JP6962546B2 - Plate-shaped molded product and its manufacturing method - Google Patents

Description

The present invention relates to a plate-shaped molded product containing a polyester resin as a main component, containing carbon fibers and glass fibers in a specific amount, and having conductive performance excellent in static electricity removal performance, and a method for producing the same.

Many of the electronic components in recent years, especially IC-related components, are sensitive to the effects of dust adhesion and dirt due to static electricity. Therefore, materials such as jigs and transport pallets used in the manufacturing process of such electronic parts are required to have conductive performance capable of satisfactorily removing static electricity.

Conventionally, a resin composition containing a thermosetting resin or a thermoplastic resin as a main component has been widely used to satisfy such a requirement. Examples of the thermosetting resin used include those in which glass cloth is impregnated with epoxy resin, those in which paper or cloth is impregnated with phenol resin, and the like. Thermosetting resin, excellent mechanical properties and heat resistance and the like, have the advantage of dimensional change is small, the conductive performance is not sufficient, the degree surface resistivity less 10 ¹⁰ Omega, among them 10 ⁸ Omega degree or less It was difficult to do.

In addition, thermosetting resin has the disadvantage of being hard and brittle, so a large amount of dust is generated during cutting, and the end face of the processed product is chipped into powder due to material deterioration during long-term use. There was a problem that it adversely affected the product.

On the other hand, vinyl chloride resin, nylon resin, those using the thermoplastic resin represented by polyester resin is good machinability, degree surface resistivity less 10 ¹⁰ Omega, among them 10 ⁸ Omega less degree of conductivity performance There was no excellent material, and it could not be suitably used as a material for jigs and transport pallets used in the manufacturing process of electronic parts and the like.

Patent Document 1 describes a polyester resin-containing sheet obtained by extruding a resin composition obtained by blending a thermoplastic polyester resin with a fibrous reinforcing material, a granular inorganic compound, and an antistatic agent. , A laminated plate in which a plurality of the sheets are stacked and heat-rolled to integrate them is described.

The sheet and laminated board described in Patent Document 1 use an anionic surfactant as an antistatic agent, and use a polyester resin having excellent crystallinity as a thermoplastic polyester resin as a main component. There, as the conductive performance, the surface resistance value was of ^{10 8} Ω~10 10 Ω. Therefore, the conductive performance is insufficient, and although the static electricity removing performance is provided to some extent, the static electricity cannot be sufficiently removed.

In addition, when jigs, transport pallets, etc. used in the manufacturing process of electronic parts are obtained by cutting a plate-shaped molded body, if the conductive performance of the plate-shaped molded body varies, the obtained cutting is performed. The conductive performance of the processed product also varies. Therefore, the uniformity of the conductive performance in the entire plate-shaped molded body has been required.

Japanese Unexamined Patent Publication No. 10-279704

The present invention solves the above-mentioned problems, has conductivity capable of sufficiently removing static electricity, has excellent uniformity of conductive performance in the entire plate-shaped molded product, and has excellent mechanical properties and the like. It is a technical subject to provide a plate-shaped molded product that can be suitably used as a material for jigs and transport pallets used in the manufacturing process of electronic parts and the like.

The present inventors have arrived at the present invention as a result of repeated diligent studies to solve the above problems.
That is, the gist of the present invention is the following (1) and (2).
(1) It is formed of a resin composition (M) containing 15 to 60 parts by mass of carbon fiber (B) and 10 to 30 parts by mass of glass fiber (C) with respect to 100 parts by mass of polyester resin (A). It is a plate-shaped molded product having a thickness of 0.5 to 90 mm, has a half-life of 40 seconds or less, and has a surface resistance of 1 × 10 ² to 1 × 10 ¹⁰ Ω. Plate-shaped molded body.
(2) 15 to 60 parts by mass of carbon fiber (B) and 10 to 30 parts by mass of glass fiber (C) were mixed with 100 parts by mass of polyester resin (A) to obtain a resin composition (M). The method for producing a plate-shaped molded product according to (1), wherein a sheet is formed by extrusion molding, two or more of the sheets are laminated, and heat-rolled.

