JP2006282911A - Pressure sensitive adhesive composition and adhesive tape - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pressure sensitive adhesive composition suitable to a mold releasing molding made from a UV ray curable type molding material. <P>SOLUTION: The pressure sensitive adhesive composition is curable by UV ray irradiation and contains a (meth)acrylic oligomer having a hydrogenated polybutadiene or hydrogenated polyisoprene skeleton and a photoinitiator and the one cured after UV ray irradiation shows a glass transition temperature (Tg) of -60°C to -20°C, an elastic modulus of 0.3-2.0 MPa at 25°C and an SP value of 17.0-19.0 [MJ/m<SP>3</SP>]<SP>1/2</SP>. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an adhesive composition and an adhesive tape.

  In the manufacture of semiconductor devices and other electronic devices or in other technical fields, UV curable resins are widely used because they are versatile, inexpensive, easy to handle, and have excellent cured properties. . For example, patent document 1 is disclosing the ultraviolet curable coating material which can be used as a wiring material in the wiring board of an electronic device. This ultraviolet curable coating material is a fat having an acryloyl or methacryloyl group as a functional group in 100 parts by weight of 1,2-polybutadiene homopolymer obtained by modifying both ends with acrylic (methacrylic) and hydrogenating unsaturated double bonds. It is characterized by blending 20 to 100 parts by weight of a cyclic monomer and a photoinitiator. Specific examples of the alicyclic monomer having an acryloyl or methacryloyl group include cyclohexyl (meth) acrylate and isobornyl (meth) acrylate.

  Patent Document 2 discloses an ultraviolet curable resin composition that can be used as a coating material, an adhesive, a paint, and the like for plastic films such as metal, glass, and polyester films. The ultraviolet curable resin composition comprises (A) a urethane acrylate resin obtained by reacting a hydrogenated polybutadiene polyol, a polyisocyanate and a hydroxyalkyl acrylate, and (B) an aliphatic or alicyclic acrylate having 6 or more carbon atoms. It is characterized by comprising. The urethane acrylate resin (A) has a Tg of −45 to 70 ° C. However, if an adhesive tape is formed using these ultraviolet curable resin compositions, the molded product may be released by casting and curing the ultraviolet curable molding material on the adhesive tape. It becomes very difficult.

JP-A-6-198114 (Claims, paragraphs 0001, 0007) JP 2002-69368 A (Claims, paragraphs 0003, 0014, 0029)

An object of the present invention is to provide a pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape particularly suitable for releasing a molded product produced from an ultraviolet curable molding material.
This and other objects of the invention will be readily understood from the following detailed description.

In one aspect of the present invention,
It can be cured by UV irradiation,
The following ingredients:
A hydrogenated polybutadiene or (meth) acryl oligomer having a hydrogenated polyisoprene skeleton, and a photoinitiator, and after curing by ultraviolet irradiation, the following characteristics:
Glass transition temperature (Tg) −60 to −20 ° C.,
Elastic modulus at 25 ° C. 0.3 to 2.0 MPa, and SP value 17.0 to 19.0 [MJ / m ³ ] ^1/2
It exists in the ultraviolet curable adhesive composition which has removability characterized by showing.

  In another aspect of the present invention, the pressure-sensitive adhesive comprises a pressure-sensitive adhesive layer containing the ultraviolet curable pressure-sensitive adhesive composition of the present invention and a base material supporting the pressure-sensitive adhesive layer. On tape.

  According to the present invention, as will be understood from the following detailed description, there is provided a pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape capable of easily releasing a molded product after obtaining the molded product from an ultraviolet curable molding material. can get. Therefore, the versatility, low price, excellent handling, etc., which are the original characteristics of the ultraviolet curable molding material, can be advantageously utilized.

  In addition, according to the present invention, the pressure-sensitive adhesive composition and pressure-sensitive adhesive tape of the present invention make use of its excellent releasability and various techniques including the manufacture of electronic devices and optical parts such as plastic lenses. It can be advantageously used in the field. In particular, the pressure-sensitive adhesive tape of the present invention is used as a temporary fixing carrier for semiconductor chips, capacitors and other electronic components in the manufacture of various electronic devices, or as a pressure-sensitive adhesive tape for sealing when manufacturing plastic lenses and the like by the tape molding method. , Each can be advantageously used.

  The present invention resides in an ultraviolet curable pressure-sensitive adhesive composition and a pressure-sensitive adhesive tape having removability, and can be advantageously implemented in various forms. Hereinafter, preferred embodiments of the present invention will be described.

The pressure-sensitive adhesive composition according to the present invention is of a type that is cured by ultraviolet irradiation, and at least as a component thereof,
A hydrogenated polybutadiene or (meth) acryl oligomer having a hydrogenated polyisoprene skeleton (as an ultraviolet curable component) and a photoinitiator are included. Furthermore, the ultraviolet curable pressure-sensitive adhesive composition of the present invention has the following characteristics after being cured by ultraviolet irradiation, that is, when it is in the state of an ultraviolet cured product:
Glass transition temperature (Tg): −60 to −20 ° C.
Elastic modulus at 25 ° C .: 0.3 to 2.0 MPa, and SP value: 17.0 to 19.0 [MJ / m ³ ] ^1/2
It is characterized by having. In addition, the ultraviolet curable adhesive composition of this invention can contain a dilutable (meth) acrylate monomer and another additive as needed.

