JPS6211749A - Propylene-ethylene copolymer composition - Google Patents

Abstract

PURPOSE:To obtain the titled composition forming a coating film having excel lent impact resistance, rigidity and impact-whitening resistance and useful for the coating of automobile, etc., by compounding a propylene-ethylene copolymer with an ester of an saturated aliphatic monobasic carboxylic acid and a polyhydric alcohol at a specific ratio. CONSTITUTION:The objective composition can be produced by compounding (A) 100 pts. (wt.) of a propylene-ethylene copolymer produced by synthesizing (i) 70-95 (wt)% propylene (co)polymer having an ethylene content of <=2% and (ii) 30-5% propylene-ethylene copolymer having an ethylene content of 10-50% using (iii) a stereoregular catalyst with (B) 0.02-2.0 pts. of an ester of a 12-22C saturated aliphatic monobasic carboxylic acid and a polyhydric alcohol.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a propylene-ethylene copolymer composition,
More specifically, the present invention relates to a propylene-ethylene copolymer composition having a novel composition which has excellent properties in terms of impact resistance, rigidity, and resistance to whitening upon impact, as well as an excellent balance among the above three properties.

[Prior Art and its Problems] Propylene-ethylene copolymers are polymers with high impact strength and rigidity, and are therefore prized in various industrial fields.

However, on the other hand, this polymer exhibits a phenomenon of impact whitening, in which stressed areas become white when an impact is applied or when the polymer is bent. Therefore, the appearance of the molded product is easily damaged, and its use is particularly limited in products where appearance is important, such as automobile parts and home appliances.

Traditionally, to solve such problems.

Method of mixing polyethylene with propylene-ethylene copolymer (JP-A-55-58245, JP-A-57-13)
7341, etc.) and a method of synthesizing the above copolymer by two-stage polymerization (Japanese Patent Publication No. 49-24593, Japanese Patent Application Laid-Open No. 1983-1989).
No. 81418, Japanese Patent Laid-Open No. 58-55418, etc.) have been proposed.

However, in the case of the former method, the improvement in impact whitening resistance is insufficient, and furthermore, it is difficult to achieve uniform mixing industrially. In the case of the latter method, the three characteristics mentioned above,
That is, there is a problem in that it is not possible to obtain a product that satisfies the balance between impact resistance, rigidity, and resistance to whitening.

[Problems to be Solved by the Invention] The present invention solves the above-mentioned problems of propylene-ethylene copolymers, and produces propylene with a new composition that is excellent in all of the above three properties and is well-balanced. - To provide an ethylene copolymer composition.

[Means for Solving the Problems] As a result of extensive research in order to achieve the above object, the present inventors have found that a predetermined amount of the fatty acid ester described below is blended into a specific propylene-ethylene copolymer produced by multi-stage polymerization. The inventors discovered that the composition can achieve the intended purpose, leading to the development of the composition of the present invention.

That is, the propylene-ethylene copolymer composition of the present invention comprises: 100 parts by weight of a propylene-ethylene copolymer; 0.02 to 2 parts by weight of an ester of an aliphatic saturated monocarboxylic acid having 12 to 22 carbon atoms and a polyhydric alcohol; .0 parts by weight; the propylene-ethylene copolymer comprises:
The following two components synthesized using a stereoregular catalyst: (A): propylene homopolymer or propylene-ethylene copolymer with an ethylene content of 2% by weight or less, 70 to 85% by weight, and (B): ethylene It is characterized by being a copolymer comprising 30 to 5% by weight of a propylene-ethylene copolymer with a content of 10 to 50% by weight.

One of the components of the present invention is a propylene-ethylene copolymer synthesized by a multi-stage polymerization method, for example, a two-stage polymerization method.

The stereoregular catalyst used in the above polymerization method is a catalyst generally used for stereoregular polymerization reactions of ethylene, propylene, etc., and is usually a catalyst consisting of a transition metal halide component and an organoaluminum compound component. . Here, as the transition metal halide compound, a titanium halide is preferable, and titanium trichloride is particularly preferable. Titanium trichloride is obtained by reducing titanium tetrachloride by various methods; these are further activated by ball milling and/or solvent washing (for example, washing with an inert solvent and/or an inert solvent containing a polar compound). titanium trichloride or titanium trichloride eutectic (e.g. T 1cJ13
+ 'A AfLC stand 3) further amine.

