JP7434745B2 - Active energy ray-curable composition, cured product, and method for producing cured product - Google Patents

Description

The present invention relates to an active energy ray-curable composition, a cured product, and a method for producing the cured product.

A technique called additive manufacturing (AM) is known as a technique for modeling three-dimensional objects.
This technique is a technique for modeling a three-dimensional object by calculating the cross-sectional shape of a thin slice in the layering direction, forming each layer according to that shape, and laminating them.
In recent years, among the additive manufacturing technologies, a three-dimensional solid object is created by placing a photocurable composition in the required location using an inkjet head and curing the placed photocurable composition with a light irradiation device. Material jetting methods are already known.

For example, Patent Document 1 discloses that, for the purpose of forming a stereolithographic product with excellent mechanical properties, the homopolymer has a glass transition temperature of 80°C or higher and a monofunctional ethylenically unsaturated monomer having no urethane group. (A), a polyfunctional ethylenically unsaturated monomer (B) whose homopolymer has a glass transition temperature of 200° C. or higher and which does not have a urethane group, an ethylenically unsaturated monomer (C) having a urethane group; ) and a photopolymerization initiator (D), an ink composition for optically shaped articles having excellent heat resistance and tensile strength is disclosed.

However, conventional material jetting methods have been mainly used for prototyping purposes, but three-dimensional objects manufactured using conventional materials often have low tensile strength and/or impact resistance, making it difficult to create prototypes. There was a problem with the performance not meeting the required performance.
An object of the present invention is to provide an active energy ray-curable composition for producing three-dimensional objects, which has both high tensile strength and high impact resistance.

The active energy ray-curable composition of the present invention that solves the above problems is as follows.
(1) An active energy ray-curable composition containing each of the following components (A) to (D), expressed as [total number of polymerizable functional groups in the composition/total number of moles of all polymerizable compounds]. An active energy ray-curable composition having a degree of crosslinking of 1.13 to 1.20.
(A) Radically polymerizable monofunctional monomer (B) Soft crosslinking agent (polyfunctional monomer)
(C) Hard radically polymerizable oligomer (D) Polymerization initiator

According to the present invention, it is possible to provide an active energy ray-curable composition that has both high tensile strength and high impact resistance.

It is a schematic diagram showing a modeling device concerning one embodiment of the present invention.

The present invention (1) below will be described in detail below, but since the embodiments thereof also include the following (2) to (8), these will also be described.
(1) An active energy ray-curable composition containing each of the following components (A) to (D), expressed as [total number of polymerizable functional groups in the composition/total number of moles of all polymerizable compounds]. An active energy ray-curable composition having a degree of crosslinking of 1.13 to 1.20.
(A) Radically polymerizable monofunctional monomer (B) Soft crosslinking agent (polyfunctional monomer)
(C) Hard radically polymerizable oligomer (D) Polymerization initiator (2) The active energy ray-curable type according to (1) above, wherein the component (C) has a glass transition temperature (Tg) higher than 0°C. Composition.
(3) The active energy ray-curable composition according to (1) or (2) above, wherein the component (C) is a urethane oligomer.
(4) The active energy ray-curable composition according to any one of (1) to (3) above, wherein the component (A) is a radically polymerizable monofunctional monomer having an elastic modulus of 100 MPa or more.
(5) The active energy ray-curable composition according to any one of (1) to (4) above, wherein the component (A) has a glass transition temperature (Tg) higher than 0°C.
(6) The active energy ray-curable composition according to any one of (1) to (5) above, wherein the component (A) is an acrylic monomer.
(7) A cured product of the active energy ray-curable composition according to any one of (1) to (6) above.
(8) A method for producing a cured product, comprising the step of irradiating the active energy ray-curable composition according to any one of (1) to (6) with active energy rays.

