Coating solution used for surface coating of mold and surface coating method for mold

Abstract

A method for coating the surface of a molding device, according to an embodiment of the present disclosure, may comprise a step of forming a pattern on at least one of a core part and cavity of the molding device. In addition, the method may comprise a step of applying a coating solution formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound to the core part and cavity of the molding device. In addition, the method may comprise a step of thermally curing the coating solution. In addition, the method may comprise a step of cooling the coating solution. Various other embodiments are possible.

Description

Coating solution used for surface coating of mold and method for surface coating of mold

[0001] Various embodiments disclosed in this document relate to coating solutions used for surface coating of molds and methods for surface coating of molds. For example, one embodiment disclosed in this document may include embodiments of a method for forming a coating layer on the surface of a mold and a method for forming a coating solution constituting the coating layer.

[0002] Various injection molded products are formed using molding equipment. For example, injection molding can be used to produce injection molded products by injecting molten resin into a mold and then cooling it. The mold used for injection molding can have a mold (core and cavity) formed with the same shape as the exterior of the injection molded product.

[0003] Meanwhile, patterns to be formed on the exterior of the molded product can be formed on the mold frame into which molten resin is injected to form various patterns on the exterior of the molded product. For example, patterns can be formed on the core and cavity of the mold through machining or etching.

[0004] Injection molded parts can suffer from gate marks, flow marks, and weld lines, which can degrade their appearance. Furthermore, the injection molding process can also cause wear and rust on the mold surface, potentially reducing the durability of the mold itself.

[0005] According to one embodiment disclosed in this document, a method for surface treatment of a core and a cavity of a mold device can be disclosed.

[0006] According to one embodiment of the present disclosure, a method for coating a surface of a mold device may include a step of forming a pattern on at least one of a core portion and a cavity of the mold device. Furthermore, the method may include a step of applying a coating solution formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound to the core portion and the cavity of the mold device. Furthermore, the method may include a step of thermally curing the coating solution. Furthermore, the method may include a step of cooling the coating solution.

[0007] According to one embodiment of the present disclosure, a coating liquid applied to the surface of a mold device includes a siloxane compound, isopropyl alcohol, and a carbon-based compound, and the siloxane compound, the isopropyl alcohol, and the carbon-based compound may be mixed in a weight ratio of 4:14:1 to 4:14:2.

[0008] According to one embodiment disclosed in the present document, a method for coating the surface of a core and the surface of a cavity of a mold device is disclosed. In one embodiment, a coating liquid may be applied to the surface of the core and the surface of the cavity. In this case, compared to when the coating liquid is not applied to the surface of the core and the surface of the cavity, the frictional force of the molten resin against the surface of the core and the surface of the cavity is reduced, thereby improving the flowability of the molten resin against the surface of the core and the surface of the cavity.

[0009] Additionally, the coating layer can reduce the coefficient of friction of the mold surface. Therefore, the appearance quality of injection-molded products can be improved.

[0010] In addition, as the coating liquid is applied to the pattern formed on the surface of the core and the pattern formed on the surface of the cavity, the penetration of the molten resin into the pattern of the core and the pattern of the cavity can be improved.

[0011] In connection with the description of the drawings, the same or similar reference numerals may be used for the same or similar components.

[0012] FIG. 1 is a drawing of a first mold and a second mold of a mold device according to one embodiment of the present disclosure in a closed state.

[0013] FIG. 2A is an exploded perspective view of a first mold according to one embodiment of the present disclosure.

[0014] FIG. 2b is an exploded perspective view of a second mold according to one embodiment of the present disclosure.

[0015] FIG. 3 is a flowchart of a series of processes for forming a coating layer on the surface of a core according to one embodiment of the present disclosure.

[0016] FIG. 4a is a flowchart illustrating a step of curing a mold having a coating solution applied to the surface of a core by placing the mold in a curing booth according to one embodiment of the present disclosure.

[0017] FIG. 4b is a flowchart illustrating a step of curing a mold having a coating solution applied to the surface of a core using a movable infrared device according to one embodiment of the present disclosure.

[0018] FIG. 5 is a drawing illustrating a process for measuring the thickness of a coating layer according to one embodiment of the present disclosure.

[0019] FIG. 6 is a drawing illustrating a process of measuring the surface tension of a coating layer using a Dyne pen evaluation method according to one embodiment of the present disclosure.

[0020] In the following description, various embodiments of this document are described with reference to the attached drawings. It should be understood that the various embodiments of this document and the terminology used herein are not intended to limit the technical features described herein to specific embodiments, but rather encompass various modifications, equivalents, or alternatives of the embodiments.

[0021] In connection with the description of the drawings, similar reference numerals may be used for similar or related components. The singular form of the noun corresponding to an item may include one or more of said items, unless the context clearly indicates otherwise.

[0022] In this document, phrases such as "A or B," "at least one of A and B," "or at least one of B," "A, B, or C," "at least one of A, B, and C," and "or at least one of C" can each include any one of the items listed together in that phrase, or all possible combinations thereof. Terms such as "first," "second," or "first" or "second" may be used merely to distinguish the corresponding component from other corresponding components and do not limit the corresponding components in any other respect (e.g., importance or order). When a component (e.g., a first) is referred to as "coupled" or "connected" to another (e.g., a second) component, with or without the terms "functionally" or "communicatively," it means that the component can be connected to the other component directly (e.g., wired), wirelessly, or through a third component.

[0023] FIG. 1 is a drawing of a first mold and a second mold of a molding device according to various embodiments disclosed in the present document in a closed state. FIG. 2a is an exploded perspective view of a first mold according to various embodiments disclosed in the present document. FIG. 2b is an exploded perspective view of a second mold according to various embodiments disclosed in the present document.

[0024] According to one embodiment disclosed in the present document, the mold (110, 120) of the mold device (or mold) (100) may include a first mold (110) and a second mold (120). The first mold (110) and the second mold (120) may be positioned to face each other. At least one of the first mold (110) and the second mold (120) may have a fixed position, and the other may be a mold that can move relative to the fixed mold. For example, the first mold (110) may be a fixed mold that has a fixed position, and the second mold (120) may be a movable mold that moves relative to the first mold (110). In another embodiment, the first mold (110) may be a movable mold, and the second mold (120) may be a fixed mold. For convenience of explanation, the following description will be made on the assumption that the first mold (110) is a fixed mold with a fixed position, and the second mold (120) is a movable mold that moves relative to the first mold (110).

