JPH0579090B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a method for producing a high quality cyclized product of a conjugated diene polymer. In particular, the present invention relates to a method for easily producing a cyclized product of a conjugated diene polymer having a quality suitable for photoresists for semiconductor manufacturing. [Prior Art] It has long been known to produce a cyclized product of a conjugated diene polymer such as natural rubber, synthetic polyisoprene, or polybutadiene by subjecting it to a cyclization reaction in an organic solvent. Conjugated diene polymer cyclized products (hereinafter sometimes simply referred to as cyclized products) have traditionally been used in insulating materials, adhesives, paints,
There are rubber compounding agents, photosensitive resins, etc. Recently, with the development of IC technology, the importance of photosensitive resins as photoresists for semiconductor manufacturing has greatly increased. The cyclized product used in this case is required to have a narrow molecular weight distribution and a high cyclization rate. In general, a photoresist with excellent resolution can be obtained when the molecular weight distribution of the cyclized product is narrow, and the cyclization rate of the cyclized product is 40 to 40.
It is preferably within the range of 75%, and together with the molecular weight of the cyclized product, it has a great effect on the sensitivity and film retention of the photoresist. In order to obtain a cyclized product with a narrow molecular weight distribution, it is necessary to use a synthetic conjugated diene polymer that has a narrow molecular weight distribution and a molecular weight that exhibits a solution viscosity that allows the cyclization reaction to be easily carried out as the raw material conjugated diene polymer. It is. This is because the cyclization reaction is generally accompanied by molecular chain scission or intermolecular cross-linking of the conjugated diene polymer, and in the best case, the cyclization reaction is a reaction that also involves molecular chain scission or intermolecular crosslinking of the conjugated diene polymer, and in the best case, the cyclization reaction is a reaction that also involves molecular chain scission or intermolecular crosslinking of the conjugated diene polymer. This is because they do not give you any monsters.
Furthermore, if the molecular weight of the conjugated diene polymer is too large, operations such as mastication will be required to obtain a solution viscosity suitable for the cyclization reaction, which will expand the molecular weight distribution. A solution polymerization method using an anionic polymerization catalyst is suitable as a method for producing a synthetic conjugated diene polymer having a narrow molecular weight distribution and a molecular weight exhibiting a solution viscosity that allows easy cyclization reaction. The cyclization reaction is carried out in the presence of an organic solvent. When the solvent used in the polymerization and the solvent used in the cyclization reaction are of the same type, the resulting polymer solution after the conjugated diene solution can be directly subjected to the cyclization reaction. For example, isoprene is solution polymerized using an anionic polymerization catalyst represented by an organolithium compound, and then the resulting polyisoprene solution is treated with a cyclization catalyst such as sulfuric acid, trichloroacetic acid, Brønsted acid such as an organic sulfonic acid, or trifluoride. A method for producing cyclized polyisoprene is known, which comprises cyclizing the polyisoprene by adding a Lewis acid such as boron, tin tetrachloride, titanium tetrachloride, antimony trichloride, zinc trichloride, or aluminum trichloride. (Tokukai Akira
47-34834). Furthermore, a method similar to the above is also known, except that a boron trifluoride ether complex and acetic acid or its halide are used as the cyclization catalyst, and methanol or ethanol is used to terminate the polymerization (Japanese Patent Laid-Open No. 59-1999). (Refer to Publication No. 96112). These methods include a step of solution polymerizing a conjugated diene, a step of isolating the polymer from a solution of the resulting polymer,
Compared to a method consisting of a step of dissolving the polymer in a cyclization solvent and a step of performing a cyclization reaction, this method has advantages in terms of process simplification and labor saving. However, in the method described in JP-A No. 47-34834, the cyclization reaction rate is slow, the cyclization reaction is not reproducible, and the cyclization reaction is not reproducible. It has drawbacks such as a wide molecular weight distribution of the cyclized product and the generation of a large amount of gel. Furthermore, the method described in JP-A-59-96112 cannot be applied to the production of cyclized products suitable for photoresists. This is because boron-containing compounds, like phosphorus-containing compounds, are used as dopants for silicon in semiconductor substrates, so even trace amounts of boron-containing compounds are not allowed in photoresists. It is difficult to completely remove the boron-containing compound used from the cyclized product. The present inventors have proposed a method for solving the above-mentioned problems based on the study of the cyclization reaction, using a Lewis acid selected from the group consisting of tin halide and titanium halide as a catalyst used in the cyclization reaction, and a general formula R-
