ADHESIVE SHEET AND POLISHING PAD WITH ADHESIVE SHEET

Abstract

The present invention aims to provide an adhesive sheet excellent in both shear strength and slurry resistance at high temperature and excellent in removability that enables removal without adhesive residue. The present invention also aims to provide a polishing pad with an adhesive sheet including the adhesive sheet. Provided is an adhesive sheet including at least one adhesive layer, the adhesive layer containing a base polymer, a tackifier resin (T1) having a hydroxy value of less than 20 mgKOH/g, and a tackifier resin (T2) having a hydroxy value of 20 mgKOH/g or more and 120 mgKOH/g or less, the base polymer being a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound, and the adhesive layer containing the tackifier resin (T1) in an amount of 10 parts by weight or more and 60 parts by weight or less relative to 100 parts by weight of the base polymer, and the tackifier resin (T2) in an amount of 1 part by weight or more and 40 parts by weight or less relative to 100 parts by weight of the base polymer.

Claims

1. An adhesive sheet comprising at least one adhesive layer, the adhesive layer containing a base polymer, a tackifier resin (T1) having a hydroxy value of lower than 20 mgKOH/g, and a tackifier resin (T2) having a hydroxy value of 20 mgKOH/g or higher and 120 mgKOH/g or lower, the base polymer being a block copolymer of a monovinyl-substituted aromatic compound and a conjugated diene compound, the adhesive layer containing the tackifier resin (T1) in an amount of 10 parts by weight or more and 60 parts by weight or less relative to 100 parts by weight of the base polymer, and the tackifier resin (T2) in an amount of 1 part by weight or more and 40 parts by weight or less relative to 100 parts by weight of the base polymer.

2. The adhesive sheet according to claim 1, wherein the tackifier resin (T1) has a softening point of 110° C. or higher.

3. The adhesive sheet according to claim 1, wherein the tackifier resin (T2) has a softening point of 120° C. or higher.

4. The adhesive sheet according to claim 1, wherein the tackifier resin (T2) comprises two or more tackifier resins.

5. The adhesive sheet according to claim 1, wherein the tackifier resin (T2) contains a coumarone resin.

6. The adhesive sheet according to claim 1, wherein the tackifier resin (T2) contains at least one tackifier resin selected from the group consisting of a terpene phenol resin, a rosin resin, and a rosin-derivative resin.

7. The adhesive sheet according to claim 6, wherein the tackifier resin (T1) contains a terpene resin, and the tackifier resin (T2) contains a terpene phenol resin.

8. The adhesive sheet according to claim 1, wherein the tackifier resin (T1) contains a styrene resin.

9. The adhesive sheet according to claim 1, wherein the adhesive layer contains a tackifier resin (T3) having a hydroxy value of higher than 120 mgKOH/g in an amount of 5 parts by weight or less relative to 100 parts by weight of the base polymer.

10. The adhesive sheet according to claim 1, wherein the block copolymer contains a diblock copolymer in an amount of 10% by weight or more and 40% by weight or less.

11. The adhesive sheet according to claim 1, wherein the block copolymer is a hydrogenated product.

12. The adhesive sheet according to claim 1, further comprising a substrate, wherein the adhesive sheet includes the adhesive layer on a first surface of the substrate, and a different adhesive layer on a second surface of the substrate.

13. A polishing pad with an adhesive sheet, comprising: the adhesive sheet according to claim 1; and a polishing pad laminated to the adhesive sheet.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0079] FIG. 1 is a cross-sectional view schematically illustrating one embodiment of the adhesive sheet of the present invention.

[0080] FIG. 2 is a cross-sectional view schematically illustrating another embodiment of the adhesive sheet of the present invention.

[0081] FIG. 3 is a cross-sectional view schematically illustrating a state in which the polishing pad with an adhesive sheet of the present invention in one embodiment is bonded to a surface plate.

DESCRIPTION OF EMBODIMENTS

[0082] Hereinafter, embodiments of the present invention will be described in more detail with reference to, but not limited to, examples.

