JPH10279755A - Resin composition suitable for transparent carrier tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a styrenic resin composition suitable for a transparent carrier tape excellent in balance of transparency, stiffness and impact resistance and further excellent in folding resistance. SOLUTION: This styrenic resin composition comprises (a) a block copolymer resin of a vinyl aromatic hydrocarbon containing 60-90 wt.% vinyl aromatic hydrocarbon, with a conjugated diene, (b) a vinyl aromatic hydrocarbon-acrylic ester copolymer resin, and (c) rubber-modified impact resistant polystyrene-based resin. Further, the composition comprises 20-50 pts.wt. component (a), 40-70 pts.wt. component (b) and 3-30 pts.wt. component (c), and optionally (d) a block copolymer elastomer comprising a vinyl aromatic hydrocarbon and a conjugated diene and having <=50 wt.% vinyl aromatic hydrocarbon content.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel styrene resin composition which is excellent in transparency, rigidity and impact resistance and which is suitable for a transparent carrier tape having excellent bending resistance.

[0002]

2. Description of the Related Art Conventionally, carrier tapes for mounting electronic parts such as ICs, LSIs and the like on electronic equipment have been formed of vinyl chloride resin, polystyrene resin or the like.

[0003] Transparent carrier tapes are required to have a balance of transparency, rigidity, impact resistance, bending resistance, etc., depending on the form of use.

[0004]

The vinyl chloride resin is excellent in all of these properties, but the carrier tape formed from the vinyl chloride resin is harmful to chlorine-based gas during incineration as waste after use. And adversely affect the global environment. Further, a carrier tape formed of a conventional polystyrene resin is excellent in rigidity and impact resistance, but is not satisfactory in transparency and bending resistance.

[0005] Therefore, a novel styrene resin composition suitable for a transparent carrier tape which has greatly improved transparency and bending resistance while maintaining excellent rigidity and impact resistance of a conventional polystyrene resin carrier tape has been developed. It is an object of the present invention to provide.

Conventionally, methods for improving the physical properties of polystyrene resins have been devised.

According to Japanese Patent Publication No. Sho 60-10052, the impact resistance is remarkably improved. The transparency has been improved but is still unsatisfactory. According to Japanese Patent Publication No. Sho 62-31017, impact resistance is improved to some extent, but transparency is greatly sacrificed. Japanese Patent Publication No. 3-12098 improves the bending characteristics, but is still insufficient.

In recent years, the mounting speed using a carrier tape has been increasing more and more in accordance with the production speed of electronic equipment, and a conventional polystyrene resin carrier tape tends to cause bending breakage. In addition, the transparency of a conventional carrier tape made of a polystyrene resin may not be able to confirm the inside state well, and thus improvement in transparency is desired. For this reason, the emergence of a carrier tape which is more excellent in transparency and bending resistance than a conventional polystyrene resin carrier tape is expected.

[0009]

Means for Solving the Problems The inventors of the present invention have studied to meet this demand, and have found that a block copolymer resin of a vinyl aromatic hydrocarbon containing a specific range of vinyl aromatic hydrocarbon and a conjugated diene, a vinyl aromatic resin, A composition comprising an aromatic hydrocarbon-acrylate copolymer resin, a rubber-modified impact-resistant polystyrene resin, and a block copolymer of a vinyl aromatic hydrocarbon and a conjugated diene containing a specific range of vinyl aromatic hydrocarbons within the composition range. The present inventors have found that a resin composition in which a polymer elastomer is added at a specific blending ratio meets this requirement, and have completed the present invention.

That is, the present invention relates to (a) a block copolymer resin 20 of a vinyl aromatic hydrocarbon and a conjugated diene having a vinyl aromatic hydrocarbon content of 60 to 90% by weight.
Not less than 50 parts by weight, preferably not less than 25 parts by weight and not more than 40 parts by weight, (b) from 40 parts by weight to 70 parts by weight of vinyl aromatic hydrocarbon-acrylate copolymer resin, and preferably not less than 50 parts by weight 60 parts by weight or less, (c)
A novel styrene-based resin composition suitable for a carrier tape comprising 3 to 30 parts by weight, preferably 10 to 20 parts by weight of a rubber-modified impact-resistant polystyrene, and (d) a vinyl fragrance within the above range. Suitable for carrier tapes comprising 0.1 to 5 parts by weight, preferably 1 to 3 parts by weight of a block copolymer elastomer of a vinyl aromatic hydrocarbon and a conjugated diene having an aromatic hydrocarbon content of 50% by weight or less. The present invention provides a novel styrenic resin composition.

