JPH0315667B2 - - Google Patents

Description

[Detailed description of the invention]

The present invention relates to an inorganic filler-containing resin composition with improved impact strength at low temperatures and stiffness at room and high temperatures. An inorganic filler-containing resin composition comprising one or more nucleating agents selected from acids, aliphatic dicarboxylic acids having 4 to 12 carbon atoms, aromatic phosphinic acids and their metal salts, and dibenzylidene sorbitol. . Conventionally, it is well known that inorganic fillers are added to polypropylene resins to improve rigidity, heat resistance, dimensional stability, etc., but impact strength, particularly impact strength at low temperatures, is significantly reduced. Among polypropylene resins, even in compositions in which an inorganic filler is blended with a propylene-ethylene block copolymer resin having excellent impact strength, the impact strength is significantly reduced. As a method of improving impact strength, adding a rubbery substance to polypropylene resin is a well-known method, but this system has the drawback of lowering rigidity and heat resistance. In addition, as a method for improving impact strength without reducing rigidity, the three components mentioned above, namely, polypropylene resin, rubbery substances such as propylene-ethylene copolymer rubber, and inorganic fillers such as talc and calcium carbonate, have been proposed. It is also possible to combine
64256, 53-64257, etc. However, in this case, there was a problem in that the effect of improving rigidity by blending the inorganic filler was significantly reduced due to the addition of the rubbery substance. Furthermore, in order to significantly improve the impact strength, especially the impact strength at low temperatures, it is necessary to increase the proportion of rubbery substances blended, which further significantly reduces the rigidity and heat resistance properties, and the polypropylene resin There was a problem in that it was no longer able to exhibit the good performance that it had. The present inventors have conducted various studies on methods for minimizing the above-mentioned problems in the prior art, improving impact strength at low temperatures, and improving rigidity at room and high temperatures.
By blending polypropylene resin, rubber-like material, inorganic filler, and nucleating agent in specific proportions, impact strength at low temperatures and rigidity at room and high temperatures are simultaneously improved, and heat resistance properties are also improved. I found out that it can be done. Therefore, the present invention uses polypropylene resins of 30 to 90
Parts by weight, 5 to 50 parts by weight of rubbery substance, 3 parts by weight of inorganic filler
~40 parts by weight and one or two selected from aromatic sulfonic acids, aromatic carboxylic acids, aliphatic dicarboxylic acids having 4 to 12 carbon atoms, aromatic phosphinic acids and their metal salts, and dibenzylidene sorbitol The above nucleating agent (here, the amount of the nucleating agent added is 0.01 to 5 parts by weight per 100 parts by weight of the total amount of the polypropylene resin and the rubbery substance).
An inorganic filler-containing resin composition characterized by improved impact strength at low temperatures and stiffness at room and high temperatures. The features of the present invention are that it has a high impact strength that cannot be obtained with a mixture of polypropylene resin and an inorganic filler, a high degree of rigidity that cannot be obtained with a mixture of polypropylene resin and a rubbery substance, and The advantage is that a composition with an excellent balance of impact strength and rigidity at low temperatures and excellent heat resistance properties, which could not be obtained even with a mixture of a polypropylene resin, a rubber-like substance, and an inorganic filler, can be obtained. The fact that by adding the nucleating agent of the present invention to a system containing an inorganic filler as in the present invention, the impact strength at low temperatures is improved and the rigidity at room temperature and high temperature is also improved. This cannot be predicted using known technology. Among them, even when using talc, which itself is said to have a nucleating effect, as an inorganic filler, by adding the nucleating agent shown in the present invention,
It was completely unexpected that a composition with further improved performance would be obtained. Another feature is that conventionally, when painting polypropylene resin, special pretreatment was required, and even with pretreatment, the adhesion of the coating film was not sufficient, but the composition of the present invention can be used. In the system, a resin composition with excellent coating film adhesion can be obtained without special pretreatment. In this manner, the present invention provides a resin composition that improves the paintability of polypropylene resins, which has been difficult to achieve in the past, and also improves the physical properties of the material. The propylene polymer used in the present invention includes a propylene homopolymer with high stereoregularity, a propylene-ethylene block copolymer,
These are copolymers of propylene and other olefins such as propylene-ethylene random copolymers, propylene-butene-1 block or random copolymers. In particular, propylene homopolymer with a melt index of 0.5 to 50 or a melt index of 0.5 to 30,
A propylene-ethylene block copolymer having an ethylene content of 30% by weight or less is preferred. The rubbery substances used in the present invention include ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, ethylene-1
-butene copolymer rubber, ethylene-isobutyl copolymer rubber, polyisobutylene, polyisoprene, polybutadiene, styrene-butadiene random copolymer rubber, styrene-butadiene block copolymer rubber, natural rubber, atactic polypropylene and mixtures thereof. Particularly preferred are ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, and styrene-butadiene block copolymer rubber. The inorganic fillers used in the present invention include commonly used calcium carbonate, talc, clay, silica, magnesium carbonate, barium sulfate,
Titanium oxide, alumina, gypsum, etc., and the particle size is
0.05-10μ is preferable. The inorganic filler may be used without treatment, but in order to improve interfacial adhesion with polypropylene resin and improve dispersibility, various commonly known silane coupling agents and titanium coupling agents may be used. Those whose surfaces have been treated with a ring agent, higher fatty acids, higher fatty acid esters, higher fatty acid amides, higher fatty acid salts, or other surfactants can be used. Alternatively, these processing agents may be added directly to the mixture. Inorganic fillers vary depending on the shape and mechanical properties required of the product.
The type, particle size, and amount added are selected. The proportion of the propylene polymer, rubbery substance, and inorganic filler used in the present invention is 30 to 90 parts by weight, preferably 35 to 80 parts by weight, and more preferably 40 parts by weight. ~70 parts by weight, the rubbery material is 5 to 50 parts by weight, preferably 10 to 45 parts by weight, more preferably 25 to 45 parts by weight, and the inorganic filler is 3 to 40 parts by weight, preferably 5 parts by weight. ~30 parts by weight. If the propylene polymer is less than 30 parts by weight, the rubbery substance is more than 50 parts by weight, or the inorganic filler is less than 3 parts by weight, the rigidity and heat resistance properties will be greatly reduced, The properties of propylene polymers cannot be expressed, and propylene polymers
