JPS5842877B2 - Synquina 2 2'- Dialkyl -1 3- Dioxolane methacrylate - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention has a novel 1,3-dioxolane group represented by the following formula: (wherein R1 is a methyl group and R2 is an alkyl group having 2 to 5 carbon atoms) Methacrylic acid ester, more specifically (2,2'-dialkyl-1,3 dioxolane-
The present invention relates to a method for producing 4-yl) methacrylates.

The compound represented by the above formula can be obtained by reacting glycidyl methacrylate with excess ketone under an acid catalyst.

The method for synthesizing 1,3-dioxolane group-containing methacrylic ester according to the present invention is the transesterification of 4-hydroxymethyl-1,3 dioxolane and (1) transesterification with methacrylic ester (2) methacrylic acid or methacrylic anhydride. Direct esterification and (3) esterification with methacrylic acid chloride are known.

Among these methods, the methods using (1) and (2) require a long reaction time, and the method (3) has problems in that the yield decreases due to exothermic reaction, which is a practical problem.

The present invention relates to a new method that overcomes the drawbacks associated with these methods.

The glycidyl methacrylate CH3 used in the present invention has a polymerizable vinyl group CH2=C-1 and an epoxy group CH2-CH-1.

Therefore, by polymerizing any one of these groups, a reactive polymer or copolymer is widely used in paints, adhesives, photosensitive materials, fiber processing agents, etc. Its unique performance has high expectations in other fields as well, and there is a tendency for it to be used more and more in industrial applications in the future.

Therefore, with the aim of making even more advanced use of glycidyl methacrylate having such properties, the present inventor focused on the reactivity of the epoxy group and attempted to synthesize a new methacrylic acid ester that has various uses. , an epoxy group and a ketone react under a phosphoric acid or sulfuric acid catalyst to form a dioxolane ring, and the compound shown in the above formula can be easily obtained in good yield by a very simple operation. I found it.

Conventionally, it has been thought that when an epoxy group is reacted with a ketone, a phosphoric acid ester is formed or a crosslinking reaction occurs, making it inappropriate to obtain a 1,3-dioxolane ring in high yield.

However, the present inventors have found that when the ketone is reacted in a larger amount than normally thought, the above-mentioned phosphoric acid ester or crosslinking reaction is suppressed, and a dioxolane ring can be obtained in high yield.

That is, the present invention uses a large excess of ketone in the range of 10 to 20 times the mole relative to glycidyl methacrylate, whereas using less than 10 times the amount of ketone by mole may result in a loss of the target compound. It cannot be obtained in high yield.

Furthermore, the use of ketones in an amount of 20 times or more by mole is also undesirable from the economic point of view.

On the other hand, the ketone used in the present invention is methyl ethyl ketone, methyl-n-propyl ketone, methyl isobutyl ketone, methyl-n-butyl ketone, or methyl-n-butyl ketone.
-amylketone, and only by using such a ketone can the desired methacrylic acid ester compound of the above general formula be advantageously produced.

In addition, when using a ketone with high water solubility such as acetone, or when using a different type of ketone such as acetophenone that is sparingly soluble in water, it is not possible to separate the target compound. Therefore, such compounds cannot be obtained.

Further, as the acid catalyst, it is preferable to use 85% phosphoric acid or concentrated sulfuric acid in equimolar amounts to glycidyl methacrylate.

Further, in order to inhibit polymerization of vinyl groups through the reaction, a commonly used polymerization inhibitor is added in an amount of 0.05 to 0.1 wt % based on glycidyl methacrylate.

For example, examples of polymerization inhibitors include hydroquinone, methylhydroquinone, and cupric chloride, but in the distillation step to obtain the target compound, polymerization inhibitors such as cupric chloride are used to prevent contamination of these polymerization inhibitors into the distillate. Addition of dicopper is desirable.

Next, in the method of the present invention, 0.05w of hydroquinone or cupric chloride as a polymerization inhibitor is added to glycidyl methacrylate.
A mixture of equimolar t% and 85% phosphoric acid or concentrated sulfuric acid and 10 to 20 times the molar addition of ketone was stirred at 60°C for 1 hour in a reaction flask equipped with a condenser to carry out the reaction. This method takes advantage of the fact that a ketalization reaction occurs between a group and a ketone.

