JP2003105144A - Resin molded parts and toilet seat parts - Google Patents

Abstract

(57) [Summary] [PROBLEMS] To form a large-sized thin-walled product requiring flame retardancy without causing molding defects such as generation of silver streaks even if molding is performed in a product having a portion such as a convex portion. Provided is a resin molded product comprising a flame-retardant polypropylene resin composition suitable as a material or the like. SOLUTION: A polypropylene resin molded article containing a flame retardant is molded with a resin composition having physical properties (A) to (C). Physical properties (A): Memory effect (ME) is 1.05
Physical property (B): melt flow index (MFR) from 0.5 to 45; physical property (C): density from 0.90 to 1.02

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin molded product molded from a novel polypropylene-based resin composition, and more particularly, it has excellent moldability and causes molding defects such as silver streak even when molded by fast filling. The present invention relates to a toilet seat component formed of a flame-retardant polypropylene resin molded body.

[0002]

2. Description of the Related Art Conventionally, in order to impart flame retardancy to a polypropylene resin, a brominated flame retardant and antimony trioxide as a flame retardant auxiliary have been combined and blended. Such flame-retardant polypropylene-based resins are widely used in various molded products that require flame retardancy as a general-purpose flame-retardant resin. By the way, even in the case of a molded product requiring flame retardancy, the molded product has a thin shape despite having a complicated shape from the viewpoint of cost and weight reduction. When a flame-retardant resin is used as a material for the large-sized thin-walled molded product or the molded product having a complicated shape, it is molded by a molding method in which it is molded at a high temperature in order to improve fluidity due to a problem of resin flow. However, since the polypropylene-based flame retardant resin is inferior in thermal stability, the flame retardant in the resin is gasified during molding and gas is generated in the flow path. This generated gas is, for example, when there is a convex portion in the shape of the molded product,
Gas accumulates there and the resin cannot contact the surface of the mold, resulting in molding defects such as silver streaks. Also, even if the filling speed is high under the molding conditions, the same problems as described above occur because the gas in the convex portion cannot be completely exhausted,
It was also difficult to deal with molding conditions.

[0003]

DISCLOSURE OF THE INVENTION The present invention is a large-scale product which is required to have flame retardancy without causing molding defects such as silver streak even if it is molded with a product shape having a portion such as a convex portion. The object of the present invention is to provide a resin molded product made of a flame-retardant polypropylene resin composition suitable as a molding material for thin products.

[0004]

Means for Solving the Problems The inventors of the present invention have conducted extensive studies to develop a flame-retardant polypropylene resin composition having the above-mentioned preferable properties.
It has been found that the object can be achieved by making the polypropylene resin composition containing antimony trioxide have a specific property, and the present invention has been completed based on this finding.

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention comprises (I) a polypropylene resin composition having a specific property, (II) a flame retardant, and (I).
II) A resin molded product made of a flame-retardant polypropylene resin composition composed of antimony trioxide which is a flame-retardant aid. Each component will be described in detail below.

The polypropylene resin composition (component (I)) used as component (I) in the flame-retardant polypropylene resin composition of the present invention will be described.

(A) Memory effect (ME: Memory
Effect: Restoration effect) It is important that the flame-retardant polypropylene resin composition of the present invention has a memory effect (ME) of 1.05 to 1.50, preferably 1.10 to 1.35. If the ME exceeds the above range, the warp property becomes poor, while
If the ME is less than the above range, the appearance becomes poor such as the occurrence of silver streak during molding. The measurement of ME is J
The melt indexer used in IS-K7210 is used, the measurement conditions are set to a cylinder temperature of 190 ° C. and a constant speed extrusion rate of 1 g / 10 minutes, and the measurement is carried out as follows. The device is filled with the sample, only the piston is placed and after 6 minutes the prescribed extrusion rate is applied. Next, a graduated cylinder containing ethyl alcohol is placed immediately below the orifice, and a straight extrudate is collected. The diameter (D) of the sampled extrudate was measured with a micrometer, and the orifice diameter of the die was D0.
Then, ME is calculated by the following equation. ME = D / D0