In order to exhibit the desired removability in the pressure-sensitive adhesive layer when the pressure-sensitive adhesive composition is applied on a substrate and used as a pressure-sensitive adhesive tape, the present inventors The resin layer) and an ultraviolet curable molding material to be brought into contact with the pressure-sensitive adhesive layer, particularly a liquid (meth) acrylic ultraviolet curable molding resin, has a low affinity. Here, it is an effective means to compare and evaluate the affinity between resins by comparing solubility parameters (usually called “SP values”). Further, the SP value δ is expressed by the following equation, where ΔEv is the molar evaporation energy of the liquid and V is the molar volume:
SP value δ = (ΔEv / V) ^1/2
Can be defined by Furthermore, the SP value δ can be estimated only from the chemical structure according to the method of Fedors (RF Fedors, Polym. Eng. Sci., 14 (2), P. 147, 1974, Polymer Handbook, 4th Edition). , "Solubility Parameter Values" edited by J. Brandrup, EH Immergut and EA Grulke).

Generally, the affinity between resins tends to increase as the SP value of each resin is closer. Therefore, in order to develop removability between resins, it is necessary that the SP values be as far apart as possible. Incidentally, the SP value of the (meth) acrylic ultraviolet curable molding resin is in the range of 20.0 to 24.0 [MJ / m ³ ] ^1/2 .

  The present inventors have conducted intensive research to find a suitable main component (ultraviolet curable component) in relation to the SP value of the (meth) acrylic ultraviolet curable molding resin in the preparation of the ultraviolet curable pressure-sensitive adhesive composition. It was discovered that the use of a (meth) acryl oligomer having a hydrogenated polybutadiene skeleton or a hydrogenated polyisoprene skeleton is effective. Because the SP value of polybutadiene is 17.5 and the SP value of hydrogenated polyisoprene is 17.7, any (meth) acryl oligomer having any polymer backbone has its own SP value, In addition, since Tg is low (−30 ° C. or lower), the SP value of the resin derived from the pressure-sensitive adhesive composition after UV curing is adjusted to less than 19.0, and Tg is adjusted to the range of −60 to −20 ° C. It is because it is advantageous to. Furthermore, the polybutadiene and polyisoprene used as the skeleton are each preferably used as a hydrogenated product. This is because both the hydrogenated polybutadiene and the hydrogenated polyisoprene have SP values of 17.0. In the practice of the present invention, a urethane (meth) acrylate having a hydrogenated polybutadiene skeleton or a hydrogenated polyisoprene skeleton is also used as the main agent, although the SP value is higher than that in the case of the (meth) acryl oligomer. Can be used as an ingredient.

  Moreover, in the ultraviolet curable adhesive composition of this invention, a photoinitiator is used together for the ultraviolet curing of the above-mentioned main ingredient component. The photoinitiator which can be used here can select the optimal compound according to the hardening characteristic of an adhesive composition, and can mix | blend it with the optimal quantity. Examples of photoinitiators suitable for the practice of the present invention are not limited to those listed below, but include benzoin initiators such as benzyl, benzoin, benzoin alkyl ether, benzophenone, methyl orthobenzoyl methyl benzoate, Benzophenone initiators such as 4-benzoyl-4'-methyldiphenyl sulfide, 4-chlorobenzophenone and diethylaminobenzophenone, thioxanthone initiators such as isopropylthioxanthone and diethylthioxanthone, 2,2-dimethoxy-1,2-diphenylethane Ketal initiators such as 1-one, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-2-methyl-1-phenylpropan-1-one, 1- [4- (2-hydroxyethoxy) phenyl] -2- Hydro Hydroxyalkylphenone initiators such as cis-2-methyl-1-propan-1-one, aminoalkyls such as 2-methyl-1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one Phenone initiators, acylphosphine oxide initiators such as 2,4,6-trimethylbenzoyldiphenylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide, anthraquinone initiators such as 2-alkylanthraquinone Includes agents. The blending amount of these photoinitiators can be changed in a wide range depending on the kind of the main ingredient component and the curing conditions, but is usually about 0.01 to 5% by weight based on the total amount of the pressure-sensitive adhesive composition. % Range. If necessary, it can be blended outside this range.

Further, in the ultraviolet curable pressure-sensitive adhesive composition of the present invention, it is preferable to add a dilutable (meth) acrylate monomer as necessary in addition to the main component and the photoinitiator as described above. The dilutable (meth) acrylate monomer is used to dilute the above (meth) acryl oligomer and other main ingredient components to lower the viscosity. In practicing the present invention, various types of dilutable (meth) acrylate monomers can be used. In the resin derived from the pressure-sensitive adhesive composition after UV curing, the Tg is adjusted in the range of −60 to −20 ° C. In consideration of adjusting the SP value to a range of 17.0 to 19.0 [MJ / m ³ ] ^1/2 , it is recommended to use a (meth) acrylate monomer having a low SP value. Examples of low SP value (meth) acrylate monomers suitable for use include, for example, lauryl acrylate (SP value: 18.7), isostearyl acrylate (SP value: 17.3), 2-octyldodecanol acrylate (SP Value: 18.2). The compounding amount of the dilutable (meth) acrylate monomer is not limited as long as the object and effect of the present invention can be achieved, but is usually in the range of about 0 to 80% by weight based on the total amount of the pressure-sensitive adhesive composition.

