Sheet having a base layer containing ABS resin

Abstract

The present invention provides a sheet having a base material layer containing an ABS-based resin as a main component and having excellent processability, producing less burrs and fluff.　There is provided a sheet comprising: a base material layer containing an ABS-based resin as a main component; and a conductive layer laminated on at least one surface of the base material layer. The ABS-based resin comprises graft rubber having a specific volume particle size distribution width and D90 value.

Description

Technical Field

[0001] The present invention relates to a sheet having a base layer containing an ABS-based resin as a main component. The present invention also relates to a molded article including a sheet having a base layer containing an ABS-based resin as a main component.

Background Art

[0002] Sheets having a base layer containing an ABS-based resin as a main component are used in various applications because of their excellent physical and chemical properties. In particular, sheets that have a base layer containing an ABS-based resin as a main component and further include a conductive layer that suppresses generation of static electricity are often used as sheets for packaging final products or intermediate products of various industrial products including electronic components.

[0003] The above-described sheet is typically processed into a molded article and used for applications of packaging industrial products. Accordingly, there is a need for sheets having good processability. For example, when the molded article is a molded article for packaging precise small electronic components such as an embossed carrier tape, burrs and fluff generated when cutting the sheet or punching holes in the sheet may cause serious defects to the electronic components. Accordingly, there is a particular need for sheets that are less prone to burrs and fluff and have excellent processability.

[0004] Many attempts have been reported to improve the processability of sheets having a base layer mainly composed of an ABS-based resin. For example, Patent Document 1 describes that using an ABS-based resin having a specific composition as the base layer improves the processability of a surface conductive laminated sheet.

[0005]

Patent Document 1

Summary of the Invention

[0006] The present invention aims to provide a sheet having a base layer mainly composed of ABS resin, which exhibits excellent processability.

[0007] The inventors of this invention have surprisingly discovered that the processability of a sheet having a base layer mainly composed of ABS resin and a conductive layer laminated on at least one surface of the base layer can be improved by using an ABS resin containing graft rubber having a specific volume particle size and volume particle size distribution width, thereby completing the present invention. In other words, the present invention provides the following embodiments. [1] A base layer mainly composed of ABS resin and a conductive layer laminated on at least one surface of the base layer, The aforementioned ABS resin includes graft rubber, The volume particle size distribution width of the graft rubber is given by equation (1): Volume particle size distribution width = (D90 - D10) / D50 ... Equation (1) [In the formula, D90 is the volume particle diameter (μm) at which 90% of the graft rubber particles are less than or equal to D90, D50 is the volume particle diameter (μm) at which 50% of the graft rubber particles are less than or equal to D50 and the remaining 50% are greater than or equal to D50, and D10 is the volume particle diameter (μm) at which 10% of the graft rubber particles are less than or equal to D10.] Calculated according to the above, and is 2.0 or less, The D90 of the graft rubber is 2.0 to 8.0 μm. Seat. [2] The sheet according to [1], wherein the conductive layer is the outermost layer. [3] The Charpy impact strength of the base material layer was evaluated according to the evaluation method in accordance with JIS-K-7111-1 and was 10 kJ / m 3 The sheet described above is as shown in [1] or [2]. [4] The sheet according to any one of [1] to [3], wherein the ABS resin comprises 20 to 40% by mass of the graft rubber and 60 to 80% by mass of an acrylonitrile-styrene copolymer based on the total mass of the ABS resin, the graft rubber comprises 5 to 15% by mass of acrylonitrile, 40 to 60% by mass of butadiene, and 25 to 55% by mass of styrene based on the total mass of the graft rubber, and the graft rate of the graft rubber is 100 to 140%. [5] The sheet according to [4], wherein the copolymer of acrylonitrile and styrene contains 20 to 40% by mass of acrylonitrile and 60 to 80% by mass of styrene, based on the total mass of the copolymer of acrylonitrile and styrene, and has a weight-average molecular weight of 80,000 to 200,000. [6] A sheet for packaging electronic components, as described in any of [1] to [5]. A molded body comprising any of the sheets described in [7], [1], to [6]. [8] The molded body according to [6], which is a molded body for packaging electronic components. [9] A molded body according to [7] or [8], which is a container.

[10] A carrier tape, the molded body according to [7] or [8].