Sulfonic acid represented by SO ₃ H (wherein R represents an alkyl group or an aryl group) and the general formula
A mixed catalyst consisting of Brønsted acid selected from the group consisting of halogenated acetic acids represented by HnX _3-o CCOOH (wherein, He discovered a method using a Lewis acid-Brensted acid two-component catalyst (sometimes referred to simply as a two-component catalyst), and has already filed a patent application (Japanese Patent Application No. 1986-
42434 and 59-146554). Note that the two-component catalyst has high selectivity and high activity as shown in the specification of the above application. [Problems to be Solved by the Invention] However, when the two-component catalyst is immediately added to a conjugated diene polymer solution obtained by solution polymerization using an organolithium compound to carry out the cyclization reaction, the two-component catalyst is The selectivity and activity of the component catalysts are impaired, eliminating the advantage of using the two component catalysts. The object of the present invention is to prepare a conjugated diene polymer in an organic solvent with a Lewis acid selected from the group consisting of tin halide and titanium halide, and with the general formula R-SO ₃ H (wherein R is an alkyl group or an aryl group). group) and halogenated acetic acids represented by the general formula HnX _3-o CCOOH (wherein, X represents a halogen atom and n represents an integer from 0 to 2) In producing a cyclized product of a conjugated diene polymer by reacting it in the presence of Brønsted acid, it is possible to produce a cyclized product of a conjugated diene polymer without impairing the selectivity and activity of the catalyst. An object of the present invention is to provide a method for easily producing a high-quality conjugated diene polymer cyclized product without significantly changing the value (/) of (average molecular weight)/(number average molecular weight). Another object of the present invention is a method for producing a cyclized conjugated diene polymer with a high cyclization rate and a narrow molecular weight distribution in a short time, with good reproducibility, and without side reactions that cause gelation or coloration. Our goal is to provide the following. In addition, in the above, "not accompanied by a side reaction that causes gelation" means that the reaction solution is
This means that when passed through a 1 μm membrane filter, virtually no gel remains on the filter. Furthermore, another object of the present invention is to provide a method for producing a cyclized product suitable for a photoresist for manufacturing semiconductors such as ICs. The cyclized product suitable for the photoresist includes a compound with a narrow molecular weight distribution, a cyclization rate of 40 to 75%, substantially no gel or catalyst residue, and a boron-containing compound or a phosphorus-containing compound. There is a demand for something that does not contain any [Means for Solving the Problems] According to the present invention, the above-mentioned object is to produce a Lewis acid selected from the group consisting of tin halide and titanium halide in an organic solvent of a conjugated diene polymer, and Sulfonic acids represented by R-SO ₃ H (wherein R represents an alkyl group or an aryl group) and general formula HnX _3-o CCOOH (wherein
represents a halogen atom, and n represents an integer of 0 to 2. A conjugated diene characterized in that the organic solvent solution of the conjugated diene polymer is a solution obtained by adding a phenol compound to a conjugated diene polymer solution obtained by solution polymerization using an organolithium compound. This is achieved by a method for producing a cyclized polymer. In the present invention, the conjugated diene polymer serving as a raw material for the cyclization reaction is obtained by polymerizing the conjugated diene in an organic solvent using an organolithium compound as a polymerization catalyst. Examples of conjugated dienes used herein include isoprene, butadiene, phenylbutadiene and mixtures thereof. Among them, isoprene is preferred. In addition, if a small amount (for example, 10% by weight based on the monomer) is used, a part of the conjugated diene may be used as a copolymerizable polymer with the conjugated diene such as styrene, α-methylstyrene, ethylene, propylene, isobutylene, or acrylonitrile. It may be substituted with a saturated monomer. Furthermore, as the organic lithium compound used here, a monolithium compound represented by the general formula R'Li is preferable. In the above general formula, R' represents a hydrocarbon residue, and preferred hydrocarbon residues are an alkyl