JPH0632965A - Thermoplastic polymer composition - Google Patents

Abstract

PURPOSE:To provide an ethylene/propylene block copolymer composition having a greatly enhanced impact strength and an improved marring resistance while retaining high rigidity. CONSTITUTION:This composition consists of an ethylene/propylene block copolymer component (a), a crosslinkable ethylene/(meth)acrylate/unsaturated silane compound terpolymer component (b) containing 0.001-15wt.% unsaturated silane compound units and 0.001-50wt.% (meth)acrylate units, and a silanol condensation catalyst (c), wherein the amount of component (a) is 50-99wt.% based on the total of components (a) and (b) and the amount of component (c) is 0.001-15wt.% based on component (b).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an ethylene / propylene block copolymer (a) which is cross-linkable with ethylene / (meth).
Acrylate / unsaturated silane compound terpolymer (b)
And the elastic modulus to which the silanol condensation catalyst (c) is added,
The present invention relates to a thermoplastic polymer composition having excellent impact resistance, which is suitable for automobile parts, industrial parts and the like.

[0002]

2. Description of the Related Art There have been many attempts to increase the value of a molded product by improving various physical properties of a thermoplastic resin such as an ethylene / propylene block copolymer as a raw material. For example, Japanese Patent Laid-Open No. 1-13
No. 2649 discloses that in a pretreatment for coating, a crystalline ethylene / propylene block copolymer is blended with an amorphous ethylene / propylene block copolymer and a low crystalline ethylene / butene copolymer. 1.1-
It is described that a resin composition for an automobile exterior, which is less likely to cause a whitening phenomenon on the surface of a molded product by steam cleaning of trichloroethane and has excellent impact resistance, is obtained. But,
Thus, even if the ethylene / propylene block copolymer is blended with the low crystalline ethylene / butene copolymer, it is not possible to expect a great effect in improving the elastic modulus and the balance of impact strength. Also, Japanese Patent Laid-Open No. 1-2714
In JP-A-51-51, two types of amorphous ethylene / propylene block copolymers, two types of talc, a crystalline ethylene / propylene block copolymer, and calcium carbonate are blended with a highly rigid ethylene / propylene block copolymer. It is described that a composition excellent in high temperature rigidity, impact resistance, coating adhesion, and appearance of molded products was obtained by the above, but an improved value of this degree is not always satisfactory for various demands in recent years. Was not.

On the other hand, there is also a report that the performance is enhanced by chemical crosslinking. For example, in Japanese Examined Patent Publication No. 3-11305, etc., a modified propylene resin grafted with an ethylenically unsaturated silane compound, an ethylene resin and ethylene
By blending an α-olefin copolymer rubber and exposing it to water, it is possible to obtain a crosslinked product that has practically sufficient performance in terms of impact strength and rigidity, which generally shows antinomy behavior not to mention heat resistance. It is described that it is possible. However, since the composition ratio of such a graft-modified propylene-based resin is large, there is a drawback that cross-linking in the matrix causes deterioration of melt fluidity and deterioration of moldability. Also, Japanese Patent Laid-Open No. 64-2
Japanese Patent No. 4847 discloses that (i) a crystalline ethylene / propylene block copolymer is grafted with (ii) a crystalline ethylene / propylene block copolymer with an ethylenically unsaturated silane compound with an organic peroxide. Then, the ethylene / propylene block copolymer obtained by exposing to water in the presence of a silanol condensation catalyst and containing a crosslinked copolymer having a gel fraction of 0.3 to 15% by water crosslinking. There is a statement that the balance of rigidity and impact resistance of the composition is improved. However, the composition has not yet reached the gel fraction that is considered to be sufficient to bring out all the effects of the crosslinking originally expected, mainly because the melt fluidity is lowered, and is insufficient. However, the improvement in impact strength of the produced composition was not sufficiently satisfactory as compared with the composition not crosslinked.

[0004]

It is well known that rubber is mixed in order to improve the impact resistance of the ethylene / propylene block copolymer, but in terms of balun and rigidity,
It is not always the best method in terms of the appearance of the molded product.
Therefore, attempts have been made to improve the method by further mixing various talcs and various rubbers, but since the system becomes complicated, it is not always a good method to meet the recent required performance. It is hard to say. On the other hand, a method has been adopted in which an ethylene / propylene block copolymer is chemically crosslinked to improve it. But,
In such a method, when a large amount of components in the resin are crosslinked, the melt fluidity is deteriorated, and when the degree of crosslinking is suppressed in order to avoid the deterioration of the melt fluidity, satisfactory physical properties cannot be obtained. there were. Therefore, it has been desired to solve the problem that impact strength and rigidity must be improved while suppressing such a decrease in melt fluidity.

