TW202239867A - Resin composition and electrical/electronic part encapsulation body - Google Patents

Abstract

To provide a resin composition for an electrical/electronic encapsulation, the composition having excellent oil resistance and insulation performance without a reduction in fluidity. Provided is a resin composition that contains a polyester resin (A) having a solubility parameter (SP) value of 10.0 (cal/cm3)1/2 or greater, a dimer acid polyamide (B), and an epoxy resin (C).

Description

Resin composition and package of electric and electronic parts

The present invention relates to resin compositions. More specifically, it relates to a resin composition for encapsulation capable of encapsulating electric and electronic parts, and an electric and electronic part package.

For the insulating resin used in the packaging of electrical and electronic parts such as automobiles and electrical appliances, two-component curing epoxy resins and silicone resins are generally used, but it is considered that it takes a long time to process, or it may be due to curing time. Therefore, in recent years, it has been known to package electrical and electronic components by low-pressure molding using thermoplastic resins.

Considering electrical insulation, water resistance, durability, and melt viscosity, polyester resin is used as an ideal material as an encapsulation resin for electrical and electronic parts, but it is molded at low temperature and low pressure to reduce damage to electrical and electronic parts In this case, the adhesiveness between electrical and electronic parts and encapsulating resin will become insufficient, and the intended electrical insulation and waterproof properties may not be fully exhibited. Therefore, an attempt to blend a tackifier having a functional group or the like from the viewpoint of fundamentally improving the adhesiveness has been actively studied (for example, Patent Document 1). [Prior Art Literature] [Patent Document]

[Patent Document 1] Japanese Patent Laid-Open No. 2004-210893

[Problem to be Solved by the Invention]

On the other hand, in addition to the physical properties required above, oil resistance is sometimes required for electrical and electronic parts, but when using a thermoplastic resin blended with a tackifier such as Patent Document 1, although the adhesiveness can be improved , but there will be problems that oil resistance and insulation cannot be guaranteed. In the prior art, no one has proposed a resin composition for encapsulation that can achieve both oil resistance and insulation while maintaining the fluidity of the resin excellent in low pressure molding.

The present invention is made on the background of the subject of this prior art. That is, the object of the present invention is to provide a resin composition that does not degrade oil resistance, especially does not degrade physical properties during cutting oil immersion while maintaining the fluidity of the resin excellent in low-pressure molding, and has insulation properties. excellent. The resin composition of the present invention is particularly suitable for encapsulation of electric and electronic parts. [Means to solve the problem]

As a result of intensive studies, the present inventors have found that the above-mentioned problems can be solved by the following means, and the present invention has been completed. That is, the present invention is constituted as follows.

[1] A resin composition comprising: polyester resin (A) with a solubility parameter (SP) value of 10.0 (cal/cm ³ ) ^1/2 or more, dimer acid polyamide (B), and epoxy resin (C).

[2] The resin composition according to the above [1], wherein the polyester resin (A) has terephthalic acid, isophthalic acid, butanediol, and polytetramethylene glycol as constituent units.

[3] The resin composition according to [1] or [2] above, wherein both the polyester resin (A) and the dimer acid polyamide (B) have a glass transition temperature of -20°C or lower.

[4] The resin composition described in any one of [1] to [3] above, further comprising a tackifier (D).

[5] The resin composition as described in [4] above, wherein the SP value of the tackifier (D) is 9.0 (cal/cm ³ ) ^1/2 or more.

[6] The resin composition described in any one of [1] to [5] above, further containing an antioxidant (E).

[7] A resin composition for encapsulation, comprising the resin composition described in any one of [1] to [6] above.

[8] A package for electrical and electronic components, which is packaged with the resin composition for packaging described in [7] above. [Effect of Invention]

The resin composition of the present invention exhibits excellent fluidity, and is excellent in oil resistance and insulation. Therefore, especially by using it as a packaging material in an electrical and electronic component package, an electrical and electronic component package with satisfactory oil resistance and insulation properties can be manufactured.

Hereinafter, the present invention will be described in detail.

＜Polyester resin (A)＞ The polyester resin (A) used in the present invention is preferably composed of the following chemical structure; the chemical structure is a hard segment mainly composed of a polyester segment and a soft segment mainly composed of a polyalkylene glycol component. formed by ester bonds. The aforementioned polyester segment is preferably mainly composed of polyester; the polyester is a structure that can be formed by polycondensation of aromatic dicarboxylic acid and aliphatic diol and/or alicyclic diol.

The polyester resin (A) used in the present invention must have an SP value of 10.0 (cal/cm ³ ) ^1/2 or more. It is preferably 10.5 (cal/cm ³ ) ^1/2 or more. Generally speaking, the SP value of cutting oil is about 7~8(cal/cm ³ ) ^1/2 . The lower the SP value, and the closer it is to the SP value of cutting oil, the better the affinity, and sometimes there will be impregnation in cutting oil. When oil is used, the resin absorbs cutting oil, and the oil resistance deteriorates due to the swelling of the resin. On the other hand, if the SP value is too high, the compatibility with the dimer acid polyamide (B) will decrease, and the insulation, oil resistance, and mechanical properties of the resin composition may be poor on the contrary. Therefore, the SP value is preferably 12.5 (cal/cm ³ ) ^1/2 or less, more preferably 12.0 (cal/cm ³ ) ^1/2 or less, and even more preferably 11.5 (cal/cm ³ ) ^1/2 or less. The SP value can be adjusted by selecting monomers and adjusting the concentration of ester bonds. By copolymerizing highly polar monomers or increasing the concentration of ester bonds, a high SP value can be obtained. Here, the SP value used in the present invention is a value obtained by the calculation method of Fedors estimated from the molecular structure. The calculation method is described in the following literature; Polym. Eng. Sci., 14[2], 147-154 (1974).

The glass transition temperature of the polyester resin (A) used in the present invention is preferably below -20°C, more preferably below -30°C.

The upper limit of the ester group concentration of the polyester resin (A) used in the present invention is preferably 8000 equivalents/10 ⁶ g. The ideal upper limit is 7500 equivalents/10 ⁶ g, more preferably 7000 equivalents/10 ⁶ g. Also, when oil resistance to cutting oil, kerosene, gasoline, engine oil, and other hydrocarbon solvents is required, the lower limit is preferably 1000 equivalents/10 ⁶ g. A more desirable lower limit is 1500 equivalents/10 ⁶ g, more preferably 2000 equivalents/10 ⁶ g. Here, the unit of ester group concentration represents the equivalent number of ester groups per 10 ⁶ g of resin, which can be calculated from the composition of polyester resin and its copolymerization ratio.

