JPH09208761A - Polyolefin-based resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a polyolefin-based resin composition having performances of an olefin-based thermoplastic elastomer excellent in mechanical properties such as elastic recovery, and good in moldability. SOLUTION: This resin composition comprises 100 pts.wt. of a propylene- based block copolymer 6-30dL/g in intrinsic viscosity composed of 1-40wt.% of polypropylene component and 60-99wt.% of propylene-ethylene random copolymer component containing 10-40mol% ethylene-based monomer unit, 40-150 pts.wt. of a plasticizer, and 20-100 pts.wt. of an ethylene-α-olefin copolymer containing 2-15mol% >=4C α-olefin-based monomer unit.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a novel thermoplastic polyolefin-based elastomer. More specifically, the present invention provides a polyolefin-based resin composition having the performance of an olefin-based thermoplastic elastomer excellent in mechanical properties such as elastic recovery and having good moldability.

[0002]

2. Description of the Related Art A resin composition made of an olefinic thermoplastic elastomer as a raw material is characterized by excellent mechanical properties such as flexibility and elastic recovery and recyclability, and is an alternative to soft vinyl chloride resin and vulcanized rubber. Has been developed for use in the automobile field and the like.

As the above-mentioned olefinic thermoplastic elastomer, a resin composition comprising (1) a crystalline polyolefin component such as polypropylene or polyethylene and a rubber component such as an ethylene-propylene copolymer is known. Also,
(2) A resin composition or the like is known which is composed of polypropylene, an ethylene-propylene-diene terpolymer (hereinafter abbreviated as EPDM), and process oil, and in which the EPDM component is partially crosslinked with an organic peroxide. ing.

[0004]

However, although the resin composition of the above (1) imparts flexibility and elastic recovery by introducing a rubber component, it has the same properties as the composition of the above (2). The flexibility and elastic recovery are insufficient as compared with those in which a higher-order structure is formed by such partial cross-linking. The resin composition of (2) requires a cross-linking reaction step at the time of production, and the step is complicated. Further, since the crosslinking reaction is involved, the molded product has a yellowish tint, and the molded product has a smaller elongation than the molded product (1).

[0005]

[Means for Solving the Problems] The inventors of the present invention have conducted extensive studies to solve the above problems. As a result, a resin composition containing a propylene-ethylene random copolymer component in a specific amount and having a specific intrinsic viscosity, a plasticizer, and a specific ethylene-α-olefin copolymer is molded and processed. Excellent elasticity and elastic recovery
They have found that they have excellent mechanical properties such as flexibility, and have completed and proposed the present invention.

That is, in the present invention, (1) the polypropylene component is 1 to 40% by weight and the propylene-ethylene random copolymer component containing 10 to 40 mol% of an ethylene-based monomer unit is 60 to 99% by weight. 100 parts by weight of a propylene-based block copolymer having an intrinsic viscosity of 6 to 30 dl / g, (2) a plasticizer of 40 to 150 parts by weight, and (3) a monomer based on an α-olefin having 4 or more carbon atoms A polyolefin resin composition comprising 20 to 100 parts by weight of an ethylene-α olefin copolymer containing 5 to 15 mol% of a unit.

The present invention will be described in detail below.

The propylene block copolymer used in the present invention comprises a polypropylene component and a propylene-ethylene random copolymer component.

The proportion of each component of the propylene-based block copolymer is 1 to 40% by weight, preferably 5 to 20% by weight of polypropylene component, and 60 to 99% by weight of propylene-ethylene random copolymer component. , Preferably 80 to 95% by weight. When the polypropylene component is less than 1% by weight, that is, when the propylene-ethylene random copolymer component exceeds 99% by weight, the propylene block copolymer tends to be agglomerated due to blocking, resulting in poor operability. On the other hand, the polypropylene component is 40% by weight
When it exceeds the above range, that is, when the content of the propylene-ethylene random copolymer component is less than 60% by weight, the flexibility and elastic recovery of the molded product are impaired.

In the propylene-ethylene random copolymer component, the ratio of ethylene-based monomer units is 10%.
It is necessary to be ˜40 mol%, preferably 15 to 35 mol%. That is, when the proportion of ethylene-based monomer units is less than 10 mol%, flexibility is impaired,
If it exceeds 40 mol%, the propylene-based block copolymer tends to be agglomerated due to blocking, resulting in poor operability.

