JP2023026100A - Molding sealant, and sealed electric and electronic component - Google Patents

Abstract

To provide a molding sealant having excellent optical visibility and adhesion, and a sealed electric and electronic component.SOLUTION: A molding sealant contains crystalline polyester and tackifier. A 1 mm thick molding has an average light transmittance of 10% or more at wavelengths of 570-780 nm.SELECTED DRAWING: None

Description

TECHNICAL FIELD The present invention relates to a molded sealing material comprising a resin composition containing a crystalline polyester and a tackifier. More specifically, for sealing various connectors, harnesses, electronic parts, switches, printed circuit boards, battery sealing materials for automobiles, communications, computers, home appliances, and electrical and electronic parts for sensors such as weight detection sensors and seating sensors. It relates to a molding encapsulant used and an electrical and electronic component encapsulant encapsulated therewith.

Two-component curing epoxy resins and silicone resins have been commonly used as insulating resins for sealing electrical and electronic components used in automobiles and electrical appliances, but they require long processes. In recent years, it has been known to seal electrical and electronic components by molding using a thermoplastic resin.

From the viewpoint of electrical insulation, water resistance, durability, and melt viscosity, polyester resin is used as a suitable material as a sealing resin for electrical and electronic parts. In low-pressure molding, the adhesion between the electrical/electronic component and the sealing resin is often insufficient, and the desired electrical insulation and waterproof properties are often not achieved. Therefore, from the viewpoint of raising the level of adhesiveness, active studies have been made on blending an adhesion imparting agent having a functional group (Patent Document 1). In addition, when a crystalline polyester resin is used for molding, the size of the spherulites increases in the process of solidifying from a fluid state, resulting in whitening and a problem of impairing the transparency of the appearance of the encapsulating resin. . As a result, the presence or absence of voids and foreign matter originating from entrained air during molding cannot be confirmed, and the state of insert parts such as electrical and electronic components, substrates, and base materials cannot be confirmed. In particular, when an insert part using a light source such as a laser, an LED, a halogen lamp, or a metal halide lamp is sealed, it becomes difficult for light to pass through, and there is a concern that the optical characteristics cannot be visually recognized from the outside of the sealing resin. As an attempt to solve the above problems, rapid cooling in a mold after molding has been studied in order to suppress the growth of spherulites (Patent Document 2).

Japanese Patent Application Laid-Open No. 2004-210893 JP-A-7-171868

The method of Patent Document 2 requires a mold temperature control system including a chiller for quenching, resulting in high cost and complicated process management such as temperature gradient management. Therefore, there has been a demand for a molded encapsulant that does not require such equipment or process control and whose optical properties can be visually recognized.

The present invention has been made against the background of such problems of the prior art. That is, an object of the present invention is to provide a molded encapsulant with excellent visibility of optical properties and excellent adhesiveness.

As a result of intensive studies, the inventors of the present invention have found that the above problems can be solved by means shown below, and have completed the present invention. That is, the present invention consists of the following configurations.

[1] A molding encapsulation comprising a crystalline polyester resin (A) and an adhesion promoter (B) and having an average light transmittance of 10% or more at a wavelength of 570 to 780 nm in a molded article having a thickness of 1 mm. material.

[2] The molding sealing material according to [1] above, which further contains a polypropylene resin (C).

[3] The above [ 2].

[4] The molded sealing material according to any one of [1] to [3], further comprising a styrene-based thermoplastic elastomer (D).

[5] The above-described [4], wherein the styrene-based thermoplastic elastomer (D) is contained in an amount of 21 to 100 parts by mass when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. molded encapsulant.

[6] The molded encapsulant according to any one of [1] to [5], wherein the tackifier (B) contains at least one of a terpene resin and a terpene phenol resin.

[7] The molded sealing material according to any one of [1] to [6], further comprising at least one of polyethylene resin (E) and maleic anhydride-modified polypropylene resin (F).

[8] A sealed electrical/electronic component sealed with the molded sealing material according to any one of [1] to [7].

Since the molding encapsulant of the present invention exhibits excellent visibility of optical properties and excellent adhesiveness, it can be used particularly as a molding encapsulant for electrical and electronic parts to improve visibility and visibility of optical properties. It becomes possible to manufacture an electrical/electronic component sealing body that satisfies adhesiveness.

FIG. 1 shows a schematic diagram of a chart measured with a differential scanning calorimeter.

The details of the embodiments for carrying out the invention will be sequentially described below. However, the present invention is not limited to this, and can be implemented in various modifications within the scope described.

<Crystalline polyester resin (A)>
The crystalline polyester resin (A) used in the molding sealing material of the present invention is a crystalline polyester resin. The melting point of the crystalline polyester resin (A) is preferably 220°C or lower, more preferably 215°C or lower, and still more preferably 210°C or lower. When the melting point is 220° C. or lower, the kneading temperature can be lowered when kneading with the polypropylene resin (C) using a twin-screw extruder. Further, the melting point of the crystalline polyester resin (A) is preferably 100° C. or higher from the standpoint of handleability and heat resistance at room temperature. It is more preferably 105° C. or higher, still more preferably 110° C. or higher, even more preferably 115° C. or higher, and particularly preferably 120° C. or higher.

The glass transition temperature of the crystalline polyester resin (A) is preferably 30°C or lower. When the glass transition temperature is 30° C. or lower, the adhesiveness of the molding encapsulant of the present invention is improved, and compatibility is improved when the polypropylene resin (C) is included. The glass transition temperature is preferably 0° C. or lower, more preferably -15° C. or lower, still more preferably -20° C. or lower, and particularly preferably -30° C. or lower. Although the lower limit is not particularly limited, -100° C. or higher is realistic considering adhesiveness and blocking resistance.

The number average molecular weight of the crystalline polyester resin (A) is preferably 8,000 or more, more preferably 9,000 or more, still more preferably 10,000 or more. Also, the upper limit of the number average molecular weight is preferably 40,000 or less, more preferably 35,000 or less, and even more preferably 30,000 or less. When the number average molecular weight is 8000 or more, excellent oil resistance and adhesiveness are exhibited even when the polypropylene resin (C) is blended. By making it 40,000 or less, it is possible to ensure compatibility during resin kneading when the polypropylene resin (C) is included, and also to suppress the pressure during molding.

