JP2019044148A - Composition for light molding - Google Patents

Abstract

To provide a composition for light molding capable of increasing mechanical physical property of a molded article under a high temperature environment, and sufficiently decreasing viscosity during molding.SOLUTION: A composition for light molding contains a photocurable resin, an inorganic filler and an additive which is a compound having an amide bond and a C=C unsaturated double bond in a molecule. The additive may be selected from N-vinylformamide and 4-acrylo morpholine. The inorganic filler may be layered silicate compound such as talc, silica, mica. Under the high temperature environment of a molded article, storage elasticity modulus can be made at 2000 MPa or more and viscosity can be made at less than 2000 mPa s during molding.SELECTED DRAWING: None

Description

  The present invention includes an optical filler composition that includes an inorganic filler and an additive in a photocurable resin to improve the storage elastic modulus of a modeled article in a high-temperature environment and can keep the viscosity during modeling low. Related to things.

  In stereolithography, a liquid tray is filled with a liquid photocurable resin in a built-up tray in which the modeling table is arranged to be movable up and down, and cured by irradiating light to the photocurable resin supplied along the modeling table, The modeling table is moved in the Z direction (vertical direction) by the stacking pitch, and the liquid photocurable resin of the next layer is fluidly supplied to the surface of the cured layer. Thereafter, the same operation is repeated to perform stacking modeling.

  As such optical modeling, as shown in Patent Document 1, the molding table is lowered (sedimented) from the liquid surface of the photocurable resin by the stacking pitch to flow the photocurable resin on the upper surface of the cured layer. A liquid thin layer is supplied to form a cured layer by sequentially irradiating light to the thin layer, or the modeling table 1 is laminated from the bottom surface of the built-in tray 2 as shown in FIG. By raising the pitch, the photocurable resin 4 is flow-supplied to the lower surface of the cured layer 3 (the gap between the cured layer 3 and the built-in tray 2) to form a liquid thin layer. A method of sequentially forming a hardened layer by irradiating light (laser) has been considered.

  The liquid photocurable resin used for the above-described optical modeling is added with a filler in order to improve mechanical properties such as storage elastic modulus under a high temperature environment of the modeled object. And the viscosity of modeling material itself will also rise with the improvement effect of a mechanical physical property. For this reason, in any of the modeling methods described above, when the modeling table is moved in the Z direction (vertical direction) by the stacking pitch, the photocurable resin cannot be smoothly supplied to the surface of the cured layer (new liquid state). Layer cannot be formed) and cannot be used as an optical modeling material.

Therefore, conventionally, in order to make the viscosity of the composition for optical modeling relatively low while increasing the mechanical properties in a high temperature environment, the composition for optical modeling shown in Patent Document 2 or 3 has been proposed. Yes.
This is a liquid photocurable resin blended with a silane coupling agent such as amino silane, epoxy silane, acrylic silane, etc., and has high mechanical properties at high temperatures, The viscosity is in the range of 5000 cps to 10000 cps (Patent Document 2), or in the range of 1000 cps to 10000 cps (Patent Document 3).

JP 2008-248026 A Japanese Patent Laid-Open No. 7-26060 JP 7-26062 A

  However, the viscosity of the optical modeling composition at the time of modeling is desirably as low as possible from the viewpoint of increasing the modeling speed and modeling accuracy. For example, when the modeling table is moved in the Z direction at a stacking pitch of several tens of μm, the viscosity of the optical modeling composition is 2000 mPa in order to smoothly supply the optical modeling composition to the surface of the cured layer. It is desirable to set it to less than s (2000 cps), more preferably less than 1000 mPa · s. For this reason, a sufficiently low viscosity has not necessarily been obtained with a conventional stereolithographic composition.

  The present invention has been made in view of such circumstances, and provides a composition for optical modeling that can increase mechanical properties in a high-temperature environment in a modeled object, and can obtain a sufficiently low viscosity at the time of modeling. The main task is to do this.

