JP2699188B2 - Cationic polymerizable composition, polymerization catalyst and polymerization method - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a cationically polymerizable composition, a polymerization catalyst, and a polymerization method. More specifically, a cationically polymerizable substance is polymerized in a short time by radiation such as light or an electron beam and / or heat to obtain a cured product having good physical properties and an oligomer of a practically cationically polymerizable vinyl compound. For polymerization, a catalyst for the polymerization and a polymerization method.

[Prior art and problems to be solved] In general, cationically polymerizable substances, especially epoxy resins, are used in various applications requiring high-performance materials. In particular, by irradiation of radiation of a predetermined wavelength such as ultraviolet rays,
The method of polymerization and curing can be cured in a short time, and the polymerization step is simple, so that it is used for various applications.

Conventionally, epoxy resins contain an active amine-containing compound or a carboxylic anhydride as a curing agent, and are widely used in a two-part system. However, a two-part system using these curing agents requires that the components be completely mixed, and the curing time is several hours.

There is a boron fluoride-monoethylamine system for curing the epoxy resin as a one-part system, which requires 1 to 8 hours at 160 ° C. or higher. U.S. Pat. No. 3,586,561, which is an improvement, also requires high temperatures. Therefore, these compositions cannot be used for coating heat-sensitive electronic components and the like. Further, a metal halide compound aryldiazonium salt has been proposed for curing an epoxy resin by light. However, they are expected to polymerize rapidly and are subject to premature gelling, resulting in compositions that cannot be stored satisfactorily even in the dark. It has been proposed to provide an epoxy material containing a metal halide aryldiazonium salt to prevent premature gelling of the composition and to provide shelf life in the dark, but at the cost of increased and completely satisfactory No results were obtained.

Also, these compositions have the problem that, due to the release of nitrogen during curing, the resulting cured material contains undesirable air bubbles.

By the way, various photodecomposable sulfonium salts are known as onium salts. For example, JP-A-54-53181 discloses that a p-hydroxyphenyldimethylsulfonium hexafluoroarsenate is used as a photocuring agent, and JP-A-50-151997 discloses that a phenylsulfonium salt is used as a photocuring agent for epoxy. It is known that
However, although these cure the epoxy resin with light, the application of heat alone cannot cure the epoxy resin. In the above disclosure, the following general formula [I]
Benzylsulfonium salts such as

On the other hand, JP-A-58-37003 and JP-A-63-223002 disclose dialkylbenzylsulfonium hexafluoro which can activate an onium salt by applying heat and can cure an epoxy resin. Benzyl sulfonium salts such as antimonate salts
JP-A-56-152833 reports a trialkyl sulfonium salt. However, this sulfonium salt is inactive to light, cannot cure the epoxy resin in a short time, and requires a temperature of 150 ° C. or higher, and is not practical in terms of heating time and temperature.

As for special esters such as spiro-type esters, JP-A-60-188425 discloses a curing agent for the heat polymerization.

On the other hand, as the cationic polymerization catalyst of the cationically polymerizable vinyl compound, mineral acids, BF ₃ , ZnCl ₂ , Lewis acid type catalysts such as AlCl ₃ and AlR ₂ Cl, halogen-containing organic aluminum compounds such as AlRCl ₂ are known. . However, at a temperature of 0 ° C. or higher, the cationic polymerization reaction of these catalysts is too violent, and the control of the polymerization reaction cannot be controlled as desired and the degree of polymerization does not increase. Of course, it is impossible to liquefy the cationic polymerizable monomer and these catalysts in advance at room temperature and store them.

In order to polymerize a vinyl compound, it is necessary to control a chain transfer reaction and a termination reaction, and usually, after cooling a cationic polymerizable monomer dissolved in an appropriate solvent to a predetermined extremely low temperature, a catalyst liquid is charged and a polymerization reaction is performed. Is performed. However, the polymerization reaction is industrially carried out at an extremely low temperature (for example, -130 to -4
(0 ° C.), it is necessary to use a low-temperature refrigerant, so that the operation is complicated, and the cooling cost is increased.

In addition, U.S. Pat. No. 3,283,010 describes release of benzyl cations, but this publication does not intend to polymerize polymers.

