JP2003213050A - Olefinic thermoplastic elastomer - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an olefinic thermoplastic elastomer capable of affording an extruded product having excellent oil resistance, flexibility, mechanical strength, rubber elasticity and extrudability with slight bleeding of a softener, scarcely causing stones and having a smooth surface and an excellent appearance, a sheet formed product and a laminate using the olefinic thermoplastic elastomer. <P>SOLUTION: This olefinic thermoplastic elastomer satisfies formulas (I) to (III). Y≤-2X+350 (I), X<95 (II) and Z≤150 (III) [wherein, X, Y and Z are as follows; X is JIS A hardness (no unit) of a molded product measured according to JIS K6253; Y is a rate of change in weight (unit: %) of the molded product measured under conditions of 120°C using No.IRM903 oil according to JIS K6258; and Z is the number of the stones (unit: number of the stones) on the surface of the extruded sheet (250 mm×1,500 mm)]. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an olefin-based thermoplastic elastomer, and a sheet molding and a laminate using the olefin-based thermoplastic elastomer. More specifically, it relates to an olefin-based thermoplastic elastomer that has little bleeding of a softening agent, is excellent in oil resistance, flexibility, mechanical strength, rubber elasticity, and moldability, has a smooth extruded product surface, has few spots, and has an excellent appearance. Is.

[0002]

2. Description of the Related Art In recent years, styrene-based, olefin-based, ester-based, amide-based, and urethane-based resins that do not require a vulcanization step and have the same moldability as thermoplastic resins from the viewpoints of process rationalization and recyclability, etc. Thermoplastic elastomers such as are attracting attention, and are widely used in the fields of automobile parts, home electric appliance parts, medical equipment parts, electric wires, and sundries.
Among them, the polypropylene-based resin and the ethylene-α-olefin-based copolymer rubber are dynamically heat-treated in the presence of an organic peroxide to crosslink the ethylene-α-olefin-based copolymer rubber. Olefin-based thermoplastic elastomers that are crosslinked products are known.

However, conventional olefinic thermoplastic elastomers are inferior to vulcanized rubbers in terms of flexibility, mechanical strength, rubber elasticity, etc., and their applications are limited. In order to improve these performances, the addition of mineral oil-based softeners and organic peroxide non-crosslinking hydrocarbon rubber-like substances gives flexibility, and the use of a crosslinking aid also increases the degree of crosslinking and improves rubber elasticity. Although various attempts have been made to improve the rubber elasticity by increasing the degree of cross-linking in these compositions, the softening of the composition or the softening agent on the surface of the composition is therefore reduced. Bleeding and the like occurred, and it was difficult to obtain a product having a good balance of physical properties.

In order to solve such a problem, 100
The oil-extended olefin-based copolymer rubber and olefin-based plastic obtained by adding a mineral oil-based softening agent to a solution containing an olefin-based copolymer rubber having a Mooney viscosity of 170 to 350 A partially crosslinked composition has been proposed (see, for example, Patent Document 1). However, even with this composition, the mechanical strength is not sufficiently improved, and when this composition is extrusion-molded, it has many small protrusions called “butsu”, and it becomes a molded product with a rough surface and a molded product with a smooth surface. There was a problem that it was difficult to get.

In general, an olefinic thermoplastic elastomer has a problem that it is difficult to form a complicated shape during extrusion molding, especially in profile extrusion molding, and it is difficult to obtain a molded article having excellent surface smoothness. On the other hand, when molded into a thin sheet, the appearance and smoothness of the surface are very important. Therefore, if the overdense gel content in the product forms spots or roughens the surface, Depending on the case, it may not be usable.

The olefin-based thermoplastic elastomer has a crystalline polypropylene resin as a matrix and forms a morphology (dispersion form) having olefin-based rubber particles as domains. The olefin-based thermoplastic elastomer has physical properties and characteristics. It is greatly related to the degree of dispersion of particles. That is, it is known that the more the olefin rubber particles are finely dispersed as fine particles of about 1 to 2 μm, the better the physical properties of the olefin thermoplastic elastomer. This also applies to the extrusion moldability of the olefin-based thermoplastic elastomer and the surface characteristics of the resulting extrusion-molded product, and these are also greatly related to the morphology of the olefin-based thermoplastic elastomer.

In the past, in order to improve the morphology, the method of finely dispersing the olefinic rubber particles relies largely on a physical method. For example, a method of improving the dispersibility of rubber is adopted by using a high shear type processing device such as a high-speed twin-screw extruder. In this case, the screw configuration of the high-speed twin-screw extruder is optimized. By increasing the L / D of the extruder, the fine dispersibility of the rubber particles can be improved. Also,
The dispersibility is also improved by passing through the extruder twice.

However, even if rubber particles are finely dispersed by such a physical method, conventionally, an extruded product having few spots, a smooth surface, and an excellent appearance is obtained with good extrudability. It was difficult to obtain a moldable olefinic thermoplastic elastomer.

[0009]

[Patent Document 1] Japanese Patent No. 2140072

[0010]

DISCLOSURE OF THE INVENTION The present invention is based on the above-mentioned problems of the prior art in olefinic thermoplastic elastomers, and has little bleeding of a softening agent, oil resistance, flexibility,
An olefin-based thermoplastic elastomer that is excellent in mechanical strength, rubber elasticity and extrusion moldability, has few spots, and can obtain an extrusion-molded product with a smooth surface and excellent appearance, and sheet molding using this olefin-based thermoplastic elastomer. It is intended to provide a body and a laminate.

[0011]

The olefinic thermoplastic elastomer of the present invention is characterized by satisfying the following formulas (I) to (III). Y ≦ −2X + 350 (I) X <95 (II) Z ≦ 150 (III) However, X, Y, and Z are as follows. X: JI of the molded product measured according to JIS K6253
S A hardness (no unit) Y: Based on JIS K6258, the weight change rate (unit:%) of the molded product measured using IRM903 oil at 120 ° C. Z: Extruded sheet surface (250 mm × 1500 mm) No. of items (unit: pieces)

When X, Y and Z satisfy the above formulas (I) to (III), bleeding of the softening agent is small, oil resistance, flexibility, mechanical strength, rubber elasticity and moldability are excellent,
It is possible to obtain an olefin-based thermoplastic elastomer having a smooth surface of an extrusion-molded product, few spots, and an excellent appearance.

