JPH11181182A - Polypropylene-based resin composition for component of toilet stool - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a propylene-based resin composition for a component of a toilet stool which is sufficiently inhibited from discoloration by urine, feces, detergents or the like and excellent in touch to hand and skin, warpage properties and rigidity and exhibits good heat aging resistance and detergent resistance. SOLUTION: There is provided a polypropylene-based resin composition comprising a highly crystalline polypropylene-based resin with an isotactic pentad fraction of 96% or more and a nucleating agent, the polypropylene-based resin composition has the following properties (A)-(C). property (A): a melt flow index(MFR) of 0.5-100 g/10 min. property (B): a memory effect(ME) of 0.90-1.30. property (C): a crystallization initiation temperature of 125-136 deg.C.

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 for toilet parts, and more particularly to a toilet seat and a toilet lid used in a toilet, a cleaning nozzle for discharging hot water to clean a local part, and a main body case of a hot water cleaning device. The surroundings of toilets such as water tanks are suppressed from discoloration due to urine and stool, detergents, etc., have excellent touch feeling, warp characteristics and rigidity, have good heat aging resistance and detergent resistance, and are particularly exposed to acidic detergents and the like. The present invention relates to a polypropylene-based resin composition for toilet parts that maintains excellent physical properties even under severe conditions.

[0002]

2. Description of the Related Art Toilet seats conventionally used in toilets,
Toilet parts such as toilet lids, washing nozzles for discharging hot water to wash local parts, body cases of hot water washing devices, and toilets around toilets, such as water tanks, are easily discolored by ammonia gas or detergents from urine and acrylonitrile. ·butadiene·
A styrene resin (hereinafter simply referred to as “ABS resin”) has been used. This ABS resin has high rigidity,
Although it has excellent physical properties such as impact resistance and gloss, it has a problem that it is inferior in chemical resistance such as acid resistance and alkali resistance, particularly acid resistance. In other words, the causes of dirt around the toilet bowl, such as germs due to the adhesion of urine and feces, dirt due to the propagation of fungi, urea, phosphate, crude protein in scale components, excretion of sick people taking medicine, and soft drinks In recent years, detergents with improved detergency have been developed and used to remove excess vitamins due to heavy drinking, to remove organic matter in urine and feces, as well as to remove scale, blood, toilet bowl cleaners, flush toilet cleaners, etc. It became so. Therefore, the above-mentioned parts for toilet bowl made of ABS resin, particularly toilet seats and toilet lids that are cleaned daily, have disadvantages such as a decrease in mechanical properties, discoloration, and, in severe cases, cracks. On the other hand, in order to solve such a problem, it is also known to use a polypropylene resin having excellent chemical resistance. However, ordinary polypropylene-based resins are not sufficiently satisfactory in such properties as excellent warpage properties and touch feeling like ABS resins, discoloration resistance for suppressing discoloration caused by urine or stool,
There was a strong need for improvement.

[0003]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention is intended to reduce the warpage characteristics of toilet seat parts, discoloration due to urine and stool, detergent, etc., and to improve the feeling of touch, warp characteristics and rigidity. It is an object of the present invention to provide a polypropylene resin composition for toilet bowl parts which is excellent in heat aging resistance and detergent resistance.

[0004]

Means for Solving the Problems The present inventors have conducted intensive studies in view of the above problems, and as a result, added a specific additive to a polypropylene resin having a specific property to obtain a composition having specific physical properties. Accordingly, the present invention has been completed based on the finding that the above object can be achieved by doing so. That is, the polypropylene resin composition for toilet parts of the present invention has an isotactic pentad fraction of 96%.
A polypropylene resin composition comprising the above highly crystalline polypropylene resin and a nucleating agent, wherein the polypropylene resin composition has the following physical properties (A) to (C). is there. Physical property (A): Melt flow index (MFR) is 0.5 to 100 g / 10 min. Physical property (B): Memory effect (ME) is 0.90.
Physical property (C): Crystallization onset temperature is 125 to 136 ° C

[0005]

