JP2009096138A - Conductive laminated sheet - Google Patents

Abstract

Disclosed is a conductive laminated sheet made of a biodegradable resin having excellent moldability, rigidity, and bending strength.
The conductive laminated sheet of the present invention comprises a layer (I layer) containing a thermoplastic resin (A) and a conductive agent (B), a polystyrene resin (C), a polylactic acid resin (D), and And a layer (II layer) containing an elastomer (E). The I layer is preferably formed as a front surface layer and a back surface layer, and the II layer is preferably formed as an intermediate layer. In the I layer, the conductive agent (B) is 1% by mass to 30% by mass in the layer, and in the II layer, the polylactic acid resin (D) is 10% by mass to 50% by mass in the layer. Hereinafter, the elastomer (E) is preferably blended in a proportion of 5% by mass or more and 20% by mass or less in the layer.
[Selection figure] None

Description

  The present invention relates to a conductive laminated sheet used for a carrier tape or the like.

  Plastics are now pervasive in every field of life and industry, with annual production of around 100 million tons worldwide. Most of them are discarded after use, and this has been recognized as one of the causes that disturb the global environment. For this reason, effective use of exhaustible resources has been emphasized in recent years, and the use of renewable resources has become an important issue. Currently, the most noticeable solution is the use of plant-based plastics. Plant-based plastics can not only use non-depleted resources, save exhaustible resources during plastic production, but also have excellent recyclability.

  Among plant-derived plastics, polylactic acid resin is made from lactic acid obtained by fermentation of starch, can be mass-produced by chemical engineering, and has excellent transparency and rigidity. As an alternative material, it is expected to be used in various applications. However, since polylactic acid-based resins are poor in heat resistance and impact resistance, it is very difficult to use them in applications where they are required.

  As a carrier tape made of a biodegradable resin typified by a polylactic acid resin, for example, Patent Document 1 listed below discloses biodegradability made of polylactic acid, a polyalkylalkanoate resin, an inorganic filler, and a conductive filler. A conductive sheet, a carrier tape for packaging electronic parts made of biodegradable plastic is disclosed in Patent Literature 2 below, and a base layer made of biodegradable plastic is disclosed in Patent Literature 3 below, and a conductive layer covering the surface of the base layer. In a reel for electronic component packaging composed of a coating layer of a material, the following Patent Document 4 describes that 17 to 40% by mass of at least one surface of a substrate layer composed of a lactic acid-based polymer containing a conductivity-imparting agent of 12% by mass or less. A conductive lactic acid-based polymer laminate in which a conductivity-imparting layer made of a lactic acid-based polymer containing a conductivity-imparting agent is formed is disclosed.

JP 11-039945 A JP-A-11-152179 JP 2000-085837 A JP 2000-355089 A JP-A-2005-060637 JP 2005-264086 A JP 2006-328318 A

A carrier tape made of a biodegradable resin typified by polylactic acid as described in the above publication requires sufficient crystallization treatment in order to impart sufficient heat resistance. However, since the secondary workability is reduced by performing the crystallization treatment, not only the molding condition range of the pocket portion of the carrier tape is narrowed, but also it is difficult to form a uniform pocket.
As described above, in the conventional technology, it has been very difficult to provide a carrier tape made of a biodegradable resin that satisfies sufficient heat resistance and moldability.

  Then, the objective of this invention is providing the electroconductive laminated sheet which consists of biodegradable resin which has the outstanding moldability, rigidity, and bending strength.

