JPH10316809A - Polypropylene resin composition - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition having an excellent stability against thermal deterioration, thermal oxidative deterioration and fogging phenomena and useful for automotive parts, household electric appliances, etc., by adding montmorillonite and an antioxidizing agent to polypropylene resin having a specific composition. SOLUTION: This composition is obtained by adding 0.01-5 pts.wt. of montmorillonite and 0.01-5 pts.wt. of an antioxidizing agent e.g. a phenol-based agent such as tetrakis[methylene-3-(3',5'-di-t-butyl-4-hydroxyphenyl) propionate]methane, a phosphorus-based agent, a sulfur-based agent, an amine- based agent} to 100 pts.wt. of a mixture comprising polypropylene and an inorganic filler (e.g. tale, calcium carbonate) preferably in an amount of <=50 wt.% based on the total amount of the polypropylene and the inorganic filler. Thus, the excellent stability can be imparted to the polypropylene containing the inorganic filler.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polypropylene resin composition having stability against thermal deterioration, thermal oxidation deterioration and fogging. More specifically, by using montmorillonite in combination with an antioxidant,
The present invention relates to a polypropylene resin composition having improved thermal oxidation deterioration and fogging phenomenon.

[0002]

2. Description of the Related Art Polypropylene resin has excellent physical properties.
Because of its chemical properties, it is widely used. In particular, the polypropylene resin blended with inorganic filler is physically,
Because of its improved electrical or chemical properties, it is used in applications that are exposed to relatively high temperatures, such as automotive parts and home appliance parts. However, when the inorganic filler is blended with the propylene polymer resin, the effect of the antioxidant is significantly reduced as compared with the propylene polymer resin not blended with the inorganic filler, so that the resistance to heat aging is significantly reduced. I have a problem. In addition, by adding a stabilizing effective amount of a metal soap and an antioxidant in combination to a polypropylene resin mixed with an inorganic filler, it is possible to improve the resistance to heat aging resistance. As a result, the bleed-out or the bleed-out vaporizes and then cools and solidifies again, resulting in so-called fogging which causes fogging on the glass surface or the like. This phenomenon is particularly problematic when used as an interior material for automobiles. In view of the above situation, a method capable of improving both heat aging resistance and non-fogging properties has been strongly desired.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide an inorganic filler-containing polypropylene resin composition having better stability against thermal deterioration, thermal oxidation deterioration and fogging phenomenon.

[0004]

Means for Solving the Problems The present inventor has continued the intensive study to develop a stabilizer capable of imparting an excellent stabilizing effect to the inorganic filler-containing polypropylene against thermal deterioration, thermal oxidation deterioration and fogging phenomenon. Have been. As a result, they have found that by using montmorillonite in combination with an antioxidant, it is possible to impart excellent stability to the inorganic filler-containing polypropylene, and have completed the present invention. That is, the present invention provides a polypropylene resin composition obtained by adding a stabilizing effective amount of montmorillonite and an antioxidant to a polypropylene resin containing an inorganic filler.

[0005]

DETAILED DESCRIPTION OF THE INVENTION The montmorillonite used in the present invention has the general formula

## STR1 ## (X, Y) in _{2 ~ 3 Z 4 O 10 (} OH) 2 · mH 2 O · (Wω) ( ^{wherein, X = Al, Fe III,} Cr III; Y = Mg, Fe
^II , Mn ^II , Ni, Zn, Li; Z = Si, Al; W =
K, Na, Ca; H ₂ O = interlayer water. ) May be used as long as it is a montmorillonite group mineral, and is not limited to a specific compound. In addition, the amount of addition may be determined by stabilizing the amount of resin and filler, the amount effective for stabilizing by the amount of filler, and is not particularly limited, but is 100 parts by weight of the total amount of the polypropylene resin and the inorganic filler. 0.0
It is preferable to use 1 to 5 parts by weight, and it is particularly preferable to use 0.01 to 1 part by weight.

Representative examples of montmorillonite include montmorillonite, magnesia montmorillonite, tetumontmorillonite, tesmagnesian montmorillonite, beidellite, amilnian bandelite, nontronite, aluminian nontronite, sapolite, aluminum Nian sapoite, hectorite, sauconite and the like can be mentioned.

Examples of the antioxidant used in the present invention include phenol-based, phosphorus-based, sulfur-based, and amine-based stabilizers, and these can be used alone or in combination.