The acid value of the polyester resin (A) used in the present invention is preferably 100 equivalents/10 ⁶ g or less, more preferably 70 equivalents/10 ⁶ g or less, even more preferably 50 equivalents/10 ⁶ g or less. When the acid value is too high, the hydrolysis of the polyester resin (A) may be accelerated by the acid derived from the carboxylic acid, and the strength of the resin may decrease. The lower limit of the acid value is not particularly limited, but it is preferably at least 10 equivalents/10 ⁶ g, more preferably at least 20 equivalents/10 ⁶ g. When the acid value is too low, the adhesiveness may decrease.

The lower limit of the number average molecular weight of the polyester resin (A) used in the present invention is not particularly limited, but it is preferably 3,000 or more, more preferably 5,000 or more, and even more preferably 7,000 or more. Also, the upper limit of the number average molecular weight is not particularly limited, but it is preferably 80,000 or less, more preferably 70,000 or less, and even more preferably 60,000 or less. If the number average molecular weight is too low, the hydrolysis resistance of the resin composition may be insufficient, and the strong extensibility under high temperature and high humidity may be insufficient. If the number average molecular weight is too high, the resin composition may melt Viscosity becomes high, making molding pressure too high or molding difficult.

The upper limit of the melt viscosity of the polyester resin (A) used in the present invention is preferably less than 5000dPa･s, more preferably less than 4000dPa･s, more preferably less than 3000dPa･s at the molding temperature (eg 230°C). Also, the lower limit of the melt viscosity is not particularly limited, but it is preferably 50 dPa･s or more, more preferably 300 dPa･s, more preferably 500 dPa･s, most preferably 1000 dPa･s. If the melt viscosity is too high, the fluidity during molding may be deteriorated or molding may be difficult. If the melt viscosity is too low, the appearance of molding such as oil resistance and mechanical properties may be reduced, or burrs cannot be removed. bad situation.

The polyester resin (A) used in the present invention is preferably a saturated polyester resin, and may also be an unsaturated polyester resin having a trace amount of vinyl groups of 50 equivalents/10 ⁶ g or less. If it is an unsaturated polyester having a high concentration of vinyl groups, crosslinking or the like may occur during melting, resulting in poor melt stability.

The polyester resin (A) used in the present invention may be prepared by copolymerizing trifunctional or higher polycarboxylic acids and polyhydric alcohols, such as trimellitic anhydride and trimethylolpropane, to produce branched polyesters.

The polyester resin (A) used in the present invention requires rapid melting at 210 to 240° C. in order to mold it so that thermal deterioration does not occur as much as possible. Therefore, the upper limit of the melting point of the polyester resin (A) is preferably 210°C. The ideal temperature is 200°C, more preferably 190°C. Considering the workability at room temperature and the usual heat resistance, the melting point of the polyester resin (A) is preferably 90°C or higher, more preferably 100°C or higher, more preferably 110°C or higher, and most preferably 120°C or higher. The best temperature is above 130°C.

A known method can be used for the production method of the polyester resin (A) used in the present invention. For example, polyester can be obtained by carrying out the polycondensation reaction at 230-300°C while reducing the pressure after carrying out the esterification reaction of the polycarboxylic acid component and the polyol component described below at 150-250°C. Or, by using derivatives such as dimethyl esters of polycarboxylic acids described later and polyhydric alcohol components to carry out transesterification at 150°C to 250°C, and then carrying out the reaction at 230°C to 300°C while reducing pressure. Polycondensation reaction, polyester can be obtained.

＜Hard segment of polyester resin (A)＞ It is preferable that the hard segment constituting the polyester resin (A) used in the present invention is mainly composed of a polyester segment. Polyester chain segments mainly use polycarboxylic acid components and polyol components as constituent units.

The polyvalent carboxylic acid component constituting the polyester segment is not particularly limited, but it is preferable from the viewpoint of improving the heat resistance of the polyester resin (A) if it contains an aromatic dicarboxylic acid. Specific examples of aromatic dicarboxylic acids include terephthalic acid, naphthalene dicarboxylic acid, diphenyl dicarboxylic acid, isophthalic acid, and sodium 5-sulfoisophthalate. In particular, when the aromatic dicarboxylic acid is terephthalic acid and/or naphthalene dicarboxylic acid, in addition to improving heat resistance, it has high reactivity with diols, and is preferable from the viewpoint of polymerizability and productivity. When the total polycarboxylic acid component constituting the polyester segment is 100 mole%, the total of terephthalic acid and naphthalene dicarboxylic acid is preferably 50 mole% or more, more preferably 60 mole% or more, and is 80 mole% More preferably more than 95% by mole, especially preferably more than 95% by mole, and it does not matter if all the polycarboxylic acid components are composed of terephthalic acid and/or naphthalene dicarboxylic acid.

Other polycarboxylic acid components constituting the polyester segment include: cyclohexanedicarboxylic acid, tetrahydrophthalic anhydride and other alicyclic dicarboxylic acids; succinic acid, glutaric acid, adipic acid, azelaic acid, decane Dicarboxylic acids such as aliphatic dicarboxylic acids such as diacids, dodecanedioic acids, dimer acids, and hydrogenated dimer acids. These dicarboxylic acid components can be used within the range that does not significantly lower the melting point of the polyester resin (A), and the copolymerization ratio thereof is 50 mol% or less, preferably 40 mol% or less, of the total polyvalent carboxylic acid components. In addition, as other polyvalent carboxylic acid components constituting the polyester segment, trifunctional or higher polycarboxylic acids such as trimellitic acid and pyromellitic acid may be used. The copolymerization ratio of polyhydric carboxylic acids with more than 3 functions is preferably set to 10 mol% or less, more preferably 5 mol% or less, based on the viewpoint of preventing gelation of the resin composition.

