TW201736404A - Method for producing (meth)acrylate polymer - Google Patents

Abstract

Provided is a method for producing a (meth)acrylate polymer having a small Mw/Mn ratio of weight-average molecular weight Mw to number-average molecular weight Mn, said method using a starting material containing a (meth)acrylic acid alkyl ester having an alkyl group with a large number of carbon atoms. A method for producing a (meth)acrylate polymer (A) including a specific structural unit and having a weight-average molecular weight Mw of 50,000-500,000 and an Mw/Mn ratio of weight-average molecular weight Mw to number-average molecular weight Mn not exceeding 1.6, said method using a starting material containing not more than 0.2 parts by mass of a compound having a hydroxy group, with respect to 100 parts by mass of a (meth)acrylate polymerizable monomer.

Description

Method for producing (meth)acrylate polymer

The present invention relates to a method for producing a (meth) acrylate-based polymer. More specifically, it relates to a method for producing a (meth) acrylate-based polymer having a ratio Mw/Mn of a weight average molecular weight Mw to a number average molecular weight Mn and containing an alkyl (meth) acrylate as a constituent unit.

A narrow-dispersion (meth)acrylate-based polymer having a small Mw/Mn ratio has been proposed as a viscosity index improver added to improve the fuel-saving performance of lubricating oils for internal combustion engines and transmissions such as automobile engines. (See, for example, Patent Documents 1 to 3).

Examples of the method for producing such a narrowly dispersed (meth)acrylate polymer include atom transfer radical polymerization (ATRP), reversible addition fragmentation chain transfer polymerization (RAFT), nitrogen oxide polymerization (NMP), and boron medium. Polymerization, catalytic chain transfer (CCT), etc. (for example, refer to Patent Documents 4 to 6). However, in such a polymerization method, it is difficult to enter a final stage in a polymerization reaction, and it takes a reaction time to completely disappear the monomer, and in the case where the polymerization reaction is stopped in the middle, it is necessary to remove the remaining monomer, and the terminal is thermally unstable. It is easy to decompose and so on, but there are problems in industrial manufacturing.

On the other hand, an anionic polymerization (typically an anionic polymerization having high activity) is exemplified as a useful production method of a narrowly dispersed (meth)acrylate polymer (see, for example, Patent Document 7). Compared with the above polymerization method, since the polymerization tends to enter the final stage, the obtained polymer has high thermal stability, so it is suitable as an industrial production method, but in the case of directly using an industrially easily available monomer, The catalyst having a hydroxyl group such as water, a polymerization inhibitor or a raw material alcohol in the monomer deactivates the catalyst for the polymerization reaction, and a narrow dispersion (meth)acrylate polymer having a small Mw/Mn cannot be obtained. Further, the influence of the compound having a hydroxyl group which deactivates the catalyst of these polymerization reactions varies depending on the type of the monomer to be used and the molecular weight of the polymer, and the threshold value of the concentration is unknown, and the (meth)acrylic acid used is used. When the boiling point of the ester-based polymerizable monomer is relatively low, a compound having a hydroxyl group can be removed by distillation separation, but a so-called (meth)acrylate monomer having an alkyl group having 5 or more carbon atoms is compared. In the case of a monomer having a high boiling point, the temperature at the time of distillation becomes high, and polymerization occurs in the distillation column, and the so-called distillation itself becomes difficult.

Prior technical literature Patent literature

Patent Document 1 Japanese Patent Laid-Open Publication No. 2015-013957

Patent Document 2 Japanese Patent Laid-Open Publication No. 2015-013962

Patent Document 3 International Publication No. 2014/017554

Patent Document 4 Japanese Patent Application Publication No. 2003-515630

Patent Document 5 Japanese Patent Publication No. 2008-518051

Patent Document 6 Japanese Patent Publication No. 2007-512413

Patent Document 7 Japanese Patent Laid-Open Publication No. 2007-084658

An object of the present invention is to provide a method for producing a (meth) acrylate-based polymer having a ratio of a weight average molecular weight Mw to a number average molecular weight Mn of Mw/Mn, which is a methyl group having an alkyl group having a large carbon number. A raw material of an alkyl acrylate.

In order to achieve the above object, the present invention including the following aspects is completed.

[1] A method for producing a (meth) acrylate-based polymer (A), which comprises a weight average molecular weight Mw of 50,000 to 500,000, a ratio of a weight average molecular weight Mw to a number average molecular weight Mn of Mw/Mn of 1.6 or less. The method for producing a (meth) acrylate-based polymer (A) having a structural unit represented by the following formula (1), which is used in an amount of 100 parts by mass of the (meth) acrylate-based polymerizable monomer. A raw material containing 0.2 part by mass or less of a compound having a hydroxyl group.

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 10 to 36 carbon atoms).

[2] A method for producing a (meth) acrylate-based polymer (A), which comprises a weight average molecular weight Mw of 50,000 to 500,000, a ratio of a weight average molecular weight Mw to a number average molecular weight Mn, Mw/Mn of 1.6 or less. The method for producing a (meth) acrylate-based polymer (A) having a structural unit represented by the following formula (1), which is used in an amount of 100 parts by mass of the (meth) acrylate-based polymerizable monomer. A raw material containing 0.005 parts by mass or less of a compound having a phenolic hydroxyl group.

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 10 to 36 carbon atoms).

[3] The method for producing a (meth) acrylate-based polymer (A) according to [1] or [2], wherein, relative to the total structural unit mass constituting the (meth) acrylate-based polymer (A), The content of the structural unit represented by the formula (1) is 40 to 80% by mass.

[4] The method for producing a (meth) acrylate-based polymer (A) according to any one of [1] to [3] wherein the (meth) acrylate-based polymerizable monomer contains a carbon number of 10~ An alkyl (meth)acrylate of a branched alkyl group of 36.

[5] The method for producing a (meth) acrylate-based polymer (A) according to any one of [1] to [4] wherein the (meth) acrylate-based polymerizable monomer contains 5 to 90 masses. % of an alkyl (meth)acrylate having a linear alkyl group having 1 to 4 carbon atoms, and 5 to 60% by mass of an alkyl (meth)acrylate having a linear alkyl group having 10 to 36 carbon atoms, And a mixture of 5 to 60% by mass of an alkyl (meth)acrylate having a branched alkyl group having 10 to 36 carbon atoms.

[6] The method for producing a (meth) acrylate-based polymer (A) according to any one of [1] to [5], wherein a mixture comprising a (meth) acrylate-based polymerizable monomer is used. As a raw material, at least a part of a compound having a hydroxyl group and/or a polymerization inhibitor is removed by an adsorption treatment, wherein the adsorption treatment is selected from the group consisting of activated alumina, vermiculite, activated clay, acid clay, activated carbon, and ion exchange resin. At least one of zeolite, molecular sieve and molecular sieve.

[7] The method for producing a (meth) acrylate-based polymer (A) according to any one of [1] to [6], which is produced by anionic polymerization.

[8] The method for producing a (meth) acrylate-based polymer (A) according to [7], wherein the anionic polymerization is carried out in the presence of an organoaluminum compound.

[9] A (meth) acrylate-based polymer (A) obtained by the production method according to any one of [1] to [8].

According to the method for producing a (meth) acrylate-based polymer of the present invention, a (meth)acrylic acid having a ratio of a weight average molecular weight Mw to a number average molecular weight Mn of less than Mw/Mn can be obtained, which is composed of an alkyl group having a large carbon number. A (meth) acrylate-based polymer of a constituent unit formed of an alkyl ester.

Used to implement the aspect of the invention

Hereinafter, the present invention will be described in detail. In addition, "meth" acryl ("meth) acryl" in this specification means the general name of "methacryl" and "acryl", so-called "(methyl)" "Acrylate" means the general term for "methacrylate" and "acrylate".

[(Meth)acrylate-based polymerizable monomer]

The (meth) acrylate-based polymerizable monomer used in the present invention contains an alkyl (meth) acrylate having an alkyl group which is a structural unit represented by the following formula (1).