The plate-shaped molded body of the present invention is made of a polyester resin composition containing a specific amount of carbon fiber and glass fiber, and has a specific voltage band half-life and surface resistance as conductive performance capable of sufficiently removing static electricity. And also has excellent mechanical properties. Therefore, the plate-shaped molded product of the present invention can be suitably used as a material for parts and jigs used in the vicinity of the manufacturing process of electronic parts, or as a material for transport pallets and the like.
Furthermore, since the plate-shaped molded product of the present invention is also excellent in the uniformity of conductive performance over the entire surface of the plate-shaped molded product, it is possible to suppress variations in the conductive performance of the processed product obtained by cutting. ..
Then, according to the method for producing a plate-shaped molded product of the present invention, it is possible to obtain a plate-shaped molded product that satisfies the characteristic values of the present invention and has a small variation in conductivity performance and mechanical characteristics in the thickness direction with good productivity. can.

It is a schematic diagram which shows the marking method for taking the measurement sample at the time of measuring the half-life of the band voltage of a plate-shaped molded body, the surface resistivity and the coefficient of variation in the surface resistivity.

Hereinafter, the present invention will be described in detail.
The plate-shaped molded body of the present invention is formed of a resin composition (M), and the resin composition (M) contains a polyester resin (A), carbon fibers (B), and glass fibers (C). It is a thing.
First, the polyester resin (A) will be described. Examples of the polyester resin (A) include polyethylene terephthalate, polybutylene terephthalate, polyethylene naphthalate, polybutylene naphthalate, polycyclohexylene methylene terephthalate, and the like, but carbon fiber (B), glass fiber (C), and granular inorganic material. In the polyester resin (A) of the compound (granular layered silicate mineral (D), granular conductive filler (E), and granular glass filler (F) may be collectively referred to as "granular inorganic compound"). In consideration of the dispersibility of the above, a copolymerized polyester resin containing a copolymerization component is preferable.

Among them, the polyester resin (A) is preferably a polyester resin containing ethylene terephthalate as a main repeating unit and isophthalic acid as a copolymerization component in an amount of 4 to 15 mol% (hereinafter, may be referred to as IPA copolymerization PET).
By using such a copolyester resin, it becomes easy to perform laminating molding of sheets in the manufacturing method of the present invention as described later, and it is possible to suppress variations in the conductive performance of the obtained plate-shaped molded product. This is because the crystallinity of the polyester resin is lowered by containing an appropriate amount of isophthalic acid as a copolymerization component, so that the polyester resin (A) of the carbon fiber (B), the glass fiber (C) and the granular inorganic compound is contained. It is presumed that this can be achieved by improving the dispersibility of.

The polyester resin (A) preferably has an ultimate viscosity of 0.9 to 1.3, particularly 1.0, in consideration of the moldability when obtaining the plate-shaped molded product and the mechanical properties of the plate-shaped molded product. It is preferably ~ 1.2. When the ultimate viscosity is less than 0.9, the strength of the obtained plate-shaped molded product tends to decrease. On the other hand, if the ultimate viscosity exceeds 1.3, the cost and moldability for obtaining the plate-shaped molded product deteriorate, and it becomes particularly difficult to obtain the plate-shaped molded product having a laminated structure.

The plate-shaped molded body of the present invention requires carbon fibers (B) and glass fibers (C), and as granular inorganic compounds, layered silicate mineral (D), granular conductive filler (E), and granular glass filler (granular glass filler). It is preferable to include F) and the like. Among them, since it contains a large amount of carbon fibers (B), the adhesiveness tends to deteriorate when a plurality of sheets are laminated to form the plate-shaped molded product of the present invention. However, by using IPA copolymerized PET as the polyester resin, the adhesiveness between the sheets during the thermal rolling process is improved due to the low crystallinity, and the plate-shaped molded product having a laminated structure with excellent adhesion between the sheets. Can be obtained.

By containing carbon fiber (B), glass fiber (C), granular inorganic compound, etc., the crystallization rate of the polyester resin tends to be high, but in addition, when the crystallization rate of the polyester resin is high, when the sheet is formed, It becomes difficult to obtain a sheet in which carbon fibers (B), glass fibers (C) and granular inorganic compounds are uniformly dispersed. However, by using IPA copolymerized PET as the polyester resin, the crystallization rate can be set to an appropriate level, so that the dispersibility of these in the polyester resin (A) is improved, and the conductivity performance and mechanical performance are improved. It is possible to obtain a sheet in which the characteristics (strength, etc.) are sufficiently exhibited and there is little variation in both performances.

