JP6762228B2 - Liquid crystal resin composition for camera module and camera module using it - Google Patents

Description

The present invention relates to a liquid crystal resin composition for a camera module and a camera module using the same.

Liquid crystal resins represented by liquid crystal polyester resins have a good balance of excellent mechanical strength, heat resistance, chemical resistance, electrical properties, etc., and also have excellent dimensional stability, so they are widely used as high-performance engineering plastics. It's being used. Recently, liquid crystal resins have come to be used for precision equipment parts by taking advantage of these features.

In the case of precision equipment, especially optical equipment with a lens, a small amount of dust, dirt, etc. affects the equipment performance. For example, in a component used for an optical device such as a camera module, if small dust, oil, or dust adheres to the lens, the optical characteristics of the camera module are significantly deteriorated. For the purpose of preventing such deterioration of optical characteristics, the parts constituting the camera module (hereinafter, may be referred to as "camera module parts") are ultrasonically cleaned before assembly and adhere to the surface. Small dust, oil, dust, etc. are removed.

As described above, in a molded product obtained by molding a liquid crystal resin composition, the surface of the molded product is easily peeled off because the molecular orientation of the polymer is particularly large at the surface portion. Peeling causes a fluffing phenomenon called fluffing, and this fluffy raised portion causes small dust to be generated.

Therefore, when the liquid crystal resin composition is used as a raw material for parts for a camera module, a special liquid crystal resin composition is used so that the surface of the molded body is not raised even when the molded body is ultrasonically cleaned. As a special liquid crystal resin composition, a liquid crystal resin composition for a camera module containing a liquid crystal resin, a specific talc, and carbon black is disclosed (see Patent Document 1).

JP-A-2009-242453

However, in the study by the present inventors, the liquid crystal resin composition for a camera module described in Patent Document 1 is insufficient to suppress the raising of the surface of the molded body, and the surface of the molded body is more difficult to raise. A liquid crystal resin composition for a camera module for manufacturing the above is required.

Further, according to the study by the present inventors, when a conventional liquid crystal resin composition for a camera module is molded to manufacture a molded body such as a lens holder, the warp deformation is large and a problem occurs when assembling the camera module. There was something.

Further, among the parts constituting the camera module, for example, the lens holder, the base, the guide and the like are manufactured from the liquid crystal resin composition, and when the camera module is assembled, for example, between the lens holder and the barrel, and between the base and the guide. Between the base and the permanent magnet, and between the base and the yoke are bonded with an epoxy adhesive. When a conventional liquid crystal resin composition for a camera module is used, the adhesive strength of the epoxy adhesive, that is, the epoxy adhesiveness is not sufficient, so that the liquid crystal property for the camera module for producing a molded product having excellent epoxy adhesiveness. A resin composition is required.

In addition, the liquid crystal polymer composition may have blistering problems. That is, liquid crystal polymers such as liquid crystal polyester and liquid crystal polyester amide are often used as materials that require heat treatment at high temperature because they have good high temperature thermal stability. However, if the molded product is left in high temperature air or liquid for a long time, there arises a problem that fine swelling called blisters occurs on the surface. In this phenomenon, decomposition gas or the like generated when the liquid crystal polymer is in a molten state is brought into the molded product, and then the gas expands when heat treatment is performed at a high temperature, pushing up the surface of the molded product softened by heating. , Because the pushed up part appears as a blister. The generation of blisters can also be reduced by sufficiently degassing the vent holes during melt extrusion of the material and by not allowing them to stay in the molding machine for a long time during molding. However, the condition range is very narrow, and it is not sufficient to obtain a molded product in which the generation of blisters is suppressed, that is, a molded product having blister resistance. A fundamental solution to the generation of blisters requires improvement in the quality of the liquid crystal polymer itself, and known liquid crystal polymers and methods using the same are insufficient to solve the problem of blistering.

The present invention has been made to solve the above problems, and an object of the present invention is to manufacture a camera module component having a surface that is difficult to raise, warp deformation and blister generation are suppressed, and excellent epoxy adhesiveness. An object of the present invention is to provide a liquid crystal resin composition for a camera module to be used.

The present inventors have conducted intensive studies to solve the above problems. As a result, the liquid crystal resin, the polycarbonate resin, the epoxy group-containing copolymer, the fibrous filler and / or the plate-like filler are contained in a specific ratio, and the weight average fiber length of the fibrous filler and We have found that the above problems can be solved by using a liquid crystal resin composition for a camera module in which the average particle size of the plate-shaped filler is in a predetermined range, and have completed the present invention. More specifically, the present invention provides the following.

(1) (A) Liquid crystal resin,
(B) Polycarbonate resin,
It contains (C) an epoxy group-containing copolymer and at least one filler selected from the group consisting of (D) (D1) fibrous filler and (D2) plate-like filler.
The weight average fiber length of the (D1) fibrous filler is 150 μm or less.
The average particle size of the (D2) plate-shaped filler is 50 μm or less.
The content of the component (A) is 47 to 78% by mass, the content of the component (B) is 2 to 8% by mass, the content of the component (C) is 0 to 5% by mass, and the content of the component (D) is A liquid crystal resin composition for a camera module having a mass content of 20 to 40% by mass.

