JP2002283502A - Resin sheet and molded product for feeding electronic parts - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a resin laminated sheet excellent in mechanical physical properties such as folding endurance (hardness to crack), buckling strength, impact resistance, rigidity or the like and comprising respective layers uniform in thickness, and a molded product for feeding electronic parts formed using the resin laminated sheet. SOLUTION: The resin laminated sheet is constituted by forming outer layers, each of which is constituted of a resin composition (B) containing a styrenic resin and a styrene/butadiene block copolymer, on both surfaces of a base material layer constituted of a resin composition (A) containing a styrenic thermoplastic elastomer and a styrenic resin. A ratio of the melt index (MIA) of the composition (A) constituting the base material layer and the melt index (MIB) of the composition (B) constituting the outer layers is MIA/MIB=0.7-3. This sheet is secondarily molded to obtain the molded product for feeding electronic parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a styrene-based resin sheet in which a plurality of resin layers are integrally laminated, and a molded article for transporting electronic parts formed from the sheet.

[0002]

2. Description of the Related Art Trays (injection trays, vacuum forming trays, etc.), magazines, carrier tapes (embossed carrier tapes, etc.) and the like are used as packaging forms for semiconductors and electronic components. These packaging and storage containers include transparent sheets made of styrene resin,
For example, a container formed of a single-layer resin sheet obtained by mixing a general-purpose polystyrene resin and a styrene-butadiene block copolymer is widely used. This container is obtained by, for example, processing a resin sheet into a predetermined shape by thermoforming or punching. However, the container formed of the resin sheet has insufficient rigidity, and is easily deformed or damaged by external force or heat acting during transportation or storage. Also,
In the conventional single-layer resin sheet molded product, since the raw material styrene-butadiene block copolymer contains a wax component, the wax component bleeds out on the surface of the molded product, and is suitable for printing and heat sealing with a cover tape. Is reduced. On the other hand, when a sheet composed of a styrene-butadiene block copolymer containing no wax component is wound around a roll, blocking occurs between the sheets.

Japanese Patent Application Laid-Open No. 11-77904 discloses that a styrene-butadiene copolymer is 45 to 90% by weight, a general-purpose polystyrene is 10 to 54% by weight, and a styrene-butadiene-styrene block copolymer is 1 to 100% by weight. A base layer containing 10% by weight, and 1 to 99
A multilayer resin sheet and a molded article having an outer layer containing 1 to 30% by weight of impact-resistant polystyrene are disclosed.

However, in this sheet, the transparency and the buckling strength of the molded product are not sufficient, and the thickness ratio of the outer layer becomes thicker at both ends and becomes thinner at the center in the cross section of the sheet (so-called outer layer wrapping phenomenon). ) Occurs, and it is difficult to improve the uniformity of the sheet.

[0005]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide excellent mechanical properties such as bending strength (hardness to crack), buckling strength, impact resistance, rigidity, etc., and uniform thickness of each layer. An object of the present invention is to provide a resin laminated sheet and a molded article for transporting electronic components formed from the sheet.

Another object of the present invention is to provide a resin laminated sheet excellent in surface smoothness and a molded article for transporting electronic parts formed from the sheet.

Still another object of the present invention is to provide a resin laminated sheet in which generation of burrs and chips is suppressed during cutting and punching, and a molded article for transporting electronic parts formed from the sheet.

It is another object of the present invention to provide a resin laminated sheet excellent in printability and heat sealability, and a molded article for transporting electronic parts formed from the sheet.

Still another object of the present invention is to provide a resin laminated sheet excellent in transparency and a molded article for transporting electronic parts formed from the sheet.

[0010]

Means for Solving the Problems The inventors of the present invention have conducted intensive studies to achieve the above object, and have found that both surfaces of a base material layer composed of a resin composition containing a styrene-based thermoplastic elastomer and a styrene-based resin are provided. , An outer layer made of a resin composition containing a styrene-based resin and a styrene-butadiene block copolymer is formed, and the melt index (M
By adjusting I) to a specific range, it has been found that a resin laminated sheet having excellent mechanical properties such as bending strength, buckling strength, impact resistance, and rigidity and having uniform thickness of each layer can be obtained. The present invention has been completed.

