Toilet lid with suppressed sink mark

Abstract

To provide a toilet lid in which an upper surface is entirely flat because of suppressed sink marks, and which is excellent in the aesthetic appearance.SOLUTION: A toilet lid which is provided to open and close relative to a toilet seat for the use includes a crystalline resin and includes a lid upper surface part exposed upward and a lid lower surface part exposed downward in the closed state. A cushion part in contact with the toilet seat is joined to the lid lower surface part. The irregularity in a region of a surface of the lid upper surface part that faces a region to which the cushion part is joined, and where the region is projected is within a range of -32 μm to 72 μm in the comparison with a peripheral edge part of the region. The toilet lid is excellent in the aesthetic appearance as the toilet lid has suppressed sink marks, and the upper surface is entirely flat.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a toilet lid combined with a toilet seat, and more particularly to a toilet lid having an excellent appearance with a flat surface throughout the lid surface.

Background Art

[0002] In a toilet device, a toilet seat is generally placed on a toilet bowl, and a toilet lid is further provided thereon so as to be openable and closable. When the toilet lid is closed, it is a member that comes into view as the appearance of the toilet device, and the appearance of its surface is also an important part that determines the image of the product. Therefore, it is important that the plane is, for example, smooth and flat.

[0003] Generally, a cushion portion that abuts against the toilet seat is provided on the toilet lid. In order to couple this cushion portion to the toilet lid body, so-called ribs are provided, and methods such as fitting the cushion portion are known (for example, Japanese Unexamined Patent Application Publication No. 2021-83663 (Patent Document 1)). However, sink marks, which are often seen in plastic molding, may occur due to the provision of ribs for joining the cushion portion. In the case of a toilet lid, there is a risk of causing a defective appearance on the back side of the cushion portion, that is, the upper surface of the toilet lid.

[0004] On the other hand, as a method of joining the cushion portion to the toilet lid, a method called insert molding has been proposed in which a member that becomes the cushion portion is placed in advance in a toilet lid mold and injection molded (for example, Japanese Unexamined Patent Application Publication No. 2018-68402 (Patent Document 2)). However, as far as the present inventors know, unevenness recognizable to the human eye may still be observed on the upper surface of the toilet lid, and there is room for improvement.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

SUMMARY OF THE INVENTION

PROBLEMS TO BE SOLVED BY THE INVENTION

[0006] The present inventors have now found that by combining a crystalline resin with insert molding and further controlling the positional relationship between the cushion part and the lid body, the generation of sink marks on the upper surface of the lid can be efficiently suppressed. The present invention is based on such findings.

[0007] Therefore, an object of the present invention is to provide a lid for a toilet bowl that is excellent in appearance, with sink marks suppressed and its upper surface being flat throughout.

MEANS FOR SOLVING THE PROBLEMS

[0008] The toilet lid according to the present invention is a toilet lid that is provided to be openable and closable with respect to a toilet seat and is composed of a crystalline resin, comprising a lid upper surface portion that is exposed upward and a lid lower surface portion that is exposed downward in its closed state, a cushion portion that abuts against the toilet seat is joined to the lid lower surface portion, and the unevenness within the surface region of the lid upper surface portion that faces the region where the cushion portion is joined and where the region is projected is in the range of -32 μm to 72 μm in contrast to the peripheral edge portion of the region.

EFFECTS OF THE INVENTION

[0009] According to the present invention, there is provided a toilet lid that is excellent in appearance, with sink marks suppressed and its upper surface being flat throughout.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Embodiments for Carrying Out the Invention

[0011] Lid The overall view of the toilet device provided with the toilet lid according to the present invention is as shown in FIG. 1. In the toilet device 1 in the figure, the toilet lid 10 and the toilet seat 20 are connected such that the toilet lid 10 can be opened and closed and are mounted on the toilet bowl 30. FIG. 2 is an overall view of the toilet device 10 with the toilet lid 10 closed. In this aspect, when the toilet lid 10 is closed, the toilet seat 20 is completely covered by the toilet lid 10. In FIGS. 1 and 2, the toilet lid 10 is composed of an upper lid portion 11 that is exposed upward in the closed state and a lower lid portion 12 that is exposed in the direction of the toilet seat, that is, downward. Further, on the lower lid portion 12, cushion portions 13 (two in the figure) that come into contact with the toilet seat 20 and mainly cushion the impact during opening and closing are joined with the structure described later. The upper lid portion 11 and the lower lid portion 12 of the toilet lid according to the present invention are flat surfaces.

