JP4828094B2 - Cover film for carrier tape of electronic parts and manufacturing method thereof - Google Patents

Description

  The present invention relates to a novel cover film for a carrier tape of an electronic component, which is extremely excellent in heat sealability, easy-openability, and transparency, and a method for producing the same.

Conventionally, an electronic component carrier tape used for storing, transporting, and mounting an electronic component such as an IC, and storing the electronic component in a form that can be easily aligned, stored and removed for mounting on an electronic circuit board. Some cover films have a two-layer structure consisting of a stretched film for maintaining the tear strength and breaking strength, and providing heat resistance for heat sealing, and a heat seal layer that develops fusion properties when heated. is there. However, in order to improve mechanical strength and the like, a three-layer structure in which an intermediate layer is disposed between a stretched film and a heat seal layer or a multilayer structure having more layers is widely used. These cover films having a multilayer structure of three layers or more are produced by an extrusion laminating method using the heat-sealing property of a heat seal layer or an intermediate layer between the heat seal layer and a stretched film. However, in this manufacturing method, as the number of layers increases, the number of extrusion laminating steps increases. As a result, the productivity is lowered and the raw material loss is increased, resulting in an increase in cost. Also, in terms of quality, the greater the number of processes, the higher the possibility of foreign matter mixing.
Such a cover film for carrier tape of electronic parts is required to have the following as basic characteristics.
(1) Heat-sealing property for easily obtaining a practical peel strength, and (2) Easy-opening property that can be easily taken out without scattering of contents when opened.
In recent years, (3) transparency is also desired. If the transparency is good, it is easy to confirm the filled contents, thereby improving the efficiency of inspection work, improving reliability, and providing a sense of security.

  For example, JP-B-57-53828 and JP-B-57-42652 disclose heat seal films that are excellent in heat sealability and easy to open. However, these have low transparency and do not sufficiently satisfy the requirement for transparency in electronic parts. Accordingly, a carrier film for electronic component carrier tapes is desired to have further excellent transparency.

  The present invention is excellent in basic characteristics such as heat sealability and easy-openability as a cover film for carrier tapes of the above-mentioned electronic parts, and further excellent in transparency and used for carrier tapes of new electronic parts with stable quality. A cover film and a method for producing the same are provided.

In the present invention, the outermost layer is a biaxially stretched polyethylene terephthalate layer, the second layer is a polyethylene resin layer, the third layer is a polyolefin-based resin layer, and the fourth layer is a sealant layer. Ri, the fourth layer sealant layer has a thickness of 4~25μm and 0-50 wt% of the total from 50 to 100% by weight and the following components of the following components (a) ~ (c) ( d) And a cover film for a carrier tape of an electronic component , wherein the haze (cloudiness value) is 25% or less .
(A) 5 to 50% by weight of a block copolymer of 50 to 95% by weight of a styrenic hydrocarbon and 5 to 50% by weight of a conjugated diene hydrocarbon,
(B) 5 to 50% by weight of an ethylene-α-olefin random copolymer,
(C) a block copolymer of 5 to 70% by weight of 10 to 50% by weight of a styrenic hydrocarbon and 90 to 50% by weight of a conjugated diene hydrocarbon,
(D) Impact resistant polystyrene.
Further, the present invention is a method of manufacturing the electronic component of the carrier tape cover film lies in the manufacturing method comprising the following (a) or (b) Tona Turkey.
(A) A process of extrusion coating the polyethylene resin of the second layer with respect to the first layer, and a polyolefin resin layer of the third layer and a sealant of the fourth layer with respect to the second layer of the obtained two-layer film Comprising the step of coextrusion coating of the layers.
(B) the first layer comprises the step of a coextruded film of the third layer of poly olefin emissions based resin layer and the sealant layer of the fourth layer is extrusion lamination through the polyethylene resin layer of the second layer.

