JP2607176B2 - Automotive polypropylene composition - Google Patents

Description

The present invention relates to a polypropylene composition for automobiles.
More specifically, the present invention relates to a polypropylene composition for automobiles having excellent antifogging properties and molding processability, and a polypropylene composition for automobiles having excellent antifogging properties and molding processability, and having improved dust adhesion prevention properties and thermal oxidation stability. It is.

[Prior art] ABS of automobile meter case is mainly for cost reduction
Materials have been changed from resins to polypropylene compositions.

Conventionally, when a polypropylene composition was used for an automobile manufacturer case, many problems occurred. For example,
Antioxidants, neutralizers, metal deactivators, and dispersants commonly used as essential additives in the polypropylene composition cause fogging of the meter panel due to their volatile components. In particular, higher fatty acid salts and waxes used as neutralizers / dispersants tend to cause fogging, and have the disadvantage of making meter readings difficult to distinguish. However, a polypropylene composition that does not use a dispersant deteriorates the dispersibility of the pigment, and also has poor mold releasability at the time of molding and poor moldability.

Further, while polypropylene and its composition have excellent electrical insulation properties, it is known that static electricity is likely to be charged during molding and causes various obstacles. Dust is very easily contaminated by static electricity, and the commercial value is significantly reduced due to the strong attachment of lightning pattern stains. In the case of a car meter case, the attached dust caused insufficient light quantity, making it difficult to distinguish the meter display.

Further, the polypropylene composition containing an inorganic filler has a drawback that the thermal oxidation stability is remarkably reduced as compared with a polypropylene composition containing no filler. This is considered to be because the added thermal oxidation stabilizer is inactivated by the inorganic filler.

JP-A No. 62-132937 as a sheet using an additive having a weight loss start temperature of 150 ° C. or higher to prevent roll contamination, and JP-A-1-301739 as a container using a specific stabilizer for imparting thermal stability. Are known. JP-A-62-36466 and JP-A-1-5-5 as antistatic agents for synthetic resins using alkylbenzenesulfonic acid sodium and wax.
No. 4068 is known.

Conventionally, many studies have been made to improve the moldability of such a polypropylene composition and to prevent dust adhesion, fogging and heat aging. However, none of the conventionally known combinations of additives has been sufficiently satisfactory.

[Problems to be Solved by the Invention] Under such circumstances, the problems to be solved by the present invention, that is, an object of the present invention is to improve the moldability, which is a drawback of the conventional polypropylene composition for automobiles, and to prevent dust adhesion. An object of the present invention is to provide a polypropylene composition for automobiles having excellent properties, antifogging property and thermal oxidation stability.

[Means for Solving the Problems] The present invention relates to a polypropylene composition for automobiles containing an inorganic filler, wherein 0.01 to 10 parts by weight of a metal hydroxide surface-treated with a fatty acid is reduced with respect to 100 parts by weight of crystalline polypropylene, and weight loss is achieved. An automotive antioxidant having a starting temperature of 150 ° C. or higher, a metal deactivator and a hydrotalcite, each of which is added with 0.01 to 2 parts by weight of an automotive polypropylene composition, and the automotive polypropylene composition,
Provided is a polypropylene composition for automobiles, wherein 0.01 to 0.5 part by weight of an anionic surfactant is added to 100 parts by weight of crystalline polypropylene.

The polypropylene used in the present invention is a propylene homopolymer or propylene and ethylene, butene-1,
Α- such as hexene-1, 4-methyl-pentene-1, etc.
It is a crystalline polymer of random and block copolymers with olefins.

