JP3306208B2 - Thermoplastic polymer composition - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a novel thermoplastic polymer composition, and more particularly to a conjugated diene compound of a vinyl alcohol polymer and a block copolymer comprising a vinyl aromatic compound and a conjugated diene compound. A modified block copolymer obtained by epoxidizing an unsaturated carbon bond. Novel thermoplastic polymer composition with improved compatibility of both components

[0002]

2. Description of the Related Art Polyvinyl alcohol and ethylene-vinyl alcohol copolymers are obtained by saponifying corresponding polyvinyl acetate, ethylene-vinyl acetate copolymer, etc., and are gas-insulating, non-static, and oil-resistant. It is a polymer with excellent properties and the like. In particular, ethylene-vinyl alcohol-based polymer has been noted as a polymer having improved moisture permeability and moldability, which are disadvantages of polyvinyl alcohol, and particularly its gas barrier properties, non-charging properties, etc. Has been evaluated for its usefulness.

[0003]

However, in the above-mentioned ethylene-vinyl alcohol copolymers, etc., there are few types of thermoplastic polymers having good adhesive properties with these, and polyamides and special polyolefins have a slight adhesive property. Just have. Further, the ethylene-vinyl alcohol copolymer has a disadvantage that the notched Izod impact strength is not large despite its toughness.

On the other hand, a block copolymer comprising a vinyl aromatic compound and a conjugated diene compound has good compatibility with styrene resins and the like, and is useful as a modifier for these compounds. Because the compatibility with the coalescence is not always good, the mutual modification effect by the blend,
Although there were some problems, there were problems such as phase separation.

[0005]

According to the present invention, there is provided a polymer composition having improved impact resistance, in which the above-mentioned disadvantages are improved, and when a vinyl alcohol-based polymer is mainly used. In addition, it has been found that when a block copolymer is mainly used, a polymer composition having improved oil resistance can be obtained.

The present invention relates to a method comprising the steps of: (a) a vinyl alcohol polymer, (b) a polymer block of an aromatic vinyl compound and a conjugated diene compound polymer block to which epoxy is partially added. A thermoplastic polymer composition comprising an epoxy-modified block copolymer.

[0007] (A) in the thermoplastic polymer composition of the present invention
The vinyl alcohol polymer as a component is a polymer having a molecular structure of vinyl alcohol or a copolymer containing a unit of vinyl alcohol. These are vinyl ester polymers, for example, polyvinyl acetate and the like, and olefin-
A vinyl ester copolymer, for example, a polymer obtained by partially saponifying or completely saponifying a vinyl ester polymer such as an ethylene-vinyl acetate copolymer or a propylene-vinyl acetate copolymer using an alkali. . Among these, polyvinyl alcohol is relatively difficult to process as a molding material because its melting point and decomposition temperature are close to each other, and requires a processing aid, a plasticizer and moisture.

[0008] The ethylene-vinyl alcohol copolymer is
This is a characteristic of the polyvinyl alcohol. Gas barrier,
It is a polymer having improved strength and processability while maintaining antistatic properties and oil resistance. For example, it is used in films and sheets under the trade name "EVAL" (manufactured by Kuraray).

The ethylene-vinyl alcohol copolymer is
The corresponding ethylene-vinyl acetate copolymer is used as a starting material, and the ethylene-vinyl acetate copolymer generally has a vinyl acetate content of 0.5 to 80 mol%. The polymer has a vinyl acetate unit of 10 to 10.
100 mol% is saponified to form an ethylene-vinyl alcohol copolymer. In the present invention, the above-mentioned various polyvinyl alcohols or olefin-vinyl alcohol copolymers can be used, but ethylene-vinyl alcohol copolymers are preferred in view of processability and mechanical properties. However, even with other vinyl alcohol polymers,
It has sufficient compatibility with the component (b) in the thermoplastic polymer composition of the present invention.

[0010] (B) in the thermoplastic polymer composition of the present invention
Examples of the vinyl aromatic compound constituting the epoxy-modified block polymer of the component include styrene, α-methylstyrene, vinyltoluene, p-tertiary butylstyrene,
One or more of divinylbenzene, p-methylstyrene, l, l-diphenylstyrene and the like can be selected, and styrene is particularly preferred. As the conjugated diene compound, for example, butadiene, isoprene,
1,3-pentadiene, 2,3-dimethyl-1,3-butadiene, piperylene, 3-butyl-1,3-octadiene, phenyl-1,3-butadiene, etc.
A species or two or more species are selected, and among them, butadiene, isoprene and a combination thereof are preferred.

