JP7730469B2 - Water-related materials - Google Patents

Description

Aspects of the present invention generally relate to plumbing components.

Toilet lids and seats manufactured by molding materials containing resin have been known for some time (see, for example, Patent Document 1). Such toilet lids and seats are made from inexpensive resins such as polypropylene (PP). However, molding plumbing components such as toilet lids and seats using resins such as PP results in low surface hardness, which can lead to scratches on the surface of the plumbing components when wiped dry with toilet paper or hard nonwoven fabric.

One possible solution to this problem is to increase the surface hardness of the plumbing components. One possible way to increase the surface hardness of plumbing components is to use heat and cool molding (H&C molding), in which a heater is installed in the mold used to mold the plumbing components, and resin is injected into the heated mold, maintaining the high temperature of the resin for a predetermined period of time to harden it. With this type of molding method, the gradual solidification process of the resin increases the crystallinity of the surface of the plumbing component, thereby increasing the surface hardness of the plumbing component.

Japanese Patent Application Laid-Open No. 2000-308601

However, increasing the degree of crystallinity on the surface increases the amount of shrinkage of the molded product, resulting in a problem of significant dimensional change over time after the molded product is removed from the mold. Therefore, applying this molding method to bathroom components may result in a decrease in dimensional accuracy. For example, cushioning members are attached to the underside of toilet lids and seats to absorb the impact when the toilet lid or seat is closed. These cushioning members are attached by fitting into recesses provided on the underside of the toilet lid or seat. Therefore, if the dimensional accuracy of the recesses decreases, it may become impossible to form the recesses in the desired shape, making it impossible to attach the cushioning members.

This aspect of the present invention was developed in recognition of these issues, and aims to provide a plumbing component that can simultaneously improve the scratch resistance of exposed portions and ensure dimensional stability of mating portions.

One aspect of the present invention is a plumbing component containing a crystalline resin, comprising a fitting portion into which a fitted component is fitted, and an exposed portion other than the fitting portion that is provided in an exposed position when attached to a fixture, and wherein the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion.

This aspect of the present invention makes it possible to provide a plumbing component that achieves both improved scratch resistance of the exposed portion and ensures dimensional stability of the fitting portion.

1 is a perspective view illustrating a toilet device according to an embodiment. FIG. 2 is a cross-sectional view showing a portion of the toilet lid according to the embodiment. FIG. 2 is a cross-sectional view showing a part of the toilet seat according to the embodiment. 4(a) to 4(c) are cross-sectional views showing a part of the manufacturing process of the toilet lid. 10 is a table showing an example of experimental results.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, like components are designated by like reference numerals and detailed descriptions thereof will be omitted where appropriate.
FIG. 1 is a perspective view illustrating a toilet device according to an embodiment.
FIG. 2 is a cross-sectional view showing a portion of the toilet lid according to the embodiment.
FIG. 3 is a cross-sectional view showing a part of the toilet seat according to the embodiment.
FIG. 2 is a cross-sectional view taken along line A1-A2 shown in FIG.
FIG. 3 is a cross-sectional view taken along line B1-B2 shown in FIG.
1 and 2 show the toilet seat and toilet lid in an open position, while Fig. 3 shows the toilet seat in a closed position.
As shown in Figures 1 to 3, the toilet device 100 according to the embodiment comprises a Western-style seated toilet bowl (hereinafter simply referred to as "toilet bowl") 10, a casing 20, a toilet lid 30, and a toilet seat 40.

The toilet 10 has a bowl portion 11 that is recessed downward. The bowl portion 11 of the toilet 10 receives waste such as urine and feces from the user. The bowl portion 11 has a rim 11a and an opening 11h surrounded by the rim 11a.

In this specification, the upper side as seen from the perspective of a user sitting on the toilet seat 40 will be referred to as "upper side," and the lower side as seen from the perspective of a user sitting on the toilet seat 40 will be referred to as "lower side." Furthermore, the left and right directions as seen from a user sitting on the toilet seat 40 with their back to the open toilet lid 30 will be referred to as "left side" and "right side," respectively, and the front and back directions will be referred to as "front" and "rear," respectively.

A casing 20 is provided above the rear of the bowl portion 11 of the toilet 10. Inside the casing 20, for example, an electric toilet lid opening/closing unit for opening and closing the toilet lid 30 and an electric toilet seat opening/closing unit for opening and closing the toilet seat 40 are housed. The casing 20 may also house, for example, a nozzle unit for cleaning the user's private parts.

