JP2015030257A - Conductive laminated sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a polylactic acid-based conductive laminated sheet having excellent bending durability, sufficient mechanical strength represented by strength and sufficient interlayer peeling strength and further having low environmental load.SOLUTION: There is provided a conductive laminated sheet having at least each one layer of a I layer obtained by molding a polylactic acid-based thermoplastic resin composition obtained by blending 40 to 70 pts.wt. of a polylactic acid-based resin (A), 5 to 53 pts.wt. of a styrene-based resin (B), 5 to 53 pts.wt. of a graft copolymer (C) and 2 to 20 pts.wt. of an inorganic filler (D) (provided that the total of (A) to (D) is 100 pts.wt) and a II layer obtained by molding a conductive thermoplastic resin composition obtained by blending the styrene-based resin (B), the graft copolymer (C) and a conductive agent (E). At least one of outermost layers is the II layer and at least one sets of the I layer and the II layer are adjacent to each other.

Description

  The present invention relates to a conductive laminated sheet using a polylactic acid resin having a low environmental load.

  Currently, in the field of sheets made of resin, different types of laminated sheets obtained by laminating sheets made of different resins are widely used to provide many functions. Specific examples of uses to which the different types of laminated sheets are applied include storage / transport materials (tray) for electronic parts typified by semiconductors. As a dust-proof measure for preventing damage to the electronic component itself and performance degradation, the surface of the electronic component storage / transport material is required to have electrical conductivity. Also, sufficient mechanical strength is required for materials for storing and transporting electronic components so that cracks do not occur due to vibration or dropping during transportation. Furthermore, these materials are required to have sufficient heat resistance because they are subjected to thermoforming such as press molding and vacuum forming to form pockets for inserting electronic components in the sheet, and then cut to a predetermined size. In addition, cutting workability such as cracking and burr suppression during cutting is required.

  On the other hand, as a cause of global warming, an increase in the concentration of carbon dioxide, one of the greenhouse gases, in the atmosphere has been pointed out, and the momentum for suppressing carbon dioxide emissions has been increasing on a global scale. For example, plant-derived plastics that can reduce the use of fossil resources and reduce carbon dioxide emissions have attracted attention.

  Against this background, materials using polylactic acid based resins for different types of laminated sheets have been developed. For example, a conductive laminated sheet having a layer containing a thermoplastic resin and a conductive agent and a layer containing a polystyrene-based resin, a polylactic acid-based resin, and an elastomer has been proposed (for example, see Patent Document 1). However, the content of polylactic acid used in the presented intermediate layer is substantially 30% by weight or less, and further examination is necessary from the viewpoint of environmental considerations. A layer comprising a polylactic acid thermoplastic resin composition containing a styrene resin, a graft copolymer and a polylactic acid resin, and a resin composition comprising a styrene resin, a graft copolymer and a polyether ester amide An antistatic laminated sheet comprising at least one B layer made of an antistatic thermoplastic resin composition obtained by blending a perfluoroalkyl compound and / or an organic ionic conductive agent with a product has been proposed (for example, Patent Document 2).

JP 2009-96138 A JP2013-59937A

  The antistatic laminate sheet described in Patent Document 2 has sufficient antistatic properties and strength, and can greatly contribute to the reduction of carbon dioxide emissions, but in the polylactic acid-based thermoplastic resin composition of the intermediate layer When the content of polylactic acid is 40% by weight or more, the adhesion strength with the conductive thermoplastic resin constituting the front and back layers is low, burrs are generated due to delamination during sheet cutting, and the bending durability is low. There was a problem of decreasing. In such a case, it is conceivable to provide an adhesive layer having good compatibility in both layers, but the process becomes complicated and the manufacturing cost increases.

  An object of the present invention is to provide a low environmental load polylactic acid-based conductive sheet having excellent bending durability and sufficient delamination strength.

As a result of intensive studies to solve the above-described problems, the present invention includes the following (1) to (6).
(1) 40 to 70 parts by weight of polylactic acid resin (A), 5 to 53 parts by weight of styrene resin (B), 5 to 53 parts by weight of graft copolymer (C) and 2 to 20 inorganic filler (D) An I layer formed by molding a polylactic acid-based thermoplastic resin composition containing parts by weight (however, the sum of (A) to (D) is 100 parts by weight), a styrene-based resin (B), a graft Comprising at least one II layer formed by molding a conductive thermoplastic resin composition comprising the copolymer (C) and the conductive agent (E), wherein at least one outermost layer is the II layer; and A conductive laminated sheet, wherein at least one pair of I layer and II layer is adjacent.
(2) The polylactic acid-based thermoplastic resin composition constituting the I layer further contains 10 parts by weight or less of acrylic resin (F) with respect to 100 parts by weight of the total of (A) to (D). The conductive laminated sheet according to (1), wherein
(3) The polylactic acid-based thermoplastic resin composition constituting the I layer is an epoxy group-containing acrylic-styrene copolymer (G) with respect to a total of 100 parts by weight of (A) to (D). 0.1 to 10 parts by weight of the conductive laminate sheet according to (1) or (2).
(4) The conductive laminate according to any one of (1) to (3), wherein the inorganic filler (D) in the polylactic acid-based thermoplastic resin composition constituting the I layer contains talc. Sheet.
(5) A molded product obtained by thermoforming the conductive laminated sheet according to any one of (1) to (4).
(6) A tray for storing and transporting electronic parts, which is obtained by thermoforming the conductive laminated sheet according to any one of (1) to (4).

  Since the conductive laminate sheet of the present invention is excellent in bending durability and delamination strength even when the amount of polylactic acid is large, it can be suitably used as a tray for storing and transporting electronic components. Further, by blending 40 parts by weight or more of the plant-derived polylactic acid resin (A) into the I layer, it can greatly contribute to the reduction of carbon dioxide emission and can further contribute to the conservation of the global environment.

  The conductive laminate sheet of the present invention will be specifically described below.

  The conductive laminated sheet of the present invention has at least one I layer composed of a polylactic acid-based thermoplastic resin composition and II layer composed of a conductive thermoplastic resin composition. First, each of these layers will be described.

[I layer (a layer formed by molding a polylactic acid-based thermoplastic resin composition)]
The I layer is composed of 40 to 70 parts by weight of a polylactic acid resin (A), 5 to 53 parts by weight of a styrene resin (B), 5 to 53 parts by weight of a graft copolymer (C), and 2 to 20 inorganic fillers (D). A polylactic acid-based thermoplastic resin composition formed by blending parts by weight (however, the total of (A) to (D) is 100 parts by weight) is formed. Since the molded product of such a polylactic acid-based thermoplastic resin composition has a high flexural modulus and excellent Charpy impact strength, the I layer plays a role of enhancing the bending durability of the conductive laminated sheet. Furthermore, by constituting the I layer from the polylactic acid-based thermoplastic resin composition, it is possible to improve the delamination strength with the II layer formed by molding a conductive thermoplastic resin composition described later.

(Polylactic acid resin (A))
In the present invention, by blending the polylactic acid-based resin (A) with the polylactic acid-based thermoplastic resin composition constituting the I layer, it is possible to obtain a conductive laminate sheet having a low environmental load and high rigidity and high strength. it can. The polylactic acid resin (A) used in the present invention is a polymer containing L-lactic acid and / or D-lactic acid as a main constituent component. Here, a main component refers to the component which occupies 50 mol% or more among all the structural components. L-lactic acid and / or D-lactic acid is preferably contained in an amount of 70 mol% or more, more preferably 90 mol% or more, based on all components. Other copolymer components other than lactic acid may be included as long as the object of the present invention is not impaired. Examples of such other copolymerization components include polyvalent carboxylic acids, polyhydric alcohols, hydroxycarboxylic acids, and lactones. Specifically, oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, dodecanedioic acid, fumaric acid, cyclohexanedicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, 2,6- Polyvalent carboxylic acids such as naphthalene dicarboxylic acid, 5-sodium sulfoisophthalic acid, 5-tetrabutylphosphonium sulfoisophthalic acid, ethylene glycol, propylene glycol, butanediol, heptanediol, hexanediol, octanediol, nonanediol, decanediol , 1,4-cyclohexanedimethanol, neopentyl glycol, glycerin, trimethylolpropane, pentaerythritol, bisphenol A, bisphenol A and aromatic polyhydric alcohols with addition reaction of ethylene oxide Polyol, diethylene glycol, triethylene glycol, polyethylene glycol, polypropylene glycol, polytetramethylene glycol and other polyhydric alcohols, glycolic acid, 3-hydroxybutyric acid, 4-hydroxybutyric acid, 4-hydroxyvaleric acid, 6-hydroxycaproic acid Hydroxycarboxylic acids such as hydroxybenzoic acid, lactones such as glycolide, ε-caprolactone glycolide, ε-caprolactone, β-propiolactone, δ-butyrolactone, β- or γ-butyrolactone, pivalolactone, δ-valerolactone, etc. Can be mentioned. These copolymer components can be used alone or in combination of two or more.

