Stereoscopic modeling resin composition, stereoscopic modeling article manufacturing method, and stereoscopic modeling article

Abstract

Provided is a stereoscopic molding resin composition containing a multifunctional urethane (meth) acrylate having a molecular weight of 700 or more and 1,300 or less.

Description

Technical Field

[0001] This invention relates to resin compositions for three-dimensional modeling, methods for manufacturing three-dimensional models, and three-dimensional models. Background Technology

[0002] In recent years, 3D printing technology, which uses resin to create three-dimensional objects, has developed. 3D printers using this technology allow anyone to easily create three-dimensional objects, and with the decreasing price of 3D printers, they have become accessible even to ordinary households.

[0003] Among the aforementioned 3D printing technologies, the photolithography method uses a liquid photocurable resin composition, which has the characteristic of high precision in the appearance of the shaped object.

[0004] As such a photocurable resin composition, for example, an active energy ray-curable resin composition of urethane (meth) acrylate with a weight average molecular weight of 3,000 to 30,000 has been proposed, which is produced by reacting polycaprolactone polyol containing a number average molecular weight of 300 to 900, an aliphatic or alicyclic diisocyanate and a hydroxyl-containing (meth) acrylate (see, for example, Patent Document 1).

[0005] In addition, a film coating composition containing urethane (meth)acrylate containing polycaprolactone polyol with a molecular weight of 800 to 8,000 as a structural unit and a monofunctional (meth)acrylate with a glass transition temperature (Tg) of 90°C or higher after curing has been proposed (for example, see Patent Document 2).

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2017-88681

[0009] Patent Document 2: Japanese Patent Application Publication No. 2000-219821 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] However, the urethane (meth)acrylates used in the aforementioned patent documents 1 and 2 have different structures from the polyfunctional urethane (meth)acrylates used in this invention, and have large molecular weights and high viscosity, thus making them unsuitable for three-dimensional molding applications. Furthermore, the compositions in the aforementioned patent documents 1 and 2 contain low molecular weight monofunctional monomers with strong odor and skin irritation, and are therefore unsuitable for general household use.

[0012] Furthermore, in suspended light modeling techniques, such as Figure 1A and Figure 1B As shown, the linear guide 13 rises in the direction of the arrow, thereby shaping the three-dimensional object 12 along the direction of gravity relative to the shaping surface 11a of the shaping platform 11. This results in a problem where the three-dimensional object 12 is easily damaged in its thin-walled sections. Furthermore, in order to solidify the three-dimensional object in a short time, stress can easily remain within the object due to solidification shrinkage, causing damage during shaping. Additionally, Figure 1A and Figure 1B 14 is the arm, 15 is the UV light source, 16 is the molding groove, and 17 is the resin composition (liquid) for three-dimensional modeling.

[0013] The objective of this invention is to solve the aforementioned problems and achieve the following: This invention relates to a resin composition for three-dimensional molding that has low odor, excellent mechanical properties, and the ability to stably mold desired three-dimensional shapes; a method for manufacturing three-dimensional molded objects; and three-dimensional molded objects.

[0014] Methods for solving problems

[0015] The method for solving the above-mentioned problem is as follows. That is,

[0016] <1> A resin composition for three-dimensional modeling, characterized in that it contains a polyfunctional urethane (meth) acrylate with a molecular weight of 700 to 1,300.

[0017] <2> According to the resin composition for three-dimensional modeling described in <1> above, the above-mentioned polyfunctional urethane (meth) acrylate has a polycaprolactone backbone.

[0018] <3> According to the resin composition for three-dimensional modeling described in <2> above, the molecular weight of the polycaprolactone backbone is 500 or more and 1,000 or less.

[0019] <4> According to any one of <2> to <3> above, the polyfunctional urethane (meth) acrylate having the above-mentioned polycaprolactone backbone is either of the following general formula (1) and general formula (2).

[0020] [Chemistry 1]

[0021]

[0022] In the above general formula (1), R1 represents a straight-chain alkyl or straight-chain alkyl ether group, n1+n2 is an integer of 2 or more and 9 or less, and n3 is an integer of 1 or more.

[0023] [Chemistry 2]

[0024]

[0025] In the above general formula (2), R2 represents a branched alkyl group, m1+m2+m3 are integers of 3 to 9, and m4 is an integer of 1 or more.

[0026] <5> In any one of <1> to <4> above, the content of the polyfunctional urethane (meth) acrylate is 90% by mass or more relative to the total amount of the resin composition for three-dimensional modeling.

