JP2007291041A - Method for producing adamantyl (meth)acrylate compound - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing an adamantyl (meth)acrylate compound having high purity while suppressing the formation of coloring materials and oligomers. <P>SOLUTION: A compound of formula (2) (R is hydrogen or methyl) is produced by reacting a compound of formula (1) (n is an integer of 1-3; R1 is hydroxyl, methyl or (meth)acryloyloxy; when n is 2 or 3, the multiple R1 groups may be the same or different provided that at least one of the R1 groups is hydroxyl) with (meth)acrylic acid in the presence of an acid catalyst and a polymerization inhibitor. In the above method, the (meth)acrylic acid has a phenol-based or quinone-based polymerization inhibitor content of ≤45 ppm. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method for producing adamantyl (meth) acrylate and derivatives thereof by dehydration esterification of an adamantyl alcohol compound and (meth) acrylic acid, and in particular, adamantyl (meta) with suppressed generation of colored substances and oligomers as impurities. ) It relates to a method for producing acrylate and its derivatives.

  Esters consisting of adamantyl alcohol and other compounds having a hydroxyl group bonded to the adamantane skeleton (also referred to as “adamantyl alcohol compounds” in this specification) and (meth) acrylic acid (hereinafter referred to as “adamantyl (meth)”) (It is also referred to as an acrylate compound.) (See Patent Document 1) is a polymer obtained by polymerizing this as a main monomer, has a high refractive index and transparency, and is excellent in mechanical properties and heat resistance. Therefore, a wide range of applications are expected as optical materials and semiconductor resist materials.

  An adamantyl (meth) acrylate compound is produced by a dehydration esterification reaction of (meth) acrylic acid and an adamantyl alcohol compound in the presence of an acid catalyst (see, for example, Patent Document 2).

  However, when an adamantyl (meth) acrylate compound is synthesized by dehydration esterification, a colored substance is usually mixed as an impurity in the product. On the other hand, there is known a method for reducing the residue of colored substances by crystallization using an aliphatic hydrocarbon-containing solvent (i) or an aliphatic hydrocarbon solvent containing an ester (patent) Reference 3). However, this method does not suppress the generation of the colored substance itself. In addition, as it is recommended that the reaction mixture is washed and then subjected to an adsorption treatment prior to crystallization, the crystallization with the solvent of (i) or (ii) above is sufficient to completely remove the colored substance. Removal is difficult.

  In addition, it is known that in the synthesis of adamantyl (meth) acrylate compounds by dehydration esterification, high molecular weight impurities (referred to as “oligomers” in the present specification) detected by gel filtration chromatography are likely to be generated. . For the purpose of suppressing the formation of oligomers, a polymerization inhibitor is added to the reaction system, but it is not necessarily sufficient to suppress the formation. On the other hand, it has been proposed to remove the oligomer by crystallizing the crude product after the esterification reaction in a solvent containing a polar solvent as a main component (see Patent Document 4). However, this method also does not teach anything about the suppression of oligomer formation during the esterification reaction.

Japanese Examined Patent Publication No. 7-61980 JP-A-8-310995 Japanese Patent No. 3507024 JP 2005-104964 A

  In the above background, the present invention provides a high purity and adamantyl (meth) acrylate compound by suppressing the formation of colored substances and oligomers during the reaction in the dehydration esterification of an adamantyl alcohol compound and (meth) acrylic acid. It aims at providing the method of manufacturing with a high yield.

  As a result of studies for the above purpose, the present inventors have found that phenols and quinone compounds, which are usually used as polymerization inhibitors in the production of (meth) acrylates, promote an increase in coloring substances and oligomers in the esterification reaction. I found it. Furthermore, the present inventor usually contains a considerable amount (50 to 300 ppm) of phenols and quinones compounds in (meth) acrylic acid used in the esterification reaction, and as a polymerization inhibitor in the esterification reaction. It has been found that even if no phenols or quinones compounds are added, coloring substances and oligomers increase in the esterification reaction due to those compounds contained in the raw material (meth) acrylic acid. The present invention has been completed with further studies based on these findings.

  That is, the present invention provides the following.

