JP2014125529A - Temporarily fixing adhesive sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a temporarily fixing adhesive sheet that is superior in solvent resistance against organic solvent and water and heat resistance, and is also easily peelable.SOLUTION: A temporarily fixing adhesive sheet comprises, on at least one face of a base film including at least one of polyimide and polyethylenenaphthalate in an amount of 80 mass% or more, an adhesive layer composed of an adhesive composition including a polyisobutylene resin (A).

Description

  The present invention relates to a temporary fixing pressure-sensitive adhesive sheet used for temporarily fixing an electronic material or the like.

In an electronic component manufacturing process, an electronic material may be temporarily fixed on a substrate such as a glass plate, and then a process such as etching may be performed. Generally, an adhesive sheet is used for temporarily fixing an electronic material and a substrate or the like.
For example, an electronic material with a substrate temporarily fixed with an adhesive sheet is an etching process performed in a state immersed in a solvent such as an organic solvent or water, a cleaning process performed by applying ultrasonic waves in a state immersed in a solvent, and drying. It is necessary to go through a process including heat treatment for the purpose.
Therefore, the pressure-sensitive adhesive sheet used for such applications is required to have solvent resistance and heat resistance. Moreover, since the adhesive sheet is removed after completion | finish of the said process, easy peelability is also calculated | required.

  For example, Patent Document 1 discloses a heat-resistant temporary wearing pressure-sensitive adhesive tape used for temporarily fixing or protecting a part having an etched polyimide resin surface in an electronic part manufacturing process. In Patent Document 1, the pressure-sensitive adhesive layer of the pressure-sensitive adhesive tape is made of a forming material containing a specific acrylic polymer mainly composed of an acrylate ester, an energy beam polymerizable oligomer, and a specific polymerization initiator. It is stated.

JP 2012-31316 A

  However, since the pressure-sensitive adhesive layer of the heat-resistant temporary wearing pressure-sensitive adhesive tape described in Patent Document 1 is formed of a material containing an acrylic polymer, it may swell when heat treatment is performed, which may hinder the etching process or the like. .

  An object of this invention is to provide the adhesive sheet for temporary fixing which is excellent in the solvent resistance and heat resistance with respect to an organic solvent or water, and is also easy to peel.

The present inventors have a pressure-sensitive adhesive sheet having a pressure-sensitive adhesive layer made of a pressure-sensitive adhesive composition containing a polyisobutylene-based resin on at least one surface of a base film containing a predetermined resin. The present invention was completed.
That is, the present invention provides the following [1] to [9].
[1] A temporary layer having an adhesive layer made of an adhesive composition containing a polyisobutylene resin (A) on at least one surface of a base film containing 80% by mass or more of at least one of polyimide and polyethylene naphthalate. Fixing adhesive sheet.
[2] The pressure-sensitive adhesive sheet for temporary fixing according to [1], wherein the pressure-sensitive adhesive composition further contains a tackifier resin (B).
[3] The pressure-sensitive adhesive sheet for temporary fixing according to the above [1] or [2], wherein the polyisobutylene resin (A) contains two or more polyisobutylene resins having different weight average molecular weights.
[4] The above, wherein the polyisobutylene resin (A) includes a polyisobutylene resin (A1) having a weight average molecular weight of 270,000 to 480,000 and a polyisobutylene resin (A2) having a weight average molecular weight of 100,000 to 250,000. The adhesive sheet for temporary fixing according to any one of [1] to [3].
[5] Any of [1] to [4] above, wherein the content of the polyisobutylene resin (A) in the adhesive composition is 50% by mass or more based on the total amount of the adhesive composition. The adhesive sheet for temporary fixing as described in 2.
[6] Any of the above [2] to [5], wherein the content of the tackifying resin (B) in the adhesive composition is 3 to 50 parts by mass with respect to 100 parts by mass of the component (A). A temporary fixing pressure-sensitive adhesive sheet according to claim 1.
[7] The above, wherein the total content of the polyisobutylene resin (A) and the tackifier resin (B) in the adhesive composition is 70 to 100% by mass with respect to the total amount of the adhesive composition [ The adhesive sheet for temporary fixing according to any one of 2] to [6].
[8] The above [2] to [2], wherein the tackifying resin (B) is at least one selected from rosin resins, hydrogenated rosin resins, terpene resins, hydrogenated terpene resins, and hydrogenated petroleum resins. 7] The adhesive sheet for temporary fixing according to any one of [7].
[9] In an electronic component manufacturing process including any one or more of an etching process, a cleaning process, a heat treatment, an exposure process, and an energy ray irradiation process, the electronic component and the substrate to be subjected to the process are temporarily fixed. The temporary fixing pressure-sensitive adhesive sheet according to any one of the above [1] to [8], which is used for the purpose.

  The pressure-sensitive adhesive sheet for temporary fixing of the present invention is excellent in solvent resistance and heat resistance to organic solvents and water, and has good easy peelability.

It is sectional drawing of this adhesive sheet which shows an example of a structure of the adhesive sheet for temporary fixing of this invention.

In the following description, “weight average molecular weight (Mw)” and “number average molecular weight (Mn)” are values in terms of polystyrene measured by a gel permeation chromatography (GPC) method, specifically examples. It is the value measured based on the method described in.
For example, “(meth) acrylic acid” is used as a term indicating both “acrylic acid” and “methacrylic acid”, and the same applies to other similar terms.

[Configuration of temporary fixing adhesive sheet]
The pressure-sensitive adhesive sheet for temporary fixing of the present invention (hereinafter, also simply referred to as “pressure-sensitive adhesive sheet”) is a polyisobutylene resin on at least one surface of a base film containing at least one of polyimide and polyethylene naphthalate at 80% by mass or more. It has the adhesive layer which consists of an adhesive composition containing (A).
FIG. 1 is a cross-sectional view of an adhesive sheet showing an example of the structure of the adhesive sheet of the present invention.
As an adhesive sheet of this invention, the adhesive sheet 1 which has the structure by which the adhesive layer 12 was provided on the base film 11 like the adhesive sheet shown by Fig.1 (a) is mentioned, for example. Moreover, it is good also as adhesive sheet 1 'which has the structure which laminated | stacked the peeling material 13 on the adhesive layer 12 of the adhesive sheet 1 like the adhesive sheet shown by FIG.1 (b).
In addition, the pressure-sensitive adhesive sheet 2 having a configuration in which the pressure-sensitive adhesive layers 12a and 12b are provided on both surfaces of the base film 11 as in the pressure-sensitive adhesive sheet shown in FIG. 1C, or FIG. It is good also as adhesive sheet 2 'which has the structure which laminated | stacked peeling materials 13a and 13b on adhesive layer 12a, 12b of adhesive sheet 2 further like the adhesive sheet shown by.