That is, the resin sheet of the present invention has a styrene-based resin and a styrene-butadiene block copolymer on both surfaces of a base layer composed of a resin composition (A) containing a styrene-based thermoplastic elastomer and a styrene-based resin. A sheet on which an outer layer composed of a resin composition (B) containing coalesced particles is formed, wherein a melt index (MI _A ) of the composition (A) composing the base layer and a composition (B) composing the outer layer ) And the melt index (MI _B ) are expressed as MI _B / MI
_A = 0.7-3. The base layer is composed of a styrene-butadiene copolymer (A ₁ ) and a polystyrene resin (A ₂ ), and the outer layer is a polystyrene resin (B ₁ ), a rubber-reinforced styrene resin (B ₂ ), and a styrene resin. Butadiene-styrene block copolymer (B ₃ ). Ratio of the melt index (MI _B / MI _A )
May be about 0.8 to 2.7 (particularly 0.9 to 2.5), and the melt index of the polystyrene resin (B ₁ ) is lower than the melt index of the polystyrene resin (A ₂ ). It may be large. In the copolymer (B ₃ ), the ratio (weight ratio) of styrene and butadiene is:
Styrene / butadiene = 10/90 to 55/45 (weight ratio). The ratio (weight ratio) of the styrene-based thermoplastic elastomer and the styrene-based resin constituting the base layer is about 20/80 to 95/5 (preferably 30/70 to 90/10). The proportion of the rubber component in the outer layer is 1 to 50% by weight, preferably 3 to 40% by weight.
% By weight. The thickness of the base layer is about 90 to 950 μm, and the total thickness of the outer layer is about 5 to 250 μm,
The ratio of the thickness of the base layer to the total thickness of the outer layer is about 30/1 to 0.3 / 1 (base layer / outer layer). The resin sheet may include a release agent component in at least one of the base layer and the outer layer.

The present invention also includes a molded article for transporting electronic parts formed of the sheet. The molded article for transporting electronic components is particularly suitable as a molded article that has a recess for accommodating electronic components, is sealed with a cover tape, and accommodates electronic components.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION [Base Layer] The base layer is formed mainly for improving impact resistance and rigidity, and is made of a styrene-based thermoplastic elastomer (the soft part is composed of polybutadiene or polyisoprene or a hydrogenated product thereof). And a resin composition (A) containing a styrene-based resin (a polystyrene-based resin or a rubber-reinforced styrene-based resin, etc.) and a styrene-based resin (a polystyrene-based resin or a rubber-reinforced styrene-based resin). I have. In particular, the resin composition (A) includes a styrene-butadiene copolymer (A ₁ ) and a polystyrene resin (A ₂ ).
It is preferable to be composed of

Examples of the styrene-butadiene copolymer (A ₁ ) include a styrene-butadiene block copolymer and a styrene-butadiene random copolymer. Usually, a styrene-butadiene block copolymer (for example,
A triblock composed of a polystyrene block and a polybutadiene block, in particular, a diblock copolymer composed of a polystyrene block and a polybutadiene block) is used.

Examples of the structure of the styrene-butadiene block copolymer include a linear (linear) type (such as AB type and ABA type), a star type (such as radial teleblock type), and a taper type. Among them, linear type and star type
B-type block copolymers can be preferably used.

The ratio (weight ratio) of styrene and butadiene constituting the copolymer is styrene / butadiene = 55 /
45-95 / 5, preferably 60 / 40-90 / 10,
More preferably, it is about 65/35 to 75/25.
The proportion of the addition form in the butadiene unit is cis-1,
4 addition: 10 to 50% by weight (particularly 20 to 40% by weight),
Trans-1,4 addition: 40 to 70% by weight (particularly 50 to 70% by weight)
60% by weight), 1, 2 addition: 5 to 20% by weight (particularly 10
１５15% by weight).

The melt index (MI) of the copolymer (A ₁ ) at 200 ° C. under a load of 5 kg (49 N) is 0.5 to 30 g / 10 min, preferably 1 to 20 g / min.
It is about 10 minutes, more preferably about 3 to 10 g / 10 minutes.

The polystyrene resin (A ₂ ) is a homopolymer or a copolymer formed by using an aromatic vinyl monomer as a main constituent unit. As the aromatic vinyl monomer for forming the resin (A ₂ ), for example, styrene, alkyl-substituted styrene (for example, vinyl toluene, vinyl xylene, p
-Ethylstyrene, p-isopropylstyrene, butylstyrene, pt-butylstyrene, etc.), halogen-substituted styrene (eg, chlorostyrene, bromostyrene, etc.), α-alkyl-substituted styrene having an alkyl group substituted at the α-position (eg, , Α-methylstyrene, etc.). These aromatic vinyl monomers can be used alone or in combination of two or more. Of these monomers,
Usually, styrene, vinyltoluene, α-methylstyrene and the like, particularly styrene, are used.

