JP2000297061A - Production of lactone-modified hydroxyalkyl (meth) acrylate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To produce the subject compound useful for a coating material or the like by subjecting a lactone and a hydroxyalkyl (meth)acrylate to an addition reaction in the presence of zirconia sulfate. SOLUTION: A lactone and a hydroxyalkyl acrylate (e.g. 2-hydroxyethyl acrylate) or a hydroxyalkyl methacrylate (e.g. 2-hydroxyethyl methacrylate) are subjected to an addition reaction in the presence of 0.1-60 wt.% zirconia sulfate based on the amount of the reaction liquid to provide the objective lactone-modified hydroxyalkyl acrylate or lactone-modified hydroxyalkyl methacrylate. The reaction temperature is 70-130 deg.C. The content of a diester in the lactone-modified hydroxyalkyl acrylate is <=0.8 wt.%, and the acid value is <=15 mg-KOH/g and color number is <=50 APHA.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a method for producing a lactone-modified hydroxyalkyl acrylate or hydroxymethacrylic acid ester (hereinafter referred to as a lactone-modified hydroxyalkyl (meth) acrylic acid ester). Lactone-modified hydroxyalkyl (meth) acrylates are widely used in many industrial fields due to differences in average molecular weight and functional groups. For example, a lactone polymer having a radical polymerizable double bond is used as an acrylic coating agent in fields such as automobiles, home appliances, metals, and building materials. The reason is that compared to other alkyd resins, polyester resins and epoxy resins, weather resistance, mechanical properties, chemical resistance,
This is because they have excellent characteristics such as stain resistance.

[0002]

2. Description of the Related Art Lactones (γ-butyrolactone, δ-
The reaction between valerolactone, ε-caprolactone) and alcohols (methanol, ethanol) is described in Journal of the Japanese Society of Agricultural Chemistry, (1974) 48 (9), p. 525-7, Hel
v. Chem. Acta, (1930) 13 , 151,
British Patent 887,180 (1962), Leibigs
Ann. Chem. , (1962) 655,76 ,
J. Org. Chem. , (1966) 31 , 485, but there is no description of the reaction product of a lactone and hydroxyethylacrylic acid or hydroxyethylmethacrylate in the present invention. U.S. Pat. No. 3,655,631 describes the reaction of .epsilon.-caprolactone with hydroxyethyl acrylic acid or hydroxyethyl methacrylate in the presence of 0.1% by weight of p-toluenesulfonic acid as a catalyst. I have.
However, since the reaction product obtained by this method contains a relatively large amount of residual acidic components derived from the catalyst, the reaction product is likely to deteriorate, and the coating resin composition prepared using the reaction product is It deteriorates storage stability (shelf life) and shortens pot life. Further, when such a reaction product containing a strong acidic component is used for a purpose such as a paint for a steel sheet, the reaction product cannot be practically used because it is highly colored or the coated board is corroded.

Further, Japanese Patent Publication No. 5-16451 discloses that perchloric acid is used as a catalyst in a method for producing a caprolactone-modified hydroxyalkyl (meth) acrylate. However, perchloric acid is extremely reactive and has the danger of explosion, and also has the danger of corroding the reactor and piping, and has a limitation in handling. In addition, if perchloric acid is present in the product, the storage stability is poor, and the problem of corrosion on a coated plate or the like is caused by p-
This is the same as the previous case using toluene sulfonic acid as a catalyst, and poses a serious problem in practical use. Tokiohei 9-5072
Japanese Patent Application Laid-Open No. 55-55980 describes a production example of a macromonomer which is reacted in the presence of phosphoric acid as a catalyst, and it is said that the catalyst is preferably used in an amount of 400 to 600 mg / Kg. However, there is no doubt that acidic components remain in the reaction product, and adverse effects on the reaction product, the coating composition, the coated plate, and the like can be easily analogized.

