JPS6018683B2 - α- Method for producing methylstyrene resin - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention uses a monomer mainly composed of Q-methylstyrene,
This invention relates to a polymerization accelerator for anionic polymerization using an organolithium compound.

High molecular weight poly-Q-methylstyrene is transparent, hard, and has excellent properties not found in conventional resins, such as a very high heat distortion temperature, and is a resin that is expected to have a variety of uses.

High molecular weight polyQ-methylstyrene that can be used as a resin can generally be produced by anionic polymerization of Q-methylstyrene using an alkali metal or an organic alkali metal compound as a catalyst. However, the polymerization rate is extremely slow and it is difficult to economically produce polyJ-Q-methylstyrene on an industrial scale.For example, Belgian Patent No. 753967 discloses that hexamethylphosphoramide is used to accelerate the polymerization. A method of adding it as an accelerator has been proposed. Although this method does improve the anionic polymerization rate of Q-methylstyrene, the effect is still unsatisfactory, and in order to increase the polymer yield, it is necessary to add a large amount of hexamethylphosphoramide and conduct the polymerization for a long time. There is. Moreover, since this promoter is expensive and difficult to separate and recover from the product mixture, it is not possible to economically produce poly-Q-methylstyrene by this method. at least 6
A similar trend is observed in the case of copolymerization of monomer mixtures containing % by weight of Q-methylstyrene. The present inventors have conducted various studies on methods for producing high-molecular-weight polymers in a short time, with good yield, and economically by anionically polymerizing Q-methylstyrene or a monomer mixture mainly composed of Q-methylstyrene. As a result,
We have discovered the method of the present invention and have developed it.

That is, the present invention provides a method for combining Q-methylstyrene or a monomer mixture containing at least 6% by weight of Q-methylstyrene with an organolithium compound and the general formula R0(CH2).
nOM (wherein R is an alkyl group having 1 or 4 carbon atoms, n is 3 or 4, and M is an alkali metal.

) is a method for producing a Q-methylstyrene resin, characterized in that the polymerization is carried out in the presence of at least one type of polymethylene glycol monoalkyl ether alkali metal alkoxide represented by: In polymerizing Q-methylstyrene, a method is known in which a compound in which a Lewis base is added to an organic alkali metal is used as a catalyst in the presence of a rubbery polymer compound in a hydrocarbon solvent. The base is a cyclic ether such as tetrahydrofuran, dioxane, a monoether such as dimethyl ether, a dialkyl ether of a glycol such as ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, and a polymethylene glycol monomer which is effective when present in the reaction of the present invention. The structure is clearly different from alkyl ether alkali metal alkoxides.

Due to the presence of the polymethylene glycol monoalkyl ether alkali metal alkoxide of the present invention, Q-methylstyrene can be polymerized in a short time and in a good yield without the presence of a rubbery polymer compound. In order for the resin obtained by the present invention to exhibit excellent properties such as high hardness, high tensile strength, and high heat distortion temperature, at least 6% by weight of the monomer used must be Q-methylstyrene.

Examples of the copolymerization component used in producing the copolymer include hydrocarbon unsaturated monomers having anionic polymerization activity such as ethylene, styrene, vinyltoluene, and improbenyltoluene. These monomers can be used alone or in combination of two or more in the polymerization with Q-methylstyrene. As the polymerization medium, any compound can be used as long as it dissolves the monomer, does not react with the organolithium compound and polymethylene glycol monoalkyl ether alkali metal alkoxide under the polymerization conditions, and is in a liquid state under the polymerization conditions. However, from an economic standpoint, hydrocarbons, ie, saturated aliphatic hydrocarbons, alicyclic hydrocarbons, or aromatic hydrocarbons are preferred.