[0027] <6> The resin composition for three-dimensional modeling according to any one of <1> to <5> above contains a photopolymerization initiator.

[0028] <7> The resin composition for three-dimensional modeling according to any one of <1> to <6> above has a viscosity of 0.1 Pa·s or more and 10 Pa·s or less at 25°C.

[0029] <8> A method for manufacturing a three-dimensional object, characterized in that it is a method for manufacturing a three-dimensional object using light modeling, comprising the following steps:

[0030] A process of immersing a molding table in a molding tank containing any one of the resin compositions for three-dimensional modeling described in <1> to <7> above, and irradiating the molding surface of the molding table with active energy rays to cure the resin composition for three-dimensional modeling.

[0031] <9> According to the manufacturing method of the three-dimensional model described in <8> above, a cured layer of the resin composition for three-dimensional modeling is stacked on the modeling surface of the modeling platform along the direction of gravity.

[0032] <10> A three-dimensional object formed by laminating a cured resin composition comprising any of the above <1> to <7>.

[0033] <11> The three-dimensional object described in <10> above is a decoy.

[0034] The effects of the invention

[0035] According to the present invention, the aforementioned problems can be solved and the above-mentioned objectives can be achieved. It can provide a resin composition for three-dimensional molding that has low odor, excellent mechanical properties, and can stably mold a desired three-dimensional shape, a method for manufacturing three-dimensional molds, and three-dimensional molds. Attached Figure Description

[0036] Figure 1A This is a schematic diagram illustrating an example of a method for manufacturing a three-dimensional object using a suspended light modeling technique.

[0037] Figure 1BThis is a schematic diagram illustrating an example of a method for manufacturing a three-dimensional object using a suspended light modeling technique.

[0038] Figure 2 The photograph shows an example of a three-dimensional object obtained by three-dimensional modeling in Examples 1-3 and Comparative Example 4.

[0039] Figure 3 A photograph is shown to illustrate an example of a three-dimensional object obtained from the three-dimensional modeling of Comparative Example 1.

[0040] Figure 4 A photograph is shown to illustrate an example of a three-dimensional object obtained from the three-dimensional modeling of Comparative Example 3.

[0041] Figure 5 A schematic diagram showing an example of the manufacturing state of the three-dimensional object in Comparative Example 1.

[0042] Figure 6 A schematic diagram showing an example of the manufacturing state of the three-dimensional object in Comparative Example 2.

[0043] Figure 7 A schematic diagram illustrating an example of a decoy. Detailed Implementation

[0044] (Resin composition for three-dimensional modeling)

[0045] The resin composition for three-dimensional modeling of the present invention contains a polyfunctional urethane (meth) acrylate with a molecular weight of 700 to 1,300, preferably contains a photopolymerization initiator, and may further contain other components as needed.

[0046] The resin composition for three-dimensional modeling of the present invention contains polyfunctional urethane (meth)acrylates with a molecular weight of 700 to 1,300, thereby achieving a viscosity suitable for three-dimensional modeling. When cured by heat or light, the resulting three-dimensional model exhibits excellent mechanical properties (elastic modulus and strength). Furthermore, the polyfunctional urethane (meth)acrylates with a molecular weight of 700 to 1,300 are considered to be free of odorous and skin-irritating low-molecular-weight monofunctional monomers, thus exhibiting low odor and high molecular weight, making them less prone to skin penetration and therefore less irritating to the skin.

[0047] Regarding the evaluation of odor, if the 5% weight loss temperature in the thermogravimetric analysis (TGA) is above 300°C, it is considered low volatility, thereby suppressing the occurrence of odor and becoming low odor.

[0048] Skin irritation (PII) can be evaluated by applying the depilated rabbit directly to the skin. Generally, skin irritation is known to be low, except for acrylates (methacrylates or high molecular weight urethane (meth)acrylates).

[0049] <Polyfunctional carbamate (meth)acrylates>

[0050] The above-mentioned polyfunctional urethane (meth)acrylates are not particularly limited if they have a urethane structure and have two or more acryloyl or methacryloyl groups, and can be appropriately selected according to the purpose.

[0051] The molecular weight of the polyfunctional urethane (meth)acrylate is 700 to 1,300, preferably 750 to 1,000.

[0052] If the molecular weight of the above-mentioned polyfunctional urethane (meth)acrylate is 700 or more and 1,300 or less, a resin composition for three-dimensional modeling with a viscosity suitable for three-dimensional modeling can be prepared.