If the copolymerization amount of isophthalic acid in the polyester resin (A) is less than 4 mol%, the crystallinity becomes high, so that the adhesiveness between the sheets as described above cannot be improved, and the adhesive force between the sheets cannot be improved. Becomes weaker and peeling is more likely to occur. Further, in order to prevent this, it is necessary to raise the heat treatment temperature and pressure during hot press molding. Further, the dispersibility of the carbon fibers (B), the glass fibers (C) and the granular inorganic compound in the polyester resin (A) is deteriorated, and the obtained plate-shaped molded product has insufficient conductivity and mechanical properties. It is easy for both performances to vary.
On the other hand, if the copolymerization amount of isophthalic acid in the polyester resin (A) exceeds 15 mol%, the crystallinity becomes too low, and the obtained plate-shaped molded product becomes inferior in heat resistance. In addition, the crystallization rate of the polyester resin composition during sheet molding becomes too slow, resulting in poor productivity.

Next, the carbon fiber (B) will be described. The carbon fiber (B) is for imparting conductivity and mechanical strength to the plate-shaped molded product, and is contained in an amount of 15 to 60 parts by mass with respect to 100 parts by mass of the polyester resin (A). Of these, it is preferably contained in an amount of 20 to 45 parts by mass.

If the content of carbon fibers with respect to 100 parts by mass of the polyester resin (A) is less than 15 parts by mass, the conductive performance of the obtained plate-shaped molded product becomes low, and the half-life of the voltage band exceeds 40 seconds. , The surface resistivity ^{exceeds 1 × 10 10} Ω. In addition, the strength of the plate-shaped molded product is also reduced. On the other hand, if the content of carbon fibers exceeds 60 parts by mass, the moldability when obtaining a sheet-shaped molded product tends to deteriorate, and the adhesiveness between the sheets when a plurality of sheets are laminated to obtain a plate-shaped molded product. Also gets worse.

Examples of the carbon fiber (B) in the present invention include polyacrylonitrile-based (PAN-based) and pitch-based carbon fibers having high strength and high conductivity. Of these, chopped fibers obtained by cutting carbon fibers to a specific length are preferable.
Specific examples of PAN-based carbon fibers include Beth Fight Chopped Fiber and Beth Fight Milled Fiber manufactured by Toho Rayon, Treca Chopped Fiber and Treka Milled Fiber manufactured by Toray, and Pyrofil manufactured by Mitsubishi Rayon. Fortafil manufactured by Fortafil Fiber, chopped fiber manufactured by Nippon Polymer Sangyo Co., Ltd. (CFEPU, etc.) can be mentioned, and specific pitch-based carbon fibers include donacabo chopped fiber and donacabo milled fiber manufactured by Osaka Gas Co., Ltd. , Creca chopped fiber and Creca milled fiber manufactured by Kureha Kagaku Co., Ltd. can be mentioned.

The carbon fiber (B) preferably has a fiber length of 0.1 to 7 mm before being blended with the polyester resin (A), and particularly preferably 1 to 6 mm. Further, the fiber diameter is preferably in the range of 5 to 15 μm.

Next, the glass fiber (C) will be described. The glass fiber (C) is for imparting mechanical strength to the plate-shaped molded body, and is contained in an amount of 10 to 30 parts by mass with respect to 100 parts by mass of the polyester resin (A), and among them, 14 to 30 parts by mass. It is preferably contained in an amount of 25 parts by mass.
If the content of the glass fiber (C) is less than the above range, the mechanical strength of the plate-shaped molded product is insufficient. On the other hand, when the amount exceeds the above range, the anisotropy due to the inclusion of the glass fiber becomes remarkable, and the conductive performance of the plate-shaped molded product varies. In addition, the surface smoothness is deteriorated, and the adhesiveness between the sheets is deteriorated when a plurality of sheets are laminated.

The glass fiber (C) preferably has a fiber length of 0.1 to 7 mm before being blended with the polyester resin (A), and more preferably 0.3 to 5 mm. The fiber diameter is preferably 3 to 20 μm, and more preferably 9 to 15 μm.

It is effective to use the glass fiber (C) treated with various compounds for the purpose of improving the interfacial adhesive force with the polyester resin (A) as the main component and improving the reinforcing effect. For example, vinyl ethoxysilane, γ-methacryloxypropyltrimethoxysilane, β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-glycidoxyp, lopiltrimethoxysilane, γ-chloropropyltrimethoxysilane, γ- Those treated with a silane-based treatment agent such as aminopropyltrimethoxysilane or γ-mercaptopropyltrimethoxysilane, or a chromium-based treatment agent such as methacrylate chromic chloride are preferable.

