improved. At that time, the polyolefin resin (A) is preferably contained in an amount of 30 to 70% by weight, more preferably 40 to 60% by weight, based on the total resin composition of the present invention. If the content of the polyolefin resin (A) is too small, the excellent water vapor barrier property and durability inherent in the polyolefin resin (A) tend to decrease. If it is too large, the flexibility and adhesiveness tend to decrease.

[0034] Furthermore, when the resin composition of the present invention is required to have weather resistance, it is preferable to add a light stabilizer. Examples of the light stabilizer include benzotriazole-based light stabilizers, benzophenone-based light stabilizers, hindered amine-based light stabilizers, nickel-based light stabilizers, benzoate-based light stabilizers, and the like. Examples of the benzotriazole-based light stabilizer include 2-(3,5-di-tert-amyl-2'-hydroxyphenyl)benzotriazole, 2-(2-hydroxy-5-tert-octylphenyl)benzotriazole, 2-(2'-hydroxy-3'-tert-butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazol-2-yl)-p-cresol, 2-(2'-hydroxy-5'-methylphenyl)-benzotriazole, 2,4-di-tert-butyl-6-(5-chlorobenzotriazol-2-yl)phenol, 2-[2-hydroxy-3,5-di(1,1-dimethylbenzyl)]-2H-benzotriazole, and the like. Examples of the benzophenone-based light stabilizer include 2-hydroxy-4-(octyloxy)benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-benzophenone-5-sulfonic acid, 2-hydroxy-4-n-dodecyloxybenzophenone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-2'-dihydroxy-4-methoxybenzophenone, 2,2'-dihydroxy-4,4'-dimethoxybenzophenone, and the like.Examples of hindered amine light stabilizers include bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, dimethyl succinate·1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-triazine-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidyl)imino}hexamethylene(2,2,6,6-tetramethyl-4-piperidyl)imino}], 1,3,5-tris(3,5-di-tert-butyl-4-hydroxybenzyl)-s-triazine-2,4,6(1H,3H,5H)trione, tris(4-tert-butyl-3-hydroxy-2,6-dimethylbenzyl)-s-triazine-2,4,6-(1H,3H,5H)trione, and the like. Examples of nickel-based light stabilizers include [2,2'-thio-bis(4-tert-octylphenolate)]-2-ethylhexylamine-nickel-(II), nickel dibutyldithiocarbamate, [2',2'-thio-bis(4-tert-octylphenolate)]n-butylamine-nickel, and the like. Examples of benzoate-based light stabilizers include 2,4-di-t-butylphenyl-3,5'-di-tert-butyl-4'-hydroxybenzoate, and the like. These light stabilizers can be used alone or in combination. When added, the addition amount is preferably 0.1% by mass or more and 5% by mass or less based on the entire resin composition. If it is less than 0.1% by mass, the weather resistance effect may be poor. If it exceeds 5% by mass, it may have an adverse effect on adhesiveness and the like.

[0035] <Hot melt adhesive composition> The resin composition of the present invention can be used as a hot melt adhesive composition. As the hot melt adhesive composition, for example, it can be suitably used as a sealing agent for electric and electronic parts. As a specific example of the usage method, by injecting the resin composition of the present invention into a mold in which a product to be waterproofed is set, a molded body in which the product is sealed can be obtained. More specifically, when using a screw type applicator for hot melt molding, it is heated and melted at around 180 to 250 °C, injected into a mold through an injection nozzle, and after a certain cooling time, the molded product can be removed from the mold to obtain a molded product.

[0036] The type of the applicator for hot melt molding is not particularly limited, and examples include the vertical extrusion molding machine IMC-18F9 manufactured by Imoto Seisakusho, the hybrid type small vertical injection molding machine STX20 manufactured by Nissei Plastic Industrial Co., Ltd., THX5S1VN, etc.

Examples

[0037] In order to explain the present invention in more detail, examples and comparative examples are given below, but the present invention is not limited by the examples. In addition, each measured value described in the examples and comparative examples was measured by the following method.

[0038] <Measurement of melting point> Using a differential scanning calorimeter "DSC220 type" manufactured by Seiko Instruments Inc., 5 mg of the measurement sample (polyolefin resin (A) or acid-modified polyolefin resin (B)) was placed in an aluminum pan, covered with a lid and sealed, heated to 230 °C at a heating rate of 20 °C / min once, and melted. Then, it was cooled to -130 °C at 20 °C / min using liquid nitrogen, held for 5 minutes, and then measured from -130 °C to 230 °C at a heating rate of 20 °C / min. The minimum point of the endothermic peak as shown in Figure 1 in the obtained curve (× mark in the figure) was defined as the melting point (Tm).

