JP4118653B2 - Method for producing 2-alkyl-2-adamantyl (meth) acrylate - Google Patents

Description

実施例５
合成例で製造した粗体２のうち１００ｇを２００ｇのアセトニトリルに溶解し、塩化亜鉛炭１０ｇを加えて室温で３時間攪拌した。活性炭をろ過してアセトニトリルを減圧留去し、メタノール９０ｇとイソプロパノール１０ｇを加えた。４０℃まで加熱し、３０分攪拌してから徐々に冷却した。液温が２０℃になったところで、結晶が出始めた。その温度で１時間攪拌を続けてから、ゆっくり０℃まで冷却した。０℃で３時間攪拌してから、ろ過して結晶を取り出した。この結晶を減圧で乾燥し、７５ｇの２−エチル−２−アダマンチル メタクリレートを得た。この結晶中のオリゴマー量はＧＰＣで０．１面積％以下であった。また、この結晶１ｇを２ｇのメタノールに溶解した時の色相は、ＡＰＨＡ１００以下であった。
【００２８】
比較例９
合成例で製造した粗体２のうち１００ｇを用い、そのままメタノール９０ｇとイソプロパノール１０ｇから実施例５に準じて晶析し、６１ｇの２−エチル−２−アダマンチル メタクリレートを得た。この結晶中のオリゴマー量はＧＰＣで１．１面積％であり、この結晶１ｇを２ｇのメタノールに溶解した時の色相はＡＰＨＡ２００であった。
【００２９】
【発明の効果】
本発明の製造方法によれば、発色性不純物及び／又は不純物オリゴマーを含有する粗２−アルキル−２−アダマンチル（メタ）アクリレートから高純度の２−アルキル−２−アダマンチル（メタ）アクリレートを製造するに際し、活性炭吸着処理によって上記不純物を効率的に除去することができる。したがって、例えば活性炭吸着処理後に晶析や蒸留といった高度の２次精製を行う場合に、当該２次精製における負荷を大幅に低減することができ、精製工程全般にわたる効率を高めることができそれに要するコストを低減することができる。[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a method for producing 2-alkyl-2-adamantyl (meth) acrylate. More specifically, the present invention relates to a method for producing high-purity 2-alkyl-2-adamantyl (meth) acrylate, which is useful as an application of a material such as a resist used in a semiconductor production process.
[0002]
[Prior art]
In recent years, in semiconductor manufacturing processes, the pitch of semiconductor patterns has become extremely fine. For this reason, it is necessary to use a semiconductor resist material that is suitable for such miniaturization. Various compounds have been proposed as resist materials for semiconductors suitable for such miniaturization, but compounds containing an adamantane skeleton (see, for example, Patent Document 1), particularly because of high dry etching resistance in semiconductor manufacturing processes, Expectations for alkyladamantyl ester polymers are increasing (see, for example, Patent Document 2).
[0003]
Various alkyladamantyl ester polymers having different substituent positions and types are known. From the viewpoint of resolution, dry etching resistance, and the like, as the resist material for semiconductor, 2-alkyl-2-adamantyl ( Those obtained by polymerizing meth) acrylate are particularly excellent (see Non-Patent Document 1 and Non-Patent Document 2). Usually, such 2-alkyl-2-adamantyl (meth) acrylate is synthesized by esterification reaction of corresponding 2-alkyl-2-adamantanol or a metal salt thereof with (meth) acrylic acid or a derivative thereof. Yes.
[0004]
Since 2-alkyl-2-adamantyl (meth) acrylate produced by such a method generally contains polymerization impurities such as oligomers and coloring impurities (coloring compounds) that cause coloration, various purification steps. In order to meet the demand for extremely low impurity concentrations in recent semiconductor manufacturing processes, crystallization and thin-film distillation are performed after roughly removing impurities by, for example, adsorption treatment or the like. A two-stage purification method is employed in which high-level purification is performed (see Patent Documents 5 and 6). As an adsorption treatment, a method using silica gel or activated carbon is known (see Patent Documents 2 to 6), but it is considered industrially advantageous to use activated carbon.