[Object of the Invention] An object of the present invention is to polymerize a cationically polymerizable substance such as an epoxy resin by radiation and / or heat, and to provide excellent storage stability, a sealant, and a matrix for a composite material. An object of the present invention is to provide a cationically polymerizable composition used for a resin or the like, and to propose a polymerization method and a polymerization catalyst.

Alternatively, a cationically polymerizable vinyl compound such as styrene is polymerized under certain conditions, and a monomer composition having excellent storage stability with a mixture with a polymerization catalyst is provided. It is to provide an oligomer industrially and propose a polymerization method and a polymerization catalyst.

[Means for Solving the Problems] The present inventors have conducted intensive studies in order to solve the above-described problems, and as a result, have arrived at the present invention.

That is, the present invention provides a polymerizable composition comprising a cationic polymerizable substance, a benzylsulfonium salt represented by the following general formula [I], which can be polymerized by radiation and / or heat; ] As a main component, and a polymerization method.

R ₂ and R ₃ are each independently hydrogen, halogen, or a C _{1 to} C ₄ alkyl group.

R ₄ is any of hydrogen, methyl group, methoxy group and halogen.

R ₅ : a C ₁ -C ₄ alkyl group.

X: Any one of SbF ₆ , AsF ₆ , PF ₆ and BF ₄ .

[Constitution of the Invention] The polymerization catalyst of the present invention is a paired compound of a (substituted or unsubstituted) -benzyl-4- (substituted or unsubstituted) oxyphenylsulfonium compound and a predetermined anion. And

Further, the cationic polymerizable substance used in the present invention,
Acid-polymerizable or acid-curable substances, especially epoxy resins, are preferably used. Examples of suitable materials include epoxide monomers, episulfide monomers, polyepoxides (or epoxy resins), polyepisulfides (or episulfide resins), phenol / formaldehyde resins, melamine / formaldehyde resins,
Urea / formaldehyde resin, spiro orthoester,
Cyclic ethers and cyclic thioethers (other than epoxies and episulfides) such as bicycloorthoesters and spiroorthocarbonates and their polymers, lactones, styrene, vinylethers and vinylthioethers, and cross-linking resins when treated with acids Alternatively, it is a resin containing a cross-linking agent to be cured, and may be a single resin or a mixture of two or more resins.

[Operation] The benzylsulfonium salt used as the polymerization catalyst of the present invention is as described above. This benzylsulfonium salt alkylates the corresponding 4-mercaptophenol, and further reacts with the benzyl halide, Synthesizing a sulfonium salt having a halogen ion,
Thereafter, by performing anion exchange with a predetermined complex salt, a high yield can be obtained.

Preferred as the benzylsulfonium salt in the present invention are benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate and benzyl-sulfonium salt.
4-hydroxyphenylmethylsulfonium hexafluorophosphate, 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate,
Benzyl-4-methoxyphenylmethylsulfonium
Hexafluoroantimonate, benzyl-2-methyl-4-hydroxyphenylmethylsulfonium Hexafluoroantimonate, benzyl-3-chloro-4-
Hydroxyphenylmethylsulfonium hexafluoroarsenate, benzyl-3-methyl-4-hydroxy-5-tert-butylphenylmethylsulfonium hexafluoroantimonate, 4-methoxybenzyl-
4-hydroxyphenylmethylsulfonium hexafluorophosphate and the like.

The benzylsulfonium salt used in the present invention not only increases the activity against heat but also has an activity against radiation such as light and electron beams. That is, these benzylsulfonium salts excited by heat or radiation are:
It is considered that benzyl cations are released and the polymerization of the above-mentioned cationically polymerizable substance proceeds.

In the present invention, when the cationically polymerizable substance is a vinyl compound, the polymerization reaction is usually carried out by a solution polymerization method using an inert solvent such as a catalyst or a monomer.
In some cases, a bulk polymerization method is also performed. As the solvent,
For example, aromatic hydrocarbons such as toluene, benzene, and xylene, aliphatic hydrocarbons such as n-hexane and n-heptane, alicyclic hydrocarbons such as cyclohexane, petroleum ether, and ligroin Hydrocarbon mixtures, chlorobenzene, halogenated hydrocarbons such as dichloroethane and the like can be used, and the polymerization reaction of these vinyl compounds is carried out at normal pressure or under pressure, and the reaction temperature is
20 ° C or higher, preferably 60 to 60 °
150 ° C.

