Polyoxyalkylene amine monomer, polymer thereof, dispersant comprising the polymer and polishing composition comprising the dispersant

Abstract

To provide: a monomer capable of forming a polymer which can reduce residual abrasive grains by agglomerating abrasive grains by a simple method of well dispersing abrasive grains during polishing and changing the pH during cleaning; a polymer thereof; a dispersant comprising the polymer; and a polishing composition comprising the dispersant.SOLUTION: There is provided a polyoxyalkylene amine monomer represented by the following formula (1) or (2). (In the formulas (1) and (2), R1 and R2 are a hydrogen atom or a methyl group; AO is an oxyalkylene group; n is an average addition mole number of oxyalkylene groups, where n is from 5 to 100; a carbon atom in the heterocyclic ring may be partially replaced by an oxygen atom; and m is 1 to 2.)SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a polyoxyalkyleneamine monomer, a polymer thereof, a dispersant containing the polymer, and a polishing composition containing the dispersant. [Background technology]

[0002] The polarity, viscosity, reactivity, etc. of polyoxyalkylene monomers can be controlled by adjusting the type of oxyalkylene units constituting the monomers and the degree of polymerization thereof, thereby imparting properties such as flexibility and steric repulsion to the monomers. Thus, the monomers are used in a variety of applications, such as detergent compositions, water treatment agents, scale inhibitors, lubricants, plasticizers, and dispersants.

[0003] Among these applications, a copolymer of a polyoxyalkylene monomer and a carboxylic acid (salt) monomer has been proposed as a dispersant, and the polyoxyalkylene monomer is used to exhibit steric repulsion properties in a solvent. Dispersants are also used in various industrial fields to disperse inorganic powders and the like in a solvent. Examples of inorganic powders include ceramics and metal powders, and dispersion compositions containing inorganic powders are used as abrasives and the like in addition to electronic components such as dielectric layers of laminated ceramic capacitors, semiconductor substrates, sensors, and liquid crystal display elements.

[0004] In the development of semiconductor devices, such as semiconductor integrated circuits, there has been a demand in recent years for miniaturization and speedup of devices, leading to demands for higher density and integration through finer wiring and layering. To achieve this, various techniques such as chemical mechanical polishing (hereinafter referred to as "CMP") have been used. CMP is an essential technique for planarizing the surface of processed films such as interlayer insulating films, forming plugs, and forming embedded metal wiring, and is used to smooth substrates.

[0005] In CMP, alumina, ceria, colloidal silica, etc. are generally used as polishing abrasives, but if these abrasives aggregate or settle, this can lead to a decrease in the polishing rate and defects on the polished surface. Therefore, Patent Document 1 uses a dispersant containing a polyoxyalkylene chain to improve the dispersibility of abrasives and to use an abrasive with excellent high-speed polishing properties.

[0006] On the other hand, in recent years, the size of abrasive grains has become smaller, and the dispersibility of the abrasive grains has been improved by the above-mentioned dispersants, which has resulted in the problem of abrasive grains remaining on the substrate surface after polishing. The residual abrasive grains on the substrate surface can cause defects in subsequent processes, leading to a decrease in yield. Therefore, Patent Document 2 reports that by using composite particles of abrasive grains and polymers, the particle size becomes larger and cleaning properties improve.

[0007] However, as the size of the abrasive grains increases, the number of defects such as scratches on the surface of the polished substrate tends to increase. Therefore, it is necessary to reduce the amount of residual abrasive grains by dispersing the fine abrasive grains during polishing and agglomerating them during cleaning. One of the factors that affects the dispersion and agglomeration state of abrasive grains is pH, but when a dispersant that can disperse abrasive grains well is added, it is difficult to control the dispersion and agglomeration state of abrasive grains by changing the pH alone, so a dispersant that can easily control the dispersion and agglomeration state of abrasive grains by changing the pH is desired. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2015-105194 A [Patent Document 2] Special Publication No. 2017-508018 Summary of the Invention [Problem to be solved by the invention]

[0009] The present invention has been made in consideration of these circumstances, and the problem to be solved by the present invention is to provide a monomer capable of forming a polymer that can disperse abrasive grains well during polishing and reduce residual abrasive grains by agglomerating the abrasive grains in a simple manner by changing the pH during cleaning, and to provide a polymer having the above-mentioned properties by containing the monomer as a constituent unit, a dispersant containing the polymer, and a polishing composition containing the dispersant. [Means for solving the problem]

[0010] The present inventors have conducted extensive research to solve the above problems, and have found that by using a polymer containing a polyoxyalkyleneamine monomer having a specific structure as a constituent unit as a dispersant, the dispersion and aggregation of abrasive grains can be controlled by a simple method of changing the pH, and the abrasive grains can be aggregated during cleaning to reduce their residue on the substrate. That is, the present invention relates to the following [1 to [4].