After these reaction solutions were cooled to room temperature, unreacted phosphoric acid and phosphoric ester (sulfuric acid and sulfuric ester when sulfuric acid was used) were removed from the reaction mixture by washing with water.
Further, by washing with water and neutralizing with an aqueous sodium hydroxide solution, an organic layer containing the target product is obtained.

Since this organic layer uses an aliphatic ketone that has low solubility in water and low specific gravity, it is clearly separated from water.

This makes it possible to obtain the target product in high yield and to reduce loss in ketone recovery.

At this time, special care must be taken because if neutralization is not completed and the mixture is acidic, the dioxolane ring will open during distillation to form a polymer.

In order to suppress dissolution of the ketone in water as much as possible, it is preferable to use water heated to about 3 to 5° C. with ice in an amount not more than about 3 times the amount of the reaction solution.

The organic layer thus obtained is dried over anhydrous calcium sulfate, and then a small amount of cupric chloride is added to distill off the ketone under reduced pressure.

Most of the ketones are recovered from this operation and can be recycled.

Finally, a brown viscous solution remains, which is vacuum distilled to obtain the desired product (2,2'-dialkyl-1,
3-dioxolan 4-yl) methacrylate in a yield of approx.
5-60%.

The compounds according to the present invention can be produced by polymerizing vinyl groups with a polymerization initiator normally used in radical polymerization, such as benzoyl peroxide, a, a'-azobisisobutyronitrile, etc., and producing a polymer or copolymer in which dioxolane rings remain. Polymers can be obtained.

In addition, these polymers and copolymers can be cross-linked and cured by acidic catalysts or ultraviolet irradiation to become solvent-insoluble and tough resins, so they are used in a wide range of applications as components of ultraviolet-curable paints, photosensitive materials, and glass adhesives. It provides a purpose.

The present invention will be described in more detail with reference to Examples below. In these Examples, unless otherwise specified, [%] is a unit of weight, (b
p) is the boiling point, (n'') is the refractive index, [d25] is the specific gravity, (
IR) indicates an infrared absorption spectrum, and (GC) indicates a gas chromatograph.

Example 1 (2-methyl-2-ethyl-1,3-dioxolane-
Synthesis of 4-yl) methacrylate A mixture of glycidyl methacrylate 60y (0.42 mol), hydroquinone 0.03P (0.05%), and methyl ethyl ketone 5205' (7 mol, 16.6 times the mol) was placed in a reaction flask, and while stirring. After slowly adding 85% phosphoric acid 48P (0.42 mol) and stirring for 1 hour at a reaction temperature of 60° C., the reaction solution was cooled to room temperature.

Pour this solution into a 1 liter separating funnel, add 500 rr of distilled water cooled to about 5° C., shake well, and leave to stand, the liquid will separate into two layers.

After removing the lower layer and washing the upper layer with 500 rnl of water, the upper organic layer was washed with 500 ml of 1% sodium hydroxide aqueous solution in two portions, and the pH of the upper organic layer was 6.8~.
It becomes 7.0.

If this is poured into a beaker containing anhydrous calcium sulfate and left for a while, most of the remaining trace amount of water will be removed.

Next, add cupric chloride to this solution and add O11? In addition, the ketone is distilled out by putting it into a distillation flask and distilling it under reduced pressure.

The remaining viscous solution was transferred to a 100 CC distillation flask and immediately vacuum distilled using a Wigreux rectification column to obtain a fraction with a bp of 88-90°C/2.3 cm.

The yield is 52% based on theory.

Also n%5. ; (Note 1) 1.4470. d25: 1.0352.

IR has an alkyl group at 2950.2920.2870cIrL-1, an ester at 1720cIrL', and 1635
A typical absorption peak based on a vinyl group at cIrL-1 and an oxolane ring at 1160CrfL-1 was shown.

(Note 1) GC showed a peak at a retention time of 10.3 minutes, and no impurities were detected.

Elemental analysis results C1, HI304 (molecular weight -214,25) Calculated value 0%: 61.68 H%: 8.41 Actual value 0%:
61.02 H%: 8.52 On the other hand, for comparison, the above experiment was repeated using 139f (1.26 moles; 3 times the moles) of methyl isobutyl ketone, and the yield was 6 times the theoretical amount. %, and the yield decreased significantly.

