JP2014004838A - Laminated sheet and molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a laminated sheet and a molded article with excellent scratch resistance and handleability.SOLUTION: In a laminated sheet, a surface layer (B) is formed on at least one face of a substrate layer (A) comprising polypropylene-based resin (A1) and polyethylene-based resin (A2) including low density polyethylene. The surface layer (B) includes a dynamic crosslinking type polyolefin-based elastomer (B1) with Duro A hardness of 60-70 according to JIS K6253 and a polymeric antistatic agent (B2). The surface layer (B) includes 60 wt.% or more of the polyolefin-based elastomer (B1) and the polymeric antistatic agent (B2) comprises a block copolymer of an olefin-based block and a hydrophilic block.

Description

  The present invention relates to a laminated sheet having excellent scratch resistance and handling properties and a molded body (for example, a packaging container) formed using the sheet.

  Containers and trays are usually produced by secondary molding of sheets. In addition to handling properties such as easy stacking and winding of sheets, the contents should be protected from scratches caused by vibration during transportation when secondary containers and trays are used for transportation. (Scratch resistance) is also required. Polyolefin-based resins are widely used as sheet materials because they are excellent in appearance, rigidity, and secondary moldability, but are not sufficiently scratch-proof, and the following sheets have been proposed.

  Japanese Unexamined Patent Application Publication No. 2007-276354 (Patent Document 1) discloses a multilayer sheet having a base layer made of a thermoplastic resin and a surface layer made of at least one surface of the base layer and made of a thermoplastic elastomer or a composition thereof. . In this document, polyethylene and polypropylene are exemplified as the thermoplastic resin, and polystyrene elastomer and polyolefin elastomer are exemplified as the thermoplastic elastomer or the composition thereof. Moreover, it is described in the Example of this literature that the multilayer sheet which has the base layer which consists of polypropylene, and the surface layer which is formed in the single side | surface of this base layer and which consists of a polystyrene-type elastomer is described.

  However, this multilayer sheet cannot achieve both scratch resistance and handling properties. That is, a sheet containing a polystyrene elastomer in the surface layer has a high coefficient of static friction, so that when sheets are stacked or wound, the dust tends to adhere and the handling property is inferior.

  Japanese Patent Laid-Open No. 63-34138 (Patent Document 2) discloses a first layer containing either an olefin elastomer or a styrene elastomer, a second layer containing a mixture of an elastomer and a polyolefin, and a polyolefin containing a polyolefin. A multilayer sheet composed of three layers is disclosed. This document describes that a polystyrene-based or polyolefin-based elastomer is advantageous from the viewpoints of cost and vacuum formability. Moreover, the hardness of polyolefin-type elastomer is described in the very wide range (JIS-A rubber hardness 45-95). Since this multilayer sheet is provided with a layer containing a mixture of elastomer and polyolefin as an intermediate layer, the layer structure is complicated and the productivity is low.

  In addition, as a multilayer sheet used for a cutting mat, a desk mat, etc., JP-A-4-341839 (Patent Document 3) has an olefin polymer as an intermediate layer, a styrene elastomer, an olefin elastomer, a polyester elastomer, etc. A multilayer sheet comprising the above-mentioned thermoplastic elastomer as upper and lower layers is disclosed. This document describes that an olefin-based elastomer can be preferably used in order to make the blade easy to bite and not slip, but details of the hardness of the olefin-based elastomer are not disclosed.

JP 2007-276354 A (Claims 1-3, Examples) JP-A-63-34138 (Claims, page 2, upper left column, lines 9-11, page 3, lower left column, lines 10-11, Examples) JP-A-4-341839 (Claim 1, paragraphs [0007] [0011], Examples)

  Accordingly, an object of the present invention is to provide a laminated sheet excellent in scratch resistance and handling properties and a molded body (for example, a packaging container) formed from this sheet.

  Another object of the present invention is a laminated sheet excellent in sheet appearance, suppressed in draw down, high in mold releasability, and excellent in secondary formability of the sheet, and molding formed from this sheet. The object is to provide a body (eg a packaging container).

  Still another object of the present invention is to provide a sheet in which defects and failures of electronic components and optical components are suppressed, and a molded body (for example, an electronic component or optical component transport tray) formed from the sheet. It is in.

  As a result of intensive studies to achieve the above object, the present inventor has found that a laminated sheet comprising a base layer made of a specific olefin resin and a surface layer made of a specific polyolefin elastomer and a polymer type antistatic agent has a scratch resistance. The present invention was completed by finding excellent handling properties.

  That is, in the laminated sheet of the present invention, the surface layer (B) is formed on at least one surface of the base material layer (A) containing the propylene resin (A1) and the polyethylene resin (A2).

  The surface layer (B) includes a dynamically cross-linked polyolefin elastomer (B1) having a Duro hardness A of 60 to 70 in accordance with JIS K6253 and a polymer antistatic agent (B2).

  The static friction coefficient of the surface layer (B) is 0.7 or less.

  The surface layer (B) contains 60% by weight or more of the polyolefin-based elastomer (B1).

  The polymer antistatic agent (B2) is composed of a block copolymer of an olefin block and a hydrophilic block.

  The proportion of the polymer antistatic agent (B2) may be about 5 to 30 parts by weight with respect to 100 parts by weight of the resin component of the surface layer (B).

  The polyolefin elastomer (B1) may be a dynamic partially cross-linked polyolefin elastomer, and is composed of a hard segment containing a polyolefin resin and a soft segment containing ethylene-propylene rubber or ethylene-propylene-diene rubber. May be.

  Each of the sodium ion and sulfate ion contents in the polymer antistatic agent (B2) may be about 1 to 150 ppm.