[0011] [1] A polyoxyalkyleneamine monomer represented by the following formula (1) or (2):

[0012] [ka]

[0013] (In formulas (1) and (2), R 1 , R 2 is a hydrogen atom or a methyl group, AO is an oxyalkylene group, n is the average number of moles of the oxyalkylene group added, n is 5 to 100, some of the carbon atoms in the heterocycle may be replaced with oxygen atoms, and m is 1 to 2.

[0014] [2] A polymer having a weight average molecular weight of 500 to 10,000, comprising 5 to 100 mol % of constitutional units derived from the polyoxyalkyleneamine monomer described in [1] above and 0 to 95 mol % of constitutional units derived from a monomer copolymerizable with the polyoxyalkyleneamine monomer. [3] A dispersant comprising the polymer according to [2] above. [4] A polishing composition comprising the dispersant described in [3] above. Effect of the Invention

[0015] According to the present invention, a monomer capable of forming a polymer capable of dispersing abrasive grains well during polishing and reducing residual abrasive grains by agglomerating the abrasive grains in a simple manner by changing the pH during cleaning is provided, and a polymer having the above-mentioned properties by containing the monomer as a constituent unit, a dispersant containing the polymer, and a polishing composition containing the dispersant can be provided. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a 1H NMR chart for Monomer 1 (monomer represented by the structural formula in FIG. 1) obtained in Synthesis Example 1. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] In this specification, a numerical range defined using the symbol "to" includes both the upper and lower limits of the range. For example, "2 to 4" means 2 or more and 4 or less. Furthermore, when a concentration or amount is specified, any higher concentration or amount can be associated with any lower concentration or amount. For example, when "2 to 10% by mass" and "preferably 4 to 8% by mass" are stated, the descriptions "2 to 4% by mass," "2 to 8% by mass," "4 to 10% by mass," and "8 to 10% by mass" are also included.

[0018] Hereinafter, embodiments of the present invention will be described in order.

[0019] (Polyoxyalkyleneamine monomer) The polyoxyalkyleneamine monomer according to the embodiment of the present invention is a monomer represented by the following formula (1) or (2). The monomer has polymerizability.

[0020] [ka]

[0021] (In formulas (1) and (2), R 1 , R 2 is a hydrogen atom or a methyl group, AO is an oxyalkylene group, n is the average number of moles of the oxyalkylene group added, n is 5 to 100, some of the carbon atoms in the heterocycle may be replaced with oxygen atoms, and m is 1 to 2.

[0022] In formulas (1) and (2), R 1 , R 2 may be a hydrogen atom or a methyl group, but is preferably a hydrogen atom.

[0023] In formulas (1) and (2), AO is an oxyalkylene group, and the number of carbon atoms is not particularly limited, but is preferably 2 to 4. The form of AO may be linear or branched. In addition, AO may be one type or two or more types, and when AO is two or more types, the addition form may be random or block.

[0024] Examples of AO include oxyethylene group (EO), oxypropylene group (PO), and oxybutylene group. From the viewpoint of dispersibility, it is preferable to use one or two selected from oxyethylene group and oxypropylene group, and it is more preferable to use oxyethylene group and oxypropylene group. When two or more AO are used in combination, the ratio can be appropriately determined depending on the type of AO. For example, when EO and PO are combined, the composition ratio of EO and PO is preferably EO:PO=10:90 to 90:10 in molar fraction (mol%), more preferably 25:75 to 75:25, and even more preferably 40:60 to 60:40.

[0025] n is the average number of moles of oxyalkylene groups added, and can be appropriately set depending on the type of AO, etc., but from the viewpoint of dispersibility, it is preferably 5 to 100, more preferably 5 to 50, and even more preferably 10 to 20. The average number of moles added n can be calculated with a certain degree of accuracy from the amounts blended during synthesis, and can be calculated, for example, by determining the molecular weight from the hydroxyl value of the polyether during synthesis.

[0026] The heterocycles in formulas (1) and (2) may have some carbon atoms replaced with oxygen atoms, m being 1 to 2, and examples thereof include 5-membered (m=1) or 6-membered (m=2) heterocycles consisting of only carbon atoms and nitrogen atoms, such as pyrrolidine and piperidine, and 5-membered (m=1) or 6-membered (m=2) heterocycles in which some carbon atoms are replaced with oxygen atoms, such as oxazolidine and tetrahydro-1,4-oxazine (morpholine). A 5-membered (m=1) or 6-membered (m=2) heterocycle in which some carbon atoms are replaced with oxygen atoms is preferred, a 6-membered (m=2) heterocycle in which some carbon atoms are replaced with oxygen atoms is more preferred, and a 6-membered (m=2) heterocycle in which some carbon atoms are replaced with oxygen atoms is particularly preferred, such as tetrahydro-1,4-oxazine.

[0027] Next, a method for producing the polyoxyalkyleneamine monomers represented by the formulas (1) and (2) will be described. The polyoxyalkyleneamine monomers represented by formula (1) and (2) can be obtained by a production method including a first step of producing a polyether and a second step of introducing a predetermined unsaturated hydrocarbon group into the polyether obtained in the first step.