  In order to satisfy the trade-off requirement of improving the mechanical properties of a modeled object in a high temperature environment and reducing the viscosity of the composition for optical modeling at the time of modeling, the present inventor added a filler to the photocurable resin. As a result of earnest research on various properties of the composition, when a certain additive was added to the photocurable resin together with an inorganic filler, it was possible to form without compromising the high mechanical properties of the shaped object in a high temperature environment. It was found that the viscosity of the composition at the time was significantly lower than expected, and the present invention was completed.

That is, the composition for optical modeling according to the present invention includes a photocurable resin, an inorganic filler, and an additive that is a compound having an amide bond and a C═C unsaturated double bond in the molecule. It is a feature.
Here, the amide bond is a bond of a carbonyl group and nitrogen, but includes —NH—C (═O) — or> NC (═O) — in the bond unit.
Such an additive is preferably at least one selected from, for example, N-vinylformamide (NVFA) represented by the following chemical formula 1 and 4-acrylomorpholine (4AMP) represented by the chemical formula 2.

Of these, N-vinylformamide is particularly preferable.
The inorganic filler is preferably a layered silicate compound. Here, the layered silicate compound may be selected from the group consisting of talc, silica, mica, and a mixture thereof.
By using the additive described above, the viscosity at 20 ° C. can be less than 2000 mPa · s, and the storage elastic modulus at 150 ° C. can be 2000 MPa or more.

  As described above, if the optical modeling composition according to the present invention is used, it becomes possible to make the viscosity sufficiently low at the time of modeling while increasing the mechanical properties of the modeled object in a high temperature environment. When the modeling table is moved in the Z direction (vertical direction) by the stacking pitch, a new liquid layer can be quickly formed.

FIG. 1 is a conceptual diagram illustrating an example of an existing stereolithography apparatus.

  The composition for optical modeling according to this example is obtained by blending a liquid photocurable resin, an inorganic filler, and an additive.

(Photo-curing resin)
As the liquid photocurable resin to be the base resin, an epoxy photocurable resin or an acrylic photocurable resin can be used. Among them, it is preferable to use an acrylic photocurable resin.

  Examples of the epoxy photocurable resin include bisphenol A diglycidyl ether, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, brominated bisphenol A diglycidyl ether, brominated bisphenol F diglycidyl ether, and brominated bisphenol S. Diglycidyl ether, epoxy novolac resin, hydrogenated bisphenol A diglycidyl ether, hydrogenated bisphenol F diglycidyl ether, hydrogenated bisphenol S diglycidyl ether, 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexyl carboxylate 2- (3,4-epoxycyclohexyl-5,5-spiro-3,4-epoxy) cyclohexane-meta-dioxane, bis (3,4-epoxycyclohexyl) Rumethyl) adipate, bis (3,4-epoxy-6-methylcyclohexylmethyl) adipate, 3,4-epoxy-6-methylcyclohexyl-3 ′, 4′-epoxy-6′-methylcyclohexanecarboxylate, ε-caprolactone Modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, trimethylcaprolactone modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, β-methyl-δ-valerolactone Modified 3,4-epoxycyclohexylmethyl-3 ′, 4′-epoxycyclohexanecarboxylate, methylene bis (3,4-epoxycyclohexane), di (3,4-epoxycyclohexylmethyl) ether, ethylene bis 3,4-epoxycyclohexanecarboxylate), dioctyl epoxycyclohexahydrophthalate, di-2-ethylhexyl epoxycyclohexahydrophthalate, 1,4-butanediol diglycidyl ether, 1,6-hexanediol diglycidyl ether , Neopentyl glycol diglycidyl ether, trimethylolpropane triglycidyl ether, polyethylene glycol diglycidyl ether, glycerin triglycidyl ether, polypropylene glycol diglycidyl ethers; one kind of aliphatic polyhydric alcohol such as ethylene glycol, propylene glycol, glycerin Or polyglycidyl ethers of polyether polyols obtained by adding two or more alkylene oxides; Diglycidyl esters of basic acids; monoglycidyl ethers of higher aliphatic alcohols; monoglycidyl ethers of polyether alcohols obtained by adding phenol, cresol, butylphenol or alkylene oxide; epoxies such as glycidyl esters of higher fatty acids Based monomers. These may be used singly or in combination of two or more. Moreover, you may use the oligomer and polymer which superposed | polymerized these.

