Resin joint and piping structure formed by connecting resin joint and resin pipe

Abstract

To provide a resin joint capable of reducing a portion to which an adhesive is not applied and a piping structure using the resin joint.SOLUTION: A resin joint 10 is a transparent joint including a body part 11 that comprises transparent or translucent resin and constitutes a flow passage 12 and a reception port 14 that is formed at least on one end edge of the body part and to which a pipe end 21 of a connected pipe 20 is inserted. Surface roughness of an inner face 15 of the reception port is set to be coarser than that of an outer face 16 of the reception port. Preferably, arithmetic mean height Sa of the surface of the inner face of the reception port is 0.5 μm or more.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention relates to a resin joint used for connecting resin pipes to each other and a piping structure formed by connecting a resin joint and a resin pipe.

Background Art

[0002] Buildings are equipped with a piping structure for discharging wastewater from drainage facilities such as kitchens, toilets, and bathrooms. The piping structure is configured by connecting pipes to each other with joints. In this type of piping structure, generally, resin pipes and joints are used. Among them, resin pipes and resin joints formed from transparent or translucent (hereinafter collectively referred to as "transparent") resins are increasingly adopted so that the state of the fluid flowing inside, clogging, and dirt of the pipes and joints can be visually recognized from the outside (for example, see Patent Document 1).

[0003] The resin pipe and the resin joint are connected using an adhesive to form a piping structure. The adhesive is applied to one or both of the outer surface of the pipe end and the inner surface of the receiving port of the resin joint, and the surface to which the adhesive is applied is dissolved by the organic solvent contained in the adhesive. In this state, the pipe end is inserted into the receiving port, and the adhesive is cured to connect the resin pipe and the resin joint.

[0004] For connecting a resin pipe and a resin joint (the pipe may be opaque), a colored adhesive such as blue or red may be used so that the remaining coating can be visually confirmed. By coloring the adhesive, when the adhesive is uniformly applied to the connection portion, it appears uniform in color when the connection portion is visually recognized through the receiving port of the resin joint after connection. However, if there is color unevenness, it can be confirmed that there is remaining adhesive coating.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] Since the adhesive is colored, a part of the pipe structure that becomes the connection part is colored, resulting in a sense of discomfort. In addition, since the colored part is difficult to transmit light, the internal visibility is also poor.

[0007] An object of the present invention is to provide a resin joint capable of reducing adhesive residue and a pipe structure using the same.

Means for Solving the Problems

[0008] The resin joint of the present invention is made of a transparent or translucent resin, and has a body portion constituting a flow path and a receiving port formed at at least one edge of the body portion into which the pipe end of the connected pipe is inserted. The inner surface of the receiving port has a rougher surface than the outer surface of the receiving port.

[0009] It is desirable that the arithmetic mean height Sa of the surface of the inner surface of the receiving port is 0.5 μm or more.

[0010] It is desirable that the arithmetic mean height Sa of the surface of the outer surface of the receiving port is less than 0.5 μm.

[0011] It is desirable that the haze value (cloudiness) of the receiving port is 40% or more.

[0012] By applying an adhesive containing an organic solvent to the inner surface of the receiving port, it is desirable that the haze value (cloudiness) of the receiving port becomes less than 40%.

[0013] The inner surface of the receiving port has a form in which a large number of protrusions are formed, and it is desirable that the average pitch of the protrusions is 50 μm or more and 200 μm or less.

[0014] The pipe structure of the present invention is a pipe structure formed by connecting the resin joint described above and a resin pipe. The resin joint and the pipe are joined by an adhesive containing an organic solvent.

[0015] The adhesive is preferably colorless and transparent.

[0016] The pipe preferably consists of a transparent or translucent resin.

[0017] It is desirable that the color difference ΔE between the portion where the adhesive is applied and the portion where the adhesive is not applied at the connection portion between the resin joint and the pipe is 5 or more.

[0018] The pipe preferably consists of an opaque resin.

[0019] In addition, the piping structure of the present invention is a piping structure in which a resin joint made of a transparent or translucent resin and a transparent pipe made of a transparent or translucent resin are connected by an adhesive, the haze value (cloudiness) of the resin joint is 40% or more, the haze value of the transparent pipe is 40% or less, and the haze value of the connection portion between the resin joint and the transparent pipe is 40% or less.

[0020] In addition, the piping structure of the present invention is a piping structure in which a resin joint made of a transparent or translucent resin and a resin pipe are connected by an adhesive, and the color difference ΔE between the portion where the transparent adhesive is applied and the portion where the adhesive is not applied at the connection portion between the resin joint and the pipe is 5 or more.