[0012] In FIG. 2, the area surrounded by the broken line indicated as 14 faces the area where the cushion portion is joined and shows the area of the surface of the upper lid portion onto which that area is projected. FIG. 3 is an enlarged view of this area 14 and its periphery. In the present invention, it is characterized in that the unevenness within this area 14 is within the range of -32 μm to 72 μm in comparison with the peripheral portion of this area 14.

[0013] In the present invention, "the unevenness within the area of the upper surface of the lid where the area facing the area where the cushion part is joined and the area is projected is within the range of -32 μm to 72 μm in comparison with the peripheral part of the area", that is, in the embodiments shown in FIGS. 1 to 3, "the unevenness within area 14 is within the range of -32 μm to 72 μm in comparison with the peripheral part of the area" is defined as described below. Note that the measurement method defined below is referred to as the "deformation amount measurement method" in this specification. Also, in this specification, the above numerical value may be referred to as the "deformation amount of the upper surface".

[0014] FIG. 4 based on FIG. 3, and further FIG. 5 are explanatory diagrams of the "deformation amount measurement method". First, as shown in FIG. 4, at the center point 16 of the straight line 15 in the length direction of area 14, a straight line 17 perpendicular to the straight line 15 is drawn, and the points where it intersects the outer peripheral part of area 14 are set as point a10 and point b10. Further, points 3 mm outside each of them are set as point a11 and point b11. The unevenness profile is measured on a straight line starting from points (point A1 and point B1 in FIG. 3) beyond points a11 and b11 on the straight line 17. The measurement is performed using a surface shape measuring instrument, for example, the Keyence one-shot three-dimensional shape measuring machine unevenness profile VR-6000.

[0015] FIG. 5 is a graph simulating the unevenness profile of the measurement result. The vertical axis represents the unevenness, the horizontal axis represents the distance, and the unevenness profile is measured from point A1 which is the starting point to point B1 which is the ending point. Next, a line segment 51 connecting the points corresponding to the positions of points a11 and b11 on this unevenness profile is drawn. A line is drawn perpendicularly from this line segment 51 to the unevenness profile, and the length 52 of the perpendicular line at the position where the line becomes the longest is defined as the "unevenness amount". At this time, when the unevenness profile is above the line segment 51 and is convex, it is expressed as a positive value, and conversely, when the unevenness profile is below the line segment 51 and is concave, it is expressed as a negative value.

[0016] Next, as shown in FIG. 4, from the center line 17 (the straight line connecting A1 and B1) of the region 14, at the position of 1 / 4 of the total length of the region 14, draw lines 18 and 19 parallel to the line 17. Similar to the case of the line 17, measure the uneven profiles from point A2 to point B2 and from A3 to B3. Further, similar to the case of the line 17, determine the points where the lines intersect the outer peripheral part of the region 14 (point a20 and point b20 for the line 18, and point a30 and point b30 for the line 19), and further determine the points 3 mm outside each of them (point a21 and point b21 for the line 18, and point a31 and point b31 for the line 19), and obtain the "amount of unevenness" in the uneven profile.

[0017] Find the average value of the three "unevenness values" thus obtained. In the present invention, the average value of these three "unevenness values" is in the range of -32 μm to 72 μm. Preferably, it is in the range of -20 μm to 50 μm.

[0018] The measurement of the above "deformation measurement method" has been described for the aspect where the cushion part has a longitudinal direction and the shape of the region 14 is rectangular. For the aspect where the region 14 is square, any side can be regarded as the longitudinal side and the above measurement method can be applied.

[0019] Since the unevenness of the region 14 is within the above range, the presence of sink marks cannot be recognized by the human eye and it can be regarded as a flat surface. Therefore, the toilet lid according to the present invention has a flat and smooth upper surface, is excellent in appearance without sink marks, and can improve the commercial value of the toilet device.

[0020] According to a preferred embodiment of the present invention, the toilet lid has a recess on the lid lower surface portion where the cushion part is joined, and a part of the cushion part penetrates into this recess. FIG. 6 shows a configuration in which a recess is provided on the lid lower surface portion 12 of the toilet lid 10 and the cushion part 13 penetrates therein. According to a preferred embodiment of the present invention, when the depth of the recess is T1 and the thickness of the toilet lid main body portion is T2, the relationship of T1 / T2 = 0.08 to 0.26 is satisfied. Thereby, sink marks are more effectively suppressed.