[0008] The present invention can provide a sheet having a base layer mainly composed of ABS resin, which has excellent processability. [Brief explanation of the drawing]

[0009] [Figure 1A] Figure 1A is a transmission electron microscope (TEM) image of the ABS resin raw material of Example 3. The image was taken from an ultrathin ABS resin section stained with osmium tetroxide (OsO4). [Figure 1B] Figure 1B is a transmission electron microscope (TEM) image of the ABS resin raw material of Comparative Example 4. The image was taken from an ultrathin ABS resin section stained with osmium tetroxide (OsO4). [Modes for carrying out the invention]

[0010] [Explanation of terms] In this disclosure, "main component" means a component whose proportion is 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more, based on the total mass of the composition or other product containing the component. For example, the expression "substrate layer containing ABS resin as the main component" means that the substrate layer is a substrate layer containing 50% by mass or more, preferably 70% by mass or more, and more preferably 90% by mass or more of ABS resin.

[0011] In this disclosure, numerical ranges described using the expressions "from" or "~" each include an upper limit and a lower limit, respectively. For example, the description "A to B" or "A~B" using numerical values ​​A and B means that it is greater than or equal to A and less than or equal to B. Furthermore, the descriptions "A to B," "A~B," or "greater than or equal to A and less than or equal to B" independently include both "greater than or equal to A is preferable" and "less than or equal to B is preferable." If multiple numerical ranges are described for a particular parameter in this disclosure, a suitable numerical range can be created by combining any upper and lower limit values ​​from among the upper and lower limits of each numerical range. Furthermore, the lower or upper limit of a numerical range described in this disclosure may be replaced with a numerical value within that range, as shown in the examples.

[0012] In this disclosure, "and / or" includes both the relationship expressed by "and" and the relationship expressed by "or". "And" may also be expressed as "and" or "as well as". "Or" may also be expressed as "or else".

[0013] In this disclosure, "including" includes "primarily from", "substantial from", and "consisting of", "primarily from" includes "substantial from" and "consisting of", and "substantial from" includes "consisting of". In this disclosure, subjects expressed in the singular form using "a," "an," "the," etc., include both singular and plural subjects unless otherwise explicitly indicated.

[0014] Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to these embodiments, and can be implemented with appropriate modifications within a range that does not impair the effects of the present invention. These embodiments may be implemented alone or in combination. When a specific description given for one embodiment also applies to other embodiments, the description may be omitted in the other embodiments. Known techniques and procedures described in the present specification are well understood by those skilled in the art and can be implemented according to common methods.

[0015] The present disclosure relates to a sheet having a base material layer containing an ABS-based resin as a main component (hereinafter also simply referred to as "sheet"). The present disclosure also relates to a molded article including a sheet having a base material layer containing an ABS-based resin as a main component.

[0016] [Sheet] The "sheet" according to the present embodiment has a base material layer containing an ABS-based resin as a main component, and a conductive layer laminated on at least one surface of the base material layer, wherein the ABS-based resin contains graft rubber, and the volume particle diameter distribution width of the graft rubber is represented by formula (1): Volume particle diameter distribution width=(D90-D10) / D50···Formula (1) [In the formula, D90 is a volume particle diameter (μm) within which 90% of graft rubber particles have a diameter smaller than D90, D50 is a volume particle diameter (μm) within which 50% of graft rubber particles have a diameter smaller than D50 and the remaining 50% have a diameter equal to or larger than D50, and D10 is a volume particle diameter (μm) within which 10% of graft rubber particles have a diameter smaller than D10] which is 2.0 or less as calculated according to the above, and the graft rubber has D90 in the range of 2.0 to 8.0 μm. The sheet according to the present embodiment has excellent processability, and generation of burrs and fuzz is effectively suppressed.

[0017] <Base material layer> The sheet according to this embodiment comprises a base layer mainly composed of an ABS resin. The ABS resin also includes graft rubber having a volume particle size distribution width of 2.0 or less and a D90 in the range of 2.0 to 8.0 μm, calculated according to the above formula (1).

[0018] (ABS resin) The "ABS-based resin" according to this embodiment is a resin or resin composition containing graft rubber, and preferably a resin or resin composition containing graft rubber and a copolymer of acrylonitrile and a styrene-based monomer (AS copolymer). The ABS-based resin may be used alone or two or more types may be used in combination.

[0019] In one embodiment, the content ratio of graft rubber to AS copolymer is preferably in the range of 20 to 40% by mass of graft rubber and 60 to 80% by mass of AS copolymer, and more preferably in the range of 20 to 30% by mass of graft rubber and 70 to 80% by mass of AS copolymer.

