JP2653100B2 - Stabilized polyolefin composition - Google Patents

Description

The present invention relates to stabilized, especially weather-resistant, polyolefin compositions.

<Conventional Technology> Polyolefins have excellent mechanical properties and are very useful as molded articles, films, fibers and the like, but generally have the disadvantage that they are easily deteriorated by light.

Therefore, for the purpose of preventing deterioration due to light, polyolefin compositions in which compounds such as benzophenone-based, benzotriazole-based, nickel chelate-based, or hindered amine-based compounds are used alone or in combination as various weathering stabilizers are known ( JP-A-58-79033, 5
8-113236, 59-219353).

<Problems to be Solved by the Invention> However, such polyolefin compositions are not yet sufficient in terms of weather resistance, and in recent years, polyolefins have been used to improve mechanical properties, to improve the performance and appearance of molded articles. In order to improve the properties and the like, other polymers, inorganic fillers, pigments, and the like are often added, but especially when an inorganic filler or the like is added, the weather resistance tends to decrease.

From these facts, the present inventors have studied to develop a polyolefin composition having excellent weather resistance even when containing an inorganic filler as well as when not containing an inorganic filler. The present inventors have found that a polyolefin composition having extremely excellent weather resistance can be obtained by using a dopiperidine compound in a specific combination, and further blending a specific benzoate compound and a specific phosphorus compound, leading to the present invention. Was.

<Means for Solving the Problems> The present invention relates to (A) 0.01 to 1 part by weight of a hindered piperidine compound having a molecular weight of 750 or more selected from the following (A-1) to (A-4) per 100 parts by weight of polyolefin. (B) 0.01 to 1 part by weight of a hindered piperidine compound having a molecular weight of 500 or less selected from the following (B-1) to (B-4) (C) 0.01 to 1 part by weight of a benzoate compound selected from the following (C-1) and (C-2) (D) 0.01 to 1 part by weight of a phosphorus compound selected from the following (D-1) to (D-5) The present invention provides a polyolefin composition characterized by comprising:

In addition, the present invention provides a method for preparing the above compound (A)
A method for improving the weather resistance of a polyolefin by blending (D) with (D).

The polyolefin used in the present invention is a polymer mainly containing an α-olefin such as ethylene, propylene, butene-1, hexene-1, and 4-methylpentene-1. For example, such α-olefin homopolymers, random copolymers and block copolymers composed of two or more α-olefins, and specifically, polyethylene, polypropylene, polybutene-
1, polyisobutene, poly-3-methylbutene-1, poly-4-methylpentene-1, a copolymer of ethylene and propylene, a copolymer of ethylene and butene-1, and a copolymer of propylene and 4-methylpentene-1 Copolymer, copolymer of propylene and butene-1, copolymer of decene-1 and 4-methylpentene-1, ethylene, propylene and butene-1
And the like.

It also includes a copolymer of an α-olefin and another unsaturated compound. For example, a polyunsaturated compound such as a conjugated diene or a non-conjugated diene, or acrylic acid, methacrylic acid, or vinyl acetate is used as a copolymer component. Copolymers of these α-olefins and other unsaturated compounds are acid-modified copolymers, for example, polymer modified by grafting with α, β-unsaturated fatty acids, alicyclic carboxylic acids, or derivatives thereof. It may be united, rubbery, fatty,
Also includes waxy polymers.

Further, in the present invention, a mixture obtained by adding a synthetic rubber or an inorganic filler to these polyolefins can be used according to the application. As the synthetic rubber that can be used in the present invention, a copolymer rubber of ethylene and α-olefin is preferable. As the copolymer rubber of ethylene and α-olefin, a copolymer rubber of ethylene and α-olefin, for example, propylene, butene-1, hexene-1, or the like, or non-conjugated as a third component in an ethylene-propylene system Dienes, for example, terpolymer rubbers (hereinafter abbreviated as “EPDM”) obtained by copolymerizing ethylidene norbornene, cyclopentadiene, and the like can be given. Among these, ethylene-propylene copolymer rubber or
EPDM is preferred.

Examples of the inorganic filler that can be used in the present invention include talc, mica, wollastonite, calcium carbonate, barium sulfate, magnesium carbonate, clay, alumina, silica, calcium sulfate, carbon fiber, glass fiber, metal fiber, and silica. Sand, silica, carbon black, titanium oxide, magnesium hydroxide, asbestos, zeolite, molybdenum, diatomaceous earth, sericite, shirasu, calcium hydroxide, calcium sulfite, sodium sulfate, bentonite, graphite and the like. Among them, talc, mica, calcium carbonate, glass fiber, wollastonite, etc. are preferred as those which improve low-temperature impact resistance, moldability, and coatability.

