JPH0725946B2 - Butadiene-based polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION <Field of Industrial Application> The present invention relates to a butadiene-based polymer composition having excellent heat resistance and coloring resistance.

<Prior Art> Butadiene-based polymers such as solution-polymerized polybutadiene rubber (BR), solution-polymerized styrene-butadiene copolymer rubber (SBR), and styrene-butadiene block copolymer (SBS) are usually used as catalysts such as Ziegler catalyst or organic. It is produced by anionic polymerization in a hydrocarbon solvent using a lithium compound, and conventionally, the polymerization solvent was removed from the polymerization solution after the completion of the polymerization reaction by the steam stripping method. A solvent direct drying method has been proposed which can theoretically minimize the amount used.

However, since this method is usually carried out at a high temperature of about 150 to 200 ° C, which is considerably higher than the boiling point of the polymerization solvent, gelation may occur during the processing, or the polymer may be colored after the high temperature treatment. It has been desired to improve the heat resistance and the coloring resistance particularly in the absence of oxygen in the polymer-based polymer manufacturing process.

In addition, extrusion molding such as SBS and injection molding, or BR, SBR
Alternatively, in extrusion molding and injection molding of impact resistant polystyrene modified with SBS, due to insufficient heat resistance due to high temperature and high processing speed, fish eye gel (fish eye gel)
gel), which causes problems that the physical properties of the film are remarkably deteriorated and coloring occurs.

Conventionally, it is well known that various phenol-based, phosphorus-based, and sulfur-based antioxidants are used by adding them during the production and processing of butadiene-based polymers.
6-di-t-butyl-4-methylphenol, 2,2'-methylenebis (4-methyl-6-t-butylphenol), n-octadecyl 3- (3,5-di-t-butyl-4-hydroxy) Phenyl) propionate, triethylene glycol bis [3- (3-t-butyl-4-hydroxy-5-methylphenyl) propionate], pentaerythritol tetrakis [3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate],
Phenol-based antioxidants such as 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene can be used alone or these phenol-based antioxidants can be used. An antioxidant is used in combination with a phosphorus-based antioxidant such as tris (nonylphenyl) phosphite or distearyl pentaerythritol diphosphite, or the above-mentioned phenolic antioxidant and dilauryl thiodipropionate or dimyristyl thiodipropioate. And a sulfur-based antioxidant such as pentaerythritol tetrakis (3-laurylthiopropionate) are known.

However, these methods are not suitable for heat deterioration (gelation) during high-temperature treatment for separating the polymer from the polymer solution during production of the butadiene-based polymer or during high-temperature processing of the butadiene-based polymer. Not able to exert sufficient effect.

Further, as a stabilizer of such a butadiene-based polymer, US Pat. No. 4,525,514 discloses 2-t-butyl-6-
(3-t-Butyl-2-hydroxy-5-methylbenzyl) -4-methylphenyl acrylate is described. This stabilizer is effective for heat deterioration (gelation) during high-temperature treatment for separating the polymer from the polymer solution during the production of butadiene-based polymer, but the hue of the separated polymer is The problem of insufficient practical use has become clear.

Further, as a difficult coloring antioxidant to prevent coloring due to oxidative deterioration in the presence of oxygen to various synthetic resins, U.S. Pat.No. 4,365,032 describes 2,2'-alkylidene bis- (4,6-disubstituted A monoester compound of (phenol) is proposed. However, in this patent specification, heat deterioration (gelation) under oxygen-free conditions such as high-temperature treatment for separating a polymer from a polymer solution during production of a butadiene-based polymer, or high-temperature processing of a butadiene-based polymer. The compound disclosed in the specification is not described in the absence of oxygen in the manufacturing process of the butadiene-based polymer, high temperature processing, etc. It did not exhibit a sufficient effect on the heat deterioration and the prevention of coloring.

<Problems to be Solved by the Invention> From the above, the present inventors have conducted a high-temperature treatment for separating a polymer from a polymer solution at the time of producing a butadiene-based polymer, or a high-temperature processing of the butadiene-based polymer. As a result of repeated research to prevent thermal deterioration (gelation) especially in the absence of oxygen, and also to prevent coloration, a butadiene-based polymer containing a phenolic compound with a specific structure is On the other hand, they have found that they are stable and do not color, and have completed the present invention.