[0028] The first step will be described. Polyether can be produced by adding alkylene oxide to nitrogen-containing heterocyclic compound having active hydrogen according to the desired structure. Usable nitrogen-containing heterocyclic compound includes, for example, pyrrolidine, oxazolidine, piperidine, tetrahydro-1,4-oxazine (morpholine), etc. Usable alkylene oxide includes, for example, ethylene oxide, propylene oxide, butylene oxide, etc.

[0029] Examples of catalysts used in the addition reaction of alkylene oxide include alkali catalysts, such as oxides and hydroxides of alkali metals and alkaline earth metals, alcoholates, alkylamines such as triethylamine, and alkanolamines such as triethanolamine. In addition to the above alkali catalysts, Lewis acid catalysts such as boron trifluoride and tin tetrachloride can be used. The amount of catalyst used is generally 0.01 to 5.0% by mass based on the mass after the addition reaction is completed.

[0030] The addition reaction of alkylene oxide can be carried out by continuously adding alkylene oxide under pressure at 50 to 200°C and 0.02 to 1.0 MPa under an inert gas atmosphere such as argon or nitrogen gas. The alkylene oxide may be added in two or more portions in the same manner. In this case, it is preferable to cool the mixture to a predetermined temperature and then add the alkylene oxide under the same conditions as described above.

[0031] Next, the second step will be described. The polyether obtained in the first step is added with an alkali metal hydroxide such as sodium hydroxide or potassium hydroxide, and then etherified with a monohalogenated unsaturated hydrocarbon such as an allyl monohalide such as allyl chloride, allyl bromide, or allyl iodide, a monohalogenated methallyl such as methallyl chloride or methallyl bromide, or a (meth)acryloyl halide such as acryloyl chloride or methacryloyl chloride, to obtain a polyoxyalkyleneamine monomer represented by formula (1) or formula (2). The reaction temperature is 60 to 150°C, preferably 70 to 140°C, and more preferably 80 to 130°C.

[0032] In both the first and second steps, the reaction may be carried out without a solvent or in a suitable dehydrated organic solvent. The solvent used in the reaction may be removed by an operation such as distillation after the reaction is completed, or may be used as it is as a diluting solvent for the obtained polyoxyalkyleneamine monomer.

[0033] The polyoxyalkyleneamine monomer obtained as described above can be confirmed, for example, by nuclear magnetic resonance spectroscopy ( 1 The measurement can be performed using 1 H NMR. The measurement conditions can be, for example, those described in the Examples section below.

[0034] (Polymer) The polymer according to the embodiment of the present invention contains 5 to 100 mol % of constitutional units derived from one or more monomers selected from the polyoxyalkyleneamine monomers represented by the formulas (1) and (2) and 0 to 95 mol % of constitutional units derived from monomers copolymerizable with the polyoxyalkyleneamine monomers. The weight average molecular weight of the polymer is 500 to 10,000.

[0035] That is, the polymer according to the embodiment of the present invention may be (i) a polymer consisting only of a structural unit (structural unit a) derived from one or more monomers selected from the polyoxyalkyleneamine monomers represented by the formulas (1) and (2), i.e., a polymer obtained by polymerizing one or more polyoxyalkyleneamine monomers (sometimes referred to as "monomer a") represented by the formulas (1) and (2), or (ii) a polymer consisting of a structural unit (structural unit a) derived from the polyoxyalkyleneamine monomer and a structural unit (structural unit b) derived from a monomer (sometimes referred to as "monomer b") copolymerizable with the polyoxyalkyleneamine monomer, i.e., a polymer obtained by copolymerizing one or more selected from the polyoxyalkyleneamine monomers and a monomer copolymerizable with the polyoxyalkyleneamine monomer.

[0036] In the polymer (i), the structural unit a is 100 mol% and the structural unit b is 0 mol% in all monomers, and in the polymer (ii), the structural unit a is 5 mol% or more and less than 100 mol%, and the structural unit b is more than 0 mol% and 95 mol% or less in all monomers. In the polymer (ii), the content of the structural unit a is 5 to 95 mol%, and the content of the structural unit b is 95 to 5 mol%, that is, the polymer obtained by copolymerizing 5 to 95 mol% of a polyoxyalkyleneamine monomer and 95 to 5 mol% of a monomer copolymerizable with the polyoxyalkyleneamine monomer is preferable. From the viewpoint of reducing residual abrasive grains, the content of the structural unit a is more preferably 15 to 50 mol%, and the content of the structural unit b is more preferably 50 to 85 mol%. Here, the content (molar ratio) of the structural unit a and the structural unit b can be calculated from the molar fraction of the monomers a and b to be mixed.

[0037] In addition, the constitutional unit derived from one or more monomers selected from the polyoxyalkyleneamine monomers represented by the formulas (1) and (2) may be composed of one single type selected from the polyoxyalkyleneamine monomers described above in both cases (i) and (ii), or may be composed of a combination of two or more types. When two or more types are combined, it may be a combination of only the monomer represented by formula (1), a combination of only the monomer represented by formula (2), or a combination of the monomers represented by formulas (1) and (2). When two or more types are combined, the content ratio can be appropriately determined.

