In-mold forming method and in-mold forming apparatus

Abstract

To provide an in-mold molding method that can suppress burr generation.SOLUTION: An in-mold molding method according to the present disclosure, in which a molded product is formed by transferring a first area R1 of a transfer film to a resin includes: a preparation process to place the transfer film between molds 1 and 2; an injection process in which the molds are clamped and a molten resin 4 is injected into a space formed between the molds; a transfer process in which the mold is opened and the first area of the transfer film is transferred to a surface of the resin; and a curing process for increasing a degree of cure or peeling weight of a second area R2 adjacent to a periphery of the first area of the transfer film.SELECTED DRAWING: Figure 4E

Description

Technical Field

[0001] The present disclosure relates to an in-mold molding method and an in-mold molding apparatus.

Background Art

[0002] Conventionally, the in-mold molding method has been known as a surface decoration technique for plastic molded products. The in-mold molding method is a molding method in which an in-mold film is set in a mold, a resin material is injected, and the in-mold film is transferred to impart decoration and functionality to the surface of the molded product in the mold. The in-mold film includes a base material such as PET, a pattern or functional layer pre-printed by a printing method such as gravure, screen, or inkjet, and an adhesive layer for adhering the functional layer to the resin.

[0003] However, in in-mold molding, there is a risk that a burr of the in-mold film called a foil burr may occur at the end of the molded product. Therefore, it is required to perform a process of removing the burr after injection molding.

[0004] Patent Document 1 discloses an in-mold molding method having a process of removing burrs generated on the end face of a molded product. FIGS. 12 and 13 are process cross-sectional views of the in-mold molding method described in Patent Document 1.

[0005] In Patent Document 1, as shown in FIG. 12, burrs 308 are generated on the end face of the molded product. On the other hand, as shown in FIG. 13, an extra replacement part 508b is provided outside the final product part 508a of the molded product 508. In a post-process after injection molding, the replacement part 508b together with the burrs can be removed using a cutter 507 to remove the burrs from the molded product 508.

[0006] On the other hand, Patent Document 2 discloses an in-mold molding method using a transfer film 202 in which inorganic fillers 307 are dispersed in an adhesive layer 306. FIG. 14 is a cross-sectional view of the in-mold film used in the in-mold molding method described in Patent Document 2.

[0007] As shown in FIG. 14, the inorganic filler 307 is dispersed in the adhesive layer 306. During injection molding, the adhesive layer 306 is softened, and the filler 307 is flowed toward the end of the molded product in accordance with the resin flow within the adhesive layer 306. Therefore, at the end of the molded product, the filler density becomes high and the adhesion between filler particles becomes weak. In this state, cracks are likely to occur in the adhesive layer 306 at the end of the molded product, and the foil of the transfer film 202 is likely to be cut. As a result, the generation of foil burrs at the end of the molded product can be suppressed.

[0008] However, in the in-mold molding method described in Patent Document 1, even if the burrs are removed from the molded product, the burrs may float or adhere in the molding environment and be included in the next molded product to be molded. Further, when the burrs are sandwiched between the mold and the in-mold film, traces due to the burrs may remain on the surface of the molded product, resulting in poor appearance.

[0009] In the in-mold molding method described in Patent Document 2, in order to maintain functions such as scratch resistance, hardness, antireflection, and fingerprint resistance of a transparent molded product in particular, there are many restrictions on the mixing amount, type, etc. of the filler. Further, in a molded product that emphasizes visibility, such as a transparent molded product in particular, even a very small burr may cause a poor appearance.

Prior Art Documents

Patent Documents

[0010]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0011] Therefore, in the in-mold molding methods described in Patent Document 1 and Patent Document 2, there is still room for improvement in terms of suppressing the generation of burrs.

[0012] The present disclosure aims to solve the above problems and provides an in-mold molding method capable of suppressing the generation of burrs.

Means for Solving the Problems

[0013] The in-mold molding method according to the present disclosure is an in-mold molding method for forming a molded product by transferring a first region of a transfer film to a resin, and includes a preparation step of disposing the transfer film between molds, a curing step of increasing the degree of curing or peel weight of a second region adjacent to the outer periphery of the first region of the transfer film, an injection step of clamping the molds and injecting molten resin into the space formed between the molds, and a transfer step of opening the molds and transferring the first region of the transfer film to the surface of the resin.

[0014] The in-mold molding apparatus according to the present disclosure is an in-mold molding apparatus for forming a molded product by transferring a transfer film to a resin, and includes a mold in which the transfer film is disposed and a space for injecting molten resin is formed, and an opening or a heating plate facing the mold forming the outer periphery of the space, and a UV irradiation device for irradiating the transfer film with UV through the opening or a local heating device for heating the transfer film through the heating plate.

[0015] The transfer film according to the present disclosure is a transfer film including a first region that is transferred to a resin to form a molded product, and includes a hard coat layer disposed on the surface of the molded product and an adhesive layer provided between the hard coat layer and the resin, and a second region adjacent to the outer periphery of the first region of the transfer film has a higher degree of curing or peel weight than the first region.

Advantages of the Invention

[0016] According to the present disclosure, an in-mold molding method capable of suppressing the generation of burrs can be provided.

Brief Description of the Drawings

[0017]

Figure 1

Figure 2

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Figure 4A

Figure 4B

Figure 4C

Figure 4D

Figure 4E

Figure 4F

Figure 4G

Figure 5

Figure 6A

Figure 6B

Figure 7

Figure 8

Figure 9A

Figure 9B

Figure 10A

Figure 10B

Figure 11

Figure 12

Figure 13

Figure 14

Embodiments for Carrying Out the Invention

[0018] The in-mold molding method according to the first aspect of the present disclosure is an in-mold molding method for forming a molded product by transferring a first region of a transfer film to a resin, and includes a preparation step of disposing the transfer film between molds, a curing step of increasing the degree of curing or peel weight of a second region adjacent to the outer periphery of the first region of the transfer film, an injection step of clamping the molds and injecting molten resin into the space formed between the molds, and a transfer step of opening the molds and transferring the first region of the transfer film to the surface of the resin.