In addition, since the sulfonium salt used as the polymerization catalyst in the present invention does not initiate the cationic polymerization reaction at room temperature, if necessary, the monomer and the catalyst can be preliminarily formed into one liquid using an appropriate solvent and stored. It is.

The benzylsulfonium salt used in the present invention is a resin
0.01 to 20 parts by weight, preferably 0.1 to 5 parts by weight per 100 parts by weight
Parts by weight. If the amount is less than 0.01 part by weight, a sufficient polymer cannot be obtained. If the amount exceeds 20 parts by weight, favorable properties cannot be obtained after polymerization, which is not preferred in terms of cost. Further, the polymerization curing is performed by radiation treatment or heat treatment, and if necessary, heating and radiation irradiation can be used in combination. Also, at the time of polymerization,
A solvent can be used if necessary.

As the radiation according to the present invention, ultraviolet rays having a wavelength in the range of 250 to 400 nm are most efficiently used. Therefore, examples of the light source include a low-pressure mercury lamp, a medium-pressure mercury lamp, a high-pressure mercury lamp, a xenon lamp, and a carbon arc lamp. And polymerizing and curing can also be performed.

In some cases, the composition of the present invention is further used by mixing an extender, a flame retardant, an antistatic agent, a surfactant, an auxiliary represented by an acid anhydride, and the like.

The composition of the present invention can be used for polishing varnishes, inks, paints, adhesives, laminates, prepregs, molding materials, sealing materials, and the like.

The curable composition of the present invention has a function that can be stored for a long period of time and rapidly initiates polymerization by irradiation with radiation such as light or an electron beam or heating at 150 ° C. or lower or a combination of heating and radiation treatment. It gives a cured product that is excellent in water resistance, chemical resistance and electrical properties without moisture absorption.

In addition, in the cationically polymerizable vinyl compound composition, it has been possible to carry out one-liquid storage of the monomer and the catalyst, which has been difficult in the past, and further enables a cationic polymerization reaction at 20 ° C. or higher, and
The point is that it has become possible to obtain a practically usable polymer having a high degree of polymerization by simple heating.

EXAMPLES Hereinafter, the present invention will be described in detail with reference to examples, but the present invention is not limited to the following.

Example 1 To 1.0 g of phenylglycidyl ether, benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate (compound of the general formula [I]: R ₁ = R
₂ = R ₃ = R ₄ = H, R ₅ = CH ₃ , X = SbF ₆ ) were mixed at 0.2 mol%.
The mixture was degassed and subjected to bulk polymerization at 100 ° C. in a sealed tube to determine the relationship between conversion and time. Conversion was determined by ¹ H-NMR spectrum. The result is shown in FIG.

Example 2 Example 1 against 0.5 g of phenylglycidyl ether
1 mol% of the benzylsulfonium salt used in 1 was mixed, degassed, and sealed. Using a 400 W high-pressure mercury lamp having a main wavelength of 312 nm as a light source, using a rotary photochemical reaction device (RH400-10W type) manufactured by Riko Kagaku Sangyo, light bulk polymerization is performed at 20 ° C, and the relationship between conversion and time is determined. I asked. The result is
Shown in the figure.

Example 3 1 g of benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was Epikote 82
8 (bisphenol A type epoxy resin manufactured by Yuka Shell Epoxy) was dissolved in 100 g, and this was applied on a glass plate to a thickness of 0.5 mm. UV lamp (80W / cm high pressure mercury lamp)
Was irradiated for 2 minutes from a distance of 10 cm. After irradiation, the resin was completely gelled.

Example 4 The mixture of Example 3 was thickened when irradiated with an ultraviolet lamp for 1 minute. When this was further treated at 120 ° C. for 5 minutes, a glassy cured product was obtained. The mixture prepared in Example 3 was allowed to stand at room temperature for one month, but no thickening was observed.

Example 5 Benzyl -1.0 g phenylglycidyl ether
1 mol% of 4-methoxyphenylmethylsulfonium hexafluoroantimonate was mixed. The mixture was degassed and sealed, and the conversion of epoxy when polymerized at 60 ° C. and 100 ° C. for 1 hour each was determined using ¹ H-NMR.
The results were 7% at 60 ° C and 62% at 100 ° C.