<Means for Solving Problems> That is, the present invention provides a compound represented by the general formula (I): [In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, and R ₂ is -C
The _{(CH 3) 2 -R '(} R' represents an alkyl group or a phenyl group having 1 to 5 carbon atoms) or phenyl group represented by, R ₃ is represented by respectively an acrylate or methacrylate groups] Butadiene-based polymer with phenol-based compound
A butadiene-based polymer composition containing 0.05 to 2 parts by weight per 100 parts by weight is provided.

As for the substituent R ₁ of the phenolic compound represented by the general formula (I), the smaller the number of carbon atoms in the alkyl group, the better the gelation prevention performance of the butadiene-based polymer at high temperature, and the methyl group is most preferable.

Further, R ₂ is a group represented by —C (CH ₃ ) ₂ —R ′ containing a quaternary carbon or a phenyl group in order to prevent coloration of the butadiene-based polymer. Examples of the group containing quaternary carbon include
A t-butyl group, a t-amyl group or a t-octyl group is preferable, and among these, a t-butyl group is most preferable.

Furthermore, R ₃ affects the gelation preventing performance of the butadiene-based polymer at high temperature, and when R ₃ is an acrylate group or a methacrylate group, it exhibits excellent gelation preventing performance. Of these, an acrylate group is more preferable.

Therefore, in order to satisfy both the gelation prevention performance and the coloration prevention performance of the butadiene-based polymer at high temperature, a combination of the substituents R ₁ , R ₂ and R ₃ of the phenolic compound represented by the general formula (I) is used. Only effective.

Next, Table 1 shows typical examples of the phenolic compound represented by the general formula (I). In the structural formula of Table-1, Is a t-butyl group, Is a t-amyl group, Means t-octyl group, respectively.

In the present invention, the content of the phenolic compound in the butadiene-based polymer is 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of the butadiene-based polymer.

Here, if the content of the phenolic compound is less than 0.05 parts by weight, the intended effect is not sufficient, and if it exceeds 2 parts by weight, the effect commensurate with it is not obtained, which is economically disadvantageous. is there.

As a method of incorporating such a phenolic compound into the butadiene-based polymer, a method of adding it to the polymerization reaction liquid after completion of the anionic polymerization reaction can be applied.

The butadiene-based polymer composition of the present invention contains the above-mentioned phenolic compound as a stabilizer, but if necessary, other additives such as an ultraviolet absorber,
It may contain a light stabilizer, an antioxidant, a metal deactivator, a metal soap, a nucleating agent, a lubricant, an antistatic agent, a flame retardant, a pigment and a filler.

Specific examples of these additives include UV absorbers and hindered amine light stabilizers such as 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-.
n-octoxybenzophenone, 2- (2-hydroxy-5-methylphenyl) benzotriazole, 2- (2
-Hydroxy-3-t-butyl-5-methylphenyl)
-5-chloro-benzotriazole, 2- (2-hydroxy-3,5-di-t-butylphenyl) -5-chloro-
Benzotriazole, 2- (2-hydroxy-3,5-di-amylphenyl) benzotriazole, 2,4-di-t
-Butylphenyl 3,5-di-t-butyl-4-hydroxybenzoate, [2,2'-thiobis (4-t-octylphenolate)]-butylamine Ni salt, 2,2,6,6-
Tetramethyl-4-piperidyl benzoate, bis (2,
2,6-Tetramethyl-4-piperidyl) sebacate, 2
-(3,5-di-t-butyl-4-hydroxybenzyl)
-2-n-butyl-malonate bis (1,2,2,6,6-pentamethyl-4-piperidyl), 1- [2- {3- (3,5-
Di-t-butyl-4-hydroxyphenyl) propionyloxy} ethyl] -4- [3- (3,5-di-t-butyl-4-hydroxyphenyl) propionyloxy]-
2,2,6,6-tetramethylpiperidine, dimethyl succinate and 1- (2-hydroxyethyl) -4-hydroxy-2,
Polycondensate with 2,6,6-tetramethylpiperidine, poly {[6- (1,1,3,3-tetramethylbutyl) amino-1,
3,5-Triazine 2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,
2,6,6-Tetramethyl-4-piperidyl) imino]},
Poly {[6-morpholino-1,3,5-triazine-2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl)
Imino] hexamethylene [(2,2,6,6-tetramethyl-
4-piperidyl) imino]}, 2-methyl-2- (2,2,2
6,6-Tetramethyl-4-piperidyl) amino-N-
(2,2,6,6-tetramethyl-4-piperidyl) propionamide and the like.