Next, the granular layered silicate mineral (D) will be described. Specifically, mica, talc, kaolin, montmorillonite and the like can be used. Of these, mica and talc are preferable, and mica can be particularly preferably used.

The above-mentioned granular layered silicate mineral (D) is used for the purpose of relaxing the orientation of carbon fibers (B) and glass fibers (C). That is, if only the carbon fiber (B) and the glass fiber (C) are blended with the polyester resin (A), orientation occurs in these fibrous reinforcing materials, which is not suitable for extrusion molding and is not only a plate-shaped molded body. Fibers tend to float or warp on the surface of the resin. Therefore, when the granular layered silicate mineral (D) is added to the resin composition (M), the anisotropy of these fibrous reinforcing materials is alleviated, and the fibers on the surface of the plate-shaped molded body are lifted or warped. It can be suppressed.

In order to enhance such an effect, the average particle size of the granular layered silicate mineral (D) is preferably 500 μm or less, and more preferably 1 to 300 μm. The content of the granular layered silicate mineral (D) in the resin composition (M) is 3 to 30 mass by mass with respect to 100 parts by mass of the polyester resin in terms of balance such as mechanical strength and surface smoothness. The amount is preferably 10 to 25 parts by mass. If the content of the granular layered silicate mineral (D) is less than 3 parts by mass, the effect of improving the mechanical strength and surface smoothness is poor, and when a plurality of sheets are laminated and hot-rolled. It tends to be inferior in stackability. On the other hand, if the content exceeds 30 parts by mass, the mechanical strength of the sheet or the laminated board is lowered, which is not preferable.

Further, in the resin composition (M) for forming the plate-shaped molded product of the present invention, at least one of the granular conductive filler (E) and the granular glass filler (F) is added to 100 parts by mass of the polyester resin (A). Therefore, it is preferably contained in an amount of 1 to 20 parts by mass, and more preferably 5 to 20 parts by mass. The granular conductive filler (E) can form an electrical conduction path between the carbon fibers when the carbon fibers (B) are too oriented and the electrical conduction path is reduced, thereby improving the conductivity performance. It is a thing. Further, it contributes to the uniformity of the conductive performance over the entire plate-shaped molded body. Further, when the carbon fibers (B) are oriented too much and the electrical conduction path is reduced, the granular glass filler (F) can appropriately disturb the orientation and form an electrical conduction path between the carbon fibers. This can improve the conductive performance.

When the content of these granular fillers is less than the above range, an electric conduction path cannot be sufficiently formed between the carbon fibers, and the conductivity performance and the uniformity of the conductivity performance cannot be improved. On the other hand, when the content of these fillers is larger than the above range, the surface smoothness of the sheet or plate-shaped molded product tends to deteriorate.

The granular conductive filler (E) in the present invention may have a granular shape with an average particle size of 100 μm or less and has conductivity, and artificial graphite powder is particularly preferable. The average particle size is preferably 20 to 60 μm.
Further, as the granular glass filler (F), glass beads having an average particle size of 100 μm or less are preferable, and among them, the average particle size of the glass beads is preferably 20 to 60 μm.

The plate-shaped molded body of the present invention is formed of the resin composition (M) as described above, and has a characteristic value indicating conductive performance such that the half-life of the voltage band is 40 seconds or less and the surface surface. The resistivity is 1 × 10 ² to 1 × 10 ¹⁰ Ω.

The half-life of the voltage band attenuation in the plate-shaped molded product of the present invention is measured as follows. The plate-shaped molded body is divided into approximately two equal parts in the vertical direction and roughly divided into two equal parts in the horizontal direction, and the plate-shaped molded body is divided into approximately four equal parts and divided into four areas (the plate-shaped molded body is divided by a diagram). Or cut out four areas). In each area, 10 to 15 samples (length 42 mm, width 42 mm) are randomly cut out and measured according to the JIS L 1094 A method (half-life measurement method). At this time, while rotating the turntable, (-) 10 KV is applied for 30 seconds, then the application is stopped, and while rotating the turntable as it is, the band voltage is attenuated to 1/2 of the initial band voltage. Measure the time (seconds). The distance between the electrodes is 15 mm for both power reception and discharge, and the turntable rotation speed is 1550 rpm. Then, the average value of n = 40 to 60 is calculated and used as the half-life of the band voltage. When the number of samples cut out from one plate-shaped molded product is less than 40, a plurality of plate-shaped molded products are used so that the number of samples is 40 to 60.