  The polylactic acid resin (A) preferably has a higher optical purity from the viewpoint of heat resistance. Specifically, among the total lactic acid component that is a constituent component of the polylactic acid-based resin (A), the L-form or D-form is preferably contained in an amount of 80 mol% or more, more preferably 90 mol% or more. It is particularly preferable that the amount is 95 mol% or more.

  The molecular weight and molecular weight distribution of the polylactic acid-based resin (A) are not particularly limited as long as the molding process such as extrusion molding can be substantially performed, but the weight average molecular weight is 50 from the viewpoint of improving the sheet strength. 1,000 or more is preferable, and 100,000 or more is more preferable. On the other hand, from the viewpoint of improving moldability, the weight average molecular weight is preferably 400,000 or less, and more preferably 300,000 or less. The weight average molecular weight herein is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by gel permeation chromatography (GPC) using hexafluoroisopropanol as a solvent.

  Although melting | fusing point of polylactic acid-type resin (A) is not specifically limited, From a viewpoint of improving the heat resistance of an electroconductive laminated sheet, 90 degreeC or more is preferable and 150 degreeC or more is more preferable.

  Examples of the method for producing the polylactic acid resin (A) include known polymerization methods such as a direct polymerization method from lactic acid and a ring-opening polymerization method via lactide.

(Styrene resin (B))
In the present invention, the impact strength of the I layer is improved by blending the styrene type (B) with the polylactic acid thermoplastic resin composition constituting the I layer, and the bending durability and delamination strength of the conductive laminated sheet are improved. Can be improved. The styrene resin (B) used in the present invention is a known block polymerization, block suspension polymerization, solution polymerization, precipitation polymerization of a monomer containing an aromatic vinyl monomer (b1) including styrene. Or it is obtained by using for emulsion polymerization. Among them, at least the aromatic vinyl monomer (b1) is contained, and if necessary, the vinyl cyanide monomer (b2), the unsaturated carboxylic acid alkyl ester monomer (b3), and these are used together. A copolymer obtained by copolymerizing a monomer mixture containing another polymerizable vinyl monomer (b4) is preferred. The styrene resin (B) referred to here is a graft copolymer obtained by graft polymerization of a monomer component containing an aromatic vinyl monomer (b1) to a rubber polymer (r) described later. The blend (C) and the epoxy group-containing acrylic-styrene copolymer (G) are not included.

  The aromatic vinyl monomer (b1) is not particularly limited, and specific examples include styrene, α-methylstyrene, o-methylstyrene, p-methylstyrene, o-ethylstyrene, p-ethylstyrene, and p-. Examples include t-butylstyrene. Of these, styrene or α-methylstyrene is preferably used. One or more of these can be used.

  The vinyl cyanide monomer (b2) is not particularly limited, and specific examples include acrylonitrile, methacrylonitrile, ethacrylonitrile and the like. Of these, acrylonitrile is preferably used. One or more of these can be used.

  From the viewpoint of further improving the impact strength of the I layer, the monomer component constituting the (B) styrene resin preferably contains 4% by weight or more of the vinyl cyanide monomer (b2), and is 25% by weight. The above is more preferable.

  The unsaturated carboxylic acid alkyl ester monomer (b3) is not particularly limited, but an ester of an alcohol having 1 to 6 carbon atoms and (meth) acrylic acid is preferable. Such an ester may further have a substituent, and examples of the substituent include a hydroxyl group and chlorine. Specific examples of the unsaturated carboxylic acid alkyl ester monomer (b3) include methyl (meth) acrylate, ethyl (meth) acrylate, n-propyl (meth) acrylate, and n-butyl (meth) acrylate. T-butyl (meth) acrylate, n-hexyl (meth) acrylate, cyclohexyl (meth) acrylate, chloromethyl (meth) acrylate, 2-chloroethyl (meth) acrylate, 2- (meth) acrylic acid 2- Hydroxyethyl, 3-hydroxypropyl (meth) acrylate, 2,3,4,5,6-pentahydroxyhexyl (meth) acrylate and 2,3,4,5-tetrahydroxypentyl (meth) acrylate Can be mentioned. Of these, methyl methacrylate is most preferably used. One or more of these can be used. Here, “(meth) acrylic acid” represents acrylic acid or methacrylic acid.

  Other vinyl monomers (b4) include aromatic vinyl monomers (b1), vinyl cyanide monomers (b2) and unsaturated carboxylic acid alkyl ester monomers (b3). There is no particular limitation as long as it can be polymerized, and specific examples thereof include maleimide monomers such as N-methylmaleimide, N-ethylmaleimide, N-cyclohexylmaleimide, N-phenylmaleimide, acrylic acid, methacrylic acid, maleic acid, Maleic acid monoethyl ester, maleic anhydride, phthalic acid, itaconic acid, and other vinyl monomers having a carboxyl group or a carboxyl group, 3-hydroxy-1-propene, 4-hydroxy-1-butene, cis-4 -Hydroxy-2-butene, trans-4-hydroxy-2-butene, 3-hydroxy-2-methyl-1-propene, Vinyl monomers having hydroxyl groups such as su-5-hydroxy-2-pentene, trans-5-hydroxy-2-pentene, 4,4-dihydroxy-2-butene, acrylamide, methacrylamide, N-methylacrylamide , Butoxymethylacrylamide, N-propylmethacrylamide, aminoethyl acrylate, propylaminoethyl acrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, N-vinyldiethylamine , N-acetylvinylamine, allylamine, methallylamine, N-methylallylamine, vinyl monomers having amino groups such as p-aminostyrene or derivatives thereof, 2-isopropenyl Oxazoline, 2-vinyl - oxazoline, 2-acryloyl - oxazoline and 2-styryl - vinyl-based monomer having oxazoline group such as oxazoline. One or more of these can be used.

  Although there is no restriction | limiting in the molecular weight of a styrene resin (B), From a viewpoint of improving the impact strength of I layer more, 10,000 or more are preferable and a weight average molecular weight are more preferable 50,000 or more. On the other hand, 400,000 or less is preferable from the viewpoint of improving moldability. The weight average molecular weight here refers to the weight average molecular weight in terms of polystyrene measured by GPC using tetrahydrofuran as a solvent.

  Specific examples of the styrenic resin (B) used in the present invention include polystyrene, acrylonitrile-styrene (AS) resin, methyl methacrylate-acrylonitrile-styrene (MAS) resin, methyl methacrylate-styrene (MS) resin. Etc. Two or more of these may be used in combination, for example, an AS resin and a MAS resin may be used in combination.

(Graft copolymer (C))
In the present invention, by blending the graft copolymer (C) with the polylactic acid thermoplastic resin composition constituting the I layer, the impact strength of the I layer is improved and the folding durability of the conductive laminated sheet is improved. Can be made. The graft copolymer (C) used in the present invention is a known block polymerization of a monomer component containing an aromatic vinyl monomer (b1) in the presence of a rubbery polymer (r). Obtained by graft polymerization of a monomer component containing an aromatic vinyl monomer (b1) to a rubbery polymer (r) by subjecting it to bulk suspension polymerization, solution polymerization, precipitation polymerization or emulsion polymerization It is. The graft copolymer (C) includes not only a graft copolymer in which a monomer component is graft polymerized to the rubber polymer (r), but also a single monomer that is not grafted to the rubber polymer (r). The body component polymer may be included. The monomer component to be graft-polymerized contains at least an aromatic vinyl monomer (b1), and, if necessary, a vinyl cyanide monomer (b2) and an unsaturated carboxylic acid alkyl ester monomer. And (b3) and other vinyl monomers (b4) copolymerizable therewith. Aromatic vinyl monomer (b1), vinyl cyanide monomer (b2), unsaturated carboxylic acid alkyl ester monomer (b3), and other vinyl monomers copolymerizable therewith ( Examples of b4) include those exemplified as monomers constituting the styrene resin (B). From the viewpoint of more uniformly dispersing the styrene resin (B) and the graft copolymer (C) and improving the surface smoothness of the conductive laminated sheet, the monomer component to be graft polymerized includes a styrene resin (B It is preferable to use the same monomer component as in (1) at the same mixing ratio.