Examples 6 to 10 The polymerization of phenylglycidyl ether was carried out using various benzylsulfonium salts according to Example 5. Table 1 shows the results. In addition, the composition prepared here was added at room temperature for 1 hour.
After standing for months, no significant thickening was observed except for the composition prepared in Example 8. When the composition prepared in Example 8 was allowed to stand at 10 ° C. for one month, no further remarkable thickening was observed.

Examples 11 to 14 1 mol% of various benzylsulfonium salts were mixed with 1.0 g of phenylglycidyl ether. The mixture was degassed, sealed, and subjected to light bulk polymerization at 20 ° C for 90 minutes to reduce the conversion.
^It was determined from ¹ H-NMR. A 400 W high-pressure mercury lamp was used as a light source, and a rotary photochemical reactor manufactured by Riko Kagaku Sangyo was used.
Table 2 shows the results.

Example 15 A mixture comprising 100 parts by weight of celloxide 2021 (cycloaliphatic epoxy resin, manufactured by Daicel Chemical Industries, Ltd.) and 1 part by weight of various benzylsulfonium salts was prepared, and about 100 mg each was taken and heated on a hot plate heated to 100 ° C. (Made by Nissin Science Co., Ltd.
Gelation time was measured with a gelling tester (GT-D-JIS type). Table 3 shows the results.

Example 16 1-phenyl-4-ethyl-2,6,7-trioxabicyclo [2,2,2] octane 0.5 g, benzyl-4
-Hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed at 3 mol%, degassed and sealed.
This mixture was subjected to bulk polymerization at 100 ° C. for 24 hours. After the polymerization, 100% conversion was confirmed from the ¹ H-NMR spectrum.
Next, the polymer was dissolved in 2 ml of methylene chloride, and 100 ml of hexane was dissolved.
Injected into. The hexane-insoluble portion was dried to obtain 0.36 g of a polymer.

Example 17 To 0.5 g of 3,9-dibenzyl-1,5,7,11-tetraoxaspiro [5,5] undecane, 3 mol% of benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate was mixed, Degassed and sealed. This mixture was subjected to bulk polymerization at 120 ° C. for 2 hours. After polymerization, ¹ H-N
A conversion of 95% was confirmed from the MR spectrum.

Next, the polymer was dissolved in 2 ml of methylene chloride and poured into 100 ml of hexane. Then, the hexane-insoluble portion was dried to obtain 0.45 g of a polymer.

Example 18 0.5 mol of purified styrene was mixed with 1 mol% of benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate, degassed and sealed. Then, polymerization was carried out at 80 ° C. with stirring. After 60 minutes, the solidified reaction solution was dissolved in 2 ml of carbon tetrachloride, and the ¹ H-NMR spectrum confirmed a conversion of 95%.

Next, this was poured into methanol to terminate the polymerization and precipitate a polymer. The purified and dried polymer was white crystals with a yield of 82%.

Mn = 4000, Mw / M by GPC (polystyrene conversion)
n = 1.95.

Examples 19 to 24 According to Example 18, styrene was polymerized using various benzylsulfonium salts. Table 4 shows the results.

Example 25 The polymerization of styrene was carried out at 50 ° C. for 60 minutes in the same manner as in Example 18, but the conversion was 0%.

Example 26 Instead of 0.5 g of styrene, n-butyl vinyl ether was used.
Polymerization was carried out in exactly the same manner as in Example 18 except that 5 g was used, to obtain a polymer of n-butyl vinyl ether. Conversion 87
%, Yield 73%, Mn = 5600, Mw / Mn = 1.60 Example 27 Solution polymerization was carried out using 2 ml of chlorobenzene as a solvent under the same conditions as in Example 18 to obtain polystyrene. Conversion rate 99%,
Yield 87%, Mn = 5200, Mw / Mn = 1.70 Example 28 10 g of purified styrene and 5 mol% of benzyl-4-hydroxyphenylmethylsulfonium hexafluoroantimonate were dissolved in 20 ml of chlorobenzene, degassed, sealed and sealed at room temperature. For one month, but polymerization of styrene did not occur.