[0020] (Graft rubber) The "grafted rubber" according to this embodiment is preferably a rubber component obtained by graft copolymerizing a vinyl cyanide monomer, a diene monomer, and an aromatic vinyl monomer. The cyanide vinyl monomer is preferably acrylonitrile, methacrylonitrile, or ethacrylonitrile, and particularly preferably acrylonitrile. The diene monomer is preferably 1,3-butadiene (hereinafter simply referred to as "butadiene"), 1,3-pentadiene, or 2-methyl-1,3-butadiene (isoprene), and particularly preferably butadiene. The aromatic vinyl monomer is preferably styrene, α-methylstyrene, p-methylstyrene, or o-methylstyrene, and particularly preferably styrene. The aromatic vinyl monomer may be used alone or in combination of two or more. Graft rubber is particularly preferably a rubber component obtained by graft copolymerizing acrylonitrile, butadiene, and styrene.

[0021] The weight-average molecular weight (Mw) of the graft chains of the graft rubber is not particularly limited as long as it does not impair the effects of the present invention, but is typically between 18,000 and 56,000. The weight-average molecular weight (Mw) of the graft chains of the graft rubber can be evaluated by known methods, such as those described in Japanese Patent Application Publication No. 2012-51249.

[0022] In one embodiment, the volume particle size distribution width of the graft rubber having the volume particle size distribution width represented by formula (1) described above is 2.0 or less, preferably 1.5 or less, and more preferably 1.0 or less, from the viewpoint of punching burr characteristics. In one embodiment, the volume particle size distribution width of the graft rubber represented by formula (1) may be from 0.5 to 2.0, or from 0.5 to 1.5.

[0023] As described above, the D90 of the graft rubber is between 2.0 and 8.0 μm. By including graft rubber in which the D90 is between 2.0 and 8.0 μm and the volume particle size distribution width represented by formula (1) is 2.0 or less, it is possible to suppress burrs during punching and to create a base layer with sufficient strength. By providing such a base layer, the sheet according to this embodiment has excellent processability. In one embodiment, the D90 of the graft rubber may be 2.0 to 6.0 μm, 4.0 to 6.0 μm, 2.0 to 4.0 μm, or 2.0 to 3.0 μm. The D50 of the graft rubber is preferably 0.9 to 3.8 μm, more preferably 1.5 to 3.0 μm. The D10 of the graft rubber is preferably 0.3 to 2.8 μm, more preferably 1.0 to 2.0 μm. Based on the measurement principle, the relationship between D90, D50, and D10 of the graft rubber is D90 > D50 > D10.

[0024] The D90, D50, and D10 values ​​of graft rubber can be determined by known methods. Typically, D90, D50, and D10 are measured on an ABS resin sample using a commercially available laser diffraction / scattering particle size distribution analyzer (e.g., Laser Micron Sizer LMS-2000e, manufactured by Seishin Corporation), following the instrument's instructions and using dimethylformamide as the dispersion medium.

[0025] In one embodiment, the graft rubber may contain 5 to 15% by mass of acrylonitrile (An), 40 to 60% by mass of butadiene (Bd), and 25 to 55% by mass of styrene (St), based on the total mass of the graft rubber. If the composition of An, Bd, and St in the graft rubber is within the aforementioned range, an ABS-based resin with a good balance of various mechanical properties is easily obtained. Furthermore, if the Bd content is above the lower limit mentioned above, the mechanical properties of the ABS resin tend to improve in terms of impact strength, flexural strength, and elongation at break. Conversely, if the Bd content is below the upper limit mentioned above, the strength properties of the ABS resin tend to improve in terms of yield strength and other characteristics. By keeping the Bd content within the above range, it becomes easier to obtain sheets with good processability.