  The rubbery polymer (r) is not particularly limited, but those having a glass transition temperature of 0 ° C. or less are suitable, and diene rubber, acrylic rubber, ethylene rubber, and the like can be preferably used. Specific examples include polybutadiene, styrene-butadiene copolymer, block copolymer of styrene-butadiene, acrylonitrile-butadiene copolymer, butyl acrylate-butadiene copolymer, polyisoprene, butadiene-methyl methacrylate copolymer. Butyl acrylate-methyl methacrylate copolymer, butadiene-ethyl acrylate copolymer, ethylene-propylene copolymer, ethylene-isoprene copolymer, ethylene-methyl acrylate copolymer, and the like. Among these rubbery polymers, polybutadiene, styrene-butadiene copolymer, styrene-butadiene block copolymer and acrylonitrile-butadiene copolymer are preferably used from the viewpoint of further improving the mechanical strength. One or more of these rubbery polymers can be used.

  Although there is no restriction | limiting in particular in the weight average particle diameter of a rubber-like polymer (r), The range of 0.05-1.0 micrometer is preferable and the range of 0.1-0.5 micrometer is more preferable. By setting the weight average particle diameter of the rubber polymer in the range of 0.05 μm to 1.0 μm, the impact strength and tensile properties of the I layer can be further improved. Further, it is preferable to use two or more kinds of rubbery polymers having different weight average particle diameters from the viewpoint of further improving impact resistance and fluidity. For example, a rubbery polymer having a small weight average particle diameter and weight average particles are used. A so-called bimodal rubber using a rubber polymer having a large diameter may be used. Here, the weight average particle diameter of the rubber-like polymer (r) is alginic acid described in “Rubber Age, Vol. 88, p.484-490, (1960), by E. Schmidt, PH Biddison”. Sodium method, that is, a method for obtaining a particle size of a cumulative weight fraction of 50% from a creamed weight fraction and a cumulative weight fraction of sodium alginate concentration by utilizing the difference in the diameter of the polybutadiene particles to be creamed depending on the concentration of sodium alginate Can be measured.

  Although there is no restriction | limiting in particular in gel content of rubber-like polymer (r), From a viewpoint of improving the impact strength and heat resistance of I layer more, it is preferable that it is 40 to 99 weight%, and 60 to 95 weight%. It is more preferable that it is 70 to 90% by weight. Here, gel content can be measured by the method of calculating | requiring weight% of the insoluble part obtained by extracting at room temperature for 24 hours using toluene.

As described above, the graft copolymer (C) is a graft copolymer having a structure in which a monomer component containing the aromatic vinyl monomer (b1) is graft-polymerized to the rubber polymer (r). In addition, it contains a polymer of monomer components not grafted to the rubber polymer (r). The graft ratio of the graft copolymer (C) is not particularly limited, but is preferably 10 to 100% by weight, particularly 30 to 70% by weight, from the viewpoint of further improving the impact strength and tensile properties of the I layer. Preferably there is. Here, the graft ratio is a value calculated by the following equation.
Graft rate (%) = [<Amount of vinyl copolymer grafted onto rubber polymer (weight)> / <Rubber content (weight) of graft copolymer>] × 100.

  The characteristics of the ungrafted polymer contained in the graft copolymer (C) are not particularly limited, but the weight average molecular weight is preferably 10,000 or more, more preferably 50,000 or more from the viewpoint of further improving the impact strength of the I layer. Is more preferable. On the other hand, from the viewpoint of improving moldability, it is preferably 40,000 or less, and more preferably 150,000 or less. The weight average molecular weight here refers to the weight average molecular weight in terms of polystyrene measured by GPC using tetrahydrofuran as a solvent. In addition, the polymer which is not grafted here shows the soluble part melt-extracted using methyl ethyl ketone among graft copolymers (C).

  As described above, the graft copolymer (C) can be obtained by a known polymerization method. For example, in the presence of a rubber polymer (r) latex, a mixture of a monomer containing an aromatic vinyl monomer (b1) and a chain transfer agent and a solution of a radical generator dissolved in an emulsifier are continuously added. It can be obtained by a method such as supplying to a polymerization vessel and emulsion polymerization.

(Inorganic filler (D))
The conductive laminate sheet of the present invention is characterized in that an inorganic filler (D) is blended with the polylactic acid-based thermoplastic resin composition constituting the I layer. Conventionally, it has been known that when an inorganic filler is generally added to a resin composition, the flexural modulus is improved, but the impact strength is reduced, and a so-called hard and brittle material is obtained. However, in the present invention, by adding an inorganic filler to the polylactic acid-based thermoplastic resin composition constituting the I layer, the flexural modulus can be greatly improved while maintaining the impact strength.

  In addition, when the blending amount of the polylactic acid-based resin (A) in the polylactic acid-based thermoplastic resin composition constituting the I layer is 40% by weight or more, the II layer formed by molding the conductive thermoplastic resin composition; The delamination strength (adhesion strength) of the sheet is reduced, and peeling occurs due to vibration and impact when cutting to a predetermined size after forming the sheet, which may cause burrs or parts that lack electrical conductivity. It was. Such a decrease in adhesion strength is thought to be because the molecular structure is completely different depending on the composition constituting the I layer and the II layer. However, in the present invention, the molecular structure is reduced by adding the inorganic filler (D). The adhesion strength between the two different layers is improved, and the delamination strength of the conductive laminate sheet can be greatly improved. Thereby, it is not necessary to use a binder having a relatively high affinity with both layers, and the manufacturing process can be further simplified.

  Furthermore, the bending durability (also referred to as bending strength) of the conductive laminated sheet can be improved by blending the inorganic filler (D) with the polylactic acid-based thermoplastic resin composition constituting the I layer. In sheet molding, since the resin is generally oriented in the MD direction, the bending strength in the TD direction, which is the non-oriented direction, tends to be weak. In particular, when the blending amount of the polylactic acid resin (A) in the polylactic acid thermoplastic resin composition constituting the I layer is 40% by weight or more, the polylactic acid resin (A) is easily oriented. Although the bending strength of the layer in the TD direction tends to be low, in the present invention, by adding an inorganic filler to the polylactic acid-based thermoplastic resin composition constituting the I layer, the impact of the I layer as described above. Since the strength is high and the delamination strength of the conductive laminated sheet is improved, the bending durability can be greatly improved in both the MD direction and the TD direction.

  Examples of the inorganic filler used in the present invention include talc, kaolinite, montmorillonite, mica, synthetic mica, clay, zeolite, silica, graphite, carbon black, zinc oxide, magnesium oxide, calcium oxide, titanium oxide, and calcium sulfide. Boron nitride, magnesium carbonate, calcium carbonate, barium sulfate, aluminum oxide and the like. Two or more of these may be blended. From the viewpoint of further improving the flexural modulus while maintaining the impact strength, talc and calcium carbonate are preferable, and talc is more preferable.

  The size and shape of the inorganic filler are not particularly limited, but from the viewpoint of further improving the impact strength of the I layer, the average particle size (D50) of the inorganic filler is preferably 10 μm or less, more preferably 7 μm or less, and 5 μm or less. Is more preferable.

  In the present invention, from the viewpoint of low environmental load, in the polylactic acid-based thermoplastic resin composition constituting the I layer, the polylactic acid-based resin (A) is based on a total of 100 parts by weight of (A) to (D). 40 parts by weight or more is blended. On the other hand, when the blending amount of the polylactic acid resin (A) exceeds 70 parts by weight, the blending amounts of the styrene resin (B) and the graft copolymer (C) are relatively lowered, and the impact strength of the I layer is reduced. Since it falls, the bending durability and delamination strength of the conductive laminated sheet are lowered. The compounding quantity of polylactic acid-type resin (A) becomes like this. Preferably it is 65 weight part or less, More preferably, it is 60 weight part or less.

  Moreover, in the polylactic acid-type thermoplastic resin composition which comprises I layer, the compounding quantity of styrene-type resin (B) is 5-53 weight part with respect to a total of 100 weight part of (A)-(D). . When the blending amount of the styrene resin (B) is less than 5 parts by weight, the impact strength of the I layer is lowered, and the bending durability and delamination strength of the conductive laminated sheet are lowered. From the viewpoint of further improving the impact strength of the I layer, the amount of the styrene resin (B) is more preferably 20 parts by weight or more. On the other hand, when the blending amount of the styrene resin (B) is more than 53 parts by weight, the blending amount of the graft copolymer (C) is relatively decreased, and the impact strength of the I layer is decreased. The bending durability of the is reduced.