  Examples of the styrenic hydrocarbon used in the present invention include styrene, α-methylstyrene, and various alkyl-substituted styrenes. Of these, styrene can be preferably used. Examples of the conjugated diene hydrocarbon include isoprene, butadiene, or those obtained by adding hydrogen to these unsaturated bonds. Among these block copolymers, one type can be used as each of the components (a) and (c), but two or more types can also be used in combination. Examples of the α olefin in the ethylene-α olefin random copolymer include propylene, butene, pentene, hexene and the like.

  The impact-resistant polystyrene is composed of a styrene hydrocarbon polymer and a conjugated diene hydrocarbon polymer. In the styrene hydrocarbon polymer forming the matrix, soft component particles comprising a conjugated diene hydrocarbon polymer are included. It exists in a distributed manner.

  Commercially available products can be used for the block copolymer of styrene-based hydrocarbon and conjugated diene-based hydrocarbon, ethylene-α-olefin random copolymer, and high-impact polystyrene.

The compounding ratio of the resin compositions of components (a) to (d) is 5 to 50% by weight of component (a), 5 to 50% by weight of component (b), and 5 to 70% by weight of component (c). The sum of a) to (c) is 50 to 100% by weight, and component (d) is 0 to 50% by weight.
When the component (a) is less than 5% by weight, it becomes difficult to form a film. When the component (a) exceeds 50% by weight, the temperature dependence of the peel strength becomes remarkable, and the easy-openability is impaired.
If the component (b) is less than 5% by weight, sufficient peel strength cannot be obtained, and if it exceeds 50% by weight, the adhesiveness to the roll during film formation is large, making it difficult to form a film.
When the component (c) is less than 5% by weight, it becomes difficult to obtain sealing conditions necessary for imparting easy-opening properties, and when it exceeds 70% by weight, film formation becomes difficult.
If the component (d) exceeds 50% by weight, transparency cannot be obtained.

Haze (cloudiness value) refers to the degree of opaque cloudy state. When diffuse transmittance and total light transmittance are measured using an integrating sphere type light transmittance measuring device, (diffuse transmittance / total light transmittance). ). Accordingly, when the transparency is excellent, the diffuse transmittance is small. Therefore, the smaller the haze value, the better the transparency. The haze of the carrier tape cover film of the electronic component of the present invention is 25 % or less, and since it is excellent in transparency, it is very easy to confirm the filled contents.

The thickness of the sealant layer is 4 μm~25μm. 25 [mu] m greater than reduces the transparency in the cover film carrier tape for electronic components having a sealant layer, transparency by visually impaired.

  The cover film for a carrier tape of an electronic component according to the present invention has a biaxially stretched polyethylene terephthalate layer as an outermost layer, a polyethylene resin layer as a second layer in contact with the outermost layer, a polyolefin resin layer as a third layer in contact with the second layer, And it can use most suitably in the structure of the sealant layer mentioned above as a 4th layer which touches a 3rd layer.

  As the biaxially stretched polyethylene terephthalate used for the biaxially stretched polyethylene terephthalate layer, in addition to those usually used, an antistatic agent for antistatic treatment is applied or kneaded, or a corona treatment is applied. It is also possible to use.

  As the polyethylene resin layer, low-density polyethylene, linear low-density polyethylene, ultra-low-density polyethylene, or the like can be used. These polyethylenes can be used alone or as a mixture of two or more thereof. Also, ethylene-1-butene or a copolymer of ethylene and a vinyl group having a carboxylic acid group, such as an ethylene-acrylic acid ester or an ethylene-vinyl acetate copolymer, or a ternary of these and an acid anhydride. A copolymer or the like can also be blended and used.

  In order to make the adhesive force between the outermost layer and the second layer more satisfactory, various commonly used anchor coating agents and surface treatment techniques can be used. As the anchor coating (AC) agent, a two-component curable isocyanate-based anchor coating agent can be used particularly for strengthening the adhesion between the biaxially stretched polyethylene terephthalate and the polyethylene resin. Furthermore, in order to strengthen the adhesion between the anchor coating agent and the biaxially stretched polyethylene terephthalate film, the biaxially stretched polyethylene terephthalate film can be subjected to corona treatment, and the polyethylene resin side can be subjected to ozone treatment. .

