Chemical mechanical polishing pads

Abstract

The present invention provides a chemical mechanical polishing pad containing a hydrogenated block copolymer having hydrogenated polymer blocks of aromatic vinyl polymer blocks and conjugated diene polymer blocks, wherein the chemical mechanical polishing pad has grooves or holes.

Description

Technical Field

[0001] This invention relates to a chemical mechanical polishing pad. Background Technology

[0002] In recent years, chemical mechanical polishing (CMP) has been widely used in the manufacture of wafers and other materials. In CMP, a slurry is supplied to the surface of a CMP pad, and the surface of the CMP pad comes into contact with the workpiece, such as a wafer, thereby polishing the workpiece. For example, foamed polyurethane CMP pads are known as CMP pads used for this type of CMP.

[0003] On the other hand, during polishing, abrasive grains and polishing debris adhere to the polishing surface of the chemical mechanical polishing pad, thereby reducing polishing performance. Therefore, in order to regenerate the polishing surface, a dresser is used to remove the surface of the chemical mechanical polishing pad (dressing). As a result, chemical mechanical polishing pads are consumables, and from the viewpoint of reducing the replacement frequency of chemical mechanical polishing pads and reducing costs, it is desirable for chemical mechanical polishing pads to have excellent wear resistance.

[0004] For example, Patent Document 1 discloses a chemical mechanical polishing pad having a polishing layer formed from a composition containing (A) polyethylene, (B) a styrene-butadiene copolymer, and (C) a water-soluble substance. According to the chemical mechanical polishing pad disclosed in Patent Document 1, it is claimed to have excellent in-plane uniformity of polishing amount on the polished surface, few scratches, and low sliding resistance; however, the wear resistance of the chemical mechanical polishing pad disclosed in Patent Document 1 may not be sufficient.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent document 1: Japanese Patent Application Publication No. 2009-252891. Summary of the Invention

[0008] The problem the invention aims to solve

[0009] The purpose of this invention is to provide a chemical mechanical polishing pad with excellent wafer transport and wear resistance.

[0010] Solution for solving the problem

[0011] In order to achieve the above-mentioned objectives, the inventors conducted research and found that the above-mentioned objectives could be achieved by a chemical mechanical polishing pad containing a hydrogenated block copolymer having hydrogenated polymer blocks of aromatic vinyl polymer blocks and conjugated diene polymers, and having grooves or holes, thus completing the present invention.

[0012] That is, according to the present invention, the following chemical mechanical polishing pads can be provided.

[0013] [1] A chemical mechanical polishing pad comprising a hydrogenated block copolymer having hydrogenated polymer blocks of aromatic vinyl polymers and conjugated diene polymers,

[0014] The aforementioned chemical mechanical polishing pad has grooves or holes.

[0015] [2] The chemical mechanical polishing pad according to [1], wherein the hydrogenated block copolymer described above contains a hydrogenated block copolymer A represented by the following general formula (A) or a hydrogenated block copolymer B represented by the following general formula (B).

[0016]

[0017] (In the above general formula (A), Ar1) a and Ar2 a For aromatic vinyl polymer blocks, HD a Ar2 is a hydrogenated polymer block of a conjugated diene polymer. a Weight-average molecular weight (Mw(Ar2)) a ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar2)) to (Mw(Ar2)) a ) / Mw(Ar1 a The value ranges from 3.0 to 20.

[0018]

[0019] (In the above general formula (B), Ar1) b and Ar2 b For aromatic vinyl polymer blocks, HD b Ar2 is a hydrogenated polymer block of a conjugated diene polymer. b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 b Weight-average molecular weight (Mw(Ar1)) b The ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 b The value ranges from 0.95 to 1.05.

[0020] [3] The chemical mechanical polishing pad according to [2] contains, as the above-mentioned hydrogenated block copolymer, both the above-mentioned hydrogenated block copolymer A and the above-mentioned hydrogenated block copolymer B.

[0021] [4] The chemical mechanical polishing pad according to [2] or [3], wherein Ar1 in the above general formula (A) and the above general formula (B) a Ar1 b and Ar2 b The weight-average molecular weight ranges from 2000 to 40000, HD a and HD b The weight-average molecular weights range from 10,000 to 300,000.

[0022] [5] The chemical mechanical polishing pad according to [3] or [4], wherein the weight ratio (A / B) of the above-mentioned hydrogenated block copolymer A to the above-mentioned hydrogenated block copolymer B is 10 / 90 to 80 / 20.

[0023] [6] The chemical mechanical polishing pad according to any one of [1] to [5], wherein the proportion of the aromatic vinyl monomer unit in all repeating units of the hydrogenated block copolymer is 20 to 60 by weight.

[0024] [7] The chemical mechanical polishing pad according to any one of [1] to [6] further contains foamed particles or cross-linked hollow particles.

[0025] Invention Effects

[0026] According to the present invention, a chemical mechanical polishing pad with excellent wafer transport and wear resistance can be provided. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of a chemical mechanical polishing apparatus 10 according to one embodiment of the present invention. Detailed Implementation

[0028] <Chemical Mechanical Polishing Pad>

[0029] The chemical mechanical polishing pad of the present invention contains a hydrogenated block copolymer having hydrogenated polymer blocks of aromatic vinyl polymer blocks and conjugated diene polymer blocks and has grooves or holes.

[0030] (Hydrogenated block copolymer)

[0031] The hydrogenated block copolymer used in this invention is a block copolymer having hydrogenated polymer blocks of aromatic vinyl polymers and conjugated diene polymers.

[0032] The hydrogenated block copolymers used in this invention can be any copolymers having aromatic vinyl polymer blocks and conjugated diene polymer hydrogenated polymer blocks, preferably containing hydrogenated block copolymers A represented by the following general formula (A).

[0033]

[0034] In the above general formula (A), Ar1 a and Ar2 a For aromatic vinyl polymer blocks, HD a Ar2 is a hydrogenated polymer block of a conjugated diene polymer. a Weight-average molecular weight (Mw(Ar2)) a ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar2)) to (Mw(Ar2)) a ) / Mw(Ar1 a The value ranges from 3.0 to 20.

[0035] Aromatic vinyl polymer block Ar1 of hydrogenated block copolymer A a Ar2 a It is a polymer block composed of aromatic vinyl monomer units.

[0036] As for the aromatic vinyl monomers used to form the aromatic vinyl monomer units, there are no particular limitations as long as they are aromatic vinyl compounds. Examples of aromatic vinyl compounds include: styrene; alkyl-substituted styrene such as α-methylstyrene, 2-methylstyrene, 3-methylstyrene, 4-methylstyrene, 2-ethylstyrene, 3-ethylstyrene, 4-ethylstyrene, 2,4-diisopropylstyrene, 2,4-dimethylstyrene, 4-tert-butylstyrene, 5-tert-butyl-2-methylstyrene; halogen-substituted styrene such as 2-chlorostyrene, 3-chlorostyrene, 4-chlorostyrene, 4-bromostyrene, 2-methyl-4,6-dichlorostyrene, 2,4-dibromostyrene; and vinylnaphthalene, etc. Among these, styrene is preferred. These aromatic vinyl monomers can be used individually or in combination in each aromatic vinyl polymer block. Furthermore, the same aromatic vinyl monomer or different aromatic vinyl monomers can be used in each aromatic vinyl polymer block. The content of aromatic vinyl monomer units in each aromatic vinyl polymer block is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably substantially 100% by weight, relative to the total aromatic vinyl polymer block.

[0037] In addition, the aromatic vinyl polymer block Ar1 constituting hydrogenated block copolymer A a Ar2 aIt may also include monomer units other than aromatic vinyl monomer units. Examples of monomers constituting monomer units other than aromatic vinyl monomer units include conjugated diene monomers such as 1,3-butadiene and isoprene (2-methyl-1,3-butadiene); α,β-unsaturated nitrile monomers; unsaturated carboxylic acid or anhydride monomers; unsaturated carboxylic acid ester monomers; and non-conjugated diene monomers.

[0038] The content of monomer units other than aromatic vinyl monomer units in each aromatic vinyl polymer block is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably substantially 0% by weight, relative to the total aromatic vinyl polymer block.

[0039] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer A a It is a polymer block composed of conjugated diene monomer units, and at least a portion of the conjugated diene monomer units constituting the polymer block are hydrogenated.

[0040] As for the conjugated diene monomer used to form the conjugated diene monomer unit, there is no particular limitation as long as it is a conjugated diene compound. Examples of conjugated diene compounds include 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 2-chloro-1,3-butadiene, 1,3-pentadiene, and 1,3-hexadiene. Among these, from the viewpoint of polymerization reactivity, 1,3-butadiene and / or isoprene are preferred, and isoprene is particularly preferred. These conjugated diene monomers can be used individually or in combination in each hydrogenated polymer block. Furthermore, the same conjugated diene monomer or different conjugated diene monomers can be used in each hydrogenated polymer block. The content of conjugated diene monomer units (including hydrogenated conjugated diene monomer units) in each hydrogenated polymer block is preferably 80% by weight or more, more preferably 90% by weight or more, and particularly preferably substantially 100% by weight relative to the total content of the conjugated diene polymer block.

[0041] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer A a It may also include monomer units other than conjugated diene monomer units. Examples of monomers constituting monomer units other than conjugated diene monomer units include aromatic vinyl monomers such as styrene and α-methylstyrene; α,β-unsaturated nitrile monomers; unsaturated carboxylic acid or anhydride monomers; unsaturated carboxylic acid ester monomers; and non-conjugated diene monomers.

[0042] The content of monomer units other than conjugated diene monomer units (including hydrogenated conjugated diene monomer units) in each hydrogenated polymer block is preferably 20% by weight or less, more preferably 10% by weight or less, and particularly preferably substantially 0% by weight, relative to the total content of the conjugated diene polymer block.

[0043] Ar2 of hydrogenated block copolymer A a Weight-average molecular weight (Mw(Ar2)) a ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar2)) to (Mw(Ar2)) a ) / Mw(Ar1 a Within the range of 3.0 to 20, therefore, hydrogenated block copolymer A is composed of aromatic vinyl polymer blocks Ar1 with a relatively low weight-average molecular weight. a Hydrogenated polymer blocks of conjugated diene polymers (HD) a And Ar2 aromatic vinyl polymer blocks with a large weight-average molecular weight a Hydrogenates of asymmetric aromatic vinyl-conjugated diene-aromatic vinyl block copolymers formed by sequentially connecting segments.

[0044] In hydrogenated block copolymer A, Mw(Ar2) a ) / Mw(Ar1 a The value is in the range of 3.0 to 20. Mw(Ar2) a ) / Mw(Ar1 a Preferably, the value is in the range of 3.1 to 17, more preferably in the range of 3.2 to 14, and even more preferably in the range of 3.3 to 11. This is achieved by making Mw(Ar2) a ) / Mw(Ar1 a Within the aforementioned range, the resulting chemical mechanical polishing pad exhibits superior wear resistance. Furthermore, in this invention, the weight-average molecular weight (Mw) and number-average molecular weight (Mn) of the polymer and polymer blocks are determined by high-performance liquid chromatography and calculated as values ​​equivalent to polystyrene.

[0045] In addition, the aromatic vinyl polymer block Ar1, which constitutes hydrogenated block copolymer A, has a relatively low weight-average molecular weight. a Weight-average molecular weight (Mw(Ar1)) a The preferred value is 2000-40000, more preferably 2500-30000, and even more preferably 3000-10000.

[0046] In addition, the aromatic vinyl polymer block Ar2, which constitutes hydrogenated block copolymer A, has a relatively high weight-average molecular weight. a Weight-average molecular weight (Mw(Ar2))a The preferred value is 5,000 to 250,000, more preferably 8,000 to 120,000, even more preferably 10,000 to 100,000, and even more preferably 10,000 to 80,000.

[0047] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer A a Weight-average molecular weight (Mw(HD)) a The preferred value is 10,000 to 300,000, more preferably 15,000 to 300,000, even more preferably 15,000 to 150,000, and particularly preferably 20,000 to 80,000.

[0048] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer A a The vinyl bond content (the proportion of 1,2-vinyl bonds and 3,4-vinyl bonds in all conjugated diene monomer units) is preferably 1 to 80 mol%, more preferably 2 to 75 mol%, and even more preferably 3 to 70 mol%. By keeping the vinyl bond content within the above range, the wear resistance of the obtained chemical mechanical polishing pad can be made more excellent. Furthermore, the hydrogenated polymer block HD... a The vinyl bond content can be 4–30 mol%, 5–20 mol%, or 5–15 mol%. The vinyl bond content of the hydrogenated polymer blocks of the conjugated diene polymer can be adjusted by using deuterated chloroform as a solvent. 1 Calculated by H-NMR.

[0049] The content of aromatic vinyl monomer units in hydrogenated block copolymer A relative to all monomer units is not particularly limited, but is preferably 30-95% by weight, more preferably 35-90% by weight, even more preferably 40-87% by weight, and particularly preferably 43-85% by weight. The content of aromatic vinyl monomer units in hydrogenated block copolymer A relative to all monomer units can be determined based on the detection intensity ratio of the differential refractometer and the ultraviolet detector in high performance liquid chromatography.