  Moreover, in the polylactic acid-type thermoplastic resin composition which comprises I layer, the compounding quantity of a graft copolymer (C) is 5-53 weight part with respect to a total of 100 weight part of (A)-(D). is there. When the blending amount of the graft copolymer (C) is less than 5 parts by weight, the impact strength of the I layer is lowered, so that the bending durability of the conductive laminated sheet is lowered. On the other hand, when the blending amount of the graft copolymer (C) is more than 53 parts by weight, the blending amount of the styrene resin (B) is relatively lowered and the impact strength of the I layer is lowered. The bending durability and delamination strength of the steel deteriorate. In addition, defects such as poor appearance due to surface irregularities of the molded product due to poor dispersion of the graft copolymer (C) may occur. From the viewpoint of further improving the surface smoothness of the conductive laminated sheet, the blending amount of the graft copolymer (C) is more preferably 35 parts by weight or less.

  Moreover, the polylactic acid-type thermoplastic resin composition which comprises I layer WHEREIN: The compounding quantity of an inorganic filler (D) is 2-20 weight part with respect to a total of 100 weight part of (A)-(D). . When the blending amount of the inorganic filler (D) is less than 2 parts by weight, the bending elastic modulus of the I layer is lowered, so that the bending durability of the conductive laminated sheet is lowered. Furthermore, the delamination strength of the conductive laminated sheet is reduced. As for the compounding quantity of an inorganic filler (D), 3 weight part or more is preferable. On the other hand, when the blending amount of the inorganic filler (D) exceeds 20 parts by weight, the impact strength of the I layer is lowered, so that the bending durability and delamination strength of the conductive laminated sheet are lowered. The blending amount of the inorganic filler (D) is preferably 15 parts by weight or less, and more preferably 10 parts by weight or less.

  Moreover, it is preferable to mix | blend acrylic resin (F) with a polylactic acid-type thermoplastic resin composition in addition to said (A)-(D). An acrylic resin is a polymer or copolymer of an alkyl (meth) acrylate monomer, and is a polylactic acid resin (A), a styrene resin (B), a graft copolymer (C), an epoxy. It is a polymer other than the group-containing acrylic-styrene copolymer (G). By mix | blending acrylic resin (F), the impact strength of I layer, the bending durability of an electroconductive laminated sheet, especially the bending durability of MD direction can be improved more.

  Examples of the alkyl (meth) acrylate monomer include, for example, methyl methacrylate, methyl acrylate, ethyl acrylate, ethyl methacrylate, butyl acrylate, butyl methacrylate, cyclohexyl methacrylate, hydroxyethyl methacrylate, methacrylic acid Glycidyl, allyl methacrylate, aminoethyl acrylate, propylaminoethyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, glycidyl acrylate, dicyclopentenyloxyethyl acrylate, dicyclopentanyl acrylate, Butanediol diacrylate, nonanediol diacrylate, polyethylene glycol diacrylate, methyl 2- (hydroxymethyl) acrylate, ethyl 2- (hydroxymethyl) acrylate, methacrylate Phosphoric acid, ethyl methacrylate, butyl methacrylate, cyclohexyl methacrylate, dimethylaminoethyl methacrylate, ethylaminopropyl methacrylate, phenylaminoethyl methacrylate, cyclohexylaminoethyl methacrylate, 2-hydroxyethyl methacrylate, methacrylic acid 2-hydroxypropyl, glycidyl methacrylate, dicyclopentenyloxyethyl methacrylate, dicyclopentanyl methacrylate, pentamethylpiperidyl methacrylate, tetramethylpiperidyl methacrylate, benzyl methacrylate, ethylene glycol dimethacrylate, propylene dimethacrylate And glycols and polyethylene glycol dimethacrylate. One or more of these can be used.

  Moreover, you may copolymerize the compound which has ring structures, such as a lactone ring, a maleic acid anhydride, and glutaric acid anhydride, with the said (meth) acrylic-acid type monomer.

  The acrylic resin (F) used in the present invention is preferably a polymethyl methacrylate resin mainly composed of a methyl methacrylate component unit, and a polymethyl methacrylate resin unit containing 70% by weight or more of the methyl methacrylate component unit in all monomers. A methyl methacrylate resin is more preferable, and a polymethyl methacrylate (PMMA) resin is more preferable.

  The molecular weight and molecular weight distribution of the acrylic resin (F) are not particularly limited as long as the molding process is substantially possible, but the weight average molecular weight is 1,000 to 450,000 from the viewpoint of molding processability. Preferably, there are 10,000 to 200,000, more preferably 30,000 to 150,000. The weight average molecular weight here is a weight average molecular weight in terms of polymethyl methacrylate (PMMA) measured by GPC using tetrahydrofuran as a solvent.

  As for the compounding quantity of acrylic resin (F), 10 weight part or less is preferable with respect to a total of 100 weight part of said (A)-(D) component. A blending amount of the acrylic resin (F) of 10 parts by weight is sufficient, and even if it is blended more, a greater effect cannot be expected. On the other hand, 3 parts by weight or more is more preferable from the viewpoint of further improving the impact strength of the I layer and the bending durability of the conductive laminated sheet.

  Further, in the present invention, an epoxy group-containing acrylic-styrene copolymer (G) is added to the polylactic acid-based thermoplastic resin composition in addition to the components (A) to (D) and, if necessary, the component (F). ) Is preferably blended. By blending the epoxy group-containing acrylic-styrene copolymer (G), the heat distortion temperature of the polylactic acid-based thermoplastic resin composition can be improved, so that the heat resistance of the conductive laminated sheet is improved. Can do. When the blending amount of the polylactic acid resin (A) is 40 parts by weight or more, the thermal deformation temperature of the polylactic acid thermoplastic resin composition when the epoxy group-containing acrylic-styrene copolymer (G) is not blended is Although it is normally 55-60 degreeC, the heat distortion temperature can be raised by the mixing | blending of an epoxy-group-containing acrylic-styrene-type copolymer (G), and the heat resistance of an electroconductive laminated sheet can be improved. In addition, since the impact strength of the I layer can be further improved by blending the epoxy group-containing acrylic-styrene copolymer (G), it is possible to further improve the bending durability of the conductive laminated sheet in the TD direction. it can.

  The epoxy group-containing acrylic-styrene copolymer (G) is a polymer containing an epoxy group, and is a styrene monomer, an acrylic monomer, and other monomers copolymerizable as required. Is a copolymer obtained by copolymerization. The introduction of the epoxy group into the copolymer may be performed by a method using an epoxy group as a styrene monomer or an acrylic monomer, or a styrene monomer and an acrylic monomer. Alternatively, it may be carried out by a method of copolymerizing with another copolymerizable monomer having an epoxy group.

  As a specific example of the acrylic monomer, an ester of an alcohol having 1 to 6 carbon atoms and (meth) acrylic acid is preferable, and the ester may further have a substituent. Examples thereof include compounds exemplified as the unsaturated carboxylic acid alkyl ester monomer (b3) which is a monomer component of the styrene resin (B). These may be used alone or in combination of two or more. Preferably it is methyl methacrylate.

  Specific examples of the styrene monomer include styrene, α-methylstyrene, vinyltoluene, p-methylstyrene, t-butylstyrene, o-chlorostyrene, and vinylpyridine. You may use 1 type, or 2 or more types of these. Styrene is preferred.

  As the styrene monomer or acrylic monomer having an epoxy group, those obtained by introducing an epoxy group into the aforementioned acrylic monomer are preferred from the viewpoint of radical polymerizability. You may use 1 type, or 2 or more types of these. Preferred is glycidyl acrylate or glycidyl methacrylate, and more preferred is glycidyl methacrylate.

  The weight average molecular weight of the epoxy group-containing acrylic-styrene copolymer (G) is not particularly limited, but the reactivity with the terminal group of the polylactic acid resin (A), the polylactic acid resin (A), and the styrene resin are not limited. From the viewpoint of compatibility with the resin (B), the weight average molecular weight of the copolymer is preferably 1,000 to 40,000. If the weight average molecular weight of the epoxy group-containing acrylic-styrene copolymer (G) is 1,000 or more, the compatibility with the polylactic acid resin (A) and the styrene resin (B) can be improved. . 1,500 or more is more preferable, and 2,000 or more is more preferable. On the other hand, if the weight average molecular weight of the epoxy group-containing acrylic-styrene copolymer (G) is 40,000 or less, the reactivity with the terminal group of the polylactic acid resin (A) can be improved. 20,000 or less is more preferable, and 10,000 or less is more preferable. Here, the weight average molecular weight is a weight average molecular weight (in terms of PMMA) measured by GPC using a tetrahydrofuran solvent as a solvent.

  Although there is no restriction | limiting in particular in the epoxy value of an epoxy-group-containing acrylic-styrene-type copolymer (G), 3.0 meq / g or more is from a viewpoint of improving the reactivity with the terminal group of a polylactic acid-type resin (A). preferable. The epoxy value here is a value measured according to JIS K 7236 (2009).