Also, the polyol component constituting the polyester segment is not particularly limited, but is preferably an aliphatic diol and/or alicyclic diol from the viewpoint of improving the heat resistance of the polyester resin (A). Among them, the aliphatic diol and/or the alicyclic diol are preferably alkylene glycols having 2 to 10 carbon atoms, more preferably alkylene glycols having 2 to 8 carbon atoms. Particularly preferred aliphatic diol and alicyclic diol components specifically include: ethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,6-hexanediol, 1,4- Cyclohexanedimethanol and the like are most suitable for 1,4-butanediol and 1,4-cyclohexanedimethanol. The aliphatic diol and/or alicyclic diol is preferably at least 50 mol%, more preferably at least 70 mol%, of the total polyol components. In addition, trifunctional or higher polyols such as glycerin, trimethylolpropane, and neopentyl glycol may be used as a part of the polyol component, and it is preferable to set it as the entire polyol component in view of preventing gelation of the resin composition. 10 mol% or less, preferably 5 mol% or less.

As for the components constituting the polyester segment, those composed of a butylene terephthalate unit or a butylene naphthalate unit can make the polyester resin (A) have a high melting point and improve heat resistance, and, Considering formability and cost performance are especially good.

The polycarboxylic acid component and polyol component constituting the polyester segment may contain biomass-derived raw materials.

＜Soft segment of polyester resin (A)＞ The soft segment of the polyester resin (A) used in the present invention is preferably composed mainly of polyalkylene glycol components. The copolymerization ratio of the soft segment is preferably 0.5 mol % or more, more preferably 2.5 mol % or more, and 5 mol % when the total polyol component constituting the polyester resin (A) is 100 mol % More than % is better. Also, it is preferably not more than 50 mol%, more preferably not more than 45 mol%, and more preferably not more than 40 mol%. If the copolymerization ratio of the soft segment is too low, problems such as high melt viscosity of the resin composition of the present invention that cannot be molded at low pressure, or high crystallization speed and short shot tend to occur. Also, if the copolymerization ratio of the soft segment is too high, problems such as insufficient heat resistance when forming a package tend to occur.

The number-average molecular weight of the soft segment is not particularly limited, and is preferably at least 400, more preferably at least 800. When the number-average molecular weight of the soft segment is too low, the problem that flexibility cannot be imparted and the stress load on the packaged electronic substrate tends to increase. Also, the number average molecular weight of the soft segment is preferably 5,000 or less, more preferably 3,000 or less. When the number average molecular weight is too high, the compatibility with other copolymerization components tends to be poor, and the problem of being unable to copolymerize tends to arise.

Specific examples of the polyalkylene glycol component used for the soft segment include polyethylene glycol, polytrimethylene glycol, polytetramethylene glycol, and the like. Polytetramethylene glycol is the best in terms of imparting flexibility and lowering melt viscosity.

The polyester resin (A) used in the present invention may be amorphous or crystalline, but is preferably crystalline. Crystallinity in the present invention refers to using a differential scanning calorimeter (DSC), heating and melting at a heating rate of 20°C/min to 230°C, and then cooling to -130°C with liquid nitrogen at a rate of 20°C/min, and keeping for 5 Minutes later, when the temperature was raised from -130° C. to 230° C. at a heating rate of 20° C./min, any one of the second heating steps showed a clear melting peak. On the other hand, the term "amorphous" means that no melting peak is exhibited in any temperature raising step.

＜Dimer acid polyamide (B)＞ The resin composition of the present invention contains dimer acid polyamide (B). Dimer acid polyamide (B) is a polyamide containing dimer acid as a constituent unit. By copolymerizing the dimer acid as the acid component of the polyamide, the oil resistance of the polyamide can be maintained while the melt viscosity can be reduced. Therefore, fluidity during molding can be imparted while maintaining excellent oil resistance in the resin composition together with the polyester resin (A). In addition, the glass transition temperature is also lowered, and the low temperature resistance is also excellent.

The glass transition temperature of the dimer acid polyamide (B) used in the present invention is preferably below -20°C, more preferably below -30°C.

The dimer acid polyamide (B) used in the present invention requires rapid melting at 210 to 240°C in order to prevent thermal deterioration as much as possible and to mold it. Therefore, the softening point of the dimer acid polyamide (B) is preferably below 210°C, more preferably below 200°C. Considering the operability at room temperature and normal heat resistance, the softening point of the dimer acid polyamide (B) is preferably 90°C or higher, more preferably 100°C or higher, more preferably 110°C or higher, and 120°C The above is especially good, and the best is above 130°C.

In the resin composition of the present invention, when the total amount of polyester resin (A) and dimer acid polyamide (B) is 100 mass parts, the content of dimer acid polyamide (B) is preferably 10 mass parts More preferably, it is more than 50 mass parts, and it is more preferably 20 mass parts or more and 40 mass parts or less. If the content of dimer acid polyamide (B) is too small, the melt viscosity of the resin composition may increase and the fluidity during molding may deteriorate. Insulation deterioration in the test environment.

＜Epoxy resin (C)＞ The resin composition of this invention contains an epoxy resin (C). The epoxy resin (C) used in the present invention is not particularly limited as long as it is a compound having one or more epoxy groups in one molecule. It is preferably a resin having a number average molecular weight of 450 to 40,000 and having an average of 1.1 or more epoxy groups per molecule. Examples include glycidyl ether types such as bisphenol A diglycidyl ether, bisphenol S diglycidyl ether, novolak resin glycidyl ether, brominated bisphenol A diglycidyl ether, and hexahydrobenzene Glycidyl ester type such as glycidyl diformate and glycidyl dimer acid; triglycidyl isocyanurate, glycidyl hydantoin, tetraglycidyl di Aminodiphenylmethane, triglycidyl p-aminophenol, triglycidyl m-aminophenol, diglycidyl aniline, diglycidyl toluidine, tetraglycidyl m-xylene Amine, Diglycidyl tribromoaniline, tetraglycidyl bisaminomethyl cyclohexane and other glycidyl amine types; 3,4-epoxycyclohexyl methyl carboxylate, epoxidized polybutylene Cycloaliphatic or aliphatic epoxide type such as diene, epoxidized soybean oil, etc. These can be used individually or in combination of 2 or more types.

The softening point of the epoxy resin (C) is preferably above 70°C, more preferably above 80°C. If the softening point is low, the physical properties may deteriorate in a high-temperature (70°C or higher) environment.

The number average molecular weight of the epoxy resin (C) is preferably not less than 450, more preferably not less than 600, and more preferably not less than 1000. When the number average molecular weight is too small, the resin composition may be easily softened and mechanical properties may be lowered. Moreover, it is preferably 40,000 or less, more preferably 30,000 or less, and more preferably 20,000 or less. When the number average molecular weight is too large, the compatibility with the polyester resin (A) and the dimer acid polyamide (B) may decrease, and the adhesiveness may be impaired.