The metal hydroxide used in the present invention is a metal hydroxide surface-treated with a fatty acid, and the fatty acid is preferably a fatty acid having 8 to 28 carbon atoms. Among the saturated fatty acids, lauric acid, palmitic acid, stearic acid, behenic acid, Examples of montanic acid and unsaturated fatty acids include oleic acid and erucic acid, and examples of metal hydroxides include Mg, Ca, Sr, Ba and Zn. The surface treatment amount of the fatty acid is preferably 0.01 to 10 parts by weight based on 100 parts by weight of the metal hydroxide. If the amount of surface treatment is less than 0.01 part by weight, the releasing effect is not improved, and if it exceeds 10 parts by weight, the fogging property is deteriorated. As the metal hydroxide surface-treated with the fatty acid, a commercially available metal hydroxide surface-treated at the same time as drying the product can be used. The amount of the metal hydroxide surface-treated with this fatty acid is 0.01 to 10 parts by weight, preferably 0.1 to 5 parts by weight, based on 100 parts by weight of polypropylene. If the amount is less than 0.01 part by weight, the releasability at the time of molding is poor and the molding processability is inferior, and if it exceeds 10 parts by weight, the effect is increased and it is economically disadvantageous. Alternatively, physical properties may be lowered, which is not preferable.

As the specific antioxidant used in the present invention, a phenol-based compound, a sulfur-based compound, a phosphorus-based compound, or the like, having a weight-loss starting temperature of 150 ° C. or more, is used alone or in combination. Specific examples of these compounds include tetrakis [methylene- (3,5-
Di-tert-butyl-4-hydroxyphenyl) propionate] methane, 1,3,5-trimethyl-2,4,6-tris (3,
5-di-t-butyl-4-hydroxybenzyl) benzene, 3,9-bis [1,1-di-t-butyl-2- {β- (3
-Tbutyl-4-hydroxy-5-methylphenyl) propyloxydiethyl] -2,4,8,10-tetraoxyspiro [5,5] undecane, tris (2,4-di-t-butylphenyl) ) Phosphite, bis (2,6-di-t-butyl-4-methylphenyl) pentaerythritol-di-
Phosphite, di (2,4-di-t-butylphenyl)
Pentaerythritol-di-phosphite, tetrakis (2,4-di-t-butylphenyl) 4,4-biphenylene-di-phosphonite and the like can be mentioned. If an antioxidant having a weight loss start temperature of less than 150 ° C. is used, it causes fogging of the panel after molding and mounting on a vehicle.

The metal deactivator used in the present invention is a metal contact having a weight loss start temperature of 150 ° C. or higher, a metal insert, an additive for preventing resin deterioration due to kneading of metal powder,
2,2'-oxamidobis [ethyl-3- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate],
3- (N-salicynoyl) amino-1,2,4-triazole and the like. Use of a metal deactivator having a temperature at which the weight loss starts below 150 ° C. causes clouding.

The hydrotalcite used in the present invention is a hydrotalcite having a weight loss onset temperature of 150 ° C. or higher, and is a neutralizing agent for neutralizing acidic components in the polymer. The hydrotalcite is preferably a fine powder, and is a magnesium or aluminum hydrated basic carbonate, and may be a natural product or a synthetic product. When a higher fatty acid metal salt or the like is used as the neutralizing agent, it causes clouding.

The amounts of these antioxidants, neutralizers, metal deactivators and hydrotalsides are 0.01 to 2 parts by weight, preferably 0.1 to 1 part by weight, per 100 parts by weight of polypropylene. If the amount is less than 0.01 part by weight, sufficient effects cannot be obtained. If the amount exceeds 2 parts by weight, the effect is not improved and the economical disadvantage is caused. It is not preferable because a decrease or the like may occur.

The weight loss start temperature in the present invention is measured by the following method.

Temperature at which weight loss starts; TG / DTA30 manufactured by Seiko Electronic Industry Co., Ltd.
Temperature rise rate 10 ° C / min, air flow rate 100ml / min using a 0-type thermobalance
Was measured. The weight loss start temperature indicates the temperature at which the sample decreases by 1 wt%.