Further, the propylene block copolymer has an intrinsic viscosity of 6 measured in a tetralin solvent at 135 ° C.
˜30 dl / g, preferably 10-20 dl / g
g. When the intrinsic viscosity of the propylene-based block copolymer is less than 6 dl / g, the elastic recovery property is impaired,
When it exceeds 1 / g, the melt fluidity is lowered and molding of the resin composition becomes extremely difficult.

The propylene-based block copolymer used in the present invention contains at least one of a polypropylene component and a propylene-ethylene random copolymer component as long as the physical properties of the obtained polyolefin-based resin composition are not impaired.
In order to improve the particle properties such as imparting fluidity to the copolymer particles, other α-olefin such as polybutene component may be copolymerized in a small amount, generally 5 mol% or less. .

In the present invention, the plasticizer is used for the purpose of improving the moldability of the resin composition and imparting flexibility to the molded product. As the plasticizer, generally, a hydrocarbon synthetic oil having a molecular weight of 2000 or less, a mineral oil, liquid paraffin, a derivative such as a polyolefin wax, or the like is used. Of these, paraffin-based mineral oils and synthetic oils are preferable in consideration of odor and transparency. The ratio of the plasticizer is 40 to 100 parts by weight of the propylene block copolymer.
150 parts by weight, preferably 60 to 120 parts by weight. When the proportion of the above plasticizer is less than 40 parts by weight, melt fluidity is lowered and molding of the resin composition becomes difficult, and when it exceeds 150 parts by weight, the plasticizer bleeds onto the surface of the molded product, resulting in molding. The product becomes sticky, which is not preferable as a product.

The above ethylene-α-olefin copolymer is
It is a copolymer of ethylene and an α-olefin having 4 or more carbon atoms. Examples of the α-olefin include butene-
1, hexene-1, 4-methylpentene-1, octene-1 and the like. This α-olefin content is 5 to 15 mol%, preferably 7 to 10 mol%. In this case, α
When the olefin content is less than 5 mol%, the flexibility and deformation recovery of the obtained polyolefin resin composition are impaired, and when it exceeds 15 mol%, the ethylene-α olefin copolymer itself blocks and the operability is increased. Becomes worse.

In the present invention, the proportion of the ethylene-α-olefin copolymer is 20 to 100 parts by weight, preferably 40 to 80 parts by weight, based on 100 parts by weight of the propylene block copolymer. When the proportion of the ethylene-α-olefin copolymer is less than 20 parts by weight, the moldability of the resin composition is lowered and the surface of the molded product is rough, which is not preferable as a molded product. On the other hand, if it exceeds 100 parts by weight, a molded product of the obtained polyolefin resin composition may be blocked or the elastic recovery property may be deteriorated. In order to impart certain properties to the resin composition of the present invention, such as self-adhesiveness, antifogging property, antistatic property, and anti-UV property, the resin composition comprising the resin composition of the present invention generally comprises Contains antioxidants, tackifiers, antiblocking agents, antifogging agents, antistatic agents, UV absorbers, colorants, freshness-retaining agents, gas adsorbents, deodorants, fragrances, flame retardants, etc. May be done. In addition, other components may be added as needed, as long as the characteristics of the present invention are not impaired.

The resin composition of the present invention can be produced as a molded product by extrusion molding, calender molding, injection molding, blow molding, etc., by a conventionally known technique. For example, in extrusion molding, it can be produced by single extrusion using a single or a plurality of extruders, co-extrusion, or extrusion-laminated T-die molding. In this case, the molding temperature is preferably in the range of 170 to 250 ° C. in consideration of a decrease in molecular weight due to heat deterioration such as shearing heat generation, kneading dispersion, and the like.

[0017]

EFFECT OF THE INVENTION The polyolefin resin composition obtained in the present invention is superior to the olefin thermoplastic elastomer in that
It is a resin excellent in elastic recovery and flexibility, and has an advantage that it is not colored as compared with a resin obtained by a conventional crosslinking reaction.