As described above, in the ultraviolet curable pressure-sensitive adhesive composition of the present invention, the SP value of the resin derived from the pressure-sensitive adhesive composition after UV curing is in the range of 17.0 to 19.0 [MJ / m ³ ] ^1/2 . Adjust to. Here, when the SP value of the cured resin derived from the pressure-sensitive adhesive composition exceeds 19.0, the affinity with the (meth) acrylic ultraviolet curable molding resin increases, so that the adhesiveness increases, The peelability cannot be obtained. In addition, in the ultraviolet curable adhesive composition of this invention, since the structure containing the above main ingredients is employ | adopted, SP value less than 17.0 cannot be implement | achieved.

  Moreover, in the ultraviolet curable adhesive composition of this invention, Tg of resin derived from the adhesive composition after ultraviolet curing is adjusted in the range of -60 to -20 degreeC, and the elasticity modulus in 25 degreeC is 0.3. Adjust to the range of ~ 2.0 MPa. Here, if the Tg of the cured resin derived from the pressure-sensitive adhesive composition is less than −60 ° C. or the elastic modulus at 25 ° C. is less than 0.3 MPa, the cohesive force of the cured resin is reduced, so that the adhesive residue is Is caused. On the other hand, if the Tg of the cured resin exceeds −20 ° C. or the elastic modulus at 25 ° C. exceeds 2.0 MPa, the adhesiveness with the (meth) acrylic ultraviolet curable molding resin increases, and the removability is improved. You will not be able to get.

  The ultraviolet curable adhesive composition of the present invention is preferably used in the form of an adhesive tape. Although the pressure-sensitive adhesive tape can be provided in various forms, it usually comprises a pressure-sensitive adhesive layer containing the ultraviolet curable pressure-sensitive adhesive composition of the present invention and a base material supporting the pressure-sensitive adhesive layer. It is advantageous to configure. FIG. 1 is a cross-sectional view showing a typical example of such an adhesive tape. As shown in the figure, the pressure-sensitive adhesive tape 10 includes a pressure-sensitive adhesive layer 2 containing an ultraviolet curable pressure-sensitive adhesive composition and a film-like substrate 1 holding the same on one side. The substrate 1 is also called a backing film.

  The substrate can be formed from a variety of materials commonly used in the manufacture of adhesive tapes. Preferably, the substrate can be formed from a plastic material. Examples of plastic materials suitable for forming the substrate are not limited to those listed below, but are polystyrene, polyolefin, polyvinyl chloride (PVC), polyester, polyether, polyurethane, polyamide, fluorine-containing polymer. Etc. The substrate can also be made of a stretchable plastic film if necessary. This is because the work of separating electronic components and the like can be improved by stretching the base material.

  In the pressure-sensitive adhesive tape of the present invention, the thickness of the substrate can be changed over a wide range depending on the use of the pressure-sensitive adhesive tape. The thickness of the substrate is usually in the range of about 1 to 2,000 μm, preferably in the range of about 1 to 1,000 μm, and more preferably in the range of about 4 to 500 μm.

  The pressure-sensitive adhesive tape of the present invention is usually constituted by two layers of a base material and a pressure-sensitive adhesive layer, but if necessary, may have an additional layer generally used in the field of pressure-sensitive adhesive tapes. Otherwise, additional treatment such as surface treatment may be applied. In particular, in the case of the pressure-sensitive adhesive tape of the present invention, it is preferable to apply an antistatic treatment to an arbitrary part as described below. Further, as an additional layer, a release paper (also referred to as a release liner) in which the pressure-sensitive adhesive layer is covered for protection can be exemplified.

  Although the pressure-sensitive adhesive tape of the present invention can be formed using various techniques, it is generally formed by applying and curing the ultraviolet curable pressure-sensitive adhesive composition of the present invention on the surface of a substrate. be able to. For the application of the pressure-sensitive adhesive composition, a conventional coating method such as curtain coating or screen printing can be used. If necessary, the ultraviolet curable pressure-sensitive adhesive composition may be diluted with a solvent. In that case, the solvent is removed by drying before curing after coating. Here, as the solvent, for example, ethyl acetate, methyl ethyl ketone, toluene, heptane and the like can be used. Moreover, you may use methods other than the coating method. In the pressure-sensitive adhesive tape of the present invention, the thickness of the pressure-sensitive adhesive layer can be changed over a wide range depending on the usage of the pressure-sensitive adhesive tape. The thickness of the pressure-sensitive adhesive layer is usually in the range of about 1 to 500 μm, preferably in the range of about 1 to 300 μm, and more preferably in the range of about 1 to 100 μm.

The ultraviolet curable pressure-sensitive adhesive composition of the present invention uses, for example, a light source having a wavelength of about 150 to 450 nm, such as a high-pressure mercury lamp, a metal halide lamp, a cequinone lamp, and the like, to emit light from such a light source. Polymerization and curing can be achieved by irradiation for a predetermined time. The amount of light irradiation is usually about 100 to 5,000 mJ / cm ² .