(In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 10 to 36 carbon atoms).

The alkyl (meth)acrylate may, for example, be an alkyl (meth)acrylate having an alkyl group having 10 to 36 carbon atoms. Examples of such an alkyl (meth)acrylate include n-decyl (meth)acrylate and (methyl). N-undecyl acrylate, n-dodecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tetradecyl (meth) acrylate, n-pentadecyl (meth) acrylate , n-hexadecyl (meth)acrylate, n-heptadecane (meth)acrylate, n-octadecyl (meth)acrylate, n-nonadecanyl (meth)acrylate, (meth)acrylic acid N-eicosyl ester, n-docosyl (meth)acrylate, n-docosyl (meth)acrylate, n-docosyl (meth)acrylate, (meth)acrylic acid Tetraalkyl ester, n-pentadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-hexadecyl (meth)acrylate, n-octadecyl (meth)acrylate Ester, n-dodecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-tridecyl (meth)acrylate, n-dodecyl (meth)acrylate, ( Methyl)n-n-tridecyl acrylate, n-tridecyl (meth) acrylate, n-tridecyl (meth) acrylate, n-tridecyl (meth) acrylate, etc. An alkyl (meth) acrylate; Isodecyl (meth)acrylate, 2,4,6-trimethylheptyl (meth)acrylate, 2-butyloctyl (meth)acrylate, 2-ethyl-positive (meth)acrylate Dialkyl ester, 2-methyl-n-tetradecyl (meth)acrylate, isohexadecyl (meth)acrylate, 2-n-octyl-n-decyl (meth)acrylate, (methyl) Isostearyl acrylate, 1-n-hexyl-n-tridecyl (meth) acrylate, 2-ethyl-n-heptadecyl (meth) acrylate, isodecyl (meth) acrylate, 1-n-octyl-n-pentadecyl (meth)acrylate, 2-n-decyl-n-tetradecyl (meth)acrylate, 2-n-dodecyl (meth)acrylate-nine Alkyl ester, isostearyl (meth)acrylate, 2-n-tetradecyl-n-heptadecane (meth)acrylate, 2-n-hexadecyl-n-heptadecane (meth)acrylate Ester, 2-n-hexadecyl-n-icosyl (meth)acrylate And a (meth)acrylic acid alkyl ester containing a branched alkyl group, such as 2-n-tetradecyl-n-dodecyl (meth)acrylate.

The (meth)acrylic acid alkyl ester having an alkyl group having 10 to 36 carbon atoms is preferably carbon-containing from the viewpoint of the viscosity index improving effect in the case of being used as a viscosity index improver such as a lubricating oil. An alkyl (meth)acrylate having a branched alkyl group of 10 to 36.

Among the alkyl (meth)acrylates having an alkyl group having 10 to 36 carbon atoms, the viscosity index improving effect in the case of use as a viscosity index improver and the shear viscosity in the case of being a lubricating oil composition From the viewpoint of stability, an alkyl (meth)acrylate having an alkyl group having 14 to 30 carbon atoms is preferred, and an alkyl group having a carbon number of 16 to 28 is more preferred, and particularly preferably having a carbon number of 16 to 24 Alkyl alkyl (meth)acrylate.

The alkyl (meth)acrylate may be used singly or in combination of two or more.

Further, the (meth) acrylate-based polymerizable monomer may contain a (meth) acrylate-based polymerizable monomer other than the above-mentioned (meth)acrylic acid alkyl ester. Examples of such other (meth)acrylate-based polymerizable monomer include cyclopentyl (meth)acrylate, cyclohexyl (meth)acrylate, isodecyl (meth)acrylate, and (methyl). a (meth) acrylate having an alicyclic alkyl group such as tricyclononyl acrylate; phenyl (meth) acrylate, benzyl (meth) acrylate, naphthyl (meth) acrylate, (methyl) (meth) acrylate having an aromatic hydrocarbon such as biphenyl acrylate; methoxymethyl (meth) acrylate, 2-methoxyethyl (meth) acrylate, 2-methyl (meth) acrylate Oxypropyl propyl ester, 2-ethoxyethyl (meth) acrylate, 2-ethoxypropyl (meth) acrylate, methoxy polyethylene (meth) acrylate (meth) acrylate having an ether group such as an alcohol ester or a methoxypolypropylene glycol (meth)acrylate; (meth)N,N-dimethyl(meth)acrylamide, N,N- N,N-dioxane such as diethyl (meth) acrylamide, N, N-diisopropyl (meth) acrylamide, N, N-di-n-butyl (meth) acrylamide (meth) acrylamide, (meth) acrylate having epoxy group, such as glycidyl (meth) acrylate; 1,3-propanediol di(meth) acrylate, 1,3-butyl Diol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(a) Acrylate, 1,10-nonanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, polyalkylene glycol di(meth)acrylate, bisphenol A di Methyl) acrylate, tricyclodecane dimethanol di(meth) acrylate, trimethylolpropane tri(meth) acrylate, glycerol tri(meth) acrylate, neopentyl alcohol tetra (methyl) a polyfunctional (meth) acrylate or the like such as an acrylate.

Further, the other (meth) acrylate-based polymerizable monomer may contain an alkyl (meth) acrylate having an alkyl group having 1 to 9 carbon atoms. The (meth)acrylic acid alkyl ester may contain, for example, methyl (meth)acrylate, ethyl (meth)acrylate, n-propyl (meth)acrylate, n-butyl (meth)acrylate, N-amyl (meth)acrylate, n-hexyl (meth)acrylate, n-heptyl (meth)acrylate, n-octyl (meth)acrylate, n-decyl (meth)acrylate, etc. have a carbon number of 1~ a linear alkyl (meth) acrylate of 9; isopropyl (meth) acrylate, isobutyl (meth) acrylate, tert-butyl (meth) acrylate, (meth) acrylate Amyl ester, tertiary amyl (meth)acrylate, isohexyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isodecyl (meth)acrylate, etc. having a carbon number of 3 to 9. Alkyl alkyl (meth)acrylate or the like.

The (meth)acrylic acid alkyl ester having an alkyl group having 1 to 9 carbon atoms preferably has a carbon number from the viewpoint of the viscosity index improving effect in the case of being used as a viscosity index improver such as a lubricating oil. The alkyl (meth)acrylate of 1 to 4 alkyl groups is more preferably methyl (meth)acrylate.

The above other (meth) acrylate-based polymerizable monomers may be used singly or in combination of two or more kinds.

As the (meth) acrylate-based polymerizable monomer, from the viewpoint of the viscosity index improving effect in the case of being used as a viscosity index improver and the shear viscosity stability in the case of being a lubricating oil composition, It is preferably an alkyl (meth)acrylate having a linear alkyl group having 1 to 4 carbon atoms, an alkyl (meth)acrylate having a linear alkyl group having 10 to 36 carbon atoms, and having a carbon number of 10 a mixture of alkyl (meth)acrylates of a branched alkyl group of ~36, more preferably an alkyl (meth)acrylate containing methyl (meth)acrylate and a linear alkyl group having 12 to 20 carbon atoms. a mixture of an ester and an alkyl (meth)acrylate having a branched alkyl group having 16 to 28 carbon atoms.

The (meth) acrylate-based polymerizable monomer is not particularly limited as long as it contains an alkyl (meth) acrylate having an alkyl group having 10 to 36 carbon atoms, but it is used as a viscosity index improver. The (meth) acrylate-based polymerizable monomer is preferably a (meth)acrylic acid alkyl group having 5 to 90% by mass of a linear alkyl group having 1 to 4 carbon atoms. An ester, 5 to 60% by mass of an alkyl (meth)acrylate having a linear alkyl group having 10 to 36 carbon atoms, and 5 to 60% by mass of a branched alkyl group having 10 to 36 carbon atoms (A) Alkyl acrylate More preferably, the mixture contains 10 to 60% by mass of methyl (meth)acrylate, 10 to 60% by mass of an alkyl (meth)acrylate having a linear alkyl group having 12 to 20 carbon atoms, and 10 ~60% by mass of a mixture of alkyl (meth)acrylates having a branched alkyl group having 16 to 28 carbon atoms.

