TWI701281B - Liquid crystalline resin composition and insert molded article - Google Patents

Abstract

[Problem] To provide a liquid crystalline resin composition capable of yielding insert molded articles excelling in airtightness, and insert molded articles having resin members consisting of said liquid crystalline resin composition.

[Solution] The above-mentioned problem is solved by a liquid crystalline resin composition comprising a liquid crystalline resin; a thermoplastic resin having a glass transition temperature Tg of less than 230℃; and a plate-shaped filler having an average particle size of at least 15 μm and at most 100 μm, and an aspect ratio of at least 10; wherein the amount of the liquid crystalline resin is at least 40 mass% and at most 65 mass% of the resin composition as a whole; the amount of the thermoplastic resin is at least 12 mass% and at most 35 mass% of the resin composition as a whole; and the amount of the plate-shaped filler is at least 10 mass% and at most 35 mass% of the resin composition as a whole.

Description

Liquid crystal resin composition and insert molding product

The present invention relates to a liquid crystal resin composition and an insert molded product.

Liquid crystalline resins represented by liquid crystalline polyester resins are widely used in the field of small connectors due to their excellent fluidity, low protrusion, and reflow resistance. Furthermore, since the liquid crystalline resin has excellent water vapor permeability, it is expected to be applied to the field of semiconductor packaging. However, since liquid crystalline resin cannot sufficiently obtain adhesion to metal, an insert molded product integrally molded with metal by injection molding may have low airtightness at the interface between the resin and metal. Therefore, liquid crystalline resins are difficult to apply to insert molded products that require water resistance. In addition, when the airtightness of the interface between the resin and the metal is low, the flux in the solder rises to the terminal portion when the insert molding is reflowed, which is the phenomenon of so-called flux rise. , There are also difficulties in the application of insert molded products that require resistance to flux rise.

As a technique for improving the adhesion of a resin composition containing a liquid crystalline resin to metal, Patent Document 1 proposes liquid crystal properties for molded articles containing 0.5 to 30 parts by mass of non-liquid crystalline resin relative to 100 parts by mass of liquid crystalline resin. Resin composition. Patent Document 2 proposes a waterproof connector formed of an electrically insulating synthetic resin mixed with a liquid crystal polyester resin and a polyphenylene sulfide resin. Patent Document 3 proposal has A thermoplastic resin composition prepared by mixing 40 to 90% by weight of polyphenylene sulfide, 5 to 50% by weight of liquid crystal resin, and 1 to 20% by weight of elastomer.

【Prior Technical Literature】

【Patent Literature】

Patent Document 1: Japanese Patent Publication No. 2003-268241

Patent Document 2: Japanese Patent Publication No. 2013-118174

Patent Document 3: Japanese Patent Publication No. 2013-227366

The subject of the present invention is to provide a liquid crystalline resin composition that can obtain an insert molded article with excellent airtightness, and an insert molded article having a resin component composed of the liquid crystalline resin composition.

The inventors of the present invention conducted research on a resin composition that can obtain an insert molded article with high adhesion to metal or the like and excellent airtightness, and found that by improving the interface between the resin composition and the insert Affinity, reducing the linear thermal expansion of the resin composition and the difference between the linear thermal expansion coefficient of the insert part, and improving the uneven transferability are three elements that are important. The uneven transferability is the surface that enters the insert part during injection molding. The fine irregularities are used to reproduce the performance of the irregularities (hereinafter also referred to as "concave-convex transferability"). However, when the main component of the resin composition is a liquid crystalline resin, it may be difficult to improve the uneven transfer properties. Moreover, since the liquid crystalline resin has anisotropy, in the case of injection molding, the difference between the shrinkage rate at right angles to the resin flow direction and the shrinkage rate in the resin flow direction (hereinafter simply referred to as "anisotropy of shrinkage rate" ") is large, and as a result, the airtightness of the insert molded product tends to decrease. In order to solve the above-mentioned problems peculiar to liquid crystalline resins, the inventors further studied and obtained Liquid crystalline resin adds thermoplastic resin with specific glass transition temperature and plate filler with specific particle size and aspect ratio to improve the uneven transfer property of the resin composition and reduce the anisotropy of the shrinkage rate. this invention.

The liquid crystalline resin composition of the present invention is characterized by comprising a liquid crystalline resin, a thermoplastic resin having a glass transition temperature Tg of less than 230°C, and a plate-shaped filler having an average particle diameter of 15 μm or more and 100 μm or less and an aspect ratio of 10 or more. The content of liquid crystal resin in the entire resin composition is 40% by mass or more and 65% by mass or less, the content of thermoplastic resin in the entire resin composition is 12% by mass or more and 35% by mass or less, and the content of plate-like filler It is 10% by mass or more and 35% by mass or less in the entire resin composition.

In the present invention, the thermoplastic resin is preferably one or more selected from polyarylene sulfide resins, polyphenylene ether resins, and cyclic olefin resins.

In the present invention, under the conditions of a cylinder temperature 10 to 30°C higher than the melting point of the liquid crystalline resin, a mold temperature of 150°C, and a holding pressure of 50 MPa, a molded product of 80mm×80mm×2mm can be formed by injection molding. The difference between the shrinkage rate in the direction perpendicular to the flow direction of the resin and the shrinkage rate in the flow direction of the resin is 0.51% or less.

In the present invention, it is preferable to further contain 6% by mass or less of the epoxy group-containing copolymer in the entire resin composition. It is preferable to further contain a fibrous filler in an amount of 12% by mass or less in the entire resin composition.

The insert molded article of the present invention is characterized by having a resin member composed of the liquid crystal resin composition described in any one of the above, and an insert member composed of a metal, an alloy, or an inorganic solid substance.

According to the present invention, it is possible to provide a liquid crystalline resin composition that can obtain an insert molded product with excellent airtightness, and an insert molded product having a resin component composed of the liquid crystalline resin composition.

1‧‧‧Resin parts

2‧‧‧Insert parts

3‧‧‧Concave

4, 4'‧‧‧Fixed fixture

10‧‧‧Insert molding

20‧‧‧Sample for air tightness test

30‧‧‧Blank sample

40‧‧‧Differential pressure gauge

100‧‧‧Test piece for shrinkage test

101‧‧‧Evaluation device for air tightness test

a‧‧‧Measurement position of flow direction

b‧‧‧Measurement position at right angle

c‧‧‧Gate

Figure 1 shows a plan view of a test piece for shrinkage test.