In the present invention, by blending the epoxy resin (C) into the resin composition, it is possible to impart good initial adhesion, adhesion durability against environmental loads such as cutting oil immersion, and Excellent characteristics such as improvement of fluidity during molding due to low viscosity. It is thought that the epoxy resin (C) will function as a compatibilizer for the polyester resin (A) and the dimer acid polyamide (B), and it will also exert the moisturizing effect on the substrate due to the introduction of the functional group. Moisture improvement effect, thereby improving insulation. The content of the epoxy resin (C) in the resin composition of the present invention is preferably 5 parts by mass or more, 10 parts by mass relative to the total of 100 parts by mass of the polyester resin (A) and dimer acid polyamide (B). More preferably, it is more than 20 parts by mass, and even more preferably more than 20 parts by mass. When the compounding quantity of an epoxy resin (C) is less than 5 mass parts, the action|action as a compatibilizer of a polyester resin (A) and dimer acid polyamide (B) may not be exhibited also in some cases. Moreover, it is preferably at most 50 parts by mass, more preferably at most 40 parts by mass. When 50 parts by mass or more of the epoxy resin (C) is blended, the productivity of the resin composition may be poor, and properties such as heat resistance of the package may be poor.

＜Tackifier (D)＞ The resin composition of the present invention may further contain a tackifier (D). The tackifier (D) used in the present invention is not particularly limited, and phenolic compounds, xylene-modified phenolic resins, terpene-modified phenolic resins, and hydrogenated terpene obtained by hydrogenating terpene-modified phenolic resins can be used. Modified phenolic resin, etc.

The SP value of the tackifier (D) used in the present invention is preferably 9.0 (cal/cm ³ ) ^1/2 or more. If the SP value is low, oil resistance to kerosene, cutting oil, etc., and mechanical properties may be poor.

The tackifier (D) used in the present invention preferably has a hydroxyl group. By having a hydroxyl group, the tackifier (D) can improve the adhesion with the substrate and improve the insulation. The hydroxyl value of the tackifier (D) is preferably 1-500KOHmg/g, more preferably 30-400KOHmg/g, even more preferably 50-300KOHmg/g.

In the present invention, by blending the tackifier (D) into the resin composition, good adhesiveness can be imparted in the encapsulation of electric and electronic parts. It is considered that the tackifier (D) exerts the effect of improving the wettability of the substrate due to the introduction of the functional group. The blending amount of the tackifier (D) in the present invention is preferably at least 5 parts by mass and 10 parts by mass with respect to the total of 100 parts by mass of the polyester resin (A) and dimer acid polyamide (B). More preferably, it is more preferably 20 parts by mass or more. Moreover, it is preferably at most 50 parts by mass, more preferably at most 40 parts by mass. When the blending ratio of the tackifier (D) is too low, good adhesiveness may not be exhibited in some cases. In addition, if the blending ratio of the tackifier (D) is too high, the flexibility of the resin may be lowered with an increase in the elastic modulus, which may adversely affect the adhesiveness, or the functional group of the tackifier (D) may A condition that reacts with the blend and embrittles the resin.

＜Antioxidant (E)＞ The resin composition of the present invention may further contain an antioxidant (E). The antioxidant (E) used in the present invention is not particularly limited as long as it can prevent oxidation of the polyester resin (A), and hindered phenolic antioxidants, phosphorus antioxidants, thioether antioxidants and the like can be used. For example, hindered phenols include: 1,3,5-paraffin (3,5-bis(tertiary butyl)-4-hydroxybenzyl) isocyanurate, 1,1,3-tris(4- Hydroxy-2-methyl-5-tertiary butylphenyl) butane, 1,1-bis(3-tertiary butyl-6-methyl-4-hydroxyphenyl) butane, 3,5- Bis(1,1-dimethylethyl)-4-hydroxyphenylpropionic acid, pentaerythritol tetrakis(3,5-bis(tertiary butyl)-4-hydroxyphenyl)propionate, 3-(1, 1-Dimethylethyl)-4-hydroxy-5-methylphenylpropanoic acid, 3,9-bis[1,1-dimethyl-2-[(3-tertiary butyl-4-hydroxy- 5-methylphenyl)propionyloxy]ethyl]-2,4,8,10-tetraoxaspiro[5.5]undecane, 1,3,5-trimethyl-2,4,6 - Refer to (3',5'-bis(tertiary butyl)-4'-hydroxybenzyl)benzene; phosphorus system can include: 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, isodecylphosphite, isodecylphenylphosphite, diphenylphosphite- 2-ethylhexyl ester, dinonylphenyl bis(nonylphenyl)phosphite, 1,1,3-paraffin(2-methyl-4-bis(tridecyl)phosphite-5 -Tertiary butylphenyl) butane, ginseng (2,4-bis(tertiary butyl)phenyl) phosphite, neopentylthritol bis(2,4-bis(tertiary butyl)phenyl) Phosphite), 2,2'-methylene bis(4,6-bis(tertiary butyl)phenyl) 2-ethylhexyl phosphite, bis(2,6-bis(tertiary butyl) )-4-methylphenyl) neopentylthritol diphosphite; thioether can be listed: 4,4'-thiobis[2-tertiary butyl-5-methylphenol]bis[3- (Dodecylthio)propionate], Thiobis[2-(1,1-dimethylethyl)-5-methyl-4,1-phenylene]bis[3-(deca Tetraalkylthio)-propionate], neopentylthritol tetra(3-n-dodecylthiopropionate), bis(tridecyl)thiodipropionate, they can be used alone , or can be used in combination.

The content of the antioxidant (E) is preferably 0.1 parts by mass or more, more preferably 0.2 parts by mass or more, and 0.3 parts by mass relative to the total of 100 parts by mass of the polyester resin (A) and dimer acid polyamide (B). The above is even better. If the content is too small, it may adversely affect the long-term durability at high temperature. Moreover, it is preferably at most 5 parts by mass, more preferably at most 3 parts by mass, and even more preferably at most 1 part by mass. When the content is too large, it may adversely affect adhesiveness, flame retardancy, and the like.

＜Resin composition＞ The resin composition of the present invention contains at least the aforementioned polyester resin (A), dimer acid polyamide (B), and epoxy resin (C), and if necessary, contains tackifier (D), antioxidant (E ) composition. Here, the term "encapsulation" refers to covering without gaps so as not to expose precision parts and the like to dust and water. The resin composition of the present invention is suitable for encapsulation of electrical and electronic parts among precision parts because of its excellent long-term reliability.