In the present invention, among such olefinic thermoplastic elastomers, domains of crosslinked olefinic copolymer rubber having an average particle size of 0.1 to 5 μm (island dispersion), particularly in an olefinic resin matrix. It is preferable that the olefin resin has a dispersed form (morphology) in which the olefin resin is dispersed in the domain with an average particle size of 0.01 to 0.5 μm.

The weight change rate Y in the above formula (I) is an index of oil resistance and is determined as follows in accordance with JIS K6258.

Injection pressure 50 MPa, cylinder temperature 220
Injection molded sheet (12 ° C, mold temperature 40 ° C)
0mm x 80mm x 2mm) 50mm x 25mm x 2
Punching to mm, soaking in IRM903 oil, 120
Leave at 22 ° C for 22 hours. After immersion, take out the sample,
The oil adhering to the surface is wiped off, the weight is measured, and the rate of weight change (%) is calculated by the following formula. ΔW = (W2-W1) × 100 / W1 ΔW: weight change rate (%) W1: mass of sample before air W2: mass of sample after immersion in air

The number (Z) of the spots in the formula (III) is 250 to 300 mm in width and 0.2 in thickness from the T die of the extruder.
A sheet of ~ 0.4 mm is extruded, and the surface of the obtained extruded product on the opposite side in contact with the first roll (250 mm x 1500
mm) is a value (pieces) obtained by measuring the number of spots (projections) having a diameter of 0.3 mm or more.

The sheet-shaped molded product of the present invention uses the composition containing such an olefinic thermoplastic elastomer of the present invention as a base material.

The laminate of the present invention has a surface layer having as a base material a composition containing such an olefinic thermoplastic elastomer of the present invention.

[0019]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described in detail below.

The olefinic thermoplastic elastomer of the present invention satisfies the above formulas (I) to (III).

Formula (I) is not satisfied, and Y> -2X + 35.
When 0, that is, Y + 2X> 350, the balance between oil resistance and hardness is poor, and problems arise depending on the application. Y + 2X
Is preferably 330 or less, more preferably 320 or less and 200 or more, and particularly preferably 60 or more.

If the JIS A hardness X is 95 or more without satisfying the formula (II), the flexibility is insufficient. X is especially 94
It is preferably 93 or less, particularly 10 or more, and more preferably 30 or more.

Those which do not satisfy the above formula (III) and the number Z of which the number of seeds exceeds 150 are not preferable because the surface smoothness and the appearance are poor. Z is particularly preferably 100 or less, and particularly preferably 50 or less.

The constitution of the olefinic thermoplastic elastomer of the present invention is not particularly limited, but in particular,
An olefin-based thermoplastic elastomer having a dispersion form (morphology) in which an olefin-based resin is used as a matrix and a cross-linked olefin-based copolymer rubber is used as island-shaped domains, and the average particle size of the domains is 0.1 to 5
and an olefin resin having an average particle size of 0.01 to 0.5 μm dispersed in at least a part of the domain easily satisfies the above formulas (I) to (III). It is possible to reduce the bleed of the softening agent, oil resistance,
Excellent flexibility, mechanical strength, rubber elasticity and extrudability,
It is preferable because it is possible to obtain an extrusion-molded product having few spots, a smooth surface, and an excellent appearance.

In the above dispersion form, rubber domains (islands, grains) are present in the olefin resin as the matrix (sea), and the olefin resin constituting the matrix resin is further finely dispersed in the domains. Is.

It is considered that such a dispersion form (morphology) is manifested due to the specifically good dispersibility of the resin of the matrix and the rubber constituting the domain, and this is due to the large physical properties of the molded product (in the surface state). It is thought that it contributes to the improvement of (represented).

On the contrary, by controlling the composition, molding conditions and the like so as to form the above-mentioned morphology,
The above formulas (I) to (III) are satisfied, and a good molded product (composition) can be obtained.

The average particle size of the olefin copolymer rubber domains and the average particle size of the olefin resin dispersed in the domains in the olefin thermoplastic elastomer suitable for the present invention are measured under a liquid nitrogen atmosphere. Frozen in, make an ultra-thin section using an ultra microtome,
It is a value obtained by performing real space measurement by transmission electron microscope measurement after performing RuO ₄ staining. By this RuO ₄ dyeing, the phase of the olefinic copolymer rubber is selectively dyed.

The average particle size of the domains of the olefinic copolymer rubber is 800 times the observation magnification of the transmission electron microscope measurement.
At 0 times, it is determined as an average value of all of the rubber particles in the 13 μm × 19 μm section which are visible and can be measured by the following method (however, the number of sections is 5 or more). In this case, the domain having a shape deviating from the circle is assumed to be an ellipse, and the average of the lengths of the major axis and the minor axis is the particle size. The measurement is performed manually on an electron micrograph with the above magnification of 8000 times using a ruler with a minimum unit of 1 mm.

The average particle size of the olefinic resin dispersed in the domain is an olefinic copolymer in a section of 5.2 μm × 7.7 μm at an observation magnification of 20000 times as measured by the transmission electron microscope. Manually measure the olefin resin particles in the rubber domain in the same manner as above,
Calculate as an average value (however, the number of sections is 5 or more). In this case, particles having a shape deviating from a circle are assumed to be elliptical, and the average of the lengths of the major axis and the minor axis is the particle size.

If it is recognized by the above-mentioned observation method that the olefin resin particles are dispersed, the effect of the improvement according to the present invention will be exhibited. Above all, the olefin resin is contained in 10% by area or more of all rubber domains. Those dispersed are preferable, and those dispersed in 20 area% or more are more preferable. If the olefin resin is not dispersed, the compatibility between the olefin resin and rubber tends to decrease, and the surface roughness of the obtained extrusion molded product tends to increase.

