JP2021030625A - Method for manufacturing support material for inkjet 3d printer, support material, and method for manufacturing optically formed product - Google Patents

Abstract

To provide a method for manufacturing a support material for an inkjet 3D printer, the support material, and a method for manufacturing an optically formed product that achieve both of hardness for supporting a model material and excellent solubility to a solvent.SOLUTION: A method for manufacturing a support material for an inkjet 3D printer according to the present invention polymerizes a composition for the support material for the inkjet 3D printer containing a water-soluble ethylenic unsaturated monomer and a polymerization initiator so that the weight-average molecular weight becomes 10,000-50,000 to manufacture the support material for the inkjet 3D printer.SELECTED DRAWING: None

Description

The present invention relates to a method for manufacturing a support material for an inkjet 3D printer, a support material, and a method for manufacturing a stereolithographic object.

In recent years, a stereolithography method by an inkjet method has been proposed in which a liquid photocurable resin discharged from an inkjet nozzle is cured, laminated, and photomolded. The ink for an inkjet 3D printer using this stereolithography method includes a model material that constitutes a molded body by photocuring such as UV, and a support material that is used as a support material when the model materials are three-dimensionally stacked. .. By laminating the model material on the support material, it is possible to form an overhang structure or a hollow structure.

Patent Document 1 describes a composition solution for 3D modeling containing at least two types of monofunctional monomers having an ethylene polymerizable group and a photoinitiator, which is a monofunctional monomer having an ionic group as a monofunctional monomer and an ion. A 3D modeling ink set containing a monofunctional monomer having no functional group and further containing a counter ion of an ionic group and a support material composition solution is described. It is described that the above-mentioned composition liquid for 3D modeling can be cured by irradiation with ultraviolet rays, and further, a 3D modeled product having high toughness and being hard to break can be obtained.

The support material is required to have hardness (supportability) that can withstand lamination. Further, after curing, the support material is removed from the model material by water dissolution, heating, chemical reaction, hydraulic cleaning, electromagnetic wave irradiation, utilization of thermal expansion difference, and the like. Therefore, the composition for a photocurable support material for an inkjet 3D printer needs to be easily removed from the model material after curing. Then, there has been a demand for a support material for an inkjet 3D printer that has both hardness to support a model material and excellent solubility in a solvent under curing conditions close to the specifications of an actual machine.

Japanese Unexamined Patent Publication No. 2016-2704

Therefore, an object of the present invention is to provide a method for manufacturing a support material for an inkjet 3D printer, a support material, and a method for manufacturing a stereolithographic object, which have both hardness to support a model material and excellent solubility in a solvent. It is in.

As a result of diligent research to solve the above problems, the present inventors have obtained a composition for a support material for an inkjet 3D printer containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator by weight average molecular weight. The present invention has been completed by finding that the above problems can be solved by producing a support material for an inkjet 3D printer by polymerizing so as to have a value in a predetermined range.

That is, in the method for producing a support material for an inkjet 3D printer of the present invention, a composition for a support material for an inkjet 3D printer containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator has a weight average molecular weight of 1.0. A support material for an inkjet 3D printer is manufactured by polymerizing so as to be 10,000 to 50,000.
The composition for a support material for an inkjet 3D printer preferably contains water.
Further, the support material for an inkjet 3D printer of the present invention has a weight average molecular weight of 10,000 to 50,000.
Further, the method for manufacturing a stereolithographic product of the present invention comprises a forming step of forming a support material; a forming step of a model material; and a removing step of the supporting material by the above-mentioned manufacturing method of a support material for an inkjet 3D printer. Including.

According to the method for manufacturing a support material for an inkjet 3D printer, the support material, and the method for manufacturing a stereolithographic object of the present invention, a support for an inkjet 3D printer that has both hardness to support a model material and excellent solubility in a solvent. A method for manufacturing a material, a support material, and a method for manufacturing a stereolithography can be provided.

[Manufacturing method of support material for inkjet 3D printer]
In the method for producing a support material for an inkjet 3D printer of the present invention, a composition for a support material for an inkjet 3D printer containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator (hereinafter, simply referred to as a composition for a support material). Is polymerized so that the weight average molecular weight is 10,000 (10,000) to 50,000 (50,000) to produce a support material for an inkjet 3D printer. The weight average molecular weight can be adjusted by using a known method such as appropriately adjusting the amount and type of the water-soluble ethylenically unsaturated monomer and / or the polymerization initiator in the composition for the support material.

According to the specifications of the actual device of the inkjet 3D printer, the composition for the support material is discharged and laminated with a thickness of several tens of μm (for example, a thickness of 15 to 35 μm), preferably ^{about 100 to 500 mJ / cm 2} , and more preferably 150 to 250 mJ. / cm ² about ultraviolet is irradiated with the support material composition is photocured (polymerization). The present inventors have found that under a thin film condition in which the composition for a support material is discharged and laminated to a thickness of several tens of μm, the effect of oxygen inhibition by the polymerization initiator is large, which is different from the curability at a thickness of several mm. .. Here, curing means that the liquid is no longer liquid and the fluidity is lost.

