Polyurethane resin for polishing pad, and polishing pad

Abstract

A polyurethane resin (U) for a polishing pad, which contains, as constituent monomers, one or more polyols (a) selected from the group consisting of polyether polyols (a11), polyester polyols (a12) and polycarbonate polyols (a13), a polyisocyanate (b), and a compound (c) having an ionic group and two active hydrogen atoms, among the constituent components of the polishing pad polyurethane resin (U), the weight ratio of a constituent component (A ') having an active hydrogen atom and having an HLB of 8.0 or more is 80-100% by weight based on the weight of the constituent component (A) having an active hydrogen atom.

Description

Technical Field

[0001] The present invention relates to a polyurethane resin for a polishing pad and a polishing pad. Background Art

[0002] The CMP (Chemical Mechanical Polishing) process is used in the polishing of semiconductors and wafers. In the CMP process, the surface of the object to be polished is flattened and waste parts are removed by polishing the object to be polished using a polishing slurry containing particles such as aluminum oxide and silicon dioxide on a polishing pad.

[0003] As a polishing pad, a polyurethane resin using polytetramethylene glycol as a polyol component has been proposed (for example, Patent Document 1).

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2019-116616 Summary of the Invention

[0007] Problems to be solved by the invention

[0008] However, even the technology of Patent Document 1 does not sufficiently reduce the damage to the surface of the object being polished, and requires improvement thereof.

[0009] Means for solving problems

[0010] The present inventors have conducted research to achieve the above-mentioned objectives and have completed the present invention. Specifically, the present invention provides: a polyurethane resin (U) for a polishing pad, comprising at least one polyol (a) selected from the group consisting of a polyether polyol (a11), a polyester polyol (a12), and a polycarbonate polyol (a13); a polyisocyanate (b); and a compound (c) having an ionic group and two active hydrogen atoms as constituent monomers; wherein, among the constituent components of the polyurethane resin (U), the weight ratio of the constituent component (A') having an active hydrogen atom and an HLB of 8.0 or greater is 80 to 100% by weight, based on the weight of the constituent component (A) having an active hydrogen atom; and a polishing pad (Uα) comprising the polyurethane resin (U) for a polishing pad of the present invention.

[0011] Effects of the Invention

[0012] According to the present invention, it is possible to provide a polyurethane resin for a polishing pad that can reduce damage to an object to be polished and provide a polishing pad having excellent durability. DETAILED DESCRIPTION

[0013] The polyurethane resin (U) for a polishing pad of the present invention comprises, as constituent monomers, one or more polyols (a) selected from the group consisting of polyether polyols (a11), polyester polyols (a12), and polycarbonate polyols (a13); a polyisocyanate (b); and a compound (c) having an ionic group and two active hydrogen atoms. Among the constituent components of the polyurethane resin (U) for a polishing pad, the weight proportion of the constituent component (A') having an active hydrogen atom and having an HLB of 8.0 or higher is 80 to 100% by weight, based on the weight of the constituent component (A) having an active hydrogen atom.

[0014] <Polyol (a)>

[0015] The polyol (a) in the present invention is selected from the group consisting of polyether polyol (a11), polyester polyol (a12) and polycarbonate polyol (a13).

[0016] The number average molecular weight (hereinafter abbreviated as Mn) of the polyol (a) is preferably 300 or more.

[0017] As the polyol (a), from the viewpoint of the retention of the polishing slurry, polyether polyol (a11) and polyester polyol (a12) are preferred, and polyester polyol (a12) is more preferred.

[0018] The polyol (a) may be used alone or in combination of two or more.

[0019] <Polyether polyol (a11)>

[0020] Examples of the polyether polyol (a11) in the present invention include aliphatic polyether polyols and aromatic polyether polyols.

[0021] Examples of the aliphatic polyether polyol include polyoxyethylene polyol (polyethylene glycol, etc.), polyoxypropylene polyol (polypropylene glycol, etc.), polyoxyethylene / propylene polyol, and polytetramethylene ether glycol.

[0022] Examples of the aromatic polyether polyols include polyols having a bisphenol skeleton such as ethylene oxide (hereinafter referred to as EO) adducts of bisphenol A [EO4 molar adducts of bisphenol A, EO6 molar adducts of bisphenol A, EO8 molar adducts of bisphenol A, EO10 molar adducts of bisphenol A, and EO20 molar adducts of bisphenol A, etc.] and propylene oxide (hereinafter referred to as PO) adducts of bisphenol A [PO3 molar adducts of bisphenol A, PO5 molar adducts of bisphenol A, etc.], and EO or PO adducts of resorcinol.

[0023] Among the polyether polyols (a11), aliphatic polyether polyols are preferred from the viewpoint of ease of adjustment of HLB and the like.

[0024] From the viewpoint of the balance between the ease of adjusting the HLB and the durability of the polishing pad, the Mn of the polyether polyol (a11) is preferably 300 to 5,000, more preferably 300 to 3,000, and particularly preferably 300 to 2,500.

