JPH0753799A - Thermoplastic elastomer composition - Google Patents

Abstract

PURPOSE:To obtain the subject composition excellent in flexibility, strengths, heat resistance and transparency by mixing a propylene (co)polymer with a specified hydrogenated diene copolymer and a butene-1(co)polymer in a specified ratio. CONSTITUTION:A block copolymer which is an A-B or A-B-A block copolymer (wherein A is a block of a polymer of a vinylaromatic compound, and B is a block of a polymer of a conjugated diene or a random copolymer of a vinylaromatic compound with a conjugated diene or an A-B-C block copolymer (wherein C is a taper block having a gradually increasing vinylaromatic compound content) and has a weight ratio of the vinylaromatic compound to the conjugated diene of 5/95 to 60/40 is hydrogenated to obtain a hydrogenated diene copolymer of a number-average molecular weight of 500000-600000. 1-98wt.% obtained hydrogenated copolymer is mixed with 1-98wt.% polypropylene or copolymer of propylene with a 2-8 C alpha-olefin and 1-98wt.% butene-1(co)polymer to obtain the objective composition.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermoplastic elastomer composition, and more particularly to a non-toxic thermoplastic elastomer composition having excellent mechanical strength, flexibility, transparency, heat resistance and moldability. , Daily goods, toys
Exercise equipment use, stationery use, automobile interior / exterior use, civil engineering / construction use, AV / home electric appliance use, O.I. A. Office equipment use,
It can be used for clothing / footwear, textiles, medical equipment, chemical / mining materials, packaging / transportation materials, agricultural / livestock / fishery materials, etc.

[0002]

2. Description of the Related Art Heretofore, various compositions have been proposed and put to practical use in the above fields as compositions for obtaining flexible and transparent molded products. For example, a metal salt of ethylene-acrylate copolymer, 1,2-polybutadiene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer or methacrylic acid copolymer is used as a flexible and transparent molded product. However, the heat resistance is insufficient, and there is a problem that it softens at a temperature of 100 ° C. or lower.

On the other hand, styrene-based elastomers such as styrene-butadiene block copolymers and styrene-isoprene block copolymers are excellent in flexibility, transparency and strength and have excellent low temperature characteristics, but have sufficient heat resistance. However, there is a problem in that even if the temperature is 100 ° C. or lower, the softening occurs and the shape cannot be maintained.

Therefore, hydrogenated derivatives (hereinafter abbreviated as hydrogenated block copolymers) obtained by improving the above styrene-based elastomers have been proposed, but these are excellent in flexibility, transparency and tensile strength, and are heat resistant. The properties are considerably improved as compared with the unhydrogenated product, but they are still insufficient, and the flowability at the time of melting is abnormal and the formability is poor.

Several proposals have been made regarding an elastomer composition using the hydrogenated block copolymer. For example, JP-A-50-14742 and JP-A-52-65551 disclose elastomer compositions in which a hydrogenated block copolymer is blended with an olefin polymer and a hydrocarbon oil. These elastomer compositions maintain their shape even at a temperature of about 100 ° C.,
Further, it is characterized by having good flexibility even at a low temperature of about -40 ° C and being excellent in heat aging resistance, ozone resistance, light stability and moldability.

However, since these compositions contain a large amount of hydrocarbon oil, elution of the hydrocarbon oil may be a problem in the fields of food packaging materials, medical devices and the like. Therefore, for the purpose of solving the above problems, a composition of a hydrogenated block copolymer containing no hydrocarbon oil has been proposed. For example, in JP-A-54-88950, polyethylene, ethylene acetic acid is used as a softening agent or a melt flow auxiliary agent for assisting processability in a composition of an ABA type hydrogenated block copolymer and a polypropylene resin. A composition containing a softening agent selected from vinyl copolymers and ethylene-propylene copolymers has been proposed.

However, since these softeners themselves do not have sufficient heat resistance, heat resistance can be obtained only in combination with a hydrogenated block copolymer having a specific structure, and the heat resistance is lowered. Therefore, the amount of the softening agent that can be used is limited, resulting in the problem that only a hard molded product can be obtained, and the transparency is insufficient.