The toilet lid 30 and toilet seat 40 are each capable of being opened and closed relative to the toilet bowl 10. The toilet lid 30 and toilet seat 40 are each pivotally supported relative to the casing 20.

The toilet lid 30 has a toilet lid main body 31, a toilet lid hinge 32, and a toilet lid cushion member 33. When closed, the toilet lid main body 31 is located above the bowl 11 and toilet seat 40. When closed, the toilet lid main body 31 covers the bowl 11 and the toilet seat 40 from above.

The toilet lid hinge portion 32 is located behind the toilet lid main body portion 31 in the closed state. The toilet lid hinge portion 32 is, for example, molded integrally with the toilet lid main body portion 31. The toilet lid hinge portion 32 may, for example, be molded separately from the toilet lid main body portion 31 and attached to the toilet lid main body portion 31. The toilet lid hinge portion 32 is rotatably supported relative to the casing 20 by fitting onto the output shaft of an electric toilet lid opening/closing unit housed inside the casing 20. The electric toilet lid opening/closing unit opens and closes the toilet lid 30 by rotating the toilet lid main body portion 31 via the toilet lid hinge portion 32.

The toilet lid cushion member 33 is a separate member from the toilet lid main body 31 and is attached to the toilet lid main body 31. The toilet lid cushion member 33 is made of, for example, an elastomer, and absorbs the impact when the toilet lid main body 31 hits the toilet seat 40.

The toilet lid main body 31 has a toilet lid upper surface 31a and a toilet lid lower surface 31b. The toilet lid upper surface 31a is exposed upward in the closed state. The toilet lid upper surface 31a faces upward in the closed state. The toilet lid lower surface 31b is exposed downward in the closed state. The toilet lid lower surface 31b faces downward in the closed state. For example, the toilet lid lower surface 31b faces the toilet seat 40 in the closed state.

A toilet lid recess 31c is provided on the toilet lid underside 31b. When the toilet lid recess 31c is closed, it is recessed upward. A toilet lid cushion member 33 is attached to the toilet lid recess 31c. The toilet lid cushion member 33 is attached to the toilet lid recess 31c by fitting into the toilet lid recess 31c.

The toilet lid 30 is an example of a plumbing component 200. The plumbing component 200 comprises an engaging portion 210 and an exposed portion 220. The engaging portion 210 is the portion into which the separately formed engaging member 250 is engaged. The exposed portion 220 is a portion other than the engaging portion 210 that is provided in an exposed position when attached to the appliance 260. The exposed portion 220 is a portion that is visible to the user when attached to the appliance 260. The engaging portion 210 is, for example, the toilet lid recess 31c. In this case, the engaging member 250 is, for example, the toilet lid cushion member 33. The engaging portion 210 may be, for example, the toilet lid hinge portion 32. In this case, the engaging member 250 is, for example, the output shaft of an electric toilet lid opening/closing unit. The exposed portion 220 includes, for example, the toilet lid upper surface portion 31a and the toilet lid lower surface portion 31b. The device 260 is, for example, a casing 20.

The plumbing component 200 contains a crystalline resin. More specifically, the toilet lid main body 31 contains a crystalline resin. The toilet lid hinge 32 contains, for example, a crystalline resin. Crystalline resin is a thermoplastic resin that has crystallinity. Examples of crystalline resins that can be used include PP or polybutylene terephthalate (PBT).

The plumbing component 200 may further contain an inorganic filler. More specifically, the toilet lid main body 31 and the toilet lid hinge 32 may further contain an inorganic filler. The inorganic filler is a filler (filling agent) made of an inorganic material. For example, a fibrous inorganic filler such as glass fiber is used as the inorganic filler. The inorganic filler does not have to be fibrous. The inorganic filler may also be a mineral such as an acicular mineral, a plate-like mineral, or a frit-type mineral. When glass fiber is used as the inorganic filler, it is preferable to use glass fiber with a fiber diameter of 6 μm to 24 μm (e.g., approximately 13 μm) and a length of 10 μm to 3000 μm (e.g., approximately 300 μm to 1000 μm). The amount of inorganic filler contained in the toilet lid main body 31 or toilet lid hinge 32 is preferably 5 to 30 parts by mass (for example, approximately 10 parts by mass) per 100 parts by mass of the combined total of the crystalline resin and inorganic filler.

The surface hardness of the mating portion 210 is less than the surface hardness of the exposed portion 220. The surface hardness of the exposed portion 220 is preferably pencil hardness B or higher. The surface hardness of the exposed portion 220 is preferably pencil hardness F or lower. The surface hardness of the mating portion 210 is preferably pencil hardness 2B or lower. The surface hardness of the mating portion 210 is preferably pencil hardness 3B or higher.