  The polyethylene resin (A2) may contain at least low density polyethylene. The melt flow rate based on JIS K7210 of the polypropylene resin (A1) may be about 0.15 to 5 g / 10 minutes.

  The static friction coefficient of the surface layer (B) may be about 0.4 to 0.7.

  In the laminated sheet of the present invention, the surface layer (B) may be formed on both surfaces of the base material layer (A), and the total thickness may be about 0.3 to 1.5 mm. Moreover, the ratio of the thickness of the base material layer (A) and the thickness of the surface layer (B) (when the surface layer (B) is formed on both surfaces of the base material layer (A), the sum of the thickness of each surface layer) is: The former / the latter may be about 4/1 to 20/1.

  This invention contains the molded object formed with the said lamination sheet, and this molded object is suitable for the conveyance use of an electronic component or an optical component.

  Since the laminated sheet of the present invention contains a polyolefin-based elastomer having a specific hardness in the surface layer, the sheet surface is soft and excellent in scratch resistance (abrasion resistance). Further, since the static friction coefficient of the surface layer is in an appropriate range, for example, even if the sheets are stacked or wound up, the sheets are easily separated from each other, and the handling properties (handleability and workability) as the sheets are also provided. These characteristics are particularly prominent when surface layers are formed on both sides of the base material layer. Furthermore, the laminated sheet of the present invention is less likely to cause dust to adhere. Further, by adjusting the hardness of the polyolefin-based elastomer constituting the surface layer, the balance of the scratch resistance, handling property, appearance, and mold release property of the sheet can be easily adjusted. Furthermore, the laminated sheet of the present invention can impart antistatic properties and can suppress the occurrence of defects and failures in electronic devices.

  In the laminated sheet of the present invention, the surface layer (B) is formed on at least one surface of the base material layer (A). In particular, since the surface layer (B) is soft and has an appropriate coefficient of static friction, the surface layer (B) may be formed on both surfaces of the base material layer (A). When the surface layer (B) is formed on both surfaces of the base material layer (A), the layer structure (component, prescription, thickness, etc.) of each surface layer may be the same or different, but is usually the same. .

[Base material layer (A)]
Since the base material layer (A) contains a polyolefin-based resin, it imparts moldability, rigidity, impact resistance, and economy to the laminated sheet. Moreover, even if a perforated cutout portion for imparting ease of cutting and folding is formed on the laminated sheet, since the base material layer (A) contains a polyolefin-based resin, it is transported starting from the perforation. It is difficult to break or crack inside.

Examples of the polyolefin resin include poly C _2-6 olefin resins such as polyethylene resin, polypropylene resin, polybutylene resin, and polymethylpentene resin. These polyolefin resins can be used alone or in combination of two or more.

  The base material layer (A) is not particularly limited as long as it contains a polyolefin resin, and preferably contains at least a polypropylene resin (A1) from the viewpoints of moldability and rigidity.

(A1) Polypropylene resin The polypropylene resin (A1) may be a propylene homopolymer or a propylene copolymer. Examples of the propylene-based copolymer include α-olefins other than propylene and propylene [for example, ethylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 3-methylpentene, 4-methylpentene, 4-methylpentene, Α-C _2-16 olefins other than propylene such as methyl-1-butene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene and 1-dodecene (particularly α-C _2-6 olefins) And the like] (for example, propylene-ethylene copolymer, propylene-butene copolymer, propylene-ethylene-butene copolymer, etc.). The form of the copolymer may be either a block copolymer or a random copolymer.

  In the propylene-based copolymer, the ratio (molar ratio) of propylene and α-olefin other than propylene is the former / the latter = 70/30 to 99.9 / 0.1, preferably 80/20 to 99.5. /0.5, more preferably about 90/10 to 99/1.

  These polypropylene resins can be used alone or in combination of two or more. Of these polypropylene resins, a propylene homopolymer (polypropylene) is preferred.

  The polypropylene resin (A1) may be an amorphous (or amorphous) polypropylene resin, but is preferably a crystalline (or crystalline) polypropylene resin.

  The polypropylene resin (A1) may be an atactic polymer, or may have a stereoregular structure such as an isotactic, syndiotactic, or polypropylene resin obtained using a metallocene catalyst. Of these, polypropylene resins having an isotactic structure are preferred from the standpoints of crystallinity and simplicity.

  The melt flow rate (MFR) of the polypropylene resin (A1) can be selected from the range of about 0.1 to 30 g / 10 minutes, but from the point of suppressing the drawdown of the sheet, 0.1 to 10 g / 10 minutes, Preferably it may be about 0.15 to 5 g / 10 min (for example, 0.2 g / 10 min), more preferably about 0.25 to 2 g / 10 min (particularly 0.3 to 1 g / 10 min). . When MFR is too high, it becomes easy to draw down at the time of thermoforming, and secondary molding becomes difficult. In addition, the thickness of the molded product becomes not only uneven, but also causes wrinkles. On the other hand, if the MFR is too low, extrusion molding becomes difficult. The MFR can be measured under the conditions of a test temperature of 230 ° C. and a nominal load of 2.16 kgf (21.2 N) according to JIS K 7210.

(A2) Polyethylene resin The base material layer (A) preferably further includes a polyethylene resin (A2) in addition to the polypropylene resin (A1) from the viewpoint of preventing drawdown.

