JP6089297B2 - Thermosetting resin molded product mold and molding method of thermosetting resin molded product - Google Patents

Description

The present invention relates to a molding method for thermosetting resin molding die contact and thermosetting resin molded article to form a thermosetting resin molding using a mold.

  An optical component such as a lens may be formed by resin molding. The molding resin material for a lens is roughly classified into a thermoplastic resin and a thermosetting resin. Among these, thermosetting resins are expected to be used in various applications because they have better heat resistance than thermoplastic resins. In resin molding using a thermosetting resin, a thermoformed resin is injected into a mold in which a molded product space is formed, and heat-cured to form a resin molded product that matches the shape of the molded product space. Yes. In addition, thermosetting resin is mass-productive because of its high fluidity, because the resin enters and adheres to the gap between the protruding pin and its sliding hole and hardens. There was a problem. However, as described in Patent Document 1, mass production has become possible by adopting a molding frame.

FIG. 5 is a view illustrating a mold structure of a lens which is a conventional thermosetting resin molded article, and shows a conventional mold structure described in Patent Document 1. In FIG.
In FIG. 5, between the pair of split molds 129 and 130, a molding frame 133 is tightly attached to the position of the relief opening 131 in accordance with the position of the lens molding space 132. When forming a lens using a mold having such a configuration, first, a thermosetting resin is injected into the lens molding space 132 and is cured by heating. Next, the molded lens is taken out by protruding the molded product by the protruding release member 134 arranged outside the lens molding space 132, and the molded lens is taken out. In this way, by forming the molding frame 133 in the mold in advance and projecting the molding frame 133 and projecting it with the release member 134, the molded product can be taken out and molding that is less likely to cause problems due to fluidity becomes possible. ing.

JP 2010-214763 A

  Heat is transferred from the mold surface to the resin injected into the lens molding space 132, and a cured layer is formed from the surface. As the resin hardens, the resin in the lens molding space 132 contracts. The shortage of resin due to the shrinkage is compensated by supplementing the lens molding space 132 with a resin that has not been cured by holding pressure. However, in the conventional mold configuration, since the curing of the resin has started from the beginning of filling, the resin close to the gate side that is the resin injection port contacts the mold before the filling end far from the gate and cures. Begin to. Therefore, the surrounding resin is cured before sufficient holding pressure is applied to the filling end portion, and molding defects such as sink marks in which the resin is not sufficiently filled in the molded product have occurred. In addition, the thickness of the molded product is not uniform, and the timing of curing is slower in the maximum thickness portion than in the thin thickness portion, so that sufficient holding pressure is not applied to the central portion of the maximum thickness portion. Molding defects such as sink marks not filled with resin occurred.

  The present invention solves the above-mentioned conventional problems, and an object thereof is to suppress the occurrence of molding defects when molding a thermosetting resin molded product.

  In order to achieve the above object, the thermosetting resin molded product mold of the present invention includes a molded product space in which a thermosetting resin is injected and a thermosetting resin molded product is molded, and the molded product space includes the molded product space. It has a gate serving as an injection port for injecting a thermosetting resin, and a first textured surface formed on at least a part of the inner surface of the molded article space, and the surface roughness of the textured surface. However, the distance from the gate is rough.

  As described above, by forming a textured surface on the inner surface of the molded product space of the mold, and increasing the surface roughness of the textured surface formed at the filling end far from the gate than in the vicinity of the gate, Since the resin can be cured in order from the filling end portion far from the resin, and the resin shortage can be supplied by holding pressure even at the filling end portion, the occurrence of molding defects such as sink marks can be suppressed.

Sectional drawing which shows the structure of the lens which is an example of the thermosetting resin molded product of this invention Sectional drawing which illustrates the structure of the thermosetting resin molded product metal mold | die of this invention The principal part enlarged view which illustrates the structure of the thermosetting resin molded product metal mold | die of this invention Flow diagram illustrating a method for molding a thermosetting resin molded product of the present invention The figure which illustrates the metallic mold structure of the lens which is the conventional thermosetting resin molded product

