JPH04311756A - Hydrogenated block copolymer composition - Google Patents

Abstract

PURPOSE:To obtain a block copolymer having excellent heat resistance, comprising a block of a vinyl aromatic compound and a block of a hydrogenated conjugated diene compound. CONSTITUTION:(A) 100 pts.wt. hydrogenated block copolymer containing one or more polymer blocks consisting essentially of a vinyl compound and one or more hydrogenated polymer blocks consisting essentially of a conjugated diene compound is blended with (B) 0.01-5 pts.wt., preferably 0.1-3 pts.wt. phenolic compound shown by formula I (R<1> is 12-3C alkyl), (C) <=15 pts.wt. based on the component B of a sulfur-based compound selected from compounds shown by formula II and formula III (R<2> is 1-28C alkyl; R<3> is 4-20C alkyl), further (D) a phosphorus-based antioxidant and (E) a hindered amine-based light stabilizer.

Description

[Detailed description of the invention]

0001

[Field of Industrial Application] The present invention relates to hydrogenated block copolymer compositions, and more particularly to the stabilization of block copolymers having a block of a vinyl aromatic compound and a block of a hydrogenated conjugated diene compound. The present invention relates to a formulated composition.

0002

[Prior Art] Thermoplastic elastomers can be molded in the same manner as thermoplastics and have rubber elasticity, so they are used in various fields, such as plastic modification,
It has become widely used in fields such as the modification of adhesives and asphalt, and various industrial applications, and its excellent properties are attracting attention. Among these, styrenic block copolymers having a styrene block and a conjugated diene block are widely used in fields where rubber elasticity is important because they have superior rubber elasticity compared to other thermoplastic elastomers. However, the styrene/conjugated diene block copolymer has an unsaturated bond derived from the conjugated diene compound in its molecule, and therefore has a drawback of poor heat resistance.

In order to improve these drawbacks, the unsaturated bonds of the conjugated diene block portion constituting the styrene/conjugated diene block copolymer are hydrogenated to form a styrene/conjugated diene block copolymer.
It is known that it can be modified to have a structure similar to that of olefin block copolymers. Although the hydrogenated block copolymer thus obtained has significantly improved heat resistance compared to an unhydrogenated block copolymer, its heat resistance is still not necessarily sufficient.

For this reason, phenolic antioxidants and sulfur antioxidants have conventionally been used alone or in combination for hydrogenated block copolymers. For example, the following are typically used as phenolic antioxidants. 2,6-di-t
-butyl-4-methylphenol, n-octadecyl
3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, pentaerythrityl tetrakis [3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate].

[0005] Further, as the sulfur-based antioxidant, for example, the following are typically used. Dilauryl 3,3'-thiodipropionate, dimyristyl
3,3'-thiodipropionate, distearyl
3,3'-thiodipropionate.

[0006]

[Problems to be Solved by the Invention] Although the heat resistance of hydrogenated block copolymers is improved by blending such phenolic antioxidants and/or sulfur antioxidants, it is still not always fully satisfied. However, it has been desired to further improve the heat resistance of hydrogenated block copolymers. Therefore, the present inventors conducted extensive research to further improve the heat resistance of hydrogenated block copolymers, and as a result, they arrived at the present invention.

[0007]

[Means for Solving the Problems] That is, the present invention provides at least one polymer block A mainly composed of a vinyl aromatic compound and at least one hydrogenated polymer block B mainly composed of a conjugated diene compound. The hydrogenated block copolymer having the general formula (I)

[0008]

[C4]

The present invention provides a hydrogenated block copolymer composition containing a phenolic compound represented by the formula (wherein R1 represents an alkyl group having 1 to 3 carbon atoms).

The present invention also provides a hydrogenated block copolymer containing a sulfur compound, a phosphorus antioxidant, and/or a hindered amine light stabilizer in addition to the phenol compound represented by the general formula (I). A composition is provided.