[0083] The block copolymers used were SIS (styrene-isoprene-styrene block copolymer) 1 to 3 available from Zeon Corporation, SEBS (styrene-ethylenebutylene-styrene copolymer) 1 available from JSR Corporation, and natural rubber as shown in Table 1 below. The natural rubber used was Crepe rubber No. 1 available from Toyota Tsusho Corporation.

TABLE-US-00001 TABLE 1 Different base Block copolymer polymer Type — SIS 1 SIS 2 SIS 3 SEBS 1 Natural rubber Trade name — Quintac Quintac Quintac Dynaron — 3450 3433N 3620 8300 P Styrene wt % 19 16 14 9 0 content Amount of wt % 30 56 12 40 0 diblock copolymer

[0084] The tackifier resins used were the tackifier resin (T1), the tackifier resin (T2), and the tackifier resin (T3) shown in Table 2 below. The C5 petroleum resin M-100 was available from Arakawa Chemical Industries, Ltd. The terpene resins PX1000 and PX1150 were available from Yasuhara Chemical Co., Ltd. The styrene resin FTR2120 was available from Mitsui Chemicals, Inc. The coumarone resin V-120 was available from Nitto Chemical Co., Ltd. The terpene phenol resins T-130, T-160, S-145, and G-150 were available from Yasuhara Chemical Co., Ltd. The rosin ester resin A-125 was available from Arakawa Chemical Industries, Ltd.

TABLE-US-00002 TABLE 2 Tackifier resin (T3) Tackifier resin (T1) Tackifier resin (T2) (Hydroxy value of (hydroxy value of lower (Hydroxy value of 20 higher than 120 than 20 mgKOH/g) to 120 mgKOH/g) mgKOH/g) Type — C5 Terpene Terpene Styrene Coumarone Terpene Terpene Terpene Rosin Terpene petroleum resin resin resin resin phenol phenol phenol ester phenol resin resin resin resin resin resin Trade — M-100 PX1000 PX1150 FTR2120 V-120 T-130 T-160 S-145 A-125 G-150 name Hydroxy mgKOH/g 0 0 0 0 30 60 60 120 25 140 value Softening ° C. 100 100 115 125 120 130 160 145 125 150 point

Example 1

[0085] As shown in Table 3 below, to 100 parts by weight of the block copolymer were added 10 parts by weight of the tackifier resin (T1) and 15 parts by weight of the tackifier resin (T2), and they were stirred to prepare an adhesive solution. A polyethylene terephthalate film having one surface subjected to release treatment was provided. The adhesive solution obtained above was applied to the release-treated surface of the polyethylene terephthalate film to a dry thickness of 50 μm, and dried at 110° C. for five minutes. Thus, a laminated sheet including the polyethylene terephthalate film and an adhesive layer provided on the release-treated surface of the polyethylene terephthalate film was produced. A total of two laminated sheets were produced in the same manner.

[0086] A polyethylene terephthalate film was provided as a substrate. To a first surface of the substrate was laminated one laminated sheet such that the adhesive layer faced the substrate, and the adhesive layer is transferred and integrally laminated to the substrate. To a second surface of the substrate was laminated the other laminated sheet such that the adhesive layer faced the substrate, and the adhesive layer is transferred and integrally laminated to the substrate. Thus, a double-sided adhesive sheet including the substrate and the adhesive layers having a thickness of 50 μm on both surfaces of the substrate was obtained.

Examples 2 to 21 and Comparative Examples 1 to 5

[0087] A double-sided adhesive sheet was obtained in the same manner as in Example 1 except that the types and amounts of the block copolymer, the tackifier resin (T1), the tackifier resin (T2), and the tackifier resin (T3) were changed as shown in Table 3 or 4.

<Evaluation>

[0088] The double-sided adhesive sheets obtained in the examples and comparative examples were evaluated as follows. Tables 3 and 4 show the results.