  The thickness of the base film is preferably 10 to 250 μm, more preferably 15 to 200 μm, and still more preferably 20 to 150 μm, from the viewpoint of ease of handling.

  The thickness of one adhesive layer becomes like this. Preferably it is 0.5-100 micrometers, More preferably, it is 1-60 micrometers, More preferably, it is 3-40 micrometers. When the thickness of the pressure-sensitive adhesive layer is 0.5 μm or more, it can be a pressure-sensitive adhesive sheet having a good adhesive force to the adherend. On the other hand, when the thickness of the pressure-sensitive adhesive layer is 100 μm or less, it is advantageous in terms of productivity and can be an easy-to-handle pressure-sensitive adhesive sheet.

  The thickness of the release material is not particularly limited, but is preferably 20 to 200 μm, more preferably 25 to 150 μm, and still more preferably 30 to 100 μm.

[Base film]
The base film that the pressure-sensitive adhesive sheet of the present invention has is a base film containing at least one of polyimide and polyethylene naphthalate in an amount of 80% by mass or more from the viewpoint of making the pressure-sensitive adhesive sheet excellent in heat resistance. It is preferable that it is a base film which consists of at least one.
As said base film, the film etc. which are marketed as a polyimide film and a polyethylene naphthalate film are mentioned.

  The total content of polyimide and polyethylene naphthalate in the base film is 80% by mass or more, preferably 80-100% by mass, more preferably 90-100, from the viewpoint of making the pressure-sensitive adhesive sheet excellent in heat resistance. It is 95 mass%, More preferably, it is 95-100 mass%, More preferably, it is 100 mass%.

  In addition, in the range which does not impair the effect of this invention, in addition to a resin other than a polyimide and a polyethylene naphthalate, a ultraviolet absorber, a light stabilizer, antioxidant, antistatic agent, slip An agent, an antiblocking agent, a coloring agent, etc. may be contained.

The base film used in the present invention may be a resin film made of a resin composition containing only polyimide or polyethylene naphthalate, or may be a resin film made of a resin composition containing both polyimide and polyethylene naphthalate.
The base film may be a laminated film in which a plurality of resin films including at least one of polyimide and polyethylene naphthalate are laminated.

From the viewpoint of improving the adhesion to the pressure-sensitive adhesive layer, the base film may be subjected to a surface treatment such as an oxidation method or a concavo-convex method.
The oxidation method is not particularly limited, and examples thereof include a corona discharge treatment method, a plasma treatment method, chromic acid oxidation (wet), flame treatment, hot air treatment, and ozone / ultraviolet irradiation treatment.
The unevenness forming method is not particularly limited, and examples thereof include a sand blast method and a solvent treatment method.
These surface treatments are appropriately selected according to the type of the base film, but the corona discharge treatment method is preferable from the viewpoint of improving the adhesion with the pressure-sensitive adhesive layer and operability. Moreover, in order to acquire the effect of an adhesive improvement, a primer process can also be given separately.
(Adhesive layer)
The pressure-sensitive adhesive layer of the present invention is formed from a pressure-sensitive adhesive composition containing a polyisobutylene resin (A).
It is preferable that the said adhesive composition contains tackifying resin (B) further.
In addition to the above components (A) and (B), an olefin polymer (C), a silane compound (D), and a platinum catalyst (E) having 0.3 or more double bonds in one molecule. And may contain other additives such as light stabilizers, antioxidants, ultraviolet absorbers, resin stabilizers, fillers, pigments, extenders and the like as long as the effects of the present invention are not impaired. .
However, from the viewpoint of improving both the solvent resistance and heat resistance of the pressure-sensitive adhesive sheet, it is preferable that the pressure-sensitive adhesive composition consists essentially of the polyisobutylene resin (A) and the tackifier resin (B).
Hereinafter, each component contained in the adhesive composition which forms the adhesive layer of the adhesive sheet of this invention is demonstrated.

<Polyisobutylene resin (A)>
The pressure-sensitive adhesive composition used in the present invention contains a polyisobutylene resin (A) (hereinafter also simply referred to as “resin (A)”).
The structure of the polyisobutylene resin (A) is a resin having a polyisobutylene skeleton in the main chain or side chain, and a resin having the following structural unit (a).

Examples of the resin (A) include polyisobutylene which is a homopolymer of isobutylene, a copolymer of isobutylene and isoprene, a copolymer of isobutylene and n-butene, a copolymer of isobutylene and butadiene, and a homopolymer of these. Examples thereof include halogenated butyl rubber obtained by bromination or chlorination of a polymer or a copolymer.
These resins (A) may be used alone or in combination of two or more.
In addition, when resin (A) is a copolymer, the structural unit which consists of isobutylene shall be contained most in all the monomer components.
The content of the structural unit composed of isobutylene is preferably 80 to 100% by mass, more preferably 90 to 100% by mass, still more preferably 95 to 100% by mass, based on all the structural units contained in the resin (A). Even more preferably, it is substantially 100% by mass.

The resin (A) used in the present invention may be a polyisobutylene resin having a polymerizable double bond at the terminal, but from the viewpoint of obtaining a pressure-sensitive adhesive sheet having high durability and excellent solvent resistance. In this case, a polyisobutylene resin having a dense molecular structure and containing a structural unit composed of isobutylene that does not leave a polymerizable double bond in the main chain and side chain is preferable.
The content of the structural unit composed of isobutylene that does not leave a polymerizable double bond in the main chain and side chain is preferably 80 to 100% by mass with respect to all the structural units contained in the resin (A). Preferably it is 90-100 mass%, More preferably, it is 95-100 mass%, More preferably, it is 100 mass% substantially.

Examples of the method for synthesizing the resin (A) include a method in which a monomer component such as isobutylene is polymerized in the presence of a Lewis acid catalyst such as aluminum chloride or boron trifluoride. Moreover, as resin (A), not only a synthetic product but a commercial item can also be used.
Examples of commercially available products include Vistanex (manufactured by Exxon Chemical Co.), Hycar (manufactured by Goodrich), Opanol (manufactured by BASF), and the like.

  The weight average molecular weight of the resin (A) is preferably 30,000 to 900,000, more preferably 50,000 to 700,000, still more preferably 80,000 to 550,000, and still more preferably 100,000 to 480,000.

  The content of the resin (A) in the pressure-sensitive adhesive composition is preferably 50% by mass or more, more preferably, based on the total amount of the pressure-sensitive adhesive composition, from the viewpoint of improving both the solvent resistance and heat resistance of the pressure-sensitive adhesive sheet. Is 60-95 mass%, More preferably, it is 70-90 mass%, More preferably, it is 75-87 mass%.