  The thermosetting resin molded product mold of the present invention has a textured surface with irregularities formed on at least a part of the inner surface of the molded product space, and has a textured surface size. The surface roughness is characterized by becoming rougher as it is farther from the gate which is the thermosetting resin injection port. When molding a thermosetting resin molded product, the thermosetting resin is injected into the molded product space of the thermosetting resin molded product mold of the present invention, the thermosetting resin is heated and cured, and then released. A thermosetting resin molded product cured by molding is obtained. The thermosetting resin molded product molded in this way has a textured surface formed by transferring irregularities on at least a part of the surface, and is formed with a textured shape on the basis of the position corresponding to the gate that is the resin injection port. The unevenness of the surface increases as the distance from the position corresponding to the gate increases. In this way, even if the resin is molded using the thermosetting resin molded product mold of the present invention, the resin starts to cure from the filling end portion away from the gate, and even if the filling end portion contracts during resin curing. The resin on the gate side that has not been cured is filled in the filling end portion, and the occurrence of molding defects such as sink marks can be suppressed.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following description, a case where a lens is molded as a thermosetting resin molded product will be described as an example. However, the thermosetting resin molded product is not limited to a lens or an optical component, and may be various resin molded products. . In the following description, a case where a molding frame is provided in the mold will be described as an example.
(Embodiment 1)
FIG. 1 is a cross-sectional view showing a configuration of a lens which is an example of a thermosetting resin molded product of the present invention.

  As shown in FIG. 1, a lens 101 molded from a thermosetting resin has a first optical lens surface 102 and a second optical lens surface 103. The first optical lens surface 102 has an optical effective range 104 and a textured surface 105, and the second optical lens surface 103 has an optical effective range 106 and a textured surface 107. In addition, the rough surfaces 105 and 107 are roughened from the gate side, which is a resin injection port during resin molding, toward the resin flow direction. The embossed shape is a shape whose surface is uneven. As an example, the surface roughness of the optical effective ranges 104 and 106 is 3 nmRa, and the surface roughness of the embossed surface is 0.5 μm to 5 μmRa, except for the optical effective ranges 104 and 106, toward a region far from the gate side. The surface roughness gradually increases. The position of the gate will be described with reference to FIG.

FIG. 2 is a cross-sectional view illustrating the configuration of the thermosetting resin molded product mold of the present invention, and is a cross-sectional view of the lens mold.
As shown in FIG. 2, the thermosetting resin molded product mold of the present invention includes a first mold 108 and a second mold 109. A first lens insert 110 and a second lens insert 111 are incorporated in the first mold 108 and the second mold 109, respectively, and the optical lens surface is formed on the lens inserts 110 and 111. In the thermosetting resin molded product mold of the present invention, the molded product space 112 is formed by clamping the first mold 108 and the second mold 109. A molding frame insertion groove 114 is formed in the second mold 109 so that the molding frame 113 can be inserted, and there are two or three positioning pins 115 for positioning the molding frame 113. A protruding pin 116 for protruding the frame 113 and taking out the molded product is formed. Since the thermosetting resin flows from a minute gap between the molding frame 113 and the molding frame insertion groove 114, the protruding pin 116 is disposed at a position sufficiently away from the resin flow portion. As a resin flow path to the molded product space 112, a sprue 117, a runner 118, and a gate 119 are provided.

FIG. 3 is an enlarged view of a main part illustrating the configuration of the thermosetting resin molded product mold of the present invention, and is an enlarged view of the molded product space.
As shown in FIG. 3, the first lens nest 110 includes a flat surface 120 corresponding to the first optical lens surface 102 (see FIG. 1), and embossed surfaces 1211 and 1212 formed around the flat surface 120. Nested with The first mold 108 incorporating the first lens insert 110 itself does not have an area for forming an optical lens surface, the runner 118 and the gate 119 have an embossed surface 122, and an embossed surface in an area corresponding to the lens outer shape portion. 1231 and 1232. Similarly, the second lens nest 111 has a flat surface 124 corresponding to the second optical lens surface 103 (see FIG. 1), and embossed surfaces 1251 and 1252 formed around the flat surface 124. The second mold 109 itself has no region for forming the optical lens surface. Further, the second mold 109 has a textured surface 126 on the surface on which the runner 118 and the gate 119 of the molding frame 113 are formed, and textured surfaces 1271 and 1272 in a region corresponding to the lens outer portion. Any grain-like surface is a grain-like surface whose surface roughness increases toward the resin flow direction 128. That is, the resin flow end portion has a rougher surface roughness.

In the above description, the case where one lens is molded has been described. Usually, in order to obtain a plurality of lenses at a time, a plurality of molded product spaces are formed in one mold.
Hereinafter, the molding method of the thermosetting resin molded product of the present invention will be described with reference to FIGS.