  As for the compounding quantity of an epoxy-group-containing acrylic-styrene-type copolymer (G), 0.1-10 weight part is preferable with respect to a total of 100 weight part of (A)-(D). If the compounding quantity of an epoxy-group-containing acrylic-styrene type copolymer (G) is 0.1 weight part or more, the heat resistance of an electroconductive lamination sheet can be improved more. 0.3 parts by weight or more is more preferable. On the other hand, if the blending amount of the epoxy group-containing acrylic-styrene copolymer (G) is 10 parts by weight or less, generation of defects due to acceleration of gelation, decrease in fluidity due to excessive increase in melt viscosity, and flow mark of appearance of molded product Appearance defects such as occurrence can be suppressed.

  In the present invention, two or more epoxy group-containing acrylic-styrene copolymers (G) having different epoxy values and weight average molecular weights may be blended. From the viewpoint of minimizing the blending amount, it is preferable to blend at least one epoxy group-containing acrylic-styrene copolymer having an epoxy value of 3.0 meq / g or more.

  The epoxy group-containing acrylic-styrene copolymer (G) can be produced and used by a known technique, but it is also possible to use a commercially available product. “ARUFON” (registered trademark) series and “RESEDA” (registered trademark) series manufactured by Gosei Co., Ltd., and “JONCRYL” (registered trademark) series manufactured by BASF are preferred, and among them, “JONCRYL ADR-4368” is more preferably used. .

  In the present invention, the polylactic acid-based thermoplastic resin composition contains phosphoric acid and / or monosodium phosphate (in addition to the components (A) to (D) and (F) to (G) as necessary. It is preferable to blend H). The graft copolymer (C) may be alkaline depending on the production process, and mineral inorganic fillers typically represented by talc are also alkaline. By blending phosphoric acid and / or monosodium phosphate (H), alkali decomposition of the polylactic acid resin (A) is suppressed, and the resulting polylactic acid resin composition, and thus the impact strength of the I layer is further increased. Can be improved. Furthermore, since heat stability can be improved more, melt viscosity is stabilized and sheet moldability can also be improved. In addition, phosphoric acid and / or monosodium phosphate (H) is a resin composition containing a raw material, a melt compound, and a safety and hygiene for the human body due to an irritating odor generated when the obtained resin composition is molded. From the viewpoint of the thermal stability of the composition, it is superior to other neutralizing agents including organic acids already known.

  In the present invention, the blending amount of phosphoric acid and / or monosodium phosphate (H) in the lactic acid-based thermoplastic resin composition is 0.01 to 5 with respect to 100 parts by weight of the total of components (A) to (D). A range of parts by weight is preferred. By making the blending amount of phosphoric acid and / or monosodium phosphate (H) 0.01 parts by weight or more, the effect of suppressing alkali decomposition of the polylactic acid resin (A) is further improved, and the impact strength of the I layer is increased. It can be improved further. The blending amount of phosphoric acid and / or monosodium phosphate (H) is preferably 0.1 parts by weight or more. On the other hand, by setting the blending amount of phosphoric acid and / or monosodium phosphate (H) to 5 parts by weight or less, foaming during heat retention of the conductive laminated sheet can be suppressed, and the surface appearance can be improved. The blending amount of phosphoric acid and / or monosodium phosphate (H) is more preferably 2 parts by weight or less, and further preferably 0.5 parts by weight or less.

  In the present invention, in addition to phosphoric acid and / or monosodium phosphate (H), a graft copolymer (C) or an inorganic filler (D) blended in a polylactic acid-based thermoplastic resin composition as necessary. Any substance can be used as long as it is an acidic substance that can neutralize the alkalinity. Specifically, inorganic acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, malonic acid, succinic acid, maleic acid, adipic acid, sebacic acid, azelaic acid, dodecanedioic acid, cyclohexanedicarboxylic acid, citric acid, terephthalic acid Acids, isophthalic acid, orthophthalic acid, benzoic acid, trimellitic acid, pyromellitic acid, phenol, naphthalenedicarboxylic acid, diphenic acid and other organic acids, oxalic acid, malonic acid, succinic acid, maleic acid, adipic acid, sebacic acid, Azelaic acid, dodecanedioic acid, citric acid, orthophthalic acid, trimellitic acid, and pyromellitic acid acid anhydride. Two or more of these may be used in combination.

  You may mix | blend various thermoplastic resins with the polylactic acid-type thermoplastic resin composition used for this invention in the range which does not impair the objective of this invention. Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, polyester resins other than the polylactic acid resin (A), polyamide resins such as nylon 6 and nylon 6, 6, modified polyphenylene ether (PPE) resin, and polycarbonate resin. , Polyacetal resins, modified products thereof, and elastomers. By blending such a thermoplastic resin, the performance of the I layer can be further improved.

  In addition, the polylactic acid-based thermoplastic resin composition includes antioxidants such as hindered phenols, sulfur-containing compounds, or phosphorus-containing organic compounds, phenols, acrylates, etc., as long as the effects of the present invention are not impaired. Heat stabilizers, UV absorbers such as benzotriazole, benzophenone or salicylate, light stabilizers such as organic nickel and hindered amines, higher fatty acid metal salts, higher fatty acid amides and other lubricants, phthalates Plasticizers such as phosphoric acid esters, brominated compounds, various flame retardants such as phosphoric acid esters or red phosphorus, flame retardant aids such as antimony trioxide and antimony pentoxide, metal salts of alkylcarboxylic acids and alkylsulfonic acids , Pigments and dyes can be blended.

  The polylactic acid-based thermoplastic resin composition can be obtained, for example, by blending each component based on a specified number of parts and melt-kneading. As a method of melt kneading each component, a method of melt kneading using a known single-screw or twin-screw extruder having a heating device and a vent port is preferable. The heating temperature at the time of melt kneading is usually selected from the range of 210 to 260 ° C. However, it is also possible to freely set the temperature gradient at the time of melt kneading within the range not impairing the object of the present invention.

[II layer (a layer formed by molding a conductive thermoplastic resin composition)]
The II layer is formed by molding a conductive thermoplastic resin composition comprising a styrene resin (B), a graft copolymer (C), and a conductive agent (E). By using the conductive thermoplastic resin composition, the II layer plays a role of lowering the surface specific resistance value of the conductive laminated sheet and imparting conductivity.

(Styrene resin (B), graft copolymer (C))
The styrene resin (B) and graft copolymer (C) used in the conductive thermoplastic resin composition constituting the II layer are the styrene resin (B) and graft copolymer in the polylactic acid thermoplastic resin composition. If it illustrates as a polymer (C), it will not restrict | limit in particular. Styrenic resin (B) and graft copolymer (C) in the polylactic acid-based thermoplastic resin composition constituting the I layer, and styrene resin (B) in the conductive thermoplastic resin composition constituting the II layer, and The graft copolymer (C) may be the same as or different from the graft copolymer (C), but is preferably the same from the viewpoint of further improving the delamination strength between the I layer and the II layer.

  In the conductive thermoplastic resin composition constituting the II layer, the blending amount of the styrene resin (B) and the graft copolymer (C) is not particularly limited, but the styrene resin (B) and the graft copolymer ( From the viewpoint of improving the strength of the conductive laminated sheet, the blending amount of the graft copolymer (C) is preferably 10 parts by weight or more with respect to 100 parts by weight of the total of C) and the conductive agent (D) described later. More preferred are parts by weight. On the other hand, from the viewpoint of more uniformly dispersing the graft copolymer (C) in the II layer and suppressing the generation of blisters, the blending amount of the graft copolymer (C) is preferably 40 parts by weight or less, and 30 parts by weight. The following is more preferable.

  As the conductive agent (E), commercially available conductive fillers, surfactants, polyether ester amide polymers, potassium ionomers, and the like can be used. From the standpoint of stabilizing the surface resistivity of the conductive laminated sheet, and suppressing the appearance defects due to bleeds when molding the sheet, mess, roll dirt, and falling off of the conductive filler during cutting. preferable.

  Examples of the conductive filler include carbon black such as ketjen black and acetylene black.

  Examples of the surfactant include glycerin fatty acid ester, polyoxyethylene alkyl ester, polyoxyethylene alkylphenyl ether, N, N-bis (2-hydroxyethyl) alkylamine, polyoxyethylene alkylamine, and polyoxyethylene alkylamine. Nonionic surfactants such as fatty acid esters, anionic surfactants such as alkylsulfonates and alkylbenzenesulfonates, cationic surfactants such as tetraalkylammonium salts and trialkylbenzylammonium salts, alkylbetaines, alkyls Examples include amphoteric surfactants such as imidazolium betaine.