Example 2 Synthesis of (2-methyl-27-propyl-1,3-dioxolan-4-yl) methacrylate Glycidyl methacrylate 58S' (0.4 mol), hydroquinone 0.03
ft, methyl-n-provirkene 400? (4,
6 mol, 11.6 times mol), 85% phosphoric acid 46f (0,
4 mol) was placed in a reaction flask and subjected to the same procedure as in Example 1 to obtain a fraction with a bp of 98 to 100°C and 10.8 h Hg.

The yield is 48% based on theory.

Further, width 5: 1.4477, d25: 1.0201.

IR has an alkyl group at 2960.2940.2880CrfL-1, an ester at 1720cIrL-1, and 1635
Based on the vinyl group at -l and the oxolane ring at 1160 cm' (a typical absorption peak was shown).

GC showed a failure at a retention time of 15.4 minutes, and no impurities were detected.

Elemental analysis result Cl2H2004 (molecular weight = 228.28) Calculated value 0
%: 63.15, H%: 8.77 Actual value 0%: 62.
51, H%: 8.87 Example 3 Synthesis of (2-methyl-27-isobutyroto-3-dioxolan-4-yl) methacrylate Glycidyl methacrylate 60S' (0.42 mol) Hydroquinone 0.03
F, methyl isobutyl ketone 530S' (5.3 mol,
12.6 times mole), 85% phosphoric acid 41 (0.42 mole)
was placed in a reaction flask and subjected to the same procedure as in Example 1 to obtain b.
p103-105°C/1. A fraction of OmtHg is obtained.

The yield was 42% based on the theoretical amount.

Also n S”: L 4473, d”: 0.99
It was 69.

IR is 2980.29601293012880tan-1
Alkyl group at 1720cm', ester at 1635
cIrL' has pi = /L/ group, 1160cIrL-
1 shows a typical absorption peak based on the oxolane ring.

GC showed a peak at a retention time of 19.2 minutes and no impurities were detected.

Elemental analysis result C13H2204 (molecular weight -242,30) Calculated value C
%: 64.46, H%: 9.09 Actual value C%: 64
．． 45, H%: 9.18 Comparative Example 1 To synthesize (2,2-dimethyl-1,3-dioxolan-4-yl)methyl methacrylate, glycidyl methacrylate 60 F (0.42 mol), hydroquinone 0.03r , acetone 500P (8,62 rmol; 20
．． 5 times molar), 85% phosphoric acid 48? (0.42 mol),
was placed in a reaction flask and the same operation as in Example (2) was carried out, but since acetone was dissolved in water, it was not possible to separate the reaction solution into an aqueous layer and an organic layer.

For this reason, it has become clear that, although the target compound can be extracted from the reaction solution, when the method of the present invention is applied to acetone, the target compound cannot be obtained.

Comparative example 2 (2-methyl-2-phenyl-1,3-dioxolane-
In order to synthesize glycidyl methacrylate 60P (0.42 mol), hydroquinone 0.03P, acetophenone 600r 5.0 mol; 12 times mol), and 85% phosphoric acid 48F (0.42 mol) to synthesize 4-yl) methyl methacrylate. The mixture was placed in a reaction flask and the same operation as in Example 1 was performed, but since the acetophenone formed an emulsion in water, the reaction solution could not be separated into an aqueous layer and an organic layer.

Therefore, it has become clear that the target compound cannot be obtained when the method of the present invention is applied to acetophenone.

Note I IR measurement was carried out by applying it to a salt plate.

Note 2 GC measurements were conducted under the following conditions.

Column: 5E-3011,857FL, 160°C carrier gas 2N2.35rrLl/min.

Detector: Thermal conductivity detector.

Claims (1)

[Scope of Claims] In producing a compound represented by the following formula: (wherein R1 is a methyl group and R2 is an alkyl group having 2 to 5 carbon atoms), methyl ethyl ketone, methyl n-propyl An aliphatic ketone selected from the group consisting of ketone, methyl isobutyl ketone, methyl-n-butyl ketone, and methyl-n-amyl ketone, which has low solubility in water and has a specific gravity lower than that of water, and glycidyl methacrylate, the former being 1. A method for producing a methacrylic acid ester having a 1,3-dioxolane group, characterized in that the reaction is carried out in the presence of a phosphoric acid or sulfuric acid catalyst at a molar ratio of 10 to 20 times that of the latter.