JP2013237732A - Energy ray-peelable adhesive composition, and adhesive tape - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an energy ray-peelable adhesive composition, whose initial adhesion to an adherend is high, whose adhesion is difficult to degrade even if the composition is exposed to high temperature, and that has an adhesion required for fixation and protection and can be peeled very easily when peeled even after exposed to the high temperature.SOLUTION: An energy ray-peelable adhesive composition 2 comprises: an acrylic polymer containing a copolymer which uses acrylonitrile as a monomer component; an energy ray-polymerizable compound; a thioxanthone-based polymerization initiator; and a crosslinking agent. The adhesive composition has an adsorption peak in a wavelength range of 330 to 410 nm.

Description

  The present invention relates to an energy ray easily peelable pressure-sensitive adhesive composition that can be easily peeled even with a small amount of energy beam irradiation, and a pressure sensitive adhesive tape having a pressure sensitive adhesive layer containing the energy ray easily peelable pressure sensitive adhesive composition.

  Generally, adhesive tapes such as dicing tapes and back grind tapes are used in the manufacturing process of electronic components. Since these adhesive tapes are used for fixing and protecting parts, they have strong adhesive strength that can withstand environmental conditions in each process of manufacture, eliminating the need for fixing and protection, and peeling and removing them. In some cases, it is desirable that it can be easily peeled off.

  Various techniques relating to such an adhesive tape have been proposed. Patent Document 1 contains an acrylic polymer, an energy beam polymerizable oligomer, a polymerization initiator, and a crosslinking agent, and the polymerization initiator is from 30 ° C. to 190 ° C. at a temperature rising rate of 10 ° C./min. There has been proposed a technique relating to an energy ray easily peelable pressure-sensitive adhesive composition in which the weight reduction rate by thermogravimetry when heated at 190 ° C. for 30 minutes is 50% or less.

  Patent Document 2 is a heat-resistant temporary wearing adhesive tape used for temporarily fixing or protecting a part having an etched polyimide resin surface, on a heat-resistant substrate, and an acrylic polymer, A pressure-sensitive adhesive layer comprising an energy ray-peelable pressure-sensitive adhesive composition containing an energy beam polymerizable oligomer, a polymerization initiator, and a crosslinking agent is formed, and the acrylic polymer has a mass average molecular weight of 200,000. It is in the range of ~ 500,000, and an acrylic ester is a main component, obtained by copolymerization of the acrylic ester with a copolymerizable hydroxyl group-containing monomer, or an acrylic ester as a main component, Obtained by copolymerization of the acrylic acid ester with a copolymerizable hydroxyl group and carboxyl group-containing monomer, the hydroxyl group-containing monomer and carboxyl group The mass ratio with the group-containing monomer is 51:49 to 100: 0, and the polymerization initiator is heated from 30 ° C. to 190 ° C. at a temperature rising rate of 10 ° C./min and held at 190 ° C. for 30 minutes. A technique relating to a heat-resistant temporary adhesive tape having a weight reduction rate of 50% or less by thermogravimetry is proposed.

  The techniques proposed in Patent Documents 1 and 2 have high initial adhesive strength to the adherend, and the adhesive strength is difficult to decrease even when exposed to high temperatures. When it is peeled and removed, the adhesive strength is reduced by irradiating energy rays, etc., and it can be easily peeled off without leaving adhesive residue. is there.

JP 2012-12506 A JP 2012-31316 A

  However, in the techniques proposed in Patent Documents 1 and 2, although the adherend can retain a high adhesive force even when the pressure-sensitive adhesive tape is heated, the pressure-sensitive adhesive tape is removed after the pressure-sensitive adhesive tape is heated to a high temperature. There was a problem that the easy releasability at the time of peeling from the adherend was insufficient.

  The present invention has solved the above-mentioned problems, and its purpose is to have a high initial adhesive force to the adherend, and the adhesive force is hardly lowered even when exposed to high temperatures. Another object of the present invention is to provide an energy ray easily peelable pressure-sensitive adhesive composition which has an adhesive force necessary for protection and can be peeled off very easily even after being exposed to a high temperature.

  Another object of the present invention is that the initial adhesive strength to the adherend is high, the adhesive strength is not easily lowered even when exposed to high temperatures, and the adhesive strength necessary for fixation and protection is provided. Furthermore, another object of the present invention is to provide an adhesive tape that can be peeled off very easily when it is peeled off from an adherend even after being exposed to a high temperature.

  The present inventor has made extensive studies to solve the above-mentioned problems. As a result, the energy ray easily peelable pressure-sensitive adhesive composition contains a thioxanthone polymerization initiator and has an absorption peak in the wavelength range of 330 nm to 410 nm. As a result, the present inventors have found that the adhesive tape can be peeled off very easily even after the adhesive tape has been heated to a high temperature, and the present invention has been completed.

  An energy ray easily peelable pressure-sensitive adhesive composition according to the present invention for solving the above problems includes an acrylic polymer containing a copolymer containing acrylonitrile as a monomer component, an energy ray polymerizable compound, and a thioxanthone polymerization initiator. And a crosslinking agent, and has an absorption peak in a wavelength range of 330 nm to 410 nm.