[0050] The weight-average molecular weight of the hydrogenated block copolymer A is not particularly limited, but is preferably 20,000 to 500,000, more preferably 25,000 to 300,000, and even more preferably 30,000 to 150,000. This is achieved by adjusting the weight-average molecular weight (Mw(Ar1)) of each polymer block constituting the hydrogenated block copolymer A. a ), Mw(Ar2 a ), Mw(HD) a When the weight-average molecular weight of the combined hydrogenated block copolymer A and the hydrogenated block copolymer A is within the above-mentioned preferred range, the resulting chemical mechanical polishing pad can exhibit superior wear resistance.

[0051] Furthermore, as a hydrogenated block copolymer, it is also preferable to contain hydrogenated block copolymer B represented by the following general formula (B).

[0052]

[0053] In the above general formula (B), Ar1 b and Ar2 b For aromatic vinyl polymer blocks, HD b Ar2 is a hydrogenated polymer block of a conjugated diene polymer. b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 b Weight-average molecular weight (Mw(Ar1)) b The ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 b The value ranges from 0.95 to 1.05.

[0054] In this case, hydrogenated block copolymer B represented by the above general formula (B) can be used instead of hydrogenated block copolymer A represented by the above general formula (A). Alternatively, in addition to containing hydrogenated block copolymer A represented by the above general formula (A), hydrogenated block copolymer B represented by the above general formula (B) can also be included. In this case, the hydrogenated block copolymer can be made into a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B.

[0055] Hydrogenated block copolymer B is composed of two aromatic vinyl polymer blocks Ar1 b Ar2 b bonded to conjugated diene polymer blocks HD b The hydrogenated form of an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer, consisting of two aromatic vinyl polymer blocks Ar1 constituting the hydrogenated block copolymer B. b Ar2 b Weight-average molecular weight (Mw(Ar1)) b ), Mw(Ar2 b Satisfying Ar2 b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 b Weight-average molecular weight (Mw(Ar1)) b The ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 b The value ranges from 0.95 to 1.05.

[0056] The two aromatic vinyl polymer blocks Ar1 that constitute hydrogenated block copolymer B b Ar2b Weight-average molecular weight (Mw(Ar1)) b ), Mw(Ar2 b The values ​​are preferably 2000–40000, more preferably 2500–30000, and even more preferably 3000–10000. Two aromatic vinyl polymer blocks Ar1 b Ar2 b Weight-average molecular weight (Mw(Ar1)) b ), Mw(Ar2 b Ar2 and Ar2 can be equal or different from each other, but are preferably substantially equal. b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 b Weight-average molecular weight (Mw(Ar1)) b The ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 b The value only needs to be within the range of 0.95 to 1.05, preferably within the range of 0.97 to 1.03, more preferably within the range of 0.99 to 1.01, and particularly preferably Mw(Ar2) b ) / Mw(Ar1 b In essence, it is 1.

[0057] Furthermore, when the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, the two aromatic vinyl polymer blocks Ar1 b Ar2 b The weight-average molecular weight (Mw(Ar1)) of at least one polymer block in the composition b ), Mw(Ar2 b It can react with the aromatic vinyl polymer block Ar1, which has a smaller weight-average molecular weight, that constitutes hydrogenated block copolymer A. a Weight-average molecular weight (Mw(Ar1)) a They can be equal, or they can be different; more preferably they are substantially equal. For example, Ar1 b Weight-average molecular weight (Mw(Ar1)) b ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar1)) to (Mw(Ar1)) b ) / Mw(Ar1 a Ar2 can be in the range of 0.9 to 2.2. b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) aThe ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 a It can also be in the range of 0.9 to 2.2. Furthermore, for example, Ar1 is preferred. b Weight-average molecular weight (Mw(Ar1)) b ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar1)) to (Mw(Ar1)) b ) / Mw(Ar1 a In the range of 0.95 to 1.05, or Ar2 b Weight-average molecular weight (Mw(Ar2)) b ()) Relative to Ar1 a Weight-average molecular weight (Mw(Ar1)) a The ratio of (Mw(Ar2)) to (Mw(Ar2)) b ) / Mw(Ar1 a The value is in the range of 0.95 to 1.05.

[0058] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer B b Weight-average molecular weight (Mw(HD)) b The preferred value is 10,000 to 300,000, more preferably 15,000 to 300,000, even more preferably 15,000 to 150,000, and particularly preferably 20,000 to 80,000.

[0059] The hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer B b The vinyl bond content (the proportion of 1,2-vinyl bonds and 3,4-vinyl bonds in all conjugated diene monomer units) is preferably 1 to 80 mol%, more preferably 2 to 75 mol%, and even more preferably 3 to 70 mol%. By keeping the vinyl bond content within the above range, the wear resistance of the resulting chemical mechanical polishing pad can be improved. Furthermore, from the viewpoint of achieving even better wear resistance, the hydrogenated polymer block HD... b The vinyl bond content can be 4–30 mol%, 5–20 mol%, or 5–15 mol%. The vinyl bond content of the hydrogenated polymer blocks of the conjugated diene polymer can be adjusted by using deuterated chloroform as a solvent. 1 H-NMR was used to determine this. Furthermore, when the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, the hydrogenated polymer block HD constituting the conjugated diene polymer of hydrogenated block copolymer B... b The vinyl bond content is preferably related to the hydrogenated polymer block HD of the conjugated diene polymer constituting hydrogenated block copolymer A.a The vinyl bond content is substantially equal. For example, the hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer B. b The vinyl bond content relative to the hydrogenated polymer blocks HD of the conjugated diene polymer constituting hydrogenated block copolymer A a The vinyl bond content is preferably in the range of 0.95 to 1.05.

[0060] Furthermore, when the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, and when manufacturing the hydrogenated block copolymer composition, for example, using the manufacturing method of the hydrogenated block copolymer composition having steps (1a) to (6a) described later, or using a manufacturing method using a coupling agent, the hydrogenated polymer block HD constituting the conjugated diene polymer of the hydrogenated block copolymer B... b It may also contain residues of a coupling agent. Specifically, hydrogenated block copolymer B may also be a compound represented by the following formula.

[0061]

[0062] That is, as shown in the above formula, the hydrogenated polymer block HD of the conjugated diene polymer b It can also be HD b’ HD b’’ The form is formed by coupling via residue X of a coupling agent. In addition, residue X of the coupling agent can be exemplified as residues of a difunctional coupling agent, as illustrated in the method for manufacturing a hydrogenated block copolymer composition having steps (1a) to (6a) described later.

[0063] The content of aromatic vinyl monomer units in hydrogenated block copolymer B relative to all monomer units is not particularly limited, but is preferably 5-40% by weight, more preferably 10-38% by weight, and even more preferably 15-35% by weight. By keeping the content of aromatic vinyl monomer units within the above range, the wear resistance of the resulting chemical mechanical polishing pad can be made more excellent. The content of aromatic vinyl monomer units in hydrogenated block copolymer A relative to all monomer units can be determined based on the detection intensity ratio of the differential refractometer and the ultraviolet detector in high-performance liquid chromatography.

[0064] The overall weight-average molecular weight of the hydrogenated block copolymer B is not particularly limited, but is preferably 20,000 to 200,000, more preferably 25,000 to 150,000, and even more preferably 30,000 to 70,000. This is achieved by adjusting the weight-average molecular weight (Mw(Ar1)) of each polymer block constituting the hydrogenated block copolymer B. b ), Mw(Ar2 b ), Mw(HD) bWhen the weight-average molecular weight of the combined hydrogenated block copolymer B is within the above-mentioned preferred range, the resulting chemical mechanical polishing pad exhibits superior wear resistance.

[0065] When the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, the molecular weight distribution of hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition and each polymer block constituting them, expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) [(Mw) / (Mn)], is not particularly limited, but is preferably 1.1 or less, and more preferably 1.05 or less.

[0066] The weight ratio (A / B) of hydrogenated block copolymer A to hydrogenated block copolymer B in the hydrogenated block copolymer composition is not particularly limited, but is preferably 10 / 90 to 80 / 20. More preferably, the weight ratio (A / B) is 12 / 88 to 60 / 40, and even more preferably 15 / 85 to 50 / 50. By keeping the weight ratio of hydrogenated block copolymer A to hydrogenated block copolymer B within the above range, the resulting chemical mechanical polishing pad exhibits superior wear resistance. The weight ratio (A / B) of hydrogenated block copolymer A to hydrogenated block copolymer B can be determined from the area ratio of the peaks corresponding to each block copolymer in a graph obtained by high-performance liquid chromatography.

[0067] When the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, the hydrogenated block copolymer composition may also contain polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B.

[0068] The total weight percentage of hydrogenated block copolymer A and hydrogenated block copolymer B in the polymer components constituting the hydrogenated block copolymer composition is not particularly limited, but is preferably 30-100% by weight, more preferably 50-100% by weight, even more preferably 70-100% by weight, even more preferably 90-100% by weight, particularly preferably 95-100% by weight, and most preferably substantially 100% by weight (i.e., containing no polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B).

[0069] Examples of polymer components other than hydrogenated block copolymer A and hydrogenated block copolymer B include: aromatic vinyl-conjugated diene-aromatic vinyl block copolymers, aromatic vinyl-conjugated diene block copolymers, aromatic vinyl homopolymers, conjugated diene homopolymers, aromatic vinyl-conjugated diene random copolymers, and their branched polymers, excluding hydrogenated block copolymer A and hydrogenated block copolymer B; thermoplastic elastomers such as polyurethane-based thermoplastic elastomers, polyamide-based thermoplastic elastomers, and polyester-based thermoplastic elastomers; and thermoplastic resins such as polyolefins, polyvinyl chloride, acrylonitrile-styrene copolymers, acrylonitrile-butadiene-styrene copolymers, and polyphenylene ether.

[0070] Furthermore, the olefin hydrogenation rate of the hydrogenated block copolymer used in this invention is preferably in the range of 10% to 100%. For example, when the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, the olefin hydrogenation rate of the polymer component constituting the hydrogenated block copolymer composition is preferably in the range of 10% to 100%. Here, the olefin hydrogenation rate refers to the olefin hydrogenation rate of all polymer components constituting the hydrogenated block copolymer; specifically, it is the proportion (mol%) of hydrogenated carbon-carbon double bonds among all non-aromatic carbon-carbon double bonds contained in the polymer component before hydrogenation. The olefin hydrogenation rate is preferably 20% to 100%, more preferably 30% to 100%, further preferably 50% to 100%, particularly preferably 70% to 100%, and most preferably 90% to 100%. By keeping the olefin hydrogenation rate within the above range, it is possible to effectively suppress the deformation of the obtained chemical mechanical polishing pad while improving its wear resistance. The olefin hydrogenation rate can be achieved by using deuterated chloroform as a solvent. 1 The determination was obtained by H-NMR spectroscopy.

[0071] In all repeating units of the polymer component constituting the hydrogenated block copolymer used in this invention (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B), the proportion of aromatic vinyl monomer units (hereinafter sometimes referred to as "total aromatic vinyl monomer unit content") is preferably 20 to 60% by weight, more preferably 25 to 57% by weight, and even more preferably 30 to 54% by weight. By keeping the total aromatic vinyl monomer unit content within the above range, the wear resistance of the resulting chemical mechanical polishing pad can be made more excellent. Furthermore, when the hydrogenated block copolymer is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, from the viewpoint of achieving even better wear resistance, the total aromatic vinyl monomer unit content can be 20 to 60% by weight, 25 to 57% by weight, or 30 to 54% by weight. The total aromatic vinyl monomer unit content can be easily adjusted by taking into account the aromatic vinyl monomer unit content of each of the hydrogenated block copolymer A, hydrogenated block copolymer B, and other polymer components constituting the hydrogenated block copolymer composition, and by adjusting their proportions. The total aromatic vinyl monomer unit content can be further adjusted by using deuterated chloroform as a solvent. 1 The determination was obtained by H-NMR measurement.

[0072] Furthermore, when all polymer components constituting the hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B) consist only of aromatic vinyl monomer units and conjugated diene monomer units, the polymer components in the hydrogenated block copolymer are ozone decomposed according to the method described in Rubber Chem. Technol., 45, 1295 (1972), followed by reduction with lithium aluminum hydride. This decomposes the conjugated diene monomer unit portion (including the hydrogenated portion), allowing only the aromatic vinyl monomer unit portion to be extracted. Therefore, the total aromatic vinyl monomer unit content can be easily determined. Using the same method, the aromatic vinyl monomer unit content and the conjugated diene monomer unit content in each block copolymer can be determined.

[0073] The weight-average molecular weight of the polymer components constituting the hydrogenated block copolymer used in this invention (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B) is not particularly limited, but is preferably 30,000 to 400,000, more preferably 35,000 to 100,000, and even more preferably 40,000 to 80,000.

