JPH11189689A - Thermoplastic elastomer composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a thermoplastic elastomer compsn. which is suitable for preparing a molded article, such as a film or sheet, excellent in softness and blocking resistance. SOLUTION: This compsn. contains (A) 1-99 pts.wt. polyolefin resin (excluding a poly-4-methylpentene-1 resin), (B) 99-1 pt.wt. hydrogenated diene copolymer of which at least 80% of conjugated diene-derived double bonds have been satd. and which has a number average mol.wt. of 50,000-700,000, the sum of ingredients A and B being 100 pts.wt., and (C) 0.1-200 pts.wt. poly-4- methylpentene-1 resin.

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 mainly comprising a specific combination of a polyolefin resin and a hydrogenated diene polymer and capable of providing a film or sheet having excellent blocking resistance and flexibility.

[0002]

2. Description of the Related Art Conventionally, flexible polyvinyl chloride resins have been widely used for extruded products such as sheets, films, tubes, etc., which require flexibility. Molded articles using a composition based on a soft polyvinyl chloride resin are widely used in various applications because of their excellent flexibility, heat resistance, and appearance and texture. However, since this polyvinyl chloride resin usually contains a large amount of a plasticizer, there is a possibility that migration of the plasticizer, a peculiar odor due to the plasticizer, and other use problems may occur. Further, a composition based on a soft polyvinyl chloride resin has insufficient low-temperature properties,
At temperatures below ℃ the flexibility is significantly reduced. More recently, the emergence of alternative materials has been strongly desired from the viewpoint of generating harmful gases during incineration.

[0003] On the other hand, polyolefin resins are used as excellent materials which do not have the problems peculiar to soft polyvinyl chloride. However, polyolefin resins are used as sheets and films because they are hard and inferior in flexibility, but cannot be a complete substitute for flexible polyvinyl chloride resins. In order to take advantage of the characteristics of polyolefin resins, various types of elastomers have been tried, and a material having flexibility and excellent elastomer elasticity is commercially available under the general name of thermoplastic polyolefin (TPO).

[0004] A thermoplastic elastomer composition comprising a polyolefin resin and a hydrogenated styrene-butadiene block copolymer or a hydrogenated styrene-butadiene random copolymer is a flexible and elastomeric material. It is attracting attention as an alternative to polyvinyl chloride resin. However, the more flexible these thermoplastic elastomer compositions, the worse the blocking resistance. There is a strict requirement for blocking resistance, particularly for films or sheets. For example, in a process of forming a film or sheet by extrusion, if the film or sheet is blocked after being wound on a roll, unwinding from the roll becomes difficult or substantially impossible. This is fatal for the production of films or sheets.

[0005]

SUMMARY OF THE INVENTION An object of the present invention is to provide a thermoplastic elastomer composition having excellent flexibility and blocking resistance and suitable for forming a film or sheet.

[0006]

According to the present invention, the following thermoplastic elastomer composition is provided to achieve the above object of the present invention. [1] (a) 1 to 99 parts by weight of a polyolefin resin (excluding poly-4-methylpentene-1 resin), and (b) 80% of a conjugated diene-based polymer has a double bond of a conjugated diene component of 80%.
99 to 1 part by weight of a hydrogenated diene copolymer which is saturated and has a number average molecular weight of 50,000 to 700,000 (here, the total of (a) the polyolefin resin and (b) the hydrogenated diene copolymer) The amount is 100 parts by weight), and (c) 0.1 to 200 parts by weight of a poly-4-methylpentene-1 resin.
Simply referred to as “composition”). [2] The thermoplastic elastomer composition according to claim 1, wherein (a) the polyolefin resin is a polypropylene resin. The present invention is described in detail below, and other objects, advantages and effects of the present invention will become apparent.

[0007]

DETAILED DESCRIPTION OF THE INVENTION The polyolefin resin used as the component (A) in the present invention is a resin obtained by polymerizing a monoolefin by either a high-pressure method or a low-pressure method. However, poly-4-methylpentene-1 resin is excluded from the component (a). Preferred polyolefin resins are polyethylene resin, polypropylene resin and polybutene-1 resin, more preferably polypropylene resin.

