JP2009242453A - Liquid crystal polyester resin composition for camera module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a resin composition, which is excellent in the balance between heat resistance, rigidity, moldability and surface exfoliation characteristics, for a surface-mountable (SMT) camera module. <P>SOLUTION: The liquid crystal polyester resin composition comprises 50-110 pts.mass of talc having a number-mean particle diameter of 10-50 μm, and 2-10 pts.mass of carbon black based on 100 pts.mass of a liquid crystal polyester. The liquid crystal polyester resin composition exhibits melt viscosity of 10-150 Pa s as determined at a shear rate of 100 sec<SP>-1</SP>at 370°C and a deflection temperature under load of 220°C or above. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a material for a camera module. More specifically, the present invention has high heat resistance and can withstand solder reflow. (The material is placed on a substrate coated with solder paste by printing or the like and soldered in a reflow furnace. “Lens Barrel” (Surface Mount Technology, abbreviated as SMT), “Lens Barrel” (the part on which the lens is mounted), “Mount Holder” (Mount the barrel and fix it on the board) Part), and further, “CMOS (image sensor) frame”, “shutter and shutter bobbin part”, etc., may generate dust during production process and use, and the dust may get on the CMOS (image sensor) The present invention relates to a liquid crystal polyester resin composition used for all plastic parts.

When transmitting AV information in a digital format, there is a camera module as a main device used for inputting and outputting information. Installed in mobile phones, laptop computers, digital cameras, digital video cameras, etc., which have not only a static still shooting function but also a dynamic monitoring function (for example, the rear monitor of a car) as a shooting function There is also.
Until now, camera modules mounted on mobile phones could not be surface mounted (as a whole camera module) because there was no plastic lens that could withstand solder reflow. For this reason, the conventional board assembly process is to mount the module parts excluding the lens surface and then mount the lens, or assemble the entire camera module and then mount it on the board by other methods. It was supported by wearing.
In recent years, an inexpensive plastic lens that can withstand solder reflow has been developed, and an environment in which the entire camera module can be mounted on the surface is now available. Therefore, a liquid crystal polymer that has high heat resistance and can be molded thinly is made up of “lens barrel part” (the part where the lens is placed), “mount holder part” (the part where the barrel is mounted and fixed to the substrate), and “CMOS ( It has come to be used for “frame of image sensor”, “shutter and shutter bobbin portion” and the like (see Patent Document 1).

  A camera module equipped with a general fixed-focus optical system has a configuration in which a CMOS (image sensor) has a multilayer chip mounted on a signal processing chip. In the assembly process, manual focus adjustment ( It is necessary to adjust the focal length by changing the distance between the lens and the image sensor by screwing the lens barrel portion screwed into the mount holder portion with a screw (see Patent Document 1). However, in the conventional liquid crystal polymer composition, in this focus adjustment step, when the lens barrel portion is screwed, a powder composed of a resin composition from the lens barrel, the screw-attached portions of both mount holders, and the surfaces of both molded products ( Particles fall off, which is one of the major causes of image defects on the CMOS image sensor or (IR cut) filter. Powder fall-off may occur during use of a product incorporating the member. Therefore, it is required to provide a liquid crystal polymer composition with less powder (particle) dropout as a material used for the lens barrel part, mount holder part, CMOS (image sensor) frame, shutter and shutter bobbin part of the camera module. It was done.

  As an example of using the liquid crystal polymer as a material used for the camera module parts described above, there are several examples in addition to the above-mentioned Patent Document 1 (see Patent Documents 2 and 3). There is no mention at all about the method for suppressing the occurrence of the above, or the development of a resin composition with little occurrence.

