HK1181797A

HK1181797A - Resin composition containing a copolymerized polyester resin

Info

Publication number: HK1181797A
Application number: HK13109133.4A
Authority: HK
Inventors: 富泽元贵; 大河内隆雄; 田中知树; 木田尚实; 种田佑路
Original assignee: 尤尼吉可股份有限公司; 日本酯股份有限公司
Priority date: 2010-08-04
Filing date: 2011-08-03
Publication date: 2013-11-15

Abstract

Disclosed is a resin composition which, based on a copolymerized polyester resin, has excellent flexibility at room temperature, remedies problems with brittleness, and has excellent adhesiveness and hygrothermal durability. The disclosed resin composition based on a copolymerized polyester resin contains as an acid component an aromatic dicarboxylic acid and a dimer acid, and contains as a glycol component 1,4-butanediols and polybutadiene glycols, wherein the content of the dimer acid is 10-50 mol% in the acid component, the content of the 1,4-butanediol is 50 mol% or greater in the glycol component, and the content of the polybutadiene glycol is 0.5-20 mol% in the glycol component.

Description

Resin composition containing copolyester resin

Technical Field

The present invention relates to a resin composition containing a copolyester resin. Specifically, the present invention relates to a resin composition containing the following copolymerized polyester resin: contains a dimer acid as an acid component and 1, 4-butanediol and a polybutadiene diol as diol components, and is excellent in flexibility, adhesiveness, moist heat durability and the like.

Background

The following copolyesters are known, namely: a copolyester mainly composed of a polyester, particularly a polyethylene terephthalate (hereinafter abbreviated as PET) unit or a polybutylene terephthalate (hereinafter abbreviated as PBT) unit, and copolymerized with an aliphatic dicarboxylic acid or various diols. The copolyester is widely used as a film, a fiber, a sheet, various molded articles, and an adhesive because of its excellent heat resistance, weather resistance, solvent resistance, flexibility, and the like.

However, when the above-mentioned copolyester is used for applications requiring high flexibility, it is weak because of lack of flexibility at low temperature or room temperature. For this reason, the above-mentioned copolyesters have a limited number of applications in which they can be used.

In order to improve such a disadvantage, a method of copolymerizing a soft segment in a polyester resin is disclosed. The polyester-polyether block copolymer having a soft segment of a polyether compound has a resin with a low glass transition point and high fluidity, and the resin has flexibility even when the molecular weight is reduced. Therefore, the resin composition is widely used as a molding material for electric and electronic parts, automobile parts, and the like. Such a polyester-polyether block copolymer is disclosed in patent document 1, for example.

However, the polyester-polyether block copolymer is easily hydrolyzed by ester bonds of hard segments. Further, the polyether compound belonging to the soft segment is likely to cause oxidative decomposition, thermal decomposition, or the like when exposed to high temperature, and therefore, there is a problem in the moist heat durability of the copolymer itself.

Patent document 2 discloses a polyester resin and a resin composition suitable for molding. The resin disclosed in patent document 2 is suitable for use in molding for electric and electronic components, and is disclosed to be excellent in water resistance, durability, fuel resistance, and the like.

However, the composition disclosed in patent document 2 cannot provide sufficient flexibility, moisture and heat durability, adhesiveness, and the like. Therefore, when the resin is used for molding applications of electric and electronic components, there is a problem that a product made of the resin is not usable for a long time because the resin portion is peeled from the internal electric and electronic components or the like or a crack is generated in the resin portion.

Prior art documents

Patent document

[ patent document 1 ]: japanese patent laid-open No. 2-3429

[ patent document 2 ]: japanese patent laid-open No. Hei 2003-176341

Disclosure of Invention

Problems to be solved by the invention

Accordingly, a main object of the present invention is to provide a polyester resin composition which is excellent in flexibility at room temperature, can improve the problem of brittleness, and is excellent in adhesiveness and moist heat durability. More specifically, the main object is to provide a resin composition containing a copolyester resin, which is suitable for use in hot melt molding, sealing, and the like of electric and electronic parts and the like. Means for solving the problems

The present inventors have made extensive studies in view of the above-mentioned problems of the prior art, and as a result, have found that the above-mentioned object can be achieved by using a specific copolyester resin, thereby completing the present invention.

Namely, the present invention relates to the following resin composition containing a copolyester resin.

1. A resin composition comprising a copolyester resin, the copolyester resin containing an aromatic dicarboxylic acid and a dimer acid as acid components, and containing 1, 4-butanediol and a polybutadiene diol as diol components, wherein the content of the dimer acid in the acid component is 10 to 50 mol%, the content of the 1, 4-butanediol in the diol component is 50 mol% or more, and the content of the polybutadiene diol in the diol component is 0.5 to 20 mol%.

2. A resin composition as described in above item 1, wherein an organophosphorus compound having 2 or more ester-forming functional groups is copolymerized in the copolyester resin, and the content of phosphorus atoms in the resin is 500 to 20000 mass ppm.

3. The resin composition according to item 1 above, wherein the Young's modulus at 20 ℃ is 100MPa or less.

4. The resin composition according to item 1 above, wherein the Shore D hardness at 20 ℃ is 50 or less.

5. The resin composition according to item 1 above, wherein the oxygen index in the burning test is 27 or more.

6. A method for manufacturing a resin molded product, comprising the steps of: a resin molded article is obtained by molding the resin composition according to item 1 under a pressure of 5MPa or less.

7. The method according to item 6 above, wherein the step is a step of injecting the resin composition according to item 1 above into a mold in which an industrial member is previously placed, thereby producing a resin molded article containing the industrial member.

8. The method according to item 6 above, wherein the above step is a step of injecting or dropping the resin composition according to item 1 above into a housing or a substrate in which an industrial member is previously arranged, thereby producing a resin molded article containing the industrial member.

Effects of the invention

The resin composition of the present invention comprises, as the main component, in particular, the following copolyester resins: since a specific amount of dimer acid is contained as an acid component and a specific amount of polybutadiene diol is contained as a diol component, the rubber composition is excellent in flexibility at room temperature, has appropriate hardness, can improve the problem of brittleness, and can exhibit excellent adhesiveness and hot and humid durability.

Therefore, the resin composition of the present invention can be used as a film, a fiber, a sheet, other various molded articles, and also as an adhesive.

