JPH06179778A - Polyolefin resin composition having improved hue - Google Patents

Abstract

PURPOSE:To provide a polyolefin resin composition having highly balanced rigidity and impact resistance and improved color. CONSTITUTION:The polyolefin resin composition is produced by compounding (A) 100 pts.wt. of a polyolefin resin with (B) 3-150 pts.wt. of calcium carbonate and (C) 0.1-10wt.% (based on the calcium carbonate) of at least one kind of organic acid selected from among aromatic phosphoric acid, saturated aliphatic dicarboxylic acid and aromatic mono or dicarboxylic acid.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a polyolefin resin composition obtained by blending calcium carbonate and a specific organic acid in a polyolefin resin, which has an excellent balance of rigidity and impact resistance and an improved hue. Regarding

[0002]

2. Description of the Related Art Conventionally, a method has been known in which a polyolefin resin is filled with various inorganic fillers such as calcium carbonate, talc, mica and glass fiber to improve physical properties such as mechanical strength and heat resistance. These inorganic filler-filled polyolefin resins are used in various applications, mainly in the field of industrial parts such as automobile parts and home electric appliances, and there is a demand for improving the mechanical strength, especially the balance between rigidity and impact resistance. The current situation is extremely high.

Calcium carbonate, which is one of the typical fillers among inorganic fillers, has various kinds having different shapes and particle diameters, but granular ones are environmentally friendly and easy to handle, Also, since it is inexpensive, it is widely used for the purpose of imparting mechanical strength, heat resistance, retardation to polyolefin resin, or increasing the amount thereof.

However, when this general-purpose granular calcium carbonate is filled in a polyolefin resin, it contributes to the improvement of impact resistance due to its shape, but no improvement in rigidity is observed. Therefore, there is a method of filling whisker-like calcium carbonate, but this has a drawback that the rigidity is considerably improved as compared with the granular one, but the impact resistance is significantly lowered. Further, in addition to this, the hue is deteriorated by filling the whisker-like calcium carbonate. Thus, regardless of the shape of calcium carbonate, there is no effect of improving the balance between rigidity and impact resistance, and improvement thereof is a major issue.

As measures against this, among calcium carbonates, those having a finer particle size, those surface-treated with fatty acids or metal salts thereof, or calcium carbonate in a slurry state with phosphoric acid / surfactant etc. There is a way to use what you did. However, the balance level of rigidity and impact resistance is not yet satisfactory, and further improvement is desired.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polyolefin resin composition having an excellent balance of rigidity and impact resistance and an improved hue.

[0007]

[Means for Solving the Problems]

[Summary of the Invention] The present inventors have conducted various studies to solve the above problems, and as a result, by blending calcium carbonate and a specific organic acid into a polyolefin resin, the balance between rigidity and impact resistance is excellent. The present invention has been completed by finding that a polyolefin resin composition having an improved hue can be obtained.

That is, the present invention relates to "a polyolefin resin, 3 to 150 parts by weight of calcium carbonate based on 100 parts by weight thereof, and 0.1 to 100 parts by weight of calcium carbonate.
A polyolefin resin composition comprising 10% by weight of at least one organic acid selected from the group consisting of aromatic phosphoric acid, saturated aliphatic dicarboxylic acids and aromatic mono- or dicarboxylic acids. .

[Detailed Description of the Invention] (1) Constituent Components (a) Polyolefin Resin The polyolefin resin used in the present invention includes ethylene, propylene, butene, pentene, hexene, 4-methylpentene-1, octene, and the like α. -Olefin homopolymers, homopolymers, or α-olefins and vinyl esters (vinyl acetate, vinyl butyrate, etc.), unsaturated carboxylic acids or their derivatives (acrylic acid, maleic anhydride, methyl methacrylate, acrylic acid) Random block or graft copolymers with other unsaturated monomers such as ethyl unsaturated group), aromatic unsaturated monomers (styrene, α-methylstyrene, etc.), saponified products or metal ionization of the copolymers. Resins such as things are mentioned.

Specifically, ultra-low density polyethylene, low density polyethylene, linear low density polyethylene, medium density polyethylene, high density polyethylene, polypropylene, polybutene, poly-3-methylpentene-1, propylene and other α-olefins. Copolymer with ethylene, vinyl ester / unsaturated carboxylic acid or its derivative / random block or graft copolymer with aromatic unsaturated monomer, polypropylene vinyl ester / unsaturated carboxylic acid or its derivative -There are graft-modified products such as aromatic unsaturated monomers.

Among the preferred specific examples, polypropylene, a propylene-ethylene block or random copolymer, and a propylene polymer of a propylene-ethylene-butene copolymer are preferable, and a propylene-ethylene block copolymer is particularly preferable. These propylene polymers are usually produced by a Ziegler-Natta catalyst, but a catalyst obtained by supporting a catalyst component on a carrier such as magnesium chloride can also be used for this catalyst. As a polymerization method, any method such as a slurry method of polymerizing in a solvent, a liquid phase method of polymerizing in a propylene monomer, or a gas phase method may be used.

