JP2010155923A - Pressure-sensitive adhesive film for protection - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure-sensitive adhesive film for protection which shows appropriate adhesion to an adherend and does not generate a pollutant derived from the pressure-sensitive adhesive film on processing such as cutting. <P>SOLUTION: The pressure-sensitive adhesive film for protection can be formed by adjusting the compounding ratio of a block copolymer mixture including an M-A type diblock copolymer and an M-A-M type triblock copolymer which are composed of a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A) and a phthalate based plasticizer in the pressure-sensitive adhesive layer. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a protective adhesive film. More specifically, the present invention relates to a protective pressure-sensitive adhesive film that exhibits appropriate adhesion to an adherend and that does not generate contaminants such as glue residue derived from the pressure-sensitive adhesive film during processing such as cutting.

  In order to protect various articles from dirt and scratches, a releasable protective adhesive film is used. Properties required for such a protective pressure-sensitive adhesive film include moderate adhesion to the adherend, easy peelability at the time of peeling and removal, low contamination, and the like. In recent years, contamination due to cutting waste derived from an adhesive film that occurs during processing has led to a decrease in workability and productivity, which has become a major problem. For this reason, various attempts have been made to prevent contamination derived from an adhesive film that may be generated by processing.

  For example, Patent Document 1 discloses a radiation curable acrylic system having an intermediate layer having a specific initial elastic modulus, loss tangent, and gel content on one side of a substrate, and a carbon-carbon double bond in the molecule. A pressure-sensitive adhesive sheet in which generation of cutting waste is prevented by providing a pressure-sensitive adhesive layer using a polymer in this order is disclosed.

However, according to the pressure-sensitive adhesive sheet, although the number of cut scraps is reduced, it has not yet been completely prevented. Therefore, it has been desired to develop a protective adhesive film that does not generate contaminants derived from the adhesive film even when processing such as cutting is performed.
JP 2007-45965 A

  The present invention has been made in view of such circumstances, and an object thereof is to show appropriate adhesiveness to an adherend and to contaminate glue residue derived from an adhesive film during processing such as cutting. An object of the present invention is to provide a protective adhesive film that does not generate substances.

  The present inventor conducted extensive research to solve the above-mentioned problems, and as a main component of the pressure-sensitive adhesive layer, M-, comprising a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A). By using a block copolymer mixture containing an A-type diblock copolymer and an M-AM-type triblock copolymer, and adding a phthalate ester plasticizer to the mixture, appropriate adhesion during the pasting period It has been found that a pressure-sensitive adhesive film having the property and non-contamination property during processing can be obtained, and the present invention has been completed. Specifically, the following are provided.

  (1) In an adhesive film in which an adhesive layer and a release layer are sequentially formed on a substrate, the adhesive layer comprises a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A). A block copolymer comprising a MA type diblock copolymer having a weight average molecular weight of 10,000 to 100,000 and a MAM type triblock copolymer having a weight average molecular weight of 10,000 to 100,000. A polymer mixture and a phthalate plasticizer having a mass average molecular weight of 300 to 1000 are contained, and in the block copolymer mixture, the proportion of the butyl acrylate polymer block (A) is 90 to 95 mass. % Diblock copolymer and the triblock copolymer in which the proportion of the butyl acrylate polymer block (A) is 72 to 80% by mass, The proportion of the triblock copolymer in the polymer mixture is 30 to 90% by mass, and the phthalate plasticizer is blended in an amount of 0 to 60 parts by mass with respect to 100 parts by mass of the block copolymer mixture. A protective pressure-sensitive adhesive film characterized by

  (2) The protective adhesive film according to (1), wherein the phthalate ester plasticizer is further blended in an amount of 15 to 60 parts by mass with respect to 100 parts by mass of the block copolymer mixture.

  (3) The peel strength after 0.5 hours has elapsed after being pasted on the adherend measured by a 180 ° peel test (based on JIS Z0237) having a peel speed of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm. The protective adhesive film according to (1) or (2), wherein the protective adhesive film has a thickness of 0.01 to 1.00 N / 20 mm.