In particular, in order to obtain a polyolefin composition having improved low-temperature impact resistance, moldability, and coatability, 25 to 90% by weight of a crystalline polyolefin and 5 to 35% by weight of a copolymer rubber of ethylene and α-olefin. % And inorganic filler are preferably mixed in an amount of 5 to 40% by weight.

The stabilizer used in the present invention includes the above (A) to
It is a compound shown to (D). (A) The hindered piperidine compound having a molecular weight of 750 or more is preferably (A-1) or (A-2), and particularly preferably (A-2). (B) The hindered piperidine compound having a molecular weight of 500 or less is preferably (B-1) or (B-2). Among the benzoate compounds of (C), (C-1) is preferred. In the phosphorus-based compound (D), (D-1), (D-2) or (D-3) is preferable.

Compounds (A-1), (A-2) and (A-
3) has a repeating unit as described above, but each terminal group is not particularly limited, and may be, for example, hydrogen, halogen, or another monofunctional group.
Of these, preferred examples of (A-2) and (A-3) are as follows.

In the present invention, each of the stabilizers (A), (B), (C) and (D) is an essential component, and omitting any of them cannot achieve the desired effect. Further, each of the stabilizers shown in (A) to (D) may be used as a mixture of two or more compounds contained in each group.

The amount of the stabilizer in each of the groups (A) to (D) is 0.01 to 1 part by weight, preferably 0.05 to 0.5 part by weight, per 100 parts by weight of the polyolefin.

Furthermore, in order to improve the exterior and appearance of a molded article molded from the composition of the present invention, various pigments can be added to the composition and colored. As the pigment used in the present invention, an inorganic pigment suitable for a polyolefin can be used. For example, titanium oxide, carbon black, yellow iron oxide, titanium yellow, Hansa Yellow, Benzine Yellow, Bengala, Permanent Red, Thioindigo Red, Thioindigo Maroon, Manganese Purple, Dioxazine Violet, Ultramarine, Phthalocyanine Blue, Phthalocyanine Green, Isoindia Linone yellow, quinophthalone yellow, condensed azo yellow, perinone orange, quinacridone red, quinacridone scarlet, perylene red, perylene scarlet condensed azo red, dioxazine violet, indanthrone blue, synchasia red, carbon black, titanium oxide, etc. . As a dispersant for the pigment, metal soaps such as calcium stearate and magnesium stearate, and polyolefin waxes such as polyethylene wax and polypropylene wax are used. When a polyolefin wax is used, it is preferable to use a pigment and wax which have been mixed in advance with a powder ball mill or the like in order to enhance the dispersing effect.

Calcium stearate is effective as a stabilizer even when it does not contain a pigment. In addition to the stabilizer specified in the present invention, calcium stearate is used in an amount of 1 per 100 parts by weight of polyolefin.
It is a preferable component to be added in a range of not more than part by weight.

In addition to the stabilizer specified in the present invention, it is also possible to use, for example, antioxidants such as phenol-based and thioether-based antioxidants which are generally used for polyolefins.

Such phenolic antioxidants include, for example,
2,6-di-t-butyl-4-methylphenol, n-octadecyl-3- (3 ', 5'-di-t-butyl-4'-
(Hydroxyphenyl) propionate, tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane, 1,3,5-tris (4-t-butyl-3- (Hydroxy-2,6-dimethylbenzyl) isocyanurate, 3,9-bis [2- {3
-(3-t-butyl-4-hydroxy-5-methylphenyl) propionyloxy {-1,1-dimethylethyl]
-2,4,8,10-tetraoxaspiro [5.5] undecane and tris (3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate. As the thioether-based compound, for example, dilauryl-3,
3'-thiodipropionate, ditridecyl-3,3'-thiodipropionate, dimyristyl-3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, pentaerythritol-tetraxy ( β-laurylthiopropionate) and 3,9-bis (dodecylthioethyl) 2,4,8,10-tetraoxaspiro [5.5]
Undecane and the like.

Among these antioxidants, thioether compounds are preferably not used in combination because they tend to inhibit weatherability. Even when they are used in combination, (A) of the stabilizers specified in the present invention may be used. It is necessary to make it 1/3 or less with respect to the total addition amount of the group (B) and the group (B).

Others The polyolefin composition of the present invention contains other additives such as process oils, plasticizers, lubricating oils, lubricants, nucleating agents, antistatic agents, release agents, fungicides, etc., as long as the properties are not impaired. May be contained.

The compounding of the various stabilizers and additives to the polyolefin is performed by kneading in a heated and melted state using a usual kneader such as a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, a Brabender, or a kneader. It can be done easily.

<Example> Hereinafter, the present invention will be described with reference to examples.