If it is more than 90 parts by weight, the rubbery substance is less than 5 parts by weight, or the inorganic filler is more than 40 parts by weight, the impact strength at low temperatures will decrease significantly,
A composition having the high level of performance aimed at by the present invention cannot be obtained. Nucleating agents used in the present invention include commonly used aromatic sulfonic acids, aromatic carboxylic acids, aliphatic dicarboxylic acids having 4 to 12 carbon atoms, aromatic phosphinic acids and their metal salts, and One or more types selected from dibenzylidene sorbitol, specifically the compounds shown below. Although some inorganic compounds have a nucleating effect, they cannot provide the high level of performance aimed at by the present invention. Further, higher fatty acids and metal salts thereof, which are often used as lubricants, cannot provide the high performance aimed at by the present invention. Aromatic sulfonic acids and their metal salts include:
Compounds having a sulfonic acid group on an aromatic ring, such as benzenesulfonic acid and naphthalenesulfonic acid, and salts of these metals belonging to group 1 of the periodic table of elements. Specifically, α-naphthalenesulfonic acid, Na , Mg, Ca, Al salt; Na salt of 8-aminonaphthalenesulfonic acid; Na, Mg, Ca, Al salt of benzenesulfonic acid; Ca, Mg salt of 2,5-diclobenzenesulfonic acid; m-xylene sulfonic acid There are Ca and Mg salts. Aromatic carboxylic acids and their metal salts include:
Benzoic acid, allyl-substituted acetic acid, aromatic dicarboxylic acids, and salts of these metals belonging to Group 1 of the Periodic Table of Elements. Specifically, benzoic acid, p
-isopropylbenzoic acid, o-tertiary butylbenzoic acid, p-tertiary butylbenzoic acid, monophenylacetic acid, diphenylacetic acid, phenyldimethylacetic acid,
Phthalic acid or these acids Li, Na, Mg,
There are Ca, Ba, and Al salts. As aliphatic dicarboxylic acids having 4 to 12 carbon atoms,
Succinic acid, glutaric acid, adipic acid, suberic acid, sebacic acid or Li, Na,
There are Mg, Ca, Ba, and Al salts. Examples of aromatic phosphinic acids and metal salts thereof include those represented by the following general formula. (In this formula, Ar and Ar' are aromatic rings such as phenyl and naphthyl, M is hydrogen and a metal element, n is l when M is hydrogen, and its valence when M is a metal.) Representative metals constituting the metal salt of aromatic phosphinic acid include Li, Na, K, Ca, Mg, and Al. Specifically, diphenylphosphinic acid, lithium diphenylphosphinate,
Sodium diphenylphosphinate, potassium diphenylphosphinate, calcium diphenylphosphinate, magnesium diphenylphosphinate, aluminum diphenylphosphinate, etc.;
4,4'-dichlorodiphenylphosphinic acid, 4,
4'-dimethyldiphenylphosphinic acid, dinaphthylphosphinic acid and their Li, Na, K,
Examples include Ca, Mg, and Al salts. Among the above nucleating agents, aromatic carboxylic acids and metal salts, particularly p-tertiary butylbenzoic acid and its aluminum salt are preferred. These nucleating agents can be used alone or in combination of two or more. These nucleating agents are based on the total amount of polypropylene resin and rubbery material.
0.01 to 5 parts by weight, preferably 0.05 to 5 parts by weight per 100 parts by weight are commonly used, especially 0.1 parts by weight.
It is preferable to use ~1 part by weight. The composition of the present invention can be produced using a single screw extruder, a twin screw extruder,
It can be manufactured using a kneading machine such as a Banbury mixer or a hot roll. The components may be mixed simultaneously or in batches. Batch addition methods include, for example, adding other components after kneading polypropylene resin and a nucleating agent, adding other components to a kneaded mixture of polypropylene resin and rubber-like material, and polypropylene resin. Examples include a method in which a high concentration inorganic filler is used as a master patch in advance and other components are added. The temperature required for kneading is 160 to 240°C, and the time required for kneading is 30 seconds to 20 minutes. Furthermore, in addition to these basic ingredients, when kneading these, stabilizers such as antioxidants and ultraviolet absorbers, lubricants, pigments,
Additives such as antistatic agents, copper damage inhibitors, and flame retardants can be added. The composition obtained by the present invention can be injection molded,
It can be extruded or blow molded, and has significantly improved impact strength, rigidity, and heat resistance at low temperatures, as well as improved paintability, so it can be used as an engineering plastic for various automobile parts materials, electrical product parts materials, etc. can do. The content of the present invention will be specifically explained below with reference to Examples, but the scope is not limited thereto. Physical properties of the composition of the present invention were evaluated using bending elastic modulus for stiffness, Izot impact strength (notched) for impact strength, and heat distortion temperature and thermal sag for heat resistance properties.The measurement methods were as follows. Flexural modulus: Performed in accordance with ASTM D790,
Measurement temperatures were 20°C and 80°C. Izod impact strength: Conducted in accordance with JIS K7110, and measured at -30°C. Heat resistance properties: Heat distortion temperature; conducted in accordance with ASTM D648. The fiber stress was 4.6Kg/cm ² . Thermal sagging: A test piece with a length of 120 mm, a width of 20 mm, and a thickness of 2 mm was prepared, one end of the test piece was fixed, and after being left in an atmosphere of 100°C for 2 hours, it was taken out and the unfixed end was fixed. The degree of sagging was measured. Example 1 A propylene-ethylene block copolymer (block pp) having a melt index of 9.0 and an ethylene content of 7% by weight, a Mooney viscosity of 60 at 100°C and an ethylene content of 50% by weight, Ethylene-propylene-ethylidenenorbornene copolymer rubber (EPDM) with an iodine value of 11 and Chilk with an average particle size of 3μ are mixed in the proportions shown in Table 1,
Furthermore, 0.5 parts by weight of aluminum salt of para-tertiary butylbenzoic acid as a nucleating agent per 100 parts by weight of the block copolymer and copolymer rubber, and Irganox 1010 (manufactured by Ciba Geigy) as an antioxidant were added to the total weight of the block copolymer and copolymer rubber. Add 0.5% by weight and use a Banbury mixer.
After kneading at 190°C for 10 minutes, the mixture was pelletized using an extruder. The pellets were molded into test pieces for measuring physical properties using a screw in-line injection molding machine. Table 1 shows the physical property measurement results. Comparative Example 1 The same procedure as in Example 1 was carried out except that aluminum salt of para-tertiary butylbenzoic acid was not added as a nucleating agent. The results are shown in Table 1. As is clear from Table 1, by adding the nucleating agent, the flexural modulus at 20°C is improved, and the impact strength at -30°C is also improved, resulting in a better balance of material properties. The flexural modulus at 80°C and heat resistance properties are also improved.