  The polyether ester amide polymer includes a diol compound to which poly (alkylene oxide) glycol and alkylene oxide are added as a constituent component, and further includes a reaction product of an aminocarboxylic acid, a lactam or a diamine and a dicarboxylic acid as a constituent component. The block or graft copolymer is shown.

  Furthermore, when the polyether ester amide polymer is used in combination with the above-described surfactant, perfluoroalkyl compound, organic ionic conductive agent, etc., the surface resistivity can be further reduced.

  Examples of the perfluoroalkyl compounds include perfluoroalkylsulfonic acids, perfluoroalkylsulfonimides (linear type and cyclic type), and perfluorosulfonamides.

  The organic ionic conductive agent is an organic compound salt having an ionic characteristic while being an organic substance, and includes an ionic liquid or a ionic liquid which is a liquid at room temperature and has a low melting point. . Examples of such organic compound salts include those composed of cations such as imidazolium, pyridinium, ammonium and phosphonium and anions containing fluorine such as fluoride ions and triflate.

  In the conductive thermoplastic resin composition constituting the II layer, the blending amount of the conductive agent (D) is not particularly limited, and the conductive agent to be blended so that a desired surface specific resistance value can be obtained in the conductive laminated sheet. The blending amount can be appropriately adjusted according to the type.

  You may mix | blend various thermoplastic resins with the conductive thermoplastic resin composition used for this invention in the range which does not impair the objective of this invention. Examples of the thermoplastic resin include polyolefin resins such as polyethylene and polypropylene, polyester resins other than the polylactic acid resin (A), polyamide resins such as nylon 6 and nylon 6, 6, modified polyphenylene ether (PPE) resin, and polycarbonate resin. , Polyacetal resins, modified products thereof, and elastomers. By blending such a thermoplastic resin, the performance of the II layer can be further improved.

  In addition, the conductive thermoplastic resin composition used in the present invention includes antioxidants such as hindered phenol-based compounds, sulfur-containing compound-based compounds, and phosphorus-containing organic compound-based compounds, phenol-based compounds within the range not impairing the object of the present invention. , Heat stabilizers such as acrylates, UV absorbers such as benzotriazoles, benzophenones or salicylates, light stabilizers such as organic nickels and hindered amines, lubricants such as higher fatty acid metal salts, higher fatty acid amides, Plasticizers such as phthalates and phosphates, brominated compounds, various flame retardants such as phosphate esters or red phosphorus, flame retardant aids such as antimony trioxide and antimony pentoxide, alkyl carboxylic acids and alkyl sulfones Acid metal salts, pigments, dyes, and the like can be blended.

  The conductive thermoplastic resin composition can be obtained, for example, by blending each component based on a specified number of parts and melt-kneading. As a method of melt kneading each component, a method of melt kneading using a known single-screw or twin-screw extruder having a heating device and a vent port is preferable. The heating temperature at the time of melt kneading is usually selected from the range of 210 to 260 ° C. However, it is also possible to freely set the temperature gradient at the time of melt kneading within the range not impairing the object of the present invention.

[Conductive laminate sheet]
The conductive laminated sheet of the present invention comprises at least one I layer formed by molding the polylactic acid-based thermoplastic resin composition and at least one II layer formed by molding the conductive thermoplastic resin composition, One outermost layer is the II layer, and at least one pair of the I layer and the II layer are adjacent to each other. By making at least one outermost layer the II layer, it is possible to impart practically excellent conductivity to the laminated sheet. Further, by using the above-mentioned polylactic acid-based thermoplastic resin composition and conductive thermoplastic resin composition, even if the I layer and the II layer are adjacent to each other, the delamination strength of these layers can be sufficiently increased. Etc. need not be provided. In general, “sheet” is a thin product as defined by JIS, and generally its thickness is small and flat instead of length and width. In general, “film” refers to length and width. A thin flat product having an extremely small thickness and an arbitrarily limited maximum thickness, usually supplied in the form of a roll (JIS K6900 (1994)). For example, in terms of thickness, in the narrow sense, a film having a thickness of 100 μm or more is sometimes referred to as a sheet, and a film having a thickness of less than 100 μm is sometimes referred to as a film. However, the boundary between the sheet and the film is not clear, and it is not necessary to distinguish the two in terms of the wording in the present invention. Therefore, even in the present invention, the term “sheet” includes “film”.

In the present invention, “conductive” means that the surface specific resistance value is 1 × 10 ¹² Ω or less. The surface resistivity of the conductive laminated sheet of the present invention is preferably 1 × 10 ¹² Ω or less, more preferably 1 × 10 ¹¹ Ω or less, and even more preferably 1 × 10 ¹⁰ Ω or less from the viewpoint of product protection by dust prevention. In addition, the surface specific resistance value here is a surface specific resistance value of the II layer of an electroconductive laminated sheet, and is a value measured by ASTM D257 (1990). Moreover, the surface specific resistance value of an electroconductive laminated sheet can be arbitrarily adjusted by adjusting the compounding quantity of the electrically conductive agent (E) in the electroconductive thermoplastic resin composition which comprises the said II layer, for example.

  The conductive laminated sheet of the present invention has at least one I layer and II layer, at least one outermost layer is the II layer, and at least one pair of the I layer and the II layer are adjacent to each other. If it is, it will not specifically limit, For example, 2 type 2 layer structure of I layer / II layer, 2 type 3 layer structure of II layer / I layer / II layer, etc. are mentioned. From the viewpoint of further improving the conductivity of the conductive laminated sheet, in the case of three or more layers, it is preferable that all outer layers are II layers, and a two-layer / three-layer configuration of II layer / I layer / II layer is more preferable. preferable.

  The thickness of the conductive laminated sheet is not particularly limited depending on the application to be used, but is preferably 200 to 1,500 m, and more preferably 300 to 1,000 μm. The thickness ratio of the I layer and the II layer with respect to the total thickness of the conductive laminated sheet is preferably 60/40 or more, and 70/30 or more, from the viewpoint of global environmental conservation. It is more preferable that On the other hand, from the viewpoint of further improving the conductivity, the thickness ratio of the I layer / II layer is preferably 95/5 or less. Here, when it has two or more I layers or II layers, the thickness of I layer or II layer points out total thickness of each.

The conductive laminate sheet of the present invention can improve the impact strength of the I layer by blending a specific amount of the inorganic filler (D) into the polylactic acid-based thermoplastic resin composition constituting the I layer as described above. it can. In order to widely apply the conductive laminated sheet of the present invention, the Charpy impact strength of the I layer measured according to ISO 179-1 (2000) type A is preferably 4 kJ / m ² or more, and 5 kJ / m. It is more preferably ² or more, and more preferably 7 kJ / m ² or more. When the Charpy impact strength of the I layer is 4 kJ / m ² or more, it is possible to suppress a crack or the like when the conductive laminated sheet is dropped. For example, in the polylactic acid-based thermoplastic resin composition constituting the I layer, the Charpy impact strength of the I layer can be adjusted to the above range by setting the blending amount of the inorganic filler (D) within the above-mentioned preferable range. .

  As described above, the conductive laminated sheet of the present invention contains a specific amount of the inorganic filler (D) in the polylactic acid-based thermoplastic resin composition constituting the I layer, thereby delamination strength between the I layer and the II layer. Can be improved.

  In addition, the conductive laminated sheet of the present invention has a bending durability (bending strength) by blending a specific amount of the inorganic filler (D) into the polylactic acid thermoplastic resin composition constituting the I layer as described above. Can be improved. The bending durability is the durability when the sheet is repeatedly bent by 180 °. Since the bending strength of the conductive laminated sheet is greatly influenced by the bending strength of the I layer, for example, in the polylactic acid-based thermoplastic resin composition constituting the I layer, the blending amount of the inorganic filler (D) is set as described above. By setting it in a preferable range, it is possible to sufficiently withstand repeated bending in both the MD direction and the TD direction.

  Moreover, it is preferable that the electroconductive laminated sheet of this invention has high heat resistance, and it can apply it to a wide use and field. For example, by adding an epoxy group-containing acrylic-styrene copolymer (G) to the polylactic acid thermoplastic resin composition constituting the I layer, the thermal deformation temperature of the I layer can be made 65 ° C. or higher. A conductive laminated sheet having high heat resistance can be obtained.

  The conductive laminated sheet of the present invention is more environmentally friendly than the conventional conductive laminated sheet, and is superior in terms of dust resistance and bending durability due to its low surface specific resistance, and is excellent because of its high interlayer strength. Has cutting and cutting workability. For this reason, the range in which the conductive laminated sheet can be applied can be greatly expanded. In addition, for applications where general-purpose resins such as ABS resin are already used, the weight of the molded product is reduced. It can be expected to increase the degree of freedom of design and design.