Examples of the anionic activator used in the present invention include an alkyl sulfonate having 8 to 22 carbon atoms or an alkylbenzene sulfonate having an alkyl group having 8 to 22 carbon atoms. The amount added is 100 parts by weight of polypropylene.
It is 0.01 to 0.5 parts by weight, preferably 0.1 to 0.3 parts by weight. If the amount is less than 0.01 part by weight, sufficient effects on dust adhesion prevention and thermal oxidation stability cannot be obtained. In some cases, bleeding or deterioration of physical properties may occur, which is not preferable. When glycerin-based or amine-based antistatic agents are used among the antistatic agents, they bleed and cause cloudiness.

An inorganic filler is added to the automotive polypropylene composition of the present invention. 1 to 100 parts by weight, preferably 10 to 90% by weight, based on 100 parts by weight of polypropylene
Is preferred. If the amount exceeds 100 parts by weight, the moldability is poor when producing the molded product, and for example, even if the molded product is produced, the appearance of the molded product is not good. On the other hand, if it is less than 1 part by weight, it is not possible to improve the mechanical properties such as rigidity, dimensional stability and heat resistance of the obtained molded product. Specific examples of the inorganic filler include talc, mica,
Clay, wollastonite, calcium carbonate, aluminum hydroxide, magnesium hydroxide, silicon dioxide, titanium dioxide, zinc oxide, magnesium oxide, zinc sulfide, barium sulfate, calcium silicate, aluminum silicate, glass fiber, potassium titanate, carbon fiber , Carbon black, graphite, metal fibers and the like, and excludes hydrotalcite used as a neutralizing agent and metal hydroxide surface-treated with a fatty acid. Among them, talc is preferably used, and these can be used alone or as a mixture.

In the present invention, other additives such as a stabilizer, a pigment, a nucleating agent, a lubricant and the like can be added as long as the characteristics are not impaired.

The composition of the present invention can be obtained 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.

As described above, the polypropylene composition of the present invention is excellent in molding processability, and the automotive meter case obtained from the polypropylene composition has extremely excellent dust-preventing properties, anti-fogging properties and thermo-oxidative stability.

(Examples) Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited in scope thereby.

The test methods for the releasability, dust adhesion, haze, and thermal oxidation stability in Examples and Comparative Examples are as follows.

(Releaseability) A box-shaped molded product having a length of 110 mm, a width of 230 mm, a height of 120 mm and a thickness of 2 mm was injection-molded, and the mold was released at an air pressure of 2.0 kg / cm ₂ .

(Dust adhesion) After forming a plate of test specimen size 150mm x 150mm x 2mm, 1
After a lapse of time, it was subjected to an ash adhesion test. The ash adhesion test is to measure the distance between the surface of the desk and the plate when the tobacco ash soars and the ash adheres to the plate, by bringing the plate one hour after molding closer to the surface of the tobacco ash left on the desk surface. Was. The larger the value, the more easily the ash due to static electricity adheres.

(Fogging test method) Put three test pieces with dimensions of 50 mm x 25 mm x 2 mm into a glass test tube with an inner diameter of 35 mm x length of 350 mm, attach a glass plate to the opening, and then test by Toyo Seiki Co., Ltd. The treatment was performed at 140 ° C. for 72 hours in a tube aging tester. After the test tube taken out was allowed to cool for 10 minutes, the glass plate was removed, and the cloudy portion was subjected to a visual test.

(Thermal Oxidation Stability) The evaluation was performed in accordance with JIS K-7122 [General rules for the thermal aging test method for thermoplastics (oven method)]. It was measured at 150 ° C using a gear open manufactured by Toyo Seiki Co., Ltd. Then, the time (GO life) until the test piece (press sheet having a thickness of 1 mm) was completely deteriorated, in other words, until the tensile strength became zero was measured.

