JPS63146947A - Butadiene polymer composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition, especially highly stable to gelling and discoloration due to heat deterioration in an oxygen-free atmosphere, by incorporating a butadiene polymer with a specific phenolic compounds as the stabilizer. CONSTITUTION:The objective composition can be obtained by incorporating (A) 100pts.wt. of a butadiene polymer (e.g., polybutadiene rubber by solution polymerization, styrene-butadiene copolymer rubber or styrene-butadiene block copolymer by solution polymerization) with (B) 0.05-2(pref., 0.1-1)pts.wt. by a phenolic compound of formula I [R1 is 1-4C alkyl, pref. methyl; R2 is of formula II (R' is 1-5C alkyl or phenyl), phenyl or (methacrylate (pref., t-butyl, t-amyl, t-octyl or phenyl, esp., t-butyl)] in the system after the completion of the polymerization for the butadiene polymer.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> 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 treated with a Ziegler catalyst as a catalyst. Alternatively, it is produced by anionic polymerization in a hydrocarbon solvent using an organic lithium compound. Conventionally, the polymerization solvent was removed from the polymerization solution after the polymerization reaction by a steam stripping method, but recently, energy saving A solvent direct drying method has been proposed that can theoretically minimize the amount of steam used.

However, since this method is usually processed at a high temperature of about 150 to 200°C, which is much higher than the boiling point of the polymerization solvent, problems occur such as gel formation during processing and coloring of the polymer after high temperature processing. It has been desired to improve heat resistance and coloring resistance, especially in the absence of oxygen during the polymer production process.

In extrusion molding and injection molding of high-impact polystyrene, etc., due to the high temperature and speed of kneading, fish eye gel is generated due to lack of heat resistance, resulting in a significant decrease in film properties. , problems such as coloring may occur.

Conventionally, it is well known that various phenolic, phosphorous, and sulfur-based antioxidants are added and used during the production and processing steps of butadiene-based polymers.
．． 6-di-t-butyl-4-methylphenol, 2,2
-Methylenebis(4-methyl-6-t-butylphenol), n-octadecyl 8-(8,5-di-t-butyl-4-hydroxyphenyl)propionate, triethylene glycol bis[8-(8-t-butyl) -4-
hydroxy-5-methylphenyl)propionate],
Pentaerythritol tetrakis C3-(8,5-di-
t-butyl-4-hydroxyphenyl)propionate], 1,8.5-trimethyl-2,4°6-tris(8
, 5-di-t-butyl-4-hydroxybenzyl)benzene or the like alone, or
These phenolic antioxidants may be used in combination with phosphorus antioxidants such as todoris (nonylphenyl) phosphite and distearyl pentaerythritol diphosphite, or the above phenolic antioxidants and dilauryl thiodipropionate, A method of using a sulfur-based antioxidant such as similystyl thiodipropionate, distearyl thiodipropionate, and pentaerythritol tetrakis (8-laurylthiopropionate) in combination is known.

However, these methods cannot prevent thermal deterioration (gelation) during high-temperature treatment to separate the polymer from a polymer solution during the production of butadiene-based polymers, or during high-temperature processing of butadiene-based polymers. cannot exert sufficient effect.

In addition, as a stabilizer for such butadiene-based polymers, 2-t-butyl-6-(8-t-butyl-2-hydroxy-5-methylbenzyl)-4 -Methylphenyl acrylate is described. This stabilizer is effective against thermal deterioration (gelation) during high-temperature treatment to separate the polymer from the polymer solution during the production of butadiene-based polymers, but
The problem has become clear that the hue of the separated polymer is insufficient for practical use.

Furthermore, U.S. Patent No. 4,365,082 discloses 2,2'-alkylidene bis-(4, 6-disubstituted phenol). However, this patent specification describes thermal deterioration (gelation) in the absence of oxygen during high-temperature treatment to separate the polymer from a polymer solution during the production of butadiene-based polymers, or during high-temperature processing of butadiene-based polymers. There is no mention of prevention of coloration or coloring, and the compounds disclosed in the same specification, for example, in which the 4-position of phenol is substituted with a methyl group, ethyl group, or propyl group, are It was not sufficiently effective in preventing thermal deterioration and discoloration in the absence of oxygen during the production process of polymers and high-temperature processing.