FIG. 4 is a flowchart for explaining the molding method of the thermosetting resin molded product of the present invention, and FIG. 4 (a) is a flowchart for explaining the molding method of the thermosetting resin molded product in the first embodiment. .
First, the molding frame 113 is set in the molding frame insertion groove 114 of the second mold 109 in a state where the first mold 108 and the second mold 109 are separated from each other with the parting line as a boundary. When the molding frame 113 is set, positioning pins 115 can be used. After that, the first mold 108 and the second mold 109 are driven by means of clamping to form a molded product space 112 in the mold (Step 1 in FIG. 4A).

  In this state, a liquid thermosetting resin is passed through the sprue 117, the runner 118, and the gate 119 to inject the thermosetting resin into the molded product space 112. When the thermosetting resin is injected, in the thermosetting resin molding method of the first embodiment, the mold is heated in advance (step 2 in FIG. 4A).

  Next, the thermosetting resin is filled into the molded product space 112 including the runner 118. At this time, since the mold is heated in advance, heat is transferred from the first mold 108 and the second mold 109, the thermosetting resin is heated, and the resin is sufficiently cured. Thereafter, by opening the mold, the second mold 109 is opened in a direction separating the parting line. At this time, due to the difference in adhesion between the first mold 108 and the second mold 109 with the thermosetting resin, the resin molded product molded in the molded product space 112 including the runner 118 becomes the first mold 108. Since it may remain, it is advisable to take measures to remain on the second mold 109 side. For example, it is possible to provide a molding frame 113 and a structure for pressing the resin molded product against the second mold 109 on the first mold 108 side (step 3 in FIG. 4A).

  Finally, after opening the mold, the ejector plate is driven by the protruding rod of the molding machine, and the thermosetting resin molded product including the molding frame 113 is protruded and taken out by the protruding pin 116. And after taking out a thermosetting resin molded product, the lens 113 is obtained by removing the flame | frame 113 for shaping | molding and cutting the gate part 119 ((step 4 of Fig.4 (a)).

  During the process of Step 3, the thermosetting resin passes through the sprue 117, the runner 118, and the gate 119 and is filled with the thermosetting resin in the molded product space 112, so that the thermosetting resin heats from the contact surface of the mold. It is added and causes a chemical reaction to harden. As the thermosetting resin hardens, the resin in the space shrinks. The shortage of thermosetting resin due to shrinkage is compensated by replenishing the thermosetting resin that has not been cured by holding pressure into the space where the thermosetting resin is insufficient. Since the curing of the thermosetting resin has started from the beginning, the thermosetting resin close to the gate 119 side comes into contact with the mold before the filling end far from the gate 119 and begins to harden. The surrounding thermosetting resin may be cured before sufficient holding pressure is applied, and molding defects such as sink marks that are not sufficiently filled with the thermosetting resin in the molded product space 112 occur. It was. In addition, the thickness of the molded product space 112 is not uniform, and since the timing of curing is delayed in the maximum thickness portion compared to the thin thickness portion, sufficient holding pressure is not applied to the central portion of the maximum thickness portion, Molding defects such as sink marks not sufficiently filled with resin occurred.