[0025] <Polyester polyol (a12)>

[0026] Examples of the polyester polyol (a12) in the present invention include condensed polyester polyol, polylactone polyol, and castor oil-based polyol.

[0027] Examples of the condensed polyester polyol include polyester polyols of a low molecular weight (Mn less than 300) polyol and a polycarboxylic acid having 2 to 10 carbon atoms or an ester-forming derivative thereof.

[0028] As the low molecular weight polyol, aliphatic polyols having a valence of 2 to 8 or more and having an Mn of less than 300 and low molar adducts of phenols having a valence of 2 to 8 or more and having an Mn of less than 300 and alkylene oxides (such as EO, PO, 1,2-butylene oxide, 1,3-butylene oxide, 2,3-butylene oxide or 1,4-butylene oxide, hereinafter referred to as AO) can be used.

[0029] Among the low molecular weight polyols that can be used in the condensation-type polyester polyol, ethylene glycol, propylene glycol, 1,4-butanediol, neopentyl glycol, 1,6-hexanediol, EO or PO low-molecular adducts of bisphenol A, and combinations thereof are preferred, and ethylene glycol, propylene glycol, 1,4-butanediol, and combinations thereof are more preferred, from the perspective of balancing the ease of adjusting the HLB and the durability of the polishing pad.

[0030] Examples of polycarboxylic acids having 2 to 10 carbon atoms or their ester-forming derivatives that can be used in the condensed polyester polyol include aliphatic dicarboxylic acids (such as succinic acid, adipic acid, azelaic acid, sebacic acid, fumaric acid, and maleic acid), alicyclic dicarboxylic acids (such as dimer acid), aromatic dicarboxylic acids (such as terephthalic acid, isophthalic acid, and phthalic acid), trivalent or higher polycarboxylic acids (such as trimellitic acid and pyromellitic acid), their anhydrides (such as succinic anhydride, maleic anhydride, phthalic anhydride, and trimellitic anhydride), their acid halides (such as adipic acid dichloride), their low-molecular-weight alkyl esters (such as dimethyl succinate and dimethyl phthalate), and combinations thereof.

[0031] Among the polycarboxylic acids having 2 to 10 carbon atoms or their ester-forming derivatives, aliphatic dicarboxylic acids are preferred, and adipic acid is more preferred, from the viewpoint of ease of adjustment of HLB and durability of the polishing pad.

[0032] Specific examples of the condensation-type polyester polyol include polyethylene adipate diol, polybutylene adipate diol, poly-1,6-hexanediol adipate diol, poly-1,6-hexanediol isophthalate diol, poly-neopentyl adipate diol, polyethylene propylene adipate diol, polyethylene butylene adipate diol, poly-1,6-hexanediol adipate diol, polyethylene diethylene adipate diol, poly-tetramethylene ether adipate diol, poly-(3-methylpentanediol adipate) diol, polyethylene azelaic acid diol, polyethylene sebacate diol, polybutylene azelaic acid diol, polybutylene sebacate diol, and poly-neopentyl terephthalate diol.

[0033] Examples of commercially available condensed polyester polyols include SANESTER 2610 [polyethylene adipate diol with Mn = 1,000, manufactured by Sanyo Chemical Industries, Ltd.], SANESTER 4620 [polybutylene adipate diol with Mn = 2,000], and SANESTER 2620 [polyethylene adipate diol with Mn = 2,000, manufactured by Sanyo Chemical Industries, Ltd.].

[0034] Polylactone polyols are lactone addition products of the above-mentioned low molecular weight polyols. Examples of the lactone include lactones having 4 to 12 carbon atoms (eg, γ-butyrolactone, γ-valerolactone, and ε-caprolactone).

[0035] Specific examples of the polylactone polyol include polycaprolactone diol, polyvalerolactone diol, and polycaprolactone triol.

[0036] Castor oil-based polyols include castor oil and modified castor oils modified with polyols or AO. Modified castor oils can be produced by transesterification and / or AO addition of castor oil with polyols. Examples of castor oil-based polyols include castor oil, trimethylolpropane-modified castor oil, pentaerythritol-modified castor oil, and castor oil EO (4-30 mol) adducts.

[0037] Among the polyester polyols (a12), condensed polyester polyols are preferred from the viewpoint of easy adjustment of HLB and durability of the polishing pad, and polyethylene adipate diol, polybutylene adipate diol, and polyhexanediol adipate diol are more preferred.

[0038] The Mn of the polyester polyol (a12) is preferably 300 to 10,000, more preferably 600 to 7,000, and particularly preferably 1,000 to 4,000.