  The pressure-sensitive adhesive tape of the present invention is preferably further subjected to antistatic treatment. The antistatic treatment can be performed by various methods. For example, the antistatic treatment can be performed at the stage of preparing the ultraviolet curable pressure-sensitive adhesive composition as described above. Specifically, it is advantageous to mix an antistatic agent in the ultraviolet curable pressure-sensitive adhesive composition. Suitable antistatic agents include, for example, nonionic antistatic agents such as polyoxyethylene alkyl ether and polyoxyethylene alkylamine, cationic antistatic agents such as lauryltrimethylammonium chloride, and amphoteric antistatic agents such as lauryl. Other antistatic agents such as betaine, such as lithium bis (pentafluoroethanesulfone) imide, can be used. By ensuring the antistatic property in addition to the removability, the range of use of the pressure-sensitive adhesive tape of the present invention is further expanded.

  According to another method, the antistatic treatment can be applied to the base material used for the construction of the adhesive tape. For example, an antistatic agent may be applied to the surface of the base material, or a base material provided with an antistatic film such as an aluminum vapor deposition film may be used.

  The pressure-sensitive adhesive tape according to the present invention can be advantageously used in various technical fields by utilizing its excellent characteristics. The pressure-sensitive adhesive tape of the present invention can be advantageously used, for example, as a temporary fixing carrier, for example, as a temporary fixing carrier for electronic components in the manufacture of various electronic devices. For example, when mass-producing electronic parts such as semiconductor chips and chip capacitors, the adhesive tape of the present invention is used together, and the electronic parts are temporarily fixed on the adhesive tape and then dicing or die bonding is performed. Thereafter, the individual electronic components can be taken out arbitrarily, so that the productivity and handling of the electronic components can be remarkably improved. Further, when used for manufacturing an electronic device or the like in this way, it is preferable that the adhesive tape is subjected to an antistatic treatment as described above.

  The use as described above will be described in more detail. As is well known, integrated circuits (ICs), large-scale integrated circuits (LSIs), and other semiconductor devices are manufactured through various processes. To describe a part of the manufacturing process of a semiconductor device, an IC, an LSI, or the like is formed on a semiconductor wafer such as silicon by a lithography technique or an etching technique, and then the semiconductor wafer is cut into a desired size. This cutting process is called dicing, and a large number of semiconductor elements having integrated circuits or the like (hereinafter also referred to as “semiconductor chips” or simply “chips”) are obtained in a lump.

  In general, in dicing, a semiconductor wafer such as a silicon wafer is fixed by an adhesive tape (in particular, sometimes referred to as “dicing tape”). This is because the individual semiconductor chips separated during dicing are not separated. Therefore, the dicing tape needs to have sufficient adhesive force or adhesive force to hold the semiconductor chip stably. On the other hand, after dicing, the used dicing tape is required to exhibit reduced adhesive strength or adhesive strength. This is because if the chip can be peeled off from the dicing tape due to such a decrease in the adhesive force, the chip can be easily taken out and incorporated into the package using a pickup rod in a subsequent packaging step. Since the pressure-sensitive adhesive tape of the present invention has excellent removability, it is suitable for such applications.

FIG. 2 is a cross-sectional view illustrating the method of using the adhesive tape of the present invention as a carrier for temporarily fixing electronic components.
First, as shown in FIG. 2A, the adhesive tape 10 of the present invention is fixed to a dicing apparatus (not shown) with the adhesive layer 2 facing upward, and a semiconductor wafer is further mounted thereon. In the drawing, a state after dicing a semiconductor wafer using a dicing saw to form an assembly of a plurality of chips (also referred to as “semiconductor chips”) 22 is shown.

  Subsequently, as shown in FIG. 2B, the semiconductor chip 22 is picked up using a vacuum suction device 28, for example. Since the adhesive layer 2 has excellent removability, the semiconductor chip 22 can be easily separated from the adhesive tape without causing breakage or damage to the chip. Although not shown, the separated semiconductor chip 22 can be mounted, for example, on a die pad portion of a circuit board to complete a target semiconductor device.

  Moreover, the adhesive tape of this invention can be advantageously used as an adhesive tape for sealing. For example, the pressure-sensitive adhesive tape of the present invention can be advantageously used as a pressure-sensitive adhesive tape for sealing when a plastic lens or other optical component is produced by a tape molding method. For example, when a plastic lens having excellent optical performance is produced by a casting polymerization method, the adhesive tape of the present invention is used to temporarily fix a set of molding dies and form a cavity for molding material casting. This is because it is very effective and excellent in workability.

FIG. 3 is a cross-sectional view illustrating the method of using the pressure-sensitive adhesive tape of the present invention as a sealing pressure-sensitive adhesive tape in order when manufacturing a plastic lens by a tape molding method.
First, as shown in FIG. 3A, a lens casting polymerization mold is assembled from two glass molds 11 and 12. After the two glass molds 11 and 12 are arranged to face each other at a predetermined interval, the adhesive tape 10 of the present invention is wound around the side surfaces of the molds, and the gap between the molds 11 and 12 is sealed with the adhesive tape 10. Stop. The adhesive tape 10 is preferably wound so as to surround the mold more than one round. As a result, the molds 11 and 12 are fixed with the adhesive tape 10, and the lens casting polymerization mold having the cavity 13 for molding the lens surrounded by the two molds 11 and 12 and the adhesive tape 10 is completed.