The term "block copolymer" as used herein means a block copolymer comprising a polymer block A mainly composed of a vinyl aromatic compound and a polymer block B mainly composed of a conjugated diene compound. The copolymerization ratio of the compound to the conjugated diene compound is 5/95 to 70/30,
A polymerization ratio of 0/90 to 60/40 is preferred. The number average molecular weight of the block copolymer used in the thermoplastic polymer composition of the present invention is 5,000 to 600,000, preferably 10 to 60,000.
000 to 500,000, and the molecular weight distribution [the ratio of the weight average molecular weight (Mw) to the number average molecular weight (Mn) (M
n / Mn)] is 10 or less. The molecular structure of the block polymer may be linear, branched, radial, or any combination thereof.

For example, ABA, BABA,
It is a vinyl aromatic compound-conjugated diene compound block polymer having a structure such as (AB-) ₄ Si or ABAABA. Further, the unsaturated bond of the conjugated diene compound of the block polymer may be partially hydrogenated.

As a method for producing the block polymer to be used in the thermoplastic polymer composition of the present invention, any production method having the above-mentioned structure can be adopted.
For example, Japanese Patent Publication No. 40-23798, Japanese Patent Publication No. 47-32
No. 52, Japanese Patent Publication No. 48-2423, Japanese Patent Application No. 49-105
No. 970, Japanese Patent Application No. 50-27094, Japanese Patent Publication No. 46-3
No. 2415, JP-A-59-166518, JP-B-49
-36957, JP-B-43-17979, JP-B-4
According to the methods described in JP-A-6-32415 and JP-B-56-28925, a vinyl aromatic compound-conjugated diene compound block copolymer can be synthesized in an inert solvent using a lithium catalyst or the like. In addition,
No. 8704, JP-B-43-6636, or JP-A-59-133203, hydrogenation in an inert solvent in the presence of a hydrogenation catalyst to give the thermoplastic resin of the present invention. A partially hydrogenated block copolymer to be provided in the polymer composition can be synthesized. In the present invention, the epoxy-modified block copolymer used in the present invention is obtained by epoxidizing the above-mentioned block copolymer.

The epoxy-modified block copolymer in the thermoplastic polymer composition of the present invention is obtained by reacting the above-mentioned block copolymer with an epoxidizing agent such as a hydroperoxide or a peracid in an inert solvent. be able to. As the peracids, a catalytic effect can be obtained by using a mixture of formic acid, peracetic acid, and perbenzoic acid with hydrogen peroxide, an organic acid with hydrogen peroxide, or molybdenum hexacarbonyl with tertiary butyl hydroperoxide. be able to.

The obtained epoxy-modified copolymer is isolated by a suitable method, for example, a method of precipitating with a poor solvent, a method of throwing the polymer into hot water with stirring and distilling off the solvent, and a direct desolvation method. It can be performed by law.

The thermoplastic polymer composition of the present invention can have an arbitrary composition ratio depending on the purpose of use, but the characteristics of the composition appear only as component (a) /
(B) Component = 1/99 to 99/1.

A feature of the thermoplastic polymer composition of the present invention is that the vinyl alcohol polymer as the component (a) is mainly used and the modified block copolymer as the component (b) contains about 1 to 50% by weight. In this case, a polymer composition in which the impact resistance of the vinyl alcohol polymer is significantly improved can be obtained. As shown in the examples, in the case of a composition of 75% by weight of an ethylene-vinyl alcohol copolymer and 25% by weight of an epoxy-modified styrene-butadiene block copolymer, the Izod impact strength of ethylene-vinyl alcohol was A remarkable improvement effect of 10 times or more of the value was observed. In this region, the addition of a small amount of the component (b) improves the adhesion to various materials.

On the other hand, when the modified block copolymer of the component (b) is mainly contained and contained in about 50% by weight or more,
By adding the component (a), a composition in which the modified block copolymer has improved mechanical strength, oil resistance, weather resistance, and the like can be obtained.

The thermoplastic polymer composition of the present invention is useful as an adhesive over a wide range of compositions, for example, an adhesive with a metal or a thermoplastic resin, and particularly, an adhesive between a vinyl alcohol polymer and another material. It is effective for

The thermoplastic polymer composition of the present invention can also obtain a material having new characteristics as a composition blended with various thermoplastic polymers. In addition, the thermoplastic polymer composition of the present invention contains various additives usually used for rubber or plastics, such as inorganic or organic fillers, plasticizers, softeners, tackifiers, colorants, and lubricants. , A flame retardant, an antioxidant and the like can be added.

[0021]

The thermoplastic polymer composition of the present invention can be produced by various moldings, for example, electric parts, machinery, etc. by using ordinary thermoplastic polymer processing methods such as extrusion molding, compression molding and injection molding. Parts, automotive parts, industrial parts, belts, hoses, sheets, films, daily necessities, footwear, anti-vibration rubber, medical supplies, miscellaneous goods, building materials, hollow molded products, solution type, hot melt type adhesives, adhesives It is a useful composition that can be used in various fields such as toys and toys. Some examples are shown below, but the scope of the present invention is not limited to these examples.