The present invention contains each of the following components (A) to (D), and has a degree of crosslinking expressed by "total number of polymerizable functional groups in the composition/total number of moles of all polymerizable compounds" from 1.13 to It is an active energy ray curable composition with a value of 1.20.
(A) Radically polymerizable monofunctional monomer (B) Soft crosslinking agent (polyfunctional monomer)
(C) Hard radically polymerizable oligomer (D) Polymerization initiator In other words, the tensile strength is improved by containing a hard radically polymerizable oligomer, and the impact resistance is improved by containing a soft crosslinking agent, and By setting the degree of crosslinking = total number of polymerizable functional groups in the composition / total number of moles of all polymerizable compounds to a value of 1.13 to 1.20, tensile strength and impact resistance properties can be prevented from being significantly impaired. It is possible to achieve both at a high level.

When a monomer with a glass transition temperature exceeding 0° C. is used as a polyfunctional monomer, as in the model material for forming a stereolithographic article described in JP-A-2016-20474, the impact resistance becomes low.

In the present invention, "hard" means that the polymer has high hardness as a property, and "hard" of a monomer means that the polymer obtained when the monomer is polymerized is a polymer with high hardness. say. Conversely, "soft" means that the hardness is low as a property of the polymer, and the fact that a monomer is "soft" means that the polymer obtained when the monomer is polymerized is a polymer with low hardness. Criteria for determining "hardness" are well known in the art, and those skilled in the art can easily determine whether a polymer is "hard" or "soft." Known hardness criteria typically include direct indicators such as pencil hardness, Mohs hardness, and Vickers hardness, as well as indirect indicators such as glass transition temperature and elastic modulus. For example, in the case of pencil hardness, if the hardness is 4B or more, it can be determined to be "hard", and if the hardness is smaller than that, it can be determined to be "soft". For example, when it comes to glass transition temperature, it can be determined that a material is "hard" if it is higher than 0.degree. C., and "soft" if it is lower than 0.degree. For example, in terms of elastic modulus, if the elastic modulus is 100 MPa or more, it can be determined that the material is "hard," and if the elastic modulus is less than 100 MPa, it can be determined that it is "soft." In one preferred embodiment, the monomer or polymer is determined to be "hard" if it is determined to be "hard" in any of the values of pencil hardness, glass transition temperature, and elastic modulus. In this case, if the pencil hardness is 5B or less, the glass transition temperature is 0°C or less, and the elastic modulus is less than 100 MPa, it can be determined to be "soft". In a preferred embodiment, the monomer or polymer is determined to be "soft" if it is not determined to be "hard" in any of the values of pencil hardness, glass transition temperature, and elastic modulus.
In the present invention, the pencil hardness, glass transition temperature, and elastic modulus of the component of the composition are the pencil hardness, glass transition temperature, and elastic modulus of the homopolymer of the component.
Examples of methods for measuring pencil hardness include the method described in JIS K-5600. Examples of the method for measuring the glass transition temperature include the method described in JIS K-7121-1987. Examples of the method for measuring the elastic modulus include the method described in JIS K 7161-1994 4.6.

Each of the components (A) to (D) of the active energy ray-curable composition of the present invention will be explained below.

<(A) Radically polymerizable monofunctional monomer>
The composition of the present invention contains a radically polymerizable monofunctional monomer as component (A). A radically polymerizable monofunctional monomer is a monomer unit in which one radically polymerizable functional group is bonded to a low molecular weight compound. Examples of the radically polymerizable monofunctional monomer (A) that can be used in the present invention include acrylic monomers and epoxy monomers, and it is particularly preferable to include acrylic monomers. Acrylic monomers have a fast curing speed and are suitable for inkjet printing.
Examples of the acrylic monomer include acrylamide, N,N-dimethylacrylamide, N-isopropylacrylamide, acryloylmorpholine, hydroxyethylacrylamide, isobornyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, and 2-hydroxyethyl (meth)acrylate. ) acrylate, 2-hydroxypropyl (meth)acrylate, caprolactone-modified tetrahydrofurfuryl (meth)acrylate, 3-methoxybutyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, lauryl (meth)acrylate, 2-phenoxyethyl ( Examples include meth)acrylate, isodecyl(meth)acrylate, isooctyl(meth)acrylate, tridecyl(meth)acrylate, caprolactone(meth)acrylate, and ethoxylated nonylphenol(meth)acrylate.
These may be used alone or in combination of two or more.