[0005]
The activated carbon treatment is usually performed by dissolving 2-alkyl-2-adamantyl (meth) acrylate, which is an object to be treated, in a solvent and bringing the solution into contact with activated carbon. Regarding the solvent used for the activated carbon treatment, Non-polar solvents such as hexane and heptane are suitable for reducing “polymeric impurities” (see paragraph 0019 of Patent Document 4), and alcohols such as methanol and ethanol are suitable for removing “coloring substances”. (See paragraphs 0055 to 0056 of Patent Document 5).
[0006]
[Patent Document 1]
JP-A-4-39665 [Patent Document 2]
JP-A-9-73173 [Patent Document 3]
JP 2001-166463 A [Patent Document 4]
JP 2000-309558 A [Patent Document 5]
JP 2001-192356 A [Patent Document 6]
JP 2001-201868 [Non-patent Document 1]
"Journal of Photopolymer Science and Technology" Photopolymer social gathering 1996, Vol.9, No.3, p.475-488.
[Non-Patent Document 2]
"Journal of Photopolymer Science and Technology" Photopolymer social gathering 1996, Vol.9, No.4, p.590-522.
[0007]
[Problems to be solved by the invention]
In the above-described two-stage purification, the efficiency of the advanced purification process in the latter stage and the efficiency of the entire purification process are generally greatly affected by the degree of purification in the previous stage. From the viewpoint of the efficiency of the entire purification process and the cost required for purification, Although it is desirable to make it as high as possible by purification, the purity of the purified product obtained by the conventional activated carbon adsorption treatment is not always satisfactory. Therefore, an object of the present invention is to increase the purification efficiency of the activated carbon treatment.
[0008]
[Means for Solving the Problems]
Inventors view of the above problems, a result of intensive studies, when the activated carbon treatment by using a specific solvent, the dielectric constant and dipole moment of the solvent, or typical solubility parameter E _T values and Z values, etc. Thus, the inventors have found that an effect far exceeding the expected effect (improvement of hue and removal of impurities in the polymerization system) can be obtained, and the present invention has been completed.
[0009]
That is, the present invention includes the above-described color-forming impurities and / or impurity oligomers by contacting a crude 2-alkyl-2-adamantyl (meth) acrylate containing color-forming impurities and / or impurity oligomers with activated carbon in acetonitrile. It is a manufacturing method of 2-alkyl- 2-adamantyl (meth) acrylate characterized by including the process of reducing quantity.
[0010]
DETAILED DESCRIPTION OF THE INVENTION
In the production method of the present invention, a crude 2-alkyl-2-adamantyl (meth) acrylate containing chromogenic impurities and / or impurity oligomers is brought into contact with activated carbon in acetonitrile, whereby the above chromogenic impurities and / or impurity oligomers are contacted. Including a step of reducing the content.
[0011]
Here, 2-alkyl-2-adamantyl (meth) acrylate is a compound in which two hydrogen atoms at the 2-position of adamantane are each substituted with an alkyl group having 1 to 5 carbon atoms and an acryloyloxy group or methacryloyloxy group. means. The alkyl group having 1 to 5 carbon atoms may be linear or branched, and specific examples of such an alkyl group include a methyl group, an ethyl group, an n-propyl group, and an i-propyl group. N-butyl group, i-butyl group, s-butyl group, t-butyl group, n-pentyl group, 1-methylbutyl group, 2-methylbutyl group, 3-methylbutyl group, 1-ethylpropyl group and the like. .
[0012]
Specific examples of 2-alkyl-2-adamantyl (meth) acrylate having such an alkyl group include 2-methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 2-propyl-2- Adamantyl acrylate, 2- (1-methylethyl) -2-adamantyl acrylate, 2-butyl-2-adamantyl acrylate, 2- (2-methylpropyl) -2-adamantyl acrylate, 2-pentyl-2-adamantyl acrylate, 2 Examples include acrylates such as-(3-methylbutyl) -2-adamantyl acrylate and 2- (2-methylbutyl) -2-adamantyl acrylate, and methacrylates corresponding thereto.
[0013]
Among the 2-alkyl-2-adamantyl (meth) acrylates, the alkyl group substituted at the 2-position is one having a methyl group or an ethyl group because of its high usefulness as a resist material for semiconductors. It is preferable to apply the production method of the present invention to -methyl-2-adamantyl acrylate, 2-ethyl-2-adamantyl acrylate, 2-methyl-2-adamantyl methacrylate or 2-ethyl-2-adamantyl methacrylate.
