Resin molded article, method of manufacturing the same, and liquid ejection head using the resin molded article

Abstract

To provide a resin molded article in which molding failure of a first resin member due to a molten second resin is suppressed, a method for manufacturing the same, and a liquid ejection head using the resin molded article SOLUTION: Preparing a mold including an accommodation portion 33 accommodating therein the first resin member, a first flow path 31 extending in a first direction, and a second flow path 32 extending in a second direction intersecting with the first direction and allowing the first flow path and the first resin member in the accommodation portion to communicate with each other; injecting a molten resin for forming the second resin member into the first flow path; A step of flowing the molten resin from the first flow path to the second flow path, a step of bringing the molten resin into contact with the first resin member to form a welded portion between the molten resin and the first resin member, and a step of cooling the molten resin to form the second resin member, wherein the welded portion 3 is formed in the second flow path.SELECTED DRAWING: Figure 4

Description

[Technical Field]

[0001] The present invention relates to a resin molded product, a manufacturing method thereof, and a liquid ejection head using the resin molded product. [Background technology]

[0002] There are resin molded products in which a first resin member (primary molded product) containing a first resin is joined to a second resin member (secondary molded product) containing a second resin. Such resin molded products are produced by preparing the first resin member in a mold, injecting a molten second resin into the same mold, and allowing the molten second resin to come into contact with the first member and then cool and solidify. This manufacturing method is called two-shot molding. Two-shot molding not only reduces the number of parts assembly processes, but also enables the production of resin molded products with complex shapes. However, with this manufacturing method, when the first resin member placed in the mold shrinks, a gap is formed between the mold and the first resin member. The molten second resin can enter this gap, potentially causing defects in the resin molded product.

[0003] Patent document 1 discloses a resin molded product manufactured using a manufacturing method in which the shape of the first resin member is devised to suppress such defects, and no gaps are formed between the first resin member and the mold. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Japanese Patent Publication No. 2022-112467 Summary of the Invention [Problem to be solved by the invention]

[0005] However, while the invention described in Patent Document 1 suppresses the occurrence of gaps between the first resin member and the mold, there is a risk that the first resin member will re-melt when the molten second resin comes into contact with the first resin member, resulting in molding defects. For example, if the molten second resin injected into the mold re-melts and entangles the first resin member, the first resin member will penetrate deeply into the second resin, resulting in molding defects and possibly impairing the functionality desired for the first resin member.

[0006] In view of the above problems, the present invention aims to provide a resin molded product that suppresses molding defects in a first resin member caused by a molten second resin, a manufacturing method thereof, and a liquid ejection head using the resin molded product. [Means for solving the problem]

[0007] The method for manufacturing a resin molded product of the present invention includes the steps of: preparing a mold having a storage section for storing the first resin member therein, a first flow path extending in a first direction, and a second flow path extending along a second direction intersecting the first direction and connecting the first flow path with the first resin member in the storage section; injecting molten resin that will form the second resin member into the first flow path and causing the molten resin to flow from the first flow path to the second flow path; bringing the molten resin into contact with the first resin member to form a welded portion between the molten resin and the first resin member; and cooling the molten resin to form the second resin member. wherein the welded portion is formed within the second flow path. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a resin molded product that suppresses molding defects in the first resin member caused by the molten second resin, a manufacturing method thereof, and a liquid ejection head that uses the resin molded product. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 10 is an enlarged cross-sectional view of a resin molded product in a conventional example. [Figure 2] FIG. 10 is an enlarged cross-sectional view showing the injection step of the second resin in a conventional example. [Figure 3] FIG. 10 is an enlarged cross-sectional view showing the injection step of the second resin in a conventional example. [Figure 4] FIG. 2 is an enlarged cross-sectional view of the vicinity of a welded portion of a resin molded product. [Figure 5] FIG. 10 is an enlarged cross-sectional view showing the injection step of the second resin. [Figure 6] FIG. 10 is an enlarged cross-sectional view showing the injection step of the second resin. [Figure 7] FIG. 10 is an enlarged cross-sectional view of a resin molded product according to a modified example. [Figure 8] FIG. 10 is an enlarged cross-sectional view of a resin molded product according to a modified example. [Figure 9] FIG. 10 is an enlarged cross-sectional view of a resin molded product according to a modified example. [Figure 10] FIG. 10 is an enlarged cross-sectional view of a resin molded product according to a modified example. [Figure 11] FIG. 10 is an enlarged cross-sectional view of a resin molded product according to a modified example. [Figure 12] FIG. [Figure 13] FIG. 10 is an exploded view of a liquid ejection head according to a conventional example. [Figure 14] FIG. 2 is an exploded view of a liquid ejection head using a resin molded product according to the present embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, a conventional example and an embodiment of the present invention will be described with reference to the drawings. Note that the following embodiments do not limit the subject matter of the present invention, and not all combinations of features described in the embodiments are necessarily essential to the solution of the present invention. Note that the same reference numerals are used to denote the same components.