The component (A) may be either soft or hard as long as a predetermined degree of crosslinking can be achieved. The hard radically polymerizable monofunctional monomer preferably has a pencil hardness of 4B or higher, an elastic modulus of 100 MPa or higher, or a glass transition temperature (Tg) higher than 0°C. Whether using a hard radically polymerizable monofunctional monomer or a soft radically polymerizable monofunctional monomer, the desired degree of crosslinking can be achieved by adjusting the ratio of the amounts of the crosslinking agent and the radically polymerizable oligomer. do it.
The radically polymerizable monofunctional monomer suitably used in the present invention includes, but is not limited to, acryloylmorpholine, cyclic trimethylolpropane formal acrylate, and the like.

Further, the content of component (A) in the resin composition is preferably 40% by mass or more and 90% by mass or less, more preferably 50% by mass or more and 70% by mass or less. (A) By including the radically polymerizable monofunctional monomer, the viscosity of the composition can be reduced. Therefore, the composition of the present invention has a viscosity low enough to be used in inkjet applications.

<(B) Soft crosslinking agent (polyfunctional monomer)>
The composition of the present invention contains a soft crosslinking agent as component (B). A crosslinking agent is a monomer unit in which a plurality of polymerizable functional groups (preferably radically polymerizable functional groups) are bonded to one molecule, and has the same meaning as a "polyfunctional monomer" in the present invention. The polyfunctional monomer that can be used as component (B) is not particularly limited as long as it is flexible and can be selected as appropriate depending on the purpose. Examples include bifunctional monomers, trifunctional or higher functional monomers, etc. . These may be used alone or in combination of two or more.
Examples of soft bifunctional monomers include triethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, neopentyl glycol hydroxypivalate di(meth)acrylate, and hydroxypivalin. Acid neopentyl glycol ester di(meth)acrylate, 1,3-butanediol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9 - Nonanediol di(meth)acrylate, diethylene glycol di(meth)acrylate, neopentyl glycol di(meth)acrylate, tripropylene glycol di(meth)acrylate, tricyclodecane dimethanol di(meth)acrylate, caprolactone-modified hydroxypivalic acid Neopentyl glycol ester di(meth)acrylate, propoxylated opentyl glycol di(meth)acrylate, ethoxy-modified bisphenol A di(meth)acrylate, polyethylene glycol 200 di(meth)acrylate, polyethylene glycol 400 di(meth)acrylate, etc. Can be mentioned.

Examples of soft trifunctional or higher functional monomers include trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, dipentaerythritol hexa(meth)acrylate, triallylisocyanurate, and ε-caprolactone-modified dipentaerythritol. tri(meth)acrylate, ε-caprolactone modified dipentaerythritol tetra(meth)acrylate, (meth)acrylate, ε-caprolactone modified dipentaerythritol penta(meth)acrylate, ε-caprolactone modified dipentaerythritol hexa(meth)acrylate, Tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, ethoxylated trimethylolpropane tri(meth)acrylate, propoxylated trimethylolpropane tri(meth)acrylate, propoxylated glyceryl tri(meth)acrylate, pentaerythritol tetra( Examples include meth)acrylate, ditrimethylolpropane tetra(meth)acrylate, dipentaerythritol hydroxypenta(meth)acrylate, ethoxylated pentaerythritol tetra(meth)acrylate, and penta(meth)acrylate ester.

<(C) Hard radically polymerizable oligomer>
The composition of the present invention contains a hard radically polymerizable oligomer as component (C). As the hard radically polymerizable oligomer, one type having a reactive unsaturated bond group at the terminal may be used alone, or two or more types may be used in combination. Further, the content is preferably 1.0% by mass or more and 40.0% by mass or less, more preferably 10.0% by mass or more and 30.0% by mass or less.
Oligomer is a general term for molecules having a repeating structure of molecules with a small molecular weight, and the number of repeating structures is generally about 2 to 20. The radically polymerizable oligomer of the present invention typically refers to a monomer unit having a radically polymerizable functional group at the end of a small-molecule oligomer. For example, "urethane acrylate oligomer" means a molecule in which a plurality of molecules having urethane groups are connected and an acrylate group is bonded to the end.
The radically polymerizable oligomer preferably includes a urethane acrylate oligomer from the viewpoint of easily obtaining high toughness due to interaction between side chains. By containing a radically polymerizable oligomer, the produced cured product generally has improved stretchability.
Note that each monomer unit (components (A) to (C)) of the present invention preferably has a radically polymerizable functional group as a functional group. Radically polymerizable functional groups have a faster polymerization rate and lower viscosity than photocationic polymerizable functional groups, and therefore can be suitably used for inkjet applications.

