TWI518130B - Block copolymer composition - Google Patents

Description

Block copolymer composition

This invention relates to a block copolymer composition, and more particularly to a block copolymer composition which maintains transparency and which does not cause fuming and odor upon extrusion.

The conjugated diene/vinyl aromatic block copolymer resin is a widely used thermoplastic polymer resin. Since the conjugated diene/vinyl aromatic block copolymer resin is excellent in transparency and impact strength, it is often used for molding articles such as beverage containers, hangers, and toys. Such copolymer resins have been mentioned in many patents, such as the Patent No. 574231 of the Republic of China or the Patent No. I300069 of the Republic of China.

In the preparation of the above block copolymer resin, a raw material such as a vinyl aromatic monomer, a conjugated diene monomer, a starter, and a solvent is usually sequentially added to the reaction tank for reaction. Then, after the polymerization reaction has completely ended, a terminator which terminates the activity of the polymer chain is added. However, the current anionic polymerization terminator (VAC) does not comply with EU EU NO 10/2011 (Food Contact Vessel Method), so it is urgent to seek other compounds that comply with EU EU NO 10/2011 and do not produce hair when it is extruded. Smoke Like the smell.

The present invention provides a block copolymer composition which maintains the transparency of the block copolymer composition and which does not generate smoke and odor when extruded.

A block copolymer composition of the present invention comprises a block copolymer (A) and a compound (B). The block copolymer (A) comprises at least one vinyl aromatic polymer block and at least one conjugated diene polymer block, and the above compound (B) is at least one selected from the group consisting of the formula (1). a phosphate and a derivative thereof, a phosphite represented by the formula (2) and a derivative thereof, a fatty acid having a carbon number of 6 to 9 and an alkyl group having a terminal carbon of 4, and a derivative thereof, or a combination thereof, In the formulae (1) and (2), R ¹ , R ² , R ³ and R ⁴ each independently represent an alkyl group having 4 to 10 carbon atoms or a phenyl group.

In one embodiment of the present invention, the composition has a block copolymer composition of 100 parts by weight, and the compound (B) has a content of from 10 ppm to 3000 ppm.

In one embodiment of the present invention, the composition has a block copolymer composition of 100 parts by weight, and the content of the compound (B) is in the range of 10 ppm to 2500 ppm.

In an embodiment of the invention, R ¹ and R ^{2 are the} same.

In an embodiment of the invention, R ³ and R ^{4 are the} same.

In one embodiment of the present invention, the phosphate ester represented by the above formula (1) is dioctyl phosphate.

In one embodiment of the present invention, the phosphite represented by the above formula (2) is diphenyl phosphite.

In one embodiment of the present invention, the above-mentioned fatty acid having an alkyl group having 6 to 9 carbon atoms and a terminal carbon of 4th stage is an alkane having a carbon number of 6 to 9 and having a terminal carbon of 4 and a main chain having a tertiary carbon structure. Base of fatty acids.

In one embodiment of the present invention, the fatty acid having an alkyl group having 6 to 9 carbon atoms and having a terminal 4 carbon and a main chain having a tertiary carbon structure is 3,5,5-trimethylhexanoic acid.

In an embodiment of the invention, the block copolymer (A) contains from 25% by weight to 80% by weight of the vinyl aromatic monomer unit, and from 20% by weight to 75% by weight of the conjugated diene monomer unit.

In an embodiment of the invention, the block copolymer (A) has a weight average molecular weight of 110,000 to 170,000.

Based on the above, the block copolymer composition provided by the present invention contains the compound (B) having a specific structure, and the block copolymer composition can be maintained by using the compound (B) to form a molded product of the block copolymer composition. Transparency, and does not produce smoke and odor when pushed out.

The above described features and advantages of the invention will be apparent from the following description.

Hereinafter, embodiments of the invention will be described in detail. However, these embodiments are illustrative, and the disclosure of the present invention is not limited thereto.

In an embodiment of the invention, the block copolymer composition comprises a block copolymer (A) and a compound (B). The block copolymer (A) and the compound (B) will be described in detail below.

