JPH045257A - Production of dicyclopentadiene acrylate - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial Field of Application) The present invention relates to a method for producing dicyclopentadiene acrylate.

The dicyclopentadiene acrylate obtained by this process can be used to produce new acrylate polymers with excellent physical and chemical properties such as transparency, heat resistance, thermal stability, solvent resistance, and dielectric properties. It is an extremely useful chemical substance used in

Specific uses thereof include modifying photocurable resins, thermosetting resins, acrylic paints, and acrylic adhesives (see, for example, Japanese Patent Laid-Open No. 159408/1983).

(Prior Art) A method for producing an ester from a carboxylic acid and an olefin by an acid addition reaction in the presence of an acid catalyst has been known for a long time. For example, a method using an ether complex of boron trifluoride as a catalyst (Chemical Abstracts 63-90
55 (1966)) and a method using a fluorine-containing ion exchange resin as a catalyst (Japanese Patent Application Laid-open No. 59736/1983).

However, the former has problems with equipment corrosion and requires complicated post-treatment, and the latter uses dicyclopentadiene (hereinafter referred to as
This method requires an excessive amount of acrylic acid compared to DCPD (sometimes abbreviated as DCPD), and has the drawback of being inefficient.

On the other hand, in the method disclosed in JP-A No. 56-40644, in which a heteropolyacid is used as a catalyst, the corrosion of the above-mentioned equipment and the inefficiency of the reaction are improved.

(Problem to be solved by the invention) By the way, in the method described in JP-A-56-40644,
A considerable amount of dicyclobentenol (hereinafter referred to as DCPI)-0H
) is produced as a by-product. Contamination with DCPD-OH is undesirable when dicyclopentadiene acrylate is used to modify resins as described above. For example, when DCPD-OH is mixed in, when aluminum is deposited on a resin plate, problems such as a decrease in the strength of the deposition and a decrease in the mechanical strength and heat resistance of the resin occur.

Therefore, it is necessary to perform distillation purification to remove DCPD-OH. However, DCPD-OH and synchropentadiene acrylate require precision distillation because their boiling points are close to each other, and the distillation time is long.
The recovery rate of dicyclopentadiene acrylate that does not contain is low.

There is also a purification method using solvent extraction (JP-A-2-171
．． No. 49), or the purification process itself is an unnecessary step.

Therefore, an object of the present invention is to provide a method for producing highly pure dicyclopentadiene acrylate from dicyclopentadiene and acrylic acid without producing DCPD-OH as a by-product, and therefore without purification. .

Separately, the selectivity for producing dicyclopentadiene acrylate from dicyclopentadiene and acrylic acid in the method described in JP-A No. 56-40644 is about 80%, and by-products other than DCPD-OH are There was also a lot of production.

Therefore, another object of the present invention is to suppress the production of by-products other than DCPD-OH, improve the selectivity of dicyclopentadiene acrylate production, and thereby increase the yield of dicyclopentadiene acrylate. The purpose is to provide a method.

(Means for Solving the Problems) The present invention has achieved the above object by using a heteropolyacid from which physically adsorbed water has been removed or an acid salt thereof as a catalyst for the reaction between dicyclopentadiene and acrylic acid.

The present invention will be explained in detail below.

In the present invention, the heteropolyacid is commonly known, and there are no particular limitations on the structure of the heteropolyacid. In other words, it does not necessarily have to be a heteropolyacid with a Keggin structure;
It may have a structure such as a son) type, a silverton type, or a t-(waugh) type.

There are no particular limitations on the polyatoms constituting the heteropolyacid, but a heteropolyacid in which at least some of the polyatoms are tungsten is preferred from the viewpoint of high acidity and high activity.

Specifically, H3PW12040, H+SiW+□
Oto, H3PW12-nMOnolo, H4PWl
i-nMOnOtl (an integer of 12>n>1), etc.