[0014]
The crude 2-alkyl-2-adamantyl (meth) acrylate used as a raw material in the present invention contains color-forming impurities and / or impurity oligomers. These impurities are inevitably by-produced in the process of synthesizing 2-alkyl-2-adamantyl (meth) acrylate, and the presence of chromogenic impurities indicates that crude 2-alkyl-2-adamantyl (meth) acrylate is It can be confirmed by coloring, and it can be confirmed by gel permeation chromatography (GPC) analysis that it contains an impurity oligomer. The content of these impurities in the crude 2-alkyl-2-adamantyl (meth) acrylate is not particularly limited. However, in the crude 2-alkyl-2-adamantyl (meth) acrylate obtained by a usual synthesis method, the color developing impurities Is contained in such an amount that the hue of the crude 2-alkyl-2-adamantyl (meth) acrylate is 1000 or more when the hue of the crude 2-alkyl-2-adamantyl (meth) acrylate is expressed by an APHA index. ) The acrylate is contained by about 0.1 to 10% in terms of the peak area of the chromatogram when GPC analysis is performed. The APHA index is also called a Hazen scale or a platinum-cobalt scale, and is a method described in American Material Testing Association ASTM D1209. Moreover, although GPC analysis conditions are not specifically limited, For example, the following conditions can be employ | adopted suitably.
[0015]
Column: Tosoh G4000 and G2000 series connected mobile phase: THF, 1 ml / min
Detector: RI detection The method for producing the crude 2-alkyl-2-adamantyl (meth) acrylate is not particularly limited, and a known method can be used as a method for synthesizing 2-alkyl-2-adamantyl (meth) acrylate. For reasons of high selectivity, adamantane obtained by oxidizing adamantane with sulfuric acid and then solvent-extracting is alkylated with alkylmagnesium halide, alkyllithium, alkylhalide and metallic lithium, and the reaction solution at this time is further treated with (Metal). It is preferably obtained by esterification by mixing with acrylic acid halide or (meth) acrylic anhydride.
[0016]
In the production method of the present invention, the crude 2-alkyl-2-adamantyl (meth) acrylate is brought into contact with activated carbon, and chromogenic impurities and / or impurity oligomers are produced from the crude 2-alkyl-2-adamantyl (meth) acrylate. The most characteristic feature is that the contact is performed in acetonitrile. By using acetonitrile, not only aliphatic hydrocarbon solvents such as heptane and alcohol solvents such as methanol, which have been used in conventional methods, but also various commonly used solvents (for example, aromatic solvents such as toluene, The effect of improving hue (in other words, the effect of removing chromogenic impurities) and the effect of removing polymerization-type impurities can be obtained at the same time as compared with ester solvents such as ethyl acetate and water-soluble solvents such as acetone.
[0017]
In the production method of the present invention, the method of contacting the crude 2-alkyl-2-adamantyl (meth) acrylate and activated carbon in acrylonitrile is not particularly limited. For example, crude 2-alkyl-2-adamantyl (meth) acrylate is used. A method of dissolving in acrylonitrile to form a solution, mixing and stirring the solution and activated carbon, a method of circulating the solution through a column packed with activated carbon, and the like can be employed. At this time, the amount of acetonitrile used is not particularly limited, but it is not economical if it is too much, and the weight of the crude 2-alkyl-2-adamantyl (meth) acrylate to be purified from the point that the removal efficiency falls if it is too little. It is preferable to use an amount of about 0.1 to 10 times, particularly about 0.5 to 5 times.
[0018]
As the activated carbon used in the production method of the present invention, commercially available normal activated carbon can be used, and the specific surface area and activation method are not particularly limited, but activated carbon activated with zinc chloride is used from the viewpoint of removal efficiency. Is preferred. The amount of activated carbon used in the production method of the present invention is not particularly limited, but considering the removal effect and cost, it is 0.1% by weight to the weight of the crude 2-alkyl-2-adamantyl (meth) acrylate to be purified. It is preferably about 50% by weight, particularly about 1% to 20% by weight.