[0011] The hydrogenated block copolymer used in the present invention is
It has a structure having at least one polymer block A mainly composed of a vinyl aromatic compound and at least one hydrogenated polymer block B mainly composed of a conjugated diene compound, for example, the following structure. can be mentioned. A-(B-A)m, B-(A-B)m, (
A-B)m, (A-B)nX, (B-A)n
X Here, m is 1 to 3, n is 2 to 4, and X represents a residue of a coupling agent. The hydrogenated block copolymer is preferably a polymer block A mainly composed of a vinyl aromatic compound.
5 to 95% by weight, more preferably 10 to 80% by weight.

Polymer block A mainly composed of vinyl aromatic compounds constituting the hydrogenated block copolymer can be obtained by homopolymerization of vinyl aromatic compounds or by copolymerization of vinyl aromatic compounds with other copolymerizable monomers. Obtained by polymerization. The vinyl aromatic compounds that make up this block are:
It is a compound in which a substituted or unsubstituted vinyl group is bonded to an aromatic ring, and examples thereof include styrene, α-methylstyrene, vinyltoluene, and pt-butylstyrene. Among these, styrene is particularly preferably used.

[0013] Furthermore, the hydrogenated polymer block B mainly composed of a conjugated diene constituting the hydrogenated block copolymer is a homopolymer of a conjugated diene or a polymer composed mainly of a conjugated diene and other copolymerizable monomers. It is a copolymer that is hydrogenated. Examples of the conjugated diene compound constituting the polymer before hydrogenation include butadiene, isoprene, 1
, 3-pentadiene, 2,3-dimethyl-1,3-butadiene, and the like. Among these, butadiene and isoprene are preferred.

The hydrogenated block copolymer used in the present invention is
A number average molecular weight of about 5,000 to 1,000,000 is preferable, and a number average molecular weight of about 20,000 to 500,000 is more preferable. Further, the molecular weight distribution represented by the ratio of weight average molecular weight to number average molecular weight is preferably 10 or less.

Such hydrogenated block copolymers are disclosed in, for example, Japanese Patent Publication No. 40-23798 and Japanese Patent Publication No. 43-1.
It can be produced by methods described in JP-A-9960, JP-A-61-34050, and the like.

In the present invention, a phenolic compound represented by the general formula (I) is blended into such a hydrogenated block copolymer. In the phenolic compound of general formula (I), R1 represents an alkyl group having 1 to 3 carbon atoms, ie, methyl, ethyl, n-propyl or isopropyl, with methyl being the most preferred in terms of heat resistance. The amount of the phenolic compound represented by general formula (I) is 0.01 to 100 parts by weight of the hydrogenated block copolymer.
About 5 parts by weight is preferable, more preferably 0.1 to 3 parts by weight.
It is about parts by weight. If the amount of the phenolic compound (I) is less than 0.01 parts by weight, it is difficult to obtain the desired effect, and even if it is added in excess of 5 parts by weight, the effect will not improve commensurately. Since it cannot be expected, it is economically disadvantageous.

Further, in the present invention, in addition to the phenolic compound of general formula (I), the following general formula (II-
1) and (II-2)

[0018]

[C5]

(In the formula, R2 represents an alkyl group having 2 to 18 carbon atoms)

[0020]

[C6]

Heat resistance can be further improved by combined use of a sulfur compound selected from the compounds represented by the formula (wherein R3 represents an alkyl group having 4 to 20 carbon atoms).

In the sulfur-based compound represented by the general formula (II-1), R2 represents an alkyl group having 2 to 18 carbon atoms, but an alkyl group having 10 to 18 carbon atoms is preferred from the viewpoint of heat resistance, particularly myristyl. is most preferred. Furthermore, in the sulfur-based compound represented by general formula (II-2),
R3 represents an alkyl group having 4 to 20 carbon atoms, preferably an alkyl group having 6 to 18 carbon atoms from the viewpoint of heat resistance, and most preferably dodecyl. These sulfur compounds can be used alone or in combination of two or more.