<(D) Polymerization initiator>
As the polymerization initiator, a polymerization initiator corresponding to the polymerizable functional group of each component can be used. Typically, any substance that generates radicals upon irradiation with light (especially ultraviolet light with a wavelength of 220 nm to 400 nm) can be used. The polymerization initiators may be used alone or in combination of two or more. Further, the content is preferably 0.1% by mass or more and 10.0% by mass or less, more preferably 1.0% by mass or more and 5.0% by mass or less.
Examples of the polymerization initiator include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-dichlorobenzophenone, p,p-bisdiethylaminobenzophenone, Michler's ketone, and benzyl. , benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-propyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl methyl ketal, thioxanthone, 2-chlorothioxanthone, 2-hydroxy-2-methyl -1-phenyl-1-one, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropan-1-one, methylbenzoylformate, 1-hydroxycyclohexylphenylketone, azobisisobutyronitrile, benzoyl Examples include peroxide, di-tert-butyl peroxide, diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide, and the like.

<Other ingredients>
The active energy ray-curable composition of the present invention contains components other than (A) a radically polymerizable monofunctional monomer, (B) a soft crosslinking agent, (C) a hard radically polymerizable oligomer, and (D) a polymerization initiator. May include. There are no particular restrictions on such components, and they can be appropriately selected depending on the purpose, and include, for example, surfactants, polymerization inhibitors, colorants, and the like.

Examples of surfactants include molecular weights of 200 or more and 5000 or less, specifically, PEG-type nonionic surfactants [ethylene oxide (hereinafter abbreviated as EO) 1-40 mole adduct of nonylphenol, stearic acid EO1-40 molar adducts, etc.], polyhydric alcohol-type nonionic surfactants (sorbitan palmitate monoester, sorbitan stearate monoester, sorbitan stearate triester, etc.), fluorine-containing surfactants (perfluoroalkyl EO 1 to 50 mole adducts) (meth)acrylate-modified silicone oil, etc.), and modified silicone oils (polyether-modified silicone oil, (meth)acrylate-modified silicone oil, etc.). These may be used alone or in combination of two or more.

Examples of polymerization inhibitors include phenolic compounds [hydroquinone, hydroquinone monomethyl ether, 2,6-di-t-butyl-p-cresol, 2,2-methylene-bis-(4-methyl-6-t-butylphenol)] , 1,1,3-tris-(2-methyl-4-hydroxy-5-t-butylphenyl)butane, etc.], sulfur compounds [dilaurylthiodipropionate, etc.], phosphorus compounds [triphenylphosphite, etc.] , amine compounds [phenothiazine, etc.], and the like. These may be used alone or in combination of two or more.

Suitable colorants include dyes and pigments that can be dissolved or stably dispersed in the active energy ray-curable composition and have excellent thermal stability. Among these, soluble dyes are preferred. Moreover, it is possible to mix two or more types of colorants as appropriate for color adjustment, etc.

<Organic solvent>
The active energy ray-curable composition of the present invention may contain an organic solvent, but it is preferable not to contain it if possible. If the composition does not contain organic solvents, especially volatile organic solvents (VOC (Volatile Organic Compounds) free), the safety of the place where the composition is handled will be increased, and it will be possible to prevent environmental pollution. . Note that "organic solvent" refers to general non-reactive organic solvents such as ether, ketone, xylene, ethyl acetate, cyclohexanone, and toluene, and should be distinguished from reactive monomers. be. Moreover, "not containing" an organic solvent means substantially not containing it, and preferably less than 0.1% by mass.

