WO2004106040A1

WO2004106040A1 - Method of curing resin and process for producing molded resin

Info

Publication number: WO2004106040A1
Application number: PCT/JP2004/007359
Authority: WO
Inventors: Tamotsu Murakami
Original assignee: Toudai Tlo, Ltd.
Priority date: 2003-05-30
Filing date: 2004-05-28
Publication date: 2004-12-09
Also published as: JPWO2004106040A1

Abstract

An object of the invention is to facilitate the reuse of an uncured resin. Another object is to improve the fixability of a masking material to a photocurable material. The invention relates to a method of curing a photocurable resin comprising a first ingredient and a second ingredient. The first ingredient is one which upon mixing with the second ingredient comes to have enhanced photocurability. An example of the first ingredient is a photopolymerizable material of the sol-gel conversion type. An example of the second ingredient is a photopolymerization initiator. The method comprises the following steps. (1) A step in which the second ingredient (12), (22) is supplied to those areas of the first ingredient (11), (21) which are to be cured. (2) A step in which the areas to be cured are exposed to light to cure the first ingredient in these areas and thereby obtain cured parts (13) and (23).

Description

Specification

Method for curing resin and method for producing resin molded product

Technical field

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

Background art

The present inventor has proposed a stereolithography method described in Patent Document 1 below. In this method, a mask material is supplied to the surface of the photocurable material, and then the photocurable material is exposed. This makes it possible to cure the photocurable material in the portion where the mask material is not supplied (exposed portion).

[0003] However, in this method, it is difficult to adjust a mask material having high fixability to the surface of the photocurable material. Further, in this method, since the mask material is mixed into the uncured portion (the portion where the mask material is supplied) of the photocurable material, it is difficult to recover and reuse the uncured resin.

Patent Document 1: International Publication No. 01Z010632

Disclosure of the invention

Problems the invention is trying to solve

[0004] The present invention has been made in view of the above circumstances. One of the objects of the present invention is to facilitate reuse of uncured resin. Another object of the present invention is to improve the fixability of a mask material to a photocurable material. Still another object of the present invention is to shorten the molding time of a resin molded product to enable high-speed molding.

Means for solving the problem

[0005] The curing method of the present invention is a method for curing a photocurable resin having a first component and a second component. The first component enhances photocurability when mixed with the second component. The method further comprises the following steps:

(1) supplying one of the first component and the second component to a curing target site in the other;

(2) By exposing the curing target site, the first Curing the components.

[0006] The first component is, for example, a photopolymerizable material. The photopolymerizable material is, for example, a photopolymerizable polymer and Z or a photopolymerizable monomer. Further, the photopolymerizable material may be of a sol-gel conversion type.

The second component is, for example, a photopolymerization initiator.

In step (1) in the above-described curing method, the other component supplied to the curing target site may have a color. The other component may have the color by coloring. This coloring is performed by, for example, a dye.

[0007] The curing method of the present invention may have the following configuration. That is, this method is a method of curing a resin having a first component and a second component, wherein the first component has enhanced photocurability when mixed with the second component. It is. The method further comprises the following steps:

(2) curing the first component at the curing target site.

[0008] In the method for producing a resin molded product according to the present invention, a photocurable resin having a first component and a second component is used. The first component enhances photocurability when mixed with the second component. The manufacturing method further includes the following steps.

(2) curing the first component in the curing target site by exposing the curing target site to form an n-th layer;

(3) supplying one of the first component and the second component to the surface of the n-th layer again;

(4) supplying the other to the one curing target site in the step (3);

(5) The curing target portion is exposed by exposing the curing target portion in the step (4). Curing the first component at the location to form the n + 1 layer.

In the manufacturing method, the supply in the step (1) or the step (4) can be performed by, for example, any one of an inkjet, an airbrush, a stamp, and a brush.

[0010] The method for producing a resin molded product using a photocurable resin having a first component and a second component according to the present invention may have a configuration including the following steps. Here, the first component enhances photocurability when mixed with the second component.

(1) forming the n-th layer by supplying the second component to a curing target site in the first component;

(2) forming the (n + 1) th layer by supplying the first component to the upper surface of the n-th layer, and then supplying the second component to a portion to be cured of the first component;

(3) curing the first component in the curing target site by exposing the curing target site in the nth layer and the (n + 1) th layer.