When such a sulfur compound is used in combination, 15% of the phenol compound of general formula (I)
It is used at a ratio of not more than 10 times the weight, preferably not more than 10 times the weight, and more preferably not more than 5 times the weight. Even if the sulfur-based compound (II-1) or (II-2) is blended in an amount exceeding 15 times the weight of the phenol-based compound (I), it is not possible to expect a commensurate improvement in the effect, so it is not economical. be disadvantageous to In order to fully exhibit the combined effect of these sulfur-based compounds, it is preferable to blend them in an amount of 0.01 part by weight or more per 100 parts by weight of the hydrogenated block copolymer.

Furthermore, in the present invention, in addition to the phenolic compound represented by the general formula (I), or this phenolic compound and the general formula (II-1) or (
In addition to the sulfur compound represented by II-2), a phosphorus antioxidant and/or a hindered amine light stabilizer may be used in combination. By using a hindered amine light stabilizer in combination, weather resistance can be improved to a desired level. In addition, heat resistance and weather resistance can be further improved by using a phosphorus antioxidant.

[0025] When a phosphorous antioxidant is used in combination, the amount is usually selected from the range of 5 parts by weight or less, preferably 3 parts by weight or less per 100 parts by weight of the hydrogenated block copolymer. In order to fully exhibit the effect of the combined use of the phosphorus-based antioxidant, it is preferable to mix it in an amount of 0.01 part by weight or more per 100 parts by weight of the hydrogenated block copolymer.

[0026] Preferred phosphorus antioxidants that can be used in the present invention include, for example, the following. Tris (nonylphenyl) phosphite,
Distearyl pentaerythritol diphosphite, tris(2,4-di-t-butylphenyl)
Phosphite, bis(2,4-di-t-butylphenyl) Pentaerythritol Diphosphite, tetrakis(2,4-di-t-butylphenyl)
4,4'-biphenylene diphosphonite, bis(2
-t-butyl-4-methylphenyl) pentaerythritol diphosphite, 2,2'-methylenebis(4,6-di-t-butylphenyl) octyl
Phosphite, tetratridecyl 4,4'-butylidenebis(3-methyl-6-t-butylphenyl)
diphosphite, 2,2'-ethylidene bis(4
, 6-di-t-butylphenyl) fluorophosphonite, bis(2,4,6-tri-t-butylphenyl) pentaerythritol diphosphite.

On the other hand, when a hindered amine light stabilizer is used in combination, the blending amount is usually selected from a range of 5 parts by weight or less, preferably 3 parts by weight or less, per 100 parts by weight of the hydrogenated block copolymer. In order to fully exhibit the combined effect of the hindered amine light stabilizer, it is preferable to mix it in an amount of 0.01 part by weight or more per 100 parts by weight of the hydrogenated block copolymer.