Moreover, in this invention, it is preferable that resin (A) contained in an adhesive composition contains 2 or more types of polyisobutylene-type resin from which a weight average molecular weight differs, and a weight average molecular weight is 270,000-480,000. More preferably, the polyisobutylene resin (A1) and the polyisobutylene resin (A2) having a weight average molecular weight of 100,000 to 250,000 are included.
By containing the polyisobutylene resin (A1) (hereinafter also referred to as “resin (A1)”), the cohesive force of the pressure-sensitive adhesive composition can be improved, and the easy peelability of the resulting pressure-sensitive adhesive sheet can be improved. . On the other hand, by containing the polyisobutylene-based resin (A2) (hereinafter also referred to as “resin (A2)”), the resin (A1) is well compatible and the resin (A1) is appropriately plasticized. It can be set as the adhesive sheet which has moderate adhesive force for temporarily fixing.

The weight average molecular weight of the resin (A1) is from 270,000 to 480,000, preferably from 300,000 to 450,000, more preferably from 320,000 to 400,000, and even more preferably from 340,000 to 370,000.
If the weight average molecular weight of resin (A1) is 270,000 or more, moderate cohesive force will be obtained and the easy peelability of the obtained adhesive sheet can be improved. Moreover, if the weight average molecular weight of resin (A1) is 480,000 or less, the wettability with respect to a to-be-adhered body can be improved, and moderate adhesive force can be obtained for temporary fixation.

Although the weight average molecular weight of resin (A2) is 100,000-250,000, Preferably it is 120,000-230,000, More preferably, it is 150,000-220,000, More preferably, it is 180,000-210,000.
If the weight average molecular weight of the resin (A2) is 100,000 or more, the phenomenon that the resin (A2) is separated as a low molecular component and the adherend is contaminated or the possibility of adversely affecting the physical properties is suppressed. it can. On the other hand, when the weight average molecular weight of the resin (A2) is 250,000 or less, the resin (A1) can be sufficiently plasticized, and an appropriate adhesive force for temporary fixing can be obtained.

  About the content rate of resin (A1) and resin (A2) in an adhesive composition, from a viewpoint of obtaining the balance of adhesive force and cohesive force, content of resin (A2) is 100 mass parts of resin (A1). On the other hand, it is preferable to adjust so that it may become 1-55 mass parts, Preferably it is 3-40 mass parts, More preferably, it is 5-30 mass parts, More preferably, it is 8-20 mass parts.

<Tackifying resin (B)>
It is preferable that the adhesive composition further contains a tackifier resin (B) from the viewpoint of improving the adhesive strength.
The tackifier resin (B) is preferably at least one selected from rosin resins, hydrogenated rosin resins, terpene resins, hydrogenated terpene resins, and hydrogenated petroleum resins, and is compatible with the resin (A). From the viewpoint of high, hydrogenated petroleum resin is more preferable.
In addition, you may use these tackifier resin (B) individually or in combination of 2 or more types.

Examples of rosin resins include rosin resins, rosin phenol resins, and ester compounds thereof. Hydrogenated rosin resins include fully hydrogenated resins or partially hydrogenated resins obtained by hydrogenating these rosin resins. Resin.
Examples of terpene resins include terpene resins, terpene phenol resins, aromatic modified terpene resins, etc., and hydrogenated terpene resins include fully hydrogenated resins or partially hydrogenated hydrogenated terpene resins. Resin.

The hydrogenated petroleum resin means a hydrogenated petroleum resin, and includes not only a completely hydrogenated resin but also partially hydrogenated resins having different hydrogenation rates.
The petroleum resin is a resin derived from petroleum, and is a concept that excludes biologically derived resins such as the above-mentioned rosin resin, hydrogenated rosin resin, terpene resin, and hydrogenated terpene resin. is there.
Specific hydrogenated petroleum resins include hydrogenated resins of C5 petroleum resins obtained by copolymerizing C5 fractions, hydrogenated resins of C9 petroleum resins obtained by copolymerizing C9 fractions, and C5. One or more selected from the group consisting of hydrogenated resins of copolymer petroleum resins of fractions and C9 fractions are preferred.
Examples of the hydrogenated resin of the C5 petroleum resin include a hydrogenated dicyclopentadiene resin or a partially hydrogenated aromatic modified dicyclopentadiene resin.
The above “C5 fraction” means an unsaturated hydrocarbon having 5 carbon atoms, such as pentene, isoprene, piperine, 1.3-pentadiene, which is produced by the thermal decomposition of petroleum naphtha. "Resin" means a resin obtained by copolymerizing this C5 fraction and containing the C5 fraction as a main component (including at least 20% by mass or more).
In addition, the “C9 fraction” means an unsaturated hydrocarbon having 9 carbon atoms such as indene, vinyltoluene, α or β-methylstyrene, which is generated by thermal decomposition of petroleum naphtha. “Resin” means a resin obtained by copolymerizing the C9 fraction and containing the C9 fraction as a main component (including at least 20% by mass or more).

The softening point of the tackifier resin (B) is preferably 70 to 150 ° C., more preferably 80 to 140 ° C., and still more preferably 90 to 135 ° C., from the viewpoints of improvement in adhesive strength and easy peelability. More preferably, it is 100-130 degreeC.
If the said softening point is 70 degreeC or more, the cohesion force of an adhesive composition will improve and adhesive force can be improved. On the other hand, if the said softening point is 150 degrees C or less, generation | occurrence | production of the zipping at the time of peeling an adhesive sheet can be suppressed, and easy peelability can be improved.
Moreover, the adhesive force can also be improved by combining two or more tackifying resins (B) having different softening points.
In the present invention, the “softening point” of the tackifier resin (B) is a value measured according to JIS K 2531, and specifically means a value measured by the method described in the examples.

The content of the tackifier resin (B) in the pressure-sensitive adhesive composition improves the adhesive strength of the pressure-sensitive adhesive sheet and, from the viewpoint of improving solvent resistance and heat resistance, with respect to 100 parts by mass of the component (A), Preferably it is 3-50 mass parts, More preferably, it is 5-40 mass parts, More preferably, it is 7-30 mass parts, More preferably, it is 8-25 mass parts.
If the said content is 3 mass parts or more, the adhesive force requested | required as an adhesive sheet for temporary fixation of a process target object can be expressed. On the other hand, if the said content is 50 mass parts or less, the solvent resistance and heat resistance of an adhesive sheet can be improved.
In addition, the content of the tackifier resin (B) with respect to the total amount of the pressure-sensitive adhesive composition is preferably 2 to 50% by mass, more preferably 4 to 35% by mass, and still more preferably 6 to 25% by mass from the above viewpoint. is there.

  Further, the total content of the polyisobutylene resin (A) and the tackifier resin (B) in the adhesive composition is from the viewpoint of improving the adhesive strength, solvent resistance and heat resistance of the adhesive sheet. The total amount is preferably 70 to 100% by mass, more preferably 75 to 100% by mass, still more preferably 80 to 100% by mass, and still more preferably 83 to 100% by mass.

