JP2017140721A - Method for producing resin molded article - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a resin molded article having a complicated streamline pattern and a feeling close to natural marble by managing flow behavior of resins injected in a metal mold.SOLUTION: Resins of different colors are injected in a metal mold 1 to mold a resin molded article having a streamline pattern. The metal mold is equipped with a main resin injection port 2 at an end thereof, a main air vent 3 at another opposite end and at least one pair of an auxiliary resin injection port 4 having a switching control valve and an auxiliary air vent 5 on both sides of the metal mold in the direction toward the main air vent from the main resin injection port. In the course from resin injection from the main resin injection port and an injection stop to subsequent ventilation by opening the main air vent, the auxiliary air vents are opened and closed in the order of closer position to the main resin injection port and then the auxiliary resin injection ports pairing the opened and closed auxiliary air vents are opened to inject resin and closed to control flow behavior of the injected resin.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a method for producing a resin molded product.

  Conventionally, resin molded products having a marble-like pattern of artificial marble have been widely used for bathtubs, wash bowls, resin sinks and the like because of their high design.

  These resin molded products are usually molded by injecting a resin material composed of two or more kinds of thermosetting resins having different color tones into a mold. Various proposals have been made so far for methods for producing artificial marble having a more natural texture.

  Specifically, for example, a method has been proposed in which two or more kinds of pigments having different color tones are pressed and joined to a thermosetting resin, and an incompletely mixed resin is injected into a mold (molding) ( For example, see Patent Document 1).

  According to this method for producing a resin molded product, a resin molded product having a marble pattern or a flow pattern can be formed by injecting a resin in which a pigment is mixed with a resin in an incomplete state into a molding die. It is supposed to be possible.

  Specifically, in this proposed method, incompletely mixed resin is injected from one resin inlet provided in the mold, and degassed from an air vent for air venting provided on the opposite side. The flow pattern is formed by filling the resin and heating it as it is to cure the resin.

  The photograph in FIG. 5 exemplifies a resin molded product having a flow pattern molded by a method similar to this method. In addition to injecting resin from the resin injection port 2 at the right end of the mold, the resin is molded by degassing from the air vents 3 provided at two locations above and below the left end.

  The resin injected from one resin injection port 2 of the mold exhibits a linear flow behavior toward the air vent 3. The flow pattern that appears on the molded resin molded product flows in one direction.

Japanese Patent Laid-Open No. 53-1255

  However, although the flow pattern is formed in the method of Patent Document 1, the flow pattern is in one linear direction. For this reason, in the method of patent document 1, when compared with the natural marble which has a complicated flow pattern, there existed a problem that there was unnatural and it was inferior in design.

  The present invention has been made in view of the above-mentioned conventional problems, and has a complicated flow pattern by manipulating the flow behavior of the resin injected into the mold, and has a texture that is closer to natural marble. It is an object of the present invention to provide a method for producing a resin molded product capable of molding a product.

  The present invention is characterized by the following in order to solve the above problems.

  A resin molded product manufacturing method for molding a resin molded product having a flow pattern by injecting a resin having a different color tone into a mold, comprising a main resin injection port at one end of the mold, A secondary resin having a main air vent at the other end facing the main resin injection port, and having an open / close control valve on each side of the mold in a direction from the main resin injection port toward the main air vent. In a mold apparatus provided with at least one set of inlet and sub-air vent, in response to resin injection from the main resin injection port and finally resin injection by opening the main air vent after the stop. (I) Degassing by opening the secondary air vent corresponding to resin injection and in the order of the set in which the arrangement position from the main resin injection port is close Stop, to control the flow behavior of the (ii) the resin injection and its stop closing the said open auxiliary barrel resin injection port forming the secondary barrel air vent and set, by injection to the resin.

  According to the present invention, by manipulating the flow behavior of the resin injected into the mold, it is possible to manufacture a resin molded product having a complicated flow pattern and capable of forming a molded product having a texture closer to that of natural marble. A method can be provided.