Specific examples of the phenolic antioxidant include the following. 2,6-di-t
tert-butyl-4-methylphenol, octadecyl 3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate, 2,2′-methylenebis (6-tert-butyl-4-methylphenol),
-Tert-butyl-6- (3-tert-butyl-2
-Hydroxy-5-methylbenzyl) -4-methylphenyl acrylate, 2- [1- (2-hydroxy-
3,5-di-tert-pentylphenyl) ethyl]-
4,6-di-tert-pentylphenyl acrylate, 4,4′-butylidenebis (6-tert-butyl-3-methylphenol), 3,9-bis [2- {3-
(3-tert-butyl-4-hydroxy-5-methylphenyl) propionyloxy {-1,1-dimethylethyl] 2,4,8,10-tetraoxaspiro [5,
5] undecane, 2- (3,5-di-tert-butyl-4-hydroxyanilino) -4.6-bis (n-octylthio) -1,3,5-triazine, 2,2′-ethylidenebis (4,6-di-tert-butylphenol), 2,2′-ethylidenebis (4-sec-butyl-6-tert-butylphenol), 1,1,3-tris (5-tert-butyl-4-hydroxy) -2-methylphenyl) butane, bis [2-tert-butyl-
4-methyl-6- (3-tert-butyl-2-hydroxy-5-methylbenzyl) phenyl] terephthalate, tetrakis [methylene-3- (3,5-di-ter)
t-butyl-4-hydroxyphenyl) propionate] methane, 2,2′-thiodimethylenebis [3-
(3,5-di-tert-butyl-4-hydroxyphenyl) propionate], triethylene glycol bis [3- (3-tert-butyl-4-hydroxy-5)
-Methylphenyl) propionate], 1,6-hexanediol bis [3- (3,5-di-tert-butyl-4-hydroxyphenyl) propionate], 1,
3,5-tris (3,5-di-tert-butyl-4-
Hydroxybenzyl) isocyanurate, 1,3,5-
Tris [2- {3- (3,5-di-tert-butyl-
4-hydroxyphenyl) propionyloxydiethyl] isocyanurate, 1,3,5-tris (3,5-
Di-tert-butyl-4-hydroxybenzyl)-
2,4,6-trimethylbenzene.

Specific examples of the phosphorus antioxidant include the following. Tris (2,4-di-
t-butylphenyl) phosphite, tetrakis (2,
4-di-t-butylphenyl) -4,4'-biphenylenediphosphonite, 2,2'-methylenebis (4,6
-Di-t-butylphenyl) octyl phosphite, cyclic neopentanetetraylbis (2,6-di-t-butyl-4-methylphenyl phosphite).

[0010] Specific examples of the sulfur-based antioxidant include the following. Dilauryl-3,3 '
Thiodipropionate, ditridecyl-3,
3'-thiodipropionate, dimyristyl-
3,3'-thiodipropionate, distearyl-3,3'-thiodipropionate, laurylstearyl-3,3'-thiodipropionate, bis [2-methyl-4- (3- n- alkyl (C ₁₂ ~
C ₁₄ ) thiopropionyloxy) -5-t-butylphenyl] sulfide, pentaerythritol tetra (β-
Lauryl-thiopropionate) ester, 2-mercaptobenzimidazole, 2-mercapto-6-methylbenzimidazole.

[0011] These antioxidants are used in an amount of 0.01 per 100 parts by weight of the total amount of the polyolefin resin and the inorganic filler.
It is preferred to use from 5 to 5 parts by weight, particularly preferably from 0.01 to 1 part by weight.

The polypropylene resin used in the present invention includes a homopolymer of polypropylene, propylene and an α-olefin such as ethylene, butene-1, pentene-1, hexene-1, 4-methyl-pentene-1, acrylic acid,
Random, block or graft copolymers of unsaturated carboxylic acids and derivatives thereof such as ethyl acrylate and maleic anhydride, vinyl esters such as vinyl acetate and vinyl butyrate, and unsaturated aromatic compounds such as styrene and methyl styrene And the like. Among them, a homopolymer of polypropylene is preferable.

An inorganic filler is blended with such a polypropylene resin. Specific examples of the inorganic filler that can be used include talc, mica, titanium oxide, zinc oxide, aluminum hydroxide, calcium carbonate, magnesium carbonate, calcium sulfate, barium sulfate, magnesium silicate, celite, kaolin, zeolite, silica, and asbestos. , Glass fiber, carbon fiber, barium titanate, lead titanate and the like. These can be used alone or in combination of two or more.