<Olefin polymer (C) having 0.3 or more double bonds in one molecule>
The adhesive composition includes an olefin polymer (C) having 0.3 or more double bonds in one molecule (hereinafter referred to as “polymer (C) as components other than the components (A) and (B). ) ”)).
The number of double bonds in one molecule of the polymer (C) is 0.3 or more, preferably 0.3 or more and less than 3.0, more preferably 0.5 or more and 3. Less than 0, more preferably 0.7 or more and less than 2.5, still more preferably 1.1 or more and less than 2.2.
It is considered that the polymer (C) is crosslinked with a silane compound (D) described later to form a pseudo crosslinked structure between the high molecular weight polymers of the resin (A).
That is, in the pressure-sensitive adhesive composition of the present invention, the (C) component, which is a low molecular weight polymer conventionally used as a plasticizer, is chemically crosslinked with the (D) component to form a three-dimensional network structure. And a plurality of high molecular weight polymers of the resin (A) are inserted into the three-dimensional network structure to constrain the high molecular weight polymers to each other, and between the high molecular weight polymers of the resin (A) It is considered that a pseudo-crosslinked structure is formed. The pressure-sensitive adhesive composition thus obtained is considered to improve the cohesive force and improve the pressure-sensitive adhesive force and holding power of the pressure-sensitive adhesive layer to be formed.

  The number average molecular weight of the polymer (C) is preferably 300 to 40,000, more preferably 500 to 20,000, still more preferably 1,000 to 10,000, and still more preferably 2,000 to 5,000. It is.

The content of the polymer (C) in the pressure-sensitive adhesive composition is preferably 3 to 100 parts by mass with respect to 100 parts by mass of the component (A) from the viewpoint of improving the adhesive strength and holding power of the pressure-sensitive adhesive sheet. Preferably it is 5-50 mass parts, More preferably, it is 7-35 mass parts.
Moreover, content of the polymer (C) with respect to the whole quantity of an adhesive composition becomes like this. Preferably it is 0.1-25 mass%, More preferably, it is 1-20 mass%, More preferably, it is 5-16 mass%.

  As the polymer (C), a copolymer (C1) having a structural unit derived from ethylene, propylene, and a norbornene compound represented by the following formula (I) or (II) is preferable.

In the above formula (I), R ¹ is a hydrogen atom or a substituent an alkyl group which may having 1 to 5 carbon atoms, R ² to R ⁴ are each independently a hydrogen atom, a substituent Is an alkyl group having 1 to 10 carbon atoms, and p is an integer of 0 to 10. Moreover, in said formula (II), R < ⁵ > -R < ⁷ > is a C1-C10 alkyl group which may have a hydrogen atom and a substituent each independently.

Examples of the alkyl group having 1 to 10 carbon atoms represented by R ^{2 to} R ⁷ include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a t-butyl group, Examples thereof include n-pentyl group, isopentyl group, t-pentyl group, neopentyl group, hexyl group, isohexyl group, heptyl group, octyl group, nonyl group, decyl group and the like.
The alkyl group having 1 to 5 carbon atoms represented by R ^1, among the specific examples of the R ² to R ^7, include alkyl groups of 1 to 5 carbon atoms.
In addition, when R < ¹ > -R < ⁷ > is an alkyl group, as a substituent which the said alkyl group may have, a halogen atom, a methyl group, an ethyl group etc. are mentioned, for example.

Examples of norbornene compounds represented by the general formulas (I) and (II) include 5-methylene-2-norbornene, 5-vinyl-2-norbornene, 5- (2-propenyl) -2-norbornene, 5 -(3-butenyl) -2-norbornene, 5- (1-methyl-2-propenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (1-methyl-3-butenyl) 2-norbornene, 5- (5-hexenyl) -2-norbornene, 5- (1-methyl-4-pentenyl) -2-norbornene, 5- (2,3-dimethyl-3-butenyl) -2-norbornene 5- (2-ethyl-3-butenyl) -2-norbornene, 5- (6-heptenyl) -2-norbornene, 5- (3-methyl-5-hexenyl) -2-norbornene, -(3,4-dimethyl-4-pentenyl) -2-norbornene, 5- (3-ethyl-4-pentenyl) -2-norbornene, 5- (7-octenyl) -2-norbornene, 5- (2- Methyl-6-heptenyl) -2-norbornene, 5- (1,2-dimethyl-5-hexyl) -2-norbornene, 5- (5-ethyl-5-hexenyl) -2-norbornene, 5- (1, 2,3-trimethyl-4-pentenyl) -2-norbornene, 5-ethylidene-2-norbornene and the like.
These compounds can be used alone or in combination of two or more.

In addition, R ² or R ³ and R ^{4 in the} general formula (I) may be bonded to each other to form a ring having a double bond. Similarly, R ⁵ in the general formula (II) may be formed. Alternatively, R ⁶ and R ⁷ may be bonded to each other to form a ring having a double bond. Examples of the norbornene compound in which a ring having such a double bond is formed include compounds represented by the following formulas (i) to (viii). In addition, the compounds represented by the following formulas (i) to (viii) may have a substituent such as a halogen atom, a methyl group, or an ethyl group.

  Among these, 5-vinyl-2-norbornene, 5-methylene-2-norbornene, 5- (2-propenyl)-has a relatively rigid skeleton and improves the cohesive strength of the adhesive composition. 2-norbornene, 5- (3-butenyl) -2-norbornene, 5- (4-pentenyl) -2-norbornene, 5- (5-hexenyl) -2-norbornene, 5- (6-heptenyl) -2- Norbornene, 5- (7-octenyl) -2-norbornene, 5-ethylidene-2-norbornene, and compounds represented by the above formulas (i) and (ii) are preferable, and 5-vinyl-2-norbornene is more preferable. .

As a content rate of the structural unit derived from ethylene in a copolymer (C1), Preferably it is 10-90 mol% with respect to 100 mol% of all the structural units of a copolymer (C1), More preferably, it is 20-90. Mol%, more preferably 25 to 87 mol%, more preferably 30 to 85 mol%, still more preferably 35 to 83 mol%, still more preferably 40 to 80 mol%, still more preferably 50 to 75 mol%. .
As a content rate of the structural unit derived from propylene in a copolymer (C1), Preferably it is 10-75 mol% with respect to 100 mol% of all the structural units of a copolymer (C1), More preferably, it is 10-65. It is mol%, More preferably, it is 20-60 mol%, More preferably, it is 20-55 mol%, More preferably, it is 30-50 mol%, More preferably, it is 30-45 mol%.
The content ratio of the structural unit derived from the norbornene compound represented by the general formula (I) or (II) in the copolymer (C1) is 100 mol% of all the structural units of the copolymer (C1). Preferably 0.3-35 mol%, more preferably 0.4-30 mol%, more preferably 0.5-25 mol%, more preferably 0.6-20 mol%, still more preferably 0.7- It is 15 mol%, More preferably, it is 0.8-12 mol%, More preferably, it is 1-5 mol%.
Moreover, the copolymer (C1) may have a structural unit derived from a compound other than ethylene, propylene, and the norbornene compound represented by the general formula (I) or (II).