(2) The (C) epoxy group-containing copolymer is at least one selected from the group consisting of (C1) epoxy group-containing olefin-based copolymer and (C2) epoxy group-containing styrene-based copolymer. The composition according to (1).

(3) A camera module component comprising the composition according to (1) or (2).

(4) A camera module including the parts described in (3).

If a camera module component is manufactured using the liquid crystal resin composition for a camera module of the present invention as a raw material, the surface is less likely to be raised, warpage deformation and blister generation are suppressed, and a camera module component having excellent epoxy adhesiveness can be obtained. Be done.

It is sectional drawing which shows typically the general camera module. FIG. 2A is a diagram showing a camera module type molded product used for the warp deformation evaluation, and FIG. 2B is a diagram showing a measurement point in the warp deformation evaluation. The unit of the numerical value in the figure is mm. FIG. 3A is a diagram for explaining a method for producing a sample for evaluating epoxy adhesiveness, and FIG. 3B is a diagram for explaining a method for evaluating epoxy adhesiveness.

Hereinafter, embodiments of the present invention will be described. The present invention is not limited to the following embodiments.

<Liquid crystal resin composition for camera module>
The liquid crystal resin composition for a camera module of the present invention comprises (A) a liquid crystal resin, (B) a polycarbonate resin, (C) an epoxy group-containing copolymer, and (D) (D1) a fibrous filler and (. D2) Contains at least one filler selected from the group consisting of plate-like fillers.

[(A) Liquid crystal resin]
The liquid crystal resin (A) used in the present invention refers to a melt-processable polymer having a property of forming an optically anisotropic molten phase. The properties of the anisotropic fused phase can be confirmed by a conventional polarization inspection method using an orthogonal polarizing element. More specifically, the confirmation of the anisotropic molten phase can be carried out by observing the molten sample placed on the Leitz hot stage at a magnification of 40 times under a nitrogen atmosphere using a Leitz polarizing microscope. Liquid crystalline polymers applicable to the present invention normally transmit polarized light and are optically anisotropy when inspected between orthogonal polarizers, even in the molten and stationary state.

The type of the liquid crystal resin (A) as described above is not particularly limited, and is preferably aromatic polyester and / or aromatic polyester amide. The range also includes polyesters that partially contain aromatic polyesters and / or aromatic polyesteramides in the same molecular chain. The liquid crystal resin (A) preferably at least about 2.0 dl / g, more preferably 2.0 to 10.0 dl / g when dissolved in pentafluorophenol at 60 ° C. at a concentration of 0.1% by mass. Those having a logarithmic viscosity (IV) of are preferably used.

The aromatic polyester or aromatic polyesteramide as the (A) liquid crystal resin applicable to the present invention is particularly preferably at least one selected from the group consisting of aromatic hydroxycarboxylic acid, aromatic hydroxyamine, and aromatic diamine. It is an aromatic polyester or an aromatic polyester amide having a repeating unit derived from a species compound as a constituent.

More specifically
(1) Polyester composed of repeating units mainly derived from one or more aromatic hydroxycarboxylic acids and derivatives thereof;
(2) Repeating units mainly derived from (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and one of their derivatives. Or a polyester consisting of a repeating unit derived from two or more kinds and (c) a repeating unit derived from at least one kind or two or more kinds of aromatic diols, alicyclic diols, aliphatic diols, and derivatives thereof;
(3) Repeating units mainly derived from (a) one or more of aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two of aromatic hydroxyamines, aromatic diamines, and their derivatives. A polyester amide consisting of a repeating unit derived from a species or more and (c) a repeating unit derived from one or more of aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and derivatives thereof;
(4) Repetitive units mainly derived from (a) one or more aromatic hydroxycarboxylic acids and their derivatives, and (b) one or two aromatic hydroxyamines, aromatic diamines, and their derivatives. Repeating units derived from species or higher, (c) aromatic dicarboxylic acids, alicyclic dicarboxylic acids, and repeating units derived from one or more of their derivatives, and (d) aromatic diols, alicyclics. Examples thereof include polyesteramides composed of group diols, aliphatic diols, and repeating units derived from at least one or more of their derivatives. Further, a molecular weight adjusting agent may be used in combination with the above-mentioned constituent components, if necessary.

（Ｘ：アルキレン（Ｃ_１〜Ｃ_４）、アルキリデン、−Ｏ−、−ＳＯ−、−ＳＯ_２−、−Ｓ−、及び−ＣＯ−より選ばれる基である）

（Ｙ：−（ＣＨ_２）_ｎ−（ｎ＝１〜４）及び−Ｏ（ＣＨ_２）_ｎＯ−（ｎ＝１〜４）より選ばれる基である。） Preferred examples of the specific compound constituting the (A) liquid crystal resin applicable to the present invention include aromatic hydroxycarboxylic acids such as p-hydroxybenzoic acid and 6-hydroxy-2-naphthoic acid, and 2,6-dihydroxy. Aromatic diols such as naphthalene, 1,4-dihydroxynaphthalene, 4,4'-dihydroxybiphenyl, hydroquinone, resorcin, the compound represented by the following general formula (I), and the compound represented by the following general formula (II). Aromatic dicarboxylic acids such as terephthalic acid, isophthalic acid, 4,4'-diphenyldicarboxylic acid, 2,6-naphthalenedicarboxylic acid, and compounds represented by the following general formula (III); p-aminophenol, p- Examples include aromatic amines such as phenylenediamine.