  According to the present invention, the energy ray easy-peelable pressure-sensitive adhesive composition contains an acrylic polymer containing a copolymer containing acrylonitrile as a monomer component and a crosslinking agent. However, the adhesive strength is not easily lowered, and the adhesive strength necessary for fixing and protection is obtained. Moreover, since the energy ray easily peelable pressure-sensitive adhesive composition contains an energy ray polymerizable compound and a thioxanthone polymerization initiator and has an absorption peak in the wavelength range of 330 nm to 410 nm, the energy ray easily peelable pressure sensitive adhesive The composition is cured by energy rays having a wavelength of 330 nm to 410 nm. Therefore, since the energy ray easily peelable pressure-sensitive adhesive composition can be efficiently cured even with a small amount of energy beam irradiation, the energy ray easily peelable pressure sensitive adhesive composition can be peeled off from the adherend very easily. As a result, the energy ray easily peelable pressure-sensitive adhesive composition of the present invention has a high initial adhesive strength to the adherend, and the adhesive strength is hardly lowered even when exposed to high temperatures. In addition, it has a necessary adhesive strength and can be peeled off very easily even after being exposed to a high temperature.

  In the energy beam easily peelable pressure-sensitive adhesive composition according to the present invention, the content of the thioxanthone polymerization initiator is 0.005 with respect to a total of 100 parts by mass of the acrylic polymer and the energy beam polymerizable compound. It is preferable that it is not less than 2 parts by mass.

  In the energy ray easily peelable pressure-sensitive adhesive composition according to the present invention, the thioxanthone polymerization initiator is preferably 2,4-diethylthioxanthone or 2-isopropylthioxanthone.

  The pressure-sensitive adhesive tape according to the present invention for solving the above-mentioned problems has a pressure-sensitive adhesive layer formed of the above-mentioned energy ray easy-peelable pressure-sensitive adhesive composition, and a transparent substrate on which the pressure-sensitive adhesive layer is provided. It is characterized by.

  According to this invention, since the pressure-sensitive adhesive tape has the pressure-sensitive adhesive layer formed of the above-described energy ray easy-peelable pressure-sensitive adhesive composition, the initial pressure-sensitive adhesive force to the adherend is high and exposed to a high temperature. Even if it is a case, the adhesive strength is difficult to decrease, it has the adhesive strength necessary for fixation and protection, and even after being exposed to high temperature, it can be peeled off very easily Become.

  In the pressure-sensitive adhesive tape according to the present invention, the transparent substrate is preferably a polyethylene terephthalate film.

  According to the energy ray easy-peelable pressure-sensitive adhesive composition according to the present invention, the initial adhesive strength to the adherend is high, and even when exposed to high temperatures, the adhesive strength is unlikely to decrease, fixing and protection Can maintain the necessary adhesive strength. Moreover, since the energy ray easily peelable pressure-sensitive adhesive composition is cured with energy rays having a wavelength of 330 nm or more and 410 nm or less, the energy ray easily peelable pressure sensitive adhesive composition can be efficiently cured even with a small amount of energy beam irradiation. As a result, even after the energy ray easily peelable pressure-sensitive adhesive composition is exposed to a high temperature, it can be peeled off from the adherend very easily.

  According to the pressure-sensitive adhesive tape of the present invention, the initial pressure-sensitive adhesive force to the adherend is high, and the pressure-sensitive adhesive force hardly decreases even when exposed to high temperatures, and has the pressure-sensitive adhesive force necessary for fixing and protection. In addition, even after being exposed to a high temperature, it can be peeled off very easily.

It is typical sectional drawing which shows an example of the adhesive tape which concerns on this invention. It is a graph which shows the spectral characteristic of the energy ray easily peelable adhesive composition of Examples 1-3 and Comparative Examples 1,2.

  Hereinafter, embodiments of the present invention will be described in detail. The present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist thereof.

[Easily peelable pressure-sensitive adhesive composition]
The energy ray easily peelable pressure-sensitive adhesive composition according to the present invention is a composition that can be easily peeled off by irradiating energy rays, and is used for forming a pressure-sensitive adhesive layer such as a pressure-sensitive adhesive tape. It has an absorption peak in the wavelength range of 330 nm or more and 410 nm or less, containing an acrylic polymer containing a copolymer having a monomer component, an energy ray polymerizable compound, a thioxanthone polymerization initiator, and a crosslinking agent. There are features.

  According to such an energy ray easy-peelable pressure-sensitive adhesive composition, the initial adhesive strength to the adherend is high, and even when exposed to high temperatures, the adhesive strength is unlikely to decrease and is necessary for fixing and protection. Can maintain adhesive strength. Moreover, since the energy ray easily peelable pressure-sensitive adhesive composition is cured with energy rays having a wavelength of 330 nm or more and 410 nm or less, the energy ray easily peelable pressure sensitive adhesive composition can be efficiently cured even with a small amount of energy beam irradiation. As a result, the energy ray easily peelable pressure-sensitive adhesive composition can be peeled off from the adherend very easily.

  Hereinafter, each component will be described in detail.

(Acrylic polymer)
An acrylic polymer is included as a main component of an energy ray easily peelable pressure-sensitive adhesive composition, and improves the transparency, heat resistance, moist heat resistance, durability, coating suitability, etc. of the energy ray easily peelable pressure sensitive adhesive composition. belongs to. Such an acrylic polymer mainly contains a copolymer having acrylonitrile having a high polarity and excellent adhesion as a monomer component. The copolymer having acrylonitrile as a monomer component is not particularly limited, and examples thereof include a copolymer of an acrylate ester and acrylonitrile, a copolymer of an acrylate ester, acrylonitrile, and another monomer. . Examples of acrylic esters include ethyl acrylate, n-butyl acrylate, 2-ethylhexyl acrylate, isooctyl acrylate, isononyl acrylate, hydroxyl ethyl acrylate, propylene glycol acrylate, and glycidyl acrylate. These can be used alone or in combination of two or more. Among the acrylic acid esters described above, n-butyl acrylate and 2-ethylhexyl acrylate are particularly preferable because they are excellent in transparency, heat resistance, moist heat resistance, durability, suitability for coating, and the like, and are low in cost.

