JPH06234701A - Production of alpha,beta-unsaturated carboxylic acid ester - Google Patents

Abstract

(57) [Summary] [Structure] α, β-unsaturated carboxylic acid and / or α, β-
An unsaturated carboxylic acid amide is catalytically reacted with an aliphatic alcohol and a solid acid catalyst to produce an α, β-unsaturated carboxylic acid ester. The solid acid catalyst is phosphorus-containing zirconium oxide, titanium oxide or a composite oxide thereof. This phosphorus is derived from at least one selected from phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, trimethyl phosphate and triethyl phosphate. The amount is 0.0001 to 0.3 atomic ratio of phosphorus to zirconium and / or titanium. [Effect] The α, β-unsaturated carboxylic acid ester can be produced in a high yield of 72 to 94 mol% without producing by-products such as amines and amides for 10 days or longer.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a method for producing an α, β-unsaturated carboxylic acid ester. More specifically, the present invention relates to an α, β-unsaturated carboxylic acid by reacting an α, β-unsaturated carboxylic acid and / or an α, β-unsaturated carboxylic acid amide with an aliphatic alcohol using a solid acid as a catalyst. The present invention relates to a method for producing an ester. α,
The β-unsaturated carboxylic acid ester is industrially very useful as a raw material for synthetic resins. Among them, methyl methacrylate is a raw material of polymethyl methacrylate having excellent weather resistance and transparency.

[0002]

2. Description of the Related Art Conventionally, as a method for producing an α, β-unsaturated carboxylic acid ester, for example, methyl methacrylate, acetone cyanohydrin is treated with concentrated sulfuric acid to form a methacrylamide sulphate. , There is a method of esterification using methyl alcohol. This method has hitherto been used industrially, but it is disadvantageous in that it corrodes equipment materials with concentrated sulfuric acid and produces a large amount of low-value ammonium sulfate as a by-product.

On the other hand, a method for producing an α, β-unsaturated carboxylic acid ester from cyanohydrin without using sulfuric acid is disclosed in, for example, Japanese Patent Publication No. 63-63537 (US Pat.
4,464,539). In this method, first, an α-hydroxycarboxylic acid amide obtained by hydration of cyanohydrin is contacted with a first-stage solid acid catalyst in the presence of water, and then the obtained α, β-unsaturated carboxylic acid is contacted. And / or contacting the reaction mixture containing the α, β-unsaturated carboxylic acid amide with the aliphatic alcohol and the second stage solid acid catalyst to obtain the α, β-unsaturated carboxylic acid ester. At this time, as a typical solid acid catalyst, a catalyst containing a phosphate such as lanthanum phosphate or cerium phosphate is used in the first step, while a titanium or zirconium phosphate is used in the second step. A catalyst containing an oxide or oxide is used. As a result, the α, β-unsaturated carboxylic acid ester can be produced in a yield of about 80 to 89 mol% without producing by-produced ether due to the dehydration reaction of the aliphatic alcohol.

However, when the α, β-unsaturated carboxylic acid ester is produced by the above-mentioned method, in addition to the desired α, β-unsaturated carboxylic acid ester, the second stage solid acid catalyst is used. Alkylamines produced by dehydration reaction between ammonia produced in the first and second stages and aliphatic alcohol as a raw material, and α, β-unsaturated carboxylic acid produced in the first stage and / or α, β-unsaturated N-alkyl α, β-unsaturated carboxylic acid amides are by-produced by a dehydration reaction between the saturated carboxylic acid amide and the alkylamines and / or the aliphatic alcohol. The yield of by-products such as alkylamines and N-alkyl α, β-unsaturated carboxylic acid amides varies depending on the type of the second stage solid acid catalyst, reaction temperature, etc., but is about 2 to 9 mol%. Become. by the way,
The production of these by-products not only complicates the separation and purification process of the α, β-unsaturated carboxylic acid ester and the circulation process of unreacted α, β-unsaturated carboxylic acid, but also produces alkylamines. Depending on the economic value of N-alkyl α, β-unsaturated carboxylic acid amides and their demand, α,
The economic efficiency of the β-unsaturated carboxylic acid ester production method itself is deteriorated.

In the present invention, in a method for producing an α, β-unsaturated carboxylic acid ester using an α, β-unsaturated carboxylic acid and / or an α, β-unsaturated carboxylic acid amide as a raw material,
The object of the present invention is to suppress by-products of alkylamines and N-alkyl α, β-unsaturated carboxylic acid amides as completely or completely as possible and obtain α, β-unsaturated carboxylic acid esters in high yield.