Conventionally, it has been known that talc is filled to improve the anisotropy, warpage, and heat resistance of a liquid crystal polyester resin molded product (see, for example, Patent Documents 4-6), and a document that mentions its surface appearance ( Although there is also a patent document 7), there is no description at all about a resin composition having a severe surface transferability of a molded article as in the present application—reducing generation of falling off of the surface as much as possible.
JP 2006-246461 A JP 2008-028838 A JP 2008-034453 A Japanese Patent Laid-Open No. 04-13758 JP 2001-207054 A Japanese Patent Laid-Open No. 06-207083 JP 2003-128893 A

  As described above, the lens barrel member, mount holder member, etc. of a camera module made of a conventional liquid crystal polymer resin composition have excellent physical properties of the liquid crystal polymer resin composition, such as rigidity, heat resistance, and thin-wall processability. While maintaining, it is not currently possible to control the generation of powder (particles) that cause the product acceptance rate and product performance to deteriorate during the camera module assembly process and during use.

  The present invention, which is currently unsolved, is intended to solve an important problem, has a good balance of rigidity, heat resistance, and thin wall workability, and is in the process of assembling the camera module. Another object of the present invention is to provide a molding material made of a liquid crystal polyester resin composition suitable for a camera module member with a small amount of generated powder (particles).

  As a result of various investigations to solve the above problems, the inventors have added a specific amount of talc having a specific particle size to a liquid crystal polyester resin having a specific viscosity range, so that the surface transferability of an injection-molded product is excellent. During assembly and use, it was possible to obtain a material with less surface dropout, and the camera module member formed from the composition was found to generate less dust, leading to the present invention. .

The first of the present invention comprises 50 to 110 parts by mass of talc having a number average particle size of 10 to 50 μm and 2 to 10 parts by mass of carbon black with respect to 100 parts by mass of the liquid crystalline polyester, and the deflection temperature under load is 220 ° C. As described above, the present invention relates to a liquid crystal polyester resin composition for a camera module, which has a melt viscosity of 10 to 150 Pa · S at a shear rate of 100 sec ⁻¹ and 370 ° C.

According to a second aspect of the present invention, when the first resin composition of the present invention is molded by injection molding, the number of fallen objects from the surface of the molded product according to the following definition is 200 or less. 1. The liquid crystal polyester resin composition according to 1.
Number of fallen objects = an injection molded body having a threaded structure with a pitch of 0.3 mm and a groove depth of 0.2 mm on the inner surface of a cylinder having an outer diameter of 70 mm, an inner diameter of 60 mm, and a height of 0.5 mm, in pure water of 266 mL, 40 kHz, 480 W Of particles having a maximum diameter in the range of 2 μm or more in 10 mL of pure water after ultrasonic cleaning for 30 seconds at an output of

The third aspect of the present invention relates to a camera module component manufactured by injection molding from the first or second liquid crystal polyester resin composition of the present invention.

  The molded body made of the liquid crystalline polyester resin composition according to the present invention has good rigidity, heat resistance, thin-wall processability, and excellent surface transferability and surface dropout characteristics. It is possible to provide an optimal member for a camera module that is possible and that generates a small amount of powder (particles) during the assembly process and in use.

  The liquid crystal polyester resin used in the present invention forms an anisotropic melt, and among these, a wholly aromatic liquid crystal polyester obtained by a polycondensation reaction of substantially only an aromatic compound is preferable.

  The structural unit of the liquid crystal polyester resin constituting the liquid crystal polyester resin composition of the present invention includes, for example, a combination of an aromatic dicarboxylic acid, an aromatic diol and an aromatic hydroxycarboxylic acid, or a heterogeneous aromatic hydroxycarboxylic acid. Specific structural units such as those comprising a combination of an aromatic hydroxycarboxylic acid, an aromatic dicarboxylic acid and an aromatic diol, and a polyester such as polyethylene terephthalate reacted with an aromatic hydroxycarboxylic acid. For example, the following may be mentioned.

Structural units derived from aromatic hydroxycarboxylic acids:

Structural units derived from aromatic dicarboxylic acids:

Repeating structural units derived from aromatic diols:

  From the viewpoint of the balance of heat resistance, mechanical properties, and processability, a preferable liquid crystal polyester resin has a structural unit (A1) of 30 mol% or more, more preferably 60 mol in total of (A1) and (B1). % Or more.