Further, the resin composition of the present invention has excellent fluidity when melted and can be injection-molded at low pressure, and therefore, can provide a molded article having a thin portion or a complicated shape by melt-molding.

The resin composition of the present invention can be suitably used for hot melt molding for insert molding of precision electronic parts and the like. Further, the present invention can be suitably used for the following packaging applications: the component is placed in the cover or on the substrate, and the cover or the substrate is integrated with the component by casting a resin thereon and using the resin composition.

Further, the resin composition of the present invention is excellent in moisture and heat durability, and therefore, an electric or electronic component obtained by insert molding an electronic component as described above can be used for a long time in a severe environment.

Detailed Description

1. Resin composition containing copolyester resin

The resin composition containing a copolyester resin of the present invention (the resin composition of the present invention) will be described in detail below. In the copolyester resin (copolyester resin of the present invention) constituting the main component of the resin composition of the present invention, the copolyester resin comprises an acid component containing an aromatic dicarboxylic acid and a dimer acid and a diol component containing 1, 4-butanediol and polybutadiene diol.

(1) Copolyester resin

(1-1) acid component

First, the acid component is explained. As the aromatic dicarboxylic acid, for example, terephthalic acid, isophthalic acid, sodium 5-sulfonate isophthalate, phthalic anhydride, naphthalenedicarboxylic acid, and the like can be used, and ester-forming derivatives of these acids can also be used. These can be used alone, or these can be used in combination of 2 or more. The aromatic dicarboxylic acid contributes to an increase in the melting point of the copolyester and imparts heat resistance, while improving mechanical strength. According to the above findings, in the present invention, at least 1 of terephthalic acid and isophthalic acid is preferable as the aromatic dicarboxylic acid.

The content of the aromatic dicarboxylic acid in the acid component is not particularly limited, however, preferably 50 to 90 mol%, particularly more preferably 60 to 85 mol%. When the content of the aromatic dicarboxylic acid is less than 50 mol%, the melting point of the copolyester is lowered, the heat resistance is poor, and the mechanical strength is easily lowered. On the other hand, if it exceeds 90 mol%, the proportion of dimer acid decreases, and the flexibility of the copolyester resin tends to be poor.

The dimer acid in the present invention means, for example, an unsaturated fatty acid obtained by thermally polymerizing an unsaturated fatty acid derived from a purified plant fatty acid such as drying oil, semi-drying oil, etc., or a saturated fatty acid obtained by partially or completely hydrogenating the unsaturated fatty acid. These dimer acids are mainly composed of dimers of unsaturated fatty acids or hydrides thereof, and include trimers, tetramers, and the like. These may be known or commercially available. Examples of commercially available products include "Pripol", "Priplast" (manufactured by Croda (R) "),", "Empol", "Sovermol" (manufactured by Cognis (R) "), and" Unidym "(manufactured by Arizona chemical Co.).

The content of the dimer acid in the acid component must be 10 to 50 mol%, particularly preferably 15 to 40 mol%. By containing a dimer acid as a copolymerization component, the resulting copolyester resin becomes a resin excellent in flexibility and can also be improved in hydrothermal durability. If the content of the dimer acid in the acid component is less than 10 mol%, it becomes difficult to impart flexibility to the resulting copolyester resin, and the effect of improving the moist heat durability is also lacking. On the other hand, when the content of the dimer acid is more than 50 mol%, the melting point of the resulting copolyester is lowered or the copolyester becomes amorphous, so that the heat resistance is poor and the mechanical strength is easily lowered.

The copolyester resin of the present invention contains the aromatic dicarboxylic acid and dimer acid as described above as the acid component, but may contain other components as the copolymerization component as long as the effects of the present invention are not impaired. Examples of such other components include: succinic acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, eicosanedioic acid, and the like.

(1-2) diol component

The copolyester resin of the present invention contains 1, 4-butanediol as a diol component. The content of 1, 4-butanediol in the diol component must be 50 mol% or more, particularly preferably 60 mol% to 98 mol%, further more preferably 80 mol% to 98 mol%. By containing 50 mol% or more of 1, 4-butanediol as a diol component, the resulting copolyester resin has an increased melting point, excellent heat resistance, and improved moldability. Particularly, when used for molding, it is preferably 80 mol% to 98 mol%. Even when a diol other than 1, 4-butanediol is used, it is difficult to obtain a desired effect. For example, when 1, 2-ethanediol is used instead of 1, 4-butanediol, the crystallization rate of the resulting copolyester resin is lowered and the moldability is deteriorated. Further, when 1, 6-hexanediol is used instead of 1, 4-butanediol, the melting point of the resulting copolyester is lowered and the heat resistance is poor.

The copolyester resin of the present invention contains a polybutadiene diol as a diol component. The content of the polybutadiene diol in the diol component must be 0.5 to 20 mol%, particularly preferably 2 to 18 mol%, further more preferably 3 to 16 mol%.

By containing a polybutadiene diol as a diol component, the resulting copolyester resin can be imparted with excellent flexibility and moist heat durability. If the proportion of the polybutadiene diol is less than 0.5 mol%, it is difficult to obtain a copolyester resin having excellent flexibility and moist heat durability. On the other hand, if the proportion of the polybutadiene diol is more than 20 mol%, the resulting copolyester tends to have a low melting point and poor heat resistance, and to have a low mechanical strength.

The polybutadiene diols preferably have an average molecular weight of 350 to 6000, particularly preferably 500 to 4500. When the average molecular weight of the polybutadiene diol is more than 6000, the compatibility is deteriorated and the copolymerization is liable to become difficult. On the other hand, when the molecular weight is less than 350, it is liable to be difficult to improve the flexibility of the resulting copolyester resin.

As the polybutadiene diol, in addition to 1, 2-polybutadiene diol, 1, 4-polybutadiene diol and the like, hydrogenated polybutadiene diol obtained by hydrogen reduction of these compounds can be used. More specifically, there may be mentioned: a diol obtained by polymerizing butadiene by anionic polymerization and introducing hydroxyl groups or groups having hydroxyl groups at both ends by terminal treatment; and diols (hydrogenated polybutadiene diols) obtained by reducing these double bonds with hydrogen.