The crystalline polyester resin (A) is preferably a polymer comprising a polyvalent carboxylic acid component and a glycol component. The polyvalent carboxylic acid component constituting the crystalline polyester resin (A) preferably contains at least one of terephthalic acid and 2,6-naphthalene dicarboxylic acid, and the total amount of the polyvalent carboxylic acid component is 100 mol%. terephthalic acid and 2,6-naphthalene dicarboxylic acid, or the total of both is preferably 60 mol % or more. It is more preferably 80 mol % or more, still more preferably 90 mol % or more, still more preferably 95 mol % or more, and may be 100 mol %. If it is 60 mol % or more, sufficient crystallinity can be expressed, and the solidification speed after molding can be increased. As a result, mold releasability can be improved.

Other polyvalent carboxylic acid components include aromatic dicarboxylic acids such as isophthalic acid and orthophthalic acid, aliphatic dicarboxylic acids such as adipic acid, azelaic acid and sebacic acid, 1,4-cyclohexanedicarboxylic acid, and 1,3-cyclohexane. Dicarboxylic acids, alicyclic dicarboxylic acids such as 1,2-cyclohexanedicarboxylic acid, 4-methyl-1,2-cyclohexanedicarboxylic acid, and the like can be mentioned. Among them, from the viewpoint of heat resistance, it is preferable to contain an aromatic dicarboxylic acid, and from the viewpoint of adhesion, an aliphatic or alicyclic dicarboxylic acid is preferable.

The crystalline polyester resin (A) preferably contains a polyalkylene glycol component as the glycol component. The polyalkylene glycol component has an average molecular weight of 200 or more and includes, for example, polyethylene glycol, polypropylene glycol, polytetramethylene glycol, etc. Among them, polytetramethylene glycol is preferred. The polyalkylene glycol component is preferably contained in an amount of 1 to 60 mol % when the total amount of glycol components is 100 mol %. It is more preferably 10 mol % or more, still more preferably 15 mol % or more, and even more preferably 20 mol % or more. Also, it is preferably 55 mol % or less, more preferably 50 mol % or less, and still more preferably 45 mol % or less. By containing a polyalkylene glycol component, compatibility can be improved when a polypropylene resin (C) is contained.

Further, as the glycol component constituting the crystalline polyester resin (A), it is preferable to contain a linear aliphatic glycol component in addition to the polyalkylene glycol component described above. Linear aliphatic glycols include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,9-nonanediol, and the like. are mentioned. Among them, ethylene glycol, 1,4-butanediol and 1,6-hexanediol are preferred, and 1,4-butanediol is particularly preferred. By containing these linear aliphatic glycol components, crystallization of the crystalline polyester resin is promoted. As a result, the solidification speed during molding can be increased, and mold releasability can be improved. The linear aliphatic glycol component is preferably contained in an amount of 40 to 99 mol%, more preferably 45 mol% or more, and still more preferably 50 mol% or more when the total glycol component amount is 100 mol%. and more preferably 55 mol % or more. Also, it is preferably 90 mol % or less, more preferably 85 mol % or less, and still more preferably 80 mol % or less.

As the glycol component, the total amount of the linear aliphatic glycol component and the polyalkylene glycol component is preferably 60 mol% or more, more preferably 80 mol% or more, and still more preferably 90 mol% or more. is more preferably 95 mol % or more, particularly preferably 99 mol % or more, and may be 100 mol %.

Other glycol components include, for example, 1,2-propanediol, 1,2-butanediol, 1,3-butanediol, 3-methyl-1,5-pentanediol, neopentyl glycol, dipropylene glycol, 2 , 2,4-trimethyl-1,3-pentanediol, cyclohexanedimethanol, tricyclodecanedimethanol, neopentyl glycol hydroxypivalic acid ester, 2-methyloctanediol, 1,10-dodecanediol, 2-butyl-2 - Aliphatic or cycloaliphatic glycols such as ethyl-1,3-propanediol can be included as appropriate. The content is preferably 40 mol % or less, more preferably 35 mol % or less, even more preferably 30 mol % or less, further preferably 25 mol % or less when the total amount of glycol components is 100 mol %. It is particularly preferably mol % or less, and may be 0 mol %. By making it 40 mol % or less, the crystallization of the crystalline polyester resin can be promoted, and mold releasability is improved.

In addition, the crystalline polyester resin (A) used in the present invention may be used as a branched polyester by copolymerizing a trifunctional or higher polycarboxylic acid or polyol such as trimellitic anhydride or trimethylolpropane, if necessary. It's okay.

The crystalline polyester resin (A) used in the present invention is desirably a saturated polyester resin containing no unsaturated groups. Being a saturated polyester resin, no cross-linking occurs during kneading or molding.

As a method for producing the crystalline polyester resin (A) used in the present invention, a method known as a method for producing a polyester resin can be employed. For example, the desired crystalline polyester resin can be obtained by subjecting the above-described polycarboxylic acid component and glycol component to an esterification reaction at 150 to 250° C., followed by polycondensation at 230 to 300° C. under reduced pressure. Alternatively, a derivative such as dimethyl ester of the above-mentioned polyvalent carboxylic acid component and a glycol component are used for transesterification at 150°C to 250°C, followed by polycondensation at 230°C to 300°C under reduced pressure to obtain the desired crystal. A curable polyester resin can be obtained.

The catalyst used in producing the crystalline polyester resin (A) used in the present invention is not particularly limited, but at least one compound selected from compounds of Ge, Sb, Ti, Al, Mn and Mg is used. preferably. These compounds are added to the reaction system in the form of, for example, powders, aqueous solutions, ethylene glycol solutions, ethylene glycol slurries, and the like.

Moreover, a stabilizer can be added to the crystalline polyester resin (A) within a range that does not impair the effects of the present invention. As a stabilizer, from the group consisting of phosphoric acid esters such as polyphosphoric acid and trimethyl phosphate, phosphonic acid compounds, phosphinic acid compounds, phosphine oxide compounds, phosphonous compounds, phosphinic acid compounds, and phosphine compounds It is preferable to use at least one selected phosphorus compound.

The acid value of the crystalline polyester resin (A) used in the present invention is preferably 1 to 40 eq/ton, more preferably 2 to 30 eq/ton, and more preferably 3 to 20 eq/ton. More preferred. If the acid value exceeds 40 eq/ton, decomposition may be accelerated during kneading. Moreover, if the acid value is less than 1 eq/ton, the compatibility with the polypropylene resin (C) may decrease.