BEST MODE FOR CARRYING OUT THE INVENTION [I] Polypropylene resin composition for toilet parts (1) Constituent component (A) Highly crystalline polypropylene resin The above component (A) used in the polypropylene resin composition for toilet parts of the present invention. The highly crystalline polypropylene resin of the above) has an isotactic pentad fraction of 9
A highly crystalline polypropylene resin of 6% or more, preferably 97% or more, that is, a highly crystalline polypropylene resin in which a homopolymer portion of propylene having high crystallinity occupies all or most of the resin is used. Specifically, a highly crystalline propylene homopolymer, a highly crystalline polypropylene resin in which the homopolymer portion of the highly crystalline propylene accounts for the majority, and such a resin is a highly crystalline propylene resin. Examples thereof include a block or random copolymer with an α-olefin having 10 or less carbon atoms such as ethylene, 1-butene, 1-pentene, 1-hexene, and 4-methylpentene-1.

Isotactic pentad fraction (P) Among the highly crystalline polypropylene resins, the isotactic pentad fraction (P) of the boiling heptane-insoluble portion, which is used as an index of crystallinity in the polypropylene resin, is used.
Is an isotactic fraction in pentad units in a polypropylene molecular chain measured using ¹³ C-NMR (nuclear magnetic resonance method). Specifically, Macromolecules, 8, 687 (197) were obtained using ¹³ C-NMR.
This is a value measured based on the method described in 5).
If the isotactic pentad fraction (P) is less than the above range, rigidity tends to be insufficient for toilet parts.

(B) Nucleating agent As the nucleating agent, various ones can be used, but it is preferable to use an organic nucleating agent such as a sorbitol compound, an aromatic carboxylate, or a rosin salt. It is preferable to use a nucleating agent selected from a compound and / or an aromatic carboxylate.

(A) Sorbitol Compounds As nucleating agents for sorbitol compounds, sorbitol compounds generally used as nucleating agents for sorbitol compounds for resin compositions can be used without particular limitation. Specific examples include the following compounds [1] to [4], but the sorbitol compound used in the present invention is not limited thereto. [1] 1,3,2,4-di- (p-methyl-benzylidene) sorbitol [2] 1,3,2,4-dimethylbenzylidene sorbitol [3] 1,3,2,4-di- (p -Ethyl-benzylidene) sorbitol [4] 1,3,2,4-di- (2 ′, 4′-di-methyl-benzylidene) sorbitol Among the sorbitol compounds of the above [1] to [4], particularly [1] And the compounds of [2] and [3] are preferred. Further, one of the above-mentioned sorbitol compounds may be used alone, or two or more may be used in combination.

(B) Aromatic carboxylate As the above-mentioned aromatic carboxylate, a metal salt of an aromatic carboxylic acid generally used as an aromatic carboxylate nucleating agent for a resin composition is particularly limited. Can be mentioned without. Specifically, for example, sodium benzoate, potassium benzoate, magnesium benzoate, aluminum benzoate, lithium benzoate, hydroxyaluminum di (pt-butyl-benzoate), Al-p-butylbenzoate, β- Examples thereof include aromatic carboxylic acid metal salt compounds such as sodium naphthoate, sodium cyclohexanecarboxylate, and sodium cyclopentanecarboxylate. Among the above aromatic carboxylate salts, metal salts of benzoic acid such as sodium benzoate, potassium benzoate, magnesium benzoate, aluminum benzoate, lithium benzoate, di (pt-butyl-benzoic acid) hydroxyaluminum, etc. preferable. Among these compounds, sodium benzoate, potassium benzoate, magnesium benzoate, aluminum benzoate, and hydroxyaluminum di (pt-butyl-benzoate) are particularly preferable. Further, one kind of the above aromatic carboxylate may be used alone, or two or more kinds may be used in combination.

(C) Rosin Salt The rosin salt is a metal salt of rosin, such as an alkali metal, alkaline earth metal, or aluminum, and specifically, lithium, sodium, potassium, or rosin.
Examples thereof include calcium salts, magnesium salts, and aluminum salts.

(C) Other components (arbitrary components) In addition to the above essential components, other optional components can be added as long as the effects of the present invention are not significantly impaired. Other optional components include, for example, antioxidants, antistatic agents, light stabilizers, ultraviolet absorbers, neutralizing agents, metal corrosion inhibitors, lubricants, surfactants, flame retardants, nucleating agents, dispersants, Coloring agents, processability stabilizers, flow improvers, fungicides, metal deactivators and the like can also be added.