The present invention employs the following configurations (1) to (11).
(1) A layer (I layer) containing a thermoplastic resin (A) and a conductive agent (B), and a layer (II layer) containing a polystyrene resin (C), a polylactic acid resin (D), and an elastomer (E) And a conductive laminate sheet.
(2) The conductive laminated sheet according to (1), wherein a front layer and a back layer are formed with the I layer, and an intermediate layer is formed with the II layer.
(3) The compounding amount of the conductive agent (B) in the I layer is 1% by mass or more and 30% by mass or less, and the compounding amount of the polylactic acid resin (D) in the II layer is 10% by mass or more. The conductive laminated sheet according to (1) or (2), wherein the blending amount of the elastomer (E) is 50% by mass or less and 5% by mass or more and 20% by mass or less.
(4) The conductive laminated sheet according to any one of (1) to (3), wherein the elastomer (E) is a styrene elastomer.
(5) The I layer further comprises a polylactic acid resin (D) in a proportion of 10% by mass to 50% by mass and an elastomer (E) in a proportion of 5% by mass to 20% by mass. The conductive laminated sheet according to any one of (1) to (4).
(6) The conductive layer (B) is further blended in the II layer at a ratio of 0.1% by mass or more and 10% by mass or less, according to any one of (1) to (5). Conductive laminate sheet.
(7) The conductivity according to any one of (1) to (6), wherein the proportion of D-lactic acid in the polylactic acid resin (D) is 3% by mass or more and 97% by mass or less. Laminated sheet.
(8) Thermoplastic resin (A) is impact-resistant polystyrene (HIPS), The conductive laminated sheet according to any one of claims (1) to (7).
(9) The conductive laminated sheet according to any one of (1) to (8), wherein the thickness of one layer of the I layer is 2 μm or more and 50 μm or less.
(10) A molded body obtained by molding the conductive laminated sheet according to any one of (1) to (9).
(11) A carrier tape formed by molding the conductive laminated sheet according to any one of (1) to (9).

  The conductive laminated sheet of the present invention has not only excellent conductivity but also excellent heat resistance, moldability, rigidity, and folding strength.

  More specifically, since the conductive laminated sheet of the present invention is excellent in rigidity, it can be made thinner than a conventionally used polystyrene-based conductive laminated sheet. Thereby, the quantity of resin used as an electroconductive lamination sheet can be reduced, and since the plant raw material plastic is used, it can contribute to the further waste reduction.

  Furthermore, the conductive laminated sheet of the present invention is excellent in heat resistance, and can be widely used for the same applications as the conductive laminated sheets generally used at present.

  Embodiments of the present invention will be described below, but the scope of the present invention is not limited to the embodiments described below.

The conductive laminate sheet of the present invention comprises a layer (I layer) containing a thermoplastic resin (A) and a conductive agent (B), a polystyrene resin (C), a polylactic acid resin (D), and an elastomer (E). And a layer containing II (layer II).
It is preferable to form the I layer as a front surface layer and / or a back surface layer and the II layer as an intermediate layer. In this case, it is sufficient that the intermediate layer has at least one layer, and a configuration of two layers, three layers, or the like can also be adopted.
Specifically, a structure composed of two layers of surface layer / intermediate layer, a structure composed of three layers of surface layer / intermediate layer / back surface layer, and the like are preferable.

(Thermoplastic resin (A))
The thermoplastic resin (A) of the present invention includes an aromatic polycarbonate resin, a polypropylene resin, a polyolefin resin such as a polyethylene resin, an aromatic polyester resin, and an aliphatic polyester in terms of heat resistance and moldability. Resin, polystyrene resin, polymethyl methacrylate resin, etc. can be used. Among these, it is preferable to use an aromatic polycarbonate-based resin, a polystyrene-based resin, or a polymethylmethacrylate-based resin in consideration of adhesion to the intermediate layer of the present invention and heat resistance, and also considers moldability and impact resistance. More preferably, a polystyrene resin is used.

(Conducting agent (B))
As the conductive agent (B) of the present invention, for example, conductive carbon, tin oxide, antimony oxide, non-dium oxide or the like can be used. These may be used alone or in combination of two or more. Among these, conductive carbon is preferable from the viewpoint of moldability, resistivity after molding, and the like. As this conductive carbon, for example, ketjen black EC, furnace black, channel black, acetylene black and the like can be used. Among these, it is more preferable to use ketjen black EC in that high conductivity can be obtained with a small addition amount. When ketjen black EC is used, since the addition amount is small, the deterioration of the mechanical properties of the conductive laminated sheet is reduced.

