JPH0476382B2 - - Google Patents

Description

[Detailed description of the invention]

[Industrial Application Field] The present invention relates to a propylene polymer composition suitably used as an extrusion, injection, and blow molding material in the automobile and home appliance fields. [Prior Art] A propylene-ethylene copolymer commercially available as a so-called propylene block copolymer is
As a resin with excellent impact resistance and rigidity, it is used in various industrial fields. However, due to its poor whitening resistance, stress points tend to whiten when subjected to impact, damaging the appearance of the molded product, which is a problem especially when applied to products where appearance is important, such as automobile parts and home appliances. I was getting used to it. Conventionally, a method of blending polyethylene into a propylene copolymer has been proposed as a method to improve this problem (Japanese Patent Application Laid-open No. 58245/1983, Japanese Patent Application Laid-Open No. 137341/1989), but the impact whitening resistance has been reduced. The improvement was insufficient, and uniform blending was difficult. In addition, a method for producing propylene block copolymers by a two-stage polymerization method (Japanese Patent Application Laid-open No. 5,655,416) has been proposed, but a product with a satisfactory balance of impact resistance, rigidity, and resistance to whitening has not been obtained. do not have. [Problems to be Solved by the Invention] The present invention solves the problems of the conventional technology and provides whitening resistance,
The purpose of this invention is to provide a propylene polymer composition with excellent impact resistance and rigidity. [Means for Solving the Problems] That is, the propylene polymer composition of the present invention comprises (A) the following three components polymerized using a stereoregular catalyst: (a) an intrinsic viscosity of 0.5 dl/g or more; (b) 3 to 30% by weight of a propylene homopolymer with an intrinsic viscosity of 2.5 dl/g or more; and (c) a propylene homopolymer with an intrinsic viscosity of 2.8 dl/g or more. Propylene-
100 parts by weight of a propylene polymer consisting of 3 to 30% by weight of an ethylene copolymer and (B) 0.02 to 2.0 parts by weight of an ester of an aliphatic saturated monocarboxylic acid having 12 to 22 carbon atoms and a polyhydric alcohol. Features. The propylene polymer polymerized using the stereoregular catalyst (A) used in the present invention is produced by a multistage polymerization method, for example, a three-stage polymerization method. In the first step, propylene is polymerized at a temperature of 30 to 90°C, and the propylene polymer has an intrinsic viscosity of 0.5 dl/g or more and less than 2.5 dl/g. By producing a homopolymer in an amount of 50 to 94% by weight of the total polymer (a)
In the second step, propylene is polymerized at a temperature of 30 to 90°C to produce a propylene homopolymer with an intrinsic viscosity of 2.5 dl/g or more in an amount of 3 to 30% of the total polymer, and the second step is to produce a propylene homopolymer with an intrinsic viscosity of 2.5 dl/g or more to form the (b) component. In the third step, ethylene and propylene are copolymerized at a temperature of 30 to 90°C to achieve an intrinsic viscosity of 2.8.
This is carried out by producing an ethylene-propylene copolymer of dl/g or more in an amount of 3 to 30% by weight of the total polymer to serve as component (c). The stereoregular catalyst used for polymerization is a catalyst commonly used for stereoregular polymerization reactions of ethylene, propylene, etc., and usually a mixture consisting of a transition metal halide component and an organoaluminum compound component is used. 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 (e.g. washing with an inert solvent and/or an inert solvent containing a polar compound). Titanium trichloride or titanium trichloride eutectic (e.g. TiCl ₃ + 1/3AlCl ₃ )
Furthermore, amines, ethers, esters, sulfur,
Co-pulverized with halogen derivatives, organic or inorganic nitrogen compounds or phosphorus compounds; obtained by precipitation from liquefied titanium trichloride in the presence of an ether compound; described in Japanese Patent Publication No. 53-3356 The following can be mentioned: Furthermore, a material in which a titanium halide is supported on a magnesium compound can also be used. Other organic aluminum compounds include:
The following formula: _{AlR o} ) are preferred. Specifically, for example, triethylaluminum, triisobutylaluminum, tri-n-propylaluminium, dimethylaluminum monochloride, diethylaluminum monochloride, diethylaluminium monobromide, diethylaluminium monoiodide, diethylaluminum monoethoxide, diisobutylaluminum Monoisobutoxide, diethylaluminum monohydride, diisobutylaluminum monohydride, ethylaluminum sesquichloride, ethylaluminum dichloride, etc.
