Polymer composition for photomodeling

Abstract

The present invention provides a novel polymer composition for photomolding, which can be used to appropriately manufacture elastic molded bodies by photomolding. A polymer composition for photomolding containing a liquid polymer and a monomer, wherein the polymer composition for photomolding is subjected to a temperature of 25°C and a relative humidity of 50% by using an E-type viscometer at a cone plate of φ25 mm and a shear rate of 100 seconds. ‑1 The viscosity measured under the conditions of is 3,000 mPa·s or less.

Description

Technical Field

[0001] The present invention relates to a polymer composition for photomolding, an elastic molded body formed by curing the composition, and a method for producing an elastic molded body using the composition. Background Art

[0002] In recent years, a three-dimensional stacking modeling device (so-called 3D printer) has been put into practical use, which manufactures a three-dimensional structure by stacking and curing resin based on the design data of the three-dimensional structure. As a three-dimensional structure manufactured by a three-dimensional stacking modeling device, a three-dimensional structure made of resin is generally known. On the other hand, if a three-dimensional structure (elastic molded body) with a lower temperature dependence of elastic modulus and a smaller permanent compression deformation than before can be manufactured, it can be expected to be used in applications different from the past.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: International Publication No. 2017 / 154335 Summary of the invention

[0006] Problems to be solved by the invention

[0007] For example, Patent Document 1 discloses a rubber composition for three-dimensional layered modeling containing liquid rubber, and the rubber composition is applied to a three-dimensional layered modeling apparatus to appropriately produce an elastic molded body.

[0008] However, in optical shaping methods such as SLA (Stereolithography Appratus), DLP (Digital Light Processing), and LCD (Liquid Crystal Display), three-dimensional shapes are optically shaped by sequentially stacking and curing liquid optical shaping compositions with a thickness of about 0.01 to 0.5 mm, and thus the optical shaping compositions are required to have low viscosity at room temperature (e.g., about 25°C). In addition, the elastic molded body of the optical shaping composition after curing is required to exhibit rubber properties.

[0009] Under such circumstances, the main object of the present invention is to provide a novel photomolding polymer composition that can appropriately produce an elastic molded body by a photomolding method. In addition, the present invention also aims to provide an elastic molded body formed by curing the photomolding polymer composition, and a method for producing an elastic molded body using the composition.

[0010] Means for solving problems

[0011] The present inventors have repeatedly conducted intensive research to solve the above problems. As a result, they have found a polymer composition containing a liquid polymer and a monomer, which has a viscosity of 25 mm at a cone plate diameter of 25 mm and a shear rate of 100 seconds under an environment of temperature 25°C and relative humidity of 50%. -1 The viscosity measured under the conditions of is 3,000 mPa·s or less, and the polymer composition can be suitably used to produce an elastic molded article by a photomolding method. The present invention has been completed through further repeated studies based on these findings.

[0012] That is, the present invention provides the following aspects of the invention.

[0013] Solution 1. A polymer composition for photomolding containing a liquid polymer and a monomer,

[0014] The photopolymer composition for photomodeling was measured by using an E-type viscometer at a temperature of 25° C. and a relative humidity of 50% at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions of is 3,000 mPa·s or less.

[0015] Aspect 2. In the polymer composition for photomodeling described in aspect 1, the liquid polymer has a (meth)acryloyl group.

[0016] Solution 3. In the photomodeling polymer composition according to Solution 1 or Solution 2, the liquid polymer contains at least one of liquid isoprene having a (meth)acryloyl group and liquid isobutylene having a (meth)acryloyl group.

[0017] Aspect 4. In the polymer composition for photomodeling according to any one of aspects 1 to 3, the number average molecular weight of the liquid polymer is 5,000 to 500,000.

[0018] Scheme 5. In the polymer composition for photomodeling described in any one of Schemes 1 to 4, the liquid polymer is subjected to a viscosity test at a temperature of 25° C. and a relative humidity of 50% using an E-type viscometer with a cone plate of φ25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions is 100 mPa·s to 1,000,000 mPa·s.

[0019] Aspect 6. In the polymer composition for photomodeling according to any one of aspects 1 to 5, the content of the liquid polymer is 15% by mass or more and 70% by mass or less.

[0020] Aspect 7. In the photomodeling polymer composition according to any one of aspects 1 to 6, when the total of the liquid polymer and the monomer is 100% by mass, the ratio of the monomer is 30% by mass or more and 85% by mass or less.