The polybutadiene diols may be those known or commercially available. Specifically, examples thereof include: hydroxylated polybutadienes having mainly 1, 4-repeating units (for example, "Poly bd R-45 HT" and "Poly bd R-15 HT" available from Shikino Co., Ltd.); hydroxylated polybutadienes having mainly 1, 2-repeating units (e.g., "" G-1000 "", "" G-2000 "", and "" G-3000 ", manufactured by Nippon Caoda), hydroxylated hydrogenated polybutadienes (e.g.," "GI-1000" "," "GI-2000" ", and" "GI-3000", manufactured by Nippon Caoda), and the like.

The polybutadiene diol in the present invention is preferably hydrogenated polybutadiene diol. Since the hydrogenated polybutadiene diol is less likely to cause side reactions in the polycondensation reaction, a copolyester resin having more excellent flexibility, moist heat durability, and the like can be obtained.

The copolyester resin of the present invention may contain a component other than 1, 4-butanediol and polybutadiene glycols as a diol component (copolymerization component) within a range not to impair the effects of the present invention. Examples of such other ingredients are: ethylene glycol, propylene glycol, 1, 3-propanediol, 1, 5-pentanediol, 1, 6-hexanediol, neopentyl glycol, ethylene oxide adduct and propylene oxide adduct of bisphenol A, polyethylene glycol, polypropylene glycol, polybutylene glycol, and the like.

(1-3) flame retardant Components

Further, in order to impart flame retardancy to the copolyester resin of the present invention, it is preferable that an organic phosphorus compound having 2 or more ester-forming functional groups is copolymerized as a flame retardant component, and the content of phosphorus atoms in the copolyester resin is 500 to 20000 mass ppm.

In the present invention, examples of the ester-forming functional group include: carboxyl, hydroxyl, and the like. When the organic phosphorus compound does not have an ester-forming functional group, it is not copolymerized in the polyester chain, and therefore, it is likely to scatter during polycondensation and sufficient flame retardancy may not be exhibited. When the number of the ester-forming functional group is 1, the polycondensation reaction is inhibited and the degree of polymerization cannot be increased, which is not preferable. Therefore, the number of ester-forming functional groups must be 2 or more, and among them, 2 to 3 are preferable.

The content of the phosphorus atom in the copolyester resin is 500 to 20000 mass ppm, and particularly preferably 2000 to 18000 mass ppm. If the phosphorus atom content is less than 500 ppm by mass, the flame retardancy of the copolyester resin may be insufficient, and it may be difficult to use the copolyester resin in applications requiring high flame retardancy. On the other hand, if it exceeds 20000 mass ppm, the melting point of the copolyester resin may be lowered or the copolyester resin may be non-crystalline, and therefore, the heat resistance may be poor.

The organic phosphorus compound having 2 or more ester-forming functional groups is preferably a compound represented by the following formula (1) from the viewpoints of reactivity of the polycondensation reaction, a residual ratio of the organic phosphorus compound, and the like.

[ chemical formula 1]

Wherein R is¹Represents an alkyl group or an aryl group having 1 to 12 carbon atoms, R²Is an alkyl group having 1 to 18 carbon atoms, an aryl group, a monohydroxyalkyl group or a group represented by formula R¹A cyclic body of (2) or a hydrogen atom, R³It is an alkyl group having 1 to 18 carbon atoms, an aryl group, a monohydroxyalkyl group or a hydrogen atom, and A is a hydrocarbon group having a valence of 2 or more. N represents the valence of A minus 1.

Preferred specific examples of the organic phosphorus compound represented by the above formula (1) include compounds represented by the following structural formulae (a) to (d).

[ chemical formula 2]

(2) Copolymerized polyester resin composition

(2-1) composition of resin composition

The resin composition of the present invention contains the above-mentioned copolyester resin. For example, the content of the copolyester resin may be appropriately set according to the kind, intended use, and the like of the copolyester resin, however, it is generally preferably set to 30 to 100% by mass, particularly 50 to 100% by mass, and still more preferably 70 to 100% by mass in the resin composition. That is, the resin composition of the present invention includes 100% by mass of the copolyester resin, and also includes a copolyester resin and other components. When the content of the copolyester resin is less than 100% by mass, additives, resin components, and the like described below may be contained.

Examples of additives include: pigments, heat stabilizers, antioxidants, weather-resistant agents, flame retardants, plasticizers, lubricants, mold release agents, antistatic agents, fillers, crystallization nucleating agents, and the like. The copolyester resin-containing resin composition of the present invention can be prepared by using these additives.

As described above, the copolyester resin of the present invention is preferably copolymerized with a specific organic phosphorus compound for imparting flame retardancy, but the resin composition of the present invention may contain a flame retardant as described below for imparting flame retardancy. Examples of such flame retardants include: phosphorus flame retardants, hydrated metal compounds (aluminum hydroxide, magnesium hydroxide, etc.), nitrogen-containing compounds (melamine-based, guanidine-based), inorganic compounds (borates, Mo compounds, etc.). Among them, at least 1 kind of aromatic condensed phosphoric ester compound, brominated aromatic compound, antimony oxide compound and the like is preferable. When a brominated aromatic compound is used in combination with an antimony oxide compound, it is preferable to use both compounds. The brominated aromatic compound is preferably a brominated epoxy resin, and the antimony oxide compound is preferably antimony trioxide (Sb)₂O₃). The content of these flame retardants is preferably 2 to 30 parts by mass with respect to 100 parts by mass of the copolyester resin.

Further, for example, a countermeasure against heat generated in various electronic components to be effectively radiated to the outside is also an important problem, and in order to solve such a problem, it is preferable to impart thermal conductivity to the copolyester resin of the present invention. Specifically, the copolyester resin of the present invention is preferably added with a thermally conductive filler.

Examples of the thermally conductive filler include: flake graphite, flake boron nitride having a hexagonal crystal structure, alumina, magnesium carbonate, zinc oxide, talc, and the like. The content of these fillers is not particularly limited, but is preferably 50 to 150 parts by volume, particularly preferably 60 to 120 parts by volume, based on 100 parts by volume of the copolyester resin.

Examples of the heat stabilizer or the antioxidant include: hindered phenols, phosphorus compounds, hindered amines, sulfur compounds, copper compounds, alkali metal halides, and the like.

The method of incorporating the above-mentioned additive into the resin composition of the present invention is not particularly limited.

The resin composition of the present invention may contain a resin component other than the copolyester resin of the present invention within a range not to impair the effects thereof. For example, resins such AS polyethylene, polypropylene, polybutadiene, polystyrene, AS resin, ABS resin, poly (acrylic acid), poly (acrylate), poly (methacrylic acid), poly (methacrylate), polyethylene terephthalate, polyethylene naphthalate, polycarbonate, and copolymers thereof may be added.