<Problems to be Solved by the Invention> For these reasons, the present inventors have developed a method for high-temperature treatment to separate a polymer from a polymer solution during the production of butadiene-based polymers, or for high-temperature processing of butadiene-based polymers. As a result of repeated research in order to prevent heat deterioration (gelation) and coloration, especially in the absence of oxygen, when carrying out products, we have found that butadiene-based polymers containing phenolic compounds with a specific structure are effective against such heat deterioration. It has been found that it is stable and does not cause coloring, leading to the present invention.

Means for Solving the Problems> That is, the present invention provides a method for solving the problems of the general formula (z) [wherein R1 is an alkyl group having 1 to 4 carbon atoms, and R2 is -
A group represented by C (for C)x* (m represents an alkyl group having 1 to 5 carbon atoms or a phenyl group) or a phenyl group,
The present invention provides a butadiene-based polymer composition containing 0.05 to 2 parts by weight of a phenolic compound represented by the following formula, respectively, per 100 parts by weight of the butadiene-based polymer.

The substituent R1 of the phenolic compound represented by the general formula (1) is most preferably a methyl group, since the fewer carbon atoms in the alkyl group, the better the gelation prevention performance of the butadiene polymer at high temperatures.

Further, R2 is a group represented by -c (cH3), -m containing 8th class carbon, or a phenyl group in order to prevent coloring of the butadiene-based polymer. The group containing 8th class carbon is preferably a t-butyl group, a t-amyl group or a t-octyl group, and among these, a t-butyl group is most preferred.

Therefore, in order to satisfy both the anti-gelation performance and the anti-coloration performance at high temperatures of butadiene-based polymers, only a combination of substituents R1, R, and the substituents of the phenolic compound represented by general formula (1) is effective. is demonstrated.

Next, the phenolic table represented by the above general formula (1)
-1 Table 1 (Continued) In the present invention, the content of the phenol compound in the butadiene polymer is 100! The amount is 0.05 to 2 parts by weight, preferably 0.1 to 1 part by weight.

Here, if the content of the phenolic compound is less than 0.05 parts by weight, the desired effect will not be sufficient, and if it exceeds 2 parts by weight, the corresponding effect will not be obtained, which is economically disadvantageous. Tend.

As a method for incorporating such a phenolic compound into the butadiene polymer, a method of adding it to the polymerization reaction solution after the 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 ultraviolet absorbers,
It may contain light stabilizers, antioxidants, metal deactivators, metal soaps, nucleating agents, lubricants, antistatic agents, flame retardants, pigments, fillers, and the like.

Specific examples of these additives include ultraviolet absorbers and hindered amine light stabilizers such as 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-
n-Octoxybenzophenone, 2-(2-hydroxy-6-methylphenyl)benzotriazole, 2-(2
-hydroxy-8-t-butyl-5-methylphenyl)
-5-chloro-benzotriazole, 2-[2-hydroxy-8,5-di-t-butylphenyl]-5-chloro-benzotriazole, 2-(2-hydroxy-8,5
-di-amylphenyl)benzotriazole, 2,4-
Di-butylphenyl 8.5-di-t-butyl-4
-Hydroxybenzoate, C2, 2'-thiobis(4
-t-octylphenolate)]-butylamine Ni salt, 2,2,6.6-tetramethyl-4-piperidylbenzoate, bis(2°2.6-tetramethyl-4-piperidyl)sebacate, 2-(8 ,5-di-t-butyl-
4-(·Hydroxybenzyl)-2-n-butyl-malonate bis(1,2,2,6,6-bentamethyl-4-piperidyl), 1-[2-(8-(8.