In the resin composition of the present invention, any one of the polyester resin (A), dimer acid polyamide (B), epoxy resin (C), and tackifier (D) that does not belong to the present invention can also be used Polyester, polyamide, polyolefin, polycarbonate, acrylic resin, ethylene vinyl acetate and other resins; isocyanate compounds, melamine and other hardeners; talc (talc), mica and other fillers; carbon black, titanium oxide Pigments such as antimony trioxide, brominated polystyrene and other flame retardants are blended within the range that does not impair the effect of the present invention, and there is no problem at all. Adhesiveness, flexibility, durability, etc. may be improved by blending these components. At this time, the polyester resin (A) is preferably contained at least 50% by mass, more preferably at least 55% by mass, and even more preferably at least 60% by mass, based on the entire resin composition of the present invention. If the content of the polyester resin (A) is less than 50% by mass, the excellent adhesiveness, adhesion durability, and flexibility to electrical and electronic parts that the polyester resin (A) itself possesses tend to decrease.

In addition, when the resin composition of the present invention requires weather resistance, it is advisable to add a light stabilizer. Examples of the photostabilizer include benzotriazole-based photostabilizers, benzophenone-based photostabilizers, hindered amine-based photostabilizers, nickel-based photostabilizers, and benzoate-based photostabilizers. Benzotriazole-based light stabilizers include: 2-(3,5-bis(tertiary pentyl)-2'hydroxyphenyl)benzotriazole, 2-(2-hydroxy-5-tertiary octyl Phenyl)benzotriazole, 2-(2'-hydroxy-3'-tertiary butyl-5'-methylphenyl)-5-chlorobenzotriazole, 2-(2H-benzotriazole -2-yl) p-cresol, 2-(2'-hydroxy-5'-methylphenyl)benzotriazole, 2,4-bis(tertiary butyl)-6-(5-chlorobenzo Triazol-2-yl)phenol, 2-[2-hydroxy-3,5-bis(1,1-dimethylbenzyl)]-2H-benzotriazole and the like. Benzophenone-based light stabilizers include: 2-hydroxy-4-(octyloxy)benzophenone, 2,4-dihydroxybenzophenone, 2-hydroxy-4-methoxybenzophenone Ketone, 2-Hydroxy-4-methoxybenzophenone, 2-Hydroxy-4-methoxy-benzophenone-5-sulfonic acid, 2-Hydroxy-4-n-dodecyloxydiphenyl Methanone, bis(5-benzoyl-4-hydroxy-2-methoxyphenyl)methane, 2-2'-dihydroxy-4-methoxybenzophenone, 2,2'-bis Hydroxy-4,4'-dimethoxybenzophenone, etc. Hindered amine light stabilizers include bis(2,2,6,6-tetramethyl-4-piperidinyl) sebacic acid, dimethyl succinate/1-(2-hydroxyethyl)-4 -Hydroxy-2,2,6,6-tetramethylpiperidine polycondensate, poly[{6-(1,1,3,3-tetramethylbutyl)amino-1,3,5-tri 𠯤-2,4-diyl}{(2,2,6,6-tetramethyl-4-piperidinyl)imino}hexamethylene(2,2,6,6-tetramethyl- 4-piperidinyl)imino}], 1,3,5-ginseng (3,5-di(tertiary butyl)-4-hydroxybenzyl)-same tris-2,4,6(1H ,3H,5H)trione, ginseng(4-tertiary butyl-3-hydroxy-2,6-dimethylbenzyl-same-tri-2,4,6-(1H,3H,5H)trione etc. Nickel-based light stabilizers include: [2,2'-thio-bis(4-tertiary octylphenolate)]-2-ethylhexylamine-nickel-(II), nickel dibutyldi Thioamine formate, [2',2'-thio-bis(4-tertiary octylphenolate)] n-butylamine-nickel, etc. Benzoate-based light stabilizers include: 2, 4-di(tertiary butyl)phenyl-3,5'-bis(tertiary butyl)-4'-hydroxybenzoate, etc. These light stabilizers can be used alone or in combination. When adding The amount is preferably not less than 0.1% by mass and not more than 5% by mass relative to the entire resin composition. If it is less than 0.1% by mass, the effect of weather resistance may sometimes be lacking. If it exceeds 5% by mass, there may be adverse Potential adverse effects such as contact.

Methods for determining the composition and composition ratio of the polyester resin (A) include, for example, ¹ H-NMR or ¹³ C-NMR in which the polyester resin (A) is dissolved in a solvent such as deuterated chloroform and measured, (A) Quantification by gas chromatography for measurement after methanolysis (hereinafter sometimes referred to as methanolysis-GC method), etc. In the present invention, when there is a solvent that can dissolve the polyester resin (A) and is suitable for ¹ H-NMR measurement, the composition and composition ratio are determined by ¹ H-NMR. When there is no suitable solvent or when the composition ratio cannot be determined only by ¹ H-NMR measurement, ¹³ C-NMR and methanolysis-GC method are used or used in combination.

The melt viscosity of the resin composition of the present invention at 230°C is preferably 5~1000dPa･s, which can be obtained by properly adjusting polyester resin (A), dimer acid polyamide (B), epoxy resin (C), The type and blending ratio of tackifier (D) and antioxidant (E) can be achieved. For example, increasing the copolymerization ratio of the polyether diol copolymerized with the polyester resin (A) or reducing the molecular weight of the polyester resin (A) will act in the direction of lowering the melt viscosity of the resin composition of the present invention. There is a tendency to increase the molecular weight of the polyester resin (A), which tends to work in the direction of increasing the melt viscosity of the resin composition of the present invention. In addition, the melt viscosity at 230 degreeC here is the value measured as follows. That is, the resin composition was dried to a water content of 0.1% or less, and then heated to 230°C and stabilized with a flow tester (model CFT-500C) manufactured by Shimadzu Corporation, at a rate of 98N/cm The measured value of the viscosity when the pressure of ² passes through a mold with a thickness of 10mm and a hole diameter of 1.0mm. If the melt viscosity is higher than 1000dPa･s, high resin cohesion and durability can be obtained, but when packaging parts with complex shapes, high-pressure injection molding is required, so parts may be damaged. By using a resin composition for encapsulation with a melt viscosity of 1000dPa･s or less, preferably less than 900dPa･s, a package (mold part) with excellent electrical insulation can be obtained at a relatively low injection pressure of 0.1~20MPa. Will not damage the characteristics of electrical and electronic components. Also, considering the injection operation of the resin composition for encapsulation, the lower the melt viscosity at 230°C, the better, but considering the adhesiveness and cohesion of the resin composition, the lower limit is preferably 5dPa･s or more, and 10dPa･ s or more is even better, 30dPa･s or more is more preferable, and 50dPa･s or more is the best.