Further, JP-A-59-74153 proposes a composition comprising an ABA type hydrogenated block copolymer and a polypropylene resin and further comprising an ethylene-acrylate copolymer. The ethylene-acrylate copolymer itself has good heat resistance and flexibility, so that a flexible and excellent heat resistance composition can be obtained. However, when an ethylene-acrylate copolymer is used,
The odor of the ethylene-acrylate copolymer not only limits its use in the fields of food packaging materials, medical devices, etc., but also causes problems such as whitening and moisture absorption due to hot water. Further, even with this composition, excellent transparency such as soft vinyl chloride cannot be obtained.

Molded articles using the composition based on soft vinyl chloride are excellent in transparency, flexibility and heat resistance and
It can be sterilized at high temperature because its shape can be maintained even at temperatures above ℃, and it is widely used in food packaging materials, medical equipment, etc. However, since a composition based on soft vinyl chloride usually contains a large amount of a plasticizer, the plasticizer may elute, which may cause hygiene and other problems in use. In addition, the composition based on soft vinyl chloride does not have sufficient low-temperature properties, and its flexibility significantly decreases at a temperature of 0 ° C or lower. Therefore, when it is stored in a frozen state or the like, there is a possibility that problems such as damage due to impact of the molded product may occur.
In addition, harmful gas may be generated during the incineration process.

[0010]

The object of the present invention is to solve the above-mentioned problems of the prior art and to provide a novel elastomer composition which is excellent in flexibility, strength, heat resistance, transparency and moldability and which is non-toxic. There is a place to do it.

[0011]

As a result of research, the present inventors have blended a hydrogenated diene-based copolymer having the above-mentioned specific structure with a polypropylene-based resin, and further added polybutene-1.
The present inventors have completed the present invention by discovering the surprising fact that a nontoxic elastomer composition having excellent flexibility, heat resistance, strength, transparency and moldability can be obtained by combining a system polymer.

That is, the present invention relates to (a) propylene homopolymer and / or copolymers 1 to 98 of propylene and an α-olefin having 2 to 8 carbon atoms.
%, And (A) a vinyl aromatic compound polymer block (A) and a conjugated diene polymer or a vinyl aromatic compound and a conjugated diene random copolymer block (B) (A)
-(B) or (A)-(B)-(A) block copolymer, or taper block (C) consisting of vinyl aromatic compound and conjugated diene and gradually increasing vinyl aromatic compound
(A)-(B)-(C) block copolymer, wherein the ratio of vinyl aromatic compound / conjugated diene is 5 by weight.
/ 95-60 / 40, the amount of vinyl aromatic compounds bound in components (A) and (C) is 3 to 50% by weight of all monomers, and the amount of vinyl aromatic compounds bound in components (A) is total monomers. 3% by weight or more, the vinyl bond amount of the conjugated diene portion in the component (B) is 60
%, The block copolymer is hydrogenated, the double bond of the conjugated diene moiety is saturated by 80% or more, and the number average molecular weight is 5 to 60.
1 to 98% by weight of hydrogenated diene copolymer, (c) butene-1 homopolymer and / or butene-1
Copolymer of 1-98 with α-olefin having 2 to 8 carbon atoms
% By weight of the thermoplastic elastomer composition.

In the present invention, as the propylene homopolymer and / or the copolymer of propylene and an α-olefin having 2 to 8 carbon atoms, which constitutes the component (a), a Ziegler-Natta type catalyst is used by a known technique. Synthesized polypropylene or a random or block polypropylene copolymer is used, and a random type polypropylene is preferable.

Examples of the α-olefin in the copolymer include ethylene, butene-1, hexene-1, octene-1, and the like. The ratio of these α-olefins is preferably 30% by weight or less. Used, more preferably 0.01 to 20% by weight, particularly preferably 0.1 to 20% by weight.
It is 10% by weight. The blending amount of the component (a) in the thermoplastic elastomer composition of the present invention is 1 to 98% by weight, preferably 10 to 90% by weight, more preferably 20 to 8%.
It is 0% by weight. If it is less than 1% by weight, heat resistance and strength are poor, and if it exceeds 98% by weight, flexibility and transparency are poor.