  Examples of the polyolefin resin used for the polyolefin resin layer include an ethylene-1-butene copolymer, an ethylene-vinyl acetate copolymer, an ethylene-acrylic acid ester copolymer, an ethylene-maleic acid copolymer, and a styrene- Examples thereof include an ethylene graft copolymer, a styrene-propylene graft copolymer, a styrene-ethylene-butadiene block copolymer, a propylene polymer, an ethylene polymer, and blends thereof.

  The cover film for carrier tape of electronic parts obtained by the present invention can be subjected to antistatic treatment on at least one surface. The antistatic treatment can be carried out by applying a surfactant type antistatic agent, a polymer type antistatic agent or a conductive agent as an antistatic agent, using a roll coater using a gravure roll or the like, or spraying. .

The heat seal film in which the outermost layer is a biaxially stretched polyethylene terephthalate layer, the second layer is a polyethylene resin layer, the third layer is a polyolefin resin layer, and the fourth layer is a sealant layer is the second layer of the first layer, which is the outermost layer. Preferably, an AC agent is applied to the axially stretched polyethylene terephthalate film, a second layer of polyethylene resin is extrusion coated onto the first layer, and a third layer is applied to the second layer of the resulting two-layer film. It can be manufactured by a process including a step of coextrusion coating a polyolefin-based resin layer as a layer and a sealant layer as a fourth layer.
Alternatively, a step of preferably applying an AC agent to the biaxially stretched polyethylene terephthalate film of the first layer, which is the outermost layer, and the third layer of the polyolefin-based resin layer and the fourth layer of the sealant layer are applied to the first layer. It can also be produced by a process that includes extrusion laminating the extruded film through a second layer of polyethylene resin.

Examples of the resin and resin composition used in the sealant layer include high density polyethylene, low density polyethylene, linear low density polyethylene, polypropylene, polybutene-1, poly-4-methylpentene-1, and ethylene-propylene copolymer. Ethylene-1-butene copolymer, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, styrene-butadiene copolymer and hydrogenated product thereof, thermoplastic polyurethane, and the like, and blends thereof. is there. A resin composition containing 50 to 100% by weight of the following mixture is preferred.
(A) 5 to 50% by weight of a block copolymer of 50 to 95% by weight of a styrenic hydrocarbon and 5 to 50% by weight of a conjugated diene hydrocarbon,
(B) 5 to 50% by weight of an ethylene-α-olefin random copolymer,
(C) 50 to 100% by weight of a block copolymer of 5 to 70% by weight of styrene hydrocarbon 10 to 50% by weight and conjugated diene hydrocarbon 90 to 50% by weight, and (d) high impact polystyrene. 0-50% by weight.

  As the production machine of the present invention, a general laminator can be used, and a tandem laminator can be suitably used. As a coater for coating the AC agent on the biaxially stretched polyethylene terephthalate film, a commonly used one such as a roll coater, a gravure coater, a reverse roll coater, a bar coater, or a die coater can be used.

A T-die can be used as the die of the laminator for extruding the polyethylene resin. Also, a deckle for adjusting the film width may be provided.
As a laminator die for co-extrusion of the polyolefin resin layer and the sealant layer, a T-die having a feed block generally used for co-extrusion, a multi-manifold die, a dual slot die, or the like can be used.

The third-layer polyolefin resin layer and the fourth-layer sealant layer can be obtained by forming a multilayer film by a co-extrusion method. Among them, in the method of obtaining a multilayer film by the T-die method, since the molten resin that has come out of the die is nipped by a mirror roll, the transparency becomes higher. Also, when trying to obtain a single-layer film consisting only of the sealant layer, the thickness is 4 to 25 μm in the present invention, so that it is difficult to obtain a good thickness accuracy and a stable and sufficient peel strength, and transparency. It tends to cause unevenness. On the other hand, a sealant layer having a stable thickness can be obtained by co-extrusion with an olefin resin. In addition, the obtained multilayer film can be laminated | stacked with a biaxially-stretched polyethylene terephthalate layer through the polyethylene resin layer which is the fuse | melted 2nd layer, and can be used as a heat seal film.