[0039] <Hydroxyl value> The value of the hydroxyl value of the adhesion promoter (D) was measured by the potentiometric titration method specified in JIS K 0070:1992.

[0040] <Melt viscosity> The compounded raw material or resin composition dried to a moisture content of 0.1% or less was filled into the cylinder at the center of the heater set at 240°C in a flow tester (CFT-500C type) manufactured by Shimadzu Corporation. After 1 minute from the filling, a load was applied to the sample via a plunger, and the melted sample was extruded from the die (aperture diameter: 1.0 mm, thickness: 10 mm) at the bottom of the cylinder at a pressure of 98 N / cm2. The descent distance and descent time of the plunger were recorded, and the melt viscosity was calculated. From the value of the melt viscosity, the melt characteristics (fluidity) were evaluated according to the following evaluation criteria. Evaluation criteria 〇: Melt viscosity @240°C is 5 dPa·s or more and less than 1000 dPa·s △: Melt viscosity @240°C is 1000 dPa·s or more and less than 1500 dPa·s ×: Melt viscosity @240°C is 1500 dPa·s or more

[0041] <Water vapor barrier property> A film with a thickness of about 120 μm was prepared from the resin composition by heat pressing using a heat press machine (SA-303 manufactured by Tester Sangyo Co., Ltd.). The heat press conditions were a temperature of 200°C, a press pressure of 10 MPa, and a press time of 30 seconds. A test piece based on JIS Z0208:1976 was cut out from the heat-pressed film using a cutting machine. Next, the film was set in a jig defined in JIS Z0208:1976 and left standing for a total of 96 hours in an environment of 25°C and 90% relative humidity (RH). Samples were taken out and weighed 24 hours, 48 hours, 72 hours, and 96 hours after the start of the test. The water vapor transmission rate (water vapor barrier property) was calculated from the weight of calcium chloride absorbed every 24 hours between (1) 24 hours and 48 hours, (2) 48 hours and 72 hours, and (3) 72 hours and 96 hours, and the average value of the three water vapor transmission rate values was taken as the water vapor transmission rate. The water vapor transmission rate was determined by the following formula. The water vapor transmission area refers to the area of the film prepared from the resin composition. Water vapor transmission rate (g / (m 2 ·24h))=(240×m) / (t×s) m: Total increased mass (mg) in the last two weighing intervals for which the test was conducted t: Time of the last two weighing intervals for which the test was conducted = 24 h s: Moisture permeation area (cm 2 ) Evaluation criteria ◎: Moisture permeability less than 0.5 (g / (m 2 ·24 h)) 〇: Moisture permeability 0.5 (g / (m 2 ·24 h)) or more and less than 1.0 (g / (m 2 ·24 h)) △: Moisture permeability 1.0 (g / (m 2 ·24 h)) or more and less than 1.5 (g / (m 2 ·24 h)) ×: Moisture permeability 1.5 (g / (m 2 ·24 h)) or more

[0042] <Adhesion test (T - peel adhesion strength)> Method for preparing T - peel adhesion test pieces The substrate (aluminum substrate: A5052 (thickness: 0.1 mm)) was cut into a size of 40 mm × 25 mm, and the surface was wiped with acetone to remove oil. Then, a film with a thickness of about 200 μm was prepared from the resin composition by heat pressing using a heat press machine (SA - 303 manufactured by Tester Sangyo Co., Ltd.). The heat press conditions were a temperature of 200 °C, a press pressure of 6 MPa, and a press time of 10 seconds. The heat - pressed film was cut into a size of 20 mm × 25 mm, and two pieces were overlapped and sandwiched between the pre - cut aluminum substrates, and heat sealing was performed using a heat - seal tester (TP - 701 - B manufactured by Tester Sangyo Co., Ltd.). The heat - seal conditions were a temperature of 220 °C, a pressure of 0.4 MPa, and a press time of 30 seconds, and a T - peel adhesion test piece in which a film made of the resin composition was sandwiched between aluminum substrates was obtained.