[0011] (Explanation of the conventional example) First, the problems with the conventional method for manufacturing the resin molded product 100 will be described with reference to the drawings.

[0012] FIG. 1 shows an enlarged cross-sectional view of a welded portion 3 of a conventional resin molded product 100. The resin molded product 100 is formed by welding a first resin member 1 containing a first resin and a second resin member 2 containing a second resin at the welded portion 3. The first resin member 1 is a primary molded product in two-color molding, and the second resin member 2 is a secondary molded product in two-color molding. That is, the molten first resin is cooled to form the first resin member 1, and then the molten second resin in a mold is cooled while in contact with the first resin member 1 to form the second resin member 2, thereby producing the resin molded product 100. The resin molded product 100 is formed so that the first resin member 1 and the second resin member 2 each have a function. For example, the first resin member 1 is molded to function as a joint seal member for joining another part and the second resin member 2.

[0013] FIG. 2 is an enlarged cross-sectional view showing the injection process of the second resin in a conventional example. A resin molded product 100 is manufactured by welding a first resin member 1 and a second resin member 2 inside a mold 30. The mold 30 has a first flow path 31 extending in a first direction. The mold 30 is provided with a storage section 30, and the first resin member 1 formed in the previous step is stored in the storage section 30 so as to face the first flow path 31. Molten resin 4, which will form the second resin member 2, is injected into the first flow path 31. The molten resin 4 flows through the first flow path 31 in the direction of the arrow shown in FIG. 2. At this time, the first resin member 1 is stored in the storage section so as to face the first flow path 31, so the molten resin 4 comes into contact with the first resin member 1. Because the molten resin 4 is in a high-temperature state, when it comes into contact with the first resin member 1, the heat of the molten resin 4 is transferred to the first resin member 1, remelting the surface of the first resin member and forming a molten portion 5. Because the molten portion 5 is softened, the molten resin 4 flowing through the first flow path 31 may penetrate the first resin member 1 and form an intrusion portion 6. When the molten resin 4 cools, a second resin member 2 is formed, and the first resin member 1 and the second resin member 2 are welded together. However, if the first resin member 1 and the second resin member 2 are welded together while the intrusion portion 6 is formed, a molding defect in the resin molded product 100 occurs. As described above, if the first resin member 1 functions as a joint seal member, a molding defect in the resin molded product 100 may cause the elastic force of the first resin member 1 to fluctuate, which may result in the resin molded product 100 not fulfilling its desired function.

[0014] 3, when the molten resin 4 flows through the first flow path 31, the first resin member 1 may be caught in the molten resin 4, and an overflow portion 7 may be formed in the first flow path 31. In such a case, a deviation in the dimensions of the first resin member 1 may occur, resulting in a molding defect in the resin molded product 100, and the first resin member 1 and the second resin member 2 may not perform the desired functions.

[0015] (First embodiment) Next, the resin molded product 100 of the present invention and the method for manufacturing the same will be described.

[0016] FIG. 4 shows an enlarged view of the vicinity of the welded portion 3 of the resin molded product 100 according to the first embodiment. First, the same content as in the conventional example will be described. The resin molded product 100 according to this embodiment is formed by welding a first resin member 1 containing a first resin and a second resin member 2 containing a second resin at the welded portion 3, as in the conventional example. The first resin member 1 is a primary molded product in two-color molding, and the second resin member 2 is a secondary molded product in two-color molding. That is, the molten first resin is cooled to form the first resin member 1, and then the molten second resin in the mold is cooled in contact with the first resin member 1 to form the second resin member 2, thereby producing the resin molded product 100. The mold 30 is preferably a metal mold.