[0026] In one embodiment, the graft rate of the graft rubber is preferably typically 100 to 140%. The graft rate may also be 100 to 120% or 120 to 140%. The graft rate can typically be measured by the following method. Approximately 20 g of the resin composition is dispersed in 100 ml of methanol, and the solid components are filtered off by suction filtration using filter paper. The filtered solid components are dried at room temperature for 24 hours, and then in a vacuum dryer for approximately 4 hours. Approximately 1.2 g of the dried solid components is placed in a 100 ml Erlenmeyer flask, and 30 g of methyl ethyl ketone (MEK) is added to it. This is stirred at 23°C for 24 hours, then subjected to a centrifuge (e.g., Hitachi CR26H; temperature: -9°C, rotation speed: 23,000 rpm, time: 50 minutes), and allowed to stand for another 30 minutes to separate the supernatant and precipitate. The supernatant is poured into a 300 ml beaker containing 150 ml of methanol, and the precipitate is filtered off by suction filtration using filter paper. The filtered precipitate is dried at room temperature for 24 hours, and then in a vacuum dryer for approximately 4 hours. The graft rubber is isolated from the resin composition by repeating the steps described above—adding MEK, stirring, centrifugation, standing, precipitation, suction filtration, and drying—on the obtained dried product. The mass of An monomer (y) contained in the isolated graft rubber is quantified by the Kjeldahl nitrogen method, and the mass of St monomer (z) is quantified by pyrolysis gas chromatography. From the quantified values, the graft rate is calculated using the formula: Graft rate (%) = 100 × (y + z) / {x - (y + z)}, where (x) is the mass of graft rubber used for quantification. Sheets having a base layer mainly composed of ABS resin with a graft ratio of above the aforementioned lower limit are more likely to suppress the generation of burrs and fuzz during processing. Furthermore, if the graft ratio of the ABS resin is below the aforementioned upper limit, synthesis is easier, and sheets having a base layer mainly composed of such ABS resin are more likely to achieve sufficient strength when used, for example, as packaging material for electronic components. The graft rate of graft rubber varies depending on the manufacturing method of various ABS-based resins, but it can be set by adjusting general polymerization conditions such as the amount and timing of polymerization initiator and chain transfer agent addition, and temperature control during polymerization. Furthermore, ABS-based resins containing graft rubber with a graft rate within this range are available on the market.

[0027] (AS copolymer) The ABS resin in this embodiment may include an AS copolymer. The AS copolymer is a copolymer obtained by copolymerizing acrylonitrile and a styrene monomer. The same styrene monomer used to obtain the graft rubber described above can be used as the styrene monomer, and the preferred examples are also the same. Particularly preferred is the AS copolymer of acrylonitrile and styrene.

[0028] In one embodiment, the AS copolymer preferably contains 20 to 40% by mass of acrylonitrile (An) and 60 to 80% by mass of styrene (St) based on the total mass of the AS copolymer. More preferably, the AS copolymer may contain 20 to 30% by mass of An and 70 to 80% by mass of St based on the total mass of the AS copolymer. If the composition of An and St in the AS copolymer is within these ranges, the sheet tends to have good extrusion moldability. In one embodiment, the weight-average molecular weight of the AS copolymer is preferably 80,000 to 200,000, more preferably 100,000 to 150,000. If the weight-average molecular weight of the AS copolymer is 80,000 or higher, the DuPont impact strength and flexural strength are less likely to decrease, and if it is 200,000 or lower, the generation of burrs is more easily suppressed. The weight-average molecular weight of the AS copolymer can be determined, for example, from the molecular weight distribution curve using GPC (gel permeation chromatography).

[0029] (Other ingredients) In one embodiment, the base layer may contain resin components other than ABS resin (other resins) and various additives in an amount not exceeding 50% by mass. Examples of other resins include, but are not limited to, polycarbonate (PC) resin and polybutylene terephthalate (PBT) resin. Examples of additives include, but are not limited to, modifiers, lubricants, plasticizers, and processing aids. Furthermore, the base layer may also contain recycled material. Recycled material is generally a material that is reused in the resin sheet manufacturing process by crushing and re-pelletizing portions that cannot be used for product manufacturing, such as the ends of the sheet (generally called "edges") generated when the resin sheet is extruded, or the starting end portion when the sheet is wound up. When the base layer contains recycled material, the content of each component in the base layer can also be adjusted by the content of each component in the recycled material. In one embodiment, the base layer contains 2 to 30% by mass, preferably 2 to 30% by mass, and more preferably 2 to 20% by mass of recycled material relative to the total mass of the base layer.

[0030] In one embodiment, the substrate layer may contain trace components derived from the raw materials or other trace components, to the extent that it does not impair the effects of the present invention. Examples of such trace components include, but are not limited to, α-methylstyrene, vinyltoluene, dimethylstyrene, chlorostyrene, vinylnaphthalene, methacrylonitrile, ethacrylonitrile, and fumaronitrile. The description of trace components will be omitted below, but the conductive layer, resin, polymer, composition, resin composition, etc. in this embodiment all include those containing such trace components, to the extent that it does not impair the effects of the present invention.