(2-2) use and Properties of resin composition

The resin composition of the present invention can be suitably used for the same molding method as that of a known resin composition, and in particular, can be suitably used for injection molding at a relatively low pressure. Specifically, the molding at a pressure of 0.1MPa to 5MPa, particularly 0.1MPa to 3MPa is most suitable. The temperature (melting temperature) at this time varies depending on the kind of the resin component, but generally may be set to 180 ℃ to 240 ℃. Therefore, the resin composition of the present invention is suitable for a hot melt molding method or an encapsulation method.

The hot melt molding method of the present invention is a method comprising: the resin composition is melted without using a solvent, and the melted resin composition is injected by low-pressure injection (preferably 0.1MPa to 3MPa) into a mold in which an industrial component (particularly, an electronic component) (hereinafter, also referred to as a "component") is placed in advance, and the resin composition is molded as a housing or a case of the component (so-called insert molding). That is, the present invention includes a method for producing a resin molded article, including the steps of: the resin composition of the present invention is injected into a mold in which an industrial member is placed in advance, thereby producing a resin molded article containing the industrial member.

The encapsulation method in the present invention refers to a method in which: a method of placing a member in a cover or on a substrate in advance, and injecting or dropping a melted resin composition into the cover or the substrate at a low pressure (preferably 1MPa or less) to integrate the cover or the substrate with the member. That is, the present invention includes a method for producing a resin molded article, including the steps of: the resin composition of the present invention is injected or dropped into a housing or a substrate in which an industrial member is previously disposed, thereby producing a resin molded article containing the industrial member.

The resin composition of the present invention is excellent in flexibility, adhesiveness, moist heat durability and the like, and therefore, when used for hot melt molding or sealing, not only is molding processability good, but also the adhesion between an electronic component inserted into a product (component) to be produced and a resin is excellent. The copolyester resin of the present invention is excellent in flexibility, moist heat durability, and the like. Therefore, the resin and the electronic component are not easily peeled off. In particular, even when used under severe environment for a long time, the resin and the electronic component are not peeled off, and cracks or fractures are not easily generated in the resin portion.

Further, as described above, when the resin composition of the present invention is imparted with flame retardancy by a specific organic phosphorus compound or other flame retardant, it can be suitably used also in applications requiring flame retardancy.

As described above, the resin composition (molded article made of the resin composition) of the present invention contains a copolyester resin, and the copolyester resin contains a specific amount of dimer acid in the acid component and a specific amount of polybutadiene diol in the diol component, and therefore has excellent flexibility. Here, as an index indicating flexibility, the Young's modulus at 20 ℃ is preferably 100MPa or less, and more preferably 60MPa or less.

The Young's modulus was measured by melting the resin composition of the present invention at a temperature higher than the melting point by 50 ℃ and injection-molding the melt at a pressure of 1MPa using an injection molding machine "PS 20E2 ASE" manufactured by Nichisu resin industries, Inc., to prepare a molded sample having a thickness of 1mm and a width of 3mm, and using a tensile testing machine "Tensilon" (UTM-4-100 manufactured by Orientec, Inc.) at a tensile rate of 10mm/min at 20 ℃.

The resin composition (molded article made of the resin composition) of the present invention has the above-described composition, and thus has excellent flexibility, appropriate hardness, and improved brittleness. As an index showing that this has an appropriate hardness and the brittleness is improved, the shore D hardness at 20 ℃ is preferably 50 or less, and among them, more preferably 45 or less.

The Shore D hardness was measured at 20 ℃ using a Shore D hardness tester (WESTOP WR-105D) by superposing 2 pieces of a molded sample having a thickness of 3mm and a width of 20mm prepared by melting the resin composition of the present invention at a temperature higher than the melting point by 50 ℃ and injection-molding the melt at a pressure of 1MPa using an injection molding machine "PS 20E2 ASE" manufactured by Hitachi resins industries. In this case, in the measurement of the shore D durometer, the peak value was read within 1 second under a pressing load of 50N, and the average value was calculated 10 times.

When the Young's modulus at 20 ℃ is more than 100MPa, the resin composition of the present invention is likely to be a resin composition lacking in flexibility. If the shore D hardness at 20 ℃ is more than 50, the resin composition of the present invention is insufficient in hardness and is brittle, and thus it is likely to be difficult to use the resin composition in various applications.

The resin composition containing a copolyester resin (molded article made of the resin composition) of the present invention has excellent flexibility, appropriate hardness, and improved brittleness, but it is preferable that the young's modulus at 20 ℃ and the shore D hardness at 20 ℃ are both in the above range.

In addition, the resin composition of the present invention has excellent moist heat durability by having the above-described composition. As an index showing the moist heat durability, the strain retention ratio described below is preferably 80% or more, more preferably 85% or more, and further preferably 90% or more. If the strain retention is less than 80%, the strength of the resin is greatly reduced by the heat-moisture treatment, and the shape stability of a molded article using such a resin composition is poor. Namely, the moist heat durability is poor.

The strain retention in the present invention is calculated by the following method. The resin composition of the present invention was melted at a temperature higher than the melting point by 50 ℃ and the melt was injection-molded into a mold under a pressure of 1MPa using an injection molding machine "PS 20E2 ASE" manufactured by Nichisu resin industries, Inc., to prepare a molded sample having a thickness of 1mm and a width of 3mm, and the tensile strain at break (tensile strain at break before treatment) was measured according to the method disclosed in ISO standard 527-2. The molded sample thus obtained was stored in an environment of 60 ℃ and 95% RH for 200 hours using a constant temperature and humidity apparatus (IG 400 manufactured by Yamato scientific Co., Ltd.) and subjected to a wet heat treatment. The tensile strain at break of the sample after the heat-moisture treatment was measured in the same manner as described above, and calculated by the following formula.

Strain retention (%) [ (tensile strain at break after treatment)/(tensile strain at break before treatment) ] × 100

When the resin composition of the present invention is imparted with flame retardancy by a specific organic phosphorus compound or other flame retardant, the resin composition of the present invention preferably has an oxygen index (hereinafter abbreviated as OI) of 27 or more, more preferably 28 or more in the combustion test disclosed in JISK7201 as an index of exhibiting flame retardancy. When the OI value is less than 27, the flame retardancy is insufficient, and the composition is not suitable for electric and electronic parts.