[0021] In addition, the piping structure of the present invention is a piping structure in which a resin joint made of a transparent or translucent resin and a transparent pipe made of a transparent or translucent resin are connected by an adhesive, and when the haze value (cloudiness) of the socket of the resin joint is defined as haze 1 and the haze value of the connection portion where the resin joint and the transparent pipe are joined using an adhesive is defined as haze 2, haze 1 - haze 2 is 20 or more.

Advantages of the Invention

[0022] In the resin joint of the present invention, by roughening the inner surface of the socket, it appears frosted glass-like in appearance. When an adhesive is applied to the inner surface of this frosted glass-like socket and joined to a pipe, the portion where the adhesive is properly applied becomes transparent. If there is a portion where the adhesive has leaked and remains, that remaining portion remains frosted glass-like. Therefore, after applying the adhesive to the inner surface of the socket, the installer can visually check the socket. If the entire socket is transparent, it can be confirmed that the adhesive has been evenly applied to the entire inner surface of the socket. On the other hand, if there are transparent portions and portions remaining frosted glass-like in the socket, it can be seen that there is remaining adhesive, and the remaining portion can be re-coated with the adhesive.

[0023] In the piping structure of the present invention, when a resin joint and a resin pipe are joined with an adhesive, if the connection portion between the socket and the pipe end inserted into the socket is transparent, the haze value changes, or the color difference ΔE changes, it can be confirmed that the adhesive has been evenly applied to the entire inner surface of the socket. On the other hand, if there are transparent portions and portions remaining frosted glass-like in the socket, it can be seen that there is remaining adhesive, and the construction can be redone. That is, according to the present invention, the application status of the adhesive can be visually confirmed.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0025] The details of the resin joint 10 of the present invention and the piping structure 30 formed by connecting the resin joint 10 (hereinafter, appropriately referred to as "joint 10") and the resin pipe 20 (also referred to as "pipe 20") will be described with reference to the drawings. Hereinafter, first, the joint 10 will be described, and then the pipe 20, the adhesive, and the joint 10 coated with the adhesive will be described, and finally the piping structure 30 will be described.

[0026] <Resin Joint 10> FIG. 1 is a perspective view of the joint 10 and the pipe 20 before connection, and FIG. 2 is a longitudinal sectional view of the joint 10.

[0027] As shown in the figure, the joint 10 has a receiving port 14 formed at the edge of at least one (both in the figure) of the body portion 11 and the body portion 11. The body portion 11 is a cylindrical body having a fluid flow path 12 formed therein as shown in FIG. 2, and has an inner diameter substantially matching the inner diameter of the pipe 20 to be connected. The receiving port 14 is a cylindrical body into which the pipe end 21 is inserted and joined to the pipe 20 with an adhesive. The receiving port 14 has a form with a larger diameter than the body portion 11 as shown in the figure, and is formed such that its inner diameter substantially matches the outer diameter of the pipe 20.

[0028] The illustrated joint 10 is a so-called elbow joint bent at 90 degrees. However, the joint 10 of the present invention may be an elbow pipe or a vent pipe bent at an angle other than 90 degrees, and the joint 10 may be a so-called cheese pipe (T pipe), Y pipe, socket, or the like.

[0029] The joint 10 is made of a transparent or translucent resin material. In the present invention, the "transparent or translucent resin material" (hereinafter referred to as "transparent resin material") is a resin material that can transmit light and is a resin material whose interior can be visually recognized when light is applied. For example, the transparent resin material is a material / part in which the total light transmittance TT defined below is at least 35% or more. And in the present invention, the joint made of the transparent resin material is referred to as a resin joint 10 or simply joint 10.

[0030] As the transparent resin material, a colorless and transparent clear one is preferable, but a resin material with a tint such as blue, yellow, green, red, etc. can also be adopted as long as the light transmittance and the internal visibility are not impaired.

[0031] Examples of this type of resin material include, but are not limited to, polypropylene, polyvinyl chloride (rigid, soft), acrylic, polycarbonate, PS, ABS, AS, etc.

[0032] Note that for the joint 10, it is sufficient that at least the receiving portion 14 is transparent (or translucent), and the body portion 11 may be transparent (or translucent) or opaque. When the body portion 11 is transparent (or translucent), the surface of the inner surface and / or outer surface of the body portion 11 may be roughened. The surface roughness of the inner surface and / or outer surface of the body portion 11 may be the same as or different from the surface roughness of the inner surface 15 of the receiving portion 14. Also, the surface roughness may be the same or different between the inner surface and the outer surface of the body portion 11. Furthermore, the surface roughness of the inner surface and / or outer surface of the body portion 11 may be uniform or may have variations in roughness.

[0033] The joint 10 can be of a single-layer structure or a multi-layer structure consisting of two or more layers. Also, the joint 10 may have a fire-resistant structure.

[0034] -Receiving portion 14- The joint 10 of the present invention is characterized in that the following difference is provided between the inner surface 15 and the outer surface 16 of the receiving portion 14.