The content ratio of the structural unit derived from ethylene in the copolymer (C1) with respect to 100 parts by mass of all the structural units of the copolymer (C1) is preferably 10 to 90% by mass, more preferably 25 to 70% by mass, More preferably, it is 35-60 mass%.
The content ratio of the structural unit derived from propylene in the copolymer (C1) with respect to 100 parts by mass of all the structural units of the copolymer (C1) is preferably 10 to 75% by mass, more preferably 20 to 60% by mass, More preferably, it is 30-50 mass%.
The content ratio of the structural unit derived from the norbornene compound represented by the general formula (I) or (II) in the copolymer (C1) with respect to 100 parts by mass of all the structural units of the copolymer (C1) is preferably 1 It is -30 mass%, More preferably, it is 2-20 mass%, More preferably, it is 3-12 mass%.

The copolymer (C1) may be any of a block copolymer, an alternating copolymer, and a random copolymer.
The number average molecular weight (Mn) of the copolymer (C1) is such that a pseudo crosslinked structure is formed between the polymers of the resin (A), the crosslinking density is increased, and the cohesive force of the adhesive composition is increased. From a viewpoint of improving, Preferably it is 300-40,000, More preferably, it is 500-20,000, More preferably, it is 1,000-10,000, More preferably, it is 2,000-5,000.

The copolymer (C1) used in the present invention is, for example, a polymerization temperature of 30 to 60 ° C., a polymerization pressure of 4 to 12 kgf / cm ^{2 in} the presence of a catalyst containing a known vanadium compound and an organoaluminum compound as main components. It is obtained by copolymerizing ethylene, propylene, and the norbornene compound represented by the general formula (I) or (II) under the conditions The copolymerization can be produced by performing it in a hydrocarbon medium.

<Silane compound (D)>
The adhesive composition may contain a silane compound (D) having a plurality of hydrosilyl groups (SiH groups) in one molecule together with the component (C). The silane compound (D) reacts with the double bond in the olefin polymer (C) and acts as a crosslinking agent.
The molecular structure of the silane compound (D) is not particularly limited, and a linear, cyclic, branched structure, or three-dimensional network structure resinous material can be used. And a hydrogen atom directly connected to the silicon atom, that is, a SiH group.

  The number of SiH groups in one molecule is preferably 2 to 6, more preferably 2 to 3, and still more preferably, from the viewpoints of forming a network by crosslinking and improving adhesive force, and improving the holding power. Two.

  The silane compound (D) is preferably a compound represented by the following general formulas (1) to (9) from the above viewpoint.

R in the general formulas (1) to (9) is each independently substituted or unsubstituted 1 having 1 to 10 carbon atoms (preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms). A valent hydrocarbon group (excluding those having an aliphatic unsaturated bond). Examples of the substituent include a halogen atom, a methyl group, and an ethyl group.
Examples of the monovalent hydrocarbon group include halogen-substituted alkyl groups such as a phenyl group and a trifluoropropyl group, in addition to the groups listed as the alkyl group having 1 to 10 carbon atoms represented by R ^{2 to} R ^7. Etc.
Among these monovalent hydrocarbons, a methyl group, an ethyl group, a propyl group, a phenyl group, and a trifluoropropyl group are preferable, a methyl group and a phenyl group are more preferable, and a part or all of R is a phenyl group. Further preferred.

  In the general formulas (1) to (9), a is an integer of 2 to 6, b is an integer of 1 or more, and c is an integer of 0 to 4. However, a is preferably an integer of 2 to 3, more preferably 2, b is preferably an integer of 1 to 5, more preferably an integer of 1 to 3, and c is preferably an integer of 0 to 1. It is an integer.

  Among the silane compounds (D) represented by the general formulas (1) to (9), a compound having two SiH groups in one molecule is preferable from the viewpoint of the balance between adhesive force and holding power. The compound represented by (5) is more preferable.

  Said silane type compound (D) can be manufactured by a well-known method. For example, when R in the above formula is a methyl group, octamethylcyclotetrasiloxane and / or tetramethylcyclotetrasiloxane, and hexamethyldisiloxane or 1,3-dihydro-1,1,3 serving as a terminal group , 3-tetramethyldisiloxane and other compounds containing a triorganosilyl group or a diorganohydrogensiloxy group in the presence of a catalyst such as sulfuric acid, trifluoromethanesulfonic acid, methanesulfonic acid, etc. It can be easily obtained by equilibrating at a certain temperature.

The content of the silane compound (D) in the pressure-sensitive adhesive composition is appropriately adjusted according to the content of the component (C). From the viewpoint of improving the pressure-sensitive adhesive force and holding power, the total amount of the pressure-sensitive adhesive composition. Is preferably 0.05 to 10% by mass, more preferably 0.1 to 5% by mass, and still more preferably 0.5 to 3% by mass.
Moreover, as mass ratio [(C) / (D)] of (C) component and (D) component, Preferably it is 60 / 40-98 / 2, More preferably, it is 70 / 30-95 / 5, More preferably Is 80/20 to 90/10.

<Platinum catalyst (E)>
The adhesive composition preferably further contains a platinum-based catalyst (E) in addition to the components (C) and (D).
By containing the platinum-based catalyst (E) in the adhesive composition, the cross-linking reaction between the double bond contained in the compound of the component (C) and the hydrosilyl group of the component (D) can be moderately accelerated. it can.

As the platinum-based catalyst, a known catalyst usually used for addition-curing type curing can be used. For example, a fine powder metal platinum catalyst described in US Pat. No. 2,970,150, US Pat. Chloroplatinic acid catalyst described in US Pat. No. 2,823,218, platinum and hydrocarbon complex compound described in US Pat. No. 3,159,601 and US Pat. No. 159,662 , Complex compounds of chloroplatinic acid and olefins described in US Pat. No. 3,516,946, US Pat. No. 3,775,452 and US Pat. No. 3,814,780 And a complex compound of platinum and vinylsiloxane.
Specific examples include platinum supported on platinum (platinum black), chloroplatinic acid, platinum-olefin complexes, platinum-alcohol complexes, alumina, silica, and the like.