The polyethylene resin (A2) may be an ethylene copolymer or an ethylene copolymer. Examples of the copolymerizable monomer include α-olefins other than ethylene [eg, propylene, 1-butene, 2-butene, 1-pentene, 1-hexene, 3-methylpentene, 4-methylpentene, 4-methyl. -1-butene, 1-hexene, 1-octene, 1-nonene, 1-decene, 1-undecene, α-C _3-16 olefins (especially α-C _3-6 olefins) and the like], Examples thereof include organic acid vinyl esters such as vinyl acetate and (meth) acrylic acid monomers such as (meth) acrylic acid. These copolymerizable monomers can be used alone or in combination of two or more.

  In the ethylene-based copolymer, ethylene and a copolymerizable monomer (for example, ratio of α-olefin other than ethylene) (molar ratio) are the former / the latter = 70/30 to 99.9 / 0.1. , Preferably 80/20 to 99.5 / 0.5, more preferably about 90/10 to 99/1.

  Examples of the polyethylene resin (A2) include low density polyethylene, medium density polyethylene, high density polyethylene, linear polyethylene (for example, linear low density polyethylene), branched polyethylene, ionomer, chlorinated polyethylene, and the like. There may be.

These polyethylene resins can be used alone or in combination of two or more. Of these polyethylene resins, an ethylene homopolymer (polyethylene) is preferable from the viewpoint of suppressing drawdown, and low density polyethylene is particularly preferable. That is, the density of the polyethylene-based resin (A2), in compliance with JIS K7112, for example, 935 kg / ^{m 3} or less (e.g., 900~935kg / m about ^3), preferably 930 kg / ^{m 3} or less (e.g., 900 930 kg / ^m about ^3), more preferably 925 kg / ^{m 3} or less (e.g., may be about 900~925kg / ^{m 3).}

  The melt flow rate (MFR) of the polyethylene resin (A2) can be selected from a range of 0.1 to 10 g / 10 minutes, and is 0.1 to 5 g / 10 minutes, preferably 0.15 to 2.5 g / 10 minutes. More preferably, it may be about 0.2 to 2 g / 10 minutes (particularly 0.2 to 1 g / 10 minutes). MFR can be measured under the conditions of a test temperature of 190 ° C. and a load of 2.16 kgf (21.2 N) according to JIS K7210.

  The ratio (weight ratio) of the polypropylene resin (A1) and the polyethylene resin (A2) is the former / the latter = 50/50 to 100/0, preferably 55/45 to 90/10, more preferably 60/40. To 85/15 (especially 70/30 to 80/20), and in particular, from the viewpoint of suppressing drawdown, the polypropylene resin (A1) and the low-density polyethylene are 50/50 to 50/50 It is preferable to combine them at a ratio of about 90/10 (for example, 60/40 to 85/15, particularly 70/30 to 80/20).

(Optional component)
The base material layer (A) may contain an optional component as long as the effects of the present invention are not impaired. Optional ingredients include fillers, processing aids, stabilizers (antioxidants, UV absorbers, light stabilizers, heat stabilizers, etc.), flame retardants (phosphorous flame retardants, halogen flame retardants, inorganic) Flame retardants), flame retardant aids, nucleating agents, lubricants, plasticizers, mold release agents, impact resistance improvers, hue improvers, fluidity improvers, colorants (pigments etc.), dispersants, antibacterial agents, etc. It can be illustrated. These optional components can be used alone or in combination of two or more. Of these optional components, the base material layer (A) contains 0.3 to 3% by weight, preferably 0.4 to 2% by weight, and more preferably about 0.5 to 1.5% by weight. But you can.

  The thickness of the base material layer (A) is, for example, 0.25 to 1.5 mm (for example, 0.5 to 1.5 mm), preferably 0.45 to 1.2 mm (for example, 0.5 to 1.0 mm). ), More preferably about 0.55 to 1.0 mm (particularly 0.6 to 1.0 mm). If the thickness of the base material layer is too small, the molded product becomes weak. Moreover, when the thickness of a base material layer is too large, it is inferior to economical efficiency.

[Surface (B)]
Since the surface layer (B) includes the polyolefin-based elastomer (B1), the surface layer (B) has excellent adhesiveness with the base material layer (A) including the polyolefin-based resin, and adheres between the surface layer (B) and the base material layer (A). Can be bonded without intervening layers.

(B1) Polyolefin-based elastomers Polyolefin-based elastomers have the same degree of hardness as polystyrene-based elastomers, but generally have a low coefficient of static friction, so that the sheets of the present invention may be stacked or wound up. , Easy to peel off each other, excellent in handling as a sheet. Moreover, when the static friction coefficient of a surface layer is low, adhesion of dust can be prevented and the appearance is excellent.

  The polyolefin-based elastomer (B1) is composed of a hard segment (hard phase) containing a polyolefin resin and a soft segment (soft phase) containing rubber.

  Examples of the polyolefin resin constituting the hard segment include the same resins as the polypropylene resin (A1) or polyethylene resin (A2). For example, a propylene polymer (single or copolymer) or ethylene single weight It may be a coalescence.

  The rubber constituting the soft segment is preferably a rubber not containing a styrene component, such as an olefin rubber, a diene rubber, an acrylic rubber, a urethane rubber, a fluoro rubber, an epichlorohydrin rubber, a polysulfide rubber, and the like. However, olefin rubber and diene rubber are preferable from the viewpoint of the uniformity and compatibility of the blend of the hard segment component and the soft segment component.

  Examples of olefin rubbers include ethylene-propylene rubber (EPM), ethylene-propylene-diene rubber (EPDM), polyoctenylene rubber, ethylene-vinyl acetate copolymer rubber, chlorosulfonated polyethylene rubber (CSM), and chlorinated polyethylene rubber. (CM) can be exemplified.