Examples of sulfur antioxidants include dilauryl thiodipropionate, distearyl thiodipropionate, dimyristyl thiodipropionate, pentaerythritol tetrakis (3-lauryl thiopropionate) and 3,9-bis (2). -Dodecylthioethyl) -2,4,8,10-tetraoxaspiro [5,5] undecane and the like are examples of phosphorus-based antioxidants such as distearyl pentaerythritol diphosphite and tris (2,4-diethyl). -T-butylphenyl) phosphite, tris (2-t-butyl-4-methylphenyl) phosphite, bis (2,4-di-t-butylphenyl) pentaerythritol diphosphite, tetrakis (2,4- J-t
-Butylphenyl) -4,4'-biphenylenediphosphite and the like, respectively.

The butadiene-based polymer applicable to the present invention includes solution-polymerized polybutadiene rubber (BR), solution-polymerized styrene-
Butadiene copolymer rubber (SBR), styrene-butadiene block copolymer (SBS), high impact polystyrene modified with BR or SBR or SBS (HI-PS), etc. May be used, or may be used by blending with another polymer.

<Effects of the Present Invention> The butadiene-based polymer composition of the present invention containing the phenolic compound specified in the present invention is extremely stable against gelation and coloration due to thermal deterioration particularly under anoxic conditions. . Therefore, after the polymerization reaction is completed, even when the polymer is separated from the polymer solution at a high temperature, it is possible to stably obtain a product without gelation or coloration. In addition, it is stable against heat deterioration in processing such as injection molding and extrusion molding, and causes, for example, the generation of fish eye gel in the film forming process and the decrease in gloss and transparency in the injection molding process. It is possible to prevent the generation of the microgel and to obtain a high-quality product without coloring.

<Example> Next, the present invention will be described with reference to Reference Examples and Examples.
The present invention is not limited to these.

Reference Example 1 2 equipped with thermometer, stirrer, cooling pipe and dropping funnel
In a four-necked flask, 2,2'-ethylidene bis (4,6-di-
(t-butylphenol) 438.7 g (1.0 mol), acrylic acid 72.06 g (1.0 mol), n-heptane 400 g and triethylamine 212.5 g (2.10 mol) were charged, and the air in the container was replaced with nitrogen, and then an oxyodor was generated while stirring. Phosphorus 200.7g
(0.70 mol) is added dropwise. After the dropping is completed, the temperature is kept at 80 ° C. for 1 hour, 500 g of water is charged, and after cooling to room temperature, the product is separated. The obtained product was washed with water until the washing liquid became neutral to give white crystalline 2,2'-ethylidene bis (4,6-di-t-butylphenol) monoacrylate having a melting point of 189 to 190 ° C. Obtained 468.1 g.

This compound is the No. 1 compound shown in Table 1 above, but some other compounds shown in Table 1 were produced by the method according to the above and used in the following Examples. In addition, the compounds shown in Table 2 below were used as comparative examples. In the structural formula of Table-2, Is a t-butyl group, Means a cyclohexyl group, respectively.

Example 1 In a nitrogen gas atmosphere, 1,3-butadiene in n-hexane was catalyzed by n-butyllithium at 60 to 65 ° C.
Was polymerized. Using isopropyl alcohol as a polymerization terminator, after the completion of the polymerization, a predetermined amount of the test compound shown in Table 3 was added, and then n-nitrogen gas atmosphere was added at 190 to 200 ° C.
-Hexane was removed by flash evaporation to obtain a polybutadiene rubber composition. Table 3 shows the addition amount of the test compound in parts by weight based on 100 parts by weight of polybutadiene.

The obtained polybutadiene rubber composition was subjected to a kneading test in a nitrogen stream using a Labo Plastomill (manufactured by Toyo Seiki Co., Ltd., 40-100 type) to prevent gelation occurring during kneading.
It was evaluated by the torque behavior associated with gelation. Table of results
3 shows.

The gelation prevention effect is represented by the time to the torque peak (gelation time), and the longer the time, the better the gelation prevention effect.