The surface resistivity of the plate-shaped molded product of the present invention is measured as follows.
The plate-shaped molded body is divided into approximately two equal parts in the vertical direction and approximately two equal parts in the horizontal direction, and the plate-shaped molded body is divided into approximately four equal parts (the plate-shaped molded body is divided into four areas according to a diagram). Divide or cut out 4 areas). In each area, 10 to 15 measurement points (length 20 mm, width 20 mm) are randomly marked. At each measurement point, the surface resistivity is measured using HIRESTA UX MCP-HT800 (ring probe type) manufactured by Mitsubishi Chemical Analytech Co., Ltd. with a measurement voltage of 10 V. Then, the average value of the values measured at 40 to 60 points (n = 40 to 60) is calculated and used as the surface resistivity. When the number of measurement points to be marked on one plate-shaped molded product is less than 40, a plurality of plate-shaped molded products are used so that the measurement points are 40 to 60.

When measuring the half-life and surface resistivity of the voltage band, these values shall be measured on the cut surface of the plate-shaped molded body after cutting the surface of the plate-shaped molded body to a thickness of 100 μm.

The plate-shaped molded product of the present invention efficiently removes static electricity from the processed product obtained by cutting the plate-shaped molded product by satisfying the above-mentioned half-life of the band voltage and the surface resistance within a specific range. It can be suitably used for jigs, transport pallets, etc. used in the manufacturing process of electronic parts.

The half-life of the voltage band of the plate-shaped molded product is preferably 35 seconds or less, more preferably 30 seconds or less, more preferably 20 seconds or less, and preferably 10 seconds or less. Most preferred. If the half-life of the withstand voltage exceeds 40 seconds, the processed product obtained from the plate-shaped molded product becomes inferior in static electricity removal performance, and it becomes difficult to use it in the manufacturing process of electronic parts.

The surface resistivity of the plate-shaped molded product ^{is preferably 1 × 10 3} to 1 × 10 ⁹ Ω, and more preferably 1 × 10 ⁴ to 1 × 10 ⁸ Ω. If the surface resistivity of the plate-shaped molded product is ^{less than 1 × 10 2} Ω, the conductivity becomes too good, which may adversely affect the electronic components, which is not preferable. On the other hand, if the surface resistivity ^{exceeds 1 × 10 10} Ω, the static electricity removal performance becomes inferior, and it becomes difficult to use it in the manufacturing process of electronic parts.

Further, the plate-shaped molded product of the present invention preferably has a coefficient of variation in surface resistivity of 250 or less, more preferably 220 or less, and further preferably 180 or less.
The coefficient of variation in the surface resistivity of the present invention is an index showing the variation in the surface resistivity. The coefficient of variation is obtained by calculating the standard deviation of the measured values of n = 40 to 60 measured at the above-mentioned surface resistivity, dividing by the average value of the surface resistivity and multiplying by 100.

Since the plate-shaped molded product has a coefficient of variation of 250 or less in the surface resistivity, the conductive performance becomes uniform over the entire surface of the plate-shaped molded product. As a result, the conductive performance of the plurality of processed products (products) obtained by cutting becomes uniform, and it becomes possible to obtain a product having excellent static electricity removal performance with high productivity.

The plate-shaped molded product of the present invention has a thickness of 0.5 to 90 mm, preferably 1 to 80 mm, and more preferably 5 to 60 mm. If the thickness is less than 0.5 mm, it becomes difficult to perform cutting. On the other hand, if the thickness exceeds 90 mm, the conductive performance and the mechanical properties in the thickness direction tend to vary, and the conductive performance of the product obtained by cutting becomes inferior in uniformity.

The plate-shaped molded product of the present invention is preferably formed by laminating two or more sheets having a thickness of 0.1 mm or more. Above all, it is preferable that three or more sheets having a thickness of 0.2 to 1.2 mm are laminated. A plate-shaped molded product having such a laminated structure can be produced by a production method described later.
By forming the plate-shaped molded product of the present invention into the above-mentioned laminated structure, the conductive performance and mechanical properties are sufficiently exhibited, and the plate-shaped molded product is conductive in the surface (longitudinal direction) and the thickness direction. It is possible to suppress variations in performance and mechanical characteristics. That is, since the conductive performance is sufficiently exhibited in each of the sheets, the conductive performance is sufficiently exhibited in the plate-shaped molded body as a whole, and the variation in the conductive performance is suppressed over the entire surface of the molded body.