  (4) The protective pressure-sensitive adhesive film according to any one of (1) to (3), which is for protecting a silicon oxide film surface.

  According to the present invention, it exhibits appropriate adhesion to an adherend, and does not generate contaminants such as glue residue derived from an adhesive film during processing such as cutting, causing contamination of products and devices. Therefore, workability and productivity can be improved.

  Hereinafter, specific embodiments of the present invention will be described in detail.

  The protective pressure-sensitive adhesive film of the present invention (hereinafter referred to as pressure-sensitive adhesive film) is a pressure-sensitive adhesive film in which a pressure-sensitive adhesive layer and a release layer are sequentially formed on a substrate. A MA-type diblock copolymer having a weight average molecular weight of 10,000 to 100,000 and a weight average molecular weight of 10,000 to 100,000 consisting of a combined block (M) and a butyl acrylate polymer block (A). A block copolymer mixture containing an M-A-M type triblock copolymer and a phthalate ester plasticizer having a mass average molecular weight of 300 to 1000, the block copolymer mixture comprising the acrylic acid The diblock copolymer in which the proportion of the butyl polymer block (A) is 90 to 95% by mass and the proportion of the butyl acrylate polymer block (A) is 72 to 80 And the proportion of the triblock copolymer in the block copolymer mixture is 30 to 90% by mass, and the phthalate plasticizer is 0-60 mass parts is mix | blended with respect to 100 mass parts of copolymer mixtures.

  As the pressure-sensitive adhesive layer constituting the pressure-sensitive adhesive film, a copolymer of an acrylic acid alkyl ester monomer and a monomer having a functional group such as an epoxy group or a hydroxyl group is cross-linked with an isocyanate-based cross-linking agent or a metal chelating agent. The ones used are generally used. On the other hand, in the present invention, a pressure-sensitive adhesive layer comprises a block copolymer mixture containing an M-A type diblock copolymer and a M-A-M type triblock copolymer, and a phthalate ester plasticizer. And is characterized by adjusting the physical properties of the adhesive film. The proportion of the butyl acrylate polymer block (A) in the M-A type diblock copolymer and the M-A-M type triblock copolymer, the M-A-M type triblock copolymer in the block copolymer mixture By adjusting the proportion of the polymer and the blending amount of the phthalate ester plasticizer, it shows appropriate adhesiveness to the adherend, and pollutants such as glue residue during processing such as cutting It is possible to form an adhesive film that does not generate any. Hereinafter, the adhesive film of the present invention will be described in the order of the substrate, the adhesive layer, and the release layer.

[Base material]
The substrate is not particularly limited as long as it has necessary strength and flexibility, and a synthetic resin film is generally used. As the material of the synthetic resin film, polyester resin, polypropylene resin, poly (4-methyl-pentene-1) resin, ethylene-vinyl acetate copolymer, ethylene-propylene copolymer, polyvinyl chloride resin, Vinyl chloride-vinyl acetate copolymer, polyvinylidene chloride resin, fluorine resin, polystyrene resin, poly (meth) acrylic resin, polyvinyl butyral resin, polyacrylonitrile resin, cellulose acetate resin, polycarbonate resin, Known resins such as polyamide resins, polyester resins, polyvinyl alcohol resins, polyphenylene sulfide resins, polyether ether ketone resins, para aramid resins, polyurethane resins and the like can be mentioned. In the present invention, among these, it is particularly preferable to use a polyester-based resin from the viewpoint of chemical resistance such as rigidity, extensibility, dimensional stability, flexibility, and stackability.

  Examples of the polyester-based resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, polytetramethylene terephthalate, etc. Among them, from the viewpoint of ease of handling, low cost, etc. Polyethylene terephthalate is particularly preferred.

  Although the thickness of a base material is not specifically limited, Preferably it is 12-188 micrometers, More preferably, it is 25-100 micrometers. If it is the said range, since the form of an adhesive film can be maintained, workability | operativity, such as sticking and peeling of an adhesive film, will become favorable.