  Particularly preferred liquid crystal polyesters are p-hydroxybenzoic acid (I), terephthalic acid (II), 4,4′-dihydroxybiphenyl (III) (including these derivatives) in an amount of 80 to 100 mol% (provided that (I ) And (II) is 60 mol% or more), and (I), (II), or any other aromatic compound capable of decondensation reaction with (III) is further polycondensed in an amount of 0 to 20 mol%. 90 of a wholly aromatic liquid crystal polyester having a melting point of 320 ° C. or higher, or p-hydroxybenzoic acid (I), terephthalic acid (II), 4,4′-dihydroxybiphenyl (III) (including these derivatives). -99 mol% (provided that the total of (I) and (II) is 60 mol% or more) and (I) (II) (III) and other aromatic compounds capable of decondensation with 1 10 mol% (both are 100 mol%. ) Is a wholly aromatic liquid crystal polyester having a melting point of 320 ° C. or higher.

As a combination of the above structural units,
(A1)
(A1), (B1), (C1)
(A1), (B1), (B2), (C1)
(A1), (B1), (B2), (C2)
(A1), (B1), (B3), (C1)
(A1), (B1), (B3), (C2)
(A1), (B1), (B2), (C1), (C2)
(A1), (A2), (B1), (C1)
As a particularly preferable monomer composition ratio, p-hydroxybenzoic acid, terephthalic acid, 4,4′-dihydroxybiphenyl (including these derivatives) is 80 to 100 mol%, and other aromatic diols, A wholly aromatic liquid crystalline polyester resin obtained by polycondensation of 0 to 20 mol% of an aromatic compound selected from the group consisting of aromatic hydroxydicarboxylic acid and aromatic dicarboxylic acid (both are 100 mol% in total). It is. When p-hydroxybenzoic acid and terephthalic acid 4,4′-dihydroxybiphenyl are 80 mol% or less, the heat resistance tends to decrease, which is not preferable.

  As a method for producing the liquid crystal polyester resin used in the present invention, a known method can be adopted, and a production method only by melt polymerization or a production method by two-stage polymerization of melt polymerization and solid phase polymerization can be used. As a specific example, after a monomer selected from an aromatic dihydroxy compound, an aromatic hydroxycarboxylic acid compound, and an aromatic dicarboxylic acid compound is charged into a reactor, acetic anhydride is added to acetylate the hydroxyl group of the monomer , Produced by deacetic acid polycondensation reaction. For example, p-hydroxybenzoic acid, terephthalic acid, isophthalic acid, and 4,4'-dihydroxybiphenyl are charged into a reactor under a nitrogen atmosphere, acetic anhydride is added, and acetoxylation is performed under acetic anhydride reflux, followed by ascending. The method of manufacturing a polyester resin is mentioned by performing deacetic acid melt polycondensation, heating and distilling acetic acid in the temperature range of 150-350 degreeC. The polymerization time can be selected in the range of 1 hour to several tens of hours. In the production of the liquid crystalline polyester resin used in the present invention, the monomer may or may not be dried before the production.

  When solid phase polymerization is further performed on the polymer obtained by melt polymerization, the polymer obtained by melt polymerization is solidified and then pulverized into powder or flakes, and then a known solid phase polymerization method such as nitrogen A method such as heat treatment at 200 to 350 ° C. for 1 to 30 hours under an inert atmosphere is preferably selected. The solid phase polymerization may be performed with stirring, or may be performed in a standing state without stirring.

  In the polymerization reaction, a catalyst may or may not be used. As the catalyst to be used, those conventionally known as polyester polycondensation catalysts can be used, such as magnesium acetate, stannous acetate, tetrabutylthiocyanate, lead acetate, sodium acetate, potassium acetate, antimony trioxide, etc. And an organic compound catalyst such as N-methylimidazole.

  The polymerization reaction apparatus in the melt polymerization is not particularly limited, but a reaction apparatus used for reaction of a general high viscosity fluid is preferably used. Examples of these reaction apparatuses include, for example, a stirring tank type polymerization reaction apparatus having a stirrer having various types of stirrer blades, a vertical type, a multistage type, a spiral band type, a helical shaft type, or the like, or And a kneader, a roll mill, a Banbury mixer, and the like, which are generally used for resin kneading.