  Examples of the diene rubber include natural rubber (NR), isoprene rubber (IR), butyl rubber (IIR), butadiene rubber (BR), 1,2-polybutadiene rubber (1,2-BR), chloroprene rubber (CR), etc. Examples include polymer rubbers of diene monomers; acrylonitrile-diene copolymer rubbers such as acrylonitrile butadiene rubber (NBR), nitrile chloroprene rubber (NCR), and nitrile isoprene rubber (NIR). The diene rubber includes hydrogenated rubber (for example, hydrogenated nitrile rubber (HNBR)).

  These rubbers can be used alone or in combination of two or more. Among these rubbers, rubbers containing olefin units such as ethylene-propylene rubber and ethylene-propylene-diene rubber are particularly preferable.

  In the ethylene-propylene rubber or the ethylene-propylene-diene rubber, the ratio (molar ratio) of the ethylene unit to the propylene unit can be selected from the range of the former / the latter = 10/90 to 90/10, for example, 50/50 to 90 / 10 (for example, 60/40 to 80/20) may be sufficient.

  The diene component constituting the ethylene-propylene-diene rubber may be a conjugated diene such as butadiene, isoprene or 1,4-hexadiene, or an alicyclic diene compound such as ethylidene norbornene or dicyclopentadiene. The iodine value of the ethylene-propylene-diene rubber (the halogen amount in terms of iodine absorbed when halogen is allowed to act on the rubber) may be, for example, about 10 to 50 (for example, 20 to 40).

  The ratio (weight ratio) between the hard segment and the soft segment can be selected from the range of the former / the latter = about 10/90 to 90/10, and low hardness is preferable for balance between scratch resistance and appearance. It may be about 10/90 to 50/50 (for example, 30/70 to 40/60).

  These polyolefin elastomers can be used alone or in combination of two or more.

  The dynamically cross-linked polyolefin elastomer may be an elastomer obtained by cross-linking rubber constituting the soft segment under kneading (kneaded state) of the hard segment component and the soft segment component. The kneading (mixing) may be performed using a conventional kneader such as a Banbury mixer or a plast mill. The kneading temperature may be, for example, about 100 to 250 ° C. (for example, 150 to 250 ° C.). The kneading time may be, for example, about 1 to 30 minutes (for example, 5 to 15 minutes). The stirring speed may be, for example, about 1 to 150 rpm (for example, 10 to 100 rpm).

  Crosslinking may be performed using a crosslinking agent (vulcanizing agent). In dynamic crosslinking, a crosslinking agent may be present at the start of kneading, or a crosslinking agent may be added at the kneading stage. Examples of the crosslinking agent include conventional crosslinking agents such as sulfur, sulfur-containing organic compounds [thiurams (eg, tetramethylthiuram monosulfide (TMTM), tetramethylthiuram disulfide (TMTD), tetraethylthiuram disulfide (TETD), etc.), etc. ], Organic peroxides {e.g. dialkyl peroxides [e.g. di-t-butyl peroxide, 2,5-di (t-butylperoxy) -2,5-dimethylhexane, 1,1-bis ( t-butylperoxy) -3,3,5-trimethylcyclohexane, 1,1-bis (t-butylperoxyisopropyl) benzene, dicumyl peroxide, etc.]}, azo compounds (for example, azobisisobutylnitrile, etc.) , Phenolic resins (eg, alkylphenols having methylol groups) Fats), maleimide compounds [for example, aromatic bismaleimides (eg, N, N′-1,3-phenylene dimaleimide), aliphatic bismaleimides (eg, N, N′-1,2-ethylenebis) Etc.) and the like. These crosslinking agents can be used alone or in combination of two or more. These crosslinking agents may be used in combination with a conventional crosslinking accelerator.

  The usage ratio of the crosslinking agent may be, for example, about 0.1 to 20 parts by weight (for example, 0.5 to 10 parts by weight) with respect to 100 parts by weight of the soft segment component.

  The crosslinking temperature may be, for example, about 100 to 250 ° C. (for example, 150 to 250 ° C.). For example, the crosslinking time may be about 1 to 60 minutes (for example, 3 to 30 minutes). The crosslinking time corresponds to the kneading time after adding the crosslinking agent.

The degree of cross-linking may be complete cross-linking or partial cross-linking, but partial cross-linking is particularly preferable from the viewpoint of moldability and appearance. The crosslinking density (vulcanization density) may be, for example, about 1 to 20 mol × 10 ⁵ mL (for example, 5 to 15 mol × 10 ⁵ mL).

  In many cases, the dynamically crosslinked polyolefin elastomer usually has a structure in which crosslinked rubber particles (soft segments) are dispersed in a polyolefin matrix (hard segments). The average particle diameter of the crosslinked rubber particles can be selected from the range of about 0.1 to 30 μm (for example, 0.1 to 5 μm), and is 0.5 to 10 μm (for example, 0.5 to 2 μm), usually 1 to 5 μm ( For example, it may be about 1 to 2 μm.

  The Duro hardness A of the polyolefin-based elastomer (B1) is 53 to 85 (for example, 53 to 84), preferably 54 to 83 (for example, for example) in accordance with JIS K6253 from the point of balance between appearance and scratch resistance. 54 to 82), more preferably about 55 to 81 (especially 55 to 80), and particularly from the viewpoint of scratch resistance, for example, 55 to 70 (for example, 57 to 70, particularly 60 to 60). 70) or so.

  The melt flow rate (MFR) of the polyolefin elastomer (B1) is 0.1 to 20 g / 10 minutes, preferably 0.5 to 18 g / 10 minutes, and more preferably about 1.0 to 15 g / 10 minutes. Also good. In addition, MFR can be measured on condition of test temperature 230 degreeC and load 49N based on JISK7210.