The mechanical properties of the plate-shaped molded product of the present invention are that the bending strength is 80 to 400 MPa in the MD direction (resin flow direction) and 80 to 140 MPa in the TD direction (perpendicular to the resin flow direction). Is preferable. Further, the flexural modulus is preferably 5 to 20 GPa in the MD direction and 5 to 8 GPa in the TD direction. The bending strength and flexural modulus are measured based on ASTMD790.

Next, a method for producing the plate-shaped molded product of the present invention will be described. A resin composition (M) is obtained by blending a polyester resin (A) with carbon fibers (B), glass fibers (C) and, if necessary, a granular inorganic compound. Specifically, using a twin-screw extruder, these are melt-kneaded and extruded into strands to prepare pellets.
Using these pellets, a sheet is produced by an extrusion sheet molding apparatus equipped with a T-die. At this time, the thickness of the sheet is preferably in the range of 0.1 to 2 mm from the viewpoint of sheet moldability and surface smoothness of the sheet, and particularly preferably in the range of 0.2 to 1.5 mm.

In the manufacturing method of the present invention, a laminated plate (plate-shaped molded body) integrated by stacking a plurality of the sheets obtained as described above and hot-rolling them is manufactured.
When hot rolling, it is preferable to use a hot press molding machine, and the heating temperature as a pressing condition needs to be higher than the glass transition point of the polyester resin (A), so this heating temperature is 100 to 260 ° C. It is preferably in the range. Further, the faster the rate of temperature rise, the easier it is to stack, so it is preferable to set the temperature in the range of 3 to 20 ° C./min. More preferably, the heating temperature is in the range of 120 to 200 ° C. and the heating rate is in the range of 5 to 10 ° C./min. The pressing force during pressing is preferably 15 to 100 kg / cm ^{2, and} more preferably 30 to 80 kg / cm ² . The pressing holding time is preferably 3 to 20 minutes, more preferably 5 to 15 minutes.

Since the plate-shaped molded product of the present invention contains a large amount of carbon fibers (B) in the resin composition (M) and also contains glass fibers (C) and the like, when it is formed into a sheet. It is difficult to evenly disperse these in both the thickness direction and the longitudinal direction and to orient them appropriately. In particular, when the plate-shaped molded product of the present invention has a single-layer structure and a large thickness, it becomes difficult to uniformly disperse them in the thickness direction and the longitudinal direction. As a result, not only the conductive performance but also the mechanical properties (strength, etc.) are not sufficiently exhibited, and both performances have a large variation in the thickness direction and the longitudinal direction.

By adopting the manufacturing method of the present invention, it is possible to solve the problems in the case of forming a plate-shaped molded product having a single-layer structure as described above. That is, since each sheet constituting the plate-shaped molded body has a small thickness and a small variation in conductive performance, the plate-shaped molded body obtained by thermally rolling these sheets has a conductive performance over the entire surface of the molded body. It is excellent and also has excellent uniformity of conductive performance. Therefore, even if the plate-shaped molded body has a large thickness, the conductive performance and mechanical properties are sufficiently exhibited and the variation in these performances is small by forming a laminated structure in which a plurality of sheets are laminated. It becomes possible to.

As described above, the plate-shaped molded product of the present invention has excellent conductive performance in static electricity removal performance, and the variation in conductive performance is small in the longitudinal direction, the width direction, and the thickness direction of the plate-shaped molded product. Even when a small processed product is obtained by cutting, a product having excellent uniformity of conductive performance can be obtained. Therefore, the plate-shaped molded product of the present invention can be suitably used as a material for parts and jigs used in the vicinity of the manufacturing process of electronic parts, or as a material for transport pallets and the like. Furthermore, it can be used as a material for various electronic parts, industrial parts, home appliances, and the like.

Next, the present invention will be specifically described based on Examples. The measurement of various physical property values in the examples was carried out by the following method.
(1) Sheet formability: Evaluation was made in the following three stages according to the situation when the sheet was extruded (continuous operation for 12 hours).
◯: No sheet breakage occurs △: Some sheet breakage occurs but sheet formation is possible ×: Sheet breakage occurs frequently and sheet formation is not possible

(2) Half-life of voltage band of plate-shaped molded product: Measured by the above method. The plate-shaped molded body (width direction: 1020 mm, longitudinal direction: 1190 mm) is roughly divided into two equal parts in the vertical direction and roughly two equal parts in the horizontal direction, and is divided into four areas as shown in FIG. In the area of, 12 measurement points (length 42 mm, width 42 mm) were marked, and samples (length 42 mm, width 42 mm) were cut out at each of the total 48 measurement points, and STTIC HONESUTOMETER S- made by Sisid Electrostatic Co., Ltd. Measurements were made using a model 5109 at 23 ° C. and 50% RH (n = 48). Further, when cutting the surface of the plate-shaped molded body to a thickness of 100 μm, a general-purpose milling cutter 2MW manufactured by Hitachi Koki Co., Ltd. was used.