Block copolymer (A)

The block copolymer (A) of the present invention comprises at least one vinyl aromatic polymer block and at least one conjugated diene polymer block. The block copolymer (A) preferably contains from 25% by weight to 80% by weight of the vinyl aromatic monomer unit and from 20% by weight to 75% by weight of the conjugated diene monomer unit, more preferably a vinyl group. 27% by weight to 78% by weight of the aromatic monomer unit and 22% by weight to 73% by weight of the conjugated diene monomer unit, preferably 30% by weight to 75% by weight of the vinyl aromatic monomer unit and conjugated The diene monomer unit is from 25% by weight to 70% by weight. The vinyl aromatic monomer unit and the conjugated diene monomer unit refer to a structural unit of a polymerized vinyl aromatic monomer and a conjugated diene monomer in the block copolymer (A). When the content of the vinyl aromatic monomer unit is from 25% by weight to 80% by weight and the content of the conjugated diene monomer unit is in the range of from 20% by weight to 75% by weight, the low temperature impact resistance of the block copolymer (A) The balance of physical properties such as strength, transparency and folding resistance is good.

The molecular structure of the block copolymer (A) of the present invention is preferably a linear molecule The structure has a good effect on the balance of physical properties such as fluidity and folding resistance of the block copolymer (A).

The molecular structure of the block copolymer (A) of the present invention, such as a molecular structure containing a branch, will contribute to the melt strength and extrusion appearance of the block copolymer (A). Further, the block copolymer (A) of the present invention is preferably a tapered block which does not contain a vinyl aromatic monomer and a conjugated diene monomer to facilitate softening point and low temperature resistance. Physical property balance such as impact strength.

Specific examples of the above vinyl aromatic monomer are: styrene (SM), o-methyl styrene, p-methyl styrene, and - third P-tert-butyl styrene, 1,3-di-butyl styrene, α-methyl styrene, ethyl styrene 2,4-dimethylstyrene, α-methyl-p-methylstyrene, bromine-styrene, of which styrene is preferred. The above vinyl aromatic monomers may be used singly or in combination of several kinds.

Specific examples of the above conjugated diene monomer are, for example, 1,3-butadiene (abbreviated as BD), 2-methyl-1,3-butadiene, and 2,3-bis-A. -1,3-butadiene, 1,3-pentadiene, 1,3-hexadiene, etc., of which 1,3-butadiene or 2-methyl-1,3-butadiene It is better. The above conjugated diene monomers may be used singly or in combination of several kinds.

The weight average molecular weight of the block copolymer (A) of the present invention is preferably from 110,000 to 170,000, more preferably from 115,000 to 165,000, and most preferably from 120,000 to 161,000.

Compound (B)

The compound (B) of the present invention is at least one selected from the group consisting of a phosphate ester represented by the following formula (1) and a derivative thereof, a phosphite represented by the following formula (2), and a derivative thereof, having a carbon number of 6 to 9 And the fatty acid and its derivative of the alkyl group of the 4-stage carbon, or a combination thereof.

Equation (1) is as follows: In the formula (1), R ¹ and R ² are each independently an alkyl group having 4 to 10 carbon atoms or a phenyl group.

The above R ¹ and R ² are each independently specific, for example, butyl, pentyl, hexyl, heptyl, octyl, decyl, decyl or phenyl; preferably octyl.

R ¹ and R ² in the formula (1) may be the same or different; preferably, R ¹ and R ^{2 are the} same.

Specific examples of the formula (1) are Dioctyl phosphate represented by the following structural formula.

Equation (2) is as follows: In the formula (2), R ³ and R ⁴ are each independently an alkyl group having 4 to 10 carbon atoms or a phenyl group.

The above R ³ and R ⁴ are each independently specific, for example, butyl, pentyl, hexyl, heptyl, octyl, decyl, decyl or phenyl. Phenyl is preferred.

R ³ and R ⁴ in the formula (2) may be the same or different; preferably, R ³ is the same as R ⁴ .

Specific examples of the formula (2) are Diphenyl phosphonate represented by the following structural formula.