In the method for producing a support material for an inkjet 3D printer of the present invention, the polymerization is carried out under the above thin film conditions, which is the specification of an actual device of an inkjet 3D printer, so that the weight average molecular weight is 10,000 to 50,000. By doing so, it is possible to achieve both the hardness that supports the model material and the excellent solubility in the solvent. In the present invention, excellent solubility in a solvent means extremely high solubility, that is, it dissolves within 30 minutes, particularly preferably within 15 minutes after being immersed in the solvent.

In the method for producing a support material for an inkjet 3D printer of the present invention, it is preferable to produce a support material for an inkjet 3D printer having a weight average molecular weight of 25,000 (25,000) to 40,000 (40,000). ..

As a water-soluble ethylenically unsaturated monomer contained in a composition for a support material containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator used in the method for producing a support material for an inkjet 3D printer of the present invention. Is a monomer having one or more ethylenically unsaturated groups in the molecule, and a water-soluble ethylenically unsaturated monomer containing an ionic group and a counter ion is preferable. A water-soluble ethylenically unsaturated monomer containing an ionic group and a counterion is highly water-soluble by containing an ionic group and a counterion. The water solubility (20 ° C.) is preferably 100 g / L or more, more preferably 200 g / L or more, and further preferably 500 g / L or more.

The ethylenically unsaturated groups include ethylene group, propenyl group, butenyl group, vinylphenyl group, (meth) acrylic group, allyl ether group, vinyl ether group, maleyl group, maleimide group, (meth) acrylamide group, acetylvinyl group and Examples include a vinylamide group. In the present specification, "(meth) acrylic" means both or either of "acrylic" and "methacryl", and "(meth) acrylate" means both or either of "acrylate" and "methacrylate". means. Among them, a (meth) acrylic group, a vinyl ether group and a (meth) acrylamide group are preferable, and a (meth) acrylic group is more preferable.

Examples of the ionic group include carboxylic acid, phosphoric acid, sulfonic acid and the like. Of these, carboxylic acid is preferable.

Examples of the counterion include monovalent counterions such as sodium ion, potassium ion and ammonium ion; and polyvalent metal ions such as zinc ion, magnesium ion, calcium ion, aluminum ion and neodium ion. Among them, a monovalent counterion is preferable, a sodium ion, a potassium ion, or an ammonium ion is more preferably used, and a potassium ion is more preferably used. In addition to the monovalent counterion, it is also preferable to use a polyvalent metal ion such as zinc ion, magnesium ion, calcium ion, aluminum ion or neodium ion.

For support materials when a water-soluble ethylenically unsaturated monomer containing a monovalent counterion and a water-soluble ethylenically unsaturated monomer containing a polyvalent metal ion are used in combination as counterions. The supportability of the cured product obtained by photocuring the composition can be further improved. Further, in addition to these, it is a preferable form of the present invention to be used in combination with an organic acid and / or a salt thereof, which will be described later. The polyvalent metal ion is preferably zinc ion, magnesium ion, or calcium ion.
In the present specification, the supportability (supporting force) is the ability of the cured product of the composition for the support material to support the cured product of the model material, and the cured product of the support material is measured by the method described later. It can be expressed by hardness (shower E).

The content of the water-soluble ethylenically unsaturated monomer containing an ionic group and a counter ion contained in the composition for a support material is preferably 50% by mass in 100% by mass of the composition. % Or less, more preferably 40% by mass or less, still more preferably less than 40% by mass, particularly preferably 35% by mass or less, and the lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass. % Or more, particularly preferably more than 20% by mass. In this case, the composition for the support material can be easily polymerized so that the weight average molecular weight is 10,000 to 50,000, the hardness supporting the model material and the excellent solubility in the solvent are obtained. Can be better compatible.

The content of the water-soluble ethylenically unsaturated monomer containing the ionic group and the counterion with respect to the total amount of the monomer contained in the support material composition is the water-soluble content of the support material composition. From the viewpoint of improving the above, the content is preferably 60 to 100% by mass, more preferably 70 to 100% by mass. When two or more kinds of water-soluble ethylenically unsaturated monomers containing the above-mentioned ionic group and counterion are contained, the content is the total content of each component.

The total content of the water-soluble ethylenically unsaturated monomer containing a monovalent counterion as a counterion and the water-soluble ethylenically unsaturated monomer containing a polyvalent metal ion as a counterion In 100% by mass of the composition for a support material, the upper limit is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.

The content of the water-soluble ethylenically unsaturated monomer containing a monovalent counterion as a counterion is preferably 50% by mass or less, more preferably 40% by mass or less, with an upper limit of 100% by mass of the composition for a support material. It is mass% or less, more preferably 30 mass% or less. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.

The content of the water-soluble ethylenically unsaturated monomer containing a polyvalent metal ion as a counterion is preferably 15% by mass or less, more preferably 10% by mass, with an upper limit of 100% by mass of the composition for a support material. % Or less, preferably 0.5% by mass or more, and more preferably 1% by mass or more as the lower limit.
When the above is done, the solubility as well as the supportability of the composition for the support material can be further improved.