Co-pulverized with ether, ester, sulfur, halogen derivative, organic or inorganic nitrogen compound or phosphorus compound, etc.: Obtained by precipitation from liquefied titanium trichloride in the presence of an ether compound, Tokkosho 53-3
Examples include those obtained by the method described in No. 358, and those obtained by supporting a titanium halide on a magnesium compound can also be used.

As for other components of organoaluminum compounds.

The following formula: AJIRnX3-n However, in the formula, R is an alkyl group having 1 to 10 carbon atoms, an alkoxy group, an aryl group, X is a halogen atom, and n is O<n
Compounds having a value of ≦3 are preferred. Specifically, for example, triethylaluminum, triisobutylaluminum, and tri-n-propylaluminum.

Examples include diethylaluminum monochloride, diethylaluminium monochloride, diethylaluminium monoiodide, diethylaluminum monoethoxide, diisobutylaluminum monoisobutoxide, diethylaluminum monohydride, diisobutylaluminum monohydride, ethylaluminum sesquichloride, etc. One or more of these can be used.

In these catalyst components, usually 1 to 10 organoaluminum compounds are used per mole of transition metal halide compound.
They are mixed and used in a ratio of 0 mol. Further, various electron-donating compounds can be used as the third component to improve the catalyst performance.

Such a stereoregular catalyst is used in each step of the polymerization reaction in a conventionally used amount and combination of components.

Known methods can be applied as the polymerization method,
Examples include slurry polymerization, solution polymerization, gas phase polymerization, and liquid phase polymerization using propylene or ethylene monomers as a medium.

When synthesizing by a two-stage polymerization method, in the first stage, a fluoropylene homopolymer or a propylene-ethylene copolymer with an ethylene content of 2% or less in the polymer is produced in an amount of 70 to 95% by weight of the total polymerization amount. Manage to make sure. It is preferably managed to produce 75 to 92% by weight. This one
If a copolymer having an ethylene content of more than 2% by weight in the stage is used, it is not suitable because the stiffness of the resulting composition will be significantly reduced.

In the second stage, ethylene is further polymerized to the copolymer obtained in the first stage polymerization reaction, so that the ethylene content is 10 to 10.
The amount of propylene-ethylene copolymer which is 50% by weight is controlled to be 5 to 30% by weight, preferably 8 to 25% by weight of the total polymerization amount.

If a copolymer with an ethylene content of less than 10% by weight is used, the impact resistance of the resulting composition will decrease, and if it is more than 50% by weight, the effect of improving the whitening resistance of the composition will decrease. is insufficient.

If the amount of the propylene-ethylene copolymer produced is less than 5% by weight of the total polymerized amount, the impact resistance of the composition will decrease, and if it is more than 30% by weight, the rigidity of the composition will decrease. .

In terms of its structural properties, the propylene-ethylene copolymer obtained by the two-stage polymerization method preferably has a triate fraction of 2 or more: [R]/fEEE measured by C-NMR. This is because a copolymer having [R]/fEEE of 2 or more further improves the whitening resistance of a composition produced using the copolymer.

Here, [R] is the sum of chains linking fluoropylene and ethylene in the copolymer (fPPE + fP
EP+ rEEP+ fEPE, E is ethylene, P
(represents propylene), and fEEE represents a chain in which three ethylenes are bonded. Regarding the peak assignment when measuring this triate fraction, see Macromolecules, Vol. 11, p. 33, 1978. (Mac
romolecules, Vol 11. pp33
．． The determination is made based on the method described in (1978).

Another component of the composition of the present invention is an ester of an aliphatic saturated monocarboxylic acid having 12 to 22 carbon atoms and a polyhydric alcohol.

The carboxylic acid may be any saturated monovalent carboxylic acid having 12 to 22 carbon atoms, but specific examples include lauric acid, myristic acid, palmitic acid, stearic acid, araxin #, and behenic acid. etc. can be given.

Examples of polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, ethyl ethylene glycol, trimethylene glycol, and tetramethylene glycol; Hydrolic alcohols: Tetrahydric alcohols such as erythriad, pentaerythritol, t, diglycerin, sorbitan; Trihydric alcohols such as atonito, arabit; arift, talit, sorbitan,
Any of the hexahydric alcohols such as manny/ ) can be mentioned. Particularly preferred are trihydric alcohols.

