JPH07140651A - Resin composition for optical three-dimensional molding - Google Patents

Abstract

PURPOSE:To provide a low-viscosity resin composition for optical three- dimensional molding excellent in curing sensitivity and capable of being easily cleaned after curing. CONSTITUTION:This resin composition for optical three-dimensional molding contains the following components A...C, and the content of the component A is controlled to 10-70wt.% of the entire composition. The component A is at least one among the ethylenic unsaturated monomers shown by formula 1 and the ethylenic unsaturated monomers shown by formula 2, the component B is an ethylenic unsaturated oligomer, and the component C is a photopolymerization initiator.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a resin for optical three-dimensional molding, and in particular, it has a low viscosity, a high curing sensitivity, and is easy to wash the resin after curing. The present invention relates to a resin composition for optical three-dimensional modeling that can be used.

[0002]

2. Description of the Related Art Optical stereolithography means, for example, forming a hardened layer having a desired pattern on the surface of a liquid photocurable resin, for example, by selectively irradiating an ultraviolet laser to form a hardened layer. It is a system that creates a stereoscopic image by stacking layers in the depth direction.

The application of this system has been rapidly developed in recent years, but most of the liquid photo-curing resin used for the system is a diversion of the existing UV-curing resin which is widely used in other fields. When trying to use the above resin for optical three-dimensional modeling, it was difficult to obtain satisfactory performance.

Therefore, in order to solve the above-mentioned problems, conventionally, the UV curable resin itself is not improved, but the system as a whole is improved, that is, the UV laser irradiation method, the irradiation pattern is changed, and the cured layer is laminated. Solutions, such as ingenuity, were being studied in areas other than the so-called ultraviolet curable resin, which is a material.

[0005]

In the optical three-dimensional molding method, the liquid photocurable resin as a material has a low viscosity and a curing sensitivity from the viewpoints of molding speed, molding accuracy, handling of a molded object, and the like. It is required to be good, have a small volume shrinkage during curing, and have a sufficiently high strength of the obtained cured product. Particularly, conventionally, only the irradiation step of the ultraviolet laser has been a problem, but after this irradiation step, the cured product is taken out from the liquid tank and the liquid photocurable resin adhering to the surface of the cured product is washed. In this cleaning process,
In order to remove the liquid photo-curable resin adhering to the details, it is effective that the resin has a low viscosity, so that the liquid photo-curable resin is required to have a low viscosity. The liquid photo-curable resin is generally classified into two types, that is, an ethylenically unsaturated monomer type and an epoxy type, when roughly classified according to the type of resin. However, in the case of the latter epoxy type, although it has the advantages that the curing shrinkage is small and the cured resin strength is high, it has the drawback of being inferior in the curing speed and curing sensitivity, so it is suitable for optical stereolithography materials. It is hard to say that Therefore, an ethylenically unsaturated monomer-based material is generally used as the optical three-dimensional modeling material.

However, even the above-mentioned ethylenically unsaturated monomer-based ones are not satisfactory because they do not have the above-mentioned required physical properties in a well-balanced manner. Then, in order to meet the required physical properties, research has been conducted, for example, as the ethylenically unsaturated monomer,
A resin composition for optical three-dimensional modeling, which contains a monomer having an aromatic group, has been proposed (JP-A-2-208305). However, the optical three-dimensional modeling resin composition containing the above-mentioned aromatic monomer has a problem of high viscosity.

The present invention has been made in view of the above circumstances, and is an optical three-dimensional molding capable of obtaining a molded article having a low viscosity, an excellent cleaning property, a good curing sensitivity, and a small curing shrinkage. It is an object of the present invention to provide a resin composition for use.

[0008]

In order to achieve the above object, the resin composition for optical three-dimensional modeling of the present invention contains the following components (A) to (C) and contains the above component (A). The ratio is set to 10 to 70% by weight of the entire resin composition for optical three-dimensional modeling. (A) At least one of an ethylenically unsaturated monomer represented by the following general formula (1) and an ethylenically unsaturated monomer represented by the following general formula (2).

[Chemical 2] (B) Ethylenically unsaturated oligomer. (C) A photopolymerization initiator.

[0009]

The present inventors have conducted a series of studies on a resin composition for optical three-dimensional modeling, which has a low viscosity, an excellent sensitivity during curing, and a cured product having a small curing shrinkage. As a result, when one or both of the amide-based monomers represented by the formulas (1) and (2) are used as the ethylenically unsaturated monomer in a specific ratio, the viscosity is low, the detergency is good, and the curing The inventors have found that a molding resin composition having excellent sensitivity can be obtained, and that a cured product having a small volume shrinkage upon curing can be obtained, and the present invention has been reached.

Next, the present invention will be described in detail.