MFR of polyolefin resin (JIS-K
7210, 230 ° C, 2.16 kg load) is 0.1-1
00 g / 10 minutes is preferable, and 1 to 50 g / 10 minutes is particularly suitable.

(B) Calcium Carbonate As the calcium carbonate used in the present invention, any of heavy calcium carbonate, light calcium carbonate and colloidal calcium carbonate can be used. The shape thereof may be any of granular, spindle-like, and whisker-like, and whisker-like is particularly preferable. Calcium carbonate whiskers have a major axis of 10-5
It is preferable that the diameter is 0 μm and the minor axis is 0.5 to 5 μm.

(C) Organic Acid The organic acid used in the present invention is at least one organic acid selected from the group consisting of aromatic phosphoric acid, saturated aliphatic dicarboxylic acid and aromatic mono- or dicarboxylic acid. This organic acid includes mono-, di- or tri-substituted or unsubstituted phenyl phosphoric acid having 4 or less carbon atoms, its bis form, mono- or di-substituted or non-substituted phenyl phosphoric acid having 4 or less carbon atoms, 2, 2′-methylene, ethylidene, propylidene or butylidene bis derivative, aliphatic saturated dicarboxylic acid having 3 to 12 carbon atoms, benzoic acid, aromatic dicarboxylic acid, naphthoic acid, cinnamic acid and the like can be mentioned.

Specifically, phenylphosphoric acid, t-butylphenylphosphoric acid, diphenylphosphoric acid, bis (t-butylphenyl) phosphoric acid, bis (di-t-butylphenyl) phosphoric acid, 2,2'- Methylenebis (dimethylphenyl) phosphoric acid, 2,2′-methylenebis (di-t-butylphenyl) phosphoric acid, 2,2′-ethylidenebis (dimethylphenyl) phosphoric acid, 2,2′-ethylidenebis (di-t) -Butylphenyl) phosphoric acid, malonic acid, succinic acid, glutaric acid, adipic acid, azelaic acid, sebacic acid, benzoic acid, methylbenzoic acid, ethylbenzoic acid, isopropylbenzoic acid, t-butylbenzoic acid, phenylbenzoic acid, α-
Examples thereof include naphthoic acid, β-naphthoic acid, cinnamic acid, methyl cinnamic acid, ethyl cinnamic acid, isopropyl cinnamic acid, t-butyl cinnamic acid, phthalic acid, isophthalic acid and terephthalic acid.

Of these, preferred are t-butylphenylphosphoric acid, diphenylphosphoric acid, and bis (di-t-phosphoric acid).
Butylphenyl) phosphoric acid, 2,2′-methylenebis (di-t-butylphenyl) phosphoric acid, 2,2′-ethylidenebis (di-t-butylphenyl) phosphoric acid, succinic acid, glutaric acid, adipic acid, Examples thereof include azelaic acid, sebacic acid, benzoic acid, t-butylbenzoic acid, α-naphthoic acid, β-naphthoic acid and cinnamic acid.

Among them, particularly preferable are 2,
2′-methylenebis (di-t-butylphenyl) phosphoric acid, succinic acid, benzoic acid, t-butylbenzoic acid, α-naphthoic acid, β-naphthoic acid, cinnamic acid and the like. The proportion of each of the above essential components is 3 to 150 parts by weight, preferably 5 parts by weight of calcium carbonate, relative to 100 parts by weight of the polyolefin resin.
˜50 parts by weight and 0.1 to 10% by weight, preferably 0.3 to 7% by weight, of the organic acid with respect to the amount of calcium carbonate.

Here, if the amount of calcium carbonate is too small, the rigidity becomes insufficient, and if it is too large, it is not preferable in terms of fluidity, impact resistance and moldability. On the other hand, if the amount of the organic acid is too small, the rigidity and hue are not satisfied, and if the amount is too large, the appearance of the product surface may be deteriorated due to bleeding, and the paintability may be impaired.

In addition to these essential components, the composition of the present invention may contain other additional components as long as the effects of the present invention are not significantly impaired. As other additional components, for example, ethylene-propylene rubber, ethylene-
Rubber components such as butene rubber, styrene-butadiene rubber (including hydrogenated products thereof), styrene-isoprene rubber (including hydrogenated products thereof); condensed azo type, isoindolinone type, quinacridone type, perylene type , Perinone-based, quinophthalone-based, anthraquinone-based, phthalocyanine-based organic pigments; titanium oxide, titanium yellow, zinc white, iron black, carbon black, red pigment, ultramarine blue, and other inorganic pigments; phenol-based, sulfur-based, Phosphorus-based antioxidants; amine-based, triazole-based, benzophenone-based, benzoate-based, nickel-based, salicylic acid-based light stabilizers; talc, mica, silica, clay, glass fibers, nylon fibers and other inorganic or organic-based antioxidants Other than the essential components of the above; organic or inorganic nucleating agents; antistatic agents; lubricants; metal deactivators; molecular weight adjustment ; Antibacterial agent; fluorescent whitening agents; anti-blocking agent and the like.

