JPH1053677A - Electrically conductive polypropylene resin composition and parts-container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain an electrically conductive polypropylene resin composition usable for the packaging and automatic feeding of parts, having antistatic property, durable to baking treatment and reutilizable to eliminate the genera tion of waste and suppress the material cost and working cost. SOLUTION: This composition contains (1) (a)wt.% (a>0) of a propylene polymer containing <=20wt.% of ethylene unit and containing a part having a crystallinity of >=95% accounting for >=60wt.% of the total polymer, (2) (b) wt.% (b>O) of a propylene random copolymer having a tensile elongation of >=100% and containing 1-7wt.% of ethylene unit and (3) (c) wt.% of an electrically conductive filler. The composition satisfies the following formulas: a+b+c=100, 0.5<=a/b<=2.0 and 10<=c<=30.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a conductive polypropylene resin composition having excellent mechanical properties, heat resistance and conductivity, which is reusable and is mainly used for packaging and automatic supply of electronic parts, and its conductive property. The present invention relates to a component storage container made of a water-soluble polypropylene resin composition.

[0002]

2. Description of the Related Art In the supply of components, there is a taping type component supply method in which a component carrier in which components are stored is mounted in an automatic supply machine in a packaging form in which the components are connected in a tape shape, and components are automatically supplied one by one. High reliability has been demonstrated in the mounting of electronic components, and has rapidly spread in recent years, and has become the mainstream of component supply methods. However, in the taping-type component supply, the paper tape and embossed tape (component carrier tape) that make up the component storage container are discarded after use. It has been pointed out. Therefore, a reusable component carrier tape as disclosed in JP-A-6-156562 has been proposed.

[0003] As a resin material for a component carrier tape, in the case of general mechanical assembly parts, the mechanical properties (rigidity, hinge strength), heat resistance, moldability, reusability, and recyclability of the resin are used. (Reformability after pulverization) and a polypropylene resin which is advantageous in cost have been used.

On the other hand, in the case of use as a storage container for electronic components, conductivity is required in particular to prevent electrostatic breakdown of the electronic components. However, when carbon is added to a conventional polypropylene resin to impart conductivity, the conductivity is increased. Conventionally, a conductive polystyrene resin to which carbon is added has been used because the mechanical strength is remarkably reduced and cannot be put to practical use. Here, particularly, the hinge strength is defined by the number of repeated bendings before breaking under the conditions of a bending angle of 45 degrees left and right by a hinge tester, a load of 800 g, and a bending speed of 60 times per minute.
The hinge strength required for improving the reusability is 100 times or more.

However, when a semiconductor package is housed as a container for mounting electronic parts, there are the following problems. That is, 90
% Or more is a package of an epoxy resin mold having high hygroscopicity, and therefore, the package absorbs moisture in the presence of moisture. If this absorbed package is soldered as it is in a reflow oven, the moisture inside the mold package will suddenly turn into steam, causing the package to explode,
Before the package is assembled and mounted, so-called baking in which the package is heated and dried at about 125 ° C. must be performed. However, since the conductive polystyrene resin is inferior in heat resistance and cannot withstand baking at 120 ° C. or higher, either the electronic component is baked immediately before mounting the electronic component, or the electronic component is separately baked. It was necessary to take measures such as kinging, storing in a container, sealing with top tape or the like.

Therefore, in recent years, conductive polypropylene resins which are excellent in mechanical properties, have high heat resistance, are low in cost, and do not emit harmful substances even at the time of disposal or incineration have been studied. However, polypropylene resin with low crystallinity and carbon added to impart electrical conductivity has insufficient rigidity, and when used as an electronic component carrier tape, the component holding force of the shutter portion that holds down the electronic component is low. Since the container is insufficient and the container is deformed due to an external force acting during the transportation, the mounting reliability is low and it cannot be used practically. On the other hand, a polypropylene resin with high crystallinity and carbon added thereto has sufficient rigidity, but the hinge strength is insufficient and the shutter part is fatigued by repeated opening and closing, so that the reusability is low, and this is also practical. Did not. As described above, the container formed from the conventional conductive polypropylene resin has heat resistance, but the rigidity or hinge strength is still insufficient, so the mounting reliability and reusability are not sufficient. Was.

Further, it is efficient that the component carrier tape or the like is wound on a reel and baked as it is together with the stored components, but the conventional reel material is generally made of the same resin as the above-mentioned container. There was a lot of paper and paper, and baking was not possible. And there was nothing other than expensive aluminum reels that could be baked as it was.