  The content of the platinum-based catalyst (E) in the adhesive composition is appropriately adjusted according to the contents of the components (C) and (D), but the crosslinking reaction is promoted, the crosslinking density is moderate, and the strength characteristics From the viewpoint of obtaining a polymer having excellent elongation characteristics, the amount is preferably 0.001 to 5% by mass, more preferably 0.010 to 3% by mass, and still more preferably 0.015%, based on the total amount of the pressure-sensitive adhesive composition. It is -2 mass%.

<Other additives>
The adhesive composition may further contain other additives as long as the effects of the present invention are not impaired.
Examples of other additives include light stabilizers, antioxidants, ultraviolet absorbers, resin stabilizers, fillers, pigments, extenders, and the like. These additives may be used alone or in combination of two or more.

Examples of the light stabilizer include hindered amine-based, benzophenone-based, and benzotriazole-based light stabilizers.
Examples of the antioxidant include phosphate ester compounds.
Examples of the ultraviolet absorber include benzotriazole compounds, oxazolic acid amide compounds, benzophenone compounds, and the like.
Examples of the resin stabilizer include an imidazole resin stabilizer, a dithiocarbamate resin stabilizer, a phosphorus resin stabilizer, and a sulfur ester resin stabilizer.

  When these additives are blended in the adhesive composition, the content of each additive is preferably 0.01 to 8% by mass, more preferably 0.02 to 4% by mass in the adhesive composition. More preferably, it is 0.03 to 2% by mass.

  Moreover, in the adhesive composition, you may contain other resin components other than the above-mentioned component in the range which does not impair the effect of this invention.

[Release material]
As the release material, a release sheet that has been release-treated on both sides of the release material substrate, a release sheet that has been release-treated on one side, or the like, and a release agent coated on the release material substrate, etc. Is mentioned.
Examples of the substrate for the release material include polyester film such as polyethylene terephthalate resin, polybutylene terephthalate resin and polyethylene naphthalate resin, and plastic film such as polyolefin resin film such as polypropylene resin and polyethylene resin.

  Examples of the release agent include rubber elastomers such as silicone resins, olefin resins, isoprene resins, and butadiene resins, long chain alkyl resins, alkyd resins, and fluorine resins.

[Method for producing temporary fixing pressure-sensitive adhesive sheet of the present invention]
There is no restriction | limiting in particular as a manufacturing method of the adhesive sheet of this invention, It can manufacture by a well-known method.
For example, a method of applying a solution of an adhesive composition obtained by adding an organic solvent to the above-mentioned adhesive composition onto a surface of a release treatment surface of a base film or a release material by a known application method is mentioned. It is done. Examples of the organic solvent include toluene, ethyl acetate, methyl ethyl ketone, and the like.
The solid content concentration of the solution of the adhesive composition when an organic solvent is blended is preferably 10 to 60% by mass, more preferably 10 to 45% by mass, and still more preferably 15 to 30% by mass. If it is 10% by mass or more, the amount of the organic solvent used is sufficient, and if it is 60% by mass or less, the viscosity becomes appropriate and a solution having excellent coating workability can be obtained.

  Examples of the coating method include spin coating, spray coating, bar coating, knife coating, roll coating, blade coating, die coating, and gravure coating.

  In addition, on the surface of the release treatment surface of the base film or release material, after applying the above-mentioned adhesive composition solution to form a coating film, in order to prevent the residual solvent and low-boiling components, On the other hand, it is preferable to heat at a temperature of 80 to 150 ° C. for 30 seconds to 5 minutes.

As a specific manufacturing method, the following method is mentioned by the structure of an adhesive sheet.
The pressure-sensitive adhesive sheet having the pressure-sensitive adhesive layer on one side of the base film shown in FIGS. 1A and 1B is, for example, a solution of the above-mentioned pressure-sensitive adhesive composition on one side of the base film 11. Is applied directly to form the pressure-sensitive adhesive layer 12, whereby the pressure-sensitive adhesive sheet 1 can be produced. Moreover, if the peeling material 13 is further laminated | stacked on the formed adhesive layer 12, it can be set as adhesive sheet 1 '.
In addition, the pressure-sensitive adhesive sheet 1 ′ is formed by directly applying the above-mentioned pressure-sensitive adhesive composition solution on the surface of the release material 13 that has been subjected to the release treatment, thereby forming the pressure-sensitive adhesive layer 12. The material film 11 can be bonded together. And if the peeling material 13 of this adhesive sheet 1 'is removed, the adhesive sheet 1 can be obtained.

Moreover, the adhesive sheet which has an adhesive layer on both surfaces of a base film shown by FIG.1 (c), (d), for example, the solution of the above-mentioned adhesive composition on both surfaces of the base film 11 is shown. By directly applying and forming the pressure-sensitive adhesive layers 12a and 12b, the pressure-sensitive adhesive sheet 2 can be produced. Moreover, if release material 13a, 13b is further laminated | stacked on the formed adhesive layer 12a, 12b, it can be set as adhesive sheet 2 '.
In addition, two pressure-sensitive adhesive sheets 2 ′ are prepared by directly applying the above-mentioned pressure-sensitive adhesive composition solution on the surface of the release material 13 that has been subjected to the release treatment, and forming a pressure-sensitive adhesive layer. The pressure-sensitive adhesive layers can be bonded to both surfaces of the film 11, respectively. And if the peeling materials 13a and 13b of this adhesive sheet 2 'are removed, the adhesive sheet 2 can be obtained.

[Use of adhesive sheet for temporary fixing of the present invention]
The pressure-sensitive adhesive sheet for temporary fixing of the present invention is excellent in solvent resistance and heat resistance to organic solvents and water, and has good easy peelability.
Therefore, the pressure-sensitive adhesive sheet for temporary fixing according to the present invention is a target for performing the process in the manufacturing process of an electronic material including any one or more of an etching process, a cleaning process, a heat treatment, an exposure process, and an energy beam irradiation process. It is suitable as an adhesive sheet used for temporarily fixing a certain electronic component and a substrate.
Among the above treatments, in view of the above characteristics of the pressure-sensitive adhesive sheet of the present invention, the pressure-sensitive adhesive sheet is more suitable as a pressure-sensitive adhesive sheet for temporarily fixing the electronic material and the substrate during the etching treatment, cleaning treatment, and heat treatment.
Examples of the electronic material include a gas barrier film such as a silicon nitride film and a silicon oxide film, and an electronic material having a conductive film. Moreover, a glass plate etc. are mentioned as a board | substrate temporarily fixed using the adhesive sheet of this invention.

  The physical property value of each component used in the following examples and comparative examples is a value measured by the following method.

<Weight average molecular weight (Mw), number average molecular weight (Mn)>
Using a gel permeation chromatograph device (product name “HLC-8020” manufactured by Tosoh Corporation), the value measured under the following conditions and measured in terms of standard polystyrene was used.
(Measurement condition)
・ Column: “TSK guard column HXL-H” “TSK gel GMHXL (× 2)” “TSK gel G2000HXL” (both manufactured by Tosoh Corporation)
-Column temperature: 40 ° C
・ Developing solvent: Tetrahydrofuran ・ Flow rate: 1.0 mL / min

<Softening point>
A value measured according to JIS K 2531 was used.