Examples 1-2 Crystalline polypropylene polymer (melt index:
Weight reduction start temperature 217 for 100 parts by weight of 6.0g / 10min) powder
° C tetrakis [methylene- (3,5-di-t-butyl-
4-Hydroxyphenyl) propionate] methane is 0.
1 part by weight of tetrakis (2,4-di-
(t-butylphenyl) 4,4-biphenylene-di-phosphonite 0.1 part by weight, hydrotalcite 0.05 part by weight, 3- (N-salicynoyl) having a temperature of starting weight loss of 168 ° C.
0.10 parts by weight of amino-1,2,4-triazole and
Magnesium hydroxide (Kisuma 5A, manufactured by Kyowa Chemical Co., Ltd.) surface-treated with 2% stearic acid shown in the table was mixed according to the compounding formula, and pelletized at 250 ° C. by an extruder. The pellets were injection molded at a resin temperature of 250 ° C. and a mold temperature of 50 ° C. into a box-shaped molded product and a plate having a thickness of 2 mm.

The releasability was tested during the molding of the box-shaped product, and the obtained plate was tested for dust adhesion and fogging. The results are shown in Table 1.

Example 3 Example 2 was repeated except that magnesium hydroxide surface-treated with 2% stearic acid in Example 2 was changed to calcium hydroxide surface-treated with 2% oleic acid.

Example 4 Example 2 was followed except that the anionic surfactants shown in Table 1 were added.

Comparative Example 1 The tetrakis [methylene- (3,5-di-t-
Butyl-4-hydroxyphenyl) propionate] methane and tetrakis (2,4-di-t-butylphenyl) 4,4
-Biphenylene-di-phosphonite weight loss onset temperature
Example 1 was repeated except that BHT at 71 ° C was changed to 0.1 part by weight and magnesium hydroxide was not used.

Comparative Example 2 The procedure of Example 1 was followed, except that the magnesium hydroxide surface-treated with 2% stearic acid of Example 1 was changed to 0.4 part by weight of zinc stearate.

Comparative Example 3 The procedure of Example 1 was followed, except that the magnesium hydroxide surface-treated with 2% stearic acid of Example 1 was changed to 0.4 part by weight of zinc stearate and 0.3 part by weight of glycerin monostearate was added.

Comparative Example 4 Example 4 was followed except that the amount of the anionic surfactant shown in Table 1 was increased.

Comparative Example 5 Tetrakis [methylene (3,5-di-tert-butyl-4-hydroxyphenyl) propionate] methane of Example 1 and tetrakis (2,4-di-tert-butylphenyl) 4,4-
Biphenylene di-phosphonite is reduced at a starting temperature of 71.
Example 1 was repeated except that the temperature was changed to 0.1 parts by weight of BHT.

<Effects of the Invention> The conventional automobile meter case has a disadvantage that the ambient temperature rises when the lamp is turned on, and the panel is fogged by the volatile components of the additives contained in the polypropylene composition. However, the automotive polypropylene composition of the present invention,
Since specific antioxidants, neutralizers, metal deactivators, hydrotalcites, and metal hydroxides were used, they had anti-fogging properties and improved moldability.

Further, the automotive polypropylene composition of the present invention containing a specific anionic activator has excellent antifogging properties, excellent moldability, as well as significantly improved dust adhesion prevention and thermo-oxidative stability. A composition is provided.

The polypropylene composition thus obtained can be used for other automobile parts, for example, automobile interior parts, lamp housings, etc., by utilizing unprecedented antifogging property and dust adhesion preventing property.

Claims (2)

(57) [Claims] The present invention relates to an automotive polypropylene composition containing an inorganic filler, wherein the metal hydroxide surface-treated with a fatty acid is used in an amount of 0.01 to 10 parts by weight based on 100 parts by weight of a crystalline polypropylene, and the weight loss starting temperature is 150 ° C. or more. An automotive polypropylene composition comprising 0.01 to 2 parts by weight of an inhibitor, a metal deactivator and hydrotalcite. 2. The automotive polypropylene composition according to claim 1, further comprising 0.01 to 0.5 parts by weight of an anionic surfactant per 100 parts by weight of the crystalline polypropylene.