  Among such polyolefin elastomers, dynamic partially crosslinked polyolefin elastomers include Thermoran (Mitsubishi Chemical Co., Ltd.), Miralastomer (Mitsui Chemicals Co., Ltd.), Espolex (Sumitomo Chemical Co., Ltd.) Are commercially available.

  In the surface layer (B), the polyolefin elastomer (B1) is 60% by weight or more (for example, about 60 to 100% by weight), preferably 70% by weight or more (about 70 to 100% by weight), and more preferably 80% by weight or more. (About 80 to 100% by weight) may be included. In particular, from the viewpoint of scratch resistance, the surface layer (B) may not contain substantially any elastomer and resin other than the polyolefin-based elastomer (B1).

(B2) Polymeric antistatic agent The surface layer (B) may further contain a polymeric antistatic agent (B2) for the prevention of charging of electronic equipment and the like. The polymer antistatic agent not only has an antistatic function, but also has a function of improving the appearance. Moreover, it can also prevent that an antistatic agent adheres to the articles | goods mounted on the sheet | seat as it is a polymer type.

  The polymer antistatic agent (B2) is not particularly limited as long as it has a high molecular weight (for example, a number average molecular weight of 1000 or more), and includes, for example, an olefin block and / or a polyamide block and a hydrophilic block. Although a block copolymer etc. can be illustrated, the block copolymer of an olefin type block and a hydrophilic block is preferable from points, such as affinity with a polyolefin-type elastomer (B1) and a dispersibility.

Examples of the olefin monomer constituting the olefin block include C _2-6 olefins such as ethylene, propylene and 1-butene. Of these olefins, at least one selected from ethylene and propylene is preferable, and at least propylene is particularly preferable. Among the olefin monomers, the proportion of propylene is preferably 80 mol% or more (particularly 90 mol% or more). In the polyolefin block, the content of the olefin monomer (C _2-6 olefin, particularly ethylene and / or propylene) may be about 80 mol% or more (particularly 90 mol% or more). The number average molecular weight of the polyolefin block may be 2000 to 50000, preferably 3000 to 40000, and more preferably about 5000 to 30000.

Examples of the hydrophilic block include polyether polymers (or nonionic polymers), cationic polymers, anionic polymers, and the like. Examples of the hydrophilic monomer constituting the hydrophilic block include alkylene oxides (for example, C _2-6 alkylene oxides such as ethylene oxide, propylene oxide, and butylene oxide), particularly C _2-4 alkylene oxides such as ethylene oxide and propylene oxide. Is preferred. Preferred hydrophilic block, polyalkylene oxides (e.g., polyethylene oxide, polypropylene oxide, polyethylene oxide - poly C _2-4 alkylene oxides such as polypropylene oxide) is preferable. The average degree of polymerization of the polyalkylene oxide may be 2 to 300 (for example, 5 to 200), preferably 10 to 150, and more preferably about 10 to 100.

  The olefin block and the hydrophilic block may be bonded through an ester bond, an amide bond, an ether bond, a urethane bond, an imide bond, or the like. These bonds can be formed, for example, by modifying the polyolefin with a modifier and then introducing a hydrophilic block. For example, after introducing an active hydrogen atom by modifying polyolefin with a modifier, it is introduced by addition polymerization of a hydrophilic monomer such as alkylene oxide. Examples of such modifiers include unsaturated carboxylic acids or anhydrides (such as (anhydrous) maleic acid), lactams or aminocarboxylic acids (such as caprolactam), oxygen or ozone, and hydroxylamine (such as 2-aminoethanol). , Diamine (ethylenediamine etc.) or a combination thereof.

  The melt flow rate (MFR) of the antistatic agent (B2) may be about 1 to 20 g / 10 minutes, preferably 5 to 18 g / 10 minutes, and more preferably about 7 to 15 g / 10 minutes. In addition, MFR can be measured on condition of test temperature 190 degreeC and nominal load 2.16kgf (21.2N) based on ASTMD1238.

The content of sodium ion (Na ⁺ ) and sulfate ion (SO ₄ ²⁻ ) in the antistatic agent (B2) is, for example, 1 to 150 ppm, preferably 1.5 to 130 ppm, more preferably 2 to 120 ppm, respectively. It may be a degree.

  The proportion of the antistatic agent is the resin component of the surface layer (B) (the total amount when the polyolefin elastomer (B1), the polyolefin elastomer (B1) and the polypropylene resin (B3) described later are used in combination) 100 weight 5 to 30 parts by weight, preferably 10 to 25 parts by weight, and more preferably about 15 to 20 parts by weight with respect to parts.

(B3) Polypropylene resin The surface layer (B) may contain a polypropylene resin (B3) for the purpose of adjusting the softness and the coefficient of static friction. Examples of the polypropylene resin (B3) include those similar to the polypropylene resin (A1), and may be a polypropylene copolymer, but in particular, the same propylene homopolymer as described above. preferable.

  The ratio (weight ratio) between the polyolefin-based elastomer (B1) and the polypropylene-based resin (B3) is the former / the latter = 60/40 to 99.9 / 0.1, preferably 70/30 to 99.5 / 0. 5, More preferably, it may be about 80/20 to 99/1.

(Optional component)
The surface layer (B) may contain the same optional components as the base material layer (A) as long as the effects of the present invention are not impaired. The surface layer (B) may contain 0.3 to 3% by weight, preferably 0.4 to 2% by weight, and more preferably about 0.5 to 1.5% by weight of the colorant among the optional components.