[Example 1]
(1) Preparation of solution of adhesive composition (A1) As component, “Opanol B50 (trade name, manufactured by BASF, weight average molecular weight 340,000)” is 100 parts by mass (solid content ratio), (A2) as component , “Opanol B30 (trade name, manufactured by BASF, weight average molecular weight 200,000)” as 10 parts by mass (solid content ratio), (B) component, “Arcon P-125 (trade name, manufactured by Arakawa Chemical Industries, Ltd., Hydrogenated petroleum resin, softening point 125 ° C.) ”is mixed with 20 parts by mass (solid content ratio) to obtain an adhesive composition (1), dissolved in toluene, and an adhesive composition having a solid content concentration of 20% by mass. A solution of (1) was prepared.
(2) Preparation of pressure-sensitive adhesive sheet Next, the pressure-sensitive adhesive prepared on the release-treated surface of a release film (manufactured by Lintec, product name “SP-PET 381031”, thickness 38 μm, surface polyethylene-treated terephthalate film). The solution of composition (1) was applied so that the film thickness after drying was 20 μm, and dried at 100 ° C. for 1 minute to form an adhesive layer.
Then, a 100 μm thick polyethylene naphthalate film (manufactured by Teijin Ltd., trade name “Teonex Q65FA”) made of polyethylene naphthalate was bonded to the surface of the formed pressure-sensitive adhesive layer to produce a pressure-sensitive adhesive sheet.

[Example 2]
As the component (A1), 100 parts by mass (solid content ratio) of “Opanol B50 (trade name, manufactured by BASF Corp., weight average molecular weight 340,000)” and as component (A2) “Opanol B30 (trade name, manufactured by BASF Corp.) , “Weight average molecular weight 200,000)” as 10 parts by mass (solid content ratio), and as component (B), “Arcon P-125 (trade name, manufactured by Arakawa Chemical Industries, hydrogenated petroleum resin, softening point 125 ° C.)” 10 parts by mass (solid content ratio), and as component (C), “PX-062 (trade name, manufactured by Mitsui Chemicals, ethylene / propylene / 5-vinyl-2-norbornene = 50.0 / 45.3 / 4. 7 (mass%) copolymer, number average molecular weight 3160) "as 20 parts by mass (solid content ratio), (D) component," X93-1260 (trade name, manufactured by Shin-Etsu Chemical Co., Ltd.) Silane compounds having two SiH groups ( In the general formula (5), the compound in the case of b = 1)) is 2.6 parts by mass (solid content ratio) and the component (E) is “X93-1410 (trade name, manufactured by Mitsui Chemicals, platinum) 0.08 parts by mass (solid content ratio) "is obtained to obtain an adhesive composition (2), dissolved in toluene, and a solution of the adhesive composition (2) having a solid content concentration of 20% by mass Was prepared.
And the adhesive sheet was produced like Example 1 using the solution of the prepared adhesive composition (2).

[Comparative Example 1]
Acrylic compound synthesized by using 30 parts by mass of n-butyl acrylate, 70 parts by mass of 2-ethylhexyl acrylate, 7 parts by mass of methyl methacrylate, 3 parts by mass of acrylic acid, and 0.9 parts by mass of 2-hydroxypropyl acrylate. Isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd.) with respect to 100 parts by mass (solid content) of ethyl acetate solution (solid content concentration 45% by mass, copolymer weight average molecular weight 500,000) of acid ester copolymer (1). , Trade name “Coronate L”, ethyl acetate solution of trimethylolpropane modified tolylene diisocyanate, solid content 75% by weight, 3 parts by weight (solid content ratio), ethyl acetate added, solid content concentration 20% by weight A solution of the adhesive composition (3) was prepared.
And the adhesive sheet was produced like Example 1 using the solution of the prepared adhesive composition (3).

[Comparative Example 2]
Ethyl acetate solution of acrylic ester copolymer (2) obtained by synthesis using 90 parts by mass of n-butyl acrylate and 10 parts by mass of acrylic acid (solid content concentration 30% by mass, weight average of copolymer) Molecular weight 500,000) 100 parts by mass (solid content), isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane, trade name “Coronate L”, ethyl acetate solution of trimethylolpropane-modified tolylene diisocyanate, solid content 75% by mass) 0.5 parts by mass (solid content ratio) was added, and ethyl acetate was added to prepare a solution of the adhesive composition (4) having a solid content concentration of 20% by mass.
And the adhesive sheet was produced like Example 1 using the solution of the prepared adhesive composition (4).

[Comparative Example 3]
Synthesis using 61 parts by mass of n-butyl acrylate, 18 parts by mass of methyl methacrylate, 12 parts by mass of methyl acrylate, 3.5 parts by mass of styrene, 5.0 parts by mass of 2-hydroxyethyl methacrylate, and 0.15 parts by mass of acrylic acid. To 100 parts by mass (solid content) of the ethyl acetate solution (solid content concentration 40% by mass, copolymer weight average molecular weight 450,000) of the acrylate copolymer (3) thus obtained 4 parts by mass (solid content ratio) of a cross-linking agent (manufactured by Nippon Polyurethane Co., Ltd., trade name “Coronate L”, ethyl acetate solution of trimethylolpropane-modified tolylene diisocyanate, solid content 75%), and another isocyanate-based cross-linking agent ( 3 parts by mass (solid content ratio) manufactured by Takeda Pharmaceutical Co., Ltd., trade name “D-110N”, solid content concentration 75% by mass) Le was added, a solid content concentration of 20 mass% of the adhesive composition solution (5) was prepared.
And the adhesive sheet was produced like Example 1 using the solution of the prepared adhesive composition (5).

[Comparative Example 4]
Ethyl acetate solution of acrylic acid ester copolymer (4) obtained by synthesis using 98 parts by mass of n-butyl acrylate and 2 parts by mass of acrylic acid (solid content concentration 40% by mass, weight of copolymer) 50 parts by mass of “Hari Star TF (trade name, manufactured by Harima Kasei Co., Ltd., rosin ester resin, softening point: 75 to 85 ° C.)” for 100 parts by mass (solid content) (average molecular weight: 1 million) (Solid content ratio), isocyanate-based crosslinking agent (manufactured by Nippon Polyurethane Co., Ltd., product name “Coronate L”, ethyl acetate solution of trimethylolpropane-modified tolylene diisocyanate, solid content 75% by mass), 0.75 part by mass (solid content ratio) ) And ethyl acetate was added to prepare a solution of the adhesive composition (6) having a solid content concentration of 20% by mass.
And the adhesive sheet was produced like Example 1 using the solution of the prepared adhesive composition (6).