[0025] According to one embodiment, the mold device (100) can be in a closed state or an open state as the second mold (120) moves with respect to the first mold (110) whose position is fixed. The closed state of the mold device (100) may mean a case where the second mold (120) moves with respect to the first mold (110) in the +Z direction with respect to FIG. 1 so that the first mold (110) and the second mold (120) are combined. The open state of the mold device (100) may mean a case where the second mold (120) moves with respect to the first mold (110) in the -Z direction with respect to FIG. 1 so that the first mold (110) and the second mold (120) are spaced apart from each other. In one embodiment, the mold device (100) may be in a closed state so that molten resin is inserted into the mold device (100) to manufacture an injection-molded product.

[0026] According to one embodiment, as illustrated in FIG. 2A, the first mold (110) may include a first clamping plate (111), a first mold base (112), and a first core (113). In one embodiment, the first mold (110) may be stacked in the following order: first clamping plate (111) - first mold base (112) - first core (113). As described below, the first core (113) may be placed in a groove formed on a back surface (e.g., a surface facing the Z direction with respect to FIG. 2A) of the first mold base (112).

[0027] In one embodiment, the first clamping plate (111) and the first mold base (112) may be coupled via a fixing member such as a bolt. For example, the first clamping plate (111) and the first mold base (112) may be formed with a plurality of fixing holes into which the fixing member is inserted. A screw thread for fixing the fixing member may be formed on the inner wall of the fixing hole. As the fixing member is fastened to the fixing hole formed in the first clamping plate (111) and the first mold base (112), the first clamping plate (111) and the first mold base (112) may be coupled. Similarly, the first mold base (112) and the first core (113) may be coupled via a fixing member such as a bolt. For example, the first mold base (112) and the first core (113) may be formed with a plurality of fixing holes into which the fixing member is inserted. A screw thread for fixing a fixing member may be formed on the inner wall of the fixing hole. As the fixing member is fastened to the second fixing hole formed in the first mold base (112) and the first core (113), the first mold base (112) and the first core (113) may be coupled. As described below, a sprue bush (201) (e.g., a sprue bush (301) of FIG. 3) may be arranged in the first mold (110) of the mold device (100). A hole (114) through which a portion of the sprue bush (201) through which molten resin passes may be formed in the first clamping plate (111), the first mold base (112), and the first core (113). In some embodiments, molten resin may be directly inserted into the hole (114) penetrating the first clamping plate (111), the first mold base (112), and the first core (113).

[0028] According to one embodiment, the mold device (100) may include a sprue bush (201). The sprue bush (201) may be placed in a first mold (110) of the mold device (100). The sprue bush (201) may be a passage through which a molten resin from an injection device (not shown) flows into the inside of the mold device (100) through a nozzle of the injection device. For example, the sprue bush (201) may be a passage through which the molten resin is transferred to a runner (not shown) formed in the first core (113). The first clamping plate (111) may be fixed to the mold device (100) so that the inlet of the sprue bush (201) and the nozzle of the injection device are in close contact with each other. The sprue bush (201) may include a hole (201-1) penetrating one end and the other end of the sprue bush (201) so that molten resin can be delivered to a cavity formed in the first core (113) and / or the second core (121). Accordingly, the molten resin in the injection device (320) can pass through the sprue bush (201) and be filled into the cavity formed in the first core (113).

[0029] In one embodiment, the cavity may be a portion formed in a negative shape formed in one of the first core (113) and the second core (121) with a shape corresponding to the shape of the injection-molded product. In one embodiment, the cavity may be a portion forming an external shape of the injection-molded product. In one embodiment, the cavity may be a space into which a core portion (not shown) formed in the other of the first core (113) and the second core (121) is inserted. In one embodiment, the core portion may be a portion forming an internal shape of the injection-molded product. In one embodiment, the core portion may be a portion forming an internal shape, such as an internal hole or groove of the injection-molded product. In one embodiment, when the first mold (110) and the second mold (120) are closed, the core portion may be inserted into the cavity. When the mold device (100) is closed, molten resin may be injected into the space formed by the core portion and the cavity. As the molten resin cools, the mold device (100) opens, allowing the core and cavity to separate. The final shape of the injection-molded product can be completed while maintaining the combined shape of the core and cavity. For convenience of explanation, the following description assumes that the cavity is formed in the first core (113) and the core is formed in the second core (121).

[0030] In one embodiment, the core and cavity may be processed with a pattern to be formed on the surface of the injection-molded product. For example, among the surfaces of the first core (113), one side of the cavity may be processed with a pattern to be formed on the surface of the injection-molded product. Among the surfaces of the second core (121), one side of the core may be processed with a pattern to be formed on the surface of the injection-molded product.

[0031] In one embodiment, a groove (111-1) in which a locating ring (202) is placed may be formed on the front surface of the first clamping plate (111). The locating ring (202) may serve to guide the fixing position of the first mold (110) when fixing the first mold (110) to the mold device (100). For example, the locating ring (202) may serve to guide the nozzle of the injection device of the mold device (100) so that the nozzle of the injection device can be positioned at the center of the sprue bush (201) placed on the first clamping plate (111).

[0032] According to one embodiment, a first mold base (112) may be arranged at the bottom of the first clamping plate (111). In one embodiment, the first mold base (112) may have a plurality of guide holes (115) formed therethrough. The guide holes (115) may be holes connecting a front surface (e.g., a surface facing the +Z direction with respect to FIG. 2A) and a back surface (e.g., a surface facing the -Z direction with respect to FIG. 2A) of the first mold base (112). A guide pin (130) coupled to a second mold base (122) of a second mold (120) may be arranged in the guide holes (115). For example, the guide hole (115) may serve to guide the guide pin (130) coupled to the second mold base (122) of the second mold (120) when the first mold (110) and the second mold (120) are coupled. A lubricant may be applied to the guide hole (115) so that the guide pin (130) can move smoothly when the first mold (110) and the second mold (120) are coupled or disassembled.