[0006]

[Means for Solving the Problems] As a result of intensive studies for solving the above problems, the present inventors have found that a solid acid catalyst derived from a specific phosphorus compound in zirconium oxide and / or titanium oxide. The present invention has been accomplished by finding the fact that a catalyst containing a specific amount of phosphorus is effective.

That is, the present invention is based on the general formula (1)

[Chemical 2] (In the formula, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is a hydroxyl group or an amino group.) Α, β-unsaturated carboxylic acid And / or when the α, β-unsaturated carboxylic acid amide is contact-reacted with a solid acid catalyst together with an aliphatic alcohol to produce an α, β-unsaturated carboxylic acid ester, the solid acid catalyst contains phosphorus, Zirconium, titanium oxide, or a composite oxide of zirconium oxide and titanium oxide, and
The atomic ratio of phosphorus to zirconium and / or titanium
The method for producing an α, β-unsaturated carboxylic acid ester is characterized in that it is 0.0001 to 0.3.

In the present invention, one of the raw materials is represented by the general formula (1)

[Chemical 3] (In the formula, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is a hydroxyl group or an amino group.) Α, β-unsaturated carboxylic acid And / or α, β-unsaturated carboxylic acid amides are used. Specifically, acrylic acid, acrylic acid amide, methacrylic acid,
Methacrylic acid amide, β-methylacrylic acid, β-methylacrylamide, α, β-dimethylacrylic acid, α,
Examples include β-dimethylacrylamide, β, β-dimethylacrylic acid, β, β-dimethylacrylamide, β-ethylacrylic acid, β-ethylacrylamide and the like.
These α, β-unsaturated carboxylic acids and / or α, β-
The unsaturated carboxylic acid amide can be used separately from the aliphatic alcohol which is another raw material, or as these aliphatic alcohol solutions or aliphatic alcohol aqueous solutions.

In the present invention, the above-mentioned α, β-unsaturated carboxylic acid and / or α, β-unsaturated carboxylic acid amide can be prepared by a known method (Japanese Patent Publication No. 63-10940 (US Pat.
No. 464,539) and Japanese Patent Publication No. 3-13213). For example, in the method described in JP-B-63-10940 (US Pat. No. 4,464,539), α-hydroxycarboxylic acid amide obtained by hydration reaction of cyanohydrin is contacted with a solid acid catalyst, preferably in the presence of water. And α, β-unsaturated carboxylic acid and / or α, β-
A reaction mixture containing an unsaturated carboxamide is obtained. α-
Hydroxycarboxylic acid amides include lactate amide, α
Examples include -hydroxybutyric acid amide, α-hydroxyisobutyric acid amide, α-hydroxyvaleric acid amide, α-hydroxyisovaleric acid amide, and α-methyl-α-hydroxybutyric acid amide. As the solid acid catalyst, a catalyst containing a phosphate such as lanthanum phosphate or cerium phosphate is used. In the method described in Japanese Patent Publication No. 3-13213, a reaction mixture containing methacrylic acid and methacrylamide is prepared by contacting an aqueous solution of α-hydroxyisobutyric acid amide obtained by hydration reaction of acetone cyanohydrin with a solid acid catalyst. To get As the solid acid catalyst, a catalyst containing a phosphate such as monobasic magnesium phosphate or a sulfate such as cadmium sulfate is used.

In the present invention, as the raw material aliphatic alcohol, methyl alcohol, ethyl alcohol,
n-propyl alcohol, i-propyl alcohol, i
-Butyl alcohol, ethylene glycol, ethylene glycol monomethyl ether, various aliphatic alcohols such as propylene glycol monomethyl ether and substituted aliphatic alcohols, depending on the type of target,
It is selected from these.