Specific examples of the above fatty acid having an alkyl group having 6 to 9 carbon atoms and a terminal 4 carbon atom are as follows: 2,3,3-trimethylbutanoic acid, 3,4,4 -3,4,4-trimethylpentanoic acid, 2,4,4-trimethylpentanoic acid, 2-ethyl-2,3,3- 2-ethyl-2,3,3-trimethylbutanoic acid, 3,5,5-trimethylhexanoic acid, 2,2,4,4- 2,2,4,4-tetramethylpentanoic acid, 4,4-dimethylpentanoic acid, 5,5-dimethylhexanoic acid (5,5- Dimethylhexanoic acid), 6,6-dimethylheptanoic acid, and the like. Further, a fatty acid having an alkyl group having 6 to 9 carbon atoms and a terminal 4 carbon and a main chain having a tertiary carbon structure is preferred.

In one embodiment, the above fatty acid having an alkyl group having 6 to 9 carbon atoms and having a terminal 4 carbon and a main chain having a tertiary carbon structure, such as 3,5,5-trimethyl having the following structural formula Acid (3,5,5-trimethylhexanoic acid)

The derivative in the above compound (B) means a phosphate represented by the formula (1), a phosphite represented by the formula (2) or a fatty acid having an alkyl group having 6 to 9 carbon atoms and a terminal 4 carbon. The salt formed after the hydrogen ion is replaced by an alkali metal ion. Specific examples of the derivative are, for example, lithium 3,5,5-trimethylhexanoate formed by substituting a hydrogen ion in the above 3,5,5-trimethylhexanoic acid with a lithium ion.

The above compound (B) may be used singly or in combination of several kinds.

In the block copolymer composition of the present invention, the content of the compound (B) is preferably from 10 ppm to 3000 ppm, more preferably from 10 ppm to 2500 ppm, based on 100 parts by weight of the above block copolymer composition; The best is between 15ppm and 2200ppm. When the content of the above compound (B) is in the range of 10 ppm to 3000 ppm, it has a preferable polymerization termination effect, and the obtained block copolymer composition has good transparency, and does not generate smoke and odor when extruded. .

Preparation of block copolymer composition

The method for preparing the block copolymer composition of the present invention comprises the steps of: first carrying out the polymerization reaction of the block copolymer (A), and then adding the compound (B) of the present invention, and removing the solvent to dry, thereby obtaining the present invention. The block copolymer composition. In more detail, the polymerization reaction of the block copolymer (A) in the block copolymer composition of the present invention is carried out by dissolving a monomer in a solvent for polymerization, and then adding the compound (B) of the present invention, followed by A polymer cement is formed in the solvent, and the above-mentioned dope usually contains 10% by weight to 35% by weight of the solid matter, and the above-mentioned dope may be pre-concentrated to 50% by weight to 99% by weight of the solid matter under reduced pressure or heating, and then The block copolymer group of the present invention can be obtained by using a vacuum oven, a devolatizing extruder, or introducing hot water to remove the remaining solvent. Adult.

In the polymerization reaction, a raw material such as a vinyl aromatic monomer, a conjugated diene monomer, a starter, and a solvent is sequentially added to the reaction vessel for reaction. After the monomer reaction is completed at each stage, the next stage of the reaction monomer feed is carried out. Whether the reaction is complete or not can be judged according to the reaction temperature, and when the reaction temperature stops rising, the reaction is completed. The polymerization temperature in the polymerization reaction is, for example, between -40 ° C and 150 ° C, preferably 40 to 120 ° C; the polymerization time and the polymerization pressure vary depending on the polymerization conditions, wherein the polymerization time is usually within 20 hours. Preferably, it is 0.1 to 10 hours, more preferably 0.5 to 5 hours. In addition, it is necessary to prevent the incorporation of impurities during polymerization, such as water, acids, carbon dioxide, and the like.

After the completion of the polymerization, the compound (B) in the block copolymer composition of the present invention is further added.

Starting agent (C)

In the block copolymer composition of the present invention, when the block copolymer (A) is subjected to a polymerization reaction, the starting agent (C) to be used is, for example, an organic alkali metal compound, and the general formula may be represented by RM, wherein R represents an alkyl group having 1 to 20 carbon atoms, a cycloalkyl group, an aryl group, preferably an alkyl group; and M represents an alkali metal such as lithium, sodium or the like, preferably lithium. The amount of the above-mentioned initiator (C) is determined depending on the molecular weight of each block or block copolymer (A) required, and is usually 0.01 to 1.0 part by weight based on 100 parts by weight of the monomer.