(X: A group selected from alkylene (C _{1 to} C ₄ ), alkylidene, -O-, -SO-, -SO _2- , -S-, and -CO-)

(Y: A group selected from − (CH ₂ ) _n − (n = 1 to 4) and −O (CH ₂ ) _n O − (n = 1 to 4).

The liquid crystal resin (A) used in the present invention can be prepared from the above-mentioned monomer compound (or mixture of monomers) by a known method using a direct polymerization method or a transesterification method, and is usually a melt polymerization method. Or slurry polymerization method or the like is used. The above compounds having an ester-forming ability may be used in the polymerization as they are, or may be modified from a precursor to a derivative having the ester-forming ability in the pre-polymerization step. Various catalysts can be used for these polymerizations, and typical ones are dialkyltin oxide, diaryltin oxide, titanium dioxide, alkoxytitanium silicates, titanium alcoholates, and alkalis of carboxylic acids. And alkaline earth metal salts, Lewis acid salts such as BF _{3 and} the like. The amount of the catalyst used is generally preferably about 0.001 to 1% by mass, particularly preferably about 0.01 to 0.2% by mass, based on the total mass of the monomer. If necessary, the polymer produced by these polymerization methods can be further increased in molecular weight by solid-phase polymerization by heating under reduced pressure or in an inert gas.

The melt viscosity of the liquid crystal resin (A) obtained by the above method is not particularly limited. Generally, a melt viscosity at a molding temperature of 10 MPa or more and 600 MPa or less at a shear rate of 1000 sec ^-1 can be used. However, the one having a very high viscosity by itself is not preferable because the fluidity is very deteriorated. The liquid crystal resin (A) may be a mixture of two or more kinds of liquid crystal resins.

In the liquid crystal resin composition for a camera module of the present invention, the content of the liquid crystal resin (A) is 47 to 78% by mass. When the content of the component (A) is 47% by mass or more, it is preferable because of fluidity and suppression of raising of the surface of the molded body, and when the content of the component (A) is 78% by mass or less, it is preferable because of heat resistance. .. The preferable content of the component (A) is 55 to 70% by mass, and the more preferable content of the component (A) is 57.5 to 67.5% by mass.

[(B) Polycarbonate resin]
(B) The polycarbonate-based resin contributes to improving the epoxy adhesiveness of the molded product obtained from the liquid crystal resin composition for a camera module. (B) The polycarbonate-based resin can be used alone or in combination of two or more. The polycarbonate resin (B) is not particularly limited, and is, for example, an aromatic homo or copolycarbonate resin having a carbonate bond and obtained by reacting an aromatic divalent phenol compound with phosgene, carbonic acid diester, or the like. And so on. The aromatic homo or copolycarbonate resin preferably has a logarithmic viscosity of 0.2 to 3.0 dl / g measured at 20 ° C. at a concentration of 1.0 g / dl in methylene chloride, 0.3 to 1. More preferably, it is 5 dl / g.

The aromatic divalent phenolic compound is not particularly limited, and for example, 2,2-bis (4-hydroxyphenyl) propane, 2,2-bis (4-hydroxy-3,5-dimethylphenyl) propane, and the like. Bis (4-hydroxyphenyl) methane, 1,1-bis (4-hydroxyphenyl) ethane, 2,2-bis (4-hydroxyphenyl) butane, 2,2-bis (4-hydroxy-3,5-diphenyl) ) Butane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, 2,2-bis (4-hydroxy-3,5-diethylphenyl) propane, 1,1-bis (4-hydroxy) Examples thereof include phenyl) cyclohexane and 1-phenyl-1,1-bis (4-hydroxyphenyl) ethane. The above aromatic divalent phenolic compounds can be used alone or in combination of two or more.

The content of the component (B) is 2 to 8% by mass in the liquid crystal composition for a camera module of the present invention. When the content of the component (B) is 2% by mass or more, the epoxy adhesiveness of the molded product obtained from the liquid crystal resin composition for the camera module is likely to be ensured. When the content of the component (B) is 8% by mass or less, the blister suppressing effect of the molded product tends to be high. The preferred content is 2.5 to 7% by mass, and the more preferable content is 3 to 5% by mass.