[Labo Plastomill test conditions]

(1) Mixer R-60 type (2) Measuring torque range 0-500Kg ^- cm (3) Charge amount 30g (4) N ₂ flow speed 1 / min (5) Test temperature 180 ℃ (6 ) Rotational speed preheating (3 minutes 10r.pm)
After that, the degree of coloration after high-temperature treatment at the time of obtaining the polybutadiene rubber (BR) was judged with the naked eye and shown in Table 3 by the following symbols.

◯: No coloration Δ: Light yellow coloration ×: Yellow coloration Example 2 In a nitrogen gas atmosphere, 0.08 of n-butyllithium was added to a cyclohexane solution containing 20 parts by weight of 1,3-butadiene.
After adding 1 part by weight and polymerizing at 70 ° C. for 1 hour, 20 parts by weight of styrene, 15 parts by weight of 1,3-butadiene, and 45 parts by weight of styrene were sequentially added, and polymerization was carried out at 70 ° C. for 1 hour. . After completion of the polymerization, a predetermined amount of the test compound shown in Table 4 was added, and cyclohexane was removed by heating under a nitrogen gas atmosphere to give a block copolymer composition having a BABAA structure having a butadiene content of 35% by weight. Got In Table 4, the addition amount of the test compound is shown in parts by weight based on 100 parts by weight of the block copolymer.

The obtained block copolymer composition was subjected to a filamentous drop extrusion test using a Labo Plastomill extruder under the following conditions, and the gel content of the obtained filamentous material was measured and evaluated as a toluene insoluble matter. The gel content is measured by immersing approximately 1 g of a precisely weighed filamentous sample in 200 ml of toluene, stirring for 24 hours, passing through a 200-mesh wire net, drying the residue, and measuring the weight, and calculating from the weight ratio before and after the test. did. The results are shown in Table-4.

〔Test condition〕

(1) Testing machine body Laboplast mill 40-100 type (manufactured by Toyo Seiki) (2) Extruder D20-25 type (manufactured by Toyo Seiki) (3) Measuring conditions Strand die diameter 0.5 mmφ Cylinder temperature 230-260 ° C times Number of revolutions 3 r.pm Fall distance 93 cm Also, in this way, styrene-butadiene copolymer (SB
The degree of coloration of the filamentous sample obtained by subjecting (S) to high temperature processing was judged with the naked eye and shown in Table 4 with the following symbols.

◯: No coloration Δ: Light yellow coloration ×: Yellow coloration

Front page continued (72) Inventor Haruki Okamura 5-1, Sokai-cho, Niihama-shi, Ehime Sumitomo Chemical Co., Ltd. Chemical Industry Co., Ltd. (56) Reference JP-A-56-61323 (JP, A) JP-A-56-77241 (JP, A) JP-A-58-84835 (JP, A) JP-A-59-71341 ( JP, A)

Claims (6)

[Claims] 1. A general formula [In the formula, R ₁ is an alkyl group having 1 to 4 carbon atoms, and R ₂ is -C
The _{(CH 3) 2 -R '(} R' represents an alkyl group or a phenyl group having 1 to 5 carbon atoms) or phenyl group represented by, R ₃ is represented by respectively an acrylate or methacrylate groups] Butadiene-based polymer with phenol-based compound
A butadiene-based polymer composition, characterized in that it is contained in an amount of 0.05 to 2 parts by weight per 100 parts by weight. 2. The butadiene-based polymer composition according to claim 1, wherein R ₁ in the general formula is a methyl group. 3. The butadiene-based polymer composition according to claim 1 or 2, wherein R ₂ in the general formula is t-butyl group, t-amyl group, t-octyl group or phenyl group. object. 4. The butadiene-based polymer composition according to claim 3, wherein R ₂ in the general formula is a t-butyl group. 5. The butadiene-based polymer is a solution-polymerized polybutadiene rubber, a solution-polymerized styrene-butadiene copolymer rubber, or a styrene-butadiene block copolymer, according to any one of claims 1 to 4. Butadiene-based polymer composition. 6. The content of the phenolic compound represented by the general formula is 100 parts by weight of the butadiene-based polymer,
The butadiene-based polymer composition according to any one of claims 1 to 5, which is 0.1 to 1 part by weight.