[0005]

[Means for Solving the Problems]

[Summary of the Invention] As a result of intensive studies conducted by the present inventors in view of the above problems, an ethylene / propylene block copolymer, an ethylene / (meth) acrylate / unsaturated silane compound terpolymer, and a silanol condensation By blending the catalyst in a specific ratio, the rubber-like domain portion having low crystallinity in the ethylene / propylene block copolymer,
An ethylene / (meth) acrylate / unsaturated silane compound terpolymer whose crystallinity is reduced by (meth) acrylate can be selectively blended, and by introducing a silanol condensation catalyst into the domain, Highly cross-linked only part, without impairing melt flowability,
The inventors have found that a thermoplastic polymer composition excellent in impact resistance and rigidity can be obtained, and completed the present invention. That is, the thermoplastic polymer composition of the present invention is a thermoplastic polymer composition comprising the following components (a) to (c), wherein the component (a) in the composition is
Is an amount of 5 based on the total amount of component (a) + component (b)
0 to 99% by weight, component (b) is 1 to 50% by weight based on the total amount of component (a) + component (b), and component (c) is component (c). It is characterized by containing 0.001 to 15% by weight of the amount based on b). Component (a): Ethylene / propylene block copolymer Component (b): Content of unsaturated silane compound unit is 0.0
01 to 15% by weight, and the content of the (meth) acrylate unit is 0.001 to 50% by weight, and the melt flow index (JIS-K7210-1976 compliant, load 2 kgf, temperature 230 ° C). Is 0.1
100 g / 10 min crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer (c): silanol condensation catalyst

[Detailed Description of the Invention] [I] Constituents (1) Ethylene / Propylene Copolymer The ethylene / propylene block copolymer constituting the thermoplastic polymer composition of the present invention comprises a stereoregular catalyst. Used to polymerize propylene to obtain 55-95% of total polymer,
Next, propylene and ethylene are mixed in a weight ratio of 90/10 to 10
It was polymerized so that the ethylene content would be 5 to 40% by weight of the total polymer at / 90. Among them, the melt flow index (MFR: measured according to JIS-K7210-1976, load 2 kgf, temperature 230 ° C.) is 0.5 to 100 g / 10 minutes, particularly 1 to 50 g from the viewpoint of moldability.
The range of / 10 minutes is preferable. The MFR is 0.5
If it is less than g / 10 minutes, it is difficult to mold, and 100 g
It is not preferable that it exceeds / 10 minutes because it is difficult to obtain satisfactory physical properties.

(2) Crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer Crosslinkable ethylene / (meth) acrylate / unsaturated silane compound 3 constituting the thermoplastic polymer composition of the present invention The original copolymer is a copolymer composed of at least three components of ethylene, (meth) acrylate and an unsaturated silane compound. (A) Ethylene The ethylene unit in the above terpolymer of crosslinkable ethylene / (meth) acrylate / unsaturated silane compound is a normal ethylene that forms the polyethylene moiety in the copolymer.

(B) (Meth) acrylate The (meth) acrylate unit in the ethylene / (meth) acrylate / unsaturated silane compound terpolymer has the general formula CH ₂ = CRCOOR '(where R is a hydrogen atom). Or a methyl group and R'is an alkyl group, preferably an alkyl group having 1 to 4 carbon atoms),
That is, it is an acrylate or a methacrylate, specifically, such as methyl acrylate, methyl methacrylate, ethyl acrylate, propyl acrylate, preferably methyl acrylate in view of ease of copolymerization, and ethylene. By the copolymerization of
It is possible to reduce the crystallinity of the polyethylene portion of the resulting copolymer. The (meth) acrylate unit is
It may be an acrylate or methacrylate alone, a mixture of acrylate and methacrylate, or a mixture with other components.