  The static friction coefficient of the surface layer (B) can be selected from the range of about 0.4 to 1.4, 0.45 to 1.3, preferably 0.45 to 1.2, and more preferably 0.45 to 1. It may be about 0 (for example, 0.5 to 1.0). Within this range, the frictional force is well balanced, and even if the sheets are stacked or wound up, they are easily peeled from each other, and the handling properties as a sheet are improved. Furthermore, slipping of the article placed on the sheet surface can be suppressed, and oblique placement and transfer are facilitated.

  The thickness of the surface layer (B) may be, for example, about 0.01 to 0.2 mm, preferably 0.01 to 0.1 mm, and more preferably about 0.01 to 0.05 mm. When the thickness of the surface layer is too large, the waist of the molded product becomes weak.

The surface resistivity is 1 × 10 ⁸ to 1 × 10 ¹¹ Ω, preferably 2 × 10 ⁸ to 8 × 10 ¹⁰ Ω, more preferably 20 ° C. and 60% RH in accordance with JIS K6911. It may be about 5 × 10 ^{8 to} 5 × 10 ¹⁰ Ω.

  The ratio of the thickness of the base material layer (A) to the thickness of the surface layer (B) is the former / the latter = 4/1 to 50/1 (for example, 10/1 to 50/1), preferably 15/1 to 40. / 1, more preferably about 20/1 to 30/1. When the surface layer (B) is formed on both surfaces of the base material layer (A), the ratio of the thickness of the base material layer (A) and the sum of the thicknesses of the respective surface layers is the former / the latter = 4/1. -20/1, preferably 8/1 to 16/1, more preferably 10/1 to 15/1 (especially 10/1 to 14/1).

  The total thickness of the sheet is 0.3 to 2.0 mm (for example, 0.3 to 1.5 mm), preferably 0.4 to 1.8 mm, and more preferably 0.5 to 1.5 mm (especially 0.3 mm). 5 to 1.0 mm).

[Production method of laminated sheet]
The laminated sheet is not particularly limited, and can be manufactured by mixing each component of each layer to prepare a resin composition, and then molding the sheet by a conventional method. The resin composition may be a mixture of powders of each component, or may be prepared by kneading each component. For kneading, a conventional method can be used. For example, each component is dry-mixed with a Henschel mixer or a ribbon mixer, and a conventional melt mixing such as a single-screw or twin-screw extruder, a Banbury mixer, a kneader, a mixing roll, etc. It can be supplied to a machine and melt kneaded. The resin composition may be in the form of pellets. Further, the order of kneading is not limited.

  Examples of the method for forming into a sheet include extrusion methods such as an extrusion method [die (flat, T-die, cylindrical, etc.) method, inflation method, etc.]. It is done. Among these molding methods, an extrusion molding method using a T-die is particularly preferable. The resin sheet may be prepared by a method such as heat lamination or dry lamination for each obtained sheet, but the resin composition for each constituent layer is used using a general-purpose die with a feed block or a multi-manifold die. It is preferable to prepare it by a co-extrusion method.

[Molded body]
The laminated sheet thus obtained can be secondary molded by conventional thermoforming such as free blow molding, vacuum forming, bending, pressure forming (compression air forming), match mold forming, hot plate forming, etc. it can. The form of the secondary molded product is not particularly limited. In the case of a container, for example, the secondary molded article may be composed of a container body and a lid body as well as a container body having a concave portion for housing the object to be accommodated.

  The surface of the sheet or secondary molded product may be subjected to surface treatment (for example, discharge treatment such as corona discharge or glow discharge, acid treatment, wrinkle treatment, etc.).

  The static friction coefficient of the mold non-contact surface of the molded body can be selected from the range of about 0.7 to 1.7 (for example, 0.7 to 1.5), 0.8 to 1.5, preferably 0.8. It may be about 85 to 1.3, more preferably about 0.87 to 1.2 (for example, 0.9 to 1.2). If this static friction coefficient is too large, the releasability decreases. On the other hand, if the static friction coefficient is too small, the scratch resistance is lowered.

  Using a single molding machine (manufactured by Asano Laboratory Co., Ltd.), set the center part in the width direction of the laminated sheet on a 480 mm x 480 mm frame, heat it to 170 ° C, and length of the most drooped part (from the level surface The drawdown measured as the length is 35 mm or less (for example, about 5 to 35 mm), preferably 30 mm or less (for example, about 5 to 30 mm), more preferably 25 mm or less (for example, about 5 to 25 mm). May be.

  Hereinafter, the present invention will be described in more detail based on examples, but the present invention is not limited to these examples. In the text, “parts” are based on weight unless otherwise specified. The evaluation method of each evaluation item in the examples and the contents of each component used are as follows.

[Duro hardness A]
The durometer A was measured according to JIS K6253. The Duro hardness A value is a value of the olefin elastomer used alone.

[Scratch resistance]
A 2 mm thick ABS plate was cut to 34 mm x 53 mm, and one side of the cut ABS plate was painted with an aqueous paint spray (Damp Black from Campehapio Co., Ltd.) to prevent unevenness. Four ridge lines were rounded with sandpaper to produce a dummy transported object. The laminated sheets obtained in the examples and comparative examples were cut into 90 mm × 90 mm, and a fall prevention fence was installed on the outer periphery of the cast surface so that the dummy conveyed object did not fall during vibration. With the cast surface side up, the laminated sheet was fixed to a shaker for chemical experiment (manufactured by ASONE, SHAKER SR-1, amplitude 30 mm). With the painted surface facing down, the dummy transported article was placed in the center of the laminated sheet, and two 100 g weights were placed on the dummy transported article to fix the dummy transported article and the weight. The shaker was vibrated at 180 rpm for 3 minutes. The degree of scratches on the painted surface of the dummy transported object was visually confirmed, and scratch resistance was evaluated according to the following criteria.
1 …… There are 10 or more scratches that can be seen immediately 2 …… There are 4 to 9 scratches that can be seen immediately 3 …… There are 1 to 3 scratches that can be seen immediately 4 …… Slightly when staring Can be confirmed 5 ... no scratch at all.