The composition of the present invention can be produced by a conventional method. For example, a powdery propylene polymer is mixed with the above-mentioned calcium carbonate and organic acid and, if necessary, other additional components, and the mixture is mixed with a low-speed stirring mixer (Nauta mixer) or the like, and then a uniaxial or biaxial kneading extruder. Melt and knead to pelletize. At this time, by mixing the organic acid component with the calcium carbonate component in advance with a low-speed stirring mixer (Nauta mixer) or the like, a higher effect can be achieved. Alternatively, the powdery propylene polymer is mixed with the above organic acid and, if necessary, other additional components, and the mixture is mixed with a high-speed stirring mixer (Henschel mixer) or the like, and then melt-kneaded with a uniaxial or biaxial kneading extruder. It is also effective to add the above-mentioned calcium carbonate to the above-mentioned mixture, knead the mixture, and pelletize the mixture. The pellets are processed into a molded body by using a molding machine such as injection molding.

[0021]

【Example】

Examples 1 to 11 and Comparative Examples 1 to 4 Table 1 shows organic acids and other compounds represented by the following abbreviations in 100 parts by weight of a propylene-ethylene block copolymer having an MFR of 10 g / 10 minutes and an ethylene content of 5% by weight. 44m after blending in a ratio and mixing with a Henschel mixer
The long diameter of 25 is obtained by melting with an m-diameter extruder (200 ° C).
Calcium carbonate whiskers having a diameter of .about.35 .mu.m and a short diameter of 1 to 2 .mu.m were mixed, kneaded and granulated to form pellets. The pellets are molded with an injection molding machine (240 ° C) and have a length of 80 m.
A test piece having m, a width of 10 mm and a thickness of 4 mm was molded. Flexural modulus using this test piece (JIS-K7203 compliant)
Was measured. Also, a sheet having a length of 120 mm, a width of 80 mm and a thickness of 2 mm is injection-molded under the same conditions, and the impact energy (DIT) required for destruction by dropping a dart having a diameter of 20 mm on this sheet and the yellowness of the sheet by a color machine. (YI value: JIS-K7103) was measured. The evaluation results are shown in Table 1.

<Contents of Abbreviated Components Used> Organic acid selected from aromatic phosphoric acid, aliphatic saturated dicarboxylic acid and aromatic mono- or dicarboxylic acid A: 2,2'-methylenebis (di-t-butylphenyl) Phosphoric acid B: Succinic acid C: p-t-Butylbenzoic acid D: α-Naphthoic acid E: Cinnamic acid Other compounds F: 3,4,5,6-dibenzo-1,2-oxaphosphane-2 -Oxide

In the above granulation, as a stabilizer,
Tetrakis [methylene-3- (3 ', 5'-di-t-butyl-4'-hydroxyphenyl) propionate] methane (trade name "IR1010") and tris (2,4-)
Di-t-butylphenyl) phosphite (trade name "I
R168 ") to 100 parts by weight of the propylene polymer, 0.11 parts by weight of each of the compositions of Examples 1 to 7 and Comparative Examples 2 and 3, and Examples 8 to 11
And 0.13 parts by weight of each of the compositions of Comparative Example 4 and 0.10 parts by weight of each of the compositions of Comparative Example 1 were added for granulation.

[0024]

[Table 1]

[0025]

EFFECTS OF THE INVENTION The present invention has a remarkable effect that a polyolefin resin composition having an excellent balance of rigidity and impact resistance and an improved hue can be obtained. The effects of the present invention are particularly great in injection-molded articles, and include, for example, automobile bumpers, exterior parts such as instrument panels, interior parts, washing machine panels, home electric appliance parts such as TV housings, injection molding of high-rigidity containers, etc. The body is effective.

Claims (6)

[Claims] 1. A polyolefin resin, 3 to 150 parts by weight of calcium carbonate per 100 parts by weight thereof, and
0.1 to 10% by weight relative to the calcium carbonate of at least one organic acid selected from the group consisting of aromatic phosphoric acid, saturated aliphatic dicarboxylic acid and aromatic mono- or dicarboxylic acid. A characteristic polyolefin resin composition. 2. The composition according to claim 1, wherein the polyolefin resin is a propylene polymer selected from polypropylene, a propylene-ethylene block or random copolymer, and a propylene-ethylene-butene copolymer. 3. The composition according to claim 2, wherein the propylene polymer is a propylene-ethylene block copolymer. 4. The polyolefin resin is MFR1-50.
The composition of claim 1 which is a g / 10 min polyolefin resin. 5. Calcium carbonate having a major axis of 10 to 50 μm
The composition according to claim 1, which is a calcium carbonate whisker having a minor axis of 0.5 to 5 µm. 6. The organic acid is 2,2′-methylenebis (di-t-butylphenyl) phosphoric acid, succinic acid, benzoic acid,
The composition according to claim 1, which is t-butylbenzoic acid, α-naphthoic acid, β-naphthoic acid or cinnamic acid.