<Preparation of active energy ray curable composition>
The active energy ray-curable composition of the present invention can be prepared using the various components described above, and the preparation means and conditions are not particularly limited. ℃ or less, a radically polymerizable oligomer with an elastic modulus of 100 MPa or more, a pigment, a dispersant, etc., are placed in a dispersing machine such as a ball mill, Kitty mill, disc mill, pin mill, or Dyno mill, and dispersed to prepare a dispersion liquid. It can be prepared by further mixing a polymerization initiator, a polymerization inhibitor, a surfactant, etc. with the dispersion.

A composition that can be used for inkjet applications preferably has a low viscosity in view of ejection properties from a nozzle. Therefore, in one embodiment, the viscosity of the active energy ray-curable composition of the present invention is preferably 200 mPa·s or less, more preferably 150 mPa·s or less in a 25° C. environment. Further, from the viewpoint of discharge performance and modeling accuracy, it is preferable that the pressure is 9 mPa·s or more in a 25° C. environment. Note that during modeling, the viscosity of the active energy ray-curable composition can be adjusted by adjusting the temperature of the inkjet head and the ink flow path.
Note that the above-mentioned viscosity can be measured by a conventional method, for example, the method described in JIS Z 8803 can be used. In addition, for example, a cone rotor (1°34' x R24) is used with a cone plate rotational viscometer VISCOMETER TVE-22L manufactured by Toki Sangyo Co., Ltd., the rotation speed is 50 rpm, and the temperature of constant temperature circulating water is 20 ° C. The temperature can be appropriately set and measured within the range of 65°C. VISCOMATE VM-150III can be used to adjust the temperature of circulating water.

Furthermore, in view of ejection stability, modeling accuracy, etc., the composition that can be used for inkjet applications preferably has a surface tension in the range of 20 to 40 mN/m in an environment of 25°C. Therefore, in one embodiment, the active energy ray-curable composition of the present invention has a surface tension of 20 to 40 mN/m in an environment of 25°C.
Note that surface tension can be measured by a conventional method, and examples of such measurement methods include a plate method, a ring method, and a pendant drop method.

The resin compound of the present invention is obtained by curing the active energy ray-curable composition of the present invention by irradiating it with active energy rays.
The method for producing a resin compound of the present invention includes the step of irradiating the active energy ray-curable composition of the present invention with active energy rays.

<Active energy rays>
The active energy ray used for curing the active energy ray-curable composition of the present invention is preferably light, particularly ultraviolet light having a wavelength of 220 nm to 400 nm. In addition to ultraviolet rays, any energy such as electron beams, α rays, β rays, γ rays, X rays, etc. can be used as long as it can impart the energy necessary to proceed with the polymerization reaction of the polymerizable components in the composition, and is not particularly limited. . In particular, when a high-energy light source is used, the polymerization reaction can proceed without using a polymerization initiator. Furthermore, in the case of ultraviolet irradiation, mercury-free devices are strongly desired from the viewpoint of environmental protection, and replacement with GaN-based semiconductor ultraviolet light-emitting devices is very useful both industrially and environmentally. Furthermore, ultraviolet light emitting diodes (UV-LEDs) and ultraviolet laser diodes (UV-LDs) are compact, long-life, highly efficient, and low-cost, and are preferred as ultraviolet light sources.

Hereinafter, a method for manufacturing a three-dimensional object using the active energy ray-curable composition of the present invention as a material for forming a model part and a manufacturing apparatus will be described. However, the use of the active energy ray-curable composition of the present invention is not limited to these embodiments.

<Modeling device>
FIG. 1 is a schematic diagram showing a modeling apparatus according to an embodiment of the present invention. The modeling device 30 includes head units 31 and 32, an ultraviolet irradiator 33, a roller 34, a carriage 35, and a stage 37. The head unit 31 discharges the model part forming material 1. The head unit 32 discharges the support part forming material 2. The ultraviolet irradiator 33 irradiates the discharged model part forming material 1 and support part forming material 2 with ultraviolet rays to cure them. The roller 34 smoothes the liquid film of the model part forming material 1 and the support part forming material 2. The carriage 35 reciprocates the head units 31, 32 and other means in the X direction in FIG. The stage 37 moves the substrate 36 in the Z direction shown in FIG. 1 and in the Y direction, which is the depth direction in FIG. Note that the movement in the Y direction may be performed by the carriage 35 instead of the stage 37.