group and an aryl group. The hydrocarbon residue preferably has 1 to 12 carbon atoms. Specific examples include alkyllithiums such as methyllithium, ethyllithium, propyllithium, isopropyllithium, butyllithium, pentyllithium, and isoamyllithium, and aryllithiums such as phenyllithium, tolyllithium, and naphthyllithium. By using such an organolithium compound, it generally has a narrow molecular weight distribution with a ratio of weight average molecular weight to number average molecular weight (/ ^N ) of 2.0 or less, preferably 1.5 or less, and moreover, it is possible to have a cyclization reaction. A conjugated diene polymer having a molecular weight exhibiting a solution viscosity that can be easily obtained can be obtained very easily. In addition, the organic solvent used here can dissolve the conjugated diene, its polymer, and the cyclized product of the polymer, and can also dissolve organic lithium compounds, tin halides,
It is an organic compound that is inert to halogenated titanium, organic sulfonic acids, and halogenated acetic acids. Those preferably used include aliphatic hydrocarbons such as pentane, hexane, heptane and cyclohexane, and aromatic hydrocarbons such as benzene, toluene and xylene. When producing a cyclized product used in a photoresist for semiconductor production, aromatic hydrocarbons, especially xylene, are preferably used. Note that the organic solvent is also used when diluting the system after the completion of polymerization to bring the system to a concentration suitable for the cyclization reaction. Polymerization is usually carried out by dissolving a conjugated diene in an organic solvent and adding an organolithium compound to it, or by adding an organolithium compound to an organic solvent and then adding a conjugated diene to it. It is carried out with The solution concentration of the conjugated diene in the polymerization system is not particularly limited, but is 10 to 90% by weight, preferably 20 to 90% by weight.
A range of 80% by weight is desirable. Within this range, polymerization can be easily controlled and efficiently carried out. In this polymerization, the average molecular weight of the produced conjugated diene polymer is a value obtained by multiplying the molar ratio of the conjugated diene to lithium in the organolithium compound by the molecular weight of the conjugated diene. Therefore, the amount of organic lithium used requires some correction, but is uniquely determined by the desired average molecular weight. In the present invention, the weight average molecular weight of the conjugated diene polymer is preferably within the range of 10,000 to 1,000,000. The weight average molecular weight of the raw material conjugated diene polymer for the cyclized product suitable for photoresists for semiconductor manufacturing is determined from the viewpoints of photoresist sensitivity, film retention, and workability during photoresist preparation.
It is desirable that the number is in the range of 30,000 to 500,000, preferably 50,000 to 300,000. Polymerization temperature is 0~150℃, preferably 20~100℃
It is desirable to be within the range of . Polymerization time is as follows: polymerization rate is 100
%, generally 0.1 to 100
time, preferably 0.5 to 20 hours. Through this polymerization, a solution of a conjugated diene polymer having a desired molecular weight and a narrow molecular weight distribution is obtained, but the resulting polymer is a so-called living polymer and has active terminals. In the method of the present invention, it is necessary to deactivate the active terminal before subjecting the living polymer to the cyclization reaction. According to the present invention, it has been found that the cyclization reaction proceeds without any problem by deactivating the active terminal of the resulting polymer by adding a phenolic compound. When an alcohol is used instead of a phenolic compound, the cyclization reaction does not proceed smoothly. The phenolic compound used here is a compound having at least one phenolic hydroxyl group in its molecule. As a specific example, 2,6-di-
t-Butyl-4-methylphenol, 2-butyl-4-hydroxyanisole, 3-butylhydroxyanisole, 6-(4-hydroxy-3,5
-di-t-butylanilino)-2,4-bisoctyl-1,3,5-triazine, 4,4'-dihydroxydiphenyl, 2,2'-methylene-bis(4
-methyl-6-t-butylphenol), 1,
1'-bis(4-hydroxyphenyl)-cyclohexane, 4,4'-thiobis(6-t-butyl-3
-methylphenol), 2,5-di-t-butylhydroquinone, 1,3,5-trimethyl, 2,
4,6-tris(3,5-di-t-butyl-4-
Hydroxybenzyl)benzene, polyphenols containing four or more phenolic hydroxyl groups in the molecule, and the like. Among these, phenolic compounds having an alkyl group, especially a butyl group, in the alpha position, especially 2,6-di-t-butyl-4-methylphenol, 6-(4-hydroxy-3,5
-di-t-butylanilino)-2,4,6-bisoctyl-1,3,5-triazine or 2,2
-methylene-bis(4-methyl-6-t-butylphenol) and the like are preferred. These phenolic compounds can be used alone or in combination of two or more. The amount of the phenolic compound to be used is determined by the equivalent ratio of the phenolic hydroxyl group of the phenolic compound to the lithium of the organolithium compound used for polymerization.