[0017] The resin molded product 100 is formed so that the first resin member 1 and the second resin member 2 each have a specific function. For example, the first resin member 1 is molded to function as a sealing member for joining another part to the second resin member 2. The resin molded product 100 according to this embodiment is suitable for a liquid ejection head, as will be described in detail later.

[0018] The differences between the resin molded product 100 according to this embodiment and the conventional example will be described below. The resin molded product 100 according to this embodiment differs from the conventional example in that the second resin member 2 has a first surface 41, a protrusion 40 protruding from the first surface 41, and a second surface 42 which is the tip surface of the protrusion 40, and the second surface 42 is welded to the first resin member 1.

[0019] FIG. 5 is an enlarged cross-sectional view showing the injection process of the second resin. The resin molded product 100 is manufactured by welding a first resin member 1 and a second resin member 2 inside a mold 30, as in the conventional example. The mold 30 accommodates the first resin member 1 and has a first flow path 31 extending in a first direction and a second flow path 32 extending along a second direction intersecting the first direction and connecting the first flow path 31 and the first resin member 1. The manufacturing method of the resin molded product 100 according to this embodiment simply requires preparing a mold that accommodates the first resin member 1 and has the first flow path 31 and the second flow path 32. Molten resin 4, which will form the second resin member 2, is injected into the first flow path 31. At this time, the molten resin flows through the first flow path 31 in the direction of the arrow shown in FIG. 5.

[0020] Next, we will explain why molding defects are suppressed by the resin molded product 100 and its manufacturing method according to this embodiment. Compared to conventional methods, in the manufacturing method for a resin molded product according to this embodiment, the mold 30 has the second flow path 32, so the first resin member 1 does not face the first flow path 31. Typically, injected molten resin 4 tends to flow in areas with large open spaces. Therefore, in this embodiment, the speed at which the molten resin 4 flows from the first flow path 31 to the second flow path 32 is slower than the speed at which it flows through the first flow path 31. Therefore, even if the first resin member 1 that comes into contact with the molten resin 4 remelts and forms a molten portion 5, the pressure acting on the molten portion 5 in the first direction is reduced. In other words, the risk of the first resin member 1 being caught in the flow of the molten resin 4 and the risk of the molten resin 4 penetrating the first resin member 1 are suppressed. Therefore, molding defects of the first resin member 1 caused by the molten second resin can be suppressed. At this time, the welded portion 3 is formed in the second flow path 32 without spilling out into the first flow path 31. When the molten resin 4 is cooled in this state, the second resin member 2 is formed, and the first resin member 1 and the second resin member 2 are welded together to produce the resin molded product 100.

[0021] Note that the smaller the cross-sectional area of ​​the second flow path 32, the more difficult it is for the molten resin 4 to flow from the first flow path 31. Therefore, it is conceivable to reduce the cross-sectional area of ​​the second flow path 32 and increase the distance of the second flow path 32. However, in order to weld the first resin member 1 and the molten resin 4 (the second resin member 2) together, a welded portion 3 must be formed. In order to form the welded portion 3 and firmly assemble the first resin member 1 and the second resin member 2 together, various conditions must be set to a preferable form. In particular, as described above, in order for the first resin member 1 to function as a joint seal member, it is necessary that the function of the first resin member 1 is not impaired and that the first resin member 1 and the second resin member 2 are firmly welded together. A preferable form will be described below.

[0022] In order to firmly bond the first resin member 1 and the molten resin 4 (second resin member 2), it is preferable that the welded portion 3 is a compatible portion between the first resin member 1 and the molten resin 4 (second resin member 2). Not only is the molten resin 4 molten, but the first resin member 1 also melts, forming a compatible portion, which enables the first resin member 1 and the second resin member 2 to be firmly bonded together.

[0023] The first resin member 1 contains a first resin as a main material, and the second resin member 2 contains a second resin as a main material, and it is preferable that the first resin and the second resin are different. By making the first resin and the second resin different, it is possible to impart desired functions to the first resin member 1 and the second resin member 2, respectively.