Therefore, the polyolefin resin composition of the present invention is useful for applications such as soft sheets such as skin materials, tapes, labels and packings.

[0019]

EXAMPLES In order to describe the present invention more specifically, examples and comparative examples will be described below, but the present invention is not limited to these examples.

1. Method for analyzing polymer and method for evaluating physical properties of molded article (1) Weight average molecular weight (Mw) G. P. C. It was measured by the (gel permeation chromatography) method. Waters GPC-15
0 ° C with o-dichlorobenzene as a solvent at 135 ° C
I went in. The column used was TSK-gel G manufactured by Tosoh Corporation.
MH6-HT, gel size 10-15 μm. The calibration curve has a weight average molecular weight of 950, 29 as a standard sample.
00, 10,000, 50,000, 49.8 million, 2.7 million, 4.9 million polystyrene were used.

(2) Measurement of Ratio of Monomer Units Based on Ethylene and Monomer Units Based on Propylene in Propylene-Ethylene Random Copolymer Component It was calculated using a chart of 13 C-NMR spectrum. That is, the respective proportions of the ethylene-based monomer units and the propylene-based monomer units in the propylene-ethylene random copolymer component are
Lymer, Vol. 29 (1988), page 1848, peak assignment was determined, and then by the method described in Micromolecules, Vol. 10 (1977), page 773. The respective proportions of ethylene-based monomer units and propylene-based monomer units were calculated.

(3) Intrinsic viscosity: Measured in a 135 ° C. tetralin solvent.

(4) A hardness The hardness was measured according to JIS K6253 to evaluate the flexibility.

(5) Melt Index (MI) The melt index was measured according to JIS K7210.

(6) Tensile permanent set A strip-shaped sheet having a width of 10 mm and a length of 140 mm is kept at room temperature at a distance of 100 mm between chucks and 40 mm between marked lines and a pulling speed of 200 mm
/ Min to 100%, hold for 10 minutes in that state, then release and let stand for 10 minutes to evaluate the dimensional deformation recovery before and after that, and set the following formula as the tensile set T.

T = (l ₂ −L ₀ ) / (l ₁ −L ₀ ) × 100 (%) However, T is the tensile permanent set (%) at 100% elongation, and L ₀ is between the marked lines before tension. Length (mm) l ₁ is the length (mm) between the marked lines during tension, l ₂ is the length (mm) between the marked lines after contraction (7) Formability evaluation T-die sheet forming machine (Ikegai) A GTR 65 mm twin-axis different-direction extruder: L / D = 18, lip width = 520 mm) was used to form a film with a lip gap of 0.5 mm, and the film formation state at that time was evaluated as follows.

◯: The film was successfully formed.

Δ: Melt fracture was slightly observed on the surface of the sheet.

X: Under normal conditions, a film cannot be formed and a product cannot be obtained.

(8) Appearance Evaluation of Sheet Surface The following evaluation was made on the appearance and corrosion feeling of the sheet formed by the T-die method sheet forming machine.

◯: A sheet having no problems such as bleeding and blocking.

Δ: There is some bleeding.

X: Blocking is large and sample adjustment such as physical property evaluation is difficult.

2. Polymerization of Block Copolymer Production Example 1 (Preliminary Polymerization) A glass autoclave reactor having an internal volume of 1 liter equipped with a stirrer was sufficiently replaced with nitrogen gas, and then 400 ml of heptane was charged. Reactor temperature 2
Keeping at 0 ° C., diethylene glycol dimethyl ether 0.18 mmol, ethyl iodide 22.7 mmol,
18.5 mmol of diethyl aluminum chloride and titanium trichloride (TOS-17 manufactured by Marubeni Solvay Chemical Co., Ltd.)
After adding 22.7 mmol, propylene was continuously introduced into the reactor for 30 minutes so that 3 g per 1 g of titanium trichloride was obtained. The temperature during this period was kept at 20 ° C.
After stopping the supply of propylene, the inside of the reactor was sufficiently replaced with nitrogen gas, and the obtained titanium-containing polypropylene was washed four times with purified heptane. As a result of the analysis, 2.9 g of propylene was polymerized per 1 g of titanium trichloride.