Here, the area ratio of the domain in which the olefin resin is dispersed to all the rubber domains means the olefin group to the total area of all the rubber domains of the sample when the particle size is calculated by the transmission electron microscope measurement. It is the ratio of the total area of the resin dispersion domain.

In Examples and Comparative Examples described later, the average particle size and the area ratio were determined by the above method.

In the present invention, the average particle size of the rubber domain is determined by, for example, scanning electron microscope measurement or various scattering observation methods such as light scattering method, in addition to the real space observation by the transmission electron microscope observation. May be.

The olefin-based thermoplastic elastomer of the present invention, in particular, the matrix of the olefin-based resin has a domain of the olefin-based copolymer rubber having an average particle size of 0.1 to 5 μm, and inside this domain, An olefinic thermoplastic elastomer suitable for the present invention, which has a morphology in which an olefinic resin is dispersed with an average particle size of 0.01 to 0.5 μm, is, for example, a specific production by the following specific raw material formulation. Can be manufactured by the method.

The raw material components suitable for the production of the olefinic thermoplastic elastomer of the present invention and the production method will be described below.

First, raw material components suitable for producing the olefinic thermoplastic elastomer of the present invention will be described.

<Olefin Copolymer Rubber (A: A1,
A2)> The olefin copolymer rubber of the component (A) is, for example, ethylene-propylene copolymer rubber or ethylene-
It is an elastic body of an amorphous random copolymer containing olefin as a main component, such as propylene-non-conjugated diene copolymer rubber, ethylene-butene-non-conjugated diene copolymer rubber, propylene-butadiene copolymer rubber. Among these,
Ethylene-propylene-non-conjugated diene copolymer rubber (E
PDM) is preferred, and as the non-conjugated diene, dicyclopentadiene, 1,4-hexadiene, cyclooctadiene, methylene norbornene, ethylidene norbornene and the like are used, and particularly ethylene-propylene-ethylidene norbornene copolymer rubber is It is preferable in that an appropriate crosslinked structure can be obtained.

In the above EPDM, the ethylene content is usually 50 to 90% by weight, preferably 60 to 80% by weight, the propylene content is usually 5 to 50% by weight, preferably 10 to 45% by weight, and the non-conjugated diene is contained. The amount is usually 1
It is 30% by weight, preferably 3 to 20% by weight. When the ethylene content exceeds 90% by weight, the flexibility of the resulting composition is lost, and when it is less than 50% by weight, the mechanical performance tends to be deteriorated. Propylene content is 50% by weight
If it exceeds 5%, the mechanical performance tends to deteriorate, and if it is less than 5% by weight, the flexibility and rubber-like elasticity tend to decrease. Further, when the content of non-conjugated diene is less than 1% by weight, mechanical properties are deteriorated because the degree of crosslinking of the obtained composition does not increase, and when it exceeds 30% by weight, injection moldability tends to be deteriorated. It is in.

In the present invention, the component (A1) described later is used.
In the preparation of B), a good molded product can be obtained by using the olefin-based copolymer rubber component (A1) having a weight average molecular weight of 500,000 or more, preferably 520,000 or more in terms of polypropylene by GPC. . Ingredient (A
When the weight average molecular weight of 1) is less than 500,000, the mechanical strength of the obtained composition tends to be insufficiently improved.
The upper limit of the weight average molecular weight of the component (A1) is usually 1,000,000.

Further, the same olefinic copolymer rubber component (A2) having a molecular weight of less than 500,000 as described above may be used in addition to (A1) within a range in which the mechanical strength of the obtained composition is not lost. it can. The lower limit of the weight average molecular weight of the component (A2) is usually 50,000.

<Mineral oil-based rubber softening agent (B)> The mineral oil-based rubber softening agent softens the obtained olefinic thermoplastic elastomer to increase flexibility and elasticity.
It is used for the purpose of improving the processability and fluidity of the resulting composition. Generally, the mineral oil-based softening agent for rubber is a mixture of aromatic hydrocarbons, naphthene-based hydrocarbons and paraffin-based hydrocarbons. Aromatic hydrocarbons having a carbon content of 35% by weight or more based on the total carbon content are aromatic oils, and those having a naphthene-based hydrocarbon content of 30 to 45% by weight are naphthenic oils and paraffinic oils. A hydrocarbon containing 50% by weight or more of carbon is called paraffin oil. Of these, paraffinic oil is preferably used in the present invention.

As the paraffin oil, the kinematic viscosity at 40 ° C. is usually 20 to 800 cSt (centistokes),
It is preferably 50 to 600 cSt and the fluidity is usually 0.
To -40 ° C, preferably 0 to -30 ° C, flash point (CO
C) is usually 200 to 400 ° C., preferably 250 to 35
Those at 0 ° C. are preferably used.

<Olefin Resin (C)> Examples of the olefin resin include propylene resin, ethylene resin, crystalline polybutene-1 resin, ethylene-vinyl acetate copolymer, ethylene- (meth) acrylic acid copolymer. Ethylene resins such as ethylene- (meth) acrylic acid ester copolymers can be mentioned, but among these olefin resins, it is preferable to use a propylene resin. As the propylene resin, a homopolymer of propylene, and a copolymer resin containing propylene as a main component, preferably a propylene-α-olefin copolymer, specifically, a propylene / ethylene random copolymer or propylene / ethylene. Examples thereof include block copolymers.

The melt flow rate (JIS K7210, 230 ° C., 21.2N load) of these propylene-based resins is usually 0.05 to 100 g / 10 minutes, preferably 0.1 to 50 g / 10 minutes. If the melt flow rate is less than the above range, the moldability deteriorates,
A defect occurs in the appearance of the obtained molded body. When a melt flow rate exceeding the above range is used,
Mechanical properties, especially tensile fracture strength, tend to decrease.