[0024] Furthermore, the molten second resin injected into the first flow path 31 needs to come into contact with the first resin member 1 without cooling and solidifying in the second flow path 32. Therefore, it is preferable that the second resin has a higher melting temperature than the first resin.

[0025] Furthermore, the first resin is preferably a thermoplastic elastomer. This allows the first resin member 1 to have the same liquid contact properties and adhesion as a rubber part while reducing costs. On the other hand, the second resin is preferably a modified polyphenylene ether. Modified polyphenylene ether generally has a higher melting temperature than thermoplastic elastomers, allowing the first resin member 1 and the second resin member 2 to be firmly assembled. In other words, the first resin is preferably a thermoplastic elastomer, and the second resin is preferably a modified polyphenylene ether.

[0026] It is also preferable that the welded portion 3 is formed only in the second flow path. That is, it is preferable that the second resin member 2 is welded to the first resin member 1 only at the second surface 42. This makes it possible to suppress molding defects in the resin molded product 100.

[0027] Furthermore, it is preferable that the tip 25 of the second resin member 2 on the side opposite to the first resin member 1 is rounded, which can improve the adhesive strength between the first resin member 1 and other members that come into contact with it.

[0028] Next, a modification of this embodiment will be described.

[0029] FIG. 7 is an enlarged cross-sectional view of a resin molded product 100 according to a modified example. In the resin member shown in FIG. 7, the side surface 43 of the convex portion 40 connecting the first surface 41 and the second surface 42 is inclined with respect to the first direction (first surface). This allows for a wider range of options for the shapes of the first resin member 1 and the second resin member 2, making it easier to impart a desired function to the resin molded product 100. The inclination angle of the side surface 43 of the convex portion 40 is not particularly limited. To manufacture a resin molded product 100 in which the side surface 43 of the convex portion 40 is inclined, it is preferable to use a mold 30 in which the wall surface of the second flow path 32 is inclined with respect to the first direction. This makes it possible to easily manufacture a resin molded product 100 in which the side surface 43 of the convex portion 40 is inclined.

[0030] Fig. 8 is an enlarged cross-sectional view of a resin molded product 100 in a modified example different from that shown in Fig. 7. As shown in Fig. 8, the side surface 43 of the protrusion 40 does not have to be aligned with the side surface of the first resin member 1. Even with this configuration, as long as the second surface 42 of the second resin member 2 is welded to the first resin member 1, molding defects in the resin molded product 100 can be suppressed.

[0031] Fig. 9 is an enlarged cross-sectional view of a resin molded product 100 in a modified example that is different from Figs. 7 and 8. In the modified example shown in Fig. 9, the welded portion 3 formed on the second surface 42 of the convex portion 40 has a curved surface. Even if the welded portion 3 has a curved surface, as long as the second surface 42 of the second resin member 2 is welded to the first resin member 1, molding defects in the resin molded product 100 can be suppressed.

[0032] Fig. 10 is an enlarged cross-sectional view of a resin molded product 100 in a modified example that is different from those shown in Figs. 7 to 9. As shown in Fig. 10, a recess 44 may be formed in the second resin member 2, and the first resin member 1 may be welded to the second surface 42 within the recess 44. Even with this configuration, as long as the first resin member 1 is welded to the second surface 42, molding defects in the resin molded product 100 can be suppressed.

[0033] 11 is an enlarged cross-sectional view of a resin molded product 100 in a modified example different from those in FIGS. 7 to 10. The resin molded product 100 shown in FIG. 11 has a runner portion 11 through which the molten first resin flows when the first resin member 1 is placed in a mold 30. That is, the runner portion 11 is formed by solidifying the first resin that flows through a third flow path (not shown) in the mold 30, which is formed to fill the molten first resin inside the mold 30. In other words, the runner portion 11 is the path through which the first resin flows, and unlike the first resin member 1, it is not provided with a desired function. Therefore, the runner portion 11 may enter the second flow path 32 when it comes into contact with the molten second resin.

[0034] (Application example of resin molded products) An application example of the resin molded product 100 according to this embodiment will be described below. The resin molded product 100 according to this embodiment is suitable for a liquid ejection head 200 of an inkjet printer.