In the present invention, the encapsulation properties of the specific member and the encapsulating resin composition are determined by manufacturing a measurement sample piece bonded with the encapsulating resin composition on a metal wiring printed circuit board, and measuring the insulation resistance value thereof. determination. The method of making the test piece for measurement and the method of measuring the insulation resistance value are carried out in accordance with the method described in the examples described later.

The resin composition for encapsulation of the present invention is molded by injection into a mold in which electrical and electronic components are placed. More specifically, when using a screw-type applicator for hot melt molding, it can be heated and melted at around 160~280°C, and injected into the mold through the injection nozzle, and then after a certain cooling time, the molding The object is removed from the mold to obtain a molded object.

The model of the hot-melt molding processing equipment is not particularly limited, and examples thereof include: ST2 manufactured by Nordson Corporation, vertical extrusion molding machine IMC-18F9 manufactured by Imoto Seisakusho, hybrid small vertical injection molding machine STX20 manufactured by Nissei Plastic Industry Co., Ltd., etc. . [Example]

In order to demonstrate this invention in more detail, although an Example and a comparative example are given below, this invention is not limited to an Example at all. In addition, each measured value described in an Example and a comparative example was measured by the following method.

＜Measurement of melting point and glass transition temperature＞ Using the differential scanning calorimeter "DSC220" manufactured by Seiko Electronics Co., Ltd., put 5 mg of the measurement sample into an aluminum pan, seal it with a gland, and heat it up to 230°C at a heating rate of 20°C/min and melt it. Then, it was cooled to -130°C with liquid nitrogen at 20°C/min, held for 5 minutes, and measured at a heating rate of 20°C/min from -130°C to 230°C. In the obtained curve, as shown in Figure 1, the part of the DSC showing the inflection point is obtained from the tangent line (1) of the baseline before the inflection point and the tangent line (2) obtained from the baseline after the inflection point The intersection point is defined as the glass transition temperature (Tg), and the minimum point of the endothermic peak portion (marked with x in the figure) is defined as the melting point (Tm).

<SP value of polymer> The SP value of a polymer is determined by the known aggregation energy of the atoms and atomic groups of the monomers constituting the polymer and the bonded atoms and atomic groups formed when the polymer is polymerized using the Fedors method. The density and the molar molecular volume were substituted into the following formula to calculate. δ=(Σe _i /Σv _i ) ^1/2 (cal/cm ³ ) ^1/2 δ: SP value ((cal/cm ³ ) ^1/2 ) e _i : Condensation energy density of atoms and atomic groups (cal/mol ) v _i : molar molecular volume (cm ³ /mol) of atoms and atomic groups (cm 3 /mol) e _i and v _i use the values described in Polym. Eng. Sci., 14[2], 147-154 (1974).

＜Melt characteristics (fluidity) test＞ Evaluation method of melt viscosity of polyester resin (A) and resin composition Using a flow tester (CFT-500C) manufactured by Shimadzu Corporation, fill the cylinder in the center of the heating body set to 230°C with the polyester resin (A) or resin composition that has been dried to a moisture content of 0.1% or less. After filling for 1 minute, apply a load to the sample by the plunger, extrude the molten sample from the mold (hole diameter: 1.0mm, thickness: 10mm) at the bottom of the cylinder with a pressure of 1MPa, and record the drop distance and time of the plunger. and calculate the melt viscosity. Based on the melt viscosity, the melting properties of the resin composition were evaluated as follows. Evaluation Benchmark ◎: The melt viscosity at 230°C does not reach 500dPa･s 〇: Melt viscosity at 230°C is more than 500dPa･s and less than 800dPa･s △: Melt viscosity at 230°C is above 800dPa･s and less than 1000dPa･s ×: Melt viscosity at 230°C is above 1000dPa･s

＜Swelling properties of cutting oil (swelling ratio after immersion in cutting oil)＞ A flat plate of the resin composition of 100 mm×100 mm×2 mmt was produced by injection molding using a vertical injection molding machine (TH40E manufactured by Nissei Plastics Co., Ltd.). The injection molding conditions were set as follows: a molding resin temperature of 210°C, a molding pressure of 20 MPa, a cooling time of 30 seconds, and an injection speed of 10 mm/sec. From the formed flat plate, three dumbbell-shaped No. 3 test pieces based on JIS K6251 were punched out using a test piece punching blade. Then, the test piece was immersed in cutting oil (HANGSTERFER S-500 manufactured by NIKKOCASTY Co., Ltd.) at room temperature (about 25° C.) for 4 weeks, and the full length (about 100 mm) of the test piece was measured with a vernier caliper immediately after taking it out, and calculated by the following formula The swelling rate of cutting oil is obtained. Swelling rate of cutting oil (%)=(full length of test piece after immersion (mm) - full length of test piece before immersion (mm))÷full length of test piece before immersion (mm)×100 The oil resistance of the resin composition was evaluated as follows based on the cutting oil swelling ratio. Evaluation Benchmark ◎: Cutting oil swelling rate less than 0.5% 〇: Cutting oil swelling rate is 0.5% or more and less than 1.0% ×: Cutting oil swelling ratio is above 1.0%