  Using the pressure-sensitive adhesive sheets prepared in the above Examples and Comparative Examples, the following tests were performed to evaluate various properties of the pressure-sensitive adhesive sheets. The results are shown in Table 1.

<Test 1: Solvent resistance (solvent immersion)>
On a glass plate used for the solvent resistance test for acetone, isopropyl alcohol (IPA) and etchant, oily magic (product name “Mckey extra fine” manufactured by Zebra Co., Ltd.) in a frame of 40 mm length × 20 mm width, 5 mm length And 40 grids were written every 4 mm in width, and the adhesive sheet produced in the examples and comparative examples in which the release film was peeled off to expose the adhesive layer was adhered so that all the writing parts of the oily magic were covered. The agent layer was attached to a glass plate to prepare a solvent resistance test plate.
Also, on a glass plate used for a solvent resistance test against distilled water, a medicine wrapping paper (manufactured by Hakuaisha Co., Ltd., trade name “Parapin”) cut to 40 mm in length and 20 mm in width is placed, and the release film is peeled off from it. Then, the pressure-sensitive adhesive sheets prepared in Examples and Comparative Examples in which the pressure-sensitive adhesive layer was exposed were pasted on a glass plate so that the entire surface of the medicine-wrapped paper was covered, thereby preparing a solvent resistance test plate.
And after immersing said solvent resistance test board in each solvent of acetone, IPA, an etchant (the Kanto Chemical Co., Ltd. make, brand name "SEA-1"), and distilled water for 1 hour, The bleeding of the writing part or the wetness of the medicine wrapping paper was visually observed, and the solvent resistance of the pressure-sensitive adhesive sheet when immersed in each solvent was evaluated according to the following criteria.
A: No penetration of solvent was observed.
B: A slight penetration of the solvent was observed, but no floating or peeling was observed.
C: Infiltration of the solvent was observed, and floating and peeling were observed.

<Test 2: Solvent resistance (ultrasonic cleaning)>
After the solvent resistance test plate prepared in the above test 1 is immersed in each solvent of IPA or distilled water for 1 hour, it is a test piece using an ultrasonic cleaning device (trade name “5510J-DTH” manufactured by Yamato Kagaku Co., Ltd.). Was subjected to ultrasonic waves for 10 minutes. After performing this operation three times, the adhesive sheet when the oily magic writing part of the test plate is blotted or the medicine-wrapping paper is visually observed and subjected to ultrasonic treatment in each solvent according to the following criteria. The solvent resistance of was evaluated.
A: No penetration of solvent was observed.
B: A slight penetration of the solvent was observed, but no floating or peeling was observed.
C: Infiltration of the solvent was observed, and floating and peeling were observed.

<Test 3: Heat resistance>
The pressure-sensitive adhesive layer of the pressure-sensitive adhesive sheet prepared in Examples and Comparative Examples in which the release film was peeled off to expose the pressure-sensitive adhesive layer was attached to a glass plate to prepare a heat resistance test plate.
After the heat resistance test plate was heated at 150 ° C. for 1 hour, the appearance of the test plate was visually observed, and the heat resistance of the pressure-sensitive adhesive sheet was evaluated according to the following criteria.
A: No swelling was observed.
F: Swelling was observed.

<Test 4: Easy peelability>
After test 3 is finished, peel off the adhesive sheet attached to the heat-resistant test plate cooled to room temperature (25 ° C) by hand, and visually observe the presence of adhesive residue on the glass plate. The peelability was evaluated.
A: No adhesive residue was formed on the glass plate, and it was peeled off cleanly.
F: Adhesive residue was formed on the glass plate.

From the results shown in Table 1, it can be seen that the pressure-sensitive adhesive sheets of Examples 1 and 2 are excellent in solvent resistance and heat resistance, and are easy to peel.
On the other hand, although the pressure-sensitive adhesive sheets of Comparative Examples 1, 2, and 4 have relatively good solvent resistance, they are inferior in heat resistance, and are not suitable, for example, in the manufacturing process of electronic components that involve heat treatment. Moreover, the adhesive sheet of Comparative Example 3 resulted in poor solvent resistance.

  The pressure-sensitive adhesive sheet for temporary fixing of the present invention is a gas barrier such as a silicon nitride film or a silicon oxide film before performing an etching process, a cleaning process, a heat treatment, an exposure process, an energy ray irradiation process or the like in an electronic component manufacturing process. It is suitable as an application as an adhesive sheet for temporarily fixing an electronic material having a film or a conductive film to a glass plate or a substrate.

1, 1 ', 2, 2' Adhesive sheet 11 Base film 12, 12a, 12b Adhesive layer 13, 13a, 13b Release material

Claims (9)

  Temporary fixing adhesive having an adhesive layer made of an adhesive composition containing a polyisobutylene resin (A) on at least one surface of a base film containing at least one of polyimide and polyethylene naphthalate at 80% by mass or more Sheet.   The pressure-sensitive adhesive sheet for temporary fixing according to claim 1, wherein the pressure-sensitive adhesive composition further contains a tackifier resin (B).   The pressure-sensitive adhesive sheet for temporary fixing according to claim 1 or 2, wherein the polyisobutylene resin (A) contains two or more polyisobutylene resins having different weight average molecular weights.   The polyisobutylene resin (A) contains a polyisobutylene resin (A1) having a weight average molecular weight of 270,000 to 480,000 and a polyisobutylene resin (A2) having a weight average molecular weight of 100,000 to 250,000. The adhesive sheet for temporary fixing as described in any of the above.   The content of polyisobutylene resin (A) in the said adhesive composition is 50 mass% or more with respect to the whole quantity of an adhesive composition, For temporary fixation in any one of Claims 1-4 Adhesive sheet.   Temporary fixing in any one of Claims 2-5 whose content of tackifying resin (B) in the said adhesive composition is 3-50 mass parts with respect to 100 mass parts of (A) component. Adhesive sheet.   The total content of the polyisobutylene resin (A) and the tackifier resin (B) in the pressure-sensitive adhesive composition is 70 to 100% by mass with respect to the total amount of the pressure-sensitive adhesive composition. The adhesive sheet for temporary fixing as described in any of the above.   The tackifier resin (B) is one or more selected from rosin resins, hydrogenated rosin resins, terpene resins, hydrogenated terpene resins, and hydrogenated petroleum resins. The adhesive sheet for temporary fixing as described.   In order to temporarily fix an electronic component and a substrate to be processed in an electronic component manufacturing process including any one or more of an etching process, a cleaning process, a heat treatment, an exposure process, and an energy ray irradiation process The pressure-sensitive adhesive sheet for temporary fixing according to any one of claims 1 to 8, which is used.