[appearance]
The laminated sheets obtained in the examples and comparative examples were evaluated according to the following criteria.
1 ... Interlayer turbulence is severe 2 ... Interlayer turbulence can be confirmed at a glance 3 ... Slightly inter-layer turbulence 4 ... Slightly inter-layer turbulence can be seen by staring 5 ... No inter-layer turbulence.

[Drawdown]
Using a single molding machine (manufactured by Asano Laboratory Co., Ltd.), the center part in the width direction of the laminated sheets obtained in the examples and comparative examples was set in a frame of 480 mm × 480 mm, heated to 170 ° C., and most drooped. The length of the part (length from the level surface) was measured.

[Surface specific resistance]
The flat part of the bottom of the container which was molded with a mold and left for 1 day is cut out and conditioned for 4 days under the conditions of a temperature of 20 ° C. and a humidity of 60% RH, and then the surface of the mold contact surface according to JIS K6911 The resistance value was measured.

[Static friction coefficient]
A tester (manufactured by Toyo Seiki Seisakusho, FRICTION TESTER TR-2) was used for testing. The sample sheet was fixed on the entire surface of the sample table with the test surface facing up. Subsequently, a sample sheet cut to the same size with the test surface down was attached to a weight plate of 63 mm length, 63 mm width, and 400 g. A weight plate is placed on the sample stage so that the test surfaces of these two sample sheets overlap. Using a load cell weighing 1 kg, the weight plate was measured by pulling it horizontally at a speed of 50 mm / min.

  In the test with a sheet, each of a glossy surface (cast roll surface) and a non-glossy surface (touch roll surface) was measured.

  In the measurement using a container, after molding with a single vacuum forming machine (manufactured by Asano Laboratory Co., Ltd.), the bottom surface is 160 mm × 200 mm and the height is 50 mm, and the sheet gloss surface is inside the container. The bottom surface was cut out and the inner side surface of the container (die non-contact surface) was measured as a test surface.

[Releasability]
Using the laminated sheets obtained in the examples and comparative examples, the sheet gloss with a cup-shaped concave mold having an opening diameter of 90 mm, a bottom diameter of 80 mm, and a height of 50 mm by a single-shot vacuum forming machine (manufactured by Asano Laboratory Co., Ltd.) It shape | molded so that a surface might become a container inner side, and the mold release property was evaluated on the following references | standards.
1 …… The catch is very strong, and the container warps when it is released 2 …… The catch is strong and the container is deformed 3 …… A little catch is seen at the time of release 4 …… The mold is released almost without catching 5 …… Release without catching.

[Content of each component]
PP1: Polypropylene resin (manufactured by Prime Polymer Co., Ltd., Prime Polypro E-105GM, homotype, MFR (230 ° C., 21.2 N) 0.5 g / 10 min)
PP2: Polypropylene resin (manufactured by Prime Polymer Co., Ltd., Prime Polypro E-200GP, Homotype, MFR (230 ° C., 21.2 N) 2.0 g / 10 min)
PP3: Polypropylene resin (manufactured by Prime Polymer Co., Ltd., Prime Polypro F-704NP, homotype, MFR (230 ° C., 21.2 N) 7.0 g / 10 min)
LD: Low density polyethylene (manufactured by Asahi Kasei Chemicals Corporation, Suntec LD M1703, MFR (190 ° C., 21.2 N) 0.3 g / 10 min, density 918 kg / m ³ )
E1: Dynamic partially cross-linked polyolefin elastomer (Mitsui Chemicals, Miralastomer 6030N, MFR (230 ° C., 49N) 4.1 g / 10 min)
E2: Dynamic partially cross-linked polyolefin elastomer (manufactured by Mitsubishi Chemical Corporation, Thermoran 3655N, MFR (230 ° C., 49N) 13 g / 10 min)
E3: Dynamic partially cross-linked polyolefin elastomer (manufactured by Mitsubishi Chemical Corporation, Thermoran 3755N, MFR (230 ° C., 49N) 4.0 g / 10 min)
E4: Dynamic partially crosslinked polyolefin elastomer (Mitsui Chemicals, Miralastomer 8032N, MFR (230 ° C., 49N) 1.0 g / 10 min)
E5: Dynamic partially cross-linked polyolefin elastomer (Mitsubishi Chemical Corporation, Thermolan 3555N, MFR (230 ° C., 49N) 2.0 g / 10 min)
E6: Dynamic partially crosslinked polyolefin elastomer (manufactured by Sumitomo Chemical Co., Ltd., Espolex 3675, MFR (230 ° C., 49 N) 0.6 g / 10 min)
E7: Dynamic partially cross-linked polyolefin elastomer (Mitsui Chemicals, Miralastomer 5030N, MFR (230 ° C., 49N) 1.8 g / 10 min)
E8: Dynamic partially cross-linked polyolefin elastomer (Mitsui Chemicals, Miralastomer 9020N, MFR (230 ° C., 49N) 1.5 g / 10 min)
E9: Non-crosslinked polyolefin elastomer (manufactured by Mitsubishi Chemical Corporation, Thermolan Z101N, MFR (230 ° C., 21.2N) 11 g / 10 min)
E10: Polymerization type polyolefin elastomer (Mitsubishi Chemical Corporation, Zelas MC707, MFR (230 ° C., 21.2 N) 3.3 g / 10 min)
E11: Styrene elastomer (manufactured by Mitsubishi Chemical Corporation, Lavalon SJ5400N)
Antistatic agent: Olefin polymer type antistatic agent (manufactured by Sanyo Chemical Industries, Ltd., trade name “Pelestat 212”, MFR (190 ° C., 21.2 N) 12 g / 10 min, density 1000 kg / m ³ , contained ions Amount = Na ⁺ : 80 ppm, SO ₄ ²⁻ : 62 ppm).