The mixing ratio of the inorganic filler is preferably not more than 50% by weight based on the total weight of the polypropylene resin and the inorganic filler. More preferably, the inorganic filler is used in a range of 35% by weight or less.
Further, in order to sufficiently exhibit the mixing effect of these inorganic fillers, it is preferable to add 1% by weight or more.

The inorganic filler-containing polypropylene resin containing montmorillonite and an antioxidant according to the present invention may be used, if necessary, for example, as a foaming agent, a weathering agent, an antistatic agent, an antifogging agent, a surface treatment agent, and a metal. Soaps, lubricants, flame retardants, nucleating agents, clarifying agents, processing aids, fungicides, bactericides, mold release agents and the like can also be included.

[0016]

[Formulation]

Polypropylene (BC4Q; manufactured by Mitsubishi Chemical Co., Ltd.) 70 parts Talc (H880; manufactured by Wando Industry Co., Ltd.) 30 parts Montmorillonite (Kunipia; manufactured by Kunimine Industries Co., Ltd.) -Di-t-butyl-4-hydroxyphenyl) propionate] methane 0.10 part: tris (2,4-di-t-butylphenyl) phosphite 0.05 part: distearyl-3,3'-thiodi Propionate 0.10 parts In order to see the effect of the present invention on polypropylene, the above blend was extruded at 200 ° C (Kobe Steel: 2FC
M) to produce a pellet. The pellet was formed into a sheet having a thickness of 0.5 mm at 230 ° C. by a press forming machine, and a test piece of 65 mm × 35 mm square was formed using a punching machine. Place the specimen in a gear oven
The air was heated under circulating heat at 30 ° C., and the time required for embrittlement (embrittlement life) was measured. Table 1 shows the test results.

Comparative Example 1 The stability of polypropylene against thermal oxidation deterioration was evaluated in the same manner as in Example 1 except that montmorillonite was not used. Table 1 shows the results.

[0018]

[Table 1]

Examples 5 to 9 Stabilization of polypropylene against fogging property [Blending] Polypropylene (BC4Q; manufactured by Mitsubishi Chemical Corporation) (100-X) part Talc (H880; manufactured by Wando Industry Co.) X part Pigment (gray; Dainichisei) 1.0 part Montmorillonite 0.1 part Antioxidant: tetrakis [methylene-3- (3 ′, 5′-di-t-butyl-4-hydroxyphenyl) propionate] methane 0.10 part: tris ( 2,4-di-t-butylphenyl) phosphite 0.05 part: distearyl-3,3'-thiodipropionate 0.10 part In order to see the effect of the present invention on polypropylene, the above compound was prepared. Extrusion at 200 ° C (Kobe Steel: 2FC
M) to produce a pellet. 2 g of the pellet was weighed and placed in a test tube (200 mm × 30 mmφ). A glass plate having a thickness of 3 mm and a diameter of 35 mm is placed on this test tube,
In an oil bath, the temperature was maintained at 120 ° C. for 24 hours. A schematic diagram of the fogging test is shown in FIG. Thereafter, the degree of fogging of the glass plate was measured using a haze meter.
In addition, a test was also performed for a case where no pellet was contained as a blank, and a value obtained by subtracting this value was taken as an actual haze value. Table 2 shows the test results.

Comparative Examples 2 to 6 Stabilization of polypropylene against fogging properties was evaluated in the same manner as in Examples 5 to 9 except that montmorillonite was not used. Table 2 shows the test results.

Comparative Examples 7 to 8 The stabilization of polypropylene against fogging properties was evaluated in the same manner as in Examples 8 to 9, except that zinc behenate was used instead of montmorillonite. Table 2 shows the test results.

[0022]

[Table 2]

[0023]

The polypropylene resin composition of the present invention has
It has low fogging properties and a satisfactory heat aging life. Therefore, the utility value of the inorganic filler-containing polypropylene resin molded article is very large.

[Brief description of the drawings]

FIG. 1 is a schematic diagram of a fogging test.

[Description of Signs] 1 Oil bath 2 Test tube 3 Glass plate 4 Pellet 5 Stirring motor 6 Temperature controller 7 Heater 8 Silicon oil

Claims (2)

[Claims] 1. A polypropylene resin composition characterized in that montmorillonite and an antioxidant are added to a polypropylene resin containing an inorganic filler. 2. The polypropylene resin composition according to claim 1, wherein the content of the inorganic filler is 50% by weight or less of the total amount of the inorganic filler and the polypropylene resin.