[Compound having a hydroxyl group in a raw material containing a (meth) acrylate-based polymerizable monomer]

In the present invention, in order to obtain a narrowly dispersed (meth) acrylate-based polymer (A), it is important to control the concentration of a compound having a hydroxyl group in a raw material containing a (meth) acrylate-based polymerizable monomer. The compound having a hydroxyl group contained in the raw material is not particularly limited, and examples thereof include water, a compound having a phenolic hydroxyl group, and a compound having an alcoholic hydroxyl group (for example, an alcohol).

The compound having a phenolic hydroxyl group is used, for example, as a polymerization inhibitor which ensures the storage stability of a (meth)acrylate-based polymerizable monomer. Examples of the compound having a phenolic hydroxyl group include hydroquinone, methoxyphenol, p-tert-butyl catechol, 2,4-dimethyl-6-tertiary butyl phenol, and 2,6-trid. Grade butyl-4-methylphenol and the like. Further, as the polymerization inhibitor, hydroquinone, methoxyphenol, and 2,6-tributylbutyl-4-methylphenol having high polymerization inhibition effect are preferably used.

The compound having an alcoholic hydroxyl group contained in the raw material may, for example, be an alcohol corresponding to an alkyl (meth)acrylate contained in the (meth)acrylate-based polymerizable monomer. In particular, an alkyl alcohol having an alkyl group having 10 to 36 carbon atoms having an alkyl (meth) acrylate having an alkyl group having 10 to 36 carbon atoms has a high boiling point, and when it is contained in a raw material, It is difficult to completely remove the alkyl (meth) acrylate without affecting it. That is, the alkyl (meth)acrylate is generally synthesized by esterification of the alkyl alcohol with (meth)acrylic acid or transesterification of the alkyl alcohol with methyl (meth)acrylate. However, it is difficult to bring the reaction rate of the alkyl alcohol to 100%, and it is difficult to leave the unreacted alkyl alcohol by distillation under reduced pressure.

The proportion of the compound having a hydroxyl group in the raw material is 0.2 parts by mass or less, preferably 0.1 parts by mass or less, based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer.

In view of the influence on the production of the (meth) acrylate-based polymer (A), the water is preferably 0.002 parts by mass or less based on 100 parts by mass of the (meth) acrylate-based polymerizable monomer. The compound having a phenolic hydroxyl group is preferably 0.005 parts by mass or less, and the compound having an alcoholic hydroxyl group is preferably 0.2 parts by mass or less.

In addition, the ratio of the compound having a hydroxyl group in the raw material is 100 parts by mass of the (meth)acrylate-based polymerizable monomer in consideration of the influence on the production of the (meth)acrylate-based polymer (A). The water is preferably 0.00001 parts by mass or more, the compound having a phenolic hydroxyl group is preferably 0.00001 parts by mass or more, and the compound having an alcoholic hydroxyl group is preferably 0.0001 part by mass or more.

The reason why the lower limit of the water and the compound having an alcoholic hydroxyl group is the above value is because the water contained in the raw material or the compound having an alcoholic hydroxyl group is removed more from the viewpoint of removal efficiency and economy. The reason for the difficulty. In addition, the reason why the lower limit of the compound having a phenolic hydroxyl group is the above value is to secure the storage stability of the (meth)acrylate-based polymerizable monomer contained in the raw material.

In particular, the alkyl (meth)acrylate having an alkyl group having 10 to 36 carbon atoms contained in the raw material of the (meth)acrylate polymer (A) has a high boiling point, and generally includes Among the raw materials of the alkyl (meth)acrylate, the residual amount of the compound having a hydroxyl group tends to be large.

The content of the compound having a hydroxyl group contained in the raw material of the (meth)acrylate polymer (A) can be determined by, for example, gas chromatography or liquid chromatography using an internal standard method or an absolute calibration method. Got it.

The method of reducing the content of the compound having a hydroxyl group contained in the raw material of the (meth)acrylate-based polymer (A) is not limited, and examples thereof include self-contained (meth)acrylate-based polymerizable monomers. a method of reducing the content of a compound having a hydroxyl group by distillation, recrystallization, or the like; and reducing a compound having a hydroxyl group by adsorption treatment using an adsorbent material from a mixture containing a (meth)acrylate-based polymerizable monomer In addition, the method of suppressing the residual amount by consuming the raw material alcohol at the time of manufacture of a (meth)acrylate type polymerizable monomer can also be mentioned.

From the viewpoint of recovery of a raw material containing a (meth) acrylate-based polymerizable monomer and ease of handling, a method of reducing the content of a compound having a hydroxyl group by adsorption treatment is preferred.

The adsorbent is not particularly limited as long as it can adsorb and remove a compound having a hydroxyl group. However, from the viewpoint of the adsorption efficiency, activated alumina, vermiculite, activated clay, acid clay, activated carbon, and Ion exchange resin, zeolite, molecular sieve. Among them, activated alumina, zeolite, and molecular sieve are more preferred.

Examples of the method of the adsorption treatment include a method in which a mixture containing a (meth)acrylate-based polymerizable monomer and a adsorbent are mixed in a batch manner, followed by stirring or standing; and continuous in a packed column filled with an adsorbent. A method of introducing a mixture containing a (meth) acrylate-based polymerizable monomer or the like is introduced.

The adsorption treatment may be carried out after diluting a mixture containing a (meth) acrylate-based polymerizable monomer in a solvent. The solvent to be used is not particularly limited as long as it does not adversely affect the adsorption treatment, and examples thereof include aliphatic hydrocarbons such as pentane, n-hexane, and octane; cyclopentane, cyclopentane, and cyclohexane. An alicyclic hydrocarbon such as an alkane, a cyclohexane or a cyclohexane; an aromatic hydrocarbon such as benzene, toluene, ethylbenzene or xylene; diethyl ether, tetrahydrofuran, 1,4-two An ether such as an alkane, anisole or a diphenyl ether. Among these, an aromatic hydrocarbon is preferable, and toluene and xylene are more preferable from the viewpoint of being directly usable in the subsequent polymerization reaction and being easy to recover and purify the solvent. These solvents may be used singly or in combination of two or more types.

The mixture to be subjected to the method of reducing the content of the compound having a hydroxyl group may contain two or more kinds of (meth)acrylate-based polymerizable monomers, or may contain only one type of (meth)acrylate-based polymerizable monomer. The object of the above-mentioned method is preferably a mixture containing only one type of (meth)acrylate-based polymerizable monomer, from the viewpoint of easily determining appropriate conditions and easily reducing a compound having a hydroxyl group. Therefore, in the case where a raw material containing two or more kinds of (meth)acrylate-based polymerizable monomers is used as a raw material of the (meth)acrylate-based polymer (A), a preferred aspect is to prepare a plurality of species. (Methyl) acrylate-based polymerizable monomer types differ only in A mixture containing one type of (meth) acrylate-based polymerizable monomer, wherein at least one or more of the compounds having a hydroxyl group-reducing compound are added, and then a plurality of kinds of the mixture are mixed in a desired state, thereby producing raw material.

[Method for Producing Mixture Containing (Meth)Acrylate Polymerizable Monomer]

The method for producing the mixture of the (meth)acrylate-based polymerizable monomer which is a raw material of the (meth)acrylate-based polymer (A) obtained in the present invention is not particularly limited and may be known or used. A well-known method to manufacture. For example, a method of transesterifying a (meth) acrylate having a short-chain alkyl group such as methyl (meth) acrylate with an alkyl alcohol in the presence of a Brilliant acid or a Lewis acid catalyst; a method of esterifying (condensing) (meth)acrylic acid with an alkyl alcohol in the presence of an acid catalyst such as sulfuric acid, p-toluic acid sulfonic acid, methanesulfonic acid or a solid acid; Or a method in which (meth)acrylic anhydride and an alkyl alcohol are reacted in the presence of a base such as triethylamine or pyridine.