The reason why the component (a) is within this range is that if the amount is less than 20 parts by weight, sufficient impact resistance cannot be obtained, and if it exceeds 50 parts by weight, sufficient rigidity cannot be obtained. The reason that the component (b) is in this range is that if the amount is less than 40 parts by weight, sufficient rigidity cannot be obtained, and if it exceeds 70 parts by weight, sufficient impact resistance cannot be obtained. The reason that the component (c) is in this range is that if the amount is less than 3 parts by weight, sufficient bending properties cannot be obtained, and if it exceeds 30 parts by weight, sufficient transparency cannot be obtained. (D)
The components are added in this range in order to provide more flexibility and obtain good bending resistance without impairing the transparency of the composition.

The block copolymer of component (a) used in the present invention has a polymer structure of A- (BA) _n , B- (AB) _n -A, B- (A-
B) _{n + 1} , (where A is a polymer block mainly composed of a vinyl aromatic hydrocarbon, B is a polymer block mainly composed of a conjugated diene, and a boundary between the A block and the B block. Need not be clearly distinguished. N is an integer of 1 or more, generally 1 to 5.) or a linear block copolymer represented by the general formula [(AB) _k ] M _{+ 2} -X, [(AB) _k -A] _{m + 2} -X [(BA) _k ] _{m + 2} -X, [(BA) _k -B] _{m + 2-} X [In the above formula, A and B are the same as described above, and k and m
Is an integer of 1 or more, generally 1 to 5. X represents a residue of a coupling agent such as silicon tetrachloride, tin tetrachloride, 1,3 bis (N, N-glycidylaminomethyl) cyclohexane or a residue of an initiator such as a polyfunctional organic lithium compound. Or a mixture of these block copolymers having an arbitrary polymer structure.

Here, the polymer block mainly composed of a vinyl aromatic hydrocarbon means 50% by weight of the vinyl aromatic hydrocarbon.
A copolymer block of a vinyl aromatic hydrocarbon and a conjugated diene and / or a homopolymer block of a vinyl aromatic hydrocarbon are shown. The polymer block mainly composed of a conjugated diene represents 50% by weight of a conjugated diene. The conjugated diene and vinyl aromatic hydrocarbon copolymer block and / or the conjugated diene homopolymer block contained in an amount exceeding the above are shown.

When a random copolymer portion of a vinyl aromatic hydrocarbon and a conjugated diene is present in a polymer block mainly composed of a vinyl aromatic hydrocarbon or a polymer block mainly composed of a conjugated diene, it is copolymerized. The vinyl aromatic hydrocarbons present may be distributed uniformly in the polymer block or may be distributed in a tapered (decreasing) form. Also,
The copolymerized portion may have a plurality of portions where vinyl aromatic hydrocarbons are uniformly distributed and / or a plurality of portions where the vinyl aromatic hydrocarbons are distributed in a tapered shape.

The vinyl aromatic hydrocarbon used in the present invention includes styrene, o-methylstyrene, p-methylstyrene, p-tert-butylstyrene, 1,3 dimethylstyrene, α-methylstyrene, vinylnaphthalene, vinyl Examples include anthracene and 1,1 diphenylethylene, and styrene is particularly preferable. These may be used alone or in combination of two or more.

The conjugated diene is a diolefin having a pair of conjugated double bonds, for example, 1,3-butadiene, 2-methyl-1,3-butadiene (isoprene),
Examples thereof include 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene, and particularly common ones include 1,3 butadiene and isoprene. These may be used alone or in combination of two or more.

The vinyl aromatic hydrocarbon content of the component (a) used in the present invention is from 60% by weight to 90% by weight, but the preferred range is from 65% by weight to 85% by weight. When the content of the vinyl aromatic hydrocarbon in the block copolymer is less than 60% by weight, the transparency and rigidity of the resin composition molded article are inferior when the content is less than 60% by weight, and when it exceeds 90% by weight, the impact resistance is reduced. It is.

