JP2005041930A - Thermoplastic resin sheet and container for transporting electronic part - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thermoplastic sheet which gives a molded article having excellent dimensional stability, when molded, especially when used as a carrier tape, and to provide an electronic part transportation container comprising the same. <P>SOLUTION: The thermoplastic resin sheet is characterized by having an absolute value difference of ≤6 % between thermal expansion coefficients in the MD and TD directions of the sheet at a molding temperature, having thermal expansion coefficients of ≤12×10<SP>-5</SP>/°C in the MD and TD directions of the sheet, respectively, at a temperature of 20 to 30°C, and having a thickness of 0.1 to 1.0 mm. A molded article having excellent dimensional stability is obtained by using the thermoplastic resin sheet. The electronic part transportation container comprises the thermoplastic resin sheet. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

【００１８】
【発明の効果】
本発明により、成形の温度におけるシートのＭＤ、ＴＤ方向の熱膨張率の差の絶対値が６％以下であり、温度２０〜３０℃におけるシートのＭＤ、ＴＤ方向の線膨張係数が共に１２×１０^−５／℃以下である、厚み０．１ｍｍ〜１．０ｍｍの熱可塑性樹脂シートを用いることにより、寸法安定性に優れた成形品を提供することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a single-layer or multilayer thermoplastic resin sheet excellent in dimensional stability during molding and an electronic component transport container comprising the same.
[0002]
[Prior art]
Conventionally, when a thermoplastic resin sheet is molded, there has been a problem that a dimensional variation of the molded product is large and a stable product cannot be obtained. In particular, in the case of molding into an embossed carrier tape, improvement in dimensional accuracy and reduction in variation for each pocket have been required due to the trend toward smaller electronic components and thinner ICs. However, due to the expansion and contraction of the resin itself due to heat and the expansion and contraction due to the distortion generated inside the sheet during sheeting, the pocket size of the finished product varies even when molded under the same conditions. To solve this problem, as shown in Patent Document 1, improvements have been made by remodeling an embossed carrier tape molding machine. However, it is not possible to meet the requirements completely by itself, and the problem is solved by adjusting the molding machine by an engineer. Therefore, there is a problem that it takes time to train engineers, and there is a problem that the operation rate decreases due to an increase in the number of adjustments. In addition, even after adjustment by an engineer, there is a problem that the dimensions change due to a change in the lot of the thermoplastic resin sheet to be molded and a stable molded product cannot be obtained continuously.
[0003]
[Patent Document 1]
Japanese Patent Laid-Open No. 10-272585
[Problems to be solved by the invention]
The present invention solves such a problem. The absolute value of the difference in thermal expansion coefficient between the MD and TD direction of the sheet at the molding temperature is 6% or less, and the MD and TD of the sheet at a temperature of 20 to 30 ° C. By using a thermoplastic resin sheet having a thickness of 0.1 to 1.0 mm, both of which have a linear expansion coefficient of 12 × 10 ⁻⁵ / ° C. or less, a molded article having excellent dimensional stability can be provided. .
[0005]
[Means for Solving the Problems]
The present invention
(1) The absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the sheet at the molding temperature is 6% or less, and the linear expansion coefficients in the MD and TD directions of the sheet at a temperature of 20 to 30 ° C. are both 12 × 10. ^A thermoplastic resin sheet having a thickness of 0.1 to 1.0 mm, which is ⁻⁵ / ° C. or less,
(2) The thermoplastic resin sheet according to (1), wherein the thermoplastic resin is at least one selected from a polyphenylene ether resin, a polystyrene resin, an ABS resin, a polycarbonate resin, or a polyester resin,
(3) The thermoplastic resin sheet according to (1) or (2), which imparts conductivity to the entire surface or thickness and has a surface resistivity of 1 × 10 ³ Ω or more and less than 1 × 10 ¹³ Ω,
(4) An electronic component transport container comprising the thermoplastic resin sheet according to any one of (1) to (3).
[0006]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described in more detail. In the thermoplastic resin sheet used in the present invention, the absolute value of the difference in thermal expansion coefficient between the MD and TD directions of the sheet at the molding temperature is 6% or less, and the MD and TD directions of the sheet at a temperature of 20 to 30 ° C. Any linear expansion coefficient is 12 × 10 ⁻⁵ / ° C. or less and the thickness is 0.1 to 1.0 mm.