[0021] Scheme 8. In any one of schemes 1 to 7, the polymer composition for photomodeling further contains an oligomer.

[0022] When the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the ratio of the monomer is 30% by mass or more and 90% by mass or less.

[0023] Scheme 9. In any one of schemes 1 to 8, the polymer composition for photomodeling further contains an oligomer.

[0024] When the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the total ratio of the monomer and the oligomer is 30% by mass or more and 90% by mass or less.

[0025] Solution 10. In the polymer composition for photomodeling described in Solution 8 or 9, the oligomer is at least one of urethane (meth)acrylate and epoxy (meth)acrylate.

[0026] Aspect 11. In the polymer composition for photomodeling according to any one of aspects 8 to 10, the oligomer contains a (meth)acrylate.

[0027] Aspect 12. In the photomodeling polymer composition according to any one of aspects 1 to 11, the monomer is at least one of monofunctional to tetrafunctional monomers.

[0028] Aspect 13. In the photomodeling polymer composition according to any one of aspects 1 to 12, the monomer contains a (meth)acrylate.

[0029] Aspect 14. An elastic molded article, which is a cured product of the polymer composition for photomodeling according to any one of aspects 1 to 13.

[0030] Solution 15. A method for manufacturing an elastic formed body, comprising:

[0031] A step of supplying the polymer composition for photomodeling according to any one of schemes 1 to 13 to a modeling table, irradiating the polymer composition for photomodeling with light, thereby curing the polymer composition for photomodeling to form a first layer of a cured product;

[0032] A step of supplying the photomodeling polymer composition for forming a second layer of the cured product onto the first layer of the cured product, and irradiating the photomodeling polymer composition with light to cure the photomodeling polymer composition to form the second layer of the cured product; and

[0033] The same steps as the step of forming the cured product of the second layer are repeated until the Nth layer is formed, thereby manufacturing an elastic molded body having a three-dimensional shape.

[0034] Effects of the Invention

[0035] According to the present invention, a novel photomolding polymer composition for appropriately manufacturing an elastic molded body by a photomolding method can be provided. In addition, according to the present invention, an elastic molded body formed by curing the photomolding polymer composition and a method for manufacturing an elastic molded body using the composition can also be provided. DETAILED DESCRIPTION

[0036] The polymer composition for photomodeling of the present invention is characterized in that it contains a liquid polymer and a monomer, and is subjected to a viscosity test at a cone plate diameter of 25 mm and a shear rate of 100 seconds using an E-type viscometer at a temperature of 25°C and a relative humidity of 50%. -1 The viscosity measured under the conditions of is 3,000 mPa·s or less. The photomolding polymer composition of the present invention has such characteristics, so that an elastic molded body can be appropriately manufactured by the photomolding method. The following describes in detail the photomolding polymer composition of the present invention, the elastic molded body formed by curing the composition, and the method for manufacturing an elastic molded body using the composition.

[0037] In addition, in the present invention, "polymer composition for photomolding" refers to a polymer composition for photomolding, which is used for manufacturing a three-dimensional structure by repeatedly stacking and photocuring the polymer composition based on, for example, design data of a three-dimensional structure using a three-dimensional stacking molding device for photomolding (so-called 3D printer, etc.). As such photomolding methods, various methods are known, such as SLA method (Stereolithography Appratus), DLP method (Digital Light Processing), LCD method (Liquid Crystal Display), etc. Since the polymer composition for photomolding of the present invention has a low viscosity at room temperature (25°C) and forms an elastic molded body by proper curing through light irradiation, it can be appropriately used in the manufacture of an elastic molded body using the photomolding method.

[0038] In addition, in the present invention, "(meth)acryloyl" means "acryloyl or methacryloyl", and similar expressions are the same. In addition, in this specification, the numerical values ​​connected with "to" refer to the numerical range including the numerical values ​​before and after "to" as the lower limit and the upper limit. When multiple lower limits and multiple upper limits are recorded separately, any lower limit and upper limit can be selected and connected with "to".

[0039] <Polymer composition for photomodeling>

[0040] The polymer composition for photomodeling of the present invention contains a liquid polymer as a polymer and a monomer, and the polymer composition for photomodeling is cured by light irradiation to form an elastic molded body.