[(C) Epoxy group-containing copolymer]
The liquid crystal composition for a camera module of the present invention may contain (C) an epoxy group-containing copolymer. The epoxy group-containing copolymer (C) can be used alone or in combination of two or more. The (C) epoxy group-containing copolymer is not particularly limited, and is at least selected from the group consisting of (C1) epoxy group-containing olefin-based copolymer and (C2) epoxy group-containing styrene-based copolymer. One type can be mentioned. By blending the component (C) into the liquid crystal resin composition for a camera module, it is possible to more effectively suppress the raising of the surface of the molded product when the molded product obtained by molding the composition is ultrasonically cleaned. Contribute.
The reason for further suppressing the raising is not clear, but it is considered that the surface condition of the molded product is changed by blending a certain amount, and the change contributes to suppressing the raising.

Examples of the (C1) epoxy group-containing olefin-based copolymer include a copolymer composed of a repeating unit derived from α-olefin and a repeating unit derived from a glycidyl ester of α, β-unsaturated acid. Be done.

The α-olefin is not particularly limited, and examples thereof include ethylene, propylene, butene, etc. Among them, ethylene is preferably used. The glycidyl ester of α, β-unsaturated acid is represented by the following general formula (IV). The glycidyl ester of α, β-unsaturated acid is, for example, acrylic acid glycidyl ester, methacrylic acid glycidyl ester, etacrylic acid glycidyl ester, itaconic acid glycidyl ester, etc., but methacrylic acid glycidyl ester is particularly preferable.

(C1) In the epoxy group-containing olefin-based copolymer, the content of the repeating unit derived from α-olefin is 87 to 98% by mass, and the content of the repeating unit derived from the glycidyl ester of α, β-unsaturated acid is contained. The amount is preferably 13 to 2% by mass.

The (C1) epoxy group-containing olefin copolymer used in the present invention contains acrylonitrile, acrylic acid ester, methacrylic acid ester, α-methylstyrene, and maleic anhydride as a third component in addition to the above two components as long as the present invention is not impaired. Repeating units derived from one or more olefinically unsaturated esters such as acids may be contained in an amount of 0 to 48 parts by mass with respect to 100 parts by mass of the above two components.

The epoxy group-containing olefin-based copolymer which is the component (C1) of the present invention can be easily prepared by a usual radical polymerization method using a monomer corresponding to each component and a radical polymerization catalyst. More specifically, usually, the presence of a suitable solvent or chain transfer agent for α-olefin and glycidyl ester of α, β-unsaturated acid at 500 to 4000 atm and 100 to 300 ° C. in the presence of a radical generator. It can be produced by a method of copolymerizing under or in the absence. It can also be produced by a method in which an α-olefin, an α, β-unsaturated acid glycidyl ester and a radical generator are mixed and melt-grafted in an extruder.

Examples of the epoxy group-containing styrene-based copolymer (C2) include a copolymer composed of a repeating unit derived from styrenes and a repeating unit derived from a glycidyl ester of α, β-unsaturated acid. Be done. The description of the glycidyl ester of α, β-unsaturated acid is omitted because it is the same as that described in the component (C1).

Examples of styrenes include styrene, α-methylstyrene, brominated styrene, divinylbenzene and the like, and styrene is preferably used.

The (C2) epoxy group-containing styrene-based copolymer used in the present invention is a multidimensional copolymer containing a repeating unit derived from one or more of other vinyl monomers as a third component in addition to the above two components. There may be. A suitable third component is a repeating unit derived from one or more olefinically unsaturated esters such as acrylonitrile, acrylic acid ester, methacrylic acid ester, and maleic anhydride. An epoxy group-containing styrene-based copolymer containing 40% by mass or less of these repeating units in the copolymer is preferable as the component (C2).

(C2) In the epoxy group-containing styrene-based copolymer, the content of the repeating unit derived from the glycidyl ester of α, β-unsaturated acid is 2 to 20% by mass, and the content of the repeating unit derived from styrenes. Is preferably 80 to 98% by mass.

(C2) The epoxy group-containing styrene-based copolymer can be prepared by a usual radical polymerization method using a monomer corresponding to each component and a radical polymerization catalyst. More specifically, styrenes and glycidyl esters of α, β-unsaturated acids are usually mixed in the presence of a radical generator at 500 to 4000 atm and 100 to 300 ° C. in the presence of a suitable solvent or chain transfer agent. Alternatively, it can be produced by a method of copolymerizing in the absence. It can also be produced by a method in which styrenes, an α, β-unsaturated acid glycidyl ester and a radical generator are mixed and melt-grafted in an extruder.

As the (C) epoxy group-containing copolymer, the (C1) epoxy group-containing olefin-based copolymer is preferable in terms of heat resistance. When the component (C1) and the component (C2) are used in combination, the ratio of these components can be appropriately selected according to the required characteristics.

The content of the epoxy group-containing copolymer (C) is 0 to 5% by mass in the resin composition for a camera module of the present invention. When the content of the component (C) is 5% by mass or less, the fluidity is not impaired and a good molded product can be easily obtained. The more preferable content is 2.0 to 4.0% by mass, and the more preferable content is 2.5 to 3.5% by mass.

[(D) Filler]
The component (D) is at least one filler selected from the group consisting of (D1) fibrous filler and (D2) plate-like filler, and the weight average fiber length of (D1) fibrous filler is , 150 μm or less, and the average particle size of the (D2) plate-like filler is 50 μm or less.