(C) Unsaturated Silane Compound The unsaturated silane compound unit in the above terpolymer of crosslinkable ethylene / (meth) acrylate / unsaturated silane compound is represented by the general formula RSiR ' _n Y _3-n (wherein R represents an ethylenically unsaturated hydrocarbon group, an ethylenically unsaturated hydrocarbonoxy group, a (meth) acryloyl group, or a (meth) acryloyloxy group, and R'is an aliphatic saturated or aromatic hydrocarbon group, or Represents an aliphatic saturated or aromatic hydrocarbonoxy group, Y
Represents an aliphatic saturated or aromatic hydrocarbon group, an aliphatic saturated or aromatic hydrocarbonoxy group, or an aliphatic acyloxy group, and n is 0, 1 or 2. When there are a plurality of Y's, they may not be the same. ) Is represented. Specific examples of the unsaturated silane compound include R in the above formula as vinyl, allyl, isopropenyl, butenyl, cyclohexenyl, and γ.
Preferred is-(meth) acryloyloxypropyl, R'is methyl, ethyl, propyl, decyl, phenyl, Y is methoxy, ethoxy, formyloxy, acetoxy, propionyloxy, alkyl or arylamino. In particular, in order to obtain the reactivity of silane crosslinking in the copolymer and an appropriate degree of crosslinking, vinyltrimethoxysilane, vinyltriethoxysilane, vinyltriacetoxysilane and γ-methacryloyloxypropyltrimethoxysilane are preferable, and among them γ- Methacryloyloxypropyltrimethoxysilane is most suitable.

(D) Manufacture of Tertiary Copolymer The above-mentioned ethylene / (meth) acrylate / unsaturated silane compound terpolymerization may be carried out under any conditions in which ternary copolymerization occurs. Specifically, for example, the pressure is 500 to 4,000.
0 kg / cm ² , preferably 1,000 to 4,000 kg / cm
² , temperature 100 ~ 400 ℃, preferably 150 ~ 250
In the presence of a radical polymerization initiator and, if necessary, a chain transfer agent under conditions of 0 ° C., the monomers are simultaneously or stepwise contacted in a tank or tubular reactor, preferably in a tank reactor. . For the copolymerization, any radical polymerization initiator and chain transfer agent known to be used for the polymerization or copolymerization of ethylene can be used. Examples of the radical polymerization initiator include lauroyl peroxide, dipropionyl peroxide, benzoyl peroxide, di-t
-Butyl peroxide, t-butyl hydroperoxide, organic peroxides such as t-butyl peroxyisobutyrate, molecular oxygen, azobisisobutyronitrile,
There are azo compounds such as azoisobutylvaleronitrile, and chain transfer agents include paraffin hydrocarbons such as methane, ethane, propane, butane, and pentane, and α-olefins such as propylene, butene-1, and hexene-1. , Aldehydes such as formaldehyde, acetaldehyde, n-butyraldehyde, acetone, methyl ethyl ketone, ketones such as cyclohexanone, aromatic hydrocarbons, chlorinated hydrocarbons and the like.

(E) Amount Ratio The ethylene / (meth) acrylate / unsaturated silane compound terpolymer used in the present invention generally has an unsaturated silane compound unit content of 0.001 to 15% by weight, In order to obtain a suitable degree of crosslinking, it is preferably 0.01 to
It contains 5% by weight, melt flow index (JIS-K7210-1976 compliant, load 2 kg
f, measured at a temperature of 230 ° C.) is 1 to 100 g / 10 minutes. Further, in order to make the dispersed particle size in the ethylene / propylene block copolymer desirable, preferably 1
0 to 30 g / 10 minutes, particularly preferably 13 to 27 g / 1
It's 0 minutes. Here, the MFR value is 1 g / 10
Both when it is less than 100 minutes and when it exceeds 100 g / 10 minutes, the dispersed particle size in the ethylene / propylene block copolymer becomes large, which is not preferable. The content of (meth) acrylate is generally 0.001 to 50.
Although it is a weight, in order to make the compatibility with the rubber component in the ethylene / propylene block copolymer suitable, a preferable amount is 5 to 40% by weight, and further, in order to obtain sufficient impact strength, It is particularly preferable that the amount is 10 to 30% by weight.