[0041] The polymer composition for photomodeling of the present invention is subjected to a viscosity test at a temperature of 25°C and a relative humidity of 50% using an E-type viscometer at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions of is 3,000 mPa·s or less. From the viewpoint of achieving a viscosity suitable for the photomolding method under room temperature and allowing the elastic molded body obtained by curing to exhibit excellent properties, the viscosity is preferably 2,500 mPa·s or less, more preferably 2,000 mPa·s or less. In addition, as the lower limit of the viscosity, for example, 5 mPa·s or more, preferably 10 mPa·s or more, more preferably 20 mPa·s or more, and further preferably 30 mPa·s or more.

[0042] The photomolding method generally includes the steps of sequentially stacking and photocuring the polymer composition for photomolding on a plane of a molding table (workbench) called a photomolding device. At this time, the thickness of one layer of the polymer composition for photomolding when cured is controlled to a stacking thickness of about 0.01 to 0.5 mm, and then irradiated with light (UV) to form a photocured layer (cured product) of about 0.01 to 0.5 mm. Then, after the photocuring, the molding table is immediately moved, and a gap of about 0.01 to 0.5 mm is generated, and the polymer composition for photomolding flows into the gap, and a photocured layer (cured product) is formed by light irradiation. This operation is repeated to gradually stack the photocured layers, so that the thickness of the elastic molded body is gradually increased. When the viscosity of the polymer composition for photomolding is higher than 3,000 mPa·s, it is difficult for the polymer composition for photomolding to flow into the gap of about 0.01 to 0.5 mm, and the photocured layer cannot be properly formed. In addition, although the movement speed of the molding table can be slowed down until the polymer composition for photomolding is fully fluid, the productivity will be reduced. Furthermore, even a slight movement of the molding table may exert a large shear force on the polymer composition for photomolding, thereby causing damage to the structure being photomolded.

[0043] As liquid polymer, it is not particularly limited, and known substances can be used, and commercial products can also be used. As specific examples of liquid polymers, liquid butadiene, liquid styrene-butadiene copolymers, liquid isoprene-butadiene copolymers, liquid isoprene, liquid hydrogenated isoprene, liquid isoprene-styrene copolymers, liquid isobutylene, etc. can be listed. Among them, from the viewpoint of becoming a viscosity suitable for light shaping and making the elastic molded body obtained by curing exert excellent properties (such as Shore hardness, tensile strength at break, tensile elongation at break, permanent compression set, repeated fatigue properties, etc. described later), preferably, a substance having an unsaturated bond such as a (meth) acryloyl group, a vinyl group, etc. that can be cross-linked by light irradiation, a substance having a cyclic ether such as an epoxy compound and an oxetane compound, etc., and a substance having a (meth) acryloyl group is particularly preferred. As the liquid polymer, from the viewpoint of improving the tensile breaking strength and tensile breaking elongation of the elastic molded body, liquid isoprene having a (meth)acryloyl group and liquid isobutylene having a (meth)acryloyl group are particularly preferred. The liquid polymer may contain one kind alone or two or more kinds.

[0044] The content of the liquid polymer in the polymer composition for photomodeling of the present invention is not particularly limited. From the viewpoint of achieving a viscosity suitable for the photomodeling method under room temperature and making the elastic molded body obtained by curing exhibit excellent properties, for example, 5% by mass or more, preferably 10% by mass or more, more preferably 15% by mass or more, further preferably 20% by mass or more, and particularly preferably 35% by mass or more. In addition, from the same viewpoint, the upper limit of the content of the liquid polymer in the polymer composition for photomodeling of the present invention can be, for example, 75% by mass or less, preferably 70% by mass or less, more preferably 65% ​​by mass or less, and further preferably 60% by mass or less.

[0045] Although the polymer composition for photomolding of the present invention contains a polymer component different from the liquid polymer (for example, a diluent polymer), from the viewpoint of achieving a viscosity suitable for the photomolding method under room temperature and enabling the elastic molded body obtained by curing to exhibit excellent properties, the content of the polymer component other than the liquid polymer is preferably 15% by mass or less, more preferably 10% by mass or less, further preferably 5% by mass or less, and particularly preferably 0% by mass.

[0046] The number average molecular weight (Mn) of the liquid polymer is not particularly limited, but from the same viewpoint, preferably 500 or more, more preferably about 5,000 to 500,000, further preferably about 5,000 to 400,000, about 5,000 to 50,000, about 5,000 to 40,000, etc. can be cited.