[0019] By such a method, due to the difference in the degree of curing or peel weight between the first region and the second region, cracks or peeling occur in the second region, and the second region easily separates from the molded product, suppressing the formation of burrs in the outer peripheral portion of the molded product.

[0020] In the in-mold molding method according to the second aspect of the present disclosure, the curing step is performed before the injection step, and in the curing step, the transfer film may be irradiated with UV or heated to form the second region.

[0021] By such a method, by performing UV irradiation or local heating, the degree of curing or the peeling weight of the transfer film corresponding to the second region can be locally increased, and the formation of burrs in the outer peripheral portion of the molded product can be suppressed.

[0022] The in-mold molding method according to the third aspect of the present disclosure may further include a suction step of sucking the transfer film into the space between the preparation step and the injection step.

[0023] By such a method, the transfer film can be made to follow the space.

[0024] In the in-mold molding method according to the fourth aspect of the present disclosure, the curing step may be performed after the suction step.

[0025] By such a method, in the suction step, after ensuring the followability of the transfer film with respect to the space, the degree of curing or the peeling weight of the transfer film corresponding to the second region can be increased.

[0026] In the in-mold molding method according to the fifth aspect of the present disclosure, the second region may be adjacent to a portion of the first region of the transfer film that is transferred last in the transfer step.

[0027] With such a configuration, the generation of burrs in the outer peripheral portion of the molded product can be suppressed particularly in the portion of the transfer film where burrs are likely to occur.

[0028] In the in-mold molding method according to the sixth aspect of the present disclosure, the second region may be a region provided over the entire outer periphery of the first region.

[0029] With such a configuration, the generation of burrs can be suppressed over a wider range in the outer peripheral portion of the molded product.

[0030] In the in-mold molding method according to the seventh aspect of the present disclosure, the transfer film includes, in a preparation step, a hard coat layer disposed facing the mold, and an adhesive layer provided on a surface of the hard coat layer opposite to the mold, and the hard coat layer after the curing step may have a higher degree of curing or peel weight than the first region in the second region.

[0031] By such a method, it is possible to increase the degree of curing or peel weight in the second region of the hard coat layer to make it more likely to crack or peel, and suppress the generation of burrs formed by the hard coat layer.

[0032] The in-mold molding apparatus according to the eighth aspect of the present disclosure is an in-mold molding apparatus that transfers a transfer film to a resin to form a molded product, and includes a mold in which the transfer film is disposed and a space for injecting molten resin is formed, and an opening or a heating plate facing the mold that forms the outer periphery of the space, and a UV irradiation device that irradiates the transfer film with UV through the opening or a local heating device that heats the transfer film through the heating plate.

[0033] With such a configuration, by performing UV irradiation through the opening or heating through the heating plate, it is possible to locally increase the degree of curing or peel weight of the transfer film corresponding to the outer peripheral portion of the space, that is, the outer peripheral portion of the molded product.

[0034] The in-mold molding apparatus according to the ninth aspect of the present disclosure may further include a suction mechanism connected to the space of the mold.

[0035] With such a configuration, the transfer film can be sucked into the space and fixed to the mold.

[0036] The in-mold molding apparatus according to the tenth aspect of the present disclosure further includes an unwinding unit and a winding unit that hold a transfer film in a conveyable manner, the unwinding unit is disposed upstream of the transfer film, the winding unit is disposed downstream of the transfer film, and a UV irradiation device or a local heating device may be provided on the outer wall of the mold on the upstream side.

[0037] With such a configuration, the injection process of a certain molded product and the curing process of the molded product formed next are performed simultaneously, and the efficiency of the in-mold molding method can be improved.

[0038] The transfer film according to the eleventh aspect of the present disclosure is a transfer film including a first region that is transferred to a resin to form a molded product, and includes a hard coat layer disposed on the surface of the molded product and an adhesive layer provided between the hard coat layer and the resin. The second region adjacent to the outer periphery of the first region of the transfer film has a higher degree of curing or peel weight than the first region.

[0039] With such a configuration, in the in-mold molding method using the transfer film, the generation of burrs at the outer peripheral portion of the molded product can be suppressed.

[0040] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings.

[0041] (Embodiment 1) [In-Mold Film Configuration] FIG. 1 is a cross-sectional view showing a layer configuration of an in-mold film used in the in-mold molding method according to Embodiment 1 of the present disclosure.

[0042] The in-mold film 400 is a continuous film that is transferred onto the surface of a resin in the in-mold molding method. As shown in FIG. 1, the in-mold film 400 is composed of a carrier film 201 and a transfer film 202. In the in-mold molding method described later, the carrier film 201 is not transferred onto the molded product, and the transfer film 202 is transferred onto the surface of the molded product.

[0043] The carrier film 201 is composed of a base film 301 and a release layer 302. The base film 301 is a continuous film that supports the transfer film 202. For the base film 301, a PET film or the like having a film thickness of 20 μm or more and 125 μm or less is used. The release layer 302 is laminated on the base film 301, and by peeling between the release layer 302 and the hard coat layer 403, the carrier film 201 and the transfer film 202 are peeled off. The release layer 302 has a film thickness of approximately 1 μm.

[0044] The transfer film 202 is a laminate in which a hard coat layer 403, an anchor layer 304, and an adhesive layer 306 are laminated. Each layer of the transfer film 202 is printed and formed on a base film of an optical PET material having a film thickness of approximately 75 μm by a gravure coater, gravure printing, screen printing, or the like.