<Mechanical properties (retention rate of tensile elongation after cutting oil immersion)> A flat plate of the resin composition of 100 mm×100 mm×2 mmt was produced by injection molding using a vertical injection molding machine (TH40E manufactured by Nissei Plastics Co., Ltd.). The injection molding conditions were set as follows: a molding resin temperature of 210°C, a molding pressure of 20 MPa, a cooling time of 30 seconds, and an injection speed of 10 mm/sec. From the formed flat plate, three dumbbell-shaped No. 3 test pieces based on JIS K6251 were punched out using a punching machine. Then, the test piece was immersed in cutting oil at room temperature (about 25° C.) for 4 weeks. After immersion, the cutting oil on the surface was wiped off, and using AUTOGRAPH (manufactured by Shimadzu Corporation AG-IS Co., Ltd.) The dumbbell-shaped No. 3 test piece was clamped in a 20 mm manner, and its mechanical properties were measured. The stretching speed was set at 500 mm/min. Tensile elongation retention was calculated using the following formula. Tensile elongation retention (%)=(tensile elongation after cutting oil immersion for 4 weeks/tensile elongation at the initial stage of forming)×100 Based on the retention of tensile elongation, the mechanical properties of the resin composition were evaluated as follows. Evaluation Benchmark ◎: Tensile elongation retention rate of more than 90% ○: Tensile elongation retention rate of 70% or more to less than 90% △: Tensile elongation retention rate of 50% or more to less than 70% ×: Tensile elongation retention rate is less than 50%

＜Insulation properties (insulation resistance value after cutting oil immersion)＞ A small electric injection molding machine (CANON ELECTRONICS Co., Ltd. Co., Ltd. LS-300i) molded resin composition, which is a molded product in which the printed part of the metal wiring and a part of the vinyl chloride insulated wire are encapsulated. The molding conditions were set as follows: a molding resin temperature of 230° C., a molding pressure of 15 MPa, a cooling time of 10 seconds, and an injection speed of 6 mm/sec. Using a super insulation resistance meter SM-8220 (manufactured by Hioki Electric Co., Ltd.), measure the sample at the initial stage of molding with an applied voltage of 500V, and immerse the test piece in cutting oil at room temperature (about 25°C) for 4 weeks. Insulation resistance value of samples wiped off by cutting oil on the surface. The insulation of the resin composition was evaluated as follows based on the insulation resistance value. Evaluation Benchmark ◎: The insulation resistance value is above 100MΩ ○: The insulation resistance value is more than 70MΩ to less than 100MΩ △: The insulation resistance value is above 50MΩ to less than 70MΩ ×: The insulation resistance value is less than 50MΩ In addition, in Table 2, E+N represents 10 to the Nth power. For example: 2.86E+03 means 2.86×10 to the third power (about 2860). In addition, in this measurement, 2.09E+00 is the minimum value of the detection limit, and ≦2.09E+00 means below the detection limit.

＜Manufacturing example of polyester resin (A)＞ Add 1,080 parts by mass of terephthalic acid, 582 parts by mass of isophthalic acid, 1,893 parts by mass of 1,4-butanediol, and tetrabutyl titanate into a reaction tank equipped with a stirrer, a thermometer, and a cooler for distillation. 1.9 parts by mass, and carry out the esterification reaction at 170~220°C for 2 hours. After the esterification reaction, 1500 parts by mass of polytetramethylene glycol "PTMG1000" (manufactured by Mitsubishi Chemical Corporation) with a number average molecular weight of 1000 and 3 parts by mass of hindered phenolic antioxidant "IRGANOX 1330" (manufactured by Ciba-Geigy Co., Ltd.) Parts, while raising the temperature to 255°C, the pressure in the reaction system was gradually reduced, and adjusted to 255°C and 665Pa over 60 minutes. Then, polycondensation reaction was carried out at 133 Pa or less for 30 minutes to obtain polyester resin (A-1). Table 1 shows the melt viscosity, melting point, glass transition temperature, and SP value of the polyester resin (A-1). Moreover, polyester resin (A-2), (A-3) was synthesize|combined by the method similar to polyester resin (A-1). The respective compositions and physical properties are shown in Table 1.

[Table 1] Polyester resin (A) A-1 A-2 A-3 A-4 Composition mole% Dicarboxylic acid component TPA 65 90 65 IPA 35 35 NDC 100 AAA 10 Diol component EG 74 BD 90 60 90 CHDM twenty three PTMG1000 10 3 10 PTMG2000 40 physical properties Melt viscosity (at 230℃) dPa･s 2705 1883 1989 390 Melting point °C 139 166 160 139 Glass transition temperature °C -70 15 -65 -70 SP value (cal/cm ³ ) ^1/2 10.8 11.6 9.6 10.8

The abbreviations in Table 1 are as follows. TPA: Terephthalic acid IPA: Isophthalic acid AA: adipic acid NDC: 2,6-naphthalene dicarboxylic acid EG: ethylene glycol BD: 1,4-butanediol CHDM: Cyclohexanedimethanol PTMG1000: polytetramethylene ether glycol (number average molecular weight 1000) PTMG2000: polytetramethylene ether glycol (number average molecular weight 2000)

By using the proportions recorded in Table 2, use a twin-screw extruder to melt and knead polyester resin (A), dimer acid polyamide (B), and epoxy resin (C) at a mold temperature of 160°C~220°C , tackifier (D), and antioxidant (E) to obtain resin compositions (S1)-(S18). The melt viscosity, cutting oil swelling property, mechanical properties, and insulation properties of the resin composition were evaluated by methods described separately. The evaluation results are shown in Table 2 below.

[table 2-1] Example Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Example 8 Example 9 Example 10 Example 11 Example 12 Resin composition name Composition 1 Composition 2 Composition 3 Composition 4 Composition 5 Composition 6 Composition 7 Composition 8 Composition 9 Composition 10 Composition 11 Composition 12 Blending (parts by weight) Polyester resin (A) Polyester (A-1) 70 70 70 85 65 70 70 70 70 70 Polyester (A-2) 70 Polyester (A-3) Polyester (A-4) 70 Dimer acid polyamide (B) Dimer acid polyamide (B-1) 30 30 30 15 35 30 Dimer acid polyamide (B-2) 30 30 30 30 30 30 Polyamide (B-3) Epoxy resin (C) Epoxide (C-1) 20 10 30 20 20 20 20 20 20 20 20 Epoxide (C-2) 20 Tackifier (D) Tackifier (D-1) 20 20 Tackifier (D-2) 20 Antioxidant (E) Antioxidant (E-1) 0.3 Antioxidant (E-2) 0.3 characteristic Melt viscosity (dPa･s) at 230°C 679 〇 803 △ 605 〇 921 △ 497 ◎ 527 〇 626 〇 368 ◎ 315 ◎ 350 ◎ 504 〇 230 ◎ Swelling rate of cutting oil (%) JIS K6251: 2017 No. 3 dumbbell cutting oil immersion for 4 weeks 0.5 〇 0.8 〇 0.3 ◎ 0.5 〇 0.5 〇 0.9 〇 0.9 〇 0.3 ◎ 0.3 ◎ 0.3 ◎ 0.2 ◎ 0.9 〇 Tensile elongation retention (%) JIS K6251: 2017 No. 3 dumbbell cutting oil immersion for 4 weeks 100 ◎ 100 ◎ 100 ◎ 100 ◎ 95 ◎ 90 ◎ 91 ◎ 90 ◎ 85 〇 92 ◎ 68 △ 75 〇 Insulation resistance value (MΩ) Cutting oil immersion for 4 weeks 2.86 E+03 ◎ 2.16 E+03 ◎ 3.44 E+03 ◎ 2.21 E+03 ◎ 4.24 E+03 ◎ 1.53 E+03 ◎ 2.02 E+03 ◎ 2.17 E+06 ◎ 6.54 E+05 ◎ 2.37 E+06 ◎ 1.42 E+03 ◎ 1.43 E+03 ◎