As the solid acid catalyst in the present invention, a catalyst in which phosphorus is favorably dispersed and contained in zirconium oxide, titanium oxide, or a composite oxide of zirconium oxide and titanium oxide is used. In these oxides or composite oxides, the atomic ratio of phosphorus (represented by P) to zirconium and / or titanium (represented by M) (P /
M) varies depending on the specific surface area (m ² / g) of the oxide or composite oxide, but is 0.0001 to 0.3, preferably 0.001 to 0.
It is 2. If this atomic ratio (P / M) is less than 0.0001,
The yield of the target α, β-unsaturated carboxylic acid ester is remarkably reduced, and when it exceeds 0.3, by-products such as alkylamines and N-alkyl α, β-unsaturated carboxylic acid amides are This is not preferable because the yield increases. Also,
Specific examples of the phosphorus component include phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, and triammonium phosphate; trimethyl phosphate, triethyl phosphate, phosphates such as tributyl phosphate and triphenyl phosphate. And phosphorus hydride, phosphorus bromide, phosphorus chloride, phosphorus oxychloride and the like. Among these, because of the ease of handling,
At least one selected from phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, trimethyl phosphate and triethyl phosphate is preferable. At the time of preparing the catalyst described below, first, these phosphorus compounds react with hydroxides and oxides of zirconium and / or titanium, and partially phosphoric acid on their surface,
It is presumed that they are fixed as zirconium phosphate and / or titanium phosphate, and then they become stable active sites by calcination.

In the present invention, the zirconium oxide containing phosphorus is prepared by using the above-mentioned phosphorus compound and zirconium hydroxide and / or zirconium oxide to prepare a known catalyst, that is, a kneading method, a dipping method, a chemical vapor deposition method. And the like. Further, after supporting zirconium hydroxide and / or zirconium oxide on a carrier such as silica, alumina or silica-alumina by a coprecipitation method, a kneading method or the like, this and the above phosphorus compound are immersed, a chemical vapor deposition method or the like. It can also be prepared by. The titanium oxide or a composite oxide of zirconium oxide and phosphorus containing phosphorus is also used as the above phosphorus compound, titanium hydroxide and / or titanium oxide, or titanium hydroxide and / or titanium oxide and zirconium hydroxide. And / or a mixture with zirconium oxide can be used and prepared by a method similar to that described above.

The amount of the raw material used in the present invention is not particularly limited. For example, when the starting raw material is α-hydroxycarboxylic acid amide, α-hydroxycarboxylic acid amide 1 is used.
Water is usually 0 to 200 mol, preferably 1 to mol.
It is 50 mol. The amount of the aliphatic alcohol based on the reaction mixture containing 1 mol of the obtained α, β-unsaturated carboxylic acid and / or α, β-unsaturated carboxylic acid amide is usually 1 to 200 mol, preferably 1 to 50 mol. It is a mole. The reaction type in the present invention may be either a gas phase method or a liquid phase method as long as the raw material and the above solid acid catalyst can be contacted, but a gas phase or a gas-liquid mixed phase method is preferable, and a fixed bed method , A fluidized bed system, etc. can be used.

In the present invention, the reaction temperature is usually 150 to 50.
At 0 ° C, preferably 200 to 450 ° C. The reaction pressure is usually atmospheric pressure, but may be under pressure or under reduced pressure. Raw material α, β-unsaturated carboxylic acid and / or α, β
The supply rates of the unsaturated carboxylic acid amide and the aliphatic alcohol can be varied within a wide range depending on the type of catalyst, the reaction temperature, etc., but are usually liquid hourly space velocity (LHSV).
A range of 0.005-10 hr ^-1 is sufficient. Further, during the reaction, the raw material may be brought into contact with the catalyst layer by entraining an inert gas such as nitrogen gas. Further, although not necessarily required, as a pretreatment of the catalyst, the reaction may be started after supplying ammonia or aqueous ammonia to the catalyst layer.

[0015]

EXAMPLES The present invention will be described in detail below with reference to examples and comparative examples. In all of these examples, a reaction tube 9 having two catalyst layers as shown in FIG. 1 was used. In the first-stage catalyst layer 5, in Examples 1 to 16, Examples 28 to 39, Comparative Examples 1 to 9 and Comparative Examples 14 to 20, the La PO ₄ catalyst prepared as described below was filled, Further, in Examples 17 to 27 and Comparative Examples 10 to 13, fused alumina balls were filled instead of the catalyst. In the following, "%" is based on weight, unless otherwise specified.

Preparation of first-stage catalyst 21.2 g (0.065 mol) of lanthanum oxide (La ₂ O ₃ ) was completely dissolved in an aqueous nitric acid solution, followed by heating and concentration to prepare lanthanum nitrate, to which water was added. To give 400 ml of lanthanum nitrate aqueous solution. Next, disodium hydrogen phosphate (Na
₂ HPO ₄ ) Aqueous solution containing 20.3 g (0.143 mol) 100 ml
Is added, a white precipitate is formed. After stirring this at 80 ° C. for 1 hour, the white precipitate was thoroughly washed with decantation,
It was separated by filtration and washed with water. The white precipitate obtained is 120
After drying at ℃ and firing in an air stream at 400 ℃ for 6 hours, it was molded into particles of 10 to 16 mesh to prepare a lanthanum phosphate (LaPO ₄ ) catalyst. Here, the expression lanthanum phosphate (LaPO ₄ ) does not necessarily indicate the structure of the phosphate contained in the catalyst, but indicates the atomic ratio of lanthanum to phosphorus in the phosphate.

