JPH10330626A - Resin composition for optical modeling - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain the subject composition that is free from thixotropy by formulating specific inorganic solid fine particles and/or whisker and phosphate ester salt surfactant to a photosetting resin in specific amounts. SOLUTION: This composition has a viscosity of >=5,000 cp at 25 deg.C and causes no change in viscosity, even when a stress is loaded. In a particularly preferred embodiment, the objective composition is prepared by formulating (A) 5-70 vol.%, based on the whole volume of the composition, of inorganic solid particles with the average particle, sizes of 3-70 μm and (B) 0.01-1 wt.%, based on the weight of the component A, of a phosphate ester salt surfactant into a liquid photosetting resin. In another embodiment, (C) 5-30 wt.%, based on the whole volume of the composition, of whisker having 0.3-1 μm diameter, 10-70 μm length and 10-100 aspect ratio and (B) 0.01-1 wt.%, based on the weight of the component C, of the component B are formulated to the photosetting resin thereby giving the objective resin composition.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin composition for stereolithography and a method for producing a stereolithography using the same. More specifically, the present invention does not have thixotropic properties in terms of flow viscosity, even when stress such as flow or stirring is applied, or even when the stress applied to the stereolithographic resin composition changes, A constant viscosity is maintained without causing a decrease in viscosity or a change in viscosity.Therefore, when manufacturing a molded article by stereolithography such as optical three-dimensional modeling, an optical molded article having excellent dimensional accuracy and physical properties can be processed with good handling properties. The present invention relates to a stereolithography resin composition that can be manufactured with workability and a stereolithography method using the same.

[0002]

2. Description of the Related Art In general, liquid photocurable resin compositions are widely used as coatings (especially hard coating agents), photoresists, dental materials, and the like.
A method of three-dimensionally optically molding the photocurable resin composition based on the data input to D has attracted particular attention. Regarding the optical three-dimensional molding technology, a required amount of controlled light energy is supplied to a liquid photo-curable resin to cure it into a thin layer, and then a liquid photo-curable resin is further supplied thereon, and then the light is controlled. Japanese Patent Application Laid-Open No. 56-144478 discloses an optical three-dimensional modeling method for producing a three-dimensional molded product by repeating a process of irradiating and laminating and hardening into a thin layer, and further discloses a basic practical method. Showa 60-
247515. After that, a number of proposals regarding optical three-dimensional modeling technology have been made, for example, JP-A-62-35966, JP-A-1-204915, JP-A-2-113925, and JP-A-2-145616. Gazette, JP-A-2-153
722, JP-A-3-15520, JP-A-3-15520
Japanese Patent Application Laid-Open No. 21432 and Japanese Patent Application Laid-Open No. 3-41126 disclose techniques relating to an optical three-dimensional printing method.

[0003] A typical method for optically producing a three-dimensional object is a computer controlled ultraviolet ray so as to obtain a desired pattern on the liquid surface of a liquid photocurable resin composition placed in a container. A laser is selectively irradiated to cure to a predetermined thickness, and then one layer of the liquid resin composition is supplied on the cured layer and similarly irradiated with an ultraviolet laser to be cured as described above. In general, a method of manufacturing a three-dimensional structure having a final shape by repeating a lamination operation of forming a continuous hardened layer by a continuous process is widely adopted.
In the case of this method, even if the shape of the modeled object is considerably complicated, the target three-dimensional modeled object can be easily manufactured in a relatively short time, so that it has been receiving particular attention in recent years.

The photocurable resin composition used in the optical three-dimensional molding method includes a photopolymerizable modified (poly) urethane (meth) acrylate-based compound, an oligoester acrylate-based compound, an epoxy acrylate-based compound, and an epoxy-based compound. Compounds include one or more of photopolymerizable compounds such as a compound, a polyimide compound, an aminoalkyd compound, and a vinyl ether compound as a main component, and a photopolymerization initiator added thereto. JP-A-1-204915, JP-A-1-213304, JP-A-2-28261, JP-A-2-7561
7, JP-A-2-145616, JP-A-3-
104626, JP-A-3-114732,
Various improved techniques are disclosed in Japanese Patent Application Laid-Open No. 3-147324.

The above-mentioned conventional photocurable resin compositions are generally high-viscosity liquids, and therefore have thixotropy. When a stress such as flow or movement is applied to the resin composition, the viscosity of the resin composition may decrease. A change in viscosity occurs and a constant viscosity cannot be maintained. In particular, in the above-described optical three-dimensional modeling technique in which the operation of supplying the photocurable resin composition to the predetermined thickness one layer at a time and curing the same is repeated, the photocurable resin composition is supplied one layer at a time. Stress is applied to the photocurable resin composition by the flow or movement of the resin composition at the time, and as a result, the viscosity of the thixotropic photocurable resin composition decreases, and the photocurable resin supplied one layer at a time is supplied. The layer thickness of the conductive resin composition is not constant, and the dimensional accuracy of the obtained molded article is likely to be reduced. Also, when trying to make the thickness of one layer of the photocurable resin composition constant,
It is necessary to strictly control the thickness of the resin composition to be supplied at the time of optical three-dimensional molding by performing precise calculations in anticipation of the viscosity decrease and viscosity change of the photocurable resin composition at the time of supply, and therefore advanced control technology And a control device are required, and the technology for optical three-dimensional printing is expensive.