It is a schematic plan view which shows one Embodiment of the die apparatus used for the manufacturing method of the resin molded product of this invention. It is the schematic which shows the resin tank which stores the resin supplied to a metal mold apparatus, (A) is a partially notched sectional view which shows the resin tank which laminated | stacked and stored the resin of the 2 or more color tone, (B ) Is a partially cutaway cross-sectional view showing a resin tank in which resins having different colors are stored. (A) (B) (C) (D) is a schematic plan view which shows one Embodiment of the manufacturing method of the resin molded product of this invention. It is a schematic plan view which shows the flow behavior of resin in one Embodiment of the manufacturing method of the resin molded product shown in FIG. It is a photograph of a resin molded product having a flow pattern molded by a conventional molding method.

  The present invention is a method for producing a resin molded product in which a resin molded product having a flow pattern is molded by simultaneously injecting resins having different color tones into a mold. That is, a mold apparatus having a main resin injection port at one end of the mold and a main air vent at the other end facing the main resin injection port is used. In addition, the mold apparatus includes at least one or more sets of a secondary resin injection port having an opening / closing control valve and a secondary air vent on each side of the mold in the direction from the main resin injection port to the main air vent. ing.

  In the process from the resin injection from the main resin injection port to the degassing corresponding to the resin injection by finally opening the main air vent after the stop, the arrangement position from the main resin injection port is close The following (i) and (ii) are performed in this order.

  (I) Deaeration by opening a secondary air vent corresponding to resin injection and its closing. (Ii) Resin injection by stopping the secondary resin inlet that forms a pair with the closed secondary air vent and stopping the injection. This controls the flow behavior of the injected resin.

  Hereinafter, modes for carrying out the invention will be described in more detail.

  First, a mold apparatus used in the method for producing a resin molded product of the present invention will be described in detail with reference to the drawings. FIG. 1 shows a schematic plan view of the mold apparatus. The mold apparatus used in the present invention includes a main resin injection port 2 at the end of the mold 1 and a main air vent 3 at the end facing the main resin injection port 2. The mold 1 is composed of an upper mold and a lower mold, and a cavity 11 is formed between the upper mold and the lower mold in accordance with the shape of the resin molded product to be molded. For example, the main resin injection port 2 connected to the cavity 11 is formed at one end of the upper part of the upper mold, and the cavity 11 is provided between the upper mold and the lower mold at the other end. The main air vent 3 connected to is provided.

  At least one main air vent 3 may be provided at the end of the mold 1, but a plurality of air vents 3 may be provided at intervals depending on the size of the mold 1 and the design of the resin molded product to be molded. it can.

  Further, in the mold 1, at least one or more sets of sub resin injection ports 4 and sub air vents 5 are provided at both end portions orthogonal to the direction from the main resin injection port 2 to the main air vent 3. It has been.

  The secondary resin injection port 4 is provided at both ends of the upper part of the upper mold so as to be connected to the cavity 11, and the secondary air vent 5 is paired with the secondary resin injection port 4 to form the upper mold. A side surface between the mold and the lower mold is provided so as to be connected to the cavity 11.

  That is, it is considered that the pair of sub resin inlets 4 and the sub air vents 5 are provided apart from each other in the direction orthogonal to the direction from the main resin inlet 2 to the main air vent 3. . Further, when a plurality of sets of secondary resin inlets 4 and secondary air vents 5 are provided at the side end portion of the mold 1, the adjacent secondary resin inlets 4 and secondary air vents 5 It is considered that they are provided apart from each other.

  The number of secondary resin injection ports 4 and secondary air vents 5 provided at both ends is not particularly limited, and should be determined appropriately according to the size of the mold 1 and the design of the flow pattern to be exposed. Can do.

  In the mold apparatus illustrated in FIG. 1, three sets are provided at one end portion and a total of six sets of secondary resin injection ports 4 and secondary air vents 5 are provided at both end portions. Each of the secondary resin injection port 4 and the secondary air vent 5 is provided with an opening / closing control valve, and the secondary resin injection port 4 and the secondary air vent 5 can be opened and closed at a desired timing.

  Further, a supply pipe 8 from a resin tank 7 that stores the raw resin 6 shown in FIGS. 2A and 2B is appropriately connected to the main resin injection port 2 and the sub resin injection port 4. The The resin 6 is supplied into the mold 1 by opening the opening / closing control valve of the main resin injection port 2 or the sub resin injection port 4.

  For example, the resin 6 from the resin tank 7 can be supplied into the mold 1 from the resin tank 7 in which the resins 6a and 6b having two or more colors shown in FIG. .