[0043] T - peel adhesion strength test method Using an autograph (AG-IS manufactured by Shimadzu Corporation), the T-peel adhesion strength test piece was used to sandwich the aluminum substrate with a chuck, and the film layer made of the resin composition was peeled off with a T-peel at 25°C or 90°C, and the T-peel adhesion strength was measured. The pulling speed was 300 mm / min. Evaluation criteria ○: T-peel adhesion strength of 70 N / 25 mm or more △: T-peel adhesion strength of 40 N / 25 mm or more and less than 70 N / 25 mm ×: T-peel adhesion strength of less than 40 N / 25 mm

[0044] <Thermal shock resistance test> Method for preparing a thermal shock resistance test sample Among the base materials (aluminum substrate: A5052 (40 mm × 30 mm × 5 mm thickness)), one side with a length of 30 mm was machined into 30 mm × 1 mm × 1 mm, and the machined part was blasted so that Rz (surface roughness) was about 5 μm, and the surface was wiped with acetone to remove oil. Next, the base material was set in a predetermined mold, and the resin composition was injection-molded into the machined part using an injection molding machine (Hybrid small vertical injection molding machine THX5S1VN manufactured by Nissei Plastic Industrial Co., Ltd.) to obtain a thermal shock resistance test sample adhered to the machined aluminum base material part. The injection molding conditions were a temperature of 240°C, a mold temperature of 80°C, an injection speed of 30 mm / s, a holding pressure of 50 MPa, an injection time of 10 seconds, a holding pressure time of 20 seconds, and a pressing time of 10 seconds.

[0045] Thermal shock resistance test method Using a thermal shock test chamber (TSE-11 manufactured by Espec Corporation), the thermal shock resistance test samples were each carried out in an environment of reciprocating between -45°C and 95°C (1 cycle: -45°C for 9 minutes and 95°C for 10 minutes), and the test was carried out up to 2000 cycles. Evaluation criteria ○: No cracks in the resin composition or peeling from the aluminum substrate after 2000 cycles ×: Cracks in the resin composition or peeling from the aluminum substrate after 2000 cycles

[0046] <Example 1 ,2,4~9, Comparative Examples 1~8 , Reference Example 3 > At the ratios described in Table 1, polyolefin resin (A), acid-modified polyolefin resin (B), styrene-isobutylene-styrene block copolymer (C) (styrene-ethylene-butylene-styrene block copolymer in Resin Composition 17), adhesion promoter (D), and filler (E) were melt-kneaded at a die temperature of 160°C to 220°C using a twin-screw extruder to obtain Resin Compositions 1 to 17. By the separately described method, the melt viscosity, water vapor barrier property, T-peel adhesion strength, and heat shock resistance of the resin compositions were evaluated. The evaluation results are as shown in Table 1 below.

[0047]

Table 1

[0048] The polyolefin resin, acid-modified polyolefin resin, styrene-isobutylene-styrene block copolymer, adhesion promoter, and filler used in Table 1 are as follows. Polyolefin resin (A-1): J107G, manufactured by Prime Polymer Co., Ltd., homopolypropylene resin, melting point: 165°C, density: 0.90 g / cm 3 Polyolefin resin (A-2): EUL731, manufactured by Sumitomo Chemical Co., Ltd., ethylene-α-olefin copolymer, melting point: 113 to 117°C, density: 0.90 g / cm 3 Polyolefin resin (A-3): Toughmer PN-20300, manufactured by Mitsui Chemicals, Inc., propylene-α-olefin copolymer, melting point: 160°C, density: 0.87 g / cm 3 Acid-modified polyolefin resin (B-1): PMA H1100P, manufactured by Toyobo Co., Ltd., maleic anhydride graft-modified polypropylene resin, melting point: 147°C, molecular weight Mw: 74000 Styrene-isobutylene-styrene block copolymer (C-1): SIBSTAR 062T, manufactured by Kaneka Corporation, styrene-isobutylene-styrene block copolymer, styrene content: 23% by weight, MFR: 10 g / 10 min (230 °C, 2.16 kg), density: 0.95 g / cm 3 Styrene-isobutylene-styrene block copolymer (C-2): SIBSTAR 102T, manufactured by Kaneka Corporation, styrene-isobutylene-styrene block copolymer, styrene content: 15% by weight, MFR: 0.6 g / 10 min (230 °C, 2.16 kg), density: 0.94 g / cm 3 Adhesion promoter (D-1): YS Polyster T160, manufactured by Yasuhara Chemical Co., Ltd., terpene-modified phenol resin, hydroxyl value: 60 mg KOH / g Adhesion promoter (D-2): YS Polyster G150, manufactured by Yasuhara Chemical Co., Ltd., terpene-modified phenol resin, hydroxyl value: 140 mg KOH / g Filler (E-1): K-1, manufactured by Nippon Talc Co., Ltd., talc, plate-like, particle size (D50): 8.0 μm, aspect ratio: 3 - 10 Filler (E-2): I.44P, manufactured by Volkley Japan Co., Ltd., montmorillonite, plate-like, size: 14 - 18 μm, aspect ratio: 100 - 500 Filler (E-3): UBS-0005E, manufactured by Unitika Ltd., glass beads, spherical, particle size: ~5 μm, aspect ratio: 1 Styrene-ethylene-butylene-styrene block copolymer (F-1): Tuftec H1043, manufactured by Asahi Kasei Corporation, styrene-ethylene-butylene-styrene block copolymer, styrene content: 67% by weight, MFR: 2.0 g / 10 min (230 °C, 2.16 kg), density: 0.97 g / cm 3