[0021] According to a preferred embodiment of the present invention, the toilet lid comprises a crystalline resin, the crystallinity of the outermost layer is 50% or more, and it is preferable that the crystallinity of the outermost layer is maintained up to at least a depth of 9.0 μm from the outermost layer, that is, the outermost surface of the member.

[0022] In the above embodiment, the crystallinity of the resin refers to the ratio of the crystalline part in the crystalline resin, and the measurement method thereof is well-known. For example, as the measurement method of crystallinity, a density method, a thermal analysis method, an NMR method, an IR method, etc. can be mentioned. In the present invention, preferably, the crystallinity is measured by an X-ray diffraction method. That is, the resin is irradiated with X-rays, and from the obtained diffraction information, the scattering region derived from the crystal and the scattering region derived from the amorphous are separated, and it is calculated as the ratio of the crystal scattering intensity to the total scattering intensity, and this is taken as the crystallinity.

[0023] In the present invention, "the crystallinity of the outermost layer is maintained" means that in addition to the crystallinity value being the same from the outermost surface of the member to at least a depth of 9.0 μm, up to at least a depth of 9.0 μm, compared with the crystallinity of the outermost layer, the change + is within the range of about 7%, preferably + is within the range of 5%.

[0024] By maintaining the predetermined crystallinity up to at least a depth of 9.0 μm from the outermost surface of the member, the surface of the member has the property of being difficult to be scratched by rubbing, and further has various properties required for the toilet lid, that is, excellent strength, durability, and small dimensional change after molding. The present invention is advantageous in that a good resin member can be realized even in properties generally considered to decrease when the resin crystallizes.

[0025] According to a preferred embodiment of the present invention, the crystallinity of the outermost layer is 50% or more, more preferably 70% or more. Further, such crystallinity of the outermost layer is maintained up to at least a depth of 9.0 μm, more preferably up to at least a depth of 50 μm.

[0026] Examples of the crystalline resin that can be used as the toilet lid member according to the present invention include polypropylene (PP), polybutylene terephthalate (PBT), polyethylene (PE), polyamide (PA), polyacetal, polyoxymethylene (POM), polyethylene terephthalate (PET), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), polytetrafluoroethylene (PTFE), and the like.

[0027] According to another preferred embodiment of the present invention, the resin can contain additives commonly used to improve the properties of the resin material. For example, it can contain a filler made of an inorganic material, preferably glass fiber, to enhance its strength.

[0028] In addition, as the material for forming the cushion portion of the toilet lid of the present invention, a thermoplastic elastomer having rubber-like flexibility at room temperature can be used. For example, an olefin-based elastomer, a styrene-based elastomer, or a polyether-based elastomer can be used.

[0029] Manufacturing method The toilet lid according to the present invention is manufactured by a method capable of controlling the crystallization of the crystalline resin, and is preferably manufactured by the following method. First, prepare a mold capable of molding a toilet lid having an insert region where the cushion portion is disposed and integrating the cushion portion by insert molding, and a pre-molded cushion portion. Then, the resin heated to the melting temperature is filled into the mold heated to a temperature in the range of the crystallization temperature of the resin + 10 °C, held in the mold for at least 20 seconds or more, and preferably manufactured by a method of obtaining a toilet lid after cooling the mold. Here, the crystallization temperature of the resin can be derived by the following method, for example, by differential scanning calorimetry (DSC measurement). The crystalline resin is heated to a temperature above the melting point, and after the resin is completely melted, the resin is cooled at a cooling rate of about 5 °C / min, for example. When the temperature is lowered, an exothermic peak associated with crystallization is observed, and the temperature of the peak is taken as the crystallization temperature.

[0030] According to one aspect of the present invention, when the resin is a PP resin, the mold is heated to a temperature of 110°C or higher and 130°C or lower, and the resin heated to a temperature higher than the temperature of the mold is filled into the mold. Here, according to a preferred aspect of the present invention, the temperature of the resin is set to 180°C or higher and 220°C or higher, more preferably about 190°C. After filling the resin into the mold, if necessary, the temperature of the mold is heated, and the mold temperature is maintained in the range of 110°C or higher and 130°C or lower for at least 20 seconds or more, preferably 40 seconds or more, and more preferably 60 seconds or less, and then a molded member is obtained after heat dissipation or cooling.