Figure 2 is a schematic diagram of an example of an insert molded product, Figure 2(a) is a plan view, Figure 2(b) is a cross-sectional view of line MM in Figure 2(a), and Figure 2(c) For the bottom view.

Fig. 3 is a schematic diagram showing an example of the insert member, Fig. 3(a) is a plan view, and Fig. 3(b) is a front view.

Figure 4 shows an explanatory diagram when the sample for airtightness test is made.

Figure 5 shows a block diagram of the evaluation device for the airtightness test.

The following is a detailed description of an embodiment of the present invention. The present invention is not limited to the following embodiments, and can be implemented with appropriate changes within a range that does not impair the effects of the present invention.

[Liquid crystal resin composition]

The liquid crystalline resin composition (hereinafter simply referred to as the "resin composition") contains a liquid crystalline resin, a thermoplastic resin with a glass transition temperature Tg of less than 230°C, and an average particle diameter of 15 μm or more, 100 μm or less, and an aspect ratio of 10 or more Plate filler. Since the resin composition contains a liquid crystalline resin, it can be made into a resin composition excellent in fluidity, low protrusion, reflow resistance, and water vapor permeability. Moreover, the resin composition contains thermoplastic resins that meet the above-mentioned specific conditions and The plate-shaped filler can improve the unevenness transferability of the resin composition and can reduce the anisotropy of the shrinkage rate. As a result, it is possible to produce a resin composition that can obtain an insert molded article having excellent performance of a liquid crystalline resin and high airtightness. In addition, as shown in the examples described later, an insert molded article using this resin composition can also prevent a decrease in airtightness after reflow treatment.

(Liquid crystal resin)

The liquid crystalline resin is a melt processable polymer having the property of forming an optically anisotropic melt phase. The properties of the anisotropic molten phase can be confirmed by a conventional polarization inspection method using a cross polarizer. More specifically, the confirmation of the anisotropic melt phase can be performed by observing a molten sample placed on a Leitz hot stage in a nitrogen atmosphere at a magnification of 40 times using a Leitz polarizing microscope. When the liquid crystalline resin is inspected between crossed polarizers, for example, even in a molten static state, polarized light usually passes through and exhibits optical anisotropy.

The liquid crystalline resin is not particularly limited, but an aromatic polyester or an aromatic polyester amide is preferred. In addition, it may be a polyester in which an aromatic polyester or an aromatic polyester amide is partially contained in the same molecular chain.

As the aromatic polyester or the aromatic polyester amide, it is particularly preferable to have an aromatic having at least one compound selected from the group of aromatic hydroxycarboxylic acid, aromatic hydroxyamine, and aromatic diamine as constituent components Polyester or aromatic polyester amide. The liquid crystal resin may be a mixture of two or more liquid crystal resins selected from the above.

More specifically, (1) polyesters mainly composed of one or more of aromatic hydroxycarboxylic acids and derivatives thereof; (2) Mainly composed of (a) one or more of aromatic hydroxycarboxylic acids and their derivatives, (b) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and one of these derivatives Or two or more, and (c) aromatic diol, alicyclic diol, aliphatic diol, and a polyester composed of one or more of these derivatives; (3) mainly ( a) One or more of aromatic hydroxycarboxylic acids and their derivatives, (b) one or more of aromatic hydroxyamines, aromatic diamines, and these derivatives, and (c) Polyesteramides composed of one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and these derivatives; (4) mainly composed of (a) aromatic hydroxycarboxylic acids and their derivatives One or two or more of the substances, (b) aromatic hydroxylamine, aromatic diamine, and one or more of these derivatives, (c) aromatic dicarboxylic acid, alicyclic dicarboxylic acid Acids, and one or more of these derivatives, and (d) aromatic diols, alicyclic diols, aliphatic diols, and one or more of these derivatives The composition of polyester amide and so on. Furthermore, the above-mentioned constituents can also be combined with a molecular weight modifier as needed.

Preferred specific examples of the specific compound (monomer) constituting the liquid crystalline resin include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 2,6-dihydroxynaphthalene , 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcinol, compounds represented by the following general formula (I), and compounds represented by general formula (II) Aromatic diols such as compounds; terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III) Aromatic dicarboxylic acids such as p-aminophenol and p-phenyl diamine.

(X: a group selected from alkylene (C ₁ to C ₄ ), alkylene, -O-, -SO-, -SO ₂ -, -S- and -CO-.)

(Y: a base selected from -(CH ₂ ) _n -(n=1~4) and -O(CH ₂ ) _n -(n=1~4))

The preparation method of the liquid crystal resin is not particularly limited. The above-mentioned monomer compound (or a mixture of monomers) can be used, and it can be prepared by a known method using a direct polymerization method or a transesterification method, but usually a melt polymerization method is used. Or slurry polymerization method. In the case of a compound having ester-forming ability, it can also be used for polymerization in its original form, and it is also possible to use a precursor that has been modified into a derivative having the ester-forming ability in the pre-polymerization stage. At the time of polymerization, various catalysts can be used. Representative materials of the catalyst that can be used include dialkyl tin oxides, diaryl tin oxides, titanium dioxide, alkoxy titanium silicates, titanium alkoxides, alkalis of carboxylic acids, and alkaline earths. Metalloid salts, such as Lewis acid salt of BF ₃ , etc. The amount of the catalyst used is generally about 0.001 to 1% by mass relative to the total weight of the monomer, and particularly preferably about 0.01 to 0.2% by mass. The polymer produced by these polymerization methods can also be solid-phase polymerized under reduced pressure or heated in an inert gas to increase the molecular weight if necessary.

The content of the liquid crystal resin is 40% by mass or more and 65% by mass or less in the entire resin composition. By making the content of the liquid crystal resin 40% by mass or more and 65% by mass or less, the liquid crystal resin has high fluidity, excellent low protrusion, reflow resistance, and water vapor permeability. While improving the unevenness transferability, it is possible to reduce the anisotropy of shrinkage. As a result, it is possible to obtain a resin composition having excellent performance of a liquid crystal resin composition and a molded article with high airtightness. The content of the liquid crystal resin is more preferably 42% by mass or more and 62% by mass or less. The lower limit of the content of the liquid crystal resin may be 45% by mass or more, and the upper limit may be 60% by mass or less.