[Table] Example 2 and Comparative Example 2 A resin composition was prepared in exactly the same manner as in Example 1, except that the inorganic filler in Example 1 was changed from talc to heavy calcium carbonate with an average particle size of 1μ. Obtained. The physical properties of the obtained composition were also measured in the same manner as in Example 1. The results are shown in Table 2. In this case as well, the material properties are improved by adding a nucleating agent.

【table】

[Table] Example 3 and Comparison 3 A propylene-ethylene block copolymer (block PP) with a melt index of 2.5 and an ethylene content of 15% by weight in the resin, and a Mooney viscosity of 45 at 100°C, Ethylene content 47% by weight,
Ethylene-propylene copolymer rubber (EPM) with an iodine value of 0 and talc with an average particle size of 1μ are mixed into a third
A resin composition was obtained in the same manner as in Example 1, except that the ingredients were mixed in the proportions shown in the table. Table 3 shows the physical properties of the obtained composition. Examples 4 and 5 and Comparative Examples 4 and 5 A propylene homopolymer (homo PP) with a melt index of 12.0 and a Mooney viscosity of 60 at 100°C
The ethylene content is 50% by weight and the iodine value is 11.
Ethylene-propylene-ethylidene norbornene copolymer rubber (EPDM) with an average particle size of 3μ
A resin composition was obtained in the same manner as in Example 1, except that talc or heavy calcium carbonate having an average particle size of 1 μm was mixed in the proportions shown in Table 3. Table 3 shows the physical properties of the obtained composition. From Table 3, it can be seen that the material properties are clearly improved by adding the nucleating agent.