Amounts ranging from 0.8 to 20, preferably from 1 to 15, are desirable. If this equivalent ratio is too small, it will be difficult to suppress the broadening of the molecular weight distribution during the cyclization reaction, making it impossible to obtain a cyclized product with a narrow molecular weight distribution. On the other hand, if the equivalent ratio is too large, the reaction rate during the cyclization reaction will decrease significantly, and furthermore, the cyclization rate of the cyclized product will decrease significantly. When the phenol compound is added to the conjugated diene polymer solution after polymerization, it may be used after being dissolved in the same solvent as the polymerization solvent. After terminating the polymerization by adding a phenolic compound, the resulting solution is subsequently subjected to a cyclization reaction using a two-component catalyst. The Lewis acid used as a component of the two-component catalyst in the present invention must be a tin halide or a titanium halide, and other Lewis acids such as boron halides, iron halides, aluminum halides, etc. When using halides or organoaluminum compounds, no improvement in catalyst activity was observed when used in combination with Bronsted acid;
The cyclization reaction rate is low, and a cyclized product with a high cyclization rate cannot be obtained in a short time. Examples of the tin halides and titanium halides include tin tetrafluoride, tin tetrachloride, tin tetrabromide, tin tetraiodide, tin difluoride, tin dichloride, tin dibromide, and tin diiodide. , titanium tetrafluoride, titanium tetrachloride, titanium tetrabromide, titanium tetraiodide, titanium trifluoride, titanium trichloride, titanium tribromide, titanium triiodide, titanium difluoride, titanium dichloride, diodor Examples include titanium oxide or titanium diiodide. Among these, tin tetrachloride, tin tetrabromide,
Preferred are tetrahalides such as titanium tetrachloride or titanium tetrabromide, especially tin tetrachloride. In addition, the Brønsted acid used as another catalyst component of the two-component catalyst in the present invention is an organic sulfonic acid represented by the general formula (1) R-SO ₃ H or a general formula (2) HnX _3-o CCOOH. It must be a halogenated acetic acid represented by the following formula. Even if Brønsted acids other than those mentioned above, such as sulfuric acid, benzoic acid, or salicylic acid, are used in combination with the specific Lewis acid, a highly active catalyst will not be obtained and the cyclization reaction rate will not increase;
A cyclized product with a high cyclization rate cannot be obtained in a short time. In the general formula (1), R represents an alkyl group or an aryl group. Preferably, these groups have a carbon number of 1 to 10. The alkyl group is preferably a lower alkyl group such as methyl, ethyl, propyl or butyl, and the aryl group is preferably a phenyl, tolyl or naphthyl group. In addition, the general formula
In (2), X represents a halogen atom such as fluorine, chlorine, bromine or iodine, and n is an integer of 0 to 2. Examples of typical organic sulfonic acids include methanesulfonic acid, ethanesulfonic acid, 1-propanesulfonic acid, 1-butanesulfonic acid, 1-pentanesulfonic acid, 1-skithanesulfonic acid, 2-butanesulfonic acid, Sulfonic acids having a linear alkyl group such as 2-pentanesulfonic acid, 3-pentanesulfonic acid, 2-hexanesulfonic acid, 3-hexanesulfonic acid, 2-methyl-1-propanesulfonic acid, 1,1-dimethyl Ethanesulfonic acid, 2-methyl-1-butanesulfonic acid, 3-methyl-1-
Butanesulfonic acid, 1,1-dimethyl-1-propanesulfonic acid, 2,2-dimethyl-1-propanesulfonic acid, 1,2-dimethyl-1-propanesulfonic acid, 2-methyl-1-pentanesulfonic acid, 3-methyl-1-pentanesulfonic acid, 4-
Methyl-1-pentanesulfonic acid, 1,1-dimethyl-1-butanesulfonic acid, 2,2-dimethyl-1-butanesulfonic acid, 3,3-dimethyl-1
-butanesulfonic acid, 1,2-dimethyl-1-butanesulfonic acid, 1,3-dimethyl-1-butanesulfonic acid, 2,3-dimethyl-1-butanesulfonic acid, 2-ethyl-1-butanesulfonic acid Examples include aliphatic sulfonic acids such as sulfonic acids having branched alkyl groups, and aromatic sulfonic acids such as benzenesulfonic acid, toluenesulfonic acid, and naphthalenesulfonic acid. In addition, typical examples of halogenated acetic acids include monochloroacetic acid,