  Examples of other monomers include methyl acrylate, methyl methacrylate, styrene, vinyl acetate, acrylic acid, methacrylic acid, itaconic acid, hydroxylethyl acrylate, hydroxylethyl methacrylate, propylene glycol acrylate, acrylamide, methacrylamide, glycidyl acrylate, Examples thereof include glycidyl methacrylate, dimethylaminoethyl methacrylate, tert-butylaminoethyl methacrylate, and n-ethylhexyl methacrylate. These can be used alone or in combination of two or more. Among the other monomers described above, methyl methacrylate is particularly preferable.

  In addition, as another monomer, the copolymerizable hydroxyl-containing monomer can be mentioned preferably, for example. The copolymerizable hydroxyl group-containing monomer refers to a monomer having in its structure a polymerizable group copolymerizable with acrylonitrile and a hydroxyl group. Examples of such copolymerizable hydroxyl group-containing monomers include 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 2-hydroxybutyl acrylate, 3-chloro-2-hydroxypropyl acrylate, and polyethylene glycol acrylate. Among these, 2-hydroxyethyl acrylate is preferable.

  The mass average molecular weight (Mw) of the acrylic polymer is preferably in the range of 150,000 to 1,500,000 and more preferably in the range of 400,000 to 1,200,000. By adjusting the mass average molecular weight of the acrylic polymer within this range, it becomes easy to adjust the initial adhesive force of the energy ray-peelable pressure-sensitive adhesive composition. Moreover, the cohesive force of an energy ray easily peelable adhesive composition can be made high. The mass average molecular weight is a value in terms of polystyrene when measured by gel permeation chromatography (GPC).

  A copolymer having acrylonitrile as a monomer component can impart a desired cohesive force to the energy ray easily peelable pressure-sensitive adhesive composition by adjusting the ratio of acrylonitrile as a monomer component. The ratio of the acrylonitrile component of the copolymer containing acrylonitrile as the monomer component is preferably 3% by mass or more and 40% by mass or less, more preferably 3% by mass or more and 10% by mass or less, and more preferably 5% by mass or more and 10% by mass or less. More preferably, it is at most mass%. Even when the energy ray easily peelable pressure-sensitive adhesive composition is exposed to a high temperature by adjusting the ratio of the acrylonitrile component of the copolymer containing acrylonitrile as a monomer component to 3 mass% or more and 40 mass% or less, It is difficult for the force to decrease, and the adhesive force necessary for fixing and protection can be maintained. In addition, adhesive residue hardly occurs when peeling from the adherend.

  The acrylic polymer may contain an acrylic polymer other than a copolymer containing acrylonitrile as a monomer component. Examples of such an acrylic polymer include an acrylate copolymer obtained by copolymerizing an acrylate ester with the above-described other monomer.

  By including such an acrylic polymer in the energy ray easily peelable pressure-sensitive adhesive composition, the initial adhesive strength of the energy ray easily peelable pressure sensitive adhesive composition to the adherend is high, and when exposed to high temperatures. Even if it exists, it will be hard to fall, and will have adhesive force required for fixation and protection.

(Energy beam polymerizable compound)
The energy ray polymerizable compound is an energy ray polymerizable oligomer and energy ray polymerizable monomer. The energy ray easily peelable pressure-sensitive adhesive composition is cured by three-dimensional crosslinking by a radical polymerization reaction by irradiation with energy rays. This is to reduce the adhesive force and increase the cohesive strength of the energy ray easily peelable pressure-sensitive adhesive composition so as not to transfer to the adherend surface. Such energy ray-polymerizable compounds are not particularly limited as long as they can be polymerized by irradiation with energy rays. For example, oligomers such as photoradical polymerizability, photocationic polymerizability, and photoanion polymerizability, and the like Monomer. Among these, the radical photopolymerizable oligomer and the radical photopolymerizable monomer have a high curing rate and can be selected from a wide variety of compounds. Furthermore, the adhesiveness before curing, the peelability after curing, etc. Preferably, the physical properties can be easily controlled as desired.

  Examples of the radical photopolymerizable oligomer include urethane (meth) acrylate, ester (meth) acrylate, epoxy (meth) acrylate, polyol (meth) acrylate, polyether (meth) acrylate, polyester (meth) acrylate, polyethylene ( Examples include meth) acrylate, polybutadiene (meth) acrylate, melamine (meth) acrylate, and silicone-based (meth) acrylate, and these may be used alone or in combination of two or more. Among these, polyurethane (meth) acrylate is preferable. In the present specification, “(meth) acrylate” means acrylate or methacrylate.

  The mass average molecular weight (Mw) of the energy beam polymerizable oligomer is not particularly limited, but is preferably 250 or more and 5000 or less, and more preferably 250 or more and 1500 or less. By making the mass average molecular weight of the energy beam polymerizable oligomer in the range of 250 or more and 5000 or less, it shows a desired adhesive force before the irradiation with the energy beam, and without any adhesive residue after the irradiation with the energy beam. A peelable energy ray-peelable pressure-sensitive adhesive composition can be obtained. The weight average molecular weight is a value in terms of polystyrene when measured by gel permeation chromatography (GPC).

  As the radical photopolymerizable monomer, a polyfunctional acrylate or a polyfunctional methacrylate is preferable. For example, trimethylol methane tri (meth) acrylate or trimethylol ethane tri having three or more (meth) acryloyl groups in one molecule. (Meth) acrylate, trimethylolpropane tri (meth) acrylate, tetramethylolmethane tetra (meth) acrylate, dipentaerythritol hexa (meth) acrylate, dipentaerythritol penta (meth) acrylate, pentaerythritol tri (meth) acrylate, and These ethylene oxide or propylene oxide adducts can be mentioned.