  Next, as shown in FIG. 3 (B), the adhesive tape 10 is peeled off until there is a gap in which the raw material composition 14 can be injected into the cavity 13, and the raw material composition (molding material) 14 is put into the cavity 13 from this gap. The gap is sealed with the adhesive tape 10 again. The raw material composition may be, for example, a photocurable type such as an ultraviolet curable type, or may be a thermosetting type. In practicing the present invention, an ultraviolet curable molding material can be advantageously used in consideration of versatility, low cost, and excellent handleability.

After the injection of the raw material composition is completed, as shown in FIG. 3C, the raw material composition 14 in the cavity 13 is polymerized and cured by, for example, ultraviolet irradiation or heating according to the curing conditions of the composition. For example, when an ultraviolet curable molding material is used as the raw material composition 14, a light source having a wavelength of about 150 to 450 nm, for example, a high pressure mercury lamp, a metal halide lamp, a xenon lamp or the like is used. Polymerization and curing can be achieved by irradiating light from a simple light source for a predetermined time. The amount of light irradiation is usually about 100 to 3000 mJ / cm ² . As shown in the drawing, a plastic lens 15 having a desired shape is obtained. Thereafter, the adhesive tape 10 is peeled off. Since the pressure-sensitive adhesive tape 10 is excellent in removability, it can be easily peeled off from the molds 11 and 12 and no problems such as adhesive residue occur. Furthermore, when the molds 11 and 12 are separated, the intended plastic lens 15 can be finally obtained.

  In the case of manufacturing a plastic lens by the tape molding method, for example, Japanese Patent Publication No. 3-8246, Japanese Patent Publication No. 5-64564, Japanese Patent Publication No. 6-346034, Japanese Patent Application Laid-Open No. 11-99527, Japanese Patent Application Laid-Open No. 2002-2002. The method described in 691368 gazette etc. can also be used.

  Subsequently, the present invention will be described with reference to examples thereof. Needless to say, the present invention is not limited to these examples. In the following examples, various materials are used as starting materials, but the following abbreviations and the like mean the following starting materials.

SPBDA-S:
Hydrogenated polybutadiene diacrylate oligomer (molecular weight: 6,000, SP value: 17.3, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
SPBA-S:
Hydrogenated polybutadiene monoacrylate oligomer (molecular weight: 6,000, SP value: 17.2, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
BAC-45:
Polybutadiene diacrylate oligomer (molecular weight: 3,000, SP value: 17.8, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
LA:
Lauryl acrylate (molecular weight: 240, SP value: 18.7, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
V # 155:
Cyclohexyl acrylate (Viscoat ^TM # 155, molecular weight: 155, SP value: 20.6, manufactured by Osaka Organic Chemical Industry Co., Ltd.)
A-HPI:
Hydrogenated polyisoprene acrylate oligomer (molecular weight: 3,000, SP value: 17.3, manufactured by Shin-Nakamura Chemical Co., Ltd.)
S-1800A:
Isostearyl acrylate (NK Ester ^™ S-1800A, molecular weight: 324, SP value: 17.3, manufactured by Shin-Nakamura Chemical Co., Ltd.)
ISA:
2-octyldodecanol acrylate (NK Ester ^™ ISA, molecular weight: 324, SP value: 18.2, Shin-Nakamura Chemical Co., Ltd.)
TEA-1000:
Polybutadiene urethane diacrylate (Molecular weight: 3,000, SP value: 18.9, manufactured by Nippon Soda Co., Ltd.)
TEAI-1000:
Hydrogenated polybutadiene urethane diacrylate (Molecular weight: 3,000, SP value: 18.5, manufactured by Nippon Soda Formula Company)
1,9-NDA:
1,9-nonanediol diacrylate (Light Acrylate ^™ 1,9-ND-A, molecular weight: 268, SP value: 21.3, manufactured by Kyoeisha Chemical Company)
IB-XA:
Isobornyl acrylate (Light Acrylate ^™ IB-XA, molecular weight: 208, SP value: 18.9, manufactured by Kyoeisha Chemical Company)
C20701:
Hydrogenated polyisoprene urethane diacrylate (molecular weight: 3,000, SP value: 18.2) and lauryl acrylate 85:15 wt% mixture (EY RESIN C20701, manufactured by Light Chemical Industries)
D-1173:
2-Hydroxy-2-methyl-1-phenylpropan-1-one (Darocur ^™ 1173, manufactured by Ciba Geigy Corporation)
Amiet ^™ 105:
Polyoxyethylene laurylamine (amine value: 136 to 156, HLB: 9.8, manufactured by Kao Corporation)
Fluorad ^™ L-13858:
Lithium bis (pentafluoroethanesulfonate) imide (manufactured by 3M)
LC-1213:
UV curable adhesive containing acrylic oligomer / phenoxyethyl acrylate / methacrylate derivative / photoinitiator (manufactured by 3M)

Example 1
The following components were mixed in the amounts shown below and summarized in Table 1 below to prepare a solution of the ultraviolet curable resin composition.