(3) Silanol Condensation Catalyst The silanol condensation catalyst constituting the thermoplastic polymer composition of the present invention is used for the silane crosslinking reaction of a terpolymer, and dehydration condensation between silanols of silicone. A catalyst that can be used as a catalyst for promoting
Such silanol condensation catalysts generally include tin,
Carboxylates of metals such as zinc, iron, lead and cobalt, organic bases, inorganic acids and organic acids. Specifically, for example, dibutyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, dioctyltin dilaurate,
Carboxylates such as stannous acetate, stannous caprylate, lead naphthenate, zinc caprylate and cobalt naphthenate, organic bases such as ethylamine, dibutylamine, hexylamine, pyridine and piperidine, inorganics such as sulfuric acid and hydrochloric acid acid,
There are organic acids such as toluene sulfonic acid, acetic acid, stearic acid, and maleic acid. Among these, organotin compounds such as dibutyltin diacetate, dibutyltin dilaurate and dioctyltin dilaurate are preferable. When using these silanol condensation catalysts, they may be added as they are or as a masterbatch of an ethylene-based polymer.

[II] Amount Ratio The blending amounts of the above-mentioned three components (a), (b) and (c) in the thermoplastic polymer composition of the present invention are the same as those of the component (a) in the composition. ) Is 50 to 99% by weight, preferably 70 to 95% by weight based on the total amount of component (a) + component (b).
%, Particularly preferably 70 to 90% by weight, the component (b) being 1 to 50% by weight, preferably 5 to 30% by weight, based on the total amount of the component (a) + component (b). %, Particularly preferably 10 to 30% by weight. further,
It is carried out by adding a silanol condensation catalyst corresponding to the amount of ethylene / (meth) acrylate / unsaturated silane compound terpolymer in the latter stage of the kneading process in order to keep the melt fluidity high until molding. The amount of the component (c) used is 0.001 to 1 based on the terpolymer of the component (b).
The proportion is 5% by weight, preferably 1 to 10% by weight, particularly preferably 1 to 5% by weight.

[III] Composition The kneading method for blending the above-mentioned constituents to obtain the thermoplastic polymer composition of the present invention is not particularly limited, and a melt-kneading method which is generally put into practical use is applied. can do. For example, the component (a) ethylene / propylene block copolymer, the component (b) ethylene / (meth) acrylate / unsaturated silane compound terpolymer, and an additive to be appropriately blended as necessary are kneaders. Alternatively, there can be mentioned a method of preparing the mixture by kneading with an extruder or the like, and then adding the component (c) silanol condensation catalyst and kneading. Examples of the kneader used here include an extruder, a Banbury mixer, a roll kneader, a ribbon blender, a V-type blender, a Henschel mixer, and a Brabender. Examples of the extruder include a single-screw extruder. It is also possible to use a twin-screw extruder. The silanol condensation catalyst of the above component (c) is a catalyst for the silane crosslinking reaction in the ethylene / (meth) acrylate / unsaturated silane compound terpolymer.

[IV] Thermoplastic Polymer Composition The thermoplastic polymer composition of the present invention comprises an ethylene / propylene block copolymer, ethylene / (meth) acrylate.
The composition comprises an unsaturated silane compound copolymer and a silanol condensation catalyst, and the ethylene / (meth) acrylate / unsaturated silane compound terpolymer in the composition is a silanol condensation catalyst. And a silane crosslinked structure can be easily formed in the presence of water.
Thereby, the gel fraction of the thermoplastic polymer composition of the present invention can be generally 70 to 90%, preferably 75 to 90%. In addition, the ethylene / (meth) acrylate / unsaturated silane compound terpolymer blended in the thermoplastic polymer composition contains a (meth) acrylate structural unit, so that By reducing the crystallinity of the polyethylene unit part that constitutes the saturated silane compound binary copolymer, the ethylene / (meth) acrylate / unsaturated silane compound terpolymer and the ethylene / propylene block copolymer amorphous The compatibility with the rubber portion of the terpolymer is increased to facilitate the selective dispersion of the terpolymer into the rubber portion of the ethylene / propylene block copolymer. Therefore, this silane-crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer is crosslinked in a state where it is selectively compounded only in the rubber domain portion of the ethylene / propylene block copolymer. Therefore, by this cross-linking, the ethylene / propylene block copolymer as the base material can be made into a higher performance material.