Examples, Reference Examples and Comparative Examples In the first single-screw extruder (screw diameter 90 mm, L / D = 32) of the feed block type multilayer extruder (two-type three-layer extruder), the base materials shown in Table 1 The mixture of the components constituting the layer is supplied at a cylinder temperature of 230 ° C., and the mixture of the components constituting the surface layer shown in Table 1 is transferred to the second single-screw extruder (screw diameter 65 mm, L / D = 28). It supplied at 230 degreeC, the surface layer was made to merge and laminate | stack on both surfaces of a base material layer within the feed block, and it extruded to the sheet form by the T die-cast method. It is cooled to 70 ° C by the so-called touch roll method in which it is pressed against a chrome-plated metal cast roll with a metal touch roll, and by adjusting the take-up speed, the total thickness is 0.8 mm, and the layer structure is surface layer / base A laminated sheet of material layer / surface layer (thickness ratio of 1/25/1) was obtained. The evaluation results of the obtained laminated sheet are shown in Table 2.

  In addition, although the sheet | seat of an Example, a reference example, and a comparative example is a sheet | seat which forms the surface layer on both surfaces of a base material layer, the component and prescription of each surface layer are the same, The component of one surface layer and The prescription is shown in Table 1.

  As is clear from Table 2, the laminated sheets of Examples and Reference Examples are superior to the laminated sheet of the comparative example in terms of scratch resistance, and have a low coefficient of static friction. Even if the sheets are stacked or wound, Easy to peel off each other and excellent in handling. Furthermore, Reference Example 1, Example 2, Reference Examples 3 to 5, Examples 6 to 7, 9, Reference Example 11 containing polypropylene and low density polyethylene with MFR 0.5 or 2.0 g / 10 min in the base material layer, And the lamination sheet of Example 12 can reduce drawdown, and is excellent in secondary moldability. Among them, the laminated sheets of Reference Example 1, Example 2, Reference Examples 3 to 5, Examples 6 to 7 and 9 are excellent in releasability.

  The laminated sheet of the present invention can be used as a packaging material, various containers, trays, embossed tapes, carrier tapes, magazines, etc., and is excellent in scratch resistance and handling properties, and is particularly suitable as a transport tray or transport container. Available. In addition, since it has antistatic properties, it is suitable for electronic parts (for example, a casing of a mobile phone), optical parts carrying trays and carrying containers. Furthermore, since the sheet surface retains a certain level of resistance to slipping, the article can be placed on an inclined sheet and the appearance is excellent, so that it can be suitably used as an exhibition stand (exhibition sheet).

Claims (11)

  On at least one surface of the base material layer (A) containing the polypropylene resin (A1) and the polyethylene resin (A2), a dynamically cross-linked polyolefin elastomer (B1) having a Duro hardness A of 60 to 70 according to JIS K6253. ) And a polymer type antistatic agent (B2), a laminated sheet on which the surface layer (B) has a static friction coefficient of 0.7 or less, and the surface layer (B) is a polyolefin. A laminated sheet comprising 60% by weight or more of an elastomer (B1), and wherein the polymer antistatic agent (B2) is composed of a block copolymer of an olefin block and a hydrophilic block.   The laminated sheet according to claim 1, wherein the proportion of the polymer antistatic agent (B2) is 5 to 30 parts by weight with respect to 100 parts by weight of the resin component of the surface layer (B).   The laminated sheet according to claim 1 or 2, wherein the polyolefin elastomer (B1) is a dynamic partially cross-linked polyolefin elastomer.   The laminated sheet according to any one of claims 1 to 3, wherein the polyolefin elastomer (B1) is composed of a hard segment containing a polyolefin resin and a soft segment containing ethylene-propylene rubber or ethylene-propylene-diene rubber.   The laminated sheet according to any one of claims 1 to 4, wherein the content of sodium ion and sulfate ion in the polymer antistatic agent (B2) is 1 to 150 ppm, respectively.   The laminated sheet according to any one of claims 1 to 5, wherein the polyethylene resin (A2) contains at least low density polyethylene.   The laminated sheet according to any one of claims 1 to 6, wherein the melt flow rate of the polypropylene resin (A1) based on JIS K7210 is 0.15 to 5 g / 10 minutes.   The ratio (weight ratio) of a polypropylene resin (A1) and a polyethylene resin (A2) is the former / the latter = 55 / 45-90 / 10, The laminated sheet in any one of Claims 1-7.   The laminated sheet according to any one of claims 1 to 8, wherein the static friction coefficient of the surface layer (B) is 0.4 to 0.7.   The laminated sheet according to any one of claims 1 to 9, wherein the surface layer (B) is formed on both surfaces of the base material layer (A).   The total thickness is 0.3 to 1.5 mm, and the thickness of the base layer (A) and the thickness of the surface layer (B) (when the surface layer (B) is formed on both sides of the base layer (A)) The ratio of the thickness of each surface layer) is the former / the latter = 4/1 to 20/1. The laminated sheet according to claim 1.