  The average particle diameter of the conductive agent (B) is preferably 0.01 μm or more and 10 μm or less, and more preferably 0.05 μm or more and 5 μm or less. If it is less than 0.01 μm, the dispersibility in the resin is poor, and if it exceeds 10 μm, the mechanical properties, particularly the folding strength, of the resulting laminated sheet may be lowered.

(Polystyrene resin (C))
As the polystyrene resin (C) of the present invention, various polystyrenes or mixtures can be used. Among them, conjugated diene hydrocarbon polymer particles or acrylic rubber particles are particularly dispersed in the styrene polymer. It is preferable to use impact-resistant polystyrene. High impact polystyrene (hereinafter referred to as “HIPS”) is a styrene polymer in which conjugated diene hydrocarbon polymer particles or acrylic rubber particles are dispersed, and the brittleness of the styrene polymer is improved with a rubber component. It is what. Examples of the styrenic polymer include homopolymers such as styrene, o-methylstyrene, p-methylstyrene, and α-methylstyrene, copolymers composed of these components, and other than styrenic hydrocarbons. A copolymer containing a copolymerizable monomer can be used, and a mixture thereof may be used. As such a copolymerizable monomer, acrylonitrile, methyl acrylate, ethyl acrylate, butyl acrylate, methyl methacrylate, chloroethyl vinyl ether, or the like can be used.

  The conjugated diene-based hydrocarbon polymer particles may be any particles that exhibit rubber elasticity at room temperature. For example, homopolymers such as butadiene, isoprene, 1,3-pentadiene, copolymers thereof, conjugated dienes, and the like. There are monomers other than the hydrocarbons that can be copolymerized, such as copolymers containing styrene monomers, and thermoplastic elastomers may also be used. As a polymerization form of HIPS, normal polymerization forms such as radical polymerization and anionic polymerization may be used. Representative examples of HIPS include the HIPS series manufactured by PS Japan and the “Sumibright DJ” series manufactured by Sumitomo Chemical.

(Polylactic acid resin (D))
The polylactic acid resin (D) of the present invention includes poly (L-lactic acid) having a structural unit of L-lactic acid, poly (D-lactic acid) having a structural unit of D-lactic acid, structural units of L-lactic acid and D -Poly (DL-lactic acid) which is lactic acid or a mixture thereof, and further a copolymer with α-hydroxycarboxylic acid or diol / dicarboxylic acid. At this time, the proportion of D-lactic acid in the polylactic acid-based resin (D) can be set to an arbitrary amount, but when the moldability is taken into consideration, the proportion of D-lactic acid is 3% by mass to 97% by mass. It is preferable that it is 5 mass% or more and 95 mass% or less. When deviating from this range, crystallization of the polylactic acid-based resin may proceed depending on the atmosphere during molding or storage, and the molding conditions may be narrowed. Typical examples of the polylactic acid resin include “Lacia” series manufactured by Mitsui Chemicals, and “Nature Works” series manufactured by Nature Works.

  As a polymerization method of the polylactic acid resin, any known method such as a condensation polymerization method or a ring-opening polymerization method can be employed. For example, in the polycondensation method, L-lactic acid or D-lactic acid, or a mixture thereof can be directly dehydrated and polycondensed to obtain a polylactic acid resin having an arbitrary composition.

  In the ring-opening polymerization method, a polylactic acid-based polymer can be obtained using a selected catalyst while using lactide, which is a cyclic dimer of lactic acid, with a polymerization regulator or the like as necessary. Lactide includes L-lactide, which is a dimer of L-lactic acid, D-lactide, which is a dimer of D-lactic acid, and DL-lactide composed of L-lactic acid and D-lactic acid. By mixing and polymerizing, a polylactic acid resin having an arbitrary composition and crystallinity can be obtained.