(1) Evaluation of Removability

[0089] The double-sided adhesive sheet was cut into a size of 25 mm×75 mm, and the release film on one side of the sheet was peeled off. The adhesive sheet piece was bonded to a polyethylene terephthalate (PET) film having a thickness of 23 μm to be supported. Thus, a test piece was produced. Under an environment of 23° C., the release film covering the other adhesive face of the test piece was peeled off, and the test piece was pressure-bonded to the surface of a stainless steel (SUS304) plate by reciprocation of a 2-kg roller once. The workpiece was allowed to stand in the same environment for 20 minutes to obtain a test sample before heat treatment. The test sample before heat treatment was left to stand in an atmosphere at 60° C. for seven days to obtain a test sample after heat treatment. The obtained test samples before and after heat treatment were evaluated for adhesive residue and measured for a rate of adhesion acceleration by the following methods.

(Evaluation of Adhesive Residue)

[0090] After the double-sided adhesive sheet of the test sample after heat treatment was peeled off, the presence or absence of adhesive residue on the stainless steel plate was observed.

(Measurement of Rate of Adhesion Acceleration)

[0091] In an atmosphere at 23° C., the double-sided adhesive sheets of the test samples before and after heat treatment were peeled off in the 180° direction at a rate of 300 ram/min using a tensile tester in conformity with JIS Z 0237. Thus, the 180° peel strength was measured. Based on the 180° peel strengths of the double-sided adhesive sheets before and after heat treatment, the rate of adhesion acceleration of the double-sided adhesive sheet was calculated using the following equation.

Rate of adhesion acceleration(%)={(180° peel strength after heat treatment)/(180° peel strength before heat treatment)−1}×100

[0092] The rate of adhesion acceleration was calculated only in the case where there was no adhesive residue in the evaluation of adhesive residue.

[0093] A case where there was no adhesive residue in the evaluation of adhesive residue and the rate of adhesion acceleration was less than 5% was rated as ∘∘ (Excellent). A case where there was no adhesive residue in the evaluation of adhesive residue and the rate of adhesion acceleration was 5% or higher was rated as ∘ (Good). A case where there was adhesive residue in the evaluation of adhesive residue was evaluated as x (Poor).

(2) Evaluation of Slurry Resistance

[0094] The double-sided adhesive sheet was cut into a size of 25 mm×75 mm, and the release film on one side of the sheet was peeled off. The adhesive sheet piece was bonded to a polyethylene terephthalate (PET) film having a thickness of 23 μm to be supported. Thus, a test piece was produced. Under an environment of 23° C., the release film covering the other adhesive face of the test piece was peeled off, and the test piece was pressure-bonded to a surface of a stainless steel (SUS304) plate by reciprocation of a 2-kg roller once to obtain a test sample before immersion in a chemical solution.

[0095] Semi-Sperse 25 (available from Cabot Microelectronics) was diluted with ion-exchanged water at a ratio of 1:1 to prepare an alkaline chemical solution. The test sample before immersion in a chemical solution was immersed in the alkaline chemical solution in an atmosphere at 60° C. for seven days. Then, the test sample was taken out from the alkaline chemical solution, washed with ion-exchanged water, and then dried at 23° C. for one hour to obtain a test sample after immersion in a chemical solution.

[0096] The obtained test samples before and after immersion in a chemical solution were subjected to evaluation of peeling after immersion in a chemical solution and measurement of a change rate in 180° peel strength by the following methods.

(Evaluation of Peeling after Immersion in Chemical Solution)

[0097] The presence or absence of peeling of the double-sided adhesive sheet from the stainless steel plate in the test samples before and after immersion in a chemical solution was observed. A case where there was no peeling of the double-sided adhesive sheet was indicated as “None”. A case where there was only slight peeling of an end portion of the double-sided adhesive sheet was indicated as “End portion”. A case where the double-sided adhesive sheet was entirely peeled was indicated as “Entirely peeled”.