[0019]
Moreover, although conditions, such as contact temperature and contact processing time, also depend on the quantity of acetonitrile and activated carbon to be used, -20 degreeC-60 degreeC is preferable for about 10 minutes to 24 hours, and it is 0 degreeC from a viewpoint of a removal effect and cost. It is particularly preferable that the temperature is about 30 minutes to 12 hours at -30 ° C.
[0020]
After such contact (after adsorption treatment), the activated carbon and the treatment liquid are separated by an ordinary method such as filtration, and acetonitrile is further removed from the treatment solution by an ordinary method such as distillation under reduced pressure to thereby remove chromogenic impurities and / or impurity oligomers. The 2-alkyl-2-adamantyl (meth) acrylate with reduced content can be recovered. The recovered 2-alkyl-2-adamantyl (meth) acrylate can be used as it is depending on the application, but when used in applications where higher purity is required, further purification treatment such as distillation and crystallization (2 (Next purification process) may be performed. Even in this case, the 2-alkyl-2-adamantyl (meth) acrylate obtained after the activated carbon adsorption treatment in the present invention is more pure than the 2-alkyl-2-adamantyl (meth) acrylate obtained after the conventional activated carbon treatment. Since it is high, the load of the secondary purification treatment can be greatly reduced. Therefore, it is possible to produce high-purity 2-alkyl-2-adamantyl (meth) acrylate for semiconductor applications more efficiently and at low cost.
[0021]
【Example】
EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated in detail, this invention is not restrict | limited at all by these Examples.
[0022]
Synthesis example 10 (l) with a stirring blade and a thermometer {unit "l (liter)" is shown in parentheses to avoid confusion with the number "1". }, 3138 g of 96% sulfuric acid and 1350 g of 30% fuming sulfuric acid were added, and 408 g of adamantane was added and suspended with stirring. The reaction was carried out at 35 ° C. for 24 hours, then at 50 ° C. for 6 hours and at 65 ° C. for 7 hours. The reaction solution was cooled, then added dropwise to 2400 g of ice water, and extracted twice with methylene chloride 4 (l). The organic layer was washed with a 10% aqueous sodium hydroxide solution and brine, dried over anhydrous magnesium sulfate, and then methylene chloride was distilled off under reduced pressure. 405 g (yield 90%) of 2-adamantanone was obtained as a pale yellow solid.
[0023]
Under a nitrogen atmosphere, 300 g (2.0 mol) of 2-adamantanone was dissolved in 900 ml of tetrahydrofuran in a 3 (l) four-necked flask equipped with a stirring blade, thermometer, condenser, and dropping funnel, and 262 g of ethyl bromide was dissolved. (2.4 mol) was added. Under a nitrogen atmosphere, 27.8 g (4.0 mol) of metallic lithium was added to this solution little by little while controlling the reaction temperature at this time to be around 40 ° C. After the addition of the entire amount, the mixture was heated to 45 ° C. and subjected to reaction ripening for 1 hour to prepare a lithium 2-ethyl-2-adamantyl alcoholate solution. At this time, the conversion of 2-adamantanone was 98%.
[0024]
A 5- (l) four-necked flask equipped with a stirring blade, thermometer, and condenser was replaced with nitrogen. To this was added 220 g (2.1 mol) of methacrylic acid chloride and 0.8 g (4 mmol) of phenothiazine as a polymerization inhibitor. In addition, the solution of lithium 2-ethyl-2-adamantyl alcoholate prepared in the previous stage was added dropwise over 2 hours so that the reaction temperature was 10 ° C. or lower in a nitrogen atmosphere. After completion of dropping, the reaction was aged by stirring at 10 ° C. or lower for 4 hours.
[0025]
After the reaction aging, 500 g of a 10% by mass aqueous sodium hydroxide solution was added at 10 ° C. or lower and stirred for 1 hour to separate the organic layer. The organic layer was further washed with a 10% by mass aqueous sodium hydroxide solution, and then the solvent was distilled off under reduced pressure. The color of crude body 1 obtained here is brown (APHA index: 1000 or more) in a solution of 1 g of crude body in 2 g of methanol, and gel permeation chromatography (GPC) (column: G4000 and G2000 manufactured by Tosoh Corporation). From the serial connection, mobile phase: THF, 1 ml / min, RI detection), the polymer content was 0.2 area% and the oligomer content was 4.3 area%. 20 g of this coarse product 1 was taken out and used in Examples and Comparative Examples. Methanol 1.5 (l) was added to the crude product and stirred, and the insoluble matter was removed by filtration. The obtained filtrate was distilled off under reduced pressure to remove the solvent to obtain 433 g of a crude product of 2-ethyl-2-adamantyl methacrylate. The hue of this crude body 2 was brown (1000 or more APHA index) in which 1 g of the crude body was dissolved in 2 g of methanol, and contained 3.9% by area of oligomer from GPC (same).