<Organic peroxide (D)> As the organic peroxide, either an aromatic type or an aliphatic type can be used.
It may be a single peroxide or a mixture of two or more peroxides. Specifically, di-t-butyl peroxide, t-butyl cumyl peroxide, dicumyl peroxide, 2,
5-dimethyl-2,5-di (t-butylperoxy) hexane, 2,5-dimethyl-2,5-di (t-butylperoxy) hexyne-3,1,3-bis (t-butylperoxy) (Oxyisopropyl) benzene, dialkyl peroxides such as 1,1-di (t-butylperoxy) -3,3,5-trimethylcyclohexane, t-butylperoxybenzoate, t-butylperoxyisopropyl carbonate, 2, 5-dimethyl-2,5-di (benzoylperoxy) hexane, 2,5-dimethyl-2,5
-Peroxyesters such as di (benzoylperoxy) hexyne-3, diacyl peroxides such as acetyl peroxide, lauroyl peroxide, benzoyl peroxide, p-chlorobenzoyl peroxide and 2,4-dichlorobenzoyl peroxide Etc. are used.
Among these, 2,5-dimethyl-2,5-di (t
-Butylperoxy) hexane and 1,3-bis (t-butylperoxyisopropyl) benzene are preferably used.

<Crosslinking aid> In addition to the above components, a crosslinking aid may be used. Examples of the main crosslinking aid include, for example, sulfur, p-quinonedioxime, p-dinitrosobenzene, peroxide aids such as 1,3-diphenylguanidine, divinylbenzene, triallyl cyanurate, triallyl isocyanate. Polyfunctional vinyl compounds such as nurate and diallyl phthalate, ethylene glycol di (meth) acrylate, diethylene glycol di (meth) acrylate, polyethylene glycol di (meth) acrylate,
Examples include polyfunctional (meth) acrylate compounds such as trimethylolpropane tri (meth) acrylate and allyl (meth) acrylate.

<Other Components> In addition to the above-mentioned components, the olefinic thermoplastic elastomer of the present invention may be blended with other optional compounding components according to various purposes within the range of not significantly impairing the effects of the present invention. You can

The optional components include, for example, fillers, antioxidants, heat stabilizers, light stabilizers, ultraviolet absorbers, neutralizing agents, lubricants, antifogging agents, antiblocking agents, slip agents, dispersions. Agents, colorants, flame retardants, antistatic agents, conductivity-imparting agents, metal deactivators, molecular weight regulators, fungicides, mildew-proofing agents, various additives such as optical brighteners, other than the above essential components Examples thereof include thermoplastic resins and elastomers other than the above essential components, and any of these may be used alone or in combination of two or more.

Here, as the thermoplastic resin other than the essential components, for example, ethylene-vinyl acetate copolymer, ethylene-acrylic acid copolymer, ethylene-methacrylic acid copolymer, ethylene-acrylic acid ester copolymer. Ethylene such as ethylene-methacrylic acid ester copolymer
α-olefin copolymer, polyethylene, polybutene-
Polyolefin resin such as 1 resin, polyphenylene ether resin, polyamide resin such as nylon 6 and nylon 66, polyester resin such as polyethylene terephthalate and polybutylene terephthalate, polyoxymethylene such as polyoxymethylene homopolymer and polyoxymethylene copolymer Examples of the resin include polymethylmethacrylate resin.

As the elastomer which can be used as an optional component, for example, ethylene-propylene copolymer rubber (EPM), ethylene-propylene-non-conjugated diene copolymer rubber (EP) other than the above essential components of the present invention is used.
DM), ethylene-butene copolymer rubber (EBM), ethylene-based elastomer such as ethylene-propylene-butene copolymer rubber, styrene-butadiene copolymer rubber, styrene-based elastomer such as styrene-isoprene copolymer rubber, polybutadiene, etc. Can be mentioned.

Further, examples of the filler include glass fiber, hollow glass sphere, carbon fiber, talc, calcium carbonate, mica, potassium titanate fiber, silica, titanium dioxide and carbon black.

Next, a preferred method for producing the olefinic thermoplastic elastomer of the present invention will be described. This manufacturing method comprises the steps of preparing the component (A1B) and the component (A1B).
And a dynamic heat treatment step of component (C).

First, the weight average molecular weight of the component (A1) is 50.
Oil-extended olefin by premixing 12 to 200 parts by weight, preferably 40 to 150 parts by weight, of the component (B) softener for mineral oil rubber with respect to 100 parts by weight or more of 10,000 or more olefin copolymer rubber. A system copolymer rubber component (A1B) is prepared.

Here, the amount of the component (B) used is the amount of the component (A
1) When the amount is less than 12 parts by weight based on 100 parts by weight, the fluidity of the obtained composition tends to be low, and particularly extrusion processability and injection moldability tend to be impaired. On the other hand, when the amount of the component (B) used exceeds 200 parts by weight with respect to 100 parts by weight of the component (A1), the plasticity of the obtained composition is remarkably increased and the processability is deteriorated, and the physical properties of the molded article are also increased. Etc. tends to decrease.

That is, in the present invention, by using the component (B) within the above range, it is possible to satisfy both the improvement of processability and the improvement of mechanical properties by securing flexibility and fluidity at the same time. It is possible to obtain a thermoplastic elastomer, and by using the component (B) in the above range, heat generation during the dynamic heat treatment described below is suppressed, and as a result, there are few spots during extrusion molding, and A smooth molded product can be obtained.

A known method can be used for the above oil extension. For example, a method of mechanically kneading the component (A1) and the component (B) by using a device such as a roll or a Banbury mixer and oil-extending, or adding a predetermined amount of (B) to the solution of the component (A1). Then, the solvent is removed by a method such as steam stripping. In particular, the latter oil extension method is preferable, and as the solution of the component (A1), it is preferable to use an olefin copolymer rubber solution obtained by polymerization because the operation is easy.

Then, 30 to 95% by weight, preferably 40 to 90% by weight of the obtained oil-extended olefin copolymer rubber component (A1B) and olefin resin 5 of component (C) are added.
~ 70 wt%, preferably 10 to 60 wt% after mixing (provided that the total amount of components (A1B) and (C) is 100
% By weight), and in the presence of an organic peroxide of component (D), a dynamic heat treatment is performed at a temperature lower than the one-minute half-life temperature.