[Table 2-2] Example Comparative example 1 Comparative example 2 Comparative example 3 Comparative example 4 Comparative Example 5 Comparative example 6 Resin composition name Composition 13 Composition 14 Composition 15 Composition 16 Composition 17 Composition 18 Blending (parts by weight) Polyester resin (A) Polyester (A-1) 100 70 70 70 Polyester (A-2) 70 Polyester (A-3) 70 Polyester (A-4) Dimer acid polyamide (B) Dimer acid polyamide (B-1) 30 30 30 30 Dimer acid polyamide (B-2) Polyamide (B-3) 30 Epoxy resin (C) Epoxide (C-1) 20 20 20 Epoxide (C-2) Tackifier (D) Tackifier (D-1) 20 30 20 Tackifier (D-2) Antioxidant (E) Antioxidant (E-1) Antioxidant (E-2) characteristic Melt viscosity (dPa･s) at 230°C 1300 × 696 〇 440 ◎ 412 ◎ 1217 × 2540 × Swelling rate of cutting oil (%) JIS K6251: 2017 No. 3 dumbbell cutting oil immersion for 4 weeks 3.6 × 3.9 × 1.2× 0.8 〇 6.5 × 0.4 ◎ Tensile elongation retention (%) JIS K6251: 2017 No. 3 dumbbell cutting oil immersion for 4 weeks 90 ◎ 91 ◎ 90 ◎ 94 ◎ 48× 75 〇 Insulation resistance value (MΩ) Cutting oil immersion for 4 weeks 2.09E+00 × ≦2.09E+00 × ≦2.09E+00 × ≦2.09E+00 × ≦2.09E+00 × ≦2.09E+00 ×

The dimer acid polyamide (B), epoxy resin (C), tackifier (D), and antioxidant (E) used in Table 2 are as follows. Dimer acid polyamide (B-1): PA673, manufactured by Henkel Corporation, softening point: 185°C, Tg: -45°C Dimer acid polyamide (B-2): PA6839, manufactured by Henkel Corporation, softening point: 195°C, Tg: -30°C Polyamide (B-3): GLAMIDE T-802, manufactured by Toyobo Co., Ltd., melting point: 220°C, Tg: 50°C Epoxy resin (C-1): jER (registered trademark ) 1007K, manufactured by Mitsubishi Chemical Corporation, softening point: 128°C epoxy resin (C-2): EPICLON (registered trademark) HP-7200HHH, manufactured by DIC Corporation, softening point: 105°C tackifier (D- 1): YSPOLYSTARK125, manufactured by YASUHARA CHEMICAL Co., Ltd., hydroxyl value: about 200KOHmg/g, SP value: 9.3 (cal/cm ³ ) ^1/2 , Tg: about 70°C Tackifier (D-2): YSPOLYSTART160, YASUHARA CHEMICAL Co., Ltd., hydroxyl value: about 60KOHmg/g, SP value: 8.8 (cal/cm ³ ) ^1/2 , Tg: about 100°C Antioxidant (E-1): IRGANOX (registered trademark) 1010, BASF Antioxidant (E-2) manufactured by JAPAN Co., Ltd.: LUSMITLG, manufactured by Daiichi Kogyo Pharmaceutical Co., Ltd.

It can be seen from Table 2 that the resin compositions of Examples 1 to 12 have excellent results in terms of melt viscosity, swelling property of cutting oil, mechanical properties, and insulation properties. On the other hand, since Comparative Example 1 does not contain dimer acid polyamide, it is poor in oil resistance, and also poor in melting properties and insulation. Since Comparative Examples 2 to 4 did not contain epoxy resin, their insulating properties were inferior. Since the SP value of the polyester resin used in Comparative Example 5 was low, the oil resistance was lowered. The polyamide used in Comparative Example 6 did not contain a dimer acid component, but had poor melting properties and insulating properties. [industrial availability]

The resin composition of the present invention has low melt viscosity when encapsulating electronic and electronic substrates, excellent bonding strength to glass epoxy resin substrates or PBT substrates, and excellent oil resistance, so it can be used as a resin composition system for encapsulating electrical and electronic parts. for useful. In addition, the electric and electronic component package of the present invention is especially excellent in adhesiveness and swelling property of cutting oil, so it can suppress leakage from electric and electronic components, which is very useful. The electrical and electronic component package of the present invention is useful as molded products of various connectors, harnesses for automobiles, communications, computers, and home appliances, or electronic components, switches with printed boards, and sensors, for example.

[ Fig. 1] Fig. 1 is a schematic diagram showing a graph measured by a differential scanning calorimeter.

Claims (8)

A resin composition comprising: a polyester resin (A) with a solubility parameter (SP) value of 10.0 (cal/cm ³ ) ^1/2 or more, a dimer acid polyamide (B), and an epoxy resin (C) . The resin composition according to claim 1, wherein the polyester resin (A) has terephthalic acid, isophthalic acid, butanediol, and polytetramethylene glycol as constituent units. The resin composition according to claim 1 or 2, wherein the glass transition temperatures of the polyester resin (A) and dimer acid polyamide (B) are both below -20°C. The resin composition according to claim 1 or 2 further contains a tackifier (D). The resin composition according to claim 4, wherein the tackifier (D) has an SP value of 9.0 (cal/cm ³ ) ^1/2 or more. The resin composition according to claim 1 or 2 further contains antioxidant (E). A resin composition for encapsulation, comprising the resin composition according to claim 1 or 2. A packaging body for electrical and electronic components, which is packaged with the packaging resin composition as claimed in claim 7.

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