[0045] The hard coat layer 403 is a layer formed to have a function of suppressing the formation of scratches and the adhesion of dust on the surface of the molded product. The hard coat layer 403 may further have functions such as fingerprint resistance, anti-glare property, and low reflectance. The hard coat layer 403 may further have a function as a coloring layer that imparts designs such as colors, patterns, and patterns to the surface of the molded product by adding a coloring layer to the hard coat layer 403 or providing a coloring layer on the hard coat layer 403. The hard coat layer 403 is formed of a UV after-cure type or a thermosetting type material. The hard coat layer 403 thus formed reacts to ultraviolet rays or heat. Therefore, by locally applying ultraviolet rays or heat to a part of the transfer film 202 before injection molding, physical properties such as the degree of curing of the said part can be changed.

[0046] The anchor layer 304 adheres the hard coat layer 403 and the adhesive layer 306. The anchor layer 304 is selected according to the compatibility between the hard coat layer 403 and the adhesive layer 306 in consideration of ensuring adhesion.

[0047] The subsequent layer 306 is a layer having a function of adhering the transfer film 202 to the surface of the molded article. For the adhesive layer 306, thermoplastic resins such as acrylic-based and vinyl chloride-based resins can be mainly used, and they are selected according to the resin material to be molded.

[0048] The transfer film 202 has a film thickness of 2 μm or more and 50 μm or less. In Embodiment 1, the hard coat layer 403 has an average film thickness of 5 μm, the anchor layer 304 has an average film thickness of 2 μm, and the adhesive layer 306 has an average film thickness of 4 μm.

[0049] [In-Mold Molding Apparatus Configuration] Subsequently, with reference to FIGS. 2 and 3, an in-mold apparatus used in the in-mold molding method of Embodiment 1 will be described. FIG. 2 is a cross-sectional view of the in-mold molding apparatus according to Embodiment 1 of the present disclosure. FIG. 3 is a plan view of the in-mold film disposed in the movable mold of the in-mold molding apparatus according to Embodiment 1 of the present disclosure.

[0050] As shown in FIG. 2, the in-mold molding apparatus 100 according to Embodiment 1 includes two molds, a fixed mold 1 and a movable mold 2, a vacuum pump 14, a UV irradiation unit 16, a pay-out unit 18, and a take-up unit 19.

[0051] The fixed mold 1 is a fixed mold. The movable mold 2 is a mold that can move along the Z direction so as to approach and separate from the fixed mold 1. When the movable mold 2 approaches and engages with the fixed mold 1, the fixed mold 1 and the movable mold 2 are clamped. Also, when the movable mold 2 separates from the fixed mold 1, the fixed mold 1 and the movable mold 2 are opened. On the parting surface P1 of the movable mold 2 facing the fixed mold 1, a frame clamp 11 and a cavity 12 are provided.

[0052] As shown in Fig. 3, the frame clamp 11 is a frame-shaped member that sandwiches and fixes the in-mold film 400 between it and the movable mold 2. Returning to Fig. 2, the frame clamp 11 is attached to a movable rod 10 protruding from the parting surface P1 and is movable along the Z direction. Also, during mold clamping, since the frame clamp 11 enters and fits into the recess 9 of the fixed mold 1, the fixed mold 1 and the movable mold 2 can be engaged.

[0053] The cavity 12 is a recess formed in the inner parting surface P1 of the frame clamp 11 and receives the in-mold film 400 for forming the molded product and the resin to be injected.

[0054] Suction holes 13 connected to a vacuum pump 14 are embedded in the inner surface of the cavity 12. The vacuum pump 14 is a suction mechanism that sucks the air inside the cavity 12 through the suction holes 13 and discharges it to the outside of the movable mold 2.

[0055] Furthermore, a molded product take-out robot (not shown) may be installed above the movable mold 2 (in the +Z direction). A UV irradiation unit 16 is installed at the tip of the arm 15 of the molded product take-out robot. The UV irradiation unit 16 is a device that irradiates UV light onto the in-mold film 400 fixed to the movable mold 2. In order to perform the irradiation with high precision, the UV irradiation unit 16 has a configuration that can move close to the parting surface P1 of the movable mold 2. Also, during mold clamping, the UV irradiation unit 16 retracts together with the arm 15 from the irradiation position between the fixed mold 1 and the movable mold 2.

[0056] The UV irradiation unit 16 includes a UV lamp 21, a shutter mechanism 17, and an opening 20. The UV lamp 21 is a light source of the UV irradiation unit 16, and the wavelength of the UV lamp 21 is in the wavelength range where the UV initiator and curing agent of the hard coat layer 403 react. The UV lamp 21 uses, for example, lamps such as metal halide, xenon, and LED. The shutter mechanism 17 can be opened and closed. When the shutter mechanism 17 is opened, the UV light generated by the UV lamp 21 is irradiated through the opening 20. The opening 20 is formed to face the parting surface P1 at the irradiation position of the UV irradiation unit 16. In particular, it faces the in-mold film 400 corresponding to the outer peripheral portion of the cavity 12.

[0057] Also, on the side (X direction) of the parting surface P1 of the movable mold 2, a pay-out portion 18 and a take-up portion 19 for supplying the in-mold film 400 along the X direction to the movable mold 2 are provided. The pay-out portion 18 pays out the in-mold film 400, and the take-up portion 19 takes up the in-mold film 400 used in the in-mold molding method. Therefore, from the viewpoint of the supply direction of the in-mold film 400, the pay-out portion 18 is arranged upstream of the take-up portion 19. The movement distance and position of the in-mold film 400 can be adjusted by the pay-out and take-up amounts of the pay-out portion 18 and the take-up portion 19.