[0008] The polyolefin resin may be a homopolymer or a copolymer. In the case of a copolymer,
Preferred copolymerizable monomers other than the main α-olefin of the polyolefin resin include linear α-olefins such as ethylene, propylene, butene-1, pentene-1, hexene-1, heptene-1, and octene-1;
4-methylpentene-1, 2-methylpropene-1,3
-Methylpentene-1,5-methylhexene-1,4-
Branched α-olefins such as methylhexene-1,4,4-dimethylpentene-1; monocarboxylic acids such as acrylic acid and methacrylic acid; dicarboxylic acids such as maleic acid and fumaric acid and monoesters thereof; methyl methacrylate; Acrylic or methacrylic esters such as methyl acrylate and ethyl acrylate; vinyl esters of saturated carboxylic acids such as vinyl acetate; aromatic vinyl compounds such as styrene, α-methyl-styrene;
Acid anhydrides such as maleic anhydride: α, β-unsaturated nitriles such as acrylonitrile; diene monomers such as dicyclopentadiene and ethylidene norbornene; acrylamide and methacrylamide.
These copolymer monomers can be used alone or in combination of two or more.

Among these copolymerized monomers, preferred monomers used for the polypropylene resin are ethylene,
Butene-1, pentene-1, hexene-1, heptene-
1, a linear α-olefin such as octene-1;
Particularly preferred are ethylene and butene-1.

The amount of these comonomer components in the polyolefin resin is preferably at most 20% by weight, more preferably at most 10% by weight. The type of the copolymer is not particularly limited, and may be, for example, any of a random type, a block type, a graft type, and a mixed type thereof.

The melt flow rate (MFR: 230 ° C., 2.16 kg load) of the polyolefin resin is not particularly limited as long as it can be molded, but an MFR according to the type of the polyolefin resin and the molding method is appropriately selected. You. The composition of the present invention containing a polypropylene resin,
When a film or sheet is formed by an extrusion molding method, the MFR of the polypropylene resin is preferably from 0.1 to 30, particularly preferably from 0.3 to 15.

The above-mentioned polyolefin resin as the component (a) may be used alone or in combination of two or more.

Next, the hydrogenated diene copolymer which is the component (b) of the composition of the present invention will be described. (B) The hydrogenated diene polymer has (1) a hydrogenation rate of a double bond of a conjugated diene component of the conjugated diene polymer of 80% or more, preferably 90% or more, and more preferably 95% or more. And (2) a hydrogenated diene copolymer having a number average molecular weight in terms of styrene of 50,000 to 700,000, preferably 100,000 to 600,000. When the hydrogenation rate is in the above range, the mechanical strength, heat resistance, and weather resistance are excellent, and when the number average molecular weight satisfies the above range, the resin component (A) and (C) can be used. When blended, a molded article having excellent mechanical strength and molded appearance can be obtained with good workability from the composition of the present invention, which is preferable.

The component (b) includes, for example, a homopolymer of a conjugated diene, a random copolymer of a conjugated diene and an aromatic vinyl compound, and a block composed of a polymer block of an aromatic vinyl compound and a polymer block of a conjugated diene. Copolymers, hydrogenated products of diene polymers such as block copolymers composed of a polymer block of an aromatic vinyl compound and a copolymer block of an aromatic vinyl compound / conjugated diene, and functional groups introduced into these. Modified products. As the component (b), the double bond of the conjugated diene component of the polymer mainly composed of a random copolymerized portion of a conjugated diene compound and an aromatic vinyl compound is saturated by 80% or more, and the number average molecular weight is 5%. A hydrogenated diene-based copolymer (b-a) having a molecular weight of 10,000 to 700,000 is preferable, and a thermoplastic elastomer composition having excellent flexibility and the like can be obtained by using this.