After supplying the second component in step (1) of this manufacturing method, and before the exposure in step (3), set a waiting time for the second component to penetrate into the first component. You can also.

According to this manufacturing method, the concentration or the supply amount of the second component in the n-th layer can be made smaller than the concentration or the supply amount in the n + 1-th layer.

[0011] The resin according to the present invention is cured by any one of the curing methods described above.

[0012] The resin molded product according to the present invention is manufactured by any of the manufacturing methods described above.

The invention's effect

According to the present invention, it is possible to easily reuse an uncured resin. Further, according to the present invention, the fixability of the mask material to the photocurable material can be improved.

BEST MODE FOR CARRYING OUT THE INVENTION

(First Embodiment)

A method for curing a resin and a method for producing a resin molded product according to the first embodiment of the present invention will be described below. However, regarding the method of curing the resin, one of the methods for manufacturing resin molded products It will be described as a part.

[0015] (Outline of the device)

First, an outline of an apparatus used in this method will be described. This device is the same as

As described in 2, the conventional force is also known. This device is an elevator

1, a light emitting unit 2 and a wavelength selection filter 3.

[0016] The elevator 1 has a resin to be cured placed on the upper surface thereof. elevator

1, the position of the upper surface can be adjusted to any height!

The light emitting section 2 irradiates the elevator 1 with light (for example, ultraviolet light) having a wavelength that can cure the photocurable resin. As the light emitting unit 2, for example, an ultraviolet lamp such as a high-pressure mercury lamp can be used, but is not limited thereto.

, Other light sources can be used.

The wavelength selection filter 3 attenuates light having an unnecessary wavelength among the light emitted from the light emitting unit 2. However, when the wavelength band of the light from the light emitting unit 2 is sufficiently narrow (for example, when a laser is used as the light emitting unit), the filter 3 can be omitted.

[0019] (Resin used)

Next, the resin used in this method will be described. This resin has a first component and a second component. The first component means a component whose photocurability is enhanced when mixed with the second component. Here, “enhance photocurability” means, for example, one of the following states.

(1) To give photocurability to those that do not have photocurability alone

(2) Improve the photocuring speed and hardness after curing although having photocurability alone.

[0020] More specifically, the first component is, for example, a photopolymerizable material (a polymerizable photocurable material that does not contain a photopolymerization initiator). The photopolymerizable material is generally a photopolymerizable polymer and Z or a photopolymerizable monomer. However, the photopolymerizable material may include other materials (for example, additives). The photopolymerizable material is, for example, a sol-gel conversion type. The sol-gel conversion type photopolymerizable material is a sol-gel conversion type photocurable resin (hereinafter referred to as “resin composition for stereolithography” in Patent Document 1). When the photopolymerization initiator is excluded (that is, it is not added) during the production of the compound (described in detail below), it can be obtained.

[0021] The second component enhances its photocurability by being mixed with the first component. Such a component is a photopolymerization initiator when the first component is, for example, a photopolymerizable material. The photopolymerization initiator may be a radical polymerization reaction type or a cation reaction type. Since the photopolymerization initiator is also described in, for example, Patent Document 1, the detailed description is omitted here.

[0022] (Manufacturing method)

A method for manufacturing a resin molded product using this apparatus will be described. First, the elevator 1 is placed at a predetermined position (FIG. 2 (a)). Next, a first component (for example, a photopolymerizable material) 11 is supplied in a layer form on the upper surface of the elevator 1 (FIG. 2 (b)). After the supply, the first component 11 is preferably cooled to increase its viscosity. This is the same as the conventional stereolithography (for example, the one described in Patent Document 1). For example, when a sol-gel conversion type photopolymerizable material is used as the first component 11, when the first component 11 is supplied, the temperature is increased to be in a sol state. Next, after the supply, the temperature of the first component 11 is lowered to a gel state, and the viscosity is increased.