(3) Coefficient of variation in surface resistivity and surface resistivity of plate-shaped molded product: Measured and calculated by the above method. Similar to (2), the plate-shaped molded body (width direction: 1020 mm, longitudinal direction: 1190 mm) is roughly divided into two equal parts in the vertical direction and roughly two equal parts in the horizontal direction, and as shown in FIG. 1, 4 It was divided into two areas, and 12 measurement points (length 20 mm, width 20 mm) were marked in each area. The surface resistance values were measured at a total of 48 measurement points (n = 48). Further, when cutting the surface of the plate-shaped molded body to a thickness of 100 μm, a general-purpose milling cutter 2MW manufactured by Hitachi Koki Co., Ltd. was used.

(4) Bending strength and flexural modulus: The size (MD direction: 20 mm) of the obtained plate-shaped molded body along the resin flow direction (MD direction) and the direction perpendicular to the resin flow direction (TD direction). , TD direction: 150 mm), 10 samples were cut out. Each sample was measured according to the method described in ASTM-D790, and the average value was calculated. An autograph AG-1 manufactured by Shimadzu Corporation was used as the measuring machine, and the test speed was set to 5 mm / min.

(5) Stackability: The state of adhesion between each sheet of the obtained plate-shaped molded product was visually observed and evaluated in the following three stages.
◯: Delamination between sheets did not occur Δ: Delamination between sheets occurred in part ×: Delamination between sheets occurred on the entire surface during thermal rolling, and lamination by thermal rolling was not possible.

(6) Machinability: The obtained plate-shaped molded body is milled using a cutting tool having a carbide tip, and the surface roughness of the machined surface is measured by a surface roughness meter (Mitsutoyo Co., Ltd., Surf Test 201). ), And evaluated in the following three stages using the numerical value of the maximum height Rmax as an index. The milling was performed under the conditions of a blade rotation speed of 1000 rpm and a feed rate of 500 mm / min.
◯: Rmax of the machined surface is less than 10 μm.
Δ: Rmax of the machined surface is 10 μm or more and less than 20 μm. Alternatively, although the Rmax of the machined surface is less than 10 μm, some chips are generated in the machined part.
X: Rmax of the machined surface is 20 μm or more. Alternatively, although the Rmax of the machined surface is less than 20 μm, a large amount of chips are generated in the machined part.

〔raw materials〕
(Polyester resin)
A-1: Unitika Ltd. "SA-1346P" (polyethylene terephthalate copolymerized with 8 mol% of isophthalic acid, ultimate viscosity 1.09)
-A-2: "SA-1206P" manufactured by Unitika Ltd. (polyethylene terephthalate, ultimate viscosity 1.07)
-A-3: "MA-1344" manufactured by Unitika Ltd. (polyethylene terephthalate copolymerized with 8 mol% of isophthalic acid, ultimate viscosity 0.72)
(Carbon fiber)
B-1: "CFEPU-LCL C5" manufactured by Nippon Polymer Sangyo Co., Ltd. Fiber length 6 mm
(Glass fiber)
C-1: PPG "HP3786" fiber length 3 mm
(Granular layered silicate mineral)
-D-1: "S200" manufactured by Mica Repco Co., Ltd. Average particle size 55 μm
(Granular conductive filler)
-E-1: Artificial graphite manufactured by Marutoyo Casting Co., Ltd. Average particle size 32 μm
(Granular glass filler)
・ F-1: UBS-0030E manufactured by Union Co., Ltd. Average particle size: 30 μm
(Anionic surfactant)
・ G-1: Chemistat 3033 manufactured by Sanyo Kasei Co., Ltd.