[0058] [Effect] According to the in-mold molding apparatus 100 according to the first embodiment, the following effects can be achieved.

[0059] The in-mold molding apparatus 100 according to Embodiment 1 transfers the transfer film 202 onto the resin to form the molded product 7. The in-mold molding apparatus 100 includes a fixed mold 1 and a movable mold 2 (mold), and a UV irradiation unit 16 (UV irradiation device). The transfer film 202 is disposed and fixed between the fixed mold 1 and the movable mold 2, and a cavity 12 (space) into which the molten resin is injected is defined. The UV irradiation unit 16 has an opening 20 facing the movable mold 2 that forms the outer periphery of the cavity 12, and irradiates the transfer film 202 with UV through the opening 20.

[0060] With such a configuration, by performing UV irradiation through the opening 20, it is possible to locally increase the curing degree or peeling weight of the transfer film 202 of the in-mold film 400 corresponding to the outer peripheral portion of the cavity 12. Therefore, the transfer film can be made more likely to crack or peel at the outer peripheral portion of the molded product corresponding to the outer peripheral portion of the cavity 12, thereby suppressing the generation of burrs.

[0061] The in-mold molding apparatus 100 according to Embodiment 1 further includes a vacuum pump 14 (suction mechanism) connected to the cavity 12 of the movable mold 2.

[0062] With such a configuration, the vacuum pump 14 can suck and fix the in-mold film 400 disposed in the movable mold 2 to the cavity 12.

[0063] [In-Mold Molding Method] Next, the in-mold molding method of Embodiment 1 will be described. FIGS. 4A to 4G are cross-sectional views of the steps of the in-mold molding method according to Embodiment 1 of the present disclosure.

[0064] The in-mold molding method of Embodiment 1 sequentially includes a preparation step S11, a suction step S12, a curing step S13, an injection step S14, and a transfer step S15.

[0065] (1) First, as shown in FIG. 4A, the in-mold film 400 is fed out in the +X direction with respect to the movable mold 2 to a specific molding position. The in-mold film 400 that has reached the molding position is fixed to the movable mold 2 by the -Z direction movement of the frame clamp 11 (preparation step S11). Although not shown, at this time, the in-mold film 400 is arranged such that the hard coat layer 403 faces the movable mold 2 through the carrier film 201, and the adhesive layer 306 faces the frame clamp 11. Also, the in-mold film 400 inside the frame clamp 11 is exposed.

[0066] (2) Subsequently, as shown in FIG. 4B, the vacuum pump 14 is operated to suck the air inside the cavity 12 through the suction hole 13 (suction step S12). By sucking the air, the inside of the cavity 12 is decompressed, and the in-mold film 400 deforms and adheres along the inner surface of the cavity 12. The portion of the in-mold film 400 that adheres to the inner surface of the cavity 12 includes the portion to be transferred to the surface of the resin in a later process, and is defined as the first region R1.

[0067] (3) Subsequently, as shown in FIG. 4C, after the suction is completed, the UV irradiation unit 16 attached to the tip of the arm 15 of the molded product take-out robot (not shown) moves close to the parting surface P1 of the movable mold 2.

[0068] As shown in FIG. 4D, by the approach movement of the UV irradiation unit 16, the UV irradiation unit 16 moves to the irradiation position and faces the in-mold film 400 exposed through the frame clamp 11. In particular, the opening 20 faces the in-mold film 400 outside the cavity 12, that is, outside the first region R1, on the parting surface P1 of the movable mold 2. Subsequently, the shutter mechanism 17 of the UV irradiation unit 16 opens, and through the opening 20, the UV light irradiates the in-mold film 400 outside the first region R1 to form the second region R2 (curing step S13). The in-mold film 400 corresponding to the second region R2 is disposed on the parting surface P1 of the movable mold 2, and deformation and deflection during irradiation are suppressed. Therefore, the UV irradiation unit 16 can accurately irradiate the UV light. In the plan view of the in-mold film 400 viewed from the Z direction, the second region R2 is adjacent to the first region R1 and corresponds to the outer peripheral portion of the cavity 12. Also, the second region R2 also corresponds to the outer peripheral portion of the molded product 7, which will be described later, formed in the cavity 12.

[0069] Since the degree of curing or the peel weight of the hard coat layer 403 in the second region R2 increases by UV irradiation, it becomes higher than the degree of curing or the peel weight of the hard coat layer 403 in the first region R1. In Embodiment 1, the peel weight is the force required to peel the hard coat layer 403 from the release layer 302. If the degree of curing is different in adjacent regions, the hard coat layer 403 is likely to crack. Also, if the peel weight is different in adjacent regions, the hard coat layer 403 is likely to be peeled from the release layer 302.

[0070] After irradiating with UV light for a certain period of time, the UV irradiation unit 16 closes the shutter mechanism 17, separates from the parting surface P1 of the movable mold 2, and retracts to the upper part of the movable mold 2.

[0071] (4) Subsequently, as shown in FIG. 4E, the movable mold 2 is brought closer to the fixed mold 1, and the fixed mold 1 and the movable mold 2 are clamped. The molten injection molding resin 4 is injected into the cavity 12 sealed by clamping from the gate 3 through the sprue portion 5 and fills the cavity 12 (injection step S14). As a result, the adhesive layer 306 of the in-mold film 400 in the first region R1 is adhered to the surface of the filled injection molding resin 4. Thereafter, the injection molding resin 4 in the cavity 12 cools to a predetermined temperature and solidifies.

[0072] (5) Subsequently, as shown in FIG. 4F, the movable mold 2 is separated from the fixed mold 1, and the fixed mold 1 and the movable mold 2 are opened. When the mold is opened, the transfer film 202 in the first region R1 is peeled off from the carrier film 201 in the first region R1 and transferred onto the surface of the injection molding resin 4 (transfer step S15). Also, the transfer film 202 in the first region R1 is separated from the transfer film 202 in the second region R2 by foil cutting. Therefore, a molded product 7 is formed on the fixed mold 1 by the transfer film 202 and the injection molding resin 4.