The fact that such a silane-crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer is compounded and crosslinked only in the rubber domain portion of the ethylene / propylene block copolymer will be described later. It is considered to be clarified by comparing the differences in the properties of the particle dispersion structure between Examples 1 and 5 and Comparative Examples 3 and 6. That is, the composition of Comparative Example 6 had poor compatibility with the rubber domain portion of the ethylene / propylene block copolymer because the silane-crosslinkable ethylene / unsaturated silane compound binary copolymer was crystalline, Not compounded in the rubber domain. Therefore, even if the ethylene / unsaturated silane compound binary copolymer in the composition is crosslinked, the physical properties of the ethylene / propylene block copolymer portion in the thermoplastic polymer composition cannot be improved. This is also because the rubber component existing on the cut surface is easily eluted by the boiling hexane treatment of the composition, and a concave portion is formed on the surface of the composition due to the dissolution of the rubber component. It can be judged (see FIG. 4). Therefore, even if the ethylene / unsaturated silane compound binary copolymer in the composition is crosslinked, the physical properties of the ethylene / propylene block copolymer portion in the thermoplastic polymer composition cannot be improved. In addition, as in Examples 1 and 5 described below, the rigidity (elastic modulus) of the thermoplastic polymer composition was not significantly reduced from that of the original material, and the impact strength was significantly increased and scratch resistance was maintained while maintaining a high value. It is not possible to expect an improvement effect of improving the property (see Table 1 and Table 2).

Further, since the composition of Comparative Example 3 uses the ethylene / acrylate copolymer containing no γ-methacryloyloxypropyltrimethoxysilane, it is a non-crosslinkable ethylene / acrylate copolymer. Therefore, the boiling hexane treatment of the composition easily elutes the rubber component existing on the cut surface, and a concave portion is formed on the cut surface of the composition due to dissolution of the rubber (see FIG. 3). ). Since the composition of Comparative Example 6 was a copolymer containing no acrylate, the compatibility of the ethylene / propylene block copolymer particles with the rubber component was poor, and therefore the composition of FIG.
The state is as shown in. However, in the compositions obtained in Examples 1 and 5, even if an attempt was made to elute the rubber component with boiling hexane after crosslinking, the rubber component was not eluted, and the cut surface had a recess due to the dissolution of the rubber component. No (see FIGS. 1 and 2). This phenomenon is because the rubber component is prevented from being eluted by the silane-crosslinked ethylene / (meth) acrylate / unsaturated silane compound terpolymer having good compatibility with the rubber component. It proves that.

With such a mechanism of action, ethylene
The propylene block copolymer can be a resin having a high rigidity and an excellent balance with impact resistance.
In particular, as mentioned above, by subjecting only the rubber domain part to a high degree of silane cross-linking, the impact strength is significantly increased while maintaining a high value without significantly lowering the rigidity (elastic modulus) from the original material. The scratch resistance is also improved. Therefore, the thermoplastic polymer composition of the present invention has an excellent balance of physical properties and is suitable as a material for various molded articles such as automobile parts and industrial parts.

[0019]

EXAMPLES The present invention will be described more specifically with reference to Examples and Comparative Examples below. [I] Evaluation Method The evaluations in Examples and Comparative Examples shown below were carried out by the following methods. Impact strength Impact strength is 64mm in length, 6mm in width, and 12.7mm in thickness. Notch tip radius is 0.25mm and notch depth is 2.54mm.
Using a notch with a notch angle of 45 degrees, JIS
According to the Izod impact test method with notch according to -7110-1984, the elastic modulus is 64 mm in length, 2 mm in width,
It was measured at a temperature of 0 ° C. by a mechanical spectrometer manufactured by Rheometrics, using a test piece having a thickness of 12.7 mm. Gel Fraction Gel fraction is a composition obtained by extracting the composition of the present invention with xylene as a solvent by a Soxhlet type extractor at a boiling point temperature for about 6 hours, and expressing the weight of the extraction residue as a percentage according to the following formula. is there. Gel fraction (%) = remaining amount of extraction (g) / crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer weight (g) before compounding × 100 scratchability Evaluation of scratchability The scratches caused by scratching with a hundred-yen coin were visually evaluated, and the scratch-resistant ones were evaluated as ◯, and the scratch-prone ones were evaluated as x.