Examples of the acrylic photocurable resin include isobornyl acrylate, isobornyl methacrylate, zinc cropentanyl acrylate, 2-hydroxyethyl acrylate, 2-hydroxypropyl acrylate, propylene glycol acrylate, diethylene glycol diacrylate, diethylene glycol dimethacrylate, Triethylene glycol diacrylate, triethylene glycol dimethacrylate, polyethylene glycol diacrylate, 1,3-butylene glycol diacrylate, 1,3-butylene glycol dimethacrylate, 1,4-butanediol diacrylate, 1,4-butanediol Dimethacrylate, tripropylene glycol diacrylate, tripropylene glycol dimethacrylate, Ripropylene glycol diacrylate, 1,6-hexanediol diacrylate, 1,6-hexanediol dimethacrylate, neopentyl glycol diacrylate, neopentyl glycol dimethacrylate, diethylene glycol diacrylate, bis (oxymethyl) tricyclo [5.2 1.02,6] decanediacrylate, bis (oxymethyl) tricyclo [5.2.1.02,6] decanedimethacrylate, bis (oxymethyl) pentacyclo [6.5.1.13, 6.02 , 7.09,13] pentadecane dimethacrylate, bis (oxymethyl) pentacyclo [6.5.1.13, 6.02, 7.09,13] pentadecane dimethacrylate, 2,2-bis (4- (acrylic) Oxydiethoxy) phenyl) pro 2,2-bis (4- (methacryloxydiethoxy) phenyl) propane, tricyclo [5.2.1.02,6] decane-3,8-diyldimethyldiacrylate, tricyclo [5.2.1 .02,6] decane-3,8-diyldimethyldimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, trimethylolpropane ethoxytriacrylate, trimethylolpropane ethoxytrimethacrylate, tetramethylolmethane triacrylate, tetra Methylol methane trimethacrylate, tetramethylol methane tetraacrylate, tetramethylol methane tetramethacrylate, pentaerythritol triacrylate, pentaerythritol trimethacrylate, pen Taerythritol tetraacrylate, pentaerythritol tetramethacrylate, ditrimethylolpropane tetraacrylate, ditrimethylolpropane tetramethacrylate, dipentaerythritol hexaacrylate, dipentaerythritol hexamethacrylate, tris (2-hydroxyethyl) isocyanate triacrylate, tris (2-hydroxy And acrylic monomers such as ethyl) isocyanurate trimethacrylate.
These may be used singly or in combination of two or more. Moreover, you may use the oligomer and polymer which superposed | polymerized these.

  The actual products of the photo-curing resin include, for example, DEMEC SCR712X, SCR735, SCR737, SCR780, SCR785, SCR955, KC1281, Seaforce's DWS resin DL360, Seamet's TSR-883W, TSR -884B, TSR-832, DMS's Somos NanoTool, and the like.

  As for content of photocurable resin, 50 mass%-72 mass% are preferable with respect to the total mass of the composition for optical modeling.

(Inorganic filler)
As the inorganic filler, a layered silicate compound may be used. Here, the layered silicate compound is a particle in which a plate-like or scaly crystal is layered or a particle in which a layer is peeled off to form a plate-like or scale-like, for example, , Talc, silica, mica, montmorillonite, bentonite, organic bentonite, hectorite, beidellite, vermiculite, saponite, nontronite, bolcon scoreite, magatite, kenyaite, sericite, kaolinite, halloysite, dickite, nacrite, allophane, imogolite , Pyrophyllite, smectite, chlorite, serpentine, sepiolite, and palygorskite. Among these, those selected from the group consisting of talc, silica, mica, and mixtures obtained by appropriately combining these are preferable.
Spherical particles such as spherical silica and spherical silicone resin that do not have a layer-to-layer boundary are excluded. Needle-like ones (for example, wollastonite) are also excluded.