The resin composition for optical three-dimensional modeling of the present invention comprises a special ethylenically unsaturated monomer (component A), an ethylenically unsaturated oligomer (component B), and a photopolymerization initiator (component C). It is obtained by using, and usually has a liquid state.

The above-mentioned special ethylenically unsaturated monomer (A
The component) is composed of one or both of the ethylenically unsaturated monomer represented by the following general formula (1) and the ethylenically unsaturated monomer represented by the general formula (2), and is an amide-based monomer. .

[0013]

[Chemical 3]

Examples of the ethylenically unsaturated monomer represented by the above general formula (1) include N, N-dimethylacrylamide, N, N-diethylacrylamide, N, N.
-Examples include dibutyl acrylamide.

Specific examples of the ethylenically unsaturated monomer represented by the above general formula (2) include N-acrylpiperidine and acryloylmorpholine.

These may be used alone or in combination of two or more.

The content ratio of the special ethylenically unsaturated monomer represented by the above general formulas (1) and (2) must be set to 10 to 70% by weight in the resin composition for optical three-dimensional molding. From the viewpoint of the physical properties of the cured product, it is more preferable to set the content ratio to 30 to 50% by weight. That is, the content of the special ethylenically unsaturated monomer is 10% by weight.
If it is less than 70% by weight, it is difficult to set the viscosity of the resin composition for optical three-dimensional molding. Is extremely reduced.

The above-mentioned special ethylenically unsaturated monomer alone may constitute the whole ethylenically unsaturated monomer component, or other ethylenically unsaturated monomer may be used in combination depending on the physical properties of the obtained cured product. Good. When the other ethylenically unsaturated monomer of the latter is used in combination, the other ethylenically unsaturated monomer is mainly vinyl-based such as vinylpyrrolidone, and acrylic, and the mixing ratio is a resin composition for optical three-dimensional modeling. It is set to 50% by weight or less in the product, and is set so as not to exceed the blending amount of the above-mentioned special ethylenically unsaturated monomer used in the present invention.

Examples of the acrylic ethylenically unsaturated monomer include 2-ethylhexyl acrylate, isononyl acrylate, isobornyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, tetrahydrofurfuryl acrylate,
Butoxyethyl acrylate, phenoxyethyl acrylate, diethylaminoethyl acrylate, poly (n
= 2 or more) oxyethylene monoacrylate, poly (n
= 2 or more) monofunctional monomers such as oxypropylene monoacrylate. Further, bifunctional monomers such as polyethylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,9-nonanediol diacrylate, neopentyl glycol diacrylate, and neopentyl glycol diacrylate hydroxypivalate can be used. Further, trimethylolpropane triacrylate, polyhydroxyethylated trimethylolpropane triacrylate, polyhydroxypropylated trimethylolpropane triacrylate, polyhydroxyethylated glycerin triacrylate, polyhydroxypropylated glycerin triacrylate, pentaerythritol triacrylate, ditritrile. Examples include trifunctional or higher functional monomers such as methylolpropane tetraacrylate. These may be used alone or in combination of two or more.

In the present invention, the ethylenically unsaturated oligomer (component B) used together with the component A means an oligomer containing a radiation-curable functional group such as an acryloyl group or a vinyl group in its molecule. Among them, those having an acryloyl group are common. The molecular weight thereof is preferably 10,000 or less, and more preferably 5,000 or less in consideration of curing sensitivity.

The above-mentioned acryloyl group-containing oligomers include urethane acrylate (having a urethane bond in the structure), epoxy acrylate (having a ring-opening bond of the epoxy group in the structure), and polyester according to the classification of the method of bonding in the molecule. It is divided into acrylate (having an ester bond in the structure) and polybutadiene acrylate (having a polybutadiene bond in the structure) and the like, but the invention is not particularly limited thereto.

The urethane acrylate is
It can be synthesized by reacting a polyisocyanate with a polyalcohol and an alcohol having an acryloyl group.

Examples of the above polyisocyanates include diisocyanates such as tolylene diisocyanate, naphthalene diisocyanate, xylylene diisocyanate, paraphenylene diisocyanate, tetramethyl xylene diisocyanate, isophorone diisocyanate, dicyclohexylmethane diisocyanate and hexamethylene diisocyanate. Further, a triisocyanate having an isocyanurate ring, which is a trimer of the above-mentioned diisocyanate, may be mentioned.

Examples of the polyalcohol include hydrocarbon diols such as 1,4-butanediol and 1,6-hexanediol. Further, alicyclic diols such as cyclohexane dimethanol, polyalkylene glycols such as polyethylene glycol, polypropylene glycol, tetramethylene glycol and mixed random diols thereof can be mentioned. Examples thereof include alkylene oxide adducts of hydrocarbon-based polyols and alkylene oxide adducts of polyphenols. Further, a polycondensation terminal polyol of a hydrocarbon-based polyol with succinic acid, adipic acid, terephthalic acid, or the like, or a terminal polyol obtained by reacting a hydrocarbon-based polyol, a polyphenol with a lactone compound such as caprolactone, γ-valerolactone Compounds.