[Adhesive layer]
The pressure-sensitive adhesive layer forming the pressure-sensitive adhesive film of the present invention contains a block copolymer mixture and a phthalate ester plasticizer. Then, the block copolymer mixture is composed of an M-A type diblock copolymer comprising a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A), and an MAM type triblock copolymer. Including polymers. The block copolymer mixture comprises an MA type diblock copolymer in which the proportion of the butyl acrylate polymer block (A) is 90 to 95% by mass, preferably 90 to 94% by mass, and the acrylic copolymer. An butyl polymer block (A) occupying a ratio of 72 to 80% by mass, preferably 75 to 80% by mass, M-A-M type triblock copolymer, and the block copolymer mixture The proportion of the triblock copolymer in is 30 to 90% by mass, preferably 50 to 90% by mass. The proportion of the butyl acrylate polymer block (A) occupying the MA range diblock copolymer and the MAM type triblock copolymer in the above range, and the triblock in the block copolymer mixture If the proportion of the block copolymer is in the above range, by adjusting the blending ratio with the phthalate ester plasticizer described later, it shows appropriate adhesion to the adherend, During processing, an adhesive film that does not generate contaminants such as glue residue derived from the adhesive film can be formed. Since the use of such an adhesive film does not cause contamination of products and devices, it leads to improvement in workability and productivity.

  The mass average molecular weight (measured by GPC) of the MA diblock copolymer is 10,000 to 100,000, preferably 80,000 to 100,000. If it is the said range, cohesion force sufficient as an adhesive layer is shown. Although it does not specifically limit as a diblock copolymer which satisfy | fills the said mass average molecular weight and the ratio for which the said butyl acrylate polymer block (A) accounts, Specifically, for example, the product of LA1114 (made by Kuraray) What is marketed by name can be used conveniently.

  The mass average molecular weight (measured by GPC) of the MAM type triblock copolymer is 10,000 to 100,000, preferably 45,000 to 100,000. If it is the said range, cohesion force sufficient as an adhesive layer is shown. The triblock copolymer satisfying the mass average molecular weight and the proportion of the butyl acrylate polymer block (A) is not particularly limited, and specifically, for example, LA2140e (manufactured by Kuraray Co., Ltd.). What is marketed with the brand name of) can be used conveniently.

  Examples of the phthalate ester plasticizer included in the pressure-sensitive adhesive layer include di-2-ethylhexyl phthalate (DOP), dimethyl phthalate (DMP), diethyl phthalate (DEP), dibutyl phthalate (DBP), and phthalate. Heptylnonyl acid (HNP), di-n-octyl phthalate (DNOP), di-i-octyl phthalate (DCapP), di-i-decyl phthalate (DIDP), ditridecyl phthalate (DTDP), dicyclohexyl phthalate ( DCHP), butyl benzyl phthalate (BDP), ethyl phthalyl ethyl glycolate (EPEG), butyl phthalyl butyl glycolate (BPBG) and the like, and one or more of these may be used in combination. In the present invention, among these, di-2-ethylhexyl phthalate (DOP) is preferably used from the viewpoint of versatility.

  The compounding quantity of a phthalate ester plasticizer is 0-60 mass parts with respect to 100 mass parts of block copolymer mixtures, it is preferable that it is 15-60 mass parts, and it is 15-40 mass parts. More preferred. In addition, when using 2 or more types together, the compounding quantity as a whole is meant. If it is the said range, an adhesive film which shows moderate adhesiveness with respect to a to-be-adhered body, and does not generate | occur | produce contaminants, such as glue residue derived from an adhesive film, in the process of cutting etc. can be formed. . Moreover, if the compounding quantity of a phthalate ester plasticizer is the range of 15-60 mass parts with respect to 100 mass parts of block copolymer mixtures, an adhesive film with favorable peelability can be formed. The mass average molecular weight (measured by GPC) of the phthalate ester plasticizer is 300 to 1000, and preferably 300 to 700. If it is the said range, the solubility to an adhesive solution is favorable.