  In the present invention, in addition to the above steps, an antistatic treatment step can be further added as necessary. As the antistatic agent, for example, a surfactant-based antistatic agent, a polymer-type antistatic agent, a conductive agent and the like can be applied by a roll coater using a gravure roll, a spray, or the like. In order to uniformly apply these antistatic agents, the film surface is preferably subjected to corona treatment or ozone treatment, particularly preferably corona discharge treatment, before performing the antistatic treatment.

  By using this cover film for carrier tape of electronic parts of the present invention, it is possible to prevent the electronic parts from being contaminated during storage, transportation and mounting of electronic parts, and to facilitate practical peel strength. Excellent heat-sealability, easy-to-open and easy-to-open, and excellent transparency makes it easy to check the filled electronic parts, making electronic parts inspection work more efficient and trusting the inspection work An improvement in sex is achieved.

Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples.
Examples 1-6
(A) Styrene-butadiene block copolymer resin (manufactured by Denki Kagaku Kogyo Co., Ltd., “Denkaclearene”, styrene content 80% by weight, butadiene content 20% by weight), (b) ) Ethylene-butene-1 random copolymer (Mitsui Chemicals, “Toughmer A”), (c) styrene-butadiene block copolymer (manufactured by Nippon Synthetic Rubber Co., Ltd., “STR resin”, styrene content 40% by weight, Butadiene content 60% by weight), (d) impact-resistant polystyrene resin (manufactured by Denki Kagaku Kogyo Co., Ltd., “Denkastyrol HI-E6”) was hand-blended so as to have the composition shown in Table 1, and 40 mm uniaxial Compounded at 200 ° C. with an extruder to obtain a resin composition.
This resin composition and low density polyethylene as a polyolefin resin were coextruded by a T-die method to obtain a two-layer film (total thickness 30 μm) having the sealant thickness listed in Table 2. This two-layer film was laminated with a biaxially stretched polyethylene terephthalate film (thickness: 12 μm) via a polyethylene resin (thickness: 15 μm) by an extrusion laminating method to obtain a carrier tape cover film for an electronic component.

Comparative Examples 1-5
In the same manner as above, components (a) to (d) were blended so as to have the compositions shown in Table 1 to obtain resin mixtures for heat sealing. Next, this mixture is coextruded with low-density polyethylene to produce a film having the thickness shown in Table 2, and this film is laminated with a biaxially stretched polyethylene terephthalate film by a dry laminating method for a carrier tape of a transparent laminated electronic component. A cover film (total thickness 40 μm only in Comparative Example 5; otherwise, total thickness 30 μm) was obtained.

The following evaluation was performed with respect to the carrier tape cover film for electronic components obtained as described above.
Evaluation of transparency (measurement of haze)
The haze (haze value) was measured using an integrating sphere type measuring apparatus according to measuring method A according to JIS-K7105 (1998). The unit is%. This is shown in Table 2.
Evaluation of heat-sealability and easy-openability Seal the film on polystyrene carrier tape for electronic packaging materials at 150 ° C under conditions of seal head width 0.5mm x 2, seal pressure 0.4MPa, seal speed 2 times / second did. A sample having an average peel strength in the range of 0.2N to 0.6N was rated as ◯, and a sample having an average peel strength outside the above range was rated as x. The results are shown in the column “Heat sealability” in Table 2. In addition, the case where the difference between the maximum value and the minimum value of the peel strength was 0.4 N or less was evaluated as ◯, and the other difference was determined as ×. The results are shown in the column of “easy opening” in Table 2.