[0033] According to one embodiment, the first mold (110) may include a first core (113). In some embodiments, the first core (113) may be integrally formed with the first mold base (112). The first core (113) may be placed in a groove formed in a shape corresponding to the first core (113) on the back surface of the first mold base (112). The first core (113) may include a hole (114) corresponding to a hole (114) connecting the front and back surfaces of the first mold base (112). A portion of the other end of the sprue bush (201) may be placed in the hole (114) formed in the first core (113).

[0034] In one embodiment, the first core (113) may include a runner and a gate. The runner may be formed on the back surface of the first core (113) (e.g., the surface facing the -Z direction with reference to FIG. 2A) and connected to the other end of the sprue bushing (201). The runner may serve to guide molten resin to the gate. In one embodiment, the runner may be connected to a heating source to maintain the molten resin in a molten state. Accordingly, the molten resin may not be fixed in the runner. The gate may refer to a final passage that transfers the molten resin from the injection device to the cavity formed on the back surface of the first core (113).

[0035] According to one embodiment, as illustrated in FIG. 2b, the second mold (120) may include a second core (121), a second mold base (122), a first ejector plate (123), a second ejector plate (124), a space block (125), and a second clamping plate (126). In one embodiment, the second mold (120) may be stacked in the following order: second core (121) - second mold base (122) - first ejector plate (123) - second ejector plate (124) - space block (125) - second clamping plate (126).

[0036] According to one embodiment, the second mold base (122) may be arranged to face the first mold base (112) of the first mold (110). The second mold base (122) may be arranged with a guide pin (130) that is inserted into a guide hole (115) of the first mold base (112). In one embodiment, when the second mold (120) moves relative to the first mold (110) so that the mold device (100) can be in a closed state, the guide pin (130) may be inserted into the guide hole (115) formed in the first mold base (112) to guide the second mold (120) so that the second mold (120) can move relative to the first mold (110).

[0037] In one embodiment, a groove may be formed on the front surface of the second mold base (122) (e.g., the surface facing the +Z direction based on FIG. 2B ) in which a second core (121) is to be seated. The second core (121) may be positioned in the groove formed in the second mold base (122) so as to face the first core (113) positioned on the back surface of the first mold base (112). In some embodiments, the second core (121) may be formed integrally with the second mold base (122).

[0038] According to one embodiment, the mold device (100) may have a cooling channel formed in the cavity of the first core (113) and an adjacent portion of the core portion of the second core (121). A user may cool the injection-molded product by opening and closing the cooling channel through a cooling valve (221).

[0039] According to one embodiment, a first ejector plate (123) may be arranged at the bottom (e.g., in the Z direction with reference to FIG. 2B) of the second mold base (122). An ejector pin (140) and a return pin (150) may be arranged on the first ejector plate (123). For example, a hole through which the ejector pin (140) and the return pin (150) pass may be formed on the first ejector plate (123). The ejector pin (140) and the return pin (150) may be arranged on the first ejector plate (123) so as to face the second mold base (122) from the first ejector plate (123). One end of the ejector pin (140) and the return pin (150) may be placed in a groove formed on the back surface of the first ejector plate (123) (e.g., the surface facing the -Z direction based on FIG. 2b). The other end of the ejector pin (140) and the return pin (150) may pass through a hole formed in the first ejector plate (123) so as to face the second mold base (122) from the first ejector plate (123). The ejector pin (140) may be used to eject a completed injection-molded product from the mold device (100). For example, when the injection-molded product is completed, the mold device (100) may be opened to extract the injection-molded product. In this case, the first ejector plate (123) may be pressed in the +Z direction based on FIG. 2b by a pressurized pillar of the mold device (100). The pressurized filler may be placed on a mold moving device (180) connected to the second clamping plate (126). The ejector pin (140) may be placed on a part of the second core (121). For example, the second core (121) may have an ejector hole formed through which the ejector pin (140) passes. The ejector pin (140) may move in the +Z direction with respect to FIG. 2B to pass through the ejector hole formed in the second core (121) and push out the injection-molded product placed on the second core (121). The return pin (150) may pass through a return hole formed in the second mold base (122).For example, as described above, when the injection molded product is completed, the pressurized filler can pressurize the first ejector plate (123) in the +Z direction with reference to FIG. 2B so that the ejector pin (140) detaches the completed injection molded product from the mold device (100). In this case, the return pin (150) can pass through a return hole formed in the second mold base (122). In addition, an elastic member (151), such as a spring, can be arranged on the return pin (150). The elastic member (151) can be compressed by coming into contact with the first ejector plate (123) and the second mold base (122) during the process in which the pressurized filler presses the first ejector plate (123) in the +Z direction. The ejector pin (140) can return to its original position through the elastic restoring force of the elastic member (151) after pushing out the injection molded product arranged on the second core (121).

[0040] According to one embodiment, a second ejector plate (124) may be arranged at the lower end of the first ejector plate (123) (e.g., in the -Z direction with reference to FIG. 2B). The second ejector plate (124) may be coupled to the first ejector plate (123) through a connecting member such as a bolt. The second ejector plate (124) may support the ejector pin (140) and the return pin (150) arranged on the first ejector plate (123). For example, as the second ejector plate (124) covers one end of the ejector pin (140) and the return pin (150) arranged on the back surface of the first ejector plate (123), the ejector pin (140) and the return pin (150) may be fixed to the first ejector plate (123).

[0041] According to one embodiment, the second mold (120) may include a second clamping plate (126). The second clamping plate (126) may be positioned at the lower end (e.g., in the -Z direction with reference to FIG. 2B) of the second ejector plate (124). A hole may be formed in the second clamping plate (126) through which a pressurized filler passes. The pressurized filler may pass through the second clamping plate (126) and come into contact with the second ejector plate (124).

[0042] According to one embodiment, the second mold (120) may include a support pillar (170). The support pillar (170) may be placed on the second clamping plate (126) and may come into contact with the second mold base (122) by passing through a hole formed in the second ejector plate (124) and the first ejector plate (123). When the mold device (100) is closed, the support pillar (170) may support the second mold base (122) in the +Z direction from the injection pressure when the molten resin is injected into the space formed by the cavity of the first core (113) and the core portion of the second core (121).