Next, a second component (for example, a photopolymerization initiator) 12 is supplied to a part (curing target portion) of the surface of the first component 11 in a predetermined shape (FIG. 2 (c)). And Figure 3). In FIG. 3, the second component 12 is supplied so as to form a star shape, and the shape is selected according to the shape of the molded product. Here, since the first component and the second component are a composition of a photocurable resin, the fixability of both is good. For this reason, in the present embodiment, there is an advantage that the supplied second component 12 is reliably fixed on the surface of the first component 11. For this reason, the accuracy of the shape of the mask formed by the second component 12 can be improved. The method for supplying the second component is, for example, any one of ink jet, airbrush, stamp and brush. In addition to these, various methods are possible, such as a method of supplying with a tube, a method of supplying with a pen, and a method of drawing and transferring on the surface of a plate or a mouthpiece.

Next, the light emitting section 2 (see FIG. 1) emits light (FIG. 2 (d)). Thereby, the first component 11 is exposed, and the hardening target portion of the first component 11 can be hardened to the lower portion. Here, in the present embodiment, the second component 12 is supplied only to the surface of the first component 11. . However, for example, when the photopolymerization initiator as the second component 12 is a radical polymerization type, the radicals generated there exert an influence on the lower side, and the first component 11 hardens to reach the lower surface thereof. As described above, even when the second component 12 is supplied only to the surface of the first component 11, the first component 11 can be cured to a required depth.

As a result, a cured portion 13 (see FIG. 2 (e)), which is a portion where the resin is cured, can be obtained. The portion of the first component 11 other than the cured portion 13 becomes an uncured portion 14. Thereby, the first layer of the resin molded product can be formed.

Next, the elevator 1 is lowered by the thickness of the first component 11. Next, the first component 21 is supplied at a predetermined thickness to the surface of the first component 11 (that is, the surface of the first layer) (FIG. 2 (f)). Next, the second component 22 is supplied to the hardened portion of the first component 21 in the same manner as described above (FIG. 2 (g)).

Next, the hardening target portion of the first component 21 is exposed (FIG. 2 (h)). As a result, the photocurable resin at the hardening target portion can be hardened, and the hardened portion 23 and the unhardened portion 24 can be obtained. In addition, this makes it possible to form the second layer (the (n + 1) th layer in the present invention) (FIG. 2 (i)).

[0028] By repeating the above operations, a resin molded product (stereolithographic product) composed of n + m layers (m is an arbitrary natural number) can be manufactured. Next, the temperature of the resin molded product is slightly raised to fluidize the uncured portion. As a result, the uncured portion of the cured portion can be removed. The removed uncured portion is recovered. Thereafter, the cured part is further irradiated with ultraviolet rays to be sufficiently cured to obtain a finished product.

[0029] In the method of the present embodiment, the second component is not supplied to the uncured portion. Therefore, there is an advantage that the recovered uncured portion (that is, the first component) can be easily reused. Therefore, waste can be reduced, and addition to the environment can be reduced.

Further, the method of the present embodiment has the following advantages because the photopolymerizable material as the first component and the photopolymerization initiator as the second component are separated.

(1) As described above, when a sol-gel conversion type photopolymerizable material is used, it may be necessary to raise the temperature to a sol state. However, if the heating temperature is too high, the photopolymerizable material is cured, and the supply nozzle is clogged or the supply amount becomes uneven. Cause problems. On the other hand, in the present embodiment, since the photopolymerization initiator is separated, the possibility that the photopolymerizable material is cured by overheating can be reduced.

(2) A conventional photopolymerizable material containing a photopolymerization initiator gradually cures even during storage before use. For this reason, the storage period (pot life) is limited. In contrast, in the present embodiment, since the photopolymerization initiator is separated from the photopolymerizable material, the storage period of the photopolymerizable material can be significantly improved.

Experimental example 1

Next, an experimental example using the method of the embodiment will be described. In this experimental example, the mask 5 shown in FIG. 4 is used. At the center of the mask 5, a cross-shaped through hole 5a is formed.

(Experiment conditions)

Ultraviolet irradiation equipment: TOSCURE251 manufactured by Toshiba Lighting & Technology Corporation

Light source: high pressure mercury lamp

Wavelength of light from light source: 220-500nm (365nm peak)

Exposure condition: 5. 83mWZcm ² for 24 seconds

In-plane uniformity of light: 80%

Light parallelism: ± 2 °

Wavelength selection filter: narrow bandpass filter (transmitted light peak: 365 nm) The first component of photocurable resin: Sol-gel conversion type photocurable resin (photopolymerizable material) (Kuraray Co., Ltd.)