  (1) Formula 1,

[In the formula, n is an integer of 1 to 3, and R1 is a group bonded to an adamantane ring and represents a hydroxyl group, a methyl group or a (meth) acryloyloxy group, and a plurality of n is a plurality Of R1 may be the same or different from each other, and at least one of R1 represents a hydroxyl group. And a compound represented by formula (2) by reacting (meth) acrylic acid in the presence of an acid catalyst and a polymerization inhibitor,

[Wherein, R represents a hydrogen atom or a methyl group, and n and R1 are the same as defined above. ] (Meth) acrylic acid ester production method, wherein (meth) acrylic acid having a total content of phenolic and quinone polymerization inhibitors of 45 ppm or less is used. .
(2) The production method according to 1 above, further characterized by reacting the reaction system without adding a phenol-based or quinone-based polymerization inhibitor.
(3) The (meth) acrylic acid is subjected to distillation to remove or reduce the quinone-based and / or phenol-based polymerization inhibitor contained therein prior to use in the reaction. The manufacturing method according to 1 or 2, further characterized.
(4) The method according to any one of (1) to (3) above, wherein an inorganic polymerization inhibitor is used as the polymerization inhibitor.
(5) The method according to any one of 1 to 4 above, wherein the inorganic polymerization inhibitor is an inorganic copper salt polymerization inhibitor and / or an inorganic iron salt polymerization inhibitor.
(6) The production method according to any one of 1 to 5 above, wherein the reaction is carried out in a saturated hydrocarbon solvent.
(7) The method according to any one of (1) to (6) above, further characterized in that the (meth) acrylic acid ester represented by formula 2 is crystallized from a reaction mixture in a saturated hydrocarbon solvent.

  According to the present invention relating to each of the above-described structures, in the dehydration esterification of an adamantyl alcohol compound and (meth) acrylic acid, the formation of colored substances and oligomers is suppressed, and the target adamantyl (meth) acrylate compound is collected. It can be obtained efficiently and with high purity.

  In the present invention, “(meth) acrylic acid” generically means acrylic acid and methacrylic acid, and “(meth) acrylate” generically means acrylate and methacrylate. In the present invention, the “(meth) acryloyloxy group” comprehensively means an acryloyloxy group and a methacryloyloxy group.

  In the above formula 1, R1 may be bonded to any carbon atom of the adamantane ring (excluding the carbon atom to which the group R is bonded), but more preferably bonded to the bridgehead carbon atom. .

  In the present invention, the phenol-based polymerization inhibitor and the quinone-based polymerization inhibitor refer to polymerization inhibitors that can be used for dehydration esterification of (meth) acrylic acid and alcohols, specifically, phenol-based polymerization is prohibited. Examples of the agent include hydroquinone, methoxyhydroquinone, catechol, p-tert-butylcatechol, cresol, dibutylhydroxytoluene, 2,4,6-tri-tert-butylphenol (BHT), and the quinone polymerization inhibitor. Benzoquinone, naphthoquinone, anthraquinone, diphenoquinone and the like. The lower the concentration of these polymerization inhibitors in the reaction system, the better. Therefore, the concentration (total) of the phenolic and quinone polymerization inhibitors in (meth) acrylic acid used in the reaction is preferably 45 ppm or less, more preferably 35 ppm or less, and 20 ppm or less. Is particularly preferred, and it is most preferred that substantially no phenolic and quinone polymerization inhibitors are contained. Commercially available (meth) acrylic acid usually contains phenolic and quinone polymerization inhibitors, and when the obtained (meth) acrylic acid is used as it is in the esterification reaction, colored substances and oligomers are produced during the reaction. The rate goes up. Therefore, prior to use in the esterification reaction, (meth) acrylic acid increases the concentration of those polymerization inhibitors depending on the concentration (total) of the phenolic and quinone polymerization inhibitors originally contained. It is preferable to subject to purification by distillation or other appropriate methods so as to reduce the concentration to a specified level.