The preferable weight average fiber length of the (D1) fibrous filler is 30 to 150 μm, and the more preferable weight average fiber length is 50 to 140 μm. When the weight average fiber length is 30 μm or more, it is easy to maintain the mechanical strength and the deflection temperature under load required for the camera module, and when it is 150 μm or less, it is easy to suppress the raising of the surface of the molded product. The average fiber diameter is a value measured by an image processing method by an image measuring machine by capturing a stereomicroscopic image from a CCD camera into a PC.

The preferable average fiber diameter of the (D1) fibrous filler is 20 μm or less, and the more preferable average fiber diameter is 5 to 15 μm. When the average fiber diameter is 20 μm or less, raising of the surface of the molded product is likely to be suppressed. The average fiber diameter is a value measured by an image processing method by an image measuring machine by capturing a stereomicroscopic image from a CCD camera into a PC.

Any fiber can be used as long as it is a fibrous filler satisfying the above shape. As the (D1) fibrous filler, for example, fibrous wollastonite, glass fiber, milled fiber, carbon fiber , Asbestos fiber, silica fiber, silica / alumina fiber, zirconia fiber, boron nitride fiber, silicon nitride fiber, boron fiber, potassium titanate fiber, and metal fibrous material such as stainless steel, aluminum, titanium, copper, brass, etc. Examples include inorganic fibrous substances. Two or more kinds of fibrous fillers may be used as the component (D1). In the present invention, it is preferable to use fibrous wollastonite and milled fiber as the component (D1).

The plate-shaped filler (D2) preferably has an average particle size of 20 to 50 μm. When the average particle size is 20 μm or more, the mechanical strength required for the camera module and the deflection temperature under load are likely to be secured, and the effect of suppressing warpage deformation of the molded product is likely to be high. When the average particle size is 50 μm or less, the effect of suppressing raising of the surface of the molded product tends to be high. The preferred average particle size is 23 to 30 μm. In addition, in this specification, the value measured by the laser diffraction / scattering type particle size distribution measurement method is adopted as an average particle diameter.

The plate-shaped filler (D2) is not particularly limited, and examples thereof include mica, talc, glass flakes, graphite, and various metal foils (for example, aluminum foil, iron foil, and copper foil). Two or more kinds may be used as the component (D). In the present invention, it is preferable to use mica and / or talc as the component (D2).

As the whole component (D), only the component (D1) may be used, only the component (D2) may be used, or a combination of the component (D1) and the component (D2) may be used. It is preferable to use a combination of mica, talc and fibrous wollastonite, and a combination of talc and milled fiber.

The content of the component (D) is 20 to 40% by mass in the liquid crystal composition for a camera module of the present invention. When the content of the component (D) is 20% by mass or more, the mechanical strength required for the camera module and the deflection temperature under load are likely to be secured, and the effect of suppressing warpage deformation of the molded product is likely to be high. When the content of the component (D) is 40% by mass or less, the effect of suppressing the raising of the surface of the molded product and / or the effect of suppressing the warp deformation of the molded product tends to be high. The preferable content is 22 to 38% by mass, and the more preferable content is 25 to 35% by mass.

[(E) Carbon Black]
The carbon black (E) used as an optional component in the present invention is not particularly limited as long as it is generally available and is used for resin coloring. Normally, (E) carbon black contains lumps formed by agglomeration of primary particles, but unless a large amount of lumps having a size of 50 μm or more is contained, the resin composition of the present invention is molded. Many bumps (fine bumpy protrusions (fine irregularities) in which carbon black is aggregated) are unlikely to occur on the surface of the molded product. When the content of the particles having a mass particle diameter of 50 μm or more is 20 ppm or less, the effect of suppressing the raising of the surface of the molded product tends to be high. The preferred content is 5 ppm or less.

The blending amount of (E) carbon black is preferably in the range of 0.5 to 5% by mass in the liquid crystal resin composition for camera modules. When the blending amount of carbon black is 0.5% by mass or more, the jet-blackness of the obtained resin composition is unlikely to decrease, and the light-shielding property is less likely to be anxious. If the blending amount of carbon black is 5% by mass or less, it is less likely to be uneconomical and less likely to cause lumps.

[Other ingredients]
The liquid crystal resin composition for a camera module of the present invention includes other polymers, other fillers, and known substances generally added to synthetic resins, that is, antioxidants, as long as the effects of the present invention are not impaired. Stabilizers such as UV absorbers, antistatic agents, flame retardants, colorants such as dyes and pigments, lubricants, mold release agents, crystallization accelerators, crystal nucleating agents, etc. may be added as appropriate according to the required performance. it can.

The other fillers include at least one filler selected from the group consisting of (D) (D1) fibrous fillers and (D2) plate-like fillers, and (E) fillers other than carbon black. A good example is a granular filler such as silica.

[Preparation of liquid crystal resin composition for camera module]
The preparation of the resin composition for a camera module of the present invention is not particularly limited. For example, a liquid crystal resin for a camera module is obtained by blending the above components (A), (B), (C), and (D) and melt-kneading them using a single-screw or twin-screw extruder. The composition is prepared.