Further, the heteropolyacid may be a salt, and examples thereof include metal salts and onium salts. However, heteropolyacid salts are
It is an acid salt because it needs to have activity as an acid catalyst. Specifically, NaH2[PW12040], K
Alkali metal salts such as H2[PW12040]1, CaH
4 [PW12040] 2, MgH211PWl! 0
40], alkali metal salts such as Nl84 [PW1204
0] 2, CoI2 [PW1204012, MnO
Fiber metal salt of 2[PWl104[]H8, (RIR2
R3R4N)H2[PW1+04o](R1,R2,R
3, R4 represents H or an alkyl group. ), (RIR2R3R4P)H2[P
Examples include, but are not limited to, phosphonium salts represented by W1204o] (R, , R2, R3, and R4 represent an alkyl group).

Acid salts of heteropolyacids are reacted with metal or onium halogen salts, carbonates, acetates, sulfates in aqueous solution,
It can be obtained by precipitation or evaporation to dryness.

The heteropolyacid or its acid salt used as a catalyst in the present invention does not have physically adsorbed water. Heteropolyacids have deliquescent properties and generally have a large amount of physically adsorbed water.

When producing dicyclopentadiene acrylate from dicyclopentadiene and acrylic acid, by-products such as DCPD-0) 1 can be suppressed by using a heteropolyacid or an acid salt thereof from which this physically adsorbed water has been removed. Physically adsorbed water of heteropolyacid can be removed, for example, by heating to 80° C. or higher at normal pressure. This temperature is
Although it varies depending on the type of heteropolyacid and acid salt, it can be easily determined by thermal analysis. Heteropolyacids also have large amounts of water of crystallization.

For example, H3PWI204o has a maximum of 29 crystal waters per unit. Depending on the heating conditions, water of crystallization may also be released next to physically adsorbed water. Considering the conversion rate of dicyclopentadiene and acrylic acid and the selectivity of dicyclopentadiene acrylate, it is particularly preferable that the number of waters of crystallization is 1 to 20, preferably 3 to 10, per unit of heteropolyacid. . The relationship between the number of water of crystallization and the heat treatment conditions can be determined by thermal analysis. For example, in the case of H3PW, □O1°, about 150 to 300°C1 at normal pressure, preferably 200 to
By heating at 300° C., H3PW, □04o, having a desired number of crystal waters can be obtained.

In addition, the above heating dehydration treatment can also be performed under reduced pressure,
However, the heating temperature can be lower than that at normal pressure depending on the degree of pressure reduction.

Furthermore, the acid salt of the heteropolyacid can be formed by introducing the dehydrated heteropolyacid and a metal or onium halide, carbonate, acetate, or sulfate into the reaction system before the reaction. You can also do it.

The amount of the catalyst used is preferably 0.5 to Swt%, and 1 to 3 Swt% based on the total weight of dicyclopentadiene and acrylic acid.
It is particularly preferable to set it as wt%. If it is used in an amount exceeding this usage range, the cationic polymerization of dicyclopentadiene may be accelerated, which is not preferable.

The reaction temperature is 40°C to 90°C, preferably 60 to 80°C.
°C range is preferred. If the temperature is lower than 40'C, it will take a long time for the reaction to proceed sufficiently. Mata, 10
If the temperature is 0°C or higher, the cationic polymerization of the olefin and the polymerization of the produced acrylate are promoted, which is not preferable. It is appropriate that the reaction time is usually in the range of 2 to IO hours.

In the method of the present invention, no solvent is particularly required. Further, there are no particular limitations on the solvent that can be used, and aromatic hydrocarbons can be mentioned, for example.

The amount of acrylic acid to be used is not particularly limited, but it is appropriate that the molar ratio is 1.5 to 1.5, preferably 0.8 to 1.0 per 1 dicyclopentadiene.

Since the ester formed by dicyclopentadiene and acrylic acid is a thermally unstable substance, it is preferable to carry out the reaction by adding a polymerization inhibitor. Examples of the polymerization inhibitor include hydroquinone, methoxyphenol, catechols, phenothiazine, naphthols, and the like. The amount used is 10% based on the total weight of reaction substrates.
0 to 5000 ppm is preferred. Addition in excess of this range is undesirable as it may result in coloring of the reaction solution and significant deterioration of catalyst activity, while addition below this range will not be effective.