[0035] -Roughness- As a first difference, as shown in FIGS. 1 and 2, the inner surface 15 of the receiving port 14 is configured to have a rougher surface than the outer surface 16. Specifically, the inner surface 15 of the receiving port 14 has a rough surface formed with fine unevenness, scratches, textures, etc. Specific patterns include stripes, checks, dots, striped patterns, pictorial patterns, and embossed patterns. Due to the rough surface, the inner surface 15 of the receiving port 14 becomes a frosted shape like ground glass.

[0036] This frosted inner surface 15 may cover the entire inner surface of the receiving port 14 or may partially be a frosted surface. Any design is acceptable as long as it can be seen that the adhesive covers the entire receiving port 14. In particular, when it is desired to confirm that the adhesive is firmly applied to the back side of the receiving port 14 rather than the front side, it is sufficient if the frosted inner surface 15 is formed at least on the back side of the receiving port 14.

[0037] -Arithmetic mean height Sa- The inner surface 15 of the receiving port 14 is preferably configured such that the arithmetic mean height Sa of the surface is 0.5 μm or more. Thereby, the inner surface 15 of the receiving port 14 can be made frosted like ground glass. The arithmetic mean height Sa of the inner surface 15 of the receiving port 14 is desirably 1.0 μm or more, and more desirably 1.5 μm or more. Also, the inner surface 15 of the receiving port 14 is preferably configured such that the arithmetic mean height Sa of the surface is 25 μm or less. Thereby, the adhesiveness between the inner surface 15 of the receiving port 14 and the resin pipe 20 is improved. The arithmetic mean height Sa of the inner surface 15 of the receiving port 14 is desirably 20 μm or less, and more desirably 15 μm or less. The arithmetic mean height Sa can be measured in accordance with ISO 25178. For example, it can be measured using a digital microscope: VHX-8000 manufactured by KEYENCE CORPORATION and calculated using the company's 3D shape software: VHX-H5M. In addition, the arithmetic mean height Sa of the outer surface 16 of the receiving port 14, and the inner and outer surfaces of the body portion 11 described below can also be measured in the same manner. In this case, at least three measurement locations of the inner surface 15 of the receiving port 14 described above can be respectively replaced with the outer surface 16 of the receiving port 14, the inner surface of the body portion 11, and the outer surface of the body portion.

[0038] The outer surface 16 of the receiving port 14 is formed smoother than the inner surface 15 of the receiving port 14. Thereby, when the receiving port 14 is viewed from the outer surface 16 side, the ground glass-like inner surface 15 of the receiving port 14 can be confirmed through the transparent outer surface 16. The arithmetic mean height Sa of the outer surface 16 of the receiving port 14 is preferably less than 0.5 μm, desirably 0.45 μm or less, and more desirably 0.4 μm or less.

[0039] -Pitch- Also, the receiving port 14 can be configured to have a large number of protrusions formed on its surface in order to be ground glass-like. In this case, the lower limit of the average pitch of the protrusions is 50 μm, and the upper limit is preferably 200 μm. The lower limit of the average pitch of the protrusions is desirably 75 μm, and more desirably 100 μm. Also, the upper limit of the average pitch of the protrusions is desirably 175 μm, and more desirably 150 μm. The average pitch can be measured, for example, by actual measurement using an optical microscope photograph.

[0040] -Haze value- The ground glass-like cloudiness of the inner surface 15 of the receiving port 14 before the adhesive is applied can also be defined by the haze value (Haze: cloudiness degree). It is preferable that the haze value measured from the outer surface 16 side of the receiving port 14 is 40% or more. Desirably, the haze value of the receiving port 14 is 50% or more, more desirably 60% or more, and particularly desirably 70% or more. By setting the haze value of the receiving port 14 in this way, the portions where the adhesive is not applied remain ground glass-like and appear cloudy in appearance. Note that the haze value of the receiving port 14 before the adhesive is applied is referred to as haze 1.

[0041] On the other hand, for the receiving port 14, the haze value after the adhesive is applied to the inner surface 15 is preferably less than 40%, desirably less than 35%. More desirably, the haze value of the receiving port 14 after the adhesive is applied is less than 30%. By setting the haze value of the receiving port 14 after the adhesive is applied as described above, the receiving port 14 after the adhesive is applied appears transparent in appearance. Therefore, as described in the examples, the remaining application of the adhesive can be visually confirmed.

[0042] The haze value can be measured in accordance with JIS K 7316 and JIS K 7136, and can be measured using a haze meter: NDH-7000 manufactured by Nippon Denshoku Industries Co., Ltd. Regarding the method of preparing the sample, cut out the part of the sample to be measured, preheat it at 190°C for 5 minutes, then press it into a flat plate, and then measure the haze value. Note that in order to prevent the unevenness on the inner surface 15 of the receiving port 14 of the joint 10 from being smoothed by pressing, a spacer was used at the peripheral part so as not to directly touch the press plate to make it a flat plate.