[Liquid crystal resin composition for camera module]
The shape of the component (D1) in the liquid crystal resin composition for a camera module of the present invention is different from the shape of the component (D1) before being blended. The shape of the component (D1) described above is the shape before blending. If the shape before compounding is as described above, it is easy to obtain a camera module component whose surface is hard to be brushed.

Similarly, the shape of the component (D2) in the liquid crystal resin composition for a camera module of the present invention is different from the shape of the component (D2) before being blended. The shape of the above-mentioned component (D2) is the shape before blending. If the shape before blending is as described above, it is easy to obtain a camera module component in which warpage deformation is suppressed.

The liquid crystal resin composition for a camera module of the present invention obtained as described above preferably has a melt viscosity of less than 70 Pa · sec. One of the features of the liquid crystal resin composition for a camera module of the present invention is that it has high fluidity when melted and is excellent in moldability. In the present specification, as the melt viscosity, a value obtained by a measuring method based on ISO 11443 is adopted under the conditions of a cylinder temperature 10 to 20 ° C. higher than the melting point of the liquid crystal resin and a shear rate of 1000 sec ^-1 .

<Camera module parts and camera module>
A camera module component is manufactured using the liquid crystal resin composition for a camera module. When the resin composition of the present invention is used as a raw material, the surface of the camera module component is less likely to be raised. Since the parts for the camera module are ultrasonically cleaned, it is required that the surface is not easily raised even if the parts are ultrasonically cleaned. When the resin composition of the present invention is used, even if the parts for the camera module are ultrasonically cleaned under stronger conditions, there is no or almost no falling off that causes dust or the like. Therefore, after the camera module parts are incorporated into the finished product, the dust generated by raising the surface of the camera module parts hardly affects the quality of the finished product.

A part for a camera module formed by molding the liquid crystal resin composition for a camera module of the present invention will be described. A cross section of a general camera module is schematically shown in FIG. As shown in FIG. 1, the camera module 1 includes a substrate 10, an image sensor 11, a lead wiring 12, a lens holder 13, a barrel 14, a lens 15, an IR filter 16, a guide 17, and a base 18. , A coil 19, a permanent magnet 20, a yoke 21, and a cover 22.

The image sensor 11 is arranged on the substrate 10, and the image sensor 11 and the substrate 10 are electrically connected by lead wiring 12.

The guide 17 is arranged on the substrate 10, the base 18 is arranged on the guide 17, the lens holder 13 is arranged up and down on the base 18, and the coil 19 is wound around the lens holder 13. ing. An opening is formed in the top of the lens holder 13, and a spiral groove is formed in the wall surface of the opening. The guide 17 has an opening formed at the top, and an IR filter 16 is arranged on the guide 17 so as to close the opening. The guide 17 and the IR filter 16 cover the image sensor 11. A yoke 21 is arranged on the base 18, a permanent magnet 20 is in contact with the inside of the yoke 21, and a cover 22 having an opening at the top is arranged on the yoke 21. The permanent magnet 20 is arranged around the coil 19.

The barrel 14 has a cylindrical shape, and the lens 15 is held inside the cylindrical shape so as to be substantially horizontal. Further, a spiral convex portion is formed on the side wall at one end of the cylinder, and the spiral convex portion and the spiral groove portion formed on the opening wall surface of the lens holder 13 are screwed together to form a spiral convex portion. The barrel 14 is connected to the lens holder 13. As shown in FIG. 1, the IR filter 16 and the lens 15 are arranged substantially in parallel. A leaf spring (not shown) is connected between the top of the lens holder 13 and the top of the yoke 21, and between the bottom of the lens holder 13 and the top of the base 18. The barrel 14, the lens 15, and the coil 19 are held in the camera module 1 via the lens holder 13 and the lens holder 13.

In the camera module 1 as shown in FIG. 1, the lens holder 13 is placed on the base 18 by the action of the magnetic force generated by the coil 19 wound around the lens holder 13 and the permanent magnets 20 arranged around the coil 19. By moving up and down, the distance between the lens 15 and the image pickup element 11 changes. By adjusting this distance, the focus of the camera can be adjusted.

In the camera module 1 as described above, the lens holder 13, the guide 17, and / or the base 18, which are parts for the camera module, can be manufactured using the liquid crystal resin composition for the camera module of the present invention as a raw material. General liquid crystal resin compositions are not suitable as raw materials for producing these parts. When the lens holder 13, the guide 17, and / or the base 18 is manufactured from a general liquid crystal resin composition as a raw material, the following problems occur.

In a molded product obtained by molding a general liquid crystal resin composition, the surface of the molded product is easily raised because the molecular orientation of the polymer is particularly large at the surface portion, and this raising causes the generation of small dust. If this small dust adheres to the lens 15 or the like, the performance of the camera module deteriorates.

