JPH082947B2 - Method for producing monomer for ring-opening polymerization - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a method for producing a monomer for ring-opening polymerization having high polymerization activity from dicyclopentadiene, more specifically, by heat-treating dicyclopentadiene. The present invention relates to a method for producing a monomer for ring-opening polymerization, which is highly active without special purification and gives a thermosetting resin having a high heat distortion temperature and an improved flexural modulus when used in reaction injection molding.

2. Description of the Related Art In recent years, a method of producing a thermosetting polymer by ring-opening polymerization of a norbornene-based monomer such as dicyclopentadiene or methyltetracyclodecene by a reaction injection molding method using a metathesis catalyst system in a mold has attracted attention. Has been done.

For example, in JP-A-58-129013, a reaction injection molding method (R
IM method) discloses a process for the preparation of thermosetting dicyclopentadiene (DCP) homopolymers using a metathesis catalyst system, and in a preferred embodiment the homopolymer comprises a tungsten halide, a tungsten oxyhalide. One solution consisting of a mixture of the catalytic component of such a metathesis catalyst system and a monomer (DCP), and the other solution consisting of a metathesis catalyst activator such as an alkylaluminum halide and a monomer (DCP). Combine the solutions in a reaction injection molding (RIM) machine, then
Manufactured by pouring into a mold.

JP-A-59-51911 discloses a ring-opening polymerization method by bulking a cyclic olefin containing a norbornene ring by a method using a metathesis catalyst system in the RIM method. For prolongation, it has been proposed to use alkoxyalkylaluminum halide or aryloxyalkylaluminum halide cocatalysts as cocatalysts (activators).

However, in the conventional RIM method, commercially available DCP was used as the starting material.
When the compounds are used as they are, the polymerization activity is not sufficient because the polymerization is hindered by the small amount of impurities contained therein. Therefore, for example, a commercially available DC with a purity of 96-97%
P had to be further purified to remove impurities such as low boiling fractions (JP-A-58-129013).

Then, in order to purify DCPs, distillation has been repeated to increase the purity. However, in this method, the recovery rate of DCP was lowered, and even when purified to high purity, it was often inactive against the polymerization reaction conditions in reaction injection molding.

Recently, a method has been proposed in which commercially available DCP is distilled and further treated with an adsorbent such as a molecular sieve or alumina or silica gel in order to remove impurities that may interfere with polymerization (US Pat. No. 4,584,425). However, since the distillation performance of this method is inadequate, it is necessary to leave a large amount of initial distillate and residual residue, which has the drawback of low yield of high-purity DCP, and the treatment process using an adsorbent. However, there are industrial disadvantages such as increase of waste and disposal of waste adsorbent.

Moreover, the ring-opening polymers obtained by these disclosed methods have relatively good performance in various physical properties required for engineering plastics such as impact resistance, high elastic modulus, and heat resistance. From the strict performance requirements of, it is not always sufficient. For example, the glass transition temperature of the DCP homopolymer obtained by these methods is usually about 90 ° C., which is somewhat insufficient as a material in a field requiring heat resistance.

By the way, in this case, as the norbornene-based monomer used becomes polycyclic, that is, as the number of cyclic structural units in the monomer increases, the heat distortion temperature of the obtained polymer rises. However, high-purity polycyclic monomers are difficult to obtain, and since they are often solids, RI
It becomes difficult to inject into the mold by the M method.

Japanese Patent Application Laid-Open No. 61-179214 discloses DCP for increasing the glass transition temperature (Tg) of a polymer product and improving the heat distortion temperature.
And a norbornene-based monomer such as trimethylolpropane-tris- (5-norbornene-2-carboxylate), and two or more reactive dipolymeric bonds that are cleaved during polymerization to increase the number of crosslinks. A copolymerization method with a comonomer and the like has been disclosed. However, in this method, it is necessary to use a special comonomer which is difficult to obtain, and there is a drawback in economical efficiency.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention As a result of intensive studies to overcome the above-mentioned problems, the inventors of the present invention have independently obtained a product obtained by heat treatment of dicyclopentadiene or a product thereof and a norbornene-based product. A mixture with a monomer has a high polymerization activity, and has a high glass transition point by ring-opening polymerization of these in a mold having a predetermined shape in the presence of a metathesis catalyst system, Moreover, they have found that a thermosetting resin having an improved flexural modulus can be obtained, and have completed the present invention based on the findings.