Examples of the water-soluble ethylenically unsaturated monomer containing a carboxylic acid as an ionic group and a counterion contained in the composition for a support material include acrylic acid, methacrylic acid, maleic acid, fumaric acid, and 2-. (Meta) acryloyloxybenzoic acid, 3- (meth) acryloyloxybenzoic acid, 4- (meth) acryloyloxybenzoic acid, 2- (meth) acryloyloxyethyl hexahydrophthalic acid, 2- (meth) acryloyloxy Ethylphthalic acid, 2- (meth) acryloyloxyethyl succinic acid, 2-vinyl benzoic acid, 3-vinyl benzoic acid, 4-vinyl benzoic acid, N- (meth) acryloyl aspartic acid, ω- (meth) acroyl alkane Alkali metal salts such as sodium salt and potassium salt and monovalent salts such as ammonium salt of -1,1 dicarboxylic acids; polyvalent salts such as zinc salt, magnesium salt, calcium salt, aluminum salt, neodium salt and the like. Be done.
Among them, alkali metal salts such as sodium salt and potassium salt and monovalent salts such as ammonium salt are preferable, and sodium salt, potassium salt or ammonium salt is more preferable. More preferably, it is a potassium salt.

When a monovalent salt of a carboxylic acid and a polyvalent metal salt are used in combination, the supportability of the cured product obtained by photocuring the composition for a support material can be further improved. Further, in addition to these, it is a preferable form of the present invention to be used in combination with an organic acid and / or a salt thereof, which will be described later. The carboxylic acid polyvalent metal salt is preferably a zinc salt, a magnesium salt, or a calcium salt.

The total content of the monovalent salt and the polyvalent metal salt of the carboxylic acid is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 40% by mass or less, based on 100% by mass of the composition for the support material. It is 30% by mass or less. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.

The content of the monovalent salt of the carboxylic acid is preferably 50% by mass or less, more preferably 40% by mass or less, and further preferably 30% by mass or less in 100% by mass of the composition for the support material. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.

The content of the polyvalent metal salt of the carboxylic acid is preferably 15% by mass or less, more preferably 10% by mass or less, and preferably 0.5% by mass as the lower limit in 100% by mass of the composition for the support material. As mentioned above, it is more preferably 1% by mass or more.
When the above is done, the solubility as well as the supportability of the composition for the support material can be further improved.

Examples of the water-soluble ethylenically unsaturated monomer containing a carboxylic acid as an ionic group and a counterion include a sodium salt, a potassium salt, a zinc salt, and a calcium salt having 3 to 15 carbon atoms contained in the carboxylic acid. Is preferable, and sodium salts, potassium salts, zinc salts, and calcium salts having 3 to 12 carbon atoms are more preferable. As the number of carbon atoms, 3 to 9 carbon atoms are more preferable, and 3 to 6 carbon atoms are further preferable. Of these, potassium (meth) acrylate, sodium (meth) acrylate, zinc (meth) acrylate, and calcium (meth) acrylate are particularly preferable. By using a monomer having a small number of carbon atoms, the hydrophobic portion in the molecule can be reduced, and the water solubility of the water-soluble ethylenically unsaturated monomer can be further enhanced.

Examples of the water-soluble ethylenically unsaturated monomer containing phosphoric acid as an ionic group and a counterion contained in the composition for a support material include mono (2-acryloyloxyethyl) acid phosphate and mono. (2-methacryloyloxyethyl) acid phosphate, diphenyl (2-acryloyloxyethyl) phosphate, diphenyl (2-methacryloyloxyethyl) phosphate, phenyl (2-acryloyloxyethyl) phosphate, acid phosphooxyethyl methacrylate, metachlorooxyethyl Acid phosphate, phosphooxypolyoxyethylene glycol monomethacrylate, acid phosphooxypolyoxypropylene glycol methacrylate, (meth) acryloyloxyethyl acid phosphate, (meth) acryloyloxypropyl acid phosphate, (meth) acryloyloxy-2-hydroxypropyl Acid phosphate, (meth) acryloyloxy-3-hydroxypropyl acid phosphate, (meth) acryloyloxy-3-chloro-2-hydroxypropyl acid phosphate, and phosphono groups in molecules such as vinyl phosphate, p-vinylbenzene phosphate, etc. Examples of the compound having the above include sodium salt, potassium salt, and ammonium salt.

Examples of the water-soluble ethylenically unsaturated monomer containing a sulfonic acid as an ionic group and a counterion contained in the composition for a support material include allyl sulfonic acid, isoprene sulfonic acid, and 2- (meth). ) Acrylethyl sulfonic acid, 3- (meth) acrylamide propyl sulfonic acid, 4- (meth) acrylamide butyl sulfonic acid, 2- (meth) acrylamide-2-methylpropan sulfonic acid, p-vinylbenzene sulfonic acid, and vinyl sulfonic Examples thereof include sodium salts, potassium salts, and ammonium salts of compounds such as acids. The water-soluble ethylenically unsaturated monomer containing the above-exemplified ionic group and counterion may be used alone or in combination of two or more.

As the water-soluble ethylenically unsaturated monomer contained in the composition for the support material, an acrylic salt is preferable, and an alkali metal salt such as lithium, sodium and potassium, an ammonium salt, an amine salt and the like, and one of acrylic acids are used. Valuable salts are more preferred, more preferably alkali metal salts or ammonium salts, and particularly preferably sodium salts, potassium salts or ammonium salts. Most preferably, it is a potassium salt.

In addition to the above, the water-soluble ethylenically unsaturated monomer contained in the composition for the support material includes an acrylic acid polyvalent metal salt such as a zinc salt, a magnesium salt, a calcium salt, an aluminum salt, or a neodium salt. May include. The acrylic acid polyvalent metal salt is preferably a zinc salt, a magnesium salt, or a calcium salt.