[0007]
The absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the thermoplastic resin sheet at the molding temperature is 6% or less. When this value is exceeded, there is a difference in the release behavior of the sheet strain when heated by molding, and no uniform expansion or contraction occurs, so the internal strain of the molded product increases and the dimensional variation of the molding pocket increases. The absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the thermoplastic resin sheet depends on various factors such as extrusion temperature, cooling capacity, take-up tension, and the like. In order to reduce the absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the thermoplastic resin sheet, sheeting is performed so that the extrusion temperature is low, the cooling capacity is high, the take-up tension is low, and the distortion in the sheet is small. Just do it. For example, if the extrusion temperature is too high, it takes time until the resin is cooled, and distortion occurs due to take-up tension and the like. On the other hand, if it is too low, distortion may occur due to orientation caused by extrusion pressure. As described above, each factor has an optimum condition, and the absolute value of the difference in thermal expansion coefficient between the MD and TD directions of the thermoplastic resin sheet can be reduced in consideration of various factors, not alone. Since these factors vary depending on the production equipment, production conditions, resin used, etc., it is necessary to adjust each time.
[0008]
Further, the linear expansion coefficients in the MD and TD directions of the sheet at a temperature of 20 to 30 ° C. are both 12 × 10 ⁻⁵ / ° C. or less. When the value is larger than this value, the size of the molded product changes more than the size of the mold due to the expansion of the resin itself during molding, so that the size variation of the molding pocket increases. As for the resin having a glass transition temperature higher than 30 ° C., the linear expansion coefficient in the MD and TD directions of the sheet at a temperature of 20 to 30 ° C. depends on the resin itself, but varies somewhat depending on the sheeting method.
[0009]
The sheet thickness is 0.1 to 1.0 mm. If it is less than the lower limit value, the molding pocket portion becomes too thin when molding, and the strength is weak and crushing occurs. Further, when the upper limit is exceeded, the sheet is thick, so that there is a problem in that the rigidity is not strong when winding, or the heating time is required at the time of molding, resulting in poor productivity.
[0010]
The polyphenylene ether resin is a resin mainly composed of a polyphenylene ether resin or a polymer alloy of a polyphenylene ether resin and a polystyrene resin.
The polystyrene resin is mainly composed of a general polystyrene resin or an impact-resistant polystyrene resin and a mixture thereof. The ABS resin is mainly composed of a copolymer mainly composed of three components of acrylonitrile-butadiene-styrene.
Polycarbonate resins are 2,2-bis (4-oxyphenyl) alkane, bis (4-oxyphenyl) ether, bis (4-oxyphenyl) sulfone, bis (4-oxyphenyl) sulfide, bis The main component is a polymer or copolymer composed of bisphenols such as (4-oxyphenyl) sulfoxide, and specific examples include aromatic polycarbonate resins and aromatic-aliphatic polycarbonate resins.
The polyester resin is a resin mainly composed of an esterification product obtained by polymerization of a polybasic acid and a polyhydric alcohol, and examples thereof include unsaturated polyester resins, alkyd resins, and polyethylene terephthalate.
These thermoplastic resins may be a single layer or a multilayered thermoplastic resin sheet.
[0011]
Methods for imparting conductivity include kneading conductive materials such as carbon, metal, and metal oxide into a resin, laminating or applying conductive resin or paint on the surface, plasma treatment or interface. There is a method of hydrophilizing the surface by application of an activator or kneading.
[0012]
When used as a packaging material for ICs and electronic parts, the surface resistance value is 1 × 10 ³ Ω / □ or more and less than 1 × 10 ¹³ Ω / □. If the surface resistance value exceeds the upper limit value, sufficient antistatic effect cannot be obtained. If the surface resistance value is less than the lower limit value, the electrical conductivity is too good and the externally generated static electricity is energized, destroying the contents such as the IC. Because there is a fear, it is not preferable.
[0013]
The resin used in the present invention contains various additives such as lubricants, plasticizers, processing aids, compatibilizers and reinforcing agents, resins, etc. in order to improve fluidity and mechanical properties as necessary. It is possible to add.
[0014]
According to the present invention, the absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the sheet at the molding temperature is 6% or less, and the linear expansion coefficients in the MD and TD directions of the sheet at 20 to 30 ° C. are both 12 ×. By using a thermoplastic resin sheet having a thickness of 0.1 to 1.0 mm that is 10 ⁻⁵ / ° C. or less, a molded product having excellent dimensional stability can be provided.
[0015]
【Example】
Hereinafter, the present invention will be described in more detail with reference to examples.
<Example 1>
Difference in thermal expansion coefficient between MD and TD direction of sheet at 150 ° C. in a feed block type sheeting equipment using polyphenylene ether resin (GE Plastics, Noryl 731) and one 20 mmφ extruder. The linear expansion coefficient in the MD direction of the sheet is 9 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 9 × 10 ⁻⁵ / ° C., and the thickness is 0.2 mm. A single layer sheet was obtained.