Examples of such compounds include pentane, hexane,
Examples include heptane, decane, kerosene, benzene, toluene, xylene, ethylbenzene, cumene, cyclohexane, methylcyclohexane, and decalin.
These media can be used alone or in combination of two or more. The amount of the medium to be used is usually equal to or 2 times the weight of the monomer, preferably 2 to 1 times the weight. The organolithium compound used in the present invention is an alkyllithium compound having 2 to 12 carbon atoms, a cycloalkyllithium compound, or an aryllithium compound.

Specifically, ethyllithium, propyllithium, trimethylene dilithium, butyl lithium, tetramethylene dilithium, amyl lithium, hexyl lithium, 2-ethylhexyl lithium, cyclohexyl lithium, decyl lithium, dodecyl lithium, phenyl lithium, and tolyllithium. , naphthyllithium, etc. The amount of these organic lithium compounds used is usually 0.005 to 5 mol%, preferably 0.05 to 2 mol%, based on the monomer. Further, these organic lithium compounds can be used alone or in combination of two or more. The polymethylene glycol monoalkyl ether alkali metal alkoxide used as a polymerization accelerator in the present invention has the general formula R○ (C ratio) nOM (where R is an alkyl group with 1 or 4 carbon atoms, and n is 3 or 4 , M is an alkali metal such as lithium, sodium, potassium, etc.

). Specifically, trimethylene glycol monomethyl ether lithium alkoxide,
Examples include trimethylene glycol monoethyl ether sodium alkoxide, tetramethylene glycol monomethyl potassium alkoxide, and tetramethylene glycol monoethyl ether sodium alkoxide. Note that polymethylene glycol monoalkyl ether can also be added to the polymerization system instead of polymethylene glycol monoalkyl ether alkali metal alkoxide. In this case, the polymethylene glycol monoalkyl ether immediately reacts with the organolithium compound in the polymerization system, and the polymethylene glycol monoalkyl ether lithium alkoxide contributes to the promotion of polymerization. Therefore, the addition of polymethylene glycol monoalkyl ethers is within the scope of this invention. However, polymethylesoglycol dialkyl ethers do not exhibit sufficient polymerization promoting effects, and when R is an alkyl group or aryl group with 5 or more carbon atoms, the polymerization promoting effect is weak, and the same is true when n is 5 or more. be. Note that polymethylene glycol monoalkyl ether or its alkali metal alkoxide may be used alone or in combination of two or more. The presence of polymethylene glycol monoalkyl ether alkali metal alkoxides is usually 0.0% relative to the organolithium compound.
The amount is 1 to 20 times molar, preferably about 2 to 1 sonic molar. The polymerization temperature is usually 150 qo to 115 qo.
000, preferably -100 o'clock to 1100 q○
It is. Further, polymerization is usually carried out at atmospheric pressure or higher pressure. Particularly when a compound such as ethylene which is in a gaseous state within the above-mentioned polymerization temperature range is used as a monomer component, it is desirable to carry out the polymerization at a pressure equal to or higher than atmospheric pressure. Polymerization time is generally 0.1 to 5 hours.
time, preferably 0. It's between 1 and 2 hours. Since organolithium compounds react with oxygen in the air and lose their effectiveness as polymerization initiators, polymerization must be carried out in an atmosphere of an inert gas such as nitrogen or helium. Furthermore, if impurities such as water, carboxylic acid, or ketoso are present in the polymerization medium or monomer, they will react with the organolithium compound and inactivate it. It is desirable to remove these impurities. After the polymerization is completed, the remaining organic lithium compound is inactivated by adding water, alcohol, acid, etc., and then the resin can be separated from the polymerization liquid by a method such as filtration or adding a poor solvent.

By the method of the present invention described so far, Q-methylstyrene resin can be produced in a shorter time, with better yield, and at a lower cost than when conventionally proposed polymerization accelerators are used.

Next, the present invention will be specifically explained with reference to Examples. The heat distortion temperature of the resin shown in the examples was determined by the method of ASTM D648-56, and the intrinsic viscosity was determined as 35 as a toluene solution.
It was measured in qo. Example 1 Hexane 3, Q-methylstyrene lk9 and trimethylene glycol monomethyl ether2. Put ' into a polymerization vessel and replace with nitrogen.