[0074] Furthermore, the molecular weight distribution of the polymer components constituting the hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B), expressed as the ratio of weight-average molecular weight (Mw) to number-average molecular weight (Mn) (Mw / Mn), is not particularly limited, but is preferably 1.01 to 10, more preferably 1.02 to 5, and even more preferably 1.03 to 3.

[0075] (Method for manufacturing hydrogenated block copolymers)

[0076] Next, the method for manufacturing the hydrogenated block copolymer used in this invention is not particularly limited. Taking the case where the hydrogenated block copolymer used in this invention is a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B as an example, the manufacturing method will be described. The hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B can be manufactured separately, for example, according to conventional block copolymer manufacturing methods and hydrogenation methods. However, from the viewpoint of being able to manufacture the hydrogenated block copolymer composition with high productivity, the manufacturing method described below is preferred.

[0077] That is, the hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B is preferably manufactured by a manufacturing method having the following steps (1) to (7).

[0078] (1): The process of using a polymerization initiator in a solvent to polymerize aromatic vinyl monomers, thereby obtaining a solution containing an aromatic vinyl polymer with active ends.

[0079] (2): A process in which a conjugated diene monomer is added to a solution containing an aromatic vinyl polymer with active ends obtained through the above-mentioned step (1), and the conjugated diene monomer is polymerized to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer with active ends.

[0080] (3): Adding an aromatic vinyl monomer to the solution containing the aromatic vinyl-conjugated diene block copolymer with active ends obtained through the above (2) process, and polymerizing the aromatic vinyl monomer to obtain a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends.

[0081] (4): In the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends obtained through the above (3) process, a polymerization terminator is added in an amount less than 1 molar equivalent relative to its active ends, thereby deactivating a portion of the active ends of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer, to obtain a solution containing block copolymer B'.

[0082] (5): Adding an aromatic vinyl monomer to the solution containing block copolymer B' obtained through the above (4) process, and polymerizing the aromatic vinyl monomer to obtain a solution containing block copolymer B' and block copolymer A'.

[0083] (6): The solution containing block copolymer B' and block copolymer A' obtained through the above process (5) is subjected to a hydrogenation reaction to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A.

[0084] (7): The process of recovering the hydrogenated block copolymer composition from the solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained through the process of (6) above.

[0085] <Process (1)>

[0086] In the method for manufacturing the hydrogenated block copolymer composition, firstly, in step (1), an aromatic vinyl monomer is polymerized in a solvent using a polymerization initiator, thereby obtaining a solution containing an aromatic vinyl polymer with active ends.

[0087] As polymerization initiators, polymerization initiators known to have anionic polymerization activity for aromatic vinyl monomers and conjugated diene monomers can be used. Examples of polymerization initiators include organoalkali metal compounds, organoalkaline earth metal compounds, and organolanthanide rare earth metal compounds.

[0088] As organoalkali metal compounds, organolithium compounds having one or more lithium atoms in their molecules are particularly preferred. Specific examples of organolithium compounds include: ethyllithium, n-propyllithium, isopropyllithium, n-butyllithium, sec-butyllithium, tert-butyllithium, hexyllithium, phenyllithium, lithium stilbene, lithium dialkylamino, lithium diphenylamino, lithium bis(trimethylsilylamino), etc.; organodilithium compounds such as methylene dilithium, tetramethylene dilithium, hexamethylene dilithium, isoprene dilithium, 1,4-dilithium ethylcyclohexane, etc.; and organotrilithium compounds such as 1,3,5-trilithiumbenzene, etc. Among these, organomonolithium compounds are particularly preferred.

[0089] Examples of organic alkaline earth metal compounds include: n-butyl magnesium bromide, n-hexyl magnesium bromide, calcium ethoxy, calcium stearate, tert-butoxystrontium, barium ethoxy, barium isopropoxy, barium ethyl mercapto, barium tert-butoxy, barium phenoxy, barium diethylamino, barium stearate, and barium ethyl.

[0090] In addition to the above, substances that are homogeneous systems in organic solvents and have active polymerization properties, such as composite catalysts formed from lanthanide rare earth metal compounds / alkylaluminum / alkylaluminum halides / alkylaluminum hydrides containing neodymium, samarium, gadolinium, etc., and metallocene catalysts containing titanium, vanadium, samarium, gadolinium, etc., can also be used.

[0091] The polymerization initiator described above can be used alone or in combination with two or more. The amount of polymerization initiator used is determined based on the molecular weight of each block copolymer being targeted, and is not particularly limited. Relative to 100g of all monomers used for polymerization, it is preferably 0.01 to 20 mmol, more preferably 0.05 to 15 mmol, and even more preferably 0.1 to 10 mmol.

[0092] The solvent used for polymerization can be any solvent that is inactive relative to the polymerization initiator; there are no particular limitations. Examples include linear hydrocarbon solvents, cyclic hydrocarbon solvents, or mixtures thereof. Examples of linear hydrocarbon solvents include linear alkanes and alkenes with 4 to 6 carbon atoms, such as n-butane, isobutane, 1-butene, isobutene, trans-2-butene, cis-2-butene, 1-pentene, trans-2-pentene, cis-2-pentene, n-pentane, isopentane, neopentane, and n-hexane. Examples of cyclic hydrocarbon solvents include aromatic compounds such as benzene, toluene, and xylene; and alicyclic hydrocarbon compounds such as cyclopentane and cyclohexane. These solvents can be used individually or in mixtures of two or more.

[0093] The amount of solvent used is not particularly limited, but it is preferably an amount that makes the concentration of all block copolymers in the solution after polymerization 5 to 60% by weight, more preferably an amount that makes the concentration 10 to 55% by weight, and even more preferably an amount that makes the concentration 20 to 50% by weight.

[0094] Furthermore, in the manufacture of hydrogenated block copolymer compositions, Lewis base compounds can be added to the reaction system to control the structure of each polymer block in each block copolymer. Examples of Lewis base compounds include: ethers such as tetrahydrofuran, dibutyl ether, diethyl ether, dioxane, ethylene glycol dimethyl ether, ethylene glycol dibutyl ether, diethylene glycol dimethyl ether, and diethylene glycol dibutyl ether; tertiary amines such as tetramethylethylenediamine, trimethylamine, triethylamine, pyridine, and quinine ring; alkali metal alkoxides such as potassium tert-amyloxide and potassium tert-butoxide; and phosphines such as triphenylphosphine. These Lewis base compounds can be used alone or in combination of two or more.

[0095] When manufacturing hydrogenated block copolymer compositions, there is no particular limitation on the timing of adding Lewis base compounds, as long as it is appropriately determined based on the structure of each block copolymer being targeted. For example, it can be added before polymerization begins, or it can be added after a portion of the polymer blocks have polymerized. Moreover, it can be added before polymerization begins, and further added after a portion of the polymer blocks have polymerized.

[0096] The polymerization temperature is preferably 10–150°C, more preferably 30–130°C, and even more preferably 40–90°C. The polymerization time is preferably within 48 hours, more preferably 0.5–10 hours. Furthermore, the polymerization pressure is not particularly limited as long as it is sufficient to maintain the monomer and solvent in a liquid phase at the polymerization temperature.

[0097] Under the conditions described above, a polymerization initiator is used in a solvent to polymerize the aromatic vinyl monomers, thereby obtaining a solution containing an aromatic vinyl polymer with active ends. In this way, the aromatic vinyl polymer with active ends obtained in step (1) constitutes the aromatic vinyl polymer block Ar1 of hydrogenated block copolymer A, which forms the hydrogenated block copolymer composition, and has a smaller weight-average molecular weight. a And the aromatic vinyl polymer block Ar1 of hydrogenated block copolymer B b Ar2 b Either of them (i.e., Ar1) b Or Ar2 b Therefore, the polymerization conditions in step (1), including the amount of aromatic vinyl monomers, can be determined based on the target weight-average molecular weight of these polymer blocks.

[0098] <Process (2)>

[0099] Next, in step (2), a conjugated diene monomer is added to the solution containing an aromatic vinyl polymer with active ends obtained by step (1) above, and the conjugated diene monomer is polymerized to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer with active ends.

[0100] According to step (2), by adding a conjugated diene monomer to the solution containing an aromatic vinyl polymer with active ends obtained through step (1) above, a conjugated diene polymer chain is formed starting from the active end, thereby obtaining a solution containing an aromatic vinyl-conjugated diene block copolymer with active ends.

[0101] The conjugated diene polymer chains formed in step (2) (constituting the conjugated diene blocks of the aromatic vinyl-conjugated diene block copolymer with active ends obtained in step (2)) constitute the hydrogenated polymer blocks HD of the conjugated diene polymer of hydrogenated block copolymer A. a Hydrogenated block copolymer B and conjugated diene polymer of hydrogenated polymer block HD b Therefore, the polymerization conditions in step (2), including the amount of conjugated diene polymer, can be determined based on the target weight-average molecular weight of these polymer blocks (for example, the polymerization conditions can be determined within the range described in step (1) above).

[0102] <Process (3)>

[0103] Next, in step (3), an aromatic vinyl monomer is added to the solution containing the aromatic vinyl-conjugated diene block copolymer with active ends obtained by step (2) above, and the aromatic vinyl monomer is polymerized to obtain a solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends.

[0104] According to step (3), by adding an aromatic vinyl monomer to the solution containing an aromatic vinyl-conjugated diene block copolymer with active ends obtained through step (2) above, an aromatic vinyl polymer chain is formed starting from the active end, thereby obtaining a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends.

[0105] The aromatic vinyl polymer chains formed in step (3) (constituting the aromatic vinyl blocks of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends obtained in step (3)) constitute the aromatic vinyl polymer blocks Ar1 of the hydrogenated block copolymer B. b Ar2 b One of them (i.e., Ar1) b Or Ar2 b A segment that is different from the segment formed in step (1), for example, Ar1 formed in step (1). b In this case, the block is Ar2 b Therefore, the polymerization conditions in step (3), including the amount of aromatic vinyl monomers, can be determined based on the target weight-average molecular weight of such polymer blocks (for example, the polymerization conditions can be determined within the range described in step (1) above).

[0106] <Process (4)>

[0107] Next, in step (4), a polymerization terminator is added to the solution containing the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends obtained by step (3) above, in an amount less than 1 molar equivalent relative to its active ends, so that a portion of the active ends of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends are deactivated, and a solution containing block copolymer B' is obtained.

[0108] The block copolymer B' obtained through step (4) becomes the unhydrogenated block copolymer used to obtain the hydrogenated block copolymer B.

[0109] A polymerization terminator is any polymerization terminator that can react with an active terminal to deactivate it, and does not react with other active terminals after reacting with one active terminal. There are no particular limitations, but compounds without halogen atoms are preferred. Particularly preferred are polymerization terminators that form metal alkoxides, metal aryl oxides, or metal hydroxides upon reaction with active terminals. Specific examples of polymerization terminators include: water; monohydric alcohols such as methanol and ethanol; and monohydric phenols such as phenol and cresol.

[0110] The amount of polymerization terminator used can be determined based on the ratio of hydrogenated block copolymer A and hydrogenated block copolymer B constituting the hydrogenated block copolymer composition. There is no particular limitation as long as it is less than 1 molar equivalent relative to the active end of the polymer. The amount of polymerization terminator used relative to the active end of the polymer is preferably in the range of 0.18 to 0.91 molar equivalents, more preferably in the range of 0.35 to 0.80 molar equivalents.

[0111] In this manner, according to step (4), by adding a polymerization terminator to a solution containing an aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends in an amount less than 1 molar equivalent relative to its active ends, the active ends of a portion of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends are deactivated, and the copolymer with deactivated active ends becomes the un-hydrogenated block copolymer B' used to form the hydrogenated block copolymer B. Then, the remaining portion of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer with active ends that has not reacted with the polymerization terminator remains in the solution in an unreacted state, maintaining the active ends.

[0112] <Process (5)>

[0113] Next, in step (5), an aromatic vinyl monomer is added to the solution containing block copolymer B' obtained through step (4) above, and the aromatic vinyl monomer is polymerized to obtain a solution containing block copolymer B' and block copolymer A'.

[0114] According to step (5), when an aromatic vinyl monomer is added to the solution obtained through step (4) above, the aromatic vinyl polymer chain on the active end side of the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer, which has never reacted with the polymerization terminator, begins to polymerize further, elongating the aromatic vinyl polymer chain, thereby obtaining block copolymer A'. Furthermore, block copolymer A', obtained by elongating the aromatic vinyl polymer chain, is the aromatic vinyl-conjugated diene-aromatic vinyl block copolymer before hydrogenation, used to obtain hydrogenated block copolymer A.

[0115] At this point, in step (5), the elongated aromatic vinyl polymer chain constitutes the aromatic vinyl polymer block Ar2 of hydrogenated block copolymer A, which has a large weight-average molecular weight and forms the hydrogenated block copolymer composition. a Therefore, the polymerization conditions in step (5), including the amount of aromatic vinyl monomers, only need to be based on the aromatic vinyl polymer block Ar2. a The target weight-average molecular weight can be determined (for example, the polymerization conditions only need to be determined within the range described in step (1) above).