[0043] - Barrel part 11 - Except for the receiving port 14 of the joint 10, that is, the roughness and arithmetic mean height Sa of the inner and outer surfaces of the barrel part 11 are not particularly limited. For example, it is preferable that the arithmetic mean height Sa of the inner and outer surfaces of the barrel part 11 is 0.5 μm or less. Also, the outer surface of the barrel part 11 is made to match the texture of the outer surface of the receiving port 14 in order to eliminate a sense of incongruity when visually observed or when touched by an operator.

[0044] - Manufacturing method of the resin joint 10 - The joint 10 with the above configuration can be manufactured, for example, by injection molding. In order to adjust the roughness of the inner surface 15 of the receiving port 14, that is, the arithmetic mean height Sa as described above, the injection mold can be processed with a rough surface, processed to generate unevenness, or formed with scratches or textures on the surface facing the inner surface 15 of the receiving port 14. On the other hand, the roughness and arithmetic mean height Sa of the inner surface 15 of the receiving port 14 may be adjusted by performing post-processing on the inner surface 15 of the receiving port 14. In the case of post-processing, sandblasting can be performed on the inner surface 15 of the receiving port 14, or surface processing can be performed, for example, with a disk grinder equipped with an appropriate surface roughening jig. In addition to the above or independently, frosting processing may also be performed. Of course, the manufacturing method of the joint 10 and the processing method of the receiving port 14 are not limited to these.

[0045] <Resin pipe 20> As shown in Fig. 1, the tube 20 is a cylindrical body with an internal flow path 22. The tube 20 can be configured to have an outer diameter corresponding to the receiving port 14 of the joint 10 and an inner diameter corresponding to the inner diameter of the body portion 11 of the joint 10. The length of the tube 20 is not particularly limited and can be appropriately cut for use.

[0046] The tube 20 can be made of the above-described transparent resin material or an opaque resin material. Note that the opaque resin material means a resin material with low light transmittance. When it is necessary to visually confirm the inside of the tube 20, the tube 20 is made of a transparent resin material.

[0047] The tube 20 can have a single-layer structure or a multi-layer structure composed of two or more layers. Also, some or all of the layers may be foamed layers or layers having fire-resistant performance. The outer diameter of the tube 20 is selected according to JIS K 6743 or JIS K6739 from the inner diameter of the receiving port 14.

[0048] The transparent resin material used for the tube 20 is preferably a resin with a total light transmittance TT of 35% or more, preferably 50% or more, desirably 60% or more, and more desirably 70% or more. However, for the tube 20, those with a total light transmittance TT lower than this can also be used. Also, the transparent resin material is preferably a colorless and transparent clear one, but a resin material with a tint such as blue, yellow, green, or red can also be adopted. The opaque resin material may be gray, green, black, dark blue, reddish-brown, etc.

[0049] Note that the total light transmittance TT can be measured in accordance with JIS K 7375 and JIS K 7361-1. For example, the total light transmittance TT can be measured using, for example, a haze meter: NDH-7000 manufactured by Nippon Denshoku Industries Co., Ltd. Since the receiving port 14 of the joint 10 and the tube 20 are annular, after cutting out the part of the sample for which the total light transmittance TT is to be measured and preheating it at 190°C for 5 minutes, it was made into a flat plate by pressing and then the total light transmittance TT was measured. Note that a spacer was used at the periphery so as not to directly touch the press plate so that the unevenness of the inner surface 15 of the receiving port 14 of the joint 10 would not be smoothed by pressing and it was made into a flat plate.

[0050] Examples of this type of transparent resin material include, but are not limited to, polypropylene, polyvinyl chloride (rigid, flexible), acrylic, polycarbonate, PS, transparent ABS, AS, etc. Examples of opaque resin materials include resins with low transparency such as polyethylene, nylon, polyacetal, etc., and materials obtained by blending such resins with low transparency and the above-mentioned transparent resin materials with colorants such as pigments and dyes, fillers such as carbon black, talc, glass fiber, impact modifiers, etc., but are not limited to these.

[0051] <Adhesive> As the adhesive for bonding the joint 10 and the tube 20, a solvent-based adhesive that dissolves the joint 10 and the tube 20 is adopted. The adhesive contains a resin and an organic solvent.

[0052] Examples of the resin include vinyl resins such as vinyl chloride resin, chlorinated vinyl chloride resin, and acrylic resin. The resin is not limited to one type, and a plurality of types may be adopted.

[0053] In order to ensure the bonding degree of the adhesive, it is preferable that the resin is contained in the solvent-based adhesive composition at 5.0 mass% or more, and desirably 10 mass% or more. The upper limit of the resin is preferably 30 mass% or less, and desirably 20 mass% or less.