The reaction method can be carried out either batchwise or continuously, but batchwise is preferred. In the case of a batch method, it is preferable to drop dicyclopentadiene into a system containing a catalyst, acrylic acid, and a polymerization inhibitor.

The reaction can be carried out under normal pressure or under pressure in an autoclave.

After the reaction is completed, the reaction solution is poured into 5 to 10 times the volume of normal hexane, and the polymer is precipitated and filtered. The recovered liquid is washed with pure water, then washed with an alkaline aqueous solution such as a 10 wt% thiosulfuric acid aqueous solution and a 5 wt% aqueous sodium bicarbonate solution, and further washed with pure water. A high yield of pure crude product is recovered.

Furthermore, if necessary, a product of even higher purity can be recovered by distillation under reduced pressure.

Since the obtained ester is highly polymerizable, it is preferable to distill it in as short a time as possible, and it is preferable to use a method such as thin film distillation. At this time, a polymerization inhibitor may be added. Polymerization inhibitors include tert-butylcatechol, N-nitrosophenylamine, N-nitrosohydroxylamine salt, phenothiazine, di-β
-naphthol, N,N-di-β-naphthyl-P-phenylenediamine, etc., and these may be used alone or in combination of two or more.

By the method of the present invention described above, the acrylate represented by general formula (I) can be obtained in high yield. In addition, the acrylate of general formula (I) is specifically the following compound.

(Effect of the invention) According to the present invention, DCPD-OH is not produced as a by-product, and
Dicyclopentadiene acrylate can be synthesized with high selectivity by suppressing the production of by-products other than DCPD-OH, and as a result, highly pure dicyclopentadiene can be easily produced in high yield.

(Example) The effects of the present invention will be specifically explained with reference to Examples below, but the present invention is not limited thereto.

Example 1 The cooling device consisted of a stirrer, a thermometer and 24 g (0.33 mol) of acrylic acid in a 1007 nl four-bottle flask.
, hydroquinone 0.03 g, H3[PW
After heating 1204°067 g in air at 300°C for 2 hours, 44 g (0.33 moj2) of DCPD (dicyclopentadiene) was added dropwise at 70°C over 1 hour.

After the dropwise addition was completed, the reaction was continued for an additional 2 hours. After cooling, the reaction crude liquid was poured into n-hexane, and the polymer was precipitated and filtered. The filtrate was collected and washed once with a 5 wt% Na2CO3 aqueous solution and twice with pure water, and then n-hexane and low-boiling fractions were removed under reduced pressure to collect a crude product.

After the completion of the reaction, the reaction crude liquid and crude product were analyzed by gas chromatography to determine the yield, conversion rate, and selectivity. The results are shown in Table 1.

Example 2 The heteropolyacid used was H4S! The reaction was carried out in the same manner as in Example 1 except that WB04o was used. The results are shown in Table 1.

Example 3 A reaction was carried out in the same manner as in Example 1 except that the heteropolyacid used was H, PWl1MOO40. The results are shown in Table 1.

Examples 4 to 6 The catalyst used was a copper salt of a heteropolyacid, and the reaction was carried out using different copper salts during its preparation. The results are shown in Table 1.

A salt was prepared by converting Cu in an amount corresponding to one of the three H present per Keggin unit of the heteropolyacid.

Regarding the reaction method, the same method as in Example 1 was performed.

Examples 7 to 8 The reaction was carried out in the same manner as in Example 1, except that the heat treatment temperature of the heteropolyacid was 2508C (Example 7) and 120C (Example 8). The reaction conditions and results are shown in Table 1.

Comparative Examples 1 and 2 A reaction was carried out using a heteropolyacid that had not been heat treated as a catalyst. The results and reaction conditions are shown in Table 1.

Claims (1)

[Claims] Dicyclopentadiene and acrylic acid are reacted in the presence of a heteropolyacid having no physically adsorbed water or its acid salt to form the general formula (I) ▲There are mathematical formulas, chemical formulas, tables, etc.▼ A method for producing dicyclopentadiene acrylate represented by (I).