[0116] <Process (6)>

[0117] Next, in step (6), the solution containing block copolymer B' and block copolymer A' obtained through step (5) is subjected to a hydrogenation reaction to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A.

[0118] There are no particular limitations on the method for hydrogenating a solution containing block copolymer B' and block copolymer A'. Examples include, for instance, contacting the solution containing block copolymer B' and block copolymer A' with hydrogen in the presence of a hydrogenation catalyst.

[0119] There are no particular limitations on hydrogenation catalysts, and examples include: supported heterogeneous catalysts in which metals such as Ni, Pt, Pd, and Ru are supported on carbon, silica, alumina, diatomaceous earth, etc.; Ziegler-type catalysts using organic salts or acetylacetone salts of Ni, Co, Fe, Cr, etc., and organic Al as reducing agents; organic complex catalysts such as organometallic compounds of Ru and Rh; and homogeneous catalysts using organic Li, organic Al, organic Mg, etc., as reducing agents in titanocene compounds. Among these, Ziegler-type catalysts are preferred.

[0120] The hydrogenation reaction can be carried out according to the methods disclosed in, for example, Japanese Patent Publication No. 42-8704, Japanese Patent Publication No. 43-6636, Japanese Patent Application Publication No. 59-133203, and Japanese Patent Application Publication No. 60-220147.

[0121] The conditions for the hydrogenation reaction can be selected based on the hydrogenation rate of the olefins in the polymer components constituting the hydrogenated block copolymer composition. The hydrogenation reaction temperature is preferably 0–200°C, more preferably 30–150°C. Furthermore, the hydrogen pressure used in the hydrogenation reaction is preferably 0.1–15 MPa, more preferably 0.2–10 MPa, and even more preferably 0.3–5 MPa. The hydrogenation reaction time is preferably 3 minutes–10 hours, more preferably 10 minutes–5 hours. Additionally, the hydrogenation reaction can be a batch process, a continuous process, or a combination thereof.

[0122] <Process (7)>

[0123] Next, in step (7), the target hydrogenated block copolymer composition is recovered from the solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained through step (6) above.

[0124] The recovery method can follow any conventional method and is not particularly limited. For example, it can be recovered by the following method: after the reaction is complete, a polymerization terminator is added as needed to deactivate the active ends of the polymer with active ends; further additives such as antioxidants are added as needed; and then the solution is treated with known solvent removal methods such as direct drying or steam stripping, thereby recovering the target hydrogenated block copolymer composition. Furthermore, the polymerization terminator described above can be used as the polymerization terminator at this time.

[0125] When recovering the hydrogenated block copolymer composition as a slurry via steam stripping or the like, it is preferable to dehydrate it using any dewatering machine such as an extruder-type dewatering mill to recover the granular hydrogenated block copolymer composition, and then dry the resulting granules using any dryer such as a belt dryer or an expander extrusion dryer. Furthermore, the hydrogenated block copolymer composition thus obtained can also be processed into granules or the like using conventional methods before being used.

[0126] The resulting solid (granular, agglomerated, etc.) hydrogenated block copolymer composition is preferably dried using a dryer such as a hopper dryer, a hot air circulating shelf dryer, a shelf vacuum dryer, or a stirred vacuum dryer to reduce the moisture content of the solid hydrogenated block copolymer composition before use. The drying conditions are not particularly limited as long as the target moisture content is achieved; they can be set according to the amount of moisture to be reduced and the type of dryer, typically within the range of a drying temperature of 40–90°C and a drying time of 1–24 hours.

[0127] Furthermore, when manufacturing a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, a silane modification step can be included. By including the silane modification step, a silane-modified structure can be introduced. As a method of silane modification, a method of reacting an unsaturated silane modifier with the hydrogenated block copolymer composition obtained through the above step (7) can be cited. Preferably, the reaction can be carried out by melt-blending the hydrogenated block copolymer composition obtained through the above step (7), the unsaturated silane modifier, and the peroxide.

[0128] As an unsaturated silane modifier, there is no particular limitation as long as it is a silane compound containing carbon-carbon unsaturated bonds in its molecule, but it is preferred to be a compound (1) represented by the following general formula (1).

[0129] [Chemistry 1]

[0130]

[0131] (In the above general formula (1), R) 1 ~R 3 Each is independently a hydrogen atom, an alkyl group having 1 to 6 carbon atoms, or an alkoxy group having 1 to 6 carbon atoms, R 4 (A hydrocarbon group containing unsaturated carbon-carbon bonds.)

[0132] In general formula (1), R 1 ~R 3 There are no particular limitations as long as each atom is an alkyl group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms. As R 1 ~R 3 The alkyl and alkoxy groups can be linear, branched, or contain cyclic structures. R 2 ~R 4 They can be the same or different.

[0133] As R 1 ~R 3 Preferably, alkyl groups having 1 to 6 carbon atoms and alkoxy groups having 1 to 6 carbon atoms are used, more preferably alkoxy groups having 1 to 6 carbon atoms. As R1 ~R 3 The number of carbon atoms in each can be 0 to 6 independently, preferably 0 to 4, more preferably 0 to 2, and even more preferably 1 (methyl or methoxy).

[0134] In general formula (1), R is preferred. 1 ~R 3 At least one of them is an alkoxy group having 1 to 6 carbon atoms, more preferably R 1 ~R 3 At least two of them are alkoxy groups having 1 to 6 carbon atoms, and R is further preferred. 1 ~R 3 All of them are alkoxy groups with 1 to 6 carbon atoms.

[0135] In general formula (1), R 4 There are no particular restrictions as long as it is a hydrocarbon group with unsaturated carbon-carbon bonds. 4 It can be linear, branched, or contain cyclic structures. As R 4 Examples of vinyl hydrocarbon groups include vinyl, allyl, 1-methylvinyl, 3-butenyl, etc.; and alkynyl groups such as propynyl, etc., with vinyl hydrocarbon groups being preferred. As R 4 The number of carbon atoms is not particularly limited, but is preferably 2 to 6, more preferably 2 to 4, and even more preferably 2 (vinyl).

[0136] For example, in R 4 In the case of containing a vinyl hydrocarbon group, compound (1) is compound (2) represented by the following general formula (2).

[0137] [Chemistry 2]

[0138]

[0139] In the above general formula (2), R 1 ~R 3 The above groups are respectively, R 5 It is a single bond or a divalent hydrocarbon group. As R... 5 The hydrocarbon group can be straight-chain, branched, or contain a cyclic structure. Additionally, the -R group in general formula (2) 5 -CH=CH2 corresponds to -R in general formula (1) 4 .

[0140] For example, when compound (2) is used as an unsaturated silane modifier, the hydrogenated block copolymer composition has a group (3) (containing a silane functional group) represented by the following general formula (3) as a modifying group from compound (2).

[0141] [Chemistry 3]

[0142]

[0143] As an unsaturated silane modifier, compound (4) represented by the following general formula (4) is preferred.

[0144] [Chemistry 4]

[0145]

[0146] In general formula (4), R 6 ~R 8 Each is independently an alkyl group having 1 to 6 carbon atoms, R 9 It is a single bond or an alkylene group having 1 to 4 carbon atoms. Additionally, the -OR in general formula (4) 6 -OR 7 and -OR 8 Corresponding to -R in general formulas (1) to (3) 1 -R 2 and -R 3 R in general formula (4) 9 R corresponds to general formulas (2) to (3) 5 .

[0147] R 6 ~R 8 Each can be a straight chain, a branched chain, or contain a ring structure. R 6 ~R 8 They can be the same or different. As R... 6 ~R 8 The number of carbon atoms in each can be 1 to 6 independently, preferably 1 to 4, more preferably 1 to 2 (methyl, ethyl), and even more preferably 1 (methyl).

[0148] R 9 It can be linear, branched, or contain cyclic structures. As R 9 The number of carbon atoms can be 0 to 4, preferably 0 to 2, more preferably 0 to 1, and even more preferably 0 (single bond).

[0149] The unsaturated silane modifier can be used alone or in combination with two or more. There is no particular limitation on the amount of unsaturated silane modifier used, but it is preferably 0.1 to 20 g, more preferably 0.5 to 15 g, and even more preferably 1 to 10 g, relative to 100 g of the polymer component modified by the unsaturated silane modifier.

[0150] Examples of peroxides include tert-butyl hydroperoxide, cumene hydroperoxide, dicumene peroxide, di-tert-butyl peroxide, tert-butyl cumene peroxide, 2,5-dimethyl-tert-butylperoxyhexane, 2,5-dimethyl-tert-butylperoxyhexyne, 1,3-bis(tert-butylperoxyisopropyl)benzene, p-chlorobenzoyl peroxide, tert-butyl peroxybenzoate, tert-butyl peroxyisopropyl carbonate, tert-butyl benzoate, and 1,1-bis(tert-butylperoxy)-3,3,5-trimethylcyclohexane. These can be used alone or in combination of two or more.

[0151] There is no particular limitation on the amount of peroxide used, but it is preferably 0.01 to 1 g, more preferably 0.02 to 0.5 g, and even more preferably 0.05 to 0.2 g, relative to 1 g of unsaturated silane modifier used.

[0152] The method for melt-blending hydrogenated block copolymers (including compositions containing hydrogenated block copolymer A and hydrogenated block copolymer B), unsaturated silane modifiers, and peroxides is not particularly limited. Examples include methods that use mixing equipment such as rollers, Banbury mixers, kneaders, laboratory mixers, unispindle extruders, and bispindle extruders to heat and melt-blend the components. The conditions for heat-melt blending are preferably those that suppress excessive decomposition of the components and prevent unexpected reactions. For example, the mixing temperature is preferably 180–260°C, more preferably 200–240°C. Furthermore, the mixing time is preferably 0.5 to 20 minutes, more preferably 1 to 10 minutes.

[0153] According to the above-described method for manufacturing hydrogenated block copolymer compositions, hydrogenated block copolymer A and hydrogenated block copolymer B can be continuously obtained in the same reaction vessel. Therefore, compared with the case where each hydrogenated block copolymer is manufactured separately and then mixed, the target hydrogenated block copolymer composition can be obtained with excellent productivity.

[0154] Alternatively, when manufacturing a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B, in addition to the preferred manufacturing method described above (the manufacturing method having steps (1) to (7), it is also preferable to use a manufacturing method having steps (1a) to (6a) described below.

[0155] (1a): The process of using a polymerization initiator in a solvent to polymerize aromatic vinyl monomers, thereby obtaining a solution containing an aromatic vinyl polymer with active ends.

[0156] (2a): A process in which a conjugated diene monomer is added to a solution containing an aromatic vinyl polymer with active ends obtained by the process (1a) above, and the conjugated diene monomer is polymerized to obtain a solution containing an aromatic vinyl-conjugated diene block copolymer with active ends.

[0157] (3a): In the solution containing the aromatic vinyl-conjugated diene block copolymer with active ends obtained by the above-mentioned step (2a), a difunctional coupling agent is added in an amount less than 1 molar equivalent of the total amount of functional groups relative to the active ends, so as to couple a portion of the aromatic vinyl-conjugated diene block copolymer with active ends, thereby obtaining a solution containing block copolymer B'.

[0158] (4a): Aromatic vinyl monomers are added to the solution containing block copolymer B' obtained through step (3a) above, and the aromatic vinyl monomers are polymerized to obtain a solution containing block copolymer B' and block copolymer A'.

[0159] (5a): A process of hydrogenating the solution containing block copolymer B' and block copolymer A' obtained through step (4a) above to obtain a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A.

[0160] (6a): A process for recovering the hydrogenated block copolymer composition from a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A obtained through the process described in (5a) above.

[0161] <Process (1a), Process (2a)>

[0162] Processes (1a) and (2a) are the same as those (1) and (2) above, and can be performed under the same conditions.

[0163] <Process (3a)>

[0164] In step (3a), a difunctional coupling agent is added to the solution containing the aromatic vinyl-conjugated diene block copolymer with active ends obtained by step (2a) above, in an amount where the total amount of functional groups is less than 1 molar equivalent relative to the active ends, so that a portion of the aromatic vinyl-conjugated diene block copolymer with active ends is coupled to obtain a solution containing block copolymer B'.

[0165] The block copolymer B' obtained by process (3a) is the pre-hydrogenated block copolymer used to obtain the hydrogenated block copolymer B.

[0166] As a difunctional coupling agent, any coupling agent having two functional groups that react with the active end is acceptable, without particular limitation. Examples include: difunctional halosilanes such as dichlorosilane, monomethyldichlorosilane, and dimethyldichlorosilane; difunctional haloalkanes such as dichloroethane, dibromoethane, dichloromethane, and dibromomethane; and difunctional tin halides such as tin dichloride, monomethyltin dichloride, dimethyltin dichloride, monoethyltin dichloride, diethyltin dichloride, monobutyltin dichloride, and dibutyltin dichloride.

[0167] The amount of difunctional coupling agent used can be determined based on the ratio of hydrogenated block copolymer A to hydrogenated block copolymer B in the hydrogenated block copolymer composition.