  In the present invention, in order to prevent polymerization during the esterification reaction, it is preferable to use a polymerization inhibitor other than a phenol-based and quinone-based polymerization inhibitor, particularly an inorganic polymerization inhibitor. Preferable inorganic polymerization inhibitors are inorganic copper salt polymerization inhibitors and inorganic iron salt polymerization inhibitors. Inorganic copper salt polymerization inhibitors include copper chloride, copper sulfate, copper nitrate, copper acetate, etc., and inorganic iron salt polymerization inhibitors include iron chloride, iron sulfate, iron nitrate, iron acetate, etc. Can be mentioned.

  The amount of polymerization inhibitor (other than phenolic and quinone polymerization inhibitors) used in the reaction is selected from the viewpoints of achieving sufficient suppression of the polymerization reaction and ensuring the ease of removal from the reaction product. ) It is preferably 0.0001 to 0.05 mol, more preferably 0.001 to 0.005 mol per mol of acrylic acid.

  In the present invention, as the acid catalyst, any conventional acid catalyst known as a catalyst for dehydration esterification reaction between an alcohol compound and (meth) acrylic acid can be suitably used. Such an acid catalyst is a strong organic or inorganic acid, and is not particularly limited. Specifically, mineral acids such as sulfuric acid, hydrochloric acid, nitric acid, phosphoric acid, boric acid and partially neutralized salts thereof; tungstic acid , Molybdic acid, tungstosilicic acid, molybdosilicic acid, tungstophosphoric acid, molybdophosphoric acid and other heteropolyacids and their partially neutralized salts; methanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid and other organic sulfones Acid; Halogenated acetic acid such as trifluoroacetic acid, trichloroacetic acid; acidic ion exchange resin having at least one ion exchange group of sulfonic acid group and alkylsulfonic acid group; Mordenite type, X type, Y type, β type, ZSM Examples include acidic zeolites such as -5 type. These acid catalysts may be used alone or in combination of two or more. Of these, sulfuric acid, phosphoric acid, methanesulfonic acid, benzenesulfonic acid, and p-toluenesulfonic acid are particularly preferable. Also, blowing air into the reaction medium is effective in making it difficult for (meth) acrylic acid polymerization to occur.

  The amount of the acid catalyst is preferably 0.005 to 1 mol, more preferably 0.01 to 0.1 mol, per mol of the adamantyl alcohol compound from the viewpoint of increasing the reaction rate.

  The dehydration esterification reaction between an adamantyl alcohol compound and (meth) acrylic acid can also be performed without using a solvent [in that case, the adamantyl alcohol compound or the like is dissolved in (meth) acrylic acid itself, which is the reaction raw material. Is preferably carried out in an organic solvent. The organic solvent is preferably a hydrophobic organic solvent having a boiling point of 50 to 200 ° C, more preferably a boiling point of 60 to 150 ° C, and particularly preferably a boiling point of 65 to 140 ° C. However, it has been found by the present inventor that the use of an aromatic solvent causes a side reaction (dehydration condensation) with adamantyl alcohol to produce impurities, and that this can be prevented by using a saturated hydrocarbon solvent. Accordingly, the organic solvent used for the esterification reaction is preferably one that does not contain an aromatic solvent, and it is particularly preferable to use a saturated hydrocarbon solvent in such an organic solvent. Examples of suitable saturated hydrocarbon solvents include, but are not limited to, hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, nonane, octane, isooctane, decane. Moreover, the organic solvent formed by mixing these may be sufficient.

  The esterification reaction is carried out under heating and reflux, and the organic solvent and water that are distilled off are condensed by a cooler and separated into water and organic solvent, and only the organic solvent is returned to the reaction system, so that water is removed from the reaction system. Removed. The amount of the organic solvent may be an amount sufficient to remove water generated by the dehydration esterification reaction by azeotropic distillation.

  In the present invention, the reaction time for dehydration esterification is usually 1 to 40 hours, preferably 5 to 30 hours, more preferably 5 to 20 hours.