The aromatic vinyl monomer may be used in combination with a copolymerizable monomer. Examples of the copolymerizable monomer include, for example, a vinyl cyanide monomer (for example, acrylonitrile), an unsaturated polycarboxylic acid or an acid anhydride thereof (for example, maleic acid, itaconic acid, citraconic acid or the like). Acid anhydride, etc.), imide-based monomers [for example, maleimide, N-alkylmaleimide (for example,
N-C _1-4 alkylmaleimide), N-cycloalkylmaleimide (eg, N-cyclohexylmaleimide), N-arylmaleimide (eg, N-phenylmaleimide), acrylic monomer [eg,
(Meth) acrylic acid, methyl (meth) acrylate, ethyl (meth) acrylate, butyl (meth) acrylate,
C _1-20 alkyl (meth) acrylates such as hexyl (meth) acrylate, octyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, cyclohexyl (meth) acrylate, (meth) Hydroxy C _2-4 alkyl (meth) acrylates such as phenyl acrylate, benzyl (meth) acrylate, glycidyl (meth) acrylate, 2-hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate And the like]. These copolymerizable monomers are:
They can be used alone or in combination of two or more. The amount of the copolymerizable monomer in all the monomers is usually 1 to 50% by weight, preferably 3 to 40% by weight, more preferably 5 to 40% by weight.
It can be selected from a range of about 30% by weight.

The weight average molecular weight of the resin (A ₂ ) is 10,
000 to 1,000,000, preferably 50,000
~ 500,000, more preferably 100,000 ~
It is about 500,000.

Among these resins (A ₂ ), polystyrene (GPP) is preferred from the viewpoint of compatibility with the copolymer (A ₁ ).
S), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer (SMA resin), especially GP
PS is preferred.

The melt index (M) of the resin (A ₂ )
I) at 200 ° C. under a load of 5 kg (49 N)
0.5 to 20 g / 10 min, preferably 1 to 10 g / 10
Min, more preferably about 1 to 5 g / 10 min.

The ratio (weight ratio) of the styrene-based thermoplastic elastomer to the styrene-based resin is the former / the latter = 20/8.
0 to 95/5, preferably 30/70 to 90/10, more preferably 40/60 to 80/20 (particularly 50/5
0-70 / 30). If the proportion of the styrene-based thermoplastic elastomer is too small, the effect of improving the impact resistance becomes insufficient, and if it is too large, the rigidity decreases.

The base material layer may include other thermoplastic resins (acrylic resin, olefin resin, vinyl resin, polyamide resin, polyester resin, polyacetal resin, thermoplastic polyurethane resin, Polyether resin, polyketone resin, polyphenylene oxide resin, etc.), stabilizer (antioxidant, ultraviolet absorber,
Light and heat stabilizers, flame retardants (phosphorous flame retardants,
Halogen flame retardants, inorganic flame retardants, etc.), fillers (granular or fibrous fillers, such as glass fibers, carbon fibers, inorganic fillers, etc.), anti-dripping agents (granular fluororesins, etc.), plastics Agents, compatibilizers, impact modifiers, reinforcing agents, hue improvers, flow improvers, flame retardant aids, colorants, dispersants, antistatic agents, foaming agents, antibacterial agents, etc. . These additives can be used alone or in combination of two or more.

The thickness of the substrate layer is 90 to 950 μm, preferably 150 to 900 μm, more preferably 200 to 950 μm.
It is about 800 μm (especially 200 to 500 μm).

[Outer Layer] The outer layer is formed to improve mechanical properties such as bending strength and impact resistance, printability and anti-blocking property.
It is composed of a resin composition (B) containing a butadiene block copolymer. The resin composition (B) is particularly preferably composed of a polystyrene resin (B ₁ ), a rubber-reinforced styrene resin (B ₂ ), and a styrene-butadiene block copolymer (B ₃ ).

The polystyrene resin (B ₁ ) is used to increase the hardness and the rigidity, and the same polystyrene resin as the resin (A ₂ ) of the base layer can be used. Among the polystyrene resins, polystyrene (GPP) is used in view of compatibility with the resin (B ₂ ) and the copolymer (B ₃ ).
S), styrene-acrylonitrile copolymer (AS resin), styrene-methyl methacrylate copolymer, styrene-maleic anhydride copolymer (SMA resin), especially GP
PS is preferred.

The rubber-modified styrenic resin (B ₂ ) is used to improve impact resistance and anti-blocking property, and is a matrix composed of a polystyrene resin by copolymerization (graft polymerization, block polymerization, etc.). It is a polymer in which the rubbery polymer is dispersed in the form of particles,
In the presence of the rubbery polymer, at least the aromatic vinyl monomer is converted to a conventional method (bulk polymerization, bulk suspension polymerization, solution polymerization,
And a graft copolymer (rubber-grafted polystyrene-based polymer) obtained by polymerization by emulsion polymerization or the like.