When the monovalent salt of acrylic acid and the polyvalent metal salt are used in combination, the supportability of the cured product obtained by photocuring the composition for the support material can be further improved. As a combination of the monovalent salt of acrylic acid and the polyvalent metal salt in combination, a combination of potassium acrylate and zinc acrylate is preferable. By using zinc acrylate in combination, a cured product having higher strength can be obtained.

The total content of the monovalent salt and the polyvalent metal salt of acrylic acid is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 40% by mass or less, based on 100% by mass of the composition for the support material. It is 30% by mass or less. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.
Above all, the total content of potassium acrylate and zinc acrylate is preferably 10 to 30% by mass in 100% by mass of the composition for a support material. By doing so, the viscosity of the composition can be lowered, and the cost can be lowered by suppressing the amount of the acrylate used.

The content of the monovalent salt of acrylic acid is preferably 50% by mass or less, more preferably 40% by mass or less, still more preferably 30% by mass or less, based on 100% by mass of the composition for the support material. is there. The lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, and further preferably 10% by mass or more.
The content of the polyvalent metal salt of acrylic acid is preferably 15% by mass or less, more preferably 10% by mass or less, and preferably 0.5% by mass as the lower limit in 100% by mass of the composition for a support material. As mentioned above, it is more preferably 1% by mass or more.
When the above is done, the solubility as well as the supportability of the composition for the support material can be further improved.

Examples of the water-soluble ethylenically unsaturated monomer other than the water-soluble ethylenically unsaturated monomer containing an ionic group and a counter ion include (meth) acrylic acid; methoxypolyethylene glycol acrylate; acryloylmorpholin; N-. Vinylpyrrolidone; acrylamide such as (meth) acrylamide, N, N-dimethylacrylamide, N-hydroxyethylacrylamide and the like can be mentioned.

The total content of the water-soluble ethylenically unsaturated monomer contained in the composition for the support material is preferably 50% by mass or less, more preferably 40% by mass, based on 100% by mass of the composition. Hereinafter, it is more preferably less than 40% by mass, particularly preferably 35% by mass or less, and the lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more, and particularly preferably 20% by mass. It's super. In this case, the composition for the support material can be easily polymerized so that the weight average molecular weight is 10,000 to 50,000, the hardness supporting the model material and the excellent solubility in the solvent are obtained. Can be better compatible.

When the composition for a support material is cured under curing conditions close to the specifications of the actual machine, the weight average molecular weight of the cured support material for an inkjet 3D printer is in the range of 10,000 to 50,000. Other unsaturated monomers other than the water-soluble ethylenically unsaturated monomer (for example, the water solubility (20 ° C.) is less than 20 g / L) may be contained. Examples of the other unsaturated monomer include methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, and pentyl (meth) acrylate. , Isoamyl (meth) acrylate, octyl (meth) acrylate, isooctyl (meth) acrylate, isononyl (meth) acrylate, decyl (meth) acrylate, isodecyl (meth) acrylate, lauryl (meth) acrylate, tridecyl (meth) acrylate, iso Myristyl (meth) acrylate, isostearyl (meth) acrylate, n-stearyl (meth) acrylate, cyclohexyl (meth) acrylate, benzyl (meth) acrylate, phenoxyethyl (meth) acrylate, phenoxyethoxyethyl (meth) acrylate, methoxyethyl (Meta) acrylate, butoxyethyl (meth) acrylate, tetrahydrofurfuryl (meth) acrylate, isobornyl (meth) acrylate, dicyclopentenyl (meth) acrylate, dicyclopentanyl (meth) acrylate, methoxyethoxyethyl (meth) acrylate , 2-Hydroxyethyl (meth) acrylate, 2-hydroxypropyl (meth) acrylate, 2-hydroxybutyl (meth) acrylate, 2-hydroxy-3-phenoxypropyl (meth) acrylate, t-butylcyclohexyl (meth) acrylate, 2-Ethylhexyl-diglycol (meth) acrylate, 4-hydroxybutyl (meth) acrylate, 2-cyanoethyl (meth) acrylate, methyl = 2- (hydroxymethyl) acrylate, 2-ethylhexyl carbitol (meth) acrylate, etc. (Meta) Acrylate; Phenylallyl Ether, o-, m-, p-cresol monoallyl ether, biphenyl-2-all monoallyl ether, biphenyl-4-all monoallyl ether, butyl allyl ether, cyclohexyl allyl ether, and cyclohexane Allyl ethers such as methanol monoallyl ether; butyl vinyl ether, butyl propenyl ether, butyl butenyl ether, hexyl vinyl ether, ethyl hexyl vinyl ether, phenyl vinyl ether, benzyl vinyl ether, ethyl ethoxy vinyl ether, acetyl ethoxy ethoki Vinyl ethers such as sivinyl ether, cyclohexyl vinyl ether, and adamantyl vinyl ether; maleimides such as phenylmaleimide, cyclohexylmaleimide, and n-hexylmaleimide; benzyl acrylate, phenoxyethyl acrylate, phenoxyethoxyethyl acrylate, isobornyl (meth) acrylate, dicyclopentenyl ( Meta) acrylate, dicyclopentanyl (meth) acrylate, bisphenol A diacrylate, EO adduct of bisphenol A Bis (meth) acrylate, PO adduct of bisphenol A Bis (meth) acrylate, EO adduct of hydrogenated bisphenol A A monomer having an aromatic group such as bis (meth) acrylate and a monomer having an alicyclic group; a polyoxyalkylene di (meth) acrylate such as a polyoxyethylene di (meth) acrylate and a polyoxypropylene di (meth) acrylate; Hydroxylalkyl (meth) acrylate and the like can be mentioned.
These may be used alone by 1 type, or may be used in combination of 2 or more type.