[0008]

SUMMARY OF THE INVENTION In view of the above-mentioned prior art, the present invention is used for packaging and automatic supply of parts, is hardly charged, resists baking treatment, and is reused.
No waste, reduced material and work costs,
An object of the present invention is to provide a conductive resin composition, particularly a conductive polypropylene resin composition and a component storage container.

[0009]

The present inventors have studied the mechanical properties of various resin compositions. As a result, the bending elastic modulus is required to achieve the rigidity required for improving the mounting reliability. Tensile elongation is required to achieve hinge strength necessary for improved usability.
In addition, it has been found that each of the heat deformation temperatures requires a certain value or more in order to achieve improved heat resistance to heat treatment. In particular, in order to use the resin composition for an electronic component storage container, conductivity and moldability are also required.

Accordingly, the present invention has studied the rigidity, hinge strength, heat resistance, and moldability of the conductive polypropylene resin composition in order to achieve the above object. As a result, the following physical properties were selected as a scale of these properties. It has been found that when the physical properties are in the following ranges, the conductive resin composition can achieve the above-mentioned object of the present invention.

Accordingly, the present invention provides the following physical properties: (1) The flexural modulus (23 ° C.)
(A) In the case of a composition for a large component or a reel, the flexural modulus is 21000 kgf / cm ² or more, or (b) In the case of a composition for a small component, the flexural modulus is 15
000kgf / cm ² or more, (2) Tensile elongation as the hinge strength (23 ° C.) of 8% or more, (3) heat distortion temperature as heat resistance (HDT) is, (a)
In the case of a composition for large parts or a reel, the stress condition is 130 ° C. or more at 4.6 kgf / cm ² , or (b) in the case of a composition for small parts, the stress condition is 2.0 k.
130 ° C. or more at gf / cm ² or 115 ° C. or more at 4.6 kgf / cm ² stress conditions; and (4) a melt flow rate of 5 to 150 as moldability.
A conductive polypropylene resin composition having g / 10 minutes is provided.

Regarding the physical properties of the above-mentioned conductive polypropylene resin composition, the flexural modulus is a physical property obtained by measuring a stress that gives a predetermined amount of deformation in accordance with ASTM D790M; the tensile elongation is in accordance with ASTM D638. Is the physical property defined by the elongation at break (23 ° C.) in the tensile test;
The physical properties obtained by measuring the temperature at which a predetermined amount of deformation is given under a constant load according to No. 58; and the melt flow rate (MFR) is calculated according to ASTM D1238.
Physical properties defined by the weight of a sample extruded for 10 minutes under the conditions of 230 ° C. and a load of 2.16 kg.

The large parts can be specifically exemplified by electric parts such as large switches and large relays and so-called mechanical parts. In addition, the small component specifically means a chip-type surface mount electronic component mounted on a so-called general-purpose electronic component mounter such as a quad flat package (QFP) and a small outline package (SOP). Can be illustrated.

According to the present invention, in order to solve the above-mentioned problems, physical properties that the conductive resin composition should have are extracted and an appropriate range of the physical properties is selected. Therefore, the conductive resin composition of the present invention is not particularly limited to the type of the conductive resin composition as long as it has the above-mentioned specific physical properties, and the conductive propylene having the above-mentioned physical properties is provided. Resin compositions (ie, compositions based on a propylene polymer or a propylene polymer obtained by polymerizing a propylene monomer and another monomer copolymerizable therewith (eg, ethylene)) are particularly preferred. preferable.

In the present invention, the term “conductive” means
When the resin composition is used in various forms, it is used in the sense that the conductivity of the resin composition can prevent destruction due to static electricity accumulated in the resin, and specifically, the use of the resin composition This property is generally obtained by including a conductive filler in the resin composition. In the present invention, the measure of the conductivity is the resistance (or volume resistivity) measured by an ohmmeter.
Is the physical properties of the as, usually, the resistance is 10 ⁸ ohm
cm or less, preferably 10 ⁶ ohm · cm or less, the resin composition can be satisfactorily applied to, for example, electronic component containers and the like. Therefore, in a preferred embodiment, the resin composition of the present invention has the above resistance.

The specific various physical properties described above are properties possessed by the entire composition including these fillers. Particularly preferred compositions of the present invention include conductive polypropylene resin compositions (for example, (a) propylene homopolymer). Polymer and at least one propylene polymer selected from propylene-ethylene copolymers and (b) a propylene polymer composition comprising at least one propylene-ethylene random copolymer) at least 70% by weight An example is a conductive propylene polymer composition in which the filling is at least 5% by weight.