  To solve this problem, as shown in FIG. 3, the present invention solves this problem by controlling the curing speed of the resin by providing a textured surface around the flat surfaces 120 and 124 corresponding to the optical lens surface. For example, a textured surface 1211, a textured surface 1231 as a first texture, a textured surface 122 as a second texture, a textured surface 1251, a textured surface 1271, a textured surface as a fourth texture, and a textured surface as a fourth texture. A textured surface 1262, a textured surface 1212 as the fifth texture, a textured surface 1232, and a textured surface 1252, a textured surface 1272 as the sixth texture. Therefore, a textured surface is formed from the gate 119 toward the flow direction 128 of the thermosetting resin so that the surface roughness becomes rough. Each wrinkle shape is such that the surface roughness of the wrinkled surface is in the range of 0.5 μmRa to 5 μmRa, such that second wrinkles, fourth wrinkles <first wrinkles, third wrinkles <fifth wrinkles, sixth wrinkles. Form the surface. For example, the surface roughness of the second and fourth wrinkles is 1.0 μmRa, the surface roughness of the first and third wrinkles is 3.0 μmRa, and the surface roughness of the fifth and sixth wrinkles is 5.0 μmRa. To do. Further, the regions of the runner 118 and the gate 119 may be flat surfaces that do not form a textured surface. Moreover, you may form an embossed surface only in a filling terminal part. When molding a thermosetting resin molded product that does not require a flat surface such as an optical component, the surface roughness is directed from the gate 119 toward the thermosetting resin flow direction 128 over the entire surface of the molded product space 112. A textured surface may be formed so as to be rough. In this way, by forming an embossed surface on the inner surface of the molded product space 112 from the gate 119 in the direction of flow 128 of the thermosetting resin so that the surface roughness becomes rough, the runner 118 and the gate 119 are formed. In addition, the filling end portion farther from the gate 119 than the gate 119 side increases the contact area with the mold due to the difference in the textured surface, so that heat energy can be efficiently transferred to the resin, The thermosetting resin can be cured in order from the portion toward the gate 119 side. And since it hardens | cures from a filling terminal part, even if the thermosetting resin of a terminal hardens | cures and volume decreases, uncured thermosetting resin can be supplied from the gate side. As a result, a thermosetting resin molded product can be obtained in the molded product space 112 without causing molding defects such as sink marks. In addition, when a lens is molded as a thermosetting resin molded product, a textured surface cannot be formed in the formation region of the optical lens surface, but in the case of a concave lens, the optical lens surface becomes thin. The portion of the thermosetting resin hardens faster than the vicinity of the gate 119. Therefore, when the thermosetting resin in the region near the optical lens surface is cured, uncured thermosetting resin is supplied from the gate side, and it is possible to suppress the occurrence of molding defects such as sink marks on the lens. In addition, even when a convex lens is molded, the filling end can be surely cured earlier than the region near the optical lens surface by forming a textured surface at the filling end. The stress due to shrinkage at the time of curing the filling end can be absorbed by the thermosetting resin in the vicinity of the uncured optical lens surface and in the vicinity of the gate 119. It is possible to suppress distortion of the optical lens surface.

  In addition, by forming a textured surface on the inner surface of the molded product space 112, it is possible to generate a resistance force against the force by which the thermosetting resin is pulled to the gate 119 side due to shrinkage during curing. Since the internal pressure of the resin when the resin is cured can always be kept constant, a molded product with less birefringence can be obtained.

  Further, the unevenness formed on the embossed surface can generate a resistance force against the force by which the thermosetting resin is pulled to the gate 119 side due to the shrinkage at the time of curing, and the resin in the optical lens surfaces 120 and 124. Can be made uniform and good lens surface shape accuracy can be obtained.

  As shown in FIG. 1, the lens as an example of the thermosetting resin molded product formed as described above is placed on the mold around the first optical lens surface 102 and the second optical lens surface 103 in the lens 101. A feature is that textured surfaces 105 and 107 having a rough surface formed by transferring the textured surface attached in step 1 are formed. In this way, by forming a textured surface around the optical lens surface, it is possible to cause a textured surface with irregularities on the surface to function as a light shielding portion. With this light shielding portion, it is possible to prevent the entry of extra light when entering and exiting the lens, and to improve ghost and flare.

In the above description, the upper optical surface is described as a convex shape and the lower optical surface is described as a concave shape. However, the opposite is also possible, and both surfaces may be concave or convex.
(Embodiment 2)
Next, the molding method of the thermosetting resin molded product in Embodiment 2 is demonstrated using FIGS.

FIG. 4B is a flowchart for explaining a method of molding a thermosetting resin molded product in the second and third embodiments.
When molding a thermosetting resin molded product having a complicated shape such as a lens having a very large thickness near the gate, in addition to the molding method of the thermosetting resin molded product of the first embodiment, the mold shown in FIG. Instead of injecting the resin into the heated mold, the mold can be controlled to be heated after the thermosetting resin is filled in the molded article space 112.

First, as in the first embodiment, the mold is clamped to form the molded product space 112 (step 1 in FIG. 4B).
Next, in the molding method of the thermosetting resin molded product of Embodiment 2, the thermosetting resin is injected without heating the mold (step 2 in FIG. 4B).

Next, after filling the molded product space 112 with a thermosetting resin, the mold is heated to cure the thermosetting resin (step 3 in FIG. 4B).
Thereafter, similar to the molding method of the first embodiment, the mold is opened, and the cured thermosetting resin molded product is taken out (step 4 in FIG. 4B).