The content of the other unsaturated monomer is preferably 50% by mass or less in 100% by mass of the composition. It is more preferably 20 to 50% by mass, still more preferably 25 to 45% by mass. Further, it is also preferable that the content of the other unsaturated monomer is less than 2% by mass in 100% by mass of the composition for the support material. In this case, the odor of the support material composition can be further suppressed.

Further, from the viewpoint of improving the water solubility of the composition for the support material, the content of the other unsaturated monomer is preferably 0% by mass or more and less than 50% by mass, and is 0% by mass or more and 40% by mass. More preferably less than%. When two or more kinds are contained, the content is the total content of each component.

The composition for a support material is organic within a range in which the weight average molecular weight of the cured support material for an inkjet 3D printer is 10,000 to 50,000 when cured under curing conditions close to the specifications of the actual machine. It may contain an acid and / or a salt thereof. The organic acid and / or a salt thereof is a compound other than the water-soluble ethylenically unsaturated monomer and the other unsaturated monomer.
Examples of the organic acid include an organic sulfonic acid such as p-toluenesulfonic acid, an organic phosphoric acid such as phenylphosphonic acid, an organic carboxylic acid, and a phosphoric acid ester. Of these, organic carboxylic acids are preferable. Examples of the organic carboxylic acid include an aliphatic carboxylic acid and an aromatic carboxylic acid. Examples of aliphatic carboxylic acids include formic acid, acetic acid, propionic acid, butyric acid, valeric acid, hexanoic acid, heptanic acid, octanoic acid, octyl acid, nonanoic acid, decanoic acid, lauric acid, myristic acid, palmitic acid and stearic acid. , Bechenic acid, tridecanoic acid, pentadecanoic acid, heptadecanoic acid, lactic acid, malic acid, citric acid, oxalic acid, malonic acid, succinic acid, fumaric acid, maleic acid, adipic acid, benzoic acid, glycine, polyacrylic acid, polylactic acid And so on. Examples of the aromatic carboxylic acid include benzoic acid, phthalic acid, salicylic acid and the like. Of these, aliphatic carboxylic acids are more preferable, and lactic acid, propionic acid, and polyacrylic acid are even more preferable.
Examples of the salt of the organic acid include a metal carboxylate. Examples of the metal of the metal carboxylate include alkali metals such as lithium, sodium and potassium; alkaline earth metals such as magnesium, calcium, strontium and barium; zinc; zirconium and the like. Of these, alkali metals such as potassium are preferable. As the salt of the organic acid, potassium lactate, potassium propanoate, sodium polyacrylate, and potassium polyacrylate are preferable.
When the composition for a support material contains an organic acid and / or a salt thereof, the storage stability is further improved.

The content of the organic acid and / or its salt is in the range where the content of water is preferably 10% by mass or less in 100% by mass of the composition for the support material, and the upper limit is preferably 60% by mass or less, more preferably. Is 50% by mass or less, more preferably 40% by mass or less, and the lower limit is preferably 1% by mass or more, more preferably 5% by mass or more, still more preferably 10% by mass or more. In this case, the storage stability can be further improved as well as the supportability and solubility of the composition for the support material.

Examples of the polymerization initiator contained in the composition for a support material include benzoin compounds such as benzoin, benzoin methyl ether, benzoin ethyl ether, benzoin propyl ether, and benzoin isobutyl ether; acetophenone, 2,2-diethoxy-2-phenyl. Acetophenone, 2,2-diethoxy-2-phenylacetophenone, 1,1-dichloroacetophenone, 2-hydroxy-2-methyl-phenylpropan-1-one, diethoxyacetophenone, 1-hydroxycyclohexylphenylketone, 2-methyl- Acetophenone compounds such as 1- [4- (methylthio) phenyl] -2-morpholinopropan-1-one; anthraquinone compounds such as 2-ethylanthraquinone, 2-t-butylanthraquinone, 2-chloroanthraquinone and 2-amylanthraquinone; 2,4-Diethylthioxanthone, 2-isopropylthioxanthone, 2-chlorothioxanthone, [3- (3,4-dimethyl-9-oxothioxanthen-2-yl) oxy-2-hydroxypropyl] -trimethylazanium chloride, etc. Thioxanthone compounds; acetophenone dimethyl ketal, ketal compounds such as benzyl dimethyl ketal; benzophenone compounds such as benzophenone, 4-benzoyl-4'-methyldiphenyl sulfide, 4,4'-bismethylaminobenzophenone; 2,4,6-trimethyl Phosphine oxides such as benzoyldiphenylphosphine oxide, bis- (2,6-dimethoxybenzoyl) -2,4,4-trimethylpentylphosphine oxide, bis (2,4,6-trimethylbenzoyl) -phenylphosphine oxide; and these. Examples include a mixture.
These may be used alone by 1 type, or may be used in combination of 2 or more type.