  Further, for example, as shown in FIG. 2B, a plurality of resin tanks 7 in which resins 6c and 6d having different colors are separately stored are prepared, and the resins 6c and 6d are transferred from the resin tanks 7 to the mold 1. You may make it supply in. In this way, when the resins 6c and 6d having different color tones are supplied from the plurality of resin tanks 7, the resin 6 is merged by combining the supply pipes 8 from the resin tanks 7 into one. The mixed resin can be supplied to the main resin injection port 2 and the sub resin injection port 4.

  As the resin 6 used in the present invention, any resin that is usually used for molding artificial marble can be used without particular limitation. Examples of these resins include thermosetting resins such as vinyl ester resins, thermosetting acrylic resins, and epoxy resins, and these can be used alone or in combination of two or more.

  As the vinyl ester resin, for example, a bisphenol type vinyl ester resin, a novolac type vinyl ester resin, or a mixture of both can be used.

  Here, the bisphenol-type vinyl ester resin is an addition reaction product of a bisphenol-type epoxy resin and an acid, and both have reactive unsaturated groups only at both ends. As the bisphenol type epoxy resin, various types such as bisphenol A type, bisphenol AD type, bisphenol S type, and bisphenol F type can be used. Usually, the vinyl ester resin contains a styrene monomer, an acrylic monomer or the like as a crosslinking agent, but its composition is not particularly limited.

  As the thermosetting acrylic resin, for example, what is called an acrylic syrup composed of a mixture of two or more of methyl methacrylate monomer, polyfunctional acrylic monomer, prepolymer, or polymer can be used.

  Epoxy resins are generally classified as shown below. Bisphenol A type epoxy resin, bisphenol F type epoxy resin, novolak type epoxy resin, cycloaliphatic type epoxy resin, long chain aliphatic type epoxy resin, glycidyl ester type epoxy resin, glycidylamine type epoxy resin and the like. Any of these can be used as the epoxy resin.

  Examples of the epoxy resin curing agent include amine-based curing agents such as diethylenetriamine, triethylenetetramine, metaphenylenediamine, diaminodiphenylmethane, and diaminophenylsulfone. Moreover, acid anhydride type curing agents such as phthalic anhydride, tetra- and hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, methyl nadic anhydride, pyromellitic anhydride, HET anhydride, and dodecenyl succinic anhydride are exemplified. Moreover, the polyamide type hardening | curing agent etc. which are formed as a condensate of a dimer acid and a polyamine are illustrated.

  Further, for example, when using a thermosetting resin such as a vinyl ester resin as the resin 6, after blending a granular pattern material, a curing agent, a colorant such as a toner, an inorganic filler, etc., uniformly mixed, Degassed and colored resin 6 can be used.

  Next, an embodiment of a method for producing a resin molded product of the present invention using the mold apparatus and the resin 6 will be described.

  In the method of manufacturing a resin molded product according to the present embodiment, resin injection from the main resin injection port 2 and the sub resin injection port 4 is sequentially switched from the main resin injection port 2 toward the main air vent 3. At the same time, only the main resin injection port 2 for performing resin injection or the secondary resin injection port 4 and then the secondary resin injection port 4 for performing resin injection and the air vent 5 for the sub pair are opened to perform deaeration. Therefore, the resin 6 is injected by deaeration from the main air vent 3.

  3 (A), (B), (C), and (D) illustrate specific procedures for the embodiment of the method for producing a resin molded product of the present invention. 3 (A), (B), (C), and (D), the main resin injection port 2, the main air vent 3, the sub resin injection ports 41 to 46, and the sub air vents 51 to 56 are opened. Is shown in white, and the closed state is filled in.

  First, in the stage shown in FIG. 3A, only the main resin injection port 2 and the secondary air vent 51 closest to the main resin injection port 2 are opened, and from the main resin injection port 2, in an incompletely mixed state, For example, a marble-colored resin 6 is injected. As a result, the injected resin 6 is drawn in the direction of the open secondary air vent 51, and the resin 6 reaches the secondary resin inlet 41 and the secondary air vent 51 as shown in FIG. Injected.