Among the above organic alkali metal compounds, specific examples of the organolithium compound are, for example, n-propyllithium, n-butyllithium (abbreviated as n-BuLi), second butyllithium, t-butyllithium, n-pentyllithium, n-hexyllithium , benzyl lithium, phenyl lithium, tolyl Tolyl lithium, trimethylene dilithium, tetramethylene dilithium, butadiene dilithium and isoprene dilithium, among which n-butyllithium is preferred. Further, the above-mentioned initiator (C) may be used singly or in combination of several kinds.

Solvent (D)

In the block copolymer composition of the present invention, the solvent (D) to be used in the polymerization reaction of the block copolymer (A) may, for example, be pentane, hexane, octane or cyclohexane. Preferably, cyclohexane is used. The above solvent (D) may be used singly or in combination of several kinds.

Polar compound (E)

The polymerization rate and 1,2-vinyl content of the block copolymer (A) in the block copolymer composition of the present invention at the time of polymerization can be adjusted by the polar compound (E). Examples of the polar compound (E) include ethers, amines, thioethers, phosphines or phosphoniumamines, and potassium or sodium salts of alkyl oxides. Specific examples suitable for the present invention are as follows:

(a) Ethers: dimethyl ether, diethyl ether, dibutyl ether, diphenyl ether, tetrahydrofuran (THF), tetrahydropyran, diethylene glycol dimethyl ether (diethylglycol dimethyl) Ester), ethylene glycol dibutyl ether, diethylene glycol diethyl ether, diethylene glycol dibutyl ether, diphenyl ether, and the like.

(b) Amines: tertiary amine, trimethylamine, triethylamine, tripropylamine, tributylamine, tetramethyl-ethylenediamine, diethylaniline, pyridine, ring tertiary Amines, etc.

(c) Phosphine or phosphoniumamines: tris-phenylphosphine, hexamethylphosphoniumamine and the like.

(d) Potassium or sodium salt of an alkyl oxide: potassium butoxide.

Among the above specific examples, tetrahydrofuran is preferred. Further, the polar compound (E) may be used singly or in combination of several kinds.

The amount of the polar compound (E) to be added is preferably 0.005 to 10 parts by weight, more preferably 0.03 to 1 part by weight, per 100 parts by weight of the total of the vinyl aromatic monomer and the conjugated diene monomer. The optimum is 0.06 to 0.6 parts by weight.

Additive (F)

The block copolymer composition of the present invention may be added with a suitable additive (F) such as an antioxidant, a chelating agent, a slip agent, an antistatic agent, a weathering agent and the like.

Among them, the antioxidant can be used, for example, a phenol-based antioxidant, a thioether-based antioxidant, or a phosphorus-based antioxidant.

The phenolic antioxidant is preferably added in an amount of 0.005 to 2.0 parts by weight (relative to 100 parts by weight of the block copolymer), and specific examples of the phenolic antioxidant are, for example, octadecyl (3,5-bis-tert-butyl group). 4-hydroxyphenyl)-propionate, triethylene glycol bis[3-(3-tert-butyl-5-methyl-4-hydroxyphenyl)propionate], tetra[methylene-based- 3-(3,5-bis-tert-butyl-4-hydroxyphenyl)propionate]methane, 2-tert-butyl-6-(3-tert-butyl-2-hydroxy-6-methyl Benzyl)-4-methylphenyl acrylate, 2,2'-methylene-bis(4-methyl-6-tert-butylphenol), 2,2'-thiobis(4-methyl) -6-tert-butylphenol), 2,6-di-t-butyl-4-methylphenol, 2,2'-thio-diethylene-bis[3-(3,5- Bis-tert-butyl-4-hydroxyphenyl)propionate], 2,2'-ethylenediamine-bis[ethyl-3-(3,5-bis-tert-butyl-4-hydroxybenzene) Propionate et al., wherein octadecyl (3,5-bis-tert-butyl-4-hydroxyphenyl)-propionate is preferred.