[0053] As a method for calculating the aforementioned molecular weight, one example is by using the hydroxyl value (OH). A The number of hydroxyl groups (OH) in the molecule B The molecular weight of potassium hydroxide (56.1) is calculated using the following mathematical formula. The hydroxyl value can be determined according to JIS K 0070:1992. The number of hydroxyl groups in the molecule can be determined by titrating a potassium hydroxide-ethanol solution.

[0054] [Number 1]

[0055]

[0056] The aforementioned multifunctional urethane (meth)acrylate preferably has an aliphatic polyester backbone, an aliphatic polycarbonate backbone, or a polycaprolactone backbone as the main backbone. From the perspective of imparting softness to three-dimensional objects, a polycaprolactone backbone is particularly preferred.

[0057] The molecular weight of the polycaprolactone backbone is preferably 500 to 1,000. If the molecular weight of the polycaprolactone backbone is less than 500, the proportion of caprolactone backbone contained in the molecule of the polyfunctional urethane (meth)acrylate with the polycaprolactone backbone becomes smaller, which cannot impart sufficient flexibility to the three-dimensional object, and sometimes the three-dimensional object becomes too stiff.

[0058] The molecular weight of the polycaprolactone backbone can be determined in the same manner as the molecular weight of the polyfunctional urethane (meth)acrylate.

[0059] As a polyfunctional urethane (meth) acrylate having the above-mentioned polycaprolactone backbone, it is preferably either of the following general formulas (1) and (2).

[0060] [Chemistry 3]

[0061]

[0062] In the above general formula (1), R1 represents a straight-chain alkyl or straight-chain alkyl ether group, n1+n2 is an integer of 2 or more and 9 or less, and n3 is an integer of 1 or more.

[0063] R1 represents a straight-chain alkyl or straight-chain alkyl ether group, for example, C2H2, C2H2OC2H2, C2H4, C2H4OC2H4, C(CH3)2(CH2)2, etc.

[0064] [Chemistry 4]

[0065]

[0066] In the above general formula (2), R2 represents a branched alkyl group, m1+m2+m3 are integers of 3 to 9, and m4 is an integer of 1 or more.

[0067] R2 represents a branched alkyl group, such as CH2CHCH2, CH3C(CH2)3, CH3CH2C(CH2)3, etc.

[0068] Polyfunctional urethane (meth)acrylates having the above-mentioned polycaprolactone backbone can be synthesized using appropriate products, or commercially available products can be used.

[0069] As a method for synthesizing polyfunctional urethane (meth)acrylates having the above-mentioned polycaprolactone backbone, for example, isocyanate (meth)acrylates (e.g., 2-isocyanate ethyl acrylate) can be compounded relative to polycaprolactone polyols (e.g., polycaprolactone diol or polycaprolactone triol) in such a way that the hydroxyl value of the polycaprolactone polyol is 0.9 equivalents, the mixture is sealed tightly, stirred at 60°C, and reacted for 3 days to synthesize the urethane.

[0070] As the aforementioned polycaprolactone polyol, commercially available products can be used, such as Placcel 205U, Placcel 305, and Placcel 308 (all manufactured by Daicel Corporation).

[0071] Examples of the aforementioned isocyanate (meth)acrylates include, for example, Karenz AOI and Karenz MOI (both manufactured by Showa Denko Corporation).

[0072] The polyfunctional urethane (meth)acrylate with a polycaprolactone backbone used in this invention, like the urethane (meth)acrylates of the prior art, does not use polycaprolactone polyol, diisocyanate, or (meth)acrylate with hydroxyl groups. Instead, (meth)acryloyl groups are introduced at the end of the polycaprolactone polyol via urethane bonds through isocyanate (meth)acrylate, thereby enabling the molecular weight of the polyfunctional urethane (meth)acrylate with a polycaprolactone backbone to be controlled to be between 700 and 1,300.

[0073] The content of the above-mentioned polyfunctional urethane (meth) acrylate relative to the total amount of the resin composition for three-dimensional modeling is preferably 90% by mass or more, and more preferably 95% by mass or more.

[0074] If the content of the above-mentioned polyfunctional urethane (meth)acrylate is 90% or more by mass, it is substantially free of low molecular weight monofunctional monomers with strong odor and skin irritation, thus having low odor and skin irritation, and can be made into a resin composition suitable for three-dimensional modeling.

[0075] <Photopolymerization Initiator>

[0076] As a photopolymerization initiator, it is suitable for use with compounds that generate free radicals by irradiation with light, especially ultraviolet light with wavelengths of 220 nm to 500 nm.