[0039] <Polycarbonate polyol (a13)>

[0040] Examples of the polycarbonate polyol (a13) include polycarbonate polyols produced by simultaneously subjecting the above-mentioned low molecular weight polyols to a dealcoholization reaction and condensation with a low molecular weight carbonate compound (e.g., a dialkyl carbonate having an alkyl group with 1 to 6 carbon atoms, an alkylene carbonate having an alkylene group with 2 to 6 carbon atoms, and a diaryl carbonate having an aryl group with 6 to 9 carbon atoms). Two or more low molecular weight polyols and low molecular weight carbonate compounds may be used in combination.

[0041] Specific examples of the polycarbonate polyol (a13) include polyhexamethylene carbonate diol, polypentamethylene carbonate diol, polytetramethylene carbonate diol, and poly(tetramethylene / hexamethylene) carbonate diol (for example, a diol obtained by simultaneously condensing 1,4-butanediol and 1,6-hexanediol with a dialkyl carbonate through a dealcoholization reaction).

[0042] Examples of commercially available polycarbonate polyols (a13) include NIPPOLLAN 980R [polyhexamethylene carbonate diol with an Mn of 2,000, manufactured by Tosoh Corporation], KURARAY Polyol C-3090 [poly(3-methyl-5-pentanediol / 1,6-hexanediol) carbonate diol with an Mn of 3,000], and T4672 [poly(tetramethylene / hexamethylene) carbonate diol with an Mn of 2,000, manufactured by Asahi Kasei Corporation].

[0043] Among the polycarbonate polyols (a13), polycarbonate diols obtained by simultaneously condensing 1,4-butanediol and 1,5-pentanediol or 1,6-hexanediol with a dialkyl carbonate through a dealcoholization reaction are preferred from the viewpoint of ease of adjusting the HLB.

[0044] From the viewpoint of ease of adjustment of HLB and durability of the polishing pad, the Mn of the polycarbonate polyol (a13) is preferably 300 to 5,000, more preferably 300 to 3,000, and particularly preferably 300 to 2,500.

[0045] Mn in the present invention can be measured by gel permeation chromatography under the following conditions, for example.

[0046] Device: "Waters Alliance 2695" [manufactured by Waters]

[0047] Column: "Guardcolumn Super HL" (1 column), "column formed by connecting 1 each of TSKgel SuperH2000, TSKgelSuperH3000, and TSKgel SuperH4000 (all manufactured by Tosoh Corporation)"

[0048] Sample solution: 0.25 wt% tetrahydrofuran solution

[0049] Solution injection volume: 10μl

[0050] Flow rate: 0.6ml / min

[0051] Measurement temperature: 40°C

[0052] Detection device: Refractive index detector

[0053] Reference material: Standard polyethylene glycol

[0054] <Polyisocyanate (b)>

[0055] The polyisocyanate (b) in the present invention is a compound having two or more isocyanate groups, and examples thereof include aromatic polyisocyanates (b1) having two or more isocyanate groups and having 6 to 20 carbon atoms (excluding the carbon atoms in the isocyanate groups, the same applies hereinafter), aliphatic polyisocyanates (b2) having 2 to 18 carbon atoms, alicyclic polyisocyanates (b3) having 4 to 15 carbon atoms, and modified products (b4) of the above polyisocyanates (b1) to (b3).

[0056] The polyisocyanate (b) may be used alone or in combination of two or more.

[0057] Examples of the aromatic polyisocyanate (b1) having 6 to 20 carbon atoms include 1,3-phenylene diisocyanate or 1,4-phenylene diisocyanate, 2,4-toluene diisocyanate or 2,6-toluene diisocyanate (TDI), 4,4'-diphenylmethane diisocyanate or 2,4'-diphenylmethane diisocyanate (MDI), 1,5-naphthalene diisocyanate, 4,4',4"-triphenylmethane triisocyanate, m-isocyanatobenzenesulfonyl isocyanate or p-isocyanatobenzenesulfonyl isocyanate, crude MDI, m-xylylene diisocyanate or p-xylylene diisocyanate (XDI), and α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI).

[0058] Examples of the aliphatic polyisocyanate (b2) having 2 to 18 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 4,4'-methylenebiscyclohexyl diisocyanate, and 2-isocyanatoethyl-2,6-diisocyanatohexanoate.

[0059] Examples of the alicyclic polyisocyanate (b3) having 4 to 15 carbon atoms include isophorone diisocyanate (IPDI), 4,4-dicyclohexylmethane diisocyanate (hydrogenated MDI, 4,4'-methylenebiscyclohexyl diisocyanate), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, and 2,5- or 2,6-norbornane diisocyanate.

[0060] As modified products (b4), there can be mentioned modified products of the above-mentioned polyisocyanates (b1) to (b3) containing a carbamate group, a carbodiimide group, an allophanate group, a urea group, a biuret group, a uretdione group, a uretonimine group, an isocyanurate group or an oxazolidone group [for example, modified MDI (carbamate-modified MDI, carbodiimide-modified MDI and trialkylphosphate-modified MDI, etc.), carbamate-modified TDI, a biuret form of HDI, an isocyanurate form of HDI and an isocyanurate form of IPDI] and the like.