The reaction liquid obtained from the mixture containing the (meth) acrylate-based polymerizable monomer can be obtained by a known method such as extraction or recrystallization, and is not particularly limited in the method. For example, a mixture of a (meth) acrylate-based polymerizable monomer derived from a reaction liquid using a reaction of (meth)acrylic acid and an alkyl alcohol can be, for example, a (meth)acrylic acid and an alkyl alcohol in toluene. In an organic solvent such as hexane, it is heated in the presence of an acid catalyst such as sulfuric acid, p-toluic acid sulfonic acid, methanesulfonic acid or a solid acid, and the resulting water is removed to the outside of the system by azeotropic dehydration. After the reaction liquid is obtained, an alkali water such as sodium hydroxide is added to the reaction liquid. The solution is neutralized with an acid catalyst, and extracted, followed by distilling off the solvent in the organic layer.

In the production of a mixture containing the above (meth)acrylate-based polymerizable monomer, a polymerization inhibitor is preferably used. Examples of the polymerization inhibitor include an anthracene such as hydroquinone, methylhydroquinone, or benzoquinone; and a methoxyphenol selected from the group consisting of methoxyphenol, p-tert-butyl catechol, and 2,4-dimethyl-6- a compound having a phenolic hydroxyl group of at least one of a tertiary butyl phenol and a 2,6-tributyl-4-methylphenol; Cupferron, thiophene (phenothiazine). Further, as the polymerization inhibitor, hydroquinone, methoxyphenol, p-tert-butyl catechol, and 2,6-tributyl-4-methylphenol having high polymerization inhibition effect are preferably used.

The amount of the polymerization inhibitor used in the production of the mixture containing the above (meth)acrylate-based polymerizable monomer is from the viewpoint of suppressing polymerization of (meth)acrylic acid and (meth)acrylic acid ester, relative to The total mass of the (meth)acrylic acid and the alkyl (meth)acrylate of the raw material is preferably 0.001% by mass or more, more preferably 0.005% by mass or more, and still more preferably 0.01% by mass or more. In addition, the amount of use is preferably 10% by mass or less, more preferably 1% by mass or less, and still more preferably 0.5% by mass or less from the viewpoint of the usefulness of the product.

The content of the polymerization inhibitor in the mixture containing the (meth)acrylate-based polymerizable monomer is from 100 parts by mass of the (meth)acrylate-based polymerizable property from the viewpoint of suppressing polymerization during storage. The monomer is preferably 0.00001 parts by mass or more, more preferably 0.0001 part by mass or more, still more preferably 0.0005 part by mass or more. Further, from the viewpoint of easiness of removal before polymerization, the content is preferably 0.5 part by mass. Hereinafter, it is more preferably 0.2 parts by mass or less, still more preferably 0.1 parts by mass or less.

The raw material of the (meth) acrylate-based polymer (A) may be a mixture containing only one type of (meth) acrylate-based polymerizable monomer, or may be composed of two or more kinds of (meth) acrylate-based polymerization. a mixture of sexual monomers. When a mixture containing two or more kinds of (meth)acrylate-based polymerizable monomers is used as a raw material, a mixture containing a plurality of (meth)acrylate-based polymerizable monomers may be prepared by using a mixture of a plurality of (meth)acrylate-based polymerizable monomers. These are mixed and used as a raw material of the (meth)acrylate type polymer (A).

[Physical properties of (meth)acrylate-based polymer (A)]

The weight average molecular weight (hereinafter referred to as "Mw") of the (meth) acrylate-based polymer (A) produced by the method of the present invention is 50,000 to 500,000, preferably 100,000 to 400,000, more preferably 150,000. 300,000.

The ratio of the Mw of the (meth) acrylate-based polymer (A) produced by the method of the present invention to the number average molecular weight (hereinafter referred to as "Mn") (Mw/Mn, hereinafter, this value is indicated as " The molecular weight distribution ") is 1.6 or less, preferably 1.01 to 1.6, more preferably 1.05 to 1.6, still more preferably 1.05 to 1.5. When a (meth) acrylate-based polymer having a molecular weight distribution within such a range is used, a viscosity index improving effect in the case of use as a viscosity index improver and a shearing in the case of a lubricating oil composition can be obtained. A polymer with excellent viscosity stability. Mw and Mn are based on, for example, a compound having a hydroxyl group and a polymerization inhibitor in a raw material of a (meth)acrylate-based polymerizable monomer used in the production of the (meth)acrylate-based polymer (A). the amount. Mw and Mn is a value obtained by gel permeation chromatography (GPC) to determine the molecular weight in terms of polystyrene.

In the (meth) acrylate-based polymer (A) produced by the method of the present invention, the content of the structural unit represented by the above formula (1) is preferably 40 to 80% by mass, preferably 50%. 70% by mass. When it is set to this range, when it is used as a viscosity index improver, it can make it easy to melt|dissolve in a base oil even at low temperature.

[Method for Producing (Methyl) Acrylate Polymer (A)]

The method for producing the (meth) acrylate-based polymer (A) of the present invention is not particularly limited, but in order to set Mw/Mn to a desired range, the production method is preferably atom transfer radical polymerization (ATRP). Reversible addition fragmentation chain transfer polymerization (RAFT), nitrogen oxide polymerization (NMP), iodine transfer polymerization, polymerization of high-period hetero-elements (organic sulfur, antimony, antimony, etc.), boron-mediated polymerization, and catalyst-transfer polymerization (CCT), and Controlled Radical Polymerization, in which a metal such as cobalt or titanium is bonded to carbon as a dormant species (OMRP), and anionic polymerization (typically active) High anionic polymerization). Among them, from the viewpoint of obtaining a (meth) acrylate-based polymer (A) having high heat stability, anion polymerization is more preferable. As such an anionic polymerization method, for example, an anion polymerization is carried out in the presence of a mineral acid salt such as an alkali metal or an alkaline earth metal salt using an organic alkali metal compound as a polymerization initiator (refer to Japanese Special Fair 7-25859). No.) A method of performing anionic polymerization in the presence of an organoaluminum compound using an organic alkali metal compound as a polymerization initiator (refer to Japanese Patent Laid-Open No. Hei 11-335432), an organic rare earth metal complex, and a metallocene type. A method in which an anion polymerization is carried out as a polymerization initiator as a metal complex (see Japanese Patent Laid-Open No. Hei 6-93060).

Among them, the shear viscosity stability in the case of being used as a viscosity index improver in order to obtain a polymer having a smaller Mw/Mn is good, and it is used as a viscosity index improver in order to obtain a polymer having a high syndiotacticity. In the case where the viscosity index increasing effect is high, a method of performing anionic polymerization in the presence of an organoaluminum compound using an organic alkali metal compound as a polymerization initiator is preferred.

As a method suitable for the method for producing the (meth) acrylate-based polymer (A), an organic alkali metal compound is used as a polymerization initiator and anion polymerization is carried out in the presence of an organoaluminum compound, for example, Further, in the presence of the organolithium compound and the organoaluminum compound represented by the following formula (2), further, in the reaction system, dimethyl ether, dimethoxyethane, and diethoxy B are further present. Ether, 12-crown-4, etc.; triethylamine, N, N, N', N'-tetramethylethylenediamine, N, N, N', N", N"-pentamethyl a nitrogen-containing compound such as ethylenediamine, 1,1,4,7,10,10-hexamethyltrimethylenetetramine, pyridine, 2,2'-bipyridyl, etc., and (meth)acrylate The polymerizable monomer is polymerized to carry out.

AlR ^a R ^b R ^c (2)

(In the formula (2), R ^a , R ^b and R ^c each independently represent an alkyl group which may have a substituent, a cycloalkyl group which may have a substituent, an aryl group which may have a substituent, and may have a substituent An aralkyl group, an alkoxy group which may have a substituent, an aryloxy group which may have a substituent or an N,N-disubstituted amine group; or R ^a represents any of the above groups, and R ^b and R ^c together represent An arylenedioxy group having a substituent).