  The content of the energy beam polymerizable compound is preferably 10 parts by mass or more and 60 parts by mass or less, and more preferably 20 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the acrylic polymer. By adjusting these total contents, it becomes possible to control the adhesive strength after irradiation with energy rays. Since the content of the energy ray polymerizable compound is within the range of 10 parts by mass or more and 60 parts by mass or less with respect to 100 parts by mass of the acrylic polymer, the crosslinking density after irradiation with the energy ray becomes sufficient. Appropriate peelability can be realized. In addition, it is difficult for adhesive residue to adhere to the adherend due to a decrease in cohesive force.

  Examples of energy rays include rays such as far ultraviolet rays, ultraviolet rays, near ultraviolet rays, and infrared rays, electromagnetic waves such as X-rays and γ rays, electron beams, proton rays, and neutron rays.

  By including such an energy ray polymerizable compound in the energy ray easily peelable pressure-sensitive adhesive composition, it is possible to cure the energy ray easily peelable pressure sensitive adhesive composition by irradiation of energy rays and reduce the adhesive force. It becomes a thing which can be easily peeled when peeling.

(Thioxanthone polymerization initiator)
The polymerization initiator is for enhancing the sensitivity of the energy beam polymerizable compound, and it is possible to reduce the polymerization curing time and energy beam irradiation amount by the energy beam. The polymerization initiator contains at least one thioxanthone polymerization initiator. In addition, a polymerization initiator other than the thioxanthone series may or may not be contained. The thioxanthone-based polymerization initiator is not particularly limited, and examples thereof include 2,4-diethylthioxanthone and isopropylthioxanthone. The polymerization initiator other than the thioxanthone series is not particularly limited as long as it is a photopolymerization initiator, and examples thereof include acetophenone series compounds and acyl phosphooxide series compounds. Examples of acetophenone compounds include acetophenone, hydroxyacetophenone, aminoacetophenone, 1-hydroxycyclohexyl phenyl ketone, oligo [2-hydroxy-2-methyl-1- {4- (1-methylvinyl) phenyl} propanone], 2 -Methyl-1- (4-methylthiophenyl) -2-morpholinopropan-1-one, 2-benzyl-2-dimethylamino-1- (4-morpholinophenyl) -butanone-1 and the like can be mentioned. Examples of the acyl phosphooxide compound include bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide. Suitable examples of such commercially available photopolymerization initiators include IRGACURE184, IRGACURE754, IRGACURE2959 and the like manufactured by BASF Japan Ltd.

  The thioxanthone polymerization initiator has an absorption peak at a wavelength of 330 nm to 410 nm. Such a thioxanthone-based polymerization initiator can absorb a wide energy beam having a wavelength of 330 nm to 410 nm, and can efficiently generate a radical that induces a radical polymerization reaction of the energy beam polymerizable compound. Therefore, the energy beam polymerizable compound can be efficiently cured even with a small amount of energy beam irradiation by containing the thioxanthone polymerization initiator in the energy beam easily peelable pressure-sensitive adhesive composition. As a result, the energy ray easily peelable pressure-sensitive adhesive composition can be peeled off from the adherend very easily. In addition, when the energy ray easy-peelable pressure-sensitive adhesive composition is used as a pressure-sensitive adhesive layer and a pressure-sensitive adhesive tape provided on a transparent base material to be described later, for example, when a polyethylene terephthalate film is used for the transparent base material, Absorbs energy rays up to a wavelength of 310 nm, but transmits energy rays of a wavelength of 330 nm or more. Therefore, by using a thioxanthone-based polymerization initiator having an absorption peak at a wavelength of 330 nm to 410 nm, the energy beam polymerizable compound can be cured using energy rays transmitted through the polyethylene terephthalate film. As a result, even if it is the adhesive tape which used the polyethylene terephthalate film for the transparent base material, an energy ray polymeric compound can be hardened efficiently.

  The content of the thioxanthone polymerization initiator is preferably 0.005 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass in total of the acrylic polymer and the energy ray polymerizable compound, and 0.05 parts by mass. More preferably, it is 1.5 parts by mass or less. By making the content of the thioxanthone polymerization initiator in the range of 0.005 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass in total of the acrylic polymer and the energy ray polymerizable compound, it is more efficient. The energy beam polymerizable compound can be cured.

(Crosslinking agent)
The cross-linking agent improves the heat resistance of the energy-peelable pressure-sensitive adhesive composition and maintains the adhesive force necessary for fixation and protection without reducing the adhesive force even when used under conditions exposed to high temperatures. Is for. Such a crosslinking agent is not particularly limited, and examples thereof include an isocyanate crosslinking agent and an epoxy crosslinking agent. Examples of the isocyanate crosslinking agent include polyisocyanate compounds, trimers of polyisocyanate compounds, urethane prepolymers having terminal isocyanate groups obtained by reacting polyisocyanate compounds and polyol compounds, and urethane prepolymers thereof. A trimer etc. are mentioned. Examples of the polyisocyanate compound include 2,4-tolylene diisocyanate, 2,5-tolylene diisocyanate, 1,3-xylylene diisocyanate, 1,4-xylylene diisocyanate, diphenylmethane-4,4′-diisocyanate, 3 -Methyldiphenylmethane diisocyanate, hexamethylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane-4,4'-diisocyanate, dicyclohexylmethane-2,4'-diisocyanate, and lysine isocyanate.