Example 1 A second stage catalyst was prepared as follows. Zirconium oxychloride (ZrOCl ₂ · 8H ₂ O) 36.1 g (0.112 mol)
Is dissolved in 50 ml of water and this is dissolved in sodium hydroxide (Na
(OH) 9.84 g (0.246 mol) was dissolved in 200 ml of water and added to the solution heated at 80 ° C. with stirring to form a white precipitate. After stirring for 1 hour, the white precipitate was thoroughly washed with water by a decantation method, filtered, washed with water and dried at 100 ° C. to obtain 16.9 g of zirconium hydroxide (Zr (OH) ₄ ). Next, 15.9 g (0.100 g) of the obtained zirconium hydroxide
(Mol) was crushed in an automatic mortar for 3 hours. Separately, 0.46 g (0.0035 mol) of diammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ ) finely pulverized in an agate mortar was added, and the mixture was ground and mixed for 10 hours. This mixture in air at 200 ° C
After leaving it in the air for 5 hours, bake it in the air at 400 ° C for 6 hours,
Molded into granular to 16 mesh, zirconium oxide containing phosphorus P / Zr = 0.035 (hereinafter referred to as P-Zr O _2.) To prepare a catalyst.

Pyrex fabric with an inside diameter of 12 mm shown in FIG.
The above-mentioned P-Zr 2 O is added to the second catalyst layer 6 of the reaction tube 9.₂Catalyst 5m
l, the above-mentioned LaPO in the first catalyst layer 5_Four5 ml of catalyst and
Then, the evaporation part 4 is filled with fused alumina balls having a diameter of 3 mm.
It was The reaction tube 9 is connected to the first stage catalyst layer temperature and the second stage catalyst.
It is fixed in an electric furnace that can control the bed temperature independently and
The reaction liquid receiver 7 cooled by the istrap 8 is shown in FIG.
It was connected as follows. Next, supply the carrier gas above the reaction tube.
Nitrogen gas from the supply pipe 3 to 10 ml / min (GHSV 120hr ^-1)
To the catalyst bed, while the catalyst bed temperature is set to
The second stage was 330 ° C. Methyl alcohol from raw material supply pipe 2
8.5 ml / hr (LHSV 1.7 hr^-1) At the speed of
Next, from the raw material supply pipe 1, 36% (9.0 mol%) of α-hi
4.4 ml / hr (LHSV of droxyisobutyric acid amide aqueous solution)
 0.88 hr^-1). 3 ~ after starting the supply of raw materials
Dry eye strap 8 for 1 hour reaction liquid of 4 hours
The raw material was collected and analyzed by gas chromatography.
Methacrylic Acid to α-Hydroxyisobutyric Acid Amide
The yield of methyl (hereinafter abbreviated as MMA) is 91.5 mol.
%Met. As a by-product other than MMA, α-hydroxy
Acetone yield is 3.5 mol% based on xyisobutyric acid amide
Alone, methylamine, dimethylamine, trimethylamine
Min, N-methylmethacrylamide, and N, N-dime
No tylmethacrylamide was detected.

Examples 2 to 12 and Comparative Examples 1 to 6 In Example 1, the atomic ratio (P / Zr) of phosphorus to zirconium in P-ZrO ₂ which is the second stage catalyst, and the second stage reaction temperature. The procedure of Example 1 was repeated except that Table 1 shows P / Zr, reaction temperature and yield of reaction product.