  In addition, various additives such as a metal chelating agent, a surfactant, an antioxidant, a tackifier, an ultraviolet absorber, a pigment, and a dye can be blended as necessary without departing from the object of the present invention. .

  Although it does not specifically limit as a formation method of an adhesive layer, For example, the method by printing, coating, etc. are mentioned. The thickness of the pressure-sensitive adhesive layer can be appropriately selected within a range that does not impair the adhesiveness to the sticking surface of the adherend in consideration of the state and shape of the sticking surface of the adherend, and is usually 10 to 60 μm. The thickness is preferably 20 to 50 μm. If it is the said range, the adhesive film which shows moderate adhesiveness with respect to a to-be-bonded body can be formed.

[Peeling layer]
A peeling layer consists of a peeling member which has the peelability laminated | stacked on the adhesive layer, and has a function which protects the surface of an adhesive layer. The release member is not particularly limited as long as it has necessary strength and flexibility, and a synthetic resin film subjected to silicone release treatment is generally used. As a material of the synthetic resin film, for example, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, polytetramethylene terephthalate are preferable. The thickness of the release layer is not particularly limited, but is preferably 25 to 125 μm.

  In the pressure-sensitive adhesive film of the present invention, a pressure-sensitive adhesive (hereinafter referred to as pressure-sensitive adhesive solution) dissolved in an organic solvent is applied to a substrate and dried to form a pressure-sensitive adhesive layer having a desired thickness. Can be manufactured. The organic solvent is not particularly limited, and examples thereof include toluene, methyl ethyl ketone, ethyl acetate, methyl isobutyl ketone (MIBK), butyl acetate, acetone, and a mixed solution thereof. As a method of applying the adhesive solution to the substrate, conventionally known methods such as a roll coating method, a gravure coating method, a micro gravure coating method, a reverse coating method, a roll brush method, a spray coating method, an air knife coating method, impregnation Method, curtain coating method, die coating method, doctor blade method, comma coating method and the like. Although the drying conditions of the applied adhesive are not specifically limited, Usually, it dries for 30 seconds-3 minutes in the temperature range of 40-120 degreeC. Although the thickness of the adhesive film of this invention can be suitably selected according to the objective, Usually, it is 47-373 micrometers.

  The pressure-sensitive adhesive film of the present invention is measured under 180 ° peel test conditions (in accordance with “JIS Z0237”) with a peel speed of 300 mm / min, a peel distance of 150 mm, and a test specimen width of 20 mm, and is 0.5 hours after being attached to an adherend. The peel strength after the lapse is preferably 0.01 to 1.00 N / 20 mm, and more preferably 0.10 to 1.00 N / 20 mm. If it is the said range, it adhere | attaches favorably with respect to a to-be-adhered body, and can peel easily, without damaging an to-be-adhered body in the case of peeling removal.

  The sticking target of the adhesive film of the present invention is not particularly limited. For example, an antireflection film, an antiglare film, a polarizing plate, an optical film such as an electromagnetic wave shield, a metal plate such as copper or iron, Examples thereof include a metal film, a film in which a metal oxide is formed on the surface and inside, glass, a film in which a silicon oxide is formed on the surface and inside, and a semiconductor wafer. Since the adhesive film of the present invention does not generate contaminants such as glue residue even after processing such as cutting, a slight amount of contaminants may cause contamination of the device or product, resulting in workability and productivity. This is particularly effective when the semiconductor wafer is used in a production line that can cause a significant decrease in the thickness of the semiconductor wafer.

  The pressure-sensitive adhesive film of the present invention may be used for protecting the silicon oxide film surface. The silicon oxide film refers to a silicon wafer having a silicon dioxide film formed on the surface thereof, and is an object to be adhered, which is inferior in adhesiveness and adhesiveness of an adhesive film as compared to a normal wafer. Since the silicon wafer is very thin, if the adhesiveness is high, the silicon wafer is damaged when the adhesive film is peeled off. Therefore, when it is used for protecting the silicon oxide film surface, it is measured by applying 180 ° peel test conditions (in accordance with “JIS Z0237”) with a peel rate of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm. The peel strength after 5 hours is preferably 0.10 to 1.00 N / 20 mm, more preferably 0.10 to 0.75 N / 20 mm, and still more preferably 0.20 to 0.75 N. / 20 mm. If it is the said range, an adhesive film will show favorable adhesiveness and adhesiveness with respect to a silicon oxide film surface, and can peel, without damaging a wafer.