  Examples of the epoxy-based crosslinking agent include sorbitol polyglycidyl ether, polyglycerol polyglycidyl ether, pentaerythritol polyglycidyl ether, diglycerol polyglycidyl ether, glycerol polyglycidyl ether, trimethylolpropane polyglycidyl ether, neopentyl glycol diglycidyl ether. , 1,6-hexanediol diglycidyl ether, hydrogenated bisphenol A diglycidyl ether, polyethylene glycol diglycidyl ether, polypropylene glycol diglycidyl ether, and polybutadiene diglycidyl ether.

  A crosslinking agent can be used individually or in combination of 2 or more types, and can be suitably selected according to the kind of acrylic polymer. For example, when the monomer constituting the acrylic polymer contains a copolymerizable hydroxyl group-containing monomer, an isocyanate-based crosslinking agent is preferable. When the copolymerizable carboxyl group-containing monomer is contained, an epoxy-based crosslinking agent is used. Agents are preferred. Here, the copolymerizable carboxyl group-containing monomer means a monomer having a copolymerizable polymerizable group and a carboxyl group in its structure, for example, acrylic acid, methacrylic acid, carboxyethyl (meth). Examples include acrylate, carboxypentyl (meth) acrylate, itaconic acid, maleic acid, fumaric acid, and crotonic acid. Thus, by appropriately selecting the type of the crosslinking agent, even when the energy ray easily peelable pressure-sensitive adhesive composition is exposed to a high temperature, the pressure-sensitive adhesive force can hardly be reduced.

  In addition, as a commercial item of an isocyanate type crosslinking agent, L-45 (made by Soken Chemical Co., Ltd.), TD-75 (made by Soken Chemical Co., Ltd.), BXX5627 (made by Toyo Ink Manufacturing Co., Ltd.), X-301- 422SK (manufactured by Seiden Chemical Co., Ltd.) or the like can be suitably used. Moreover, as a commercial item of an epoxy-type crosslinking agent, E-5XM (made by Soken Chemical Co., Ltd.), E-5C (made by Soken Chemical Co., Ltd.) etc. can be used suitably, for example.

  The content of the crosslinking agent varies depending on the type of the crosslinking agent. For example, in the case of an isocyanate-based crosslinking agent, 0.01 mass with respect to a total of 100 mass parts of the acrylic polymer and the energy beam polymerizable compound. Part to 15 parts by weight, preferably 0.01 part to 10 parts by weight. By making content of an isocyanate type crosslinking agent into the range of 0.01 mass part-15 mass parts with respect to a total of 100 mass parts of an acryl-type polymer and an energy-beam polymeric compound, energy-beam easy peeling type The adhesive force of the pressure-sensitive adhesive composition can be further improved. If less than 0.01 parts by mass, the energy ray easy-peeling pressure-sensitive adhesive composition has insufficient adhesive strength, or when it peels from the adherend when it peels from the adherend, In some cases, the peelable pressure-sensitive adhesive composition causes cohesive failure to cause adhesive residue. If it exceeds 15 parts by mass, it remains as an unreacted monomer in the energy ray easy-peelable pressure-sensitive adhesive composition, and thus the cohesive force may decrease.

  Moreover, in the case of an epoxy-type crosslinking agent, it is preferable that it is 0.01 mass part or more and 15 mass parts or less with respect to 100 mass parts in total of an acrylic polymer and an energy-beam polymeric compound, 0.01 mass More preferably, it is 10 parts by mass or more. By making the content of the epoxy-based crosslinking agent within a range of 0.01 parts by mass or more and 15 parts by mass or less with respect to a total of 100 parts by mass of the acrylic polymer and the energy beam polymerizable compound, easy release of energy rays The pressure-sensitive adhesive strength and cohesive strength before energy beam irradiation of the mold pressure-sensitive adhesive composition can be controlled to a desired strength. If it is less than 0.01 parts by mass, it is difficult for the energy ray easily peelable pressure-sensitive adhesive composition to have sufficient strength, and the energy ray easily peelable pressure sensitive adhesive composition causes cohesive failure when peeled from the adherend. This may cause adhesive residue. If it exceeds 15 parts by mass, the adhesive strength before irradiation with energy rays is reduced, so that it is difficult to appropriately fix and protect the electronic component.

  By including such a crosslinking agent in the energy ray easily peelable pressure-sensitive adhesive composition, the initial adhesive strength of the energy ray easily peelable pressure sensitive adhesive composition to the adherend is high, and when it is exposed to a high temperature. However, the adhesive strength is not easily lowered, and the adhesive strength necessary for fixing and protection is obtained.

  In addition to the energy ray easily peelable pressure-sensitive adhesive composition, a silane coupling agent, a tackifier, a metal chelating agent, a surfactant, an antioxidant, an ultraviolet ray, and the like, as long as the object of the present invention is not impaired. Various additives such as an absorbent, a pigment, a dye, a colorant, an antistatic agent, an antiseptic, an antifoaming agent, and a wettability adjusting agent can be blended.

[Adhesive tape]
The pressure-sensitive adhesive tape 10 according to the present invention is used for temporarily fixing or protecting an electronic component having one or both of an inorganic glass surface and a silicon surface in a manufacturing process of the electronic component, as shown in FIG. It has the characteristics in having the adhesive layer 2 containing an energy ray easily peelable adhesive composition, and the transparent base material 1 in which the adhesive layer 2 is provided. Reference numeral 3 represents a release layer.

  According to such an adhesive tape 10, the initial adhesive force on the adherend is high, and even when exposed to high temperatures, the adhesive force is difficult to decrease, and has an adhesive force necessary for fixation and protection, Furthermore, even after being exposed to a high temperature, it becomes very easy to peel when peeling.

