Organic compounds -- part of the class 532-570 series – Organic compounds – Heterocyclic carbon compounds containing a hetero ring...
Reexamination Certificate
2003-03-10
2003-11-04
Owens, Amelia (Department: 1625)
Organic compounds -- part of the class 532-570 series
Organic compounds
Heterocyclic carbon compounds containing a hetero ring...
C549S313000, C549S328000, C549S329000, C560S205000
Reexamination Certificate
active
06642394
ABSTRACT:
TECHNICAL FIELD
This invention relates to a process for producing (meth)acrylic anhydride, in particular, to a process for producing (meth)acrylic anhydride as a raw material for (meth)acrylic ester monomer which is usable as a raw material for polymer for semiconductor resist use. This invention also relates to a process for producing (meth)acrylic ester, in particular, to a process for producing (meth)acrylic ester as a raw material for polymer for semiconductor resist use.
BACKGROUND ART
As a process for producing (meth)acrylic anhydride, there have been known processes in which (meth)acrylic acid is reacted with (meth)acrylic chloride (Khim. Prom. (Moscow) (1969), 45 (11), 822-3) and in which (meth)acrylic acid is reacted with acetic anhydride and the resultant reaction product is distilled (Japanese Patent Laid-Open No. 62-158237).
The process in which (meth)acrylic anhydride is produced by reacting (meth)acrylic acid with (meth)acrylic chloride, however, involves generating an acidic gas, and therefore, requires a reactor made up of special materials which have a resistance to corrosion. Thus it is not suitable for the production in industrial scale.
On the other hand, in the process in which (meth)acrylic anhydride is produced by reacting (meth)acrylic acid with acetic anhydride and distilling the resultant reaction product, the materials for the reactor is not a problem, but it is hard to purify the (meth)acrylic anhydride into a high-purity product. That is, the distillation, a common purifying process, has a problem that concentrated (meth)acrylic anhydride is very likely to polymerize because it is exposed to high temperatures under an acidic condition in the final stage of distilling step in which (meth)acrylic acid, mixed acid anhydride of (meth)acrylic acid and acetic acid, and unreacted acetic anhydride are distilled off from an intended product.
A process is known in which (meth)acrylic esters are produced from (meth)acrylic anhydride and alcohols; however, this process is not suitable for industrially producing (meth)acrylic ester having the following the formula (3) or (4), which is useful in the electronic material applications, in particular, as a raw material monomer for polymer for semiconductor resist use, because it is hard to produce high-purity (meth)acrylic anhydride as a raw material for the esters, as described above. Specifically, there is a problem that the use of low-purity (meth)acrylic anhydride as a raw material causes a side reaction or a polymerization reaction, resulting in production of low-purity (meth)acrylic esters in low yield.
In the formula, R
1
represents hydrogen atom or alkyl group; n and m represent independently 0 or 1 as the number of methylene group; and R
3
represents hydrogen atom or methyl group.
In the formula, R
2
represents alkyl group; and R
3
represents hydrogen atom or methyl group.
DISCLOSURE OF THE INVENTION
Accordingly, one object of this invention is to provide a process for industrially producing high-purity (meth)acrylic anhydride, especially (meth)acrylic anhydride used as a raw material for (meth)acrylic ester monomer which is usable as a raw material for polymer for semiconductor resist use, while avoiding polymerization. Another object of this invention is to provide a process for producing high-purity (meth)acrylic ester of a secondary or tertiary alcohol in high yield, in particular, a process for producing high-purity (meth)acrylic ester having the formula (3) or (4), which is a raw material monomer for polymer for semiconductor resist use, in high yield.
The inventors of this invention found that in the process of producing (meth)acrylic anhydride by reacting (meth)acrylic acid with a fatty acid anhydride, high-purity (meth)acrylic anhydride can be obtained by neutralizing the resultant reaction mixture with an aqueous alkaline solution while avoiding distillation, and accomplished this invention.