(B) Melt Flow Rate (MFR) The polypropylene resin composition of the present invention has a melt flow rate (MFR) of JIS-K7210 (230 ° C.).
2.16 kg load), a value measured according to
˜45 g / 10 min, preferably 20 to 43 g / 10 min, particularly preferably 30 to 40 g / 10 min. When the MFR of the polypropylene resin composition is less than the above range, the fluidity is insufficient, and a molding machine having a large mold clamping force is required when molding a thin molded product, or
Since it becomes necessary to raise the molding temperature, molding defects such as silver streaks occur. On the contrary, when the MFR of the polypropylene resin composition exceeds the above range, the weld appearance properties are inferior. MF of the polypropylene resin composition
R may be adjusted at the time of polymerization, or adjusted at the time of polymerization with an organic peroxide such as diacyl peroxide or dialkyl peroxide.

(C) Density The polypropylene resin composition of the present invention has a density of 0.90.
~ 1.03. Preferably 1.10 to 1.02
Is important. Density is JIS-K2249
According to. If the density is lower than the above range, the strength will be insufficient, while if the density is higher than the above range, silver will be generated. A highly stereoregular catalyst is used in the production of the polypropylene resin composition. As an example of producing the catalyst,
A method of combining a titanium trichloride composition obtained by reducing titanium tetrachloride with an organoaluminum compound and further treating it with various electron donors and electron acceptors, an organoaluminum compound and an aromatic carboxylic acid ester. 56-
No. 100806, JP-A-56-120712, JP-A-58-104907), and a supported catalyst method in which titanium tetrachloride and various electron donors are brought into contact with magnesium halide (JP-A No. 57-63310
JP-A-63-43915, JP-A-63-8311
6), etc.) and the like.
It can be obtained by polymerizing using propylene and ethylene by applying a production process such as a gas phase fluidized bed, a solution method, a slurry method or the like in the presence of the catalyst.

In the flame-retardant polypropylene resin composition of the present invention, examples of the brominated flame retardant used as the component (II) include decabromodiphenyl ether, tetrabromobisphenol A, tetrabromobisphenol S, bistribromophenoxyethane, poly Examples include dibromophenylene oxide, tetrabromobisphenol A epoxy polymer, tetrabromobisphenol A carbonate oligomer, polytribromopolypropylene, hexabromocyclododecane, hexabromobenzene, ethylenebistetrabromophthalimide, decabromodiphenylethane, and the like. Among them, tetrabromobisphenol A epoxy polymer, decabromodiphenylethane and decabromodiphenyl ether are preferable.

In the flame-retardant polypropylene resin composition of the present invention, the brominated flame retardant as the component (II) may be used alone or in combination of two or more kinds. It is necessary to select the compounding amount in the range of 0.1 to 30 parts by weight, preferably 6 to 25 parts by weight, relative to 100 parts by weight of the component (I) polypropylene resin composition. If the amount is less than 0.1 part by weight, the flame retardancy is insufficient, and if it exceeds 30 parts by weight, the flame retardant is easily decomposed during molding, and gas is generated more.

In the flame-retardant polypropylene resin composition of the present invention, the antimony trioxide used as the component (III) has an orthorhombic crystal content of 30% by weight or less, preferably 25% as measured by an X-ray diffraction method. It should be less than or equal to wt%. When the content of the orthorhombic crystal exceeds 30% by weight, the thermal stability of the composition during molding is lowered.

In the flame-retardant polypropylene resin composition of the present invention, the compounding amount of the component (III) antimony trioxide is 1 to 12 parts by weight based on 100 parts by weight of the component (I) polypropylene resin composition. Parts, preferably 2 to 8 parts by weight. If the amount is less than 1 part by weight, the flame retardancy is insufficient, and if it exceeds 12 parts by weight, the impact resistance is lowered.

In the flame-retardant polypropylene resin composition of the present invention, various known additives such as calcium carbonate, talc, and the like may be added, if necessary, within a range that does not impair the object of the present invention.
Inorganic fillers such as mica, silica and asbestos, reinforcing agents such as glass fibers, carbon fibers and metal whiskers, antioxidants, UV absorbers, heat stabilizers, lubricants, additives such as antistatic agents, and other A thermoplastic resin can be included.