The resin composition of the present invention also has excellent heat resistance. Specifically, the melting point of the copolyester resin and the resin composition of the present invention is preferably 115 ℃ to 180 ℃, more preferably 130 ℃ to 170 ℃. If the melting point is less than 115 ℃, the heat resistance is poor and the use thereof is limited. On the other hand, if the temperature is higher than 180 ℃, the processing temperature at the time of molding must be increased, which is disadvantageous in terms of cost and may increase thermal deterioration of the resin.

The melting point is measured by using a Diamond DSC manufactured by Perkinelmer, Inc., and by raising and lowering the temperature at 10 ℃ per minute, and measuring the temperature at the melting peak.

The resin composition of the present invention is excellent in adhesion, and also excellent in adhesion to various resins and metals constituting electric and electronic components and the like. Among them, the adhesive property with PET, PBT or polyphenylene sulfide is excellent.

Further, the melt viscosity of the resin composition of the present invention at 200 ℃ is preferably 1 to 300pa.s, and more preferably 3 to 150 pa.s. By setting the melt viscosity within this range, molding at low pressure can be carried out, and a resin composition suitable for hot melt molding or sealing applications can be obtained. If the melt viscosity is more than 300pa.s, the fluidity may be lowered, and the molding at low pressure may be difficult. When the melt viscosity is reduced by increasing the melt temperature, the load on the apparatus is increased, and the thermal deterioration of the copolyester resin is also remarkable. On the other hand, when the melt viscosity is less than 1pa.s, the strength of the copolyester resin composition (resin molded article) tends to be lowered.

The melt viscosity was measured by a flow rate tester (model CFT-500, manufactured by Shimadzu corporation) using a nozzle having a nozzle diameter of 1.0mm and a nozzle length of 10mm, and the shear rate was measured for 1000sec^-1Melt viscosity in time.

2. Method for producing resin composition containing copolyester resin

First, a method for producing a copolyester resin of the present invention will be described. The method for producing the copolyester resin is not particularly limited as long as it can be copolymerized using the above components. Therefore, the same conditions as those for producing a known copolyester resin can be adopted in addition to the use of the above components at a predetermined ratio.

The method for producing the copolyester resin of the present invention is, for example, a method in which the acid component and the diol component are subjected to esterification reaction at 150 to 250 ℃, and then polycondensation is carried out at 230 to 300 ℃ in the presence of a polycondensation reaction catalyst under reduced pressure (preferably reduced from atmospheric pressure to 10 to 30Pa), thereby producing the copolyester resin of the present invention. The copolyester resin of the present invention can be obtained by, for example, subjecting a derivative such as dimethyl ester of an aromatic dicarboxylic acid and a diol component to transesterification at 150 to 250 ℃, and then subjecting the resulting product to polycondensation at 230 to 300 ℃ while reducing the pressure (preferably from atmospheric pressure to 10 to 30Pa) in the presence of a polycondensation catalyst.

When the organic phosphorus compound is copolymerized, an organic phosphorus compound having 2 or more ester-forming functional groups is added in addition to the acid component and the diol component, and the copolymerization polyester resin of the present invention in which the organic phosphorus compound is copolymerized can be obtained by performing esterification reaction or transesterification reaction under the same conditions as described above and then performing polycondensation.

The copolyester resin obtained as described above can be mixed with additives, other resin components, and the like (hereinafter referred to as "additives and the like") as needed to obtain a resin composition. As a method for adding an additive, other resin components, and the like (hereinafter referred to as "additive and the like") to the copolyester, for example, any of the following methods can be employed: 1) a batch blending method in which a copolyester resin and additives are added simultaneously using a screw extruder, and the mixture is melted, kneaded and pelletized; 2) the split blending method is a method in which a copolyester resin is melted and kneaded, and then an additive or the like is supplied from another supply port of an extruder, and the resulting mixture is melted and kneaded and pelletized.

The resin composition of the present invention is suitable for hot melt molding and sealing, but can be used in various forms as in the case of known polyester resin compositions. For example, the resin composition can be used as various molded articles such as films, fibers, and sheets, and can also be used as an adhesive. In particular, when a film, a fiber, or the like is produced, it can be produced by using a known method, apparatus, or the like. In addition, when a sheet or a molded body is produced, it can be molded by a known molding method such as injection molding, blow molding, or extrusion molding. When used as an adhesive, the adhesive can be formed into a desired shape such as a sheet and then subjected to heat treatment to be used as an adhesive.

Examples

The following examples and comparative examples are provided to more specifically describe the features of the present invention. However, the scope of the present invention is not limited to the examples.

The measurement and evaluation methods of various characteristic values and the like in the examples are as follows.

(1) Melting point and melt viscosity

The measurement was carried out by the same method as described above.

(2) Polymer composition

The obtained copolyester resin was dissolved in a mixed solvent of deuterated hexafluoroisopropanol and deuterated chloroform at a volume ratio of 1/20, and 1H-NMR was measured by an LA-400 NMR apparatus manufactured by japan electronics, and the integrated intensity of proton peak of each copolymerization component in the obtained graph was obtained.

(3) Content of phosphorus atom in copolyester resin

The measurement was carried out by means of a fluorescent X-ray spectrometer 3270 manufactured by Rigaku corporation.

(4) Shore D hardness, Young's modulus

The measurement was carried out by the same method as described above.

(5) Tensile breaking strain, strain retention (moisture and heat durability)

The measurement was carried out by the same method as described above.

(6) Tensile strength

The molded sample obtained in the measurement of (5) was used in the same manner as the molded sample obtained in the measurement of (5), and the measurement was carried out at a tensile rate of 10mm/min at 20 ℃ by using a tensile tester "Tensilon" (model UTM-4-100, manufactured by Orlimat Co.).

(7) Adhesion Property

The resulting copolyester resin (or resin composition) was formed into a sheet having a thickness of 50 μm, sandwiched between polyphenylene sulfide sheets having a thickness of 100 μm, and heat-treated at a temperature higher than the melting point by 50 ℃ and a pressure of 0.2MPa for 30 seconds to prepare a sample having a width of 15mm and a length of 100 mm. A tensile tester "Tensilon" (model UTM-4-100 manufactured by Oriental corporation) was used to peel the test piece at a peel speed of 50 mm/min in accordance with JIS K-6854. The adhesiveness was evaluated on the following 3 scales.