[0028] Preferred hindered amine light stabilizers that can be used in the present invention include, for example, the following. Bis(2,2,6,6-tetramethyl-4-piperidyl) sebacate, polycondensation of dimethyl succinate and 1-(2-hydroxyethyl)-4-hydroxy-2,2,6,6-tetramethylpiperidine 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}], bis(1,2,2,6,6-pentamethyl-
4-piperidyl) 2-(3,5-di-t-butyl-
4-Hydroxybenzyl)-2-butyl malonate, 4
-[3-(3,5-di-t-butyl-4-hydroxyphenyl)propionyloxy]-1-[2-{3-(3
,5-di-t-butyl-4-hydroxyphenyl)propionyloxy}ethyl]-2,2,6,6-tetramethylpiperidine, bis(1,2,2,6,6-pentamethyl-4-piperidyl) Decanedioate, Tetrakis (2,2,6,6-tetramethyl-4-piperidyl) 1,2,3,4-butanetetracarboxylate, Poly[{6-(1,1,3,3-tetramethyl butyl)imino-1,3,5-triazine-2,4-diyl}
{(2,2,6,6-tetramethyl-4-piperidyl)
imino}hexamethylene {(2,2,6,6-tetramethyl-4-piperidyl)imino}], 1,2,3,4-
Mixed ester of butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 1-tridecanol, 1,2,3,4-butanetetracarboxylic acid and 2,2,6,6 -tetramethyl-
Mixed esterified product of 4-piperidinol and 1-tridecanol, 1,2,3,4-butanetetracarboxylic acid and 1,2,2,6,6-pentamethyl-4-piperidinol and 3,9-bis(2- Hydroxy-1,
1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]mixed ester with undecane,
1,2,3,4-butanetetracarboxylic acid and 2,2
, 6,6-tetramethyl-4-piperidinol and 3
,9-bis(2-hydroxy-1,1-dimethylethyl)-2,4,8,10-tetraoxaspiro[5.5]
Mixed esterified product with undecane, N,N'-bis(2
, 2-methyl-2-(2,2,6,6-tetramethyl-4- piperidyl)amino-N-(2,2,6,6
-tetramethyl-4-piperidyl)propionamide,
N,N',4,7-tetrakis[4,6-bis{N-butyl-N-(2,2,6,6-tetramethyl-4-piperidyl)amino}-1,3,5-triazine- 2-yl]-4,7-diazadecane-1,10-diamine, N,
N',4-tris[4,6-bis{N-butyl-N-(
2,2,6,6-tetramethyl-4-piperidyl)amino}-1,3,5-triazin-2-yl]-4,7-
Diazadecane-1,10-diamine, bis(1-acryloyl-2,2,6,6-tetramethyl-4-piperidyl)2,2-bis(3,5-di-t-butyl-4-hydroxybenzyl) malonate, N,N',4,7-tetrakis[4,6-bis{N-butyl-N-(1,2,2
,6,6-pentamethyl-4-piperidyl)amino}-
1,3,5-triazin-2-yl]-4,7-diazadecane-1,10-diamine, N,N',4-tris[
4,6-bis{N-butyl-N-(1,2,2,6,6
-pentamethyl-4-piperidyl)amino}-1,3,
5-triazin-2-yl]-4,7-diazadecane-
1,10-diamine, bis(2,2,6,6-tetramethyl-4-piperidyl) succinate, 2,2,6
, 6-tetramethyl-4-piperidyl methacrylate, 1,2,2,6,6-pentamethyl-4-piperidyl methacrylate, tetrakis(1,2,2,6,
6-pentamethyl-4-piperidyl)1,2,3,4-
Butane tetracarboxylate, poly[methyl 3-
(2,2,6,6-tetramethyl-4-piperidyloxy)propylsiloxane].

In addition, in the present invention, other additives such as heat stabilizers, phenolic antioxidants other than those of formula (I), ultraviolet absorbers, lubricants, pigments, plasticizers, flame retardants, Antistatic agents, reinforcing resins, softeners for non-aromatic rubbers, inorganic fillers, etc. can also be blended. Specific examples of these other additives are shown below.

[0030] Examples of the heat stabilizer include the following. 2-t-butyl-6-(3-t-butyl-2-hydroxy-5-methylbenzyl)-4-methylphenyl acrylate, 2-[1-(2-hydroxy-3,5-di-t-pentyl) phenyl)ethyl]-
4,6-di-t-pentylphenyl acrylate.

Examples of phenolic antioxidants other than those of formula (I) include the following. n-octadecyl 3-(3,5-di-t-butyl-4-hydroxyphenyl)propionate, pentaerythrityl tetrakis [3-(3,5-di-t-butyl-4-
hydroxyphenyl)propionate], triethylene glycol bis[3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionate], 1,
3,5-trimethyl-2,4,6-tris(3,5-di-t-butyl-4-hydroxybenzyl)benzene, tris(4-t-butyl-3-hydroxy-2,6-dimethylbenzyl) Isocyanurate, 2,4-bis(
n-octylthio)-6-(3,5-di-t-butyl-
4-hydroxyanilino)-1,3,5-triazine,
Tris(3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate, 2,2'-ethylidenebis(4,6-di-t-butylphenol).