<Example 2>
Using a high-impact polystyrene resin (made by Nippon Polystyrene Co., Ltd., H640), the sheet of the block at 110 ° C. has a thermal expansion coefficient in the TD direction with a feed block type sheeting equipment using one 20 mmφ extruder. The absolute value of the difference is 4%, the linear expansion coefficient in the MD direction of the sheet at a temperature of 20-30 ° C. is 10 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 10 × 10 ⁻⁵ / ° C., and the thickness is 0.2 mm. A single layer sheet was obtained.
<Example 3>
Using ABS resin (manufactured by Nippon A & L Co., Ltd., Santac MT-81), with a feed block type sheeting equipment using one 20 mmφ extruder, the thermal expansion coefficient in the MD and TD directions of the sheet at 115 ° C. The absolute value of the difference is 4%, the linear expansion coefficient in the MD direction of the sheet at a temperature of 20-30 ° C. is 10 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 10 × 10 ⁻⁵ / ° C., and the thickness is 0.2 mm. A single layer sheet was obtained.
<Example 4>
Using a polycarbonate resin (GE Plastic Co., Ltd., Lexan 131) and a feed block type sheeting facility using one 20 mmφ extruder, the difference in thermal expansion coefficient between the MD and TD directions of the sheet at 160 ° C. Single layer having an absolute value of 4%, a linear expansion coefficient in the MD direction of 9 × 10 ⁻⁵ / ° C., a linear expansion coefficient in the TD direction of 910 ⁻⁵ / ° C., and a thickness of 0.2 mm at a temperature of 20 to 30 ° C. A sheet was obtained.
<Example 5>
Using an A-PET sheet (manufactured by Kanebo Synthetic Co., Ltd., AST7CR), the absolute value of the difference in thermal expansion coefficient in the MD and TD directions at 85 ° C. is 2%, and the MD direction of the sheet at 20 to 30 ° C. A single-layer sheet having a linear expansion coefficient of 8 × 10 ⁻⁵ / ° C., a linear expansion coefficient in the TD direction of 9 × 10 ⁻⁵ / ° C., and a thickness of 0.2 mm was obtained.
<Example 6>
As a conductive resin composition, impact resistant polystyrene (A & M Styrene Co., Ltd., HT516, 73.8 parts by weight, SBR containing (B) (Asahi Kasei Kogyo Co., Ltd., Tuffprene 125) 6.6 parts by weight, 1.6 parts by weight of copolymer resin of ethylene and vinyl acetate (Mitsui DuPont, Evaflex V406) and conductive carbon black (Denka Black (granular), Denka Black (granular)) 18.0 wt The part described above was used as a base material layer by kneading the parts with a banbury and pelletizing them by strand cutting with an extruder. Lamination of the conductive layer and the base material layer is carried out by coextrusion using a two-type three-layer feed block type sheeting equipment using two 20 mmφ extruders, and the sheet MD and TD direction heat at 115 ° C. The absolute value of the difference in expansion coefficient is 4%, the linear expansion coefficient in the MD direction of the sheet at a temperature of 20-30 ° C. is 10 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 10 × 10 ⁻⁵ / ° C., and the thickness. A three-layer sheet surface conductive sheet having a layer ratio of 0.2 mm and a conductive layer / base material layer / conductive layer = 1/8/1 was obtained.
<Example 7>
A conductive paint (UPT-100 (V) black UI3 manufactured by Osaka Printing Ink Manufacturing Co., Ltd.) was applied to both sides of the sheet used in Example 5 with a gravure plate in a thickness of 1 μm, and the MD and TD directions of the sheet at 85 ° C. The absolute value of the difference in thermal expansion coefficient is 2%, the linear expansion coefficient in the MD direction of the sheet at a temperature of 20-30 ° C. is 8 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 9 × 10 ⁻⁵ / ° C., A surface conductive sheet having a thickness of 0.2 mm was obtained.
<Comparative Example 1>
Using a polyethylene resin (L211, manufactured by Sumitomo Mitsui Polyolefin Co., Ltd.) and a feed block type sheeting equipment using one 20 mmφ extruder, the difference in thermal expansion coefficient in the MD and TD directions of the sheet at 90 ° C. The linear expansion coefficient in the MD direction of the sheet at an absolute value of 4%, a temperature of 20-30 ° C. is 15 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 15 × 10 ⁻⁵ / ° C., and the thickness is 0.2 mm. A single layer sheet was obtained.