Comparative Examples 7 and 8 The procedure of Example 1 was repeated except that the second stage catalyst species and the second stage reaction temperature were changed. The second stage catalyst was prepared as follows. Zirconium oxychloride (Z
rOCl ₂ · 8H ₂ O) 36.1 g (0.112 mol) in water 50 m
It is dissolved in l, and disodium hydrogen phosphate (Na ₂
When 200 ml of an aqueous solution containing 31.8 g (0.224 mol) of HPO ₄ ) is added, a white precipitate is formed. After stirring this at 80 ° C. for 1 hour, the white precipitate was thoroughly washed with decantation,
After separation by filtration, washing with water, and drying at 120 ° C., 30.1 g of zirconium phosphate (Zr (HPO ₄ ) ₂ ) was obtained. This is fired in air at 500 ° C. for 6 hours, molded into particles of 10 to 16 mesh, and zirconium phosphate (Zr (H
A PO ₄ ) ₂ ) catalyst was prepared. Here, the expression zirconium phosphate (Zr (HPO ₄ ) ₂ ) does not necessarily indicate the structure of the phosphate contained in the catalyst, but indicates the atomic ratio of zirconium to phosphorus in the phosphate. Table 1 shows P / Zr, reaction temperature and yield of reaction product.

Example 13 The procedure of Example 1 was repeated, except that the second-stage catalyst species was changed. The second stage catalyst was prepared as follows. Zirconium oxychloride (ZrOCl ₂ · 8H ₂
O) 36.1 g (0.112 mol) was dissolved in 50 ml of water, and this was added with stirring to a solution of sodium hydroxide (NaOH) 9.84 g (0.246 mol) dissolved in 200 ml of water and heated to 80 ° C. And a white precipitate forms. After stirring for 1 hour, the white precipitate was thoroughly washed with water by a decantation method, filtered, washed with water, and then dried at 100 ° C. This was calcined in air at 330 ° C. for 4 hours to obtain 13.0 g of zirconium oxide (ZrO ₂ ). Next, the obtained zirconium oxide 10.0 g (0.081
Mol) to trimethyl phosphate ((CH ₃ O) ₃ PO ₄ )
Add to 50 ml of aqueous solution containing 3.5 g (0.025 mol),
It was soaked for 6 hours. Then, wash it with water, filter and
After drying at 0 ℃, calcination in air at 400 ℃ for 6 hours, P /
Zirconium oxide containing phosphorus of Zr = 0.035 (P-
A ZrO ₂ ) catalyst was prepared. The phosphorus content in zirconium oxide was measured by a fluorescent X-ray analysis method. Also,
Table 2 shows the yield of the reaction product.

Example 14 The procedure of Example 1 was repeated, except that the second-stage catalyst species was changed. The second stage catalyst was prepared as follows. Zirconium oxychloride (ZrOCl ₂ · 8H ₂
O) 36.1 g (0.112 mol) was dissolved in 50 ml of water, and this was added with stirring to a solution of sodium hydroxide (NaOH) 9.84 g (0.246 mol) dissolved in 200 ml of water and heated to 80 ° C. And a white precipitate forms. After stirring for 1 hour, the white precipitate was thoroughly washed with water by a decantation method, filtered, washed with water, and then dried at 100 ° C. This was calcined in air at 330 ° C. for 4 hours to obtain 13.0 g of zirconium oxide (ZrO ₂ ). Next, the obtained zirconium oxide 10.0 g (0.081
Was added to 50 ml of an aqueous solution containing 0.58 g (0.005 mol) of 85% phosphoric acid and immersed at room temperature for 120 hours. After that, wash it with water, filter it, and dry it at 100 ℃, then in the air.
P-ZrO with P / Zr = 0.035 after firing at 400 ° C for 6 hours
_Two catalysts were prepared. The phosphorus content in zirconium oxide was measured by a fluorescent X-ray analysis method. In addition, Table 2 shows the yield of the reaction product.

Example 15 The same operation as in Example 1 was carried out except that the second stage catalyst species was changed. The second stage catalyst was prepared as follows. Zirconium oxychloride (ZrOCl ₂ · 8H
₂ O) 36.1 g (0.112 mol) was dissolved in 50 ml of water, and this was dissolved in a solution of sodium hydroxide (NaOH) 9.84 g (0.246 mol) dissolved in 200 ml of water and heated to 80 ° C with stirring. A white precipitate forms upon addition. After stirring for 1 hour,
The white precipitate was thoroughly washed with water by a decantation method, filtered, washed with water, and then dried at 100 ° C. 330 ℃ in the air
Zirconium oxide (ZrO ₂ ) 13.0g
Got Next, the obtained zirconium oxide 10.0 g (0.0
81 mol) of diammonium hydrogen phosphate ((NH ₄ )
₂ HPO ₄ ) was added to 50 ml of an aqueous solution containing 1.3 g (0.010 mol), and the mixture was immersed at room temperature for 72 hours. Then, this was washed with water, filtered, dried at 100 ° C., and calcined in air at 400 ° C. for 6 hours to prepare a P-ZrO ₂ catalyst having P / Zr = 0.035. The phosphorus content in zirconium oxide was measured by a fluorescent X-ray analysis method. In addition, Table 2 shows the yield of the reaction product.