Hydrogenated polybutadiene diacrylate oligomer: SPBDA-S (molecular weight: 6,000, SP value: 17.3, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 90 parts by weight Diluent monomer: LA (lauryl acrylate, molecular weight: 240, SP value) : 18.7, Osaka Organic Chemical Co., Ltd.) 10 parts by weight Photoinitiator: Darocur ^TM 1173 (Ciba Geigy Co., Ltd.) 1 part by weight

The obtained ultraviolet curable resin composition solution was applied to one side of a 50 μm-thick corona discharge-treated PET film (product name “S”, manufactured by Unitika Ltd.) with a film thickness of 50 μm, and an additional 50 μm on the resin coating. A thick release-treated PET film (product name “A50”, manufactured by Teijin Limited) was laminated. Next, the obtained laminate was irradiated with 1,000 mJ / cm ² of ultraviolet rays from the side of the release-treated PET film. The ultraviolet irradiation device used in this example was UVC-183 (product name) manufactured by USHIO INC. Equipped with a high-pressure mercury lamp (160 W / cm) having a peak wavelength near 350 nm. The ultraviolet curable resin composition was cured by ultraviolet irradiation, and the intended ultraviolet curable removable adhesive tape was obtained.

[Measurement of adhesive tape properties]
About the ultraviolet curable resin composition and the ultraviolet curable removable adhesive tape produced as described above, (1) SP value, (2) glass transition temperature (Tg), (3) elastic modulus at 25 ° C, ( 4) JIS adhesive strength and (5) Removability to UV adhesive were measured according to the following procedure. The measurement results described below and summarized in Table 2 below were obtained.

(1) SP value When the SP value of the cured product of the ultraviolet curable resin composition was calculated by the method of Fedors, it was 17.4 (MJ / m ³ ) ^0.5 . For details of the Fedors method, see RF Fedors, Polym. Eng. Sci., 14 (2), P. 147, 1974 (supra).

(2) Glass transition temperature (Tg)
The glass transition temperature (Tg) of the ultraviolet curable resin composition was measured using a viscoelasticity measuring device ARES manufactured by Rheometrics Scientific. When the storage elastic modulus G ′ (Pa) and loss tangent tan δ were measured in a shear mode, a frequency of 1.0 rad / sec and a temperature range of −80 to 80 ° C., the temperature (Tg) showing the maximum tan δ was −47.1 ° C. Met.

(3) Elastic modulus at 25 ° C. Similar to the measurement of glass transition temperature (Tg), using a viscoelasticity measuring device ARES made by Rheometrics Scientific, shear mode, frequency 1.0 rad / sec and temperature 25 ° C. Was measured for storage elastic modulus G ′ (Pa), it was 0.9 MPa.

(4) JIS adhesive strength After removing the release-treated PET film from the UV curable removable adhesive tape, the adhesive strength of the exposed pressure-sensitive adhesive layer (referred to as JIS adhesive strength in the present invention) is defined in JIS Z0237. When measured at a peeling speed of 300 mm / min and a peeling angle of 180 °, the result was 0.020 N / 25 mm.

(5) Removability with respect to UV adhesive After removing the release-treated PET film from the UV curable removable adhesive tape, the (meth) acrylic UV curable adhesive (product name “ Light Cure Adhesive LC-1213 "(manufactured by 3M) is applied with a film thickness of 500μm, and a 38μm thick corona discharge-treated PET film (product name“ S ”, manufactured by Unitika Ltd.) is laminated on the adhesive layer. did. Next, the obtained laminate was irradiated with 200 mJ / cm ² of ultraviolet rays from the corona discharge-treated PET film side. The ultraviolet irradiation device used in this test was UVC-183 (product name) manufactured by USHIO INC. Equipped with a high-pressure mercury lamp (160 W / cm) having a peak wavelength near 350 nm. After the UV curable adhesive is cured by UV irradiation, the corona discharge-treated PET film is peeled from the UV curable removable adhesive tape, and the state of peeling at that time and the adhesive residue at the interface between the PET film and the adhesive tape are removed. The state was observed visually. In this example, it was observed that the removability was good and the adhesive residue was small.

Examples 2-4
The method described in Example 1 was repeated. In this example, the composition of the ultraviolet curable resin composition was changed as shown in Table 1 below.

  The SP value, glass transition temperature (Tg), elastic modulus at 25 ° C., JIS adhesive strength and removability to UV adhesive of the obtained ultraviolet curable removable pressure-sensitive adhesive tape were determined according to the procedure described in Example 1. As a result of the measurement, the measurement results summarized in Table 2 below were obtained. As can be understood from the obtained measurement results, good removability was obtained in any of the examples.

Comparative Example 1
The procedure described in Example 1 was repeated, but in this example, a commercially available ordinary removable acrylic for comparison with the ultraviolet curable resin composition described in Examples 1-4. A non-ultraviolet curable releasable pressure-sensitive adhesive tape was prepared using an adhesive.

100 parts by weight of acrylic solvent-based adhesive (product name “Olivein ^™ BPS-5978”, manufactured by Toyo Ink Manufacturing Co., Ltd.) and 9 parts by weight of aziridine-based crosslinking agent (product name “BXX-5134”, Toyo Ink Co., Ltd.) The resulting adhesive solution was applied to one side of a 50 μm thick corona discharge-treated PET film (product name “S”, manufactured by Unitika Ltd.) so that the film thickness after drying would be 50 μm. , Dried. A 50 μm-thick release-treated PET film (product name “A50”, manufactured by Teijin Ltd.) was further laminated on the pressure-sensitive adhesive layer on the PET film. It was 0.09 N / 25mm when the JIS adhesive force of the obtained releasable adhesive tape was measured according to the procedure of the said Example 1. FIG.