  The pressure-sensitive adhesive film of the present invention may be laminated with other layers such as a printing layer as long as the effects of the present invention are not impaired.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not limited to these Examples.

[material]
<Diblock polymer>
LA1114 (manufactured by Kuraray Co., Ltd.): 90 to 95% by mass of butyl acrylate polymer block (A), solid content of 100%, molecular weight of about 85,000
<Triblock polymer>
LA2140e (manufactured by Kuraray Co., Ltd.): The proportion of butyl acrylate polymer block (A) is 72 to 80% by mass, the solid content is 100%, and the molecular weight is about 80,000.
<Phthalate ester plasticizer>
Di-2-ethylhexyl phthalate (DOP) (manufactured by J-Plus): molecular weight 390.6
<Acrylic adhesive of butyl acrylate (BA) -acrylonitrile (AN) copolymer>
SK Dyne AG790 (manufactured by Soken Chemical): 23% solid content
<Acrylic adhesive of butyl acrylate (BA) -2 ethylhexyl acrylate (2EHA) copolymer>
ATR340 (manufactured by Seiden Chemical Co., Ltd.): Solid content 42%
<Isocyanate-based crosslinking agent>
L-45 (manufactured by Soken Chemical): Solid content 45%
K200 (manufactured by Seiden Chemical): 100% solid content
<Aluminum metal chelating agent>
M2 (manufactured by Seiden Chemical): 5% solid content

[Method of forming adhesive film]
<Production Example 1> Comparative Examples 1 to 22 and Examples 1 to 56
Using the applicator, the compositions shown in Tables 1 to 3 so that the film thickness after drying on the corona-treated surface of the substrate (PET film, trade name “S105”, film thickness 50 μm, manufactured by Toray Industries, Inc.) is 40 μm. The pressure-sensitive adhesive solution was applied to form a pressure-sensitive adhesive layer. Next, the diluted solvent in the pressure-sensitive adhesive layer was volatilized in an oven (90 ° C., 1 minute), and a release layer (PET separator film, trade name “0010BD”, film thickness 50 μm, Fujimori on the coated surface of the pressure-sensitive adhesive layer after drying. The release treatment surface of Kogyo Co., Ltd. was laminated to form an adhesive film.

<Production Example 2> Comparative Examples 23 to 32
Compositions shown in Tables 4 and 5 using an applicator so that the film thickness after drying on the corona-treated surface of the substrate (PET film, trade name “S105”, film thickness 50 μm, manufactured by Toray Industries, Inc.) is 40 μm. The pressure-sensitive adhesive solution was applied to form a pressure-sensitive adhesive layer. Next, the diluted solvent in the pressure-sensitive adhesive layer was volatilized in an oven (90 ° C., 1 minute), and a release layer (PET separator film, trade name “0010BD”, film thickness 50 μm, Fujimori on the coated surface of the pressure-sensitive adhesive layer after drying. The peel-treated surface of Kogyo Co., Ltd. was laminated and subjected to an aging treatment at 40 ° C. for 3 days to form an adhesive film.

  About each adhesive film formed by the said method, the following items were evaluated. The results are shown in Table 1 (Comparative Examples 1 to 6), Table 2 (Examples 1 to 32), Table 3 (Examples 33 to 56, Comparative Examples 7 to 22), Table 4 (Comparative Examples 23 to 28), and Tables. 5 (Comparative Examples 29 to 32).