Example 16 The procedure of Example 1 was repeated except that the second stage catalyst species was changed. The second stage catalyst was prepared as follows. Zirconium oxychloride (ZrOCl ₂ · 8H ₂
O) 7.9 g (0.024 mol) was dissolved in 30 ml of water and heat-treated at 1000 ° C for 5 hours on silica (trade name; SILICA
951W, made by Fuji Davison Co.) 7.0 g
Add. This was evaporated to dryness and calcined in air at 400 ° C. for 3 hours to obtain silica carrying 3% zirconium oxide.
Next, 9.0 g of the obtained zirconium oxide-supported silica.
(0.0022 mol ZrO ₂ equivalent) was added to 50 ml of an aqueous solution containing 0.5 g (0.0036 mol) of trimethyl phosphate ((CH ₃ O) ₃ PO ₄ ) and immersed at 80 ° C. for 6 hours. After that, wash it with water, filter it, and dry it at 100 ℃, then in the air.
It was calcined at 400 ° C. for 6 hours to prepare a silica catalyst supporting zirconium oxide containing P / Zr = 0.035 phosphorus. The phosphorus content in zirconium oxide was determined by the fluorescence X
It was measured by a line analysis method. In addition, Table 2 shows the yield of the reaction product.

Comparative Example 9 The procedure of Example 1 was repeated except that the second stage catalyst species was changed. The second stage catalyst was prepared as follows. Zirconium phosphate (Zr (HPO ₄ ) ₂ ) catalyst of P / Zr = 2.00 obtained in Comparative Example 7 0.41 g (0.0014
(Mol) was pulverized in an agate mortar. On the other hand, Example 13
Zirconium oxide (ZrO ₂ ) obtained in Step 10.0 g (0.08
1 mol) was ground for 3 hours in an automatic mortar. To this one,
The former finely divided product was added, and the mixture was ground and mixed for 10 hours. This mixture was calcined in air at 400 ° C. for 6 hours and molded into particles of 10 to 16 mesh to prepare a P-ZrO ₂ catalyst having P / Zr = 0.035. The phosphorus content in zirconium oxide is
It was measured by a fluorescent X-ray analysis method. In addition, Table 2 shows the yield of the reaction product.

Example 17 In Example 1, the first-stage catalyst layer 5 was filled with molten alumina balls having a diameter of 3 mm instead of the catalyst, and the second-stage catalyst layer 6 was formed with P-obtained in Example 13. ZrO ₂ catalyst (P / Z
r = 0.035), and the same operation as in Example 1 except that the kind of raw material and the supply amount thereof were changed as follows. As a raw material, a 36% α-hydroxyisobutyric acid amide aqueous solution and a 20% methacrylamide-methyl alcohol solution were used in place of methyl alcohol, and this was fed from the raw material supply pipe 1 at 3.4 ml / hr (LHSV 0.68 hr ⁻¹ ). Feed at rate. Further, nothing was supplied from the raw material supply pipe 2. Table 3 shows the yield of the reaction product.

Examples 18 to 21 In Example 17, except that the kind and concentration of the raw materials were changed,
The same operation as in Example 17 was performed. Table 3 shows the types and concentrations of raw materials and the yield of reaction products.

Example 22 In Example 1, the first stage catalyst layer 5 was filled with fused alumina balls having a diameter of 3 mm instead of the catalyst, and the kind of raw material and its supply amount / time were changed as follows. Other than that, the same operation as in Example 1 was carried out. As a raw material, 36% α
-A 20% methacrylamide-methyl alcohol solution was used in place of the hydroxyisobutyric acid amide aqueous solution and methyl alcohol, and this was supplied from the raw material supply pipe 1 at 3.4 ml / hr (L
The feed rate was 0.68 hr ^{−1 (} HSV). Nothing was supplied from the raw material supply pipe 2. 3-4 after starting the supply of raw materials
For 1 hour and 240 to 241 hours, the reaction solution for 1 hour each was collected by the dry ice trap 8 and analyzed by gas chromatography. Table 4 shows the yield of the main product (MMA) of the reaction and the productivity of the catalyst.