The melt viscosity of the liquid crystal resin is not particularly limited. The melt viscosity measured at a cylinder temperature 10-30°C higher than the melting point of the liquid crystal resin and a shear speed of 1000sec ^-1 is 5Pa. Above s, 100Pa. s or less, more preferably 10Pa. Above s, 50Pa. s or less. The so-called "cylinder temperature 10 to 30°C higher than the melting point of the liquid crystal resin" refers to the cylinder temperature at which the liquid crystal resin can be melted to the extent that the melt viscosity can be measured. The range of 10 to 30°C varies with the type of liquid crystal resin. For example, in Japanese Patent Laid-open No. 2010-3661 (especially refer to paragraphs 0048 and 0051), as polymer-1, it is disclosed that the structural unit introduced by 4-hydroxybenzoic acid is 2 mol%, which is composed of 6 Liquid crystals of 48% mol% of structural units introduced by hydroxy-2-naphthoic acid, 25 mol% of structural units introduced by terephthalic acid, and 25 mol% of structural units introduced by 4,4'-dihydroxybiphenyl性resin. Its melting point is 352°C, and its melt viscosity is measured at a cylinder temperature of 380°C. In addition, as polymer-2, it is disclosed that the structural unit introduced by 4-hydroxybenzoic acid is 50 mol%, the structural unit introduced by 6-hydroxy-2 naphthoic acid is 2.5 mol%, and the structure is introduced by terephthalic acid. A liquid crystal resin containing 23.9 mol% of the unit, 18.6 mol% of the structural unit introduced with 4,4'-dihydroxybiphenyl, and 5 mol% of the structural unit introduced with 4-acetaminophenol. Its melting point is 367°C, and its melt viscosity is measured at a cylinder temperature of 380°C. Furthermore, as polymer-3, it is disclosed that the structural unit introduced by 4-hydroxybenzoic acid is 60 mol%, the structural unit introduced by 6-hydroxy-2 naphthoic acid is 5 mol%, and the structure is introduced by terephthalic acid. A liquid crystal resin containing 17.7 mol% of the unit, 112.3 mol% of the structural unit introduced from 4,4'-dihydroxybiphenyl, and 5 mol% of the structural unit introduced from 4-acetaminophenol. Its melting point is 335°C, and its melt viscosity is measured at 350°C of cylinder temperature.

(Thermoplastic resin)

The resin composition contains a thermoplastic resin having a glass transition temperature Tg of less than 230°C (hereinafter simply referred to as "thermoplastic resin"). According to the study of the present inventors, when a thermoplastic resin having a glass transition temperature Tg of less than 230°C is added, the uneven transfer property of the resin composition can be improved. As a result, as shown in the embodiments described later, the airtightness of the insert molded product can be improved, and the reduction of the airtightness can be prevented after the reflow treatment of the molded product.

In addition, the glass transition temperature Tg is a value measured by the DSC method (method described in JIS K7121) on the condition of a temperature increase rate of 10°C/min. The lower limit of the glass transition temperature Tg is not particularly limited, and it may be 60°C or higher or 80°C or higher. The upper limit of the glass transition temperature Tg may be 220°C or less.

Examples of thermoplastic resins having a glass transition temperature Tg of less than 230°C include polyarylene sulfide (PAS); polyphenylene ether (PPE); cyclic olefin resin; Polycarbonate resin (PC); polyethylene resin (PE); polypropylene resin (PP); polyacetal resin (POM); polyamide 6, polyamide 66, or polyamide 46, etc. Amine resin (PA); polybutylene terephthalate (PBT); polyethylene naphthalate (PEN); modified polyester resin such as polyethylene terephthalate (PET); polyether Ether ketone (PEEK); polystyrene (PS); polyvinyl chloride resin (PVC); acrylonitrile-styrene copolymer resin (AS); polymethyl methacrylate resin (PMMA); acrylonitrile-butadiene Ene-styrene copolymer resin (ABS); polyarylate resin (PAR); polyether imide resin (PEI); and polyether maple resin (PES), etc.

Among them, it is preferable to select one or more of polyarylene sulfide resins, polyphenylene ether resins, and cyclic olefin resins.

The so-called polyarylene sulfide resin (PAS resin) refers to a resin whose repeating unit is mainly composed of -(Ar-S)- (moreover, "Ar" represents an arylene group). A PAS resin having a generally known molecular structure can be used.

The arylene group is not particularly limited, and examples include: p-phenylene, m-phenylene, o-phenylene, substituted phenylene, and p,p'-biphenylene , P,p'-biphenylene, p,p'-biphenylene ether, p,p'-biphenylcarbonyl, naphthylene, etc. Among the arylene sulfide groups composed of the above-mentioned arylene sulfide groups, a homopolymer of the same type of repeating unit is used. In addition, a copolymer containing different types of repeating units may also be used due to application.

As the homopolymer, it is preferable to use a p-phenylene sulfide group as a repeating unit depending on the application. The homopolymer with p-phenylene sulfide group as the repeating unit has extremely high heat resistance, and shows high strength, high rigidity, and high dimensional stability in a wide range of temperature range. By using such a homopolymer, it is possible to obtain Molded products with very good physical properties.

Furthermore, as the copolymer, two or more different arylene sulfide groups may be used in combination from the arylene sulfide group containing the above arylene group. Among these, from the viewpoint of obtaining a molded product having high physical properties such as heat resistance, moldability, and mechanical properties, it is preferable to include a combination of a p-phenylene sulfide group and an m-phenylene sulfide group. Furthermore, it is preferably a polymer containing a p-phenylene sulfide group at a ratio of 70 mol% or more, and more preferably a polymer containing a ratio of 80 mol% or more. Furthermore, the polyarylene sulfide resin having a phenylene sulfide group is a polyphenylene sulfide resin.

The preparation method of polyarylene sulfide resin can use a conventional polymerization method. The polyarylene sulfide resin produced by a general method is usually washed with water or acetone several times in order to remove by-product impurities, and then washed with acetic acid, ammonia chloride, etc. As a result, the terminal of the polyarylene sulfide resin contains a carboxyl terminal group in a ratio of a predetermined amount.