The surface hardness of the exposed portion 220 may be, for example, the surface hardness of at least a portion of the exposed portion 220. If the exposed portion 220 has multiple portions with different surface hardnesses, the surface hardness of the portion of the exposed portion 220 with the highest surface hardness can be considered to be the surface hardness of the exposed portion 220. If the bathroom component 200 is a toilet lid 30, for example, the surface hardness of the toilet lid upper surface 31a can be considered to be the surface hardness of the exposed portion 220. In other words, if the fitting portion 210 is a toilet lid recess 31c, the surface hardness of the toilet lid recess 31c is, for example, less than the surface hardness of the toilet lid upper surface 31a. If the fitting portion 210 is a toilet lid hinge portion 32, the surface hardness of the toilet lid hinge portion 32 is, for example, less than the surface hardness of the toilet lid upper surface 31a.

Furthermore, the surface hardness of the toilet lid underside 31b is, for example, less than the surface hardness of the toilet lid upper side 31a. The surface hardness of the toilet lid recess 31c is, for example, the same as the surface hardness of the toilet lid underside 31b. The surface hardness of the toilet lid hinge portion 32 is, for example, the same as the surface hardness of the toilet lid underside 31b.

The surface hardness of the toilet lid upper surface 31a is preferably pencil hardness B or higher. The surface hardness of the toilet lid upper surface 31a is preferably pencil hardness F or lower. The surface hardness of the toilet lid lower surface 31b is preferably pencil hardness 2B or lower. The surface hardness of the toilet lid lower surface 31b is preferably pencil hardness 3B or higher.

The surface hardness of the toilet lid recess 31c is preferably a pencil hardness of 2B or less. The surface hardness of the toilet lid recess 31c is preferably a pencil hardness of 3B or more. The surface hardness of the toilet lid hinge portion 32 is preferably a pencil hardness of 2B or less. The surface hardness of the toilet lid hinge portion 32 is preferably a pencil hardness of 3B or more.

Surface hardness can be determined as a pencil hardness in accordance with JIS K 5600-5-4:1999. Pencil hardness of less than 6B, which is not specified in JIS K 5600-5-4:1999, can be determined in the same manner as JIS K 5600-5-4:1999 using Mitsubishi Pencil Co., Ltd.'s Hi-uni series pencils.

The surface hardness of the toilet lid upper surface 31a is, for example, the surface hardness at any position that overlaps vertically with the opening 11h of the bowl portion 11 in the closed state. The surface hardness of the toilet lid lower surface 31b is, for example, the surface hardness at a position that overlaps vertically with the position where the surface hardness of the toilet lid upper surface 31a was measured in the closed state. The surface hardness of the toilet lid hinge portion 32 is, for example, the surface hardness of the flat portion of the hinge bearing portion into which the output shaft of the electric toilet lid opening/closing unit is fitted.

The toilet seat 40 has a toilet seat main body 41, a toilet seat hinge 42, and a toilet seat cushion member 43. In the closed state, the toilet seat main body 41 is located above the bowl 11. In the closed state, the toilet seat main body 41 has an opening 41h that penetrates in the vertical direction.

The toilet seat hinge portion 42 is located behind the toilet seat main body 41 in the closed state. The toilet seat hinge portion 42 is, for example, molded integrally with the toilet seat main body 41. The toilet seat hinge portion 42 may, for example, be molded separately from the toilet lid main body 31 and attached to the toilet seat main body 41. The toilet seat hinge portion 42 is rotatably supported relative to the casing 20 by fitting onto the output shaft of an electric toilet seat opening/closing unit housed inside the casing 20. The electric toilet seat opening/closing unit opens and closes the toilet seat 40 by rotating the toilet seat main body 41 via the toilet seat hinge portion 42.

The toilet seat cushion member 43 is a separate member from the toilet seat main body 41 and is attached to the toilet seat main body 41. The toilet seat cushion member 43 is made of, for example, an elastomer, and absorbs the impact when the toilet seat main body 41 hits the rim 11a of the bowl portion 11.

The toilet seat main body 41 has an upper seat surface 41a and a lower seat surface 41b. The upper seat surface 41a is exposed upward in the closed state. The upper seat surface 41a faces upward in the closed state. The upper seat surface 41a is the seating surface on which a user sits. The lower seat surface 41b is exposed downward in the closed state. The lower seat surface 41b faces downward in the closed state. For example, the lower seat surface 41b faces the rim 11a of the bowl portion 11 in the closed state.