(2) Compounding ratio The compounding ratio of the highly crystalline polypropylene resin and the nucleating agent selected from sorbitol compounds and / or aromatic carboxylate in the polypropylene resin composition for toilet bowl parts of the present invention is Is a highly crystalline polypropylene resin 10
0.01 to 1 part by weight, preferably 0.03 to 0.5 part by weight, particularly preferably 0.1 to 1 part by weight, based on 0 part by weight.
0.3 parts by weight. If the compounding amount of the nucleating agent is less than the above range, the crystallization start temperature is low, and there is a tendency that the defect of warpage occurs.
On the other hand, if it exceeds the above range, the crystallization start temperature tends to be high, and the disadvantage of warpage tends to occur.

(3) Melt-kneading The polypropylene resin composition for toilet bowl parts of the present invention comprises:
It is manufactured by kneading at a set temperature of 180 to 250 ° C. using a usual extruder, a Banbury mixer, a roll, a Brabender plastograph, a kneader Brabender, etc. It is preferable to produce using an extruder. In addition, at the time of melt-kneading, an organic peroxide as an ME and MFR regulator can be added.

(4) Physical properties It is important that the polypropylene resin composition for toilet parts of the present invention produced by the above method has the following physical properties (A) to (C). Physical property (A): Melt flow index (MFR) is 0.5 to 100 g / 10 min. Physical property (B): Memory effect (ME) is 0.90.
Physical property (C): Crystallization starting temperature is 125 to 136 ° C. The highly crystalline polypropylene resin itself used as a raw material is slightly more than the MFR value in the above range or the ME value in the above range. If it shows a high value, it is expected that the MFR and ME of the composition obtained after melt-kneading will show a value that falls within the above range. It is also possible to control the MFR and ME of the composition obtained after melt-kneading.

(A) Melt flow rate (MFR) The polypropylene resin composition for toilet parts of the present invention has a melt flow rate (MFR) of JIS-K7210.
0.5 to 100 g / 10 min, preferably 2 to 50 g at a value measured according to (230 ° C. 2.16 kg load).
It is important that it is / 10 minutes, particularly preferably 7 to 30 g / 10 minutes. If the MFR is less than the above range, the fluidity during molding will be insufficient, while if the MFR exceeds the above range, the impact strength will be poor.

(B) Memory effect (ME: Memory E)
ffect: Restoration effect) It is important that the polypropylene resin composition for toilet parts of the present invention has a memory effect (ME) in the range of 0.9 to 1.3, preferably 1.0 to 1.2. . The M
If E exceeds the above range, the warpage becomes poor, while M
If E is less than the above range, the appearance due to fluidity becomes poor. Measurement of Memory Effect (ME) The measurement of the ME was carried out by using a melt indexer used in JIS-K7210 and setting measurement conditions to a cylinder temperature of 190 ° C. and a constant speed extrusion rate of 1 g / 10 minutes.
This is performed as follows. The device is filled with the sample, only the piston is loaded and a defined extrusion rate is applied after 6 minutes.
Next, a measuring cylinder containing ethyl alcohol is placed directly below the orifice, and a straight extrudate is collected. The diameter (D) of the collected extrudate is measured with a micrometer,
The orifice diameter of the die as D _0, ME is obtained from the following equation. ME = D / D ₀

(C) Crystallization Starting Temperature The polypropylene resin composition for toilet bowl parts of the present invention has a crystallization starting temperature of 125 to 136 ° C., preferably 127 to 136 ° C.
It is important that the temperature is 136 ° C. The crystallization onset temperature is
JIS-K7121 using a differential scanning calorimeter (DSC)
It is a value measured at a cooling rate of 10 ° C. per minute according to the above. If the crystallization start temperature is lower than the above range, warpage may be insufficient, while if the crystallization start temperature exceeds the above range, warpage may be poor.

(D) Other Physical Properties The polypropylene resin composition for toilet bowl components of the present invention preferably has the following physical properties in addition to the above physical properties (A) to (C). Physical properties (D): Acid resistance: 23 ° C, 30 in hydrochloric acid (38%)
Almost no change in wall thickness and weight after immersion for one day. Physical properties (E): Alkali resistance: Almost no change in wall thickness and weight when immersed in a 10% by weight solution of caustic soda at 23 ° C. for 30 days. Physical properties (F): Flexural modulus: 14,000 kg / cm ² or more, more preferably 15,000 or more. Physical property (G): Izod (IZOD) Impact value: 1.5k
g · cm / cm ² or more, preferably 2.0 kg · cm /
cm ² or more. Physical properties (H): Heat aging resistance: Time required for cracks to occur in an atmosphere at 120 ° C. is 1,000 hours or more.