[0168] In this manner, according to step (3a), a portion of the aromatic vinyl-conjugated diene block copolymer with active ends is coupled to a solution containing such copolymers, with the total amount of functional groups being less than 1 molar equivalent relative to the active ends, to become the unhydrogenated block copolymer B' used to form the hydrogenated block copolymer B. Then, the remaining portion of the aromatic vinyl-conjugated diene block copolymer with active ends, which has not reacted with the difunctional coupling agent, remains in the solution in an unreacted state, maintaining the active ends.

[0169] <Process (4a)>

[0170] Next, in step (4a), an aromatic vinyl monomer is added to the solution containing block copolymer B' obtained by step (3a) above, and the aromatic vinyl monomer is polymerized to obtain a solution containing block copolymer B' and block copolymer A'.

[0171] According to step (4a), when an aromatic vinyl monomer is added to the solution obtained through step (3a) above, the aromatic vinyl monomer begins to polymerize from the active ends of the aromatic vinyl-conjugated diene block copolymer that has not reacted with the difunctional coupling agent, forming an aromatic vinyl polymer chain, thereby obtaining block copolymer A'. Furthermore, block copolymer A' becomes the unhydrogenated block copolymer used to obtain hydrogenated block copolymer A.

[0172] At this point, in step (4a), the aromatic vinyl polymer chains formed constitute the aromatic vinyl polymer blocks Ar2 of hydrogenated block copolymer A, which have a large weight-average molecular weight and constitute the hydrogenated block copolymer composition. a Therefore, the polymerization conditions in step (4a), including the amount of aromatic vinyl monomers, only need to be based on the aromatic vinyl polymer block Ar2. aThe target weight-average molecular weight can be determined (for example, the polymerization conditions only need to be determined within the range described in step (1) above).

[0173] <Process (5a), Process (6a)>

[0174] Then, using the solution containing block copolymer B' and block copolymer A' obtained in step (4a), the hydrogenated block copolymer composition used in this invention can be obtained by performing the operations in steps (5a) and (6a) described above. Furthermore, steps (5a) and (6a) described above are the same as steps (6) and (7) described above, and the same conditions can be used. In addition, if necessary, a modification step can be further performed to react the hydrogenated block copolymer composition obtained in step (6a) with an unsaturated silane modifier, thereby introducing a silane-modified structure.

[0175] In the hydrogenated block copolymer composition manufactured above, antioxidants or other compounding agents can be added at any time as needed. The method of adding the compounding agent is not particularly limited; examples include methods such as heating and melting the components using a mixing apparatus such as a Banbury mixer, kneader, laboratory mixer, single-spindle extruder, or twin-spindle extruder, preparing a solvent in which the components are dissolved, and then removing the solvent by heating or the like. Furthermore, for example, a solution containing a pre-hydrogenated block copolymer B' for obtaining hydrogenated block copolymer B and a pre-hydrogenated block copolymer A' for obtaining hydrogenated block copolymer A can be prepared, and after adding a compounding agent, a hydrogenation process is performed to obtain the hydrogenated block copolymer composition. Alternatively, a solution containing hydrogenated block copolymer B and hydrogenated block copolymer A can also be prepared.

[0176] Examples of antioxidants include hindered phenolic compounds such as pentaerythritol tetrakis[3-(3,5-di-tert-butyl-4-hydroxyphenyl)propionate], 2,6-di-tert-butyl-p-cresol, and di-tert-butyl-4-methylphenol; thiodicarboxylic acid esters such as dilauryl thiopropionate; and phosphites such as tris(nonylphenyl) phosphite. Antioxidants can be used alone or in combination of two or more. The content of antioxidants in the hydrogenated block copolymer composition is not particularly limited, but is preferably 10 parts by weight or less, more preferably 0.5 to 5 parts by weight, relative to 100 parts by weight of the hydrogenated block copolymer.

[0177] (Chemical Mechanical Polishing Pad)

[0178] The chemical mechanical polishing pad of the present invention contains the above-mentioned hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B), and the chemical mechanical polishing pad has grooves or holes.

[0179] When the chemical mechanical polishing pad of the present invention has grooves, it is preferable to have grooves with a depth of 15% or more relative to the thickness of the chemical mechanical polishing pad, and the depth of the grooves is more preferably 15-65%, further preferably 20-60%, and even more preferably 23-40%. By having grooves in the chemical mechanical polishing pad, its wafer transport performance can be improved, and by keeping the depth of the grooves within the above range, the wafer transport performance can be further improved.

[0180] When the chemical mechanical polishing pad of the present invention has grooves, the groove pattern is not particularly limited, but is preferably grid-like or concentric circle-like, and more preferably concentric circle-like.

[0181] As a method for forming the grooves of the chemical mechanical polishing pad of the present invention, it can be formed by compression molding using a mold with a groove pattern, or by cutting a chemical mechanical polishing pad without grooves. From a cost perspective, it is preferable to use a mold with a groove pattern for compression molding.

[0182] The groove depth of the chemical mechanical polishing pad of the present invention is preferably 15% or more of the thickness of the chemical mechanical polishing pad, but is not particularly limited. It is preferably 0.1 to 2.0 mm, more preferably 0.2 to 1.5 mm, and even more preferably 0.3 to 0.8 mm. Furthermore, the thickness of the chemical mechanical polishing pad itself is not particularly limited, but is preferably 0.5 to 5 mm, more preferably 0.5 to 3 mm, and even more preferably 0.5 to 2 mm.

[0183] The width of the groove in the chemical mechanical polishing pad of the present invention is not particularly limited, but is preferably 0.05 to 6.0 mm, more preferably 0.15 to 5.5 mm, and even more preferably 0.20 to 5.0 mm.

[0184] When the chemical mechanical polishing pad of the present invention has holes, it is preferable to have holes with a depth of 15% or more relative to the thickness of the chemical mechanical polishing pad, and the depth of the holes is more preferably 15-65%, further preferably 20-60%, and even more preferably 23-40%. Furthermore, the holes may also be through holes (100% hole depth). By having holes in the chemical mechanical polishing pad, its wafer transport performance is improved, and by keeping the hole depth within the above-mentioned range, the wafer transport performance can be further improved.

[0185] When the chemical mechanical polishing pad of the present invention has a hole, the shape of the hole (the shape viewed from the top surface) is not particularly limited, but it is preferably circular or elliptical, and more preferably circular.

[0186] As a method for forming the holes in the chemical mechanical polishing pad of the present invention, it can be formed by compression molding using a mold with a hole pattern, or by cutting a chemical mechanical polishing pad without holes. From a cost perspective, it is preferable to use a mold with a hole pattern for compression molding.

[0187] The hole depth of the chemical mechanical polishing pad of the present invention is preferably 15% or more of the thickness of the chemical mechanical polishing pad, but is not particularly limited. More preferably, it is 0.1 to 2.0 mm, further preferably 0.2 to 1.5 mm, and even more preferably 0.3 to 0.8 mm. Furthermore, the thickness of the chemical mechanical polishing pad itself is not particularly limited, but is preferably 0.5 to 5 mm, more preferably 0.5 to 3 mm, and even more preferably 0.5 to 2 mm.

[0188] The diameter of the holes in the chemical mechanical polishing pad of the present invention is not particularly limited, but is preferably 0.5 to 4 mm, more preferably 1.0 to 3.0 mm, and even more preferably 1.5 to 2.5 mm.

[0189] As the chemical mechanical polishing pad of the present invention, it is preferable to have individual or continuous pores, without particular limitation, more preferably individual pores, and particularly preferably micro-individual pores (e.g., micron-sized bubbles) dispersed in the chemical mechanical polishing pad. By having individual or continuous pores, when the surface of the chemical mechanical polishing pad is cut away (trimmed), the pores are exposed, and the slurry enters the pores, enabling efficient polishing of the workpiece.

[0190] The method for giving the chemical mechanical polishing pad of the present invention independent or continuous pores is not particularly limited, but it is preferable to use a method in which a hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B) contains a physical foaming agent, foaming particles, and / or cross-linked hollow particles. Specifically, examples include: dissolving or dispersing a physical foaming agent in the hydrogenated block copolymer and converting the dissolved or dispersed physical foaming agent into a gas phase; mixing the hydrogenated block copolymer and foaming particles, and then expanding the foaming particles dispersed in the hydrogenated block copolymer, etc. Alternatively, it is also possible to use a method in which independent or continuous pores are introduced by mixing the hydrogenated block copolymer and cross-linked hollow particles, thereby utilizing the voids of the cross-linked hollow particles. Among these, from the viewpoint of being able to uniformly disperse fine independent pores in the chemical mechanical polishing pad, foaming particles are preferred. Furthermore, from the viewpoint of operability, cross-linked hollow particles are preferred. In this case, the average pore size, whether it is an independent pore or a continuous pore, is not particularly limited depending on the foamed particles or cross-linked hollow particles used, and is preferably 0.1 to 300 μm, more preferably 1 to 200 μm, even more preferably 2 to 190 μm, and particularly preferably 3 to 180 μm.

[0191] Physical foaming agents are liquefied gases or supercritical fluids that are converted into a gaseous phase through decompression and heating. Examples of physical foaming agents include aliphatic hydrocarbons such as butane, alicyclic hydrocarbons such as cyclobutane, and inorganic gases such as carbon dioxide, nitrogen, and air.

[0192] Examples of foamed granules include granules encapsulating low-boiling-point hydrocarbon compounds within a shell formed of a thermoplastic polymer such as acrylonitrile copolymer. Upon heating, the thermoplastic polymer shell softens, and the internal hydrocarbon compounds vaporize, causing expansion. Commercially available products can be used as foamed granules, such as the Advancell EM series manufactured by Sekisui Chemicals Co., Ltd., including Advancell EM501.

[0193] The proportion of foamed particles is not particularly limited, but is preferably 0.1 to 20 parts by weight, more preferably 0.2 to 15 parts by weight, and even more preferably 0.3 to 10 parts by weight, relative to 100 parts by weight of hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B).

[0194] The volume average particle size (Dv) of the foamed particles before foaming is not particularly limited, but is preferably 0.1–100 μm, more preferably 1–60 μm, even more preferably 5–50 μm, and particularly preferably 10–45 μm. Furthermore, the volume average particle size (Dv) of the foamed particles after foaming is not particularly limited, but is preferably 0.2–200 μm, more preferably 1–180 μm, even more preferably 15–170 μm, and particularly preferably 30–160 μm.

[0195] Crosslinked hollow particles consist of an outer shell and voids surrounded by the outer shell. The outer shell of the crosslinked hollow particles is made of a resin formed from a shell polymer containing crosslinked monomer units.

[0196] Shell polymers are polymers used to form the shells of crosslinked hollow particles, comprising crosslinked monomer units. The crosslinked monomers forming the crosslinked monomer units are monomers having two or more polymerizable functional groups that form crosslinks in a resin through a polymerization reaction. Typically, compounds having at least one olefinic unsaturated bond as a polymerizable functional group are used as crosslinked monomers.

[0197] Examples of cross-linking monomers that form cross-linking monomer units include cross-linking hydrocarbon monomers and cross-linking monomers containing heteroatoms.

[0198] There are no particular limitations on the crosslinking hydrocarbon monomers used, and examples include divinylbenzene, divinylbiphenyl, divinylnaphthalene, dicyclopentadiene, and ethylenetetracyclododecene, among which divinylbenzene is preferred. In addition, crosslinking hydrocarbon monomers formed from polymers can also be used. Examples include polybutadiene, polyisoprene, styrene-butadiene block copolymers (SBS), and styrene-isoprene block copolymers (SIS).

[0199] As a heteroatom-containing crosslinking monomer, there is no particular limitation, but examples include: diallyl phthalate, allyl acrylate (meaning allyl acrylate and / or allyl methacrylate. The same applies below.), ethylene glycol di(meth)acrylate, pentaerythritol di(meth)acrylate, and other difunctional heteroatom-containing crosslinking monomers; trimethylolpropane tri(meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, dipentaerythritol hexa(meth)acrylate, dipentaerythritol poly(meth)acrylate, and other trifunctional or higher heteroatom-containing crosslinking monomers. Among these, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and pentaerythritol tri(meth)acrylate are preferred, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate are more preferred, and ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetramethacrylate are even more preferred.

[0200] As crosslinking monomers, preferred crosslinking hydrocarbon monomers include ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, dipentaerythritol poly(meth)acrylate, and pentaerythritol tri(meth)acrylate; more preferably, divinylbenzene, ethylene glycol di(meth)acrylate, trimethylolpropane tri(meth)acrylate, and pentaerythritol tetra(meth)acrylate; and even more preferably, divinylbenzene, ethylene glycol dimethacrylate, trimethylolpropane trimethacrylate, and pentaerythritol tetramethacrylate.

[0201] Crosslinking monomers can be used individually or in combination of two or more. Additionally, shell polymers can also contain difunctional crosslinking monomer units and trifunctional or higher crosslinking monomer units. Furthermore, shell polymers can also contain crosslinking hydrocarbon monomer units and heteroatom-containing crosslinking monomer units.