As the polyphenylene ether resin, in addition to polyphenylene ether, modified polyphenylene ether can be cited. Examples of cyclic olefin resins include cyclic olefin polymers (COP) and cyclic olefin copolymers (COC).

The content of the thermoplastic resin in the total resin composition is 12% by mass or more and 35% by mass or less. By making the content of the thermoplastic resin in the total resin composition 12% by mass or more and 35% by mass or less, high fluidity can be maintained Improve the uneven transfer property while maintaining the low shrinkage anisotropy. The content of the thermoplastic resin is preferably 15% by mass or more and 30% by mass or less.

The weight average molecular weight (Mw) of the thermoplastic resin is not particularly limited, but it is preferably 15,000 or more and 40,000 or less. By making the weight average molecular weight of the thermoplastic resin within this range, it can have better mechanical properties and Resin composition with balanced fluidity. The weight average molecular weight of the thermoplastic resin is more preferably 20,000 or more and 38,000 or less.

(Plate filler)

The resin composition contains a plate-shaped filler. The average particle size of the plate-shaped filler is 15 μm or more and 100 μm or less, and the aspect ratio is 10 or more. By containing such a plate-shaped filler, the anisotropy of the shrinkage rate during injection molding can be reduced. As a result, as shown in the examples described later, the airtightness of the insert molded product can be improved, and the reduction of the airtightness can be prevented even after the reflow treatment of the molded product.

The average particle size is preferably 20 μm or more and 50 μm or less. The aspect ratio is preferably 35 or more, more preferably 35 or more and 55 or less. Furthermore, this definition relates to the shape of the plate-shaped filler before the plate-shaped filler is blended with the resin composition. The average particle size is the value measured by the laser diffraction/scattering particle size distribution measurement method, and is the particle size at which the cumulative value of the volume-based particle size distribution is 50%. The average aspect ratio is calculated by observing dozens of filler materials with an electron microscope (SEM) and measuring the length and width.

As the plate-like filler, for example, mica, talc, glass flakes, graphite, various metal foils (for example, aluminum foil, iron foil, copper foil), etc. can be cited, and one or more of these can be selected and used. Among them, mica is preferred from the viewpoint of making it easier to make the difference between the shrinkage rate in the flow direction of the resin and the shrink rate in the direction perpendicular to the flow direction of the resin smaller.

The content of the plate-shaped filler is 10% by mass or more and 35% by mass or less in the entire resin composition. By making the content of the plate-like filler in the total resin composition 10% by mass or more and 35% by mass or less, it is possible to sufficiently obtain anisotropy of shrinkage during injection molding in a state with high unevenness transferability Getting smaller Effect.

(Epoxy-containing copolymer)

The resin composition preferably further contains an epoxy group-containing copolymer. By containing the epoxy group-containing copolymer, the affinity with the interface of the insertion member can be improved.

The epoxy group-containing copolymer is not particularly limited. For example, at least one type may be selected from the group consisting of epoxy group-containing olefin copolymers and epoxy group-containing styrene copolymers. . The epoxy group-containing copolymer can be used by selecting 1 type or combining 2 or more types as mentioned above.

As an epoxy group-containing olefin-based copolymer, for example, a copolymer composed of a repeating unit derived from an α-olefin and a repeating unit derived from a glycidyl ester of an α,β-unsaturated acid is mentioned.

The α-olefin is not particularly limited. For example, ethylene, propylene, butene, etc. can be mentioned, and among them, ethylene is preferably used. The glycidyl ester of α,β-unsaturated acid is represented by the following general formula (IV). Furthermore, in the general formula (IV), R′ represents hydrogen or an alkyl group of 1 to 10 carbon atoms. The glycidyl ester of α,β-unsaturated acid is, for example, glycidyl acrylate, glycidyl methacrylate, glycidyl ethacrylate, glycidyl itaconate, etc., particularly preferred It is glycidyl methacrylate.

In the epoxy-containing olefin copolymer, the content of the repeating unit derived from α-olefin is preferably 87 to 98% by mass, and the epoxy derived from α, β-unsaturated acid The content of the repeating unit of the propyl ester is 13 to 2% by mass.

The epoxy-containing olefin-based copolymer may contain 0 to 48 parts by mass relative to 100 parts by mass of the above-mentioned 2 components, which is derived from acrylonitrile, acrylate, and methacrylate within the scope that does not impair the present invention. , Olefin-based unsaturated esters such as α-methylstyrene, maleic anhydride, etc., select one or two or more repeating units as the third component other than the above two components.

The epoxy group-containing olefin copolymer can be easily prepared by a normal radical polymerization method using monomers corresponding to each component and a radical polymerization catalyst. More specifically, it can usually be used in the presence of α-olefins, α,β-unsaturated acid glycidyl esters and free radical generators, at 500-4000 atmospheric pressure, 100-300°C and at a suitable temperature It is manufactured by a method of copolymerization in the presence or absence of solvents and chain transfer agents. Furthermore, it is also possible to mix α-olefins, α,β-unsaturated acid glycidyl esters, and radical generators, and melt graft polymerize them in an extruder.

As an epoxy group-containing styrene-based copolymer, for example, a copolymer composed of a repeating unit derived from styrene and a glycidyl ester derived from α,β-unsaturated acid is mentioned. Regarding the glycidyl ester of the α,β-unsaturated acid, since it is the same as the description in the epoxy group-containing olefin-based copolymer, its description is omitted. Examples of styrenes include styrene, α-methylstyrene, brominated styrene, divinylbenzene, etc., but styrene is preferably used.

The epoxy-containing styrene copolymer may also be a multi-component copolymer containing one or two or more repeating units derived from other vinyl monomers as the third component other than the two components. ingredient. Those suitable as the third component are those derived from acrylonitrile, acrylate, methacrylate, and Malay One or more repeating units of olefinic unsaturated esters such as acid anhydrides. It is preferable that these repeating units contain 40% by mass or less of the epoxy group-containing styrenic copolymer in the copolymer.

In the epoxy-containing styrene copolymer, the content of the repeating unit derived from the glycidyl ester of α,β-unsaturated acid is preferably 2-20% by mass, and the content of the repeating unit derived from the styrene It is 80~98% by mass.

