JP3605461B2 - Resin composition - Google Patents

Description

【図面の簡単な説明】
【図１】本発明の洗濯機排水パンの代表的形状を示す斜視図である。
【符号の説明】
１ 洗濯機排水パン
２ 補強用リブ
３ 排水穴[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a novel resin composition. Specifically, the resin composition is excellent in rigidity, impact resistance, surface scratch resistance, gloss, and good in chemical resistance, and is suitable for molding a molded article, particularly a washing machine drain pan.
[0002]
[Prior art]
Conventionally, acrylonitrile-butadiene-styrene resin (hereinafter abbreviated as ABS resin) is generally used as a material resin used for molding a washing machine drain pan. This ABS resin has appropriate rigidity, impact resistance, and gloss.
[0003]
Therefore, the drain pan made of ABS resin is free from deformation and cracking when a washing machine is installed, is resistant to impact, has good gloss, and is excellent in product appearance.
[0004]
However, since the above-mentioned ABS resin is generally a resin having poor chemical resistance, a washing machine drain pan using the same may be deteriorated in mechanical properties such as rigidity and impact resistance when an acidic cleaning agent is used during cleaning. In the worst case, yellowing and inconvenience such as cracks occur. In addition, there is also a problem that, when the contact is made with soft vinyl chloride which is generally used for covering the feet of a washing machine for a long time, the contact surface is melted and cracks occur due to the vibration of the washing machine.
[0005]
It has also been proposed to use polypropylene as the resin for the washing machine drain pan.
[0006]
[Problems to be solved by the invention]
However, there has been no study on the optimal polypropylene resin having the above-mentioned properties required for such applications, and there is no propylene homopolymer or propylene ethylene block having low crystallinity used in ordinary molding. Only polymers are shown.
[0007]
And the above polypropylene is not sufficient in the above-mentioned rigidity and the balance of impact resistance and physical properties such as surface scratch resistance and gloss, and furthermore, at the time of chemical resistance test, yellowing occurs or various physical properties decrease. In some cases, this was not enough for practical use as a resin material for a washing machine drain pan.
[0008]
Accordingly, an object of the present invention is to provide a resin composition which is excellent in rigidity, impact resistance, surface scratch resistance, gloss, and chemical resistance, and is particularly suitable as a molding material for a washing machine drain pan. It is in.
[0009]
[Means for Solving the Problems]
The present inventors have conducted intensive studies on the above-mentioned problems, and as a result, a resin composition comprising a specific propylene ethylene block copolymer and a nucleating agent satisfied all of the above characteristics, and was used as a material resin for a washing machine drain pan. The present invention has been found to be extremely useful, and the present invention has been completed.
[0010]
That is, the present invention is a resin composition for a washing machine drain pan comprising 100 parts by weight of a highly crystalline propylene ethylene block copolymer and 0.01 to 3.0 parts by weight of a nucleating agent.
[0011]
As the highly crystalline propylene ethylene block copolymer used in the present invention, known ones can be used without any limitation as long as they are highly crystalline.
[0012]
Highly crystalline propylene ethylene block copolymer, the isotactic pendat fraction of the boiling heptane insoluble portion used as an index of the crystallinity of polypropylene is 0.96 or more , more preferably 0.965 or more is suitable. is there. Here, the isotactic pentad fraction of the boiling heptane-insoluble portion refers to the boiling heptane-insoluble portion of polypropylene as defined by A.I. According Zambelli et al method published by (Macromolecules 6 925 1973), propylene monomer units with a pen Dutt units in the polypropylene molecule 5 contiguous to measure the fraction of propylene monomer units in the center of the chain that meso bound value Say.
[0013]
In addition, the boiling heptane insoluble portion of the polypropylene is, for example, after completely dissolving the polymer in boiling xylene, the temperature is lowered to 20 ° C. and allowed to stand still, then the insoluble portion is separated and filtered, and the insoluble portion is dried. And boiling heptane extraction in a Soxhlet extraction tube.