  Furthermore, as required to improve heat resistance, terephthalate is used as a small amount copolymerization component in a range that does not impair the essential properties of the polylactic acid resin, that is, in a range containing 90% by mass or more of the polylactic acid resin component. Non-aliphatic diols such as non-aliphatic dicarboxylic acids such as acids and / or ethylene oxide adducts of bisphenol A may be used. Furthermore, for the purpose of increasing the molecular weight, a small amount of a chain extender such as a diisocyanate compound, an epoxy compound, and an acid anhydride can be used.

  Examples of the other hydroxycarboxylic acid units copolymerized with the polylactic acid resin include optical isomers of lactic acid (D-lactic acid for L-lactic acid, L-lactic acid for D-lactic acid), glycol 2 such as acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 2-hydroxyn-butyric acid, 2-hydroxy3,3-dimethylbutyric acid, 2-hydroxy-3-methylbutyric acid, 2-methyllactic acid, 2-hydroxycaproic acid, etc. Lactones such as functional aliphatic hydroxy-carboxylic acid, caprolactone, butyrolactone, and valerolactone can be used.

  Examples of the aliphatic diol copolymerized with the polylactic acid resin include ethylene glycol, 1,4-butanediol, 1,4-cyclohexanedimethanol, and the like. As the aliphatic dicarboxylic acid, succinic acid, adipic acid, suberic acid, sebacic acid, dodecanedioic acid and the like can be used.

  The preferred range of the weight average molecular weight of the polylactic acid-based resin (D) is 50,000 to 400,000, preferably 100,000 to 250,000, and practical properties are hardly expressed when below this range. Is inferior in moldability because the melt viscosity is too high.

(Elastomer (E))
As the elastomer (E) of the present invention, a styrene elastomer, an acrylic elastomer, an olefin elastomer, an ester elastomer, an amide elastomer or the like can be used, and one kind or a mixture of two or more kinds can be used. Of these, styrene-based elastomers, ester-based elastomers, or mixtures thereof are preferable.

(Styrene elastomer)
As the styrenic elastomer of the present invention, a resin comprising a styrene component and an elastomer component and containing a styrene component in a proportion of 10% by mass to 50% by mass, preferably 15% by mass to 30% by mass can be used. . Examples of the elastomer component include conjugated diene hydrocarbons such as butadiene, isoprene, and 1,3-pentadiene. More specifically, styrene and butadiene copolymer (SBS) elastomer, styrene and isoprene, and the like. And a copolymer (SIS) elastomer. Specific examples of the styrenic elastomer include, for example, “Hiblur” series manufactured by Kuraray.

  In addition, as the styrene elastomer, SBS elastomer or a resin obtained by adding hydrogen to SIS elastomer (SEBS, SEPS) can also be used. Specific examples of the elastomer to which hydrogen is added include “Tuftec H” series manufactured by Asahi Kasei Chemicals Corporation.

  Furthermore, as said styrene-type elastomer, the modified styrene-type elastomer in which many elastomer components are contained can also be used, and among these, the modified body of SEBS and SEPS can be used more preferably. Specific examples include maleic anhydride-modified SEBS, maleic anhydride-modified SEPS, epoxy-modified SEBS, and epoxy-modified SEPS, and at least one selected from these groups can be used. Specific examples of the modified styrenic resin include “Tuftec M1943” manufactured by Asahi Kasei Chemicals Co., Ltd., “Dynalon 8630P” manufactured by JSR, and epoxidation heat, which are polymers modified with a highly reactive functional group on a hydrogenated styrene thermoplastic elastomer. There are “Epofriend” series made by Daicel Chemical Industries, which are plastic elastomers.