The epoxy group-containing styrene copolymer can be easily prepared by a normal radical polymerization method using monomers corresponding to each component and a radical polymerization catalyst. More specifically, it can usually be used in the presence of styrenes, glycidyl esters of α,β-unsaturated acids and free radical generators at 500-4000 atmospheric pressure, 100-300°C and appropriate It is manufactured by a method of copolymerization in the presence or absence of solvents and chain transfer agents. Furthermore, it is also possible to mix styrenes, glycidyl esters of α,β-unsaturated acids, and a radical generator, and melt graft polymerize them in an extruder.

Furthermore, as the epoxy group-containing copolymer, an epoxy group-containing olefin-based copolymer is preferred from the viewpoint of heat resistance. When the epoxy group-containing olefin copolymer and the epoxy group-containing styrene copolymer are used in combination, the ratio of these components can be appropriately selected according to the required characteristics.

Since combustibility is deteriorated, the content of the epoxy group-containing copolymer is preferably 6% by mass or less in the entire resin composition. The lower limit of the content of the epoxy group-containing copolymer is not particularly limited. For example, it may be 0.01% by mass, 0.1% by mass, or 1% by mass or more in the entire resin composition.

(Fibrous filler)

The resin composition further contains a fibrous filler. By containing fibrous filling The filler can improve the mechanical strength. In addition, the average diameter ratio of the fibrous filler is 1 or more and 4 or less, and the aspect ratio is 2 or more and 1500 or less. This definition refers to the shape of the fibrous filler before the fibrous filler is blended into the resin composition.

As the fibrous filler, it can be used as a filler or reinforcing agent in various conventional resin compositions without particular limitation. Specific examples of fibrous fillers include glass fibers, milled glass fibers, asbestos fibers, carbon fibers, silica fibers, and silica. Alumina fiber, alumina fiber, zirconia fiber, boron nitride fiber, boron fiber, potassium titanate fiber, silicate fiber like wollastonite, magnesium sulfate fiber, aluminum borate fiber, stainless steel, aluminum , Inorganic fibrous materials such as fibrous materials of metals such as titanium, copper and brass. These fibrous fillers can be used in combination of two or more types.

Among these, the difference between the shrinkage rate in the flow direction of the resin and the shrinkage rate in the direction perpendicular to the flow direction of the resin can be easily adjusted from the viewpoint that it is inexpensive and easy to obtain, and molded under predetermined conditions. Preferably it is glass fiber. As the glass fiber, those having a circular or slightly circular cross-section are generally used, and glass fibers having a so-called irregular cross-section may also be used. The shape of the irregular cross-section is not limited to these, and examples include polygons such as rectangles and rhombuses, ellipses, and cocoons.

(Other additives)

The resin composition may contain other additives in order to impart desired physical properties within a range that does not impair the effects of the present invention. Examples of other additives include nucleating agents, carbon black, pigments, antioxidants, stabilizers, plasticizers, slip agents, mold release agents, or flame retardants. The content of other additives can be adapted to the desired physical properties And adjust appropriately.

(Resin composition)

When the resin composition is used for injection molding of a molded product of 80mm×80mm×2mm under the conditions of a cylinder temperature 10-30°C higher than the melting point of the liquid crystal resin, a mold temperature of 150°C, and a holding pressure of 50MPa, it is better to The difference between the shrinkage rate at right angles to the flow direction of the resin and the shrinkage rate in the flow direction of the resin is 0.51% or less. By setting the difference between the shrinkage rate at right angles to the flow direction of the resin and the shrinkage rate in the flow direction of the resin to 0.51% or less, the curing shrinkage of the resin portion during the manufacture of insert moldings by injection molding can be changed. small. If the curing shrinkage of the resin part is small, it is difficult to generate a minute gap between the insert part and the resin part, and it is easy to obtain an insert molded product with high airtightness. In addition, the "cylinder temperature 10 to 30°C higher than the melting point of the liquid crystalline resin" here will be omitted here because it is the same as above.

Here, the shrinkage ratio is used as the reason for the difference between the shrinkage ratio in the flow direction of the resin and the shrinkage ratio in the direction at right angles to the flow direction of the resin (hereinafter also referred to as the direction at right angles to the flow) in actual molded products , The shrinkage between the insert part and the resin part varies depending on the shape, but only one of the shrinkage rate in the flow direction of the resin and the shrink rate in the right-angle direction of the flow is rarely affected. The shrinkage rate of both are affected, so it is presumed that both must be considered together.

The melt viscosity of the resin composition is preferably 5Pa at a shear speed of 1000sec ^-1 measured at a cylinder temperature 10-30°C higher than the melting point of the liquid crystal resin. Above s, 100Pa. s or less, more preferably 10Pa. Above s, 50Pa. s or less. The melt viscosity is 5Pa. Above s, 100Pa. In the case of s or less, better adhesion between the insertion member and the resin member can be obtained.

(Manufacturing method of resin composition)

The production method of the resin composition is not particularly limited as long as it can uniformly mix the components in the resin composition, and it can be appropriately selected from conventionally known production methods of resin compositions. For example, a melt-kneading device using a single-shaft or double-shaft extruder is used to melt and knead the components and extrude them, and then process the resulting resin composition into a desired shape such as powder, flakes, pellets, etc.的方法。 The method.

[Insert molded product]

The insert molded article has a resin member composed of the above-mentioned liquid crystalline resin composition and an insert member. The insert molded product is obtained by integrally molding the resin member and the insert member composed of the above-mentioned liquid crystalline resin composition by insert molding.

The insert member is not particularly limited, and it is used in order to make use of its characteristics and compensate for the shortcomings of the resin. It is preferable to use one that does not change in shape and does not melt when it comes into contact with the resin during molding. For example, metals such as aluminum, magnesium, copper, iron, brass, and these alloys are mainly used, or inorganic solids such as glass and ceramics are formed into rods, pins, screws, etc. In the present invention, the use of metal for the insert member significantly exhibits the effects of the present invention. There are no restrictions on the shape of the insertion member, etc.