[0014]
The ethylene content of this highly crystalline propylene ethylene block copolymer is preferably in the range of 1 to 10% by weight because the balance between rigidity and impact resistance is excellent.
[0015]
Further, the propylene ethylene block copolymer may contain an α-olefin such as 1-butene, 1-pentene, and 4-methylpentene-1 as long as the effects of the present invention are not impaired.
[0016]
In the present invention, the fluidity of the highly crystalline propylene ethylene block copolymer is not particularly limited, but the melt flow rate (hereinafter, also abbreviated as MFR) is considered in consideration of moldability, rigidity, and impact resistance. It is preferably 0.1 to 80 g / 10 min. Here, the melt flow rate is a value at a cylinder temperature of 230 ° C. according to JIS K7210.
[0017]
In the present invention, such a highly crystalline propylene ethylene block copolymer may be obtained by any method. Generally, it is a Ziegler-Natta type stereospecific catalyst, and a catalyst comprising a titanium compound supported on magnesium chloride or a titanium trichloride compound and an organoaluminum compound is used.
[0018]
As the titanium compound, a known compound used for polymerization of an olefin is employed without any limitation. In particular, a titanium compound containing titanium, magnesium and halogen as components and having a high catalytic activity and capable of obtaining a highly crystalline polymer is preferable. Examples of such a titanium compound include titanium halides, particularly titanium tetrachloride supported on various magnesium compounds. As a method for producing the catalyst, a known method is employed without any limitation. For example, a method of co-milling titanium tetrachloride with a magnesium compound such as magnesium chloride, a method of co-milling a titanium halide and a magnesium compound in the presence of an electron donor such as alcohol, ether, ester, ketone or aldehyde, or a solvent. And a method in which a titanium halide, a magnesium compound and an electron donor are brought into contact with each other.
[0019]
Next, as the organoaluminum compound, a known compound used for olefin polymerization can be used without any limitation. For example, alkyl aluminums such as trimethyl aluminum, triethyl aluminum and tri-n-propyl aluminum; halogen-containing alkyl aluminums such as ethyl aluminum sesquichloride and diethyl aluminum chloride can be used.
[0020]
Further, in order to enhance the crystallinity of the obtained polymer, it is preferable to use an electron donor in addition to the titanium compound and the organoaluminum compound. Examples of the electron donor include ether, amine, amide, sulfur-containing compound, nitrile, carboxylic acid, acid amide, acid anhydride, acid ester, and organosilicon compound. Of these, organosilicon compounds are most preferred.
[0021]
In the above polymerization method, polymerization may be performed in either a gas phase or a liquid phase. Further, it may be polymerized in an inert liquid or an inert solvent with respect to the catalyst.The polymerization may be performed by introducing hydrogen during polymerization, or the obtained polymer may be adjusted with a molecular weight regulator such as an organic peroxide. Degraded ones may be used. Further, the polymerization can be carried out by any of a batch system, a semi-batch system, and a continuous system.
[0022]
The polymerization conditions are not particularly limited as long as the effects of the present invention are recognized, and known conditions can be employed. For example, the polymerization temperature ranges from 20 to 200 ° C, preferably from 50 to 150 ° C. Further, the polymerization can be carried out in two or more stages under different conditions.
[0023]
In the present invention, the highly crystalline propylene ethylene block copolymer may be used as a mixture with another resin as long as the effects of the present invention are not impaired. Such other resins include, in addition to ordinary polypropylene, homopolymers of α-olefins such as ethylene, 1-butene, 1-pentene and 4-methylpentene-1, or block copolymers of these α-olefins and propylene. Polymers or random copolymers are preferred. In this case, such other resin is suitably blended in an amount of 40 parts by weight or less, preferably 25 parts by weight or less, based on 100 parts by weight of the highly crystalline propylene ethylene block copolymer.