Examples include chlorinated acetic acids such as dichloroacetic acid or trichloroacetic acid, or fluorinated acetic acids such as monofluoroacetic acid, difluoroacetic acid, or trifluoroacetic acid. Among these Bronsted acids, organic sulfonic acids, especially methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, toluenesulfonic acid,
The alkanesulfonic acids mentioned above are particularly preferred. In general, in cyclization reactions using two-component catalysts, side reactions that result in gelation or coloration may occur, the molecular weight distribution may significantly expand due to the cyclization reaction, the cyclization reaction rate may be low, etc. This will cause inconvenience. For example, when polyisoprene is cyclized using a combination of tin tetrachloride and sulfuric acid, significant gelation occurs during the cyclization reaction, and a great deal of effort is required to remove the gel.
Furthermore, when polyisoprene is cyclized in a solvent using aluminum halide and an organic halogen compound in combination, the viscosity of the cyclization reaction solution increases, and even if the reaction is continued for a long time, the cyclization rate of the produced cyclized product is high. It only accounts for a few percent and forms a gel. On the other hand, in the present invention, the above-mentioned disadvantages do not occur due to the combination of a specific Lewis acid and a specific Bronsted acid. Furthermore, the mixing ratio of the Lewis acid and Bronsted acid in the two-component catalyst used in the present invention is 2.
The type of catalyst components to be combined for the component-based catalyst, the type of conjugated diene, the concentration of the conjugated diene polymer in the cyclization reaction system, the cyclization reaction temperature, the cyclization reaction time,
Furthermore, it depends on the target value of the cyclization rate of the produced cyclized product, and it cannot be said unconditionally, but when the Bronsted acid is an aromatic sulfonic acid or a halogenated acetic acid, it is 150:1 to 1:10, especially 50:1 to 1:10. :1
to 1:2, and if the Brønsted acid is an aliphatic sulfonic acid, 200:1 to 1:
200, preferably 150:1 to 1:20, particularly preferably 150:1 to 1:10.
If the amount of Brønsted acid mixed is too small, the cyclization reaction rate will be low and a cyclized product with a high cyclization rate cannot be obtained in a short time, and even if a cyclized product with a high cyclization rate is produced over a long period of time, The resulting cyclized product has an extremely wide molecular weight distribution. On the other hand, if the amount of Brønsted acid mixed is too large, side reactions leading to gelation and coloring tend to occur, making it impossible to obtain a high-quality cyclized product. The total amount of the Lewis acid and Brønsted acid used in the cyclized product reaction varies depending on the types of catalysts combined for the two-component catalyst, their mixing ratio, reaction temperature, and the desired cyclization rate of the product. ,
Although it cannot be generalized, when aromatic sulfonic acid or halogenated acetic acid is used as the Brønsted acid, per 100 conjugated diene monomer units of the conjugated diene polymer obtained by solution polymerization using an organolithium compound. The total number of moles used (hereinafter simply referred to as catalyst amount) is 0.005 to 5, preferably 0.01 to 5.
It is desirable that the amount is in the range of 3, or in the case of using an aliphatic sulfonic acid as the Brønsted acid, in the range of 0.001 to 5, preferably 0.005 to 3.
If the amount of catalyst is too large, the cyclization reaction rate will increase,
Although this is preferable, it is difficult to control the cyclization reaction because the cyclization reaction is too fast, and it is inconvenient to obtain a cyclized product with a desired cyclization rate with good reproducibility.