US Pat. No. 4,188,472 discloses the reaction of .epsilon.-caprolactone with hydroxyethyl acrylate, for example with tetrapropyl titanate (over 2,000 ppm) or with stannous octylate and dibutyltin dilaurate. Mixture (1,500 ppm or more)
Has been added. When these catalysts are used, a large amount of ethylene glycol diacrylate or ethylene glycol dimethacrylate (hereinafter referred to as diester) is produced as a side reaction product, and it is impossible to reduce the amount to 0.8% by weight or less. (Comparative Example 5). When producing a resin for a paint or the like, if a large amount of the above diester is present, a crosslinking reaction proceeds during a polymerization or copolymerization reaction, which may cause gelation and eventually form an insoluble and infusible resin. . European Patent Publication No. 0044393A2 states that
At least one monoester of acrylic acid or methacrylic acid with an alkanediol having 2 to 4 carbon atoms;
The species and ε-caprolactone in a molar ratio of 1.5: 1 to 1: 3
Is described. This reaction is described to be performed in the presence of an organotin. Especially in Example 1,
The preparation of adducts from 2-hydroxyethyl acrylate and ε-caprolactone is described.
However, the tin catalyst used in the reaction product must remain, and the storage stability of the product, reduction of the pot life, subsequent abnormalities in the polymerization reaction, coloring, decrease in the weatherability of the resin, and so on It can cause problems.

[0005] JP-A-6-107595 discloses that a lactone and a hydroxyalkyl acrylate or a hydroxyalkyl methacrylate [hereinafter referred to as a hydroxyalkyl (meth) acrylate] in an oxygen-containing atmosphere. Is reacted at a temperature of 100 to 140 ° C. in the presence of 200 ppm or less of a catalyst and 1,000 ppm or less of a polymerization inhibitor. The method wherein the catalyst is a member selected from the group consisting of organometallic compounds, Lewis acids, protonic acids, and mixtures thereof and the organometallic compounds are stannous octoate, dibutyldilaurate, tetraisopropyl titanate, butyl titanate and A process is described which is a member selected from the group consisting of mixtures thereof, wherein the catalyst used remains in the reaction product and, as in the prior patent,
When used for paint applications and the like, it still has various adverse effects. JP-A-6-248060 describes a method for producing a lactone polymer characterized by using a composite catalyst comprising a metal compound and a ligand, and specific examples of a tin compound among the metal compounds include: Dibutyltin oxide, dimethyltin oxide, monobutyltin oxide hydroxide and the like are mentioned. Examples of composite catalysts of these tin compounds and nitrogen-based ligands, oxygen-based ligands, and phosphorus-based ligands are described. Phosphine-based phosphine-based ligands such as trimethylphosphine, tributylphosphine, and triphenylphosphine are described. Although the compound is described, the catalyst used remains in the reaction product.

As a method for solving the above-mentioned many problems, it is conceivable to use a solid acid catalyst. As one method, Japanese Patent Application Laid-Open No. 63-284146 discloses an addition reaction of ethylene with 2-hydroxyethyl methacrylate in the presence of activated clay which is a solid acid. There is no description. In addition, an attempt was made to react ε-caprolactone with 2-hydroxyethyl methacrylate using activated zeolite (Mizuka Sieve Y420, manufactured by Mizusawa Chemical Co., Ltd.), but did not reach a sufficient conversion (Comparative Example 2 and Comparative Example 2). Example 3). JP-A-1-1-1
51537 has β-methyl-δ-valerolactone and 2-
Although the reaction with hydroxyethyl methacrylate is carried out in the presence of a cation exchange resin, there is no description about the reaction with ε-caprolactone. Such a cation exchange resin (Amberlyst 15, manufactured by Rohm & Haas)
Was applied to the reaction between the lactone and the hydroxyalkyl methacrylate in the present case, large coloring of the product was confirmed, and the product could not be practically used (Comparative Example 1). For a review on sulfated zirconia, for example, CT
AL. REV. SCI. ENG. , 38 (3), 32
9-412 (1996), and as application examples of zirconia sulfate as a catalyst, application examples such as isomerization, hydrocracking, alkylation, and Fischer-Tropsch synthesis are described. No description of the reaction is found.

