JP2580237B2 - Crystalline propylene polymer composition - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a crystalline propylene polymer composition, and more particularly to a crystalline propylene polymer composition having significantly improved heat aging resistance.

[Prior art] A crystalline propylene polymer is excellent in mechanical properties, moldability, appearance, etc., but is easily deteriorated by heat and oxidation. Therefore, various types of stabilizers are compounded according to each purpose and injected. Widely used for molded products, extruded products, films and the like.

[Problems to be Solved by the Invention] However, in particular, products in the field used in a mode receiving heat are required to have heat aging resistance and to be improved.

Therefore, the addition of phenolic antioxidants,
Although various techniques have been developed, such as improvement by the combined use of these with a thioether-based antioxidant, further improvement is desired.

[Means for Solving the Problems] The present inventors have found that the heat aging resistance can be improved by using a specific antioxidant and an additive in combination, and have accomplished the present invention.

That is, the present invention is a crystalline propylene polymer composition comprising 100 parts by weight of a crystalline propylene polymer and the following components (A) to (C).

(A) 3,9-bis [1,1-dimethyl-2- {β- (3-t
-Butyl-4-hydroxy-5-methylphenyl) propionyloxydiethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane 0.01 to 1 part by weight (B) [C ₁₂ H ₂₅ SCH ₂ CH ₂ (COOCH ₂ ) ₄ C 0.01 to 1 part by weight (C) Hydrotalcites is 1/20 to 4/5 by weight of the thioether shown in (B) (1) Crystalline propylene polymer As the propylene polymer, a random and block copolymer of propylene and another α-olefin such as ethylene, butene, pentene, hexene, 4-methylpentene, heptene, octene, etc., in addition to propylene homopolymer, Specifically, propylene / ethylene block or random copolymer, propylene / ethylene / butene copolymer, propylene / hexene copolymer, propylene / hexene Sen-butene copolymer.

These crystalline propylene polymers are polymerized in a gas phase, a liquid phase or a solvent such as hexane or heptane with a Ziegler-Natta type catalyst, and then deactivated with a catalyst decomposer such as an alcohol or an epoxy compound. Although generally produced by a process, a polymer obtained by a process in which these steps are simplified or eliminated may be used.
As for the catalyst to be used, a catalyst in which a catalyst component is supported on a carrier such as magnesium chloride has been developed, but a crystalline propylene polymer produced by such a catalyst may be used.

Among these, those having an MFR of 1 to 100 g / 10 minutes are particularly preferred.

(2) 3,9-bis [1,1-dimethyl-2- {β- (3-t
-Butyl-4-hydroxy-5-methylphenyl) propionyloxydiethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane 3,9-bis [1,1-dimethyl] component (A) -2-
{Β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl] -2,4,8,10-
Commercially available tetraoxaspiro [5.5] undecane can be used.

The addition amount is 0.01 to 1 part by weight, preferably 0.02 to 0.5 part by weight, based on 100 parts by weight of the crystalline propylene polymer. If it is less than this range, no effect will be obtained, and if it exceeds this range, problems such as color and bleeding will occur.

(3) [C ₁₂ H ₂₅ SCH ₂ CH ₂ COOCH ₂ ] ₄ C As the thioether of the component (B), a commercially available thioether can be used as appropriate.

The addition amount is 0.01 to 1 part by weight per 100 parts by weight of the polymer,
Preferably it is 0.03-0.7 weight part.

(4) Hydrotalcite As the hydrotalcite of the component (C), those conventionally used for neutralization, corrosion improvement and other purposes as an antacid are used. 20m ² /
g or less are preferred.

The amount added is 1/20 to 4/5, preferably 1/10 to 2/3 by weight with respect to the component (B). Below the above range, the effect is insufficient, and above the range, the effect is not only uneconomic but also saturates,
In some cases, it has an adverse effect.

(5) Other Compounding Components Other additional components can be added to the composition of the present invention as long as the effects of the present invention are not significantly impaired. These include, for example, benzotriazole-based, benzophenone-based ultraviolet absorbers, hindered amine-based, benzoate-based, nickel-based light stabilizers, metal salts of stearic acid such as sodium, calcium, zinc, etc., and talc and other inorganic fillers. Phosphites, phosphonites, other hindered phenolic antioxidants, etc., antistatic agents, nucleating agents, pigments, pigment dispersants, copper damage inhibitors, lubricants, antiblocking agents and the like.

(6) Production and Processing of Composition In order to produce the composition of the present invention, in addition to the above-mentioned essential components, other components are added to the powdery or pellet-like crystalline propylene polymer, if necessary, and then rolled. Melt kneading with a kneader such as a Brabender plastograph or an extruder. This composition is processed and commercialized by conventional molding. Molding methods include injection molding, extrusion molding, hollow molding, compression molding, and film molding.

The composition of the present invention is particularly effective in thick molded articles such as injection molding, extrusion molding, and hollow molding.

[Example] Example 1, Comparative Examples 1 to 6 Powdered propylene homopolymer (MFR = 10 g / 10
Minutes) An antioxidant and other additives were added to 100 parts by weight as shown in Table 1 and pelletized with a vent type 30 mm diameter extruder (230 ° C.).

The obtained pellets were set on an injection molding machine to form 1 mm thick square sheets. A test piece of 65 × 30 mm square was cut out from the square sheet, and the deterioration start time was measured with a gear oven type heat aging tester set at 160 ° C. The results are shown in Table 1.

The antioxidants and other compounds indicated by symbols in Table 1 are the compounds A, B, and-shown below.

(Hindered phenolic antioxidant) A: 3,9-bis [1,1-dimethyl-2- {β- (3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy} ethyl]- 2,4,8,10-tetraoxaspiro [5.5] undecane (manufactured by Sumitomo Chemical Co., Ltd.): tetrakis [methylene-3- (3,5-di-t-butyl-4-hydroxyphenyl) propionate] methane (Ciba-Geigy) (Thioether-based antioxidant) B: [C ₁₂ H ₂₅ SCH ₂ CH ₂ COOCH ₂ ] ₄ C (Mitsubishi Yuka): distearyl thiodipropionate (Yoshitomi) (Manufactured by Yakusha) (Other compounds): Hydrotalcite (manufactured by Kyowa Chemical Co., Ltd.): Calcium stearate (manufactured by Kosei Co., Ltd.) [Effect of the Invention] Regarding the mechanism of manifesting the effect of the crystalline propylene polymer composition of the present invention Is not clear. Hydrotalside is
Although it is known to be used as an antacid for neutralization, corrosion improvement, and other purposes, it was unexpected that a limited thioether blended system would be effective in heat aging resistance.

──────────────────────────────────────────────────続 き Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical indication location C08K 5:13 5:36) (56) References JP-A-62-112643 (JP, A) JP-A-61-133251 (JP, A) JP-A-60-197747 (JP, A) JP-A-59-231089 (JP, A)

Claims (1)

(57) [Claims] 1. A crystalline propylene polymer composition comprising 100 parts by weight of a crystalline propylene polymer and the following components (A) to (C). (A) 3,9-bis [1,1-dimethyl-2- {β- (3-t
-Butyl-4-hydroxy-5-methylphenyl) propionyloxydiethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane 0.01 to 1 part by weight (B) [C ₁₂ H ₂₅ SCH ₂ CH ₂ COOCH ₂ ] ₄ C 0.01 to 1 part by weight (C) Hydrotalcites are mixed with 1/20 to 4/5 by weight of the thioether shown in (B).