The flame-retardant polypropylene resin composition of the present invention contains, for example, the above-mentioned component (I), component (II) and component (III) in the respective prescribed proportions, and a Banbury mixer, a single screw extruder, It can be prepared by sufficiently kneading with a twin-screw extruder, a co-kneader, a multi-screw extruder or the like.

The flame-retardant polypropylene resin composition of the present invention thus obtained is molded into a resin molded product having a desired shape according to a commonly used method such as an injection molding method or an extrusion molding method. You can

The flame-retardant polypropylene resin composition of the present invention produced by the above method has the following physical properties (A) to
It is important to have (C). Physical property (A):
Memory effect (ME) is 1.05 to 1.30, physical properties (B): melt flow index (MF)
R) is 0.5 to 45 g / 10 minutes, and physical properties (C): the density is 0.90 to 1.03.

Since the flame-retardant polypropylene resin composition of the present invention is a material capable of exhibiting the above-mentioned properties, it can be processed into various molded articles. Among them, toilet seats, toilet lids, hot water are locally discharged. Cleaning nozzles for washing, main body case of hot water washing device, injection molded products of water tank, especially toilet seat,
It is preferably used for a toilet lid, a main body case of a warm water washing device, a water tank, and the like.

[0019]

EXAMPLES The present invention will be described in more detail with reference to the following experimental examples.

Evaluation Method Measurement of Memory Effect (ME) The above memory effect (ME) was measured by setting the temperature inside the cylinder of the melt indexer to 190 ° C., length 8.00 mm, diameter 1.00 mmΦ, L / D. = 8 orifices are used. Further, a graduated cylinder containing ethyl alcohol is placed just below the orifice, and the distance directly below the orifice and the liquid surface of ethyl alcohol is set to 20 ± 2 mm. In this state, the sample was put into the cylinder, the load was adjusted so that the amount of extrudate per minute was 0.10 ± 0.03 g, and the extrudate after 6 to 7 minutes was dropped into ethanol. , Collect after solidification. Then, the diameters of the collected strand-shaped samples of the extrudate were maximum values at 3 points, that is, 1 cm portion from the upper end, 1 cm portion from the lower end, and the central portion,
The minimum value is measured, and the average value of the diameters measured at a total of 6 points is used as the memory effect (ME) value.

Melt flow rate (MFR) measurement According to JIS-K7210, 230 ° C., 2.16 kg load

Density measurement According to JIS-K2249

Test piece shape The test piece confirmed to be defective was 120 mm × 120 mm.
A plate-like member having a protrusion (concave shape in the mold) having a length of 30 mm, a width of 1.5 mm and a height of 4.5 mm in the same direction as the direction of flow of the resin is formed on the surface of the substrate having a thickness of 3 mm and a thickness of 3 mm. The gate shape for resin injection was a film gate.

Table 1 shows examples and comparative examples of the present invention. A molded product having a recess was molded using a resin composition having the following composition, and a molding defect such as a silver streak was confirmed.

[0025]

[Table 1]

Example 1 The polypropylene resin composition of the flame-retardant polypropylene resin composition had an (A) MFR of 40 g / 10 minutes and an ME value of 1.0.
60% of the propylene homopolymer of (B) MFR is 30
g / 10 minutes, 20% ethylene-propylene copolymer with an ME value of 0.9, (C) 5% propylene homopolymer with an MFR of 10 g / 10 minutes and an ME value of 1.2, (D) 25 parts by weight of a brominated flame retardant was mixed with 100 parts by weight of the resin composition and 25 parts by weight of the additive in a nitrogen atmosphere using a Henschel mixer. Then, using an extruder,
Granulated under conditions of 0 ℃, MFR 36, ME 1.2
A pellet-shaped resin composition having a density of 1.01 was obtained. A test piece was molded using the obtained flame-retardant polypropylene resin composition.

Example 2 The procedure of Example 1 was repeated, except that the composition of Example 1 was 55% (A) and 10% (C). Then, using an extruder, granulate under the conditions of 240 ° C. and MFR of 28,
A pelletized resin composition having an ME of 1.31 and a density of 1.00 was obtained. A test piece was molded using the obtained flame-retardant polypropylene resin composition.