When there is a plurality of model part forming materials for each color, the modeling device 30 may be provided with a plurality of head units 31 for discharging the model part forming materials of each color.
As the nozzles in the head units 31 and 32, nozzles in known inkjet printers can be suitably used.

Examples of metals that can be used for the roller 34 include SUS300 series, 400 series, 600 series, hexavalent chromium, silicon nitride, and tungsten carbide. Furthermore, the roller 34 may be made of metal coated with any of these materials, such as fluorine or silicone. Among these metals, SUS600 series is preferred in terms of strength and workability.
When using the roller 34, the modeling device 30 stacks the objects while lowering the stage 37 according to the number of times of stacking in order to keep the gap between the roller 34 and the surface of the object constant. The roller 34 is preferably configured to be adjacent to the ultraviolet irradiator 33.

Further, in order to prevent the ink from drying during the pause, the modeling apparatus 30 may be provided with means such as a cap for closing the nozzles in the head units 31 and 32. Further, in order to prevent nozzle clogging during continuous use for a long period of time, the modeling device 30 may be provided with a maintenance mechanism for maintaining the head.

<Modeling method>
Hereinafter, the steps performed by the modeling device will be explained.
While moving the carriage 35 or the stage 37, the engine of the modeling device 30 moves the model part forming material 1 from the head unit 31 based on the two-dimensional data indicating the cross section on the bottom side of the input two-dimensional data. Droplets are discharged, and droplets of the support portion forming material 2 are discharged from the head unit 32.
As a result, a droplet of the model part forming material 1 is placed at a position corresponding to a pixel indicating the model part in the two-dimensional data showing the cross section on the most bottom surface side, and a droplet of the support part forming material 1 is placed at a position corresponding to the pixel indicating the support part. Two droplets are arranged, and a liquid film is formed in which the droplets at adjacent positions touch each other.
Note that when there is only one object to be modeled, a cross-sectional liquid film is formed in the center of the stage 37. When there are a plurality of objects to be modeled, the modeling device 30 may form liquid films with a plurality of cross-sectional shapes on the stage 37, or may stack the liquid films on the previously formed objects.

It is preferable that heaters be installed in the head units 31 and 32. Furthermore, it is preferable to install a preheater in the path for supplying the model part forming material to the head unit 31 and the path for supplying the support part forming material to the head unit 32.

In the smoothing process, the roller 34 scrapes off excess parts of the model part forming material and the support part forming material discharged onto the stage 37, thereby removing the liquid consisting of the model part forming material and the support part forming material. Smooth out the unevenness of the film or layer. The smoothing step may be performed once for each lamination in the Z-axis direction, or once for every 2 to 50 laminations.
In the smoothing process, the roller 34 may be stationary or may be rotating at a positive or negative relative speed with respect to the advancing direction of the stage 37. Further, the rotational speed of the roller 34 may be constant speed, constant acceleration, or constant deceleration. The rotation speed of the roller 34 is preferably 50 mm/s or more and 400 mm/s or less as an absolute value of the relative speed with the stage 37. If the relative velocity is too small, smoothing will be insufficient and smoothness will be impaired. Furthermore, if the relative velocity is too large, the device needs to be large-sized, and the ejected droplets are likely to be misaligned due to vibrations, etc., and as a result, smoothness may deteriorate.
In the smoothing process, it is preferable that the rotation direction of the roller 34 is opposite to the direction in which the head units 31 and 32 move.

In the curing process, the engine of the modeling device 30 moves the ultraviolet irradiator 33 using the carriage 35, and applies photopolymerization contained in the model part forming material and the support part forming material to the liquid film formed in the liquid film forming process. Irradiate ultraviolet light according to the wavelength of the initiator. Thereby, the modeling device 30 hardens the liquid film to form a layer.