[0043] According to one embodiment, a space block (125) may be disposed between the second clamping plate (126) and the second mold base (122). The space block (125) may be coupled to the second clamping plate (126) and the second mold base (122) through a connecting member such as a bolt. The space block (125) may be disposed between the second mold base (122) and the second clamping plate (126) to form a space in which a combination of the first ejector plate (123) and the second ejector plate (124) can move between the second mold base (122) and the second clamping plate (126). The space block (125) can prevent the second mold base (122) from being warped by the injection pressure when the molten resin is injected into the space formed by the cavity of the first core (113) and the core portion of the second core (121) while the mold device (100) is closed.

[0044] FIG. 3 is a flowchart illustrating a series of processes for forming a coating layer on the surface of a core according to an embodiment of the present disclosure. FIG. 4a is a flowchart illustrating a step of curing a mold having a coating solution applied to the surface of a core by placing the mold in a curing booth according to an embodiment of the present disclosure. FIG. 4b is a flowchart illustrating a step of curing a mold having a coating solution applied to the surface of a core using a movable infrared device according to an embodiment of the present disclosure. FIG. 5 is a diagram illustrating a process of measuring a thickness of a coating layer according to an embodiment of the present disclosure. FIG. 6 is a diagram illustrating a process of measuring the surface tension of a coating layer using a Dyne pen evaluation method according to an embodiment of the present disclosure.

[0045] According to one embodiment, as illustrated in FIG. 3, at least one of the cavity of the first core (113) and the core portion of the second core (121) may be processed with a pattern to be formed on the surface of the injection-molded product (S101). For example, among the surfaces of the first core (113), one side of the cavity may be processed with a pattern to be formed on the surface of the injection-molded product. Among the surfaces of the second core (121), one side of the core portion may be processed with a pattern to be formed on the surface of the injection-molded product. In one embodiment, the pattern may include both a positive and a negative pattern.

[0046] In one embodiment, referring to FIG. 3, after a pattern is formed in the cavity and the core, the surfaces of the mold (e.g., the first core (113) and the second core (121)) may be primarily cleaned using a cleaning agent (S102). In one embodiment, the surface of the first core (113) in which the cavity is formed and the surface of the second core (121) in which the core is formed may be primarily cleaned. Accordingly, the surface of the cavity and the surface of the core may be primarily cleaned using a cleaning agent to remove oil and foreign substances present in the cavity and the core.

[0047] In one embodiment, referring to FIG. 3, after the surface of the first core (113) and the surface of the second core (121) in which the core portion is formed are primarily cleaned, a masking adhesive may be attached to the remaining area of ​​the surfaces of the first core (113) and the second core (121) except for the area where the coating liquid is to be sprayed (S103). In one embodiment, a masking adhesive may be attached to the remaining area of ​​the first core (113) except for the cavity. In one embodiment, a masking adhesive may be attached to the remaining area of ​​the second core (121) except for the core portion. In one embodiment, the masking adhesive may be a non-penetrating vinyl tape. Thereafter, the surfaces of the first core (113) and the second core (121) may be secondarily cleaned using a cleaning agent (S104). After the secondary cleaning of the first core (113) and the second core (121), the surfaces of the first core and the second core (121) can be dried for a sufficient period of time so that the chemical reaction between the cleaning agent and the coating solution can be minimized. In the step immediately before the coating solution is applied to the first core (113) and the second core (121), oil and foreign substances present in the cavity and the core portion can be removed through the secondary cleaning step.

[0048] In one embodiment, the first core (113) and the second core (121) can be washed in the first and second washing steps using a detergent containing an isopropyl alcohol (IPA) component.

[0049] In one embodiment, referring to FIG. 3, after the surfaces of the first core (113) and the second core (121) are secondarily washed, a coating solution may be applied to the cavity of the first core (113) and the core portion of the second core (121) (S105). Thereafter, the masking adhesive attached to the first core (113) and the second core (121) may be removed (S106). Thereafter, the coating solution applied to the first core (113) and the second core (121) may be thermally cured (S107). As described below, the coating solution applied to the first core (113) and the second core (121) may be thermally cured using an infrared device (e.g., a curing booth, a mobile infrared device). In one embodiment, the first core (113) and the second core (121) can be thermally cured by being placed in a curing booth having a plurality of far-infrared heaters installed under certain conditions. In one embodiment, the first core (113) and the second core (121) can be thermally cured by a mobile infrared device including an infrared heater that can be moved under certain conditions. Thereafter, the first core (113) and the second core (121) can be naturally cooled (S108). For example, the first core (113) and the second core (121) can be naturally cooled at room temperature for 8 to 24 hours. Thereafter, a test step is performed to confirm whether the thickness and surface tension of the coating layer formed in the cavity of the first core (113) and the core portion of the second core (121) satisfy certain conditions (S109), thereby completing the process of forming the coating layer on the surfaces of the first core (113) and the second core (121) of the mold device (100).

[0050] Below, each step of forming a coating layer on the surface of the first core (113) and the second core (121), as described through Fig. 3, will be described in detail.

[0051] In one embodiment, a detailed description of a step (S101) in which a pattern to be formed on the surface of an injection-molded product is processed in at least one of the cavity of the first core (113) and the core portion of the second core (121) is as follows.

[0052] In one embodiment, the pattern formed on the injection-molded product may be formed for various purposes, such as improving the appearance design, grip, or function of the injection-molded product. In one embodiment, a pattern having a shape corresponding to the pattern to be formed on the injection-molded product may be formed on the cavity and / or the core. In one embodiment, the pattern formed on the cavity and / or the core may be formed through machining (e.g., laser etching, CNC process). In one embodiment, the pattern formed on the cavity and / or the core may be formed through a chemical etching method that selectively etches the surface of the cavity and / or the core with a chemical substance. In one embodiment, the pattern formed on the cavity and / or the core may be formed through electrical discharge machining (EDM) on the surface of the cavity and / or the core.

[0053] In one embodiment, the coating solution applied to the surfaces of the first core (113) and the second core (121) can be formed by adding a siloxane compound, isopropyl alcohol, and a carbon-based compound.