[0073] On the other hand, the carrier film 201 in the first region R1 remains on the movable mold 2. Further, the transfer film 202 in the second region R2 separated from the transfer film 202 in the first region R1 also remains on the movable mold 2. By such a method, the formation of burrs can be suppressed at the outer periphery of the molded product 7 by the transfer film 202 in the second region R2.

[0074] Subsequently, as shown in FIG. 4G, the molded product 7 becomes removable by the protrusion of the protruding pin 6 embedded in the fixed mold 1. Also, in the movable mold 2, the frame clamp 11 opens and the in-mold film 400 becomes movable. The in-mold film 400 is fed out by the unwinding portion 18 and the winding portion 19 and moved to the molding position corresponding to the next molded product.

[0075] [UV Irradiation Unit] Here, with reference to FIG. 5, UV irradiation will be described in more detail. FIGS. 5(a-1), (b) to (d) are plan views of the UV irradiation unit 16 as viewed from the opening 20 side. FIG. 5(a-2) is a cross-sectional view of the UV irradiation unit 16. FIG. 5(a-3) is a plan view of the cavity 12.

[0076] As described above, UV irradiation is performed on the cavity 12, that is, the in-mold film 400 corresponding to the outer peripheral portion of the molded product 7, to form the second region R2. Therefore, the opening 20 corresponds to the in-mold film 400 hitting the second region R2, and the mask portion 20a inside the opening 20 corresponds to the first region R1. In order to position the opening 20 and the cavity 12, the UV irradiation unit 16 further includes a guide groove 22. The guide groove 22 engages with a guide pin formed on the movable mold 2 to position the UV irradiation unit 16 with respect to the movable mold 2.

[0077] Regarding the setting of the dimensions of the opening 20, when the outer peripheral portion of the molded product 7 is cut and removed in a subsequent process, a clearance of approximately 1 mm or more and approximately 2 mm or less is provided from the outer peripheral length A0 of the cavity 12, that is, the molded product 7. On the other hand, when the outer peripheral portion of the molded product 7 remains as the product as it is, a clearance of 0.5 mm is provided with respect to the outer peripheral length A0 of the molded product 7 in consideration of the intrusion of the UV irradiation light from the opening 20 and the like. Therefore, the length of the mask portion 20a is set to A1 = A0 + 0.5 mm. By providing such a clearance, it is possible to suppress the generation of burrs and maintain the appearance of the molded product 7 without forming cracks, whitening, etc. due to UV irradiation in the first region R1.

[0078] As shown in FIG. 5(a-1), the opening 20 may be designed to match the entire outer periphery of the molded product 7. With such a configuration, the second region R2 can be formed over the entire outer periphery of the molded product 7, and the generation of burrs can be suppressed in a wide range of the outer peripheral portion of the molded product 7.

[0079] Further, as shown in FIGS. 5(b) to 5(c), the opening 20 may be set to be limited to a location where burrs are likely to occur. As shown in FIG. 5(d), the opening 20 may be set to be limited to a location where the transfer film 202, that is, the molded product 7 is finally peeled off from the carrier film 201 in the transfer step S15. Burrs are likely to occur at the location where the molded product 7 is finally peeled off from the carrier film 201. With such a configuration, the irradiation efficiency can be improved, the second region R2 adjacent to the location where burrs are likely to occur is formed, and the generation of burrs can be suppressed.

[0080] [Effect] According to the in-mold molding method according to the first embodiment, the following effects can be achieved.

[0081] The in-mold molding method according to the first embodiment is a method of forming a molded product 7 by transferring the first region R1 of the transfer film 202 to the injection molding resin 4 (resin), and includes a preparation step S11, a curing step S13, an injection step S14, and a transfer step S15. In the preparation step S11, an in-mold film 400 (transfer film) is disposed between the fixed mold 1 and the movable mold 2 (mold) and fixed to the movable mold 2. In the curing step S13, the curing degree or the peeling weight of the second region R2 is increased adjacent to the outer periphery of the first region R1 of the transfer film 202. In the injection step S14, the fixed mold 1 and the movable mold 2 are clamped, and the molten injection molding resin 4 is injected into the cavity 12 (space) formed between the fixed mold 1 and the movable mold 2. In the transfer step S15, the fixed mold 1 and the movable mold 2 are opened, and the first region R1 of the transfer film 202 is transferred to the surface of the injection molding resin 4.

[0082] By such a method, due to the difference in the curing degree or the peeling weight between the first region R1 and the second region R2, cracks and cracks are likely to occur in the second region R2 of the transfer film 202. Therefore, the second region R2 is likely to be cut off from the first region R1, that is, the molded product 7. Therefore, the generation of burrs can be suppressed at the outer peripheral portion of the molded product 7. Therefore, the occurrence of defects in the appearance quality of the molded product 7 and the man-hour for deburring in the subsequent process can be reduced.

[0083] In the in-mold forming method according to Embodiment 1, the curing step S13 is performed before the injection step S14. In the curing step S13, the transfer film 202 is irradiated with UV light to form the second region R2.

[0084] By such a method, by performing UV irradiation, the degree of curing or peeling weight of the transfer film 202 corresponding to the second region R2 can be locally increased. Therefore, the generation of burrs can be suppressed at the outer peripheral portion of the molded product 7.

[0085] The in-mold forming method according to Embodiment 1 further includes a suction step S12 of sucking the transfer film into the cavity 12 between the preparation step S11 and the injection step S14.