[II] Experimental Examples Examples 1 to 3 Preparation of Component (a ¹ ) The ethylene / propylene block copolymer used was Mitsubishi Yuka Co., Ltd., trade name BC-8. Its properties are as follows: ethylene content 10% by weight, melt flow index (JIS-K7210-1976 compliant, load 2 kgf,
It is 1.8 g / 10 minutes (measured at a temperature of 230 ° C.) (hereinafter, this is referred to as component (a ¹ )). Preparation of Component (b ¹ ) The ethylene / acrylate / unsaturated silane compound terpolymer is prepared at a pressure of 2000 kg / cm ² and a temperature of 190 ° C.
It was obtained by polymerization by a high pressure radical reaction in an autoclave of 0.0015 m ³ . The composition of the obtained copolymer was such that the content of methyl acrylate was 21.8% by weight, γ-
The content of methacryloyloxypropyltrimethoxysilane was 1% by weight, and the properties were melt flow index (JIS-K7210-1976 compliant, load 2 kgf,
It was 13.2 g / 10 minutes (measured at a temperature of 230 ° C.) (hereinafter referred to as component (b ¹ )). Preparation of component (c ⁰ ) Ethylene / vinyl acetate copolymer (Mitsubishi Petrochemical Co., Ltd., "Mitsubishi Polyethylene EVA" (EVA-41H) (generally polymerized in a tubular reactor using a Ziegler catalyst)) 100 weight A catalyst masterbatch containing 1 part by weight of dibutyltin dilaurate (hereinafter referred to as (c ⁰ )) was produced.

Production of Thermoplastic Polymer Composition A composition prepared by blending the above-mentioned components (a ¹ ) and (b ¹ ) with Brabender (180 ° C., 5 minutes) in a weight percentage as shown in Table 1. In addition, the weight ratio (b ¹ ) :( c ⁰ ) = 100: 5 of the ethylene / vinyl acetate copolymer of the above component (c ⁰ ).
After adding for 2 minutes and kneading for 2 minutes, test pieces for each evaluation test were prepared by press molding and evaluated. It was confirmed from the gel fraction that a sufficient degree of crosslinking was obtained. Table 1 shows the measurement results of impact strength, elastic modulus, scratch resistance and gel fraction of this composition at 0 ° C. The thermoplastic polymer composition produced in Example 1 was cut with a microtome, the cut surface (cut surface) was treated with boiling hexane for 30 seconds, and the cut surface was photographed with a scanning electron microscope. The result of photographing is shown in FIG.

Example 4 Preparation of Component (a ² ) The ethylene / propylene block copolymer used was Mitsubishi Yuka Co., Ltd., trade name BC-3G. Its properties are that the ethylene content is 16.1%, melt flow index (JIS-K7210-1976 compliant, load 2 kgf,
(Measured at a temperature of 230 ° C.) 10 g / 10 minutes (hereinafter referred to as component (a ² )). The ingredients (b ¹ ) are shown in Table 1
The component (c ⁰ ) was added to the composition blended to the value shown in Example 1 in the same manner as in Examples 1 to 3 to prepare a test piece and the test was conducted.
Table 1 shows the measurement results of various physical properties at 0 ° C.

Examples 5 to 8 Preparation of component (b ² ) Ethylene / acrylate / unsaturated silane compound terpolymer copolymerized in the same manner as in Examples 1 to 3 (composition: methyl acrylate content 40% by weight) , Γ-methacryloyloxypropyltrimethoxysilane content is 4.0% by weight, and MFR (measured at 230 ° C., 2 kg load, according to JIS-K-7210-1976) is 26.5 g / 10 minutes.) Was used (hereinafter referred to as (b ² )). Production of thermoplastic polymer composition The components (a ¹ ), (a ² ), and (b ² ) described above were kneaded in the compositions shown in Table 1, and the same method (c ⁰⁾ as in Examples 1 to 3 was used. ) Was added to prepare a test piece for evaluation. The results are shown in Table 1. Further, the thermoplastic polymer composition produced in Example 5 was treated with boiling hexane for a minute, and the surface thereof was photographed with a scanning electron microscope. The results are shown in FIG.

Comparative Examples 1 and 2 Table 2 shows various physical properties of the component (a ¹ ) and the component (a ² ) at 0 ° C.

Comparative Examples 3 to 4 Preparation of Component b ⁰ Melt flow index (measured at a load of 2 kgf and a temperature of 230 ° C. according to JIS-K7210-1976) was 27 g / 10 by the same polymerization method as the above-mentioned component (b ¹ ). In minutes,
An ethylene / acrylate copolymer containing 40% by weight of methyl acrylate and not containing γ-methacryloyloxypropyltrimethoxysilane (hereinafter referred to as (b ⁰ )) was prepared. Production of thermoplastic polymer composition Component (a ¹ ) or component (a ² ) and component (b)
⁰ ) was kneaded at a composition ratio as shown in Table 2 and various physical properties at 0 ° C. were measured in the same manner as in Examples 1 to 4 except that no silanol condensation catalyst was added. Show. Further, the thermoplastic polymer composition produced in Comparative Example 3 was treated with boiling hexane for 30 seconds, and then the surface thereof was photographed by a scanning electron microscope. The results are shown in FIG.