(Ester elastomer)
As the ester elastomer of the present invention, for example, a high melting point / high crystallinity aromatic polyester can be used as a hard segment, and a non-crystalline polyester or amorphous polyether block copolymer can be used as a soft segment.

(Mixture of styrene elastomer and ester elastomer)
The elastomer (E) of the present invention includes a mixture of the styrene elastomer and the ester elastomer, which is disclosed in Japanese Patent Nos. 3381488 and 3702704. As products actually sold, there are Primaloloy A1600, A1700 series, etc. manufactured by Mitsubishi Chemical Corporation.

(Combination)
As a compounding quantity of the electrically conductive agent (B) in the layer (I layer) containing a thermoplastic resin (A) and an electrically conductive agent (B), 1 to 30 mass% is preferable, and 5 to 25 mass% is preferable. The following is more preferable, and 10% by mass or more and 20% by mass or less is more preferable. When the blending amount of the conductive agent (B) is 1% by mass or more, the effect of conductivity is sufficiently exhibited, and when it is 30% by mass or less, the mechanical properties of the sheet, particularly the folding strength can be sufficiently satisfied.
The blending amount of the polylactic acid resin (D) in the layer (II layer) containing the polystyrene resin (C), the polylactic acid resin (D), and the elastomer (E) is 10% by mass to 50% by mass. 20 mass% or more and 40 mass% or less are more preferable, and 25 mass% or more and 35 mass% or less are more preferable. If the blending amount of the polylactic acid-based resin (D) is 10% by mass or more, the sheet has sufficient rigidity, and if it is 50% by mass or less, the heat resistance and mechanical strength can be sufficiently satisfied.
As a compounding quantity of the elastomer (E) in the said II layer, 5 to 20 mass% is preferable, 7 to 18 mass% is more preferable, 10 to 15 mass% is more preferable. If the blending amount of the elastomer (E) is 5% by mass or more, mechanical properties, in particular, an effect of improving the bending strength is sufficiently obtained, and if it is 20% by mass or less, the rigidity and heat resistance of the sheet are sufficiently satisfied. be able to.

  The proportion of the polylactic acid resin (D) in the I layer is preferably 10% by mass to 50% by mass, more preferably 20% by mass to 40% by mass, and further preferably 25% by mass to 35% by mass. In this case, the rigidity of the sheet can be improved as necessary.

  The elastomer (E) is preferably blended in the I layer at a ratio of 5% by mass to 20% by mass, more preferably 7% by mass to 18% by mass, and even more preferably 10% by mass to 15% by mass. Thus, excellent conductivity can be imparted without impairing mechanical properties.

  The proportion of the conductive agent (B) in the II layer is preferably 0.1% by mass or more and 10% by mass or less, more preferably 1% by mass or more and 8% by mass or less, and further preferably 3% by mass or more and 6% by mass or less. In this case, the electrical conductivity can be further improved as necessary.

  In addition, an additive such as a heat stabilizer, an antioxidant, an ultraviolet absorber, a light stabilizer, a crosslinking agent, a plasticizer, a crystallization accelerator, a pigment, and a dye may be blended within a range not impairing the effects of the present invention. Can do.

(Production method)
Although it does not restrict | limit especially as a manufacturing method of the electroconductive lamination sheet of this invention, A melt extrusion method etc. can be used. Examples of the die include a die, an I die, and a round die. As a thickness of a sheet | seat, 0.05 mm or more and 3 mm or less are preferable practically, and 0.1 mm or more and 1 mm or less are more preferable. The thickness of one layer of the I layer is preferably 2 μm or more and 50 μm or less, and more preferably 5 μm or more and 40 μm or less. The thickness of the II layer is preferably 100 μm or more and 600 μm or less, and more preferably 150 μm or more and 450 μm or less.