Here, when the content of the component (C) is less than 5% by weight in the total amount of 100% by weight of the components (A1B) and (C), the fluidity of the obtained composition tends to decrease. When the amount exceeds 70% by weight, the flexibility of the obtained composition may be lost.

The amount of the component (D) used is usually 0.05 based on 100 parts by weight of the total of the component (A1B) and the component (C).
To 3.0 parts by weight, preferably 0.07 to 2.0 parts by weight. The addition amount of this component (D) is 0.0
If it is less than 5 parts by weight, the effect of promoting the crosslinking reaction will be small, and if it exceeds 3.0 parts by weight, it may be difficult to control the crosslinking reaction.

When the above-mentioned cross-linking auxiliary agent is used in combination, the total amount of the components (A1B) and (C) is 100.
It is usually selected from the range of 0.01 to 4 parts by weight, preferably 0.05 to 2 parts by weight, based on parts by weight. If the addition amount of this crosslinking aid is less than 0.01 parts by weight, the effect due to the addition is difficult to appear, and even if it is used in excess of 4 parts by weight, the effect corresponding to the increase of the addition amount cannot be obtained, and it is economically economical. Not an advantage.

In the present invention, it is important to carry out the dynamic heat treatment (kneading treatment) at a temperature lower than the one-minute half-life temperature of the component (D) used. By such dynamic heat treatment,
Since the raw material is finely dispersed and then crosslinked, an olefin resin is used as a matrix, and the domains are partially or completely crosslinked, which is an olefin copolymer rubber having an average particle size of 0.1 to 5 μm. It becomes possible to disperse and form a morphology in which an olefin resin is dispersed in a part or all of the domain with an average particle diameter of 0.01 to 0.5 μm. The olefin copolymer rubber and the olefin resin It is possible to produce a composition in which the compatibility of the compound (1) is increased, and when extrusion molding is carried out, little molding is generated and a molded product having a smooth surface can be obtained.

The term "dynamic heat treatment temperature" as used herein means the temperature of the composition, and its preferable range is 10 ° C. or more lower than the one-minute half-life temperature of the component (D) used. The lower limit of the dynamic heat treatment temperature is usually 100 ° C. lower than the one-minute half-life temperature. The state of the material during the dynamic heat treatment varies depending on the type of material used and the temperature of the dynamic heat treatment, and is usually a semi-molten state or a molten state, but is not particularly limited.

The above-mentioned method is generally used as the means for forming the morphology of the dispersed particles in the matrix-domain-domain of the present invention, but the melting point of the olefin resin as the raw material, the crosslinking rate of the olefin copolymer rubber, The morphology of dispersed particles in the matrix-domain-domain can be realized by other methods by balancing the affinity of the olefin resin and the olefin copolymer rubber.

Mixing used in the dynamic heat treatment according to the present invention
Examples of the kneading device include a conventionally known non-open type Banbury mixer, a twin-screw extruder, and the like, and the twin-screw extruder is particularly preferably used. For example, a twin-screw extruder having a screw structure in which a dispersion zone and a cross-linking zone of the component (A1B) and the component (C) are sequentially formed is used. From the hopper of the twin-screw extruder, the component (A1B) While supplying (C) and the component (D), the temperature of the composition in the dispersion zone is adjusted to a temperature lower than the 1-minute half-life temperature of the component (D) to be used, and the dynamic heat treatment is performed.

When the aforementioned component (A2) is used in combination, the component (A2) is mixed with the component (A1B), the component (C) and the component (D) and supplied. The amount of the component (A2) used is preferably not more than twice the total amount of the components (A1B) and (C) in order not to lose the mechanical strength of the resulting composition. The component (A2) may be used by blending with the component (A1B), or may be used together with the component (A1) in the preparation of the component (A1B). By using the component (A2), the flowability may be improved and the injection moldability may be improved.

When the component (B) is further added after the dynamic heat treatment (hereinafter, the component (B) to be added thereafter may be referred to as "additional component (B)"), from a separate hopper,
For example, an injection port may be provided at a position corresponding to a position downstream of the cross-linking zone of the above twin-screw extruder, and the additional component (B) may be supplied.

The above-mentioned additional component (B) is 1.5 times the total amount of the components (A1B) and (C) after the dynamic heat treatment, for the purpose of adjusting the composition to give the desired flexibility. Further mixing can be performed in a ratio of less than the amount. If the proportion of the additional component (B) added thereafter exceeds the above range, bleeding tends to be a problem.

Other additives may be added at any stage of producing the composition according to the present invention, and further during the processing of the composition or the use of the product after the processing.

The olefinic thermoplastic elastomer of the present invention can be produced by the molding method used for the thermoplastic elastomer (for example, injection molding method, extrusion molding method, hollow molding method, compression molding method, etc.) or the secondary Molded body (single body or laminate with other materials) by processing (lamination molding, thermoforming, etc.)
It is said that And automobile parts (weather strip,
Ceiling materials, interior sheets, bumper moldings, side moldings,
Air spoilers, air duct hoses, packings, etc.), civil engineering / building material parts (waterproofing materials, jointing materials, architectural window frame packings, etc.), sports equipment (golf clubs, tennis racket grips, etc.), industrial parts ( It is used as a material in a wide range of fields such as hose tubes, gaskets, etc., home electric appliances parts (hoses, packing, etc.), medical equipment parts, electric wires, and miscellaneous goods.

In particular, the thermoplastic elastomer of the present invention is
By extrusion molding, it is possible to obtain a molded product having a smooth surface, few scratches, and a good appearance, and therefore it is suitable for a sheet-shaped molded product. Examples of the molding machine used in this case include a general molding machine such as an extruder equipped with a calender roll, a T die or an annular die. Further, an embossed pattern (texture) can be applied to the surface of the sheet-shaped molded product. A resin, rubber, foam, woven cloth, non-woven cloth, cotton cloth, paper or the like can be laminated on the sheet-shaped molded body, and
A coat layer can be applied to at least one surface of the sheet-shaped molded product. Furthermore, the sheet-shaped molded product and the laminate thereof can be shaped by vacuum molding, pressure molding, or the like.