  Next, in the stage shown in FIG. 3B, the main resin injection port 2 is closed, only the secondary resin injection port 41 and the opposing secondary air vent 52 are opened, and the resin 6 is injected from the secondary resin injection port 41. To do. As a result, the injected resin 6 is drawn in the direction of the open secondary air vent 52, and the resin 6 reaches the secondary resin inlet 42 and the secondary air vent 52 as shown in FIG. Injected.

  Next, in the step shown in FIG. 3C, the secondary resin injection port 41 is closed, only the secondary resin injection port 42 and the opposing secondary air vent 53 are opened, and the resin 6 is discharged from the secondary resin injection port 42. inject. As a result, the injected resin 6 is drawn in the direction of the open secondary air vent 53, and the resin 6 reaches the secondary resin inlet 43 and the secondary air vent 53 as shown in FIG. Injected.

  Thereafter, as in FIGS. 3B and 3C, the secondary resin injection ports 43, 44, and 45 for injecting resin, and the secondary resin injection ports 44, 45, and 46 for injecting resin next to each other, Only the air vents 54, 55, 56, which are the sub-pairs, are opened, and the injection of the resin 6 is repeated.

  Finally, at the stage shown in FIG. 3D, only the main air vent 3 and the secondary resin injection port 46 closest to the main air vent 3 are opened, and the resin 6 is injected from the secondary resin injection port 46. Thereby, the injection of the resin 6 into the entire mold 1 is completed.

  As described above, in the method of manufacturing a resin molded product according to this embodiment, in an incompletely mixed state, for example, the resin 6 that is a marble-colored resin 6 is added to the main air vent 3 from the main resin injection port 2. The inlets 41 to 46 are sequentially switched for injection. Thereby, as shown by a solid line in FIG. 4, the resin 6 can be injected into the mold 1 while controlling the flow behavior of the resin 6.

  In the method for manufacturing a resin molded product of the above embodiment, the heating conditions of the mold 1 can be appropriately determined according to the curing characteristics of the resin 6 to be injected. Then, after the injected resin 6 is cured, the molded product is taken out from the mold 1 so that a resin molded product having a complicated flow pattern and a texture closer to natural marble can be obtained.

  As mentioned above, although the manufacturing method of the resin molded product of this invention was demonstrated based on embodiment, the manufacturing method of the resin molded product of this invention is not limited to said embodiment, In the range which does not deviate from the summary Various changes can be made.

  For example, in the method of manufacturing a resin molded product of the above embodiment, the injection of the resin 6 into the planar rectangular mold 1 has been described, but the present invention can also be applied to the mold 1 having a more complicated shape.

  Moreover, in the said embodiment, although resin 6 was inject | poured from all the resin injection ports 41-46 provided in both side surfaces toward the main air vent 3 from the main resin injection port 2, for example, resin injection of sub The resin 6 can be selectively injected from the inlet 41, the auxiliary resin injection port 44, and the auxiliary resin injection port 45. Thereby, the flow behavior of the resin 6 injected into the mold 1 can be more complicatedly operated.

1 Mold 2 Main resin inlet 3 Main air vent 4 Sub resin inlet 5 Sub air vent

Claims (3)

A resin molded product manufacturing method for molding a resin molded product having a flow pattern by injecting resins of different colors into a mold,
A main resin inlet is provided at one end of the mold, and a main air vent is provided at the other end facing the main resin inlet,
A mold apparatus provided with at least one set of a secondary resin injection port having an opening / closing control valve and a secondary air vent on each side portion of the mold in a direction from the main resin injection port toward the main air vent. In
In the process of resin injection from the main resin injection port and degassing corresponding to the resin injection by finally opening the main air vent after the stop,
In order of the set, the arrangement position from the main resin injection port is close,
(I) Deaeration by opening the sub air vent corresponding to resin injection and its closing;
(Ii) Resin injection by opening the secondary resin inlet that forms a pair with the closed secondary air vent, and stopping the resin injection,
To control the flow behavior of the injected resin.   The plurality of sets of the secondary resin inlet and the secondary air vent are provided to be separated from each other in a direction from the primary resin inlet to the primary air vent. A method for producing a resin molded product according to 1. The method for producing a resin molded product according to claim 1, wherein the set of the auxiliary resin inlet and the auxiliary air vent are provided separately from each other.