The surface of the insert part can also be roughened or untreated. The roughening treatment can be done by physical methods such as sandblasting or laser irradiation, or it can be a chemical treatment. In the case of chemical treatment, it is easy to increase the gas at the interface between the insert member and the resin member due to the chemical bonding effect such as covalent bond, hydrogen bond, or intermolecular force between the insert member and the resin member. Tightness. As the chemical treatment, for example, dry treatment such as corona discharge, triazine treatment (refer to Japanese Patent Publication No. 2000-218935), chemical etching (refer to Japanese Patent Publication No. 2001-225352), and the like can be cited. In addition, when the material constituting the insert member is aluminum, warm water treatment may also be cited (please refer to Japanese Patent Laid-Open No. Hei-142110). As the warm water treatment, immersion in water at 100°C for 3 to 5 minutes can be mentioned. It can also be performed in combination with plural chemical treatments.

A general method can be used for the insert molding method. For example, an insert member formed of metal or the like is first put into a molding film tool, and the outer side of the insert member is filled with a resin composition and composite molded. As a molding method for filling the resin composition in a mold, there are injection molding methods, extrusion compression molding methods, etc., and injection molding methods are generally used. In particular, in the case of the injection molding method, excellent fluidity like the resin composition of the present invention is required.

(use)

The insert molded article manufactured using the resin composition of the present invention can be used for various applications. In particular, the resin composition of the present invention can provide an insert molded product with excellent airtightness, and is suitable for applications requiring high airtightness.

For example, the insert molded product manufactured using the resin composition of the present invention is suitable for use as a connector that is susceptible to adverse effects due to humidity or moisture, and electrical equipment provided in semiconductor packages, etc. Internal insert molded products such as electronic parts. In particular, it is suitable for use as parts for electrical or electronic equipment that require high-level waterproofing, such as those that are preset to be used in rivers, ponds, ski resorts, bathrooms, etc., where moisture or moisture intrusion may cause malfunctions. Furthermore, the insert molded product is, for example, a sensor that is also used for a tilt sensor, a fuel sensor, and the like. As tilt The sensor may be used for vehicle-mounted users such as gesture control, or used for game controllers. As the fuel sensor, a vehicle-mounted user used for fuel quantity measurement or the like can be exemplified. Furthermore, insert-molded products are also used as electrical appliances with resin-made bosses or holding parts, for example. Frame for electronic equipment. Here, as electrical. Housings for electronic devices include not only mobile phones, but also housings for mobile video electronic devices such as cameras, video integrated cameras, digital cameras, notebook computers, pocket computers, computers, electronic notebooks, and personal digital devices. Mobile information such as telephone (Personal Digital cellular, PDC), personal handy-phone system (PHS), etc. or communication terminal frame, mini disc (Minidisc, MD), cassette player, radio, etc. The frame of audio electronic equipment, LCD TV. Housings of household electrical appliances such as displays, telephones, fax machines, and handheld scanners.

Example

The following embodiments further specifically describe the present invention, but these embodiments will not limit the interpretation of the present invention.

[Examples 1-12, Comparative Examples 1-11]

Using the materials shown below, the composition and the content ratio shown in Tables 1 and 2 were melt-kneaded with a biaxial extruder with a cylinder temperature of 350°C to produce pellets of the resin compositions of the Examples and Comparative Examples. Furthermore, the plate-shaped filler and the fibrous filler are introduced into the extruder through the side feeder. Furthermore, in Tables 1 and 2, the unit of content is "mass%".

[Examples 13~16]

The pellets of the resin composition were produced in the same manner as in Example 1, except that the composition and content ratio shown in Table 3 were used for the materials shown below. Still, in the first 3 In the table, the unit of content is "mass%".

[Examples 17, 18, Comparative Example 12]

The resin composition pellets were produced in the same manner as in Example 1, except that the materials shown below used the composition and content ratio shown in Table 3, and were melt-kneaded with a two-axis extruder with a cylinder temperature of 380°C.

(Liquid crystal resin: LCP)

The liquid crystal polyester amide resin (LCP) was prepared as follows. After the following raw materials were placed in the polymerization vessel, the temperature of the reaction system was raised to 140°C and reacted at 140°C for 1 hour. Thereafter, the temperature was increased to 340° C. in 4.5 hours, and the pressure was reduced to 10 Torr (that is, 1330 Pa) over 15 minutes, and acetic acid, excess acetic anhydride, and other low-boiling components were distilled out and melt-polymerized. After the stirring torque reaches a predetermined value, nitrogen is introduced from a reduced pressure state to a normal pressure to become a pressurized state, the polymer is discharged from the lower part of the polymerization vessel, and the strands are pelletized to obtain pellets. The obtained pellets were heat-treated at 300°C for 2 hours under a nitrogen stream to obtain the target polymer. The resulting polymer has a melting point of 335°C and a melt viscosity of 14.0Pa. s. In addition, the melt viscosity of the above-mentioned polymer is measured in the same manner as the melt viscosity measurement method described later.

[raw material]

(I) 4-Hydroxybenzoic acid; 188.4g (60 mol%)

(II) 2-Hydroxy-6-naphthoic acid; 21.4g (5 mol%)

(III) Terephthalic acid; 66.8g (17.7 mol%)

(IV) 4,4'-Dihydroxybiphenyl; 52.2g (12.3mol%)

(V) 4-Acetoxyaminophenol; 17.2g (5mol%)

Metal catalyst (potassium acetate catalyst); 15mg

Aging agent (acetic anhydride); 226.2g

(Liquid crystal resin: LCP2)

The liquid crystal polyester amide resin (LCP2) was prepared as follows. After the following raw materials were placed in the polymerization vessel, the temperature of the reaction system was raised to 140°C and reacted at 140°C for 1 hour. Thereafter, the temperature was increased to 360° C. in 5.5 hours, and the pressure was reduced to 5 Torr (that is, 667 Pa) over 30 minutes. The acetic acid, excess acetic anhydride, and other low-boiling components were distilled out and melt-polymerized. After the stirring torque reaches a predetermined value, nitrogen is introduced from the reduced pressure state through normal pressure to become a pressurized state, the polymer is discharged from the lower part of the polymerization vessel, and the strands are pelletized to obtain pellets. The obtained pellets were heat-treated at 300°C for 8 hours under a nitrogen stream to obtain the target polymer. The obtained polymer had a melting point of 352°C and a melt viscosity of 27.0Pa at 380°C. s. In addition, the melt viscosity of the above-mentioned polymer is measured in the same manner as the melt viscosity measurement method described later.