Specifically, this invention is a process for producing (meth)acrylic anhydride comprising a step of reacting (meth)acrylic acid with a fatty acid anhydride; and a step of neutralization-washing the resultant reaction mixture with an aqueous alkaline solution having a pH of 7.5 to 13.5.
In this process, preferably the above resultant reaction mixture is dissolved in a low-polar solvent prior to the above neutralization-washing step.
The (meth)acrylic anhydride produced in this process is suitable for the raw material for (meth)acrylic ester monomer, which is a raw material for polymer for semiconductor resist use.
Further, this invention is a process for producing (meth)acrylic ester which includes an esterifying step of reacting the (meth)acrylic anhydride produced by the above described process with a secondary or tertiary alcohol in the presence of a basic compound which in 25° C. water has an acidity (pKa) of 11 or less.
As the secondary or tertiary alcohol used in the reaction, are preferable alcohols having the following formula (1) or (2), and as the (meth)acrylic ester produced through the reaction, are preferable (meth)acrylic esters having the following formula (3) or (4).
In the formula, R
1
represents a hydrogen atom or an alkyl group; and n and m represent independently 0 or 1 as the number of methylene group.
In the formula, R
2
represents alkyl group.
In the formula, R
1
represents a hydrogen atom or an alkyl group; n and m represent independently 0 or 1 as the number of methylene group; and R
3
represents a hydrogen atom or a methyl group.
In the formula, R
2
represents an alkyl group; and R
3
represents a hydrogen atom or a methyl group.
When the (meth)acrylic ester thus produced is that expressed by the above formula (3), (meth)acrylic ester with higher-purity can be obtained by adding a washing step of washing the (meth)acrylic ester obtained after the above esterifying step with a low-polar solvent and then with an aqueous acid solution and/or an aqueous alkaline solution.
Further, when the (meth)acrylic ester thus produced is that expressed by the above formula (4), (meth)acrylic ester with higher-purity can be obtained by adding a washing step of washing the (meth)acrylic ester obtained after the above esterifying step with an aqueous alkaline solution and then with an aqueous acid solution. Further, thus obtained (meth)acrylic ester may be subjected to thin-film distillation to provide higher-purity (meth)acrylic ester.
The (meth)acrylic ester produced in accordance with the process of this invention is suitable for the raw material for polymer for semiconductor resist use.
BEST MODE FOR CARRYING OUT THE INVENTION
In this invention, (meth)acrylic anhydride is produced by reacting (meth)acrylic acid with a fatty acid anhydride. The term “(meth)acrylic acid”, as is commonly used, means a general term for the acrylic acid and the methacrylic acid. Preferably the fatty acid anhydrides used in this invention are compounds having the following structural formula:
wherein R
4
represents alkyl group.
In the above formula, R
4
is preferably an alkyl group with 1 to 3 carbon atoms, and the two units of R
4
may be different, but preferably they may be generally the same.
The reaction temperature is preferably −30° C. to 120° C., and more preferably 0° C. to 100° C. The higher the reaction temperature becomes, the higher the reaction rate becomes, and lower the reaction temperature becomes, the more the side reaction is inhibited. Preferably the reaction is conducted while removing the fatty acid produced as a by-product outside the system under reduced pressure. This reaction can be conducted without a solvent, but an inert solvent may be used depending on the situation. The inert solvents include, for example, n-hexane, toluene and xylene.
A catalyst may also be used for the reaction, if necessary, and the catalysts applicable include, for example, phosphoric acid, potassium acetate and sulfuric acid.
To inhibit polymerization during the reaction, preferably a polymerization inhibitor is appropriately used.
In this invention, the reaction mixture after the reaction step
Murata Naoshi
Ohkita Motomu
Tamura Kimio
Yoshida Yasukazu
Mitsubishi Rayon Co. Ltd.
Oblon & Spivak, McClelland, Maier & Neustadt P.C.
Owens Amelia
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