[0086] By such a method, the in-mold film 400 can be deformed and made to follow the cavity 12. Further, since the in-mold film 400 is fixed in the cavity 12 by suction, the alignment between the in-mold film 400 corresponding to the second region R2 and the opening 20 of the UV irradiation unit 16 becomes easy.

[0087] In the in-mold forming method according to Embodiment 1, the curing step S13 is performed after the suction step S12.

[0088] By such a method, after ensuring the followability of the in-mold film 400 with respect to the cavity 12 in the suction step S12, the degree of curing or peeling weight of the in-mold film 400 corresponding to the second region R2 can be increased.

[0089] In the in-mold forming method according to Embodiment 1, the transfer film 202 used in the in-mold forming method includes a hard coat layer 403 and an adhesive layer 306. The hard coat layer 403 is disposed facing the movable mold 2. The adhesive layer 306 is provided on the surface of the hard coat layer 403 opposite to the movable mold 2. The hard coat layer 403 has a higher degree of curing or peeling weight in the second region R2 than in the first region R1.

[0090] By such a method, the degree of curing or peeling weight of the hard coat layer 403 can be increased. Therefore, it is possible to suppress the generation of burrs mainly composed of the hard coat layer 403. Further, by increasing the degree of curing or peeling weight of the hard coat layer 403, the volume of burrs can be reduced according to the film thickness of the hard coat layer 403.

[0091] In Embodiment 1, an example in which the curing step S13 is performed after the suction step S12 has been described, but the present invention is not limited to this. The curing step S13 may be performed before the suction step S12. In this case, by heating and softening the second region R2 formed in the curing step S13 and then sucking, the followability of the in-mold film 400 in the suction step S12 can be ensured.

[0092] In Embodiment 1, an example in which the degree of curing or peeling weight of the hard coat layer 403 is changed by UV irradiation has been described, but the present invention is not limited to this. In the in-mold film 400, other layers other than the hard coat layer 403 related to the generation of burrs may be changed.

[0093] In Embodiment 1, an example in which the degree of curing or peeling weight of the hard coat layer 403 is changed has been described, but the present invention is not limited to this. Other physical properties related to the generation of burrs may be changed by UV irradiation.

[0094] (Embodiment 2) With reference to FIGS. 6A and 6B, an in-mold forming method and an in-mold forming apparatus according to Embodiment 2 of the present disclosure will be described. In Embodiment 2, mainly, differences from Embodiment 1 will be described. In Embodiment 2, the same reference numerals are given to the same or equivalent configurations as those in Embodiment 1, and redundant descriptions are omitted.

[0095] FIGS. 6A and 6B are cross-sectional views showing an in-mold forming apparatus according to Embodiment 2 of the present disclosure.

[0096] In Embodiment 2, the arrangement of the UV irradiation unit 16A in the in-mold forming apparatus 100A is different from that in Embodiment 1.

[0097] As shown in FIGS. 6A and 6B, the UV irradiation unit 16A is fixed to the outer wall P2 of the fixed mold 1 on the upstream side with respect to the parting surface P1. The UV irradiation unit 16A protrudes from the outer wall P2 in the -X direction.

[0098] With such a configuration, as shown in FIG. 6B, when the movable mold 2 performs a mold clamping operation, the UV irradiation unit 16A approaches the in-mold film portion 400A of the in-mold film 400 outside the frame clamp 11. The in-mold film portion 400A is located on the upstream side of the parting surface P1. The opening 20 of the UV irradiation unit 16A faces the in-mold film portion 400A. When the UV irradiation unit 16A irradiates UV light, the degree of curing or the peel weight of the irradiated in-mold film portion 400A increases.

[0099] In addition, the winding distance between the unwinding portion 18 and the winding portion 19 between consecutive molded products 7 is set in accordance with the distance between the UV irradiation unit 16A and the cavity 12. In this case, the in-mold film portion 400A corresponds to the in-mold film used for the molded product 7 to be formed next to the molded product 7 that is being clamped. Also, the irradiated area corresponds to the second area R2 of the in-mold film portion 400A. Therefore, by using the in-mold molding apparatus 100A, it is possible to simultaneously perform the clamping of the in-mold film 400 and the UV irradiation of the in-mold film portion 400A.

[0100] [Effect] According to the in-mold molding apparatus 100A according to the second embodiment, the following effects can be achieved.

[0101] The in-mold molding apparatus 100A according to the second embodiment further includes an unwinding portion 18 and a winding portion 19 that hold the transfer film 202 in a conveyable manner. The unwinding portion 18 is disposed upstream of the transfer film 202, and the winding portion 19 is disposed downstream of the transfer film 202. The UV irradiation unit 16A is provided on the outer wall P2 of the fixed mold 1 on the upstream side.

[0102] With such a configuration, the clamping of the in-mold film 400 used for a certain molded product 7 and the UV irradiation of the in-mold film portion 400A used for the molded product 7 to be formed next to the molded product 7 are performed simultaneously. Therefore, in mass production, the time required for the in-mold molding method can be reduced, and the efficiency of the in-mold molding method can be improved. Also, the alignment between the UV irradiation unit 16A and the in-mold film 400 becomes easier.

[0103] On the other hand, in the in-mold forming method of Embodiment 2, in the molded product 7 using the in-mold film portion 400A, the curing step S13 is performed before the preparation step S11 and the suction step S12. Therefore, the second region R2 may be heated and softened while being sucked so as to maintain the followability of the in-mold film 400 in the suction step S12.

[0104] Although the example in which the UV irradiation unit 16A is installed in the fixed mold 1 has been described, the present invention is not limited thereto. It may be installed in the movable mold 2 and the UV light may be irradiated from the carrier film 201 side.