[II] Forming The method of forming the polypropylene resin composition for toilet parts of the present invention is not particularly limited, but an injection molding method should be used in view of the effect of the invention. Is suitable.

[III] Applications Since it is a material capable of exhibiting the above-mentioned physical properties, a toilet seat, a toilet lid, a cleaning nozzle for discharging hot water to wash a local part, a main body case of a hot water cleaning device, a water tank used in a toilet It can be processed into various molded products around the toilet, such as toilet seat, toilet lid, cleaning nozzle that discharges hot water and cleans the local area, body case of hot water cleaning device, injection molded product of water tank, especially It is preferably used for a toilet seat, a toilet lid, a body case of a hot water washing device, a water tank, and the like.

[0021]

The present invention will be described more specifically with reference to the following experimental examples. [I] Evaluation Method Measurement of Melt Flow Rate (MFR) According to JIS-K7210, 230 ° C., 2.16 kg load

Measurement of Memory Effect (ME) The memory effect (ME) was measured by setting the temperature in the cylinder of the melt indexer to 190 ° C., length 8.00 mm, diameter 1.00 mmφ, L / D = 8. Orifices are used. A graduated cylinder containing ethyl alcohol is placed directly below the orifice. The distance between immediately below the orifice and the liquid level of ethyl alcohol is 20 ± 2 mm. In this state, the sample was put into a cylinder, the load was adjusted so that the amount of the extrudate per minute was 0.10 ± 0.03 g, and the extrudate after 6 to 7 minutes was dropped into ethanol. After solidification, collect. Then, the diameter of the strand-shaped sample of the extrudate obtained was the maximum value at three places of 1 cm from the upper end, 1 cm from the lower end, and the center,
The minimum value is measured, and the average value of the diameter measured at a total of six points is defined as a memory effect (ME) value.

Measurement of crystallization onset temperature [Preparation of sample for measurement] Preheating and pressure control of the sample for measurement were carried out at a temperature of 230 ° C. to 0.3 to 0.3 ° C.
Create a 0.4 mm sheet. About 5m from this sheet
g was collected and used as a sample for a differential scanning calorimeter (DSC). [Measurement] The crystallization onset temperature was measured by using DSC and JIS.
The measurement was performed at a cooling rate of 10 ° C. per minute according to -K7121.

Measurement of Flexural Modulus The pellet-shaped sample was molded at an injection temperature of 240.
C. and a mold cooling temperature of 40.degree. C. to prepare a flexural modulus measurement test piece. The flexural modulus is measured according to JIS-K720.
3 was measured.

Measurement of Warpage A pellet sample was prepared using an injection molding machine (Toshiba IS220) at a temperature of 220 ° C., an injection time of 12 seconds, a mold temperature of 30 ° C., a cooling time of 6 seconds, a diameter of 200 mm, a thickness of 2 mm, and a gate diameter of 8 mm. A disk with a direct gate was molded. After molding, the condition was adjusted for 72 hours in an atmosphere at a temperature of 23 ° C. and a humidity of 50%, and the degree of warpage was determined by pressing one of the disks and the amount of deformation in the opposite direction was determined according to the following criteria. [Judgment Criteria] A: No warping deformation. ：: Warpage deformation is slight to less than 5 mm △: Warpage deformation is 5 mm to 10 mm ×: Warpage deformation exceeds 10 mm