The layered silicate compound preferably has a particle size of 1 μm to 50 μm, and more preferably 4 μm to 10 μm.
When the particle size of the layered silicate compound is 1 μm or more, it is advantageous in that the viscosity of the optical modeling composition is prevented from becoming too high. On the other hand, when the particle diameter of the layered silicate compound is 50 μm or less, it is advantageous in that the thickness per layer of the shaped article is reduced.

The content of the layered silicate compound is preferably 20% by mass to 30% by mass with respect to the total mass of the optical modeling composition.
When the content of the layered silicate compound is 20% by mass or more, it is advantageous in that the mechanical properties of the molded article are increased in a high temperature environment. On the other hand, when the content of the layered silicate compound is 30% by mass or less, it is advantageous in that the viscosity of the optical modeling composition is prevented from becoming too high.

(Additive)
As an additive, a compound having an amide bond and a C═C unsaturated double bond in the molecule may be used.
Here, the amide bond is a bond of a carbonyl group and nitrogen, but includes —NH—C (═O) — or> NC (═O) — in the bond unit.
Such an additive is preferably at least one selected from, for example, N-vinylformamide (NVFA) represented by the following chemical formula 3 and 4-acrylomorpholine (4AMP) represented by the chemical formula 4.

Of these, N-vinylformamide is particularly preferable.

  The content of the additive is preferably 8 to 20% by mass. When it is 8% by mass or more, it is advantageous in that the viscosity of the optical shaping composition is lowered. On the other hand, when the addition amount is 20% by mass or less, it is advantageous in that the mechanical properties of the modeled object in a high-temperature environment are prevented from becoming too low.

(Photopolymerization initiator)
The composition for optical modeling may contain a photopolymerization initiator.
The photopolymerization initiator is a compound that absorbs light and generates a polymerization initiating species (for example, radical, cation).
Known compounds can be used as the photopolymerization initiator. Examples of photopolymerization initiators include carbonyl compounds such as aromatic ketones, acylphosphine oxide compounds, aromatic onium salt compounds, organic peroxides, thio compounds, oxime ester compounds, azo compounds, alkylamine compounds, onium salts , Sulfonium salts, phosphonium salts, pyridinium salts, and the like.
These photopolymerization initiators may be used alone or in combination of two or more.
The photopolymerization initiator may be added separately from the photocurable resin. For example, if the photopolymerization initiator is commercially available as a photocurable resin containing a photopolymerization initiator, the photopolymerization initiator and the photopolymerization resin are used. An initiator may be added simultaneously.

(Method for producing composition for optical modeling)
In order to manufacture the composition for optical modeling, it is preferable to mechanically mix an inorganic filler and an additive in a liquid granular form with a liquid photocurable resin. For example, even when using a mixing device such as a tumbler, ribbon mixer, Henschel mixer, etc., a liquid photocurable resin and a powdered layered silicon salt compound are placed in a container and manually stirred, vibrated, etc. You may mix evenly.

EXAMPLES Hereinafter, although an Example and a comparative example are given and this invention is demonstrated further more concretely, this invention is not limited only to these Examples.
In the following examples and comparative examples, the case where an acrylic photocurable resin is used as the photocurable resin will be described.
[Method for evaluating composition for stereolithography]
In measuring the physical properties of the optical modeling composition, the viscosity (mPa · s) is measured for each optical modeling composition in an environment of 20 ° C., which is an environment at the time of modeling. After modeling using a storage modulus (MPa) was measured in an air atmosphere at 150 ° C.