More specifically, the conductive polypropylene resin composition having the above-mentioned specific physical properties is prepared by mixing (A) a specific crystallinity and a specific ethylene content (an ethylene content of 0) Propylene polymer having a large flexural modulus, (B) having a specific ethylene content,
A random type propylene copolymer having a large tensile elongation, and (C) a conductive filler that imparts conductivity and improves rigidity, and essentially comprises (A + B) at least 70% by weight based on the whole composition. % And C is at least 5% by weight.

Therefore, according to one aspect of the present invention, in the conductive polypropylene resin composition, (1) a portion having a crystallinity of 95% by weight or more occupies 60% by weight or more of the whole, and 20% by weight of ethylene. % Of propylene polymer A containing not more than 10% by weight (a> 0), and (2) a tensile elongation (23 ° C.) of 100%
As described above, the propylene random copolymer B containing 1 to 7% by weight of ethylene contains b% by weight (b> 0), and (3) the conductive filler C contains c% by weight (c> 0), The following relational expressions are satisfied: a + b + c = 100, 0.5 ≦ a / b ≦ 2.0, and 10 ≦ c ≦ 30.

In the present invention, the crystallinity of the propylene polymer A and the proportion of a portion having a specific crystallinity range are as follows:
It is calculated from the isotactic pentad fraction determined by nuclear magnetic resonance absorption (NMR); the tensile elongation of the propylene copolymer B
Elongation at break (23 ° C.) in tensile test according to STM D638; melt flow rate at 230 ° C., load 2. according to ASTM D1238 as described above.
The weight of the sample extruded for 10 minutes under the condition of 16 kg.

The degree of crystallinity can be measured by DSC (thermal differential analysis), X-ray diffraction, solvent solubility, density, etc. in addition to NMR. In this case, at least one measured value is substantially What is necessary is just to satisfy the requirement of the above-mentioned propylene polymer A.

In a particularly preferred embodiment of the present invention, the conductive polypropylene resin composition further comprises an elastomeric resin. In this case, in the conductive polypropylene resin composition of the present invention, (1) a propylene polymer A having a crystallinity of 95% by weight or more occupies 60% by weight or more of the entirety and 20% by weight or less of ethylene. a weight% (a
> 0), (2) tensile elongation (23 ° C.) is 100% or more,
The propylene random copolymer B containing 1 to 7% by weight of ethylene is b weight% (b ≧ 0), and (3) the conductive filler C is c
% (C> 0), and (4) an elastomeric resin D having a tensile elongation at 23 ° C. of 100% or more, a rubber elasticity at −20 ° C., and a glass transition point of −20 ° C. or less. d =% (d> 0), and the following relational expressions are satisfied: a + b + c + d = 100, 0.5 ≦ a / (b + d) ≦ 29.0, and 5 ≦ c ≦ 30.

In the above composition, “rubber elasticity” is a property well known to those skilled in the art and need not be particularly described.
Its properties are described, for example, in "Rubber Elasticity" by Ryogo Kubo (published by Shokabo). The glass transition point is a property measured by DSC (differential scanning calorimeter) according to JIS K7121.

According to the present invention, there is provided a conductive resin composition having excellent rigidity, hinge strength, heat resistance, conductivity, and moldability, particularly a conductive polypropylene resin.
Therefore, the conductive resin composition of the present invention can be applied to a component storage container for storing electronic components and automatic supply, in addition to general mechanical components.

Therefore, using the conductive polypropylene resin composition according to the present invention, a concave portion for holding and housing an electronic component,
An openable and closable shutter portion provided at an opening of the recess to prevent the electronic component from jumping out, a pair of fitting connection portions formed at front and rear edges of the recess, and formed at left and right side edges of the recess. To form an electronic component carrier with
A plurality of carriers can be connected by the connecting portion to form a long tape-shaped component carrier tape, and such a carrier or component carrier tape has the following advantages:
It has excellent mechanical properties, is hardly charged, and withstands baking treatment, so it is used with high reliability in packaging and automatic supply of electronic components, is reused, prevents electrostatic breakdown of electronic components, and bake with the electronic components. Can be processed.