[0006] The photocurable resin composition used in the optical three-dimensional molding method is a liquid in view of handleability, molding speed, molding accuracy, etc., and its viscosity is not too high. It is required that the volumetric shrinkage is small and that the three-dimensional structure obtained by photocuring has good mechanical properties. In recent years, the demand and use of optical three-dimensional objects have tended to expand, and depending on the application, the three-dimensional objects having a high heat deformation temperature and excellent heat resistance in addition to the above-described characteristics depending on the application. Is required.

The present inventors have been conducting various studies to obtain an optical three-dimensional object having excellent heat resistance and small volume shrinkage. However, a specific filler is mixed in a liquid photocurable resin. By performing optical three-dimensional modeling, it is possible to obtain an optical three-dimensional molded article that has a small volume shrinkage during curing, excellent dimensional accuracy, good mechanical properties, high heat deformation temperature and excellent heat resistance And filed an application (Patent No. 255)
4443 and JP-A-8-20620). And
Photocurable resin compositions containing fillers tend to have higher viscosities and greater thixotropic properties than those without fillers. Therefore, in the photocurable resin composition containing a filler, the viscosity difference between when flowing, when moving, etc., and when standing still, is larger than when not containing a filler, and the viscosity when flowing or moving is higher. The lower the viscosity and the higher the flow speed or moving speed, the more the viscosity decreases. Therefore, when performing the above-described optical three-dimensional modeling using a photocurable resin composition containing a filler, the photocurable resin composition is supplied one layer at a time while the resin composition for stereolithography is supplied under flow. Advanced control techniques and control devices are required for layer thickness.

[0008]

SUMMARY OF THE INVENTION An object of the present invention is to provide no thixotropic property, so that there is no difference in viscosity between standing, flowing, moving, etc., and the flow speed, supply speed, and movement speed. An object of the present invention is to provide a non-thixotropic stereolithography resin composition that can maintain a constant viscosity even when the composition changes, and is excellent in handleability and workability. Further, an object of the present invention is to provide a method for producing a molded article by performing optical molding using the above-described non-thixotropic optical molding resin composition.

The present inventors have intensively studied to achieve the above object. As a result, despite having a high viscosity of 5,000 cp or more, there is no thixotropy, and even if stress such as flow, movement, and stirring is applied, the viscosity does not decrease, and the flow speed, Even if the moving speed and the stirring speed were changed, a stereolithography resin composition in which the viscosity did not change could be obtained for the first time. The present inventors have found that such a resin composition for stereolithography having no thixotropic property allows specific inorganic solid fine particles and / or whiskers to be contained in a photocurable resin at a specific ratio and a phosphate ester. It can be obtained by including a salt-based surfactant in a specific amount, and the use of such a stereolithographic resin composition having no thixotropic property allows the resin to be formed even when the stress applied to the resin composition changes. Because the viscosity does not change, with extremely good handling and workability,
The inventors have found that it is possible to manufacture an optically shaped article having excellent heat resistance and mechanical properties with high dimensional accuracy, and based on those findings, completed the present invention.

That is, the present invention is a resin composition for stereolithography which has a viscosity at 25 ° C. of 5,000 cp or more and does not cause a change in viscosity even when stress is applied. In the photocurable resin composition of the present invention, it is preferable that the viscosity at 25 ° C. is 5,000 to 100,000 cp from the viewpoint of handleability, optical shaping property, dimensional accuracy of the obtained optically shaped article, and the like. It is more preferably 10,000 to 70,000 cp, and 20,000 to 60,000 c
More preferably, p. Here, the viscosity of the resin composition for stereolithography referred to in the present specification indicates a viscosity when measured using a rotary B-type viscometer.

The present invention relates to a liquid photocurable resin comprising 5 to 70% by volume of inorganic solid fine particles having an average particle size of 3 to 70 μm, based on the total volume of the resin composition for stereolithography, and a phosphate ester. The resin composition for stereolithography described above, which contains a salt-based surfactant in a ratio of 0.01 to 1% by weight based on the weight of the inorganic solid fine particles, is included as a preferred embodiment thereof.

Further, the present invention provides a method for forming a whisker having a diameter of 0.3 to 1 μm, a length of 10 to 70 μm and an aspect ratio of 10 to 100 in a photocurable resin based on the total volume of the resin composition for stereolithography. -30% by volume and a phosphate ester based surfactant based on the weight of the whisker.
As a preferred embodiment, the above-mentioned resin composition for stereolithography, which is contained at a ratio of 01 to 1% by weight, is included.

[0013] The present invention also provides a liquid photocurable resin,
Based on the total volume of the stereolithography resin composition, the average particle size is 3 to
5 to 70% by volume of 70 μm inorganic solid fine particles and 5 to 30% by volume of whiskers having a diameter of 0.3 to 1 μm, a length of 10 to 70 μm and an aspect ratio of 10 to 100, and a phosphate ester-based surfactant as described above. The resin composition for stereolithography described above, which is contained in a ratio of 0.01 to 1% by weight based on the total weight of the inorganic solid fine particles and the whiskers, is included as a preferred embodiment.

Further, the present invention includes, as a preferred embodiment thereof, the above-mentioned resin composition for stereolithography, wherein the above-mentioned phosphate ester-based surfactant is a surfactant comprising an amine salt of an acidic phosphate ester. I do.

Further, according to the present invention, as the inorganic solid fine particles, the relative standard deviation represented by the following formula (1) is 0.1.
The above-mentioned resin composition for stereolithography using inorganic solid fine particles having a sphericity of less than 5 is included as a preferred embodiment thereof.