(Main Polymerization) Polymerization of Propylene and Copolymerization of Propylene-Ethylene 1 liter of liquid propylene and 0.70 mmol of diethylaluminum chloride were added to a 2 liter autoclave subjected to nitrogen substitution, and the internal temperature of the autoclave was 55 ° C. The temperature was raised to. 0.087 as titanium trichloride
mmol was added, and propylene was polymerized at 55 ° C. for 30 minutes. During this time, hydrogen was not used. Then, the internal temperature of the autoclave is rapidly lowered to 55 ° C., and at the same time, a mixed solution of 0.50 mmol of ethylaluminum sesquiethoxide and 0.014 mmol of methyl methacrylate is added, ethylene is supplied, and the ethylene gas concentration in the gas phase is
Copolymerization of propylene and ethylene was carried out at 55 ° C. for 100 minutes so as to be 13.0 mol%. Check the ethylene gas concentration during this period with a gas chromatograph.
Retained 3.0 mol%. During this time, hydrogen was not used. After the polymerization was completed, unreacted monomers were purged to obtain a particulate polymer. No adhesion was observed in the polymerization tank or on the stirring blade. The yield was 140 g, and the polymerization ratio of all polymers was 7300 g-polymer / g-titanium trichloride.

Production Example 2 Polymerization of propylene of Production Example 1 was carried out at 55 ° C. for 30 minutes, and copolymerization of propylene and ethylene was carried out to obtain ethylene concentration in the gas phase of 7.
The same operation as in Production Example 1 was carried out except that the content was adjusted to 0 mol% and the reaction was carried out at 55 ° C. for 120 minutes. Production Example 3 Polymerization of propylene of Production Example 1 was carried out at 60 ° C. for 30 minutes, and copolymerization of propylene and ethylene was conducted in an ethylene concentration of 5.
The same operation as in Production Example 1 was performed except that 0 mol% was performed for 120 minutes. Production Example 4 The procedure of Production Example 1 was repeated except that the polymerization of propylene in Production Example 1 was changed to 70 ° C. for 150 minutes, and the copolymerization of ethylene-propylene was changed to 55 ° C. for 80 minutes.

Production Example 5 To 30 kg of the polymer obtained in the above Production Example 1, 1,3-bis- (t-butylperoxyisopropyl) benzene was added as an organic peroxide in an appropriate amount, and 0.1 phr of a commonly used antioxidant was added and mixed for 1 minute with a Henschel mixer, and then melt-kneaded with a φ50 mm single screw extruder at 230 ° C. to obtain pellets.

[0038]

[Table 1]

Example 1 100 parts by weight of the copolymer obtained in Production Example 1 and 80 parts by weight of a plasticizer (paraffinic oil manufactured by Idemitsu Kosan: Diana Process Oil PW-380, molecular weight 746) were added to Ikegai P.
Melt-kneading was carried out at 200 ° C. with a CM extruder to obtain pellets. Ethylene-octene copolymer (manufactured by Dow Chemical Japan: Engage EG8100) was added to the obtained pellets.
Octene content 7.6 mol% MFR at 190 ° C =
1.0 g / 10 min Density 0.87 g / cm ³ ) 60 parts by weight was melt-kneaded with an extruder with respect to 100 parts by weight of the copolymer obtained in Production Example 1 to obtain pellets. The blending ratio of the pellets is shown in Table 2. The above pellets were processed by a T-die method sheet forming machine (Ikegai GTR65mm biaxial different direction extruder:
(L / D = 18, lip width = 520 mm) with a lip gap of 0.5 mm to form a film, and a soft sheet having a thickness of 0.6 mm was obtained.

Example 2 A propylene-based block copolymer was prepared by converting the copolymer obtained in Production Example 2 and an ethylene-α-olefin copolymer into ethylene-
Octene copolymer (manufactured by Dow Chemical Japan: Engage EG8200 Octene content 7.6 mol% 190
MFR at ℃ = 5.0g / 10min Density 0.87g / c
except that the m ³⁾ performs the same operation as in Example 1 to obtain a soft sheet. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2.