Examples of the polystyrene resin forming the matrix include the same polystyrene resins as the resin (A ₂ ) of the base material layer.

Examples of the rubbery polymer include diene-based polymers.
Rubber [Polybutadiene (low cis type or high cis type polybuta
Diene), polyisoprene, styrene-butadiene copolymer
Coal, styrene-isoprene copolymer, butadiene-a
Acrylonitrile copolymer, isobutylene-isoprene copolymer
Polymer, styrene-isobutylene-butadiene copolymer
Rubber, etc.], ethylene-vinyl acetate copolymer, acrylic resin
(Polyacrylic acid C _2-8Alkyl ester as main component
Copolymerized elastomer), ethylene-α-olefin
-Based copolymer [ethylene-propylene rubber (EPR)
Etc.], ethylene-α-olefin-polyene copolymer
[Ethylene-propylene-diene rubber (EPDM)
Etc.], urethane rubber, silicone rubber, butyl rubber, water
-Added diene rubber (hydrogenated styrene-butadiene copolymer)
, A hydrogenated butadiene-based polymer, etc.). What
The above copolymer is a random or block copolymer.
AB copolymers, ABA
Type, tapered type, and radial teleblock type structure
Copolymers and the like. These rubbery polymers are simply
They can be used alone or in combination of two or more.

Preferred rubbery polymers are polymers of conjugated 1,3-dienes or derivatives thereof, especially diene rubbers [polybutadiene (butadiene rubber), isoprene rubber, styrene-butadiene copolymer, etc.].

In the resin (B ₂ ), the content of the rubbery polymer is 3 to 80% by weight (for example, 4 to 70% by weight),
Preferably 5 to 60% by weight (for example, 6 to 55% by weight),
More preferably, it is about 7 to 50% by weight (particularly 7 to 30% by weight). If the content of the rubber-like polymer is too small, the effect of improving the impact resistance is not sufficient, and if the content of the rubber-like polymer is too large, the transparency and the rigidity decrease.

The form of the rubbery polymer dispersed in the matrix composed of the polystyrene resin is not particularly limited, and may be a salami structure, a core / shell structure, an onion structure or the like.

The particle size of the rubbery polymer constituting the dispersed phase is, for example, 0.5 μm or more (for example, volume average particle size).
0.5 to 30 μm), preferably 0.5 to 10 μm, more preferably 0.5 to 7 μm (particularly 0.5 to 5 μm).
You can choose from a range of degrees. If the volume average particle diameter of the rubbery polymer is less than 0.5 μm, the effect of preventing the release agent component from bleeding out and the impact resistance are not sufficient. The graft ratio of the rubbery polymer is 5 to 150%, preferably 1
It is about 0 to 150%.

Of these rubber-reinforced styrenic resins,
Impact polystyrene (HIPS), styrene-acrylonitrile-butadiene copolymer (ABS resin), α-
Methylstyrene-modified ABS resin, imide-modified ABS resin, MBS resin, particularly HIPS are preferred.

The styrene-butadiene block copolymer (B ₃ ) is used for improving mechanical properties (particularly bending strength) and appearance (particularly surface smoothness).
Examples thereof include a diblock copolymer of styrene and butadiene and a triblock copolymer of styrene and butadiene, and a triblock copolymer, particularly a styrene-butadiene-styrene (SBS) block copolymer is preferred.

The ratio (weight ratio) of styrene and butadiene constituting the copolymer was styrene / butadiene = 10 /
90-55 / 45, preferably 15 / 85-50 / 5
0, and more preferably about 35/65 to 45/55. The form of addition in the butadiene unit is the same as the component (A ₁ ). The component (B ₃ ) has an MI of 5 g.
/ 10 min or more (for example, 5 to 30 g / 10 min), preferably 10 to 30 g / 10 min, more preferably 15 to 3
It is about 0 g / 10 minutes.

The components (B ₁ ), (B ₂ ) and (B ₃ )
The ratio (weight ratio) to the total amount of the components is (B ₁ ) / (B ₂ + B
₃ ) = 50 / 50-95 / 5, preferably 60 / 40-
90/10, more preferably 70/30 to 80/20
It is about. If the proportion of the component (B ₁ ) is too small, the moldability, rigidity and transparency will be reduced, and if the proportion of the component (B ₁ ) is too large, the impact resistance will be reduced.

The ratio (weight ratio) of the component (B ₂ ) to the component (B ₃ ) is (B ₂ ) / (B ₃ ) = 20/1 to 0.03 / 1,
It is preferably about 10/1 to 0.05 / 1, more preferably about 5/1 to 0.1 / 1 (particularly about 3/1 to 0.2 / 1).