[0061] Among the polyisocyanates (b), aromatic polyisocyanates (b1) having 6 to 20 carbon atoms are preferred from the viewpoint of durability, and MDI is more preferred.

[0062] <Compound (c) Having an Ionic Group and Two Active Hydrogen Atoms>

[0063] The ionic groups in the present invention are cationic nitrogen atoms (>N + <、=N + <etc.) and cationic groups, and -SO3 - and -COO - A general term for anionic groups such as .

[0064] The active hydrogen atom refers to a hydrogen atom that is bonded to an oxygen atom, a nitrogen atom, a sulfur atom, etc. and has high reactivity with an isocyanate group. Examples of groups having such active hydrogen atoms (active hydrogen atom-containing groups) include hydroxyl groups, primary amino groups, secondary amino groups, and mercapto groups.

[0065] As the compound (c) having an ionic group and two active hydrogen atoms in the present invention, preferably there are compounds (c1) having an anionic group and an active hydrogen atom and having a number average molecular weight (Mn) or a chemical formula weight of less than 300, and compounds (c2) having a cationic group and an active hydrogen atom.

[0066] The compound (c) may be used alone or in combination of two or more.

[0067] Compound (c2) is preferably a compound having an Mn or chemical formula weight of less than 300.

[0068] The anionic group in the compound (c1) refers to an acid group and a neutralized acid anion group.

[0069] Examples of the compound (c1) include compounds having 2 to 10 carbon atoms, which contain a carboxyl group as an anionic group and a hydroxyl group or an amino group as a group containing an active hydrogen atom [dialkylalkanoic acids (e.g., dimethylolpropionic acid, 2,2-dimethylolbutanoic acid, 2,2-dimethylolheptanoic acid, and 2,2-dimethyloloctanoic acid), tartaric acid, and amino acids (e.g., glycine, alanine, and valine)]; compounds having 2 to 16 carbon atoms, which contain a sulfonic acid group as an anionic group and a hydroxyl group as a group containing an active hydrogen atom [3-(2,3-dihydroxypropoxy)-1-propanesulfonic acid and di(ethylene glycol) sulfoisophthalate]; compounds having 2 to 10 carbon atoms, which contain an aminosulfonic acid group as an anionic group and a hydroxyl group as a group containing an active hydrogen atom [N,N-bis(2-hydroxyethyl)aminosulfonic acid]; and salts obtained by neutralizing these compounds with a neutralizing agent.

[0070] Examples of the neutralizing agent used for neutralizing the compound (c1) include ammonia, amine compounds having 1 to 20 carbon atoms, and alkali metal hydroxides (such as sodium hydroxide, potassium hydroxide, and lithium hydroxide).

[0071] Examples of the compound (c2) include salts obtained by neutralizing with a neutralizing agent a compound having a tertiary amino group as a cationic group and a hydroxyl group as a group containing an active hydrogen atom, for example, a compound having a tertiary amino group-containing diol having 1 to 20 carbon atoms [N-alkyldialkanolamines (e.g., N-methyldiethanolamine, N-propyldiethanolamine, N-butyldiethanolamine, and N-methyldipropanolamine)], an N,N-dialkylmonoalkanolamine (e.g., N,N-dimethylethanolamine), and a trialkanolamine (e.g., triethanolamine).

[0072] Examples of the neutralizing agent used for neutralizing compound (c2) include monocarboxylic acids having 1 to 10 carbon atoms (such as formic acid, acetic acid, and propionic acid), carbonic acid, dimethyl carbonate, dimethyl sulfate, methyl chloride, and benzyl chloride.

[0073] Among the above compounds (c), compound (c1) is preferred from the viewpoint of retention of the polishing slurry, and dialkyl alcohol alkanoic acid and salts thereof are more preferred.

[0074] The polyurethane resin (U) for a polishing pad may contain, as necessary, a chain extender (d) and a reaction terminator (e) as constituent monomers in addition to the polyol (a), the polyisocyanate (b), and the compound (c).