Moreover, in order to measure the removability of this pressure-sensitive adhesive tape with respect to the UV adhesive according to the procedure described in Example 1, the surface of the pressure-sensitive adhesive layer of the obtained removable pressure-sensitive adhesive tape was cured with (meth) acrylic ultraviolet light. An adhesive (product name “LC-1213”) was applied, and a corona discharge-treated PET film (product name “S”) was further laminated on the adhesive layer. After curing the UV curable adhesive by UV irradiation, an attempt was made to peel the corona discharge treated PET film from the releasable adhesive tape. In this example, the cured adhesive layer (LC-1213) and The interface of the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape was completely integrated, and both could not be peeled off. In the case of a normal removable acrylic pressure-sensitive adhesive, the SP value is in the range of 19.0 to 21.0 (MJ / m ³ ) ^0.5. It is considered that the cause is the high affinity with the resin.

Comparative Examples 2 and 3
Although the method described in Example 1 was repeated, in the case of this example, the composition of the ultraviolet curable resin composition was changed as shown in Table 1 below for comparison.

  The SP value, glass transition temperature (Tg), elastic modulus at 25 ° C., JIS adhesive strength and removability to UV adhesive of the obtained ultraviolet curable removable pressure-sensitive adhesive tape were determined according to the procedure described in Example 1. As a result of the measurement, the measurement results summarized in Table 2 below were obtained. In the case of this example, when the removability of the pressure-sensitive adhesive tape to the UV adhesive was measured, the corona discharge-treated PET film could be peeled off from the removable pressure-sensitive adhesive tape, but an adhesive residue was produced. Such adhesive residue is caused by a decrease in the cohesive force of the ultraviolet curable (meth) acrylic resin when the Tg is less than −60 ° C. or the elastic modulus is less than 0.3 MPa. It is considered that there is.

Comparative Examples 4-6
Although the method described in Example 1 was repeated, in the case of this example, the composition of the ultraviolet curable resin composition was changed as shown in Table 1 below for comparison.

  The SP value, glass transition temperature (Tg), elastic modulus at 25 ° C., JIS adhesive strength and removability to UV adhesive of the obtained ultraviolet curable removable pressure-sensitive adhesive tape were determined according to the procedure described in Example 1. As a result of the measurement, the measurement results summarized in Table 2 below were obtained. In the case of this example, when the removability of the pressure-sensitive adhesive tape to the UV adhesive is measured, the interface between the cured adhesive layer (LC-1213) and the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is completely integrated, and both are peeled off. I could not. Such a result is caused by an increase in adhesive strength with an ultraviolet curable (meth) acrylic resin when Tg exceeds -20 ° C or the elastic modulus exceeds 2.0 MPa. It is considered.

Example 5
In this example, an ultraviolet curable releasable pressure-sensitive adhesive tape subjected to an antistatic treatment was produced in order to prevent problems due to static electricity when the releasable pressure-sensitive adhesive tape was peeled off from the adherend.

After preparing an ultraviolet curable resin composition according to the method described in Example 1, an aluminum vapor-deposited PET film (product name “PET VPAL25”, manufactured by Asia Aluminum Co., Ltd.) having a thickness of 25 μm was used as a solution of the ultraviolet curable resin composition. A 50 μm thick release-treated PET film (product name “A50”, manufactured by Teijin Ltd.) was further laminated on the resin coating. Next, the obtained laminate was irradiated with 1,000 mJ / cm ² of ultraviolet rays from the side of the release-treated PET film. The ultraviolet curable resin composition was cured by ultraviolet irradiation, and the intended antistatic ultraviolet curable releasable pressure-sensitive adhesive tape was obtained.

  The antistatic UV curable releasable pressure-sensitive adhesive tape produced as described above was measured for JIS adhesive strength and removability to UV adhesive according to the procedure described in Example 1, and the following Table 3 was obtained. The measurement results summarized in Fig. 1 were obtained. In the case of this example, as in the case of Example 1, it was confirmed that the removability to the UV adhesive was good.

Next, when the peel charge (charge amount at the time of peel) of the releasable adhesive tape was measured, it was +1,250 V, and the effect of the antistatic treatment was recognized. The apparatus used for the measurement of the charge amount was a surface potential meter manufactured by Kansai Electronics Co., Ltd., product name “Monro Electronics Model 244”, Isoprove ^™ surface potential meter, 1017 small probe). In addition, as can be understood from the measurement results of the releasable pressure-sensitive adhesive tape not subjected to the antistatic treatment shown as a reference example in Table 3 below, the peeling charge becomes +3,000 V or more when the antistatic treatment is not performed. The generation of static electricity during peeling cannot be avoided.

Example 6
In this example, an ultraviolet curable releasable pressure-sensitive adhesive tape subjected to an antistatic treatment was produced in order to prevent problems due to static electricity when the releasable pressure-sensitive adhesive tape was peeled off from the adherend.

After preparing the ultraviolet curable resin composition according to the method described in Example 1, 0.5 parts by weight of an antistatic agent: polyoxyethylene laurylamine with respect to 100 parts by weight of the ultraviolet curable resin composition solution. (Product name “Amiet ^™ 105”, manufactured by Kao Corporation) was added. The obtained solution was applied to one side of a 50 μm-thick corona discharge-treated PET film according to the method described in Example 1, and a 50 μm-thick release-treated PET film was further laminated on the resin coating. Next, the obtained laminate was irradiated with 1,000 mJ / cm ² of ultraviolet rays from the side of the release-treated PET film. The ultraviolet curable resin composition was cured by ultraviolet irradiation, and the intended antistatic ultraviolet curable releasable pressure-sensitive adhesive tape was obtained.

