JPH0410463B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for producing zinc salt of acrylic acid,
More specifically, when producing zinc acrylate by reacting acrylic acid with a zinc compound, after the reaction is carried out in a solvent in the absence of water, metal salts of higher fatty acids such as zinc stearate are added to the reaction solution. The present invention relates to a method for producing zinc acrylate, which comprises adding and stirring and then drying.

Conventionally, it is well known to obtain zinc acrylate by reacting acrylic acid and a zinc compound in a solvent, and then removing the solvent under reduced pressure after the reaction is completed, or drying under reduced pressure after the reaction. According to this method, the reaction product adheres to the inner wall of the reactor or the stirring blade, or forms large lumps, which causes problems in the process, resulting in a significantly poor yield.

Furthermore, when the solvent is removed under reduced pressure, the solvent contained in the produced zinc acrylate is scattered, but at the same time, the zinc acrylate is also violently scattered, resulting in poor yield and difficulty in recovering the solvent. Becomes,
The disadvantage was that there was also a large economic loss.

As a method for overcoming the above drawbacks, the present inventors have
After various studies, it was found that after the reaction between acrylic acid and zinc compound in a solvent is completed, 5-20 parts by weight of acrylic acid added to the reaction solution in the solvent.
After adding and stirring a heated solution of zinc salt of higher fatty acid such as zinc stearate, or 40 parts by weight,
It has been found that by adding stearic acid to the reaction solution heated to 90°C to 90°C, stirring it, and then drying it, the above-mentioned drawbacks can be overcome and the desired powdery solid can be obtained.
The invention has been completed. Thus, the present invention provides an industrially extremely advantageous method for producing zinc acrylate powder that overcomes the drawbacks of conventional production methods, and produces zinc acrylate powder with extremely easy operation and control and at a high yield. The present invention provides a method.

The zinc acrylate of the present invention can be used, for example, as a co-crosslinking agent in the inner core formulation of golf balls, particularly solid balls and two-piece balls (usually composed of zinc white and peroxide as specific gravity adjusting agents, and further a co-crosslinking agent and polyptadiene). When used as a vulcanized ball, the physical properties of the vulcanized ball were extremely good.

Furthermore, the physical properties of the vulcanized product (e.g.,
It was also observed that the inner core hardness and durability) were further improved. Furthermore, the feel and sound of the two-piece golf ball produced using this golf ball when hit were sufficiently satisfactory as a golf ball.

Hydrocarbon compounds are suitable as the solvent used in the present invention, and specific examples include methanol, benzene, toluene, xylene, n-heptane, and n-heptane.
-hexane, etc.

The acrylic acid used in the present invention is ordinary acrylic acid that is not diluted with water, but it may contain some amount of water. Furthermore, the mixture of polymerization inhibitors such as hydroquinone and hydroquinone monomethyl ether contained in acrylic acid does not cause any problem.

The zinc compound used in the present invention is an ordinary powdery solid. Specific examples of zinc compounds include zinc oxide, zinc hydroxide, zinc carbonate, and zinc bicarbonate.

The reaction temperature between acrylic acid and the zinc compound is not particularly limited, but is preferably 90°C or lower. If the reaction temperature is too high, a partial polymerization reaction will occur and the purity of the product will deteriorate.

The addition of a zinc salt of higher fatty acid such as zinc stearate is further carried out using a solution heated and dissolved in a solvent. Stearic acid can also be added to the reaction solution.

The present invention will be explained below with reference to Examples.

Example 1 600 g of zinc oxide and 2000 ml of toluene were placed in a jacket-type vertical mixer (No. 5) and suspended while stirring. Next, 1060 g of acrylic acid was added dropwise over 30 minutes and mixed, followed by a reaction at room temperature for 60 minutes. Ta. After the reaction is complete, add 130 g of zinc stearate to 100 ml of toluene and dissolve by heating at 45-50°C, stir for 30 minutes, make a slurry,
The product was coated with zinc stearate.
Next, the mixture was heated at 50° C. for 3 hours under a reduced pressure of 120 to 60 mmHg to distill out produced water and toluene, and drying was performed.
1620 g of zinc acrylate coated with zinc stearate was obtained. The loss on heating was 0.3%. During vacuum drying, almost no scattering of the generated zinc acrylate was observed, and no adhesion to the inner wall of the reactor was observed. Further, even after drying, the particles remained fine and no lumps were observed.

The same can be said for all Examples 2 to 4 below.

Example 2 2,260 g of zinc oxide and 2,000 ml of methanol were charged into a 10-capacity jacket-type kneader and mixed to form a slurry, and then 4,000 g of acrylic acid was added to 30
It dripped in minutes. After reacting for 1 hour after dropping, 820 g of zinc stearate was added and kneaded at a temperature of 40 to 50°C to perform coating. Next, steam was passed through the jacket to distill methanol out at a temperature of 70°C, followed by removal using a kneader and drying in a low temperature dryer at 40°C. Zinc acrylate 6290
I got g. The loss on heating was 0.25%.

Example 3 900 g of zinc oxide and 3000 ml of benzene were placed in a jacket-type vertical mixer (No. 5), stirred and mixed to make a suspension. Next, 1590 g of acrylic acid was added dropwise over 30 minutes while stirring and mixed, and the mixture was heated to 60 ml at room temperature. A minute reaction was carried out. After the reaction, 80 g of zinc stearate was added to 500 ml of benzene and dissolved by heating at 45 to 50°C. The mixture was stirred and mixed for 30 minutes, and the resulting slurry was poured with hot water at 50°C under a reduced pressure of 275 to 100 mmHg. The mixture was passed through a jacket and heated for 2 hours to distill out produced water and benzene, followed by further drying to obtain 492 g of zinc acrylate coated with stearic acid. The volatile matter content of the obtained product was 0.25%.

Comparative Example 1 The same procedure as in Example 1 was carried out, except that after the reaction was completed, zinc stearate was added to toluene and a heated solution was added to coat the product.

When drying under reduced pressure was carried out after completion of the reaction, zinc acrylate was significantly scattered and entered the distilled solvent, making its recovery difficult. In addition, it is quite complicated to recover the zinc acrylate that has scattered into the reactor, clean the reactor, and remove the reactant that has stuck to the inner wall of the reactor, and the resulting zinc acrylate is also lost due to sticking and scattering. Most were 1.120gr. It was observed that some of the particles formed into large lumps as they dried, and it was quite difficult to crush them.

Comparative Example 2 Zinc acrylate obtained in Comparative Example 1 was crushed in a pulverizer to
When 30 parts by weight of the powder crushed to a size of 17μ was kneaded with 100 parts by weight of polyptadiene rubber using a 6-inch roll, agglomerates of 0.5 mmφ were significantly formed in the rubber, and they also adhered to the roll surface. It was also significant.

Claims (1)

[Claims] 1. A method for producing zinc acrylate, which comprises reacting acrylic acid with a zinc compound, adding a zinc salt of a higher fatty acid such as zinc stearate to the reaction solution, stirring, and drying.