The hydrogenated diene copolymer preferably used as the component (b-a) in the present invention is a polymer mainly composed of a random copolymerized portion of a conjugated diene compound and an aromatic vinyl compound (hereinafter, referred to as "the" -a) component. (Also referred to as "pre-hydrogenated polymer"). The proportion of the random copolymerized portion in the polymer before hydrogenation is preferably at least 50% by weight, more preferably at least 60% by weight, further preferably at least 70% by weight. When the proportion of the random copolymerized portion is at least 50% by weight, molded articles such as films and sheets obtained from the composition of the present invention are excellent in flexibility, cold resistance, and the like, and thus are preferable. In the random copolymer portion,
1, relative to all conjugated diene components in the random copolymerized moiety,
The conjugated diene component content of 2 and 3, 4 bonds (hereinafter, referred to as
"Content such as vinyl bond") is preferably 60
%, More preferably at least 65%, even more preferably at least 70%. When the content of the vinyl bond or the like is 60% or more, for example, when the polyolefin resin (a) is a polypropylene resin, the effect of improving flexibility is remarkably exhibited.

The random copolymerized portion of the pre-hydrogenated polymer is composed of a conjugated diene compound component and an aromatic vinyl compound component. The conjugated diene compound used here includes 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 2-
Methyl-1,3-pentadiene, 1,3-hexadiene, 4,5-diethyl-1,3-octadiene, 3-butyl-1,3-octadiene, chloroprene and the like can be mentioned, but they can be industrially used, and In order to obtain a hydrogenated diene polymer having excellent physical properties, 1,3-butadiene, isoprene and 1,3-pentadiene are preferred, and 1,3-butadiene and isoprene are particularly preferred. As the aromatic vinyl compound, styrene, α-methylstyrene, p-
Methylstyrene, t-butylstyrene, divinylbenzene, N, N-dimethyl-p-aminoethylstyrene,
N, N-diethyl-p-aminoethylstyrene, vinylpyridine and the like can be mentioned, and styrene and α-methylstyrene are preferable.

The ratio of the conjugated diene compound component / aromatic vinyl compound component constituting the random copolymer portion of the pre-hydrogenated polymer is not particularly limited in the present invention, but is preferably 95% by weight. / 5 to 40/60, more preferably 93/7 to 50/50. Satisfying the above ratio results in excellent flexibility and processability of the thermoplastic elastomer composition of the present invention, which is preferable.

The component (b-a) of the present invention can be obtained by hydrogenating a polymer mainly composed of a random copolymer portion as described above. And the following polymer blocks may be contained. Examples of the polymer block which may be contained in the pre-hydrogenated polymer include an aromatic vinyl compound polymer, a polybutadiene polymer mainly containing 1,4-bonds, and an aromatic vinyl compound comprising an aromatic vinyl compound and a conjugated diene. Examples include a tapered polymer in which the compound gradually increases. When these polymer blocks are present, the properties of the component (b-a) are slightly impaired in physical properties, but the handling properties are improved due to a decrease in the blocking properties of the material, which may be industrially useful. .

The proportion of the polymer block in the polymer before hydrogenation is preferably 50% by weight or less, from the viewpoint of maintaining good flexibility and cold resistance of the composition of the present invention.
% Or less, more preferably 30% by weight or less.

The above-mentioned polymer before hydrogenation may be a polymer in which the molecular chain of the polymer is extended or branched via the residue of the coupling agent by using a coupling agent. As the coupling agent used at this time, for example, diethyl adipate, divinylbenzene, methyldichlorosilane, silicon tetrachloride, butyltrichlorosilicon, tetrachlorotin,
Butyltrichlorotin, dimethyldichlorosilicon, tetrachlorogermanium, 1,2-dibromoethane, 1,4
-Chloromethylbenzene, bis (trichlorosilyl) ethane, epoxidized linseed oil, tolylene diisocyanate, 1,2,4-benzene triisocyanate and the like.

The component (b-a) of the present invention comprises 2
Those obtained by hydrogenating a mixture of at least one kind of pre-hydrogenated polymer are also preferably used. Furthermore, a blend of two or more hydrogenated diene polymers is also suitable as the component (b) of the present invention.