  The shape of the liquid crystalline polyester resin used in the present invention may be any of powder, granule, and pellet, but is preferably powder or granule from the viewpoint of dispersibility when mixed with a filler.

<About talc>
If the talc used for this invention is a well-known talc used as a material which comprises a resin composition, there will be no restriction | limiting in particular on a chemical composition.
However, although the theoretical chemical structure is hydrous magnesium silicate, particularly a natural product, it may contain impurities such as iron oxide and aluminum oxide, and the total amount of impurities contained in talc is 10 mass. It is preferable to use talc that is less than%.
In the present invention, it is considered that the flaky and smooth physical shape is involved in the balance of characteristics relating to rigidity and low wear, but these balances can be most effectively exhibited by the number of laser diffraction methods. The average particle diameter is in the range of 10 to 50 μm. If it is less than 10 μm, handling at the time of compounding is difficult, and the amount of falling off from the surface of the molded product increases. On the other hand, if it exceeds 50 μm, the dispersibility in the molded product is deteriorated and the surface becomes rough, resulting in an increase in the amount of falling off from the surface of the molded product. For this reason, as an average particle diameter, it is preferable that it is 10-50 micrometers.
As a compounding quantity of talc, the range of 50-110 mass parts is preferable with respect to 100 mass parts of liquid crystalline polyester. When the amount of talc exceeds 110 parts by mass, the strength and impact resistance of the composition of the present invention are lowered. Moreover, when the compounding quantity of talc is less than 50 mass parts, the compounding effect is inadequate and the objective of this invention of the fallen substance reduction from the surface of a molded article by the improvement of surface transferability cannot be achieved.

<About carbon black>
The carbon black used in the present invention is not particularly limited and is generally available for use in resin coloring. However, when the primary particle diameter is less than 20 nm, the surface of the resulting molded product has a rough surface (carbon A large number of fine protrusions with agglomerated black are generated and the surface tends to become rough, which is not preferable.
As a compounding quantity of carbon black, the range of 2-10 mass parts is preferable with respect to 100 mass parts of liquid crystalline polyester. If the blending amount of the carbon black is less than 2 parts by mass, the jet blackness of the resulting resin composition will be lowered, and the light-shielding property will be uneasy, and if it exceeds 10 parts by mass, it will be uneconomical. The possibility of occurrence of irregularities increases.

  Further, the composition of the present invention includes an antioxidant and a heat stabilizer (for example, hindered phenol, hydroquinone, phosphites and substituted products thereof), an ultraviolet absorber (in the range not impairing the object of the present invention). Resorcinol, salicylate, benzotriazole, benzophenone, etc.), lubricants and mold release agents (such as montanic acid and salts thereof, esters thereof, half esters thereof, stearyl alcohol, stearamide and polyethylene wax), plasticizers, antistatic agents, flame retardants Ordinary additives such as these and other thermoplastic resins can be added to impart predetermined characteristics.

The liquid crystal polyester resin composition according to the present invention can be obtained by melting the liquid crystal polyester and kneading it with other components. The equipment and operation method used for the melt kneading are generally those used for melt kneading of the liquid crystal polyester. There is no particular limitation.
It is preferable to use a method in which liquid crystal polyester, talc, and (pellet-like) carbon black are introduced from a popper, melt-kneaded, extruded, and pelletized with a kneader having a pair of screws.
These are called twin-screw kneaders. Among these, a rotating mechanism that enables uniform dispersion of the filler by switching and having a mechanism, and between the barrel and the screw that makes it easy to bite. Those having a large air gap and a cylinder diameter of 40 mmφ or more, those having a two-row type, and those having a large mesh between the screws, specifically, having a mesh rate of 1.45 or more are preferable.