[0016]

(Equation 2)

[0017]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail. As mentioned above, 5,000 cp or more (25 ° C)
The high-viscosity resin composition for stereolithography having a viscosity of (1) generally has thixotropic properties, and the viscosity decreases when a stress such as flow, movement, or stirring is applied to the resin composition. Moreover, as the applied stress increases, the viscosity decreases, so that the viscosity changes variously according to the stress. On the other hand, the stereolithography resin composition of the present invention has a viscosity at 25 ° C. of 5,
Despite having a high viscosity of at least 000 cp and exhibiting a high viscosity, it does not exhibit thixotropic properties, and even if the stress applied to the resin composition (eg, the flow rate of the resin composition, the moving speed of the stirring speed, etc.) changes, The viscosity does not change and shows a constant viscosity. In this respect, it can be said that it has a unique property that has never been seen before.

Any stereolithography resin composition having no thixotropic property and having a viscosity at 25 ° C. of 5,000 cp or more is included in the scope of the present invention. Particularly preferred are the following resin compositions for stereolithography. In the liquid photocurable resin, 5 to 70% by volume of inorganic solid fine particles having an average particle size of 3 to 70 μm based on the total volume of the resin composition for stereolithography, and a phosphate ester-based surfactant as the inorganic solid A stereolithographic resin composition containing 0.01 to 1% by weight based on the weight of the fine particles. 0.3-1 μm in diameter and 10-10 in length in photocurable resin
A whisker having a thickness of 70 μm and an aspect ratio of 10 to 100 is 5 to 30% by volume based on the total volume of the resin composition for stereolithography, and a phosphate surfactant is 0.01 to 1% by weight based on the weight of the whisker. % Of the resin composition for stereolithography. In the liquid photocurable resin, based on the total volume of the resin composition for stereolithography, 5 to 70% by volume of inorganic solid fine particles having an average particle size of 3 to 70 μm, a diameter of 0.3 to 1 μm, and a length of 10 to 10%.
5 to 30% by volume of whiskers having 70 μm and an aspect ratio of 10 to 100, and 0.01 to 1% by weight of a phosphate-based surfactant based on the total weight of the inorganic solid fine particles and the whiskers. A resin composition for stereolithography.

The inorganic solid fine particles used in the resin composition for stereolithography described above and above include glass beads, talc fine particles, silicon oxide fine particles, aluminum oxide fine particles,
Aluminum hydroxide fine particles, magnesium oxide fine particles,
Fine particles of calcium oxide, fine particles of aluminum nitride, fine particles of calcium carbonate, fine particles of carbon black, and the like can be given. The resin composition for stereolithography of the present invention may contain only one kind of the inorganic solid fine particles described above, or may contain two or more kinds. May be contained.

As described above, the inorganic solid fine particles used in the present invention preferably have an average particle diameter of 3 to 70 μm. When the average particle size of the inorganic solid fine particles is less than 3 μm, the viscosity of the resin composition for stereolithography increases, and it becomes difficult to mix a predetermined amount of the resin composition, or the handleability of the resin composition during stereolithography becomes poor. May be. On the other hand, when the average particle diameter of the inorganic solid fine particles exceeds 70 μm, the increase in the viscosity of the resin composition for stereolithography is not so significant, but at the time of stereolithography, scattering of irradiation energy such as ultraviolet rays occurs to lower the modeling accuracy. In addition, the molding accuracy is easily reduced due to the limitation of the film thickness per layer when performing the optical shaping, particularly the optical three-dimensional shaping. The handleability and moldability of the resin composition for stereolithography,
In light of the dimensional accuracy of the obtained optical product, the average particle diameter of the inorganic solid fine particles is more preferably from 10 to 60 μm, and still more preferably from 15 to 50 μm. In addition, the average particle diameter of the inorganic solid fine particles referred to in this specification refers to the average particle diameter of the inorganic solid fine particles obtained by measuring with a scanning electron microscope, the details of which are described in the following Examples. That's right.

The inorganic solid fine particles used in the present invention may be transparent or opaque, but are generally obtained from the resin composition for stereolithography of the present invention containing the above-mentioned inorganic solid fine particles. Artifacts often become opaque.
Therefore, while ensuring the effect of improving the heat resistance of the inorganic solid fine particles, when it is desired to make the molded article transparent, the above-mentioned inorganic solid fine particles are formed into extremely small submicron fine particles, and an appropriate surface treatment is performed. When the resin composition for stereolithography is stably dispersed in the resin composition, it may be possible to obtain a transparent molded article while suppressing an increase in the viscosity of the resin composition for stereolithography.

The shape of the inorganic solid fine particles is preferably a smooth sphere, so that the resin composition for stereolithography no longer exhibits thixotropic properties. Irregular reflection of irradiation energy is reduced, and it is possible to obtain an optically shaped object with high dimensional accuracy. Further, the resin composition for stereolithography does not increase in viscosity of the resin composition for stereolithography, and a resin composition for stereolithography excellent in handleability and moldability can be obtained. In particular, as the inorganic solid fine particles, those having a sphericity having a sphericity smaller than 0.5 (that is, less than 0.5) or a shape close thereto having a relative standard deviation value represented by the following formula (1) are used. It is preferable to obtain a resin composition for stereolithography without thixotropic properties, from the viewpoint of preventing an increase in the viscosity of the resin composition for stereolithography and improving the dimensional accuracy of the stereolithographic article,
More preferably, it is 0.3 or less.