As the organolithium compound used in the above method for performing anionic polymerization, for example, methyl lithium, ethyl lithium, n-propyl lithium, isopropyl lithium, n-butyl lithium, secondary butyl lithium, isobutyl lithium can be used. , alkyl lithium and alkyl dilithium such as tertiary butyl lithium, n-pentyl lithium, n-hexyl lithium, tetramethylene dilithium, pentamethylene dilithium, hexamethylene dilithium; , aryl lithium, aryl lithium, etc.; benzyl lithium, diphenylmethyl lithium, trityl lithium, 1, 1- Diphenyl-3-methylpentyl lithium, α-methylstyryl lithium, aralkyl lithium and aralkyl group formed by the reaction of diisopropenylbenzene and butyllithium Lithium; lithum amide of dimethylamino lithium, diethylamino lithium, diisopropylamino lithium, etc.; lithium methoxide, lithium ethoxide, lithium n-propoxide, different Lithium propoxide, lithium n-butoxide, lithium dibasic butoxide, lithium tertiary hydride, lithium pentoxide, lithium hexoxide, lithium heptoxide, lithium octyl oxide, lithium phenoxide, Lithium 4-methylphenoxy, lithium benzyloxy, 4-methylbenzyloxy One or two or more kinds of lithium alkoxides such as lithium.

Further, as the organoaluminum compound represented by the above formula (2), for example, a trialkylaluminum such as trimethylaluminum, triethylaluminum, triisobutylaluminum or tri-n-octylaluminum; (2,6-di-tri-butyl-4-methylphenoxy)aluminum, dimethyl(2,6-di-tris-butylphenoxy)aluminum, diethyl (2,6) -di-tertiary butyl-4-methylphenoxy)aluminum, diethyl(2,6-di-tris-butylphenoxy)aluminum, diisobutyl (2,6-di-tridyl) Dialkylphenoxy aluminum such as butyl-4-methylphenoxy)aluminum, diisobutyl(2,6-di-tert-butylphenoxy)aluminum; methyl bis (2, 6-di-tertiary butyl-4-methylphenoxy)aluminum, methylbis(2,6-di-tertiarybutylphenoxy)aluminum, ethyl[2,2'-methylene Bis(4-methyl-6-tris-butylphenoxy)]aluminum, ethyl bis(2,6-di-three Butyl-4-methylphenoxy)aluminum, ethylbis(2,6-di-tris-butylphenoxy)aluminum, ethyl[2,2'-methylenebis(4-methyl Base-6-tertiary butylphenoxy)]aluminum, isobutylbis(2,6-di-tri-butyl-4-methylphenoxy)aluminum, isobutyl bis(2,6- Alkyldiphenyloxide of di-tertiary butylphenoxy)aluminum, isobutyl[2,2'-methylenebis(4-methyl-6-tris-butylphenoxy)]aluminum Base aluminum; methoxybis(2,6-di-tributyl-4-methylphenoxy)aluminum, methoxybis(2,6-di-tris-butylphenoxy)aluminum, Methoxy[2,2'-methylenebis(4-methyl-6-tris-butylphenoxy)]aluminum, ethoxybis(2,6-di-tertiary butyl-4- Methylphenoxy)aluminum, ethoxybis(2,6-di-tris-butylphenoxy)aluminum, ethoxy[2,2'-methylenebis(4-methyl-6- Tert-butylphenoxy)]aluminum, isopropoxy bis(2,6-di-tri-butyl-4-methylphenoxy)aluminum, isopropoxy bis(2,6-di- Alkoxydiphenyloxide such as tris-butylphenoxy)aluminum, isopropoxy[2,2'-methylenebis(4-methyl-6-tris-butylphenoxy)]aluminum Base aluminum; ginseng (2,6-di-tri-butyl-4-methylphenoxy)aluminum, ginseng (2,6-diphenylphenoxy)aluminum One or two or more kinds of trisphenoxy aluminum or the like. Among them, it is particularly preferable to use isobutyl bis (2,6- from the viewpoint of easy handling and polymerization of a (meth) acrylate-based polymerizable monomer without losing activity under relatively mild temperature conditions. Di-tertiary butyl-4-methylphenoxy)aluminum, isobutylbis(2,6-di-tertiarybutylphenoxy)aluminum, isobutyl[2,2'-methylene Bis(4-methyl-6-tris-butylphenoxy)]aluminum or the like.

The method of carrying out the above anionic polymerization is preferably carried out in a solvent. The solvent is not particularly limited as long as it does not adversely affect the reaction, and examples thereof include aliphatic hydrocarbons such as pentane, n-hexane, and octane; cyclopentane, cyclopentane, cyclohexane, and a ring. An alicyclic hydrocarbon such as hexane or ethylenecyclohexane; an aromatic hydrocarbon such as benzene, toluene, ethylbenzene or xylene; diethyl ether, tetrahydrofuran, and 1,4-di An ether such as an alkane, anisole or a diphenyl ether. Among them, from the viewpoints of high solubility of the produced homopolymer or copolymer, difficulty in mixing waste water, and easy recovery and purification of the solvent, aromatic hydrocarbons are preferred, and toluene and xylene are more preferred. These solvents may be used singly or in combination of two or more. Further, from the viewpoint of allowing the polymerization reaction to proceed smoothly, the solvent is preferably subjected to degassing and dehydration treatment in advance and purified.

Further, when the (meth) acrylate polymer (A) is produced, it is preferably carried out in a gas atmosphere of an inert gas such as nitrogen, argon or helium.

The polymerization temperature at the time of producing the (meth) acrylate-based polymer (A) may be appropriately selected depending on the type of the (meth) acrylate to be used, the concentration in the polymerization reaction liquid, and the like, but may be used. In the case where the organic alkali metal compound is produced as a polymerization initiator and is subjected to an anionic polymerization in the presence of an organoaluminum compound, it is usually preferred from the viewpoint of shortening the polymerization time and reducing the inactivation reaction in the polymerization. It is a temperature in the range of -20 to 80 °C. Compared with the anionic polymerization conditions of the conventional (meth)acrylate-based polymerizable monomer, since the method of the present invention is industrially carried out, the method of the present invention can be greatly reduced compared with the conventional method. The cost of cooling equipment.

As a polymerization method for producing the (meth)acrylate polymer (A), for example, a batch polymerization method, a continuous polymerization method, or the like can be used.

The (meth) acrylate-based polymer (A) can be obtained, for example, by stopping the polymerization reaction by adding a polymerization terminator to the polymerization reaction liquid which is continuously discharged from the final reactor. Terminated as a polymerization Examples of the agent include protic compounds such as water, methanol, acetic acid, and hydrochloric acid. The amount of the polymerization terminator used is not particularly limited, but is usually in the range of 1 to 100 moles per mole of the polymerization initiator to be used.

In the (meth) acrylate-based polymer (A) obtained by separating the polymerization reaction liquid after the termination of the polymerization, if the aluminum derived from the organoaluminum compound used remains, the (meth) acrylate system may be generated. When the physical properties of the polymer (A) and the material using the same are lowered, it is preferred to remove the aluminum derived from the organoaluminum compound after completion of the polymerization. In the method for removing aluminum, a method in which a polymerization reaction solution obtained by adding a polymerization terminator is washed with an acidic aqueous solution, a method in which adsorption treatment using an adsorbent such as an ion exchange resin, or the like is effective.

The method for separating the (meth) acrylate-based polymer (A) from the polymerization reaction liquid after the polymerization is terminated and the aluminum removal treatment operation is carried out is not particularly limited, and a known method can be suitably employed. For example, a method of injecting a polymerization reaction liquid into a poor solvent of a (meth) acrylate-based polymer (A) to precipitate the (meth) acrylate-based polymer (A); and a self-polymerization reaction solution under reduced pressure The method of obtaining a (meth)acrylate type polymer (A), etc. by distilling off a solvent. Further, first, a large amount of solvent and a low-boiling component are removed from the polymerization reaction solution by using a thin film evaporation apparatus or the like, and then the obtained residue is continuously supplied to a melt extruder, and distilled under reduced pressure in the melt extruder. The solvent (meth)acrylate-based polymer (A) can also be recovered as a strand, a granule or a cake. Further, it may be taken out as a polymerization reaction liquid, or may be removed by adding a solvent having a higher boiling point than the solvent to be used, and may be taken out as a solution dissolved in another solvent used for polymerization.