[0075] <Chain Extender (d)>

[0076] Examples of the chain extender (d) include compounds having two or more active hydrogen atoms other than the above compounds, such as water, aliphatic diols having 2 to 8 carbon atoms [straight-chain aliphatic diols (ethylene glycol, diethylene glycol, 1,3-propylene glycol, 1,4-butanediol, 1,5-pentanediol, and 1,6-hexanediol, etc.) and diols having a branched alkyl chain (1,2-propylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, 1,2-butanediol, 1,3-butanediol, and 2,3-butanediol, etc.); diols having an alicyclic group having 6 to 10 carbon atoms [1,4-bis(hydroxymethyl)cyclohexane and 2,2-bis(4-hydroxycyclohexyl)propane, etc.]; aromatic diols having 8 to 20 carbon atoms [m-phenylenediol or p-phenylenediol] diols, bis(hydroxyethyl)benzene, bis(hydroxyethoxy)benzene]; AO adducts of bisphenols (bisphenol A, bisphenol S, bisphenol F, etc.), AO adducts of dihydroxynaphthalene, and bis(2-hydroxyethyl)terephthalate, etc.; diamines having 2 to 10 carbon atoms (for example, ethylenediamine, propylenediamine, 1,6-hexanediamine, isophoronediamine, toluenediamine, and piperazine); polyalkylene polyamines having 2 to 10 carbon atoms (for example, diethylenetriamine and triethylenetetramine); hydrazine or its derivatives (dibasic acid dihydrazide, for example, adipic acid dihydrazide); polyepoxides having 2 to 30 carbon atoms (for example, 1,6-hexanediol diglycidyl ether, trimethylolpropane triglycidyl ether, etc.); amino alcohols having 2 to 10 carbon atoms (for example, monoethanolamine, diethanolamine, isopropanolamine, 2-amino-2-methylpropanol).

[0077] The chain extender (d) preferably has an Mn or chemical formula weight of less than 300.

[0078] Among the chain extenders (d), aliphatic diols having 2 to 8 carbon atoms are preferred, linear aliphatic diols having 2 to 8 carbon atoms are more preferred, and ethylene glycol is particularly preferred.

[0079] <Reaction terminator (e)>

[0080] As the reaction terminator (e), monohydric alcohols having 1 to 8 carbon atoms (such as methanol, ethanol, isopropanol, n-butanol, cellosolves, and carbitols), and monoamines having 1 to 10 carbon atoms (such as monoalkylamines or dialkylamines like monomethylamine, monoethylamine, monobutylamine, dibutylamine, and monooctylamine) can be cited.

[0081] <Component (A') having an active hydrogen atom with an HLB of 8.0 or more>

[0082] Among the components of the polyurethane resin (U), as the component (A) having an active hydrogen atom (hereinafter also simply referred to as component (A)), the above-mentioned polyol (a), compound (c), chain extender (d), and reaction terminator (e) can be cited. The component (A') having an active hydrogen atom with an HLB of 8.0 or more (hereinafter also simply referred to as component (A')) in the present invention is the component among the above-mentioned component (A) having an HLB of 8.0 or more.

[0083] Among the above-mentioned component (A'), from the aspect of the retention of the polishing slurry, as the polyol (a), polyether polyol (a11) and polyester polyol (a12) having an HLB of 8.0 or more are preferred, and polyester polyol (a12) having an HLB of 8.0 or more is further preferred.

[0084] Among the above-mentioned component (A'), from the aspect of the retention of the polishing slurry, as the compound (c), compound (c1) having an HLB of 8.0 or more is preferred, and among them, a compound having a carboxyl group and / or a sulfonic acid group as an anionic group is further preferred.

[0085] Among the above-mentioned component (A'), from the aspect of the retention of the polishing slurry, as the chain extender (d), aliphatic diols having 2 to 8 carbon atoms with an HLB of 8.0 or more are preferred, and linear aliphatic diols having 2 to 8 carbon atoms are further preferred.​​​​​​​​Among the components of the polyurethane resin (U) for a polishing pad, the weight ratio of the component (A') having an active hydrogen atom with an HLB of 8.0 or higher is 80 to 100 weight %, based on the weight of the component (A) having an active hydrogen atom, and preferably 85 to 100 weight %, from the perspective of the retention of the polishing slurry.

[0089] If the weight ratio is less than 80% by weight, the retention of the polishing slurry deteriorates.

[0090] HLB (Hydrophile-Lipophile Balance) is an index that indicates the balance between hydrophilicity and lipophilicity. For example, it is known as a calculated value based on the Oda method as described in "Surfactant Introduction" [published by Sanyo Chemical Industries, Ltd. in 2007, written by Takehiko Fujimoto], page 212, rather than a calculated value based on the Griffin method.

[0091] The HLB value of a compound can be calculated as follows based on the ratio of the organic value to the inorganic value of the compound.

[0092] HLB=10×Inorganic value / Organic value

[0093] The organic and inorganic values used to derive the HLB are calculated using the organic value, assuming 20 carbon atoms per carbon atom, and the inorganic value, using the values in the table described on page 213 of the aforementioned "Surfactants Primer" ("Numerical Values" in the inorganic group, or "Numerical Values" in the organic / inorganic group). An example of calculation is:

[0094] -CH3 group: organic value 20, inorganic value 0,

[0095] -CH2- group: organic value 20, inorganic value 0,

[0096] =CH2 group: organic value 20, inorganic value 1,

[0097] =CH- group: organic value 20, inorganic value 1,

[0098] Benzene ring: organic value 120, inorganic value 15,

[0099] -O- group: inorganic value 20,

[0100] -COO-: organic value 20, inorganic value 60,

[0101] -OH group: inorganic value 100,

[0102] -COOH group: organic value 20, inorganic value 150.