  After completion of the reaction, the catalyst, polymerization inhibitor, unreacted (meth) acrylic acid, and the like can be removed by washing the reaction mixture with water or an aqueous alkaline solution. Washing can be performed once or multiple times as needed. If necessary, an organic solvent may be added to the reaction mixture so that the adamantyl (meth) acrylate compound is dissolved in the organic phase upon washing. When added, the solvent may be the same as or different from that used in the dehydration esterification reaction, but it is more preferable to use the same solvent as that used in the subsequent crystallization step. Examples of the alkaline aqueous solution include alkali metal hydroxides (sodium hydroxide, potassium hydroxide, etc.), alkali metal carbonates (sodium carbonate, potassium carbonate, etc.), alkali metal hydrogen carbonates (sodium bicarbonate, potassium bicarbonate), Particularly preferred.

  The above washing sufficiently removes impurities such as a catalyst, a polymerization inhibitor, and unreacted (meth) acrylic acid from the reaction product, and according to the method of the present invention, a colored substance and an oligomer are produced. Therefore, the reaction product can be separated from the organic layer by a known method such as concentration, distillation, crystallization and filtration, and can be obtained as a highly pure product without coloring. Of these, crystallization is particularly preferred. When crystallization is performed, it can be performed from various solvents, but is preferably performed from a saturated hydrocarbon solvent. Saturated hydrocarbon solvents include, but are not limited to, hexane, cyclohexane, methylcyclohexane, ethylcyclohexane, heptane, nonane, octane, isooctane, and decane. Moreover, the organic solvent formed by mixing these 2 or more types may be sufficient. One particularly preferred solvent for crystallization is methylcyclohexane.

  Hereinafter, the present invention will be described more specifically with reference to typical examples. However, the present invention is not intended to be limited to the examples.

[Example 1]
Purification of methacrylic acid:
A glass concentrator with an internal volume of 500 mL equipped with a stirrer, an air introduction tube, a distillation column, a cooling tube, a distillation tube, a distillation receiver and a thermometer, and 300 g of commercial methacrylic acid (methoxyhydroquinone content 50 ppm) and chloride Cuprous 0.3g was put, and the temperature of the liquid was raised to 80-90 degreeC, blowing a small amount of air in the liquid under reduced pressure (1-5 kPa), and methacrylic acid was distilled off. By this operation, 270 g of methacrylic acid having a methoxyhydroquinone content of 3 ppm was obtained.

Dehydration esterification reaction:
In a glass container having an internal volume of 300 mL equipped with a stirrer, an air introduction tube, a cooling tube, a water separator (decanter) and a thermometer, 50 g of 1,3-adamantanediol, methacrylic acid purified as described above (methoxyhydroquinone content 3 ppm) ) 103 g, 2.9 g of methanesulfonic acid, 0.6 g of sulfuric acid, 0.05 g of cuprous chloride, 100 g of methylcyclohexane, and the temperature of the liquid is raised to 90-100 ° C. while blowing a small amount of air into the liquid, Water produced as a by-product in the reaction was removed from the reaction system by azeotropy with methylcyclohexane, and the reaction was carried out for about 4 hours while returning only methylcyclohexane to the reaction vessel. Next, the reaction solution was cooled, transferred to a 1 L glass washer equipped with a stirrer, added with 400 g of methylcyclohexane, and then washed once with ion-exchanged water at room temperature. The obtained organic phase was heated to 50 ° C. and washed with a 15% sodium hydroxide aqueous solution three times, a 2.5% sulfuric acid aqueous solution twice, and ion-exchanged water three times in this order. 100 g of the washing solution was used. The organic phase obtained by this washing operation was transferred to a glass concentrator having an internal volume of 1 L equipped with a stirrer, an air introduction tube, a cooling tube, a water separator (decanter) and a thermometer, and reduced in pressure at 20 ° C. (20 to 30 kPa) After dehydration by azeotropy with methylcyclohexane / water under reflux, insoluble matters were removed by filtration.
Crystallization was performed by lowering the temperature of the filtrate. Crystals precipitated at about 40 ° C. The resulting slurry was cooled to 10 ° C., the crystals were filtered off, and the crystals were rinsed with 50 g of cold methylcyclohexane. The crystals were dried by a vacuum dryer at 45 ° C. for 2 hours to obtain 51 g of white 1-methacryloyloxy-3-hydroxyadamantane. The yield was 73% based on 1,3-adamantanediol. The purity of the obtained 1-methacryloyloxy-3-hydroxyadamantane was 99.9% by gas chromatography, and the amount of oligomer detected by gel filtration chromatography was 0.79 with a differential refraction (RI) detector. The area% was 0.05 area% with a UV detector (254 nm) (UV detection at 254 nm is the most sensitive and accurate for detecting the amount of oligomers attributed to the polymerization inhibitor).