The molecular weight of the component (a) used in the present invention can be arbitrarily adjusted depending on the amount of a catalyst used for polymerization. However, from the viewpoint of moldability, a melt flow index (JIS K6) is used.
Measured according to 870. The conditions are G, temperature 200 ° C., load 5 kgf) is 0.1 to 50 g / 10 min, preferably 1 to 20 g / 10 min.

The monomers constituting the (b) component vinyl aromatic hydrocarbon- (meth) acrylate copolymer used in the present invention include the following. Vinyl aromatic hydrocarbons are styrene, α-methylstyrene,
p-methylstyrene, p-tert-butylstyrene, etc., and (meth) acrylic acid ester is methyl methacrylate, ethyl ester, n-butyl ester, i-butyl ester, tert-butyl ester, 2-ethylhexyl Esters, acrylic acid methyl ester, ethyl ester, n-butyl ester, 2-
It is an ester of (meth) acrylic acid such as ethylhexyl ester and an alcohol having 1 to 8 carbon atoms. Of these, acrylic acid n-butyl ester is preferred.

The content of the n-butyl acrylate unit in the component (b) is preferably from 10 to 20% by weight in order to exhibit transparency and rigidity of the final composition. The component (b) is 0.1 to
It may contain 2% by weight of other monomer units.

The rubber-modified impact-resistant polystyrene of the component (c) of the present invention is prepared by dissolving a butadiene-based rubber-like polymer in styrene, then initiating the polymerization of styrene, and grafting styrene onto the rubber-like polymer. The average particle diameter of the rubber particles formed by the grafted rubber-like polymer is preferably from 1.5 μm to 5.0 μm, and more preferably from 1.8 μm to 4.0 μm. More preferred.

The average particle diameter as used herein means a transmission electron micrograph of a rubber-modified impact-resistant polystyrene by an ultra-thin section method, and measures the particle diameter of 500 rubber particles in the photograph. It is calculated.

Average particle diameter = ΣniDi ⁴ / ΣniDi ³ (where ni is the number of particles having a long diameter of rubber particles Di) These rubber particles have a so-called salami structure in which polystyrene is embedded therein. , Core-shell structure.

The average particle diameter in this range is 1.5 μm.
If it is less than 4, the effect of improving the impact resistance of the final composition is small.
If it exceeds 0 μ, the transparency will be remarkably deteriorated.

The reason why the content of the vinyl aromatic hydrocarbon in the component (d) of the present invention is within this range is to effectively exhibit impact resistance and bending resistance without impairing transparency.

The composition of the present invention contains (a)
In addition to the components (b), (c) and (d), thermoplastic elastomers and other polymers other than the component (d), antioxidants, lubricants, antiblocking agents, and fluidity improvements without departing from the object of the present invention. Agents, coloring agents and other additives can be used.

The resin composition of the present invention is formed into a sheet by an extruder or the like, and the sheet is subjected to compression molding, vacuum molding,
Embossing is performed by pressure molding or other molding methods, and after filling electronic components and the like inside, a cover tape is adhered by a method such as heat sealing to be used as a carrier tape.

[0028]

The present invention will be described in more detail with reference to the following examples, but the present invention is not limited by these examples.

The properties of the resin composition sheet were measured by the following methods. The haze value (unit%) of JISK7105-81 was used for transparency. Rigidity is ASTM D638
A tensile modulus of -91 was used. ASTM impact resistance
According to the dart impact test of D1709-72. Folding characteristics according to ASTM D2176, load 1.5kg
f, the number of bends before breaking at a rotation speed of 175 cpm and a bend angle of 135 degrees left and right was used.

In Examples and Comparative Examples, the determination of suitability / inappropriateness was made based on transparency indicated by COLER AN manufactured by Nippon Denshoku Industries Co., Ltd.
D COLOR DEFFERENCE METER
When the haze value measured by Model 1001DP was less than 7, the mark was good, the mark was good, the mark was 7 or more and less than 13, and the mark was 13 or more. Stiffness preferred and with ○ mark the 15000kgf / cm ² or more in the value of the tensile modulus measured at a tension Ltd. Shinko Telecommunication Industry Co. tester Model TCM-500D, 10000kgf / cm 2 or more 1500
△ to less than 0 kgf / cm ² and 10,000 kgf / cm ²
Less than was unsuitable and marked with x. Impact resistance is 1/2 radius with a dirt impact tester manufactured by Toyo Seiki Seisaku-sho, Ltd.
Measured using an inch-drop weight, 30 kgf · cm or more is preferred, and a circle is 15 kgf · cm or more and 30 kgf · cm.
Less than △ and less than 15 kgf · cm were unsuitable and marked with x. The bending resistance is preferably 500 times or more before breaking under a tension load of 1.5 kgf with a MIT bending strength tester manufactured by Yasuda Seiki Co., Ltd.
Less than 0 times were marked with a triangle, and less than 200 times were judged unsuitable, with a cross.