Examples 1 to 21, Comparative Examples 1 to 9 100 parts by weight of a powdery propylene-ethylene copolymer (ethylene content: 8.0% by weight, melt index: 2.8 g / 10 minutes), 0.05 part by weight of calcium stearate and Table 1 (Additional amounts are listed in Table 1 in parts by weight)
Was added, mixed with a Henschel mixer, and extruded at 230 ° C. using a 30 mm extruder to form pellets.

From the pellets, use a 5.5 oz.
At 1 ° C., a sheet having a thickness of 1 mm and an area of 60 mm × 60 mm was prepared and used as a test piece for a weather resistance test.

The weather resistance test was performed in a sunshine weather meter (black panel 83 ° C., water spray 18 minutes / 120 minutes). The evaluation of the weather resistance was performed based on the time until cracks (cracks) occurred on the surface of the test piece, and the results are shown in Table 1.

In addition, among the symbols of the test additives in Table 1, (A-1)
To (A-4), (B-1) to (B-4), (C-1),
(C-2) and (D-1) to (D-5) are the compounds described above as additives used in the present invention, among which (A-1), (A-2) and (A-3) used a mixture having a repeating unit n of 2 to 10. Other symbols are as follows.

Tinuvin 622LD: Ciba-Geigy AO-2: tetrakis [methylene-3- (3 ', 5'-di-t
-Butyl-4'-hydroxyphenyl) propionate] methane AO-3: tris 3,5-di-t-butyl-4-hydroxybenzyl) isocyanurate AO-4: 1,3,5-tris (4-t- Butyl-3-hydroxy-2,6-dimethylbenzyl) isocyanurate AO-5: 3,9-bis [2- {3- (3-t-butyl-4-
(Hydroxy-5-methylphenyl) propylniloxy {-1,1-dimethylethyl] -2,4,8,10-tetraoxaspiro [5.5] undecane AO-6: pentaerythritol-tetrakis (β-laurylthio AO-7: dimyristyl-3,3'-thiodipropionate AO-8: distearyl-3,3'-thiodipropionate Examples 22 to 41, Comparative Examples 10 to 18 100 parts by weight of a powdery propylene-ethylene copolymer (ethylene content: 4% by weight, melt index: 6.0 g / 10 minutes), talc having an average particle size of 1.5 μm as a filler 20 parts by weight, 0.5 parts by weight of carbon black as a pigment, 0.05 parts by weight of calcium stearate, and the test additives shown in Table 2 (addition amounts are shown in parts by weight in Table 2) were added. Extrusion and injection molding were carried out in the same manner as in Examples 1 to 21 and subjected to a weather resistance test.

The conditions of the weather resistance test were the same as in Examples 1 to 21, and the results are shown in Table 2. The symbols of the test additives in Table 2 are the same as those in Table 1.

<Effects of the Invention> As described above, the polyolefin composition of the present invention has extremely excellent weather resistance not found in conventional products, and its industrial utility value is extremely high.

Continuation of the front page (51) Int.Cl. ⁶ Identification code Agency reference number FI Technical display location C08K 5: 105 5: 527 5: 5393) (72) Inventor Hiroki Yamamoto 3 Kasuganaka, Konohana-ku, Osaka-shi, Osaka No. 1-98 Sumitomo Chemical Co., Ltd. (72) Inventor Yuyuki Takahashi 3-1-1 98 Kasuganaka, Konohana-ku, Osaka-shi, Osaka Sumitomo Chemical Co., Ltd. (56) References JP-A 52-127954 (JP, A) JP-A-61-136533 (JP, A)

Claims (6)

(57) [Claims] (A) 0.01 to 1 part by weight of a hindered piperidine compound having a molecular weight of 750 or more selected from the following (A-1) to (A-4): (B) 0.01 to 1 part by weight of a hindered piperidine compound having a molecular weight of 500 or less selected from the following (B-1) to (B-4) (C) 0.01 to 1 part by weight of a benzoate compound selected from the following (C-1) and (C-2) (D) 0.01 to 1 part by weight of a phosphorus compound selected from the following (D-1) to (D-5) A polyolefin composition characterized by comprising: 2. The polyolefin composition according to claim 1, further comprising an inorganic filler. 3. The polyolefin composition according to claim 1, further comprising a pigment. 4. The polyolefin composition according to claim 1, further comprising calcium stearate. 5. The method according to claim 1, further comprising a phenolic antioxidant and / or a thioether antioxidant.
5. The polyolefin composition according to 2, 3 or 4. 6. A polyolefin having a molecular weight of 75 selected from (A) (A-1) to (A-4) according to claim 1.
0 or more hindered piperidine compounds, (B) a molecular weight of 50 selected from (B-1) to (B-4)
0 or less hindered piperidine compound, (C) a benzoate compound selected from (C-1) and (C-2), and (D) a phosphorus compound selected from (D-1) to (D-5) And a method for producing a polyolefin composition.