  Although the manufacturing method of the electroconductive lamination sheet of this invention is not specifically limited, It is preferable to use the melt extrusion molding already implemented widely as a well-known technique. For example, as a polylactic acid-based thermoplastic resin composition that constitutes the I layer and a conductive thermoplastic resin composition that constitutes the II layer, all compounded raw materials are compounded and pelletized in advance, and these are extruded. Examples thereof include a method of melt-kneading and extrusion molding in a machine, and a method of extruding them while melt-kneading the blended raw materials constituting each layer using an extruder or the like. As a method of laminating the I layer and the II layer, a known technique can be used, and examples thereof include a multi-manifold method and a feed block method.

  In order to increase the thickness of the entire conductive laminated sheet and the thickness accuracy of each layer, it is preferable to reduce the difference in melt viscosity of the thermoplastic resin constituting each layer. Furthermore, since the polylactic acid-based thermoplastic resin composition is likely to be thermally deteriorated due to retention in the extrusion molding equipment, it is usually preferable to adjust the resin temperature in the range of 185 to 220 ° C.

  The conductive laminated sheet of the present invention may be further molded as appropriate to form a molded product. Examples of the method for obtaining a molded product from the conductive laminated sheet include a method of thermoforming the conductive laminated sheet. In thermoforming, the conductive laminated sheet may be preheated to a molding temperature with an infrared heater, a hot plate heater, hot air, or the like.

  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.

  The use of the conductive laminated sheet of the present invention is not particularly limited, but a tray for storing and transporting electronic components is preferable as an application that makes full use of these advantages. Electronic component storage / transport trays are rarely used repeatedly and are often treated as combustion waste after use. Moreover, high dust resistance and intensity | strength are required from a viewpoint of protection of an electronic component. The conductive laminated sheet of the present invention can be suitably used as a tray for storing and transporting electronic components, in total, from the usage method and required characteristics of the tray to disposal.

  Examples of the electronic parts include parts of various devices equipped with precise electric / electronic control devices. For example, car navigation systems, car audio systems, automotive electrical components such as fuel cell peripherals mounted on electric vehicles, IC peripheral components or casings such as commercial or home electronic toys equipped with ICs, commercial Or a household digital electronic device part, slot machines, pachinko machines, electronic game machines, etc. for business gaming / entertainment equipment.

  In order to more specifically explain the conductive laminated sheet of the present invention, the polylactic acid-based thermoplastic resin composition (A) and the conductive thermoplastic resin composition (B) constituting the same, the following examples are given. . The present invention is not limited to these examples. In the following examples and comparative examples, unless otherwise specified, “parts” and “%” represent “parts by weight” and “% by weight”, respectively.

[Characteristics of conductive laminated sheet]
(1) Bending durability Two test pieces having a length of 50 mm and a width of 50 mm were cut out from the conductive laminated sheets obtained in the examples and comparative examples. After storage for 48 hours in an environment of a temperature of 23 ° C. and a humidity of 50% RH, one of the test pieces was bent in the MD direction and the other in the TD direction, and then 180 ° bent, and then visually cracked. The presence or absence of was observed. When the occurrence of cracks in the surface layer and the inner layer was observed after one folding, the bending durability was evaluated as x. When the occurrence of cracks was not observed, the 180 ° bending was further repeated, and the presence or absence of cracks was visually observed each time. When the occurrence of cracks in the surface layer and the inner layer is observed, the number of folding is more than 1 and less than 20 times, Δ is 20 to less than 50 times, and cracks are generated even if it is repeatedly bent 50 times or more The case where it did not was evaluated as ◎. It is desirable that cracks do not occur even when folded repeatedly.

(2) Conductivity (surface resistivity)
After the conductive laminated sheets obtained in each of the examples and comparative examples were allowed to stand for 24 hours in an environment of temperature 23 ° C. and humidity 50% RH, in accordance with ASTM D257 (1990), the surface characteristic of the II layer surface The resistance value (Ω) was measured. The applied voltage was 500 V, and the surface specific resistance value (Ω) when 1 minute passed after the voltage application was read.

(3) Interlaminar peel strength The conductive laminate sheets obtained in each Example and Comparative Example were cut using a press cutting machine, and the cut surface was visually observed. When the burr or delamination of the I layer / II layer was observed on the cut surface, it was evaluated as x, and when it was not confirmed, it was evaluated as ◯.

[Characteristics of polylactic acid-based thermoplastic resin composition]
(4) Weight average molecular weight The weight average molecular weight of the polylactic acid resin (A) is a gel permeation chromatography (GPC) apparatus manufactured by Water, a differential refractometer is used as a detector (Water 2414), and a polymer laboratory is used as a column. MIXED-B (2) manufactured by using hexafluoroisopropanol as a distillate, and measured as a polymethyl methacrylate (PMMA) weight average molecular weight under conditions of a flow rate of 1 ml / min and a column temperature of 40 ° C.

  Methyl ethyl ketone soluble weight average molecular weight of styrene resin (B) and graft copolymer (C) is the same apparatus and conditions as those measured with polylactic acid resin (A) except that tetrahydrofuran is used as the distillate. And measured as a weight average molecular weight in terms of polystyrene.

  The weight-average molecular weight of the epoxy group-containing acrylic-styrene copolymer is measured using the same equipment and conditions as in the styrene resin (B) and graft copolymer (C), and converted to polymethyl methacrylate (PMMA). The weight average molecular weight was measured.

(5) Graft ratio of graft copolymer (C) The graft ratio of the graft copolymer (C) was determined by the following method. Acetone was added to a predetermined amount (m) of the graft copolymer and refluxed for 4 hours. The solution was centrifuged at 8000 rpm (centrifugal force 10,000 G for 30 minutes, and then the insoluble matter was filtered. The insoluble matter was dried under reduced pressure at a temperature of 70 ° C. for 5 hours, and the weight (n) was measured. The graft ratio was determined by the following formula, where L represents the rubber content (% by weight) of the graft copolymer.
Graft rate (%) = [(n) − {(m) × L / 100}] / [(m) × L / 100] × 100

(6) Charpy impact strength From the polylactic acid-based thermoplastic resin composition pellets obtained in each of the examples and comparative examples, a test piece was prepared by injection molding under conditions of a cylinder temperature of 220 ° C and a mold temperature of 60 ° C. The Charpy impact strength was measured according to ISO 179.

(7) Flexural modulus From the polylactic acid-based thermoplastic resin composition pellets obtained in each of the examples and comparative examples, a test piece was prepared by injection molding under conditions of a cylinder temperature of 220 ° C. and a mold temperature of 60 ° C. The flexural modulus was measured according to ISO 178 (2001). The tensile speed was 50 mm / min.

(8) Deflection temperature under load From the polylactic acid-based thermoplastic resin composition pellets obtained in each of the examples and comparative examples, a test piece was prepared by injection molding under conditions of a cylinder temperature of 220 ° C. and a mold temperature of 60 ° C. According to ISO75-1 (2004) flatwise, the deflection temperature under load was measured under the condition of a load of 0.45 MPa.

  Hereinafter, the raw material used in the Example of an electroconductive lamination sheet, its manufacturing method, etc. are shown.

[Polylactic acid resin (A)]
Polylactic acid (poly-L-lactic acid having a weight average molecular weight of 200,000, a D-lactic acid unit of 1%, and a melting point of 175 ° C.) manufactured by NatureWorks.

[Styrene resin (B)]
(B-1)
In a stainless steel autoclave having a capacity of 20 L and equipped with a baffle and a foudra type stirring blade, 0.05 part by weight of methyl methacrylate / acrylamide copolymer (described in Japanese Patent Publication No. 45-24151) is added to 165 parts by weight of ion-exchanged water. The dissolved solution was added and stirred at 400 rpm, and the system was replaced with nitrogen gas. Next, the following mixed substances were added with stirring in the reaction system, and the temperature was raised to 60 ° C. to initiate polymerization.
Styrene 70 parts by weight Acrylonitrile 30 parts by weight t-dodecyl mercaptan 0.33 parts by weight 2,2′-azobisisobutyronitrile 0.31 parts by weight

  After raising the reaction temperature to 65 ° C. over 30 minutes, the temperature was raised to 100 ° C. over 120 minutes. Thereafter, the reaction system was cooled, the polymer was separated, washed, and dried according to the usual method to obtain a bead-shaped polymer. The weight average molecular weight of the obtained styrene resin (B-1) was 134,000.