The same additives as in the base layer may be added to the outer layer.

In the resin composition (B), the content of the rubber component (the rubber component in the rubber-reinforced styrene resin and the styrene-butadiene block copolymer) is 1 to 50% by weight, preferably 3 to 40% by weight, and Preferably 5
It is about 30% by weight (particularly 7 to 25% by weight). When the ratio of the rubber component is in the above range, the surface of the sheet is less roughened, and the sheet is hardly broken.

The ratio of the melt index of the resin composition constituting the base material layer _(A) (MI A), the resin composition constituting the outer layer and the melt index (MI _B) of (B) is
MI _A / MI _B = 0.7-3, preferably 0.8-2.
7, more preferably 0.9 to 2.5 (especially 1-2.
5) about. If the MI ratio is out of the above range, the thickness of each layer tends to be uneven. The melt index (MI _B ) of the resin composition (B) was 200 ° C., 5 kg load (49
N) Under 1 to 30 g / 10 min, preferably 3 to
It is about 20 g / 10 min, more preferably about 5 to 15 g / 10 min.

The total thickness of the outer layer is 5 to 250 μm, preferably 10 to 200 μm, more preferably 20 to 15 μm.
It is about 0 μm (particularly 30 to 100 μm). The ratio between the upper outer layer thickness and the lower outer layer thickness of the outer layer was 5/1 to 1/1.
5, preferably 3/1 to 1/3, more preferably 2 /
It is about 1 to 1/2, and the upper outer layer and the lower outer layer are generally the same thickness.

The ratio of the thickness of the base layer to the total thickness of the outer layer is as follows: base layer / outer layer = 30/1 to 0.3 / 1, preferably 20/1 to 0.5 / 1, more preferably 15/1. / 1-1
/ 1 (particularly 10/1 to 2/1).

[Resin Sheet] In the present invention, by providing the base layer and the outer layer having the above-mentioned composition, the two layers are firmly joined to each other, and exfoliation does not occur. A resin sheet that does not cause defects can be obtained.

The resin sheet of the present invention may contain a release agent component in at least one of the substrate layer and the outer layer. The release agent component is usually contained in a component constituting the base material layer, for example, a styrene-butadiene copolymer (A ₁ ) or a component constituting the outer layer, for example, an SBS block copolymer (B ₃ ). ing.

The ratio of the release agent component is 0.1 to 30 parts by weight, preferably 1 to 20 parts by weight, more preferably 3 to 30 parts by weight, based on 100 parts by weight of the resin constituting the resin sheet.
It is about 15 parts by weight. As the release agent component, waxes such as polyolefin wax, silicone resin,
Examples thereof include polyvinyl alcohol and paraffin. In the present invention, by including the release agent component, the generation of burrs and chips during cutting and punching is suppressed. From the viewpoint of suppressing burrs and chips, it is preferable that at least the outer layer contains a release agent component.

The thickness of the resin sheet is not particularly limited, but is 10 μm to 1 mm, preferably 50 μm to 800 μm.
More preferably, it is about 100 to 500 μm.

[Method for Producing Resin Sheet] The substrate layer and the outer layer are not particularly limited, and can be produced by mixing the respective components and then forming a sheet by a conventional method. For example, an extrusion method such as an extrusion method (die (flat, T-shaped (T-die), cylindrical (circular die), etc.) method, inflation method, etc.), a stretching method by a tenter method, a tube method, an inflation method, etc. And the like. The resin sheet may be stretched (uniaxial stretching, biaxial stretching, etc.) or may be unstretched. Laminated sheet, the resulting sheet may be prepared by a method such as heat lamination or dry lamination, but the resin composition for each constituent layer, using a general-purpose feed block die or multi-manifold die and the like It is preferably prepared by a co-extrusion method. In the coextrusion method, a thin surface layer can be obtained and mass productivity is excellent. Note that the lamination method does not necessarily require an adhesive.

[Secondary Molding Method and Secondary Molded Article] The resin sheet thus obtained is excellent in moldability, and is therefore formed by pressure forming (extrusion pressure forming, hot plate pressure forming, vacuum pressure forming, etc.), Conventional blow molding such as free blow molding, vacuum molding, bending, match molding, hot plate molding, etc.
Secondary molding can be easily performed. The resin sheet is excellent in various mechanical properties, and examples of the secondary molded product include a tray, a carrier tape, an embossed tape, a magazine, a food container, a chemical container, and the like.

The surface of the sheet or the secondary molded article may be subjected to a surface treatment (for example, discharge treatment such as corona discharge or glow discharge, acid treatment, flame treatment, etc.). Since the surface of the sheet or the secondary molded article has excellent printability, a conductive film or an antistatic layer (for example, a film using a conductive ink) may be formed.