[0077] Examples of photopolymerization initiators include acetophenone, 2,2-diethoxyacetophenone, p-dimethylaminoacetophenone, benzophenone, 2-chlorobenzophenone, p,p'-dichlorobenzophenone, p,p-bis(diethylamino)benzophenone, michidone, benzoin, benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin isopropyl ether, benzoin-n-propyl ether, benzoin isobutyl ether, benzoin-n-butyl ether, benzyl methyl ketal, thioxanone, 2-chlorothioxanone, 2-hydroxy-2-methyl-1-phenylpropanone, 1-(4-isopropylphenyl)2-hydroxy-2-methylpropanone, methyl benzoyl carbamate, 1-hydroxycyclohexylphenyl ketone, azobisisobutyronitrile, benzoyl peroxide, di-tert-butyl peroxide, etc. One of these can be used alone, or two or more can be used in combination.

[0078] Furthermore, it is preferable that the light source of the photocurable molding device is LED (wavelength 405nm), and the visible area has an absorbing photopolymerization initiator, such as 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, etc.

[0079] The content of the aforementioned photopolymerization initiator relative to the total amount of the resin composition for three-dimensional modeling is preferably 1% by mass or more, more preferably 3% by mass or more. Furthermore, the content of the aforementioned photopolymerization initiator is preferably 10% by mass or less.

[0080] <Other Ingredients>

[0081] Other components are not particularly restricted and can be appropriately selected according to the purpose. Examples include stabilizers, surface treatment agents, colorants, viscosity modifiers, adhesive agents, antioxidants, anti-aging agents, crosslinking accelerators, ultraviolet absorbers, plasticizers, preservatives, dispersants, and pH adjusters.

[0082] The viscosity of the resin composition for three-dimensional modeling according to the present invention is preferably 0.1 Pa·s or more and 10 Pa·s or less at 25°C, more preferably 0.1 Pa·s or more and 9 Pa·s or less, and even more preferably 0.1 Pa·s or more and 8 Pa·s or less. If the viscosity at 25°C is 0.1 Pa·s or more and 10 Pa·s or less, it is suitable for use in a method for manufacturing three-dimensional objects using photolithography.

[0083] The viscosity mentioned above can be measured, for example, using a rotational rheometer (device name: AR-G2, manufactured by TA Instruments) at 25°C with a shear rate of 100 (1 / s).

[0084] The glass transition temperature (Tg) of the cured resin composition for three-dimensional shaping according to the present invention is preferably -60°C to 50°C, more preferably -20°C to 30°C. If the glass transition temperature is -60°C to 50°C, sufficient hardness can be obtained in order to maintain the shape of the cured product.

[0085] The aforementioned glass transition temperature can be determined using a dynamic viscoelasticity measuring device (DMA: Dynamic Mechanical Analysis, product name: RSA-3, manufactured by TA Instruments). Specifically, the temperature at which the maximum tanδ (loss modulus of elasticity / storage modulus of elasticity) is obtained under the following measurement conditions: sample size: 5 mm width × 20 mm length, frequency: 1 MHz, is defined as the glass transition temperature.

[0086] There are no particular limitations on the method for manufacturing three-dimensional objects using the resin composition for three-dimensional modeling of the present invention, and it can be appropriately selected according to the purpose. For example, a method for manufacturing three-dimensional objects using photoforming method can be cited.

[0087] (Methods for manufacturing three-dimensional objects)

[0088] The method for manufacturing a three-dimensional object according to the present invention is a method for manufacturing a three-dimensional object using light modeling, which includes the following steps:

[0089] The process of immersing a molding table in a molding tank containing the resin composition for three-dimensional modeling of the present invention, and irradiating the molding surface of the molding table with active energy rays to cure the resin composition for three-dimensional modeling, may further include other processes as needed.

[0090] In this invention, the preferred method is the light modeling method, which involves suspending a cured layer of the resin composition for three-dimensional modeling that is stacked along the direction of gravity on the modeling surface of the modeling platform.

[0091] Specifically, the method for manufacturing a three-dimensional object of the present invention involves selectively irradiating a layer of a resin composition for three-dimensional shaping with active energy rays to form a cured layer based on shape data of the three-dimensional object for shaping purposes, thereby obtaining a cured layer having a desired pattern. Then, in contact with the cured layer, an uncured layer of the resin composition for three-dimensional shaping is supplied and similarly irradiated with active energy rays to form a new cured layer continuous with the cured layer. This operation is repeated to obtain the final target three-dimensional object.