[0047] The number average molecular weight (Mn) of the liquid polymer is a value measured by gel permeation chromatography in terms of standard polystyrene.

[0048] The liquid polymer was measured at a temperature of 25°C and a relative humidity of 50% using an E-type viscometer with a cone plate of 25 mm and a shear rate of 100 s -1 From the same viewpoint, the viscosity measured under the conditions of is preferably 100 to 1,000,000 mPa·s, more preferably 100 to 500,000 mPa·s, and further preferably 10,000 to 450,000 mPa·s.

[0049] The monomers contained in the polymer composition for photomodeling of the present invention are not particularly limited as long as they are photopolymerizable monomers that can be cured by light irradiation. For example, monofunctional monomers and polyfunctional monomers (such as difunctional monomers, trifunctional monomers, tetrafunctional monomers, etc.) can be listed. From the viewpoint of having a viscosity suitable for photomodeling and making the elastic molded body obtained by curing exhibit excellent properties, monofunctional to tetrafunctional monomers can be listed. The use of monofunctional monomers is more preferred from the viewpoint of reducing the viscosity of the polymer composition for photomodeling under room temperature. In addition, the use of polyfunctional monomers is more preferred from the viewpoint of making the elastic molded body exhibit excellent properties. The monomers contained in the polymer composition for photomodeling of the present invention can be either one or more than two.

[0050] As the monomer, it is preferred to contain a (meth)acrylate because the viscosity is suitable for photomolding, the elastic molded body obtained by curing exhibits excellent properties, and the photocuring reactivity is excellent.

[0051] Preferred monofunctional monomers include monofunctional acrylates. Specific examples of monofunctional monomers include ethoxylated nonylphenol acrylate, methyl 2-allyloxy methacrylate, isostearyl acrylate, m-phenoxybenzyl acrylate, dicyclopentyl acrylate, isobornyl acrylate, phenoxyethyl (meth)acrylate, phenoxy-2-methylethyl (meth)acrylate, phenoxyethoxyethyl (meth)acrylate, 3-phenoxy-2-hydroxypropyl (meth)acrylate, 2-phenylphenoxyethyl (meth)acrylate, 4-phenylphenoxyethyl (meth)acrylate, 3-(2-phenylphenyl)-2-hydroxypropyl (meth)acrylate, (meth)acrylate of p-cumylphenol reacted with ethylene oxide, 2-bromo Phenoxyethyl (meth)acrylate, 2,4-dibromophenoxyethyl (meth)acrylate, 2,4,6-tribromophenoxyethyl (meth)acrylate, phenoxy (meth)acrylate modified with multiple ethylene oxide and propylene oxide moles, isobornyl (meth)acrylate, bornyl (meth)acrylate, tricyclodecyl (meth)acrylate, dicyclopentyl (meth)acrylate, dicyclopentenyl (meth)acrylate, cyclohexyl (meth)acrylate, 4-butylcyclohexyl (meth)acrylate, acryloyl morpholine, 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, 2-hydroxybutyl (meth)acrylate, methyl (meth)acrylate, propyl (meth)acrylate, Ethyl (meth)acrylate, propyl (meth)acrylate, isopropyl (meth)acrylate, butyl (meth)acrylate, isobutyl (meth)acrylate, tert-butyl (meth)acrylate, amyl (meth)acrylate, isoamyl (meth)acrylate, hexyl (meth)acrylate, heptyl (meth)acrylate, octyl (meth)acrylate, 2-ethylhexyl (meth)acrylate, isooctyl (meth)acrylate, nonyl (meth)acrylate, isononyl (meth)acrylate, decyl (meth)acrylate, isodecyl (meth)acrylate, undecyl (meth)acrylate, dodecyl (meth)acrylate, stearyl (meth)acrylate, isostearyl (meth)acrylate, tetrahydrofurfuryl (meth)acrylate, butoxyethyl (Meth)acrylate, ethoxydiethylene glycol (meth)acrylate, polyethylene glycol mono(meth)acrylate, polypropylene glycol mono(meth)acrylate, methoxyethylene glycol (meth)acrylate, ethoxyethyl (meth)acrylate, methoxypolyethylene glycol (meth)acrylate, methoxypolypropylene glycol (meth)acrylate, diacetone (meth)acrylamide, isobutoxymethyl (meth)acrylamide, N,N-dimethyl (meth)acrylamide, tert-octyl (meth)acrylamide, dimethylaminoethyl (meth)acrylate, diethylaminoethyl (meth)acrylate, 7-amino-3,7-dimethyloctyl (meth)acrylate, N,N-diethyl (meth)acrylamide, N,N-dimethylaminopropyl (meth) acrylamide, hydroxybutyl vinyl ether, dodecyl vinyl ether, hexadecyl vinyl ether, 2-ethylhexyl vinyl ether, polyoxyethylene nonylphenyl ether (meth) acrylate, vinyl monomers (such as N-vinyl pyrrolidone, N-vinyl caprolactam, vinyl imidazole, vinyl pyridine, etc.).