<Measurement method of viscosity>
Measurement model: Rotational viscometer TV-22 type viscometer Cone plate type (manufactured by Toki Sangyo Co., Ltd.)
Measurement method: The sample was filled between the cone rotor and the plate, and the viscosity of the sample was measured by measuring the resistance value at a predetermined rotational speed.
Measurement conditions: cone rotation speed 2.5rpm
Numerical value reading conditions 90 seconds have passed since the rotation started and the numerical value is stable.
Temperature condition 20.0 ℃

<Method for measuring storage modulus>
Measurement model: Solid viscoelasticity measuring device DMA Q800 (TA Instrument)
Measurement method: In a three-point bending mode, a strain that changes periodically (Sin curve, 1 Hz) was given to the sample, and the storage elastic modulus was calculated by measuring the displacement and load at that time.
Measurement conditions: Sample shape 14.0 mm × 3.0 mm × 1.0 mmt
Temperature condition 150 ° C
Atmosphere Air atmosphere

[result]
Based on the viscosity and storage elastic modulus obtained by the above measurement method, evaluation was performed according to the following criteria.
First, from the viewpoint of increasing modeling speed and modeling accuracy, it is desirable that the viscosity be as low as possible in the environment during modeling. For this reason, when the modeling table is lowered (sedimented) or raised by several tens of μm, which is the stacking pitch, the composition for optical modeling is smoothly supplied to the surface (upper surface or lower surface) of the cured layer to obtain a uniform thickness. In order to be able to form a liquid layer, the viscosity was set to be less than 2000 mPa · s, more preferably less than 1000 mPa · s, at 20 ° C., which is an environment during modeling. In addition, the viscosity was evaluated as A less than 1000 mPa · s, B as 1000 mPa · s or more and less than 2000 mPa · s, and C as 2000 or more mPa · s.

  Next, since the modeling object modeled using each optical modeling composition needs to have mechanical properties that have no practical problems at high temperatures (under 150 ° C.), the modeling object is stored at 150 ° C. The conforming condition was that the elastic modulus was 2000 MPa or more, more preferably 2700 MPa or more. In addition, the storage elastic modulus evaluated 2700 MPa or more as A, 2000 MPa or more and less than 2700 MPa as B, and less than 2000 MPa as C.

  The evaluation results are as follows: A is excellent, C is inferior, the viscosity and storage modulus are inferior, the evaluation result is A or B, and the evaluation result is C. .

The above-described evaluation was performed based on an optical modeling composition (Comparative Example 1) consisting only of a base resin, and an optical modeling composition (Comparative Example 2) in which only a layered silicate compound was added as an inorganic filler to the base resin. Stereolithography composition obtained by blending a base resin with a layered silicate compound as an inorganic filler, and further blending an additive that is a compound having an amide bond and a C = C unsaturated double bond in the molecule Compound (Examples 1 to 10) and a base resin compounded with a layered silicate compound as an inorganic filler, and an addition that is a compound having no amide bond and no C = C unsaturated double bond in the molecule Table 1 shows the results obtained with respect to the composition for optical modeling (Comparative Examples 3 to 5) obtained by blending the agent.
In addition, the acrylic photocurable resin in the following Table 1 is a resin composition containing 60% by mass of an acrylic monomer, 5% by mass of a photopolymerization initiator, and 35% by mass of other components.

The types of fillers in Table 1 are as follows.
SJ-010: muscovite (mica) (mascobite MUSCOVITE), average particle size 10 μm, average aspect ratio 20; manufactured by Yamaguchi Mica Co., Ltd. FH106: talc average particle size 6 μm; manufactured by Fuji Talc Kogyo Co., Ltd. Particle diameter 4.1μm; manufactured by AGC S-Tech Co., Ltd.

Moreover, in the additive of Table 1, an additive is as follows.
A-HD-N: 1,6-hexanediol diacrylate (1,6-Hexaned
iol Diacrylate); Shin-Nakamura Chemical Co., Ltd.

NVFA: N-Vinylformamide represented by Chemical Formula 6; manufactured by Tokyo Chemical Industry Co., Ltd.

4AMP: 4-Acryloylmorpholine represented by Chemical Formula 7; manufactured by Tokyo Chemical Industry Co., Ltd.