A crystal nucleating agent may be added to the crystalline polyester resin (A) used in the present invention. By adding 0.01 to 5 parts by mass of a crystal nucleating agent to 100 parts by mass of the crystalline polyester resin (A), the crystallization after molding can be promoted, and the solidification speed is increased. Releasability can be improved. The crystal nucleating agent accelerates the crystallization rate of the crystalline polyester resin (A) to quickly complete the crystallization, and also has the effect of controlling the size of the spherulites by adjusting the number of crystal nuclei. Specific examples of crystal nucleating agents include inorganic fine particles such as talc, silica, graphite, carbon powder, pyroferrite, gypsum, and neutral clay, metal oxides such as magnesium oxide, aluminum oxide, and titanium dioxide, hexanoate, and laurin. acid salts, stearates, montanates, sulfates, phosphates, silicates, oxalates, stearates, benzoates, salicylates, tartrates, sulfonates, montanic acid wax salts, montan Examples thereof include acid wax ester salts, terephthalates, carboxylates, and ionic copolymers composed of α-olefins and α,β-unsaturated carboxylic acids. Among them, metal salts such as zinc salts, calcium salts, magnesium salts, sodium salts and lithium salts of fatty acids such as hexanoic acid, lauric acid, stearic acid and montanic acid are preferable because the crystallization speed can be easily controlled. In particular, when a sodium salt of fatty acid is used, the spherulite size can be easily controlled, and a sealing body having good light transmission properties can be easily obtained.

As a method for determining the composition and composition ratio of the crystalline polyester resin (A) used in the present invention, for example, the crystalline polyester resin is dissolved in a solvent such as heavy chloroform and measured by 1H-NMR (nuclear magnetic resonance spectroscopy). ), 13C-NMR, and quantification by gas chromatography measured after methanolysis of a crystalline polyester resin (hereinafter sometimes abbreviated as methanolysis-GC method). In the present invention, if there is a solvent that can dissolve the crystalline polyester resin (A) and is suitable for 1H-NMR measurement, the composition and composition ratio are determined by 1H-NMR. If there is no suitable solvent or if the composition ratio cannot be specified by 1H-NMR measurement alone, 13C-NMR or methanolysis-GC method is adopted or used in combination.

The crystallinity referred to in the present invention is measured by using a differential scanning calorimeter (DSC), once held at 250 ° C. for 5 minutes, then rapidly cooled with liquid nitrogen, and then from -150 ° C. to 250 ° C., 20 ° C./ A substance that exhibits a clear absorption peak (melting peak) when measured at a heating rate of min.

<Adhesion imparting agent (B)>
The molded encapsulant of the present invention essentially contains an adhesion imparting agent (B). Typical tackifiers include terpene phenolic resins, terpene resins (polymers such as α-pinene, β-pinene, and limonene), terpene resins such as aromatic hydrocarbon-modified terpene resins, gum rosin, and tall oil rosin. , rosin resins such as wood rosin, hydrogenated rosin, disproportionated rosin, polymerized rosin, maleated rosin, and rosin ester, petroleum resins such as aliphatic petroleum resins, alicyclic petroleum resins, and aromatic petroleum resins, Examples include coumarone-indene resins, styrene resins, phenol resins such as alkylphenols, phenol xylene formaldehyde, and rosin-modified phenol resins, xylene resins, and epoxy resins. These can be used alone or in combination of two or more. Among these, in particular, those having good compatibility with the crystalline polyester resin (A) are preferable in order to improve light transmittance and exhibit high adhesive strength, and are also compatible with the polypropylene resin (C) described later. Those having good solubility are preferred. Specifically, terpene phenol resins, terpene resins, aromatic hydrocarbon-modified terpene resins, epoxy resins, petroleum resins, rosin resins, and hydrogenated petroleum resins are particularly preferred, and crystalline polyester resin (A) and polypropylene resin (C ), terpene resins are preferred, and terpene phenolic resins and terpene resins are particularly preferred.

The content of the tackifier (B) in the molding encapsulant of the present invention is 100 parts by mass of the crystalline polyester resin (A), or when the polypropylene resin (C) is mixed, the crystalline polyester resin ( When the total amount of A) and the polypropylene resin (C) is 100 parts by mass, it is preferably 1 to 300 parts by mass, more preferably 5 to 200 parts by mass, even more preferably 10 to 100 parts by mass or more, and 15 to 80 parts by mass. Parts by weight are particularly preferred. By setting the amount of the tackifier (B) to be 1 part by mass or more, the adhesion is improved, and the tackifier acts as a compatibilizer between the crystalline polyester resin and the polypropylene resin, resulting in a good kneading state. As a result, adhesion is improved. Also, by making it 300 parts by mass or less, the mold releasability of the crystalline polyester resin (A) and the polypropylene resin (C) is not impaired.

<Polypropylene resin (C)>
The molded sealing material of the present invention may contain a polypropylene resin (C) in addition to the crystalline polyester resin (A). Polypropylene resin is mainly composed of a highly rigid homopolymer (homopolymer) polymerized only with propylene, a flexible random copolymer copolymerized with a small amount of ethylene, and a homo-random polymer with a rubber component (EPR) that is uniformly finely divided. Although it can be divided into dispersed block copolymers with high impact resistance, from the viewpoint of compatibility with the crystalline polyester resin (A) and transparency, the polypropylene resin (C) used in the present invention is , random copolymers are preferred.

The melting point of the polypropylene resin (C) used in the present invention is not particularly limited, but from the viewpoint of excellent heat resistance, it is preferably 70° C. or higher, more preferably 80° C. or higher, and 90° C. or higher. is particularly preferred. From the viewpoint of reducing the difference in melt viscosity from the crystalline polyester resin (A) during kneading, the temperature is preferably 150°C or less.

As the random copolymerized polypropylene resin (C), a propylene random copolymer is preferable. Specifically, a propylene/ethylene random copolymer, a propylene/1-butene random copolymer, a propylene/ethylene/1 -Butene random copolymer and the like are preferred. In addition, from the viewpoint of fluidity during molding, the MFR at 230 ° C. measured based on JIS K7210-1: 2014 is preferably 7 g / 10 min or more. Specific examples of such a polypropylene resin (C) Examples thereof include J-2021GRP and J-3021GRP manufactured by Prime Polymer Co., Ltd., and WFW5T, WFX4M, WXK1233, WFX4TA, WFW4M, WMG3B, WMH02, WSX03, WMX03, WSX02, WMG03, and WMG03UX manufactured by Japan Polypro Corporation. From the viewpoint of compatibility with the polyester resin (A), WXK-1233, WSX03, WMG03, WFW4M, WMX03, WMX03UX, J-2021GRP and J-3021GRP are particularly preferred. By containing the polypropylene resin (C), the difference in melt viscosity from the crystalline polyester resin (A) during kneading can be reduced, so that uniform kneading and dispersion can be achieved. As a result, the molding surface becomes smooth, which leads to improved light transmittance and improved releasability from the mold.