[0038] Examples of the monomer b copolymerizable with the polyoxyalkyleneamine monomer represented by formula (1) or (2) include polyoxyalkylene monoalkyl monoallyl ether, styrene, vinyl acetate, vinyl sulfonic acid, allyl sulfonic acid, methallyl sulfonic acid, acrylic acid, methacrylic acid, acrylic acid ester, methacrylic acid ester, acrylonitrile, methacrylonitrile, acrylamide, methacrylamide, isobutylene, diisobutylene, and vinylcyclohexane, and other compounds having an ethylenic unsaturated bond, and maleic acid compounds such as maleic anhydride, maleic acid, maleic acid salts, and maleic acid esters. The monomer b may be used alone or in combination of two or more. From the viewpoint of dispersibility and reduction of residual abrasive grains, it is preferable to combine two or more. From the viewpoint of reduction of residual abrasive grains, the monomer b is preferably polyoxyalkylene monoalkyl monoallyl ether or maleic acid compound.

[0039] As the polyoxyalkylene monoalkyl monoaryl ether, the polyoxyalkylene group in the ether compound is preferably, for example, the same as that of the monomer represented by the formula (1) or (2), and the alkyl group in the ether compound is preferably, for example, one having 1 to 4 carbon atoms.

[0040] The synthesis of the polymer according to the embodiment of the present invention can be performed by a known method such as solution polymerization or bulk polymerization, and is not particularly limited. For example, the polymer according to the embodiment of the present invention can be obtained by filling a reaction vessel with the above-mentioned polyoxyalkyleneamine monomer or the polyoxyalkyleneamine monomer and monomer b, a polymerization initiator, and a solvent as necessary, and polymerizing the mixture at a predetermined temperature for a predetermined time under an inert gas atmosphere. The reaction temperature and time can be appropriately determined according to a standard method, but it is preferable to increase the temperature stepwise. In addition, the polymerization reaction can be performed without a solvent or in the presence of a solvent. When the polymerization reaction is performed in the presence of a solvent, for example, water; alcohols such as methyl alcohol, ethyl alcohol, and isopropyl alcohol; ketones such as acetone and methyl ethyl ketone; cyclic ethers such as tetrahydrofuran and dioxane; aliphatic hydrocarbons such as n-hexane, 2-ethylhexane, and methylcyclohexane; aromatic hydrocarbons such as toluene and xylene can be used as the solvent, and water, toluene, and methylcyclohexane are preferably used. The amount of the solvent used is usually 1 to 50% by mass based on the total mass of the monomers. The solvent used in the reaction may be removed by distillation or the like, or may be used as it is as a solvent for diluting the polymer obtained. The solution polymerization may be carried out in a batch or continuous manner.

[0041] Examples of the polymerization initiator include peroxide-based initiators such as benzoyl peroxide, azo-based polymerization initiators such as dimethyl 2,2'-azobis(isobutyrate), and persulfate-based initiators such as ammonium persulfate and sodium persulfate. From the viewpoint of dispersibility, it is preferable to use an azo-based polymerization initiator, and dimethyl 2,2'-azobis(isobutyrate) is particularly preferable. The amount of the polymerization initiator used may be appropriately set depending on the type of monomer, the type of polymerization initiator, and the like. For example, the amount of the azo-based initiator used is usually 1 to 10 mol%, preferably 2 to 8 mol%, based on the total weight of the monomer.

[0042] If desired, a chain transfer agent can be used. Examples of the chain transfer agent include dodecyl mercaptan and α-methylstyrene dimer. The amount of the chain transfer agent used may be appropriately determined depending on various conditions, but is usually 1 to 20 mol% based on the total weight of the monomers. The chain transfer agent can be used alone or in combination of two or more kinds.

[0043] The polymerization temperature is usually 50 to 130°C, preferably 60 to 120°C. The polymerization time is usually 3 to 25 hours, preferably 5 to 10 hours. As described above, when the temperature is raised stepwise, it is preferable to shorten the polymerization time at each stage with each increase in temperature. Note that the above-mentioned polymerization time when the temperature is raised stepwise is the total time.

[0044] The weight average molecular weight (Mw) of the polymer according to the embodiment is 500 to 10,000, and preferably 3,000 to 8,000. In this specification, the weight average molecular weight refers to the weight average molecular weight calculated as standard polyethylene glycol by gel permeation chromatography (GPC).

[0045] (Dispersant) The dispersant according to the embodiment of the present invention contains the polymer of the polyoxyalkyleneamine monomer. That is, the dispersant contains the polymer of the polyoxyalkyleneamine monomer as an active ingredient for dispersing a desired dispersed material such as abrasive grains in a desired medium, and may be composed of the polymer alone, or may be composed of the polymer and other additives that do not inhibit the function of the polymer. Examples of such additives include solvents such as the polymerization solvent used when synthesizing the polymer as described above, surfactants, etc. The content of the additive can be appropriately determined.