Next, the hydrogenated diene copolymer as the component (b) will be described. The component (A) is a polymer block containing a vinyl aromatic compound as a main component, and another copolymerizable vinyl compound may be copolymerized in an amount of 10% by weight or less, preferably 5% by weight or less. Examples of the vinyl aromatic compound that constitutes the hydrogenated diene-based copolymer include styrene, α-methylstyrene, p-methylstyrene, and the like. These are used alone or as a mixture, and the conjugated diene is butadiene. And isoprene, with butadiene being particularly preferred.

The weight ratio of vinyl aromatic compound / conjugated diene is from 5/95 to 60/40, preferably from 7/93.
50/50, more preferably 8/92 to 40/60. When the vinyl aromatic compound is less than 5% by weight (the conjugated diene exceeds 95% by weight), the strength and heat resistance are poor, and when the obtained hydrogenated diene copolymer is pelletized, blocking is likely to occur. When blended with other resins, the molding appearance is inferior. When the vinyl aromatic content exceeds 60% by weight (the conjugated diene content is less than 40% by weight), impact resistance, low temperature properties and transparency are poor.

The amount of the vinyl aromatic compound bonded in the component (A) or (C) is 3 to 50% by weight based on all the monomers,
Preferably 5-40% by weight, more preferably 5-30
% By weight. If it is less than 3% by weight, heat resistance and strength are poor,
Further, when the obtained hydrogenated diene-based copolymer is pelletized, blocking is likely to occur, and when blended with another resin, the molding appearance is poor, and when it exceeds 50% by weight, transparency, flexibility and low temperature properties are deteriorated. Inferior. The amount of the vinyl aromatic compound bonded in the component (A) is 3% by weight of all monomers.
The above is preferably 5 to 40% by weight. If it is less than 3% by weight, the strength is poor.

The vinyl bond content of the conjugated diene moiety in the component (B) exceeds 60%, preferably 65% or more, more preferably 70% or more. If it is 60% or less, the effect of improving flexibility when blended with a resin is lowered and the transparency is deteriorated. The hydrogenation rate of the double bond of the conjugated diene moiety is usually
It is 80% or more, preferably 90% or more, and more preferably 95% or more. If it is less than 80%, heat resistance, transparency and mechanical strength are poor. The number average molecular weight of the hydrogenated diene-based copolymer is 5 to 600,000, preferably 100 to 500,000,
More preferably, it is 200,000 to 400,000. If it is less than 50,000, the heat resistance, strength and transparency will be reduced, and if it exceeds 600,000, the fluidity, processability and transparency will be poor.

The hydrogenated diene copolymer of the present invention is produced by living anion polymerization and further hydrogenation as disclosed in JP-A-3-72512.

The hydrogenated diene-based copolymer used in the present invention is
It may be a block copolymer in which the polymer molecular chain is extended or branched as represented by the following general formula by adding a coupling agent. [(A)-(B)] n-X, [(A)-(B)-(C)] n-X, or [(A)-(B)-(A)] n-X [wherein , (A), (B) and (C) are the same as above. n is 2
~ 4, X represents a coupling agent residue. Examples of the coupling agent at this time include diethyl adipate, divinylbenzene, methyldichlorosilane, and silicon tetrachloride.

The hydrogenated diene copolymer used in the present invention is
It may be modified with a functional group, and using an unsaturated compound having at least one functional group selected from an acid anhydride group, a carboxyl group, a hydroxyl group, an amino group, an isocyanate group and an epoxy group, a kneader or a mixer. It can be modified with an extruder or the like.

The amount of the component (b) in the thermoplastic elastomer composition of the present invention is 1 to 98% by weight, preferably 5 to 95% by weight, more preferably 10 to 90% by weight.
Is. If it is less than 1% by weight, flexibility and transparency are poor and 98
If it exceeds 5% by weight, heat resistance and strength are poor.