<About melt viscosity range>
In the present invention, the liquid crystal polyester resin composition thus obtained needs to have a melt viscosity measured at a shear rate of 100 sec ⁻¹ and 370 ° C. in the range of 10 to 150 (Pa · S). . This is because if the resin viscosity is out of this range, the surface properties of the injection-molded product are deteriorated and the amount of fallen substances increases. The melt viscosity is a capillary rheometer (Model 2010) manufactured by Intesco Corporation, a capillary having a diameter of 1.00 mm, a length of 40 mm, and an inflow angle of 90 °, and a shear rate of 100 sec ⁻¹ from 320 ° C. to + 4 ° C./min. The apparent viscosity is measured while heating at a constant rate at a constant heating rate, and the apparent viscosity at 370 ° C. is obtained.
<About deflection temperature under load>
In the present invention, it is necessary that the deflection temperature under load of the injection-molded product of the liquid crystal polyester resin composition thus obtained is 220 ° C. or higher. Here, the deflection temperature under load means the deflection temperature under load (DTUL) measured according to ASTM D648. This is because if the deflection temperature under load is out of this range, there may be a problem in heat resistance during solder reflow in surface mounting.

  The camera module member of the present invention can be obtained from the above composition by injection molding, but the above melt viscosity range is essential for the molded product to exhibit the desired rigidity and sliding performance. In the case where the minimum thickness of the member is as thin as 0.2 to 0.8 mm, a space having a thickness of 0.2 to 0.8 mm in the mold is obtained by using the resin composition in the melt viscosity range of the above range. When the product is injected and filled at a high speed, a molded product that flows uniformly in the mold and has no compositional deviation can be obtained. The camera module member thus obtained is excellent in wear resistance and rigidity, and is prevented from falling off the surface of the molded product. In addition, the above-mentioned deflection temperature range of load is indispensable for exhibiting the desired solder reflow performance in the molded product.

  The injection molding conditions or injection molding machine used in the present invention is not particularly limited as long as it is a known one generally used for molding liquid crystal polyester.

  EXAMPLES Hereinafter, although an Example and a comparative example demonstrate this invention further more concretely, this invention is not limited to a following example.

(Test method)
The measuring methods and evaluation methods for the performance of the thermotropic liquid crystal polyester resin compositions and molded products obtained therefrom in Examples and Comparative Examples are shown below.
(1) Measurement of melt viscosity The melt viscosity of the thermotropic liquid crystal polyester resin composition is a capillary rheometer (2010 manufactured by Intesco Corporation), and has a diameter of 1.00 mm, a length of 40 mm, and an inflow angle of 90 °. The apparent viscosity was measured while heating at a constant rate from 300 ° C. to + 4 ° C./min at a shear rate of 100 sec ⁻¹ , and the apparent viscosity at 370 ° C. was determined as a test value. In the test, a resin composition dried in advance in an air oven at 150 ° C. for 4 hours was used.
(2) Measurement of weld strength Using an injection molding machine (manufactured by Nissei Plastic Industrial Co., Ltd., UH-1000), the pellets of the obtained resin composition were used, the maximum cylinder temperature was 370 ° C., the injection speed was 300 mm / sec, and the mold temperature. Injection molding was performed at 80 ° C., and an injection molded body having a weld at the center of 13 mm (width) × 80 mm (length) × 1.0 mm (thickness) was used as a test piece for measuring the strength of the weld. About each test piece, the bending strength of the weld part was measured based on ASTM D790 with a span interval of 25 mm.
(3) Measurement of deflection temperature under load (DTUL) Using an injection molding machine (SG-25, manufactured by Sumitomo Heavy Industries, Ltd.), pellets of the resin composition obtained were subjected to a maximum cylinder temperature of 370 ° C. and an injection speed of 100 mm / An injection-molded body of 13 mm (width) × 130 mm (length) × 3 mm (thickness) was obtained at a mold temperature of 80 ° C., and used as a test piece for measuring the deflection temperature under load. About each test piece, the deflection temperature under load was measured based on ASTM D648.
(4) Measurement of the number of omissions The pellets of the obtained resin composition were molded using an injection molding machine (Nissei Resin Co., Ltd., UH-1000), the cylinder maximum temperature 370 ° C., the injection speed 300 mm / sec, the mold Cylindrical injection-molded body (carrier and carrier) having a threaded structure of 0.3 mm pitch and groove depth of 0.2 mm inside 7 mm (outer diameter) × 4 mm (height) × 6 mm (inner diameter) at a temperature of 80 ° C. To obtain a test piece for measuring the number of fallen objects. Two test pieces were put into 266 mL of pure water and subjected to ultrasonic cleaning for 30 seconds at an output of 40 kHz and 480 W. The number of specimens falling in the range of the maximum diameter of 2 μm or more included in 10 mL of pure water after ultrasonic cleaning is measured using SURFEX200 manufactured by Sonac Co., Ltd., and measured three times. The average value was taken as the measurement result.