  As shown in FIG. 1, the pressure-sensitive adhesive tape 10 is provided with a pressure-sensitive adhesive layer 2 and a release layer 3 in this order on a transparent substrate 1, but is not limited to such a configuration. Moreover, the thickness of the adhesive tape 10 is not particularly limited, but is preferably 80 μm or more and 350 μm or less, and more preferably 90 μm or more and 140 μm or less. If the thickness of the pressure-sensitive adhesive tape 10 is in the range of 80 μm or more and 350 μm or less, the adhesive tape 10 has appropriate flexibility and is easy to handle.

  The sticking target of the adhesive tape 10 is an electronic component having one or both of an inorganic glass surface and a silicon surface, and includes an electronic component made of inorganic glass or silicon. According to the adhesive tape 10, the initial adhesive strength to the inorganic glass surface and the silicon surface is high, and even when exposed to high temperatures, the adhesive strength is not easily lowered, and has an adhesive force necessary for fixation and protection. Furthermore, when peeling from the adherend, it is possible to peel off very easily without leaving any adhesive by a simple operation of irradiating energy rays, so appropriate fixing and protection are required during the process. In the end, it is suitable as a tape for an electronic component manufacturing process that involves use under a high temperature condition where it is peeled off and removed. Specifically, it is suitable as an adhesive tape used for temporarily fixing or protecting components in a printed wiring board manufacturing process. Examples of the component include an electronic component used for manufacturing an IC chip.

  As a usage method of the adhesive tape 10, the following method is mentioned, for example. First, the adhesive tape of the present invention is attached to one or both of the inorganic glass surface and the silicon surface of the electronic component to be attached. Then, after the heat treatment, processing, chemical treatment, and the like, the adhesive layer is cured by irradiating energy rays such as ultraviolet rays from the base material side of the adhesive tape when the necessity for fixing or protection is eliminated. Thus, the adhesive tape is peeled off and removed from either one or both of the inorganic glass surface and the silicon surface of the electronic component. Hereinafter, each configuration will be described in detail.

(Transparent substrate)
The transparent substrate 1 is not particularly limited as long as it has transparency that does not prevent the transmission of energy rays and heat resistance. Specifically, heat resistance refers to being able to withstand use at an assumed heating temperature (120 ° C.) in the manufacturing process of an electronic component. Therefore, the melting point of the transparent substrate 1 is higher than 120 ° C. Higher than that. The transparent substrate 1 is preferably a substrate having necessary strength and flexibility. Examples of the material for forming such a transparent substrate 1 include polyester resins, polyvinyl chloride resins, fluorine resins, polystyrene resins, poly (meth) acrylic resins, cellulose resins, polycarbonate resins, and polyimide resins. And synthetic resin films made of known resins such as polyolefin resins, polyvinyl alcohol resins, polyimide resins, phenol resins, and polyurethane resins. These can be used alone or in combination of two or more.

  The transparent substrate 1 may be a single layer or a laminate of two or more layers. From the viewpoint of mechanical strength, a uniaxially stretched or biaxially stretched film is preferred. Since the adhesive tape 10 is used for temporarily fixing or protecting the electronic component in the manufacturing process of the electronic component, in addition to the heat resistance, dimensional stability, energy ray permeability, flexibility, strength, etc. In addition, it is preferable to use a polyester-based resin that is excellent in rigidity, extensibility, suitability for lamination, and chemical resistance.

  Examples of the polyester-based resin include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, polytetramethylene terephthalate, etc. Among them, polyethylene that is easy to handle and inexpensive Terephthalate is particularly preferred.

  Although the thickness of the transparent base material 1 is not specifically limited, It is preferable that they are 30 micrometers or more and 300 micrometers or less, and it is more preferable that they are 50 micrometers or more and 100 micrometers or less. If the thickness of the transparent substrate 1 is in the range of 30 μm or more and 300 μm or less, the form of the pressure-sensitive adhesive tape 10 can be maintained, and workability such as sticking or peeling of the pressure-sensitive adhesive tape 10 is good. In addition, since warp, slack, breakage and the like hardly occur and sufficient mechanical strength is exhibited, it is also possible to supply and process in a continuous belt shape. Furthermore, in the manufacturing process of the electronic component, it is possible to appropriately protect the surface of the electronic component that is the adherend. In addition, when the thickness of the transparent base material 1 exceeds 300 μm, the cost may increase due to excessive performance.

  When using a light ray as an energy ray, it is preferable that the transmittance | permeability with respect to the light of 410 nm or less of the transparent base material 1 is 80% or more. The light transmittance can be measured using a commercially available spectrophotometer, for example, MPC2200 manufactured by Shimadzu Corporation.

  The formation method of the transparent base material 1 is not specifically limited, For example, conventionally well-known formation methods, such as a solution casting method, a melt extrusion method, a calender method, can be used. Moreover, you may use the commercially available transparent base material 1 previously formed in the film form by the above-mentioned method.

  In order to improve the wettability with the pressure-sensitive adhesive, the transparent substrate 1 has a known one such as corona treatment, plasma treatment, ozone treatment, flame treatment, primer treatment, vapor deposition treatment, and alkali treatment on one or both sides. Easy adhesion treatment may be performed.

(Adhesive layer)
The pressure-sensitive adhesive layer 2 is formed of the energy ray easy-peelable pressure-sensitive adhesive composition described above. The energy ray easily peelable pressure-sensitive adhesive composition has been described in the above-mentioned "energy ray easily peelable pressure sensitive adhesive composition" column, and therefore the description thereof is omitted here.