[0054] The organic solvent contained in the adhesive is a solvent that can dissolve the resin materials constituting the joint 10 and the pipe 20. Examples of the organic solvent include, but are not limited to, alcohol-based organic solvents, ester-based organic solvents, ketone-based organic solvents, aliphatic hydrocarbon-based organic solvents, ether-based organic solvents, chlorine-based organic solvents, aromatic hydrocarbon-based organic solvents, amide-based organic solvents, glycol ether-based organic solvents, etc. The organic solvent is not limited to one type and may be a mixed organic solvent obtained by mixing multiple types.

[0055] In order to adjust the viscosity of the adhesive and have coatability to facilitate inserting the pipe 20 into the receiving port 14, it is preferable that the solvent-based adhesive composition contains 70% by mass or more of the organic solvent, and desirably 80% by mass or more. The upper limit of the solvent is preferably 95% by mass or less, and desirably 90% by mass or less.

[0056] The adhesive is preferably colorless and transparent, but may contain a colorant such as a pigment or a dye as necessary.

[0057] <Resin joint 10 coated with adhesive> After applying the adhesive to at least one of the inner surface 15 of the receiving port 14 and the outer surface of the pipe end 21, preferably both, the pipe end 21 is inserted into the receiving port 14 and connected. In the case of the present invention, the adhesive is applied to at least the inner surface 15 of the receiving port 14.

[0058] As shown in FIGS. 1 and 2, the inner surface 15 of the receiving port 14 of the joint 10 has a ground glass-like cloudy form. When the above-described adhesive is applied to the inner surface 15 of the receiving port 14 and the pipe 20 is joined, as shown in FIG. 3, the receiving port 14 becomes transparent as a whole.

[0059] In addition, if there is a remaining portion of the adhesive that has oozed out on the inner surface 15 of the socket 14, the rough surface (including unevenness) of the inner surface 15 will remain as it is. That is, since the remaining portion remains cloudy like ground glass, the socket will not become transparent and color unevenness will occur. Since the constructor can visually confirm the remaining adhesive after applying the adhesive to the inner surface of the socket 14, the constructor may simply reapply the adhesive to the remaining portion.

[0060] <Pipe structure 30> Prepare the joint 10 coated with the adhesive in the above manner and the pipe 20 coated with the adhesive at the pipe end 21. Then, before the adhesive dries, insert the pipe end 21 all the way into the socket 14 of the joint 10, hold it down for a predetermined time, and wait for the adhesive to cure. When the adhesive cures, as shown in FIG. 3, a pipe structure 30 in which the joint 10 and the pipe 20 are connected can be obtained.

[0061] In the obtained pipe structure 30, the socket 14 of the joint 10 and the pipe end 21 are connected to each other by the organic solvent of the adhesive. Therefore, when visually observing the socket 14, if there is no color unevenness in the socket 14, it can be confirmed that the adhesive has been applied evenly. On the other hand, when there is a cloudy portion like ground glass remaining in the socket 14, it can be confirmed that there is a remaining portion where the adhesive could not be applied. In this case, the construction may be redone.

[0062] When a transparent pipe is adopted as the pipe 20 in the obtained pipe structure 30, it is preferable that the total light transmittance TT of the connection portion with the transparent pipe is 35% or more, desirably 50% or more, more desirably 60% or more, and particularly desirably 70% or more.

[0063] And when the haze value of the connection portion between the resin joint 10 and the pipe 20 is defined as haze 2, haze 2 is preferably 60% or less, desirably 50% or less, and more desirably 45% or less. Thereby, the state of the fluid flowing inside the pipe structure 30, clogging, and fouling of the pipe 20 and the joint 10 can be easily visually recognized from the outside.

[0064] According to the present invention, by visually inspecting when the adhesive is applied to the receiving port 14 or after the construction, it is possible to confirm whether the adhesive is evenly applied or was applied to the receiving port 14 based on the presence or absence of color unevenness in the receiving port 14. At this time, the value obtained by subtracting the haze value of haze 2 from the haze value of haze 1 is preferably 20 or more, 30 or more, or 35 or more.

[0065] By using a transparent adhesive, it is possible to suppress the sense of incongruity that only the connection part has a different color compared to other parts. Also, by using a transparent adhesive, since the receiving port 14 is not colored, the visibility inside the piping structure 30 can be maintained.

Example

[0066] As a pseudo-model of the receiving port 14 of the resin joint 10 and the pipe 20, a semi-transparent PVC film Q and a semi-transparent PVC film X appropriately stacked on a transparent PVC sheet TS or a gray PVC plate G were used.

[0067] The semi-transparent PVC film Q is a PVC film for hiding eyes: YQ-100 manufactured by Qualsen Co., Ltd., and its thickness is 200 μm. The semi-transparent PVC film X is a PVC dull and off-white film manufactured by HDFILM Co., Ltd., and its thickness is 210 μm.