One or more of these can be used. These catalyst components are usually mixed in a ratio of 1 to 100 moles of the organoaluminum compound to 1 mole of the transition metal halide compound. Further, various electron-donating compounds can be used as the third component to improve the catalyst performance. Such stereoregular catalysts can be used in commonly used amounts and combinations of components.
Used at each stage of the polymerization reaction. When producing by a three-step polymerization method, the first step is
Propylene homopolymer is polymerized at a temperature of 30 to 90°C, preferably 50 to 75°C, and has an intrinsic viscosity [η] of 0.5 to 2.5 dl/g, preferably 0.7 to 2.3 dl/g. 50-94% by weight of the total polymer,
Preferably, 60 to 85% by weight of the component (a) is produced. Here, if the polymerization temperature is less than 30°C, the productivity of the polymer will decrease, and if [η] is less than 0.5 dl/g, the impact strength of the obtained polymer will decrease;
When it is more than dl/g, moldability deteriorates. Furthermore, if the amount of the polymer is less than 50% by weight, the rigidity of the resulting polymer will decrease, and if it exceeds 94% by weight, the impact strength of the polymer will decrease. Next, in the second step, propylene is polymerized at a temperature of 30 to 90°C, preferably 40 to 70°C, so that [η]
2.5 dl/g or more, preferably 2.6 to 10 dl/g of propylene homopolymer, 3 to 30% by weight of the total polymer amount,
It is preferably produced in an amount of 5 to 25% by weight as component (b). If [η] is less than 2.5 dl/g, the impact strength of the resulting polymer will decrease, and if the amount of polymer is 3% by weight
If it is less than 30% by weight, the rigidity of the polymer decreases, and if it exceeds 30% by weight, the impact strength of the polymer decreases, which is not preferable. The third stage is a temperature of 30-90℃, preferably 40-70℃
By copolymerizing ethylene and propene at a temperature of
3 to 30% by weight, preferably 5 to 20% by weight of the total polymer amount of the ethylene-propylene copolymer (g) is used as component (c). In addition, if [η] of component (c) is less than 2.8 dl/g, the impact strength of the polymer decreases, and the amount of copolymer decreases by 3.
If it is less than % by weight, the impact strength of the polymer will decrease,
If it exceeds 30% by weight, the rigidity of the polymer decreases, which is not preferable. Furthermore, the ethylene content in the obtained copolymer is 10 to 70% by weight, preferably 20% by weight.
It is preferable to adjust the amount to 65% by weight. If the ethylene content is low, the impact strength will be low, and if the ethylene content is high, the rigidity will be low. In the above polymerization reaction, the limiting viscosity [η] can be adjusted by appropriately changing the concentration of the molecular weight regulator (H ₂ etc.). The appropriate pressure in the polymerization reaction is 1 to 30 kg/cm ² , preferably 2 to 15 kg/cm ² at each stage. In addition, the first and second stages of the above polymerization reaction are both steps for producing a propylene homopolymer, and the order thereof can be changed. In addition, the above polymerization method can be carried out continuously using various polymerization means, for example, three or more polymerization tanks,
A batch method using one or more polymerization tanks, or a combination of these continuous methods and batch methods can be applied. There are also no restrictions on the polymerization method, including suspension polymerization,
Solution polymerization, gas phase polymerization, etc. can be employed. In addition, examples of the inert solvent used in suspension polymerization include aliphatic hydrocarbons such as hexane and heptane; alicyclic hydrocarbons such as cyclohexane; and aromatic hydrocarbons such as benzene and toluene. Component (B), which is another component of the composition of the present invention, is an ester of an aliphatic saturated monohydric carboxylic acid having 12 to 22 carbon atoms and a polyhydric alcohol. The carboxylic acid may be any aliphatic saturated monocarboxylic acid having 12 to 22 carbon atoms, but specific examples include lauric acid, myristic acid,
Palmitic acid, stearic acid, arachidic acid, behenic acid, etc. can be mentioned. Polyhydric alcohols include dihydric alcohols such as ethylene glycol, propylene glycol, ethyl ethylene glycol, trimethylene glycol, and tetramethylene glycol; trihydric alcohols such as propanetriol, methylpropanetriol, butanetriol, puntantriol, and hexanetriol. Tetrahydric alcohols such as erythritol, pentaerythritol, diglycerin and sorbitan; Pentahydric alcohols such as adonite and arabitite; Hexahydric alcohols such as aritritol, talitol, sorbitol and mannitol. Particularly preferred is trihydric alcohol. 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 20 carbon atoms and a polyhydric alcohol. It is a monoester of Specifically, stearic acid monoglyceride, palmitic acid monoglyceride, myristic acid monoglyceride, etc. can be mentioned. Each of these may be used alone, or two