Reference Example <Preparation of Modified Block Copolymer><< Examples 1 to 5, Comparative Examples 1 to 4 >> EVAL of ethylene-vinyl acetate copolymer as a vinyl alcohol-based polymer
Using EP-E (manufactured by Kuraray Co., Ltd.), using the modified block copolymer samples A to D and, for comparison, the unmodified block copolymer samples EF, a composition having the composition shown in Table 1 Was obtained by kneading using a 160 ° C. mixing roll. Compression molded articles of these compositions (180
Table 1 shows the physical property values and the measured values of the adhesiveness to high-density polyethylene.

As a result of observing the samples of Example 1 and Comparative Example 1 with an electron microscope, the sample of Example 1
In the matrix of the vinyl alcohol copolymer, the modified block copolymer was uniformly dispersed as particles having a particle size of 2 μ or less, whereas the sample of Comparative Example 1 had a block copolymer particle size of about 5 to 10 μ or more. Are dispersed, and a difference in compatibility between the two was recognized.

<< Examples 6 and 7 and Comparative Examples 5 and 6 >> Table 3
Was prepared using a mixing lawn at a temperature of 160 ° C. using a modified block copolymer of the component (b) having the composition shown in (1). Compression molded articles of these compositions (180
Table 3 shows the measurement results of the physical properties, oil resistance, and adhesiveness of (C molding at ° C). As is evident from the results in Table 3, the composition of the present invention has improved tensile stress while maintaining sufficient workability, and has greatly improved oil resistance by adding a small amount of the component (A). In addition, all of the compositions of the present invention had better adhesion to polyethylene than the comparative examples.

<< Preparation Example 1 >> 300 g of a block copolymer of polystyrene-polybutadiene-polystyrene (trade name: TR2000, manufactured by Nippon Synthetic Rubber Co., Ltd.) and 3000 g of cyclohexane were placed in a jacketed reactor equipped with a stirrer and a thermometer. The mixture was dissolved at a temperature of 60 ° C. and a di-P-tolylbis (1-cyclopentadienyl) titanium / cyclohexane solution (concentration: 1 mmol) was used as a hydrogenation catalyst.
/ 1) 40 ml and 8 ml of n-butyllithium solution (concentration 5 mmol / 1) at 0 ° C.
A mixture mixed under a hydrogen pressure of 0 kg / cm ² was added and reacted at a hydrogen partial pressure of 2.5 kg / cm ^{2 for} 30 minutes. The solvent was removed from the obtained partially hydrogenated polymer solution by drying under reduced pressure (the hydrogenation ratio of the entire butadiene portion was 30%). 300 g of this partially hydrogenated polymer and 1500 g of cyclohexane were charged and dissolved.

Then, 300 g of a 30% by weight solution of peracetic acid in ethyl acetate was continuously dropped, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature, taken out of the reactor, and a large amount of methanol was added to precipitate a polymer. The polymer was separated by filtration, washed with water, and dried to obtain an epoxy-modified polymer. The obtained epoxy-modified polymer is referred to as polymer A (epoxy equivalent of the polymer is 275).

<< Preparation Example 2 >> A hydrogenated styrene-butadiene block copolymer (manufactured by Asahi Kasei Corporation, Tuftec H-series) was placed in a jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer.
1041) 400 g of cyclohexane and 1500 g of cyclohexane were charged, and 39 g of a 30% by weight solution of peracetic acid in ethyl acetate was continuously added dropwise thereto, and an epoxidation reaction was carried out at 50 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature, taken out of the reactor, washed with water, and the solvent was removed by steam stripping to obtain an epoxy-modified polymer. The obtained epoxy-modified polymer is referred to as polymer B (epoxy equivalent of the polymer is 5340).

<< Preparation Example 3 >> A block copolymer of polystyrene-polybutadiene-polystyrene (trade name: TR2000, manufactured by Nippon Synthetic Rubber Co., Ltd.) was placed in a jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer. 300
g and 1500 g of ethyl acetate were charged and dissolved. Subsequently, 169 g of a 30% by weight solution of peracetic acid in ethyl acetate was continuously dropped, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature, taken out of the reactor, and a large amount of methanol was added to precipitate a polymer. The polymer was separated by filtration, washed with water, and dried to obtain an epoxy-modified polymer. The obtained epoxy-modified polymer is referred to as polymer C (the epoxy equivalent of the polymer is 470).