[0068] Other physical property values of the semi-transparent PVC films Q and X are shown in Table 1. In Table 1, Sa is the arithmetic mean height of the surface, Sz is the maximum height, Sq is the root mean square height, Ssk is skewness (degree of bias), Sku is kurtosis (degree of sharpness), Sp is the maximum peak height, Sv is the maximum valley depth, and Sha(c) indicates the average peak area. All of these are measured values on the uneven surface side of the semi-transparent PVC film and were measured in accordance with ISO 25178 using the above-mentioned device. The haze value and the total light transmittance TT are as described in the above-mentioned measurement method.

[0069]

Table 1

[0070] When the average pitch of the protrusions of the translucent PVC film Q and X was measured, it was found that both were in the range of 50 μm to 200 μm.

[0071] Fig. 4 shows (a) a photograph, (b) an enlarged photograph, and (c) a contour of the uneven surface side of the translucent PVC film Q. Referring to the figure, it can be seen that a large number of unevenness are formed on the translucent PVC film Q. Also, referring to (b), it can be confirmed that the tip of the convex portion is sharp.

[0072] Fig. 5 is (a) a photograph and (b) an enlarged photograph of the uneven surface side of the translucent PVC film X. Referring to the figure, it can be seen that a large number of unevenness are formed on the translucent PVC film X. Also, referring to (b), it can be seen that the tip of the convex portion has a relatively round shape.

[0073] The transparent PVC sheet TS is a transparent PVC plate manufactured by Acry Sande Co., Ltd., and its thickness is 1 mm. The haze value of the transparent PVC sheet is 4, and the total light transmittance TT is 86.

[0074] The gray PVC plate G used a PVC pipe (VP pipe for water supply with a thickness of 3 mm) manufactured by Kubota Chemical Co., Ltd.

[0075] <Example 1> First, for a pseudo-model using the translucent PVC film Q, it was measured how the haze value and the total light transmittance TT change when an adhesive is applied. In order to confirm the transparency visually, the test pieces are each placed on a piece of paper printed with a black line.

[0076] The smooth surface of the translucent PVC film Q was adhered to the inner surface of the receiving port of a PVC resin transparent joint (manufactured by Kubota Chemical Co., Ltd., thickness 3 mm) to form a pseudo-opaque joint model. The haze value (haze 1) of the receiving port portion of this pseudo-opaque joint was 85%, and the total light transmittance TT was 80%. The results of the following examples and comparative examples are summarized in Table 2.

[0077]

Table 2

[0078] A transparent PVC pipe (thickness 3 mm, manufactured by Nippon Plast Co., Ltd.) was inserted into the above joint model to create a piping structure. For the connection part of this piping structure, the haze value of the socket part was 93%, and the total light transmittance TT was 70%.

[0079] Next, an adhesive: Tough Dyn HI (transparent) (manufactured by Kubota Chemical Co., Ltd.: registered trademark) was evenly applied to the socket part of the above joint model, and a transparent PVC pipe (thickness 3 mm) was inserted to create a piping structure. Tough Dyn HI (transparent) was also appropriately applied to the insertion port of the transparent PVC pipe. For the connection part of this piping structure, the haze value (haze 2) of the socket part was 30%, and the total light transmittance TT was 70%. Also, the value of haze 1 - haze 2 was 55.

[0080] A white thick paper with a 5 mm square black grid pattern line drawn on it was inserted into the above joined body, and the visibility at the socket part was confirmed. The black lines on the paper surface were clearly visible, indicating good visibility. Also, since the entire socket part was uniformly transparent and had a low haze value, it was excellent in the discrimination of coating unevenness.

[0081] <Comparative Example 1> In Example 1, the evaluation was carried out by replacing the pseudo-opaque joint model with a transparent PVC joint. The haze value (haze 1) of the joint was 10%, and the total light transmittance TT was 80%. On the other hand, an adhesive: Tough Dyn HI (transparent) (manufactured by Kubota Chemical Co., Ltd.: registered trademark) was evenly applied to the socket part of the resin joint, and a transparent PVC pipe (thickness 3 mm) was inserted to create a piping structure. Tough Dyn HI (transparent) was also appropriately applied to the insertion port of the transparent PVC pipe. The haze value (haze 2) of the socket part of this joined body was 20%, and the total light transmittance TT was 75%. Since the difference in haze value due to the presence or absence of the adhesive was small, it was difficult to discriminate even if there was coating unevenness. The value of haze 1 - haze 2 was -10. <Comparative Example 2> Adhesive: The same evaluation as in Comparative Example 1 was conducted by replacing Toughbond HI (transparent) with Toughbond HI (blue) (manufactured by Kubota Chemical Co., Ltd.: registered trademark). The haze value (haze 2) of the receiving part of the piping configuration coated with the blue adhesive was 25%, and the total light transmittance TT was 72%. Since the adhesive was colored blue, the discrimination of coating unevenness was good, but it was colored blue. The value of haze 1 - haze 2 was -15.