[0007]

SUMMARY OF THE INVENTION The present inventors have found that when producing a lactone-modified hydroxy (meth) alkyl acrylate, in the method disclosed above, when the amount of catalyst added and the reaction temperature are increased, The amount of the reaction product, diester, increases, and these diesters have a high boiling point, so that separation from the target reaction product is extremely difficult;
In addition, it was discovered that when the target product containing these diesters was copolymerized with other acrylic acid ester monomers, three-dimensional cross-linking occurred in the resin, the viscosity was significantly increased, and gelation was caused when the cross-linking proceeded further. . In addition, when an organic metal compound, an inorganic metal compound, a Lewis acid, a proton acid, or the like is used as a catalyst, many catalysts remain in the reaction product, and the reaction product or a product using the reaction product is significantly colored,
It was also found that the storage stability was reduced and that handling was greatly restricted. It is an object of the present invention to overcome the disadvantages of the prior art, i.e., the yield of diester, a by-product, is low, substantially less than 0.8% by weight, more preferably less than 0.5% by weight, Another object of the present invention is to produce a lactone-modified hydroxyalkyl (meth) acrylate ester having no remaining catalyst under mild reaction conditions and with a sufficient reaction rate.

[0008]

Means for Solving the Problems As a result of diligent studies, the present inventors have found that the amount of diester produced in the side reaction is extremely small, and there is no residual catalyst and the lactone-modified hydroxy (meth)
Alkyl methacrylate under mild temperature conditions,
Moreover, it has become possible to produce at a sufficient reaction rate. That is, the present invention is a method for producing a lactone-modified hydroxy (meth) alkyl acrylate by subjecting a lactone and a hydroxy (meth) alkyl acrylate to an addition reaction in the presence of zirconia sulfate.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION The lactone-modified hydroxy (meth) alkyl acrylate produced by the method of the present invention is obtained by adding one or more lactones to hydroxyl groups of hydroxy (meth) alkyl methacrylate. It is. The hydroxyalkyl acrylate used in the reaction of the present invention includes 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, 3-hydroxypropyl acrylate and 4-hydroxybutyl acrylate. The hydroxyalkyl methacrylate used in the reaction of the present invention includes 2-hydroxyethyl methacrylate, 2-hydroxypropyl methacrylate, 3-hydroxypropyl methacrylate, and 4-hydroxybutyl methacrylate. The lactone used in the reaction of the present invention includes 8-valerolactone, ε-caprolactone, enantholactone (7-
(Hydroxyheptanoic acid lactone). When the product is used in a coating material, ε-caprolactone is preferred among the lactones because it provides favorable coating properties.
Ratio of lactone and hydroxyalkyl (meth) acrylate used [lactone: hydroxy (meth)
The alkyl acrylate varies depending on the properties and molecular weight of the desired lactone-modified hydroxyalkyl acrylate or methacrylate, but usually in a molar ratio of 1: 2 to 20: 1, preferably 1: 1 to 10: 1. Range.

[0010] The reason that zirconia sulfate is preferred as a catalyst is that it is relatively easy to obtain and has a strong catalytic activity, so that the reaction can be completed sufficiently at a low reaction temperature, and as a result, the amount of diester produced by a side reaction can be kept low. Can,
This is because the amount of diester produced can be substantially reduced to a negligible level by selecting the reaction conditions, and in addition, the coloring of the reaction solution can be almost completely suppressed.
When the catalyst is used as a fluidized bed and, for example, a reaction vessel equipped with a stirrer is used, zirconia sulfate is directly added to the reaction vessel and the reaction is allowed to proceed while gently stirring. In this case, a product can be obtained by passing the reaction product liquid through a simple filter. When these solid acids are used as a fixed bed, the reaction solution may be passed through a catalyst layer at a predetermined temperature for a predetermined time to complete the reaction. The reaction mode is not limited to these methods, and the mode may be appropriately selected.