  The thickness of the pressure-sensitive adhesive layer 2 is usually 5 μm or more and 50 μm or less, preferably 10 μm or more and 30 μm or less. When the thickness of the pressure-sensitive adhesive layer 2 is in the range of 5 μm or more and 50 μm or less, the pressure-sensitive adhesive properties are stabilized. If the thickness of the pressure-sensitive adhesive layer is less than 5 μm, sufficient adhesive strength may not be obtained. If the thickness exceeds 50 μm, energy rays cannot be sufficiently transmitted to the inside of the pressure-sensitive adhesive layer. Power may not decrease. Also, excessive performance can be costly.

(Peeling layer)
The release layer 3 is not essential, but is preferably provided on the adhesive layer 2 of the pressure-sensitive adhesive tape 10. The release layer 3 means a release sheet made of a release member having peelability and having a function of protecting the surface of the pressure-sensitive adhesive layer 2. The release member is not particularly limited as long as it has the required strength and flexibility, and generally a synthetic resin film subjected to silicone release treatment is used. As a material for the synthetic resin film, for example, polyester resins such as polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, polyarylate, and polytetramethylene terephthalate are preferable. The thickness of the release layer 3 is not particularly limited, but is preferably 25 μm or more and 100 μm or less.

  The manufacturing method of the adhesive tape 10 is not specifically limited, A conventionally well-known method can be used. For example, the energy ray easily peelable pressure-sensitive adhesive composition is added with the above-described various additives as necessary, and dissolved or dispersed in an organic solvent to adjust the viscosity. Next, the energy ray easily peelable pressure-sensitive adhesive composition is coated on the entire surface of the transparent substrate 1 with an applicator or the like to form the pressure-sensitive adhesive layer 2. Then, the adhesive tape 2 can be manufactured by drying the adhesive layer 2 and laminating a peelable synthetic resin film or the like. Although it does not specifically limit as an organic solvent, For example, toluene, methyl ethyl ketone, ethyl acetate, dimethylacetamide, these mixed solutions, etc. can be used conveniently.

  The method for coating the energy ray easily peelable pressure-sensitive adhesive composition on the transparent substrate 1 is not particularly limited, and a conventionally known method can be used. Examples of the forming method by printing include a gravure printing method, a flexographic printing method, and an offset printing method. Examples of the coating method include roll coating, reverse coating, comma coating, knife coating, die coating, and gravure coating.

When using ultraviolet rays as energy rays, for example, using a high-pressure mercury lamp, ultrahigh-pressure mercury lamp, carbon arc lamp, metal halide lamp, xenon lamp, chemical lamp, etc. Irradiation may be performed so as to be 50 mJ / cm ² or more, preferably 200 mJ / cm ² or more.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention does not receive a restriction | limiting at all in these description.

[Example 1]
Acrylic pressure-sensitive adhesive (mixture of acrylic polymer, energy beam polymerizable compound and polymerization initiator, trade name: E-306, acrylic polymer: n-butyl acrylate, methyl methacrylate, 2-hydroxyethyl acrylate, and acrylonitrile Weight ratio of copolymer and constituent monomers: (total of n-butyl acrylate, methyl methacrylate and 2-hydroxyethyl acrylate / acrylonitrile) = (95/5), mass average molecular weight of acrylic polymer: about 650,000, energy beam Polymerizable compound: polyurethane acrylate oligomer and dipentaerythritol triacrylate, polymerization initiator: 1-hydroxycyclohexyl phenyl ketone) 100 parts by mass of urethane acrylate (energy ray polymerizable compound, solid Min 100%, trade name: UV-7600B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd. 60 parts by mass, 2,4-diethylthioxanthone (thioxanthone polymerization initiator, trade name: KAYACURE DETX-S, solid content: 100%, 0.2 parts by mass of Nippon Kayaku Co., Ltd.) and 1.6 parts by mass of an isocyanate-based crosslinking agent (crosslinking agent, trade name: Coronate L, solid content: 75%, manufactured by Nippon Polyurethane Industry Co., Ltd.) The energy ray easily peelable pressure-sensitive adhesive composition of Example 1 was obtained.

  The obtained energy ray easily peelable pressure-sensitive adhesive composition is diluted with 50 parts by mass of a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1: 1, trade name: KT11, manufactured by DIC Graphics Co., Ltd.) and sufficiently dispersed. After adjusting the viscosity, an applicator is used on a transparent substrate (biaxially stretched polyester film, trade name: Lumirror S56, thickness: 50 μm, manufactured by Toray Industries, Inc.) so that the thickness after drying becomes 10 μm. The whole surface is coated and then dried, and a release sheet (PET separator, trade name: SP-PET-01, thickness: 38 μm, manufactured by Mitsui Chemicals, Inc.) is laminated and subjected to aging treatment at 40 ° C. for 3 days. Thus, an adhesive tape of Example 1 was obtained.

[Example 2]
Example 1 except that the type of thioxanthone polymerization initiator was changed from 2,4-diethylthioxanthone to isopropylthioxanthone (thioxanthone polymerization initiator, trade name: Speedcure ITX, solid content 100%, manufactured by LAMBSON) In the same manner, the energy ray easy-peelable pressure-sensitive adhesive composition of Example 2 and the pressure-sensitive adhesive tape of Example 2 were obtained.

[Example 3]
Except that the content of the thioxanthone polymerization initiator was changed to 0.5 parts by mass, the energy ray easily peelable pressure-sensitive adhesive composition of Example 3 and the pressure-sensitive adhesive tape of Example 3 were used in the same manner as Example 1. Obtained.