A toilet seat recess 41c is provided on the toilet seat underside 41b. When the toilet seat is closed, the toilet seat recess 41c is recessed upward. A toilet seat cushion member 43 is attached to the toilet seat recess 41c. The toilet seat cushion member 43 is attached to the toilet seat recess 41c, for example, by fitting into the toilet seat recess 41c.

As shown in FIG. 3, the toilet seat 40 is hollow and includes a bottom plate 45, an upper plate 46, a first connecting member 47, and a second connecting member 48. The bottom plate 45 includes a toilet seat lower surface portion 41b. The toilet seat lower surface portion 41b corresponds to the underside of the bottom plate 45 in the closed state. The upper plate 46 is located above the bottom plate 45 in the closed state. In this example, the upper plate 46 has a first portion 46a including the toilet seat upper surface portion 41a, a second portion 46b extending downward from one end of the first portion 46a, and a third portion 46c extending downward from the other end of the first portion 46a. The toilet seat upper surface portion 41a corresponds to the upper surface of the first portion 46a in the closed state. The first connecting member 47 is provided on the inner periphery of the toilet seat 40 and connects the bottom plate 45 and the second portion 46b of the upper plate 46. The second joining member 48 is provided on the outer periphery of the toilet seat 40 and joins the bottom plate 45 and the third portion 46c of the top plate 46. The toilet seat hinge portion 42 is composed of, for example, the bottom plate 45 and the top plate 46.

The toilet seat 40 is an example of a plumbing component 200. The mating portion 210 is, for example, a toilet seat recess 41c. In this case, the mated component 250 is, for example, a toilet seat cushion component 43. The mating portion 210 may also be, for example, a toilet seat hinge portion 42. In this case, the mated component 250 is, for example, an output shaft of an electric toilet seat opening/closing unit. The exposed portion 220 includes, for example, a toilet seat upper surface portion 41a and a toilet seat lower surface portion 41b. The fixture 260 is, for example, a casing 20.

The toilet seat main body 41 contains a crystalline resin. The toilet seat hinge 42 contains, for example, a crystalline resin. The toilet seat main body 41 and the toilet seat hinge 42 may further contain an inorganic filler. The crystalline resin and inorganic filler may be the same as those exemplified in the description of the toilet lid 30. The amount of inorganic filler to be blended may also be the same as that exemplified in the description of the toilet lid 30.

When the plumbing component 200 is a toilet seat 40, for example, the surface hardness of the toilet seat upper surface 41a can be considered to be the surface hardness of the exposed portion 220. In other words, when the fitting portion 210 is a toilet seat recess 41c, the surface hardness of the toilet seat recess 41c is, for example, less than the surface hardness of the toilet seat upper surface 41a. When the fitting portion 210 is a toilet seat hinge portion 42, the surface hardness of the toilet seat hinge portion 42 is, for example, less than the surface hardness of the toilet seat upper surface 41a.

Furthermore, the surface hardness of the toilet seat lower surface portion 41b is, for example, less than the surface hardness of the toilet seat upper surface portion 41a. The surface hardness of the toilet seat recess portion 41c is, for example, the same as the surface hardness of the toilet seat lower surface portion 41b. The surface hardness of the toilet seat hinge portion 42 is, for example, the same as the surface hardness of the toilet seat lower surface portion 41b.

The surface hardness of the toilet seat upper surface 41a is preferably pencil hardness B or higher. The surface hardness of the toilet seat upper surface 41a is preferably pencil hardness F or lower. The surface hardness of the toilet seat lower surface 41b is preferably pencil hardness 2B or lower. The surface hardness of the toilet seat lower surface 41b is preferably pencil hardness 3B or higher.

The surface hardness of the toilet seat recess 41c is preferably a pencil hardness of 2B or less. The surface hardness of the toilet seat recess 41c is preferably a pencil hardness of 3B or more. The surface hardness of the toilet seat hinge portion 42 is preferably a pencil hardness of 2B or less. The surface hardness of the toilet seat hinge portion 42 is preferably a pencil hardness of 3B or more.

The surface hardness of the toilet seat upper surface 41a is, for example, the surface hardness at any position that overlaps vertically with the rim 11a of the bowl portion 11 in the closed state. The surface hardness of the toilet seat lower surface 41b is, for example, the surface hardness at a position that overlaps vertically with the position where the surface hardness of the toilet seat upper surface 41a was measured in the closed state. The surface hardness of the toilet seat hinge portion 42 is, for example, the surface hardness of the flat portion of the hinge bearing portion into which the output shaft of the toilet seat electric opening and closing unit is fitted.