Second component of photocurable resin: radical polymerization initiator (Kuraray Co., Ltd.)

Thickness per layer: 250 m

Material of mask 5: 0.3mm thick stainless steel plate

Airbrush spray pressure: 1.8 kg / cm ²

Experimental conditions other than those described above were the same as in the above embodiment. Under these conditions, a resin molded product was produced by the method of the above embodiment. However, as a method for supplying the second component to the surface of the first component, a method was used in which a mask 5 was arranged on the upper surface of the first component, and the second component was sprayed on the surface of the first component with an airbrush through the mask 5. . Here, the lower surface of the mask 5 is the first The components were brought into close contact with the upper surface. In this experimental example, after the second component was sprayed on the surface of the first component, it was left for 1 minute to wait for its penetration, and then exposed. Further, in this experimental example, up to the tenth layer was formed.

As a result, a resin molded product shown in FIG. 5 was obtained.

[0034] The description of the embodiment and the experimental example is merely an example, and does not show a configuration essential to the present invention. The configuration of each unit is not limited to the above as long as the purpose of the present invention can be achieved.

For example, in the above-described embodiment, after the first component is formed in a layer, the second component is supplied to the curing target site, and is exposed and cured. After forming the second component into a layer while applying force, the first component can be supplied to the curing target site, and the first component can be cured by exposure.

Further, in the above-described embodiment, the photopolymerizable material is used as the first component, and the photopolymerization initiator is used as the second component. However, the first component may be, for example, a photocrosslinking type or a photodecomposition type. The possible modes are shown below.

[0037] [Case of photocrosslinking type]

In the case of the photocrosslinkable type, the combination shown in Table 1 below can be considered as the first and second components.

[0038] [Table 1]

[0039] Alternatively, a polymer compound and a photo-crosslinking substance can be used as the first component, and a photoacid generator (Photo Acid Generator: PAG) can be used as the second component. One (single or plural) of these three components can be the first component, and the rest can be the second component.

[0040] [Photolysis type] In the case of the photodecomposition type, it is conceivable to use, for example, a photodegradable resin as the first component and, for example, a decomposition reaction inhibitor as the second component. In this manner, the portion to which the decomposition reaction inhibitor has been provided is hardened and remains, and the unpowered portion is decomposed and removed by light.

Further, in the above-described embodiment, the photocurable resin has been described as an example, but is not limited thereto.

Alternatively, the resin may be cured by some physical change (for example, heat).

(Second Embodiment)

Next, a method for manufacturing a resin molded product according to the second embodiment of the present invention will be described below with reference to FIG. In the second embodiment, the second component 1 supplied to the surface of the first component 11

2 is colored by a dye.

According to the method of the second embodiment, since the second component 12 is colored, the obtained resin molded product can be colored. Further, in the method of the present embodiment, since the second component 12 is colored with a dye, the dye can also be diffused into the first component 11. Then, the molded product can be colored over a wide range.

[0044] The second component 12 can be colored with a pigment. In general, pigments are not easily diffused into the first component 11, so that the range in which coloring can be performed tends to be limited. Also

The second component 12 may have a color as such. In short, if the supplied component has a color, the molded product can be colored.

[0045] Other configurations and advantages of the second embodiment are the same as those of the first embodiment, and thus detailed description will be omitted.

(Third Embodiment)

Next, a method for manufacturing a resin molded product according to the third embodiment of the present invention will be described with reference to FIGS.

[0047] Also in the method of the present embodiment, first, the first component 11 is supplied to the upper surface of the elevator 1.

(See Fig. 6 (a)). Next, the second component 12 is supplied to the upper surface of the hardened portion of the first component 11. Thereby, a first layer (that is, an n-th layer) is formed.

Next, the first component 21 is supplied to the upper surface of the first layer. Next, the second component 22 is supplied to the upper surface of the hardening target portion in the first component 21. Thus, a second layer (that is, an (n + 1) th layer) is formed. By repeating this operation, the n + m-th layer (m is an arbitrary natural number) is formed I do. In this example, since n (initial value) is 1 and m is 4, the total number of layers is n + m = 5. However, the initial value n may be a natural number of 2 or more.