[0046] (Polishing composition) The polishing composition according to the embodiment of the present invention contains the above-mentioned dispersant. Also, it contains abrasive grains and a dispersion medium, and the polishing composition is generally in the form of a slurry. When the dispersant contains a solvent, the solvent can function as the dispersion medium. The content of the dispersant can be appropriately determined according to the type of the polymer contained in the polishing object, the abrasive grains, and the dispersant, but it is preferable that the above-mentioned polymer is 0.1 to 10 parts by mass per 100 parts by mass of the abrasive grains.

[0047] Usable abrasive grains can be appropriately selected depending on the object to be polished. For example, in the case of CMP applications, abrasive grains generally used in CMP can be appropriately selected depending on the object to be polished, such as alumina, ceria (cerium oxide), colloidal silica, manganese oxide, etc. The size of the abrasive grains can be a size generally used in this technical field, and for example, an average grain size of 10 to 1000 nm can be appropriately selected depending on the application. The content of the abrasive grains is preferably 0.1 to 20 mass% in the entire polishing composition.

[0048] The dispersion medium that can be used can be appropriately selected depending on the application. For example, aqueous solvents and organic solvents can be used. Examples of aqueous solvents include water such as ion-exchanged water. Examples of organic solvents include aromatic hydrocarbon solvents, aliphatic hydrocarbon solvents, ketone solvents, ester solvents, glycol ether solvents, terpene solvents, and alcohol solvents. In the case of CMP applications, aqueous solvents are preferred. The content of the dispersion medium is preferably 400 to 100,000 parts by mass per 100 parts by mass of the abrasive grains.

[0049] In addition to the above-mentioned components, the polishing composition according to the embodiment may contain other additives within the range that does not inhibit the functions of the dispersant and the abrasive grains. Such additives include pH adjusters, surfactants, defoamers, oxidizers, rust inhibitors, polishing adjusters, etc.

[0050] The polishing composition according to the embodiment can be prepared by a known method. For example, a method of adding a dispersant, a dispersion medium, an abrasive grain, and an additive to be added as required to a container, and then dispersing at room temperature can be mentioned. The order of adding each component is not particularly limited. As a dispersing device for dispersing, a known dispersing machine can be used. For example, a roll mill, a ball mill, a bead mill, a sand mill, a homogenizer, a disperser, a rotation-revolution type mixer, etc. can be mentioned. Dispersing can also be performed in an ultrasonic bath.

[0051] The polishing composition according to the embodiment contains the above-mentioned polymer that functions as a dispersant, and thus it is possible to disperse the abrasive grains well during polishing, and reduce the residual abrasive grains by agglomerating the abrasive grains during cleaning. In particular, the above-mentioned polymer can suppress the agglomeration of the abrasive grains and maintain a good dispersion state when the pH during polishing of the substrate is neutral to basic at 7 to 12 (e.g., about pH 8), and after the completion of polishing, the pH during cleaning is acidic at 2 to 5 (e.g., about pH 4), thereby agglomerating the abrasive grains and suppressing the residual abrasive grains on the substrate surface. Thus, the polishing composition is more suitable when using an acidic cleaning solution with a pH of about 4. Evaluation of dispersibility and agglomeration due to changes in pH, and suppression of residual abrasive grains (cleaning ability) can be performed by the method described below. EXAMPLES

[0052] Next, the embodiment of the present invention will be described in more detail based on examples.

[0053] (Identification of Monomers 1 to 6) Monomers 1 to 6 obtained in Synthesis Examples 1 to 6 described below were identified by nuclear magnetic resonance spectroscopy ( 1 1 H NMR) was used. 1 The measurement conditions for H NMR are as follows. Equipment: JNM-ECA-600 manufactured by JEOL Ltd. Solvent: deuterated chloroform Standard: Tetramethylsilane Temperature: 25℃ Frequency: 400MHz Accumulation count: 64

[0054] (Identification of Polymers in Examples 1 to 6 and Comparative Examples 1 and 2) The weight average molecular weights of the polymers obtained in Examples 1 to 6 and Comparative Examples 1 and 2 described below were measured by GPC (gel permeation chromatography). The measurement conditions for GPC are shown below. Equipment: Tosoh Corporation HLC-8320GPC Column: Shodex-OHPak SB806M-HQ+SB802-HQ Eluent: 0.05mol / L NaNO 3 Water with added Flow rate: 1.0mL / min Detector: Refractive index (RI) Temperature: 40℃ Standard: Polyethylene glycol Sample: 100 μL of an aqueous solution containing 0.1% by mass of active ingredient was injected