The manufacturing process for the toilet lid 30 and toilet seat 40 according to the embodiment will be described below.
4(a) to 4(c) are cross-sectional views showing a part of the manufacturing process of the toilet lid according to the embodiment.
As shown in Figures 4(a) to 4(c), the toilet lid 30 is manufactured by molding using molds M1 and M2. Mold M1 is equipped with a heating section H and a cooling section C1. Mold M2 is equipped with a cooling section C2, but does not have a heating section.

In the manufacturing process, as shown in FIG. 4(a), material X, including the crystalline resin described above, is first filled into the space formed by mold M1, heated by heating unit H, and unheated mold M2. At this time, material X is filled into the space formed by mold M1 and mold M2 while heated to a temperature higher than that of mold M1. In other words, material X is filled into the space formed by mold M1, heated to a temperature equal to or higher than minus 70°C below the heat distortion temperature (ISOR 75) and lower than the temperature of the injection cylinder, and unheated mold M2 while heated by the injection cylinder. As a result, material X is gradually cooled on the side in contact with mold M1 and rapidly cooled on the side in contact with mold M2. Next, as shown in FIG. 4(b), mold M1 is cooled by cooling unit C1, and mold M2 is cooled by cooling unit C2, thereby cooling and hardening material X inside mold M1 and mold M2. Next, as shown in Figure 4(c), the toilet lid 30 formed by hardening material X is removed from molds M1 and M2.

In this way, material X, which has been heated to a higher temperature than that of mold M1 by heating unit H, is filled into mold M1, which is heated by heating unit H, and material X is gradually cooled. Then, mold M1 is further cooled by cooling unit C1 to harden material X, thereby forming the toilet lid upper surface 31a of the toilet lid 30. This promotes crystallization near the surface of the toilet lid upper surface 31a of the toilet lid 30, thereby increasing the surface hardness of the toilet lid upper surface 31a of the toilet lid 30. Furthermore, by providing heating unit H on mold M1 on the toilet lid upper surface 31a side and not providing a heating unit on mold M2 on the toilet lid lower surface 31b side, the surface hardness of the toilet lid lower surface 31b and toilet lid recess 31c can be made less than the surface hardness of the toilet lid upper surface 31a. In other words, the surface hardness of the mating portion 210 can be made less than the surface hardness of the exposed portion 220.

Hereinafter, this molding method, in which a heating section is provided in at least one of the molds M1 and M2 and material X is gradually cooled and hardened, will be referred to as "heat and cool molding (H&C molding)." In contrast, a molding method, in which neither mold M1 nor M2 has a heating section and material X is rapidly cooled and hardened, will be referred to as "normal molding."

When the toilet lid hinge portion 32 is molded integrally with the toilet lid main body portion 31, for example, no heating portion is provided in the portion of the mold that molds the toilet lid hinge portion 32 that comes into contact with the hinge bearing portion. This allows the surface hardness of the toilet lid hinge portion 32 to be less than the surface hardness of the toilet lid upper surface portion 31a. In other words, the surface hardness of the fitting portion 210 can be less than the surface hardness of the exposed portion 220.

While the manufacturing process for the toilet lid 30 is described in Figures 4(a) to 4(c), the toilet seat 40 can also be manufactured using a similar method. The toilet seat 40 can be manufactured, for example, by creating the bottom plate 45 and top plate 46 using the method described above and then joining the bottom plate 45 and top plate 46 with the first joining member 47 and the second joining member 48. By molding the toilet seat top surface 41a of the top plate 46 using a mold M1 equipped with a heating element H and molding the toilet seat bottom surface 41b of the bottom plate 45 using a mold M2 equipped with no heating element, the surface hardness of the toilet seat bottom surface 41b can be made smaller than the surface hardness of the toilet seat top surface 41a.

Alternatively, when molding the top plate 46, heating units can be provided on both mold M1 and mold M2, except for mating locations where high dimensional accuracy is required, and when molding the bottom plate 45, heating units can be not provided on either mold M1 or mold M2, thereby making the surface hardness of the toilet seat underside 41b less than the surface hardness of the toilet seat upper side 41a. In other words, the bottom plate 45 can be molded using "normal molding."

In addition, instead of providing a heating section H on the mold M1, the surface of the mold M1 that forms the molded product may be coated with a heat insulating material. By coating the surface of the mold M1 with a heat insulating material, the cooling rate of the heated and melted material X is slowed down, thereby achieving the same effect as H&C molding.