Production of Component (a) Table 1 shows the block copolymer of component (a). In the production, n-butyllithium was used as an initiator in a cyclohexane solvent, styrene, a styrene-butadiene mixture, and a styrene solution of styrene were added in the order of styrene to carry out polymerization. Hydroxy-3-tert-butyl-5-methylbenzyl) -4
Block copolymer 10-methyl-6-t-butylphenyl acrylate and trisnonylphenyl phosphite
0.5 parts each was added as a stabilizer to 0 parts by weight, and the solvent was distilled off. The content (% by weight) of styrene units in the block copolymer was measured by decomposing the block copolymer with osmic acid and reprecipitating it in methanol. Melt flow rate (MI) was measured under G conditions.

[0032]

[Table 1]

Production of Component (b) Table 2 shows copolymers of the component (b). For the production, 5 kg of a mixture of styrene and n-butyl acrylate was added to an autoclave equipped with a stirrer, and at the same time, 0.3 parts of ethylbenzene was added.
In order to adjust kg and MI (G), a predetermined amount of 1,1 bis (t-butylperoxy) cyclohexane was charged, and 11
After polymerization at 0 ° C. for 2 hours, 130 ° C. for 3 hours, and 150 ° C. for 2 hours, an extruder was used to remove unreacted styrene, n-butyl acrylate, and ethylbenzene to obtain.

[0034]

[Table 2]

The following components were used as the component (c).

Production of Component (c) Table 3 shows the impact-resistant polystyrene of component (c).
Manufacturing dissolves styrene-butadiene rubber in styrene,
An organic peroxide catalyst and cyclohexane were added thereto, and polymerization was carried out by an autoclave equipped with a stirrer to obtain cyclohexane and unreacted styrene.

Production of component (d) A block copolymer elastomer having a vinyl aromatic hydrocarbon content of 40% by weight was obtained in the same manner as in the production of component (a).

[0038]

[Table 3]

(Examples 1-3) (a) / (b) /
As shown in Table 4, the compounding ratio of (c) was 30 parts by weight / 55 parts by weight / 15 parts by weight, and as shown in Table 4, component (a) was a-2, a-3,
As a-4, the component (b) is b-3 and the component (c) is c-
A polymer of three components was mixed as 3, and pelletized with a 40 mm single screw extruder, a sheet of a resin composition having a thickness of 0.3 mm was formed with a 40 mm sheet extruder, and a test piece was formed from the sheet. It was subjected to physical property measurement. Table of measured values
It is shown in FIG.

(Comparative Examples 1-2) The component (a) was a-1
Except for a-5, a test piece was prepared from a sheet in the same manner as in Examples 1-3, and physical properties were measured. The measured values are shown in Table-5.

(Examples 4 to 5) The component (a) was a-3,
The component (c) is referred to as c-3, and the component (b) is referred to as b-2 and b-4.
A test piece was prepared from the sheet in the same manner as in Example 2 except that the above-mentioned conditions were used, and the physical properties were measured. The measured values are shown in Table-5.

(Examples 6 to 7) The component (b) is represented by b-1,
Except for b-5, a test piece was prepared from the sheet in the same manner as in Example 4, and the physical properties were measured. The measured values are shown in Table-5.

(Examples 8 to 9) The component (c) is represented by c-2,
A test piece was prepared from a sheet in the same manner as in Example 2 except that c-4 was used, and physical properties were measured. The measured values are shown in Table-5.

(Examples 10 to 11) The component (c) was replaced with c-
A test piece was prepared from a sheet in the same manner as in Example 6, except that the sample was set to 1, c-5, and the physical properties were measured. The measured values are shown in Table-5.