Examples 23 to 27 and Comparative Examples 10 to 13 Example 22 is the same as Example 22 except that the atomic ratio of phosphorus to zirconium (P / Zr) in P-ZrO ₂ which is the second stage catalyst is changed. The same operation was performed. Table 4 shows P / Zr, the yield of the main product (MMA) of the reaction, and the productivity of the catalyst.

Example 28 The same operation as in Example 1 was conducted except that P-ZrO ₂ was changed to P-TiO ₂ as the second stage catalyst species in Example 1. The second stage catalyst was prepared as follows. 80 ml of ice-cooled water containing 40.1 g (0.211 mol) of titanium chloride (Ti Cl ₄ ).
A 28% aqueous ammonia solution was gradually added dropwise to an aqueous solution obtained by adding and dissolving it in water, and the pH was adjusted to pH = 7, followed by stirring at 80 ° C. for 1 hour. The obtained precipitate was thoroughly washed with water by a decantation method, separated by filtration, further washed with water, and then dried at 100 ° C,
20.2 g of titanium hydroxide (Ti (OH) ₄ ) was obtained. next,
The obtained titanium hydroxide (11.6 g, 0.100 mol) was pulverized in an automatic mortar for 3 hours. Separately, diammonium hydrogen phosphate ((NH ₄ ) ₂ H was pulverized in an agate mortar.
0.46 g (0.0035 mol) of PO ₄ ) was added, and the mixture was ground and mixed for 10 hours. This mixture was allowed to stand in air at 200 ° C. for 2 hours, then calcined in air at 400 ° C. for 6 hours, molded into 10 to 16 mesh granules, and titanium oxide containing phosphorus with P / Ti = 0.035 (hereinafter referred to as P Designated as —TiO ₂ ) A catalyst was prepared. Table 5 shows P / Ti, reaction temperature and yield of reaction product.

Examples 29 to 32 and Comparative Examples 14 to 17 In Example 28, the atomic ratio (P / Ti) of phosphorus to titanium in P-Ti O ₂ which is the second stage catalyst, and the second stage reaction The same operation as in Example 28 was performed except that the temperature was changed. Table 5
Shows P / Ti, reaction temperature and yield of reaction product.

Example 33 The procedure of Example 1 was repeated, except that P-ZrO ₂ was replaced with P-ZrTiO ₂ as the second-stage catalyst species. The second stage catalyst was prepared as follows. Example 1
Zirconium hydroxide (Zr (OH) ₄ ) 12.7 obtained in
g (0.080 mol) and 1.6 g (0.020 mol) of titanium hydroxide (Ti (OH) ₄ ) obtained in Example 28 were pulverized in an automatic mortar for 3 hours. Separately, diammonium hydrogen phosphate ((NH ₄ ) ₂ HP was pulverized in an agate mortar.
0.46 g (0.0035 mol) of O ₄ ) was added, and the mixture was ground and mixed for 10 hours. After leaving this mixture in air at 200 ° C for 5 hours,
It is baked in air at 400 ° C. for 6 hours, molded into 10 to 16 mesh granules, and P / (Zr + Ti) = 0.035 and Zr / Ti = 4.0 phosphorus-containing composite oxide (hereinafter referred to as P-ZrTi O ₂ The catalyst was prepared. Also, Table 6 shows P / (Zr + Ti), Z
The r / Ti, reaction temperature and yield of reaction product are shown.

Examples 34 to 39 and Comparative Examples 18 to 22 In Example 33, in the second stage catalyst, P-ZrTiO ₂ ,
The same operation as in Example 33 was performed except that P / (Zr + Ti) and Zr / Ti and the second-step reaction temperature were changed. Table 6 shows P / (Zr +
Ti), Zr / Ti, reaction temperature and yield of reaction products are shown.

[0034]

According to the present invention, by-products of alkylamines and / or N-alkyl α, β-unsaturated carboxylic acid amides are almost completely suppressed over a long period of time, and α, β can be produced at a high yield. -Unsaturated carboxylic acid esters can be produced.

[0035]

[Table 1] * 1: Methylamine, dimethylamine, and trimethylamine are not directly produced from α-hydroxyisobutyric acid amide, but for the sake of convenience, the total production amount of these is defined as the amine yield (mol%) with respect to the supply amount of α-hydroxyisobutyric acid amide To do. * 2: For the amount of α-hydroxyisobutyric acid amide supplied,
The total amount of N-methylmethacrylamide and N, N-dimethylmethacrylamide produced was defined as the amide yield (mol%).