[0202] Shell polymers can consist essentially of only cross-linked monomer units, or they can contain monofunctional monomer units in addition to cross-linked monomer units.

[0203] A monofunctional monomer that forms a monofunctional monomer unit is a monomer that has only one polymerizable functional group, typically a compound with an olefinic unsaturated bond as the polymerizable functional group. Examples of monofunctional monomers that form monofunctional monomer units include monofunctional hydrocarbon monomers and monofunctional monomers containing heteroatoms.

[0204] As a monofunctional hydrocarbon monomer, there are no particular limitations, and examples include: aromatic vinyl monomers such as styrene, ethyl vinylbenzene, vinyltoluene, α-methylstyrene, p-methylstyrene, and halostyrene; monoolefin monomers such as ethylene, propylene, butene, and 4-methyl-1-pentene; and diene monomers such as butadiene and isoprene. Among these, styrene and ethyl vinylbenzene are preferred.

[0205] As a heteroatom-containing monofunctional monomer, there are no particular limitations, but examples include: hydrophilic monofunctional monomers; acrylic monovinyl monomers such as methyl methacrylate, ethyl methacrylate, butyl methacrylate, 2-ethylhexyl methacrylate, dodecyl methacrylate, and glycidyl methacrylate; cyano-containing monomers such as acrylonitrile and methacrylonitrile; amino-containing monomers such as aminoethyl methacrylate, dimethylaminoethyl methacrylate, and dimethylaminopropyl methacrylate; vinyl acetate and other carboxylic acid vinyl ester monomers; vinyl chloride and other haloethylene monomers; vinylidene chloride and other vinylidene haloethylene monomers; vinylpyridine monomers; polyurethane (meth)acrylates, allyl glycidyl ethers, etc.

[0206] The solubility of the hydrophilic monofunctional monomer in water is preferably 1% by mass or more. There are no particular limitations on the hydrophilic monofunctional monomer; examples include monofunctional monomers with hydrophilic groups, such as monomers containing acid groups, monomers containing hydroxyl groups, monomers containing amide groups, and monomers containing polyoxyethylene groups.

[0207] Acid-containing monomers refer to monomers that contain an acid group. The acid group mentioned here includes both proton donor groups (Brønsted acid groups) and electron pair acceptor groups (Lewis acid groups). There are no particular limitations on the presence of an acid group in an acid-containing monomer; examples include monomers containing carboxyl groups and monomers containing sulfonic acid groups. Examples of carboxyl-containing monomers include: acrylic acid, methacrylic acid, crotonic acid, cinnamic acid, itaconic acid, fumaric acid, maleic acid, and butylated tricarboxylic acid, etc., which are olefinic unsaturated carboxylic acid monomers; and monoalkyl esters of unsaturated dicarboxylic acids such as monoethyl itaconic acid, monobutyl fumarate, and monobutyl maleate, etc. Examples of sulfonic acid-containing monomers include: styrene sulfonic acid, etc.

[0208] Examples of hydroxyl-containing monomers include 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate.

[0209] Examples of monomers containing amide groups include acrylamide and dimethylacrylamide.

[0210] Examples of polyoxyethylene monomers include methoxy polyethylene glycol (meth)acrylate.

[0211] Monofunctional monomers can be used individually or in combination of two or more.

[0212] The proportion of crosslinking monomer units in the shell polymer is not particularly limited, but is preferably 20-100% by mass, more preferably 40-100% by mass, even more preferably 60-100% by mass, and particularly preferably 80-100% by mass. By keeping the proportion of crosslinking monomers within the above range, a dense covalent network is formed in the shell, and the generation of shell pores and shell defects is suppressed, resulting in excellent mechanical strength.

[0213] The proportion of monofunctional monomer units in the shell polymer is not particularly limited, but from the viewpoint of obtaining the mechanical strength of cross-linked hollow particles, it is preferably 0 to 80% by mass, more preferably 0 to 60% by mass, even more preferably 0 to 40% by mass, and particularly preferably 0 to 20% by mass.

[0214] The shell polymer may also contain heteroatom-containing monomer units. Examples of heteroatom-containing monomers forming these units include the aforementioned heteroatom-containing crosslinking monomers and heteroatom-containing monofunctional monomers. The proportion of heteroatom-containing monomer units in the shell polymer is not particularly limited, but is preferably 1–99% by mass, more preferably 5–95% by mass, and even more preferably 10–90% by mass.

[0215] There are no particular limitations on the manufacturing method of crosslinked hollow particles. Examples include: polymerizing a suspension containing a crosslinking monomer, a hydrophobic organic solvent, a polymerization initiator, and an aqueous medium to obtain precursor particles with hollow portions, removing the hydrophobic solvent from the precursor particles by bubbling, and then removing the aqueous solvent; or polymerizing a suspension containing a crosslinking monomer, a hydrophobic organic solvent, a polymerization initiator, and an aqueous medium to obtain precursor particles with hollow portions, performing solid-liquid separation to separate the precursor particles, and then removing the hydrophobic solvent from the precursor particles in the gas phase.

[0216] As a hydrophobic organic solvent, there are no particular limitations, and hydrocarbon solvents can be preferred. Specific examples include saturated hydrocarbon solvents such as butane, pentane, n-hexane, cyclohexane, heptane, and octane; aromatic hydrocarbon solvents such as benzene, toluene, and xylene; and solvents with high volatility such as carbon disulfide and carbon tetrachloride.

[0217] Examples of polymerization initiators include benzoyl peroxide, lauroyl peroxide, tert-butyl peroxy-2-ethylhexanoate, tert-butyl peroxy-diethylacetic acid, tert-butyl peroxy-neopentate, 2,2'-azobis(2,4-dimethylpentanonitrile), and azobisisobutyronitrile.

[0218] The polymerization method is not particularly limited and can be, for example, batch, semi-continuous, or continuous. The polymerization temperature is preferably 40–90°C, more preferably 50–80°C. Furthermore, the polymerization reaction time is preferably 1–48 hours, and more preferably 3–24 hours.

[0219] As cross-linked hollow particles, the cross-linked hollow particles are not limited to those described above, as long as they can form a shell with a three-dimensional cross-linked structure. The shell polymer can also be, for example, phenolic resins, melamine resins, urea resins, unsaturated polyester resins, epoxy resins, polyurethane resins, silicone resins, alkyd resins, thermosetting modified polyphenylene ether resins, thermosetting polyimide resins, benzoxazine resins, urea resins, allyl resins, aniline resins, maleimide resins, bismaleimide triazine resins, liquid crystal polyester resins, vinyl ester resins, unsaturated polyester resins, cyanate ester resins, polyetherimide resins, etc.

[0220] Crosslinked hollow particles can also be particles whose outer shell surface has been treated with a coupling agent. A coupling agent has functional groups in one molecule that can bond with organic matter and functional groups that can bond with inorganic matter, and is a substance that can improve the affinity between organic and inorganic materials. Preferably, the coupling agent has functional groups in its molecular structure that can undergo crosslinking reactions with hydrogenated block copolymers.

[0221] The volume average particle size (Dv) of the crosslinked hollow particles is not particularly limited, but is preferably 0.1 to 100 μm, more preferably 1 to 50 μm, even more preferably 5 to 45 μm, and particularly preferably 2 to 40 μm.

[0222] The particle size distribution (Dv / Dn) of the cross-linked hollow particles (volume average particle size (Dv) / number average particle size (Dn)) is not particularly limited, but is preferably 1.02 to 2.00, more preferably 1.04 to 1.60, further preferably 1.06 to 1.40, even more preferably 1.06 to 1.30, particularly preferably 1.08 to 1.25, and most preferably 1.10 to 1.20.

[0223] Crosslinked hollow particles are particles having a shell (outer shell) and a hollow portion (void) surrounded by the shell. The hollow portion is a void-like space clearly distinguished from the shell of the crosslinked hollow particle formed by resin. Crosslinked hollow particles may have one or more hollow portions, but to maintain a good balance between high porosity and mechanical strength, it is preferable to have only one hollow portion. The proportion of crosslinked hollow particles having only one hollow portion is preferably 90% or more, more preferably 95% or more, and even more preferably more than 95%. As a method for determining the proportion of crosslinked hollow particles having only one hollow portion, one can, for example, observe and calculate the cross-section of a sample formed by curing epoxy resin in which crosslinked hollow particles are dispersed by TEM (transmission electron microscopy). By calculating the proportion of cross-sections containing only one hollow portion among 100-150 cross-linked hollow particles observed using TEM, the proportion of particles with only one hollow portion among the cross-linked hollow particles can be determined. Furthermore, as a sample, it is preferable to prepare a thin slice by cooling and curing epoxy resin in which the cross-linked hollow particles are dispersed to -80°C and then cutting it using a slicer. The concentration of cross-linked hollow particles in the sample cross-section is preferably adjusted to a concentration such that, for example, 30-50 cross-linked hollow particles can be observed in a 56 μm × 70 μm area. Moreover, the number of hollow portions is determined by observing the image of the cross-section. It is preferable to exclude cross-sections containing particles with a volume average particle size of more than twice the volume average particle size, cross-sections containing particles smaller than 10% of the volume average particle size, and cross-sections containing cross-linked hollow particles that do not show a hollow portion from the evaluation. The above method is just one example; the method for determining the proportion of particles with only one hollow portion is not particularly limited.

[0224] Typically, the shell of cross-linked hollow particles does not have connecting pores or shell defects, and the hollow portion is isolated from the outside of the particle by the shell. However, it is also possible for the shell to have one or more connecting pores, through which the hollow portion communicates with the outside of the particle. Furthermore, a single cross-linked hollow particle may have two or more hollow portions. In this case, the two or more hollow portions can exist independently or can be connected together.

[0225] In addition, the hollow section can be filled with gases such as air, or it can contain solvents.

[0226] The shape of the cross-linked hollow particles is not particularly limited as long as a hollow portion is formed inside. The external shape of the cross-linked hollow particles is not particularly limited, but a spherical shape is preferred for ease of manufacture. The cross-linked hollow particles may contain a small amount of particles with low sphericity due to particle breakage, deformation, etc., as impurities. However, from the viewpoint of further improving the effectiveness of this disclosure, the proportion of particles with a sphericity of 0.85 or less in 100% by mass of the cross-linked hollow particles is preferably less than 15% by mass, more preferably less than 10% by mass, and even more preferably less than 8% by mass.

[0227] The morphology of cross-linked hollow particles can be confirmed by observing the particles, for example, using SEM or TEM. Furthermore, the internal shape of cross-linked hollow particles can be confirmed by, for example, SEM observation of the particle cross-section or TEM observation of the particles.

[0228] The true density of cross-linked hollow particles is not particularly limited, but is preferably 0.95–1.4 g / cm³. 3 More preferably, it is 1.0–1.3 g / cm³. 3 .

[0229] Furthermore, the true density of cross-linked hollow particles refers to the density of the shell portion only. The true density of cross-linked hollow particles is specifically determined by the following method: After pre-crushing the cross-linked hollow particles, they are subjected to a 100cm³ volumetric precipitate test. 3 Approximately 10 g of cross-linked hollow particle powder was filled into a volumetric flask, and the mass of the powder was accurately weighed. Next, similar to the apparent density determination described above, isopropanol was added to the volumetric flask, and the mass of the isopropanol was accurately weighed. The true density (g / cm³) of the cross-linked hollow particles was calculated based on the following formula (I). 3 ).

[0230]

[0231] The porosity of the cross-linked hollow particles is preferably 40-95%, more preferably 50-90%, further preferably 55-88%, particularly preferably 60-85%, and most preferably 65-80%.

[0232] The porosity of cross-linked hollow particles is calculated using their apparent density D1 and true density D0. Apparent density D1 corresponds to the overall density of the cross-linked hollow particles when the hollow portion is considered part of the particle. Furthermore, if the hollow portion of the cross-linked hollow particles contains components other than the shell-forming components (such as the shell polymer), considering that most of these components originate from residual solvent, the density of these components is considered equal to the true density D0 of the cross-linked hollow particles, and the porosity is calculated accordingly. Specifically, the apparent density D1 is calculated using the mass of the cross-linked hollow particles, which also includes the mass of the components other than the shell-forming components. Then, the porosity of the cross-linked hollow particles is calculated using this calculated apparent density D1.

[0233] The method for determining the apparent density D1 of cross-linked hollow particles is as follows. First, in a volume of 100 cm³... 3 Fill the volumetric flask with approximately 30cm 3 The cross-linked hollow granules were precisely weighed. Then, while taking care to prevent air bubbles from entering, isopropanol was precisely added to the volumetric flask filled with the cross-linked hollow granules up to the mark. The mass of isopropanol added to the volumetric flask was precisely weighed, and the apparent density D1 (g / cm³) of the cross-linked hollow granules was calculated based on the following formula (II). 3 ).

[0234]

[0235] The porosity (%) of the cross-linked hollow particles is calculated from the apparent density D1 and true density D0 of the cross-linked hollow particles by the following formula (III).