Comparative Example 1 The composition of the polypropylene resin composition is (A) of Example 1,
The same procedure as in Example 1 was carried out except that only (B) and (D) were used, and (A) was 65% and (C) was 20%. afterwards,
Granulated using an extruder at 240 ° C and MFR of 4
9, a pelletized resin composition having an ME of 0.99 and a density of 1.04 was obtained. A test piece was molded using the obtained flame-retardant polypropylene resin composition.

Comparative Example 2 The composition of Example 1 was changed to 55% (A) and (C), and (E) an ethylene-propylene copolymer having an MFR of 40 g / 10 minutes and an ME value of 1.2. Was carried out in the same manner as in Example 1 except that 10% was added. After that, granulation was carried out at 240 ° C. using an extruder, and MFR was 46 and ME was 1.
A resin composition in the form of a pellet having a density of 04 and a density of 1.05 was obtained.
A test piece was molded using the obtained flame-retardant polypropylene resin composition.

Comparative Example 3 The composition of Example 1 was changed to 60% (A) and (C), and (F) an ethylene-propylene copolymer having an MFR of 40 g / 10 minutes and an ME value of 1.0. Was carried out in the same manner as in Example 1 except that 5% was added. Then, using an extruder, 2
Granulated under the condition of 40 ℃, MFR is 48, ME is 1.0
2, a pellet-shaped resin composition having a density of 1.06 was obtained. A test piece was molded using the obtained flame-retardant polypropylene resin composition.

[0031]

EFFECTS OF THE INVENTION The flame-retardant polypropylene resin composition of the present invention does not cause molding defects such as occurrence of silver streaks even when molded in a shape having recesses, and has good moldability. Therefore, it is preferably used as a high temperature molding material for large thin-walled products which require flame retardancy such as toilet seats for warm water washing toilet seats, toilet lids, and body cases.

[Brief description of drawings]

FIG. 1 is an external view of a locally washed toilet seat having toilet seat parts molded from the flame-retardant polypropylene resin composition of the present invention,
(A); The figure which looked at the toilet seat from above, (b); The figure which looked at the toilet seat from the side.

[Explanation of symbols]

1 ... Toilet seat, 2 ... Toilet lid, 3 ... Main body case, 4 ... Washing nozzle, 5 ... Operation part

Continued front page    F term (reference) 2D037 AA13                 2D038 JC01                 4F071 AA15X AA20 AA20X AA42                       AA75X AA80 AA88 AB18                       AC03 AE07 AF06Y                 4J002 BB121 BB141 BB151 BP021                       CD122 DE127 EB096 EB136                       FA040 FA060 FD010 FD070                       FD100 FD132 FD136 FD137                       FD170 GC00

Claims (5)

[Claims] 1. A polypropylene resin molding containing a flame retardant, wherein the resin molding has the following physical properties (A) to
A resin molded product, which is molded with a resin composition comprising (C). Physical property (A): Memory effect (ME) is 1.05
From 1.50 to 1.50 Physical properties (B): Melt flow index (MFR) from 0.5 to 45 Physical properties (C): Density from 0.90 to 1.02 2. A polypropylene-based resin molded article containing a flame retardant, wherein the resin molded article has the following physical properties (A) to
A resin molded product, which is molded with a resin composition comprising (B). Physical property (A): Memory effect (ME) is 1.05
To 1.50 Physical Properties (B): Melt Flow Index (MFR) 0.5 to 45 3. A polypropylene resin molding containing a flame retardant, wherein the resin molding has the following physical properties (A) to
A resin molded product, which is molded with a resin composition comprising (B). Physical property (A): Memory effect (ME) is 1.05
To 1.50 Physical property (B): Density is 0.90 to 1.02 4. The resin molding according to claim 1, which is made of a resin composition containing 0.1 to 30 parts by weight of a flame retardant with respect to 100 parts by weight of polypropylene resin. 5. A toilet seat component, which is a component of a warm water washing toilet seat, wherein the case cover, the toilet seat sheet, the toilet seat bottom plate, and the toilet lid are the resin moldings according to any one of claims 1 to 4.