[0031] (Charpy impact strength) In one embodiment, the Charpy impact strength of the substrate layer is preferably 10 kJ / m 3 The above is more preferable: 10 kJ / m 3 From 20 kJ / m 3 Generally, the Charpy impact strength of the substrate layer is 10 kJ / m². 3 If the above conditions are met, the strength (especially the toughness) of the base material layer tends to be good, and the sheet having this base material layer can be suitably used, for example, as a sheet for packaging electronic components. The Charpy impact strength of the base layer is typically evaluated using a notched test specimen prepared with a resin composition for the base layer, employing an edgewise impact direction according to the evaluation method specified in JIS-K-7111-1. A commercially available impact testing device (for example, a digital impact testing machine manufactured by Toyo Seiki Seisakusho Co., Ltd.) can be used as the measuring device. In the resin composition according to this embodiment, a notched test specimen can be prepared using the aforementioned resin composition containing the ABS-based resin and measured using the method described above.

[0032] <Conductive layer> The sheet according to this embodiment comprises a conductive layer laminated on at least one surface of the aforementioned base material layer. The conductive layer may be laminated on one surface of the base material layer or on both surfaces. In one embodiment, the conductive layer is preferably the outermost layer of the sheet. When the conductive layer is on the outermost surface of the sheet, for example, burrs and fuzz are less likely to occur during sheet punching, and the processability of the sheet tends to improve.

[0033] The conductive layer is not particularly limited as long as it contains a conductive component. Carbon black is preferably used as the conductive component. Examples of carbon black include, but are not limited to, furnace black, channel black, and acetylene black. To obtain high conductivity with a small amount of carbon black added, it is preferable to use carbon black with a large volume particle size and a large specific surface area. Specifically, the average primary volume particle size of the carbon black is preferably 10 to 100 nm, more preferably 20 to 60 nm. The average primary volume particle size can be measured, for example, using a transmission electron microscope. The conductive layer contains a conductive component, preferably 5 to 40% by mass, more preferably 10 to 30% by mass. The conductive layer may also contain one or more of the following: polystyrene resin, ABS resin, polyvinyl chloride resin, polypropylene resin, polyester resin, polyphenylene ether resin, polybutylene terephthalate resin, and polycarbonate resin. In this case, the conductive layer contains these components preferably 60 to 95% by mass, more preferably 70 to 90% by mass. The conductive layer may contain various additives. Examples of additives include, but are not limited to, modifiers, lubricants, plasticizers, and processing aids. Furthermore, the conductive layer may contain the recycled material described above, to the extent that it does not impair the effects of the present invention. In this case, the content of each component in the conductive layer can also be adjusted by the content of each component in the recycled material. In one embodiment, the conductive layer contains 2 to 30% by mass, preferably 2 to 30% by mass, and more preferably 2 to 20% by mass, of the recycled material relative to the total mass of the components constituting the conductive layer.

[0034] <Thickness of the base layer and conductive layer, and total thickness of the sheet, etc.> The thicknesses of the base layer and the conductive layer, as well as the total thickness of the sheet, can be arbitrarily set within a range that does not impair the effects of the present invention. For example, the thickness of the base layer may be preferably 50 to 700 μm, more preferably 75 to 500 μm, and even more preferably 100 to 300 μm. The thickness of the conductive layer may be preferably 1 to 100 μm, more preferably 5 to 75 μm, and even more preferably 10 to 50 μm. The total thickness of the sheet may be preferably 51 to 800 μm, more preferably 80 to 150 μm, and even more preferably 110 to 350 μm. In one embodiment, the ratio of the thickness of the substrate layer to the thickness of the conductive layer (thickness of the substrate layer / thickness of the conductive layer) may be in the range of 90 / 10 to 60 / 40. These thicknesses can be evaluated by known methods. For example, these thicknesses may be evaluated using a microscope or the like. Specifically, these thicknesses may be evaluated by measuring the thickness of the layers in the cross-section of a sample cut with a single-edged knife using a laser microscope for shape analysis (e.g., shape measuring laser microscope VK-X100, manufactured by Keyence Corporation). When a sheet is extruded with an extruder, these thicknesses are typically evaluated from the average value of measurements taken at both ends and the center of the cross-section in a direction perpendicular to the flow direction of the sheet.