[0092] Examples of active energy rays mentioned above include ultraviolet rays, electron beams, X-rays, radiation, and high-frequency rays. From an economic point of view, ultraviolet rays with wavelengths of 300 nm to 400 nm are preferred. As light sources, ultraviolet lasers, high-pressure mercury lamps, ultra-high-pressure mercury lamps, low-pressure mercury lamps, xenon lamps, halogen lamps, metal halide lamps, ultraviolet LEDs (light-emitting diodes), and ultraviolet fluorescent lamps can be used. Examples of ultraviolet lasers include semiconductor-excited solid-state lasers, Ar lasers, and He-Cd lasers.

[0093] (Three-dimensional objects)

[0094] The three-dimensional model of the present invention is formed by laminating a cured product containing the resin composition for three-dimensional modeling of the present invention.

[0095] There are no particular limitations on the applications of the aforementioned three-dimensional objects; they can be appropriately selected according to the purpose and can be used for various purposes such as sporting goods, medical care products, prostheses, dentures, artificial bones, industrial machinery / equipment, precision equipment, electrical / electronic equipment, electrical / electronic components, building materials, lures, etc. Among these, lures are preferred considering the advantages shown below.

[0096] <Bait>

[0097] The lure has a structure that mimics the body parts of a small fish. Lures shaped using the three-dimensional molding resin composition of this invention can be created using a light-machining 3D printer. Because it lacks the odor from low-molecular-weight monofunctional monomers, it prevents repulsive reactions from target fish. Furthermore, since it lacks the odor from low-molecular-weight monofunctional monomers, adding fish-pleasing scents (amino acid scents) will not interfere with the odor.

[0098] Furthermore, since the resin composition for three-dimensional modeling of the present invention is biodegradable, it can be decomposed in water using enzymes. Additionally, by mixing biodegradable pigments into the resin composition for three-dimensional modeling of the present invention and using a UV-curing 3D printer such as an inkjet printer for modeling, multiple colors can coexist in a single three-dimensional model without painting or other finishing processes, thus creating a colored decoy.

[0099] here, Figure 7 As shown, the lure has a structure that mimics the body parts of a small fish. Additionally, for securing it to the fishing line and the hook, it may have several hooks (1, 7, 8) as needed. Further considering water resistance, it may have several fillets, preferably fin 3, pectoral fin 4, pelvic fin 5, and caudal fin 6. The size of the lure depends on the limits allowed by the 3D printer, but the size (length L, height M) can be adjusted arbitrarily. Figure 7 The middle 2 is a fish eye.

[0100] Example

[0101] The following describes embodiments of the present invention, but the present invention is not limited by these embodiments.

[0102] (Example 1)

[0103] Synthesis of polyfunctional carbamate (meth)acrylates with a polycaprolactone backbone-

[0104] In a 300 mL three-necked flask, 209 g (0.39 mol) of Placcel 205U (PCL205U, polycaprolactone diol, molecular weight: 530, manufactured by Daicel Co., Ltd.) and 100 g (0.71 mol) of 2-isocyanate ethyl acrylate (trade name: Karenz AOI, manufactured by Showa Denko Co., Ltd.) were added in such a way that the hydroxyl value relative to polycaprolactone diol was 0.9 equivalents. The flask was sealed tightly and stirred at 60 °C for 3 days to obtain a colorless liquid (polyfunctional urethane (meth) acrylate with a polycaprolactone backbone).

[0105] Regarding the obtained liquid, a Fourier transform infrared spectrophotometer (FT-IR, device name: Nicolet iS2, Thermo Scientific) was used to confirm 2,250 cm⁻¹. -1 The disappearance of the peak of the nearby isocyanate and 3,100 cm⁻¹ -1 ~3,600cm -1 The hydroxyl (OH) peak disappeared at 1,550 cm⁻¹. -1 The peak of the nearby amide (HNC=O) bond was regenerated.

[0106] -Preparation of resin compositions for three-dimensional modeling-

[0107] Next, relative to 100 parts by weight of the obtained polycaprolactone-based polyfunctional urethane (meth)acrylate, 4 parts by weight of photopolymerization initiator (Omnirad TPO-H, manufactured by IGM Resins BV) were added and mixed to prepare a resin composition for three-dimensional modeling.