The (meth) acrylate-based polymer (A) produced by the method of the present invention may be a homopolymer produced from a single monomer or a copolymer produced from a plurality of monomers. The homopolymer may be linear or star-shaped. The copolymer may also be a random copolymer, a block copolymer, a graft copolymer or a star copolymer.

An antioxidant, a thermal deterioration inhibitor, a light stabilizer, an ultraviolet absorber, a lubricant, a mold release agent, and a polymer processing may be added to the (meth)acrylate polymer (A) produced by the method of the present invention. Auxiliaries, antistatic agents, flame retardants, dyes, light diffusing agents, organic pigments, matting agents, impact-resistant modifiers, phosphors, anti-wear agents (or extreme pressure agents), It is used as a preservative, rust inhibitor, viscosity index improver, pour point depressant, anti-emulsifier, metal deactivator, antifoaming agent, ashless friction modifier and other additives.

The (meth) acrylate-based polymer (A) produced by the method of the present invention is excellent in mechanical properties such as narrow molecular weight distribution and shear viscosity stability, and can be used for polyolefins in addition to the viscosity index improver. Various applications such as surface-enhancing coating agents such as modifiers, adhesives, adhesives, primers, and hard coat films. Because of its high solubility in oil and the temperature dependence of the viscosity of the oil, it is particularly useful as a viscosity index improver.

[Examples]

Hereinafter, the present invention will be specifically described by way of Examples and Comparative Examples, but the present invention is not limited to the embodiments described below. Further, the measurement of the physical property value or the like is carried out by the following method.

(content of (meth)acrylate-based polymerizable monomer, content of compound having a phenolic hydroxyl group, content of a compound having an alcoholic hydroxyl group)

Inert Cap 1 (df = 0.4 μm, 0.25 mm I.D. × 60 m) manufactured by GL Sciences Inc. was attached to the gas chromatograph GC-2014 manufactured by Shimadzu Corporation as a column to raise the injection temperature to 240 ° C. The detector temperature was raised to 300 ° C, and the column temperature was raised from 180 ° C at a temperature increase rate of 10 ° C / min to 280 ° C, and the measurement was carried out for 10 minutes. The purity of the (meth) acrylate-based polymerizable monomer is calculated from a simple area detected by gas chromatography, and the content of the compound having a phenolic hydroxyl group and the compound having an alcoholic hydroxyl group is determined by absolute inspection. The amount line method was calculated as a mass ratio with respect to 100 parts by mass of the monomer.

(the amount of water in the raw material)

The amount of water in the monomer was measured using a calorimetry method Carter-Fisher Moisture Analyzer CA-200 manufactured by Mitsubishi Chemical Analytech Co., Ltd. as a mass ratio with respect to 100 parts by mass of the monomer.

(weight average molecular weight (Mw), number average molecular weight (Mn), molecular weight distribution (Mw/Mn))

The gel permeation chromatography (GPC) measurement was carried out under the following conditions, and the values of Mw, Mn, and Mw/Mn converted to the molecular weight of the standard polystyrene were calculated from the obtained chromatogram. In addition, the baseline is set such that the slope of the peak on the high molecular weight side of the GPC chart is observed from the earlier of the retention time and changes from zero to positive, and the slope of the peak on the low molecular weight side is observed from the earlier retention time. A line connecting points from negative to zero.

GPC device: manufactured by TOSOH Co., Ltd., HLC-8320

Detector: differential refractive index detector

Pipe string: Two TSKOH SuperMultipore HZM-M made by TOSOH Co., Ltd. are connected in series with SuperHZ4000.

Solvent: tetrahydrofuran

Dissolution agent flow rate: 0.35ml/min

Column temperature: 40 ° C

Checking line: Made with standard polystyrene 10 points data

(monomer composition in the polymer)

Using a nuclear magnetic resonance apparatus (ULTRA SHIELD 400 PLUS manufactured by Bruker Co., Ltd.), ¹ H-NMR spectrum was measured with respect to 10 mg of the resin under the conditions of 1 mL of deuterated chloroform, room temperature, and the cumulative number of times 64 times, and the spectrum was set from TMS. The (meth) acrylate polymer (A) is calculated from the area value of the signal of the methylene group or the methine group or the methyl group adjacent to the oxygen atom of the ester group which is present at 0.3 to 4.2 ppm at 0 ppm. The composition of the structural unit derived from the monomer.

(Manufacturing Example 1)

In a 500 mL three-necked flask equipped with a thermometer, a glass-filled Raschig Ring distillation column (inner diameter 2 cm, length 25 cm), glass capillary, 455 g was charged by 2-octyl ten 2-octyldodecyl methacrylate ((meth)acrylate-based polymerizable monomer) synthesized by esterification (condensation) of a dialkyl alcohol and methacrylic acid a mixture of 2-octyldodecyl methacrylate 98.67%; relative to 100 parts by mass of 2-octyldodecyl methacrylate: 0.0101 parts by mass of methoxyphenol, 0.2533 parts by mass of 2-octyldodecanol and 0.0203 parts by mass of water), and 0.46 g of ADK STAB AO-60 (a compound having a phenolic hydroxyl group: manufactured by ADEKA Co., Ltd.) as a polymerization inhibitor The air was bubbled from the glass capillary tube, and the distillation was carried out by dividing the fraction into about 70 g at an internal pressure of 0.1 kPa, an internal temperature of 214 to 234 ° C, and an overhead temperature of 185 to 191 ° C for 18 hours. A fraction having a small content of 2-octyldodecanol and methoxyphenol was used as a raw material of the (meth)acrylate-based polymer (A) to obtain 82.1 g (recovery rate: 18.0%) of a raw material (1). ). As a result of measurement by gas chromatography and a Karl Fischer moisture meter, 2-octyldodecyl methacrylate was used as the raw material (1) of the (meth) acrylate-based polymer (A). The content is 99.54%, and the content of water is 0.0007 parts by mass based on 100 parts by mass of the (meth) acrylate-based polymerizable monomer, and the content of 2-octyldodecanol is 0.017 parts by mass. Oxyphenol and ADK STAB AO-60.

(Manufacturing Example 2)

In a 1 L three-necked flask equipped with a thermometer and a mechanical stirrer, 250 g of a product comprising esterification (condensation) of n-stearyl alcohol and methacrylic acid was charged. a mixture of n-stearyl acrylate ((meth)acrylate-based polymerizable monomer) (n-stearyl methacrylate 99.26%; in terms of 100 parts by mass of n-stearyl methacrylate) : containing 0.0252 parts by mass of methoxyphenol, 0.3425 parts by mass of n-stearyl alcohol, and 0.0181 Part by mass of water and 583 g of isopropanol were dissolved by n-stearyl methacrylate by stirring at 25 °C. Subsequently, it took 4 hours to cool to -20 °C. The precipitated crystal was filtered and dried to obtain 243.3 g (recovery rate: 97.3%) of the crystalline (meth)acrylate polymer (A) starting material (2). As a result of measurement by gas chromatography and a Karl Fischer moisture meter, the content of n-stearyl methacrylate in the raw material (2) of the (meth) acrylate-based polymer (A) was 99.67. % is 0.001 parts by mass with respect to 100 parts by mass of the (meth) acrylate-based polymerizable monomer, and the content of n-stearyl alcohol is 0.006 parts by mass, and no methoxyphenol is detected.