[0049] As is clear from Table 1, Example 1 ,2,4The resin composition of 0 to 9 had excellent results in terms of each property of melt viscosity (fluidity), moisture permeability (water vapor barrier property), T-peel adhesion strength (adhesion property), and heat shock resistance. On the other hand, in Comparative Example 1, since no filler was contained, the water vapor barrier property was poor. In Comparative Example 2, the filler content was high, the melt viscosity was high, and the adhesion property and heat shock resistance were poor. In Comparative Example 3, since spherical filler was contained, the water vapor barrier property was poor. In Comparative Example 4, the adhesion promoter was less, the melt viscosity increased, and the adhesion property was poor. In Comparative Example 5, because the adhesion promoter was too much, the adhesion property rather decreased. In Comparative Example 6, since styrene-isobutylene-styrene block copolymer was not contained, the heat shock resistance was poor. In Comparative Example 7, the content of styrene-isobutylene-styrene block copolymer was high and the adhesion property was poor. In Comparative Example 8, since styrene-ethylene-butylene-styrene block copolymer was used instead of styrene-isobutylene-styrene block copolymer, the moisture permeability and adhesion property were poor.

Industrial Applicability

[0050] The resin composition of the present invention has a low melt viscosity during product molding, excellent adhesion to an aluminum substrate, excellent water vapor barrier property and heat shock resistance, and is thus useful as a hot melt adhesive composition for waterproof applications.

Claims

1. A resin composition comprising a polyolefin resin (A), an acid-modified polyolefin resin (B), a styrene-isobutylene-styrene block copolymer (C), an adhesion imparting agent (D), and a filler (E), wherein, when the total amount of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion imparting agent (D) is taken as 100 parts by mass, the content of the styrene-isobutylene-styrene block copolymer (C) is 8 to 28 parts by mass, the content of the adhesion imparting agent (D) is 8 to 27 parts by mass, and the content of the filler (E) is 1 to 13 parts by mass, and the filler (E) is plate-shaped and is any one of glass beads, calcium carbonate, kaolin, talc, glass fiber, carbon fiber, clay, and montmorillonite.

2. The resin composition according to claim 1, wherein the polyolefin resin (A) comprises a polypropylene resin and further comprises at least one of an ethylene-α-olefin copolymer and a propylene-α-olefin copolymer.

3. The resin composition according to claim 1, wherein the acid-modified polyolefin resin (B) has a melting point of 100°C or higher.

4. 2. The resin composition according to claim 1, wherein the styrene-isobutylene-styrene block copolymer (C) has a styrene content of 10 to 30% by weight.

5. 2. The resin composition according to claim 1, wherein the adhesion promoter (D) has a hydroxyl value of 1 to 100 mgKOH / g.

6. The resin composition according to claim 1, wherein the content of the polyolefin resin (A) is 38 to 70 parts by mass, and the content of the acid-modified polyolefin resin (B) is 1 to 22 parts by mass, when the total amount of the polyolefin resin (A), the acid-modified polyolefin resin (B), the styrene-isobutylene-styrene block copolymer (C), and the adhesion promoter (D) is 100 parts by mass.

7. A hot melt adhesive composition comprising the resin composition according to any one of claims 1 to 6.

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