[0045]

[Table 4]

[0046]

[Table 5]

(Examples 12 to 19, Comparative Examples 3 to 6)
A-3 as the component (a), b-3 as the component (b),
(A) / (b) / (c) using c-3 as the component (c)
Example 2 except for changing the mixing ratio of each component shown in Table-6
A test piece was prepared from the sheet in the same manner as described above, and the physical properties were measured. The measured values are shown in Table-7.

[0048]

[Table 6]

[0049]

[Table 7]

(Comparative Example-7) a-3 was used as the component (a).
(B) Melt flow rate 5 g / 10 mi instead of component
A test piece was prepared from a sheet in the same manner as in Example-2, using n-polystyrene, using c-3 as the component (c), and adjusting the mixing ratio to 30/55/15, and measuring the physical properties. . The measured values are shown in Table-8.

(Comparative Example-8) A test piece was prepared from a sheet in the same manner as in Comparative Example-7, except that the mixing ratio of component (a), polystyrene, and component (c) was changed to 30/67/3. Physical properties were measured. The measured values are shown in Table-8.

(Example-20) As the component (a), a-
3, b-3 as component (b) and c-3 as component (c)
And a block copolymer elastomer [component (d)] of a vinyl aromatic hydrocarbon and a conjugated diene having a vinyl aromatic hydrocarbon content of 40% by weight was added, and the mixing ratio of each was 30/54/15. A test piece was prepared from the sheet in the same manner as in Example 2 and the physical properties were measured.
The measured values are shown in Table-8.

(Example-21) (a), (b),
The mixing ratio of the components (c) and (d) is 30/52/15/3
A test piece was prepared from the sheet in the same manner as in Example 20 except that the measurement was performed, and the physical properties were measured. The measured values are shown in Table-8.

(Example-22) A commercially available styrene-methyl methacrylate copolymer resin (trade name "Estyrene MS-200" manufactured by Nippon Steel Chemical Co., Ltd.) was used as the component (b). A test piece was prepared from the sheet in the same manner as in -2, and the physical properties were measured. The measured values are shown in Table-8.

[0055]

[Table 8]

The sheets obtained in Examples 1 to 22 were preheated at a set temperature of 400 ° C. for 3 seconds, and vacuum-molded in a mold at 30 ° C. to obtain a carrier tape-shaped molded article having a width of 10 mm. Transparency was higher than that of the molded product obtained in -7 and 8, and it was not cut by bending by hand.

[0057]

The carrier tape made of the resin composition of the present invention has a good balance of transparency, rigidity and impact resistance and is excellent in bending resistance as compared with a conventional polystyrene resin carrier tape.

Claims (2)

[Claims] (A) a content of a vinyl aromatic hydrocarbon of 60
A block copolymer resin of vinyl aromatic hydrocarbon and conjugated diene of not less than 90% by weight and not more than 90% by weight; (b) a vinyl aromatic hydrocarbon-acrylate copolymer resin; and (c)
A resin composition comprising a rubber-modified impact-resistant polystyrene resin, wherein (a) is from 20 parts by weight to 50 parts by weight,
(B) is 40 to 70 parts by weight, (c) is 3 to 30 parts by weight, and if necessary, (d) vinyl aromatic hydrocarbon content is 50% by weight.
A novel styrene resin composition suitable for a transparent carrier tape containing the following block copolymer elastomer of a vinyl aromatic hydrocarbon and a conjugated diene. 2. (a) a vinyl aromatic hydrocarbon content of 60
A block copolymer resin of vinyl aromatic hydrocarbon and conjugated diene of not less than 90% by weight and not more than 90% by weight; (b) a vinyl aromatic hydrocarbon-acrylate copolymer resin; and (c)
A rubber-modified impact-resistant polystyrene resin, (d) a resin composition comprising a block copolymer elastomer of a vinyl aromatic hydrocarbon having a vinyl aromatic hydrocarbon content of 50% by weight or less and a conjugated diene, wherein (a) is 20 to 50 parts by weight, (b) 40 to 70 parts by weight,
(C) is not less than 3 parts by weight and not more than 30 parts by weight, and (d) is not more than 0.1 part by weight.
A novel styrene resin composition suitable for a transparent carrier tape having a blending ratio of not less than 5 parts by weight and not more than 5 parts by weight.