Means for Solving the Problems Thus, according to the present invention, there is provided a method for producing a monomer for ring-opening polymerization, which comprises heat treating dicyclopentadiene at 120 to 250 ° C. in the presence of an antioxidant. is there.

 Hereinafter, the components of the present invention will be described in detail.

(Dicyclopentadiene) The raw material dicyclopentadiene used in the present invention usually has a purity of 90% by weight or more, preferably 95% by weight or more.
If it is at least wt%, it is not necessarily required to be purified in advance, and the heat-treated product is highly active and gives a good ring-opening polymer.

Dicyclopentadiene usually contains low-boiling point impurities and high-boiling point impurities as impurities, and specific examples of the former include, for example, hydrocarbons having 4 to 6 carbon atoms, cyclopentadiene and butadiene, isoprene, piperylene and the like. Examples thereof include co-dimerization products with diolefins (vinyl norbornene, isopropenyl norbornene, propenyl norbornene, etc.), and examples of the latter include, for example, cyclopentadiene trimer, cyclopentadiene and isoprene dimer. Compounds (methylbicyclononadiene) and the like. Among them, hydrocarbons having 4 to 6 carbon atoms cause defective molding of reaction injection molding, and therefore, conventionally, they had to be sufficiently removed, but in the present invention, the purity is 98.5% (Example 1). .About.2) or less, it has sufficient polymerization activity.

The dicyclopentadiene used in the present invention is an alkyl-substituted product such as dicyclopentadiene (DCP) or its methyl-substituted product and ethyl-substituted product. The starting DCP is an endo isomer, an exo isomer or a mixture thereof.

(Heat Treatment of Dicyclopentadiene) The heat treatment condition is as follows: dicyclopentadiene under an inert gas atmosphere such as nitrogen gas at a temperature of 120 to 250 ° C., preferably 150 to 220 ° C. for 0.5 to 20 hours, preferably Is 1
Examples of the method include heating for 10 hours. The reaction form of the treatment may be either batch type or continuous type. Further, during the treatment, an inert solvent such as benzene, toluene, xylene, etc. can coexist in the reaction, but in this case, an operation of removing the solvent after the treatment is required,
It is preferable to carry out the treatment using as little solvent as possible.

Further, the heat treatment is performed in the presence of an antioxidant. As the antioxidant, phenol-based ones are preferable, for example, 4,4
-Dioxydiphenyl, hydroquinone monobenzyl ether, 2,4-dimethyl-6-t-butylphenol,
2,6-di-t-butylphenol, 2,6-di-aluminohydroquinone, 2,6-di-t-butyl-p-cresol, 4
-Hydroxymethyl-2,6-di-t-butylphenol, 4,4'-methylene-bis- (6-t-butyl-o-
Cresol), butylated hydroxyanisole, phenol condensate, butylated phenol, dialkyl phenol sulfide, high molecular weight polyhydric phenol, bisphenol and the like. Quinones such as t-butylcatechol, hydroquinone, resorcin, pyrogallol and the like can also be used. The amount of antioxidant used is usually
10 to 10,000 ppm, preferably 100 to 1,000 pp for DCPs
m.

The obtained product can be used as it is as a raw material for producing a thermosetting resin by ring-opening polymerization, but if necessary, unreacted DCPs or low boiling point impurities may be removed by distillation.

The products obtained by heat treatment of DCPs are waxy or oily. A waxy substance has a freezing point of usually 100 ° C. or lower, preferably 60 ° C. or lower, and an oily substance has a viscosity at 30 ° C. of usually 200 centipoise (cps) or lower, preferably 100 CPS or lower. These products contain unreacted DCPs and thermal reaction products of DCPs, but in the present invention, those containing 5% by weight or more, further 10% by weight or more of thermal reaction products of DCPs. Is preferred.