[0082] <Example 2> The joint model using the above film was replaced with an opaque joint made to be in a frosted glass state (created by sandblasting) such that the receiving part of the resin joint had Sa = 2 μm, and the same evaluation as in Example 1 was conducted.

[0083] The haze value (haze 1) of the receiving part of this opaque joint was 70%, and the total light transmittance TT was 80%.

[0084] Next, an adhesive: Toughbond HI (transparent) (manufactured by Kubota Chemical Co., Ltd.: registered trademark) was evenly applied to the receiving part of the above joint, a transparent PVC pipe (thickness 3 mm) was inserted to create a piping structure. Toughbond HI (transparent) was also appropriately applied to the insertion port of the transparent PVC pipe. The haze value (haze 2) of the receiving part of this piping structure was 25%, and the total light transmittance TT was 73%. Also, the value of haze 1 - haze 2 was 45.

[0085] <Example 3> When the semi-transparent PVC film Q used in Example 1 was pasted on the inner surface of the receiving part of a joint using a PVC compound with a dye component of 0.5 mass% described in Comparative Example 2 of Patent No. 7096094 (total light transmittance TT was 35%) to make a pseudo-joint, the haze value (haze 1) was 95%. This joint was joined to a transparent PVC pipe using an adhesive in the same manner as in Example 1. In this piping structure, the total light transmittance TT of the connection part was 36%, but the haze value (haze 2) was 50. Also, haze 1 - haze 2 was 45.

[0086] <Example 4> In Example 1, instead of the transparent PVC pipe, a PVC pipe for water supply VP pipe (opaque gray pipe) manufactured by Kubota Chemical Co., Ltd. was used.

[0087] The above-mentioned opaque PVC pipe (thickness 3 mm) was inserted into the joint model created in Example 1 above to create a piping structure. In this piping structure, no adhesive was applied. As a result of measuring the lightness L1-1 of the socket part of this piping structure with a spectrophotometer CM-26dG manufactured by Konica Minolta, the lightness L1-1 was 60.

[0088] Next, an adhesive: Toughdin HI (transparent) was evenly applied to the socket part of the joint model created in Example 1 above, and the above-mentioned opaque PVC pipe (thickness 3 mm) was inserted to create a piping structure. Toughdin HI (transparent) was also appropriately applied to the insertion port of the transparent PVC pipe. The lightness L1-2 of the socket part of this joined body was 45.

[0089] Fig. 6 shows a comparison of the lightness difference when an adhesive was applied to a part of the joint socket in Example 4 in a model. In Fig. 6, the upper part is the part where the adhesive was applied, and the lower part is the part where no adhesive was applied. It can be seen that ΔE before and after applying the adhesive is 15, and the coating unevenness can be clearly distinguished even visually.

[0090] <Example 5> Instead of the opaque joint, an opaque joint made of a resin joint created in Example 2 with the socket having Sa = 2, made into a frosted glass-like state (created by sandblasting), was used, and the same evaluation as in Example 3 was performed.

[0091] The lightness L1-1 of the socket part of the connection part prepared without applying the adhesive was 53. Next, the lightness L1-2 of the socket part of the connection part prepared by applying the adhesive was 46. The discrimination of coating unevenness was good based on the visual visibility difference and lightness difference depending on the presence or absence of applying the adhesive. Also, the color difference ΔE (= lightness (L1-2) - lightness (L1-2)) was 7.

[0092] <Comparative Example 3> In Example 3, a similar evaluation was performed by replacing the pseudo-opaque joint model with a transparent PVC joint. The brightness L1-1 of the receiving part of the connection part where the adhesive was not applied was 40. Also, the brightness L1-2 of the receiving part of the connection part where the adhesive was applied was also 40, and it was difficult to determine uneven coating visually by confirming with or without the adhesive or by measurement with a spectrocolorimeter.

[0093] <Color difference meter brightness L1, color difference ΔE> As shown in Table 2, for the joints, the visibility, and for the piping structure using the transparent pipe, the total light transmittance TT, haze value, visibility, and uneven coating discriminability were compared. On the other hand, for the piping structure using the gray pipe, the visibility, uneven coating discriminability, color difference meter brightness (L1-1, L1-2), and color difference ΔE (=brightness (L1-1) - brightness (L1-2)) were measured.

[0094] The visibility (joints and transparent pipes) was evaluated according to the following criteria by inserting a PVC resin pipe with printing on the outer surface into the connection part of the piping structure and visually observing the printing state. ◎: The printed characters can be clearly seen. ○: Although there are some parts that are a bit difficult to see, the characters can generally be clearly seen. △: There are parts that are difficult to see, but the characters can be seen. ×: It is difficult to see the characters.