[0055] (Synthesis Example 1: Synthesis of Monomer 1) A 5-liter stainless steel pressure vessel equipped with an agitator, pressure gauge, thermometer, safety valve, gas inlet tube, exhaust tube, cooling coil, and steam jacket was charged with 261 g (3 mol) of tetrahydro-1,4-oxazine (trade name: Morpholine, manufactured by Tokyo Chemical Industry Co., Ltd.), and the system was replaced with nitrogen gas. Under stirring, 132 g (3 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas inlet tube under conditions of 140°C and 0.05 to 0.5 MPa (gauge pressure, the same applies to the following pressures) while pressurizing with nitrogen gas. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. After cooling to 40°C, 1.2 g of sodium methoxide was added, and the system was replaced with nitrogen gas. After heating to 120°C under stirring, 1454g (33mol) of ethylene oxide was added through a gas inlet tube under pressure of 0.05-0.5MPa with nitrogen gas. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. The hydroxyl value of the obtained polyether was 91, and the molecular weight calculated from the hydroxyl value was 616. After cooling to 40°C, 247g of allyl chloride and 424g of potassium hydroxide were added, and the inside of the reaction vessel was replaced with nitrogen gas, and the reaction was continued for 1 hour at 80°C and 0.2-0.3MPa, and for 2 hours at 120°C and 0.2-0.3MPa. Thereafter, the reactant was taken out of the pressure vessel, neutralized with 19% hydrochloric acid, dehydrated under reduced pressure, and the resulting salt was removed by filtration to obtain Monomer 1. The obtained Monomer 1 was identified by the above-mentioned measurement method. From the chart shown in FIG. 1, it was confirmed that the monomer 1 was a polyoxyalkyleneamine monomer represented by formula (1) and had the structure shown in Table 1 based on the peaks A (δ 5.88-5.93 ppm), B (δ 5.25-5.29 ppm, 5.16-5.19 ppm), C (δ 4.03 ppm), D (δ 2.59 ppm), and E (δ 2.5 ppm).

[0056] (Synthesis Example 2: Synthesis of Monomer 2) Monomer 2 was obtained in the same manner as in Synthesis Example 1, except that the amount of ethylene oxide added the second time was changed from 1454 g (33 mol) to 1850 g (42 mol). When identified in the same manner as in Synthesis Example 1, it was confirmed from the obtained chart that Monomer 2 was a polyoxyalkyleneamine monomer represented by formula (1) and had the composition shown in Table 1.

[0057] (Synthesis Example 3: Synthesis of Monomer 3) A 5-liter stainless steel pressure vessel equipped with an agitator, pressure gauge, thermometer, safety valve, gas inlet tube, exhaust tube, cooling coil, and steam jacket was charged with 261 g (3 mol) of tetrahydro-1,4-oxazine (trade name: Morpholine, manufactured by Tokyo Chemical Industry Co., Ltd.), and the system was replaced with nitrogen gas. Under stirring, 132 g (3 mol) of ethylene oxide was added from a separately prepared pressure vessel through the gas inlet tube while pressurizing with nitrogen gas under conditions of 140°C and 0.05 to 0.5 MPa. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. After cooling to 40°C, 1.2 g of sodium methoxide was added, and the system was replaced with nitrogen gas. After heating to 120°C under stirring, 859 g (19.5 mol) of ethylene oxide was added through the gas inlet tube while pressurizing with nitrogen gas under conditions of 0.05 to 0.5 MPa. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. Subsequently, under stirring, 1307 g (22.5 mol) of propylene oxide was added from a separately prepared pressure-resistant vessel through a gas inlet tube while pressurizing with nitrogen gas under conditions of 100°C and 0.05 to 0.5 MPa. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. The hydroxyl value of the obtained polyether was 66, and the molecular weight calculated from the hydroxyl value was 853. After cooling to 40°C, 247 g of allyl chloride and 424 g of potassium hydroxide were added, and the inside of the reaction vessel was replaced with nitrogen gas, and the reaction was continued for 1 hour at 80°C and 0.2 to 0.3 MPa, and for 2 hours at 120°C and 0.2 to 0.3 MPa. Thereafter, the reactant was taken out of the pressure-resistant vessel, neutralized with 19% hydrochloric acid, dehydrated under reduced pressure, and the resulting salt was removed by filtration to obtain Monomer 3. When identified in the same manner as in Synthesis Example 1, the obtained chart confirmed that Monomer 3 was a polyoxyalkyleneamine monomer represented by formula (1) and had the structure shown in Table 1.

[0058] (Synthesis Example 4: Synthesis of Monomer 4) Monomer 4 was obtained in the same manner as in Synthesis Example 1, except that 261 g (3 mol) of tetrahydro-1,4-oxazine was replaced with 255 g (3 mol) of piperidine. When identified in the same manner as in Synthesis Example 1, it was confirmed from the obtained chart that Monomer 4 was a polyoxyalkyleneamine monomer represented by formula (1) and had the structure shown in Table 1.

[0059] (Synthesis Example 5: Synthesis of Monomer 5) Monomer 5 was obtained in the same manner as in Synthesis Example 1, except that 247 g of allyl chloride was replaced with 292 g of acryloyl chloride. When identified in the same manner as in Synthesis Example 1, it was confirmed from the obtained chart that Monomer 5 was a polyoxyalkyleneamine monomer represented by formula (2) and had the structure shown in Table 1.