As for the content of the polymerization initiator, when the composition for the support material is cured under the curing conditions close to the specifications of the actual machine, the weight average molecular weight of the cured support material for the inkjet 3D printer is 10,000 to 5. Adjust so that it is 0,000. Specifically, for example, with respect to 100% by mass of the water-soluble ethylenically unsaturated monomer, preferably 0.05 to 10.0% by mass, more preferably 0.1 to 7.0% by mass, and further. It is preferably 0.2 to 5.0% by mass, and particularly preferably 0.5 to 4.0% by mass.

The composition for a support material is polar in a range in which the weight average molecular weight of the cured support material for an inkjet 3D printer is 10,000 to 50,000 when cured under curing conditions close to the specifications of the actual machine. It may contain a solvent. Examples of the protic solvent include water; monohydric alcohols such as methanol, ethanol and propanol; oxypropylene groups such as ethylene glycol, propylene glycol, diethylene glycol, dipropylene glycol, triethylene glycol, polyethylene glycol, glycerol and polyoxypropylene glycol. Examples thereof include glycols such as alkylene oxide adducts containing. Only one type of the solvent may be used, or two or more types may be used in combination.
The polar solvent is preferably used so that the content of water is 10% by mass or less in 100% by mass of the composition for the support material. As the polar solvent, glycol having 2 to 6 carbon atoms is preferable, ethylene glycol, propylene glycol, diethylene glycol and glycerol are more preferable, and propylene glycol and glycerol are particularly preferable.

The content of the polar solvent in 100% by mass of the composition is preferably 5% by mass or more, more preferably 10% by mass or more, further preferably 15% by mass or more, and preferably 90% by mass as the upper limit. % Or less, more preferably 85% by mass or less, still more preferably 60% by mass or less. However, the content of water in 100% by mass of the above composition is preferably 10% by mass or less. It is more preferably less than 10% by mass, further preferably 5% by mass or less, and particularly preferably 3% by mass or less.

The glycols having 2 to 6 carbon atoms in total are preferably contained in an amount of 30 to 90% by mass, more preferably 40 to 90% by mass, and 55 to 90% by mass in 100% by mass of the composition. It is more preferably contained in an amount of 70% by mass, and particularly preferably contained in an amount of 70 to 90% by mass.
Above all, the content of propylene glycol or glycerol in 100% by mass of the above composition is preferably 20 to 90% by mass, more preferably 30 to 90% by mass, and 40 to 90% by mass. Is more preferable, and 45 to 90% by mass is particularly preferable.

The composition for a support material is required within a range in which the weight average molecular weight of the cured support material for an inkjet 3D printer is 10,000 to 50,000 when cured under curing conditions close to the specifications of the actual machine. Can contain other additives. Specific examples thereof include photoinitiator aids, polymerization inhibitors, surfactants, colorants, antioxidants, chain transfer agents, fillers and the like.

Photoinitiator aids include N, N-dimethylaniline, N, N-diethylaniline, N, N-dimethyl-p-toluidine, N, N-dimethylamino-p-benzoic acid ethyl ester, N, N-dimethyl. Examples thereof include tertiary amine compounds such as amino-p-benzoic acid isoamylethyl ester, N, N-dihydroxyethylaniline, triethylamine and N, N-dimethylhexylamine.

Examples of the polymerization inhibitor include (alkyl) phenol, hydroquinone, catechol, resorcin, p-methoxyphenol, t-butylcatechol, t-butylhydroquinone, pyrogallol, 1,1-picrylhydrazyl, phenothiline, p-benzoquinone, and nitroso. Benzene, 2,5-di-t-butyl-p-benzoquinone, dithiobenzoyl disulfide, picric acid, cuperon, aluminum N-nitrosophenyl hydroxylamine, tri-p-nitrophenylmethyl, N- (3-oxyanilino-1, 3-Dimethylbutylidene) Aniline oxide, dibutyl cresol, cyclohexanone oxime cresol, guayacol, o-isopropylphenol, butyraldoxime, methyl ethyl ketoxim, cyclohexanone oxime and the like can be mentioned.

Examples of the surfactant include PEG-type nonionic surfactants such as ethylene oxide (hereinafter abbreviated as EO) 1 to 40 mol additive of nonylphenol and EO 1 to 40 mol additive of stearate; sorbitan palmitate monoester, sorbitan stearate. Polyhydric alcohol-type nonionic surfactants such as monoesters and sorbitan stearic acid triesters; fluorine-containing surfactants such as perfluoroalkyl EO 1 to 50 molar additions, perfluoroalkyl carboxylates, perfluoroalkyl betaines; poly Examples thereof include modified silicone oils such as ether-modified silicone oils and (meth) acrylate-modified silicone oils.

Colorants include toluidine red, permanent carmine FB, fast yellow G, disazo yellow AAA, disazo orange PMP, soluble azo pigment, condensed azo pigment, chelate azo pigment, phthalocyanine blue, indantron blue, quinacridone red, dioxazine violet, base Examples thereof include sex dyes, acidic dyes, aniline blacks, daylight fluorescent pigments, nitroso pigments, nitro pigments, natural pigments, metal oxides as inorganic pigments, carbon black and the like.