[raw material]

(I) 2-hydroxy-6-naphthoic acid (HNA); 166g (48 mol%)

(II) Terephthalic acid (TA); 76g (25 mol%)

(III) 4,4'-Dihydroxybiphenyl (BP); 86g (25 mol%)

(IV) 4-Hydroxybenzoic acid (HBA); 5g (2mol%)

Metal catalyst (potassium acetate catalyst); 22.5mg

Aging agent (acetic anhydride); 191g

(Thermoplastic resin)

Polyphenylene sulfide resin (PPS): manufactured by KUREHA Co., Ltd., "W302A", glass transition temperature Tg85°C

Polyphenylene ether resin (PPE): Mitsubishi Engineering Plastic Co., Ltd. "PX100F" made by the company, glass transition temperature Tg213℃

Cyclic olefin copolymer (COC): manufactured by TOPAS Advanced Polymers, "TOPAS6017S-04", glass transition temperature Tg178°C

Polyetheretherketone resin (PEEK): manufactured by Daicel-Evonik Co., Ltd., "VESTAKEEP2000P", glass transition temperature Tg143°C

Polyamide resin (PI): manufactured by Mitsui Chemicals Co., Ltd., "PL450C", glass transition temperature Tg250°C

(Plate filler)

Mica: "AB-25S" manufactured by Yamaguchi Mica Industrial Co., Ltd., average particle size 23.4μm, aspect ratio 40-50

Mica: manufactured by Yamaguchi Mica Industrial Co., Ltd., "A-41S", average particle size 48.5μm, aspect ratio 40-50

Glass flakes: manufactured by Nippon Sheet Glass Co., Ltd., "REF160", average particle size 160μm, aspect ratio 32

Talc: "Crown talc PP" manufactured by Songcun Industrial Co., Ltd., average particle size 12.8μm, aspect ratio 8

(Epoxy-containing olefin copolymer)

Ethylene-glycidyl methacrylate-methyl acrylate copolymer (EGMA): manufactured by Sumitomo Chemical Co., Ltd., "Bondfast 2C" (glycidyl methacrylate unit content 6% by mass)

(Fibrous filler)

Glass fiber: "ECS03T-786H" manufactured by Nidec Glass Co., Ltd., chopped fiber with a fiber diameter of 10μm and a length of 3mm

Milled glass fiber: manufactured by Nittobo Co., Ltd., "PF70E-001", Fiber diameter 10μm, average fiber length 70μm

[Evaluation]

(Melt viscosity)

Regarding the resin composition pellets of the Examples and Comparative Examples, the melt viscosity of the external appearance was measured with a capillary rheometer (Capirograph 1D manufactured by Toyo Seiki Seisakusho Co., Ltd.: Piston diameter 10 mm) under the following conditions, based on ISO 11443. The measurement uses an orifice with an inner diameter of 1 mm and a length of 20 mm. The results of Examples 1 to 12 and Comparative Examples 1 to 11 are shown in Tables 1 and 2. The results of Examples 13 to 18 and Comparative Example 12 are shown in Table 3.

Cylinder temperature: 350°C (Examples 1-12, Comparative Examples 1-11)

350°C (Examples 13~16)

380°C (Example 17, 18, Comparative Example 12)

Cutting speed: 1000sec ^-1

(Shrinkage)

The shrinkage of the resin composition is measured by the following method. Using the resin composition pellets of the Examples and Comparative Examples, they were molded under the following molding conditions using a molding machine ("SE-100DU" manufactured by Sumitomo Heavy Industries, Ltd.).

Cylinder temperature: 350°C (Examples 1-12, Comparative Examples 1-11)

350°C (Examples 13~16)

380°C (Example 17, 18, Comparative Example 12)

Mold temperature: 150℃

Injection speed: 33mm/sec

Holding pressure: 50MPa

Figure 1 is a plan view of the obtained test specimen 100. Test The size of the sheet 100 is 80 mm×80 mm×thickness 2 mm. The size of this test piece left to stand for 1 day was measured at the flow direction measurement site a and the right angle direction measurement site b shown in Fig. 1. Furthermore, c in Figure 1 represents a gate. From the measured size of the test piece and the size of the part on the mold corresponding to the above-mentioned measured part, the molding shrinkage rate is calculated according to the formula (1). Moreover, the mold size is 80.021 mm in the flow direction and 79.991 mm in the right-angle direction.

(Mold size-test piece size)/Mold size×100...(1)

The average value of the shrinkage in the flow direction and the shrinkage in the right-angle direction is calculated as the "shrinkage rate (average)", and the difference between the shrinkage in the flow direction and the shrinkage in the right-angle direction is taken as the "shrinkage rate (in each direction). opposite sex)". The results of Examples 1 to 12 and Comparative Examples 1 to 11 are shown in Tables 1 and 2. The results of Examples 13 to 18 and Comparative Example 12 are shown in Table 3. In addition, in Tables 1 to 3, the unit of shrinkage rate is "%".

(Manufacturing of Insert Molded Products)

Fig. 2(a) is a plan view of the insert molded product 10, Fig. 2(b) is a cross-sectional view of M-M in Fig. 2(a), and Fig. 2(c) is a bottom view. In order to provide an evaluation of the unevenness transferability and airtightness, the resin member 1 and the insert member 2 composed of the resin compositions of the examples and comparative examples were used to integrally mold the resin member 1 and the insert member 2 to produce an example And the insert molded product 10 of the comparative example. Furthermore, in order to be used in the evaluation described later, the insert molded article 10 has six recesses 3 on the upper surface as shown in FIG. 2.

Fig. 3 shows a schematic diagram of the insert member 2, Fig. 3(a) is a plan view, and Fig. 3(b) is a front view. The insert member 2 is a copper member. The length of this part 2 in the long side direction is 19mm, and the length in the short side direction is 8.5mm And the thickness is 0.2mm. In addition, the insertion member 2 uses those whose surface has not been treated, and those that have been chemically treated in advance by the following method. The chemical treatment is to immerse the surface of the copper insert in the etching solution A (aqueous solution) of the following composition for 1 minute to remove the anti-rust film, and then soak it in the etching solution B (aqueous solution) of the following composition for 5 minutes. Etch the surface.