After forming the bottommost layer, the engine of the modeling device 30 lowers the stage by one layer.
While moving the carriage 35 or the stage 37, the engine of the modeling device 30 discharges droplets of the model part forming material 1 based on the two-dimensional image data showing the second cross section from the bottom side, and forms the support part. Droplets of forming material 2 are ejected. The discharge method is the same as that for forming the liquid film on the bottom side. As a result, a liquid film having a cross-sectional shape indicated by the second two-dimensional data from the bottom side is formed on the layer closest to the bottom side. Further, the engine of the modeling device 30 moves the ultraviolet irradiation device 33 using the carriage 35 to irradiate the liquid film with ultraviolet rays, thereby curing the liquid film and depositing two layers from the bottom side onto the bottommost layer. Form the second layer.
The engine of the modeling device 30 uses the input two-dimensional data in order from the one closest to the bottom side, repeats the formation of a liquid film and hardening, and laminates layers in the same manner as described above. The number of repetitions varies depending on the number of input two-dimensional image data or the height, shape, etc. of the three-dimensional model. When the modeling using all the two-dimensional image data is completed, a model part supported by the support part is obtained.

The modeled object modeled by the modeler 30 has a model part and a support part. The support part is removed from the modeled object after modeling. Removal methods include physical removal and chemical removal. Physical removal involves applying mechanical force. On the other hand, in chemical removal, the support part is immersed in a solvent to disintegrate and be removed. Although there are no particular limitations on the method for removing the support portion, chemical removal is more preferable since physical removal may damage the modeled object. Furthermore, in consideration of cost, a method of removing by immersion in water is more preferable. When a method of removing by immersion in water is adopted, the cured material of the support part forming material is selected to be water-disintegratable.

As described above, the active energy ray-curable composition of the present invention can be suitably used for inkjet applications, particularly for producing three-dimensional objects by inkjet. Therefore, the present invention also includes three-dimensional objects formed using the active energy ray-curable composition of the present invention. The method for producing such a three-dimensional object is not particularly limited as long as an inkjet method is used, and examples thereof include the method detailed in the section of <Building method> above.

EXAMPLES Hereinafter, the present invention will be explained in more detail with reference to Examples, but the present invention is not limited to these Examples.

(Example 1)
<Preparation of photocurable composition>
Isobornyl acrylate (IBXA, Tg 88°C, manufactured by Osaka Organic Chemical Industry Co., Ltd.) 56 parts by mass, polypropylene glycol #400 diacrylate (trade name: APG-400, Tg -8°C, manufactured by Shin Nakamura Chemical Industry Co., Ltd.) 24 22 parts by mass of urethane acrylate oligomer (trade name: UV-6630B, Tg 38°C, manufactured by Mitsubishi Chemical Corporation) were uniformly mixed. Next, 4 parts by mass of diphenyl (2,4,6-trimethylbenzoyl)phosphine oxide (trade name: Omunirad TPO, manufactured by BASF) as a photopolymerization initiator was added and mixed uniformly. Next, the photocurable composition of Example 1 was obtained by passing through a filter (trade name: CCP-FX-C1B, manufactured by ADVANTEC, average pore size: 3 μm).
The number of moles of isobornyl acrylate, polypropylene glycol #400 diacrylate, and urethane acrylate oligomer in the composition was determined, and the degree of crosslinking was determined.

(Examples 2-3, Comparative Examples 1-8)
According to the formulation in Table 1, photocurable compositions of Examples 2 to 3 and Comparative Examples 1 to 8 were produced using the same production procedure as that of the photocurable composition of Example 1.
The unit of blending amount in Table 1 is parts by mass.

The obtained photocurable composition was evaluated as follows. The results are shown in Table 1.
(Strength)
A tensile test was performed on the test piece using a precision universal testing machine (Autograph AG-X, Shimadzu Corporation), and the stress at the maximum point was determined. Note that the test was conducted under the conditions of a tensile speed of 5 mm/min and a distance between tensile jigs of 50 mm.