A spindle for winding a component carrier tape using the conductive polypropylene resin composition according to the present invention;
A carrier tape reel can be constituted by a pair of flanges provided at both ends of the main shaft and accommodating the wound tape, and the reel has the following advantages:
The carrier tape reel has excellent mechanical properties, is hardly charged, and withstands baking treatment, so it is used with high reliability in packaging and automatic supply of electronic components, is reused, and prevents electrostatic breakdown of electronic components, In particular, baking can be performed together with the electronic component and the component carrier tape without dismantling the package.

[0026]

Next, the conductive polypropylene resin composition of the present invention will be described in detail.

The conductive polypropylene resin composition according to the present invention comprises, as its main components, a propylene polymer A, a propylene random copolymer B, and a conductive filler C and optionally an elastomeric resin D as described above. , And may further contain other components as necessary, as long as the object of the present invention is not adversely affected.

The propylene polymer A has a crystallinity of 95%.
At least 60% by weight, preferably at least 70% by weight,
It contains 20% by weight or less of ethylene, preferably 16% by weight or less, for example, 5 to 15% by weight, and its number-based average molecular weight is, for example, about 8,000 to 100,000, and preferably about 8,000 to 20,000. The propylene polymer A may be a homopolymer of polypropylene as long as it satisfies the physical properties of the conductive resin composition of the present invention described above. Accordingly, the propylene polymer A may be a polymer having the above-mentioned specific properties, which is obtained by polymerizing a propylene monomer or a propylene monomer and an ethylene monomer.

Such a propylene polymer A can be produced, for example, by the methods described in the following patent documents: JP-A-61-209207, JP-A-62-104810, Kaisho 62-10481
No. 1, Japanese Patent Application Laid-Open No. 62-104812, Japanese Patent Application Laid-Open
JP-A-2-104814, JP-A-1-311106, JP-A-1-318011, JP-A-2-166
No. 104 publication.

For example, the production using the following catalyst is preferable because a high crystallinity can be easily obtained. That is, M
g and Ti halides are polymerized in the presence of an organoaluminum compound and an organosilicon compound to polymerize propylene and ethylene using an α-olefin polymerization catalyst which is brought into contact with an olefin.

As such a propylene polymer A,
For example, BC0 commercially available from Nippon Polychem Co., Ltd.
8AHSW (MFR = 80), BC06C (MFR = 6
0) and MAIHB (MFR = 20) and MA04
(MFR = 40) and the like can be used.

The propylene random copolymer B has a tensile elongation of 100% or more, preferably 300% or more, and contains 1 to 7% by weight, preferably 2.5 to 7% by weight, for example, 2.5 to 5% by weight of ethylene. %, But the average molecular weight based on the number is, for example, about 8000 to 100,000, preferably 100 to 100,000.
It is about 00 to 60000. This copolymer B can be obtained by a method for producing a propylene copolymer well known to those skilled in the art. For example, it is preferable to randomly polymerize propylene and ethylene using a general Ziegler-based catalyst because the crystallinity of the obtained polymer can be suppressed to some extent and the tensile elongation can be increased. When the elastomeric resin D is present in the resin composition, the propylene random copolymer B may be omitted.

Such a propylene random copolymer B
Is, for example, M commercially available from Nippon Polychem Co., Ltd.
G2T (MFR = 15), MG05BS (MFR = 4
5) and MG03D (MFR = 30) can be used.

The number average molecular weight of the polymer (or copolymer) used in the present specification is ASTM D3536-9.
1 according to GPC (gel permeation chromatography).

The propylene polymer A and the propylene random copolymer B may be blended by a reactor blend in the same process such as multi-stage polymerization, or may be blended by a post-reactor blend performed during granulation after polymerization of each. Alternatively, it may be blended by a pellet blend of the respective polymers.

The type of the conductive filler C is not particularly limited as long as it can impart the conductivity required for the application to which the resin composition is applied. The conductive resin composition is not particularly limited as long as it satisfies the conditions and the conductive resin composition has the specific physical properties described above.

For example, single fiber carbon having a length of 10 mm or less or chopped strand thereof, average particle diameter 500 μm
It is preferable to use the following powdered carbon (such as carbon black) and Ketjen black. Materials other than carbon, for example, metal fillers such as Cu powder can also be used.
Of course, the above-mentioned fillers may be used in combination.

Preferably, the single fiber carbon is 5 mm or less,
If carbon black or Ketjen black has an average particle size of 200 μm or less, the mechanical properties, particularly the tensile elongation, are unlikely to decrease. Specifically, Ketjen Black EC600DJ marketed by Mitsubishi Chemical Corporation and fiber carbon HTA-C marketed by Toho Rayon Co., Ltd.
3-3R or the like can be used.