Examples of the alcohol having an acryloyl group include hydroxyethyl acrylate, hydroxypropyl acrylate, a ring-opening reaction product of caprolactone and acrylic acid, a ring-opening reaction product of caprolactone and hydroxyethyl acrylate, polyalkylene glycol and acrylic acid. Partial esterification products and the like can be mentioned.

Next, the epoxy acrylate is
It is a reaction product of an epoxy compound and an acrylic group-containing terminal carboxylic acid, or an epoxy compound and an alcohol compound.

The epoxy compound referred to here is butyl glycidyl ether, phenyl glycidyl ether,
Examples include monoepoxy compounds such as allyl glycidyl ether, nonylphenyl glycidyl ether, and α-olefin epoxy compounds. Further, neopentyl glycol diglycidyl ether, 1,6-hexanediol diglycidyl ether, polyalkylene glycol diglycidyl ether, adipic acid diglycidyl ester,
Examples thereof include diepoxy compounds such as phthalic acid diglycidyl ester, dibromoneopentyl glycol diglycidyl ether, bisphenol A diglycidyl ether, and tetrabromobisphenol A diglycidyl ether. Further, a triepoxy compound such as trimethylolpropane triglycidyl ether, tris (hydroxyethyl) isocyanurate triglycidyl ether, and glycerin triglycidyl ether can be given. And
Examples thereof include polyepoxy compounds such as polyglycidyl ether of novolac phenol.

As the above-mentioned acrylic group-containing carboxylic acid or alcohol compound, acrylic acid, hydroxyethyl acrylate, hydroxypropyl acrylate, hydroxyethyl acrylate or hydroxypropyl acrylate and maleic anhydride, succinic anhydride or phthalic anhydride are used. Examples thereof include a terminal carboxylic acid ester produced by a ring-opening reaction (molar ratio of 1: 1).

The polyester acrylate is an acrylic acid ester synthesized by an esterification reaction of polycarboxylic acid, polyalcohol, and acrylic acid.

Examples of the polycarboxylic acid include succinic acid,
Examples include dicarboxylic acids such as adipic acid, azelaic acid, and het acid, and further examples include tricarboxylic acids such as trimellitic acid.

Examples of the polyalcohol include the same as the polyalcohol used in the above-mentioned polyurethane acrylate.

The polybutadiene acrylate may be 1,2-polybutadiene glycol or 1,2-polybutadiene glycol.
An esterification product of 4-polybutadiene glycol and acrylic acid can be mentioned.

The content ratio of the ethylenically unsaturated oligomer (component B) is preferably set to 10 to 60% by weight, more preferably 20 to 50% by weight, based on the entire optical three-dimensional modeling resin composition. . That is, when the content ratio of the ethylenically unsaturated oligomer is less than 10% by weight, the mechanical strength of the cured product is insufficient, and when it exceeds 60% by weight, it is practically unusable due to the high viscosity of the oligomer. This is because it tends to have a high viscosity.

The photopolymerization initiator (C component) used together with the above A component and B component is not particularly limited, and those used in conventional UV curable resins can be used. Specifically, acetophenone, benzophenone, xanthone, fluorene, carbazole, 2-chlorobenzophenone, 3-dimethyl-4-methoxybenzophenone, 4,4'-diaminobenzophenone, Michler's ketone, benzoinpropyl ether, acetophenone dimethyl ketal, 2-hydroxy. -2-methyl-1-phenylpropan-1-one,
2-Methyl-1- [4- (methylthio) phenyl] -2
-Morpholinopropan-1-one, 1-hydroxycyclohexyl phenyl ketone, benzyl dimethyl ketal, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, thioxanthone compounds, camphorquinone and the like can be mentioned. These may be used alone or in combination of two or more. Furthermore, if necessary, a sensitizer such as a tertiary amine can be used.

The content ratio of the photopolymerization initiator (component C) is preferably set to 0.1 to 10% by weight, more preferably 0.3% by weight based on the whole optical three-dimensional resin composition.
~ 8% by weight. That is, if the content of the photopolymerization initiator is less than 0.1% by weight, the curability of the obtained cured product tends to decrease, and if it exceeds 10% by weight, the strength of the obtained cured product tends to decrease. .

In the resin composition for optical three-dimensional modeling of the present invention, in addition to the above components A to C, if necessary, a surfactant,
You may mix | blend additives, such as a dye, suitably.