[0060] (Synthesis Example 6: Synthesis of Monomer 6) As monomers not containing a heterocyclic structure, the following monomers were synthesized. A stainless steel 5-liter pressure vessel equipped with an agitator, pressure gauge, thermometer, safety valve, gas inlet tube, exhaust tube, cooling coil, and steam jacket was charged with 96 g (3 mol) of methanol and 1.2 g of sodium methoxide, and the inside of the system was replaced with nitrogen gas. Under stirring, 1586 g (36 mol) of ethylene oxide was added from a separately prepared heat-resistant vessel through the gas inlet tube while pressurizing with nitrogen gas under conditions of 120°C and 0.05 to 0.5 MPa. After the addition was completed, the reaction was continued under the same conditions until the internal pressure became constant. The hydroxyl value of the obtained polyether was 100, and the molecular weight calculated from the hydroxyl value was 561. After cooling to 40°C, 247 g of allyl chloride and 424 g of potassium hydroxide were added, and the inside of the reaction vessel was replaced with nitrogen gas, and the reaction was continued at 80°C and 0.2 to 0.3 MPa for 1 hour and at 120°C and 0.2 to 0.3 MPa for 2 hours. Thereafter, the reaction product was removed from the pressure vessel, neutralized with 19% hydrochloric acid, and then dehydrated under reduced pressure, and the resulting salt was removed by filtration to obtain Monomer 6. When identified in the same manner as in Synthesis Example 1, it was confirmed from the obtained chart that Monomer 6 was represented by the following formula (3).

[0061] [ka]

[0062] The structures of the polyoxyalkyleneamine monomers, Monomers 1 to 5, are shown in Table 1. In the following, the polyoxyalkyleneamine monomers, Monomers 1 to 5, are collectively referred to as Monomer (a). Moreover, monomers copolymerizable with Monomer (a) are collectively referred to as Monomer (b).

[0063] [Table 1]

[0064] Example 1 In a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 100 g (0.15 mol) of Monomer 1 obtained in Synthesis Example 1 was added as Monomer (a), and 14.9 g (0.15 mol) of maleic anhydride was added as Monomer (b). Under a nitrogen gas atmosphere, 2.07 g (0.009 mol) of dimethyl 2,2'-azobis(isobutyrate) was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (copolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 5,100.

[0065] Example 2 To a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 120 g (0.15 mol) of monomer 2 in Table 1 was added as monomer (a). Under a nitrogen gas atmosphere, 1.15 g (0.005 mol) of 2,2'-azobis(isobutyric acid) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (homopolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 6,700.

[0066] Example 3 In a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 60.0 g (0.09 mol) of Monomer 1 in Table 1 as Monomer (a), 52.6 g (0.09 mol) of Monomer 6 in Table 1 as Monomer (b), and 17.7 g (0.18 mol) of Maleic Anhydride were added. Under a nitrogen gas atmosphere, 2.30 g (0.01 mol) of 2,2'-azobis(isobutyric acid) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (copolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 6,300.

[0067] Example 4 In a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 80.5 g (0.09 mol) of monomer 3 in Table 1 as monomer (a), 52.6 g (0.09 mol) of monomer 6 in Table 1 as monomer (b), and 1.96 g (0.02 mol) of maleic anhydride were added. Under a nitrogen gas atmosphere, 1.61 g (0.007 mol) of 2,2'-azobis(isobutyric acid) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (copolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 5,600.

[0068] Example 5 To a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 100 g (0.15 mol) of monomer 4 in Table 1 was added as monomer (a). Under a nitrogen gas atmosphere, 1.15 g (0.005 mol) of 2,2'-azobis(isobutyric acid) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (homopolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 6,200.

[0069] Example 6 In a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 47.0 g (0.07 mol) of Monomer 5 in Table 1 was added as Monomer (a), 2.94 g (0.03 mol) of maleic anhydride as Monomer (b), and 75 g of toluene as a solvent. In a nitrogen gas atmosphere, 1.84 g (0.008 mol) of 2,2'-azobis(isobutyric acid) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 3 hours. The solvent was removed under reduced pressure to obtain a polymer (copolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 9,400.

[0070] Comparative Example 1 100g (0.17 mol) of Monomer 6 in Table 1 was added to a 0.3 liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube. 1.15g (0.005 mol) of 2,2'-azobis(isobutyrate)dimethyl was added as a polymerization initiator under a nitrogen gas atmosphere, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (homopolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 4,600.