[0032] Examples of the ultraviolet absorber include the following. 2-hydroxy-4-methoxybenzophenone, 2-hydroxy-4-octoxybenzophenone, 2,2'-dihydroxy-4-methoxybenzophenone, bis(5-benzoyl-4-hydroxy-2
-methoxyphenyl)methane, 2,2',4,4'-tetrahydroxybenzophenone, 2-(2-hydroxy-5-methylphenyl)benzotriazole, 2-[2
-hydroxy-3-(3,4,5,6-tetrahydrophthalimidomethyl)-5-methylphenyl]benzotriazole, 2-(3-t-butyl-2-hydroxy-5
-methylphenyl)-5-chlorobenzotriazole,
2-(3,5-di-t-butyl-2-hydroxyphenyl)benzotriazole, 2-(2-hydroxy-5-
t-octylphenyl)benzotriazole, 2-(3
,5-di-t-amyl-2-hydroxyphenyl)benzotriazole, 2-[2-hydroxy-3,5-bis(α,α-dimethylbenzyl)phenyl]-2H-benzotriazole, 2-(3, 5-di-t-butyl-2-
hydroxyphenyl)-5-chlorobenzotriazole, 2,2'-methylenebis[6-(2H-benzotriazol-2-yl)-4-(1,1,3,3-tetramethylbutyl)phenol], poly( 3-11) (ethylene glycol) and methyl 3-[3-(2H-benzotriazol-2-yl)-5-t-butyl-4-
Condensate with hydroxyphenyl]propionate, 2-
Ethylhexyl 3-[3-t-butyl-5-(5-
Chloro-2H-benzotriazol-2-yl)-4-
Hydroxyphenyl]propionate, octyl 3
-[3-t-butyl-5-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]
Propionate, methyl 3-[3-t-butyl-5
-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionate, 3-[
3-t-butyl-5-(5-chloro-2H-benzotriazol-2-yl)-4-hydroxyphenyl]propionic acid, 2,2'-methylenebis[4-t-butyl-
6-(2H-benzotriazol-2-yl)phenol].

[0033] The reinforcing resin is preferably blended in order to improve the processability, hardness, heat deformation resistance and mechanical strength of the hydrogenated block copolymer composition. Examples include copolymers with α-olefins.

Non-aromatic rubber softeners are preferably added to improve the flexibility and processability of the hydrogenated block copolymer composition, and include mineral softeners such as paraffinic and naphthenic softeners. Examples include oil-based softeners.

In producing the composition of the present invention, a phenolic compound represented by the general formula (I), an optional sulfur compound, a phosphorus antioxidant and a hindered amine light stabilizer, or if necessary, As a means of blending other additives used in hydrogenated block copolymers into hydrogenated block copolymers, known equipment and operating methods for blending stabilizers, pigments, fillers, etc. into polymers can be applied almost directly. can. For example, after adding these stabilizers or additives to the polymer solution when producing a hydrogenated block copolymer, the solvent may be removed, or after polymerization, the hydrogenated block obtained by removing the solvent may be used. These stabilizers or additives may be dry blended into the copolymer.

[0036]

EXAMPLES Next, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples. Note that "parts" in the examples are based on weight unless otherwise specified.

The test stabilizers used in the examples are as follows, and are indicated by the respective symbols below. I: 3,9-bis[2-{3-(3-t-butyl-4-hydroxy-5-methylphenyl)propionyloxy}-1,1-dimethylethyl]-2,4,8,
10-tetraoxaspiro[5,5]undecane [compound in which R1 is methyl in general formula (I)] AO
-1: n-octadecyl 3-(3,5-di-t
-Butyl-4-hydroxyphenyl)propionate A
O-2: Pentaerythrityl tetrakis [3-
(3,5-di-t-butyl-4-hydroxyphenyl)
Propionate] II-1: Dimyristyl 3,3'-thiodipropionate [In general formula (II-1), R2 is C
14 alkyl compound] II-2: Pentaerythrityl tetrakis (3
-Laurylthiopropionate) [General formula (II-2)
P-1: tris(2,4-di-t-butylphenyl) phosphite HA-1: dimethyl succinate and 1-(
2-hydroxyethyl)-4-hydroxy-2,2,6
, polycondensate with 6-tetramethylpiperidine