Example 3 The copolymer obtained in Production Example 3 of the propylene-based block copolymer and the ethylene-α-olefin copolymer were converted into ethylene-
Octene copolymer (manufactured by Dow Chemical Japan: Engage EG8200 Octene content 7.6 mol% 190
MFR at ℃ = 5.0g / 10min Density 0.87g / c
m ³ ) and Example 1 except that the plasticizer was a hydrocarbon-based synthetic oil (Mitsui Petrochemical Industry Co., Ltd .: Lucant HC-40).
A similar operation was performed to obtain a soft sheet. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2.

Example 4 Liquid polybutene (manufactured by Nippon Petrochemical Co., Ltd .: Nisseki Polybutene LV-100) was used as the plasticizer, and ethylene-butene copolymer was used as the ethylene-α-olefin copolymer (Mitsui Petrochemical Industry:
Tuffmer A4085 Butene content 11.7 mol%
MFR at 190 ° C. = 3.6 g / 10 min Density 0.87
except that in g / cm ³⁾ performs the same operation as in Example 1 to obtain a soft sheet. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2.

Comparative Example 1 A flexible sheet was obtained in the same manner as in Example 1, except that the propylene block copolymer was changed to the copolymer obtained in Production Example 4. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2. As shown in Table 2, the moldability and the surface of the sheet are good, but the flexibility and elastic recovery are deteriorated.

Comparative Example 2 A flexible sheet was obtained in the same manner as in Example 1 except that the propylene block copolymer was changed to the copolymer obtained in Production Example 5. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2. As shown in Table 2, stickiness occurs on the surface of the sheet and elasticity recovery decreases.

Comparative Examples 3 and 4 The same operation as in Example 1 was performed with the compounding ratios shown in Table 2. In Comparative Example 3, the melt fluidity of the resin composition was significantly reduced, and film formation was difficult. In Comparative Example 4, melt fracture occurred and it was difficult to measure the physical properties of the sheet.

Comparative Example 5 A flexible sheet was obtained in the same manner as in Example 1 except that the propylene block copolymer was changed to the copolymer obtained in Production Example 2. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2. As shown in Table 2, stickiness occurs on the sheet surface, which is not preferable as a product.

Comparative Example 6 The propylene-based block copolymer was obtained by preparing the copolymer obtained in Production Example 2 and the ethylene-α-olefin copolymer as ethylene-
Butene Copolymer (Mitsui Petrochemical Co., Ltd .: Tuffmer A4
085 butene content 11.7 mol% M at 190 ° C.
FR = 3.6 g / 10 min The same operation as in Example 1 was carried out except that the density was 0.87 g / cm ³ ) to obtain a soft sheet. The blending ratio, moldability, and evaluation of physical properties are shown in Table 2. As shown in Table 2, blocking occurs on the sheet, which is not preferable as a product.

Comparative Example 7 A propylene-based block copolymer was prepared using the copolymer obtained in Production Example 2 and a plasticizer as a paraffin oil (manufactured by Idemitsu Kosan: Diana Process Oil PW-380, molecular weight 74).
6), ethylene-propylene copolymer (manufactured by Mitsui Petrochemical Co., Ltd .: Tuffmer P-0280, propylene content 1
8.2 mol% MFR at 190 ° C. = 5.4 g / 10 min Density 0.914 g / cm ³ ) The same operation as in Example 1 was performed to obtain a soft sheet. Table 2 shows the blending ratio, moldability, and evaluation of physical properties. As shown in Table 2, flexibility and elastic recovery are reduced. From the evaluation of the molding processability and physical properties in Table 2, it can be seen that the soft sheets of Examples have good elastic recovery and flexibility.

[0049]

[Table 2]

Claims (1)

[Claims] 1. A polypropylene component of 1 to 40% by weight and an ethylene-based monomer unit of 10 to 40% by mole.
The propylene-ethylene random copolymer component containing 60
~ 99% by weight and an intrinsic viscosity of 6 to 30 dl / g
100 parts by weight of a propylene block copolymer which is
(2) Plasticizer 40 to 150 parts by weight, and (3) Ethylene-α olefin copolymer 20 to 10 containing 2 to 15 mol% of a monomer unit based on α olefin having 4 or more carbon atoms.
A polyolefin resin composition comprising 0 parts by weight.