(Manufacturing Example 3)

In a 500 mL three-necked flask equipped with a magnetic stir bar, 90 g of 2-octyl methacrylate synthesized by esterification (condensation) of 2-octyldodecanol with methacrylic acid was charged. a mixture of a dialkyl ester (a (meth) acrylate-based polymerizable monomer) (98.67% of 2-octyldodecyl methacrylate; relative to 100 parts by mass of 2-octyldodecane methacrylate) The content of the ester: containing 0.0101 parts by mass of methoxyphenol, 0.2533 parts by mass of 2-octyldodecanol, and 0.0203 parts by mass of water), 210 g of toluene, and 30 g of water-based chemical system as an adsorbent material Activated alumina GP-20 was stirred at 25 ° C for 4 hours. Subsequently, the activated alumina was removed by filtration, and toluene was distilled off at a liquid temperature of 35 ° C or lower by using an evaporator to obtain 86.1 g of a raw material of a liquid (meth) acrylate-based polymer (A) (3) ). As a result of measurement by gas chromatography and a Karl Fischer moisture meter, 2-octyldodecane methacrylate was used as the raw material (3) of the (meth) acrylate-based polymer (A). The content of the ester is 98.88%, and the content of water is 100 parts by mass of the (meth) acrylate-based polymerizable monomer. The amount was 0.0006 parts by mass, and the content of 2-octyldodecanol was 0.14 parts by mass, and no methoxyphenol was detected.

(Manufacturing Example 4)

In a 500 mL three-necked flask equipped with a magnetic stirrer, 90 g of n-stearyl methacrylate synthesized by esterification (condensation) of n-stearyl alcohol and methacrylic acid ((methyl)) was charged. a mixture of acrylate-based polymerizable monomers (mercapto-methacrylate 99.26%; with respect to 100 parts by mass of the content of n-stearyl methacrylate: containing 0.0252 parts by mass of methoxyphenol, 0.3425 parts by mass of n-stearyl alcohol and 0.0181 parts by mass of water), 210 g of toluene, and 30 g of hydrothermal chemical activated alumina GP-20 as an adsorbent were stirred at 25 ° C for 4 hours. Subsequently, the activated alumina was removed by filtration, and toluene was distilled off at a liquid temperature of 35 ° C or lower by using an evaporator to obtain 87.2 g of a liquid (meth) acrylate-based polymer (A). ). As a result of measurement by gas chromatography and a Karl Fischer moisture meter, the content of n-stearyl methacrylate in the raw material (4) of the (meth) acrylate-based polymer (A) was 99.20. %, the content of water is 0.0007 parts by mass, and the content of 2-stearyl alcohol is 0.11 parts by mass with respect to 100 parts by mass of the (meth) acrylate-based polymerizable monomer, and methoxyphenol is not detected.

(Manufacturing Example 5)

In the raw material (3) containing 2-octyldodecyl methacrylate obtained in Production Example 3, it is 0.0005 parts by mass based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer. In the manner of adding p-methoxyphenol, the raw material (5) of the (meth) acrylate-based polymer (A) is prepared.

(Manufacturing Example 6)

In the raw material (4) containing the n-stearyl methacrylate obtained in the production example 4, the pair is added in an amount of 0.0005 parts by mass based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer. The methoxy phenol is used to prepare the raw material (6) of the (meth) acrylate-based polymer (A).

(Manufacturing Example 7)

In the raw material (3) containing 2-octyldodecyl methacrylate obtained in Production Example 3, it was 0.32 parts by mass based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer. In the manner of adding 2-octyldodecanol, the raw material (7) of the (meth)acrylate-based polymer (A) is prepared.

(Manufacturing Example 8)

In the raw material (4) containing n-stearyl methacrylate obtained in Production Example 4, the amount is added to 0.36 parts by mass based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer. Stearyl alcohol, whereby the raw material (8) of the (meth) acrylate-based polymer (A) is prepared.

<Example 1>

A (meth) acrylate-based polymer is produced as follows, with reference to JP-A-2007-84658. After replacing the inside of a 2 L three-necked flask in which the hydroxy group was sufficiently dried with nitrogen, 480 g of toluene, 24 g of 1,2-dimethoxyethane, and 10 g of 0.45 M isobutyl bis were charged at room temperature. A toluene solution of (2,6-di-tris-butyl-4-methylphenoxy)aluminum was further added with 0.62 g of a mixed solution of cyclohexane and n-hexane containing 1.0 mmol of diethyl butyllithium. Next, 85 g of the following mixture was added as a raw material (phase 100 parts by mass of the (meth) acrylate-based polymerizable monomer, the content of the alcohol is 0.0070 parts by mass, the content of water is 0.0006 parts by mass, and the content of the compound having a phenolic hydroxyl group is below the detection limit) at room temperature. The mixture was stirred for 12 hours, and the mixture contained 30% by mass of the raw material (1) obtained in Production Example 1 containing 2-octyldodecyl methacrylate as a (meth) acrylate-based polymerizable monomer. In the production example 2, the raw material (2) obtained by the production example 2 (30% by mass) and the methyl methacrylate raw material (the stearyl methacrylate which is a (meth)acrylate type polymerizable monomer) Kuraray Co., Ltd.: methyl methacrylate content of 99.9% or more; relative to 100 parts by mass of methyl methacrylate, water content of 0.0003 parts by mass, methanol content of 0.0002 parts by mass or less, as a polymerization inhibitor The content of 2,4-dimethyl-6-tertiary butylphenol was 0.0001 part by mass) of 40% by mass. The reaction solution was initially yellow, but became colorless after stirring for 12 hours. Subsequently, 1.0 g of methanol was added to stop the polymerization. The obtained reaction liquid was poured into 6.0 kg of methanol to precipitate a white sediment. Subsequently, this white sediment was recovered by filtration and dried to obtain 80 g of a methacrylate polymer.

The results of ¹ H-NMR measurement and GPC measurement of the obtained methacrylate polymer were random copolymers, and the weight average molecular weight (Mw) was 81,800, and the number average molecular weight (Mn) was 75,600. Mw/ Mn) was 1.08.

In addition, it is understood that the mass ratio of the structure derived from each monomer in the obtained methacrylate polymer is 40% by mass of the structure derived from methyl methacrylate, and the structure derived from stearyl methacrylate The structure of 30% by mass and 2-octyldodecyl methacrylate was 30% by mass. The results are shown in Table 1.

<Example 2>

In addition to 0.62 g of a mixed solution of cyclohexane and n-hexane containing 1.0 mmol of the second butyllithium, it was changed to 0.39 g of a mixed solution of cyclohexane and n-hexane containing 0.64 mmol of the second butyllithium. The same procedure as in Example 1 was carried out to obtain 80 g of a methacrylate polymer. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Example 3>

In addition to 0.62 g of a mixed solution of cyclohexane and n-hexane containing 1.0 mmol of secondary butyllithium, it was changed to 0.33 g of a mixed solution of cyclohexane and n-hexane containing 0.55 mmol of secondary butyllithium. The same procedure as in Example 1 was carried out to obtain 80 g of a methacrylate polymer. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Example 4>

In addition to 0.62 g of a mixed solution of cyclohexane and n-hexane containing 1.0 mmol of secondary butyllithium, it was changed to 0.27 g of a mixed solution of cyclohexane and n-hexane containing 0.44 mmol of secondary butyllithium. The same procedure as in Example 1 was carried out to obtain 80 g of a methacrylate polymer. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Example 5>

In addition to 0.62 g of a mixed solution of cyclohexane and n-hexane containing 1.0 mmol of secondary butyllithium, changed to 0.25 g of a mixed solution of cyclohexane and n-hexane containing 0.41 mmol of secondary butyllithium. Further, in the same manner as in Example 1, 80 g of a methacrylate-based polymer was obtained. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Example 6>