Etching solution A (temperature 20℃): hydrogen peroxide 26g/L, sulfuric acid 90g/L

Etching solution B (temperature 25°C): hydrogen peroxide 80g/L, sulfuric acid 90g/L, benzotriazole 5g/L, sodium chloride 0.2g/L

Insert molding is performed as follows. The insert 2 was placed in a mold for injection molding, and a vertical injection molding machine (manufactured by Sodick Co., Ltd., TR-40VR) was used to melt the resin composition pellets of the examples and comparative examples under the following conditions and put them in the mold It is injected internally to become the resin component 1 to produce an insert molded product 10.

Cylinder temperature: 350°C (Examples 1-12, Comparative Examples 1-11)

350°C (Examples 13~16)

380°C (Example 17, 18, Comparative Example 12)

Mold temperature: 160℃

Injection speed: 70mm/s

Holding pressure: 50MPa

(Concave-convex transferability)

The insert molding 10 is immersed in a mixed solution of hydrochloric acid (10wt% aqueous solution) and nitric acid (60wt% aqueous solution) and the insert part 2 is dissolved at room temperature. The surface of the remaining resin part 1 is measured with a scanning electron microscope (Hitachi High- "S-3000H" manufactured by Technologies Co., Ltd., magnification: 1000 Times) observe. The degree of irregularities on the surface of the resin member 1 was evaluated in five stages, with the larger irregularities being 1, and the smaller irregularities being 5. Below 3, it can be said that the uneven transfer property is high. The results of Examples 1 to 12 and Comparative Examples 1 to 11 are shown in Tables 1 and 2. The results of Examples 13 to 18 and Comparative Example 12 are shown in Table 3.

(Initial air tightness)

The airtightness of the insert molded product 10 was evaluated as follows. For the evaluation of airtightness, a DP Gauge MODEL DP-330BA differential pressure meter (accuracy ±0.03kPa, differential pressure range 100kPa) manufactured by Cosmo Meter Co., Ltd. was used. The specific evaluation method will be described in accordance with Figures 4 and 5. Fig. 4 is an explanatory diagram when the sample 20 for the airtightness test is produced, and Fig. 5 is a block diagram of the evaluation device 101 for the airtightness test. First, as shown in FIG. 4, an insert molded product 10 is arranged as a sample 20 in the internal space of the fixing jig 4, 4'divided into two upper and lower parts. Next, this sample 20 is connected to the evaluation device 101 shown schematically in Fig. 5. The sample 20, the blank sample 30, and the differential pressure gauge 40 are connected using pipes arranged as shown in FIG. 5. Furthermore, in the sample 20, the tube is connected to the fixing jig 4 on the upper side. As a result, the tube sends air into the fixing jig and applies pressure to the six recesses 3 formed on the upper surface of the insert molded product 10. Then, if the junction between the resin member 1 and the insert member 2 is peeled from the boundary between the resin member 1 and the insert member 2 under the recess 3, air will leak to the lower side of the fixture. In addition, the blank sample 30 is for confirming the pressure applied to the above-mentioned recessed portion while maintaining the state of bonding between the resin member 1 and the insertion member 2. If there is a gap at the junction of the resin part 1 and the insert part 2, a pressure difference ΔP will be generated between the pressure applied to the blank sample 30 and the pressure applied to the sample, and the air of the insert molded product can be evaluated by this evaluation. Tightness.

The air leakage amount Q is calculated by the following equation (2) as an index of airtightness. The results of Examples 1 to 12 and Comparative Examples 1 to 11 are shown in Tables 1 and 2. The results of Examples 13 to 18 and Comparative Example 12 are shown in Table 3.

Q=Ve×△P/T...(2)

Q: Leakage (Pa.m ³ /s)

Ve: Volume (m ³ ) (=0.000005m ³ )

△P: Differential pressure (Pa)

T: Detection time (s) (=60s)

The leakage Q is 2.8×10 ^-4 Pa. When m ³ /s or less, it can be called an insert molded product with high airtightness.

(Air tightness after reflow)

The airtightness of the insert molded product 10 after the reflow treatment was evaluated. The reflow treatment was performed under the following conditions using TPF-20L manufactured by Asahi Engineering Co., Ltd.

Sample conveying speed: 0.4m/min

Reflow furnace passing time: 5min

Temperature conditions: preheat 200℃, reflow area 395℃, peak temperature 258℃

The airtightness is measured as described above. The results of Examples 1 to 12 and Comparative Examples 1 to 11 are shown in Tables 1 and 2. The results of Examples 13 to 18 and Comparative Example 12 are shown in Table 3.

It can be seen from Table 1 and Table 3 that the liquid crystalline resin compositions of the examples all have high unevenness transferability to the metal surface and low anisotropy of shrinkage. Furthermore, an insert molded article using this resin composition has excellent initial airtightness and can prevent the airtightness from being reduced after reflow treatment.

Claims (5)

A liquid crystalline resin composition comprising a liquid crystalline resin, a thermoplastic resin with a glass transition temperature Tg of less than 230°C, and a plate-shaped filler having an average particle size of 20 μm or more and 50 μm or less and an aspect ratio of 10 or more, the aforementioned liquid crystal resin The content of the entire resin composition is 40% by mass or more and 65% by mass or less, the content of the aforementioned thermoplastic resin in the entire resin composition is 12% or more and 35% by mass or less; and the content of the aforementioned plate-like filler is within 10% by mass or more and 35% by mass or less in the total resin composition, wherein the aforementioned thermoplastic resin is selected from one or more of polyarylene sulfide resins, polyphenylene ether resins, cyclic olefin resins, and polyether ether ketone resins . The liquid crystal resin composition described in the first item of the scope of the patent application, wherein the injection molding is 80mm under the conditions of a cylinder temperature 10-30°C higher than the melting point of the liquid crystal resin, a mold temperature of 150°C, and a holding pressure of 50MPa In the case of a molded product of ×80mm×2mm, the difference between the shrinkage rate in the direction perpendicular to the flow direction of the resin and the shrinkage rate in the flow direction of the resin is 0.51% or less. The liquid crystal resin composition as described in item 1 or 2 of the scope of patent application, which further contains 0 mass% to 6 mass% of the epoxy group-containing copolymer in the entire resin composition. The liquid crystal resin composition according to the first or the second item of the scope of the patent application, wherein the entire resin composition further contains 0% to 12% by mass of a fibrous filler. An insert molded product having a resin part made of the liquid crystalline resin composition described in any one of items 1 to 4 in the scope of patent application, and an insert part made of metal, alloy, or inorganic solid material.

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