[0103] In addition, in the calculation of the HLB value in the present invention, the organic value and the inorganic value shown below are used for the following constitution.

[0104] COO - M + : Organic value 20, Inorganic value 400 (It should be noted that "M + "COO - " counter ion, representing a metal cation or an ammonium cation)

[0105] Si atom: organic value 0, inorganic value 0

[0106] It should be noted that when two or more compounds are used as the polyurethane resin (U), the weight ratio of component (A') in component (A) is calculated based on the total weight of all compounds corresponding to component (A) and the total weight of all compounds corresponding to component (A') among the constituent components of each polyurethane resin.

[0107] From the perspective of retention and handling properties of the polishing slurry, the concentration of the ionic groups possessed by the polyurethane resin (U) (the content of ionic groups in the polyurethane resin (U)) is preferably 0.020 to 0.500 mol / kg, more preferably 0.025 to 0.450 mol / kg, and particularly preferably 0.030 to 0.400 mol / kg.

[0108] The concentration of the above ionic groups can be determined by 1 H-NMR measurement and / or 13 It was calculated by C-NMR measurement.

[0109] From the viewpoint of durability and handling properties, the Mn of the polyurethane resin (U) is preferably 1,000 to 20,000, more preferably 2,000 to 15,000, and particularly preferably 3,000 to 10,000.

[0110] The urethane group concentration of the polyurethane resin (U) is preferably 1.0 to 6.0 mol / kg, more preferably 1.5 to 5.0 mol / kg, and particularly preferably 2.0 to 4.5 mol / kg, from the viewpoint of durability and handling properties.

[0111] The concentration of urethane groups in the polyurethane resin (U) can be determined by the nitrogen content quantified by a nitrogen analyzer [ANTEK7000 (manufactured by Antek)] and the 1 The ratio of carbamate groups to urea groups was calculated by H-NMR quantification. 1H-NMR measurement was performed by the method described in "Structural Study of Polyurethane Resins by NMR: Takeda Research Institute Report 34(2), 224-323(1975)". That is, when aliphatic polyisocyanate (b2), alicyclic polyisocyanate (b3) or modified products thereof are used, the following is the method described in "Structural Study of Polyurethane Resins by NMR: Takeda Research Institute Report 34(2), 224-323(1975)". 1 The weight ratio of urea groups to carbamate groups was calculated from the ratio of the integrated amount of hydrogen derived from urea groups near the chemical shift of 6 ppm in H-NMR to the integrated amount of hydrogen derived from carbamate groups near the chemical shift of 7 ppm. The carbamate group concentration was calculated based on this weight ratio and the above-mentioned nitrogen atom content. When an aromatic polyisocyanate (b1) or a modified product thereof is used, the concentration of the carbamate group was calculated based on the ratio of the integrated amount of hydrogen derived from urea groups near the chemical shift of 7 ppm. 1 The weight ratio of urea groups to carbamate groups was calculated from the ratio of the integrated amount of hydrogen derived from urea groups near a chemical shift of 8 ppm to the integrated amount of hydrogen derived from carbamate groups near a chemical shift of 9 ppm in H-NMR. The carbamate group concentration was calculated based on this weight ratio and the above-mentioned nitrogen atom content.

[0112] The concentration of the ionic groups contained in the polyurethane resin (U), the Mn of the polyurethane resin (U), and the urethane group concentration can be appropriately adjusted by adjusting the types and weight ratios of the monomers constituting the polyurethane resin (U).

[0113] From the viewpoint of the durability of the polishing pad, the weight of the polyol (a) is preferably 35 to 75 wt %, more preferably 40 to 70 wt %, based on the total weight of the monomers constituting the polyurethane resin (U).

[0114] The constituent monomers of the polyurethane resin (U) are preferably reacted so that the equivalent ratio of isocyanate groups to active hydrogen atoms (isocyanate groups / active hydrogen atoms) in all the constituent monomers becomes 0.80 to 1.20.

[0115] The polyurethane resin (U) of the present invention can be produced by any of the following methods, for example.

[0116] (1) If necessary, a polyol (a), a polyisocyanate (b), a compound (c), and, if necessary, a chain extender (d) and a reaction terminator (e) are reacted in a solvent (s).

[0117] (2) If necessary, the polyol (a), the polyisocyanate (b), the compound (c), and, if necessary, the chain extender (d) are reacted in a solvent (s) to obtain an NCO group-terminated prepolymer, and then a reaction terminator (e) is further reacted.

[0118] Of the above (1) and (2), (2) is preferred from an industrial point of view.

[0119] Examples of the solvent (s) include ethyl acetate, N,N-dimethylformamide (DMF), and toluene.

[0120] The polyurethane resin (U) may also contain additives such as an antioxidant (such as butylated hydroxytoluene), an anti-gelling agent (such as benzoyl chloride), an anti-coloring agent, a weathering stabilizer, a plasticizer, and a release agent, as needed. The amount of these additives used is generally 10% by weight or less, more preferably 3% by weight or less, and particularly preferably 1% by weight or less, based on the weight of the polyurethane resin (U).