[0108] (Example 2)

[0109] In Example 1, 209 g (0.39 mol) of Placcel 205U (PCL205U, polycaprolactone diol, molecular weight: 530, manufactured by Daicel Corporation) was replaced with 217 g (0.39 mol) of Placcel 305 (PCL305, polycaprolactone triol, molecular weight: 550, manufactured by Daicel Corporation). Otherwise, the procedure was the same as in Example 1, and a colorless liquid (polyfunctional urethane (meth)acrylate having a polycaprolactone backbone) was obtained.

[0110] -Preparation of resin compositions for three-dimensional modeling-

[0111] Next, relative to 100 parts by weight of the obtained polyfunctional urethane (meth) acrylate with a polycaprolactone backbone, 4 parts by weight of photopolymerization initiator (Omnirad TPO-H, manufactured by IGM Resins BV) were added and mixed to prepare the three-dimensional modeling resin composition of Example 1.

[0112] (Example 3)

[0113] In Example 1, 209 g (0.39 mol) of Placcel 205U (PCL205U, polycaprolactone diol, molecular weight: 530, manufactured by Daicel Corporation) was replaced with 335 g (0.39 mol) of Placcel 308 (PCL308, polycaprolactone triol, molecular weight: 850, manufactured by Daicel Corporation). Otherwise, the procedure was the same as in Example 1, and a colorless liquid (polyfunctional urethane (meth)acrylate having a polycaprolactone backbone) was obtained.

[0114] -Preparation of resin compositions for three-dimensional modeling-

[0115] Next, relative to 100 parts by weight of the obtained polycaprolactone-based polyfunctional urethane (meth)acrylate, 4 parts by weight of photopolymerization initiator (Omnirad TPO-H, manufactured by IGM Resins BV) were added and mixed to prepare the three-dimensional modeling resin composition of Example 3.

[0116] (Comparative Example 1)

[0117] In Example 1, 209 g (0.39 mol) of Placcel 205U (PCL205U, polycaprolactone diol, molecular weight: 530, manufactured by Daicel Corporation) was replaced with 118 g (0.39 mol) of Placcel 303 (PCL303, polycaprolactone triol, molecular weight: 300, manufactured by Daicel Corporation). Otherwise, the procedure was the same as in Example 1, and a colorless liquid (polyfunctional urethane (meth)acrylate having a polycaprolactone backbone) was obtained.

[0118] -Preparation of resin compositions for three-dimensional modeling-

[0119] Next, relative to 100 parts by weight of the obtained polycaprolactone-based polyfunctional urethane (meth)acrylate, 4 parts by weight of photopolymerization initiator (Omnirad TPO-H, manufactured by IGM Resins BV) were added and mixed to prepare the three-dimensional modeling resin composition of Comparative Example 1.

[0120] (Comparative Example 2)

[0121] In Example 1, 209 g (0.39 mol) of Placcel 205U (PCL205U, polycaprolactone diol, molecular weight: 530, manufactured by Daicel Corporation) was replaced with 492 g (0.39 mol) of Placcel 312 (PCL312, polycaprolactone triol, molecular weight: 1250, manufactured by Daicel Corporation). Otherwise, the procedure was the same as in Example 1, and a colorless liquid (polyfunctional urethane (meth)acrylate having a polycaprolactone backbone) was obtained.

[0122] -Preparation of resin compositions for three-dimensional modeling-

[0123] Next, relative to 100 parts by weight of the obtained polycaprolactone-based polyfunctional urethane (meth)acrylate, 4 parts by weight of photopolymerization initiator (Omnirad TPO-H, manufactured by IGM Resins BV) were added and mixed to prepare the three-dimensional modeling resin composition of Comparative Example 2.

[0124] (Comparative Example 3)

[0125] Prepare the product name: "ELEGOO", UV resin (gray) for light modeling 3D printers, a resin composition for stereoscopic modeling manufactured by ELEGOO Corporation as Comparative Example 3.

[0126] The inventors analyzed the composition of “ELEGOO” in Comparative Example 3 and found that it contained a low molecular weight acrylic monomer (acryloylmorpholine) and a high molecular weight carbamate acrylate.

[0127] (Comparative Example 4)

[0128] Prepare a product name: "eSun", LED UV resin for light-curing 3D printers, a PLA resin composition for stereolithography manufactured by eSun Corporation as Comparative Example 4, which is a light-curing 3D printer.

[0129] The inventors analyzed the composition of “eSun” in Comparative Example 4 and found that it contained a low molecular weight acrylic monomer (acryloylmorpholine) and a high molecular weight carbamate acrylate.

[0130] Next, for each of the obtained resin compositions for three-dimensional modeling, the following procedures were followed to evaluate each property. The results are shown in Tables 1 and 2.