[0035] The sheet according to this embodiment may have any layer other than the base layer and the conductive layer. Furthermore, the base layer and the conductive layer may each have a single-layer structure or a multi-layer structure. When an arbitrary layer is included, it is preferable to provide the arbitrary layer such that the conductive layer is the outermost layer, from the viewpoint of easily suppressing burrs and fuzz when the sheet is punched out.

[0036] [Application] The sheet according to this embodiment is typically a sheet that can be used as a material for a molded body for packaging an intermediate or final product of an industrial product. The industrial product is typically an electronic component or a product containing an electronic component. That is, in this embodiment, the sheet may be used as a sheet for packaging electronic components. Examples of electronic components or products containing electronic components include, but are not limited to, semiconductors, integrated circuits (ICs), light-emitting diodes (LEDs), diodes, resistors, capacitors, transistors, piezoelectric resistors, filters, crystal oscillators, crystal resonators, connectors, switches, potentiometers, relays, inductors, or combinations thereof. Another embodiment relating to the above-mentioned sheet is its use as packaging material for electronic components or a method of using it in this way.

[0037] The sheet according to this embodiment has good processability. For example, the sheet according to this embodiment has the property of being less prone to burrs and fuzzing when the sheet is cut or holes are punched in the sheet. Therefore, when a molded article containing the sheet according to this embodiment is used to package electronic components, for example, there is less possibility of defects occurring in the electronic components due to burrs and fuzzing. However, sheets that are less prone to burrs and fuzzing generally tend to have low strength and tend to be unsuitable for use as, for example, electronic component packaging sheets. However, the sheet according to this embodiment maintains appropriate strength and can be used appropriately as, for example, electronic component packaging sheets.

[0038] [Method of manufacturing the sheet] In these embodiments, the method for manufacturing the sheet is not particularly limited and can be manufactured by general methods. For example, the raw materials constituting the base layer and the conductive layer are supplied to separate extruders and preferably manufactured by extrusion molding using a multi-layer T-die with a multi-manifold, or by T-die extrusion molding using a feed block method. In these manufacturing methods, portions that cannot be used for the final product, such as the ends of the sheet (generally referred to as "edges") generated during the sheet extrusion process and the starting end portion when winding the sheet, can generally be crushed and re-pelletized to be used as recycled material. In the above embodiments, such recycled material can be included in the base layer, conductive layer, etc., to the extent that the effects of the present invention are not lost.

[0039] [Molded articles and methods for manufacturing the same] In these embodiments, the molded article can be obtained by processing the sheet according to these embodiments. The sheet can be processed by known methods including vacuum forming, pressure forming, and press forming. The sheet processing may also include steps of cutting the sheet into a desired shape and punching sprocket holes in the sheet. The molded body according to this embodiment is typically a molded body for packaging electronic components. In one embodiment, the molded body may be a container, and in particular a container having a storage section for housing electronic components. In another embodiment, the molded body may be a carrier tape, and in particular an embossed carrier tape. [Examples]

[0040] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the following description.

[0041] [Create a sheet] ABS-based resin raw materials were prepared by known methods using graft rubbers 1 to 7 shown in Table 1 and AS copolymers shown in Table 2, blended in the compositions shown in Table 3. Ten parts by mass of recycled material were weighed out for every 100 parts by mass of the ABS-based resin raw material and uniformly mixed using a high-speed mixer to obtain the composition for use in the base layer. The recycled material used was obtained by crushing and re-pelletizing portions that could not be used as products, such as the ends (edges) of the sheet extruded from the T-die or the starting end portion when winding the sheet. Furthermore, the recycled materials used in Examples 1 to 3 and Comparative Examples 1 to 4 were obtained from the manufacturing processes of Examples 1 to 3 and Comparative Examples 1 to 4, respectively. The D90, D50, and D10 grades of graft rubber were measured using ABS resin samples with a Laser Micron Sizer LMS-2000e (manufactured by Seishin Corporation), following the instructions in the instrument's user manual, and using dimethylformamide as the dispersion medium. In the table below, An represents acrylonitrile, St represents styrene, Bd represents butadiene, PC represents polycarbonate, PBT represents polybutylene terephthalate, CB represents carbon black, and Mw represents weight-average molecular weight.