(Norbornene-based Monomer) In the present invention, the norbornene-based monomer, which is optionally mixed with the heat-treated product of DCP, is a substituted or unsubstituted norbornene, dicyclopentadiene, dihydrodicyclopentadiene, tricyclopentadiene. , Tetracyclopentadiene, tetracyclododecene, etc., and specific examples include dicyclopentadiene, methyltetracyclododecene, 2-norbornene,
5-methyl-2-merbornene, 5,6-dimethyl-2-
Norbornene, 5-ethyl-2-norbornene, 5-butyl-2-norbornene, 5-hexyl-2-norbornene, 5-octyl-2-norbornene, 5-dodecyl-2-norbornene and the like can be mentioned.

(Mixing of heat-treated product of DCPs and norbornene-based monomer) The waxy or oily product obtained by heat-treatment of DCPs can be used alone as a monomer for ring-opening polymerization. It can be mixed and used. In that case, the mixing ratio of the heat-treated product and the norbornene-based monomer may be appropriately selected according to the purpose. Usually, the former is 100 to 10% by weight, preferably 100 to 20% by weight, and the latter is 0 to 90% by weight. %,
It is preferably 0 to 80% by weight, and the thermal reaction product of DCPs contained in the heat-treated product is preferably present in the mixture in an amount of 5% by weight or more, more preferably 10% by weight or more. As the proportion of heat treated product decreases, the glass transition temperature and flexural modulus of the resulting thermosetting resin decrease.

The properties of the mixture of the two are not particularly limited, but it is advantageous for the operation such as pouring into a mold that they are liquid at 30 ° C, preferably 10 ° C. The viscosity of liquids at 30 ° C is usually 500 cps or less, especially 200 cps or less, especially 10 cps or less.
Those below 0 cps are preferred.

Incidentally, it is possible to lower the freezing point by adding a polymer modifier such as an elastomer or DSP resin, a filler, etc. to the heat-treated product or mixture. It suffices that the contained mixture is liquid at the above temperature.

The mixture of the heat-treated product and the norbornene-based monomer is
It can be easily carried out using a mixer such as a power mixer, static mixer, collision mixer, etc., but when the heat-treated product is a wax, it is mixed with the norbornene-based monomer in the molten state after the heat treatment is completed. The method is efficient.

(Other Optional Components) Various additives such as a filler, an antioxidant, a pigment, a colorant, and a polymer modifier can be added to the monomer for ring-opening polymerization of the present invention, which is obtained. The properties of the ring-opening polymer can be modified.

Fillers include inorganic fillers such as glass, carbon black, talc, calcium carbonate and mica.

Polymer modifiers include elastomers and thermopolymerized DCP resins. For example, blending an elastomer can increase the impact strength of the thermosetting resin, and blending a thermopolymerized DCP resin can further improve the flexural modulus.
The polymer modifier is dissolved in the monomer reaction solution and blended.

As the elastomer, natural rubber, polybutadiene,
There are polyisoprene, styrene-butadiene-styrene block copolymer, styrene-isoprene-styrene block copolymer, ethylene-propylene-diene-polymer and the like. The usage ratio of these is usually 0.1 to 20% by weight.
Is.

(Polymerization Method of Ring-Opening Polymerization Monomer) The ring-opening polymerization monomer of the present invention can be polymerized using a known metathesis catalyst and activator.

That is, the heat treatment product of the present invention or a mixture of the product and a norbornene-based monomer is introduced into a mold having a predetermined shape and heat-cured by a polymerization method in which bulk polymerization is performed in the mold in the presence of a metathesis catalyst system. Resin can be produced. It suffices if it is substantially bulk polymerization, and a small amount of the solvent for the deactivator may be present. Although the metathesis catalyst system is preferably used by dissolving it in the monomer, it may be used by suspending or dissolving it in a small amount of solvent as long as it does not substantially impair the properties of the product.

In a preferred method for producing a thermosetting resin, the heat-treated product or a mixture of the product and a norbornene-based monomer is divided into two liquids and placed in separate containers, one containing a metathesis catalyst and the other containing an activator. Add and prepare two stable reaction solutions. The two kinds of reaction solutions are mixed, and then injected into a molding die maintained at a high temperature, where ring-opening polymerization by lumps is started to obtain a thermosetting resin.