[0236]

[0237] The proportion of crosslinked hollow particles is not particularly limited, but is preferably 0 to 40 parts by weight relative to 100 parts by weight of hydrogenated block copolymer (including the case of hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B), more preferably 5 to 30 parts by weight, and even more preferably 10 to 20 parts by weight.

[0238] In addition to containing hydrogenated block copolymers (including compositions of hydrogenated block copolymers containing hydrogenated block copolymer A and hydrogenated block copolymer B) and physical foaming agents, foaming particles or cross-linked hollow particles, the chemical mechanical polishing pad of the present invention may, as needed, contain processing aids, fillers, pigments, antistatic agents, flame retardants, water repellents, waterproofing agents, conductivity imparting agents, thermal conductivity imparting agents, electromagnetic wave shielding imparting agents, fluorescent agents, antibacterial agents, light stabilizers, ultraviolet absorbers, dyes, lubricants and other various compounding agents.

[0239] The method for manufacturing the chemical mechanical polishing pad of the present invention is not particularly limited, and it can be manufactured, for example, by compression molding the aforementioned hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B). In this case, it is preferable to use a mold having a groove pattern having a depth of 15% or more relative to the thickness of the chemical mechanical polishing pad, and to perform compression molding using a compression molding machine.

[0240] Furthermore, when the chemical mechanical polishing pad of the present invention has independent or continuous pores by using foamed particles, the following method can be used: The aforementioned hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B) is mixed with the foamed particles at a temperature below the expansion start temperature of the foamed particles; the resulting mixture is then compressed at a temperature above the expansion start temperature of the foamed particles. The compression molding temperature is not particularly limited, but can be selected according to the expansion start temperature of the foamed particles used; preferably 120–280°C, more preferably 150–250°C. In this case, it is also preferable to use a mold with a groove pattern having a depth of at least 15% of the thickness of the chemical mechanical polishing pad, and to perform compression molding using a compression molding machine.

[0241] Alternatively, when the chemical mechanical polishing pad of the present invention has independent or continuous pores by using cross-linked hollow particles, a method can be employed such as mixing the aforementioned hydrogenated block copolymer (including the case of a hydrogenated block copolymer composition containing hydrogenated block copolymer A and hydrogenated block copolymer B) with cross-linked hollow particles and then compressing the resulting mixture. The temperature during compression molding is not particularly limited, but is preferably 120–280°C, more preferably 150–250°C. In this case, it is also preferable to use a mold with a groove pattern having a depth of at least 15% relative to the thickness of the chemical mechanical polishing pad, and to perform compression molding using a compression molding machine.

[0242] The specific gravity (apparent density) of the chemical mechanical polishing pad of the present invention is not particularly limited, but is preferably 0.5 to 1 g / cm³.3 More preferably, it is 0.7–0.96 g / cm³. 3 .

[0243] The porosity of the chemical mechanical polishing pad of the present invention is not particularly limited, but is preferably 0 to 50% by volume, more preferably 0 to 25% by volume.

[0244] Chemical Mechanical Polishing Apparatus

[0245] The chemical mechanical polishing pad of the present invention can be suitably used as a polishing pad, for example, for chemical mechanical polishing of silicon wafers.

[0246] Figure 1 This is a schematic diagram of a chemical mechanical polishing apparatus 10 according to one embodiment of the present invention. Figure 1 As shown, the chemical mechanical polishing (CMP) apparatus 10 is configured such that a CMP pad 12 is mounted on a platen 20, and an oxide-coated wafer 14, which is the object to be polished, is pressed against the CMP pad 12 by a polishing head 18 while being fixed by a retaining ring 16. Furthermore, the CMP apparatus 10 includes a dresser 22 for removing (trimming) the surface of the CMP pad 12 and a slurry supply unit 26 for supplying slurry 24. In this embodiment, the CMP pad of the present invention described above is used as the CMP pad 12.

[0247] In the chemical mechanical polishing (CMP) apparatus 10, slurry 24 is supplied to the surface of the CMP pad 12 via the slurry supply unit 26. Simultaneously, the platen 20 and the polishing head 18 rotate in the same direction at the same or different speeds. Thus, through the rotation of the platen 20 and the polishing head 18, the CMP pad 12 and the oxide-coated wafer 14 rotate relative to each other while being pressed together, thereby polishing the oxide-coated wafer 14. Furthermore, in the CMP apparatus 10, when the CMP pad 12 is rotated, the surface of the CMP pad 12 is removed (trimmed) by the dresser 22, regenerating the polished surface and thus maintaining polishing performance.

[0248] Example

[0249] The present invention will be further illustrated below with examples and comparative examples, but the present invention is not limited to these examples. In addition, unless otherwise specified, "parts" and "%" are based on weight.

[0250] The experimental methods used in this embodiment and comparative example are described below.

[0251] [Weight-average molecular weight and molecular weight distribution of the hydrogenated block copolymer composition]

[0252] The weight-average molecular weight and molecular weight distribution of the hydrogenated block copolymer compositions were obtained by high-performance liquid chromatography (HPLC) using tetrahydrofuran as a carrier at a flow rate of 0.35 ml / min. A graph based on polystyrene was then used to calculate the molecular weight using standard polystyrene. The apparatus used was a Tosoh HLC8320, and the column was a combination of three Shodex KF-404HQ columns (registered trademark) manufactured by Showa Denko Corporation (column temperature 40°C). Differential refractometers and UV detectors were used. Molecular weight calibration was performed using 12 points of standard polystyrene (5 million to 3 million) manufactured by Polymer Laboratories.

[0253] [Weight ratio of each block copolymer in the hydrogenated block copolymer composition]

[0254] The weight ratio of each block copolymer in the hydrogenated block copolymer composition is determined based on the area ratio of the peaks corresponding to each block copolymer in the graph obtained by the above high performance liquid chromatography.

[0255] [Weight-average molecular weight of styrene polymer blocks in hydrogenated block copolymers]

[0256] First, the hydrogenated block copolymer is reacted with ozone and reduced by lithium aluminum hydride, as described in Rubber Chem. Technol., 45, 1295 (1972), thereby decomposing the isoprene polymer blocks of the hydrogenated block copolymer.

[0257] Specifically, the decomposition of the isoprene polymer block was carried out according to the following steps: 300 mg of the sample was dissolved in a reaction vessel containing 100 ml of dichloromethane treated with molecular sieves. The reaction vessel was placed in a cooling bath set to -25°C, and ozone generated by an ozone generator was introduced into the reaction vessel while oxygen was being bubbled through it at a flow rate of 170 ml / min. After 30 minutes from the start of the reaction, the gas flowing out of the reaction vessel was introduced into a potassium iodide aqueous solution to confirm the completion of the reaction. Next, in another reaction vessel purged with nitrogen, 50 ml of diethyl ether and 470 mg of lithium aluminum hydride were added. While cooling the reaction vessel with ice water, the solution that had reacted with ozone was slowly added dropwise. The reaction vessel was then placed in a water bath and gradually heated, refluxed at 40°C for 30 minutes. Then, while stirring the solution, dilute hydrochloric acid was added dropwise to the reaction vessel in small amounts until the generation of hydrogen gas was almost imperceptible. After the reaction, the solid product formed in the solution was filtered out, and then extracted with 100 ml of diethyl ether for 10 minutes. The extract was combined with the filtrate, and the solvent was removed by distillation to obtain the solid sample.

[0258] For the sample obtained in this way, the weight-average molecular weight is determined according to the method for determining the weight-average molecular weight of the hydrogenated block copolymer composition described above, and this value is taken as the weight-average molecular weight of the styrene polymer block.

[0259] [Weight-average molecular weight of hydrogenated isoprene polymer blocks in hydrogenated block copolymers]

[0260] The weight-average molecular weight of the hydrogenated isoprene polymer block is calculated by subtracting the weight-average molecular weight of the corresponding styrene polymer block from the weight-average molecular weight of the hydrogenated block copolymers obtained as described above.

[0261] [Styrene unit content of hydrogenated block copolymers]

[0262] The styrene unit content of the hydrogenated block copolymer was determined based on the detection intensity ratio of the differential refractometer and the ultraviolet detector in the above-mentioned high-performance liquid chromatography determination. In addition, copolymers with different styrene unit contents were prepared in advance, and calibration curves were constructed using them.

[0263] [Styrene unit content of the hydrogenated block copolymer composition as a whole]

[0264] The total styrene unit content of the hydrogenated block copolymer composition is based on the use of deuterated chloroform as a solvent. 1 The determination was obtained by H-NMR measurement.

[0265] [Vinyl bond content of (hydrogenated)isoprene polymer blocks]

[0266] The vinyl bond content of the (hydrogenated)isoprene polymer blocks is based on the use of deuterated chloroform as a solvent. 1 The determination was obtained by H-NMR measurement.

[0267] [Olefin hydrogenation rate (mol%) of the hydrogenated block copolymer composition]

[0268] By using deuterated chloroform as a solvent 1 H-NMR spectroscopy was used to determine the olefin content of the block copolymer composition before hydrogenation and the hydrogenated block copolymer composition after hydrogenation. Based on the difference in olefin content before and after hydrogenation, the olefin hydrogenation rate (mol%) of the hydrogenated block copolymer composition was calculated.

[0269] exist 1 In the H-NMR spectroscopy determination, deuterated chloroform was used as the solvent, and a JMN-AL series AL400 (manufactured by JEOL) was used as the NMR measuring device.

[0270] Furthermore, in this embodiment and comparative example, both the pre-hydrogenated block copolymer composition and the post-hydrogenated block copolymer composition contain only isoprene units as monomer units derived from olefins. Therefore, during the measurement, the hydrogenation rate of the isoprene units is determined and used as the olefin hydrogenation rate.

[0271] [Shore A hardness of the hydrogenated block copolymer composition]

[0272] Determine the Shore A hardness of the hydrogenated block copolymer composition according to ISO 7619.

[0273] [Specific gravity and porosity of chemical mechanical polishing pads]

[0274] The specific gravity (apparent density) of the chemical mechanical polishing pads obtained in the Examples and Comparative Examples was determined according to JIS K 7311:1995 (displacement method in water). Similarly, the specific gravity (true density) of the hydrogenated block copolymer composition used to manufacture the chemical mechanical polishing pads was determined, and the porosity of the chemical mechanical polishing pads was calculated from the specific gravity (apparent density) of the chemical mechanical polishing pads and the specific gravity (true density) of the hydrogenated block copolymer composition. In Comparative Example 2, the specific gravity (true density) of general-purpose polyurethane rubber was used for determination.

[0275] [Polishing Test]

[0276] Using the chemical mechanical polishing pads obtained in the examples and comparative examples, by Figure 1 Polishing tests were conducted using the chemical mechanical polishing apparatus 10 shown. Specifically, using... Figure 1 The chemical mechanical polishing apparatus 10 shown uses an adhesive to attach the chemical mechanical polishing pads obtained in the examples and comparative examples to the platen 20. A 4-inch silicon wafer 14 with an oxide film is used as the silicon wafer to be polished. Under the following conditions, the 4-inch silicon wafer with an oxide film is polished while silica slurry 14 is added dropwise at a drop rate of 100 cc / min.

[0277] The rotational speed of the pressure plate 20 is 60 rpm.

[0278] Polishing head 18 rotation speed: 61 rpm

[0279] The clamping pressure of the 14-inch silicon wafer is 3.0 psi.

[0280] Maintain the clamping pressure of ring 16: 3.6 psi

[0281] Then, in the polishing test, the wafer polishing rate and the wafer transportability of the chemical mechanical polishing pad were evaluated as described below.

[0282] • Wafer polishing rate

[0283] An interferometric film thickness gauge (manufactured by Ocean Photonics, product name "SR4-RF Fiber Optic Multichannel Spectrometer for Reflectance Measurement") was used to measure the oxide film thickness of a 4-inch silicon wafer before and after polishing. The wafer polishing rate was determined by calculating the difference in oxide film thickness before and after polishing.

[0284] • Wafer transport properties of chemical mechanical polishing pads

[0285] After polishing, as the polishing head 18 rises, visually observe the adhesion between the silicon wafer 14 and the chemical mechanical polishing pad, and evaluate it according to the following criteria.

[0286] ○: The silicon wafer rises while still mounted on the polishing head.

[0287] ×: Silicon wafer residue on the chemical mechanical polishing pad

[0288] In addition, the surface of the chemical mechanical polishing pad 12 is removed (trimmed) by the dressing tool 22, and the wear resistance of the chemical mechanical polishing pad 12 is evaluated.

[0289] • Abrasion resistance of chemical mechanical polishing pads

[0290] The wear resistance of the chemical mechanical polishing pad 12 was evaluated by measuring the thickness of the pad 12 using a depth gauge (manufactured by Mitutoyo, product name "digital depth gauge") and calculating the thickness difference before and after dressing by the dresser 22.

[0291] [Manufacturing Example 1]

[0292] (1) Preparation of block copolymer compositions before hydrogenation

[0293] 56.6 kg of cyclohexane, 387 mmol of dibutyl ether, and 1.23 kg of styrene were added to a pressure reactor. While stirring the entire mixture at 40°C, 208 mmol of n-butyllithium (1.6 M solution) was added. After the addition was complete, the temperature was raised to 50°C, and polymerization was carried out for 1 hour (stage 1 of polymerization). The styrene polymerization conversion rate at this stage was 100% by weight.