More preferably, when a surface treatment (silicone coating or the like) is applied to these fillers, the mechanical strength of the molded product is further increased.

The addition amount of the filler C is the above-mentioned specific amount. In a particularly preferred embodiment in which the conductivity and the mechanical strength of the article formed from the resin composition are taken into consideration, the filler C contains the elastomeric resin D. Even if not, when using a carbon single fiber, 10 to 20% by weight,
When carbon black is used, it may be used in an amount of 13 to 25% by weight, and when elastomeric resin D is contained, 6 to 10 when Ketjen black is used.
It may be used in amounts by weight.

The elastomeric resin D is not particularly limited as long as it is a resin exhibiting rubber elasticity having the above specific physical properties. Particularly preferred elastomeric resins D have a tensile elongation (23 ° C.) of 500% or more and / or a glass transition point of −50 ° C. or less. Specifically, low density polyethylene (LDPE), linear low density polyethylene (LLDPE), ethylene-propylene rubber (EPR), styrene-butadiene rubber (SBR) and natural rubber may be used. In particular, polyethylene polymerized with a metallocene catalyst is preferable because it exhibits sufficient rubber elasticity and is inexpensive.

Such an elastomeric resin D may have a number average molecular weight of about 10,000 to 200,000, preferably about 8,000 to 30,000. For example, EG8180 commercially available from Dow Chemical Co. EP0 commercially available from JSR)
2P or the like can be used.

The method of compounding the propylene polymer A, the propylene random copolymer B, the conductive filler C, and the optional elastic resin D is not particularly limited as long as the respective components are sufficiently kneaded. It is not something to be done. For example, a blend at the time of resin granulation or a blend by a master batch may be used.

In the case of blending at the time of granulation, for example, the filling may be carried out by side feeding by biaxial extrusion. By uniformly blending / kneading the composition of the present invention at a blending ratio, a conductive polypropylene resin having excellent rigidity, hinge strength, heat resistance, conductivity, and moldability can be obtained.

The kneading is performed by a Banbury mixer, a kneader ruder, a single screw extruder, a twin screw extruder, a gear pump,
Or a combination thereof. More preferably, the carbon is made into a masterbatch by strong kneading such as a Banbury mixer and a twin screw extruder, and then kneaded with polypropylene or further improved in dispersibility by side-feeding carbon to improve mechanical strength and conductivity. Is improved. The kneading apparatus is not particularly limited as long as the kneading of the resin and the conductive filler is sufficient.

In the conductive resin composition of the present invention, the portion of the propylene polymer A having a crystallinity of 95% by weight or more is 60%.
If the amount is less than 20% by weight or the ethylene content exceeds 20% by weight, the flexural modulus of the resin composition after compounding usually decreases, which is not preferable.

In the resin composition of the present invention, when the ethylene content of the propylene random copolymer B is less than 1% or the tensile elongation is less than 100%, the tensile elongation of the polypropylene resin composition usually decreases. It is not preferable. When the ethylene content exceeds 7% by weight, usually,
It is not preferable because the flexural modulus of the polypropylene resin composition decreases.

When the resin composition of the present invention does not contain the elastomeric resin D, the mixing ratio a / b of the propylene polymer A and the propylene random copolymer B is 0.5.
When the value is less than the above, the flexural modulus of the propylene resin composition decreases, and when it exceeds 2.0, the tensile elongation of the polypropylene resin composition decreases, which is not preferable. When the resin composition does not contain the elastomeric resin D, the resin composition of the present invention is particularly suitable for large parts and reels. In this case, the resin composition preferably has a flexural modulus of at least 21000 kgf / cm2.

Further, in the conductive resin composition of the present invention containing the elastomeric resin D, the compounding ratio a / (b + d)
Is less than 0.5, the flexural modulus usually decreases, for example, the flexural modulus is less than 15,000 kgf / cm2, and is generally not suitable as a component container in terms of component holding power and rigidity. Heat resistance decreases. On the other hand, if it exceeds 29, the tensile strength decreases, which is not preferable.

Regardless of the presence or absence of the elastomeric resin D, particularly when used for large parts, in terms of holding power,
When used on a reel, the bending elastic modulus of the resin composition is 21,000 kg in terms of heat resistance, dimensional stability and prevention of blurring.
f / cm2 or more is particularly preferable.