Antioxidants include 1,3,5-trimethyl-2,4,6-tris (3,5-di-t-butyl-4-hydroxybenzyl) benzene, dilauryl 3,3'-thiodipropionate, Examples thereof include triphenylphosphine, octylated diphenylamine, 2,6-di-t-butyl-p-cresol, 2,2'-methylenebis (4-methyl-6-t-butylphenol) and the like.

Chain transfer agents include hydroquinone, diethylmethylamine, diphenylamine, diethyldisulfide, di-1-octyldisulfide, toluene, xylene, 1-butene, 1-nonen, dichloromethane, carbon tetrachloride, methanol, 1-butanol, ethylthiol. , 1-octylthiol, acetone, methylethylketone, 2-methyl-2-propylaldehyde, 1-pentylaldehyde, phenol, m-cresol, p-cresol, o-cresol and the like.

As fillers, alumina powder, silica powder, talc, mica, clay, aluminum hydroxide, calcium carbonate, calcium silicate, aluminum powder, copper powder, carbon fiber, glass fiber, cotton fiber, nylon fiber, acrylic fiber, rayon. Examples include fiber, microballoon, carbon black, metal sulfide, wood powder and the like.

If necessary, the composition for a support material may further contain other additives within a range that does not impair the effects of the present invention. For example, emulsion stabilizers, penetration promoters, UV absorbers, preservatives, fungicides, rust preventives, pH regulators, surface tension regulators, defoamers, viscosity regulators, dispersants, dispersion stabilizers, chelates. Known additives such as agents, anti-drying agents (wetting agents), colorants, anti-fading agents, specific resistance regulators, film regulators, antioxidants, and surfactants can be mentioned. These various additives can be added directly, for example.

The above additives may be used alone or in combination of two or more.
The content of the additive is preferably 0.02 to 30% by mass, more preferably 0.05 to 20% by mass, based on 100% by mass of the composition.

The composition for a support material contains a total of 10% by mass or more and less than 40% by mass of a water-soluble ethylenically unsaturated monomer, and a polymerization initiator is added to 100% by mass of the water-soluble ethylenically unsaturated monomer. It is preferable to contain 0.1% by mass or more and less than 5.0% by mass.

In the above composition for a support material, since the cured product after curing is used as the support material, the water solubility of the cured product is excellent as an essential requirement for the support material. The water solubility is preferably dissolved within 30 minutes when 0.5 g (surface area 4 cm ² ) of the cured product is placed on a wire mesh and immersed in 10 g of water at room temperature (for example, around 25 ° C.). More preferably, it dissolves within 15 minutes and no insoluble matter is visually observed.

The composition for the support material preferably contains water. The water content in the support material composition is preferably 10% by mass or less, more preferably less than 10% by mass, still more preferably 5% by mass or less, and particularly preferably 3 in 100% by mass of the support material composition. It is mass% or less. The lower limit of the water content is preferably 0% by mass. Within such a range, the weight average molecular weight of the cured support material for an inkjet 3D printer tends to be 10,000 to 50,000 when cured under curing conditions close to the specifications of the actual machine, and the curing property is set. Therefore, the hardness of the cured product after curing is sufficient, the supportability can be improved, and the solubility in a solvent can be improved. The water content in the composition for the support material can be calculated from the water content of each compound charged. It can also be obtained by the Karl Fischer measurement method.

The composition for the support material can be prepared by using the various components described above, and the preparation means and conditions thereof are not particularly limited. For example, a general stirring blade, an ultrasonic homogenizer, a high-speed homogenizer, a high-pressure homogenizer, etc. Examples thereof include a method of stirring and mixing using a planetary stirring device, a three-roll, ball mill, kitty mill, disc mill, pin mill, dyno mill, or other mixing or stirring device. After preparing the solution, it may be filtered using various filters.

In the above composition for a support material, the viscosity at 25 ° C. is preferably 5 to 300 mPa · s. The surface tension at 25 ° C. is preferably 25 to 70 mN / m.

The composition for the support material preferably has a viscosity at the ejection temperature of 20 mPa · s or less from the viewpoint of improving the ejection property from the inkjet head. The viscosity of the support material composition is measured using an R100 type viscometer in accordance with JIS Z 8803.

From the viewpoint of improving the ejection property from the inkjet head, the support material composition preferably has a surface tension of 25.0 to 35.0 mN / m at the ejection temperature. The surface tension is measured using, for example, a fully automatic equilibrium electrosurface tension meter ESB-V (manufactured by Kyowa Interface Science Co., Ltd.).

The composition for a support material contains a total of 10% by mass or more and less than 40% by mass of a water-soluble ethylenically unsaturated monomer, and a polymerization initiator is added to 100% by mass of the water-soluble ethylenically unsaturated monomer. It is preferable to contain 0.1% by mass or more and less than 5.0% by mass.

The composition for a support material can be used as an ink for an inkjet 3D printer.

[Support material for inkjet 3D printers]
The support material for an inkjet 3D printer of the present invention has a weight average molecular weight of 10,000 to 50,000. In the support material for an inkjet 3D printer of the present invention, by setting the weight average molecular weight to 10,000 to 50,000, it is possible to achieve both the hardness of supporting the model material and the excellent solubility in a solvent.

[Manufacturing method of stereolithography]
The method for manufacturing a stereolithographic product of the present invention includes a forming step of forming a support material; a forming step of a model material; and a removing step of the supporting material by the manufacturing method of a support material for an inkjet 3D printer of the present invention. I'm out.