In addition, instead of providing a heating section H in the mold M1, warm water or pressurized warm water may be run through the cooling section C1. By running warm water or pressurized warm water through the cooling section C1, the temperature of the mold M1 becomes higher than in normal molding, thereby achieving the same effect as H&C molding.

FIG. 5 is a table showing an example of the experimental results.
The surface hardness of each molded article (Experimental Examples 1 to 11) molded using the materials shown in each table in Figure 5 by normal molding, H&C molding, or adiabatic molding is measured and the results are shown in Figure 5. The scratch resistance and dimensional stability of the recesses and hinges of each molded article are also shown in Figure 5. Note that PP Type A used in Experimental Examples 1 and 11, PP Type B used in Experimental Examples 2 to 5, PP Type C used in Experimental Examples 6 and 8 to 10, and PP Type D used in Experimental Example 7 are all polypropylene (PP), but each has a different structure.

In normal molding, the mold temperatures for the top side (cavity side), bottom side (core side), and hinge section are set to the temperatures shown in Figure 5, the heated and molten material is filled into the mold, and the mold is cooled using the cooling section, causing the material to cool and harden inside the mold to obtain a molded product. Note that the mold temperature for the recessed section is the same as the mold temperature for the bottom side.

In H&C molding, the mold temperatures for the top, bottom, and hinge sections are set to the temperatures shown in Figure 5, the heated and melted material is filled into the mold and gradually cooled, and the mold is further cooled in the cooling section, thereby cooling and hardening the material inside the mold to obtain a molded product. Note that the mold temperature for the recess is the same as the mold temperature for the bottom section.

In adiabatic molding, the mold on the top side was coated with insulating material, and the mold temperatures for the top, bottom, and hinge sections were set to the temperatures shown in Figure 5. The heated and melted material was then filled into the mold and gradually cooled, and the material was cooled and hardened inside the mold to obtain the molded product. Note that the mold temperature for the recessed section was the same as the mold temperature for the bottom section.

Surface hardness was measured in accordance with JIS K 5600-5-4:1999.

To evaluate scratch resistance, a piece of felt was attached to the tip of a rubbing tester, and toilet paper, which is likely to be used to clean toilet lids and seats, was placed on top of it. The surface of the molded product was rubbed back and forth five times, and the scratch resistance of the molded product after the test was evaluated. The molded product was visually inspected for scratch resistance after the test, with scratches across the entire rubbed area rated as "X", scratches only partially rated as "△", and no scratches across the entire rubbed area rated as "○". The load applied during the test was 3 kg on the top surface. Note that some paper towels used to wipe down sink counters and bathroom counters have a hardness similar to that of toilet paper, and the results of evaluating scratch resistance using paper towels were the same as those obtained when using toilet paper.

The dimensional stability of the recesses and hinges was evaluated by leaving the resulting molded products at room temperature for 48 hours and then measuring the dimensions of the recesses and hinges. Dimensional stability was evaluated as follows: "Good" indicates a tolerance of the medium grade or less as specified in JIS B 0405:1991; "Good" indicates a tolerance greater than the medium grade and less than the middle grade of the coarse grade; and "Poor" indicates a tolerance greater than the middle grade of the coarse grade.

As shown in Figure 5, in Experimental Example 1, where the surface hardness of the top surface, the surface hardness of the recess, and the surface hardness of the hinge were all less than 6B (7B), the dimensional stability of the recess and hinge (fitting portion) was good, but the scratch resistance of the top surface (exposed portion) was poor. Furthermore, in Experimental Example 9, where the surface hardness of the top surface, the surface hardness of the recess, and the surface hardness of the hinge were all F, the scratch resistance was good, but the dimensional stability of the recess and hinge (fitting portion) was poor. In other words, when the surface hardness of the top surface (exposed portion) and the surface hardness of the recess and hinge (fitting portion) were the same, it was difficult to achieve both improved scratch resistance of the exposed portion and ensure dimensional stability of the fitting portion.

In contrast, in Experimental Examples 2 to 8, 10, and 11, in which the surface hardness of the recess and hinge portions was lower than that of the top surface, the scratch resistance of the top surface (exposed portion) was good, and the dimensional stability of the recess and hinge portion (fitting portion) was also good. In particular, in Experimental Examples 2 to 4, 6 to 8, and 10, in which the surface hardness of the top surface was a pencil hardness of B or higher, the scratch resistance of the top surface (exposed portion) was better than in Experimental Examples 1, 5, and 11, in which the surface hardness of the top surface was less than a pencil hardness of B. Furthermore, in Experimental Examples 2 to 7 and 10, in which the surface hardness of the recess and hinge portion was a pencil hardness of 2B or less, the dimensional stability of the recess and hinge portion (fitting portion) was better than in Experimental Examples 8 and 9, in which the surface hardness of the recess and hinge portion was a pencil hardness of more than 2B. In other words, it was suggested that by setting the surface hardness of the upper surface to a pencil hardness of B or higher and the surface hardness of the recessed portion and hinge portion (fitting portion) to a pencil hardness of 3B or higher and 2B or lower, it is possible to achieve a better balance between scratch resistance and dimensional stability of the recessed portion and hinge portion (fitting portion).