The mass ratio of the crystalline polyester resin (A)/polypropylene resin (C) constituting the molded sealing material of the present invention is preferably 40 to 99/1 to 60, and preferably 42 to 97/3 to 58. is more preferred, and a ratio of 44-95/5-56 is even more preferred. Within the above range, it is possible to satisfy light transmittance, adhesiveness, releasability from mold, and the like.

In the resin composition of the present invention, the difference in melting point between the crystalline polyester resin (A) and the polypropylene resin (C) is preferably within 50°C. The melting point difference is more preferably within 45°C, still more preferably within 40°C, and particularly preferably within 35°C. Within the above range, the difference in viscosity during melt-kneading can be reduced, and uniform kneading and dispersion can be achieved. As a result, the surface of the encapsulant is also smooth, so that the light transmittance is improved and the releasability from the mold is improved.

The molded sealing material of the present invention may contain a styrene-based thermoplastic elastomer (D). By containing the styrene-based thermoplastic elastomer (D), the light transmittance can be improved, and the compatibility between the crystalline polyester resin (A) and the polypropylene resin (C) can be improved. As a result, the surface smoothness of the molding encapsulant is improved, and the releasability from the mold is improved. In addition, as a result of the smoothness of the surface, it is possible to prevent penetration of the oil solution through irregularities and defects on the molding surface, thereby improving the oil resistance. The styrene-based thermoplastic elastomer (D) refers to styrene-based elastomers such as styrene-based block copolymers, styrene-ethylene-butylene-styrene block copolymers, and styrene-butadiene-styrene block copolymers. Among the above, from the viewpoint of imparting compatibility between the crystalline polyester resin (A) and the polypropylene resin (C), the double bond portion of a block copolymer of styrene and butadiene or a block copolymer composed of styrene and butadiene It is particularly preferred to contain hydrogenated elastomers. Specific examples of such styrenic thermoplastic elastomers include Asaprene, Tufprene, Asaflex, Tuftec H, Tuftec M, and Tuftec P (manufactured by Asahi Kasei Corporation). Among the above, from the viewpoint of increasing the compatibility between the crystalline polyester resin (A) and the polypropylene resin (C), those having a low styrene content are preferred. Specifically, Tuftec H1221 and H1521 having a styrene content of 30 mass% or less. , H1943, H1062, H1052, H1053, H1041, M1943, and M1911 are more preferable, and among them, H1221, H1521, H1062, H1052, and M1943 having a styrene content of 20% by mass or less are particularly preferable.

The content of the styrene-based plastic elastomer (D) in the molded sealing material of the present invention is 100 parts by mass of the crystalline polyester resin (A), or when the polypropylene resin (C) is mixed, the crystalline polyester resin When the total amount of (A) and polypropylene resin (C) is 100 parts by mass, it is preferably 21 to 100 parts by mass, more preferably 22 to 90 parts by mass, and even more preferably 23 to 80 parts by mass. By setting the content of the styrene-based plastic elastomer (D) to 21 parts by mass or more, the light transmittance can be improved, and the compatibility between the crystalline polyester resin (A) and the polypropylene resin (C) can be improved. As a result, surging does not occur during kneading, and the strand surface and pellet surface conditions are improved. In addition, the surface smoothness as a molding encapsulant is improved, and the releasability from the mold is improved. In addition, as a result of the smoothness of the surface, it is possible to prevent penetration of the oil solution through irregularities and defects on the molding surface, thereby improving the oil resistance. By making it 100 parts by mass or less, blocking between pellets can be suppressed.

<Polyethylene resin (E)>
The molded sealing material of the present invention preferably contains at least one of polyethylene resin (E) and maleic anhydride-modified polypropylene resin (F). When these components are contained, it is possible to promote compatibility between the crystalline polyester resin (A) and the polypropylene resin (C), which improves the strand surface and pellet surface conditions, and also contributes to the improvement of adhesion. do. Any one of the polyethylene resin (E) and the maleic anhydride-modified polypropylene resin (F) may be present in the molding encapsulant. Both may be contained, and by containing both, the above effects can be synergistically enhanced.

The polyethylene resin (E) used in the present invention is a resin having ethylene as a main structural unit, and is preferably an ultra-low density polyethylene resin. By using a low-density polyethylene resin, the polyethylene resin (E) can be easily finely dispersed and mixed with the molded sealing material containing the crystalline polyester resin (A) and the adhesion promoter (B). can. In addition, due to its low density and low crystallinity, it acts to relieve residual stress over time during molding and contributes to improvement in adhesiveness. As the polyethylene resin (E) having such properties, polyethylene and ethylene copolymers are particularly preferable from the viewpoint of improving adhesiveness. Specifically, low-density polyethylene, ultra-low-density polyethylene, linear low-density polyethylene, ethylene propylene elastomer, ethylene-vinyl acetate copolymer, ethylene-ethyl acrylate copolymer, ethylene-vinyl acetate-maleic anhydride tri Original copolymer, ethylene-ethyl acrylate-maleic anhydride terpolymer, ethylene-glycidyl methacrylate copolymer, ethylene-vinyl acetate-glycidyl methacrylate terpolymer, ethylene-methyl acrylate-methacryl Glycidyl acid terpolymers and the like can be mentioned. Among them, linear low-density polyethylene is preferable, and specifically, Excelen and Sumikasen manufactured by Sumitomo Chemical Co., Ltd., Yumerit manufactured by Ube Maruzen Polyethylene Co., Ltd., Lumitac manufactured by Tosoh Corporation, Nipolon manufactured by Tosoh Corporation, Novatec, Kernel, Harmolex manufactured by Nippon Polyethylene Co., Ltd. , Ultozex, Neozex and Evolue manufactured by Prime Polymer Co., Ltd. Among them, Excellen VL series EUL731, VL100, VL102, VL200, VL700 and EUL830 are preferable. The polyethylene resin (E) may contain polar groups such as carboxyl groups and glycidyl groups without any problem.