[0054] In one embodiment, the siloxane compound may be a compound in which silicon atoms (Si) and oxygen atoms (O) are alternately bonded to form a chain structure. In one embodiment, the general formula of the siloxane is (R2SiO) n may be. In one embodiment, R may be a functional group (organic group). In one embodiment, the functional group may be a hydrocarbon composed of carbon and hydrogen, and may be a general concept for compounds composed only of carbon and hydrogen. In one embodiment, n is the number of repeating units of the siloxane compound and may be an integer. In one embodiment, the siloxane compound used to form the coating solution may be composed of the following chemical formula.

[0055]

[0056] In one embodiment, the siloxane compound constituting the coating liquid may be at least one of hexamethyldisiloxane, polysiloxane, and polydimethylsiloxane.

[0057] In one embodiment, the siloxane compound has heat resistance that can withstand high temperatures and has low surface tension, so it can be used as a surfactant, lubricant, coating layer, and can be used for waterproofing.

[0058] In one embodiment, the base compound constituting the coating solution may be formed by mixing a siloxane compound and isopropyl alcohol in a weight ratio of about 2:7 to about 3:7. The weight ratio may be a comparison of the masses of two or more substances or components in a mixture or chemical reaction. In one embodiment, the base compound may be formed by mixing a siloxane compound and isopropyl alcohol in a weight ratio of about 2:7 to about 3:7. The weight ratio of the siloxane compound and isopropyl alcohol constituting the coating solution may be modified within a range of error that can be performed by a person skilled in the art.

[0059] In one embodiment, a carbon-based compound may be added to the base compound of the coating solution. In one embodiment, the carbon-based compound may be at least one of carbon black and graphene. In one embodiment, the coating solution may be formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound in a weight ratio of about 4:14:1 to about 4:14:2. In one embodiment, the coating solution may be formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound in a weight ratio of about 4:14:1 to 4:14:2. The weight ratio of the siloxane compound, isopropyl alcohol, and carbon-based compound constituting the coating solution may be modified within an error range that can be implemented by a person skilled in the art.

[0060] In one embodiment, a colored sample may be added to the mixture of a siloxane compound, isopropyl alcohol, and a carbon-based compound that constitutes the coating solution. In one embodiment, the colored sample may be a cyan-colored sample. In one embodiment, the colored sample may be mixed in the coating solution at a weight ratio of about 1% to 2%. In one embodiment, when applying the coating solution to the first core (113) and the second core (121), the worker can visually confirm the formation of a coating layer through the colored sample.

[0061] In one embodiment, the coating solution may comprise from 8% to 10% of the total composition of nonvolatile components.

[0062] In one embodiment, the coating layer may be formed by heat-curing a coating solution composed of a siloxane compound, isopropyl alcohol, and a carbon-based compound. In one embodiment, the coating layer may have heat resistance of 400°C to 600°C. In one embodiment, the coating layer may have cold resistance of -20°C to -10°C. In one embodiment, the coating layer may have a surface hardness (Mohs hardness) of 9H. In one embodiment, the coating layer may have a viscosity of about 2 CPS (centipoise) to about 5 CPS. In one embodiment, the coating layer may include all or at least one of the above-described properties.

[0063] In one embodiment, the coating liquid may be applied to the entire area of ​​the surface of the first core (113) where the cavity is formed, and may be applied to the entire area of ​​the surface of the second core (121) where the core portion is formed. In one embodiment, the coating liquid may be applied only to one area of ​​the surface of the first core (113) where the cavity is formed, and may be applied only to one area of ​​the surface of the second core (121) where the core portion is formed.

[0064] According to one embodiment, the coating liquid may be applied to the surfaces of the first core (113) and the second core (121) by the following application method. In one embodiment, a worker may apply the coating liquid to the surfaces of the first core (113) and the second core (121) by using a spraying device containing the coating liquid. In one embodiment, the coating liquid may be sprayed by a spray gun of the spraying device. In one embodiment, the coating liquid may be applied to the surfaces of the first core (113) and the second core (121) such that the thickness of the coating layer is about 2 μm to about 3 μm. In one embodiment, the coating liquid may be applied to the surface of the first core (113) by five reciprocating passes with a thickness of 0.4 μm to 0.6 μm per reciprocating pass. The coating liquid may be applied to the surface of the second core (121) by five reciprocating passes with a thickness of 0.4 μm to 0.6 μm per reciprocating pass.

[0065] In one embodiment, the coating solution may be applied from a spray gun at a pressure of about 1 bar to about 3 bar. For example, the pressure at which the coating solution is sprayed from the spray gun may be 1 bar to 3 bar.

[0066] In one embodiment, the spray amount of the spray gun may be about 0.235 cc / cm2. In one embodiment, the operator may perform the operation of applying the coating liquid to the first core (113) and the second core (121) such that the spray gun has a moving speed of about 200 CPM (centimeters per minute) to about 300 CPM. In one embodiment, CPM may be the distance that the spray gun moves per minute. For example, the operator may spray the coating liquid onto the surface of the first core (113) and / or the surface of the second core (121) at a moving speed of 200 cm to 300 cm per minute.

[0067] In one embodiment, the operator can spray the coating liquid onto the surface (or cavity) of the first core (113) while the spraying portion of the spray gun, from which the coating liquid is foamed, is spaced apart from the surface (or cavity) of the first core (113) by about 150 mm to about 200 mm. In one embodiment, the operator can spray the coating liquid onto the surface (or core portion) of the second core (121) while the spraying portion of the spray gun is spaced apart from the surface (or core portion) of the second core (121) by about 150 mm to about 200 mm.

[0068] In one embodiment, the temperature of the location where the coating liquid is sprayed on the surface of the first core (113) (or cavity) and the second core (121) (or core portion) may be about 25°C and the humidity may be about 70%.

[0069] According to one embodiment, if the coating liquid is not applied under the conditions described above, the amount of the coating liquid applied to the surface of the first core (113) and the surface of the second core (121) may be more or less than the standard amount, and thus the quality of the coating layer may not be secured.

[0070] According to one embodiment, the coating layer may be formed as the coating liquid applied to the first core (113) and the second core (121) is cooled after undergoing thermal curing. In one embodiment, before thermal curing the first core (113) and the second core (121), the masking adhesive attached to the surface of the first core (113) and the surface of the second core (121) may be removed (S106).