The camera module parts such as the lens holder 13, the guide 17, and the base 18 are ultrasonically cleaned before being incorporated into the camera module 1 for the purpose of removing dust and small dust on the surface. However, since the surface of a molded product obtained by molding a general liquid crystal resin composition is easily raised, the surface becomes fluffy when ultrasonically cleaned. Due to such problems, it is usually not possible to ultrasonically clean a molded product obtained by molding a liquid crystal resin composition.

The focus adjustment is performed by moving the lens holder 13 up and down on the base 18 by the action of the magnetic force generated by the coil 19 wound around the lens holder 13 and the permanent magnets 20 arranged around the coil. At this time, as described above, the surface of the molded product obtained by molding a general liquid crystal resin composition is easily raised, so that the surface may be peeled off to form a peeled product. There is a high possibility that this peeled material becomes small dust and adheres to the lens 15 or the like to deteriorate the performance of the camera module.

As described above, when the liquid crystal resin composition is usually used as a raw material for the lens holder 13, the guide 17, and / or the base 18, problems are likely to occur, but the liquid crystal resin composition for a camera module of the present invention is a molded product. As a result, the surface condition of the molded product has been improved so that the problem of brushing hardly occurs even if the molded product is ultrasonically cleaned. Therefore, as a raw material for the lens holder 13, the guide 17, and / or the base 18. It can be preferably used.

The present invention will be described in more detail with reference to Examples below, but the present invention is not limited to these Examples.

<Liquid crystal resin>
-After charging the following raw materials into a liquid crystal polyesteramide resin polymerization vessel, the temperature of the reaction system was raised to 140 ° C., and the reaction was carried out at 140 ° C. for 1 hour. Then, the temperature is further raised to 340 ° C. over 4.5 hours, and then the pressure is reduced to 10 Torr (that is, 1330 Pa) over 15 minutes while distilling acetic acid, excess acetic anhydride, and other low boiling points. Melt polymerization was performed. After the stirring torque reached a predetermined value, nitrogen was introduced to bring the mixture from a reduced pressure state to a pressurized state through normal pressure, the polymer was discharged from the lower part of the polymerization vessel, and the strands were pelletized to obtain pellets. The obtained pellets were heat-treated at 300 ° C. for 2 hours under a nitrogen stream to obtain the desired polymer. The melting point of the obtained polymer was 336 ° C., and the melt viscosity was 19 Pa · s. The melt viscosity of the polymer was measured in the same manner as the method for measuring the melt viscosity described later.
(I) 4-Hydroxybenzoic acid; 1380 g (60 mol%)
(II) 2-Hydroxy-6-naphthoic acid; 157 g (5 mol%)
(III) Terephthalic acid; 484 g (17.5 mol%)
(IV) 4,4'-dihydroxybiphenyl; 388 g (12.5 mol%)
(V) 4-acetoxyaminophenol; 126 g (5 mol%)
Metal catalyst (potassium acetate catalyst); 110 mg
Acylating agent (acetic anhydride); 1659 g

<Materials other than liquid crystal resin>
-Polycarbonate resin: Panlite L-1225L (made by Teijin Chemicals Ltd., polycarbonate resin)
Fibrous filler: NYGLOS 8 (manufactured by NYCO Materials, fibrous wollastonite, aspect ratio 17, average fiber length 136 μm, average fiber diameter 8 μm)
-Epoxide group-containing olefin copolymer: Bond First 2C (manufactured by Sumitomo Chemical Co., Ltd., ethylene-glycidyl methacrylate copolymer, glycidyl methacrylate content 6% by mass)
-Plate-shaped filler 1: AB-25S (manufactured by Yamaguchi Mica Industry Co., Ltd., mica, average particle diameter 24 μm)
-Plate-shaped filler 2: Crown talc PP (manufactured by Matsumura Sangyo Co., Ltd., talc, average particle size 12.8 μm, average aspect ratio 6)
-Carbon black: VULCAN XC305 (manufactured by Cabot Japan Co., Ltd., average particle diameter 20 nm, proportion of particles with a particle diameter of 50 μm or more is 20 ppm or less)

<Manufacturing of liquid crystal resin composition for camera module>
The above components are melt-kneaded at a cylinder temperature of 350 ° C. using a twin-screw extruder (TEX30α type manufactured by Japan Steel Works, Ltd.) at the ratio shown in Table 1 to obtain liquid crystal resin composition pellets for a camera module. It was.

<Melting viscosity>
The melt viscosities of the liquid crystal resin compositions for camera modules of Examples and Comparative Examples were measured using the pellets. Specifically, the apparent melt viscosity under the conditions of a cylinder temperature of 350 ° C. and a shear rate of 1000 sec ^-1 was measured by a capillary rheometer (Capillary Graph 1D manufactured by Toyo Seiki Co., Ltd .: piston diameter 10 mm) in accordance with ISO 11443. An orifice having an inner diameter of 1 mm and a length of 20 mm was used for the measurement. The results are shown in Table 1.