Example 1
A resin composition obtained by blending 100 parts by mass of polyester resin (A-1) with 35 parts by mass of carbon fiber (B-1), 16 parts by mass of glass fiber (C-1), and 25 parts by mass of mica (D-1). (M) was obtained. This resin composition (M) was melt-kneaded at 280 ° C. using a twin-screw extruder, extruded into strands, cooled, and cut to obtain pellets.
These pellets were used as a raw material for a sheet and supplied to an extrusion sheet molding apparatus equipped with a T-die to prepare a polyester resin-containing sheet having a thickness of 0.63 mm.
Next, 11 of the above sheets were prepared, and the polyester resin-containing sheet was ^{heated at a pressure of 70 kg / cm 2} from room temperature to 180 ° C. at a heating rate of 5 to 10 ° C./min using a 17-stage multi-stage heat press molding machine. While pressing, the press state was held at 180 ° C. for 15 minutes, and then quickly cooled, and a plate-shaped molded product having a thickness of 6 mm (11 sheets were laminated, and each sheet had a thickness of 0. 55 mm) was obtained. At this time, a matted aluminum alloy plate having a thickness of 2 mm was used as the press plate.

Examples 2 to 7 , Comparative Examples 1 to 8
As the resin composition (M) used as a raw material for a sheet, pellets were obtained in the same manner as in Example 1 except that a predetermined amount of the raw material shown in Table 1 was used.
Using these pellets as a raw material for a sheet, a sheet was prepared in the same manner as in Example 1, and the obtained sheet was thermally rolled in the same manner as in Example 1 to obtain a plate-shaped molded product having a thickness of 6 mm.

Table Example 1 7 and Comparative Examples 1 to formability evaluation results of the sheet 8, Example 1 to 7 evaluated the characteristic value of the obtained plate-shaped molded body in Comparative Example 1-8 Results Shown in 1.

As is clear from Table 1, in Examples 1 to 7 , the formability of the sheet was good, and the obtained plate-shaped molded product was also excellent in stackability and machinability. Since the half-life of the band voltage and the surface resistivity were within the range of the present invention, the static electricity removal performance was excellent. Furthermore, the coefficient of variation in the surface resistivity was 250 or less, and the uniformity of the conductive performance was excellent over the entire surface of the plate-shaped molded product. Furthermore, it was also excellent in mechanical properties such as strength and elastic modulus.

On the other hand, in Comparative Examples 1 and 3, since the carbon fiber content was small, the obtained plate-shaped molded product had a half-life of the voltage band and a surface resistivity outside the range of the present invention, and the static electricity removal performance was improved. It was inferior. In Comparative Example 2, since the content of carbon fibers was too large, the sheet formability was poor, and the obtained plate-shaped molded product was inferior in stackability and machinability. In Comparative Example 4, since the content of the glass fiber was too large, the adhesiveness between the sheets deteriorated, and when pressing while heating, delamination between the sheets occurred on the entire surface, and a plate-shaped molded product could be obtained. could not. In Comparative Examples 5 and 6, an anionic surfactant was used instead of the carbon fiber as the conductive substance, so that the obtained plate-shaped molded product had both the half-life of the voltage band and the surface resistivity of the present invention. It was out of the range and was inferior in static electricity removal performance.

Claims (6)

The thickness is formed of the resin composition (M) containing 15 to 60 parts by mass of carbon fiber (B) and 10 to 30 parts by mass of glass fiber (C) with respect to 100 parts by mass of the polyester resin (A). The polyester resin (A) is a plate-shaped molded product having a size of 0.5 to 90 mm, and the polyester resin (A) is a polyester resin containing ethylene terephthalate as a main repeating unit and isophthalic acid as a copolymerization component in an amount of 4 to 15 mol%. A plate-shaped molded product having a voltage half-life of 40 seconds or less and a surface resistance of 1 × 10 ² to 1 × 10 ^{10 Ω.} The plate-shaped molded product according to claim 1, wherein the coefficient of variation in the surface resistivity is 250 or less. The first or second claim, wherein the resin composition (M) contains 3 to 30 parts by mass of the granular layered silicate mineral (D) with respect to 100 parts by mass of the polyester resin (A). Plate-shaped molded body. The resin composition (M) contains at least one of the granular conductive filler (E) and the granular glass filler (F) in an amount of 1 to 20 parts by mass with respect to 100 parts by mass of the polyester resin (A). The plate-shaped molded product according to any one of claims 1 to 3. The plate-shaped molded product according to any one of claims 1 to 4, wherein two or more sheets having a thickness of 0.1 mm or more are laminated. 15 to 60 parts by mass of carbon fiber (B) and 10 to 20 parts by mass of glass fiber (C) are mixed with 100 parts by mass of polyester resin (A), and the obtained resin composition (M) is extruded and molded. The method for producing a plate-shaped molded product according to any one of claims 1 to 5, wherein a sheet is formed by this method, two or more of the sheets are laminated, and hot-rolled.

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