[0294] Next, while maintaining the temperature at 50–60°C, 5.00 kg of isoprene was continuously added to the reactor over one hour. After the isoprene addition was complete, a further polymerization reaction (polymerization stage 2) was carried out for another hour. At this point, the isoprene polymerization conversion rate was 100%.

[0295] Next, while maintaining the temperature at 50–60°C, 1.23 kg of styrene was continuously added over 1 hour. After the addition of styrene was complete, the polymerization reaction was carried out for another hour, thereby obtaining a solution containing a styrene-isoprene-styrene triblock copolymer with active ends (polymerization stage 3). At this point, the styrene polymerization conversion rate was 100%.

[0296] Next, 145 mmol of methanol was added as a polymerization terminator and mixed, thereby deactivating some of the active ends in the styrene-isoprene-styrene triblock copolymer with active ends, resulting in a solution containing a styrene-isoprene-styrene triblock copolymer as a block copolymer B' for obtaining hydrogenated block copolymer B.

[0297] Following this, while maintaining the temperature at 50–60°C, 2.53 kg of styrene was continuously added over 1 hour. After the styrene addition was complete, the polymerization reaction was carried out for another hour to obtain a solution containing a styrene-isoprene-styrene triblock copolymer with active ends. This triblock copolymer became block copolymer A' (polymerization stage 4) used to obtain hydrogenated block copolymer A. At this point, the styrene polymerization conversion rate was 100%.

[0298] Finally, 271 mmol of methanol was added as a polymerization terminator and mixed to deactivate all active ends of the styrene-isoprene-styrene triblock copolymer with active ends, thus completing the polymerization reaction and obtaining a solution containing the unhydrogenated block copolymer composition.

[0299] The amounts of each reagent used in the reaction are summarized in Table 1.

[0300] (2) Hydrogenation reaction of the block copolymer composition before hydrogenation

[0301] The solution containing the unhydrogenated block copolymer composition obtained above was subjected to a hydrogenation reaction to obtain a solution containing the hydrogenated block copolymer composition. The hydrogenation reaction was carried out as follows: Ni(AcAc)2-TIBAL catalyst was added as a hydrogenation catalyst to the solution containing the unhydrogenated block copolymer composition obtained above at a ratio of 0.5% by weight relative to the unhydrogenated block copolymer composition, and the reaction was carried out under the conditions of hydrogen pressure of 3 MPa, reaction temperature of 80°C, and reaction time of 3 hours.

[0302] A portion of the solution containing hydrogenated block copolymer composition 1 was taken out, and the weight-average molecular weight of each block copolymer contained in the composition, the weight ratio of each block copolymer in the composition, the weight-average molecular weight of the styrene polymer block of each block copolymer, the weight-average molecular weight of the isoprene polymer block of each block copolymer, the styrene unit content of each block copolymer, the styrene unit content of the block copolymer composition (as a whole), the vinyl bond content of the isoprene polymer block of each block copolymer, the olefin hydrogenation rate, the density of the block copolymer composition (as a whole), and the Shore A hardness (-) of the block copolymer composition (as a whole) were determined. These values ​​are summarized in Table 2.

[0303] (3) Recovery of hydrogenated block copolymer composition 1

[0304] In a solution containing the hydrogenated block copolymer composition obtained as described above, 0.3 parts of 2,6-di-tert-butyl-p-cresol were added as an antioxidant and mixed. The mixed solution was then added dropwise in small amounts to warm water heated to 85–95°C to allow the solvent to evaporate and obtain a precipitate. The precipitate was pulverized and dried with hot air at 85°C to recover the granular hydrogenated block copolymer composition 1.

[0305] [Manufacturing Example 2]

[0306] The amounts of each reagent used in the reaction (dibutyl ether, n-butyllithium, styrene, isoprene, and methanol) were varied as shown in Table 1. Otherwise, the process was carried out in the same manner as in Manufacturing Example 1 to obtain hydrogenated block copolymer composition 2. The determination and evaluation were performed in the same manner as in Manufacturing Example 1. The results are shown in Table 2.

[0307] [Manufacturing Example 3]

[0308] Cross-linked hollow particles are manufactured using the following method.

[0309] (A) Mixture preparation process

[0310] First, mix the following materials to prepare the oil phase.

[0311] Divinylbenzene (crosslinked hydrocarbon monomer) 22.5 parts

[0312] 0.9 parts of ethyl vinylbenzene (monofunctional hydrocarbon monomer)

[0313] Ethylene glycol dimethacrylate (containing heteroatom crosslinking monomer) 7.8 parts

[0314] Pentaerythritol tetraacrylate (containing heteroatom crosslinking monomer) 7.8 parts

[0315] 1.04 parts of 2,2'-azobis(2,4-dimethylvaleronitrile) (oil-soluble polymerization initiator)

[0316] Hydrophobic solvent: 60.8 parts of heptane

[0317] Next, in a stirred tank, an aqueous solution containing 7.83 parts magnesium chloride (a water-soluble polyvalent metal salt) dissolved in 225 parts ion-exchanged water was gradually added while stirring. This process prepared a magnesium hydroxide colloid (a water-insoluble metal hydroxide colloid) dispersion as the aqueous phase. The resulting aqueous phase was then mixed with the oil phase to prepare a mixed solution.

[0318] (B) Suspension Process

[0319] Next, using the mixture obtained through the above-mentioned mixture preparation process, a suspension of monomeric droplets encapsulated with hydrophobic solvent dispersed in water was prepared by using an inline emulsifying disperser to suspend the mixture.

[0320] (C) Polymerization process

[0321] The suspension obtained through the above suspension process is heated from 40°C to 65°C in a nitrogen atmosphere and stirred at 65°C for 24 hours to carry out a polymerization reaction. Through this polymerization reaction, a precursor composition of a slurry containing precursor particles of an encapsulating hydrophobic solvent dispersed in water is obtained.

[0322] (D) Solvent removal process

[0323] The hydrophobic solvent encapsulated in the precursor particles is removed by a liquid-based desolventizing method, thereby obtaining a cross-linked hollow particle slurry containing cross-linked hollow particles and water. Specifically, nitrogen gas is bubbled into the precursor composition obtained through the above polymerization process from the bottom of the container at a temperature of 90°C for 12 hours, thereby replacing the hydrophobic solvent encapsulated in the precursor particles with nitrogen gas. At this time, the amount of nitrogen bubbling per minute is the same as the volume of the precursor composition obtained through the above polymerization process.

[0324] (E) Cleaning process and solid-liquid separation process

[0325] The cross-linked hollow particle slurry obtained from the above solvent removal process was washed with dilute sulfuric acid (25°C, 10 minutes) to bring the pH to below 5.5. Next, after water separation by filtration, 200 parts of ion-exchange water were added for re-slurrying. The slurry was then repeatedly washed several times at room temperature (25°C) (washing, filtration, dehydration), followed by filtration separation to obtain the solid components.

[0326] (F) Moisture removal process

[0327] In a vacuum dryer, the solid component obtained through the above solid-liquid separation process was heated for 12 hours under vacuum conditions at 40°C to remove moisture from the surface of the crosslinked hollow particles, thus obtaining crosslinked hollow particles. Furthermore, the monomer composition of the shell polymer in the obtained crosslinked hollow particles is approximately consistent with the composition of the polymerizable monomers used for polymerization. In addition, when the true density, porosity, volume average particle size (Dv), and particle size distribution (Dv / Dn) of the obtained crosslinked hollow particles were measured, the true density was 1.090 g / cm³. 3 The porosity is 71%, the volume average particle size (Dv) is 7.10 μm, and the particle size distribution (Dv / Dn) is 1.21.

[0328] [Example 1]

[0329] 100 parts of the hydrogenated block copolymer composition 1 obtained in Manufacturing Example 1 and 1.5 parts of foamed particles (manufactured by Sekisui Chemicals Co., Ltd., product name "Advancell EM501", foamed particles encapsulating low-boiling-point hydrocarbons in a thermoplastic polymer shell formed by acrylonitrile copolymer) were fed into a mixer and mixed at a mixing temperature of 120°C to obtain a compound. Using a mold with a reverse pattern of concentric circular grooves with a groove depth of 0.4 mm (a mold capable of forming a concentric circular groove pattern with a groove depth of 0.4 mm) and a compression molding machine, the obtained compound was compressed for 3 minutes at a temperature of 220°C and a pressure of 6 MPa. After cooling to 80°C, the mold was opened, thereby molding while foaming the foamed particles. Thus, a disc-shaped chemical mechanical polishing pad with a concentric circular groove pattern with a groove depth of 0.4 mm, a width of 0.25 mm, a diameter of 38 cm, and a thickness of 1.3 mm (grooves with a depth of 30% relative to the pad thickness) was produced. The obtained chemical mechanical polishing pads were then evaluated using the method described above. The results are shown in Table 3.

[0330] [Example 2]

[0331] The hydrogenated block copolymer composition 2 was used instead of hydrogenated block copolymer composition 1, and the amount of foamed particles used in the preparation of the chemical mechanical polishing pad was changed from 1.5 parts to 1.2 parts. Otherwise, the chemical mechanical polishing pad was prepared in the same manner as in Example 1, and the measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 3.

[0332] [Example 3]

[0333] In the preparation of the chemical mechanical polishing pad, the cross-linked hollow particles obtained in Manufacturing Example 3 were used instead of the foamed particles in an amount of 16 parts. Otherwise, the preparation of the chemical mechanical polishing pad was carried out in the same manner as in Example 1, and the measurements and evaluations were performed in the same manner as in Example 1. The results are shown in Table 3.

[0334] [Comparative Example 1]

[0335] A mold without a concentric groove pattern was used as the molding mold. Otherwise, the same procedure as in Example 1 was followed to produce a chemical mechanical polishing pad without a groove pattern, and polishing tests were conducted in the same manner as in Example 1. The results are shown in Table 3.

[0336] [Comparative Example 2]

[0337] Polishing tests were conducted using a cross-linked polyurethane chemical mechanical polishing pad (manufactured by Nitta-DuPont, product name "IC1400") with a concentric circular groove pattern having a groove depth of 0.4 mm, in the same manner as in Example 1. The results are shown in Table 3.

[0338] [Table 1]

[0339]

[0340] [Table 2]

[0341]

[0342] [Table 3]

[0343]

[0344] As shown in Table 3, the chemical mechanical polishing pads of Examples 1 to 3, which contain hydrogenated block copolymers and have grooves, achieve a sufficient polishing rate while suppressing the amount of wear during dressing by the dresser 22, exhibiting excellent wear resistance and, consequently, excellent wafer transport performance.

Claims

1. A chemical mechanical polishing pad comprising a hydrogenated block copolymer having hydrogenated polymer blocks of aromatic vinyl polymers and conjugated diene polymers, The chemical mechanical polishing pad has grooves or holes.

2. The chemical mechanical polishing pad of claim 1, wherein, The hydrogenated block copolymer contains either hydrogenated block copolymer A represented by the following general formula (A) or hydrogenated block copolymer B represented by the following general formula (B). In the above general formula (A), Ar1 a and Ar2 a are aromatic vinyl polymer blocks, HD a is a hydrogenated polymer block of a conjugated diene polymer, the ratio (Mw(Ar2 a ) / Mw(Ar1 a )) of the weight average molecular weight (Mw(Ar2 a )) of Ar2 a to the weight average molecular weight (Mw(Ar1 a )) of Ar1 a is 3.0 to 20, In the above general formula (B), Ar1 b and Ar2 b are aromatic vinyl polymer blocks, HD b is a hydrogenated polymer block of a conjugated diene polymer, the ratio (Mw(Ar2 b ) / Mw(Ar1 b )) of the weight average molecular weight (Mw(Ar2 b )) of Ar2 b to the weight average molecular weight (Mw(Ar1 b )) of Ar1 b is 0.95 to 1.

05.

3. The chemical mechanical polishing pad of claim 2, wherein, The hydrogenated block copolymer contains both hydrogenated block copolymer A and hydrogenated block copolymer B.

4. The chemical mechanical polishing pad of claim 2 or 3, wherein, Ar1 a , Ar1 b , and Ar2 b in the general formula (A) and the general formula (B) are in the range of 2000 to 40000, respectively, and the weight average molecular weight of HD a and HD b is in the range of 10000 to 300000, respectively.

5. The chemical mechanical polishing pad of claim 3 or 4, wherein, The weight ratio (A / B) of the hydrogenated block copolymer A to the hydrogenated block copolymer B is 10 / 90 to 80 / 20.

6. The chemical mechanical polishing pad of any of claims 1-5, wherein, The aromatic vinyl monomer unit accounts for 20 to 60% by weight of all repeating units in the hydrogenated block copolymer.

7. The chemical mechanical polishing pad according to any one of claims 1 to 6, further comprising foamed particles or cross-linked hollow particles.

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