In the resin composition of the present invention, if the conductive filler C is less than 10% by weight (or less than 5% by weight when the elastic resin D is contained), the polypropylene resin composition Flexural modulus and electrical conductivity are lowered, and conversely, if it exceeds 30% by weight, tensile elongation and moldability of the polypropylene resin composition are lowered, and material cost is increased.

In particular, in the conductive resin composition of the present invention containing the elastomeric resin D, if ketjen black is used as the conductive filler C, and if it is used in the range of 5 to 10% by weight, kneading is performed. It is particularly preferable to use Ketjen Black, since a necessary and sufficient conductivity which is not affected by the strength and the number of times is obtained, so that the production control of the resin composition is facilitated and the physical properties are hardly reduced.

The conductive polypropylene resin composition of the present invention may contain various additives according to the purpose of the composition, if necessary, as long as the object of the present invention is not hindered. Examples of additives that can be used include various antioxidants, neutralizing agents, crystallization nucleating agents, antistatic agents, light stabilizers, ultraviolet absorbers, inorganic fillers, slip agents, dyes, pigments, peroxides, and the like. it can. The amount of this additive is usually
20 parts per 100 parts of the conductive polypropylene resin composition
Is preferred.

The conductive polypropylene resin composition of the present invention has a melt flow rate (MFR) of 5 to 150 g / 1.
0 minutes, preferably 10 to 80 g / 10 minutes.
If the melt flow rate is lower than 5 g / 10 minutes, the moldability decreases. If the melt flow rate exceeds 150 g / 10 minutes, the degree of polymerization is low, and the flexural modulus is undesirably lowered. The resin composition of the present invention can generally achieve such a predetermined melt flow rate by using the polymer A and the copolymer B having the specific properties described above.

Further, it can be adjusted by increasing or decreasing the melt flow rate by a method well known to those skilled in the art. For example, by appropriately selecting the molecular weight of the polymer used in the composition (specifically, by changing the molecular weight of polymer A, polymer B, and / or resin D), and / or as needed. The melt flow rate can be supplementarily changed by adding other components as described above (for example, peroxides).

When the melt flow rate is less than 5 g / 10 minutes, the moldability is generally poor and is not suitable for injection molding. On the other hand, when the melt flow rate exceeds 150 g / 10 minutes, the mechanical strength generally decreases.

Next, an embodiment of an electronic component storage container using the conductive polypropylene resin composition of the present invention will be described with reference to the drawings.

FIG. 1 (plan view) and FIG. 2 (front view) schematically show the component carrier tape of the present invention. The component carrier tape 5 includes a plurality of component carriers 1 connected to each other.
These carriers 1 are formed from the conductive polypropylene resin composition of the present invention, and are provided in the concave portion 7 for holding and housing the electronic component 10, and provided in the opening of the concave portion 7. The protrusions 3 prevent the electronic component 10 from jumping out and can be elastically opened and closed by an external operation.
And a shutter portion 2 comprising a spring portion (or an elastic portion) 6 and a pair of fitting connection portions 8 formed at front and rear outer edges.
And 9, and a perforation 4 formed in the left and right side edges. Many of these carriers 1 are connected to each other in a long tape shape by the pair of connecting portions 8 and 9.

The component carrier tape 5 has excellent mechanical properties, is hardly charged, and withstands baking treatment. Therefore, the component carrier tape 5 is used with high reliability in packaging and automatic supply of the electronic component 10, and is reused. Prevent electrostatic breakdown,
A baking process can be performed together with the electronic component 10.

FIG. 3 schematically shows a state where the shutter section 2 of the component carrier tape 5 is opened. In this state, the electronic component 10 can be taken out of the carrier 1.
Although not shown in the drawing, in a state where the component carrier tape 5 is supplied on the automatic feeder, the protrusion 3 of the shutter unit 2 is opened and closed by a guide or the like provided on the automatic feeder, and The shutter 2 is opened and closed, the electronic component 10 is taken out (or stored), and supplied (or collected) to the mounting site.

FIG. 4 shows a reel for a carrier tape according to the present invention. The carrier tape reel 11 is made of the conductive polypropylene resin composition of the present invention, and has a main shaft on which the component carrier tape 5 is wound and a pair of main shafts provided at both ends of the main shaft for accommodating the wound tape 5. Flange 1
And 2. Since the carrier tape reel 11 has excellent mechanical properties, is hardly charged, and withstands baking processing, it is used with high reliability in packaging and automatic supply of the electronic component 10, is reused, and causes electrostatic breakdown of the electronic component 10. Electronic components 10 without dismantling the packaging.
And baking device 13 together with component carrier tape 5
Can be baked.