The resin composition for optical three-dimensional modeling of the present invention is produced using the above-mentioned components, for example, as follows. That is, the desired optical three-dimensional modeling resin composition is produced by mixing the above-mentioned components A to C and, if necessary, additives in a predetermined ratio and mixing them.

The resin composition for optical three-dimensional modeling thus obtained is used for optical three-dimensional modeling, and the viscosity of the resin composition can be adjusted to 100 to 1000 cp. Then, the sensitivity of ultraviolet curing is good, and the curing shrinkage of the resin composition can be adjusted to 9% or less.

In the optical three-dimensional modeling method, usually, after irradiating an ultraviolet laser to cure the photocurable resin,
It is necessary to wash the cured product with water or an aqueous surfactant solution, and in this cleaning step, the liquid resin attached to the surface of the cured product is removed. After that, perform after-cure again. In this series of steps, removal of the liquid resin by the washing step is important for improving the dimensional accuracy of the cured product.

Next, examples will be described together with comparative examples.

[0041]

Examples 1 to 9 and Comparative Examples 1 to 5 The components shown in Tables 1 to 3 below are blended in the proportions shown in the same table and mixed to give a liquid resin composition for optical three-dimensional modeling. Manufactured.

[0042]

[Table 1]

[0043]

[Table 2]

[0044]

[Table 3]

The viscosity of the thus obtained optical three-dimensional modeling resin composition was measured with a B-type viscometer. The results are shown in Table 4 below. Further, the resin composition for optical three-dimensional modeling is put into a stainless steel tank, and focused Ar laser light (output 150 mW, wavelength 364 nm) is irradiated from a direction perpendicular to the surface of the composition, and 20 mm × 20 mm ×
A cured product having a thickness of 0.3 mm was produced. Then, the shrinkage rate, gelation rate and detergency of the cured product were measured according to the following methods. These results are shown in Table 4 below.
Are also shown. The gelation rate corresponds to the curing sensitivity of the resin composition for optical three-dimensional modeling, and it is judged that a resin having a high gelation rate has a high curing sensitivity.

[Shrinkage of Cured Product] The density (D1) of the liquid optical three-dimensional modeling resin composition before curing and the density (D2) of the cured optical three-dimensional modeling resin composition (cured product) are shown. The measurement was performed and the shrinkage rate (%) of the cured product was calculated using the following formula. Curing shrinkage rate (%) = {(1 / D1)-(1 / D2)} /
(1 / D1) x 100

[Gelization rate of cured product] After measuring the weight of the cured product, the cured product was immersed in methylene chloride at 25 ° C,
It was left for 24 hours and then taken out. Then, this is 40 ℃
After drying for 2 hours in the constant temperature bath, the temperature was returned to room temperature and the weight was measured. The gelation rate was calculated from the weight change before and after that.

[Cleanability of Cured Product] The cured product was dipped in the liquid resin composition before curing. This was pulled up using tweezers and 2 kg / cm ² of nitrogen gas was blown from a distance of 20 cm for 1 minute to remove the resin composition attached. Then it was left in water overnight. Then, this was taken out and dried, and then the weight was measured. Using the weight after this test and the weight before subjecting to the test, the weight change was calculated from the following formula, and this value was used as the standard for the detergency. The smaller this value is, the better the cleanability is. Detergency = (weight after cleaning test−weight before test) × 100
/ Weight before test

[0049]

[Table 4]

From the results of Table 4 above, the comparative example product may have a higher viscosity and a comparatively lower curing shrinkage than the example product, but it is still higher than the example product. Further, it can be seen that the standard value of the cleaning property is high and the cleaning property is low. On the other hand, all of the example products have low viscosity and low curing shrinkage. Furthermore, the cleanability and gelation rate are also high. From these facts, the superiority of the example product is clear.

[0051]

As described above, the resin composition for optical three-dimensional modeling of the present invention has at least one of the special ethylenically unsaturated monomers represented by the general formulas (1) and (2) ( Component A) is contained at a specific ratio. For this reason, it has a low viscosity and excellent washability, and also has little curing shrinkage during curing and good curing sensitivity. Therefore, a molded product (cured product) with high modeling accuracy can be manufactured by an optical three-dimensional modeling method such as ultraviolet irradiation.

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Claims (1)

[Claims] 1. A composition comprising the following components (A) to (C), wherein the content ratio of the component (A) is set to 10 to 70% by weight based on the entire resin composition for optical three-dimensional modeling. A characteristic resin composition for optical three-dimensional modeling. (A) At least one of an ethylenically unsaturated monomer represented by the following general formula (1) and an ethylenically unsaturated monomer represented by the following general formula (2). [Chemical 1] (B) Ethylenically unsaturated oligomer. (C) A photopolymerization initiator.