[0035] 12 shows an exploded perspective view of the liquid ejection head 200. The liquid ejection head 200 has an ejection element substrate (shown) for ejecting liquid, a support member 14 for supporting the ejection element substrate, a storage member 22 for storing the liquid to be supplied to the ejection element substrate, and a housing 12 that houses the storage member inside.

[0036] The ejection element substrate (shown in the accompanying drawings) is equipped with energy generating elements, and the pressure generated by the energy generating elements acts on the liquid in the ejection element substrate to eject the liquid. The energy generating elements may be of a thermal type that uses a thermoelectric conversion element to generate pressure for ejecting the liquid, or of a piezo type that uses a piezoelectric element to generate pressure for ejecting the liquid. Various other liquid ejection types may also be used.

[0037] When the liquid ejection head 200 ejects liquids of multiple colors, multiple storage members 22 (22a, 22b, 22c, 22d) are provided as shown in Fig. 12. The storage members 22 preferably have pressure adjustment means (shown) for adjusting the pressure of the liquid ejected from the ejection element substrate and a circulation pump (not shown) for circulating the liquid within the flow path of the liquid ejection head 200.

[0038] Furthermore, the liquid ejection head 200 includes an electric wiring board 21 for supplying power to the ejection element board, and a joint member 20 for connecting the reservoir member 22 to the main body of the inkjet printer.

[0039] FIG. 13(a) is an exploded view of a conventional liquid ejection head that does not use the resin molded product 100 according to this embodiment, and FIG. 13(b) is a cross-sectional view taken along the Xa-Xa line in FIG. 13(a). The support member 14 and the housing 12 are assembled with fixing members (screws) 15. The housings 12 are aligned in a first direction and have housing openings 17 for supplying liquid to the support member 14, and the support member 14 has a plurality of support member openings 16 through which liquid is supplied from the housing 12. A joint seal 13 is pressed against the periphery of the housing opening 17 of the housing 12 and the periphery of the support member opening 16 of the support member 14. A liquid ejection head 200 is formed. In this configuration, the joint seal 13 must be pressed against both the periphery of the housing opening 17 and the periphery of the support member opening 16 to seal the gap, which requires a large pressure.

[0040] FIG. 14(a) is an exploded view of a liquid ejection head 200 using a resin molded product 100 according to this embodiment, and FIG. 14(b) is a cross-sectional view taken along the Xb-Xb line in FIG. 14(a). In the liquid ejection head 200 according to this embodiment, the support member 14 and the housing 12 are assembled with fixing members (screws) 15, as in the conventional example. The housing 12 has housing openings 17 arranged in a first direction and for supplying liquid to the support member 14, and the support member 14 has a plurality of support member openings 16 arranged in a first direction and for supplying liquid from the housing 12. The liquid ejection head 200 shown in FIG. 14 differs from the conventional example in that the housing 12 and the joint seal portion 18 are integrally formed as the resin molded product 100 according to this embodiment. In other words, the housing 12 is the second resin member 2, the joint seal portion 18 is the first resin member 1, and the first resin member 1 is pressed against the peripheries of the plurality of support member openings 16. With this configuration, the first resin member 1 and the second resin member 2 are integrally molded, reducing the risk of liquid leaking from their interface. Also, since resin molded product 100 only needs to ensure the sealing between first resin member 1 and support member 14, it is possible to reduce the force pressing down on housing 12 and support member 14 to about half of that in the conventional example.

[0041] 14(a), the housing 12 and the joint seal portion 18 are disassembled for the purpose of explanation, but in reality, the housing 12 and the joint seal portion 18 are integrally formed. Also, the runner portion 11 does not necessarily have to be formed.

[0042] In a liquid ejection head that ejects ink, ink leakage causes more serious damage than leakage of other liquids, so the resin molded product 100 of this embodiment is suitable for the housing (joint seal portion) of the liquid ejection head 200. In particular, if the first resin member 1 is an elastomer, this is preferable because it improves the adhesive force with the support member 14 and suppresses liquid leakage.