[0071] In one embodiment, referring to FIG. 4A, the first core (113) and the second core (121) to which the coating liquid is applied may be placed in a curing booth including a plurality of far-infrared heaters (S201). In one embodiment, the curing booth may be a room in which a plurality of far-infrared heaters are installed. In one embodiment, the curing booth may be installed with a plurality of far-infrared heaters so that the entire area of ​​the surface of the first core (113) to which the coating liquid is applied and the surface of the second core (121) can be sufficiently irradiated.

[0072] In one embodiment, the temperature of the far-infrared heater can be controlled so that the internal temperature of the curing booth is heated to about 180°C at a heating rate of 60°C to 70°C per hour (S202) while the first core (113) and the second core (121) to which the coating liquid is applied are placed in the curing booth. Thereafter, after the internal temperature of the curing booth reaches about 180°C, the first core (113) and the second core (121) to which the coating liquid is applied can be thermally cured for about 2 to 4 hours (S203). In one embodiment, after the temperatures of the first core (113) and the second core (121) reach about 180°C, the first core (113) and the second core (121) to which the coating liquid is applied can be thermally cured for about 2 to 4 hours. Afterwards, the first core (113) and the second core (121) can be taken out of the hardening booth and cooled at room temperature for about 8 to 24 hours (S204).

[0073] In one embodiment, the first core (113) and the second core (121) to which the coating liquid is applied may be placed inside the curing booth and thermally cured for about 2 to 4 hours after the internal temperature of the curing booth reaches about 180°C.

[0074] According to one embodiment, damage may occur in at least one of the coating layers formed on the first core (113) and the second core (121) depending on the use of the mold device (100). In this case, a coating solution may be applied to the damaged area. In one embodiment, the coating solution applied to the damaged area may be thermally cured by a mobile infrared device. In one embodiment, the mobile infrared device may be a near infrared device. The mobile infrared device described above may be used not only to apply the coating solution to the damaged area, but also to apply the coating solution to a portion of the surface of the first core (113) and / or a portion of the surface of the second core (121) and then thermally cure it.

[0075] In one embodiment, referring to FIG. 4B, a coating solution may be applied to a portion of the first core (113) and / or a portion of the second core (121). In this way, the coating solution applied to a portion of the surface of the first core (113) and / or the coating solution applied to a portion of the surface of the second core (121) may be cured by a mobile infrared device (S301). In one embodiment, the mobile infrared device may be controlled to be heated to about 180° C. at a heating rate of 60° C. to 70° C. per hour (S302). In one embodiment, after the temperature of the mobile infrared device reaches about 180° C., the portion of the first core (113) and / or the portion of the second core (121) to which the coating solution is applied may be thermally cured for about 2 to 4 hours (S303). In one embodiment, after the temperature of the first core (113) and / or the second core (121) reaches about 180° C., a portion of the first core (113) and / or a portion of the second core (121) to which the coating liquid has been applied may be thermally cured for about 2 to 4 hours. In one embodiment, the temperature of the first core (113) and / or the second core (121) may be measured using a laser thermometer. Thereafter, after removing the movable infrared device, the first core (113) and / or the second core (121) may be cooled at room temperature for about 8 to 24 hours (S304).

[0076] According to one embodiment, as illustrated in FIG. 5, the process for measuring the thickness of the coating layer formed on the first core (113) and / or the second core (121) may be as follows. In one embodiment, after the thermal curing and cooling of the coating layer are completed, it may be confirmed through testing whether the thickness of the coating layer satisfies a required level. In one embodiment, the patterns and / or unevenness formed on the first core (113) and the second core (121) may cause an error in measuring the thickness of the coating layer. Therefore, the coating layer may be formed on a sample core during the process of forming the coating layer. In one embodiment, the sample core may be a core having a smaller size than the first core (113) and / or the second core (121) and not having a pattern and / or unevenness formed on the surface. In one embodiment, the thickness of the coating layer formed on the first core (113) and / or the second core (121) on which the coating layer is formed and the coating layer formed on the sample core may be measured using a test device (S401). In one embodiment, the thickness of the coating layer formed on the first core (113) and / or the second core (121) may have an error of about -0.3 μm to about +0.3 μm of the thickness of the coating layer formed on the sample core.

[0077] According to one embodiment, as illustrated in FIG. 6, the process for measuring the surface tension of a coating layer using a Dyne pen evaluation method may be as follows. In one embodiment, the Dyne pen evaluation method may be a method of measuring the tension of a surface to be measured by applying a liquid or ink to the surface to be measured. In one embodiment, a Dyne pen may be applied to a core having a coating layer formed thereon and a core having no coating layer formed thereon to compare the surface tensions (S402). In one embodiment, the surface tension of the coating layer may be adjusted to be approximately 40 Dyne.

[0078] According to one embodiment disclosed in the present document, a method for coating a surface of a core portion and a surface of a cavity of a mold device (100) may be disclosed. In one embodiment, a coating liquid may be applied to a surface (e.g., cavity) of a first core (113) and a surface (e.g., core portion) of a second core (121). In this case, compared to when the coating liquid is not applied to the surface of the core portion and the surface of the cavity, the frictional force of the molten resin against the surface of the first core (113) and the surface of the second core (121) may be reduced, thereby improving the flowability of the molten resin against the surface of the first core (113) and the surface of the second core (121).

[0079] In one embodiment, a coating solution in which a siloxane compound, isopropyl alcohol, and a carbon-based compound are mixed in a weight ratio of about 4:14:1 to about 4:14:2 can ensure penetration into the surfaces of the first core (113) and the second core (121). The coating solution can penetrate into the pattern formed in the cavity and the pattern formed in the core portion. Therefore, the flowability of the molten resin for the patterns of the first core (113) and the second core (121) can be improved compared to when the coating solution is not applied to the first core (113) and the second core (121). For example, the molten resin can easily penetrate into the patterns of the first core (113) and the second core (121) compared to when the coating solution is not applied to the first core (113) and the second core (121).