Since the resulting cyclized product contains a large amount of catalyst residue, it cannot be used as a cyclized product that requires high purity, such as a photoresist. On the other hand, if the amount of catalyst is too small, the cyclization reaction rate will be slow, making it impractical. The multicomponent catalyst used in the production method of the present invention is
Although it exhibits high activity whether it is in a homogeneous state or in a non-uniform state in the cyclization reaction solution, the former is preferred. The two-component catalyst is added by sequentially adding a Lewis acid and a Brønsted acid to a conjugated diene polymer solution obtained by solution polymerization;
Any method may be used in which a mixed solution of Lewis acid and Brønsted acid is prepared in advance and then added. In the present invention, the solution of the conjugated diene polymer used in the cyclization reaction is diluted with a solvent of the same type as the polymerization solvent after the completion of polymerization of the conjugated diene, if necessary, to 40% by weight or less, preferably 5 to 20% by weight. It is desirable that the concentration be within the range of . If this concentration is too high, the viscosity of the cyclization reaction system increases, making it difficult to control the reaction, while if it is too low, a large amount of solvent is required, which is uneconomical in terms of production efficiency. The cyclization reaction is usually carried out at a temperature in the range of 0 to 200°C, but in order to efficiently obtain a cyclized product without causing gelation or coloring, it is carried out at a temperature in the range of 30 to 100°C. is preferable. Further, during the cyclization reaction, it is desirable to eliminate the influence of moisture as much as possible. [Operation] In the present invention, the mechanism of action of the organolithium compound, phenolic compound, and specific Lewis acid-Brensted acid two-component catalyst is not necessarily clear, but the organolithium compound is used in the polymerization of conjugated diene. When used for this purpose, a conjugated diene polymer having a narrow molecular weight distribution, as is generally said, can be obtained. Moreover, since the two-component catalyst has high selectivity and high activity, it can be used under mild conditions to smoothly proceed the cyclization reaction in a short time. On the other hand, when a phenol compound is added to a conjugated diene polymer solution after solution polymerization, it acts on the active end of the resulting conjugated diene polymer and prevents the active end from deactivating the two-component catalyst. On the other hand, during the cyclization reaction, oxidation and molecular chain scission of the conjugated diene polymer do not act on the two-component catalyst to the extent that they have a large effect on the cyclization reaction, and moreover, they generally tend to occur during the cyclization reaction. It is also presumed to suppress side reactions such as intermolecular crosslinking. [Example] Hereinafter, the present invention will be specifically explained using Examples.
The present invention is not limited to these examples in any way. In addition, in Examples and Comparative Examples, weight average molecular weight () and molecular weight distribution (/
M ^N ) was measured by gel permeation chromatography, and the cyclization rate and microstructure were measured by nuclear magnetic resonance spectroscopy. Example 1 68.1 g (1 mol) of isoprene purified and dehydrated in two autoclaves was purified and dehydrated to produce xylene.
Dissolve each in 390g of each and add n-butyllithium to this.
0.003 g (0.6 mmol) was added and polymerization was carried out at 60°C. After confirming that the polymerization rate was 100% by gas chromatography analysis of the gas phase, 0.52 g (2.4 mmol) of 2,6-di-t-butyl-4-methylphenol was added to the system. .
As a result of taking out the product from one autoclave and analyzing it, the weight average molecular weight () was found to be
It was found that polyisoprene having a molecular weight distribution (/) of 162,000 and a molecular weight distribution (/) of 13.9 was produced. Add 900g of xylene to the remaining autoclave to make a 5% by weight solution of polyisoprene, keep the solution at 40°C, and add 5.21g of tin tetrachloride (20% by weight) to the solution.
mmol) and p-toluenesulfonic acid 0.172
g (1 mmol) was added thereto, and the cyclization reaction was carried out for 2.5 hours while stirring. The reaction solution was slightly colored during the reaction, but it became colorless by washing with water after the reaction was completed. In addition, the catalyst residue is removed by washing with water, and the pore size is
When passed through a 1 μm membrane filter, no gel was observed. The degree of cyclization, cyclization ratio, microstructure, cyclization rate, and molecular weight distribution of the cyclized product were as shown in Table 1.