[Graft Copolymer (C)]
(C-1)
50 parts by weight of polybutadiene (weight average particle size 0.35 μm, gel content 75% by weight, “Nipol LX111A2” manufactured by Nippon Zeon Co., Ltd.) (in terms of solid content)
Potassium oleate 0.5 parts by weight Glucose 0.5 parts by weight Monosodium pyrophosphate 0.5 parts by weight Ferrous sulfate 0.005 parts by weight Deionized water 120 parts by weight

  The above substances were charged into a polymerization vessel and heated to 65 ° C. with stirring. When the internal temperature reached 65 ° C., polymerization was started, and 35 parts by weight of styrene, 15 parts by weight of acrylonitrile, and 0.3 parts by weight of t-dodecyl mercaptan were continuously added dropwise over 5 hours. In parallel, an aqueous solution consisting of 0.25 parts by weight of cumene hydroperoxide, 2.5 parts by weight of potassium oleate and 25 parts by weight of pure water was continuously added dropwise over 7 hours to complete the reaction. The obtained graft copolymer latex was coagulated with sulfuric acid, neutralized with caustic soda, washed, filtered and dried to obtain a powder. The graft ratio of the obtained graft copolymer was 50%, and the weight average molecular weight of methyl ethyl ketone-soluble component was 83,000.

[Inorganic filler (D)]
(D-1) Talc LS-402 (Ube Materials Co., Ltd. average particle size (D50) 4.7 μm).

[Acrylic resin (F)]
(F-1) Polymethyl methacrylate resin (“SUMIPEX” (registered trademark) MH, Mw 182,000, manufactured by Sumitomo Chemical Co., Ltd.).

[Conducting agent (E)]
(Production method of (E-1))
45 parts by weight of ε-caprolactam, 45 parts by weight of an ethylene oxide adduct of bisphenol A having a number average molecular weight of 1,800, 5 parts by weight of polyethylene glycol having a number average molecular weight of 1,800, 5.2 parts by weight of terephthalic acid, and “Irganox” (Registered trademark) 1098 (Antioxidant) 0.2 part by weight was charged into a reaction vessel, purged with nitrogen, heated and stirred at 260 ° C. for 60 minutes to obtain a transparent homogeneous solution, and then reduced in pressure to 0.07 kPa or less. did. Tetrabutyl titanate (0.1 part by weight) was added and reacted for 2 hours under the conditions of a pressure of 0.07 kPa or less and a temperature of 260 ° C. The obtained polymer was discharged in the form of strands and cut to obtain pellets of polyetheresteramide polymer (F-1).

  (E-2) Organic ion conductive agent 1-butyl-3-methylpyridinium trifluoromethanesulfonate (manufactured by Nippon Carlit Co., Ltd.).

[Epoxy group-containing acrylic-styrene copolymer (G)]
(G-1) “JONCRYL” ADR-4368 manufactured by BASF (methyl methacrylate-styrene-glycidyl methacrylate copolymer, Mw (converted to PMMA) 8,000, epoxy value 3.5 meq / g)
(G-2) “ARUFON” UG-4035 (methyl methacrylate-styrene-glycidyl methacrylate copolymer, Mw (PMMA conversion) 12,000, epoxy value 1.8 meq / g, manufactured by Toagosei Co., Ltd.

[Phosphate (H)]
(H-1) Phosphoric acid (0.5 mol / L aqueous solution) (manufactured by Kanto Chemical Co., Inc.).

[Examples 1-11, Comparative Examples 1-8]
The above-mentioned polylactic acid resin (A), styrene resin (B), graft copolymer (C), inorganic filler (D), acrylic resin (F) if necessary, epoxy group-containing acrylic Styrene copolymer (G) and phosphoric acid (H) were blended in the blending ratios shown in Tables 1 and 2, respectively, and melted using a vented 30 mmφ twin screw extruder (PCM-30 manufactured by Ikegai Co., Ltd.). By kneading (barrel setting temperature 230 ° C.) and extruding, a pellet-shaped polylactic acid-based thermoplastic resin composition was produced. Similarly, Table 1 shows the styrene resin (B), the graft copolymer (C), the polyether polymer (E-1), and the organic ionic conductive agent (E-2) as necessary. The mixture is blended at a blending ratio, melt-kneaded (barrel set temperature 230 ° C.) using a 30 mmφ twin-screw extruder with a vent (PCM-30 manufactured by Ikegai Co., Ltd.), and extruded to form a pellet-like conductive thermoplastic resin. A composition was prepared.

  The pellets of the polylactic acid-based thermoplastic resin composition and the pellets of the conductive thermoplastic resin composition are respectively supplied to a single-screw extruder (each barrel set temperature 210 ° C.), extruded and supplied to a feed block, and an inner layer A two-layer / three-layer laminate sheet of II layer / I layer / II layer having an (I layer) of 600 μm, an outer layer (II layer) of 75 μm, and a total thickness of 750 μm was produced. The above-mentioned evaluation was performed with respect to the obtained electroconductive laminated sheet, and the result was shown according to Tables 1-2.

  As shown in Table 1, the conductive laminate sheet of the present invention uses a polylactic acid resin composition in which a polylactic acid resin is highly blended. It can contribute to global environmental conservation. Moreover, since it has high bending durability, electroconductivity, and delamination strength, it is judged that it is excellent practically.

  In Comparative Examples 1 and 2, the inorganic filler (D) was not blended, delamination was confirmed, the bending elastic modulus of the I layer was significantly reduced, and the bending durability of the conductive laminated sheet was lowered. did.

  Comparative Example 3 has a large blending amount of the polylactic acid-based resin (A) in the polylactic acid-based thermoplastic resin composition constituting the I layer, and does not provide sufficient bending durability as a conductive laminated sheet. Peeling was confirmed.

  In Comparative Example 4, the blending amount of the graft copolymer (C) was small, and sufficient bending durability as a conductive laminated sheet could not be obtained.

  In Comparative Example 5, the blending amount of the inorganic filler (D) was excessive, the impact strength of the I layer was lowered, and sufficient bending durability as a conductive laminated sheet could not be obtained. Moreover, delamination was confirmed.

  In Comparative Example 6, the resin composition constituting the II layer did not contain the antistatic agent (F), and the surface specific resistance value required as a dust-proof measure could not be obtained.

  In Comparative Example 7, the blending amount of the polylactic acid-based resin (A) in the polylactic acid-based thermoplastic resin composition constituting the I layer was less than 40 parts by weight, which was insufficient in terms of environmental considerations. When the blending amount of the polylactic acid resin (A) was small as in Comparative Example 7, sufficient bending durability and interlayer strength were obtained without blending an inorganic filler.

  In Comparative Example 8, the blending amount of the styrene resin (B) in the polylactic acid thermoplastic resin composition constituting the I layer was small, and sufficient bending durability and interlayer strength were not obtained.

  The conductive laminated sheet of the present invention has a low surface resistivity and is excellent in bending durability and delamination strength. In addition, by providing the inner layer with a polylactic acid-based thermoplastic resin that is highly blended with the polylactic acid-based resin (A), it is possible to greatly contribute to the reduction of carbon dioxide emissions and contribute to the conservation of the global environment. Taking advantage of such characteristics, the conductive laminated sheet of the present invention is suitably used as a tray for storing and transporting electronic components.

Claims (6)

40 to 70 parts by weight of polylactic acid resin (A), 5 to 53 parts by weight of styrene resin (B), 5 to 53 parts by weight of graft copolymer (C) and 2 to 20 parts by weight of inorganic filler (D) ( However, the I layer formed by molding a polylactic acid-based thermoplastic resin composition containing (A) to (D) as a total of 100 parts by weight), a styrene-based resin (B), and a graft copolymer (C) and a conductive thermoplastic resin composition formed by blending a conductive agent (E) are provided at least one II layer, at least one outermost layer is an II layer, and at least one set A conductive laminated sheet characterized in that the I layer and the II layer are adjacent to each other. The polylactic acid-based thermoplastic resin composition constituting the I layer is formed by further blending 10 parts by weight or less of an acrylic resin (F) with respect to 100 parts by weight of the total of (A) to (D). The conductive laminated sheet according to claim 1, wherein: The polylactic acid-based thermoplastic resin composition constituting the I layer is further added with an epoxy group-containing acrylic-styrene copolymer (G) in an amount of 0.00 with respect to 100 parts by weight of the total of (A) to (D). The conductive laminated sheet according to claim 1, wherein 1 to 10 parts by weight is blended. The conductive laminate sheet according to any one of claims 1 to 3, wherein the inorganic filler (D) in the polylactic acid-based thermoplastic resin composition constituting the I layer contains talc. The molded product formed by thermoforming the electroconductive laminated sheet in any one of Claims 1-4. A tray for storing and transporting electronic parts, which is obtained by thermoforming the conductive laminated sheet according to claim 1.