(Elongation at break)
A tensile test was performed on the test piece using a precision universal testing machine (Autograph AG-X, Shimadzu Corporation), and the elongation rate of the test piece at break was determined. Note that the test was conducted under the conditions of a tensile speed of 5 mm/min and a distance between tensile jigs of 50 mm.

(Izod shock)
The energy required for destruction (J/m) was determined using a digital impact tester (Impact Tester IT, Toyo Seiki Seisakusho) using a hammer of 0.5 J and Izod test mode.

Details of the materials in Table 1 are as follows.
・(A) Radically polymerizable monofunctional monomer A-1: IBXA, isobornyl acrylate, Tg 88°C, molecular weight 208,
Manufactured by Osaka Organic Chemical Industry Co., Ltd. (B) Soft crosslinking agent (polyfunctional monomer)
B-1: APG-400, polypropylene glycol #400 diacrylate,
Tg -8°C, molecular weight 536, manufactured by Nakamura Chemical Industry Co., Ltd. B-2: APG-700, polypropylene glycol (#700) diacrylate,
Tg -32°C, molecular weight 808, manufactured by Nakamura Chemical Industry Co., Ltd. (b) Hard crosslinking agent (polyfunctional monomer)
b-1: APG-100, dipropylene glycol diacrylate, molecular weight 242,
Nakamura Chemical Industry Co., Ltd. b-2: APG-200, tripropylene glycol diacrylate, Tg 90°C,
Molecular weight 300, manufactured by Nakamura Chemical Industry Co., Ltd. (C) Hard radically polymerizable oligomer C-1: UV-6630B, UV-curable urethane acrylate oligomer,
Molecular weight 3000, number of oligomer functional groups 2, Tg 38°C,
Manufactured by Mitsubishi Chemical Corporation C-2: UV-7000B, UV-curable urethane acrylate oligomer,
Molecular weight 3500, number of oligomer functional groups 2-3, Tg 52°C,
Manufactured by Mitsubishi Chemical Corporation C-3: UV-7600B, UV-curable urethane acrylate oligomer,
Molecular weight 1400, number of oligomer functional groups 6, manufactured by Mitsubishi Chemical Corporation (c) Soft radically polymerizable oligomer c-1: UV-3300B, UV-curable urethane acrylate oligomer,
Molecular weight 13000, number of oligomer functional groups 2, manufactured by Mitsubishi Chemical Corporation (D) Polymerization initiator D-1: TPO, diphenyl (2,4,6-trimethylbenzoyl) phosphine oxide
Sid, Omunirad TPO, manufactured by BASF

From the results in Table 1, active energy ray-curable compositions containing a radically polymerizable monofunctional monomer, a hard radically polymerizable oligomer, and a soft crosslinking agent and having a degree of crosslinking of 1.13 to 1.20 have a high tensile strength. It can be seen that a stereolithographic product that has both strength and high impact resistance (Izod impact value) has been produced.

1 Model part forming material 2 Support part forming material 10 Model part 20 Support part 30 Modeling device (an example of a device for manufacturing a three-dimensional object)
31 Head unit (an example of discharge means)
32 Head unit (an example of discharge means)
33 Ultraviolet irradiation machine (an example of curing means)
34 roller 35 carriage 36 substrate 37 stage

Japanese Patent Application Publication No. 2016-20474

Claims (3)

An active energy ray-curable composition containing each of the following components (A) to (D), which has crosslinking expressed by [total number of polymerizable functional groups in the composition/total number of moles of all polymerizable compounds] The content of the following component (A) in the active energy ray-curable composition is 40% by mass or more and 90% by mass or less, and the content of the following component (C) is 1.13 to 1.20. An active energy ray-curable composition having a content of 10.0% by mass or more and 30.0% by mass or less .
(A) Isobornyl (meth)acrylate
(B) Polypropylene glycol di(meth)acrylate with a glass transition temperature of 0°C or less
(C) Urethane acrylate oligomer with a glass transition temperature higher than 0°C
(D) Polymerization initiator A cured product of the active energy ray-curable composition according to claim 1 . A method for producing a cured product, comprising the step of irradiating the active energy ray-curable composition according to claim 1 with active energy rays.

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