Since the resin sheet is excellent in printability and can be imparted with an antistatic treatment satisfactorily and suppresses the generation of burrs and chips during cutting and punching, the resin sheet is one of the secondary molded articles. And electronic components (for example, IC and I
A molded article for conveyance having an accommodating concave portion for accommodating an electronic component using C [for example, an electronic component conveyance tray (injection tray, vacuum molding tray, etc.), a magazine,
Carrier tape (such as an embossed carrier tape)]. In addition, because of its excellent heat-sealing property, the adhesiveness to the cover tape is high, and in particular, a molded article for transporting electronic components (for example, a tray or a carrier) in which a concave portion for storing the electronic components is sealed with the cover tape and the electronic components are stored. Tape, etc.)
Useful for

[0053]

The resin laminated sheet of the present invention has excellent mechanical properties such as bending strength (hardness to crack), buckling strength, impact resistance and rigidity, and the thickness of each layer is uniform. In addition to being excellent in surface smoothness, generation of burrs and chips during cutting and punching is suppressed. Furthermore, it has excellent printability and heat sealability, and also has good transparency. Therefore, the sheet of the present invention is suitable as a tray for transporting semiconductors and electronic components (such as an injection tray or a vacuum forming tray), a magazine, or a carrier tape (such as an embossed carrier tape).

[0054]

EXAMPLES The present invention will be described below in more detail with reference to Examples, but the present invention is not limited to these Examples. The contents of the abbreviations of each component used in Examples and Comparative Examples, and the evaluation methods of each evaluation item are as follows.

[Contents of Abbreviations of Each Component] GPPS (1): polystyrene (Toyostyrol G
PG-14L, manufactured by Toyo Styrene Co., Ltd., MI: 10 g
/ 10 min) GPPS (2): polystyrene (Toyostyrol G
PHG915, manufactured by Toyo Styrene Co., Ltd., MI: 4 g /
GPPS (3): polystyrene (general-purpose GPPS heat-resistant Toporex 550-51, Nippon Polystyrene Co., Ltd.)
Made).

HIPS (1): Impact-resistant polystyrene (Toyostyrol HIE850, manufactured by Toyo Styrene Co., Ltd., rubber content: 7% by weight, rubber structure: salami structure, volume average rubber particle diameter: 2.0 μm) HIPS (2): Impact-resistant polystyrene (High gloss grade impact-resistant polystyrene TL3000, manufactured by Sumitomo Chemical Co., Ltd., rubber content: 7.0% by weight, rubber structure: core / shell structure, volume average rubber particle diameter: 0.25 μm).

SB (1): Styrene-butadiene block copolymer (Asaflex 830, manufactured by Asahi Kasei Corporation)
Rubber content: 30% by weight, MI: 4.7 g / 10 min, linear type, no wax content) SB (2): Styrene-butadiene block copolymer (K Resin KK38, manufactured by Philips Sekiyu KK, rubber) Content: 30% by weight, MI: 7.7 g / 10 min, star, wax content) SB (3): Styrene-butadiene block copolymer (K Resin KR05, manufactured by Philips Sekiyu KK, rubber content) : 24% by weight, MI = 7 g / 10 min, star, wax-containing material) SBS (1): SBS block copolymer (Tufprene 1)
26, manufactured by Asahi Kasei Corporation, rubber content: 60% by weight, M
I: 17 g / 10 min, linear type, containing wax) SBS (2): SBS block copolymer (TR200
4. Nippon Synthetic Rubber Co., Ltd., rubber content: 57% by weight,
MI = 4.5 g / 10 min, linear type, wax-containing material).

[Folding strength of molded article]
JI using an IT folding tester, Yasuda Seiki Seisakusho
According to SP 8115, the bending strength in the sheet flow direction was measured (average value of n = 5), and evaluated according to the following criteria.

：: 1000 times or more Δ: 50 times or more and less than 1000 times ×: less than 50 times

[Impact resistance] In accordance with the JIS
A No. 2 dumbbell stipulated in K 7113 was punched out to obtain a test piece. Both ends of the test piece were supported and subjected to a Charpy impact tester to measure the impact strength, and the impact strength was evaluated according to the following criteria.

：: 50 kJ / m ² or more Δ: 30 kJ / m ² or more and less than 50 kJ / m ² ×: less than 30 kJ / m ²

[Transparency] Using a haze measuring device (300A, manufactured by Nippon Denshoku Co., Ltd.), the haze was measured according to ASTM D 1003 (average value of n = 5), and the haze was evaluated based on the following criteria. did. The lower the value, the higher the transparency.