[0024]
In the present invention, known nucleating agents can be used without any limitation. Specifically, carboxylate metal salts such as aluminum benzoate, potassium benzoate, sodium benzoate, lithium benzoate, Al-p-butylbenzoate, sodium β-naphthoate, sodium cyclohexanecarboxylate and sodium cyclopentanecarboxylate Compounds: sodium bis (4-t-butylphenyl) phosphate, lithium bis (4-t-butylphenyl) phosphate, aluminum bis (4-t-butylphenyl) phosphate, bis (4-t-butylphenyl) phosphate -Butylphenyl) phosphate calcium salt, magnesium bis (4-t-butylphenyl) phosphate, sodium 2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate, 2,2 ′ -Methylene-bis (4,6-di-t-butylphenyl) lithium phosphate, 2,2′-methylene Aluminum bis- (4,6-di-t-butylphenyl) phosphate, calcium 2,2′-methylidene-bis (4,6-di-t-butylphenyl) phosphate, 2,2′-methylidene-bis Magnesium (4,6-di-t-butylphenyl) phosphate, Sodium 2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, 2,2′-ethylidene-bis Lithium (4,6-di-t-butylphenyl) phosphate, aluminum 2,2′-ethylidene-bis (4,6-di-t-butylphenyl) phosphate, bis- (4-t-butyl) Phenyl) phosphate calcium salt, bis- (4-t-butylphenyl) magnesium phosphate, etc .; aromatic metal phosphate compounds; dibenzylidenesorbitol, 1.3,2.4-di (methylbenzylidene) Rubitol, 1.3, 2.4-di (ethylbenzylidene) sorbitol, 1.3, 2.4-di (butylbenzylidene) sorbitol, 1.3, 2.4-di (methoxybenzylidene) sorbitol, 1.3 , 2.4-di (ethoxybenzylidene) sorbitol, 1.3-chlorobenzylidene, 2.4-methylbenzylidene sorbitol, mono (methyl) dibenzylidene sorbitol and other dibenzylidene sorbitol compounds; silica, titanium dioxide, carbon black, Inorganic compounds such as talc, mica, alum, pigments and the like can be mentioned. Among them, Al-p-butylbenzoate, 2,2′-methylene-bis (4,6-di-t-butylphenyl) phosphate metal salt, 1.3,2.4-di (methylbenzylidene) The use of sorbitol or the like is most suitable for achieving the object of the present invention.
[0025]
In the present invention, the compounding amount of the nucleating agent is 0.01 to 3.0 parts by weight based on 100 parts by weight of the highly crystalline propylene ethylene block copolymer, and among them, 0.05 to 1. 0 parts by weight is particularly preferred. That is, when the nucleating agent is less than 0.01 part by weight, the rigidity is insufficiently developed, and when the nucleating agent exceeds 3.0 parts by weight, the effect is flattened out and it is not economical. The above nucleating agents may be used alone or in combination of two or more.
[0026]
The high crystalline propylene ethylene block copolymer composition used in the present invention contains, in addition to the above components, wollastonite, barium sulfate, calcium carbonate, an inorganic filler such as glass, preferably barium sulfate. You may mix. Here, two or more fillers may be used in combination. Further, in the use of the above-mentioned inorganic filler, the use of barium sulfate as one component can improve the rigidity and gloss of the product, and is preferable in the present invention. The amount of the inorganic filler is preferably 0.1 to 15 parts by weight based on 100 parts by weight of the highly crystalline propylene ethylene block copolymer.
[0027]
In addition, various additives can be appropriately added to the resin composition of the present invention to such an extent that the effects of the present invention are not impaired. Specifically, phenol, organic phosphite, organic phosphorus-based, such as host scan Honaito, antioxidants thioether like; heat stabilizers hindered amine and the like; benzophenone, benzotriazole, ultraviolet ray absorbing benzoate etc. agents; nonionic, cationic, antistatic agents anionic like; bisamide, wax, dispersant of the organic metal salt-based and the like; chlorinated capturing 捉 agent of the carboxylic acid salt and the like alkaline earth metal salts; amide , Wax-based, organic metal salt-based, ester-based lubricants; oxide-based, hydrotalcite-based, etc. decomposers; hydrazine-based, amine-based, etc. metal deactivators; bromine-containing organic, phosphoric, and trioxide Flame retardants such as antimony, magnesium hydroxide, and red phosphorus; organic pigments; foaming agents; organic fillers; and inorganic and organic antibacterial agents such as metal ions.