Example

[0031] The present invention will be further described by the following examples, but the present invention is not limited to these examples.

[0032] Preparation of cushion An olefin-based elastomer (CP / EXC-004P manufactured by Okay Kasei Co., Ltd.) was prepared as a cushion material, and injection molding was performed at a resin temperature of 190°C and a mold temperature of 40°C. Four types of cushion molded products with a length of 109.6 mm, a width of 13.6 mm for insert molding, and heights of 8.7 mm, 9.2 mm, 10.2 mm, and 11.6 mm were manufactured while changing the mold inserts.

[0033] Manufacture of lid A lid mold with a space for inserting a cushion molded product at the cushion part position was used, and the production of the lid was carried out as follows.

[0034] First, as a lid material, a PP resin with an MFR (temperature 230°C, load 2.16 kgf) conforming to JIS K-7210 of 19 g / 10 min was used. Glass fiber (GF) was melt-kneaded using an extruder to a content of 20 parts by mass to prepare resin pellets.

[0035] The cushion molded product obtained above was inserted into the space for inserting the cushion of the lid mold. Then, the resin pellets obtained above were heated to 190 °C and filled into the mold heated to 120 °C. Thereafter, the temperature of the mold was maintained at 120 °C for 40 seconds. After cooling, the molded body was removed from the mold, and a molded product of the lid with the cushion and the lid joined together was obtained. The wall thickness of the lid was 5.7 mm. Also, since the height of the cushion molded product was different, cushions were joined in the form of invading at thicknesses of 0 mm, 0.5 mm, 1.5 mm, and 2.9 mm in the lid wall thickness direction respectively (hereinafter, these numerical values are referred to as "cushion part invasion depth"), and lids were obtained. These are referred to as Example 1 to Example 3 and Comparative Example in order.

[0036] The "lid wall thickness", "height of the cushion part", "wall thickness of the cushion part", and "cushion part invasion depth" of Example 1 to Example 3 and Comparative Example were summarized in Table 1 below.

[0037] Measurement of deformation amount of upper surface Measurement was carried out with a Keyence one-shot 3D shape measuring machine VR-6000 in accordance with the above-mentioned "deformation amount measurement method". That is, the "deformation amount of the upper surface" of the region with a width of 13.6 mm and a length of 109.6 mm corresponding to the region 14 in FIG. 3 of the surface (appearance surface) on the side opposite to the surface where the cushion of the lid was joined was measured. The results were as shown in Table 1 below.

[0038] Appearance evaluation Under indoor lighting, visually observe the vicinity of the surface of the upper surface part of the lid where the upper surface of the lid, particularly the region where the cushion part is joined, is projected. When no unevenness was confirmed, it was evaluated as ○, and when unevenness could be confirmed, it was evaluated as ×. The results were as shown in Table 1 below.

[0039]

Table 1

[0040] Measurement of crystallinity As the material for the toilet lid, a PP resin with an MFR (temperature: 230°C, load: 2.16 kgf) conforming to JIS K-7210 of 19 g / 10 min was used, and the crystallinity of the toilet lid obtained under the same conditions as in the examples was measured with the following measuring apparatus and conditions. Analyzer: SmartLab manufactured by Rigaku Corporation X-ray source: CuKα (45 kV - 200 mA) Optical system: Out-of-plane (incident angles: 0.3, 1, 2, 3, 5°) Stage: RxRy attachment head Detector: HyPix-3000 Scan mode: 0 dimension Scan speed: 3.5°·min-1 Step width: 0.056° Scan axis: 2θ Scan range: 5 - 40° Incident slit box: 0.072 mm Longitudinal limiting slit: 10 mm Light-receiving slit box 1: 1.0 mm Light-receiving slit box 2: 1.1 mm The X-ray incident angle (ω) was changed from 0.3 to 5 degrees. This X-ray incident angle (ω) corresponds to an analysis depth (X-ray penetration depth) of 2.4 μm to 46.0 μm.

[0041] For each X-ray incident angle, the area of the crystal part and the area of the non-crystalline part were determined from the X-ray diffraction pattern, and the crystallinity was calculated using the following arithmetic formula. Crystallinity (%) = [(area of crystal part) / (area of crystal part + area of non-crystalline part)] × 100

[0042] The depth from the measured surface and the crystallinity were as shown in Table 1 below.