[0042] [Table 1]

[0043] [Table 2]

[0044] [Table 3]

[0045] Figures 1A and 1B show transmission electron microscope (TEM) images of the ABS resin raw materials of Example 3 and Comparative Example 4, respectively. In the ABS resin raw material of Example 3, which has a narrow volume particle size distribution, relatively large, uniformly sized spherical graft rubber is observed. On the other hand, in the ABS resin raw material of Comparative Example 4, which has a wide volume particle size distribution, relatively small, non-uniformly sized spherical graft rubber is observed. Compared to the ABS resin raw material of Comparative Example 4, the ABS resin raw material of Example 3 is thought to have a tendency for more uniform rupture and therefore improved punching burr characteristics due to the more uniform size of the graft rubber. Furthermore, the ABS resin raw material of Example 3 is thought to have a tendency for increased Charpy impact strength compared to the ABS resin raw material with smaller graft rubber due to the larger size of the graft rubber.

[0046] As a composition to be used for the conductive layer, a composition was prepared by kneading 80% by mass of polycarbonate resin (manufactured by Teijin Limited, product name: "Panlite® L-1225L") and 20% by mass of acetylene black (manufactured by Denka Co., Ltd., product name: "Denka Black® Granular", average primary volume particle size: 35 nm) using a φ30 mm vented twin-screw extruder and then pelletizing it by the strand-cut method.

[0047] The average primary volume particle size of acetylene black in the conductive layer was determined by the following method. First, a dispersed sample was prepared by dispersing acetylene black in chloroform for 10 minutes using an ultrasonic disperser at 150 kHz and 0.4 kW. This dispersed sample was sprinkled onto a carbon-reinforced support film and fixed, and then photographed with a transmission electron microscope (JEOL Ltd., JEM-2100). From images magnified 50,000 to 200,000 times, the particle diameter (maximum diameter for non-spherical shapes) of more than 1,000 inorganic fillers was randomly measured using an Ender device, and the average value was defined as the average primary particle diameter.

[0048] The composition used for the base layer and the composition used for the conductive layer were processed using a feed block method with a φ65 mm extruder (L / D=28), a φ50 mm extruder (L / D=28), a φ40 mm extruder (L / D=26), and a 500 mm wide T-die to obtain a sheet having conductive layers on both sides of the base layer. The thickness of the conductive layer, the thickness of the base layer, and the total thickness of the sheet are shown in Table 4. These thicknesses are the average of the thicknesses at both ends and the center of the cross-section perpendicular to the flow direction of the sheet, measured with a shape analysis laser microscope (shape measurement laser microscope VK-X100, manufactured by Keyence Corporation) on a sheet fragment cut with a single-edged knife.

[0049] [Table 4]

[0050] [Evaluation of the sheet] Sheet samples were prepared by cutting the sheets of Examples 1 to 3 and Comparative Examples 1 to 4 in the direction of sheet extrusion, and left for 24 hours in an atmosphere of 23°C and 50% relative humidity. Subsequently, the punching burr characteristics and Charpy impact strength were evaluated under the following conditions.

[0051] (Punching burr characteristics) Sheet samples slit to a width of 8 mm were punched out using a vacuum rotary molding machine (Muehlbauer, product name: "CT8 / 24") under an atmosphere of 23°C and 50% relative humidity, and the burrs and fuzz of the punched holes were evaluated. The punching was performed at a speed of 240 m / h using a punching device equipped with a cylindrical punching pin with a tip diameter of 1.5 mm and a die hole with a diameter of 1.58 mm. The sheet punched holes formed as described above were photographed using a microscopic measuring instrument (Mitutoyo Corporation, product name "MF-A1720H (image unit 6D)") in a light source environment with 0% reflected light, 40% transmitted light, and 0% ring. Ten holes with a diameter of 1.5 mm were observed, and the number of burrs and lint with a length of 0.15 mm or more was counted. The following criteria were used for evaluation, and a score of "good" or higher was considered a pass (indicating suppressed generation of burrs and lint). <Judgment criteria> Excellent: The number of burrs and lint was less than 6. Good: The number of burrs and lint was between 6 and 10. Unacceptable: The number of burrs or lint was 10 or more.