[0105] (Embodiment 3) With reference to FIGS. 7 and 8, an in-mold forming method and apparatus according to Embodiment 3 of the present disclosure will be described. In Embodiment 3, mainly, differences from Embodiment 1 will be described. In Embodiment 3, the same reference numerals are given to the same or equivalent configurations as those in Embodiments 1 and 2, and redundant descriptions are omitted.

[0106] FIG. 7 is a cross-sectional view of an in-mold forming apparatus according to Embodiment 3 of the present disclosure. FIGS. 8(a-1), (b) to (d) are plan views of the local heating unit as viewed from the heating plate side. FIG. 8(a-2) is a cross-sectional view of the local heating unit. FIG. 8(a-3) is a plan view of the cavity 12.

[0107] In Embodiment 3, the in-mold forming apparatus 100B includes a local heating unit 24 instead of the UV irradiation unit 16, which is different from Embodiment 1.

[0108] As shown in FIG. 7, a local heating unit 24 is installed at the tip of the arm 15 of the molded product take-out robot. The local heating unit 24 is a device for locally heating the in-mold film 400 fixed to the movable mold 2. The local heating unit 24 is provided with a convex heating plate 25. The heating plate 25 contacts the in-mold film 400 and locally heats it. The heating plate 25 particularly corresponds to the outer peripheral portion of the cavity 12 and heats the in-mold film 400 that hits the second region R2. Due to the local heating, the degree of curing or peeling weight of the in-mold film 400 that hits the second region R2 increases. According to the in-mold molding apparatus 100B according to Embodiment 3, similar to Embodiment 1, the formation of burrs can be suppressed at the outer peripheral portion of the molded product 7.

[0109] The heating plate 25 is formed of, for example, metal, heat-resistant rubber, or the like.

[0110] As shown in FIG. 8, when the outer peripheral portion of the molded product 7 is cut and removed in a subsequent process, considering the heat propagation, a clearance of approximately 3 mm is provided from the outer peripheral length A0 of the cavity 12, that is, the molded product 7, and the dimension A2 of the heating plate 25 is set. With such a configuration, the appearance effects such as cracks and whitening at the heating boundary portion can be suppressed.

[0111] Similar to the opening 20 of Embodiment 1, the heating plate 25 may be designed according to the entire outer peripheral region of the molded product 7, or may be set limited to the locations where burrs are likely to occur.

[0112] In the above description, examples of changing the degree of curing or peeling weight by UV irradiation and heating have been described, but it is not limited thereto. For example, the configuration or material of the in-mold film 400 in the second region R2 may be locally changed.

[0113] (Embodiment 4) With reference to FIGS. 9A and 9B, the in-mold forming method and apparatus according to Embodiment 4 of the present disclosure will be described. In Embodiment 4, mainly, the differences from Embodiment 3 will be described. In Embodiment 4, the same or equivalent components as those in Embodiments 1 to 3 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0114] FIGS. 9A and 9B are cross-sectional views showing an in-mold forming apparatus according to Embodiment 4 of the present disclosure.

[0115] In Embodiment 4, the arrangement of the local heating unit 24A in the in-mold forming apparatus 100C is different from that in Embodiment 3.

[0116] As shown in FIGS. 9A and 9B, the local heating unit 24A is fixed to the outer wall P2 of the fixed mold 1 on the upstream side with respect to the parting surface P1. The local heating unit 24A performs the same operation as the UV irradiation unit 16A according to Embodiment 2.

[0117] According to the in-mold forming apparatus 100C according to Embodiment 4, similarly to Embodiment 2, in mass production, the time required for the in-mold forming method can be reduced, and the efficiency of the in-mold forming method can be improved.

[0118] (Embodiment 5) With reference to FIGS. 10A and 10B, the in-mold forming method and apparatus according to Embodiment 5 of the present disclosure will be described. In Embodiment 5, mainly, the differences from Embodiment 1 will be described. In Embodiment 5, the same or equivalent components as those in Embodiment 1 are denoted by the same reference numerals, and redundant descriptions are omitted.

[0119] FIG. 10A is a cross-sectional view showing an in-mold forming apparatus according to Embodiment 5 of the present disclosure. FIG. 10B is a plan view showing an in-mold forming apparatus according to Embodiment 5 of the present disclosure.

[0120] In Embodiment 5, the configuration of the UV continuous irradiation unit 16B of the in-mold molding apparatus 100D is different from that in Embodiment 1.

[0121] As shown in FIG. 10A, the UV continuous irradiation unit 16B is fixed to the outer wall P2 of the fixed mold 1 on the unwinding unit 18 side.

[0122] As shown in FIG. 10B, the UV continuous irradiation unit 16B of the in-mold molding apparatus 100D irradiates a part of the in-mold film 400 during the process of transporting the in-mold film 400.

[0123] When the conveyance of the in-mold film 400 starts before the preparation step S11, the UV continuous irradiation unit 16B starts irradiation. In the conveyance of the in-mold film 400, since the UV irradiation is continuously performed, the degree of curing or the peel weight increases, and the second region R12 is formed. The second region R12 corresponds to the outer peripheral portion of the cavity 12, that is, the outer peripheral portion of the molded product 7, and overlaps each other in a plan view in the Z direction. When the in-mold film 400 corresponding to the molded product 7 reaches the molding position of the cavity 12 and the conveyance stops, the irradiation also stops. By stopping the irradiation, it is possible to suppress giving excessive energy to the in-mold film 400. By repeating the operation of the UV continuous irradiation unit 16B, a continuous second region R12 is formed on the in-mold film 400.

[0124] According to the in-mold molding method according to Embodiment 5, since the in-mold film 400 is irradiated simultaneously with the conveyance, in mass production, the time required for the in-mold molding method can be reduced, and the efficiency of the in-mold molding method can be improved.