[0071] Comparative Example 2 In a 0.3-liter flask equipped with a stirrer, a thermometer, and a nitrogen gas inlet tube, 100 g (0.17 mol) of monomer 6 in Table 1 and 16.7 g (0.17 mol) of maleic anhydride were added. Under a nitrogen gas atmosphere, 2.30 g (0.01 mol) of 2,2'-azobis(isobutyrate) dimethyl was added as a polymerization initiator, and the reaction was carried out at 70±5°C for 4 hours in the first stage and at 90±5°C for 3 hours in the second stage to obtain a polymer (homopolymer). The molecular weight of the obtained polymer was measured by GPC according to the above-mentioned method, and the weight average molecular weight was 6,900.

[0072] Table 2 shows the blending ratios (mol %) and weight average molecular weights of the monomers used in the synthesis of the polymers obtained in Examples 1 to 6 and Comparative Examples 1 and 2.

[0073] [Table 2]

[0074] (Preparation of Slurry) Using each of the polymers obtained in Examples 1 to 6 and Comparative Examples 1 and 2 as a dispersant, a slurry was prepared as a polishing composition as follows: 0.3 g of abrasive grains (ceria, Fujifilm Wako Pure Chemical Industries, cerium (IV) oxide, average particle size about 300 nm), 2.7 g of ion-exchanged water, and 0.015 g of dispersant were weighed into a 50 mL screw tube, and the mixture was stirred for 2 minutes with a planetary centrifugal mixer to obtain a slurry.

[0075] (Dispersibility evaluation) <ph7> The dispersibility of each slurry prepared above was evaluated. The pH of each slurry was adjusted to 7±0.5 using 0.1M hydrochloric acid or 0.1M potassium hydroxide aqueous solution, and the particle size distribution was measured using a concentrated particle size analyzer (Otsuka Electronics Co., Ltd., FARP-1000). The median diameter D50 was measured, and the measurement results were evaluated according to the following criteria. ◎: D50 is less than 500 nm ○: D50 is 500nm or more and less than 900nm ×: D50 is 900nm or more or has settled and cannot be measured

[0076] <ph4> the above <ph7>The pH of each slurry was adjusted to 4±0.5 in the same manner as in the case of 1., and the particle size distribution was measured using a concentrated particle size analyzer (Otsuka Electronics Co., Ltd., FARP-1000), the median diameter D50 was measured, and the measurement results were evaluated according to the following criteria. 〇: D50 is 1000nm or more ×: D50 is less than 1000 nm

[0077] (Cleaning evaluation) The polymers obtained in Examples 1 to 6 and Comparative Example 2 were used as dispersants to prepare slurries in the same manner as described above, and cleaning properties were evaluated. The pH of each slurry was adjusted to 4±0.5 using 0.1 M hydrochloric acid, and a glass substrate was immersed in the slurry. After the glass substrate was pulled out of the slurry and naturally dried, a surface area of ​​250×300 μm was observed under a microscope, and the number of particles adhering to the surface was counted. The results were evaluated according to the following criteria. In addition, the slurry of Comparative Example 1 was not evaluated for dispersibility or cleaning properties at pH 4 because the abrasive grains precipitated in the evaluation of dispersibility at pH 7. ◎: Number of particles is less than 25 ○: Number of particles is 25 or more and less than 50 ×: Number of particles is 50 or more

[0078] The above results are shown in Table 3.

[0079] [Table 3]

[0080] It can be seen that the polishing compositions, that is, slurries prepared using each of the polymers obtained in Examples 1 to 6 as a dispersant all showed good dispersibility under neutral conditions of pH 7, and that by changing to acidic conditions of pH 4, the abrasive grains aggregated and were less likely to adhere to the substrate surface. On the other hand, the slurry of Comparative Example 1 had poor dispersibility regardless of the pH, and the slurry of Comparative Example 2 showed good dispersibility under neutral conditions of pH 7, but maintained good dispersibility even when changed to acidic conditions of pH 4, resulting in small abrasive grains that were likely to remain on the substrate surface. From the evaluation results of the above examples and comparative examples, it can be seen that the polymer obtained using a specified polyoxyalkyleneamine monomer is capable of dispersing and agglomerating abrasive grains depending on the pH conditions, and is also capable of making it difficult for the agglomerated abrasive grains to adhere to the substrate, thereby suppressing the generation of residual abrasive grains, and is therefore effective as a component of a dispersant, and that the dispersant is effective as a component of a polishing composition.

Claims

1. A polyoxyalkyleneamine monomer represented by the following formula (1) or (2): 【Chemistry 1】 (In formulas (1) and (2), R １ , R ２ is a hydrogen atom or a methyl group, AO is an oxyalkylene group, n is the average number of moles of the oxyalkylene group added, n is 5 to 100, some of the carbon atoms in the heterocycle may be replaced with oxygen atoms, and m is 1 to 2.

2. A polymer having a weight average molecular weight of 500 to 10,000, comprising 5 to 100 mol % of constitutional units derived from the polyoxyalkyleneamine monomer according to claim 1 and 0 to 95 mol % of constitutional units derived from a monomer copolymerizable with the polyoxyalkyleneamine monomer.

3. A dispersant comprising the polymer according to claim 2.

4. A polishing composition comprising the dispersant according to claim 3.

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