[0023]

(Equation 3)

The resin composition for stereolithography described above and
As described above, the inorganic solid fine particles are preferably contained at a ratio of 5 to 70% by volume, more preferably at a ratio of 10 to 40% by volume, based on the total volume of the resin composition for stereolithography. preferable. When the content of the inorganic solid fine particles is less than 5% by volume, the properties of the inorganic solid fine particles as a reinforcing material and a heat resistance improving material are hardly sufficiently exhibited. The viscosity of the composition becomes abnormally high, so that it is difficult to perform optical shaping, and the average particle size of the inorganic solid fine particles to be used tends to be greatly restricted.

The whisker used in the resin composition for stereolithography according to the present invention has a diameter of 0.3 to 1 μm, a length of 10 to 70 μm, and an aspect ratio of 10 to 100, as described above. Is preferred, and the diameter is 0.3 to
0.7 μm, length 20-50 μm, aspect ratio 2
More preferably, it is 0 to 70. When the diameter of the whisker is less than 0.3 μm, the thermal deformation temperature, the bending elastic modulus, and the mechanical properties of the optically formed article tend to be low, and when it exceeds 1 μm, the viscosity of the optically molded resin composition is increased. , Handleability and formability are likely to be reduced. When the length of the whisker is less than 10 μm, the heat deformation temperature,
Flexural modulus and mechanical properties tend to be low, while 70
If it exceeds μm, the viscosity of the resin composition for stereolithography is increased,
The handleability and the formability are easily reduced. In particular, the aspect ratio of the whisker is in the above range of 10 to 100, the viscosity of the resin composition for stereolithography becomes appropriate,
It is preferable from the viewpoint of facilitating the molding operation, reducing the volume shrinkage at the time of optical molding, and improving the mechanical properties and the lateral accuracy of the obtained molded article. In addition, the dimension and aspect ratio of the whisker referred to in the present specification refer to the dimension and aspect ratio measured using a laser diffraction / scattering type particle size distribution analyzer, and details thereof are described in the following Examples. It is as follows.

The type of whisker is not particularly limited, and examples thereof include aluminum borate whiskers, aluminum oxide whiskers, aluminum nitride whisker water, magnesium oxide whiskers, and titanium oxide whiskers. Whisker 1
Species or two or more can be used.

The resin composition for stereolithography according to the present invention is characterized in that whiskers are used in an amount of 5 to 3 based on the total volume of the resin composition for stereolithography.
The content is preferably 0% by volume, more preferably 7 to 25% by volume. When the content of the whisker is less than 5% by volume, the effect of improving the heat deformation temperature and the flexural modulus by blending the whisker is difficult to be exhibited, and the mechanical strength of the optical three-dimensional structure is likely to be low. . On the other hand, when the content of the whisker exceeds 30% by volume, the viscosity of the resin composition for stereolithography increases, so that it is difficult to perform optical three-dimensional molding, and the dimensional accuracy of the stereolithography is likely to decrease.

In the above-mentioned stereolithography resin composition containing both the inorganic solid fine particles and the whiskers, the total content of the inorganic solid fine particles and the whiskers is 10 to 70 volumes based on the total volume of the stereolithography resin composition. %, More preferably 20 to 60% by volume. If the total content of the inorganic solid fine particles and the whiskers is less than 10% by volume, volumetric shrinkage during stereolithography increases, and the dimensional accuracy of the resulting molded article is likely to be reduced. Temperature, flexural modulus and mechanical strength tend to be low. On the other hand, when the total content ratio of the inorganic solid fine particles and the whiskers exceeds 70% by volume, the viscosity of the resin composition for stereolithography increases, and the handleability and the moldability tend to be poor. Dimensional accuracy tends to be low.

In the stereolithography resin composition containing the inorganic solid fine particles and / or whiskers, one or both of the inorganic solid fine particles and the whiskers may be surface-treated with a silane coupling agent, It is preferred that both the whiskers and the whiskers have been surface-treated with a silane coupling agent. When the inorganic solid fine particles and / or whiskers are surface-treated with a silane coupling agent, heat deformation temperature, flexural modulus,
It is possible to obtain an optically formed object having a higher mechanical strength.

As the silane coupling agent in this case, any of the silane coupling agents conventionally used for surface treatment of a filler or the like can be used. Preferred silane coupling agents are aminosilane, epoxysilane, Vinyl silane and (meth) acryl silane can be mentioned. More specifically, γ-aminopropyltriethoxysilane, N-β- (aminoethyl)-
aminosilanes such as γ-aminopropyltriethoxysilane, N-β- (aminoethyl) -γ-aminopropylmethyldimethoxysilane; β- (3,4-epoxycyclohexyl) -ethyltrimethoxysilane, γ-glycidoxypropyl Epoxysilanes such as trimethoxysilane; vinylsilanes such as vinyltrichlorosilane, vinyldiethoxysilane and vinyl-tris (β-methoxyethoxysilane); and (meth) acrylsilanes such as trimethoxysilane methacrylate. One or more of the above silane coupling agents can be used.

When the surface treatment of the inorganic solid fine particles and / or whiskers is carried out with the silane coupling agent, the manner of exerting the function of the silane coupling agent may differ depending on the type of the photocurable resin used. Therefore, it is preferable to select a silane coupling agent suitable for each photocurable resin and perform surface treatment of the inorganic solid fine particles and / or whiskers. For example, it is preferable to use vinylsilane and / or (meth) acrylsilane for a photocurable resin mainly composed of a vinyl-based unsaturated compound, and it is preferable to use epoxysilane for a photocurable resin mainly composed of an epoxy-based compound. .