  In addition, as a method of mixing the thermoplastic resin (A), the conductive agent (B), the polystyrene resin (C), the polylactic acid resin (D), the elastomer (E), and the additive, all raw materials are compounded in advance. Then, a pelletized product or a product obtained by dry blending all raw materials is used to produce a laminated sheet using a co-extrusion equipment having a feed block or a multi-manifold die. At this time, since the viscosity of the resin varies depending on the blending ratio of the thermoplastic resin (A), the conductive agent (B), the polystyrene resin (C), the polylactic acid resin (D), the elastomer (E), and the additive, The kneading conditions need to be adjusted as appropriate, but it is preferable to prepare the sheet at a resin temperature of 180 ° C. or higher and 220 ° C. or lower.

Thus, it is preferable that the surface resistivity of the electroconductive lamination sheet obtained is in the range of 10 ³ to 10 ⁸ Ω. If the surface resistivity is 10 ³ Ω or more, there is no possibility that the terminals of the electronic component are conducted and short-circuited, and if the surface resistivity is 10 ⁸ Ω or less, sufficient conductivity can be obtained and generation of static electricity can be suppressed. it can.

  In order to obtain a molded body from the obtained conductive laminated sheet, the conductive laminated sheet is preheated to a molding temperature by an infrared heater, a hot plate heater, hot air or the like and thermoformed. Although it is necessary to appropriately adjust the molding temperature depending on the composition, a range of 105 ° C. to 130 ° C. is preferable, and a range of 110 ° C. to 125 ° C. is more preferable. If the molding temperature is less than 105 ° C, the sheet may not be sufficiently softened and may be difficult to mold. If the molding temperature exceeds 130 ° C, the sheet may be drawn down (drooped by its own weight) during preheating. It may be difficult to obtain a uniform molded body.

  Examples of the thermoforming method include a vacuum forming method, a pressure forming method, a male / female forming method, and a method of expanding a forming male die after deforming a sheet along the forming male die. Various moldings can be obtained by these molding methods. In particular, it is preferable to use it as a carrier tape since it has sufficient conductivity, heat resistance, folding strength and formability.

  Examples are shown below, but the present invention is not limited by these. First, measurement / evaluation methods of physical property values in Examples and Comparative Examples are shown below.

(Folding strength)
Based on ASTM D2176, a test piece having a length of 120 mm, a width of 15 mm, and a thickness of 0.3 mm was prepared, and MIT folding resistance strength was measured in both MD and TD directions using an MIT folding fatigue tester manufactured by Toyo Seiki Seisakusho. It was. At this time, the test was performed at a bending angle of 135 degrees, a bending speed of 175 cpm, and a measurement load of 9.8 N. Folding strength is set to pass 700 times or more for both MD and TD.

(Softening temperature)
A test piece having a length of 50 mm, a width of 50 mm, and a thickness of 0.3 mm was prepared based on JIS K7196, and the softening temperature was measured using TMA120C manufactured by SII Nanotechnology. At this time, the test was performed at a measurement load of 0.5 N and a temperature increase rate of 5 ° C./min. The softening temperature is 80 ° C. or higher.

(Tensile modulus)
Based on JIS K7127, a test piece having a length of 400 mm, a width of 10 mm, and a thickness of 0.3 mm was prepared, and tensile modulus was measured in both MD and TD directions using an Intesco universal material tester MODEL205. At this time, measurement was performed at an ambient temperature of 23 ° C. and a tensile speed of 5 mm / min. The tensile modulus of elasticity is determined to be 1500 MPa or more for both MD and TD.

(Surface resistivity)
Based on JIS K7194, a test piece having a length of 100 mm, a width of 100 mm, and a thickness of 0.3 mm was prepared and allowed to stand at 23 ° C. and 50% RH for 90 hours, and then a surface resistance measuring instrument Lorester HP (Mitsubishi Chemical Corporation). The surface resistivity of the cast surface of the sheet was measured using a product manufactured by MCP-T410. A surface resistivity of 1 × 10 ³ Ω to 1 × 10 ⁸ Ω is acceptable.