Although not shown in the figure, the carrier tape reel 11 is mounted on an automatic supply machine, the component carrier tape 5 is pulled out, the electronic component 10 is taken out (or stored) as described above, and mounted. It is supplied (or collected) to the site.

The structure of such a component carrier, a carrier tape and a reel for a carrier tape is disclosed in, for example, JP-A-6-156562, the disclosure of which is incorporated herein by reference. .

[0064]

According to the present invention, it is possible to provide a conductive resin, particularly a conductive polypropylene resin, having excellent rigidity, hinge strength, heat resistance, conductivity, and moldability. Therefore, the present invention can be applied not only to general mechanical components but also to a component storage container for storing and automatically supplying electronic components.

According to the present invention, a component carrier tape is provided. The component carrier tape has excellent mechanical properties, is hardly charged, and withstands a baking process, so that it can be used with high reliability in packaging and automatic supply of components. It can be reused and used, and in particular, prevents electrostatic breakdown of electronic components, and can be baked together with the electronic components. Therefore, no waste is generated, and material costs and work costs can be reduced.

According to the present invention, a reel for a carrier tape is provided. The reel for a carrier tape has excellent mechanical properties, is hardly charged, and can withstand baking treatment.
Used with high reliability in parts packaging and automatic supply,
It can be reused to prevent, in particular, electrostatic breakdown of electronic components, and can be baked together with the electronic components and the component carrier tape without dismantling the packaging. Therefore, no waste is produced, and material costs and work costs can be further reduced.

[0067]

Conventional Examples, Comparative Examples and Examples Next, the conductive polypropylene resin composition of the present invention will be specifically described. For comparison, a conventional example and a comparative example were also implemented.

First, the compositions and evaluation results of two conventional examples, two comparative examples, two comparative examples and two examples of the present invention are shown in Tables 1 and 2, respectively, when no elastomeric resin D is contained. And Table 3 below. The “ratio of high crystal parts” in the table means the percentage of parts having a crystallinity of 95% or more.

In addition, when compounding the components, in Comparative Example 1, 2
Carbon was side-fed using a screw extruder. In Comparative Example 1, a single-screw extruder was used. In Comparative Example 3, a master batch having twice the carbon composition was prepared using a Banbury mixer. It was compounded using a twin-screw extruder so as to be as follows. Comparative Examples 4 and 5 described later were also blended in the same manner as Comparative Example 3. In Example 1, it was compounded in the same manner as Comparative Example 1, in Example 2, a single screw extruder was used, and in Examples 3 and 4, it was compounded as in Comparative Example 3, and in Example 5, it was compounded as in Comparative Example 1. did.

[0070]

[Table 1]

[0071]

[Table 2]

[0072]

[Table 3]

As in Conventional Example 1, the heat deformation temperature of polystyrene alone is less than 130 ° C., and baking cannot be performed.

When only the random propylene copolymer B is used as in Conventional Example 2, the flexural modulus is 15,000.
It is less than kgf / cm2, and is not suitable as a component storage container in terms of component holding force and rigidity.

As in Comparative Example 1, when only high-crystalline polypropylene was used, the tensile elongation was remarkably smaller than 20%, so that the hinge strength was low, and it was not suitable for reuse.

When a / b is 0.5 or less as in Comparative Example 2, the flexural modulus is less than 21,000 kgf / cm 2, which is not suitable as a large component storage container in terms of component holding power and rigidity. In this sense, this composition is described as a comparative example, but the flexural modulus is 21,000 kg.
f / cm 2 or less (for example, at least 15,000
When the composition is used for an application, for example, as a container for storing small parts or a reel, Comparative Example 2 can be considered to be an example of the present invention. The heat distortion temperature of the composition of Comparative Example 2 (2
kgf / cm ² load) was 140 ° C.

When a / b exceeds 2, as in Comparative Example 3, the tensile elongation is remarkably smaller than 20%, so that the hinge strength is low, and the material is not suitable for reuse.

Examples 1 and 2 satisfy all the necessary physical properties of all the resin compositions of the present invention and can be put to practical use. In particular, Example 1 has an a / b of 1.7, has a large flexural modulus, and therefore has high rigidity and excellent component holding force of the shutter, and is therefore suitable for use as a component storage container having a heavy component weight. . In Example 2, a / b was 0.8.
5, which is large in tensile elongation and therefore excellent in hinge strength, so that the reusability is improved and the life as a component storage container is excellent.