A resin composition for stereolithography containing the above-mentioned inorganic solid fine particles and / or whiskers in a photocurable resin, for example, 5,000 cp or more (25
C)), the resin composition for stereolithography having a high viscosity such as generally has thixotropy, and the viscosity decreases when a stress such as flow, stirring, or movement is applied to the resin composition for stereolithography, The higher the applied stress, the lower the viscosity. Therefore, such a stereolithographic resin composition having thixotropic properties cannot be said to be sufficiently good in handleability, and it is necessary to carefully calculate such a decrease in viscosity during stereolithography in advance and perform close control. For example, it is necessary to precisely control the amount of the resin composition supplied as one layer at the time of stereolithography, the thickness of the layer, and the amount and intensity of light irradiation.

On the other hand, the resin composition for stereolithography of the present invention does not have thixotropic properties, and
In the resin composition for stereolithography of the present invention, the phosphate ester-based surfactant is used together with the inorganic solid fine particles and / or whiskers in an amount of 0.01 to 1 weight based on the weight of the inorganic solid fine particles and / or whiskers. %, There is no thixotropic property. In the stereolithography resin composition of the present invention, the phosphate ester-based surfactant is used in an amount of 0.03 based on the weight of the inorganic solid fine particles and / or whiskers.
More preferably, it is contained at a ratio of 0.5% by weight. When the content of the phosphate ester-based surfactant is 0.01
When the amount is less than 1% by weight, it becomes difficult to eliminate the thixotropy of the resin composition for stereolithography. On the other hand, even if it exceeds 1% by weight, there is no difference in the effect on the thixotropy.

As the phosphate ester-based surfactants,
As the anionic surfactant, a conventionally known salt of an acidic phosphate and a basic compound can be used, and a typical example is a polyoxyalkylene alkyl ether represented by the following general formula (I). Acidic phosphoric acid esters such as phosphoric acid, polyoxyalkylene alkylphenyl ether phosphoric acid represented by the general formula (II), and alkyl phosphoric acid represented by the general formula (III);

[0035]

Embedded image [Wherein, R ¹ is an alkyl group, R ² is an alkylene group such as a methylene group or an isopropylene group, and q is an alkyleneoxy group.
(-R ² -O-) repeating units (degree of polymerization), m is 1 or 2, n is 1 or 2, m + n = 3], and a basic compound, Surfactants.

Among them, in the phosphate ester salt surfactant used in the present invention, the basic compound which forms a salt with the acidic phosphate ester is preferably an amine,
As amines in that case, for example, monoethanolamine, diethanolamine, triethanolamine,
Alkanolamines such as isopropanolamine;
Examples include N-alkylated alkanolamines such as methyldiethanolamine, ethylmonoethanolamine, and butyldiethanolamine; and cyclic amines such as morpholine and pyridine. The acidic phosphoric acid ester can form a salt with one or more of the above-mentioned amines.

In the present invention, as the liquid photocurable resin, any of the liquid photocurable resins conventionally used in stereolithography can be used, and various oligomers, various monofunctional vinyl compounds, polyfunctional vinyl compounds, A liquid photocurable resin containing one or more of epoxy compounds and the like, a photopolymerization initiator and, if necessary, a sensitizer and the like is preferably used. Although not limited, specific examples of oligomers, monofunctional vinyl compounds, polyfunctional vinyl compounds, and epoxy compounds that can be used in the present invention include the following.

[Oligomer] Urethane acrylate oligomer, epoxy acrylate oligomer, ester acrylate oligomer and the like.

[Monofunctional vinyl compound] Acrylic compound : isobornyl acrylate, isobornyl methacrylate, dicyclopentenyl acrylate, dicyclopentenyl methacrylate, dicyclopentenyloxyethyl acrylate, dicyclopentenyloxyethyl methacrylate , Dicyclopetanyl acrylate, dicyclopetanyl methacrylate, bornyl acrylate, bornyl methacrylate, 2-hydroxyethyl acrylate, cyclohexyl acrylate, 2-
Hydroxypropyl acrylate, phenoxyethyl acrylate, morpholine acrylamide, morpholine methacrylamide, acrylamide and the like. ○ Other monofunctional compounds : N-vinylpyrrolidone, N-vinylcaprolactam, vinyl acetate, styrene and the like.

[Polyfunctional vinyl compound] Trimethylolpropane triacrylate, ethylene oxide-modified trimethylolpropane triacrylate, ethylene glycol diacrylate, tetraethylene glycol diacrylate, polyethylene glycol diacrylate,
1,4-butanediol diacrylate, 1,6-hexanediol diacrylate, neopentyl glycol diacrylate, dicyclopentanyl diacrylate,
Polyester diacrylate, ethylene oxide-modified bisphenol A diacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, propylene oxide-modified trimethylolpropane triacrylate, propylene oxide-modified bisphenol A diacrylate, tris (acryloxyethyl) isocyanurate and the like.

[Epoxy compound] hydrogenated bisphenol A diglycidyl ether, 3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexanecarboxylate, 2- (3,4-epoxycyclohexyl-
5,5-spiro-3,4-epoxy) cyclohexane-
Meta-dioxane, bis (3,4-epoxycyclohexylmethyl) adipate and the like.

The photopolymerization initiator used in the photocurable resin used in the resin composition for stereolithography of the present invention is not particularly limited, and the photopolymerization initiator conventionally used in the photocurable resin composition is used. Any of these can be used. Although not limited, typical examples of the photopolymerization initiator include 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexylphenylketone, acetophenone, benzophenone, xanthone, fluorenone, benzaldehyde, fluorene, anthraquinone, Examples thereof include triphenylamine, carbazole, 3-methylacetophenone, and Michler's ketone, and one or more of these can be used. Also, if necessary,
A sensitizer such as an amine compound may be used in combination.