<< Preparation Example 4 >> A block copolymer of polystyrene-polybutadiene polystyrene [manufactured by Shell Chemical Co., Ltd., trade name: Califflex D1122] 3 was placed in a jacketed reactor equipped with a stirrer, a reflux condenser, and a thermometer.
00g and cyclohexane 1500g were charged and dissolved.
Subsequently, 177 g of a 30% by weight solution of peracetic acid in ethyl acetate was continuously dropped, and an epoxidation reaction was carried out at 40 ° C. for 3 hours with stirring. The reaction solution was returned to room temperature, taken out of the reactor, and a large amount of methanol was added to precipitate a polymer. The polymer was separated by filtration, washed with water, and dried to obtain an epoxy-modified polymer. The obtained epoxy-modified polymer is referred to as polymer D (the epoxy equivalent of the polymer is 448).

E: block copolymer hydrogenated in Preparation Example 1 F: Tuftec H-1041 used in Preparation Example 2
(Manufactured by Asahi Kasei) G: TR2000 (manufactured by Nippon Synthetic Rubber) used in Preparation Example 3 Table 1 Example 1 Example 2 Example 3 Example 4 Example 5 Composition of composition (A) Component EVAL EP-E30 (weight) Part) 90 75 75 75 75 (b) Component Type of sample A ABCD (parts by weight) 10 25 25 25 25 Characteristic value of composition Melt index 32.0 38.0 10.2 13.0 11.2 (g / 10min) [200 ° C. × load 5 kg] Izod impact strength 27 73 17 32 25 (kg · cm / cm. notched) tensile strength at break ^{(kg / cm 2) 250 230} 310 320 350 elongation at break (%) 110 90 80 75 85 with high density polyethylene Contact property [T peel strength (kg / 25mm)] 3.0 4.1 2.9 4.8 4.2 T peel strength (kg / 25mm) conforms to JIS-K-6854 Oil resistance: weight increase rate is JIS3 Table 2 Comparative Example 1 Comparative Example 2 Comparative Example 3 Comparative Example 4 Composition of Reference Example Composition (a) Component EVAL EP-E30 (parts by weight) 75 90 75 75 100 (b) Component Type of Sample E EF G − (parts by weight) 25 10 25 25 -Characteristic value of composition Melt index 26.5 28.0 27.7 23.5 28.4 (g / 10min) [200 ° C load 5 kg] Izod impact strength 6.4 3.5 3.6 6.8 2.4 (kg · cm / cm With notch) Tensile breaking strength 343 419 351 320 450 (kg / cm ² ) Elongation at break (%) 15 27 22 10 200 Adhesion to high-density polyethylene [T peel strength (kg / 25 mm)] 0.30 0.5 1.0 1.2 0.1 or less T peel strength (kg / 25mm) conforms to JIS-K-6854 (hereinafter, blank) Table 3 Example 6 Example 7 Comparative Example 5 Comparative Example 6 Reference Example Reference Example Composition blending the object component (i) EVAL EP-E (type of sample) (parts by weight) 25 10 25 10-- (b) Component AAEEE (parts by weight) 75 90 75 90 100 100 Physical properties of the composition Melt index (g / 10min) [200 ° C load 5 kg] 25.3 40.5 30.0 45.0 90 80 Hardness (JIS A) 75 68 80 78 62 73 300 300% tensile stress (kg / cm ² ) 58 33 43 30 15 31 Elongation at break 890 920 1100 1100 980 900 Oil resistance: Weight increase rate (%) 27 40 50 56 45 73 73 Adhesion with high-density polyethylene [T peel strength (kg / 25mm)] 7.5 7.0 2.0 2.2 7.4 2.3 T peel strength (kg / 25mm) conforms to JIS-K-6854 Oil resistance: The weight increase rate is measured in JIS No. 3 oil immersion for 24 hours (below margin)

Claims (6)

(57) [Claims] 1. Component (a): a vinyl alcohol polymer and component (b): a polymer block of a conjugated diene compound in which a polymer block of a vinyl aromatic compound and epoxy are partially added in the same molecule, and And / or an epoxy-modified block copolymer comprising a hydrogenated conjugated diene compound polymer block to which epoxy is partially added. 2. The vinyl alcohol-based polymer of component (a) is an ethylene-vinyl alcohol copolymer obtained by saponifying an ethylene-vinyl acetate copolymer.
A composition as described. 3. The composition according to claim 2, wherein the ethylene-vinyl acetate copolymer contains 0.5 to 80 mol% of vinyl acetate as a monomer. 4. The composition according to claim 2, wherein the degree of saponification of vinyl acetate is 10 to 100 mol%. 5. The composition according to claim 1, wherein the modified block copolymer (b) has an epoxy equivalent of 250 to 10,000. 6. The composition according to claim 1, wherein the content of the vinyl aromatic compound in the block copolymer comprising the vinyl aromatic compound and the conjugated diene compound as the component (b) is 70% by weight or less.