<Bending test>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to prepare a bending test piece of 130 mm × 13 mm × 0.8 mm. .. Using this test piece, bending strength, flexural modulus, and breaking strain were measured according to ASTM D790. The results are shown in Table 1.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 90 ° C
Injection speed: 33 mm / sec
Holding pressure: 50 MPa

<Number of dust generated>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE30DUZ” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a molded product having a size of 12.5 mm × 120 mm × 0.8 mm. This molded product was used as a test piece.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 90 ° C
Injection speed: 80 mm / sec
[Evaluation]
The test piece was subjected to an ultrasonic cleaner (output 300 W, frequency 45 kHz) in water at room temperature for 3 minutes. Then, the number of particles of 2 μm or more existing in the water was measured with a particle counter (RION Co., Ltd. liquid particle counter KL-11A (PARTICLE COUNTER)) and evaluated as the number of dust generated. The results are shown in Table 1.

<Sledding deformation>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE30DUZ” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions, and 10.0 mm × as shown in FIG. 2 (a). A camera module type molded product having a size of 10.0 mm × 1.0 mm was obtained. The obtained camera module type molded product was allowed to stand on a horizontal desk, and the height of the camera module type molded product was measured by a Mitutoyo Quick Vision 404PROCNC image measuring machine. At that time, the heights were measured at a plurality of positions indicated by black circles in FIG. 2B, and the difference between the maximum height and the minimum height from the least squares plane was defined as the warp deformation. The results are shown in Table 1.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 80 ° C
Injection speed: 100 mm / sec
Holding pressure: 50 MPa

<Epoxy adhesiveness>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a test piece (ISO test piece Type 1A, thickness 4 mm). .. This test piece was divided into two parts and bonded with an epoxy adhesive (Loctite 3128NH manufactured by Henkel) as shown in FIG. 3A (curing condition: 80 ° C. × 30 minutes). Then, as shown in FIG. 3 (b), the bonded test pieces were installed, a load was applied in the direction of the arrow using a tensile tester, and the adhesive strength was evaluated from the load when peeled off. The results are shown in Table 1.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 80 ° C
Injection speed: 33 mm / sec
[Tensile test conditions]
Testing machine: Orientec, Tensilon RTC-1325A
Test speed: 10 mm / min

<Surface roughness (Ra)>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions to obtain a test piece (ISO test piece Type 1A, thickness 4 mm). .. The surface roughness Ra of the end portion of this molded product was measured using an ultra-depth color 3D shape measuring microscope VK-9500 (manufactured by KEYENCE CORPORATION). The results are shown in Table 1.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 80 ° C
Injection speed: 33 mm / sec

<Blister temperature>
The pellets of Examples and Comparative Examples were molded using a molding machine (“SE100DU” manufactured by Sumitomo Heavy Industries, Ltd.) under the following molding conditions, and had a weld portion of 12.5 mm × 120 mm × 0.8 mm. A molded product was obtained. A fragment obtained by dividing this molded product into two parts at the weld portion was used as one sample and sandwiched in a hot press at a predetermined temperature for 5 minutes. Then, it was visually examined whether or not blisters were generated on the surface of the sample. The blister temperature was set to the maximum temperature at which the number of blisters generated was zero. The predetermined temperature was set in the range of 250 to 300 ° C. in increments of 10 ° C.
〔Molding condition〕
Cylinder temperature: 350 ℃
Mold temperature: 80 ° C
Injection speed: 33 mm / sec

As is clear from the results shown in Table 1, it was confirmed that the molded product produced by using the pellets of the examples generated a small amount of dust even after ultrasonic cleaning. In addition, the molded product had a small value of warpage deformation. From these results, the molded product obtained by molding the pellets of the examples has a significantly different surface state as compared with the molded product obtained by molding the ordinary liquid crystal resin composition pellets of the comparative example, and is deformed by warpage. Can be said to be suppressed.

Further, it was confirmed that the molded product produced by using the pellets of the examples was excellent in epoxy adhesiveness even though the content of the polycarbonate resin was small and the surface roughness (Ra) was small. Furthermore, it was also confirmed that this molded product suppressed the generation of blisters.

1 Camera module 10 Board 11 Image sensor 12 Lead wiring 13 Lens holder 14 Barrel 15 Lens 16 IR filter 17 Guide 18 Base 19 Coil 20 Permanent magnet 21 York 22 Cover

Claims (4)

(A) Liquid crystal resin,
(B) Polycarbonate resin,
It contains (C) an epoxy group-containing copolymer and at least one filler selected from the group consisting of (D) (D1) fibrous filler and (D2) plate-like filler.
Does not contain red phosphorus
The weight average fiber length of the (D1) fibrous filler is 150 μm or less.
The average particle size of the (D2) plate-shaped filler is 50 μm or less.
The content of the component (A) is 47 to 78% by mass, the content of the component (B) is 2 to 8% by mass, the content of the component (C) is 0 to 5% by mass, and the content of the component (D) is A liquid crystal resin composition for a camera module having a mass content of 20 to 40% by mass. Claim 1 that the (C) epoxy group-containing copolymer is at least one selected from the group consisting of (C1) epoxy group-containing olefin-based copolymer and (C2) epoxy group-containing styrene-based copolymer. The composition according to. A part for a camera module comprising the composition according to claim 1 or 2. A camera module including the component according to claim 3.

Images