Table 2

[0043] Preferred embodiment of the present invention Preferred embodiments of the present invention are as follows. (1) A toilet lid that is provided to be openable and closable with respect to a toilet seat and is used, comprising a crystalline resin, consisting of a lid upper surface portion that is exposed upward and a lid lower surface portion that is exposed downward in its closed state, a cushion portion that abuts against the toilet seat is joined to the lid lower surface portion, and the unevenness within the surface region of the lid upper surface portion that faces the region where the cushion portion is joined and where the region is projected is within the range of -32 μm to 72 μm in comparison with the peripheral edge portion of the region, the toilet lid. (2) The toilet lid according to (1) above, wherein the lid lower surface portion has a recess to which the cushion portion is joined, and a part of the cushion portion is embedded in the recess. (3) The toilet lid according to (1) or (2) above, wherein when the depth of the recess is T1 and the thickness of the toilet lid main body portion is T2, the relationship T1 / T2 = 0.08 to 0.26 is satisfied. (4) The toilet lid according to any one of (1) to (3) above, wherein the crystallinity in its outermost layer is 50% or more, and the crystallinity of the outermost layer is maintained to a depth of at least 9.0 μm from the outermost layer. (5) The toilet lid according to any one of (1) to (4) above, wherein the crystalline resin is at least one selected from the group consisting of polypropylene (PP), polybutylene terephthalate (PBT), polyethylene (PE), polyamide (PA), polyacetal, polyoxymethylene (POM), polyethylene terephthalate (PET), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and polytetrafluoroethylene (PTFE). (6) A method for manufacturing a toilet lid having a cushion portion, preparing a mold capable of molding a toilet lid having an insert region where the cushion portion is disposed and integrating the cushion portion by insert molding, and a previously molded cushion portion, placing the cushion portion in the insert region, and heating the mold to a temperature in the range of the crystallization temperature of the resin ±10°C, Fill the mold with a resin heated to a temperature equal to or higher than the temperature of the mold, maintain the mold temperature within the range of the crystallization temperature of the resin ±10°C for at least 20 seconds or more, then cool the mold, and obtain a lid from the mold A method comprising the above.

Claims

1. A toilet lid that is provided to be openable and closable with respect to a toilet seat and is used, comprising a crystalline resin, consisting of a lid upper surface portion that is exposed upward in its closed state and a lid lower surface portion that is exposed downward, a cushion portion that abuts against the toilet seat is joined to the lid lower surface portion, and the unevenness in the surface area of the lid upper surface portion that faces the region where the cushion portion is joined and where the region is projected is within the range of -32 μm to 72 μm in comparison with the peripheral edge portion of the region. A toilet lid.

2. The toilet lid according to claim 1, wherein the lid lower surface portion has a recess to which the cushion portion is joined, and a part of the cushion portion is embedded in the recess.

3. The toilet lid according to claim 1 or 2, wherein when the depth of the recess is T1 and the thickness of the toilet lid main body portion is T2, the relationship T1 / T2 = 0.08 to 0.26 is satisfied.

4. The toilet lid according to claim 1 or 2, wherein the crystallinity in its outermost layer is 50% or more, and the crystallinity of the outermost layer is maintained to a depth of at least 9.0 μm from the outermost layer.

5. The crystalline resin is at least one selected from the group consisting of polypropylene (PP), polybutylene terephthalate (PBT), polyethylene (PE), polyamide (PA), polyacetal, polyoxymethylene (POM), polyethylene terephthalate (PET), polyetheretherketone (PEEK), polyphenylene sulfide (PPS), and polytetrafluoroethylene (PTFE). The toilet lid according to claim 1 or 2.

6. A method for manufacturing a toilet lid having a cushion portion, preparing a mold capable of molding a toilet lid in which a cushion portion is integrated by insert molding and having an insert region where the cushion portion is disposed, and a previously molded cushion portion, placing the cushion portion in the insert region, heating the mold to a temperature in the range of the crystallization temperature of the resin ±10°C, filling the mold with resin heated to a temperature equal to or higher than the temperature of the mold, holding the mold temperature in the range of the crystallization temperature of the resin ±10°C for at least 20 seconds or more, then cooling the mold, and obtaining a toilet lid from the mold comprising the above.

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