Furthermore, the results of Experimental Examples 4 and 11 suggest that adding an inorganic filler such as glass fiber increases the surface hardness compared to when no inorganic filler is added.

In the above description, the plumbing component 200 is described as a toilet seat or toilet lid, but the plumbing component is not limited to these. The plumbing component may be, for example, a washbasin counter, a bathroom counter, or a hand-washing basin provided at the rear of a toilet device. In other words, the plumbing component can be, for example, a toilet seat, a toilet lid, a washbasin counter, a bathroom counter, or a hand-washing basin provided at the rear of a toilet device.

If the bathroom component 200 is a washbasin counter, the fixture 260 is, for example, a cabinet provided below the washbasin counter. The exposed portion 220 is, for example, the surface of the bowl or counter. The mated component 250 is, for example, a drain plug component or a drain pipe component. The mating portion 210 is, for example, a drain outlet provided in the bowl.

If the bathroom fixture 200 is a bathroom counter, the fixture 260 is, for example, the wall of the bathroom. The exposed portion 220 is, for example, the counter (top). The mated member 250 is, for example, a support base that supports the counter. In this case, the mating portion 210 is, for example, a portion that is fixed to the support base on the underside of the counter (top). The mated member 250 may also be, for example, a decorative cover that is attached to the counter. In this case, the mating portion 210 is, for example, a recess into which the decorative cover fits.

When the plumbing component 200 is a hand-washing basin, the fixture 260 is, for example, the tank portion of a toilet bowl located below the hand-washing basin. The exposed portion 220 is, for example, the surface of the hand-washing basin. The mating member 250 is, for example, a mating portion located on the top of the tank portion. The mating portion 210 is, for example, a recess located on the bottom of the hand-washing basin.

The following aspects, for example, can be considered as plumbing components based on the above-described embodiments.

The first aspect is a plumbing component containing a crystalline resin, comprising a fitting portion into which a fitted component is fitted, and an exposed portion other than the fitting portion that is provided in an exposed position when the component is attached to a fixture, and characterized in that the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion.

According to the first aspect, by relatively increasing the surface hardness of the exposed portion, scratches on the surface of the exposed portion can be reduced even when wiping with toilet paper or a hard nonwoven fabric. This improves the scratch resistance of the exposed portion, which is easily visible to the user, and reduces damage to the aesthetic appearance. On the other hand, under normal use conditions, the mating portion is hidden by the mated member. Therefore, wiping is difficult to perform on the mating portion. Even if wiping does result in scratches on the surface of the mating portion, the scratches are in a location that is difficult for the user to see, so there is little risk of the aesthetic appearance being damaged. In other words, even if the surface hardness of the mating portion is relatively low, the impact on the aesthetic appearance is small. In this way, because the surface hardness of the mating portion can be relatively low, the mold temperature can be relatively low when curing the resin when molding the mating portion, for example. This reduces dimensional change over time due to increased shrinkage in the mating portion, thereby improving dimensional accuracy. Therefore, the mating portion can be formed in the desired shape, and the mated member can be properly fitted into the mating portion. In this way, the first aspect achieves both improved scratch resistance of the exposed portion and ensuring dimensional stability of the mating portion.

The second aspect is a plumbing component according to the first aspect, characterized in that the surface hardness of the exposed portion is a pencil hardness of B or higher, and the surface hardness of the fitting portion is a pencil hardness of 2B or lower.

According to the second aspect, by setting the surface hardness of the exposed portion to a pencil hardness of B or higher, scratches on the surface of the exposed portion can be prevented even when wiping with strong force using toilet paper, hard nonwoven fabric, etc. Furthermore, by setting the surface hardness of the mating portion to a pencil hardness of 2B or less, the dimensional accuracy of the mating portion can be more reliably improved. In other words, a better balance can be achieved between improving the scratch resistance of the exposed portion and ensuring the dimensional stability of the mating portion.

The third aspect is a plumbing component according to the second aspect, characterized in that the surface hardness of the exposed portion is a pencil hardness of F or less.