[0080] In one embodiment, during an injection molding process using the first core (113) and the second core (121) on which a coating layer is not formed, the molten resin may have reduced fluidity (flowability) in the internal space between the cavity and the core due to surface friction with the cavity and surface friction with the core. In this case, due to the low fluidity of the molten resin, the molten resin flowing into the cavity may cool and form a boundary (e.g., a flow mark) with the molten resin flowing into the cavity. In one embodiment, the molten resin may have reduced fluidity (flowability) in the internal space between the cavity and the core due to surface friction with the first core (113) and surface friction with the second core (121). In this case, a gate mark may be formed on the injection-molded product by the molten resin passing through the gate. In one embodiment, the gate mark may have a shape corresponding to a gate through which the molten resin passes. In addition, since the coating layer is not formed on the cavity and the core, the fluidity (flowability) in the internal space between the cavity and the core may be reduced, which may cause various molding defects, such as weld lines, in the injection-molded product. According to one embodiment of the present disclosure, the coating layer can reduce the coefficient of friction between the surface of the first core (113) (e.g., the cavity) and the surface of the second core (121) (e.g., the core). Since the coating layer is formed on the surfaces of the first core (113) and the second core (121), compared to when the coating liquid is not applied to the first core (113) and the second core (121), the phenomenon of flow marks, gate marks, and weld lines being formed on the injection-molded product during the injection process can be improved. Therefore, the appearance quality of the injection-molded product can be improved.

[0081] In one embodiment, the coating layer can reduce wear that may occur on the surface of the first core (113) and the surface of the second core (121) depending on the operation of the mold device (100). In one embodiment, the surface of the first core (113) and the surface of the second core (121) can be protected from discoloration, contamination, and rust through the coating layer. Accordingly, the durability of the surface of the first core (113) and the surface of the second core (121) can be enhanced through the coating layer.

[0082] According to one embodiment of the present disclosure, a method for coating a surface of a mold device may include a step (S101) of forming a pattern in at least one of a core portion and a cavity of the mold device, a step (S105) of applying a coating solution formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound to the core portion and the cavity of the mold device, a step (S107) of thermally curing the coating solution, and a step of cooling the coating solution.

[0083] In addition, the coating solution applied to the core portion and cavity of the mold device can be formed by mixing a siloxane compound and isopropyl alcohol in a weight ratio of 2:7 to 3:7.

[0084] In addition, the coating solution can be formed by mixing the siloxane compound, the isopropyl alcohol, and the carbon-based compound in a weight ratio of 4:14:1 to 4:14:2.

[0085] Additionally, the carbon-based compound may be at least one of carbon black and graphene.

[0086] Additionally, the siloxane compound may be at least one of hexamethyldisiloxane, polysiloxane, and polydimethylsiloxane.

[0087] In addition, the method may include a step of adding a colored sample to the coating solution at a weight ratio of 1% to 2%, and, in the step of thermally curing the coating solution, checking whether a coating layer is formed on the core portion and the cavity through the color of the colored sample.

[0088] In addition, the coating layer formed by heat curing the coating liquid may have heat resistance of 400°C to 600°C, cold resistance of -20°C to -10°C, surface hardness of 9H, and viscosity of 2 CPS to 5 CPS.

[0089] In addition, the step of applying the coating liquid to the core portion and the cavity may be such that the coating liquid is applied to the core portion and the cavity at a pressure of 1 bar to 3 bar through a spray gun that sprays the coating liquid, the coating liquid is applied while the spraying part of the spray gun is spaced apart from the core portion by 150 mm to 200 mm, and the coating liquid may be applied while the spraying part of the spray gun is spaced apart from the cavity by 150 mm to 200 mm.

[0090] In addition, the coating solution can coat the surface of a mold device at a temperature of 25°C and a humidity of 70% at a location where the coating solution is applied to the core portion and the cavity.

[0091] In addition, the step of applying the coating liquid to the core portion and the cavity may be applied so that the thickness of the coating liquid is 2 ㎛ to 3 ㎛.

[0092] In addition, the coating solution can be applied to the surface of the core and cavity five times in a reciprocating manner with a thickness of 0.4 ㎛ to 0.6 ㎛ per reciprocating motion.

[0093] Additionally, the spray amount of the spray gun may be 0.235 cc / ㎠, and the movement speed of the spray gun may be 200 CPM (centimeter per minute) to 300 CPM.

[0094] In addition, the step of thermally curing the coating liquid may include a step (S201) of placing a first core including the cavity and a second core including the core portion in a curing booth having a plurality of far-infrared heaters installed, a step (S202) of heating the internal temperature of the curing booth to 180°C at a heating rate of 60 to 70°C per hour, and a step (S203) of thermally curing the coating liquid for 2 to 4 hours after the internal temperature of the curing booth reaches 180°C.

[0095] In addition, the step of thermally curing the coating liquid may include a step (S301) of heating at least one of a first core including the cavity to which the coating liquid is applied and a second core including the core portion to which the coating liquid is applied through a movable infrared device including an infrared heater, a step (S302) of heating the movable infrared device to 180° C. at a heating rate of 60 to 70° C. per hour, and a step (S303) of thermally curing the coating liquid for 2 to 4 hours after the heat radiation temperature of the movable infrared device reaches 180° C.

[0096] In addition, the step of cooling the coating liquid may include a step (S204, S304) of cooling the first core and the second core to which the coating liquid has been applied at room temperature for 8 to 24 hours.

[0097] In addition, as a step between the step of forming a pattern in the core part and the cavity and the step of applying a coating solution to the core part and the cavity, the method further includes a step (S102) of first cleaning the surface of the cavity and the core part, a step (S103) of attaching a masking adhesive to the remaining area of ​​the first core excluding the cavity and the remaining area of ​​the second core excluding the core part, and a step (S104) of second cleaning the surface of the cavity and the core part; and after applying the coating solution to the surface of the cavity and the core part, in a step before thermal curing, the method may further include a step (S106) of removing the masking adhesive attached to the surface of the first core and the second core.

[0098] In addition, the method further includes a step (S108) in which the surface tension of the coating layer formed in the cavity and the core portion is measured using the DynePen evaluation method as the coating liquid is cooled, and the surface tension of the coating layer may be 40 Dyne.