[Peel strength]
The adhesive film was cut into a width of 20 mm to prepare a test piece. A CVD oxide film is formed on the surface of the single crystal silicon wafer by the CZ method on the test piece in a CVD furnace under the conditions: target: 20 mm, atmosphere: helium gas base, monosilane, oxygen gas, temperature: 400 ° C., holding time: 15 seconds The surface of the oxide film was laminated using a 2 kg roller, and allowed to stand at normal humidity and room temperature for 0.5 hour. Then, using a tensile tester (RTF-1150-H), the peel strength at normal temperature and normal temperature was measured (speed: 300 mm / min, peel distance: 150 mm, peel angle: 180 °) (based on JIS Z0237) ).

[Confirmation of glue residue after Gakushin friction test]
The presence or absence of occurrence of adhesive residue (width of 1 mm or more) derived from the adhesive after the Gakushin friction test (JIS L0849 compliant) was confirmed. AB-301 Gakushin type friction fastness tester (manufactured by Tester Sangyo) conforming to JIS L0849 was used for the test apparatus, and the size of the test piece of the adhesive film was 3 cm × 22 cm. Cover the tip of the friction piece with JIS L0803 JIS dyeing fastness test cotton (made by the Japanese Standards Association) and fix it on the test stand (surface radius: 200 mm, shape: kamaboko plate type) with a load of 200 g. The test piece was rubbed 20 times between 22 cm at a reciprocating speed of 30 times per minute, and then the presence or absence of glue residue on the test piece was confirmed. The confirmation was performed visually and with an optical microscope (VHX-600, manufactured by Keyence Corporation, magnification 100).

  From the measurement results of the peel strength against wafer and the generation of glue residue shown in Tables 1 to 5, the acrylic adhesive that is commonly used as the adhesive for the protective adhesive film is an adhesive film in which a large amount of glue residue is generated. It was confirmed that it was formed (Comparative Examples 23 to 32). The pressure-sensitive adhesive film using the diblock copolymer LA1114 as the pressure-sensitive adhesive caused cohesive failure of the pressure-sensitive adhesive layer when the release layer was peeled off (Comparative Examples 1 to 6). On the other hand, the proportion of the diblock copolymer LA1114 in which the butyl acrylate polymer block (A) occupies 90 to 95% by mass and the ratio of the butyl acrylate polymer block (A) to 72 to 80% by mass By adjusting the blending ratio of the triblock copolymer LA2140e and DOP, which is a phthalate ester plasticizer, it showed good adhesion to the object and severe friction was performed. As a result, it was confirmed that a protective adhesive film free from adhesive residue derived from the adhesive film can be formed (Examples 1 to 56, Comparative Examples 7 to 22).

Claims (4)

In the adhesive film in which the adhesive layer and the release layer are sequentially formed on the substrate,
The pressure-sensitive adhesive layer comprises a M-A diblock copolymer having a mass average molecular weight of 10,000 to 100,000 and a mass comprising a methyl methacrylate polymer block (M) and a butyl acrylate polymer block (A). A block copolymer mixture containing an MAM type triblock copolymer having an average molecular weight of 10,000 to 100,000, and a phthalate ester plasticizer having a mass average molecular weight of 300 to 1000,
The block copolymer mixture is composed of a diblock copolymer in which the proportion of the butyl acrylate polymer block (A) is 90 to 95% by mass and the proportion of the butyl acrylate polymer block (A). A triblock copolymer that is 72-80% by weight,
The proportion of the triblock copolymer in the block copolymer mixture is 30 to 90% by mass,
A protective pressure-sensitive adhesive film comprising 0 to 60 parts by mass of the phthalate ester plasticizer per 100 parts by mass of the block copolymer mixture.   The protective adhesive film according to claim 1, wherein the phthalate ester plasticizer is blended in an amount of 15 to 60 parts by mass with respect to 100 parts by mass of the block copolymer mixture.   The peel strength measured after a 180 ° peel test (based on JIS Z0237) with a peel speed of 300 mm / min, a peel distance of 150 mm, and a specimen width of 20 mm is 0.01 to It is 1.00N / 20mm, The adhesive film for protection of Claim 1 or 2 characterized by the above-mentioned.   The protective adhesive film according to claim 1, which is for protecting a silicon oxide film surface.