【table】

[Table] The above polymerization of isoprene, addition of a phenolic compound, and subsequent cyclization reaction were repeated several times. The cyclization ratio, degree of cyclization, microstructure and molecular weight distribution of the compound were almost unchanged, and this example had good reproducibility. On the other hand, after the above polymerization of isoprene, the produced polyisoprene was isolated and purified by pouring the produced solution into a large amount of acetone, and then dissolved in xylene to obtain a 5% by weight polyisoprene solution, and the above cyclization reaction was carried out. The cyclization reaction was carried out under similar conditions. The cyclization ratio, degree of cyclization, percentage of each structure in the microstructure, and molecular weight distribution of the produced cyclized product were almost the same as the respective values in Table 1. Example 2 Isoprene purified and dehydrated in eight autoclaves was dissolved in purified and dehydrated xylene, and n-butyllithium was added to the isoprene.
An amount corresponding to 0.075 mol% was added and polymerization was carried out at 60°C. After confirming that all isoprene was consumed, 2,6-di-t was added to six autoclaves.
-Butyl-4-methylphenol was added so that the equivalent ratio of the phenolic hydroxyl group to lithium of n-butyllithium (indicated as P/I ratio in Table 2) became the value shown in Table 2. Meanwhile, the remaining 1
When the solution in the autoclave was poured into a large amount of acetone and the product was recovered and analyzed, it was found that polyisoprene with a weight average molecular weight () of 131,000 and a molecular weight distribution (/) of 1.41 was produced. I understand. Xylene was added to the above seven autoclaves including the autoclave containing the polymer solution to which no phenol was added to form a 5% by weight polyisoprene solution, and then tin tetrachloride and p-toluenesulfonic acid were added. (Number of moles of tin tetrachloride used)/(Number of moles of p-toluenesulfonic acid used)
(hereinafter referred to as catalyst mixing ratio) is 3/1, and the total number of moles of tin tetrachloride and p-toluenesulfonic acid used per 100 monomer units of polyisoprene (hereinafter referred to as catalyst amount). 0.5, and the cyclization reaction was carried out at 40°C for 3 hours. The product was examined for the presence or absence of a cyclization rate gel. In addition, the ratio of the molecular weight distribution (/) _C of the product after the cyclization reaction to the molecular weight distribution (/) _R of polyisoprene after polymerization (hereinafter referred to as C/R value) was investigated and ranked. The results are shown in Table 2. Example 3 Isoprene was polymerized in the same manner as in Example 2,
2,6-di-t-butyl-4-methylphenol was added at a rate such that the P/I ratio was 3.0. Next, tin tetrachloride and p-toluenesulfonic acid were each added so that the catalyst mixing ratio and catalyst amount became the values shown in Table 2, and the reaction time was the same as that shown in Table 2. The cyclization reaction was carried out in the same manner as in Example 2. The products were examined for their cyclization rate, presence or absence of gel, and rank of C/R value. The results are shown in Table 2.

[Table] Example 4 Isoprene purified and dehydrated in an autoclave was dissolved in purified and dehydrated xylene, and n-butyllithium was added in an amount of 0.055 mol% based on the isoprene.
Polymerization was carried out at 60°C. When all isoprene is consumed, 6-(4-hydroxy-3,5-t-butylanilino)-2,4-
Bisoctyl-thio-1,3,5-triazine (denoted as I-565 in Table 3) and 2,2'-methylene-bis(4-methyl-6-t-butylphenol) (in Table 3, Table 3 shows the equivalent ratio of the phenolic hydroxyl group of each of the phenolic compounds to the lithium of n-butyllithium (denoted as P/I ratio in Table 3, similar to Table 2). The amount was added to give the value shown in . Analysis revealed that the polymer produced was 191,000 and (/) was 1.48.
It was made of polyisoprene. The thus obtained polyisoprene solution was diluted with xylene to make a 5% by weight solution, and then tin tetrachloride and p-toluenesulfonic acid were mixed at a mixing ratio of 2.3/1 and a catalyst amount of 2.0. The cyclization reaction was carried out at 60°C for 3 hours. The products were examined for their cyclization rate, presence or absence of gel, and rank of C/R value. The results are shown in Table 3.