Example 1 A hydrogenated block copolymer having a structure of [polystyrene/hydrogenated polybutadiene/polystyrene] and having a number average molecular weight of 80,000 was synthesized, and based on 100 parts of the copolymer in the polymer solution, After adding the test stabilizers in the proportions shown in Table 1, the solvent was removed. The resulting composition was heated to 200°C.
Compression molding was performed to create a sheet with a thickness of 2 mm, and the sheet was subjected to a heat resistance test. Heat resistance test is JIS K 6301
The specimen was placed in a gear oven at 140°C for 3
The test was carried out by allowing the test piece to stand for 0 hours and measuring the tensile strength and elongation of the test piece before and after the test. Then, the tensile strength and elongation retention after heating were calculated, and the results are shown in Table 1.

[0039]

Example 2 A hydrogenated block copolymer having a structure of [hydrogenated polybutadiene/polystyrene/hydrogenated polybutadiene/polystyrene] and having a number average molecular weight of 60,000 was synthesized, and the copolymerization in the polymer solution was After adding the test stabilizer in the ratio shown in Table 2 based on 100 parts of the combined product, the solvent was removed. The resulting composition was compression molded at 200°C to a thickness of 2
A sheet of 1.0 mm in diameter was prepared and subjected to a heat resistance test and a weather resistance test. The heat resistance test was conducted in the same manner as in Example 1, and the weather resistance test was conducted in accordance with JIS K 6301 by placing the test piece in a sunshine weather meter, with a black panel temperature of 63°C, and a water spray cycle of 18 minutes/120 minutes. The test was carried out by exposing the specimen for 300 hours under the following conditions and measuring the tensile strength and elongation of the specimen before and after the exposure. The tensile strength and elongation retention after each test were calculated, and the results are shown in Table 2.

[0041]

[0042]

[Effects of the Invention] The hydrogenated block copolymer composition of the present invention has greatly improved heat resistance by incorporating a specific phenolic compound. Furthermore, heat resistance can be further improved by blending a specific sulfur-based compound. Furthermore, by blending a hindered amine light stabilizer in addition to this phenolic compound, or in addition to these phenolic compounds and sulfur compounds, weather resistance can be particularly improved, and phosphorous oxidation inhibitors can be added. By blending the agent, heat resistance and weather resistance can be improved. Therefore, the composition of the present invention is particularly useful in fields where heat resistance is required, such as when it is used at high temperatures.

Claims (5)

[Claims] Claim 1: A hydrogenated block copolymer having at least one polymer block A mainly composed of a vinyl aromatic compound and at least one hydrogenated polymer block B mainly composed of a conjugated diene compound. , general formula (I) [
A hydrogenated block copolymer composition characterized by containing a phenolic compound represented by the following formula: (wherein R1 represents an alkyl group having 1 to 3 carbon atoms). 2. The composition according to claim 1, containing 0.01 to 5 parts by weight of the phenolic compound per 100 parts by weight of the hydrogenated block copolymer. Claim 3: Furthermore, general formulas (II-1) and (II-
2) [Chemical formula 2] (wherein, R2 represents an alkyl group having 2 to 18 carbon atoms)
[Formula 3] (wherein, R3 represents an alkyl group having 4 to 20 carbon atoms)
3. The composition according to claim 1, which contains a sulfur-based compound selected from the compounds represented by the following in an amount of 15 times or less by weight relative to the phenol-based compound. 4. The composition according to claim 1, further comprising a phosphorus antioxidant. 5. The composition according to claim 1, further comprising a hindered amine light stabilizer.