(Measurement of Change Rate of 180° Peel Strength)

[0098] In an atmosphere at 23° C., the double-sided adhesive sheets of the test samples before and after immersion in a chemical solution were peeled off in the 180° direction at a rate of 300 ram/min using a tensile tester in conformity with JIS Z 0237. Thus, the 180° peel strength was measured. The change rate (%) of the 180° peel strength of the adhesive layer before and after immersion in a chemical solution was calculated by the following equation.

Change rate(%)={(180° peel strength after immersion in alkaline chemical solution)/(180° peel strength before immersion in alkaline chemical solution)×1}×100

[0099] The change rate of the 180° peel strength was calculated only in the case where the double-sided adhesive sheet was not peeled or only slightly peeled at an end portion in the evaluation of peeling after immersion in chemical solution (cases determined to be “None” or “End portion”).

[0100] A case where the evaluation of peeling after immersion in a chemical solution was “None” and the change rate of the 180° peel strength was a decrease by less than 20% was evaluated as ∘∘ (Excellent). A case where the evaluation of peeling after immersion in a chemical solution was “None” and the 180° peel strength decreased by 20% or more and a case where the evaluation of peeling after immersion in a chemical solution was “End portion” were evaluated as ∘ (Good). A case where the evaluation of peeling after immersion in a chemical solution was “Entirely peeled” was evaluated as x (Poor).

(3) Measurement of Shear Strength

[0101] The double-sided adhesive sheet was cut into a size of 15 mm×15 mm, the release film on one side was peeled off, and the adhesive sheet was pressure-bonded to a stainless steel (SUS304) plate by reciprocation of a 2-kg roller once. Thus, a test piece was prepared. Under an environment of 23° C., the release film covering the other adhesive face of the test piece was peeled off, and the test piece was thermally pressure-bonded to a surface of a stainless steel (SUS304) plate at 80° C. and 3 kg/cm.sup.2 for ten seconds. Thus, a test sample was obtained. Under an atmosphere of 60° C., the double-sided adhesive sheet of the test sample was peeled off at a rate of 10 mm/min in a direction in which shear stress was applied, and the shear strength was measured.

[0102] A case where the shear strength was 160 [N/15×15 mm] or more was evaluated as ∘∘ (Excellent). A case where the shear strength was less than 160 [N/15×15 mm] and 120 [N/15×15 mm] or more was evaluated as ∘ (Good). A case where the shear strength was less than 120 [N/15×15 mm] and 80 [N/15×15 mm] or more was evaluated as Δ (Fair). A case where the shear strength was less than 80 [N/15×15 mm] was evaluated as x (Poor).

TABLE-US-00003 TABLE 3 Example 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 Ad- Block SIS 1 100 100 100 100 100 100 100 — — — 100 100 100 100 — hesive co- SIS 2 — — — — — — — 100 — — — — — — — layer polymer SIS 3 — — — — — — — — 100 — — — — — — (parts SEBS 1 — — — — — — — — — 100 — — — — 100 by Different Natural — — — — — — — — — — — — — — — weight) base rubber polymer Tackifier M-100: 10 50 60 45 45 45 45 45 45 45 — — — — — resin (T1) C5 (Hydroxy Petroleum value resin — — — — — — — — — — — — — 40 — of lower PX1000: than 20 Terpene mgKOH/ resin g) PX1150: — — — — — — — — — — 40 40 40 — 40 Terpene resin FTR2120: — — — — — — 10 — — — — — — — — Styrene resin Tackifier V-120: 15 15 15 5 15 40 5 15 15 15 — — — — — resin (T2) Couma- (Hydroxy rone value resin of 20 T-130: — — — — — — — — — — — — — — — to 120 Terpene mgKOH/ phenol g) resin T-160: — — — — — — — — — — 5 — — 5 — Terpene phenol resin S-145: — — — — — — — — — — — 5 — — 5 Terpene phenol resin A-125: — — — — — — — — — — — — 5 — — Rosin ester resin Tackifier G-150: — — — — — — — — — — — — — — — resin (T3) Terpene (Hydroxy phenol value resin of higher than 120 mgKOH/ g) Eval- Shear strength ◯ ◯ ◯ ◯ ◯◯ ◯◯ ◯◯ Δ ◯ Δ ◯ ◯ ◯ Δ ◯ uation Slurry Eval- ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯ ◯◯ ◯◯ ◯◯ ◯◯ ◯◯ ◯◯ resistance uation Peeling End End End End End End End End End None None None None None None after por- por- por- por- por- por- por- por- por- im- tion tion tion tion tion tion tion tion tion mersion Change −17.1 −9.0 −15.1 ≥0 ≥0 ≥0 ≥0 −21.1 −10.6 ≥0 −1.8 −2.0 −13.9 ≥0 ≥0 rate of 180° peel strength (%) Removability ◯ ◯◯ ◯ ◯◯ ◯◯ ◯ ◯◯ ◯ ◯◯ ◯◯ ◯◯ ◯ ◯◯ ◯ ◯◯