[0131] <Viscosity>

[0132] The viscosity of each resin composition for three-dimensional modeling was measured at a shear rate of 100 (1 / s) using a rotational rheometer (AR-G2, manufactured by TA Instruments) at 25°C.

[0133] <Three-dimensional modeling>

[0134] The obtained resin compositions for three-dimensional modeling were used in a three-dimensional modeling manufacturing apparatus (apparatus name: ELEGOO MARS PRO UV, manufactured by ELEGOO Corporation) for suspension modeling, and the models were shaped... Figure 2 and Figure 4 Evaluate the three-dimensionality of a three-dimensional object of the shape and size shown.

[0135] Examples 1-3 and Comparative Example 4 are as follows Figure 2 As shown, it can accurately depict three-dimensional forms. Furthermore, Comparative Example 3 is as follows... Figure 4 As shown, it can accurately create a three-dimensional model.

[0136] In contrast, Comparative Example 1 is as follows: Figure 3 As shown, the three-dimensional object will be damaged. This is because the three-dimensional object in Comparative Example 1 is too hard, thus becoming brittle and causing damage to thin-walled sections, etc. Figure 5 As shown in A, the three-dimensional object is divided into upper and lower sections.

[0137] Furthermore, the resin composition for three-dimensional modeling in Comparative Example 2 has a high viscosity, therefore... Figure 6 As shown in Figure B, even if the molding platform 11 is raised, the resin composition for three-dimensional molding under the molding platform 11 will not return, so molding is not possible.

[0138] <5% weight reduction temperature (volatility)>

[0139] The evaluation method for odor is to replace the 5% weight reduction temperature with "volatility". The following procedure is followed to measure the 5% weight reduction temperature of the cured product. A higher 5% weight reduction temperature indicates less volatile matter and thus less odor.

[0140] Each three-dimensional model was sandwiched between two sheets of polyethylene terephthalate (PET) film using a resin composition and coated. It was then subjected to UV irradiation (0.5 J / cm²) using a UV conveyor belt. 2 The process was repeated 6 times, resulting in various cured materials with dimensions of 3cm x 3cm x 0.5mm (length x width x thickness).

[0141] For each cured product obtained, thermogravimetric analysis (TGA: ThemoGarvimetric Analysis, device name: TG-DTA 6000, manufactured by Hitachi High Tech Co., Ltd.) was performed to determine the 5% weight reduction temperature.

[0142] <Methods for determining glass transition temperature (Tg) and elastic modulus>

[0143] The loss modulus and storage modulus were measured using a Dynamic Mechanical Analysis (DMA) apparatus (RSA-3, manufactured by TA Instruments) under the following conditions. The temperature at which the loss tangent tanδ (loss modulus / storage modulus) reaches its maximum was defined as the glass transition temperature. Furthermore, the modulus of elasticity below the glass transition temperature (representing the hardness of the cured material) was defined as the modulus of elasticity in the glass region, and the modulus of elasticity above the glass transition temperature (reflecting the crosslinking density) was defined as the modulus of elasticity in the rubber equilibrium region. The modulus of elasticity below the glass transition temperature Tg was preferably 1 GPa to 2.5 GPa, and the modulus of elasticity above the glass transition temperature Tg was preferably 5 MPa to 50 MPa. Additionally, samples with a width of 5 mm and a length of 20 mm were prepared for measurement using the same procedure as at the 5% weight reduction temperature.

[0144] -Determination Conditions-

[0145] • Frequency: 1Hz

[0146] • Heating rate: 10℃ / min.

[0147] • Strain control: 0.1%

[0148] [Table 1]

[0149]

[0150] [Table 2]

[0151]

[0152] The details of each component in Tables 1 and 2 are as follows.

[0153] *PCL205U: Placcel 205U, polycaprolactone diol, molecular weight 530, manufactured by Daicel Corporation. *PCL303: Placcel 303, polycaprolactone triol, molecular weight 300, manufactured by Daicel Corporation.

[0154] *PCL305: Placcel 305, polycaprolactone triol, molecular weight 550, manufactured by Daicel Co., Ltd.

[0155] *PCL308: Placcel 308, polycaprolactone triol, molecular weight 850, manufactured by Daicel Co., Ltd.

[0156] *PCL312: Placcel 312, polycaprolactone triol, molecular weight 1250, manufactured by Daicel Corporation. *KarenzAOI: 2-isocyanate ethyl acrylate, manufactured by Showa Denko Corporation.