Next, when the above-mentioned surface of the (n + m) -th layer is exposed, the n-th layer is exposed up to the (n + m) -th layer to obtain a cured portion 13-53. As a result, a resin molded product having an n + m force can be obtained (see FIG. 6 (b)). In this method, the photopolymerizable material can be cured by a single exposure, so that the molding time of the molded product can be significantly reduced. This will be described in more detail below.

[0050] In order for the first component having a certain thickness to cure, it is preferable to supply the second component and then wait for the effect to permeate in the depth direction. FIG. 7 shows the relationship between the thickness of the first component and the preferred permeation waiting time. There are multiple ▲ s because the same experiment was performed multiple times.

As can be seen from FIG. 7, when the thickness of one layer is about 50 μm, the waiting time is almost unnecessary. However, when the thickness of one layer is 100 m, a waiting time of about 30 seconds is required. Generally, the thickness of one layer in stereolithography is often about 100 m.

[0052] V, and the time required for each step is shown in Table 2:

[0053] [Table 2]

[0054] Assuming that the curing of the resin laminated in 10 layers is performed by the usual exposure curing for each layer, the required time is as follows.

(T + T + T + T) X 10

Table Resin Penetration Single exposure

It becomes.

[0055] For example,

T: 10 seconds

table

T: 10 seconds

Resin

T: 30 seconds T: 10 seconds

Single exposure

Then, the required time is 600 seconds. In other words, the required time per layer is 60 seconds.

[0056] On the other hand, when the lamination curing of 10 layers is performed by batch exposure curing of a plurality of layers every 5 layers, the required time is as follows.

{(Τ + Τ) Χ 5+ (Τ + Τ) X I} Χ 2

Table resin penetration multiple exposure

(If the permeation waiting time in the fifth layer is satisfied, the second component for the first to fourth layers supplied earlier should be sufficiently permeated).

Here, Τ: Even if it is 20 seconds, the required time is reduced to 300 seconds. In other words, multiple exposures per layer

Takes 30 seconds. Τ and Τ are generally considered short. Single exposure Multiple exposure

Force Here, we use a value with a margin.

[0058] Therefore, even when the difference between Τ and Τ is taken into consideration, the multi-layer collective exposure curing is more effective in forming one layer multiple exposure

The total time for is shorter.

Further, according to the method of the third embodiment, it is possible to smooth the side surface shape of the obtained molded product. This will be described in detail below. As shown in FIG. 8, the second component supplied to the upper surface of the first component permeates the first component existing around the second component. Then, as shown in FIG. 9, the end face shape of the molded product obtained after curing becomes smooth.

If there is a waiting time for the second component to penetrate into the first component between the time when the second component is supplied to the surface of the first component and the time when the batch exposure is performed, such a smooth state is obtained. It is suitable for obtaining a shape.

In the third embodiment, the concentration or the supply amount of the second component in the lower layer (the η-th layer) is set to the concentration or the supply amount of the second component in the upper layer (the η + 1-th layer). It would be preferable to have less than the amount. Since the permeation time becomes shorter as the concentration or the supply amount becomes higher, it is considered that in this way, the permeation amount can be made uniform and the end face of the molded product can be made smooth.

The other configurations and advantages of the third embodiment are the same as those of the first embodiment, and thus detailed description will be omitted.

Experimental example 2

[0062] Figs. 10 and 11 show experimental examples of the molded article according to the third embodiment. Experimental conditions are as follows Table 3 shows the results. The conditions other than those described below are the same as in the third embodiment. Therefore, the T table

, T are the same as above. As for Τ, as shown in Table 2, one layer of

In order to set it to 00 m, it was set to 120 seconds based on the relationship in FIG. For T, 3rd implementation Multiple exposure

The value in the example is a general theory with a margin, and in the case of: In this example, it was performed at 2 cultivation points as shown in Table 3 as a possible value for this modeling.

(Experiment conditions)

[Table 3]

FIG. 10 shows the results. From these figures, it can be seen that the end shape of the molded product is formed on a smooth slope.