[0121] <Polishing Pad (Uα)>

[0122] The polishing pad (Uα) of the present invention comprises the polyurethane resin (U) for polishing pads of the present invention. Preferably, the polishing pad is a molded article formed by molding the polyurethane resin (U) for polishing pads or a solution thereof using a known method. When molding a solution of the polyurethane resin (U), the weight of the polyurethane resin (U) (resin concentration of the solution) is preferably 10 to 60% by weight based on the weight of the solution for ease of handling.

[0123] The molded article may be a foamed article or a non-foamed article, and may be appropriately selected according to the purpose of polishing.

[0124] The polyurethane resin (U) for polishing pads and the polishing pad (Uα) of the present invention have excellent retention of polishing slurry, thereby reducing damage to the object being polished. In addition, the polishing pad has excellent durability, making it suitable for various polishing applications, and is particularly useful for CMP (chemical mechanical polishing) applications.

[0125] For example, in CMP (chemical mechanical polishing), a method is used in which an object to be polished (semiconductor, wafer) is polished on a polishing pad using a polishing slurry containing fine particles of alumina, silica, or the like to flatten the surface and remove waste.

[0126] This specification discloses the following matters.

[0127] The present disclosure (1) relates to a polyurethane resin (U) for a polishing pad, comprising, as constituent monomers, one or more polyols (a) selected from the group consisting of polyether polyols (a11), polyester polyols (a12), and polycarbonate polyols (a13), a polyisocyanate (b), and a compound (c) having an ionic group and two active hydrogen atoms, wherein, among the constituent components of the polyurethane resin (U), the weight ratio of the constituent component (A') having an active hydrogen atom and having an HLB of 8.0 or higher is 80 to 100% by weight, based on the weight of the constituent component (A) having an active hydrogen atom.

[0128] The present disclosure (2) relates to the polyurethane resin (U) for a polishing pad described in the present disclosure (1), wherein the concentration of the ionic groups possessed by the polyurethane resin (U) is 0.020 to 0.500 mol / kg.

[0129] The present disclosure (3) relates to a polishing pad (Uα) comprising the polyurethane resin (U) for a polishing pad described in the present disclosure (1) or (2).

[0130] Example

[0131] The present invention is further described below with reference to examples, but the present invention is not limited thereto.

[0132] <Example 1>

[0133] In a four-necked flask, 17880 g of a solvent (s-1) [N,N-dimethylformamide], 3328 g of a polyester polyol (a12-1) [polyethylene adipate diol, Mn 2,000, trade name: SANESTER 2620], 284 g of a chain extender (d-1) [ethylene glycol], 287 g of a compound (c-1) [2,2-dimethylolpropionic acid], 3.3 g of dibutylhydroxytoluene, 0.72 g of benzoyl chloride, and 2101 g of a polyisocyanate (b-1) [4,4'-diphenylmethane diisocyanate; 4,4'-MDI] were added. After reacting at 60° C. for 10 hours under a dry nitrogen atmosphere, 120 g of a reaction terminator (e-1) [n-butanol] was added and reacted for 1 hour to obtain a solution of a polyurethane resin (U-1) for a polishing pad (resin concentration: 25 wt%).

[0134] The polyurethane resin (U-1) had an ionic group concentration of 0.350 mol / kg, an Mn of 5,700, and a urethane group concentration of 2.7 mol / kg.

[0135] Next, the obtained polyurethane resin (U-1) solution was applied to a polyester film at a thickness of 2 mm, and the film was immersed in a 30 wt % N,N-dimethylformamide aqueous solution prepared at 35° C. for 30 minutes for coagulation.

[0136] Next, the polishing pad was washed with hot water at 60° C. for 30 minutes and with water at 25° C. for 20 minutes, and then dried with hot air at 80° C. to obtain a polishing pad (Uα-1).

[0137] The obtained polishing pad (Uα-1) was evaluated by the evaluation method described below. The results are shown in Table 1.

[0138] <Examples 2 to 11, Comparative Examples 1 to 3>

[0139] Solutions of the polyurethane resins for polishing pads (U) and polishing pads (Uα) were obtained in the same manner as in Example 1 except that the raw materials and weight (g) were changed to those in Table 1.

[0140] <Evaluation of Retention of Polishing Slurry>

[0141] The polishing pad (Uα) was cut into a size of 2 cm × 2 cm to obtain an evaluation sheet (A). Using a fully automatic contact angle meter DM700 (manufactured by Kyowa Interface Science Co., Ltd.), 30 μL of aqueous colloidal silica slurry [silicon dioxide concentration 30% by weight, particle size 5-15 nm, pH 9-10] was added dropwise to the evaluation sheet (A) at a temperature of 25°C. The droplet's sliding angle was measured, and a sliding angle of 35 degrees or more was judged as ◎, a sliding angle of 34-32 degrees was judged as 0, a sliding angle of 31-29 degrees was judged as △, and a sliding angle of 28 degrees or less was judged as ×. The results are shown in Table 1.