The hydrogenated diene copolymer can be produced, for example, by the method disclosed in JP-A-3-72512. Furthermore, the hydrogenated diene copolymer used as the component (b) of the present invention is, as described above, a modified product obtained by introducing one or more functional groups into the hydrogenated diene copolymer described above. It may be. As the functional group, for example, a carboxyl group, an acid anhydride group, a hydroxyl group, an epoxy group, an amino group, an ammonium group, a halogen atom-containing group, a sulfonic acid group, and the like, and a group derived from these functional groups, such as an ester group Is mentioned. Such a functional group is introduced before or after hydrogenation at the time of producing the hydrogenated diene copolymer (b) depending on the type.

Next, the poly-4-methylpentene-1 resin as the component (c) will be described. The poly-4-methylpentene-1 resin is a homopolymer of 4-methyl-1-pentene or a copolymer of 4-methyl-1-pentene and another α-olefin. Here, the α-olefin is
Ethylene, propylene, 1-butene, 1-hexene, 1
-Octene, 1-decene, 1-tetradecene, 1-octadecene, 1-hexadecene, 1-dodecene and 1-
Α-olefins having 2 to 30 carbon atoms such as tetradodecene, which can be used alone or in combination of two or more. In addition, poly-4 as the component (c)
-Methylpentene-1 resin is obtained by modifying the above homopolymer or copolymer with, for example, maleic anhydride, maleic acid, acrylic acid, methacrylic acid, itaconic acid, itaconic anhydride, or another polar group-containing monomer. And various functional groups may be introduced. 4-methyl-1
-Copolymers of pentene and these α-olefins,
Usually, the 4-methyl-1-pentene component is at least 80 mol%,
Preferably, it is a polymer mainly composed of 4-methyl-1-pentene containing 85 mol% or more. Melt flow rate of poly 4-methylpentene-1 resin (MFR: ASTM D1)
238, 260 ° C., load 5 kg) is preferably 0.5
~ 200g / 10min, more preferably 5-120g
/ 10 min.

(C) The poly-4-methylpentene-1 resin component functions to prevent blocking while maintaining the strength and flexibility of a molded article such as a film or sheet molded from the composition of the present invention. I do.

(C) Poly 4- used in the present invention
Methylpentene-1 resin is available, for example, from TP
It is sold under the trade name X and can be used.

The above-described (a) polyolefin resin component, (ii) hydrogenated diene copolymer, and (iii) poly-4
In the composition of the present invention containing -methylpentene-1 resin, the proportions of these components are as follows from the viewpoint of the strength, flexibility and prevention of blocking of the molded product. Component (i): 1 to 99 parts by weight, preferably 10 to 90 parts by weight, more preferably 20 to 90 parts by weight. (B) Component: 99 to 1 part by weight, preferably 90 to 10 parts by weight, more preferably 80 to 10 parts by weight. (C) component: 0.1 to 200 parts by weight, preferably 0.3
-100 parts by weight, more preferably 0.5-50 parts by weight. By satisfying the above mixing ratio, the molded product exemplified by the film or sheet can prevent blocking while maintaining its strength and flexibility.

The composition of the present invention may optionally contain an inorganic filler within a range not to impair the achievement of the object of the present invention. As inorganic fillers that can be used, light calcium carbonate, heavy or calcium carbonate, other calcium-based fillers, hard clay, soft clay,
Kaolin clay, talc, wet silica, dry silica, amorphous silica, wollastonite, synthetic or natural zeolite, diatomaceous earth, silica sand, pumice powder, slate powder, alumina, aluminum sulfate, barium sulfate, lithopone, calcium sulfate, disulfide Molybdenum, magnesium hydroxide, and those obtained by treating these fillers with silane can be used. These inorganic fillers can be used in combination of two or more. The compounding amount of these inorganic fillers is 200 parts by weight or less, preferably 100 parts by weight or less, per 100 parts by weight of the total amount of (a) the polyolefin resin and (b) the hydrogenated diene copolymer.

When the above-mentioned inorganic filler is blended, the water contained or adsorbed in the inorganic filler can be consumed by the reaction or an adsorbable inorganic substance is used together from the viewpoint of preventing foaming of the molded article. preferable. As such an inorganic substance, calcium oxide, in particular, calcium oxide synthesized by a wet method can be preferably mentioned.