[0072]

EXAMPLES The present invention will be specifically described below with reference to Examples and Comparative Examples, but the present invention is not limited to the following Examples unless it exceeds the gist.

Materials and evaluation methods used in the following Examples and Comparative Examples are as follows.

<Material> Oil-extended olefin copolymer rubber (A1B-a) Ethylene-propylene-ethylidene norbornene terpolymer rubber (ethylene content 66% by weight, ethylidene norbornene content 4.5% by weight, GPC The weight average molecular weight of polypropylene is 647,000),
It contains 100 parts by weight of component (B) described below per 100 parts by weight of the copolymer rubber.

Oil-extended olefin-based copolymer rubber (A1
B-b) an ethylene-propylene-ethylidene norbornene terpolymer rubber (ethylene content 66% by weight, ethylidene norbornene content 4.5% by weight, polypropylene-equivalent weight average molecular weight 487,000 by GPC),
It contains 75 parts by weight of component (B) described below per 100 parts by weight of the copolymer rubber.

Olefin-based copolymer rubber (A2) Ethylene-propylene-ethylidene norbornene terpolymer rubber (ethylene content 66% by weight, ethylidene norbornene content 4.5% by weight, polypropylene-based weight average molecular weight by GPC) 241,000 olefin copolymer rubber)

Mineral oil type rubber softener (B) Paraffin type oil (weight average molecular weight 746, kinematic viscosity at 40 ° C. 382 cSt, pour point -15 ° C., flash point 300)
℃, "PW380" manufactured by Idemitsu Kosan Co., Ltd.)

Olefin resin (C) Propylene-ethylene random copolymer resin (ethylene content 3.1% by weight, melt flow rate (230 ° C.,
21.2N load) 0.7g / 10 minutes)

Organic peroxide (D) 2,5-dimethyl-2,5-di (t-butylperoxy) hexane (POX) (1 minute half-life temperature 179 ° C.)

Crosslinking aid (a) Divinylbenzene (DVB)

Crosslinking aid (b) Trimethylolpropane trimethacrylate (TMP)

<Evaluation Method> The following (1) to (3),
For measurement of (7) and (8), an in-line screw type injection molding machine (“IS130” manufactured by Toshiba Machine Co., Ltd.) was used to inject pressure 50 MPa, cylinder temperature 220 ° C., mold temperature 40.
Sheet obtained by injection molding under the condition of ℃ (120m wide)
m, length 80 mm, wall thickness 2 mm) was used.

(1) JIS A hardness: JIS K625
It measured according to 3.

(2) Tensile fracture strength (MPa): JIS
Compliant with K6251 (JIS-3 dumbbell, pulling speed 5
(00 mm / min) and measured.

(3) Compression set (%): JIS K6
It measured based on 262 (70 degreeC, 22 hours, 25% compression).

(4) Surface roughness Ra (μm): JIS B
In accordance with 0601, from the T-die of a 45 mmφ extruder (single flight type screw) manufactured by Watanabe Processing Machine,
A sheet having a width of 250 mm and a thickness of 0.35 mm was extruded, and the center line average roughness Ra of the obtained extruded product surface was measured using a surface roughness meter (Surfcom 570A) manufactured by Toyo Seimitsu Co., Ltd.

(5) Evaluation of spots on extruded sheet: The number of spots having a diameter of 0.3 mm or more in the range of a sheet width of 0.25 m and a length of 1.5 m formed in the same manner as in (4) was measured, and the spots were measured. Depending on the number (Z) of, ○: excellent (the number of lumps is 150 or less), Δ: good (the number of lumps exceeds 150 to 500 or less), ×: defective (number of lumps exceeds 500) It was judged in three stages.

(6) Extrudability: A 40 mmφ single screw extruder (manufactured by Mitsubishi Heavy Industries, Ltd.) was used, and the screw rotation speed was 7
The shape of the molded product extruded from the profile die at 0 rpm and a temperature of 180 ° C. was evaluated. The reflectivity of the die shape and the surface condition of the molded product were visually observed, and judged in three stages of ◯: excellent, Δ: good, and ×: poor.

(7) Softening agent (oil) bleeding property for mineral oil type rubber: The injection molded product was left in an oven at 80 ° C. for 24 hours, and the oil bleeding on the surface of the molded product was visually observed.
○: No bleeding, △: Slight bleeding,
X: Judgment was made in three stages with bleeding.

(8) Oil resistance (weight change rate): 50 mm ×
Injection-molded product punched out to 25 mm x 2 mm is IRM90
It was immersed in No. 3 oil and left at 120 ° C. for 22 hours. After the immersion, the sample was taken out, the oil adhering to the surface was wiped off, and the weight was measured. Then, the weight change rate was calculated by the following formula. ΔW = (W2-W1) × 100 / W1 ΔW: weight change rate (%) W1: mass of sample before air W2: mass of sample after immersion in air

(9) Average particle size of rubber domain and olefin resin dispersed in the domain: A molded article molded in the same manner as in (4) was frozen in a liquid nitrogen atmosphere, and then super-sized using an ultramicrotome. A thin section was prepared, stained with RuO _4, and then subjected to transmission electron microscope measurement. The average particle size of the rubber domain is 8000 times the observation magnification of the transmission electron microscope measurement, and all of the rubber particles in the 13 μm × 19 μm section that are visible and can be measured with a ruler with a minimum unit of 1 mm. It was calculated as an average value. The number of sections to be measured was 5. The average particle size of the olefin resin dispersed in the domain is 5.2 μm × 7.7, when the observation magnification of the transmission electron microscope measurement is 20000 times.
The olefin-based resin particles in the domain of the olefin-based copolymer rubber in the section of μm were manually measured in the same manner as above and determined as an average value. The number of sections to be measured was 5.