The content of the polyethylene resin (E) in the molding sealing material of the present invention is 1 to 200 parts by mass when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. 3 to 190 parts by mass is more preferable, and 5 to 180 parts by mass is even more preferable. By setting the content of the polyethylene resin (E) to 1 part by mass or more, a compatibilizing effect can be obtained, and the generated stress can be reduced. On the other hand, by setting the amount to 200 parts by mass or less, it is possible to suppress a decrease in adhesiveness to the substrate.

<Maleic anhydride-modified polypropylene resin (F)>
The molding encapsulant of the present invention can improve adhesiveness by containing the maleic anhydride-modified polypropylene resin (F), and when it contains the polypropylene resin (C), the crystalline polyester resin (A) and compatibility can be improved. Specific examples of the maleic anhydride-modified polypropylene resin (F) include "Hardlen" manufactured by Toyobo Co., Ltd., "Modic" manufactured by Mitsubishi Chemical Corporation, "Admer" manufactured by Mitsui Chemicals, "Unistor" manufactured by Sanyo Chemical Industries, Ltd. "Umex" etc. are mentioned.

The content of the maleic anhydride-modified polypropylene resin (F) in the molded encapsulant of the present invention is 1 to 100 parts when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. It is preferably parts by mass, more preferably 3 to 90 parts by mass, even more preferably 5 to 80 parts by mass. Adhesion to various substrates can be improved by setting the content of the maleic anhydride-modified polypropylene resin (F) to 1 part by mass or more. On the other hand, by making it 100 parts by mass or less, deterioration of compatibility with the crystalline polyester resin (A) can be suppressed.

<Compatibilizer>
There is no problem even if what is called a compatibilizer is added to the molded sealing material of the present invention. Specific examples of compatibilizing agents include resins obtained by adding carboxylic acid or hydroxyl groups to polyethylene. Specific examples include Malicon (manufactured by Asahi Kasei Corporation) and Epocross (manufactured by Nippon Shokubai Co., Ltd.). The content of the compatibilizer is preferably 0.1 to 50 parts by mass, preferably 0.5 to 50 parts by mass, when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. 40 parts by mass is more preferable, and 1 to 35 parts by mass is even more preferable. By setting the content of the compatibilizer to 0.1 parts by mass or more, the compatibility between the crystalline polyester resin (A) and the polypropylene resin (C) can be improved. A decrease in adhesiveness can be suppressed.

<Release agent>
The mold sealing material of the present invention may further contain a release agent. Mold releasability can be further improved by adding a release agent. In addition to improving the filling property, it also has the effect of improving productivity such as lowering the molding temperature and shortening the injection time.

Examples of release agents include petroleum waxes such as paraffin wax, microcrystalline wax and petrolactam, plant waxes such as carnauba wax, candelilla wax, rice wax, Japan wax and jojoba oil, beeswax, lanolin and spermaceti. animal waxes, mineral waxes such as montan wax and ozokerite, synthetic hydrocarbon waxes (olefin waxes) such as polyethylene wax, polyethylene oxide wax, polypropylene wax, and polypropylene oxide wax, 12-hydroxystearic acid and stearic acid amide, ethylenebiscapric acid amide, ethylenebisstearic acid amide, ethylenebisbehenic acid amide, hexamethylenebisstearic acid amide, ethylenebisoleic acid amide, ethylenebislauric acid amide, N,N'-distearyladipic acid amide, N-hydroxyethyl-12-hydroxystearylamide, N,N'-ethylene-bis-12-hydroxystearylamide, N,N'-hexamethylene-bis-12-hydroxystearylamide, N,N'-xylylene-bis Fat-based synthetic waxes (amide waxes) such as 12-hydroxystearylamide, modified waxes such as montan wax derivatives, paraffin wax derivatives, and microcrystalline wax derivatives, and fluorine-modified waxes such as tetrafluoroethylene (PTFE) wax wax, rice bran wax, metallocene wax, partially saponified wax, ester wax, higher fatty acid wax, higher fatty acid ester wax, Fischer-Tropsch wax, and the like. There is no problem in using the releasing agents alone or in combination of two or more. Among these, amide waxes, polyethylene waxes and polypropylene waxes are preferred. Specifically, amide waxes such as Slipax O, Slipax H (manufactured by Mitsubishi Chemical Corporation), ITOHWAX J-530, J-630, J-700 (manufactured by Ito Oil Co., Ltd.), Sanwax 161-P , Sanwax 131-P, Sanwax 151-P, Sanwax 171-P and other low molecular weight polyethylene waxes; Co., Ltd.) is preferred from the viewpoint of compatibility between the crystalline polyester resin (A) and the polypropylene resin (C), and can impart mold releasability without impairing adhesiveness.

From the viewpoint of mold releasability and adhesiveness, the amount of the release agent in the molded sealing material of the present invention is based on the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) being 100 parts by mass. Furthermore, it is preferably 0.05 to 20 parts by mass, more preferably 0.1 to 15 parts by mass, and even more preferably 0.15 to 10 parts by mass. By setting the amount of the release agent to 0.05 parts by mass or more, the releasability can be improved, and by setting the amount to 20 parts by mass or less, the decrease in adhesiveness can be suppressed.

The release agent is preferably in the form of powder, granules, or granules. Being powdery, granular, or granular, it can be easily dispersed in the crystalline polyester resin (A) and the polypropylene resin (C). More preferably, it is powdery. If it is in the form of a plate or the like, it needs to be pulverized into a shape that is easy to put in, which takes time in the production process and may lead to an increase in cost. Moreover, the average particle diameter thereof is preferably 100 nm to 20 mm. It is more preferably 200 nm to 10 mm, still more preferably 500 nm to 1 mm, still more preferably 1 μm to 100 μm, and particularly preferably 2 μm to 80 μm. If the thickness is 100 nm or more, the wax does not float when the wax is added (at the time of preparation), which is preferable in terms of the production process. In addition, when the thickness is 20 mm or less, additional pulverization becomes unnecessary when kneading with a twin-screw extruder, which is preferable in terms of the production process.

For the purpose of improving durability, etc., the molded sealing material of the present invention contains a crystalline polyester resin (A), a tackifier (B), a polypropylene resin (C), a styrene-based thermoplastic elastomer (D), and polyethylene. Resin (E), maleic anhydride-modified polypropylene resin (F), compatibilizer, polyester other than release agent, polyamide, epoxy resin, polycarbonate, acrylic resin, ethylene vinyl acetate resin, other resin such as phenolic resin, isocyanate Compounds, curing agents such as melamine, fillers such as talc and mica, and pigments such as carbon black and titanium oxide may be added to the extent that the effects of the present invention are not impaired. When the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass, the blending amount is preferably 0.1 to 50 parts by mass, and 0.5 to 40 parts by mass. More preferably, 1 to 35 parts by mass is even more preferable. By making it 0.1 parts by mass or more, mechanical strength can be improved, and by making it 50 parts by mass or less, deterioration of compatibility can be suppressed.