The addition of the thioether antioxidant is 0.005 to 2.0 parts by weight (relative to the embedded 100 parts by weight of the segment copolymer is preferred, and specific examples of the thioether-based antioxidant are: distearyl thiodipropionate, dipalmitoside dipropionate, pentaerythritol-tetra-(β-tweldium) Methyl-thiopropionate, dioctadecyl sulfide, 2,4-bis(n-octylthiomethyl)-6-methylphenol [2,4-bis(n-octyl thio methyl) -6-methyl phenol], 2,4-bis(2',3'-di-hydroxypropylthiomethyl)-3,6-dimethylphenol [2,4-bis(2',3'- Di-hydroxy propylthio methyl)-3,6-di-methyl phenol], 2,4-bis(2'-acetoxyethylthiomethyl)-3,6-di-methylphenol [2,4 -bis(2'-acetyloxy ethyl thiomethyl)-3,6-di-methyl phenol], 4,6-bis(octylthiomethyl)-o-cresol [4,6-bis(octyl thio methyl) -0-cresol] and the like, wherein 4,6-bis(octylthiomethyl)-o-cresol is preferred.

The phosphorus-based antioxidant is a phosphite-based antioxidant or a phosphate-based antioxidant, and the amount thereof is preferably 0.015 to 2.0 parts by weight (100 parts by weight based on the block copolymer), and specific examples of the phosphorus-based antioxidant are as follows: Tris(nonylphenyl)phosphite, dodecyl phosphite, cyclic neopentane tetrahydronaphthyl bis(octadecylphosphite), 4,4'-butylene double (3- Methyl-6-t-butylphenyl-bistridecylphosphite), tris(2,4-t-butylphenyl)phosphite, tetrakis(2,4-t-butylbenzene) Base)-4,4'-extended biphenyl phosphate, 9,10-dihydro-9-oxy-10-phosphate phenanthrene-10-oxo, and the like.

The amount of the chelating agent to be added is preferably 0.001 to 2.0 parts by weight (100 parts by weight based on the block copolymer), and specific examples thereof include a sodium salt of benzhydrylmethane and ethylenediaminetetraacetic acid.

The amount of the slip agent added is preferably 0.03 to 5.0 parts by weight (relative to 100 parts by weight of the block copolymer), and specific examples thereof include calcium stearate, magnesium stearate, lithium stearate, and the like. Metal soap, ethylene distearylamine, methyl distearylamine, palmitate, butyl stearate, palmitate stearate, polypropionate tristearate, n-docosane A compound such as an acid or a stearic acid, a polyethylene wax, a octadecanoic acid wax, a carnauba wax, a petroleum wax or the like.

The following experiments are listed to verify the effects of the present invention, but the scope of the present invention is not limited to the following experiments. The following examples describe the invention in more detail.

Experimental example 1~11

The raw materials used are:

1. The vinyl aromatic monomer is styrene (SM for short).

2. The conjugated diene monomer is 1,3-butadiene (abbreviated as BD).

3. The initiator (C) is n-butyllithium (abbreviated as n-BuLi) at a concentration of 8 wt%.

4. The polar compound (E) is tetrahydrofuran (abbreviated as THF).

5. The compound (B) has (1) dioctyl phosphate, (2) diphenyl phosphite, and (3) 3,5,5-trimethylhexanoic acid, respectively.

6. Solvent (D) uses cyclohexane.

First, polymerization is carried out in a batch reactor in the presence of nitrogen, wherein the reaction pressure is about 1 kg/cm ² to 3 kg/cm ² , the reaction temperature is 50 ° C to 120 ° C, and the reaction time is about 60 minutes to 150 minutes. The reactor volume was 160 liters, the solvent (D) used cyclohexane, and the feed sequence and material weight were as shown in Table 1. After the completion of the above reaction, the compound (B) shown in Table 1 was added.