(10) Ratio of rubber domain in which polyolefin is dispersed in all rubber domains: Electron microscope measurement was performed in the same manner as in (9), and the observation magnification was 8000 times and 13 μ.
The ratio of the total area of the olefin resin dispersion domain to the total area of all the rubber domains was calculated from the rubber particles in the m × 19 μm section (the number of measurement sections was 5).

Example 1 0.30 part by weight of POX and 0.40 part by weight of DVB were added to 100 parts by weight of a mixture of 80% by weight of the component (A1B-a) and 20% by weight of the component (C), and a Henschel mixer was used. After blending for 1 minute in the same direction, a twin-screw extruder in the same direction with a screw configuration having three kneading zones (Kobe Steel “KTX44”, L / D = 4).
1 、 Cylinder block number = 11) 30k to the first supply port
Input at a speed of g / h, screw rotation speed 350 rpm
Granulation was carried out at.

Further, a platinum resistance thermometer is installed at a position corresponding to the first kneading zone (dispersion zone) in the cylinder and in contact with the composition, and the cylinder temperature is adjusted so that the temperature of the composition becomes 130 ° C. The cylinder temperature is set so that the temperature of the composition in the cylinder at a position corresponding to the second kneading zone (crosslinking zone) and the third kneading zone (the dispersion zone when the component (B) is present) is 200 ° C. Set,
Melt-kneading was performed and pelletized.

In this Example 1, a test piece was cut out from a molded article molded in the same manner as in (4) for the evaluation of morphology, and a transmission electron microscope measurement was carried out by the RuO ₄ dyeing method described above. Images are shown in FIG. 1 (8000 ×) and FIG. 2 (20,000 ×). 1 and 2, the white part is the polyolefin phase and the black part is the rubber phase,
In the molded article of Example 1, it is observed that polyolefin is incorporated in the rubber domain.

When the average particle size of the rubber domain and the polyolefin particles in the domain was determined by the above-mentioned method, the average particle size of the rubber domain was 1.1 μm, and the average particle size of the polyolefin in the rubber domain was 0. It was 0.2 μm. Further, the ratio of the rubber domain in which the polyolefin was dispersed to the entire rubber domain was 68 area%.
The results of these evaluations are shown in Table 1. The blank in the table indicates that there is no added amount, and the symbol "-" indicates that the evaluation was impossible.

[Example 2] In Example 1, the component (A
The proportion of 1B-a) is 90% by weight, and the proportion of component (C) is 1
The same operation as in Example 1 was performed except that the content was changed to 0% by weight. The evaluation results are shown in Table 1.

[Example 3] In Example 1, the component (A
1B-a) in a proportion of 60% by weight and component (C) in a proportion of 4
The same operation as in Example 1 was performed except that the content was changed to 0% by weight. The evaluation results are shown in Table 1.

Example 4 The same operation as in Example 1 was carried out except that 0.8 part by weight of TMP was used in place of DVB in Example 1. The evaluation results are shown in Table 1.

[Example 5] The same operation as in Example 1 was carried out except that the temperature of the composition in the cylinder in the portion corresponding to the first kneading zone was changed to 160 ° C in Example 1. It was The evaluation results are shown in Table 1.

[Example 6] In Example 1, 0.15 times amount of the component (A2) was further added to the total weight of the component (A1B-a) and the component (C), and the second kneading zone and the second kneading zone were added. Three
At the second supply port installed in the cylinder between the kneading zones,
Based on the total weight of the component (A1B-a) and the component (C),
The same operation as in Example 1 was performed except that the amount of the component (B), which was 0.2 times the amount, was supplied. The evaluation results are shown in Table 1.

Example 7 In Example 1, the component (A
1B-a) in a proportion of 40% by weight and component (C) in a proportion of 6
The amount of the component (A2) was changed to 0% by weight, and 0.8 times the amount of the component (A2) was added to the total weight of the components (A1B-a) and the component (C). Example 1 except that the second supply port installed in the cylinder was supplied with the component (B) in an amount 0.2 times the total weight of the component (A1B-a) and the component (C). The same operation was performed. The evaluation results are shown in Table 1.

Example 8 In Example 1, the component (A
The proportion of 1B-a) is 43% by weight, and the proportion of component (C) is 5%.
The amount was changed to 7% by weight, and 1.15 times the amount of the component (A2) was added to the total weight of the component (A1B-a) and the component (C), and the amount between the second kneading zone and the third kneading zone was increased. Example 1 except that the amount of component (B), which was 0.7 times the total weight of component (A1B-a) and component (C), was supplied to the second supply port installed in the cylinder. The same operation was performed. The evaluation results are shown in Table 2.

[Example 9] In Example 1, the component (A
The proportion of 1B-a) is 43% by weight, and the proportion of component (C) is 5%.
The same operation as in Example 1 was performed except that the amount was changed to 7% by weight, and 0.43 times the amount of the component (A2) was added to the total weight of the component (A1B-a) and the component (C). It was The evaluation results are shown in Table 2.

Comparative Example 1 Ingredient (A1)
Example 1 except that B-a) was changed to (A1B-b)
The same operation was performed.

Further, in Comparative Example 1, images obtained by the transmission electron microscope image measurement by the RuO ₄ staining method in the same manner as in Example 1 are shown in FIG. 3 (8000 times) and FIG. 4 (20 times).
000 times).

As is apparent from FIGS. 3 and 4, this comparative example 1
In the molded article of No. 1, no dispersion of polypropylene in the rubber domain is observed.

When the average particle size of the rubber domain was determined by the above method, it was 2.0 μm. Table 2 shows the evaluation results
Shown in.

[Comparative Example 2] In Example 1, the temperature of the composition in the cylinder in the portion corresponding to the first kneading zone was 1
The same operation as in Example 1 was performed except that the temperature was changed to 90 ° C. The evaluation results are shown in Table 2.

[Comparative Example 3] In Example 1, the component (A
1B-a) in a proportion of 20% by weight and component (C) in a proportion of 8
The same operation as in Example 1 was performed except that the content was changed to 0% by weight. The evaluation results are shown in Table 2.