Furthermore, it is preferable to add an antioxidant to the molded sealing material of the present invention when it is exposed to a high-temperature, high-humidity environment for a long period of time. For example, hindered phenols include pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, 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, pentaerythrityltetrakis(3,5-di-t-butyl-4-hydroxy Phenyl)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, 1,3,5-trimethyl-2,4,6-tris(3′,5′-di-t -butyl-4′-hydroxybenzyl), 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, tri(monononylphenyl)phosphite, triphenoxyphosphine, isodecylphos Phite, isodeciphenylphosphite, diphenyl 2-ethylhexylphosphite, dinonylphenylbis(nonylphenyl)ester phosphoric acid, 1,1,3-tris(2-methyl-4-ditridecylphosphite-5-t -butylphenyl)butane, tris(2,4-di-t-butylphenyl)phosphite, pentaerythritolbis(2,4-di-t-butylphenylphosphite), 2,2'-methylenebis(4,6 -di-t-butylphenyl)2-ethylhexyl phosphite, bis(2,6-di-t-butyl-4-methylphenyl)pentaerythritol diphosphite, 4,4'-thiobis[2-t as thioether -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) and bis(tridecyl)thiodipropionate, and these can be used singly or in combination. Among these, 1,3,5-trimethyl-2,4,6-tris(3',5'-di-t-butyl-4' is particularly useful as an antioxidant contributing to both crystalline polyester and polypropylene resins. -hydroxybenzyl), pentaerythrityl tetrakis[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate are particularly preferred. The amount added is preferably 0.01 to 20 parts by mass, more preferably 0.05 to 15 parts by mass when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. is more preferable, and 0.1 to 10 parts by mass is even more preferable. By adding 0.01 parts by mass or more, the effect of preventing thermal deterioration can be exhibited. Adhesiveness is not deteriorated by making it 20 mass parts or less.

Furthermore, an inorganic substance can be added to the molded sealing material of the present invention. Examples of inorganic substances include various carbides such as silicon carbide, boron carbide, titanium carbide, zirconium carbide, hafnium carbide, vanadium carbide, tantalum carbide, niobium carbide, tungsten carbide, chromium carbide, molybdenum carbide, calcium carbide, diamond carbon lactam; Various nitrides such as titanium nitride and zirconium nitride, various borides such as zirconium boride; various oxides such as titanium oxide (titania), calcium oxide, magnesium oxide, zinc oxide, copper oxide, and aluminum oxide; calcium titanate, Various titanate compounds such as magnesium titanate and strontium titanate; sulfides such as molybdenum disulfide; various fluorides such as magnesium fluoride and fluorocarbon; aluminum stearate, calcium stearate, zinc stearate, magnesium stearate, etc. various metal soaps; In addition, talc, bentonite, talc, calcium carbonate, bentonite, kaolin, glass fiber, mica, montmorillonite, inorganic ion scavengers, and the like can be used. By adding these inorganic substances, it may be possible to improve heat resistance and mechanical strength.

Furthermore, carbodiimide or the like can be appropriately used as a resin decomposition inhibitor in the molded sealing material of the present invention.

A flame retardant may be added to the molded encapsulant of the present invention to impart flame retardancy. Although the type of flame retardant is not particularly limited, brominated polystyrene, phosphate ester, ammonium polyphosphate, melamine polyphosphate, melamine cyanurate, aluminum hydroxide, magnesium hydroxide, halogen compounds, antimony trioxide, thermally expandable Graphite, red phosphorus, and the like. From the viewpoint of imparting flame retardancy, the content of the flame retardant is preferably 10 to 80 parts by mass when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. , more preferably 20 to 70 parts by mass, more preferably 30 to 60 parts by mass. When the amount is 10 parts by mass or more, the effect of imparting flame retardancy can be exhibited, and when the amount is 80 parts by mass or less, a decrease in adhesiveness can be suppressed.

Furthermore, various known additives can be used in the molding encapsulant of the present invention as long as they do not impair the effects of the present invention. Additives include impact modifiers, slidability modifiers, colorants, plasticizers, thixotropic agents, hydrolysis inhibitors, leveling agents, UV absorbers, pigments, dyes, and thermoplastic resins other than polyester. mentioned.

In the molding encapsulant of the present invention, it is preferable that the average light transmittance at a wavelength of 570 to 780 nm of a molded article having a thickness of 1 mm is 10% or more. When the light transmittance at a wavelength of 570 to 780 nm is 10% or more, the transmittance of yellow to red LED light is particularly good. It is more preferably 12% or more, still more preferably 14% or more.

Furthermore, conventionally known methods can be used as a method for blending additives into the molded encapsulant of the present invention. For example, a method of dry blending each component, or a method of melt-kneading each component using a twin-screw extruder can be used.

<Electrical/electronic component encapsulant>
As a method for obtaining the molded sealing material for the sealed body of electric and electronic parts of the present invention, for example, after setting the electric and electronic parts in a mold, the molded sealing material of the present invention is applied to a screw-type hot-melt molding applicator. The mixture is heated and melted at around 120 to 250° C., and poured into a mold through a nozzle. After a certain cooling time, the molded product is removed from the mold to obtain a sealed electrical/electronic component in which the electrical/electronic component and the like are sealed with the molding sealing material. The temperature and pressure during injection of the molded sealing material are preferably 200° C. or higher and 260° C. or lower and the pressure is 0.1 MPa or higher and 20 MPa or lower. By encapsulating under such conditions, it is possible to obtain a sealed body that does not damage the electric/electronic component and that is free from breakage and misalignment. In addition, it is easy to obtain a well-shaped electrical/electronic component sealed body free from short shots, burrs, and sink marks.

Molding machines and processing machines for obtaining the electrical and electronic component encapsulant of the present invention include ordinary injection molding machines, extrusion molding machines, plunger-type molding machines, hot-melt molding applicators, and the like. can be used.

Examples and comparative examples are given below to describe the present invention in more detail, but the present invention is not limited by the examples. Each measured value described in Examples and Comparative Examples was measured by the following method.