[II] Examples and Comparative Examples Example 1 A propylene homopolymer (highly crystalline PP) having an isotactic pentad fraction of 97% and an MFR of 8 g / 10 min.
0.1 parts by weight of pentaerythrityl-tetrakis [3- (3,5, -di-t-butyl-4-hydroxyphenyl) propionate as an antioxidant and 100 parts by weight of tris (2,4-dithiol) 0.1 parts by weight of -t-butylphenyl) phosphite, 0.05 parts by weight of calcium stearate as a neutralizing agent, 0.2 parts by weight of erucic acid amide as a lubricant, 1,3,2,4-diene as a nucleating agent − (P
-Methyl) -benzylidene sorbitol 0.1 part by weight,
1.5 parts by weight of titanium oxide as a pigment and 0.012 parts by weight of 2,5-dimethyl-2,5-di- (t-butylperoxin) hexane as a control agent for memory effect and melt flow rate in a nitrogen atmosphere Mix using a Henschel mixer below. Thereafter, granulation was carried out at 240 ° C. using an extruder, and the MFR was 15, and the ME was 1.
Eleven pellet-shaped samples were obtained.

Examples 2 and 9 The same procedures as in Example 1 were carried out except that the raw materials shown in Tables 1 and 2 were used in the ratios shown in Tables 1 and 2. The results are shown in Tables 1 and 2.

Examples 3 to 7 The same procedures as in Example 2 were carried out except that the types and amounts of nucleating agents were changed to those shown in Tables 1 and 2. The results are shown in Tables 1 and 2.

Example 8 The propylene homopolymer (highly crystalline PP) of Example 1 was treated with M
2,5-dimethyl-2,5-di- (t-butylperoxin) hexane used as a ME and MFR control agent after changing the propylene homopolymer (FR) to 8 g / 10 min. Was carried out in the same manner as in Example 1, except that the amount of was added to 0.006 parts by weight. Table 2 shows the results.

Comparative Examples 1-2 The propylene homopolymer of Example 1 (highly crystalline PP) was
The propylene homopolymer (highly crystalline PP) having an MFR of 16 g / 10 min or 14 g / 10 min was changed to ME and M
The procedure was performed in the same manner as in Example 1, except that the FR control agent was not added. Table 3 shows the results.

Comparative Examples 3 and 4 The same procedures as in Example 1 were carried out except that the raw materials shown in Tables 1 and 2 were used at the ratios shown in Tables 1 and 2. The results are shown in Tables 1 and 2.

Comparative Example 5 The propylene homopolymer of Comparative Example 4 (highly crystalline PP) was
MFR of general PP produced using titanium trichloride catalyst
Example 13 was carried out in the same manner as in Example 1, except that the homopolymer was changed to 13. Table 3 shows the results.

Comparative Example 6 The same procedure as in Example 2 was carried out except that no nucleating agent was added and cyanine blue was changed to 2 parts by weight in place of the titanium oxide pigment. Table 3 shows the results.

[0034]

[Table 1]

[0035]

[Table 2]

[0036]

[Table 3]

[0037]

As described above, the polypropylene resin composition for toilet parts of the present invention can sufficiently suppress the warp characteristic of the toilet seat part, discoloration due to urine and stool, detergent, etc., and is excellent in the touch feeling, the warp characteristic and the rigidity. It has good heat aging resistance and detergent resistance, and is ideal for various molded products such as toilet seats around the toilet bowl, toilet lid, cleaning nozzles for discharging hot water and cleaning local parts, body cases of hot water cleaning equipment, water tanks, etc. Material.

──────────────────────────────────────────────────続 き Continued on front page (51) Int.Cl. ⁶ Identification code FI C08L 93/04 C08L 93/04

Claims (4)

[Claims] An isotactic pentad fraction of 96%
A polypropylene resin composition comprising the above highly crystalline polypropylene resin and a nucleating agent, wherein the polypropylene resin composition has the following physical properties (A) to (C): Polypropylene resin composition for parts. Physical property (A): Melt flow index (MFR) is 0.5 to 100 g / 10 min. Physical property (B): Memory effect (ME) is 0.90.
Physical property (C): Crystallization onset temperature is 125 to 136 ° C 2. The polypropylene resin composition for toilet bowl parts according to claim 1, wherein a nucleating agent is blended in an amount of 0.01 to 1 part by weight based on 100 parts by weight of the highly crystalline polypropylene resin. 3. The polypropylene resin composition for toilet bowl parts according to claim 1, wherein the nucleating agent is an organic nucleating agent. 4. The polypropylene for toilet parts according to claim 1, wherein the titanium oxide pigment is contained in an amount of 0.1 to 2.0 parts by weight based on 100 parts by weight of the highly crystalline polypropylene resin. Resin composition.