【table】

[Table] Example 5 Brønsted acid shown in Table 4 was used instead of p-toluenesulfonic acid at the catalyst ratio and catalyst amount shown in Table 4, and the cyclization reaction was carried out for the time shown in Table 4. Polymerization, addition of 2,6-di-t-butyl-4-methylphenol, and cyclization reaction were carried out in the same manner as in Example 1 except for the following. Properties of the produced solution, cyclization rate of the produced polyisoprene cyclized product,
The rank of C/R value was examined. The results are shown in Table 4. For comparison, polyisoprene cyclization was carried out in the same manner as in Example 1 except for the conditions shown in Table 4, when sulfuric acid was used as Brønsted acid, and when Brønsted acid was used alone. Manufactured. In the same manner as above, the properties of the produced solution, the cyclization rate of the produced cyclized product, and the degree of change in molecular weight distribution were investigated. The results are shown in Table 4.

〔effect〕

The production method of the present invention uses a polymer solution obtained by solution polymerization of a conjugated diene as an organic solvent solution of the conjugated diene polymer used in the cyclization reaction, and does not impair the selectivity and activity of the catalyst used in the cyclization reaction. A cyclized conjugated diene polymer can be easily obtained without significantly changing the value of (weight average molecular weight)/(number average molecular weight) of the polymer before and after the cyclization reaction. Incidentally, in the production method of the present invention, the ratio of the molecular weight distribution (/) _C of the produced cyclized product to the molecular weight distribution (/) _R of the conjugated diene polymer obtained by liquid polymerization is less than 2, and preferably 1.5. It is as follows. Furthermore, the production method of the present invention allows a high quality cyclized conjugated diene polymer having a narrow molecular weight distribution to be obtained in a short time, with good reproducibility, and without side reactions that cause gelation or coloration. Furthermore, the present invention does not use any boron-containing compounds or phosphorus-containing compounds. In addition, since the catalyst used is highly active, only a small amount is required, which not only has economical advantages, but also
The catalyst can be easily removed after the reaction, and the amount of catalyst residue in the cyclized product can be minimized, resulting in a highly pure cyclized product. Therefore, the cyclized product obtained by the method of the present invention is preferably used as a cyclized product suitable for photoresists, which strongly dislike the presence of impurities such as metals. In addition, in the present invention, a polymer solution obtained by solution polymerization of a conjugated diene is used as an organic solvent solution of a conjugated diene polymer used in the cyclization reaction. This method has great advantages in terms of process simplification and labor saving compared to a method consisting of a step of isolating a combined solution, a step of dissolving the polymer in a cyclization solvent, and a step of performing a cyclization reaction. Therefore, the production method of the present invention is suitable for industrial production, as the amount of catalyst used is small.

Claims (1)

[Scope of Claims] 1. A conjugated diene polymer is prepared in an organic solvent with a Lewis acid selected from the group consisting of tin halide and titanium halide, and with the general formula R-SO ₃ H (wherein R is an alkyl group or (representing an aryl group); and halogenated acetic acid represented by the general formula HnX _3-o CCOOH (wherein, X represents a halogen atom and n represents an integer from 0 to 2). A conjugated diene polymer solution obtained by using an organolithium compound as an organic solvent solution of the conjugated diene polymer in producing a cyclized product of the conjugated diene polymer by reacting the conjugated diene polymer in the presence of Brønsted acid. 1. A method for producing a cyclized conjugated diene polymer, the method comprising using a solution obtained by adding a phenol compound to a cyclized product of a conjugated diene polymer. 2. The production method according to claim 1, wherein the phenol compound has an alkyl group at the α-position. 3 The phenolic compound is 2,6-di-t-butyl-4-methylphenol, 6-(4-hydroxy-3,5-di-t-butylanilino)-2,
4-bisoctyl-1,3,5-triazine or 2,2'-methylene-bis(4-methyl-6-t
-butylphenol)
Manufacturing method described in section. 4. The production method according to claim 1, 2, or 3, wherein the phenolic compound is used in a ratio such that the phenolic hydroxyl group in the compound is 0.8 to 20 equivalents to lithium of the organolithium compound. 5. Claims 1 and 2, wherein the Lewis acid is tin tetrachloride, and the Bronsted acid is methanesulfonic acid, ethanesulfonic acid, propanesulfonic acid, butanesulfonic acid, benzenesulfonic acid, or toluenesulfonic acid. The manufacturing method described in Section 3, Section 3 or Section 4.