<Measurement of melting point and glass transition temperature>
The melting points of the crystalline polyester resin (A) and polypropylene resin (C) were measured using a differential scanning calorimeter "DSC220 type" manufactured by Seiko Electronics Industries, Ltd. Put 5 mg of the measurement sample in an aluminum pan, press the lid and seal it. was once heated to 250° C. at a heating rate of 20° C./min and melted. Then, it was cooled to −130° C. at a rate of 20° C./min using liquid nitrogen, held for 5 minutes, and then measured from −130° C. to 250° C. at a heating rate of 20° C./min. In the obtained curve, the intersection of the tangent line (1) obtained from the baseline before the inflection point and the tangent line (2) obtained from the baseline after the inflection point in the portion where the inflection point appears in DSC as shown in FIG. was taken as the glass transition temperature (Tg), and the minimum point of the endothermic peak (x mark in the figure) was taken as the melting point (Tm).
When multiple peaks appeared, the minimum point of the endothermic peak at the highest temperature was defined as the melting point (Tm).

<Measurement of number average molecular weight>
A 0.0050 g sample of the crystalline polyester resin was heated and dissolved in 5 ml of chloroform and filtered through a membrane filter to remove insoluble matter. Thereafter, 80 μl of the filtrate (sample solution) was measured with a gel permeation chromatograph (GPC) “EZChrom Elite for Hitachi” manufactured by Hitachi High-Tech Fielding Co., Ltd. to determine the number average molecular weight. A polystyrene solution was prepared as a standard substance and used as a sample for the GPC calibration curve.

<Evaluation of kneading state>
After each raw material was uniformly mixed by dry blending at the compounding ratio shown in Tables 2 and 3, the mixture was supplied to the main supply port of a twin-screw extruder TEM-26SS (manufactured by Shibaura Kikai Co., Ltd.). Then, the screw rotation speed is set to 300 rpm and the extrusion temperature is set to 250° C., melt-kneading is performed, and the resin composition drawn in a strand shape from the die orifice is cooled and solidified through a water bath, and cut with a pelletizer to form and seal pellets. got the wood. The state of surging and the state of the surface of the strand and the surface of the pellets were observed when the material was taken into a strand, and the kneading state was evaluated.
<Evaluation Criteria>
⊚: No surging occurred, no rough feeling on the strand surface, and no rough feeling on the pellet surface after pelletizing.
◯: No surging occurs, but the strand surface and/or the pellet surface after pelletizing has a rough feeling.
Δ: Surging occurs, and the strand surface and/or pellet surface after pelletizing has a rough feeling.
x: Surging occurred and the strand could not be pulled.

<Evaluation of Mold Releasability>
A coin-shaped mold with a diameter of 25 mm and a thickness of 2 mm was set, and a small electric injection molding machine (Canon Electronics LS300i) was used to continuously mold the molded sealing material, and the mold releasability of the molded product was evaluated. did The molding conditions were a molding temperature of 220° C., a filling speed of 10 mm/s, a pressure of 15 MPa, and a cooling time of 20 seconds. After that, the mold was opened, and mold releasability was evaluated based on the following evaluation criteria.
<Evaluation Criteria>
⊚: Even after 101 times of continuous molding, the molded product does not stick to the upper mold and can be easily removed from the lower mold.
◯: The molded product sticks to the upper mold of the mold, or the molded product breaks during 51 to 100 continuous moldings.
Δ: The molded product sticks to the upper mold of the mold, or the molded product breaks during 11 to 50 times of continuous molding.
x: The molded product sticks to the upper mold of the mold, or the molded product breaks within 10 times of continuous molding.

<Evaluation of Visibility of Optical Properties>
By injection molding using a vertical injection molding machine (TH40E manufactured by Nissei Plastic Industry Co., Ltd.), a molded product (flat plate) of 100 mm × 100 mm × 1 mmt molded sealing material was produced. The injection molding conditions were a molding resin temperature of 240° C., a molding pressure of 20 MPa, a cooling time of 30 seconds, and an injection speed of 10 mm/second. Cut the molded flat plate into 30 × 30 mm, and use an ultraviolet-visible spectrophotometer V-650 (manufactured by JASCO Corporation) in transmission mode to obtain transmittance from 200 nm to 800 nm at intervals of 2 nm. The average light transmittance at a wavelength of 780 nm was calculated.
<Evaluation Criteria>
A: Average light transmittance at 570 nm to 780 nm is 14% or more.
◯: The average light transmittance at 570 nm to 780 nm is 12% or more and less than 14%.
Δ: The average light transmittance at 570 nm to 780 nm is 10% or more and less than 12%.
x: The average light transmittance at 570 nm to 780 nm is less than 10%.

<Adhesion evaluation (shear adhesion strength)>
Method for preparing shear bond strength test piece A PBT substrate (polybutylene terephthalate (GF (glass fiber) content of 30% by mass) manufactured by Polyplastics: Duranex 3300) was cut into sizes of 70 mm × 25 mm and 40 mm × 25 mm, The surface was wiped with acetone to remove oil. Next, the base materials are overlapped by a length of 10 mm so that the base materials come into contact with the melted molding sealing material, and the width is 25 mm, and the thickness of the molding molding material to be molded is 1 mm. It was fixed inside the test mold. Then, using a screw type hot melt molding applicator (vertical low pressure extrusion molding machine IMC-18F9 manufactured by Imoto Seisakusho Co., Ltd.), a molding sealant having a moisture content of 0.1% or less was injected and molded. . The molding conditions were a molding resin temperature of 220° C., a molding pressure of 3.5 MPa, a holding pressure of 3.5 MPa, a holding pressure time of 20 seconds, and a discharge rotation rate of 80% (maximum discharge set to 100%). The molded product was removed from the mold to obtain a shear adhesive strength test piece (substrate/molded sealing material layer/substrate) in which the molded molding sealing material was sandwiched between the respective substrates.

Shear Adhesion Strength Test Method The shear adhesion test piece was stored for one day in an atmosphere of 23° C. and 50% relative humidity. Next, using an autograph (AG-IS manufactured by Shimadzu Corporation), each substrate was sandwiched between chucks and the resin composition was peeled off in the shear direction to measure the initial shear adhesive strength. The tensile speed was 50 mm/min.
<Evaluation Criteria>
◎: Shear adhesive strength 2.5 MPa or more ○: Shear adhesive strength 2.0 MPa or more and less than 2.5 MPa △: Shear adhesive strength 1.5 MPa or more and less than 2.0 MPa ×: Shear adhesive strength less than 1.5 MPa or not measurable , The base material (adherend) was evaluated using the following PBT base material.
* Unmeasurable: When the shear adhesive strength test piece is set in the autograph, it peels off and cannot be measured.