The stereolithographic resin composition of the present invention may further comprise, if necessary, a leveling agent, a surfactant other than a phosphate ester-based surfactant, an organic polymer modifier, It may contain an organic plasticizer, organic polymer beads, or the like.

When the resin composition for stereolithography of the present invention is stored in a state where light can be blocked, it is usually used at a temperature of 10 to 40 ° C. for a long period of about 6 to 18 months. It can be stored while maintaining good photocuring performance while preventing denaturation and polymerization. The resin composition for stereolithography of the present invention has its properties, particularly showing no thixotropy, handling properties during stereolithography, properties of being excellent in stereolithography, and further, volume shrinkage when cured with light. It can be used in various stereolithography techniques by making use of its small size, excellent dimensional accuracy, high heat deformation temperature, excellent heat resistance, and excellent mechanical properties. Although not limited,
The resin composition for stereolithography of the present invention can be used, for example, for optical three-dimensional molding, casting with light irradiation, casting, molding by coating, and the like. Molded products, simple molds, films, and other products can be manufactured.

In the case of performing optical three-dimensional modeling using the resin composition for stereolithography of the present invention, any of conventionally known optical three-dimensional modeling methods and apparatuses can be used. Among them,
In the present invention, as light energy for curing the resin, it is preferable to use an active energy ray generated from an Ar laser, a He-Cd laser, a xenon lamp, a metal halide lamp, a mercury lamp, a fluorescent lamp, or the like,
Laser beams are particularly preferably used. When a laser beam is used as the active energy beam, it is possible to increase the energy level and shorten the molding time, and to obtain a three-dimensional object with high modeling accuracy by utilizing the good light condensing property of the laser beam. be able to.

As described above, in performing optical three-dimensional modeling using the resin composition for stereolithography of the present invention, any of a conventionally known method and a conventionally known stereolithography system apparatus can be adopted, and there is no particular limitation. However, typical examples of the optical three-dimensional modeling method preferably used in the present invention include the light of the present invention which further contains a light energy absorber together with the above-mentioned inorganic solid fine particles and / or whiskers and a phosphate ester-based surfactant. One layer of the molding resin composition is selectively irradiated with an active energy ray so as to obtain a cured layer having a desired pattern to form a cured layer, and then the uncured liquid photocured on the cured layer By repeating the operation of supplying a reactive resin composition, irradiating active energy rays in the same manner, and laminating a new cured layer continuous with the cured layer. And a method of obtaining a three-dimensional shaped object to be finally purposes. The three-dimensional structure obtained thereby can be used as it is, or in some cases, post-curing by light irradiation or post-curing by heat, etc., to use it after further improving its mechanical properties and shape stability etc. You may do so.

At this time, the structure, shape, size, and the like of the three-dimensional structure are not particularly limited, and can be determined according to each use. Typical application fields of the optical three-dimensional modeling method of the present invention include a model for verifying an external design during a design, a model for checking the functionality of parts, and a resin for producing a mold. Examples include the production of a mold, a base model for producing a mold, a direct mold for a prototype mold, and a simplified mold for producing a resin molded product. More specifically, production of precision parts, electric / electronic parts, furniture, building structures, automobile parts, various containers, castings, molds, models for molds, and models for processing. Can be. Especially its good heat resistance,
Utilizing characteristics such as mechanical characteristics and high dimensional accuracy, it can be used very effectively for prototyping high-temperature components, for example, designing components for complex heat transfer circuits, and planning for analysis of heat transfer behavior of complex structures. be able to.

Further, as described above, the resin composition for stereolithography of the present invention can be used not only for optical three-dimensional molding but also for various molding techniques involving light irradiation, for example, cast molding with light irradiation, casting. , Coating, etc., whereby the above-mentioned various molded products, film-like products, and other products can be obtained.

[0049]

EXAMPLES The present invention will be specifically described below with reference to examples and the like, but the present invention is not limited to the following examples. In the following examples, the average particle size of the inorganic solid fine particles (glass beads) and the size and aspect ratio of the whisker were determined as follows. In addition, the tensile strength, tensile elongation, tensile modulus, thermal conductivity, heat deformation temperature, and volumetric shrinkage during optical three-dimensional modeling of an optical three-dimensional model obtained by optical three-dimensional modeling are obtained as follows. Was.

[Average Particle Size of Inorganic Solid Fine Particles (Glass Beads)] Glass beads are scattered on a sample stage of an electron microscope so that the individual particles do not overlap as much as possible. Deposition layer thickness 2
Formed at 100-300 °, and with a scanning electron microscope,
Observed at 000 to 30,000 times, using a particle size measuring device ("Luzex 500" manufactured by Nippon Regulator Co., Ltd.), the area equivalent circle diameter of at least 100 glass beads was determined, and the average value was taken. .

[Dimensions and aspect ratio of whisker]
Using a laser diffraction / scattering particle size distribution analyzer (“LA-7000” manufactured by Matoba Seisakusho Co., Ltd.), whiskers are dispersed in ion-exchanged water at a ratio of 1% by weight using ion-exchanged water as a dispersion medium. The particle size distribution was examined, and the particle size at the 10% portion (D10) from the smaller one was defined as the diameter (fiber diameter), and the particle size at the 90% portion (D90) was defined as the length (fiber length). When the aspect ratio is D90 / D
It was determined as 10.

[Tensile Strength, Tensile Elongation and Tensile Elasticity of Optical Three-Dimensional Object] Using a dumbbell-shaped test piece manufactured by optical three-dimensional molding, its tensile strength and tensile elongation are measured in accordance with JIS K 7113. The degree and tensile modulus were measured.