<Comparative example 2>
Using an ABS resin (manufactured by Nippon A & L Co., Ltd., Clarastic GA-501), the feed block type sheeting equipment using one 20 mmφ extruder has a higher extrusion temperature and cooling capacity than <Example 3>. The tensile strength is increased, the absolute value of the difference between the thermal expansion coefficients in the MD and TD directions at 115 ° C. is 10%, and the linear expansion coefficient in the MD direction at 10 to 10 ° C. is 10 × 10 ^{− A} single layer sheet having a linear expansion coefficient in the TD direction of 10 × 10 ⁻⁵ / ° C. and a thickness of 0.2 mm was obtained at ⁵ / ° C.
<Comparative Example 3>
Using ABS resin (manufactured by Nippon A & L Co., Ltd., Santac MT-81), with a feed block type sheeting equipment using one 20 mmφ extruder, the thermal expansion coefficient in the MD and TD directions of the sheet at 115 ° C. The absolute value of the difference is 4%, the linear expansion coefficient in the MD direction of the sheet at a temperature of 20 to 30 ° C. is 10 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 10 × 10 ⁻⁵ / ° C., and the thickness is 0.05 mm. A single layer sheet was obtained.
<Comparative example 4>
Using ABS resin (manufactured by Nippon A & L Co., Ltd., Santac MT-81), with a feed block type sheeting equipment using one 20 mmφ extruder, the thermal expansion coefficient in the MD and TD directions of the sheet at 115 ° C. When the absolute value of the difference is 4%, the linear expansion coefficient in the MD direction is 10 × 10 ⁻⁵ / ° C., the linear expansion coefficient in the TD direction is 10 × 10 ⁻⁵ / ° C., and the thickness is 1.5 mm. A single layer sheet was obtained.
[0016]
Table 1 shows the characteristic values (absolute value of difference in thermal expansion coefficient, linear expansion coefficient, thickness, formability, rollability) of the sheet obtained above.
The difference in thermal expansion coefficient is the absolute value of the difference in thermal expansion coefficient in the MD and TD directions of the sheet at the molding temperature, and the linear expansion coefficient (MD) is the MD direction of the sheet at a temperature of 20 to 30 ° C. The linear expansion coefficient and the linear expansion coefficient (TD) are the linear expansion coefficient in the TD direction of the sheet at a temperature of 20 to 30 ° C., and were measured by TMA (manufactured by Seiko Instruments Inc., EXSTR 6000).
The thickness is the thickness of the sheet.
Formability is an evaluation of the dimensional stability of a molded product. After forming a 6 mm width x 6 mm length x 2 mm depth pocket on a 16 mm width sheet, the width, length, and depth of 10 consecutive molding pockets After measuring the dimensions, ◯ indicates that there is no pocket whose size is shifted by ± 0.2 mm or more, and x indicates that there is no pocket.
The rollability was evaluated as “◯” when the sheet was wound without any problem when the formed carrier tape was wound on a reel of 80 mmφ, “X” when the sheet was not wound well due to repulsion, or when the pocket was crushed.
[0017]
[Table 1]

[0018]
【The invention's effect】
According to the present invention, the absolute value of the difference between the thermal expansion coefficients in the MD and TD directions of the sheet at the molding temperature is 6% or less, and the linear expansion coefficients in the MD and TD directions of the sheet at 20 to 30 ° C. are both 12 ×. By using a thermoplastic resin sheet having a thickness of 0.1 mm to 1.0 mm that is 10 ⁻⁵ / ° C. or less, a molded article having excellent dimensional stability can be provided.

Claims (4)

The absolute value of the difference in thermal expansion coefficient between the sheet flow direction (MD) and the width direction (TD) at the molding temperature is 6% or less, and the linear expansion coefficients in the MD and TD directions of the sheet at a temperature of 20 to 30 ° C. Both are 12 * 10 < ^-5 > / degrees C or less, and the thickness is 0.1-1.0 mm, The thermoplastic resin sheet characterized by the above-mentioned. The thermoplastic resin sheet according to claim 1, wherein the thermoplastic resin is at least one selected from a polyphenylene ether resin, a polystyrene resin, an ABS resin, a polycarbonate resin, or a polyester resin. The thermoplastic resin sheet according to claim 1 or 2, wherein conductivity is imparted to the entire surface or thickness, and the surface resistivity is 1 x 10 ³ Ω or more and less than 1 x 10 ¹³ Ω. The container for electronic component conveyance which consists of a thermoplastic resin sheet in any one of Claims 1-3.