IBA: Isobornyl Acrylate represented by Chemical Formula 8; manufactured by Tokyo Chemical Industry Co., Ltd.

A-DOD-N: 1,10-decanediol diacrylate represented by chemical formula 9; manufactured by Shin-Nakamura Chemical Co., Ltd.

Examples 1 to 5 are examples showing that the effect can be obtained even when the contents of the inorganic filler (mica) and the additive (NVFA) are changed to give a width.
Examples 6-7 are examples which show that an inorganic filler (talc, silica) other than 10 μm plate-like mica is also effective.
Examples 8 to 10 are examples in which another compound (4AMP) having an amide bond and a C═C unsaturated double bond in the molecule was used as an additive.
Comparative Example 1 is an example in which neither an inorganic filler nor an additive is added to the base resin.
Comparative Example 2 is an example in which only an inorganic filler (mica) is added to the base resin.
Comparative Examples 3 to 5 are examples using compounds that are not “compounds having an amide bond and a C═C unsaturated double bond in the molecule”.

(Evaluation)
As can be seen from Table 1, "NVFA" and "4AMP", which are "compounds having an amide bond and a C = C unsaturated double bond in the molecule", all show an effect. (The viscosity at 20 ° C. is less than 2000 mPa · s, and the storage elastic modulus at 150 ° C. is 2000 MPa or more).
When A-HD-N which is not a “compound having an amide bond and a C═C unsaturated double bond in the molecule” is used, the viscosity cannot be lowered so much and is adopted as a composition for stereolithography. It was impossible. In addition, IBA and A-DOD-N which are not “compounds having an amide bond and a C═C unsaturated double bond in the molecule” were able to have a viscosity of 1000 mPa · s, but at the same time the storage elastic modulus was large. The mechanical properties at high temperatures could not be satisfied due to the decrease.

  For NVFA and 4AMP, which are “compounds having an amide bond and a C═C unsaturated double bond in the molecule”, Examples 3 and 8, Examples 4 and 9, and Examples 5 and 10 have the same conditions. When comparing the evaluations of Examples 3, 4 and 5 (Examples of NVFA), the viscosity tends to be lower and the storage elastic modulus tends to be higher. In addition, when the additive content is increased, the viscosity also decreases. However, with 4AMP, the storage modulus tends to decrease as the additive content increases. With NVFA, the additive content increases. When the amount is increased, the storage elastic modulus may be higher than when the content of the reducing agent is small. From this, it is considered that NVFA is superior in the effect of increasing the storage elastic modulus at a high temperature while maintaining a low viscosity.

In the above description, an example in which an acrylic photocurable resin is used as the photocurable resin is shown. However, when photocuring, the terminal vinyl group of NVFA or 4AMP is a monomer of the photocurable resin. Reacted to form a polymer with NVFA or 4AMP residues incorporated at the terminal, and the N portion of NC = O of this NVFA residue or 4AMP residue and the OH on the surface of the inorganic filler should be hydrogen bonded. It is thought that the storage elastic modulus after curing is improved (decrease in the storage elastic modulus is suppressed), and so long as the structure is such that NVFA or 4AMP is taken in, the same applies to photocurable resins other than acrylic. It is thought that the effect of is expressed.

Claims (5)

  A photolithographic composition comprising a photocurable resin, an inorganic filler, and an additive which is a compound having an amide bond and a C═C unsaturated double bond in the molecule.   The composition for optical modeling according to claim 1, wherein the additive is at least one selected from N-vinylformamide and 4-acrylomorpholine.   The composition for optical modeling according to claim 1 or 2, wherein the inorganic filler is a layered silicate compound.   The composition for stereolithography according to claim 3, wherein the layered silicate compound is selected from the group consisting of talc, silica, mica, and a mixture thereof. The composition for optical modeling according to any one of claims 1 to 4, wherein the viscosity at 20 ° C is less than 2000 mPa · s, and the storage elastic modulus at 150 ° C is 2000 MPa or more.