By such heating control, the thermosetting resin is not cured until the thermosetting resin passes through the sprue 117, the runner 118, and the gate 119 and is filled in the molded product space 112. For this reason, it is suppressed that the vicinity of the gate 119 into which the thermosetting resin is injected first starts to be hardened before the filling end portion, and the influence on the hardening speed due to the difference in the surface roughness of the molded article space 112 is remarkable. Become. Accordingly, curing starts from the filling end portion having a rough surface roughness, and the holding pressure can be transmitted to the molded product space 112 more reliably than in the first embodiment, resulting in molding defects such as sink marks. It is possible to obtain a thermosetting resin molded product having no heat. In addition, since the timing at which the gate 119 side and the filling end portion far from the gate 119 start to be hardened coincides, the surface roughness becomes rougher in the resin flow direction 128 in the lens molded product space 112 shown in FIG. The thermosetting resin from the filling end portion farther from the gate 119 is more reliably secured by the embossed surfaces 1211, 1231, 122, 1251, 1271, 1271, 12612, 1232, 1252, and 1272 around the optical lens surface. A thermosetting resin molded product that can be cured and has no molding defects such as sink marks can be obtained.
(Embodiment 3)
Next, the molding method of the thermosetting resin molded product in Embodiment 3 is demonstrated using FIG. 2, FIG.

  Furthermore, when molding a thermosetting resin molded product such as a highly accurate lens, in addition to the molding method of the thermosetting resin molded product of the second embodiment, the molded product space 112 is filled with the thermosetting resin. You may perform control which heats a metal mold | die in order toward the reverse direction to the flow direction 128 of a thermosetting resin. In this way, after the thermosetting resin is filled into the molded product space 112, the surface roughness of the embossed surface is controlled by controlling the heating of the mold in order from the filling end to the gate 119. Since it begins to harden from the rough filling end portion, the holding pressure can be transmitted better into the molded product space 112, and the filling end portion can be reliably filled with the thermosetting resin. A thermosetting resin molded article free from molding defects can be obtained.

  The present invention can suppress the occurrence of molding defects such as sink marks, and is a thermosetting resin molded product mold for forming a thermosetting resin molded product using a mold, and a thermosetting formed using the mold. It is useful for molding methods for resin molded products and thermosetting resin molded products.

DESCRIPTION OF SYMBOLS 101 Lens 102 1st optical lens surface 103 2nd optical lens surface 104 Optical effective range 105 Wrinkled surface 106 Optical effective range 107 Wrinkled surface 108 1st metal mold 109 2nd metal mold 110 1st lens nest 111 2nd Lens insert 112 Molded product space 113 Molding frame 114 Molding frame insertion groove 115 Positioning pin 116 Projection pin 117 Sprue 118 Runner 119 Gate 120 Flat surface 1211 Embossed surface 1212 Embossed surface 122 Embossed surface 1231 Embossed surface Surface 1232 Textured surface 124 Flat surface 1251 Textured surface 1252 Textured surface 126 Textured surface 1271 Textured surface 1272 Textured surface 128 Flow direction of resin 129 Split mold 130 Split mold 131 Escape opening 132 Lens Molding space 133 Molded product flare Beam 134 protrudes release member

Claims (6)

A molded product space in which a thermosetting resin is injected and a thermosetting resin molded product is molded; and
A gate serving as an inlet for injecting the thermosetting resin into the molded article space;
A first textured surface formed on at least a part of the inner surface of the molded article space, and the surface roughness of the textured surface is rougher as it is separated from the gate. Curable resin molded product mold.   2. The thermosetting resin molded product mold according to claim 1, wherein the thermosetting resin molded product is an optical component, and the first textured surface is formed only in a region where a light shielding portion is formed. . Injecting a thermosetting resin from the gate of the thermosetting resin molded product mold according to claim 1 into the molded product space;
Heating the thermosetting resin molded product mold after filling the molded product space with a thermosetting resin and curing the thermosetting resin in the molded product space; and
Opening the thermosetting resin molded product mold and taking out the thermosetting resin molded product molded into the molded product space.   The method for molding a thermosetting resin molded product according to claim 3, wherein the heating of the thermosetting resin molded product mold is sequentially performed from a region away from the gate. Injecting a thermosetting resin from the gate into the molded product space while the thermosetting resin molded product mold according to claim 1 is heated;
Curing the thermosetting resin in the molded article space;
Opening the thermosetting resin molded product mold and taking out the thermosetting resin molded product molded into the molded product space.   The thermosetting resin molded product is an optical component, and the first textured surface is formed only in a region where a light-shielding portion is formed. The molding method of the thermosetting resin molded article of description.

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