The antistatic UV curable releasable pressure-sensitive adhesive tape produced as described above was measured for JIS adhesive strength and removability to UV adhesive according to the procedure described in Example 1, and the following Table 3 was obtained. The measurement results summarized in Fig. 1 were obtained. In the case of this example, as in the case of Example 1, it was confirmed that the removability to the UV adhesive was good.
Next, the peel charge of the releasable pressure-sensitive adhesive tape was measured according to the procedure described in Example 5. As a result, it was −20 V, and the effect of the antistatic treatment was recognized.

Example 7
In this example, an ultraviolet curable releasable pressure-sensitive adhesive tape subjected to an antistatic treatment was produced in order to prevent problems due to static electricity when the releasable pressure-sensitive adhesive tape was peeled off from the adherend.

After preparing the ultraviolet curable resin composition according to the method described in Example 1, 0.5 parts by weight of the antistatic agent solution: lithium bis (penta) with respect to 100 parts by weight of the ultraviolet curable resin composition solution. A 20% by weight propylene carbonate solution of fluoroethanesulfone) imide (product name “Fluorad ^™ L-13858”, 3M) was added. The obtained solution was applied to one side of a 50 μm-thick corona discharge-treated PET film according to the method described in Example 1, and a 50 μm-thick release-treated PET film was further laminated on the resin coating. Next, the obtained laminate was irradiated with 1,000 mJ / cm ² of ultraviolet rays from the side of the release-treated PET film. The ultraviolet curable resin composition was cured by ultraviolet irradiation, and the intended antistatic ultraviolet curable releasable pressure-sensitive adhesive tape was obtained.

The antistatic UV curable releasable pressure-sensitive adhesive tape produced as described above was measured for JIS adhesive strength and removability to UV adhesive according to the procedure described in Example 1, and the following Table 3 was obtained. The measurement results summarized in Fig. 1 were obtained. In the case of this example, as in the case of Example 1, it was confirmed that the removability to the UV adhesive was good.
Next, the peel charge of the releasable pressure-sensitive adhesive tape was measured by the procedure described in Example 5. As a result, it was +1,000 V, and the effect of the antistatic treatment was recognized.

Example 8
Although an ultraviolet curable removable adhesive tape subjected to antistatic treatment was prepared according to the method described in Example 7, in this example, the thickness of 25 μm used in Example 5 was used instead of the corona discharge treated PET film. The aluminum vapor-deposited PET film was used, and a solution of the ultraviolet curable resin composition was applied to the aluminum vapor-deposited surface.

The antistatic ultraviolet curable removable pressure-sensitive adhesive tape thus obtained was measured according to the procedure described in Example 1 for the JIS adhesive strength and the removability of the UV adhesive. The results are summarized in Table 3 below. Measurement results were obtained. In the case of this example, as in the case of Example 1, it was confirmed that the removability to the UV adhesive was good.
Next, when the peel charge of the releasable pressure-sensitive adhesive tape was measured by the procedure described in Example 5, it was +700 V, and the effect of the antistatic treatment was recognized.

It is sectional drawing which showed one preferable form of the adhesive tape by this invention. It is sectional drawing which showed the method of using the adhesive tape shown in FIG. 1 as a carrier for temporary fixation of a semiconductor chip. It is sectional drawing which showed the method of using the adhesive tape shown in FIG. 1 as an adhesive tape for sealing, when manufacturing a plastic lens by a tape molding method.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Base material 2 Adhesive layer 10 Adhesive tape 11 Molding die 12 Molding die 13 Cavity 14 Lens raw material 15 Plastic lens 22 Semiconductor chip 28 Vacuum suction apparatus

Claims (8)

It can be cured by UV irradiation,
The following ingredients:
A hydrogenated polybutadiene or (meth) acryl oligomer having a hydrogenated polyisoprene skeleton, and a photoinitiator, and after curing by ultraviolet irradiation, the following characteristics:
Glass transition temperature (Tg) −60 to −20 ° C.,
Elastic modulus at 25 ° C. 0.3 to 2.0 MPa, and SP value 17.0 to 19.0 [MJ / m ³ ] ^1/2
An ultraviolet curable pressure-sensitive adhesive composition having removability, wherein   The ultraviolet curable pressure-sensitive adhesive composition according to claim 1, further comprising a dilutable (meth) acrylate monomer.   A pressure-sensitive adhesive tape comprising a pressure-sensitive adhesive layer comprising the ultraviolet curable pressure-sensitive adhesive composition according to claim 1 and a base material supporting the pressure-sensitive adhesive layer.   The pressure-sensitive adhesive tape according to claim 3, wherein an antistatic treatment is applied.   The pressure-sensitive adhesive tape according to claim 4, wherein the base material is subjected to an antistatic treatment.   The pressure-sensitive adhesive tape according to claim 4, wherein the pressure-sensitive adhesive composition is subjected to an antistatic treatment.   The pressure-sensitive adhesive tape according to claim 3, wherein the pressure-sensitive adhesive tape is used as a temporary fixing carrier.   It is used as an adhesive tape for sealing, The adhesive tape of any one of Claims 3-6 characterized by the above-mentioned.

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