5-di-t-butyl-4-hydroxyphenyl)propionyloxy)ethyl)-4-[8-(8゜5-di-t
-butyl-4-hydroxyphenyl)propionyloxy)-2,2,6,6-titramethylbiveridine, dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6 - polycondensed metal with titramethylbiperidine, poly([:6-(1,1,8,8-tetramethylbutyl)amino-1,8,5-)lyazine 2.4
-diyl]l: (2,2,6,6-tetramethyl-4-
piperidyl)imino]hexamethylene[(2,2,6,
6-titramethel-4-piperidyl)imino]), poly([6-morpholino-1,8,5-1-lyazine-2,
4-diyl)((2,2,6,6-tetramethyl-4-
Piperidyl)imino]hexamethylene In addition, examples of sulfur-based antioxidants include dilauryl thiodipropionate, distearyl thiodipropionate, simiristylthiodipropionate, pentaerythritol tetrakis(8-laurylthiopropionate), 8
．． 9-bis(2-dodecylthioethyl)-2,4,8,
Examples of phosphorus antioxidants include distearyl pentaerythritol diphosphite, tris(2,4-
di-t-butylphenyl) phosphite, tris(2-
t-Butyl-4-methylphenyl) phosphite, bis(2,4-di-t-butylphenyl)pentaerythritol diphosphite, tetrakis(2,4-di-t-butylphenyl)-4,4-bipheny Examples include range phosphite.

Examples of butadiene-based polymers applicable to the present invention include solution polymerized polybutadiene rubber (BR), solution polymerized styrene-butadiene copolymer rubber (SBR), styrene-butadiene block copolymer (SBS), BR or SBR.
or high-impact polystyrene modified with SBS (HI-
PS ), and these butadiene-based polymers may be used alone or in combination with other polymers.

<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 coloring due to thermal deterioration, especially in the absence of oxygen. .

Therefore, even when the polymer is separated from the polymer solution at high temperature after the polymerization reaction is completed, a product without gel formation or coloration can be stably obtained.

It is also stable against thermal deterioration during processing processes such as injection molding and extrusion molding, and is a cause of, for example, fish eye gel formation during film forming processes, and decreased gloss and transparency during injection molding processes. It is possible to prevent the formation of microgels and obtain high-quality products without coloring.

<Examples> Next, the present invention will be explained by referring to reference examples and examples.
The present invention is not limited to these.

Reference example 1 2j equipped with a thermometer, stirrer, cooling tube and dropping funnel
In a four-eye flask, add 2,2'-ethylidene bis (4,
6-di-t-butylphenol) 488.7 f (1
,0 mol), 7ri'JruT72.06F (1,0 mol)
, n-hebutane 400F and triethylamine 212
．． 59 (2.10 mol), and after replacing the air in the container with nitrogen, add phosphorus oxybromide 200.7 without stirring.
0.70 mol of FC) is added dropwise. 80C after completion of dripping
The mixture was kept warm for 1 hour, then 500 g of water was charged, and after cooling to room temperature, the product was filtered off. The resulting product was washed with water until the washings became neutral, resulting in a melting point of 189.
~190℃ white crystalline 2,2'-ethylidene bis(
4,6-di-t-butylphenol)monoacrylate)
468.1F was obtained.

This compound is the compound of Tooth 1 shown in Table 1 above, but several other compounds shown in Table 1 were produced by a method similar to the above, and each of them has the following meanings.

Table 2 (continued) Table 2 (continued) Example 1 In a nitrogen gas atmosphere, 1,8-butadiene was
60~ with n-butyllithium as a catalyst in hexane
Polymerization was carried out at 65°C. Using isopropyl alcohol as a polymerization terminator, after the completion of polymerization, a predetermined amount of the test compound shown in Table 3 was added, and then under a nitrogen gas atmosphere, 190~
N-hexane was removed by flash evaporation at 200°C to obtain a polybutadiene rubber composition. In -3-s, the amount of the test compound added is shown in terms of the amount of N relative to the amount of polybutadiene 100].