According to the third aspect, by setting the surface hardness of the exposed portion to a pencil hardness of F or less, it is possible to more easily manufacture plumbing components while preventing scratches on the surface of the exposed portion. For example, by combining known techniques such as adding glass fiber and H&C molding with an inexpensive PP material as a base, plumbing components with exposed portions that have sufficient hardness can be manufactured at low cost.

The fourth aspect is a plumbing component according to the second or third aspect, characterized in that the surface hardness of the fitting portion is 3B or higher on the pencil hardness scale.

According to the fourth aspect, by setting the surface hardness of the mating portion to a pencil hardness of 3B or higher, scratches on the surface of the mating portion can be prevented even when the mated member is removed and the mating portion is wiped. This prevents scratches on the surface of the mating portion, which could prevent the mated member from being able to be properly mated.

As described above, this embodiment provides a plumbing component that achieves both improved scratch resistance of the exposed portion and ensures dimensional stability of the fitting portion.

The above describes the embodiments of the present invention. However, the present invention is not limited to these descriptions. Design modifications made by a person skilled in the art to the above-described embodiments are also included within the scope of the present invention as long as they incorporate the features of the present invention. For example, the shape, dimensions, materials, arrangement, installation form, etc. of each element of the plumbing components are not limited to those exemplified and can be modified as appropriate.
Furthermore, the elements of each of the above-described embodiments can be combined to the extent technically possible, and such combinations are also included within the scope of the present invention as long as they include the features of the present invention.

10 Toilet bowl, 11 Bowl portion, 11a Rim, 11h Opening, 20 Casing, 30 Toilet lid, 31 Toilet lid main body portion, 31a Toilet lid upper surface portion, 31b Toilet lid lower surface portion, 31c Toilet lid recess portion, 32 Toilet lid hinge portion, 33 Toilet lid cushion member, 40 Toilet seat, 41 Toilet seat main body portion, 41a Toilet seat upper surface portion, 41b Toilet seat lower surface portion, 41c Toilet seat recess portion, 41h Opening, 42 Toilet seat hinge portion, 43 Toilet seat cushion member, 45 Bottom plate, 46 Top plate, 46a-46c First to third portions, 47, 48 First and second connecting members, 100 Toilet device, 200 Plumbing component, 210 Fitting portion, 220 exposed part, 250 fitted member, 260 instrument, C1, C2 cooling part, H heating part, M1, M2 mold, X material

Claims (8)

A water-related component containing a crystalline resin,
a fitting portion into which a fitted member is fitted;
an exposed portion that is a portion other than the fitting portion and is provided at a position that is exposed when the device is attached;
Equipped with
the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion;
The plumbing member is a toilet lid having a toilet lid main body,
The toilet lid body is a bathroom component characterized in that it is made up of a single member . A water-related component containing a crystalline resin,
a fitting portion into which a fitted member is fitted;
an exposed portion that is a portion other than the fitting portion and is provided at a position that is exposed when the device is attached;
Equipped with
the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion;
The plumbing component is a toilet seat having a top plate and a bottom plate,
The upper plate is formed of a single member,
the fitted member is a toilet seat cushion member,
The plumbing member is characterized in that the fitting portion is a toilet seat recess provided in the bottom plate . A water-related component containing a crystalline resin,
a fitting portion into which a fitted member is fitted;
an exposed portion that is a portion other than the fitting portion and is provided at a position that is exposed when the device is attached;
Equipped with
the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion;
The bathroom component is characterized in that the bathroom component is a washbasin counter . A water-related component containing a crystalline resin,
a fitting portion into which a fitted member is fitted;
an exposed portion that is a portion other than the fitting portion and is provided at a position that is exposed when the device is attached;
Equipped with
the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion;
The plumbing member is a bathroom counter . A water-related component containing a crystalline resin,
a fitting portion into which a fitted member is fitted;
an exposed portion that is a portion other than the fitting portion and is provided at a position that is exposed when the device is attached;
Equipped with
the surface hardness of the fitting portion is lower than the surface hardness of the exposed portion;
The plumbing component is a hand-washing basin . the surface hardness of the exposed portion is B or more in pencil hardness;
6. The member for use in a bathroom according to claim 1, wherein the surface hardness of the fitting portion is 2B or less in pencil hardness. 7. The plumbing member according to claim 6 , wherein the exposed portion has a surface hardness of F or less in pencil hardness. 8. The plumbing member according to claim 6 , wherein the surface hardness of the fitting portion is 3B or more in pencil hardness.