[0103] In Example 6 and Example 14, the evaluation result in the evaluation of removability was 0 (no adhesive residue in the evaluation of adhesive residue, and the rate of adhesion acceleration was 5% or more), but the rate of adhesion acceleration exceeded 20%.

TABLE-US-00004 TABLE 4 Example Comparative Example 16 17 18 19 20 21 1 2 3 4 5 Ad- Block copolymer SIS 1 100 100 100 100 100 100 — 100 100 100 100 hesive SIS 2 — — — — — — — — — — — layer SIS 3 — — — — — — — — — — — (parts SEBS 1 — — — — — — — — — — — by Different base polymer Natural — — — — — — 100 — — — — weight) rubber Tackifier resin (T1) M-100: C5 — — — — — — — — — — — (Hydroxy value of lower Petroleum than 20 mgKOH/g) resin PX1000: — — — — — — — — — — — Terpene resin PX1150: 40 40 40 40 40 40 40 70 40 40 40 Terpene resin FTR2120: — — — — — — — — — — — Styrene resin Tackifier resin (T2) V-120: 15 15 30 15 5 5 — — — 15 — (Hydroxy value of 20 Coumarone to 120 mgKOH/g) resin T-130: 5 — — — — — — — — — — Terpene phenol resin T-160: — 5 5 — 5 5 5 5 — 40 — Terpene phenol resin S-145: — — — 5 — — — — — — — Terpene phenol resin A-125: — — — — — — — — — — — Rosin ester resin Tackifier resin (T3) G-150: — — — — — 2.5 — — — — 5 (Hydroxy value of higher Terpene than 120 mgKOH/g) phenol resin Eval- Shear strength ◯◯ ◯◯ ◯◯ ◯◯ ◯ ◯ Δ ◯ X ◯◯ ◯ uation Slurry resistance Evaluation ◯◯ ◯◯ ◯◯ ◯◯ ◯◯ ◯◯ ◯ ◯◯ X ◯◯ ◯◯ Peeling after None None None None None None None None Entirely None None immersion peeled Change ≥0 ≥0 ≥0 ≥0 −5.9 −5.9 −23.5 −0.3 — ≥0 ≥0 rate of 180° peel strength (%) Removability ◯◯ ◯◯ ◯ ◯ ◯◯ ◯ X X ◯◯ X X

INDUSTRIAL APPLICABILITY

[0104] The present invention can provide an adhesive sheet excellent in both shear strength and slurry resistance at high temperature and excellent in removability that enables removal without adhesive residue. The present invention can also provide a polishing pad with an adhesive sheet including the adhesive sheet.

REFERENCE SIGNS LIST

[0105] 1 adhesive sheet [0106] 2 substrate [0107] 3a, 3b adhesive layer [0108] 4 polishing pad [0109] 5 Polishing pad with adhesive sheet [0110] 6 surface plate (polishing machine)