As a comparison, a molded product was obtained by the layer-by-layer exposure method described in the third embodiment. The experimental conditions of the comparative example were the same as those of the experimental example 2 except that the exposure was performed for each layer. Regarding the further exposure of T, the value described in the third embodiment is a general theory with a margin, and here, as a possible value for this shaping, it was performed every 2 seconds. FIG. 11 shows the results of the comparative example. In this example, a step appears at the end.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is an explanatory view showing a schematic configuration of an apparatus used for a method for manufacturing a resin molded product according to a first embodiment of the present invention.

FIG. 2 is an explanatory view showing a production process in a method for producing a resin molded product according to one embodiment of the present invention.

FIG. 3 is an explanatory diagram showing a shape of a second component supplied to the surface of the first component.

FIG. 4 is a plan view of a mask used in Experimental Example 1 of the present invention. [5] FIG. 5A is a photograph of a resin molded product obtained in Experimental Example 1 of the present invention, wherein FIG. 5A is a photograph from a plan view and FIG.

FIG. 6 is an explanatory view showing a production process in a method for producing a resin molded product according to a third embodiment of the present invention. Figure (a) shows the state after exposure after lamination, and Figure (b) shows the state after exposure. [7] A graph showing the relationship between the lamination thickness of the first component and the permeation waiting time.

FIG. 8 is an explanatory diagram for explaining penetration of a second component.

[9] FIG. 9 is an explanatory diagram showing an example of an end face shape formed by utilizing the penetration of a second component.

[10] FIG. 10 is a view showing a molded product obtained by Experimental Example 2 of the present invention, wherein FIG. 10A shows a left side surface, and FIG. 10B shows a right side surface.

[11] FIG. 11 is a view showing a molded product obtained by a comparative example corresponding to Experimental Example 2, in which (a) shows a left side surface and (b) shows a right side surface.

Explanation of reference numerals

1 Elevator ¹ ~ "ta

2 Light emitting section

3 Wavelength selection filter

11-21 1st component (photopolymerizable material)

12-22 Second component (Photopolymerization initiator)

13-23 Hardened part

14-24 Uncured part

5 Mask

6 Molded product

Claims

Claims [1] A method for curing a photocurable resin having a first component and a second component, wherein the first component has enhanced photocurability when mixed with the second component. Curing method, further comprising the following steps:

(2) curing the first component in the curing target site by exposing the curing target site;

[2] The curing method according to claim 1, wherein the first component is a photopolymerizable material.

3. The curing method according to claim 2, wherein the photopolymerizable material is a photopolymerizable polymer and Z or a photopolymerizable monomer.

4. The curing method according to claim 2, wherein the photopolymerizable material is of a sol-gel conversion type.

[5] The curing method according to any one of claims 14 to 14, wherein the second component is a photopolymerization initiator.

[6] The curing method according to any one of claims 15 to 15, wherein in step (1), the other component supplied to the curing target portion has a color.

7. The curing method according to claim 6, wherein the other component has the color by coloring.

[8] The coloring is performed by a dye! 8. The curing method according to claim 7, wherein:

[9] A method for curing a resin having a first component and a second component, wherein the first component has enhanced photocurability when mixed with the second component. And a curing method characterized by having the following steps:

(2) curing the first component at the curing target site.

[10] A method for producing a resin molded product using a photocurable resin having a first component and a second component, wherein the first component is photocured while being mixed with the second component. Is strengthened And further comprising the following steps:

(4) supplying the other to the one curing target site in the step (3);

(5) A step of exposing the hardening target portion in the step (4) to harden the first component in the hardening target portion to form an (n + 1) th layer.

11. The manufacturing method according to claim 10, wherein the supply in the step (1) or the step (4) is performed by any one of an ink jet, an airbrush, a stamp, and a brush.

[12] A method for producing a resin molded article using a photocurable resin having a first component and a second component, wherein the first component is photocured while being mixed with the second component. Manufacturing method characterized by enhanced properties and further comprising the following steps:

[13] After supplying the second component in step (1), before the exposure in step (3), the second component permeates the first component. 13. The production method according to claim 12, wherein a waiting time exists.

14. The method according to claim 13, wherein the concentration or the supply amount of the second component in the n-th layer is smaller than the concentration or the supply amount in the n + 1-th layer.

[15] A resin cured by the curing method according to any one of claims 11 to 9.

[16] A resin molded product produced by the production method according to any one of claims 10 to 14.