In the polymerization of the monomer for ring-opening polymerization of the present invention, a collision mixture device conventionally known as a RIM molding device can be used for mixing two kinds of reaction solutions.
In this case, the containers containing the two types of reaction solutions serve as separate flow sources. RIM machine mixing
The mixture is instantaneously mixed by a head, and then poured into a high-temperature molding die, where it is immediately subjected to bulk polymerization to obtain a thermosetting resin.

Thus, the collision mixing device can be used, but it is not limited to such a mixing means, and when the pot life at room temperature is as long as 1 hour, mixing of two kinds of reaction solutions in a mixer is possible. After completion of the above, injection or injection may be performed once or several times into the preheated mold (see, for example, JP-A-59-51911). This system has the advantage that the device can be downsized and can be operated at low pressure, as compared with the impingement mixing device.

Further, the polymerization method is not limited to the case of using the two types of reaction solutions. As can be easily understood by those skilled in the art, various modifications are possible, for example, putting the reaction solution and the additive in the third container and using it as the third stream.

The mold temperature is 50 ° C or higher, preferably 60 to 200 ° C, particularly preferably 90 to 130 ° C. Mold pressure is usually 0.1 ~ 100Kg /
Within the range of cm ² .

The polymerization time may be appropriately selected, but is usually shorter than about 20 minutes, preferably 5 minutes or less, but may be longer than that.

The polymerization reaction components must be stored and operated under an atmosphere of an inert gas such as nitrogen gas. The molding die may or may not be sealed with an inert gas.

Thus, the monomer produced by the production method of the present invention is
It is possible to polymerize by the RIM method, and it is not always necessary to highly purify DCPs, so there is an advantage that the monomer cost can be kept low.

(Properties of Thermosetting Resin) The bulk polymer obtained by using the monomer of the present invention is
It is a thermosetting resin that becomes a hard solid when cooled. The glass transition point (Tg) is 95 ° C. or higher, preferably 100 ° C. or higher, and has a high heat distortion temperature.

Examples Hereinafter, the present invention will be described more specifically with reference to Examples and Reference Examples, but the present invention is not limited to these Examples. All parts, ratios and percentages are by weight.

Example 1 500 ppm of 2,6-di-tert-butylphenol (B
HT) containing 98.5% pure dicyclopentadiene (DCP)
(700 g) was charged into an autoclave (1), and after sufficiently substituting with nitrogen, the temperature was raised to 170 ° C. and the reaction was performed for 4 hours to obtain an oily substance. The viscosity of this oil is 10 cps at 30 ° C, and the composition is
The unreacted DCP was 75% and the trimer or higher component of cyclopentadiene (CP) was 25%.

Example 2 A waxy product was obtained in the same manner as in Example 1 except that the reaction condition was 180 ° C. for 4 hours. This waxy product has a freezing point of 50 ° C (viscosity of 30 cp at 55 ° C).
s. ), 40% unreacted DCP, CP trimer or higher
The composition was 60%.

Table 1 shows the respective freezing points when DCP was further added and mixed to the waxy product thus obtained and the mixing ratio was changed.

Example 3 DCP (CP dimer containing 500 ppm of BHT and having a purity of 94.5%, wherein propenyl norbornene was 3.2%, isopropenyl norbornene was 0.7%, and vinyl norbornene was an impurity.
Includes 0.2% and 1.4%. Heat treatment was performed in the same manner as in Example 1 except that (Zeon Co., Ltd.) was used, and the temperature was 30 ° C.
An oily substance having a viscosity of 10 cps was obtained. The composition of this oily matter was such that 76% of unreacted DCP and 24% of components of CP trimer or higher.

Reference Example 1 The oil obtained in Example 1 was placed in two containers, and in one of them, diethylaluminum chloride (DEA) was added to the oil.
C) was added to a concentration of 33 mmol, and n-propanol was added to a concentration of 4.95 mmol (solution A).