：: less than 10% Δ: 10% or more and less than 15% X: 15% or more.

[Printability] A cellophane tape was adhered to a sheet on which the conductive ink was printed, rubbed with a finger five times, then rapidly peeled off, and the degree of adhesion of the ink to the cellophane tape was visually observed. Evaluation was based on criteria.

A: Ink did not adhere to the cellophane tape. Δ: Ink partially adhered to the cellophane tape. X: Ink adhered to the entire cellophane tape.

[Anti-blocking property] Two sheets were superposed on each other so that the outer surface and the inner surface of the winding were in contact with each other, pressed at 60 ° C in an atmosphere of 1 MPa for 5 hours, and then the two sheets were peeled off. evaluated.

：: No white mark left X: White mark left

[Surrounding Prevention of Outer Layer] The ratio (t ₁ / t ₂ ) of the outer layer thickness (t ₁ ) at the center of the sheet to the thickness (t ₂ ) of the outer layer at a position 300 mm away from the center of the sheet. It was measured and evaluated according to the following criteria.

：: 0.9 or more Δ: 0.7 or more and less than 0.9 ×: less than 0.7

[Buckling Strength] A cubic carrier tape having a bottom and a size of 5 mm × 8 mm × 4 mm in height was manufactured from an embossed carrier tape molding machine. The pockets were cut off one by one and placed on a horizontal surface with the pocket openings facing upward. And 50m using a circular jig
The sample was pressed vertically at a speed of m / min, and the load was measured with Tensilon (manufactured by Orientec Co., Ltd.). The point at which the load suddenly decreased within 20% during the measurement process was defined as the end point.
The maximum load point up to this time was evaluated as buckling strength according to the following criteria.

：: buckling strength of 0.1 N or more Δ: buckling strength of 0.08 N or more and less than 0.1 N ×: buckling strength of less than 0.08 N

[Appearance] The appearance of the sheet surface was visually observed and evaluated according to the following criteria.

：: The surface is uniform. ：: The surface is rough. X: The surface is severely rough, and the feel varies.

Example 1 With the composition shown in Table 1, the base material layer was an extruder having a diameter of 65 mm, and the outer layer was an extruder having a diameter of 50 mm (both having a cylinder temperature of 200 mm).
C.) and co-extruded into a sheet with a T-die (die temperature 200 ° C.). By cooling with a cooling roll (80 ° C.), a sheet having a thickness of 300 μm [each outer layer thickness 25 μm (total outer layer thickness 50 μm)] was obtained. Table 1 shows the evaluation results of the obtained sheets.

Examples 2 to 11 Sheets were obtained in the same manner as in Example 1 except that the composition of each component and the thickness of each layer were changed to those shown in Table 1. Table 1 shows the evaluation results of the obtained sheets.

Comparative Examples 1-2 Extrusion of 65 mm in diameter (cylinder temperature 2
(00 ° C.) and extruded into a sheet with a T-die (die temperature 200 ° C.). By cooling with a cooling roll (80 ° C.), a sheet having a thickness of 300 μm was obtained. Table 1 shows the evaluation results of the obtained sheets.

Comparative Examples 3 to 6 Sheets were obtained in the same manner as in Example 1 except that the composition of each component and the thickness of each layer were changed to those shown in Table 1. Table 1 shows the evaluation results of the obtained sheets.

[0078]

[Table 1]

As is clear from Table 1, the sheets of the examples are excellent in various performances. On the other hand, Comparative Example 1 does not have an outer layer and does not have a wax component, and thus has insufficient antiblocking properties. Comparative Example 2 has no outer layer and the wax component bleeds out, so that the printability is not sufficient.
In Comparative Example 3, since the outer layer was composed only of polystyrene, the bending strength, the antiblocking property, and the appearance were not sufficient. In Comparative Example 4, the outer layer was composed of only HIPS, and M
Since the I ratio is also small, the wraparound phenomenon of the outer layer occurs, and the transparency and appearance are reduced. In Comparative Example 5, the outer layer was SB.
Since it is composed of only the S block copolymer and has a large MI ratio, printability, antiblocking property and buckling strength are not sufficient. In Comparative Example 6, since the outer layer does not contain the SBS block copolymer, the smoothness and appearance are reduced, and the printability is also reduced due to insufficient appearance. Further, since the base material contains the SBS block copolymer, transparency and buckling strength are not sufficient.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) B65D 85/86 C08L 51/00 4J002 C08L 25/04 53/02 51/00 B65D 1/00 B 53/02 85/38 MF term (reference) 3E033 AA10 BA22 BB08 CA03 FA01 FA02 FA03 FA04 GA03 3E067 AA11 AB41 AC04 BA25A BB14A BB25A CA11 CA24 CA30 EA29 EA32 FA01 FB02 FC01 GD03 3E086 AB01 AD02 AD05 AD09 BA04 BA15 BB62 BA03 BA85 BB62 BB62 BA08 AK12B AK12C AK12J AK28J AK73A AK73B AK73C AL02B AL02C AL05A AL05B AL05C AL09A AT00A BA03 BA10B BA10C BA15 CA30A CA30B CA30C GB15 HB31 JA06A JA06B JA06C JA20A JA20B JA20C JB16A JK01 JK04 JK10 JL12 JN01 YY00A YY00B YY00C 4J002 BC03W BC031 BC04W BC041 BC05X BC06W BC061 BC07W BC071 BC08W BC081 BC09W BC091 BC11W BC111 BN033 BN063 BN073 BN123 BN143 BN153 BN163 BN173 BN213 BP01X BP012 BP033 FD010 GF00 GG01 GQ00