[Table] Example 6 and Comparative Example 6 In Example 2-2, the rubbery material was replaced with EPDM.
A resin composition was obtained in the same manner as in Example 2-2, except that styrene-butadiene-styrene block copolymer rubber (styrene 28% by weight, molecular weight 75,000) was used. The physical properties of the obtained compositions are shown in Table 4. Even if the rubbery substance is changed, the physical properties of the material are improved by adding a nucleating agent.

【table】

[Table] Examples 7, 8 and Comparative Example 7 In Example 1-2, the nucleating agent was changed from aluminum salt of para-tertiary butylbenzoic acid to Example 7.
The same method as in Example 1-2 was used, except that sodium benzenesulfonate was used in Example 8, dibenzylidene sorbitol was used in Example 8, and calcium stearate as a lubricant was used in place of the nucleating agent in Comparative Example 7. A resin composition was obtained. The physical properties of the resulting composition are shown in Table 5. Calcium stearate, which is generally well known as a lubricant, does not exhibit the effect of improving material properties that is featured in the present invention.

[Table] Comparative Examples 8 and 9 For comparison, in Examples 1 to 8, talc was not used (Comparative Example 8) and EPDM
Even in the case where no component was used (Comparative Example 9), a resin composition was obtained by mixing in the same manner as in Example 1. The results are shown in Table 6. From Table 6, when talc is not used, the rigidity and impact strength at -30°C are low, and the heat resistance properties are also poor. Furthermore, when EPDM is not used, although the rigidity is improved, the impact strength at -30°C is significantly reduced.

[Table] Example 9 In order to examine the coating properties of the resin compositions obtained in the present invention, the compositions obtained in Examples 1-1 to 1-3 and, for comparison, the compositions in Comparative Examples 8 and 9 were used. The resulting composition was subjected to a coating performance test using the method described below. Paintability test method: First, an ethylene-vinyl acetate copolymer primer ("RB-196" manufactured by Nippon B Chemical Co., Ltd.) was spray-painted on a test plate measuring 90 mm in length, 90 mm in width, and 2 mm in thickness, and then, A urethane top coat (RB-263 manufactured by Nippon B Chemical Co., Ltd.) was spray-painted to a film thickness of 40 microns. After being left for 10 minutes, it was baked at 80°C for 40 minutes. The adhesion of the paint was determined by the number of peeled marks after leaving it for 3 days, making 100 dots on the paint film and peeling them off with cellophane tape.

[Table] As shown in Table 7, the coating film adhesion of the paint to the resin composition obtained according to the present invention is superior to that of the comparative example.

[Brief explanation of the drawing]

Figure 1 shows Examples 1-1 to 1-3 and Comparative Example 1.
Flexural modulus at 20℃ and -30 in -1 to 1-3
The graph shows the relationship between the Izot impact strength and the Izot impact strength at ℃. This figure shows that the balance between stiffness and Izot impact strength at low temperatures is improved by adding a nucleating agent. A... Shows a comparison between Example 1-1 and Comparative Example 1-1, B... Shows a comparison between Example 1-2 and Comparative Example 1-2, C... Shows a comparison between Example 1-3 and Comparative Example 1 -3 comparisons are shown.

Claims (1)

[Scope of Claims] 1 30 to 90 parts by weight of polypropylene resin, 5 to 50 parts by weight of rubbery material, 3 to 40 parts by weight of inorganic filler, aromatic sulfonic acid, aromatic carboxylic acid, carbon number 4 to 50 parts by weight One or more nucleating agents selected from 12 aliphatic dicarboxylic acids, aromatic phosphinic acids and their metal salts, and dibenzylidene sorbitol (per 100 parts by weight of the total amount of polypropylene resin and rubbery substance) (0.01 to 5 parts by weight) of an inorganic filler-containing resin composition. 2. The resin composition according to claim 1, wherein the polypropylene resin is a propylene homopolymer and/or a propylene-ethylene block copolymer. 3. The resin composition according to claim 1, wherein the rubbery substance is ethylene-propylene copolymer rubber, ethylene-propylene-nonconjugated diene copolymer rubber, and/or styrene-butadiene block copolymer rubber. 4. The resin composition according to claim 1, wherein the inorganic filler is talc and/or calcium carbonate. 5. The resin composition according to claim 1, wherein the nucleating agent is p-tertiary butylbenzoic acid or an aluminum salt thereof.