[0095] For the discriminability of uneven coating, for all piping structures, the receiving part was visually observed, and the area where the adhesive was applied and the area where the adhesive was intentionally not applied were visually observed to determine the presence or absence of uneven coating of the adhesive according to the following criteria. ◎: The area where the adhesive was applied and the area where it was not applied can be clearly distinguished. ○: The area where the adhesive was applied and the area where it was not applied can be distinguished. ×: It is difficult to distinguish between the area where the adhesive was applied and the area where it was not applied.

[0096] The results are shown in Table 2.

[0097] Referring to Table 2, first, for the total light transmittance TT and the haze value, Examples 1 and 2 were equivalent to Comparative Examples 1 and 3. This is because by applying the adhesive, the resin-made hand receptacle of the examples changed from a ground glass state to a transparent state. On the other hand, in Example 3, since a blue joint was used, the total light transmittance TT was small and the haze value was also slightly higher.

[0098] Regarding visibility, among the examples, Examples 3 and 5, which are blue resin joints, were slightly inferior compared to the other examples, but had better visibility than Comparative Examples 1 and 3.

[0099] Also, regarding the discriminability of coating unevenness, all of the examples were either "◎" or "○". This is because it was easily confirmed visually that the parts with adhesive residue remained cloudy in a ground glass state. On the other hand, in Comparative Examples 1 and 3, since it was difficult to distinguish between the part where the adhesive was applied and the residue part, the visibility was "×" for both. In Comparative Example 2, since a blue adhesive was used, there was no coloring for the residue part and the coating unevenness could be discriminated.

[0100] Next, regarding the lightness (L1), when comparing Examples 4 and 5 connected to the gray tube with Comparative Example 3, in the inventive examples, the changes in the color difference meter lightness (L1-1) and the color difference meter lightness (L1-2) were large, and the color difference ΔE was also large.

[0101] The description of the above examples is for explaining the present invention, and should not be construed as limiting the invention described in the claims or reducing the scope. Also, the respective components of the present invention are not limited to the above examples, and it goes without saying that various modifications are possible within the technical scope described in the claims.

Claims

1. A resin joint comprising a body portion made of a transparent or translucent resin and constituting a flow path, and a receiving port formed at at least one edge of the body portion and into which a pipe end of a connected pipe is inserted, wherein the inner surface of the receiving port has a rougher surface than the outer surface of the receiving port, a resin joint.

2. The inner surface of the receiving port has an arithmetic mean height Sa of the surface of 0.5 μm or more, The resin joint according to claim 1.

3. The outer surface of the receiving port has an arithmetic mean height Sa of the surface of less than 0.5 μm, The resin joint according to claim 1.

4. The haze value (cloudiness) of the receiving port is 40% or more, The resin joint according to claim 3.

5. By applying an adhesive containing an organic solvent to the inner surface of the receiving port, the haze value (cloudiness) of the receiving port becomes less than 40%, The resin joint according to claim 4.

6. The inner surface of the receiving port has a form in which a large number of protrusions are formed, and the average pitch of the protrusions is 50 μm or more and 200 μm or less, The resin joint according to claim 5.

7. A piping structure formed by connecting the resin joint according to any one of claims 1 to 6 and a resin pipe, wherein the resin joint and the pipe are joined by an adhesive containing an organic solvent, a piping structure.

8. The adhesive is colorless and transparent, The piping structure according to claim 7.

9. The pipe is made of a transparent or translucent resin, The piping structure according to claim 8.

10. The color difference ΔE between the portion where the adhesive is applied and the portion where the adhesive is not applied at the connection portion between the resin joint and the pipe is 5 or more, The piping structure according to claim 9.

11. The pipe is made of an opaque resin, The piping structure according to claim 10.

12. A piping structure formed by connecting a resin joint made of a transparent or translucent resin and a transparent pipe made of a transparent or translucent resin with an adhesive, wherein the haze value (cloudiness) of the resin joint is 40% or more, the haze value of the transparent pipe is 40% or less, and the haze value of the connection portion between the resin joint and the transparent pipe is 40% or less, a piping structure.

13. A piping structure formed by connecting a resin joint made of a transparent or translucent resin and a resin pipe with an adhesive, wherein the color difference ΔE between the portion where a transparent adhesive is applied and the portion where the adhesive is not applied at the connection portion between the resin joint and the pipe is 5 or more, a piping structure.

14. A pipe structure formed by connecting a resin joint made of a transparent or translucent resin and a transparent pipe made of a transparent or translucent resin with an adhesive, when the haze value (cloudiness degree) of the socket of the resin joint is haze 1 and the haze value of the connection part where the resin joint and the transparent pipe are joined using an adhesive is haze 2, haze 1 - haze 2 is 20 or more, Pipe structure.

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