[0125] (Embodiment 6) Referring to FIG. 11, an in-mold film and an in-mold molding method according to Embodiment 6 of the present disclosure will be described. In Embodiment 6, mainly, the differences from Embodiment 1 will be described. In Embodiment 6, the same reference numerals are given to the same or equivalent configurations as those in Embodiment 1, and redundant descriptions are omitted.

[0126] FIG. 11 is a plan view of an in-mold film according to Embodiment 6 of the present disclosure.

[0127] In Embodiment 6, the order of the steps of irradiating the in-mold film 410 with UV light or heating it is different from that in Embodiment 1.

[0128] The in-mold film 410 includes a carrier film 201 and a transfer film 202 (not shown), similar to the in-mold film 400. As shown in FIG. 11, the in-mold film 410 corresponding to the outer peripheral portion of the continuous molded product 7 is irradiated with UV light or heated to change physical properties such as the degree of curing or the peel weight, thereby forming the second region R22. Thereafter, the in-mold film 410 is wound up in a roll shape.

[0129] The in-mold molding method (S11, S12, S14, S15) can be carried out using the wound-up in-mold film 410. The in-mold film 410 is fed out by a pay-out section 18 and a take-up section 19. The in-mold molding method is carried out with the alignment such that the second region R22 with a previously increased degree of curing or peel weight corresponds to the outer peripheral portion of the molded product 7.

[0130] The in-mold film 410 according to Embodiment 6 includes a first region R21 in the transfer film 202 that is transferred to the resin to form a molded product. The transfer film 202 includes a hard coat layer 403 disposed on the surface of the molded product 7 and an adhesive layer 306 provided between the hard coat layer 403 and the injection molding resin 4. The second region R22 adjacent to the outer periphery of the first region R21 of the transfer film 202 has a higher degree of curing or peel weight than the first region R21.

[0131] With such a configuration, due to the difference in the degree of curing or the peeling weight between the first region R21 and the second region R22, cracks are likely to occur in the transfer film 202 in the second region R22. In the transfer film 202, the second region R22 is likely to separate from the first region R21. Therefore, generation of burrs can be suppressed in the first region R21, that is, the outer peripheral portion of the molded product 7.

[0132] In addition, in the sixth embodiment, an example in which the second region R22 is formed by UV irradiation or heating has been described, but it is not limited thereto. Before winding up in a roll shape, a separate material may be applied to the portion of the in-mold film 410 corresponding to the second region R22 by coating and printing to form the second region R22. As the printing method, screen printing, gravure printing, or the like may be used.

[0133] The present disclosure has been fully described in connection with the preferred embodiments with reference to the accompanying drawings. However, various modifications and corrections will be apparent to those skilled in this technology. Such modifications and corrections should be understood to be included therein as long as they do not depart from the scope of the present disclosure according to the appended claims.

Industrial Applicability

[0134] The in-mold molding method and the in-mold molding apparatus of the present disclosure are useful in imparting functions and coloring to the surface of a molded product.

Explanation of Signs

[0135] 1 Fixed mold 2 Movable mold 4 Injection molding resin 7 Molded product 10 Rod 11 Frame clamp 12 Cavity 13 Suction hole 14 Vacuum pump 15 Arm 16 UV irradiation unit 17 Shutter mechanism 18 Unwinding section 19 Rewinding section 20 Opening 21 UV lamp 22 Guide groove 24 Local heating unit 25 Heating plate 100 In-mold forming device 201 Carrier film 202 Transfer film 301 Base film 302 Release layer 304 Anchor layer 306 Adhesive layer 400 In-mold film 403 Hard coat layer R1 First region R2 Second region

Claims

1. An in-mold molding method for forming a molded article by transferring a first region of a transfer film to a resin, comprising: a preparation step of disposing the transfer film between molds; a curing step of increasing the degree of curing or peel weight of a second region adjacent to the outer periphery of the first region of the transfer film; an injection step of clamping the molds and injecting the molten resin into the space formed between the molds; a transfer step of opening the molds and transferring the first region of the transfer film to the surface of the resin; An in-mold molding method having the above steps.

2. The curing step is performed before the injection step, In the curing step, the transfer film is irradiated with UV or heated to form the second region. The in-mold molding method according to claim 1.

3. The in-mold molding method according to claim 2, further comprising a suction step of sucking the transfer film into the space between the preparation step and the injection step.

4. The curing step is performed after the suction step. The in-mold molding method according to claim 3.

5. The second region is a region provided over the entire outer periphery of the first region. The in-mold molding method according to any one of claims 1 to 4.

6. The transfer film includes a hard coat layer disposed to face the mold in the preparation step, and an adhesive layer provided on a surface of the hard coat layer opposite to the mold. The hard coat layer after the curing step has a higher degree of curing or peel weight in the second region than in the first region. The in-mold molding method according to any one of claims 1 to 5.

7. An in-mold molding apparatus for forming a molded article by transferring a transfer film to a resin, comprising: a mold in which the transfer film is disposed and a space for injecting the molten resin is formed; a UV irradiation device having an opening or a heating plate facing the transfer film, and irradiating the transfer film with UV through the opening, or a local heating device for heating the transfer film through the heating plate; Having the above components, Further comprising an unwinding unit and a winding unit for holding the transfer film in a transportable manner, The unwinding unit is disposed upstream of the transfer film, The winding unit is disposed downstream of the transfer film, The UV irradiation device or the local heating device is provided on the outer wall of the mold on the upstream side. An in-mold molding apparatus.

8. A transfer film having a first region that is transferred to a resin to form a molded article, a hard coat layer disposed on the surface of the molded article, and an adhesive layer provided between the hard coat layer and the resin, wherein a second region adjacent to the outer periphery of the first region of the transfer film has a higher degree of curing or peel weight than the first region.

Images