In the forming step of forming a support material by the method for producing a support material for an inkjet 3D printer of the present invention, as described above, for a support material for an inkjet 3D printer containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator. The composition is polymerized to form a support material for an inkjet 3D printer having a weight average molecular weight of 10,000 to 50,000. The preferred embodiment is as described above.

In the process of forming a model material, a known composition for a model material is sprayed from a nozzle, formed by printing, or the like, ^{and then irradiated with ultraviolet rays of about 100 to 2000 mJ / cm 2} to be photocured to form a model material.

In the step of removing the support material, since the support material formed by the method for producing the support material for an inkjet 3D printer of the present invention has excellent water solubility, the support material can be easily removed with a polar solvent such as water. As a removing method, a method of allowing the cured product to stand in water to remove the support material is preferable from the viewpoint of safety and cost.

In the method for manufacturing a stereolithographic product of the present invention, since the support material has both hardness supporting the model material and excellent solubility in a solvent, it is easy to manufacture a stereolithographic product having excellent moldability. can do.

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited by the following examples as well as the present invention, and appropriate modifications are made to the extent that it can be adapted to the gist of the above and the following. Of course, it is possible to carry out, and all of them are included in the technical scope of the present invention.

-Preparation of composition for support material Each component shown in Table 1 was blended in the amount (part by mass) shown in Table 1 and uniformly mixed using a mixing and stirring device to be compared with Examples 1 to 8 and Comparative Example 1. Compositions for support materials of ~ 6 were prepared.
The supportability and solubility of the obtained support material composition were evaluated by the following methods. The results are shown in Table 1.

(I) Evaluation of supportability 1.0 mL of the support material composition was dropped onto a 5 cm × 4 cm glass plate placed horizontally. The film was thinned with a spin coater so that the film thickness after curing was 20 μm. Then, 200 mJ / cm ^{2 was} irradiated using a UV irradiation device, and the operation was repeated to obtain a cured product having a thickness of 3 mm. The cured product was evaluated by measuring its hardness using a Durometer E type (manufactured by Polymer Instruments Co., Ltd.). The evaluation criteria are as follows.
⊚: 50 or more ○: 30 or more and less than 50 Δ: 10 or more and less than 30 ×: less than 10

(Ii) Evaluation of Solubility (i) In the evaluation of curability, 1.0 g of the cured support material composition was held in 10 mL of water at a water temperature of 25 ° C., and the solubility was evaluated. The evaluation criteria are as follows.
⊚: Dissolved within 15 minutes.
◯: Dissolved within 30 minutes.
Δ: Dissolved within 1 hour.
X: Not dissolved within 1 hour.

(Iii) Measurement of weight average molecular weight (i) The weight average molecular weight of the composition for a support material cured in the curability evaluation was measured by GPC as follows.
<Measurement of weight average molecular weight>
Equipment: Tosoh high-speed GPC equipment (HLC-8320GPC)
Detector: RI
Column: Showa Denko SHODEX Asahipak GF-310-HQ, GF-710-HQ, GF-1G 7B
Column temperature: 40 ° C
Flow velocity: 0.5 ml / min
Calibration curve: POLYACRYLIC ACID STANDARD manufactured by Sowa Kagaku Co., Ltd.
Eluent: 0.1N sodium acetate aqueous solution / acetonitrile = 3/1 (weight ratio)

ACMO: Acryloyl morpholine (manufactured by Tokyo Kasei Co., Ltd.)
HEAA: Hydroxyethyl acrylamide (manufactured by Tokyo Kasei Co., Ltd.)
AM-90G: Methoxypolyethylene glycol # 400 acrylate (manufactured by Shin-Nakamura Chemical Industry Co., Ltd.)
PEG400: Polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.)
PEG1000: Polyethylene glycol (manufactured by Wako Pure Chemical Industries, Ltd.)
Irgacure 184: 1-Hydroxycyclohexyl-phenylketone (manufactured by BASF)
Lucillin TPO: 2,4,6-trimethylbenzoyldiphenylphosphine oxide (manufactured by BASF Japan Ltd.)
Irgacure 2959: 1- [4- (2-Hydroxyethoxy) -phenyl] -2-hydroxy-methylpropanone (manufactured by BASF)
Surflon S647: (manufactured by AGC Seimi Chemical Co., Ltd.)
Surflon S693: (manufactured by AGC Seimi Chemical Co., Ltd.)
Surflon S211: (manufactured by AGC Seimi Chemical Co., Ltd.)

Claims (4)

A composition for a support material for an inkjet 3D printer containing a water-soluble ethylenically unsaturated monomer and a polymerization initiator is polymerized so as to have a weight average molecular weight of 10,000 to 50,000 to be an inkjet 3D printer. A method for manufacturing a support material for an inkjet 3D printer, which manufactures a support material for an inkjet 3D printer. The composition for a support material for an inkjet 3D printer contains water.
The method for manufacturing a support material for an inkjet 3D printer according to claim 1. A support material for an inkjet 3D printer having a weight average molecular weight of 10,000 to 50,000. A forming step of forming a support material by the method for manufacturing a support material for an inkjet 3D printer according to claim 1 or 2.
Model material formation process and
A method for manufacturing a stereolithographic object, which comprises a step of removing the support material.