The concentration of the catalyst in the reaction solution at the time of the reaction is 0.1.
1 wt% to 60 wt%, more preferably 0.5 wt% to
It is 30% by weight, and can be appropriately selected depending on the degree of stirring and the catalyst removal method. When the reaction is completed, zirconia sulfate as a catalyst can be easily separated from the reaction product liquid by a simple operation such as filtration, and the zirconia sulfate thus separated and recovered can be reused. When zirconia sulfate is used as a catalyst, the target reaction product does not contain any acidic components derived from the catalyst. In addition, acidic components (due to grinding or the like) coming from zirconia sulfate can be completely removed by simple filtration, and the acid value of the reaction product is reduced to 15%.
mgKOH / g, preferably 10 mgKOH / g or less. The reaction temperature is from 70C to 130C, preferably from 80C to 120C. If the reaction temperature is lower than 70 ° C., a sufficient reaction rate cannot be obtained. If the reaction temperature is higher than 130 ° C., it becomes difficult to suppress polymerization of the hydroxyalkyl (meth) acrylate and the target substance, and the amount of diester formed increases. .

In order to prevent polymerization due to the radical polymerizable double bond of the hydroxyalkyl (meth) acrylate as a raw material, it is preferable to add a polymerization inhibitor appropriately selected. , 6-di-t-butyl-4-methylphenol or the like in an amount of 50 to 50,000 mg / Kg, preferably 100 to 50,000 mg / Kg.
It is added to the reaction solution so as to be 20000 mg / Kg. Further, an antioxidant is added to the reaction solution for the purpose of preventing coloring during the reaction, and the antioxidant includes a thioether type and a phosphite type. Adegas Tab AO-412S, Adegas Tab AO-503A and Adegas Tab AO-23 (manufactured by Asahi Denka Kogyo) as thioether-based antioxidants, and Adegas Tab 260, Adegas Tab 329K, Adegas Tab 1178 and Adegas Tab C (Asahi Dentabaku) as phosphite-based antioxidants. (Made by Denka Kogyo). The concentration of the antioxidant in the reaction solution is in the range of 10 to 2000 mg / Kg, preferably 20 to 1000 mg / Kg.

The addition reaction is preferably carried out while blowing air into the reaction solution. In this case, air prevents polymerization of the monomer. Air is 0.1 to 1 kg of reaction solution.
A blowing rate of 30 ml / min is preferred. Examples of the solvent for the reaction include toluene, xylene, and ethylbenzene having no active hydrogen, and ethylbenzene is preferred. Now that the invention has been described in general terms, certain embodiments thereof will be described in more detail with reference to examples, but the invention is not limited thereto.

[0014]

EXAMPLES Example 1 2-L was placed in a 1 L reaction vessel equipped with a stirrer and an air blowing tube.
267 g of hydroxyethyl methacrylate, 234 g of ε-caprolactone, 2.5 g of 4-methoxyphenol as a polymerization inhibitor were charged, and 5 g of zirconia sulfate (manufactured by Japan Energy) (1% by weight based on the charged amount) was added as a catalyst. This mixture was gently stirred, and air was blown at a rate of 0.5 ml / min.
For 16 hours. At this point, gas chromatography analysis revealed that the concentration of ε-caprolactone was 0.5% by weight or less, and the reaction was completed. The mixture was cooled to room temperature and filtered with filter paper to obtain a product. The obtained product was a transparent liquid (color number APHA) 15 and had an acid value of 5.3 mgKOH / g and a diester content of 0.18% by weight (a diester content of 0.12% by weight at the beginning of the reaction). It can be seen that diester formation is almost negligible.

Example 2 The amount of zirconia sulfate added was 100 g (2 parts based on the charged amount).
0% by weight) and the amount of 4-methoxyphenol added is 0.1%.
The reaction was carried out in the same manner as in Example 1 except that the amount was changed to 25 g.
After 4 hours at 95 ° C., gas chromatography analysis revealed that the concentration of ε-caprolactone was 0.22% by weight, indicating completion of the reaction. The mixture was cooled to room temperature and filtered with filter paper to obtain a product. The obtained product was a transparent liquid, having a color number (APHA) of 25, an acid value of 6.1 mg KOH / g, and a diester content of 0.20% by weight without producing a polymer or the like.
(0.13% by weight of diester at the beginning of the reaction).