Claims (11)

[Claims] 1. A styrenic thermoplastic elastomer and
Substrate composed of resin composition (A) containing a tylene-based resin
Styrene resin and styrene-butadiene on both sides of the layer
Consisting of a resin composition (B) containing a block copolymer
A sheet having an outer layer formed thereon, the composition constituting the base layer
Index (MI) of the product (A) _A) And the outer layer
The melt index (MI) of the resulting composition (B)_B)When
Is the ratio of MI_A/ MI_B= 0.7 to 3 resin sheet
G. 2. A base material layer comprising a styrene-butadiene copolymer (A ₁ ) and a polystyrene resin (A ₂ ), and an outer layer comprising a polystyrene resin (B ₁ ) and a rubber-reinforced styrene resin (B _2). ) styrene - butadiene - styrene block copolymer (sheet B ₃₎ the de configured claim 1. 3. The melt index of the polystyrene resin (B ₁ ) is larger than the melt index of the polystyrene resin (A ₂ ), and the melt index ratio (MI _A / MI _B ) is 0.8 to 2. The sheet according to claim 2, which is 7. 4. The polystyrene resin (B ₁ ) has a melt index of 5 to 30 g / 10 minutes and a melt index ratio (MI _A / MI _B ) of 0.9 to 2.5. The described sheet. 5. In the styrene-butadiene-styrene block copolymer (B ₃ ), the ratio (weight ratio) of styrene to butadiene is styrene / butadiene = 10/9.
The resin sheet according to claim 2, wherein the ratio is 0 to 55/45 (weight ratio). 6. The ratio (weight ratio) of the styrene-based thermoplastic elastomer to the styrene-based resin constituting the base layer is the former / the latter = 20/80 to 95/5, and the ratio of the rubber component in the outer layer Is 1 to 50% by weight. 7. The sheet according to claim 1, wherein at least one of the base material layer and the outer layer contains a release agent component. 8. The thickness of the base layer is 90 to 950 μm, the total thickness of the outer layer is 5 to 250 μm, and the ratio of the thickness of the base layer to the total thickness of the outer layer is (base layer / outer layer = 30). / 1
2. The sheet according to claim 1, wherein the ratio is 0.3 to 0.3 / 1. 9. A styrene-butadiene copolymer (A ₁ )
And on both sides of the polystyrene resin (A ₂₎ a resin composition comprising (A) a substrate layer composed of a polystyrene-based resin (B _1), rubber-reinforced styrene resin (B ₂₎ and styrene - butadiene - styrene A sheet having an outer layer formed of a resin composition (B) containing a block copolymer (B ₃ ), wherein a ratio of a copolymer (A ₁ ) to a resin (A ₂ ) in a base material layer (Weight ratio) is the former / the latter = 30/7
0 to 90/10, and in the outer layer, the resin (B ₁ )
And the ratio (weight ratio) to the total amount of the resin (B ₂ ) and the copolymer (B ₃ ) is (B ₁ ) / (B ₂ + B ₃ ) = 50 / 50-
95/5, and the ratio (weight ratio) of the resin (B ₂ ) to the copolymer (B ₃ ) is (B ₂ ) / (B ₃ ) = 20/1 to 0.0
3/1, the content of the rubber component in the outer layer is 3 to 40% by weight, the melt index (MI _A ) of the composition (A) constituting the base material layer, and the composition (M ratio of the melt index (MI _B) of B) is a resin sheet is a MI _B / MI _a = 0.9~2.5. 10. A molded article for transporting electronic components formed of the sheet according to claim 1. 11. The molded article for transporting electronic components according to claim 10, further comprising a concave portion for storing the electronic components, and sealing the electronic component with a cover tape to store the electronic components.