Next, butene-1 homopolymer and / or butene-1 and (a) having 2 to 8 carbon atoms constituting the component (c).
As the copolymer with the olefin, polybutene-1 or polybutene-1 copolymer synthesized by a known technique using a Ziegler-Natta type catalyst is used, and a copolymer type polybutene-1 is preferable. is there.

Examples of the α-olefin in the copolymer include ethylene, propylene, hexene-1, octene-1, and the like. The ratio of these α-olefins is preferably 50% by weight or less, and is preferable. Is 0.5-40
% By weight, particularly preferably 1 to 30% by weight.

The content of the component (c) in the thermoplastic elastomer composition of the present invention is 1 to 98% by weight, preferably 10 to 90% by weight, more preferably 20 to 80% by weight. If it is less than 1% by weight, heat resistance, strength and transparency are poor, and if it exceeds 98% by weight, flexibility and transparency are poor.

The thermoplastic elastomer composition of the present invention comprises
If necessary, cross-linking such as sulfur cross-linking, peroxide cross-linking, metal ion cross-linking, and silane cross-linking can be performed by a conventionally known method.

The thermoplastic elastomer composition of the present invention has mechanical strength, flexibility, transparency and heat resistance in addition to the above components (a), (b) and (c), depending on the application. Antioxidant, antistatic agent, weatherproofing agent, UV absorber, lubricant, antiblocking agent, sealability improving agent, crystal nucleating agent, flame retardant, antibacterial / antibacterial agent in such an amount that does not impair the properties Molds, tackifiers, softeners, plasticizers, colorants such as titanium oxide and carbon black, glass fibers, carbon fibers, metal fibers, aramid fibers, glass beads, asbestos, mica, calcium carbonate, potassium titanate whiskers,
Fillers such as talc, barium sulfate, glass flakes, and fluororesins, or other rubbery polymers, thermoplastic resins, and the like can be appropriately added.

The composition of the present invention can be obtained by melt-kneading with an extruder, kneader, Banbury mixer or the like, or by dry blending with an injection molding machine. In order to produce the composition of the present invention, the respective components may be mixed at once, or the optional components may be premixed in advance and then the remaining components may be added and mixed.
The most preferable mixing device is a single-screw or twin-screw extruder, which allows efficient and continuous kneading and pelletization. The composition of the present invention can be prepared by a conventionally known method such as extrusion molding, injection molding, blow molding, compression molding,
It can be processed into a practically useful molded product by calender molding or the like. Further, if necessary, processing such as foaming, powdering, stretching, adhesion, printing, painting, and plating can be performed.

Examples of the extrusion-molded article obtained by using the composition of the present invention include a sheet, a film, a tube, a shaped article, a net and a block, which can be used for various purposes.

[0030]

The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples. In Examples and Comparative Examples, parts and%
Is by weight unless otherwise specified. Also, examples
Various measurements and evaluations in Comparative Examples were based on the following methods.

The bound vinyl aromatic compound content was measured by infrared analysis based on the absorption of a phenyl group at 679 cm ⁻¹ . Vinyl bond content of conjugated diene Calculated by Hampton method using infrared analysis. Hydrogenation rate Using tetrachloroethylene as a solvent, 100 MHz, ¹ H-N
It was calculated from the MR spectrum. Number-Average Molecular Weight of Hydrogenated Diene Copolymer Trichlorobenzene was used as a solvent, and it was determined in terms of polystyrene using gel permeation chromatography (GPC) at 135 ° C. Tensile Breaking Strength A sample was punched out from a 2 mm thick compression-molded sheet with a No. 3 dumbbell and measured according to JIS K6301. Heat resistance A 2 cm square sample was cut out from a compression molded sheet having a thickness of 2 mm, and three stacked samples were used as a sample. A 5 mmφ steel ball probe was placed on the sample by applying a load of 100 g. 5
The temperature was raised at 0 ° C./hr, the temperature at which the steel ball probe penetrated vertically by 1 mm was determined, and the heat resistance was evaluated. Parallel light transmittance Using a multi-source spectrophotometer manufactured by Suga Test Co., Ltd., JIS
It measured based on K6714. A 2 mm thick injection sheet was used as the sample. Flexibility JIS A hardness was measured according to JIS K6301.