[0142] <Durability Evaluation>

[0143] The polishing pad (Uα) was punched into a dumbbell-shaped No. 3 mold to obtain an evaluation sheet (B). The evaluation sheet (B) was then heated in a constant temperature and humidity chamber at 50°C and 60% for 20 hours to obtain an evaluation sheet (C).

[0144] The obtained evaluation sheets (B) and (C) were stretched at a speed of 500 mm / min using an Autograph (manufactured by Shimadzu Corporation) at a temperature of 25°C and a humidity of 50%. The tensile strength (unit: MPa) was determined from the maximum stress and the cross-sectional area.

[0145] Regarding durability, the value calculated by the following formula (1), that is, the reduction rate of tensile strength before and after the constant temperature and humidity test, was evaluated as 0 if it was less than 6.0%, △ if it was 6.0% or more and less than 8.0%, and × if it was 8.0% or more. The results are shown in Table 1.

[0146] 100×{1-(C1) / (B1)}(unit:%)···(1)

[0147] B1: Tensile strength of evaluation sheet (B) (unit: MPa)

[0148] C1: Tensile strength of evaluation sheet (C) (unit: MPa)

[0149]

[0150] It should be noted that the contents of the various raw materials described in Table 1 are as follows.

[0151] [Polyether polyol (a11)]

[0152] (a11-1): Polyethylene glycol (Mn: 600, HLB: 21.1) Trade name: PEG-600, manufactured by Sanyo Chemical Industries, Ltd.

[0153] (a11-2): Polytetramethylene ether glycol (Mn: 1,000, HLB: 4.1) Trade name: PTMG1000, manufactured by Mitsubishi Chemical Corporation

[0154] [Polyester polyol (a12)]

[0155] (a12-1): Polyethylene adipate diol (Mn: 2,000, HLB: 8.3) Trade name: SANESTER 2620, manufactured by Sanyo Chemical Industries, Ltd.

[0156] [Polycarbonate polyol (a13)]

[0157] (a13-1): Poly(tetramethylene / hexamethylene) carbonate diol (molar ratio of raw material diols: 1,6-hexanediol:1,4-butanediol = 1:9, Mn: 2000, HLB: 8.5)

[0158] [Polyisocyanate (b)]

[0159] (b-1): 4,4'-diphenylmethane diisocyanate Trade name: MILLIONATE MT, manufactured by Tosoh Corporation

[0160] (b-2): 4,4'-methylenebiscyclohexyl diisocyanate Trade name: Desmodur W, manufactured by Sumika Covestro Urethane Co., Ltd.

[0161] [Compound (c)]

[0162] (c-1): Dimethylolpropionic acid (HLB: 43.8)

[0163] (c-2): 2,2-dihydroxymethylbutanoic acid (HLB: 35.0)

[0164] (c-3): 3-(2,3-dihydroxypropoxy)-1-propanesulfonic acid (HLB: 65.5)

[0165] [Chain extender (d)]

[0166] (d-1): Ethylene glycol (HLB: 50.0)

[0167] [Reaction terminator (e)]

[0168] (e-1): n-Butanol (HLB: 12.5)

[0169] [Solvent(s)]

[0170] (s-1): N,N-dimethylformamide

[0171] [Antioxidants]

[0172] Butylated hydroxytoluene

[0173] [Anti-gelling agent]

[0174] Benzoyl chloride

[0175] The results in Table 1 indicate that the polishing pad (Uα) containing the polyurethane resin (U) for a polishing pad of the present invention has excellent durability and excellent retention of the polishing slurry, and thus can reduce damage to the workpiece.

[0176] Industrial Applicability

[0177] The polyurethane resin (U) for polishing pads and the polishing pad (Uα) of the present invention are suitable for various polishing applications, and are particularly useful for CMP (chemical mechanical polishing) applications.

Claims

1. A polyurethane resin (U) for a polishing pad, comprising, as constituent monomers, at least one polyol (a) selected from the group consisting of polyether polyol (a11), polyester polyol (a12), and polycarbonate polyol (a13), a polyisocyanate (b), and a compound (c) having an ionic group and two active hydrogen atoms, wherein: In the components of the polyurethane resin (U) for a polishing pad, the weight ratio of the component (A') having an HLB of 8.0 or higher and having active hydrogen atoms is 80 to 100 weight % based on the weight of the component (A) having active hydrogen atoms.

2. The polyurethane resin (U) for a polishing pad according to claim 1, wherein The concentration of the ionic group contained in the polyurethane resin (U) is 0.020 mol / kg to 0.500 mol / kg. A polishing pad (Uα) comprising the polyurethane resin (U) for a polishing pad according to claim 1 or 2.

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