O … peel strength of 10N/15mm or more

The peel strength of delta … is less than 10N/15mm to more than 5N/15mm

X … Peel Strength less than 5N/15mm

(8) Formability 1 (Hot melt mold)

The obtained copolyester resin (or resin composition) was melted at a temperature higher than the melting point by 50 ℃ and injection-molded under a pressure of 1MPa using "PS 20E2 ASE" manufactured by Nichisu resin industries. At this time, a circuit board to which 2 wires made of vinyl chloride were soldered was used as a material to be molded, and insert molding was performed using an aluminum mold, thereby obtaining an electric component in which a copolyester resin (or a resin composition) was integrated with the circuit board.

The moldability in the case of producing a part was evaluated on the following 3-point scale based on the time (demold time) for demolding from a mold.

The demolding time of … is less than 10 seconds.

The mold release time delta … is more than 10 seconds and less than 20 seconds.

X … demold time was greater than 20 seconds.

The insulating properties in the circuit board were evaluated as follows for the above-mentioned parts having good formability (before treatment) and after leaving the parts at 80 ℃ for 500 hours in a 95% atmosphere (after heat-moisture treatment).

O … maintained insulation.

X … insulation was destroyed.

In the circuit board, the 2 wires are not connected at the bonding portion (2 portion), and therefore, normally, no current flows between the wires (insulation is maintained). After the wet heat treatment, if water enters between the resin and the circuit board, the water becomes a conductor and a current flows between the leads (insulation is destroyed).

(9) Formability 2 (encapsulation)

The resulting copolyester resin (or resin composition) was melted at a temperature 50 ℃ higher than the melting point. Further, the same circuit board as used in moldability 1 was placed in a housing (container type), and a molten copolyester resin (or resin composition) was injected thereto at a pressure of 0.5MPa to integrate the housing, the resin, and the circuit board, thereby obtaining an electrical component.

The formability in obtaining the parts was evaluated by visual observation on the following 3 grades.

The resin … flowed into the entire part, and no unevenness was observed on the surface.

The Δ … resin flowed into the entire part, but had irregularities in shape.

The resin x … flowed insufficiently, and a part of the circuit board was exposed.

With respect to the above-mentioned parts having formability, the insulation properties in the circuit board were evaluated as follows for both the case of obtaining the parts (before treatment) and the case of leaving the parts at 80 ℃ and 95% for 500 hours (after heat-moisture treatment).

O … maintained insulation.

X … insulation was destroyed.

In the circuit board, the 2 wires are not connected at the bonding portion (2 portion), and therefore, electric current does not flow between the wires (insulation is maintained). After the wet heat treatment, if water enters between the resin and the circuit board, the water becomes a conductor and a current flows between the leads (insulation is destroyed).

(10) Oxygen Index (OI)

The combustion test described in JIS K7201 was carried out to obtain OI. The product was judged to be acceptable if 27 or more. (11) Thermal conductivity

The thermal conductivity λ is calculated by the following equation by obtaining the thermal diffusivity α, the density ρ, and the specific heat Cp by the following method and calculating the product thereof.

λ＝αρCp

λ: thermal conductivity (W/(m.K))

α: thermal diffusivity (m)²/sec)

ρ: density (g/m)³)

Cp: specific heat (J/(g. K))

The thermal diffusivity, α, is determined as follows: the obtained copolyester resin composition was molded into a disk shape having a diameter of 30mm by an injection molding machine, and a sample having a predetermined size was cut out from the molded article obtained by the laser flash method using a thermal constant measuring apparatus TC-7000 (manufactured by Ulvaco Co., Ltd.) and measured by the laser flash method. The density ρ is measured using an electron densitometer ED-120T (manufactured by Mirage trade company). The specific heat Cp was measured using a differential scanning calorimeter DSC-7 (manufactured by Perkin Elmer) under a condition of a temperature rise rate of 10 ℃ per minute.

Examples 1 to 1

An esterification reaction was carried out by heating 60 parts by mass of terephthalic acid, 9 parts by mass of isophthalic acid, and 60 parts by mass of a hydrogenated dimer acid having 36 carbon atoms (Pripol 1009, manufactured by Nippon Poa Daco.) as an acid component, 58 parts by mass of 1, 4-butanediol, and 78 parts by mass of a polybutadiene diol (hydroxylated hydrogenated polybutadiene mainly having 1, 2-repeating units; manufactured by Nippon Kao Co., Ltd., "GI-1000") as a diol component to 240 ℃. Subsequently, 0.1 part by mass of tetra-n-butyl titanate was added as a catalyst, and the degree of vacuum was gradually increased at a temperature of 240 ℃ for 60 minutes to maintain a high vacuum of 10Pa to 30Pa, and then, a polycondensation reaction was performed for 4 hours, thereby obtaining a copolyester resin having a composition shown in Table 1.

Example 1-2 to example 1-8, comparative example 1-1 to comparative example 1-2, comparative example 1-4 to comparative example 1-6

A copolyester resin was obtained in the same manner as in example 1-1, except that the composition (content) shown in Table 1 was changed to the type and amount of terephthalic acid, isophthalic acid, hydrogenated dimer acid, 1, 4-butanediol, and polybutadiene diol. In examples 1 to 7, "GI-2000" (hydroxylated hydrogenated polybutadiene having mainly 1, 2-repeating units) manufactured by Nippon Caoda corporation was used as the polybutadiene diol. In examples 1 to 8, a dimer acid having 36 carbon atoms (Pripol 1013, manufactured by procolla japonica) was used as the dimer acid.

Examples 1 to 9

A copolyester resin was obtained in the same manner as in example 1-1, except that 1, 4-butanediol and 1, 6-hexanediol were used as diol components and the composition (content) shown in Table 1 was changed.

Comparative examples 1 to 3

A copolyester resin was obtained in the same manner as in example 1-1, except that 1, 6-hexanediol alone was used as the diol component and the composition (content) shown in Table 1 was changed.

Table 1 shows the compositions, characteristic values and evaluation results of the copolyester resins obtained in examples 1-1 to 1-9 and comparative examples 1-1 to 1-6.