[0028]
In the present invention, the above-mentioned components can be blended by any ordinary method used for mixing resins without any limitation. For example, after adding the component (b) and, if necessary, other additive components to the powder or pellet-shaped component (a) and mixing them with a tumbler or Henschel mixer, the mixture is melt-kneaded with an extruder. A method of forming pellets or the like is preferable. The order of addition of each component is not particularly limited, and each component may be mixed in a different order from the above method. Furthermore, a masterbatch in which each component is concentrated and blended at a high concentration can be prepared and mixed and used.
[0029]
In the present invention, the above-mentioned highly crystalline propylene ethylene block copolymer and nucleating agent are used as essential components, and a resin composition in which these are blended in a specific ratio is used as a material resin of a washing machine drain pan, whereby rigidity is improved. This makes it possible to provide a washing machine drain pan having a good balance between the water and the impact resistance, and also having excellent surface scratch resistance, glossiness and chemical resistance.
[0030]
As a method of molding the resin composition of the present invention into a washing machine drain pan, any method such as injection molding, press molding, extrusion molding, and stampable molding may be employed. Usually, it is common to mold by injection molding. This injection molding may be performed by any method such as single-axis injection, multi-axis injection, high-pressure injection, low-pressure injection, gas-assisted injection, melt core molding, insert molding, core back molding, two-color molding, and foam molding. The shape of the washing machine drain pan to be formed is not particularly limited, and may be any known shape. For example, FIG. 1 is a partial sectional view showing a typical structure of a washing machine drain pan. In the figure, reference numeral 1 denotes a main body, which is formed of a flat plate having a weir around it. In addition, a drain port 3 is provided in the flat plate. Further, the weir generally has a hollow structure, and in this case, reinforcing ribs 2 are provided at a plurality of locations at intervals.
[0031]
【The invention's effect】
The resin composition of the present invention has excellent characteristics such as excellent rigidity, impact resistance, surface scratch resistance, gloss, and good chemical resistance due to the above constitution.
[0032]
Therefore, the washing machine drain pan molded from the resin composition of the present invention sufficiently satisfies all the properties such as rigidity, impact resistance, surface scratch resistance, and gloss required for the molded article. . Furthermore, since it is excellent in chemical resistance, the above-mentioned properties are effectively maintained even when it comes into contact with soft vinyl chloride used for cleaning with a detergent or covering the feet of a washing machine.
[0033]
【Example】
Hereinafter, examples will be described in order to more specifically describe the present invention, but the present invention is not limited to these examples.
[0034]
(1) Isolating the boiling heptane insoluble portion in isotactic pentad fraction After completely dissolving in boiling xylene, the temperature was lowered to 20 ° C. and allowed to stand still for 4 hours. Thereafter, the insoluble portion was separated and filtered, and the insoluble portion was dried. Thereafter, boiling heptane extraction was performed for 8 hours in a Soxhlet extraction tube, and the obtained insoluble portion was subjected to A. According to the method published by Zambelli et al. (Macromolecules 6 925 1973), the fraction of propylene monomer units at the center of a chain of five meso-bonded propylene monomer units in pentad units in a polypropylene molecule was determined.
[0035]
(2) Ethylene content
It calculated using the chart of the < ¹³ > C-NMR spectrum. That is, the percentage of the monomer unit based on ethylene was determined by first determining the assignment of the peak by the method described in Polymer, Vol. 29, Item 1848 (1988), and then Macromolecules, Volume 10, Item 773. (1977).
[0036]
(3) MFR
The measurement was performed according to JIS K7210.
[0037]
(4) Glossiness The resin sample was molded into a flat plate of 80 mm × 50 mm × 3 mm by an injection molding machine, and the glossiness of the flat plate was measured at an incident angle of 60 ° and a light receiving angle of 60 ° according to JIS K7105.