[Comparative Example 4] In Example 1, the component (A
1B-a) in a proportion of 97% by weight, and component (C) in a proportion of 3
The same operation as in Example 1 was carried out except that the content was changed to wt%. The evaluation results are shown in Table 2.

[0112]

[Table 1]

[0113]

[Table 2]

Example 10 The olefinic thermoplastic elastomer obtained in Example 1 was manufactured by Watanabe Koki Co., Ltd.
5mmφ extruder (single flight type screw)
A sheet having a width of 250 mm and a thickness of 0.35 mm is extruded from the T-die, and one surface is embossed with an average grain depth of 100 μm between the embossing roll (30 ° C.) and the pressure roll, and the other is embossed. When the polypropylene resin foam sheet was taken up on the surface and laminated, it had spreadability and the laminated sheet moldability was good.

As is clear from the above results, the olefinic thermoplastic elastomers of the examples have less bleeding of the softening agent in the low hardness region, as compared with the comparative examples.
It can be seen that oil resistance, flexibility, mechanical strength, rubber elasticity, and extrusion moldability are excellent, and the obtained extrusion molded product has few spots and the surface appearance is smooth.

[0116]

As described in detail above, according to the present invention, the mechanical properties such as tensile strength, elongation at break, and compression set in the low hardness region of the olefin-based thermoplastic elastomer are improved, and then extrusion processing is further performed. Olefin-based thermoplastic elastomer having improved surface properties such as heat resistance, spots and smoothness, extruded product surface appearance, oil bleeding on the surface of the molded product, and oil resistance, and sheets using this olefin-based thermoplastic elastomer Molded bodies and laminates are provided.

[Brief description of drawings]

FIG. 1 is a transmission electron microscope image (× 8000) of the molded product obtained in Example 1.

2 is a transmission electron microscope image (20,000 times) of the molded product obtained in Example 1. FIG.

FIG. 3 is a transmission electron microscope image (8000 ×) of the molded product obtained in Comparative Example 1.

FIG. 4 is a transmission electron microscope image (20,000 times) of the molded product obtained in Comparative Example 1.

   ─────────────────────────────────────────────────── ─── Continued front page    F-term (reference) 4F070 AA12 AA16 AA63 AC56 AE08                       GA05 GB07 GB08                 4F071 AA10 AA13 AA15X AA20X                       AA21X AA71 AC08 AE02                       AE04 BB06 BC01 BC14                 4J002 AE05X BB03Y BB12Y BB15W                       BB17Y BC06Y BC07Y BC08Y                       EK036 EK046 EK056 FD146

Claims (11)

[Claims] 1. An olefin-based thermoplastic elastomer characterized by satisfying the following formulas (I) to (III). Y ≦ −2X + 350 (I) X <95 (II) Z ≦ 150 (III) However, X, Y, and Z are as follows. X: JI of the molded product measured according to JIS K6253
S A hardness (no unit) Y: Based on JIS K6258, the weight change rate (unit:%) of the molded product measured using IRM903 oil at 120 ° C. Z: Extruded sheet surface (250 mm × 1500 mm) No. of items (unit: pieces) 2. The olefin-based thermoplastic elastomer according to claim 1, wherein the olefin-based thermoplastic elastomer has a dispersion form in which an olefin-based resin is used as a matrix and a cross-linked olefin-based copolymer rubber is used as island-shaped domains. The average particle size of the domain is 0.1 to 5 μm, and the olefin resin is dispersed in at least a part of the domain with an average particle size of 0.01 to 0.5 μm. Characteristic olefinic thermoplastic elastomer. 3. The olefin-based thermoplastic elastomer according to claim 2, wherein the ratio of the domains in which the olefin-based resin is dispersed is 10% or more in terms of the area ratio with respect to all the domains. 4. The gel permeation chromatography (hereinafter referred to as GP) according to any one of claims 1 to 3.
The olefin copolymer rubber having a weight average molecular weight in terms of polypropylene of 500,000 or more (hereinafter referred to as C) (hereinafter,
Component (A1)) and 12 to 100 parts by weight thereof
An oil-extended olefin copolymer rubber (hereinafter referred to as component (A1B)) is prepared by mixing with 200 parts by weight of a mineral oil-based softener for rubber (hereinafter referred to as component (B)), and then the component After mixing 30 to 95% by weight of (A1B) and 5 to 70% by weight of an olefin resin (hereinafter referred to as component (C)) (however, the total amount of components (A1B) and (C) is 100).
% By weight) and an organic peroxide (hereinafter referred to as component (D)) in the presence of an organic olefin, which is obtained by dynamic heat treatment at a temperature lower than the 1-minute half-life temperature thereof. Thermoplastic elastomer. 5. The olefin-based copolymer rubber according to claim 4, which has a weight average molecular weight in terms of polypropylene of less than 500,000 by GPC (hereinafter referred to as component (A2)),
An olefin-based thermoplastic elastomer, which is used in addition to the component (A1) in a ratio of not more than twice the total weight of the components (A1B) and (C). 6. The method according to claim 4 or 5, wherein after the dynamic heat treatment, the component (B) is further mixed in a ratio of not more than 1.5 times the total weight of the components (A1B) and (C). An olefinic thermoplastic elastomer. 7. The component (A1) according to claim 5 or 6.
At least one of (A2) and (A2) is an ethylene-propylene-non-conjugated diene rubber, and an olefin-based thermoplastic elastomer. 8. The ethylene-propylene-nonconjugated diene rubber according to claim 7, wherein the ethylene content is 50 to 90.
An olefin-based thermoplastic elastomer, which is an ethylene-propylene-non-conjugated diene copolymer rubber having a wt%, a propylene content of 5 to 50 wt% and a non-conjugated diene content of 1 to 30 wt%. 9. The olefinic thermoplastic elastomer according to any one of claims 4 to 8, wherein the component (C) is polypropylene and / or propylene-α-olefin copolymer. 10. A sheet-like molded article comprising a composition containing the olefinic thermoplastic elastomer according to claim 1 as a base material. 11. A laminate having a surface layer, the base layer of which is a composition containing the olefinic thermoplastic elastomer according to any one of claims 1 to 9.