After the reaction is completed, the obtained cement contains about 25% by weight of solid content, after which The slurry is passed through hot water to remove the solvent, and the wet colloidal particles are recovered and then dehydrated by an extruder to dry and dehydrate to obtain a block copolymer composition of the present invention for comparison.

testing method

1. Determination of content:

After 1 gram of the block copolymer composition is dissolved in acetone, methanol is added to cause the high molecular weight polymer to aggregate and settle, and the upper layer liquid is taken and used as a gas chromatograph (FID) with a flame ionization detector (FID). Quantitative analysis was performed (manufactured by Hewlett Packard; model 6890, column HP-5).

2. Terminate the effect test:

After the block copolymer composition was granulated by an extruder, the particles were subjected to hot press forming, and the test pieces which were incomplete were easily yellowed. The results are shown in Table 1.

○: The test piece did not yellow.

×: The test piece is yellow.

3. Departure smoke test:

The smoldering behavior was observed in the above-mentioned termination effect test. The results are shown in Table 1.

○: No smoking.

×: There is a smoke phenomenon.

4. Execution of the odor test:

The odor was observed in the extrusion process in the aforementioned termination effect test. The results are shown in Table 1.

○: No odor.

×: There is a smell.

Comparative Example 1~11

The compound added after the completion of the reaction was changed to (1) Lauric acid, (2) tributyl phosphate, 3-mercapto propionic acid, 4) Trimethylhexanol (3,5,5-Trimethyl-1-hexanol), using the same raw materials, weights and feed sequences as in Experimental Examples 1 to 11, see Table 2.

The test results of the block copolymer compositions of Comparative Examples 1 to 11 and the test results of the smog and the odor were obtained by the above test methods, and are shown in Table 2.

From the results of Tables 1 and 2, it is understood that the block copolymer composition of the present invention has a good termination effect, so that the test piece has no yellowing and the transparency of the block copolymer composition can be maintained. Further, the block copolymer composition of the present invention does not generate smoke and odor when it is extruded.

Although the present invention has been disclosed in the above embodiments, it is not intended to limit the present invention, and any one of ordinary skill in the art can make some changes and refinements without departing from the spirit and scope of the present invention. The scope of protection of the present invention It is subject to the definition of the scope of the patent application attached.

Claims (10)

A block copolymer composition comprising: a block copolymer (A) comprising at least one vinyl aromatic polymer block and at least one conjugated diene polymer block; and a compound (B), which is at least one And a fatty acid ester represented by the formula (1) and a derivative thereof, a phosphite represented by the formula (2) and a derivative thereof, a fatty acid having an alkyl group having a carbon number of 6 to 9 and a terminal carbon of 4, and a derivative thereof, or a combination thereof, In the formulae (1) and (2), R ¹ , R ² , R ³ and R ⁴ are each independently an alkyl group having 4 to 10 carbon atoms or a phenyl group, wherein the block copolymer composition is 100 parts by weight. The content of the compound (B) ranges from 10 ppm to 3000 ppm. The block copolymer composition according to claim 1, wherein the block copolymer composition is 100 parts by weight, and the compound (B) is contained in an amount ranging from 10 ppm to 2500 ppm. The block copolymer composition according to claim 1, wherein R ¹ and R ^{2 are the} same. The block copolymer composition according to claim 1, wherein R ³ is the same as R ⁴ . The block copolymer composition according to claim 1, wherein the phosphate represented by the formula (1) is dioctyl phosphate. The block copolymer composition according to claim 1, wherein the phosphite represented by the formula (2) is diphenyl phosphite. The block copolymer composition according to claim 1, wherein the fatty acid having an alkyl group having 6 to 9 carbon atoms and a terminal 4 carbon is a carbon number of 6 to 9 and a terminal 4 carbon. A fatty acid having an alkyl group having a 3-stage carbon structure in the main chain. The block copolymer composition according to claim 7, wherein the fatty acid having an alkyl group having 6 to 9 carbon atoms and having a terminal 4 carbon and a main chain having a tertiary carbon structure is 3, 5, 5 - Trimethylhexanoic acid. The block copolymer composition according to claim 1, wherein the block copolymer (A) contains from 25 to 80% by weight of the vinyl aromatic monomer unit, and the conjugated diene monomer The unit is from 20% by weight to 75% by weight. The block copolymer composition according to claim 1, wherein the block copolymer (A) has a weight average molecular weight of 110,000 to 170,000.