[0038]
(5) in the bottom surface of the static load test washing machine drain pan of the washing machine drain pan, diameter 30mm was stuck rubber thickness 3 mm, place the stainless steel cylinder of height 50 mm, a load of 100kg thereon 10 after applying minutes, to observe the presence or absence of abnormality of the drain pan bottom surface. The evaluation was performed in the following three-step evaluation.
[0039]
；: No abnormality.
[0040]
Δ: Some whitening is observed.
[0041]
X: Remarkable whitening and cracks are observed.
[0042]
(6) Dropping weight impact test of washing machine drain pan According to JIS K7211, a 1 kg weight was dropped on the lower surface of the washing machine drain pan, and the 50% breaking height was measured.
[0043]
(7) in the washing machine drain pan bottom surface in an atmosphere of contacting a test temperature 50 ° C. of a soft vinyl chloride, place the soft vinyl chloride 50 mm × 50 mm × thickness 3 mm, carrying a load of 1kg thereon, after 10 days The surface change was observed. The evaluation was performed in the following three-step evaluation.
[0044]
；: No change.
[0045]
Δ: Slight skin roughness is observed.
[0046]
X: remarkable rough skin is observed.
[0047]
(8) Pencil hardness According to JIS K5401, the pencil hardness was measured when the surface of the molded product had a scratch of 3 μm or more in depth.
[0048]
Example 1
100 parts by weight of a highly crystalline propylene ethylene block copolymer having an isotactic pentad fraction of 0.970, an ethylene content of 3.8 wt% and an MFR of 15 g / 10 min, and Al-p-butyl benzoate 0.3 part by weight parts, hindered phenol antioxidant 0.04 part by weight, were blended and a Fosufai preparative antioxidant 0.04 part by weight, and the content of 1.3 parts by weight of the ivory-based, sufficiently stirred and mixed in a Henschel mixer went. Thereafter, the mixture was melt-kneaded by an extruder having a cylinder temperature set to 230 ° C. to obtain pellets of a highly crystalline propylene ethylene block copolymer composition. The MFR and gloss of this highly crystalline propylene ethylene block copolymer composition were measured, and the results are shown in Table 1.
[0049]
Next, injection molding was performed using the above-mentioned highly crystalline propylene ethylene block copolymer composition to prepare a standard type washing machine drain pan as shown in FIG. In addition, this washing machine drain pan has a length of 900 mm, a width of 640 mm, a height of 85 mm, a thickness of a bottom plate of 4 mm, and a rib having a height of 7 mm and a thickness of 1 mm on a low surface, and a length of 60 mm in a length direction. They are provided at a pitch of 30 mm in the pitch and width directions. The obtained washing machine drain pan was subjected to a static load test, a falling weight impact test, a contact test with soft vinyl chloride, and a pencil hardness measurement. The results are also shown in Table 1.
[0050]
Examples 2 and 3, Comparative Example 1
The same test as in Example 1 was performed, except that the isotactic pentat fraction of the highly crystalline propylene ethylene block copolymer composition was changed as shown in Table 1. The results are shown in Table 1.
[0051]
Examples 4 to 6, Comparative Example 2
A test similar to that of Example 1 was performed, except that the type and amount of the nucleating agent were changed as shown in Table 1. The results are shown in Table 1.
[0052]
Comparative Example 3
In Example 1, the same test as in Example 1 was performed except that the ABS resin was used. The results are shown in Table 1.
[0053]
[Table 1]

[Brief description of the drawings]
FIG. 1 is a perspective view showing a typical shape of a washing machine drain pan of the present invention.
[Explanation of symbols]
1 Washing machine drain pan 2 Reinforcing rib 3 Drain hole

Claims (1)

A resin composition for a washing machine drain pan comprising 100 parts by weight of a highly crystalline propylene ethylene block copolymer and 0.01 to 3.0 parts by weight of a nucleating agent.

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