Example 3 A reaction was carried out in the same manner as in Example 1 except that the reaction temperature was changed to 115 ° C. Eight hours later, gas chromatography analysis revealed that the concentration of ε-caprolactone was 0.38% by weight, and the reaction was terminated. After cooling to room temperature, the product is filtered through filter paper to obtain a product. The obtained product is a transparent liquid (color number AP).
HA) 40, the acid value is 5.7 mg KOH / g, the diester content is 0.21% by weight (the diester content at the beginning of the reaction is 0.1
3% by weight).

Example 4 An inner tube (7.9 ml) of a double-tube type column having an inner diameter of 10 mm and a height of 100 mm was filled with 6.7 g of zirconia sulfate, heated to 95 ° C. with a heating medium, and heated from the bottom of the column. 267 g of 2-hydroxyethyl methacrylate and ε-caprolactone 23
4 g, 4-methoxyphenol 0.2 as a polymerization inhibitor
5 g of the mixed solution were fed at a rate of 7.4 g / h (residence time 25 minutes). When the solution passed through the reaction column after the stabilization was analyzed by gas chromatography, the concentration of ε-caprolactone became 0.40% by weight, and it was confirmed that the reaction was completed. The product obtained is a clear liquid with a color number (A
PHA) was 30, the acid value was 6.1 mg KOH / g, and the amount of diester was 0.22% by weight (the amount of diester at the beginning of the reaction was 0.14% by weight).

Example 5 2-hydroxyethyl methacrylate 267 g, ε
-468 g of caprolactone, 100 g of zirconia sulfate
The reaction was carried out in the same manner as in Example 1 except that a reaction solution consisting of (14% by weight based on the charged amount) and 1.0 g of 4-methoxyphenol was used. After 4 hours, gas chromatography analysis showed that the concentration of ε-caprolactone was 0.5
It became 2% by weight, and the reaction was completed. After cooling to room temperature, the product was filtered through filter paper to obtain a product. The obtained product was a transparent liquid (color number APHA) 25, and the acid value was 5.5 mgKOH /.
g and the amount of diester were 0.15% by weight (the amount of diester at the beginning of the reaction was 0.13% by weight).

Example 6 The procedure of Example 5 was repeated except that ε-caprolactone was changed to 702 g. After 5 hours, the concentration of the residual ε-caprolactone was 0.48% by weight, and the completion of the reaction was confirmed.
The product obtained is a transparent liquid having a slight viscosity, a color number (APHA) of 20, and an acid value of 5.0 mg KO.
H / g and the amount of diester were 0.13% by weight (the amount of diester at the initial reaction value was 0.10% by weight).

Example 7 116 g of 2-hydroxyethyl acrylate, ε-
The reaction was carried out in the same manner as in Example 1 except that a reaction solution comprising 267 g of caprolactone, 5 g of zirconia sulfate (1.3% by weight based on the charged amount) and 0.38 g of 4-methoxyphenol was used. After 15 hours, gas chromatography analysis revealed that the concentration of ε-caprolactone was 0.5
The reaction was completed when it reached 5% by weight. After cooling to room temperature, the product was filtered through filter paper to give a product. The obtained product was a transparent liquid (color number APHA) 20, and the acid value was 5.0 mgKOH /
g, the amount of diester was 0.21% by weight (the amount of diester at the beginning of the reaction was 0.15% by weight).

Comparative Example 1 30 g of cation exchange resin (Amberlyst 15, manufactured by Rohm & Haas) as a catalyst (6% by weight based on the charged amount)
The reaction was carried out in the same manner as in Example 1 except that the reaction temperature was changed to 50 ° C. Two hours after the start of the reaction, the reaction was completed. At that time, the acid value of the product was 6.6 mg KOH / g, the amount of the diester was 0.57% by weight, but the color number (APHA) was 20.
0 was not acceptable.