Reference Example Various components used in the formulation of Examples, Comparative Examples and evaluation are as follows. PP polypropylene [Polypropylene F manufactured by Mitsubishi Petrochemical Co., Ltd.]
L25R] PB-1 Polybutene -1 [Mitsui Petrochemical Co., Ltd., Bureau M
3080] SEBS polystyrene-polybutadiene-polystyrene copolymer block copolymer obtained by hydrogenating the polybutadiene portion [Shell Chemical Co., Ltd., Kraton G1657] hydrogenated diene copolymer hydrogenated diene copolymer (T- 1 to 14) are manufactured by Nippon Synthetic Rubber Co., Ltd., and the microstructure, number average molecular weight, and hydrogenation rate of T-1 to 14 are as shown in Table 1.

Examples 1 to 9 and Comparative Examples 1 to 12 The performances of the elastomer compositions having the compositions shown in Tables 2 and 3 were evaluated, and the results are shown in the same table. Example 1 shown in Table 2
From the results of No. 9, it can be seen that the elastomer composition of the present invention has an excellent balance of transparency, heat resistance, flexibility and strength as compared with Comparative Examples 1 to 12 shown in Table 3. Comparative Example 4 ~
No. 11 is a hydrogenated diene-based copolymer outside the scope of the present invention, and therefore the balance of transparency, heat resistance, flexibility and strength is poor. In Comparative Examples 1 to 3, the compounding ratio is out of the range of the present invention, and therefore the balance of transparency, heat resistance, flexibility, and strength is poor. Comparative Example 12 is an example in which commercially available SEBS is used instead of the hydrogenated diene-based copolymer of the component (b), and since the vinyl bond content in the polybutadiene block is less than the range of the present invention, transparency, The balance of heat resistance, flexibility and strength is poor, which is not preferable.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

The thermoplastic elastomer composition of the present invention has essentially the same physical properties as the thermoplastic elastomer composition, has extremely good transparency, and has excellent heat resistance, strength and flexibility. The thermoplastic elastomer composition of the present invention, which is a material having the above-mentioned excellent properties, is used for food, daily sundries, toys and sports equipment, stationery, automobile interior / exterior applications, civil engineering / construction applications. , AV / home appliances, O.I. A. Highly industrially valuable material that can be used for office equipment, clothing / footwear, textiles, medical equipment, chemical / mining industry materials, packaging / transportation materials, agricultural / livestock / fisheries materials, etc. Is.

Claims (1)

[Claims] 1. A propylene homopolymer and / or a copolymer of propylene and an α-olefin having 2 to 8 carbon atoms in an amount of 1 to 98% by weight, and (b) a vinyl aromatic compound polymer block (A). ) And a conjugated diene polymer or a random copolymer block (B) of a vinyl aromatic compound and a conjugated diene (A).
-(B) or (A)-(B)-(A) block copolymer, or taper block (C) consisting of vinyl aromatic compound and conjugated diene and gradually increasing vinyl aromatic compound
(A)-(B)-(C) block copolymer, wherein the ratio of vinyl aromatic compound / conjugated diene is 5 by weight.
/ 95 to 60/40, the amount of vinyl aromatic compounds bound in components (A) and (C) is 3 to 50% by weight of all monomers, and the amount of vinyl aromatic compounds bound in component (A) is at least total. 3% by weight or more of the monomer, and the vinyl bond amount of the conjugated diene portion in the component (B) is 60.
%, The block copolymer is hydrogenated, the double bond of the conjugated diene moiety is saturated by 80% or more, and the number average molecular weight is 5 to 60.
1 to 98% by weight of hydrogenated diene copolymer, (c) homopolymer of butene-1 and / or butene
Copolymers of 1 and α-olefins having 2 to 8 carbon atoms 1-9
A thermoplastic elastomer composition comprising 8% by weight.