[0036]

[Table 2]

[0037]

[Table 3] * 3: Alkylamines corresponding to aliphatic alcohols are not directly produced from methacrylic acid and / or methacrylamide, but for the sake of convenience, the total production of these alkylamines is calculated based on the amount of methacrylic acid and / or methacrylamide supplied. Mol%). * 4: The total amount of N-alkyl methacrylamide and N, N-dialkyl methacrylamide corresponding to the aliphatic alcohol produced relative to the amount of methacrylic acid and / or methacrylamide supplied is defined as the amide yield (mol%). .

[0038]

[Table 4] * 5; The total amount of amides was calculated assuming that the amide yield of * 2 is the N-methylmethacrylamide yield. * 6: Catalyst productivity (g / g-catalyst) is the total amount of MMA or amides produced per unit amount of catalyst 241 hours after feeding the raw materials.

[0039]

[Table 5]

[0040]

[Table 6]

[Brief description of drawings]

FIG. 1 is a reactor used in Examples and Comparative Examples.

[Explanation of symbols]

 1 Raw Material Supply Pipe 2 Raw Material Supply Pipe 3 Carrier Gas Supply Pipe 4 Evaporator 5 First Stage Catalyst Layer 6 Second Stage Catalyst Layer 7 Reaction Liquid Receiver 8 Dry Eye Strap 9 Pyrex Reaction Tube

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kenji Hiraiwa 1900 Togo, Mobara-shi, Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Hiroharu Kageyama 1900, Togo, Mobara-shi Chiba Prefecture Mitsui Toatsu Chemical Co., Ltd. (72) Inventor Kanemitsu Miyama 1900 Togo, Mobara-shi, Chiba Mitsui Toatsu Chemical Co., Ltd.

Claims (12)

[Claims] 1. General formula (1) (Chemical formula 1) (In the formula, R ₁ , R ₂ and R ₃ are hydrogen or an alkyl group having 1 to 4 carbon atoms, and X is a hydroxyl group or an amino group.) Α, β-unsaturated carboxylic acid And / or when the α, β-unsaturated carboxylic acid amide is contact-reacted with a solid acid catalyst together with an aliphatic alcohol to produce an α, β-unsaturated carboxylic acid ester, the solid acid catalyst contains phosphorus, Zirconium, titanium oxide, or a composite oxide of zirconium oxide and titanium oxide, and
The atomic ratio of phosphorus to zirconium and / or titanium
A method for producing an α, β-unsaturated carboxylic acid ester, which is 0.0001 to 0.3. 2. The production method according to claim 1, wherein the atomic ratio of phosphorus to zirconium and / or titanium is 0.001 to 0.2. 3. The production method according to claim 1, wherein the oxide containing phosphorus is zirconium oxide. 4. The production method according to claim 1, wherein the oxide containing phosphorus is titanium oxide. 5. The production method according to claim 1, wherein the oxide containing phosphorus is a composite oxide of zirconium oxide and titanium oxide. 6. The solid acid catalyst is at least one selected from phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, trimethyl phosphate and triethyl phosphate, and zirconium hydroxide and / or
Alternatively, the production method according to claim 1, which is zirconium oxide containing phosphorus prepared from zirconium oxide. 7. The solid acid catalyst comprises at least one selected from phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, trimethyl phosphate and triethyl phosphate, titanium hydroxide and / or Alternatively, the production method according to claim 1, which is titanium oxide containing phosphorus prepared from titanium oxide. 8. The solid acid catalyst comprises at least one selected from phosphoric acid, ammonium dihydrogen phosphate, diammonium hydrogen phosphate, triammonium phosphate, trimethyl phosphate and triethyl phosphate, zirconium hydroxide and 2. The production method according to claim 1, which is a composite oxide of zirconium oxide containing phosphorus and titanium oxide, prepared from zirconium oxide, titanium hydroxide and / or titanium oxide. 9. The method according to claim 1, wherein the α, β-unsaturated carboxylic acid and / or the α, β-unsaturated carboxylic acid amide is a mixture of methacrylic acid and methacrylamide. 10. The production method according to claim 1, wherein the α, β-unsaturated carboxylic acid and / or the α, β-unsaturated carboxylic acid amide is methacrylamide. 11. The aliphatic alcohol is methyl alcohol, ethyl alcohol, n-propyl alcohol, i-
The production method according to claim 1, which is at least one selected from propyl alcohol, i-butyl alcohol, and ethylene glycol. 12. The production method according to claim 1, wherein the aliphatic alcohol is methyl alcohol.