[Example 4]
Urethane acrylate (energy ray polymerizable compound, solid content 100%, trade name: UV-7600B, manufactured by Nippon Synthetic Chemical Industry Co., Ltd.) of Example 1 was converted to urethane acrylate (energy ray polymerizable compound, solid content 100%, product). Name: U-6HA, manufactured by Shin-Nakamura Chemical Co., Ltd.), and in the same manner as in Example 1 except that the content of the thioxanthone polymerization initiator was changed to 0.5 parts by mass. The energy ray peeling type adhesive composition and the adhesive tape of Example 4 were obtained.

[Comparative Example 1]
Except that the thioxanthone polymerization initiator was not blended, the energy ray easily peelable pressure-sensitive adhesive composition of Comparative Example 1 and the pressure-sensitive adhesive tape of Comparative Example 1 were obtained in the same manner as Example 1.

[Comparative Example 2]
Except that 2-mercaptothiazole was blended in place of the thioxanthone polymerization initiator, the energy ray easily peelable pressure-sensitive adhesive composition of Comparative Example 2 and the pressure-sensitive adhesive tape of Comparative Example 2 were obtained in the same manner as Example 1. .

[Evaluation and results]
About the energy-beam easy-peeling-type adhesive composition obtained in Examples 1, 2 and Comparative Examples 1, 2, the light transmittance was measured. For the adhesive tapes obtained in Examples 1 to 4 and Comparative Examples 1 and 2, (a) measurement of initial adhesive strength, (b) measurement of adhesive strength after heat treatment, and (c) ultraviolet rays after heat treatment. The adhesive strength after irradiation was measured.

  The light transmittance was measured by preparing a transmittance measurement sample obtained by bonding the obtained energy ray easy-peelable pressure-sensitive adhesive composition to a glass substrate, and using this transmittance measurement sample as a spectrophotometer (Shimadzu Corporation). Using a manufacturing method, model number: UV-3100PC), the measurement was performed by a method based on JIS Z8701. A sample for transmittance measurement was prepared as follows. First, the energy ray easily peelable adhesive composition is diluted with 50 parts by mass of a mixed solvent of toluene and methyl ethyl ketone (mass ratio 1: 1, trade name: KT11, manufactured by DIC Graphics Co., Ltd.) and sufficiently dispersed. After adjusting the viscosity, the entire surface is dried with an applicator so that the thickness after drying on a release sheet (PET separator, trade name: SP-PET-03, thickness: 38 μm, manufactured by Mitsui Chemicals, Inc.) is 10 μm. Coated. Subsequently, this energy ray easily peelable adhesive composition was dried, and a release sheet (PET separator, trade name: SP-PET-01, thickness: 38 μm, manufactured by Mitsui Chemicals, Inc.) was laminated at 40 ° C. Hold for 3 days. Next, one release sheet was peeled off, and the energy ray easily peelable pressure-sensitive adhesive composition on the peeled surface was bonded to a glass substrate, and then the other release sheet was peeled off to obtain a transmittance measurement sample.

  The obtained transmission spectrum is shown in FIG. In addition, the code | symbol ad in FIG. 2 has shown the measurement result of the light transmittance of the energy ray easily peelable adhesive composition of Examples 1, 2 and Comparative Examples 1, 2, respectively. Moreover, the code | symbol P has shown the absorption peak of wavelength 391nm.

  The adhesive force was measured by attaching the obtained adhesive tape to a polyimide sheet and then peeling the adhesive tape using a universal material testing machine (model 5565, manufactured by Instron Japan). Peeling was performed in accordance with JIS Z0237 at a peeling speed of 300 mm / min, a peeling distance of 50 mm, and a peeling angle of 180 °.

  The heat treatment was performed by holding at 120 ° C. for 15 minutes.

Ultraviolet irradiation was performed by irradiating ultraviolet rays having a peak wavelength of 365 nm so that the integrated light amount was 130 mJ / cm ² .

  Table 1 shows the results of measurement of adhesive strength.

  As shown in FIG. 2, the energy ray easily peelable pressure-sensitive adhesive composition of Examples 1 and 2 had an absorption peak at a wavelength of 391 nm, and thus had an absorption peak within a wavelength range of 330 nm to 410 nm. Met. Moreover, as shown in Table 1, the adhesive tapes of Examples 1 to 4 showed good initial adhesive strength, and even after heat treatment, retained high adhesive strength and after heat treatment. However, when peeled from the adherend, it showed an adhesive force that could be peeled off very easily.

DESCRIPTION OF SYMBOLS 1 Transparent base material 2 Adhesive layer 3 Release layer 10 Adhesive tape

Claims (5)

  It contains an acrylic polymer containing a copolymer containing acrylonitrile as a monomer component, an energy beam polymerizable compound, a thioxanthone polymerization initiator, and a crosslinking agent, and has an absorption peak in the wavelength range of 330 nm to 410 nm. An easy-to-peel adhesive composition for energy rays.   The content of the thioxanthone polymerization initiator is 0.005 parts by mass or more and 2 parts by mass or less with respect to 100 parts by mass in total of the acrylic polymer and the energy beam polymerizable compound. Energy ray easily peelable pressure-sensitive adhesive composition.   The energy ray easily peelable pressure-sensitive adhesive composition according to claim 1 or 2, wherein the thioxanthone polymerization initiator is 2,4-diethylthioxanthone or 2-isopropylthioxanthone.   It has an adhesive layer formed with the energy ray easily peelable adhesive composition according to any one of claims 1 to 3, and a transparent substrate on which the adhesive layer is provided. Adhesive tape.   The pressure-sensitive adhesive tape according to claim 4, wherein the transparent substrate is a polyethylene terephthalate film.

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