Among these esters synthesized from an aliphatic saturated monocarboxylic acid and a polyhydric alcohol, those suitable for use in the present invention are those synthesized from an aliphatic saturated monocarboxylic acid having 13 to 2 carbon atoms and a polyhydric alcohol. It is a monoester of Specifically, stearic acid monoglyceride, balmitic acid monoglyceride, and myristic acid monoglyceride can be exemplified.

Each of these may be used alone, or two or more types may be mixed as appropriate.
As long as it is 0% by weight or less, unsaturated acid esters, other carboxylic acids, alcohols, etc. may be contained.

When producing the composition of the present invention, 100 parts by weight of the propylene-ethylene copolymer described above is mixed with 0.02 to 2 parts by weight of ester. The amount of ester blended is 0
．． If the amount is less than 2 parts by weight, the effect of improving the whitening resistance of the composition will be poor, and if it exceeds 2% by weight, the bleeding phenomenon will occur frequently and the surface properties will deteriorate, which may limit the use of the composition, especially in food-related applications. I have no choice but to accept it. Preferably 0.05-1
．． The amount is 5 parts by weight, more preferably 0.1-1.0 parts by weight.

The composition can be prepared by premixing the above two components using, for example, a Henschel mixer or a ribbon blender, and then melt-kneading the mixture using an extruder to form pellets, which are then injection molded, or by adding the above to a pelletized propylene-ethylene copolymer. It can be manufactured by adding and mixing an ester and then injection molding the mixture. At this time, predetermined amounts of commonly used antioxidants, antistatic agents, ultraviolet light inhibitors, neutralizing agents, pigments, and the like may be added and blended as necessary.

[Examples of the Invention] Examples 1 to 11 Propylene-ethylene copolymers of types A to ■ shown in Table 1 were synthesized by two-stage polymerization using a conventional method.

The ethylene content per polymerization amount in each stage and the [R]/fEEE of the obtained copolymer are shown.

As the esters in Table 1, a: Nistearic acid monoglyceride (page C18; trade name, Rigamal S-100, manufactured by Riken Vitamin ■), b: Palmitic acid monoglyceride (01s;
Product name, NAA-180, manufactured by NOF ■), C: myristic acid glyceride (C14; product name, NAA-142,
(manufactured by NOF ■), d: Lauric acid glyceride (C, 2;
Five types of products were prepared: NAA-122 (trade name, manufactured by Nippon Oil & Fats Corporation) and e-nioleic acid monoglyceride (Oss, unsaturated; trade name, Rikamar OL-100, manufactured by Riken Vitamin ■).

Both were combined as shown in Table 2, premixed in a Henschel mixer, and then melted and kneaded in an extruder to form pellets, which were injection molded.

The flexural modulus, Izot impact strength, and impact whitening area of each of the obtained molded products were measured according to the following specifications, and the results are summarized in Table 2.

Flexural modulus: According to JIS K-7203 Izot impact strength: JIS K-7110 (with notch, 23°C
) Impact whitening area: Square plate after injection molding (65a+aX65m
mX 3.2mm) by DuPont's Nj! Place it on the pedestal of the impact tester, and place the tip of a striking rod with an inch diameter in contact with the center of the square plate, and place a 1 kg weight on the striking rod at a height of 50cm (temperature 23°C). After whitening 6 parts of the square plate by dropping it from a glass plate, the whitened area (cm2) was measured after leaving it for one day. The smaller this value is, the better the whitening resistance is.

[Effects of the Invention] As is clear from the above explanation, the composition of the present invention has excellent impact resistance, rigidity, and impact whitening resistance! At the same time, it also has a good balance of the three properties, making it useful as a sheet molding material and blow molding material in the fields of automobiles and home appliances where appearance is important, and its industrial value is great.

Claims (1)

[Claims] 100 parts by weight of propylene-ethylene copolymer; carbon number: 1
0.02 to 2.0 parts by weight of an ester of 2 to 22 aliphatic saturated monocarboxylic acids and a polyhydric alcohol, wherein the propylene-ethylene copolymer has a stereoregular catalyst. The following two components were synthesized using: (A): Propylene homopolymer or propylene-ethylene copolymer with an ethylene content of 2% by weight or less, 70 to 95% by weight, and (B): ethylene content of 10 to 50% by weight % propylene-ethylene copolymer, characterized in that it is a copolymer consisting of 30 to 5% by weight of a propylene-ethylene copolymer.
Ethylene copolymer composition.