A production example of liquid crystal polyester (LCP) is shown below.
(Production example Production of thermotropic liquid crystal polyester A)
P-Hydroxybenzoic acid (manufactured by Ueno Pharmaceutical Co., Ltd.) 298 kg (2.16 kgol), 4,4′- in a 1700 L polymerization tank (manufactured by Kobe Steel Co., Ltd.) having a double helical stirring blade made of SUS316. Dihydroxybiphenyl (Honshu Chemical Industry Co., Ltd.) 134 kg (0.72 kgmol), Terephthalic acid (Mitsui Chemicals Co., Ltd.) 90 kg (0.54 kgmol), Isophthalic acid (Ai International Chemical Co., Ltd.) 30 kg ( 0.18 kgmol), 0.04 kg of potassium acetate (manufactured by Kishida Chemical Co., Ltd.) as a catalyst, and 0.10 kg of magnesium acetate (manufactured by Kishida Chemical Co., Ltd.) were charged. After that, 386 kg (3.78 kgol) of acetic anhydride was added, and the rotating speed of the stirring blade was 45 r. 2 hours acetylation reaction was carried out at a Atsushi Nobori to reflux for 1.5 hours 0.99 ° C. by m. After completion of acetylation, acetic acid was distilled off and the temperature was raised at 0.5 ° C./min. When the reactor temperature reached 305 ° C., the polymer was taken out from the outlet at the bottom of the reactor and solidified by cooling with a cooling device. The obtained polymer was pulverized by a pulverizer manufactured by Hosokawa Micron Co., Ltd. into a size passing through a sieve having an opening of 2.0 mm to obtain a prepolymer.
The obtained prepolymer was subjected to solid phase polymerization using a rotary kiln manufactured by Takasago Industry Co., Ltd. The prepolymer was filled in the kiln, nitrogen was passed at a flow rate of 16 Nm 3 / hr, the heater temperature was raised from room temperature to 350 ° C. in 1 hour at a rotation speed of 2 rpm, and the temperature was maintained at 350 ° C. for 10 hours. After confirming that the temperature of the resin powder in the kiln reached 295 ° C., the heating was stopped and the rotary kiln was rotated and cooled for 4 hours to obtain a powdery liquid crystal polyester. The melting point was 360 ° C. and the melt viscosity was 70 Pa · S.
(Production example Production of thermotropic liquid crystal polyester B)
A prepolymer was obtained in the same manner as the thermotropic liquid crystal polyester A.
The obtained prepolymer was subjected to solid phase polymerization using a rotary kiln manufactured by Takasago Industry Co., Ltd. The prepolymer was filled in the kiln, nitrogen was passed at a flow rate of 16 Nm 3 / hr, the heater temperature was raised from room temperature to 350 ° C. in 1 hour at a rotation speed of 2 rpm, and held at 350 ° C. for 9 hours. After confirming that the temperature of the resin powder in the kiln reached 290 ° C., the heating was stopped and the rotary kiln was rotated and cooled for 4 hours to obtain a powdery liquid crystalline polyester. The melting point was 350 ° C. and the melt viscosity was 20 Pa · S.
(Production example Production of thermotropic liquid crystal polyester C)
A prepolymer was obtained in the same manner as the thermotropic liquid crystal polyester A.
The obtained prepolymer was subjected to solid phase polymerization using a rotary kiln manufactured by Takasago Industry Co., Ltd. The prepolymer was filled in the kiln, nitrogen was passed at a flow rate of 16 Nm 3 / hr, the heater temperature was raised from room temperature to 350 ° C. in 1 hour at a rotation speed of 2 rpm, and the temperature was maintained at 350 ° C. for 11 hours. After confirming that the temperature of the resin powder in the kiln reached 300 ° C., the heating was stopped and the rotary kiln was rotated and cooled for 4 hours to obtain a powdery liquid crystalline polyester. The melting point was 370 ° C. and the melt viscosity was 140 Pa · S.