[0043] Furthermore, when the housing 12 and the joint seal portion 18 of the liquid ejection head are formed as the resin molded product 100 of this embodiment, the resin molded product 100 is adapted to the shape of the support member 14, and therefore has a shape that is elongated in the first direction. The fact that the resin molded product 100 is elongated in the first direction means that the first flow path 31 in the manufacturing process of the resin molded product 100 is also elongated in the first direction. If the first flow path 31 is elongated in the first direction, there is a risk that the molten second resin will cool and solidify as it flows from the front to the back when it flows through the first flow path 31. If the second resin cools and solidifies, it will be impossible to form a weld with the first resin member 1, and the resin molded product 100 will not be manufactured. Therefore, it is necessary to fill the molten second resin at a higher temperature. In the manufacturing method of the resin molded product 100 of this embodiment, even if the temperature of the molten second resin is made higher, molding defects of the first resin member 1 can be suppressed, and therefore the resin molded product 100 of this embodiment and its manufacturing method are suitable for liquid ejection heads.

[0044] From the above, the present invention can be summarized as including the following methods and configurations.

[0045] (Method 1) A method for manufacturing a resin molded product formed by welding a first resin member and a second resin member, preparing a form having a housing portion that houses the first resin member therein, a first flow path extending in a first direction, and a second flow path that extends along a second direction intersecting the first direction and that connects the first flow path with the first resin member in the housing portion; a step of injecting a molten resin that forms the second resin member into the first flow path and causing the molten resin to flow from the first flow path to the second flow path; bringing the molten resin into contact with the first resin member to form a welded portion between the molten resin and the first resin member; cooling the molten resin to form the second resin member; Including, A method for manufacturing a resin molded product, characterized in that the welded portion is formed within the second flow path.

[0046] (Method 2) The method for manufacturing a resin molded product according to Method 1, wherein the welded portion is formed by the molten resin and the first resin member becoming compatible with each other.

[0047] (Method 3) the first resin member contains a first resin as a main material, the second resin member contains a second resin as a main material, 3. The method for producing a resin molded product according to Method 1 or 2, wherein the first resin and the second resin are different.

[0048] (Method 4) The method for producing a resin molded product according to Method 3, wherein the second resin has a higher melting temperature than the first resin.

[0049] (Method 5) 5. The method for producing a resin molded product according to Method 3 or 4, wherein the first resin is a thermoplastic elastomer and the second resin is a modified polyphenylene ether.

[0050] (Method 6) 6. The method for manufacturing a resin molded product according to any one of methods 1 to 5, wherein the wall surface of the second flow path is inclined with respect to the first direction.

[0051] (Method 7) 7. The method for manufacturing a resin molded product according to any one of methods 1 to 6, wherein the welded portion is formed only within the second flow path.

[0052] (Method 8) the mold includes a third flow path for filling with a molten resin that forms the first resin member; A method for manufacturing a resin molded product described in any one of methods 1 to 7, wherein the preparing step involves filling the mold with molten resin that will form the first resin member through the third flow path, not through the first flow path, and cooling the molten resin that will form the first resin member to form the first resin member.

[0053] (Configuration 1) a first resin member; a second resin member; and A resin molded product in which the first resin member and the second resin member are welded together, the second resin member has a first surface, a protruding portion protruding from the first surface, and a second surface that is a tip surface of the protruding portion, The second surface is welded to the first resin member.

[0054] (Configuration 2) the first resin member contains a first resin as a main material, the second resin member contains a second resin as a main material, 2. The resin molded product according to claim 1, wherein the first resin and the second resin are different.

[0055] (Configuration 3) 3. The resin molded product according to claim 2, wherein the second resin has a higher melting temperature than the first resin.

[0056] (Configuration 4) 4. The resin molded article according to claim 2 or 3, wherein the first resin is a thermoplastic elastomer and the second resin is a modified polyphenylene ether.

[0057] (Configuration 5) 5. The resin molded product according to any one of configurations 1 to 4, wherein the tip of the first resin member opposite the second resin member is rounded.

[0058] (Configuration 6) 6. The resin molded product according to any one of configurations 1 to 5, wherein a side surface of the protrusion connecting the first surface and the second surface is inclined with respect to the first surface.

[0059] (Configuration 7) 7. The resin molded product according to any one of configurations 1 to 6, wherein the second resin member is welded to the first resin member only at the second surface.

[0060] (Configuration 8) an ejection element substrate for ejecting liquid; a support member that supports the ejection element substrate; a reservoir member for storing liquid to be supplied to the ejection element substrate; a housing that accommodates the storage member therein; A liquid ejection head having The housing is the resin molded product according to any one of configurations 1 to 7, The liquid ejection head is characterized in that the support member and the first resin member are in pressure contact with each other.