(Formability)
Compressed air molding (air pressure: 2 kg / cm ² ) was performed using a molding die (die temperature 25 ° C.) having a diameter of 100 mm, a depth of 30 mm, and a drawing ratio of 0.3, and the mold forming state of the molded product was observed. Evaluation was performed in stages. The evaluation criteria are indicated by “◯” when a molded body having a good shape is formed, “Δ” when it is at a practical level, and “X” when the molded body has a defective shape.

  Next, each raw material used for the Example and comparative example of this invention is shown below.

(Thermoplastic resin (A))
A-1: 475D (HIPS) manufactured by PS Japan
A-2: Iupilon H4000 manufactured by Mitsubishi Engineering Plastics
(Polycarbonate)

(Conducting agent (B))
B-1: Ketjen Black EC manufactured by International

(Polystyrene resin (C))
C-1: 475D (HIPS) manufactured by PS Japan

(Polylactic acid resin (D))
D-1: Nature Works 4060D manufactured by Nature Works
(D-lactic acid ratio: 14.0% by mass)
D-2: Nature Works 4042D manufactured by Nature Works
(D-lactic acid ratio: 4.3% by mass)

(Elastomer (E))
E-1: Kuraray Hibler 7125 (SIS)
E-2: Primalloy A1700N (polybutylene terephthalate / polytetramethylene glycol ether / styrene copolymer) manufactured by Mitsubishi Chemical Corporation
E-3: Asahi Kasei Chemicals Corporation Tuftec H1041 (SEBS)
E-4: Modiper A4200 manufactured by NOF Corporation (poly (ethylene-stat-glycidyl methacrylate) -polymethyl methacrylate graft copolymer)

Example 1
After mixing A-1 as the thermoplastic resin (A) and B-1 as the conductive agent (B) at a mass ratio of 80:20, the mixture is supplied to a twin-screw extruder, melt-kneaded to form a strand. After discharging, the pellets were pulverized with a pelletizer to obtain raw material pellets for the front surface layer and the back surface layer.

  Next, C-1 as a polystyrene resin (C), D-1 as a polylactic acid resin (D), and E-1 as an elastomer (E) are mixed at a mass ratio of 60/30/10, The mixture was supplied to a twin screw extruder, melted and kneaded, discharged into a strand, and then pulverized into pellets with a pelletizer to obtain intermediate layer raw material pellets.

  The above surface layer and back layer raw material pellets and intermediate layer raw material pellets are supplied to each single-screw extruder and extruded from one T die, and the thickness is 10 μm each for the front layer and back layer, and the intermediate layer is 280 μm. A laminated sheet was produced. Table 1 shows the results of measurement of bending strength, softening temperature, tensile modulus, surface resistivity, and evaluation of formability of the obtained sheet.

(Example 2)
A laminated sheet was produced and evaluated in the same manner as in Example 1 except that the elastomer of the intermediate layer in Example 1 was changed to E-2. The results are shown in Table 1.

(Example 3)
A laminated sheet was produced and evaluated in the same manner as in Example 1 except that the elastomer of the intermediate layer in Example 1 was changed to E-3. The results are shown in Table 1.

Example 4
A laminated sheet was produced and evaluated in the same manner as in Example 1 except that the elastomer of the intermediate layer in Example 1 was changed to E-4. The results are shown in Table 1.

(Example 5)
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that the thermoplastic resin (A) of the front surface layer and the back surface layer in Example 1 was changed to A-2. The results are shown in Table 1.

(Example 6)
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that the mixing ratio of A-1 and B-1 of the front surface layer and back surface layer of Example 1 was 90:10. The results are shown in Table 1.

(Example 7)
The production and evaluation of the laminated sheet were performed in the same manner as in Example 1 except that the mixing ratio of C-1, D-1, and E-1 in the intermediate layer of Example 1 was changed to 55:30:15. went. The results are shown in Table 1.