A hexane solution of n-butyllithium (concentration 1.58 holes/hole) was gradually added dropwise to this solution at 110 pm.
After the polymerization solution took on a pale red color due to the Q-methylstyrene anion, when 5.0 g of a hexane solution of n-butyllithium was added, poly-Q-methylstyrene particles instantly precipitated. The dispersion state of the polymer particles was extremely good. Polymerization was carried out at -loo0 for 20 minutes, and the resulting slurry was treated with methanol and dried at 60oo to obtain polyQ-methylstyrene in a yield of 75%. The weight average molecular weight of this polyQ-methylstyrene is 2
60,000, and the heat distortion temperature of the injection molded product is 13
is 0, straight light transmittance is 90%, Rockwell hardness (R
) was 127. Example 2 In Example 1, hexane 3 was replaced with toluene 3, trimethylene glycol monomethyl ether 2.5 was replaced with tetramethylene glycol monomethyl ether 2.2, and n-butyllithium was replaced with n. - Polymerization and post-treatment were carried out in the same manner as described in Example 1, except that 10 mmole of amyllithium was used.

As a result, polyQ-methylstyrene having a weight average molecular weight of 230,000 was obtained with a yield of 70%. The heat distortion temperature of the injection molded product was 135°C. Examples 3 to 6, Comparative Examples 1 and 2 In Example 1, polymethylene glycol monoalkyl ether or polymethylene glycol dimethyl ether of the first notation number was used instead of 2.5M of trimethylene glycol monomethyl ether. Polymerization and post-treatment were carried out as described in Example 1.

The results are shown in Table 1. Examples 7 to 10 Copolymerization and post-treatment were carried out in accordance with the method described in Example 1, except that the monomer mixture shown in Table 2 was used in place of Q-methylstyrene lk9 in Example 1.

The results are shown in Table 2. Examples 11 to 15 Polymerization was carried out using 100 g of Q-methylstyrene, 0.35 g of trimethylene glycol monomethyl ether (and the polymerization medium and organolithium compound listed in Table 3, under the conditions listed in Table 3). I did it.

The results are shown in Table 3. Example 16 In Example 1, a 10% hexane solution of potassium alkoxide of trimethylene glycol monomethyl ether was used instead of trimethylene glycol monomethyl ether.
Polymerization was carried out in the same manner as in Example 1, except that the solvent was used.

The yield of poly-Q-methylstyrene was 65%. Example 17 Polymerization was carried out in the same manner as in Example 1, except that a 10% hexane solution of sodium alkoxide of tetramethylene glycol monomethyl ether was used instead of trimethylene glycol monomethyl ether.

The yield of polyQ-methylstyrene was 63%. Comparative Example 3 In Example 1, hexamethylphosphoramide 3 was used instead of trimethylene glycol monomethyl ether.
．． Polymerization and post-treatment were carried out in the same manner as in Example 1, except that Z in No. 5 was used.

As a result, the yield of poly-Q-methylstyrene was 55%, the weight average molecular weight was 75,000, and a satisfactory compression molded product could not be obtained. Comparative Example 4 Copolymerization and post-treatment were carried out in accordance with the method described in Example 1, except that a mixture of 550 kg of Q-methylstyrene and 450 kg of styrene was used in place of 1 kg of Q-methylstyrene.

The yield of the copolymer was 86%, and the ratio was 0.83.
The heat distortion temperature of the injection molded product was 104 qo. Table 1 Table 2 Table 3

Claims (1)

[Scope of Claims] 1. α-methylstyrene or a monomer mixture containing at least 60% by weight of α-methylstyrene is combined with an organolithium compound and the general formula RO(CH_2)_nOM (wherein R has 1 to 4 carbon atoms). an alkyl group, n is 3 or 4, and M is an alkali metal. Manufacturing method.