As is apparent from table 1, since the copolyester resins obtained in examples 1-1 to 1-9 satisfy the composition of the present invention, the young's modulus at 20 ℃ is 55MPa or less, the shore D hardness at 20 ℃ is 45 or less, and the copolyester resin is excellent in flexibility, has an appropriate hardness, and is improved in brittleness. The adhesive composition is excellent in adhesiveness, high in tensile strain at break and retention, excellent in strength, and excellent in moisture and heat resistance. Among them, the copolyester resins obtained in examples 1-1 to 1-8 were excellent in moldability when molded articles were obtained by hot melt molding or sealing, and the obtained molded articles had sufficient insulation characteristics both at the time of molding and after heat-moisture treatment. That is, the molded articles obtained by the two methods have good adhesion between the resin and the member, and can be used for a long time even under severe environments.

On the other hand, the copolyester resin obtained in comparative example 1-1 had a low dimer acid content in the acid component, and thus had high Shore D hardness and Young's modulus, poor flexibility and poor adhesiveness. Further, since the strain retention is low and the moist heat durability is poor, the resulting molded article has no insulating property after the moist heat treatment.

The copolyester resin obtained in comparative example 1-2 had a high dimer acid content in the acid component and a low aromatic dicarboxylic acid content, and thus the melting point (non-crystallinity) could not be measured, and the copolyester resin had poor heat resistance and poor moldability. Also, the tensile strength was poor.

The copolyester resins obtained in comparative examples 1 to 3 had low melting points and poor heat resistance and poor moldability because the diol component contained no 1, 4-butanediol and 1, 6-hexanediol as a main component.

The copolyester resins obtained in comparative examples 1 to 4 contained no polybutadiene diol as a diol component, and the copolyester resins obtained in comparative examples 1 to 5 contained a small amount of polybutadiene diol as a diol component, and therefore had high Young's modulus and Shore D hardness, poor flexibility, and poor adhesiveness. Further, since the strain retention is low and the moist heat durability is poor, the resulting molded article has no insulating property after the moist heat treatment.

The copolyester resins obtained in comparative examples 1 to 6 had a low melting point and poor heat resistance and poor moldability because they had too much polybutadiene diol content as the diol component. Also, the tensile strength was poor.

Example 2-1

An organophosphorus compound represented by the above structural formula (a) is used as the organophosphorus compound. First, an esterification reaction was carried out by heating 58 parts by mass of terephthalic acid, 7 parts by mass of isophthalic acid, 73 parts by mass of a hydrogenated dimer acid having 36 carbon atoms (Pripol 1009, manufactured by Nippon Seawa Dakoku Co., Ltd.) as an acid component, 60 parts by mass of 1, 4-butanediol, 57 parts by mass of polybutadiene diol (hydroxylated hydrogenated polybutadiene mainly having 1, 2-repeating units; manufactured by Nippon Cao Co., Ltd., "GI-1000") as a glycol component, and 9 parts by mass of an organic phosphorus compound (a) to 240 ℃. Then, 0.1 part by mass of tetra-n-butyl titanate was added as a catalyst, and the degree of vacuum was gradually increased at a temperature of 240 ℃ for 60 minutes and finally maintained at a high vacuum of 0.4hPa, and then, polycondensation reaction was carried out for 4 hours to obtain a copolymer polyester resin composition having a composition shown in Table 2.

Example 2-2 to example 2-9, comparative example 2-1 to comparative example 2-2, comparative example 2-4 to comparative example 2-8

A copolyester resin composition was prepared in the same manner as in example 2-1, except that the composition (content) shown in Table 2 was changed to the types and amounts of terephthalic acid, isophthalic acid, hydrogenated dimer acid, 1, 4-butanediol, polybutadiene diol and organic phosphorus compound.

Examples 2 to 10

A copolyester resin composition was obtained in the same manner as in example 2-1, except that 1, 4-butanediol and 1, 6-hexanediol were used as diol components and the composition (content) shown in Table 2 was changed.

Comparative examples 2 to 3

A copolyester resin composition was obtained in the same manner as in example 2-1, except that 1, 6-hexanediol alone was used as the diol component and the composition (content) shown in Table 2 was changed.

Comparative examples 2 to 9

A copolyester resin composition was obtained in the same manner as in example 2-1, except that an organic phosphorus compound represented by the following structural formula (x) was used as the organic phosphorus compound.

[ chemical formula 3 ]

Table 2 shows the compositions, property values, and evaluation results of the copolyester resin compositions obtained in examples 2-1 to 2-10 and comparative examples 2-1 to 2-9.

As is clear from table 2, the copolyester resin compositions obtained in examples 2-1 to 2-10 satisfied the composition of the present invention, and thus had excellent flexibility, moderate hardness, and improved brittleness. The adhesive composition is excellent in adhesiveness, high in tensile strain at break and retention, excellent in strength, and excellent in moisture and heat resistance. Further, the OI value was 28 or more, and the flame retardance was also sufficient. Among them, the copolyester-based resin compositions obtained in examples 2-1 to 2-9 were excellent in moldability when molded articles were obtained by hot melt molding or sealing, and the obtained molded articles had sufficient insulation properties both at the time of molding and after heat and humidity treatment. That is, the molded articles obtained by the two methods have good adhesion between the resin and the member, and can be used for a long time even under severe environments.

On the other hand, in the copolyester resin composition obtained in comparative example 2-1, the content of dimer acid in the acid component was small, and therefore, the Shore D hardness and Young's modulus were high, the flexibility was poor, and the adhesiveness was also poor. Further, since the strain retention is low and the moist heat durability is poor, the resulting molded article has no insulating property after the moist heat treatment.

The copolyester resin composition obtained in comparative example 2-2 had a high content of dimer acid in the acid component and a low content of aromatic dicarboxylic acid component, and thus the melting point could not be measured, the heat resistance was poor, and the moldability was poor. Also, the tensile strength was poor.

The copolyester resin compositions obtained in comparative examples 2 to 3 had low melting point and poor heat resistance and poor moldability because the diol component contained no 1, 4-butanediol and 1, 6-hexanediol as the main component.

The copolyester resin compositions obtained in comparative examples 2 to 4 did not contain any polybutadiene diol as a diol component, and the copolyester resin compositions obtained in comparative examples 2 to 5 contained a small amount of polybutadiene diol as a diol component, and therefore had high Shore D hardness and Young's modulus, poor flexibility, and poor adhesiveness. Further, since the strain retention is low and the moist heat durability is poor, the resulting molded article has no insulating property after the moist heat treatment.