The inorganic filler used in the following examples is shown.
(1) Talc A: “MS-KY” manufactured by Nippon Talc Co., Ltd. (number average particle size 23 μm)
(2) Talc B: “5000S” manufactured by Hayashi Kasei Co., Ltd. (number average particle size 4 μm)
(3) Carbon black (CB): “REGAL 660” (primary particle size: 24 nm), manufactured by Cabot Corporation

Example 1
100 parts by mass of powdered liquid crystalline polyester A obtained in the above production example, 69 parts by mass of talc A, and 3 parts by mass of carbon black were mixed using a ribbon blender, and the mixture was mixed at 150 ° C. in an air oven. Dried for 2 hours. This dried mixture was melt kneaded at an extrusion speed of 140 kg / hr using a twin screw extruder (PCM-30 manufactured by Ikegai Co., Ltd.) with a cylinder diameter of 30 mm set at a maximum temperature of 380 ° C. A pellet of the liquid crystal polyester resin composition was obtained. Each physical property was measured by the test method using the obtained pellet. The results are shown in Table 1.

(Examples 2-3 and Comparative Examples 1-5)
Similar to Example 1, except that powdered liquid crystal polyester, talc, and carbon black have the compositions described in Table 1, pellets of each liquid crystal polyester resin composition were prepared by the same equipment and operation method as in Example 1. Manufactured. Moreover, each physical property was measured with the said test method using the pellet obtained similarly to Example 1. FIG. The results are shown in Table 1.

*note)
1. In all the measurements, those of 30 μm or more were not detected.
2. When the sample after the dropout test of the example composition was ultrasonically cleaned again under the same conditions, almost no dropout was observed, whereas in the comparative composition, the sample was again superheated under the same conditions. When sonic cleaning was performed, the occurrence of further fallen objects (in many cases, generation of 20 or more) was observed.

As shown in Table 1, the liquid crystal polyester resin compositions (Examples 1 to 3) of the present invention have a melt viscosity that falls within the specified range of the present invention, and as a result, exhibit good moldability and fall off. Good results were obtained in that the deflection temperature under load was high and the deflection temperature under load was high.
On the other hand, in the case of a resin composition that deviates from the specified range of the present invention as in Comparative Examples 1 to 5, at least one of the moldability, dropout, and deflection temperature under load was inferior.

  The resin composition for a camera module of the present invention and the camera module component obtained from the composition have high heat resistance, can withstand solder reflow, and have very few falling objects from the component. Lens barrels and mount holders that can be surface-mounted in top computers, digital cameras, digital video cameras, etc. In addition, various types such as “CMOS (image sensor) frame” and “shutter and shutter bobbin” Can be used for applications.

Claims (3)

It is composed of 50 to 110 parts by mass of talc having a number average particle size of 10 to 50 μm and 2 to 100 parts by mass of carbon black with respect to 100 parts by mass of the liquid crystalline polyester, the deflection temperature under load is 220 ° C. or higher, and the shear rate is 100 sec ^−1. A liquid crystal polyester resin composition for a camera module, having a melt viscosity at 370 ° C. of 10 to 150 Pa · s. 2. The liquid crystal polyester resin composition according to claim 1, wherein the number of fallen objects from the surface of the molded product molded by injection molding is 200 or less.
Number of falling objects: An injection molded body having a threaded structure with a pitch of 0.3 mm and a groove depth of 0.2 mm on the inner surface of a cylinder having an outer diameter of 70 mm, an inner diameter of 60 mm, and a height of 0.5 mm is obtained at 40 kHz, 480 W in 266 mL of pure water. Of particles having a maximum diameter in the range of 2 μm or more in 10 mL of pure water after ultrasonic cleaning for 30 seconds at an output of   A camera module component produced by injection molding from the liquid crystal polyester resin composition according to claim 1 or 2.