Next, three examples of the resin composition of the present invention containing the elastomeric resin D and two comparative examples to be compared therewith will be described.

The mixing conditions and the evaluation method are as described above, and the mixing compositions and the evaluation results are shown in Tables 4 and 5.

[0081]

[Table 4]

[0082]

[Table 5]

In Comparative Example 4, since the flexural modulus was low, the rigidity was insufficient, and it was not suitable for holding parts, and the heat deformation temperature was considerably low. In Comparative Example 5, since the hinge strength was insufficient, it was inferior in repeated use and had a problem in reusability.

While Examples 3 to 5 all have the specific physical properties of the present invention, the compositions of Examples 3 and 5 are particularly suitable for carriers and reels for large parts.
Are particularly suitable for carriers for small parts.

[Brief description of the drawings]

FIG. 1 is a schematic plan view showing a part of an embodiment of a component carrier tape formed by using a conductive resin composition of the present invention.

FIG. 2 is a schematic front view of the component carrier tape of FIG.

FIG. 3 is a schematic plan view showing a part of a tape for component carriers formed using the conductive resin composition of the present invention in a state where a shutter portion is opened.

FIG. 4 is a schematic perspective view showing one embodiment of a carrier tape reel formed by using the conductive resin composition of the present invention and showing a state of baking as it is.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Component carrier 2 Shutter part 3 Projection part 4 Feed hole 5 Component carrier tape 6 Spring part 7 Concave part 8, 9 Connecting part 10 Electronic component 11 Reel 12 Flange 13 Baking device

 ──────────────────────────────────────────────────の Continued on the front page (72) Inventor Hidehiko Funaoka 4-1-1 Tsukiji, Chuo-ku, Tokyo Inside Tonen Kagaku Co., Ltd.

Claims (12)

[Claims] (1) A portion having a degree of crystallinity of 95% or more is 60% by weight or more, and ethylene is 20% by weight.
A) Propylene polymer a wt.
0), and (3) conductive filler c weight percent (c> 0),
A conductive polypropylene resin composition, wherein the following relational expressions are satisfied: a + b + c = 100, 0.5 ≦ a / b ≦ 2.0, and 10 ≦ c ≦ 30. 2. A propylene polymer comprising ethylene in an amount of 5-1.
The conductive polypropylene resin composition according to claim 1, which contains 5% by weight. 3. The conductive polypropylene resin composition according to claim 1, wherein the propylene random copolymer contains 2.5 to 5% by weight of ethylene. 4. A recess made of the conductive polypropylene resin composition according to claim 1 for holding and housing a component, and an openable and closable shutter provided at an opening of the recess to prevent the component from jumping out. A parts storage container characterized in that: 5. A component carrier tape formed by connecting the component storage containers according to claim 4 to form a tape. 6. A carrier tape reel comprising the conductive polypropylene resin composition according to claim 1 and wound with the component carrier tape according to claim 3. (1) A portion having a degree of crystallinity of 95% or more is 60% by weight or more, and ethylene is 20% by weight or more.
A propylene polymer a weight% (a> 0) containing: (2) b) propylene random copolymer b weight% (b ≧ 1) having a tensile elongation of 100% or more and containing 1 to 7% by weight of ethylene
0), (3) an elastomeric resin having a tensile elongation of 100% or more, exhibiting rubber elasticity at −20 ° C., and having a glass transition point of −20 ° C. or less d weight% (d>0); and (4) ) That the conductive filler comprises c wt% (c> 0) and satisfies the following relations: a + b + c + d = 100, 0.5 ≦ a / (b + d) ≦ 29, and 5 ≦ c ≦ 30 Characteristic conductive polypropylene resin composition. 8. A propylene polymer comprising ethylene in an amount of 5-1.
The conductive polypropylene resin composition according to claim 7, wherein 5% by weight is contained and a portion having a crystallinity of 97% or more is 70% by weight or more of the whole. 9. The conductive polypropylene resin composition according to claim 7, wherein the propylene random copolymer contains 2.5 to 7% by weight of ethylene and has a tensile elongation of 300% or more. 10. A recess made of the conductive polypropylene resin composition according to claim 7 for holding and storing a component, and an openable and closable shutter provided at an opening of the recess to prevent the component from flying out. A parts storage container characterized in that: 11. A component carrier tape formed by connecting the component storage containers according to claim 10 into a tape shape. 12. A carrier tape reel comprising the conductive polypropylene resin composition according to claim 7 and wound around the component carrier tape according to claim 11.