Examples 29 to 35 Compositions comprising 100 parts by weight of Epikote 828 (bisphenol A type epoxy resin made by Yuka Shell Epoxy) and 3 parts by weight of various benzylsulfonium salts were prepared. Heat in bath, 15
A curing test was performed at 0 ° C., and the time required for curing was measured. Table 5 shows the results.

Example 36 When the compositions prepared in Examples 29 to 35 were allowed to stand at 40 ° C for one month, no significant thickening was observed except for the composition of Example 31. When the composition of Example 31 was allowed to stand at 10 ° C. for one month, no remarkable thickening was observed.

[Effects of the Invention] As described below, the predetermined benzylsulfonium salt according to the present invention is effective as a polymerization catalyst for a cationically polymerizable substance, and a polymer composition containing these is irradiated with radiation such as light or an electron beam and / or Alternatively, it can be polymerized and cured by a polymerization method by heat treatment. The one-part composition is stable even after mixing, and has excellent storage properties at room temperature.
Therefore, the intended purpose can be achieved.

[Brief description of the drawings]

FIG. 1 is a graph showing the conversion of phenylglycidyl ether by the benzylsulfonium salt of the present invention in the heat polymerization of Example 1, and FIG. 2 is a graph showing the conversion in the photopolymerization of Example 2. In each graph, the vertical axis indicates the conversion.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C08G 59/68 C08G 59/68 65/02 65/02 75/06 75/06

Claims (14)

(57) [Claims] 1. A composition comprising one or more cationically polymerizable substances and a benzylsulfonium salt represented by the general formula [I] in a weight ratio of 100 parts by weight to the general formula [I] ] The benzylsulfonium salt is 0.01 to 20 parts by weight. R ₁ is any of hydrogen, acetyl group, methoxycarbonyl group, and methyl group. R ₂ and R ₃ are each independently hydrogen, halogen, or a C _{1 to} C ₄ alkyl group. R ₄ is any of hydrogen, methyl group, methoxy group and halogen. R ₅ : a C ₁ -C ₄ alkyl group. X: Any one of SbF ₆ , AsF ₆ , PF ₆ and BF ₄ . 2. The polymerizable composition according to claim 1, wherein the cationically polymerizable substance is a compound having an epoxy group. 3. The polymerizable composition according to claim 1, wherein the cationically polymerizable substance is a cationically polymerizable vinyl compound. 4. The polymerizable composition according to claim 1, wherein the cationically polymerizable substance is a compound having one or more of spiro orthoester groups, bicycloorthoester groups, and spiroorthocarbonate groups. 5. A polymerization catalyst for a cationically polymerizable substance comprising a benzylsulfonium salt represented by the general formula [I] according to claim 1 as a main component. 6. The benzylsulfonium salt is benzyl-4-.
The polymerization catalyst according to claim 5, which is hydroxyphenylmethylsulfonium hexafluoroantimonate. 7. The polymerization catalyst according to claim 5, wherein the benzylsulfonium salt is 4-acetoxyphenylbenzylmethylsulfonium hexafluoroantimonate. 8. The method according to claim 8, wherein the benzylsulfonium salt is benzyl-4-.
The polymerization catalyst according to claim 5, which is methoxyphenylmethylsulfonium hexafluoroantimonate. 9. The method according to claim 9, wherein the benzylsulfonium salt is benzyl-4-.
The polymerization catalyst according to claim 5, which is hydroxyphenylmethylsulfonium hexafluorophosphate. 10. The polymerization catalyst according to claim 5, wherein the benzylsulfonium salt is benzylethyl-4-hydroxyphenylsulfonium hexafluoroantimonate. 11. A catalyst comprising one or more of the benzylsulfonium salts represented by the general formula [I] according to claim 1 as one or more of the cationically polymerizable substances. A method for polymerizing a cationically polymerizable substance, wherein the polymerization is performed by heat. 12. The method according to claim 11, wherein the radiation is ultraviolet light. 13. The method according to claim 11, wherein the polymerization is carried out at a temperature of 20 ° C. or higher. 14. A benzyl sulfonium salt represented by the general formula [I] according to claim 1 is added in an amount of 0.01 to 20 parts by weight based on 100 parts by weight of the cationically polymerizable substance.
The polymerization method described in 1.