On the other hand, tri (tridecyl) ammonium molybdate was added to the oil to a concentration of 4 mmol (solution B).

Both the A and B reaction solutions were mixed at a ratio of 1: 1. This mixture maintained a stable state where there was no change in viscosity at 35 ° C. for 1 hour (hereinafter referred to as pot life).

Both reaction solutions have a space volume of 200 × 200 × 2 mm, 90 ° C.
Immediately injected into the mold heated by using a gap pump and a power mixer. The injection time was about 15 seconds.
Thirty seconds after the end of the injection, heat was generated rapidly and the reaction started. Then, the reaction was performed in the mold for a total of 3 minutes. These series of operations were carried out under a nitrogen gas atmosphere.

The glass transition point of the molded article thus obtained was measured and found to be 110 ° C., and the flexural modulus was 21,000 Kg / cm ² .

Reference Example 2 Using a mixture of each composition shown in Table 1 of Example 2, in exactly the same manner as in Reference Example 1 (however, only wax was injected by heating to a liquid temperature of 55 ° C.). I got the goods. Table 2 shows the pot life, glass transition point, and flexural modulus of these molded products.

Example 4 A mixture of 50 parts of the waxy product obtained in Example 2, 30 parts of DCP and 20 parts of methyltetracyclododecene was prepared by mixing the components at 55 ° C. The freezing point of the mixture was below 0 ° C and the viscosity at 30 ° C was 20 cps.

Polymerization was carried out using this mixture in the same manner as in Reference Example 1. The resulting molded article had a Tg of 130 ° C. and a flexural modulus of 27,
It was 500 Kg / cm ² .

Reference Example 3 The oil obtained in Example 1 was put into two containers, DEAC was added to one of the oils so as to have a concentration of 48 mmol, and tungsten hexachloride of 7 was added to the other container. It was added so as to have a nirimole concentration. The two types of reaction solutions thus prepared were injection molded under the same mold and temperature conditions as in Reference Example 1 using a collision mixing type RIM machine so that the mixing ratio was 1: 1.

The Tg of the molded product thus obtained was 108 ° C. The pot life of the mixture at 35 ° C was about 15 seconds.

Reference Example 3 A molded article was obtained in the same manner as in Reference Example 1 except that the oily substance obtained in Example 3 was used. The Tg of the obtained molded product is 105
° C., the flexural modulus was 21,000 kg / cm ² .

Example 5 A waxy product was obtained in the same manner as in Example 2 except that DCP having a purity of 94.5% used in Example 3 was used. This waxy product has a freezing point of 45 ° C.
The viscosity at ° C was 30 cps. In addition, unreacted DCP is 42%,
The composition of the CP trimer and higher was 58%.

50 parts of the waxy product thus obtained, 50 parts of DCP
A mixture having the ratio of parts was treated in the same manner as in Reference Example 1 to obtain a molded product.

The freezing point of the mixture is 3 ° C and the Tg of the obtained molded product is
The flexural modulus at 115 ° C was 23,500 Kg / cm ² .

EFFECTS OF THE INVENTION According to the present invention, a monomer for ring-opening polymerization having a high degree of polymerization activity can be obtained by simply heat-treating dicyclopentadiene or by mixing the heat-treated product with a norbornene-based monomer. Yes, coarse with impurities
Even in the case of DCP, it is not always necessary to perform special purification such as distillation, so that the monomer cost can be reduced.

Moreover, by using this monomer, it is possible to economically obtain a thermosetting resin that is superior in heat distortion temperature and flexural modulus as compared with conventional polyDCP polymers. This resin has an excellent effect that it can be applied to various fields requiring heat resistance.

Claims (3)

[Claims] 1. A process for producing a monomer for ring-opening polymerization, which comprises heat-treating dicyclopentadiene at 120 to 250 ° C. in the presence of an antioxidant. 2. The method for producing a monomer for ring-opening polymerization according to claim 1, further comprising mixing a norbornene-based monomer after the heat treatment. 3. A dicyclopentadiene having a purity of 90 to 90.
The method for producing a monomer for ring-opening polymerization according to claim 1 or 2, wherein 98.5% of dicyclopentadiene is used.