[0099] According to one embodiment of the present disclosure, a coating solution applied to a surface of a mold device includes a siloxane compound, isopropyl alcohol, and a carbon-based compound, and the siloxane compound, the isopropyl alcohol, and the carbon-based compound can be applied to the surface of the mold device in a mixed weight ratio of 4:14:1 to 4:14:2.

[0100] In addition, the coating liquid can be applied to the surface of a mold device having heat resistance of 400°C to 600°C, cold resistance of -20°C to -10°C, surface hardness of 9H, and viscosity of 2 CPS to 5 CPS.

[0101] In addition, the siloxane compound may be at least one of hexamethyldisiloxane, polysiloxane, and polydimethylsiloxane, and the carbon-based compound may be at least one of carbon black and graphene.

[0102] Although the above description assumes that the coating layer is formed on the first core (113) and the second core (121), it may not be limited thereto. In one embodiment, the coating liquid may be applied to at least a portion of the mold device (100) and undergo a heat curing and cooling step to form a coating layer.

Claims

1. A method for coating the surface of a mold device, A step (S101) in which a pattern is formed in at least one of the core portion and cavity of the mold device; A step (S105) of applying a coating solution formed by mixing a siloxane compound, isopropyl alcohol, and a carbon-based compound to the core portion and cavity of the mold device; Step of heat-curing the above coating solution (S107); and A method for coating a surface of a mold device, comprising: a step of cooling the coating liquid.

2. In paragraph 1, The coating liquid applied to the core and cavity of the above mold device is: A method for coating the surface of a mold device formed by mixing a siloxane compound and isopropyl alcohol in a weight ratio of 2:7 to 3:

7.

3. In paragraph 2, The above coating solution is, A method for coating the surface of a mold device formed by mixing the above siloxane compound, the above isopropyl alcohol, and the above carbon-based compound in a weight ratio of 4:14:1 to 4:14:

2.

4. In paragraph 2 or 3, The above carbon compound is at least one of carbon black and graphene, The above siloxane compound is, A method for coating the surface of a mold device with at least one of hexamethyldisiloxane, polysiloxane and polydimethylsiloxane.

5. In paragraph 1, Add a colored sample to the coating solution at a weight ratio of 1% to 2%, and mix it into the coating solution. At the stage where the above coating solution is heat-cured, A method for coating the surface of a mold device, comprising the step of confirming whether a coating layer is formed on the core portion and the cavity through the color of a colored sample.

6. In paragraph 1, The step of applying the coating liquid to the core portion and the cavity is: The coating liquid is applied to the core portion and the cavity at a pressure of 1 bar to 3 bar through a spray gun through which the coating liquid is sprayed, The coating liquid is applied while the spray part of the spray gun is spaced 150 mm to 200 mm away from the core part, The coating liquid is applied while the spraying part of the spray gun is spaced 150 mm to 200 mm away from the cavity, The spray amount of the above spray gun is 0.235 cc / ㎠, A method for coating the surface of a mold device wherein the moving speed of the spray gun is 200 CPM (centimeter per minute) to 300 CPM.

7. In paragraph 6, The step of applying the coating liquid to the core portion and the cavity is: A method for coating the surface of a mold device so that the coating liquid has a thickness of 2 ㎛ to 3 ㎛.

8. In paragraph 1, The step of heat-curing the above coating solution is: Step (S201) of placing a first core including the cavity and a second core including the core portion in a curing booth having a plurality of far-infrared heaters installed; Step (S202) of raising the internal temperature of the above-mentioned hardening booth to 180°C at a heating rate of 60 to 70°C per hour, and A method for coating the surface of a mold device, comprising a step (S203) of thermally curing the coating solution for 2 to 4 hours after the internal temperature of the curing booth reaches 180°C.

9. In paragraph 1, The step of heat-curing the above coating solution is: A step (S301) of heating at least one of a first core including the cavity to which the coating liquid is applied and a second core including the core portion to which the coating liquid is applied, using a movable infrared device including an infrared heater and capable of moving; Step (S302) of heating the above-mentioned mobile infrared device to 180°C at a heating rate of 60 to 70°C per hour, and A method for coating the surface of a mold device, comprising a step (S303) of thermally curing the coating solution for 2 to 4 hours after the heat dissipation temperature of the above-mentioned mobile infrared device reaches 180°C.

10. In clause 8 or 9, The step of cooling the above coating solution is: A method for coating the surface of a mold device, comprising the step (S204, S304) of cooling the first core and the second core to which the coating liquid has been applied at room temperature for 8 to 24 hours.

11. In paragraph 1, As a step between the step of forming a pattern in the core portion and the cavity and the step of applying a coating liquid to the core portion and the cavity, Step of first cleaning the surface of the cavity and the core portion (S102); Step (S103) of attaching a masking adhesive to the remaining area excluding the cavity in the first core and the remaining area excluding the core part in the second core; and Further comprising a step (S104) of secondary cleaning of the surface of the cavity and the core portion; After applying the coating liquid to the surface of the cavity and the core, in the stage before thermal curing, A method for coating the surface of a mold device, further comprising the step of removing masking adhesive attached to the surfaces of the first core and the second core (S106).

12. In paragraph 1, Further comprising a step (S108) in which the surface tension of the coating layer formed on the cavity and the core portion is measured using the DynePen evaluation method as the coating liquid is cooled; A method for coating the surface of a mold device having a surface tension of 40 Dyne in the coating layer.

13. In the coating liquid applied to the surface of the mold device, Siloxane compounds; Isopropyl alcohol; and Containing carbon compounds; The above siloxane compound, the above isopropyl alcohol and the above carbon compound, A coating liquid applied to the surface of a mold device mixed in a weight ratio of 4:14:1 to 4:14:

2.

14. In paragraph 13, The above coating solution is, A coating liquid applied to the surface of a mold device having heat resistance of 400°C to 600°C, cold resistance of -20°C to -10°C, surface hardness of 9H, and viscosity of 2 CPS to 5 CPS.

15. In paragraph 13, The above siloxane compound is, At least one of hexamethyldisiloxane, polysiloxane and polydimethylsiloxane, The above carbon-based compound is a coating solution applied to the surface of a mold device, which is at least one of carbon black and graphene.

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