The composition of the present invention contains known coupling agents, flame retardants, antioxidants, ultraviolet absorbers, HALS, plasticizers, coloring agents, inorganic or organic antibacterial agents as long as the gist of the present invention is not impaired. Additives such as agents, lubricants and silicone oils can be blended.

The composition of the present invention contains ethylene-propylene copolymer rubber (EPM), ethylene-propylene-diene terpolymer rubber (EPDM), ethylene-propylene copolymer as long as the object of the present invention is not impaired. Butene copolymer rubber (EBM), amorphous poly-α-olefin (APA)
O) and a flexible olefin-based polymer such as an ethylene-octene copolymer may be used in combination. When these are used in combination, (b) the amount of the hydrogenated diene-based copolymer component may be reduced, and in that case, it may be advantageous in terms of cost.

The thermoplastic elastomer composition of the present invention comprises:
It is prepared by kneading each component at least while melting the components (a), (b) and (c) using various extruders, Banbury mixers, kneaders, rolls and the like. A preferred production method is a method using a twin-screw extruder. When kneading the components, the components may be kneaded at once, or may be kneaded by a multi-stage addition method. The kneading temperature varies depending on the melting point of the polyolefin resin component (a) and the melting point of the poly (4-methylpentene-1) resin, but when the polyolefin resin is a polyethylene resin, a polypropylene resin, or a polybutene resin, (k) ) Since the melting point of poly-4-methylpentene-1 resin is the highest, (c) poly-4-methylpentene-1
It is preferable to knead the resin in a temperature range of 200 ° C. to 250 ° C. for melting the resin.

The thermoplastic elastomer composition of the present invention obtained as described above can be molded into various molded articles by injection molding, extrusion molding, inflation molding, vacuum molding, heteromorphic molding, foam molding, injection press, press molding, blow molding, or the like. Can be molded into Further, it can be formed into a nonwoven fabric by melt blow molding or the like. Various molded products obtained by the above molding method include stationery products such as desk mats and cutting mats utilizing the excellent properties of the thermoplastic elastomer of the present invention; automotive interior and exterior materials such as instrument panel skin materials and bumper materials; Civil engineering construction materials such as decorative films and civil engineering waterproofing sheets; sanitary fields such as kitchens and bathrooms; medical infusion bags, blood transfusion bags and transfusions; medical supplies such as liquid tubes; clothing materials such as ponchos; It can be used for various applications such as parts for AV and home appliances such as vacuum cleaner bumper materials, office equipment parts, and miscellaneous goods such as tablecloths. In particular, the extruded film or sheet can be used as a desk mat, a cutting mat, an instrument panel skin material, a decorative film, a waterproof sheet for civil engineering, and the like.

[0033]

EXAMPLES The present invention will now be described in detail with reference to examples, but the scope of the present invention is not limited to the examples.
In the examples, parts and% are by weight unless otherwise specified. Various evaluations in the examples are values and evaluations measured as follows.

(1) Bound aromatic vinyl compound component content It was measured by infrared analysis based on the absorption of a phenyl group at 679 cm-1. (2) Vinyl bond content of conjugated diene component Calculated by the Hampton method using infrared analysis. (3) Hydrogenation rate 100 MHz, ¹ HN using ethylene tetrachloride as a solvent
It was calculated from the MR spectrum. (4) Number average molecular weight of hydrogenated diene copolymer Trichlorobenzene was used as a solvent, and gel permeation chromatography (GPC) at 135 ° C. was used to determine the number in terms of polystyrene. (5) Flexibility Judgment was made based on the following criteria. 〇: Flexible ×: Inflexible (6) Blocking resistance The sheet was wound up at a constant tension of 20 m under a constant tension of 50 m.
The unrolling property after standing at 24 ° C. for 24 hours was evaluated according to the following criteria. 〇: Easily unrolled ×: Unfolded or unrollable when unwinding