[0061] (Configuration 9) 9. The liquid ejection head according to configuration 8, wherein the support member and the resin molded product are assembled with screws.

[0062] (Configuration 10) the support member has a plurality of openings through which liquid is supplied from the housing; 10. The liquid ejection head according to configuration 8 or 9, wherein the first resin member is pressed against the peripheries of the plurality of openings. [Explanation of symbols]

[0063] 1. First resin member 2 Second resin member 3 Welded area 4 Molten resin 30 Formwork 31 First Channel 32 Second Channel 40 Convex part 41 First Side 42 Second Side 100 Resin molded products

Claims

1. A method for manufacturing a resin molded product formed by welding a first resin member and a second resin member, a step of preparing a form having a housing portion that houses the first resin member therein, a first flow path extending in a first direction, and a second flow path that extends along a second direction intersecting the first direction and that connects the first flow path with the first resin member in the housing portion; a step of injecting a molten resin that forms the second resin member into the first flow path and causing the molten resin to flow from the first flow path to the second flow path; bringing the molten resin into contact with the first resin member to form a welded portion between the molten resin and the first resin member; cooling the molten resin to form the second resin member; Including, A method for manufacturing a resin molded product, characterized in that the welded portion is formed within the second flow path.

2. The method for manufacturing a resin molded product according to claim 1 , wherein the welded portion is formed by the molten resin and the first resin member being compatible with each other.

3. the first resin member contains a first resin as a main material, the second resin member contains a second resin as a main material, The method for manufacturing a resin molded product according to claim 1 , wherein the first resin and the second resin are different from each other.

4. The method for manufacturing a resin molded product according to claim 3 , wherein the second resin has a melting temperature higher than that of the first resin.

5. 4. The method for producing a resin molded product according to claim 3, wherein the first resin is a thermoplastic elastomer, and the second resin is a modified polyphenylene ether.

6. The method for manufacturing a resin molded product according to claim 1 , wherein a wall surface of the second flow path is inclined with respect to the first direction.

7. The method for manufacturing a resin molded product according to claim 1 , wherein the welded portion is formed only in the second flow path.

8. the mold includes a third flow path for filling with molten resin that forms the first resin member; 2. The method for manufacturing a resin molded product according to claim 1, wherein the preparing step comprises filling the mold with molten resin that will form the first resin member through the third flow path, without passing through the first flow path, and cooling the molten resin that will form the first resin member to form the first resin member.

9. a first resin member; a second resin member; and A resin molded product in which the first resin member and the second resin member are welded together, the second resin member includes a first surface, a protruding portion protruding from the first surface, and a second surface that is a tip surface of the protruding portion, The second surface is welded to the first resin member.

10. the first resin member contains a first resin as a main material, the second resin member contains a second resin as a main material, The resin molded product according to claim 9 , wherein the first resin and the second resin are different from each other.

11. The resin molded product according to claim 10 , wherein the second resin has a melting temperature higher than that of the first resin.

12. 11. The resin molded product according to claim 10, wherein the first resin is a thermoplastic elastomer, and the second resin is a modified polyphenylene ether.

13. The resin molded product according to claim 9 , wherein a tip of the first resin member opposite to the second resin member is rounded.

14. The resin molded product according to claim 9 , wherein a side surface of the protrusion connecting the first surface and the second surface is inclined with respect to the first surface.

15. The resin molded product according to claim 9 , wherein the second resin member is welded to the first resin member only at the second surface.

16. an ejection element substrate for ejecting liquid; a support member that supports the ejection element substrate; a reservoir member for storing liquid to be supplied to the ejection element substrate; a housing that accommodates the storage member therein; A liquid ejection head having The housing is a resin molded product according to claim 9, The liquid ejection head is characterized in that the support member and the first resin member are in pressure contact with each other.

17. The liquid ejection head according to claim 16, wherein the support member and the resin molded product are assembled with screws.

18. the support member has a plurality of openings through which liquid is supplied from the housing; The liquid ejection head according to claim 16 , wherein the first resin member is pressed against peripheral edges of the plurality of openings.

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