(Example 8)
The production and evaluation of the laminated sheet were performed in the same manner as in Example 1 except that the mixing ratio of C-1, D-1, and E-1 in the intermediate layer of Example 1 was 80:10:10. went. The results are shown in Table 1.

Example 9
The front surface layer and the back surface layer of Example 1 were a mixture of A-1, B-1, D-1, and E-1, and A-1, B-1, D-1, and E-1 were mixed. A laminated sheet was produced and evaluated in the same manner as in Example 1 except that the ratio was 50: 30: 10: 10. The results are shown in Table 1.

(Example 10)
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that the thickness of the front surface layer and the back surface layer was 20 μm and the thickness of the intermediate layer was 260 μm in Example 1. The results are shown in Table 1.

(Example 11)
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that the thicknesses of the surface layer and the back layer in Example 1 were 30 μm and the thickness of the intermediate layer was 240 μm. The results are shown in Table 1.

Example 12
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that D-2 was used as the polylactic acid resin (D) in Example 1. The results are shown in Table 1.

(Comparative Example 1)
A laminated sheet was prepared and evaluated in the same manner as in Example 1 except that the intermediate layer of Example 1 was changed to C-1 and D-1 in a mixing ratio of 70:30. The results are shown in Table 1.

(Comparative Example 2)
A laminated sheet was produced and evaluated in the same manner as in Example 1 except that only the intermediate layer of Example 1 was C-1. The results are shown in Table 1.

(result)
The conductive laminated sheets of Examples 1 to 12 were satisfactory in terms of bending resistance, softening temperature, tensile elastic modulus, surface resistivity, and formability, and had no practical problems. . On the other hand, the conductive laminated sheet of Comparative Example 1 has no bending strength in the TD direction, and the conductive laminated sheet of Comparative Example 2 has a low tensile elastic modulus and was not practical.

Claims (11)

  A layer (I layer) containing a thermoplastic resin (A) and a conductive agent (B), and a layer (II layer) containing a polystyrene resin (C), a polylactic acid resin (D), and an elastomer (E) A conductive laminated sheet comprising:   2. The conductive laminated sheet according to claim 1, wherein the I layer forms a front surface layer and a back surface layer, and the II layer forms an intermediate layer.   The blending amount of the conductive agent (B) in the I layer is 1% by mass or more and 30% by mass or less, and the blending amount of the polylactic acid resin (D) in the II layer is 10% by mass or more and 50% by mass. The conductive laminated sheet according to claim 1 or 2, wherein the blending amount of the elastomer (E) is 5% by mass or more and 20% by mass or less.   The conductive laminated sheet according to any one of claims 1 to 3, wherein the elastomer (E) is a styrene-based elastomer, an ester-based elastomer, or a mixture thereof.   The polylactic acid resin (D) is further blended in the I layer in a proportion of 10% by mass to 50% by mass and the elastomer (E) in a proportion of 5% by mass to 20% by mass. Item 5. The conductive laminated sheet according to any one of Items 1 to 4.   The electroconductive agent according to any one of claims 1 to 5, wherein a conductive agent (B) is further blended in the II layer at a ratio of 0.1% by mass or more and 10% by mass or less. Laminated sheet.   The proportion of D-lactic acid in the polylactic acid resin (D) is 3% by mass or more and 97% by mass or less, and the conductive laminated sheet according to any one of claims 1 to 6.   The conductive laminate sheet according to any one of claims 1 to 7, wherein the thermoplastic resin (A) is impact-resistant polystyrene (HIPS).   The thickness of one layer of the said I layer is 2 micrometers or more and 50 micrometers or less, The electroconductive lamination sheet of any one of Claims 1-8 characterized by the above-mentioned.   The molded object formed by shape | molding the electroconductive laminated sheet of any one of Claims 1-9.   The carrier tape formed by shape | molding the electroconductive laminated sheet of any one of Claims 1-9.