More than one species may be appropriately mixed and used. Further, the ester may contain unsaturated esters, other carboxylic acids, alcohols, etc. as long as it is 20% by weight or less. When producing the composition of the present invention, the ester (B) is added to 100 parts by weight of the above propylene polymer (A).
Add 0.02 to 2.0 parts by weight. If the amount of ester added is less than 0.02 parts by weight, the effect of improving the whitening resistance of the composition will be poor, and if it exceeds 2.0 parts by weight, the bleeding phenomenon will occur frequently and the surface properties will deteriorate, especially in food-related products. It is inevitable that there will be restrictions on its use. Preferably it is 0.1 to 1.5 parts by weight, more preferably 0.1 to 1.0 parts by weight. Furthermore, other commonly used antioxidants, antistatic agents, ultraviolet light inhibitors, neutralizing agents, pigments, etc. may be added or blended in predetermined amounts to the composition of the present invention, as required. [Examples] Hereinafter, the present invention will be described in detail based on Examples, but the present invention is not limited thereto. Examples 1 to 6, Comparative Examples 1 and 2 Production of propylene polymer Dehydrated in an autoclave with an internal volume of 10 and equipped with a stirrer.
- Heptane 5 was charged, and 1.0 g of diethylaluminum chloride and 0.3 g of titanium trichloride were added. In the first stage polymerization reaction, the liquidus temperature was maintained at 65°C, and hydrogen and reaction pressure were adjusted to 90°C so that the polypropylene produced had a predetermined intrinsic viscosity.
Propylene was continuously supplied at a concentration of Kg/cm ² and polymerization was carried out with stirring for 90 minutes. After that, unreacted propylene is removed and the liquidus temperature is lowered to 50℃.
I lowered it to. Next, the second stage polymerization reaction was carried out for 40 minutes by continuously supplying measured amounts of hydrogen and propylene while maintaining a temperature of 50° C. and a pressure of 9 kg/cm ² . Further, the third stage polymerization reaction was carried out for 30 minutes by supplying a propylene-ethylene mixture and a metered amount of hydrogen while maintaining the temperature at 50°C.
Thereafter, unreacted propylene was removed, 50 ml of n-butanol was added to the polymerized product, and the mixture was stirred at 65 DEG C. for 1 hour to perform catalytic decomposition. Thereafter, a white powdery polymer was obtained through a separation process, a washing process, and a drying process. Production of Composition Fatty acid esters include a: stearic acid monoglyceride (manufactured by Riken Vitamin Co., Ltd., trade name Rikemar S-100), b: palmitic acid monoglyceride (manufactured by NOF Corporation, trade name NAA-160), c: Lauric acid monoglyceride (manufactured by NOF Corporation, trade name NAA)
-122), d: Oleic acid monoglyceride (unsaturated carboxylic acid ester) was prepared. The above propylene polymer and fatty acid ester were combined and melt-kneaded according to the formulation shown in Table 1 to form pellets, and the pellets were injection molded to prepare test pieces. The test results are shown in Table 1. Ethylene content: Intrinsic viscosity [η] by infrared spectrum: Measured in tetralin at 135°C Izot impact strength: JIS K-7110 (notched,
(23℃) Flexural modulus: According to JIS K-7203 Impact whitening area: Place the square plate (65 mm x 65 mm x 3.2 mm) after injection molding on the pedestal of a Dupont falling weight impact tester. ,
Place the tip of a 1/2 inch diameter striking rod in contact with the center of the square plate, and place a 1 kg weight on the striking rod at a height.
After dropping from 50 cm (temperature 23° C.) to whiten the center of the square plate, the whitened area (cm ² ) was measured after being left for one day. The smaller this value is, the better the whitening resistance is.

【table】

〔Effect of the invention〕

The propylene polymer composition of the present invention has excellent whitening resistance, impact resistance, and rigidity, as well as a good balance of the three properties, and is suitable for extrusion, injection, and other applications in the automobile and home appliance fields where appearance is important. It is useful as a blow molding material, and its industrial value is extremely large.

Claims (1)

[Scope of Claims] 1 (A) The following three components polymerized using a stereoregular catalyst: (a) 50 to 94% by weight of a propylene homopolymer having an intrinsic viscosity of 0.5 dl/g or more and less than 2.5 dl/g (b) 3 to 30% by weight of a propylene homopolymer with an intrinsic viscosity of 2.5 dl/g or more; and (c) propylene with an intrinsic viscosity of 2.8 dl/g or more.
100 parts by weight of a propylene polymer consisting of 3 to 30% by weight of an ethylene copolymer and (B) 0.02 to 2.0 parts by weight of an ester of an aliphatic saturated monocarboxylic acid having 12 to 22 carbon atoms and a polyhydric alcohol. Characteristic propylene polymer composition.