The various components used in the formulations of the examples, comparative examples and evaluations are as follows. (A) Ingredients i-1 Polypropylene (XF1800, manufactured by Chisso Petrochemical Co., Ltd.) a-2 Polypropylene (BC5C, manufactured by Mitsubishi Chemical Corporation) i-3 Polypropylene (FB3C, manufactured by Mitsubishi Chemical Corporation) (b) ) Component (1) b-1,2 hydrogenated diene-based copolymer The microstructure, number average molecular weight, and hydrogenation rate of these b-1,2 are as shown in Table 1. (2) b-3-5 hydrogenated diene copolymer b-3: hydrogenated styrene-butadiene-styrene block copolymer (SEBS) Clayton G-16 manufactured by Shell Co., Ltd.
57X b-4: hydrogenated styrene-isoprene-styrene block copolymer (SEPS) Septon 2043 manufactured by Kuraray Co., Ltd. b-5: hydrogenated styrene-vinyl isoprene-styrene block copolymer manufactured by Kuraray Co., Ltd. Hibler HVS- 3

(C) Component C-1: MX002 MFR manufactured by Mitsui Chemicals, Inc. MFR: 26 g / min C-2: MX004 MITSUI CHEMICAL CO., LTD. MFR: 22 g / min C-3: RT18 manufactured by Mitsui Chemicals, Inc. MFR: 26 g / min (MFR is measured at 260 ° C. under a load of 5 kg)

[0037]

[Table 1]

(Example 1) Each of the above (a), (b),
(C) The components were mixed according to the formulation shown in Table 2 below, melt-kneaded using a vented twin-screw extruder, and pelletized. Next, using a DMG-50 extruder manufactured by Nippon Placon Co., Ltd. and a 400 mmT die, the extruding temperature was 230 ° C.
The sheet was extruded at a discharge rate of 20 kg / h to obtain a sheet having a thickness of 1 mm. The obtained sheet was a beautiful sheet excellent in strength, flexibility and blocking resistance. The results are shown in Table 2.

(Examples 2 to 8) (a), (b), (c)
Example 1 except that the compounding amounts of the components were as shown in Table 2 below.
, And the obtained sheet was evaluated in the same manner as in Example 1. The results are shown in Table 2.

[0040]

[Table 2]

Comparative Example 1 The procedure of Example 1 was repeated, except that the component (c) was not added. The obtained sheet was evaluated in the same manner as in Example 1. The obtained sheet was inferior in blocking resistance. The results are shown in Table 3.

(Comparative Examples 2 to 4) (a), (b), (c)
Evaluation was performed in the same manner as in Example 1 except that the amounts of the components were as shown in Table 2. The results are shown in Table 3. In Comparative Example 2, the amount of the component (c) used was outside the range of the present invention, and the blocking resistance was poor. Comparative Example 3 is inferior in flexibility because the ratio of the components (a) and (b) is out of the range of the present invention.

[0043]

[Table 3]

[0044]

The thermoplastic elastomer composition of the present invention can provide a molded article having excellent strength, flexibility and blocking resistance. Therefore, the composition of the present invention can be used in a wide range of applications, for example, stationery products such as desk mats and cutting mats; interior and exterior materials for automobiles such as instrument panel skin materials and bumper materials; Materials; Medical infusion bags, blood transfusion bags, infusion tubes and other medical supplies; Sanitary fields such as kitchen and bathroom areas; Clothing materials such as ponchos;
It is useful for various uses such as miscellaneous goods such as tablecloths; AV / consumer electronics-related parts; In particular, it is suitable for producing stationery products such as desk mats and cutting mats, films and sheets used for instrument panel skin materials, bumper materials, and the like, as well as tubes and hoses.

Claims (2)

[Claims] 1. A polyolefin resin (excluding poly-4-methylpentene-1 resin) in an amount of 1 to 99 parts by weight,
(B) 99 to 1 part by weight of a hydrogenated diene-based copolymer having a double bond of a conjugated diene component of the conjugated diene-based polymer of 80% or more saturated and having a number average molecular weight of 50,000 to 700,000 (here,
(A) the total amount of the polyolefin resin and (b) the hydrogenated diene copolymer is 100 parts by weight), and (c) 0.1 to 200 parts by weight of a poly-4-methylpentene-1 resin;
A thermoplastic elastomer composition comprising: 2. The thermoplastic elastomer composition according to claim 1, wherein (a) the polyolefin resin is a polypropylene resin.