[0157] *Omnirad TPO-H, 2,4,6-trimethylbenzoyl-diphenylphosphine oxide, manufactured by IGM Resins BV

[0158] As shown in Tables 1 and 2, Examples 1-3 do not contain low-molecular-weight monofunctional monomers. The single component, a polyfunctional urethane (meth)acrylate with a molecular weight of 700-1300, achieves good stereolithography. Furthermore, the 5% weight loss temperature in thermogravimetric analysis (TGA) is above 300°C, indicating low volatility and thus suppressing odor. Additionally, the large molecular weight prevents skin penetration, resulting in low skin irritation. Moreover, the polyfunctional urethane (meth)acrylate possesses a polycaprolactone backbone, making the stereolithographic products non-brittle and elastic.

[0159] Furthermore, in Comparative Example 1, the ratio of caprolactone backbone contained in the polyfunctional urethane (meth)acrylate with polycaprolactone backbone (300 / 720) is small, resulting in insufficient flexibility of the molded object, high elastic modulus at temperatures above the glass transition temperature Tg, and excessive stiffness of the three-dimensional molded object, leading to its destruction during molding.

[0160] In Comparative Example 2, the polyfunctional urethane (meth) acrylate with a polycaprolactone backbone has a large molecular weight, thus the viscosity of the resin composition for stereolithography becomes high, and it cannot be shaped as described above.

[0161] In Comparative Examples 3 and 4, the resin composition for stereolithography is low in viscosity and has a high glass transition temperature (Tg) of the cured product, which enables stereolithography. However, the 5% weight loss temperature during thermogravimetric analysis (TGA) is below 200°C, indicating that it is easily volatile. It also contains a low molecular weight monofunctional monomer (acryloylmorpholine), resulting in a strong odor, making it unsuitable for general household use.

[0162] Industry availability

[0163] The resin composition for three-dimensional modeling of the present invention has a low odor, excellent mechanical properties, and can stably shape objects into desired three-dimensional shapes, thus making it suitable for manufacturing, for example, three-dimensional objects such as bait.

[0164] Explanation of symbols

[0165] 11 Styling Table

[0166] 11a Shaped surface

[0167] 12 Three-dimensional objects

[0168] 13 Linear Guide

[0169] 14 arms

[0170] 15 UV light source

[0171] 16 Shaping Grooves

[0172] 17. Resin composition for three-dimensional modeling (liquid)

Claims

1. A resin composition for three-dimensional modeling, characterized in that, It contains polyfunctional urethane (meth) acrylates with a molecular weight of 700 to 1,300. The content of the polyfunctional urethane (meth) acrylate is 90% or more by mass relative to the total amount of the resin composition for three-dimensional modeling.

2. The resin composition for three-dimensional modeling according to claim 1, wherein the polyfunctional urethane (meth)acrylate has a polycaprolactone backbone.

3. The resin composition for three-dimensional modeling according to claim 2, wherein the molecular weight of the polycaprolactone backbone is 500 to 1,000.

4. The resin composition for stereolithography according to claim 2 or 3, wherein the polyfunctional urethane (meth)acrylate having the polycaprolactone backbone is any one of the following general formulas (1) and (2), [Chemistry 1] in, In the general formula (1), R1 represents a straight-chain alkyl group or a straight-chain alkyl ether group, n1 + n2 are integers of 2 to 9, and n3 is an integer of 1 or more. [Chemistry 2] In the general formula (2), R2 represents a branched alkyl group, m1+m2+m3 is an integer of 3 or more but less than 9, and m4 is an integer of 1 or more.

5. The resin composition for three-dimensional modeling according to claim 1 or 2, comprising a photopolymerization initiator.

6. The resin composition for three-dimensional modeling according to claim 1 or 2, wherein the viscosity at 25°C is 0.1 Pa·s or more and 10 Pa·s or less.

7. A method for manufacturing a three-dimensional object, characterized in that, A method for manufacturing three-dimensional objects using light modeling includes the following steps: A process of immersing a molding table in a molding tank containing a resin composition for three-dimensional modeling as described in any one of claims 1 to 6, and irradiating the molding surface of the molding table with active energy rays to cure the resin composition for three-dimensional modeling.

8. The method for manufacturing a three-dimensional object according to claim 7, The cured layer of the resin composition for three-dimensional modeling is stacked along the direction of gravity on the modeling surface of the modeling platform.

9. A three-dimensional object formed by laminating a cured product of a resin composition comprising any one of claims 1 to 6 for three-dimensional shaping.

10. The three-dimensional object according to claim 9, which is a decoy.

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