[Thermal conductivity of optical three-dimensional molded article] Length × width × thickness = 50 mm × 50 manufactured by optical three-dimensional molding
Using a test piece of mm × 6 mm, the thermal conductivity was measured by DSC according to JIS K0129 by a temperature gradient method.

[Thermal deformation temperature of optical three-dimensional molded article] Using a dumbbell-shaped test piece manufactured by optical three-dimensional molding, method A (load 18.5) according to JIS K7207
kg / mm ² ).

[Volume shrinkage rate during optical three-dimensional modeling] The specific gravity (d ₁ ) of the stereolithographic resin composition before photocuring used in the optical three-dimensional modeling, and the optical three-dimensional model obtained by the optical three-dimensional modeling The specific gravity (d ₂ ) of the molded article (dumbbell-shaped test piece) was measured, and the volume shrinkage (%) was determined by the following equation (2).

[0056]

## EQU4 ## Volume shrinkage (%) = {(d ₂ −d ₁ ) / d ₂ } × 100 (2)

<< Production Example 1 >> [Production of a reaction product containing a urethane acrylate oligomer and morpholine acrylamide] (1) A 5-liter three-necked flask equipped with a dropping funnel equipped with a stirrer, a condenser tube and a side tube. , 888 g of isophorone diisocyanate, 906 g of morpholine acrylamide and 1.0 g of dibutyltin dilaurate were heated in an oil bath so that the internal temperature was 80 to 90 ° C. (2) A liquid obtained by uniformly mixing and dissolving 0.7 g of methylhydroquinone in 856 g of glycerin monomethacrylate monoacrylate is charged into the dropping funnel with the side tube previously heated to 50 ° C., and the liquid in the dropping funnel is mixed with The contents in the flask of (1) were dropped and mixed under stirring in a nitrogen atmosphere while maintaining the temperature of the contents of the flask at 80 to 90 ° C, and reacted by stirring at the same temperature for 2 hours. (3) Then, after lowering the temperature of the contents of the flask to 60 ° C., a 4-mol adduct of propylene oxide of pentaerythritol charged in another dropping funnel (each of 1 mol of propylene oxide was added to 4 hydroxyl groups of pentaerythritol) 366 g was quickly added dropwise and the temperature of the contents of the flask was maintained at 80 to 90 ° C.
The reaction was carried out for a time to produce a reaction product containing a urethane acrylate oligomer and morpholine acrylamide, and the obtained reaction product was taken out of the flask while it was still warm.

<< Example 1 >> [Production of Resin Composition for Stereolithography] (1) Obtained in Production Example 1 in a 5-liter three-necked flask equipped with a stirrer, a cooling tube, and a dropping funnel with side tubes. 2020 g of a reaction product containing the urethane acrylate oligomer and morpholine acrylamide, 454 g of morpholine acrylamide, and 1060 g of dicyclopentanyl diacrylate were charged, and the atmosphere was replaced with nitrogen under reduced pressure. Next, 118 g of 1-hydroxycyclohexyl phenyl ketone (“Irgacure 184” manufactured by Ciba Geigy; photopolymerization initiator) was added in an environment where ultraviolet rays were blocked, and mixed and stirred at a temperature of 25 ° C. until completely dissolved ( The mixing and stirring time was about 1 hour) to obtain a photocurable resin which was a colorless and transparent viscous liquid. The viscosity of this photocurable resin at a temperature of 25 ° C. was measured using a rotary B-type viscometer, and was 2100 cp.

(2) 3652 g of the photocurable resin obtained in the above (1) was put into a universal stirrer (Dalton Co., Ltd .; internal volume: 10 liters), and a morpholine salt of an acidic phosphoric acid ester (polyoxypropylene glycol phosphorus) was added. Glass beads treated with 28 g of a morpholine salt of an acid ester ("Super Dyne V201" manufactured by Takemoto Yushi Co., Ltd.) and an acrylic silane coupling agent [manufactured by Toshiba Silicone; γ (methacryloxypropyl) trimethoxysilane] [average particle size] Diameter 15 μm, relative standard deviation of sphericity according to the above formula (1) 0.3] 4169 g (32% by volume based on the total volume of the finally obtained stereolithography resin composition), and the same acrylic silane Aluminum borate whisker treated with an organic coupling agent ("Albolex YS" manufactured by Shikoku Chemicals Co., Ltd.) 4 "; diameter 0.5~0.7μm,
1251 g (aspect ratio 50 to 70) (8% by volume based on the total volume of the finally obtained stereolithography resin composition) is added, and the mixture is stirred for one day, defoamed, and processed. Was manufactured. (3) 2 of the resin composition for stereolithography obtained in the above (2)
The viscosity at 5 ° C. was measured by changing the rotation speed of the rotor of the rotary B-type viscometer as shown in Table 1 below, and the results were as shown in Table 1 below.

[0060]

[Table 1] Rotational speed of rotor Viscosity of stereolithographic resin composition (25 ° C) (times / min) (cp) 2 40,000 4 40,500 10 39,800 20 40,000

As is evident from the results shown in Table 1 above, the resin composition for stereolithography of the present invention exhibits a change in the stress applied to the resin composition for stereolithography even when the rotation speed of the rotor changes. However, it maintains a constant viscosity and does not exhibit thixotropic properties.