Comparative Example 5 Preparation of component (s ¹ ) Ethylene / propylene rubber (manufactured by Mitsubishi Petrochemical Co., Ltd., trade name EP07P, melt flow index (JIS-K)
7210-1976 compliant, load 2kgf, temperature 230 ° C
Water-crosslinkable silanized ethylene / propylene rubber (hereinafter referred to as component (s ¹ )) obtained by grafting vinylsilane with peroxide and benzoyl peroxide to 0.7 g / 10 min (measured by fluorescent X-ray method). The silane content was measured to be 1% by weight) (graft ratio = 1%). Production of Thermoplastic Polymer Composition The above component (a ² ) and the above component (s ¹ ) are kneaded at a composition ratio shown in Table 2, and (c ⁰ ) is mixed in a weight ratio (s ¹ ):
(C ⁰ ) = 100: 5 was added, and the mixture was kneaded for 2 minutes, and then a test piece for each test was prepared.
The test piece was exposed to water for 8 hours and tested at 0 ° C. The results are shown in Table 2.

Comparative Example 6 Instead of preparing an ethylene / acrylate / unsaturated silane compound terpolymer in “Preparation of component (b ¹ )” of Example 1, ethylene / unpolymer containing no methyl acrylate was used. The same procedure as in Example 1 was carried out except that a saturated silane compound binary copolymer was prepared. The results are shown in Table 2 and FIG.

[0028]

[Table 1]

[0029]

[Table 2]

[0030]

EFFECT OF THE INVENTION Since the thermoplastic polymer composition of the present invention cross-links only the rubber domain in the ethylene / propylene block copolymer, the rigidity (elastic modulus) is not significantly reduced from the original material and a high value is obtained. We succeeded in significantly increasing the impact strength while maintaining the above value (Examples 1, 2, 3,
4, 5, 6, 7, 8 and Comparative Examples 1 and 2). On the other hand, the copolymers of Comparative Examples 3 and 4 not containing a crosslinked portion could not have high impact strength as shown in Examples 1, 4, 5 and 7. In addition, the ethylene / propylene rubber grafted with vinyl silane was not as effective as ethylene / (meth) acrylate and unsaturated silane terpolymer in terms of the balance of elastic modulus and impact strength. Further, the scratch resistance was also improved by the thermoplastic polymer composition of the present invention. The thermoplastic polymer composition of the present invention has an excellent physical property balance and is suitable as a material for various molded articles such as automobile parts and industrial parts.

[Brief description of drawings]

FIG. 1 is a scanning electron micrograph of a dispersed particle structure of a cut surface of a thermoplastic polymer composition after a boiling hexane treatment in Example 1 of the present invention.

FIG. 2 is a scanning electron micrograph of the dispersed particle structure of the cut surface of the thermoplastic polymer composition after the boiling hexane treatment in Example 5 of the present invention.

FIG. 3 is a scanning electron micrograph of the dispersed particle structure of the cut surface of the thermoplastic polymer composition after the boiling hexane treatment in Comparative Example 3 of the present invention.

FIG. 4 is a scanning electron micrograph of the dispersed particle structure of the cut surface of the thermoplastic polymer composition after the boiling hexane treatment in Comparative Example 6 of the present invention.

Claims (1)

[Claims] 1. A thermoplastic polymer composition comprising the following components (a) to (c), wherein component (a) in the composition comprises component (a) + component (b): The component (b) is 1 to 50% of the amount based on the total amount of the component (a) + the component (b), in an amount of 50 to 99% by weight based on the total amount.
A thermoplastic polymer composition, characterized in that the content of component (c) is 0.001 to 15% by weight based on the amount of component (b). Component (a): Ethylene / propylene block copolymer Component (b): Content of unsaturated silane compound unit is 0.0
01 to 15% by weight, and the content of the (meth) acrylate unit is 0.001 to 50% by weight, and the melt flow index (JIS-K7210-1976 compliant, load 2 kgf, temperature 230 ° C). Is 0.1
100 g / 10 min crosslinkable ethylene / (meth) acrylate / unsaturated silane compound terpolymer (c): silanol condensation catalyst