[Comparative Example 1]
The reaction and post-treatment were carried out in the same manner as described in the dehydration esterification part of Example 1 except that methacrylic acid having a methoxyhydroquinone content of 50 ppm was used. The purity of the obtained 1-methacryloyloxy-3-hydroxyadamantane (white) is 99.8% by gas chromatography, and the oligomer detected by gel filtration chromatography is 1.00 area by a differential refraction detector. %, 0.68 area% by UV detector (254 nm). Yield 73.4%.

[Comparative Example 2]
As described in the dehydration esterification reaction part of Example 1, except that methacrylic acid having a methoxyhydroquinone content of 50 ppm was used and 0.05 g of methoxyhydroquinone was used instead of 0.05 g of cuprous chloride. Reaction and post-treatment were performed. The obtained 1-methacryloyloxy-3-hydroxyadamantane is slightly light yellow and its purity is 99.8% by gas chromatography. The oligomer detected by gel filtration chromatography is 3 by the differential refraction detector. 0.53% by area, 2.95% by UV detector (254 nm). Yield 67.5%.

[Comparative Example 3]
Using methacrylic acid having a methoxyhydroquinone content of 50 ppm as methacrylic acid, except that 100 g of toluene was used instead of 100 g of methylcyclohexane, the reaction and washing were carried out in the same manner as described in the dehydration esterification part of Example 1, After completion of washing, toluene was distilled off, and 500 g of methylcyclohexane was added for crystallization. The purity of the obtained 1-methacryloyloxy-3-hydroxyadamantane (white) was 98.8% by gas chromatography, and the oligomer detected by gel filtration chromatography was 1.37 area by a differential refraction detector. %, 0.52 area% by UV detector. Yield 69.8%.

  As seen from the above results, according to the method of the present invention, the amount of oligomer can be significantly reduced. Moreover, the possibility that the product is colored can be prevented.

INDUSTRIAL APPLICATION Compared with the conventional manufacturing method of an adamantyl (meth) acrylate compound, this invention is useful as a manufacturing method which can suppress the production | generation of an oligomer significantly and can also prevent the production | generation of a colored substance. .

Claims (7)

(1) Formula 1,

[In the formula, n is an integer of 1 to 3, and R1 is a group bonded to an adamantane ring and represents a hydroxyl group, a methyl group or a (meth) acryloyloxy group, and a plurality of n is a plurality Of R1 may be the same or different from each other, and at least one of R1 represents a hydroxyl group. And a compound represented by formula (2) by reacting (meth) acrylic acid in the presence of an acid catalyst and a polymerization inhibitor,

[Wherein, R represents a hydrogen atom or a methyl group, and n and R1 are the same as defined above. ] (Meth) acrylic acid ester production method, wherein (meth) acrylic acid having a total content of phenolic and quinone polymerization inhibitors of 45 ppm or less is used. .   The method according to claim 1, further comprising reacting the reaction system without adding a phenol-based or quinone-based polymerization inhibitor.   Further characterized in that the (meth) acrylic acid is subjected to distillation in order to remove or reduce the quinone-based and / or phenol-based polymerization inhibitor contained therein prior to use in the reaction. The manufacturing method according to claim 1 or 2.   4. The production method according to claim 1, wherein an inorganic polymerization inhibitor is used as the polymerization inhibitor.   The production method according to any one of claims 1 to 4, wherein the inorganic polymerization inhibitor is an inorganic copper salt polymerization inhibitor and / or an inorganic iron salt polymerization inhibitor.   The production method according to claim 1, wherein the reaction is carried out in a saturated hydrocarbon solvent.   The method according to any one of claims 1 to 6, further comprising crystallizing the (meth) acrylic acid ester represented by the formula 2 in a saturated hydrocarbon solvent from the reaction mixture.