The resulting polybutadiene rubber composition was subjected to a crosstalk test in a nitrogen stream using a Labo Blast Mill (manufactured by Toyo Seiki, model 40-100), and the gelation It was evaluated based on the torque behavior associated with the torque. The results are shown in Table-3.

The anti-gelation effect is indicated by the time to torque peak (gelation time), and the longer the time, the better the anti-gelation effect.

[Lab blast mill test conditions]

(1) Mixer R-60 type (2) Measuring torque range θ~5001z-'' (3) Charge amount 802 (4) Nx flow rate 1z/m1n (5) Test temperature 180℃ (6) Number of rotations Preheat (8 minutes 10 r, l
), m, ) after 6g r, p, m.

Further, the degree of coloration after the high temperature treatment in the dark to obtain polybutadiene rubber (BR) was visually determined and is shown in Table 8 using the following symbols.

O: No coloring △: 4 pale yellow colors ×: 4 yellow colors Example 2 In a nitrogen gas atmosphere, 0.08 i'jA of n-butyllithium was added to a cyclohexane solution containing 20 parts by weight of 1,8-butadiene. 70℃
After polymerization for 1 hour, 20 parts by weight of styrene, 1.
15 parts by weight of 8-butadiene and 45 parts by weight of styrene were added, and polymerization was carried out at 70° C. for 1 hour. After the completion of the M reaction, 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 obtain a block copolymer composition having a B-A-B-A structure with a butadiene content of 851%. I got something. Table 4 shows the amount of the test compound added in parts by weight relative to 100 parts by weight of the block copolymer.

The obtained block copolymer composition was subjected to a filament drop extrusion test under the following conditions using a Labo Plastomill extruder, and the gel content of the filament thus obtained was measured and evaluated as toluene insoluble matter. To measure the gel content, a precisely weighed filamentous sample of approximately 1 F is immersed in 200 ITIJ of toluene, stirred for 24 hours, filtered through a 200 mesh wire gauze, dried, and weighed. Calculated from the weight ratio before and after the test. did. The results are shown in Table 4.

〔Test conditions〕

(1) Testing machine body Laboplast Mill 40-100 type (manufactured by Toyo Seiki) (2) Extruder D20-25 type (manufactured by Toyo Seiki) (3) Measurement conditions Strand die diameter 0.5wφ Cylinder temperature 280-260℃ Number of revolutions: 3r, pom.

Falling distance: 980 Also, as shown above, styrene-butadiene copolymer (SB
The degree of coloration of the filamentous sample obtained by subjecting S) to Tsutsuten JJ14 processing was determined visually and is shown in Table 4 using the following symbols.

○: No appeasement △: Colored pale yellow X: Colored yellow

Claims (6)

[Claims] (1) General formula▲ Numerical formula, chemical formula, table, etc.▼ [In the formula, R_1 is an alkyl group having 1 to 4 carbon atoms, R_2
is a group represented by -C(CH_3)_2-R'(R' represents an alkyl group having 1 to 5 carbon atoms or a phenyl group) or a phenyl group, and R_3 represents an acrylate group or a methacrylate group, respectively] A butadiene-based polymer composition comprising 0.05 to 2 parts by weight of a phenolic compound per 100 parts by weight of a butadiene-based polymer. (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 a t-butyl group, a t-amyl group, a t-octyl group, or a phenyl group. (4) The butadiene-based polymer composition according to claim 8, wherein R_2 in the general formula is a t-butyl group. (5) The butadiene-based polymer according to any one of claims 1 to 4, wherein the butadiene-based polymer is a solution-polymerized polybutadiene rubber, a solution-polymerized styrene-butadiene copolymer rubber, or a styrene-butadiene block copolymer. Polymer composition. (6) The content of the phenolic compound represented by the above general formula is 0.00 parts by weight per 100 parts by weight of the butadiene polymer.
The butadiene-based polymer composition according to any one of claims 1 to 5, wherein the amount is 1 to 1 part by weight.