[0052] (Charpy impact strength) Charpy impact strength was measured using notched test specimens made with the resin composition for the base layer, according to the evaluation method in accordance with JIS K7111-1, with the impact direction being edgewise. The measuring instrument used was a digital impact tester manufactured by Toyo Seiki Seisakusho Co., Ltd. Generally, sheets using base layers with low Charpy impact strength tend to have less burr and fuzz generation. However, sheets using base layers with excessively low Charpy impact strength are unsuitable for use as electronic component packaging sheets because they do not provide sufficient strength for the molding process.

[0053] As shown in Table 4, the compositions of Examples 1 to 3, in which the volume particle size distribution width of the graft rubber particles was 2 or less and the D90 of the graft rubber particles was between 2.0 μm and 8.0 μm, were judged to have excellent or good punching burr characteristics. Furthermore, these compositions were judged to have a yield of 10 kJ / m 3 It possessed the above Charpy impact strength. On the other hand, the composition of Comparative Example 1, in which the D90 of the graft rubber particles was lower than 2.0 μm, exhibited lower Charpy impact strength compared to the compositions of Examples 1 to 3. Furthermore, the composition of Comparative Example 2, in which the D90 of the graft rubber particles was higher than 8.0 μm, the composition of Comparative Example 3, in which the volume particle size distribution width of the graft rubber particles was wider than 2 and the D90 of the graft rubber particles was higher than 8.0 μm, and the compositions of Comparative Examples 3 and 4, in which the volume particle size distribution width of the graft rubber particles was wider than 2, were all judged to have unacceptable punching burr characteristics. These results demonstrate that the sheet of the present invention exhibits good processability, particularly the ability to suppress the generation of burrs and fuzz during sheet punching. In other words, the sheet of the present invention is useful, for example, for packaging electronic components, and can effectively suppress the possibility of defects occurring in electronic components due to burrs and fuzz.

[0054] Furthermore, the disclosures of patents, patent applications, and publications cited in this disclosure are incorporated herein by reference in their entirety. [Industrial applicability]

[0055] The sheet having a base layer mainly composed of the ABS resin of the present invention has good processability and can therefore be suitably used as a packaging sheet for industrial products (for example, electronic components including semiconductors, integrated circuits (ICs), light-emitting diodes (LEDs), diodes, resistors, capacitors, transistors, piezoelectric elements, resistors, filters, crystal oscillators, crystal resonators, connectors, switches, potentiometers, relays, inductors, or combinations thereof). Therefore, the present invention has industrial applicability.

Claims

1. It has a base layer mainly composed of ABS resin and a conductive layer laminated on at least one surface of the base layer, The aforementioned ABS resin includes graft rubber, The volume particle size distribution width of the graft rubber is given by equation (1): Volume particle size distribution width = (D90 - D10) / D50 ... Equation (1) [In the formula, D90 is the volume particle diameter (μm) at which 90% of the graft rubber particles are less than or equal to D90, D50 is the volume particle diameter (μm) at which 50% of the graft rubber particles are less than or equal to D50 and the remaining 50% are greater than or equal to D50, and D10 is the volume particle diameter (μm) at which 10% of the graft rubber particles are less than or equal to D10.] Calculated according to the above, and is 2.0 or less, The D90 of the graft rubber is 2.0 to 6.0 μm. Seat.

2. The sheet according to claim 1, wherein the conductive layer is the outermost layer.

3. The Charpy impact strength of the aforementioned substrate layer was evaluated according to the evaluation method in accordance with JIS-K-7111-1 and was 10 kJ / m ３ The sheet described in claim 1 is as described above.

4. The sheet according to claim 1, wherein the ABS resin comprises 20 to 40% by mass of the graft rubber and 60 to 80% by mass of an acrylonitrile-styrene copolymer, the graft rubber comprises 5 to 15% by mass of acrylonitrile, 40 to 60% by mass of butadiene, and 25 to 55% by mass of styrene, the graft rate of the graft rubber is 100 to 140%.

5. The sheet according to claim 4, wherein the copolymer of acrylonitrile and styrene contains 20 to 40% by mass of acrylonitrile and 60 to 80% by mass of styrene, based on the total mass of the copolymer of acrylonitrile and styrene, and has a weight-average molecular weight of 80,000 to 200,000.

6. The sheet according to claim 1, which is a sheet for packaging electronic components.

7. A molded article comprising the sheet described in any one of claims 1 to 6.

8. The molded body according to claim 7, which is a molded body for packaging electronic components.

9. A molded body according to claim 7, which is a container.

10. A molded article according to claim 7, which is a carrier tape.

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