<Production example of crystalline polyester resin>
Production Example of Crystalline Polyester Resin (A1) Into a reactor equipped with a stirrer, a thermometer and a condenser for distillation, 166 parts by mass of terephthalic acid, 180 parts by mass of 1,4-butanediol and 0.25 parts of tetrabutyl titanate were charged. Parts by mass were added, and an esterification reaction was carried out at 170 to 220° C. for 2 hours. After completion of the esterification reaction, 300 parts by mass of polytetramethylene glycol "PTMG1000" (manufactured by Mitsubishi Chemical Corporation) having a number average molecular weight of 1000 and 0.5 parts of hindered phenol-based antioxidant "Irganox 1330" (manufactured by BASF Japan Ltd.) were added. 5 parts by mass were added, and the temperature was raised to 245°C, while the pressure in the system was slowly reduced to 665 Pa at 245°C over 60 minutes. Further, a polycondensation reaction was carried out at 133 Pa or less for 60 minutes to obtain a crystalline polyester resin A1. This crystalline polyester resin A1 had a glass transition temperature of −65° C., a melting point of 160° C., and a number average molecular weight of 24,000.

Crystalline polyester resins A2 to A6 were synthesized in the same manner as for crystalline polyester resin A1, except that the types and amounts of raw materials and the reaction time were changed. Table 1 shows the composition and physical property values of each.

Abbreviations in Table 1 are as follows.
TPA: terephthalic acid, NDC: 2,6-naphthalenedicarboxylic acid, IPA: isophthalic acid, DA: dimer acid, AA: adipic acid, BD: 1,4-butanediol, EG: ethylene glycol, PTMG1000: polytetramethylene ether Glycol (number average molecular weight 1000), PTMG2000: polytetramethylene ether glycol (number average molecular weight 2000), CHDM: 1,4-cyclohexanedimethanol

<Example 1>
68 parts by mass of crystalline polyester resin A1 as crystalline polyester resin, 22 parts by mass of TO125 as tackifier B1, 32 parts by mass of WXK1233 as polypropylene resin C1, and 47 parts by mass of Tuftec H1521 as styrene thermoplastic elastomer D1 are added. After mixing them uniformly, they were melt-kneaded at a die temperature of 230° C. using a twin-screw extruder to obtain a molded encapsulant 1 . The kneading state of the molded encapsulant 1, the releasability from the mold during molding, the light transmittance of the molded article, and the adhesiveness were evaluated by the methods described separately. Table 2 shows the results.

<Examples 2 to 25, Comparative Examples 1 to 11>
Molding encapsulants 2 to 36 containing a crystalline polyester resin and a tackifier were prepared in the same manner as in Example 1 except that the types and blending amounts of each component were in accordance with the combinations shown in Tables 2 and 3. Items were evaluated. The evaluation results are shown in Tables 2 and 3.

Abbreviations in Tables 2 and 3 are as follows.
Tackifier B1: TO125, manufactured by Yasuhara Chemical Co., Ltd., modified terpene resin Tackifier B2: KR85, manufactured by Arakawa Chemical Industries, Ltd., ultra-light colored rosin polypropylene resin C1: WXK1255, manufactured by Nippon Polypro Co., Ltd., melting point 125°C
Polypropylene resin C2: WSX03, manufactured by Japan Polypropylene Corporation, melting point 125°C
Styrene-based thermoplastic elastomer D1: Tuftec H1521, manufactured by Asahi Kasei Corporation, hydrogenated styrene-ethylene-butylene copolymer polyethylene resin E1: Excellen (registered trademark) VL EUL731, manufactured by Sumitomo Chemical Co., Ltd., α-olefin copolymer ultra-low density polyethylene Maleic anhydride-modified polypropylene resin F1: PMA-H1100P, manufactured by Toyobo

As shown in Examples in Table 2, the molding encapsulant of the present invention has a good kneading state, good mold releasability at the time of molding, and good light transmittance and adhesiveness of the molded product. It was good.

On the other hand, since Comparative Examples 1 to 5 in Table 3 did not contain the polyester resin (A), the adhesiveness was inferior. Since Comparative Examples 6 to 8 did not contain the tackifier (B), the adhesiveness was inferior. , Comparative Examples 9 to 11 had low light transmittance, and thus the visibility of the optical characteristics was poor.

A molding encapsulant containing the crystalline polyester resin of the present invention and an adhesion promoter and having a predetermined light transmittance can improve mold releasability in continuous production and improve the visibility of optical properties. It is suitable as a molding sealing material in insert molding, which inserts and molds substrates and parts used in electrical and electronic parts and industrial equipment because it has excellent adhesion and mold releasability. used. In particular, as molding sealing materials for various connectors, harnesses, electronic parts, switches, printed circuit boards, battery sealing materials for automobiles, communications, computers, home appliances, and electrical and electronic parts for sensors such as weight detection sensors and seating sensors. Useful.

Claims (8)

A molding encapsulant comprising a crystalline polyester resin (A) and an adhesion promoter (B), and having an average light transmittance of 10% or more at a wavelength of 570 to 780 nm in a molded article having a thickness of 1 mm. The molded encapsulant according to claim 1, further comprising a polypropylene resin (C). Claim 2, wherein the mass ratio of the crystalline polyester resin (A) to the polypropylene resin (C) (crystalline polyester resin (A)/polypropylene resin (C)) is in the range of 40 to 99/1 to 60. molded encapsulant. The molded sealing material according to any one of claims 1 to 3, further comprising a styrene-based thermoplastic elastomer (D). The molding encapsulation according to claim 4, which contains 21 to 100 parts by mass of the styrene-based thermoplastic elastomer (D) when the total amount of the crystalline polyester resin (A) and the polypropylene resin (C) is 100 parts by mass. material. The molded sealing material according to any one of claims 1 to 5, wherein the tackifier (B) contains at least one of a terpene resin and a terpene phenolic resin. The molded sealing material according to any one of claims 1 to 6, further comprising at least one of polyethylene resin (E) and maleic anhydride-modified polypropylene resin (F). A sealed electrical/electronic component sealed with the molded sealing material according to any one of claims 1 to 7.

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