[0026]
Examples 1-4 and Comparative Examples 1-8
10 g of the crude 1 or 2 of 2-ethyl-2-adamantyl methacrylate synthesized in the synthesis example was weighed into a sample bottle, and the solvent shown in Table 1 was charged into the sample bottle by the weight times shown in Table 1. Next, zinc chloride charcoal or steam charcoal was added by weight% as shown in Table 1, and the mixture was stirred at room temperature for 1 hour while stirring with a magnetic stirrer. As zinc chloride charcoal, purified white rice cake manufactured by Takeda Pharmaceutical Company Limited was used, and as steam charcoal, NORIT SX ULTRA manufactured by Nippon Norit was used. Next, the activated carbon was removed by filtration, and the color of the filtrate was compared with the APHA standard solution (1000, 500, 200, 100). The solvent was distilled off under reduced pressure, and the amount of oligomer was calculated from GPC. The results are shown in Table 1.
[0027]
[Table 1]

Example 5
100 g of the crude product 2 produced in the synthesis example was dissolved in 200 g of acetonitrile, 10 g of zinc chloride charcoal was added, and the mixture was stirred at room temperature for 3 hours. The activated carbon was filtered and acetonitrile was distilled off under reduced pressure, and 90 g of methanol and 10 g of isopropanol were added. The mixture was heated to 40 ° C., stirred for 30 minutes, and then gradually cooled. Crystals started to appear when the liquid temperature reached 20 ° C. Stirring was continued at that temperature for 1 hour and then slowly cooled to 0 ° C. After stirring at 0 ° C. for 3 hours, the crystals were collected by filtration. The crystals were dried under reduced pressure to obtain 75 g of 2-ethyl-2-adamantyl methacrylate. The amount of oligomer in the crystal was 0.1 area% or less by GPC. Moreover, the hue when 1 g of this crystal was dissolved in 2 g of methanol was APHA 100 or less.
[0028]
Comparative Example 9
Of the crude product 2 produced in the synthesis example, 100 g was used and crystallized as it was from 90 g of methanol and 10 g of isopropanol according to Example 5 to obtain 61 g of 2-ethyl-2-adamantyl methacrylate. The amount of oligomer in this crystal was 1.1 area% by GPC, and the hue when 1 g of this crystal was dissolved in 2 g of methanol was APHA200.
[0029]
【The invention's effect】
According to the production method of the present invention, high-purity 2-alkyl-2-adamantyl (meth) acrylate is produced from crude 2-alkyl-2-adamantyl (meth) acrylate containing chromogenic impurities and / or impurity oligomers. In this case, the impurities can be efficiently removed by the activated carbon adsorption treatment. Therefore, when performing advanced secondary purification such as crystallization and distillation after activated carbon adsorption treatment, for example, the load in the secondary purification can be greatly reduced, and the efficiency of the entire purification process can be increased and the cost required for it. Can be reduced.

Claims (3)

A step of reducing the content of the chromogenic impurities and / or impurity oligomers by contacting a crude 2-alkyl-2-adamantyl (meth) acrylate containing chromogenic impurities and / or impurity oligomers with activated carbon in acetonitrile. The manufacturing method of 2-alkyl- 2-adamantyl (meth) acrylate characterized by including. The manufacturing method according to claim 1, wherein the activated carbon is zinc chloride activated charcoal. The crude 2-alkyl-2-adamantyl (meth) acrylate is alkylated with alkylmagnesium halide or alkyllithium or alkylhalide and metal lithium with adamantane obtained by oxidizing adamantane with sulfuric acid and then solvent extraction, 3. The production according to claim 1, wherein the obtained reaction solution is obtained by further esterification by mixing with (meth) acrylic acid halide or (meth) acrylic anhydride. Method.