In the copolyester resin compositions obtained in comparative examples 2 to 6, the melting point was lowered and the heat resistance was poor and the moldability was poor because the polybutadiene diol content was too high as the diol component. Also, the tensile strength was poor.

The copolyester resin compositions obtained in comparative examples 2 to 7 did not contain an organic phosphorus compound, and therefore had a low OI value and poor flame retardancy.

The copolyester resin compositions obtained in comparative examples 2 to 8 had an excessively high content of the organic phosphorus compound, and thus had non-crystallinity (melting point could not be measured), poor heat resistance, and poor moldability.

The copolymerized polyester resin compositions obtained in comparative examples 2 to 9 had only 1 ester-forming functional group in the organic phosphorus compound, and therefore, the polymerization degree was not increased by inhibiting the polycondensation reaction, and the polymerization degree was too low. Therefore, various evaluations cannot be performed.

Example 3-1

Using the copolyester resin obtained in example 1-1 and talc (K-1 manufactured by Nippon talc K-1, average particle diameter 8 μm, thermal conductivity 10W/(m.K)), density 2.7g/cm³]As the thermally conductive filler, 100 parts by volume of a copolyester resin and 80 parts by volume of a thermally conductive filler were supplied to a main hopper of a biaxial extruder (TEM 26SS, spiral diameter 26mm, manufactured by Toshiba machine Co., Ltd.), and melt-kneaded at a temperature of 200 ℃. The polyester resin composition was extruded in a strand form, cooled to solidify, and then cut into pellets to obtain a copolyester resin composition.

Examples 3 to 2

Except for using alumina (manufactured by the electric chemical industry Co., Ltd., average particle diameter 10 μm, thermal conductivity 38W/(m.K), density 3.97 g/cm)³Copolyester resin composition was obtained in the same manner as in example 3-1, except that the thermally conductive filler was used.

Examples 3 to 3

Except for using magnesium carbonate (made by Shendao chemical Co., Ltd., average particle diameter 10 μm, thermal conductivity 15W/(m.K), density 3.05g/cm³Copolyester resin composition was obtained in the same manner as in example 3-1, except that the thermally conductive filler was used.

Examples 3 to 4

A copolyester resin composition was prepared in the same manner as in example 3-1, except that the copolyester resin obtained in example 1-3 was used.

Examples 3 to 5

A copolyester resin composition was prepared in the same manner as in example 3-2, except that the copolyester resin obtained in example 1-3 was used.

Table 3 shows the compositions, characteristic values and evaluation results of the copolyester resin compositions obtained in examples 3-1 to 3-5. In addition, the copolymer polyester resin compositions obtained in examples 3-1 to 3-5 contain a large amount of thermally conductive filler and have high melt viscosity, and thus are difficult to use for sealing applications. Therefore, the moldability 2 was not evaluated.

As is clear from Table 3, the copolyester-based resin compositions obtained in examples 3-1 to 3-5 were resin compositions containing a thermally conductive filler in a copolyester resin satisfying the composition of the present invention, and therefore had the advantages of the copolyester resins obtained in examples 1-1 or 1-3 and were imparted with thermal conductivity. Therefore, the present invention can be suitably used for various electronic components and the like in applications requiring heat countermeasures for efficiently radiating generated heat to the outside.

The copolyester resin (containing no thermal conductive filler) obtained in example 1-1 had a thermal conductivity of 0.1W/mk.

Example 4-1

The copolyester resin obtained in example 1-1 and an aromatic condensed phosphoric acid ester compound as a flame retardant (PX 200 manufactured by Dai eight chemical industries Co., Ltd.) were used, and 100 parts by mass of the copolyester resin and 20 parts by mass of the flame retardant were supplied to a twin screw extruder (TEX 30C, model No. 30mm, spiral diameter 30mm, manufactured by Nippon Steel works Co., Ltd.) and melt kneaded at a constant temperature of 255 ℃ with a spiral rotation number of 200 rpm. The polyester resin composition is extruded in a strand form, cooled to solidify, and then cut into pellets to obtain a copolyester resin composition.

Example 4-2 to example 4-5

A copolyester resin composition was obtained in the same manner as in example 4-1, except that the kind of the copolyester resin and the amount of the flame retardant were changed as shown in Table 4.

Examples 4 to 6

A copolymerized polyester resin composition was obtained in the same manner as in example 4-1, except that 20 parts by mass of brominated epoxy resin and 10 parts by mass of antimony trioxide were used as flame retardants.

Examples 4-7 to examples 4-10

Copolyester resin compositions were prepared in the same manner as in examples 4 to 6, except that the kind of the copolyester resin used and the amount of the flame retardant added were changed as shown in table 4.

Table 4 shows the compositions, characteristic values and evaluation results of the copolyester resin compositions obtained in examples 4-1 to 4-10.

As is clear from Table 4, in the copolyester resin compositions obtained in examples 4-1 to 4-10, since the copolyester resin satisfying the composition of the present invention contains the aromatic condensed phosphate ester compound, the brominated aromatic compound, and the titanium oxide compound as the flame retardant, the copolyester resins obtained in examples 1-1 to 1-4 have the advantages and are imparted with flame retardancy. Thus, the flame retardant resin composition can be suitably used for various electronic parts requiring flame retardancy.

Claims

2. The resin composition according to claim 1, wherein an organophosphorus compound having 2 or more ester-forming functional groups is copolymerized in the copolymerized polyester resin, and the content of phosphorus atoms in the resin is 500 to 20000 mass ppm.

3. The resin composition according to claim 1, wherein the Young's modulus at 20 ℃ is 100MPa or less.

4. The resin composition according to claim 1, wherein the Shore D hardness at 20 ℃ is 50 or less.

5. The resin composition according to claim 1, wherein an oxygen index in a burning test is 27 or more.

6. A method for producing a resin molded article, comprising the steps of:

a resin molded article is obtained by molding the resin composition according to claim 1 under a pressure of 5MPa or less.

7. The method according to claim 6, wherein the step is a step of injecting the resin composition according to claim 1 into a mold in which an industrial member is placed in advance to produce a resin molded article containing the industrial member.

8. The method according to claim 6, wherein the step is a step of injecting or dropping the resin composition according to claim 1 into a housing or a substrate in which an industrial member is previously arranged, to obtain a resin molded article containing the industrial member.