  The cover film for carrier tapes of electronic parts of the above examples has excellent heat sealing properties for easily obtaining a practical peel strength, there is no scattering of contents at the time of opening, and basic properties such as easy opening that can be easily removed Excellent transparency without damaging

Example 7
Manufacture of polystyrene resin for sealant layer (a) Styrene-butadiene block copolymer resin (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Denkaclearene, styrene content 80% by weight, butadiene content 20% by weight), (b) ethylene -Butene-1 random copolymer (trade name: Tuffmer A, manufactured by Mitsui Chemicals), (c) styrene-butadiene block copolymer resin (trade name: STR resin, manufactured by Nippon Synthetic Rubber Co., Ltd., 40% by weight of styrene) Butadiene content 80% by weight), (d) high impact polystyrene resin (manufactured by Denki Kagaku Kogyo Co., Ltd., trade name: Denkastyrol HI-E6), blended to be 40, 25, 25, 10% by weight, respectively, It melt-kneaded at 200 degreeC with the 40mm single screw extruder, and obtained the resin pellet for the target sealant layers.
Using a tandemuraminator, a biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name: Toyobo Ester Film, thickness 16 μm) is drawn out, and an isocyanate-based two-component curable AC agent (manufactured by Takeda Pharmaceutical Company Limited, product) Name: Takelac A971, Takenate A3) was coated and dried to obtain a coated film. This film was coated with a low-density polyethylene resin (trade name: Novatec LD, manufactured by Nippon Polychem Co., Ltd.) extruded at a temperature of 320 ° C. with a 65 mm extrusion laminator equipped with a T-die so as to have a thickness of 13 μm. Furthermore, by using a 65 mm extrusion laminator equipped with a multi-manifold die, a low-density polyethylene (manufactured by Ube Industries, trade name: UBE polyethylene) and a polystyrene resin for the sealant layer produced as described above are added to this film using polyethylene, polystyrene. Co-extrusion coating was performed at a temperature of 230 ° C. so that the resin thicknesses were 30 and 10 μm, respectively, to obtain a carrier tape cover film for a four-layer electronic component.

Example 8
Biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name: Toyobo Ester Film, thickness 16 μm) is supplied using a tandemuraminator, and an isocyanate-based two-component curable AC agent (manufactured by Takeda Pharmaceutical Co., Ltd., Product names: Takelac A971, Takenate A3) were coated and dried to obtain a coated film. This film was coated with a low-density polyethylene resin (trade name: Novatec LD, manufactured by Nippon Polychem Co., Ltd.) extruded at a temperature of 320 ° C. with a 65 mm extrusion laminator equipped with a T-die so as to have a thickness of 13 μm. Furthermore, by using a 65 mm extrusion laminator equipped with a multi-manifold die, a low-density polyethylene (manufactured by Ube Industries, trade name: UBE polyethylene) and a polystyrene resin for the sealant layer produced as described above are added to this film using polyethylene, polystyrene. Co-extrusion coating was performed at a temperature of 230 ° C. so that the thickness of the resin was 30 and 10 μm, respectively, to obtain a cover film for carrier tape of a four-layer electronic component. Next, the surface of the film was subjected to corona treatment with a corona treatment machine. Subsequently, a surfactant-based antistatic agent (manufactured by Nippon Pure Chemical Co., Ltd., trade name: SAT-4) was sprayed to obtain the intended film.

Example 9
Biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name: Toyobo Ester Film, thickness 16 μm) is supplied using a tandemuraminator, and an isocyanate-based two-component curable AC agent (manufactured by Takeda Pharmaceutical Co., Ltd., Product names: Takelac A971, Takenate A3) were coated and dried to obtain a coated film. On the other hand, with a 65 mm extrusion laminator equipped with a multi-manifold die, low density polyethylene (manufactured by Ube Industries, trade name: UBE polyethylene) and the polystyrene resin for the sealant layer produced as described above, the thickness of the polyethylene and polystyrene resin Were coextruded at a temperature of 230 ° C. so as to be 30 and 10 μm, respectively, to obtain a coextruded film. Next, polyethylene is passed through a low-density polyethylene resin (trade name: Novatec LD, manufactured by Nippon Polychem Co., Ltd.) obtained by extruding the coated film and the coextruded film at a temperature of 320 ° C. with a 65 mm extrusion laminator equipped with a T-die. Extrusion laminating was performed so that the thickness of the resin was 13 μm to obtain a cover film for a carrier tape of a desired four-layer electronic component.