Comparative Example 2 A reaction was carried out in the same manner as in Example 1 except that 30 g (6% by weight based on the charged amount) of galeonite # 212 (natural zeolite, manufactured by Mizusawa Chemical Co., Ltd.) was used as a catalyst and the reaction temperature was 90 ° C. Was. Eight hours after the start of the reaction, the reaction was completed, and the color number (APHA) of the obtained product was as high as 250, which was unacceptable.

Comparative Example 3 A reaction was carried out in the same manner as in Example 1 except that 60 g (12% by weight based on the charged amount) of Mizuka Sieve Y420 (synthetic zeolite, manufactured by Mizusawa Chemical Co., Ltd.) was used as a catalyst and the reaction temperature was 100 ° C. Was. Even after 6 hours from the start of the reaction, the conversion was as low as 51%, and the color number (APHA) of the product was as high as 160, which was unacceptable.

Comparative Example 4 As a catalyst, 30 g (5% by weight based on the charged amount) of ZCP-50 (silica-alumina type, manufactured by Kasei Kagaku Kogyo KK) was used.
It carried out like Example 1 except having made the reaction temperature 100 degreeC. 16 hours after the start of the reaction, the reaction rate was 75%, the color number (APHA) of the reaction solution was 80, and the reaction was stopped.

COMPARATIVE EXAMPLE 5 Silica titania # 313 (JP-A-7-275) was used as a catalyst.
701 was performed in the same manner as in Example 1 except that 25 g (5% by weight based on the charged amount) of the compound of silicon and titanium described in 701 was used and the reaction temperature was 100 ° C. After 16 hours, the reaction was completed. The color number (APHA) of the product at the end of the reaction is 180
The diester content was as high as 1.6%.

Comparative Example 6 In the same apparatus as in Example 1, the catalyst zirconia sulfate was changed and 1.2 g of tetraisopropyl titanate (2,000 mg / Kg based on the charged amount) was added. After an hour, the reaction was terminated. The color number (APHA) at the end of the reaction was 400 or more, and the color was strongly colored, and the diester content was as high as 3.96% by weight.

[0027]

(1) According to the method of the present invention, a lactone-modified (meth) alkyl acrylate having no catalyst-derived acidic component, organic metal or inorganic metal component can be obtained, and is suitably used for applications such as paints. . (2) By the method of the present invention, a lactone-modified alkyl (meth) acrylate having a very small amount of ethylene glycol diacrylate or ethylene glycol dimethacrylate, which is a side reaction product, can be obtained, which is suitable for applications such as paints. used. (3) Lactone modification in which the by-product ethylene glycol diacrylate or ethylene glycol dimethacrylate is 0.8% by weight or less and the color number APHA of the reaction product is 50 or less by the method of the present invention ( A (meth) alkyl acrylate is obtained, and is suitably used for applications such as paints.

Claims (5)

[Claims] 1. A lactone and a hydroxyalkyl acrylate or hydroxymethacrylate,
A method for producing a lactone-modified hydroxyalkyl acrylate or a lactone-modified hydroxyalkyl methacrylate, wherein the addition reaction is carried out in the presence of zirconia sulfate. 2. The method according to claim 1, wherein the addition reaction is carried out at 70 ° C. to 130 ° C. 3. The zirconia sulfate is added in an amount of 0.1 to the reaction solution.
The method according to claim 1, wherein the amount is from 60% by weight to 60% by weight. 4. The lactone is ε-caprolactone,
The method according to claim 1, wherein the hydroxyalkyl acrylate and the hydroxyalkyl methacrylate are 2-hydroxyethyl acrylate and 2-hydroxyethyl methacrylate, respectively. 5. The lactone-modified hydroxyacrylate or lactone-modified hydroxymethacrylate obtained has a diester content of 0.8% by weight or less, an acid value of 15 mg KOH / g or less and a color number APHA of 50 or less. Manufacturing method.