In addition to 85 g of the following mixture, as a raw material (100 parts by mass of the (meth)acrylate-based polymerizable monomer, the content of the alcohol is 0.0751 parts by mass, the content of water is 0.0005 parts by mass, and the compound having a phenolic hydroxyl group In the same manner as in Example 3 except that the raw material used in Example 3 was used instead of the raw material used in Example 3, 80 g of a methacrylate polymer was obtained, and the mixture contained: as a (meth)acrylate system. The octyl dodecyl methacrylate of the polymerizable monomer is 30% by mass of the raw material (3) obtained in Production Example 3, and contains methacrylic acid as a (meth) acrylate-based polymerizable monomer. The fat ester is 30% by mass of the raw material (4) obtained in Production Example 4, and the methyl methacrylate raw material (manufactured by Kuraray Co., Ltd.: methyl methacrylate content of 99.9% or more; relative to 100 parts by mass of the methyl ester) Methyl methacrylate, the content of water is 0.0003 parts by mass, the content of methanol is 0.0002 parts by mass or less, and the content of 2,4-dimethyl-6-tertiary butyl phenol as a polymerization inhibitor is 0.0001 parts by mass) 40 quality%. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Example 7>

In addition to 85 g of the following mixture, as a raw material (100 parts by mass of the (meth)acrylate-based polymerizable monomer, the content of the alcohol is 0.0751 parts by mass, the content of water is 0.0005 parts by mass, and the compound having a phenolic hydroxyl group The content is 0.0003 parts by mass instead of the embodiment 3 In the same manner as in Example 3, except that the raw materials used were used, 80 g of a methacrylate polymer was obtained, and the mixture contained 2-octyl methacrylate containing a (meth) acrylate-based polymerizable monomer. 30% by mass of the raw material (5) obtained in Production Example 5, and the raw material obtained in Production Example 6 containing stearyl methacrylate as a (meth) acrylate-based polymerizable monomer ( 6) 30% by mass, and methyl methacrylate raw material (Kuraray Co., Ltd.: methyl methacrylate content of 99.9% or more; with respect to 100 parts by mass of methyl methacrylate, water content is 0.0003 parts by mass The content of methanol is 0.0002 parts by mass or less, and the content of 2,4-dimethyl-6-tertiary butylphenol as a polymerization inhibitor is 0.0001 part by mass) of 40% by mass. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Comparative Example 1>

In addition to the addition of 85 g of the following mixture as a raw material (with respect to 100 parts by mass of the (meth)acrylate-based polymerizable monomer, the content of the alcohol is 0.2066 parts by mass, the content of water is 0.0134 parts by mass, and the compound having a phenolic hydroxyl group The content was 0.0123 parts by mass, and was carried out in the same manner as in Example 5 except that the raw material used in Example 5 was used, and 80 g of a methacrylate polymer was obtained, which mixture contained: 2-octyl-12 a mixture of 2-octyldodecyl methacrylate synthesized by esterification of an alkanol with methacrylic acid (2-octyldodecyl methacrylate content 98.67%; relative to 100 parts by mass of methyl group) The content of 2-octyldodecyl acrylate includes: 0.0101 parts by mass of methoxyphenol, 0.2533 parts by mass of 2-octyldodecanol, and 0.0203 parts by mass of water) of 35 mass%, including Esterification of n-stearyl alcohol and methacrylic acid a mixture of n-stearyl methacrylate (n-stearyl methacrylate content: 99.26%; relative to 100 parts by mass of n-stearyl methacrylate: containing 0.0252 parts by mass of methoxy group Phenol, 0.3425 parts by mass of n-stearyl alcohol, and 0.0181 parts by mass of water) 35 mass%, and methyl methacrylate raw material (manufactured by Kuraray Co., Ltd.: methyl methacrylate content of 99.9% or more; relative to 100 The mass fraction of methyl methacrylate has a water content of 0.0003 parts by mass, a methanol content of 0.0002 parts by mass or less, and a polymerization inhibitor of 2,4-dimethyl-6-tertiary butyl phenol of 0.0001. Parts by mass) 30% by mass. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

<Comparative Example 2>

In addition to 85 g of the following mixture, a compound having a phenolic hydroxyl group is contained in an amount of 0.2041 parts by mass based on 100 parts by mass of the (meth) acrylate-based polymerizable monomer, and the content of the water is 0.0005 parts by mass. In the same manner as in Example 3 except that the raw material used in Example 3 was used instead of the raw material used in Example 3, 80 g of a methacrylate polymer was obtained, and the mixture contained: as a (meth)acrylate system. The (meth)acrylate-based polymerizable property of the raw material (7) obtained in the production example 7 (30% by mass) of the polymerizable monomer of 2-octyldodecyl methacrylate was synthesized in the production example 8. a monomeric stearyl methacrylate of 30% by mass of the raw material (8) obtained in Production Example 8 and a methyl methacrylate raw material (manufactured by Kuraray Co., Ltd.: methyl methacrylate content of 99.9% or more; The content of water is 0.0003 parts by mass, the content of methanol is 0.0002 parts by mass or less, and 2,4-dimethyl-6-three as a polymerization inhibitor, relative to 100 parts by mass of methyl methacrylate. The content of the butyl phenol was 0.0001 part by mass) of 40% by mass. The evaluation results of the obtained methacrylate polymer are shown in Table 1.

From the above results, the amount of the compound having a hydroxyl group (for example, a raw material alcohol, water, a polymerization inhibitor, etc.) is set to 0.2 mass based on 100 parts by mass of the (meth)acrylate-based polymerizable monomer. In the following, a (meth) acrylate-based polymer having a small Mw/Mn ratio can be obtained.

Claims (9)

A method for producing a (meth) acrylate-based polymer (A), wherein the weight average molecular weight Mw is 50,000 to 500,000, and the ratio of the weight average molecular weight Mw to the number average molecular weight Mn Mw/Mn is 1.6 or less. The method for producing a (meth) acrylate-based polymer (A) of the structural unit represented by the formula (1), which is used in an amount of 0.2 mass based on 100 parts by mass of the (meth) acrylate-based polymerizable monomer. a raw material of the following compound having a hydroxyl group, (In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 10 to 36 carbon atoms). A method for producing a (meth) acrylate-based polymer (A), wherein the weight average molecular weight Mw is 50,000 to 500,000, and the ratio of the weight average molecular weight Mw to the number average molecular weight Mn Mw/Mn is 1.6 or less. The method for producing a (meth) acrylate-based polymer (A) of the structural unit represented by the formula (1), which is used in an amount of 0.005 by mass based on 100 parts by mass of the (meth) acrylate-based polymerizable monomer. a raw material of the following compound having a phenolic hydroxyl group, (In the formula (1), R ¹ represents a hydrogen atom or a methyl group, and R ² represents an alkyl group having 10 to 36 carbon atoms). The method for producing a (meth) acrylate-based polymer (A) according to claim 1 or 2, wherein the total structural unit mass of the (meth) acrylate-based polymer (A) is based on the formula ( 1) The content of the structural unit shown is 40 to 80% by mass. The method for producing a (meth) acrylate-based polymer (A) according to any one of claims 1 to 3, wherein the (meth) acrylate-based polymerizable monomer contains a branched alkyl group having 10 to 36 carbon atoms. Alkyl (meth) acrylate. The method for producing a (meth) acrylate-based polymer (A) according to any one of claims 1 to 4, wherein the (meth) acrylate-based polymerizable monomer has a carbon number of 5 to 90% by mass. 1 to 4 linear alkyl (meth) acrylate, 5 to 60% by mass of alkyl (meth) acrylate having a linear alkyl group having 10 to 36 carbon atoms, and 5 to 60 mass a mixture of % alkyl (meth)acrylate having a branched alkyl group having 10 to 36 carbon atoms. The method for producing a (meth) acrylate-based polymer (A) according to any one of claims 1 to 5, which is to use a mixture of a (meth) acrylate-based polymerizable monomer by adsorption treatment. As a raw material, at least a part of a compound having a hydroxyl group and/or a polymerization inhibitor is removed, wherein the adsorption treatment is selected from the group consisting of activated alumina, vermiculite, activated clay, and acid. At least one of clay, activated carbon, ion exchange resin, zeolite, and molecular sieve. The method for producing a (meth) acrylate-based polymer (A) according to any one of claims 1 to 6, which is produced by anionic polymerization. The method for producing a (meth) acrylate-based polymer (A) according to claim 7, which is subjected to anionic polymerization in the presence of an organoaluminum compound. A (meth) acrylate-based polymer (A) obtained by the production method according to any one of claims 1 to 8.