Example 10
Biaxially stretched polyethylene terephthalate film (manufactured by Toyobo Co., Ltd., trade name: Toyobo Ester Film, thickness 16 μm) is supplied using a tandemuraminator, and an isocyanate-based two-component curable AC agent (manufactured by Takeda Pharmaceutical Co., Ltd., Product names: Takelac A971, Takenate A3) were coated and dried to obtain a coated film. On the other hand, with a 65 mm extrusion laminator equipped with a multi-manifold die, low density polyethylene (manufactured by Ube Industries, trade name: UBE polyethylene) and the polystyrene resin for the sealant layer produced as described above, the thickness of the polyethylene and polystyrene resin Were coextruded at a temperature of 230 ° C. so as to be 30 and 10 μm, respectively, to obtain a coextruded film. Next, a polyethylene resin is passed through a low density polyethylene resin (trade name: Novatec LD, manufactured by Nippon Polychem Co., Ltd.) obtained by extruding the coated film and the coextruded film at a temperature of 320 ° C. with a 65 mm extrusion laminator equipped with a T-die. Extrusion laminating was carried out so that the thickness of the film became 13 μm to obtain a cover film for a carrier tape of a desired four-layer electronic component. Subsequently, after corona-treating the film surface with a corona treatment machine, a surfactant-based antistatic agent (trade name: SAT-4, manufactured by Nippon Pure Chemical Co., Ltd.) was sprayed to obtain a desired film.
According to the production method of the above embodiment, in the production of the multilayer film, the process is simplified, contributing to cost reduction such as reduction of operators and reduction of raw material loss, and more stable quality electronic component carrier tape cover film Can be obtained.

Claims (7)

A first layer which is the outermost layer is a biaxially oriented polyethylene terephthalate layer, a second layer of polyethylene resin layer, the third layer is a polyolefin resin layer, Ri fourth layers Do from the sealant layer, said first Resin having a thickness of 4 to 25 μm and a total of the following components (a) to (c) of 50 to 100% by weight and 0 to 50% by weight of the following component (d): A cover film for a carrier tape of an electronic component, comprising the composition and having a haze (cloudiness value) of 25% or less .
(A) 5 to 50% by weight of a block copolymer of 50 to 95% by weight of a styrenic hydrocarbon and 5 to 50% by weight of a conjugated diene hydrocarbon,
(B) 5 to 50% by weight of an ethylene-α-olefin random copolymer,
(C) a block copolymer of 5 to 70% by weight of 10 to 50% by weight of a styrenic hydrocarbon and 90 to 50% by weight of a conjugated diene hydrocarbon,
(D) Impact resistant polystyrene. The cover film according to claim 1 , wherein at least one surface is subjected to an antistatic treatment. The step of extrusion coating the second layer of polyethylene resin on the first layer, and the third layer of the polyolefin-based resin layer and the fourth sealant layer on the second layer of the obtained two-layer film the method according to claim 1 or 2 cover film carrier tape of electronic components according to comprising the step of extrusion coating. Relative to the first layer, the third layer of poly olefin emissions based resin layer and the claim 1 or coextruded film comprising a sealant layer of the fourth layer comprises the step of extrusion laminating through the polyethylene resin layer of the second layer The manufacturing method of the cover film for carrier tapes of the electronic component of 2 . Furthermore, the manufacturing method of Claim 3 or 4 which consists of the process of performing an antistatic process to at least one side of a 1st layer and a 4th layer . The manufacturing method according to claim 5 , wherein at least a surface to be subjected to the antistatic treatment is subjected to a corona discharge treatment before the step of performing the antistatic treatment. The method according to any one of claims 3-6 for performing all steps in the same line.