<< Example 2 >> [Production of optical three-dimensional molded article] An ultra-high-speed optical molding system (manufactured by Teijin Seiki Co., Ltd.) was obtained by using the resin composition for stereolithography obtained in (2) of Example 1. "SO
LIFORM 500 ”) using a water-cooled Ar laser beam (output: 500 mW; wavelength: 333, 351, 364 n)
m) is irradiated perpendicularly to the surface, and the irradiation energy 2
Under the conditions of 0 to 30 mJ / cm ² , the slice pitch (lamination thickness) is 0.05 mm, and the optical modeling is performed with an average modeling time of 2 minutes per layer, and the tensile strength, the tensile elongation, the tensile elastic modulus, and the thermal conductivity are performed. An optical three-dimensional object (test piece) for measuring the rate and the heat distortion temperature was manufactured. After the obtained optical three-dimensional structure (test piece) was washed with isopropyl alcohol, it was irradiated with 3 KW ultraviolet rays for 10 minutes to perform post cure. The physical properties of the optical three-dimensional structure (test piece) obtained by the measurement were measured by the above-described methods, and were as shown in Table 2 below. Further, the specific gravity (d ₁ ) of the stereolithographic resin composition before photocuring and the specific gravity (d ₂ ) of the three-dimensional molded article after post-curing used in the production of the optical three-dimensional molded article of Example 2 were respectively determined. Measure and use the above equation (2)
The volumetric shrinkage was determined by the above, and was as shown in Table 2 below.

[0063]

[Table 2] [Physical properties of optically three-dimensional objects] Tensile strength 8.3 kg / mm ² Tensile elongation 1.4% Tensile elasticity 1650 kg / m ² Thermal conductivity 0.43 KCal / m · Hr · ° C Heat deformation temperature 271 ° C Volume shrinkage 1.7%

From the results shown in Table 2 above, when the stereolithography was performed using the resin composition for stereolithography of the present invention, the light having excellent mechanical properties, high heat deformation temperature and excellent heat resistance was obtained. It can be seen that the molded article can be obtained with a very small volume shrinkage of 1.7% and good dimensional accuracy.

[0065]

The resin composition for stereolithography of the present invention does not have thixotropic properties in terms of flow viscosity, and is subjected to stress such as flow or stirring, or added to the resin composition for stereolithography. Even if the stress changes, a constant viscosity can be maintained without a decrease in viscosity or a change in viscosity. Therefore, the resin composition for stereolithography of the present invention is extremely excellent in handleability. And, when using the resin composition for stereolithography of the present invention to produce molded articles and various products by optical three-dimensional molding and other optical molding, an optical molded article having excellent dimensional accuracy and physical properties can be easily handled. It can be manufactured smoothly with good workability. Furthermore, an optically molded article or a product obtained by using the optically molded resin composition of the present invention containing the inorganic solid fine particles and / or whiskers together with the phosphate ester-based surfactant has mechanical properties and heat resistance. Also has excellent characteristics.

──────────────────────────────────────────────────の Continued on the front page (51) Int.Cl. ⁶ Identification code FI C08K 5/521 C08K 5/521 7/18 7/18 (72) Inventor Tatsuhiko Ozaki 74-1, Nakahamacho, Toyohashi-shi, Aichi 72) Inventor Toshiharu Suzuki 142-1, Makino-cho, Toyohashi-shi, Aichi

Claims (10)

[Claims] 1. A stereolithography resin composition having a viscosity at 25 ° C. of 5,000 cp or more and which does not change in viscosity even when stress is applied. 2. An average particle size of 3 to 7 in the liquid photocurable resin.
The inorganic solid fine particles having a particle size of 0 μm are 5 to 70% by volume based on the total volume of the resin composition for stereolithography, and the phosphate ester-based surfactant is 0.1% based on the weight of the inorganic solid fine particles.
2. The composition according to claim 1, wherein the content is from 0.01 to 1% by weight.
Resin composition for stereolithography. 3. A photocurable resin, comprising: a diameter of 0.3 to 1 μm;
Whiskers having a length of 10 to 70 μm and an aspect ratio of 10 to 100 are prepared based on the total volume of the stereolithography resin composition by 5
The stereolithographic resin composition according to claim 1, further comprising a phosphate ester salt surfactant in an amount of 0.01 to 1% by weight based on the weight of the whisker. 4. An inorganic solid fine particle having an average particle size of 3 to 70 μm, based on the total volume of the resin composition for stereolithography, in a liquid photocurable resin, having a volume of 5 to 70% by volume and a diameter of 0.3 to 1 μm.
5 to 30% by volume of whiskers having a length of 10 to 70 μm and an aspect ratio of 10 to 100, and 0.01 to 1% by weight of a phosphate ester-based surfactant based on the total weight of the inorganic solid fine particles and the whiskers. The resin composition for stereolithography according to claim 1, which is contained at a ratio of: 5. The resin composition for stereolithography according to claim 1, wherein the phosphate ester-based surfactant is a surfactant comprising an amine salt of an acidic phosphate ester. 6. The method according to claim 2, wherein the inorganic solid fine particles have a sphericity with a relative standard deviation value represented by the following formula (1) smaller than 0.5. Resin composition for stereolithography. (Equation 1) 7. The resin composition for stereolithography according to claim 2, wherein the inorganic solid fine particles and / or whiskers are surface-treated with a silane coupling agent. 8. The resin composition for stereolithography according to claim 1, wherein the liquid photocurable resin is a liquid photocurable resin containing a photopolymerizable compound and a photopolymerization initiator. 9. The resin composition for stereolithography according to claim 1, which is used for optical three-dimensional modeling. 10. A method for producing a molded article by carrying out optical molding using the resin composition for optical molding according to any one of claims 1 to 9.