[0052] Specific examples of the multifunctional monomer include polyethylene glycol di(meth)acrylate, dipropylene glycol diacrylate, propoxylated pentylene glycol diacrylate, propoxylated glyceryl triacrylate, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trihydroxypropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, ethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, polypropylene glycol di(meth)acrylate, 1,4-butanediol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, neopentyl glycol di(meth)acrylate, trihydroxypropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, Methylpropane trioxyethyl (meth)acrylate, tris(2-hydroxyethyl)isocyanurate tri(meth)acrylate, tri(acryloxy)isocyanurate, bis(hydroxymethyl)tricyclodecane di(meth)acrylate, dipentaerythritol hexa(meth)acrylate, diol di(meth)acrylate which is an adduct of polyethylene oxide or propylene oxide to bisphenol A, diol di(meth)acrylate which is an adduct of ethylene oxide or propylene oxide to hydrogenated bisphenol A, epoxy (meth)acrylate obtained by adding (meth)acrylate to diglycidyl ether of bisphenol A, triethylene glycol divinyl ether, and the like.

[0053] From the viewpoint of achieving a viscosity suitable for photomolding at room temperature and making the elastic molded body obtained by curing exhibit excellent properties, in the polymer composition for photomolding of the present invention, when the total amount of liquid polymer and monomer is 100% by mass, the proportion of monomer is, for example, 95% by mass or less, preferably about 30 to 85% by mass, more preferably about 40 to 80% by mass, and further preferably about 50 to 70% by mass. The increase in the ratio of monomers (and oligomers described later) in the polymer composition for photomolding can reduce the permanent compression set of the elastic molded body.

[0054] The polymer composition for photomodeling of the present invention may further contain an oligomer, preferably an oligomer. An oligomer refers to, for example, a polymer in which about 10 to 100 monomers are combined. As the oligomer contained in the polymer composition for photomodeling of the present invention, as long as it can be cured by light irradiation, it is not particularly limited. The oligomer preferably contains a (meth)acrylate, for example, urethane (meth)acrylate (a substance having a urethane bond and an acrylic group by reacting an isocyanate group and a hydroxyl group), epoxy (meth)acrylate (a substance formed by polymerizing an epoxy resin and (meth)acrylic acid), etc. are preferred, and other oligomers to which (meth)acrylates are added may also be used. One oligomer may be used alone, or two or more oligomers may be used in combination.

[0055] When the polymer composition for photomolding of the present invention contains an oligomer, from the viewpoint of achieving a viscosity suitable for the photomolding method under room temperature and making the elastic molded body obtained by curing exhibit excellent properties, in the polymer composition for photomolding of the present invention, when the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the proportion of the oligomer is preferably about 30 to 90% by mass, more preferably about 40 to 80% by mass, and further preferably about 50 to 70% by mass. By containing an oligomer in the polymer composition for photomolding, the permanent compression set of the elastic molded body can be reduced. In addition, when the polymer composition for photomolding of the present invention contains an oligomer, from the viewpoint of achieving a viscosity suitable for the photomolding method under room temperature and making the elastic molded body obtained by curing exhibit excellent properties, in the polymer composition for photomolding of the present invention, when the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the total proportion of the monomer and the oligomer is preferably about 30 to 90% by mass, more preferably about 40 to 80% by mass, and further preferably about 50 to 70% by mass. As described above, the permanent compression set of the elastic molded body can be reduced by increasing the ratio of the monomers and oligomers in the polymer composition for photomolding.

[0056] In the polymer composition for photomodeling of the present invention, the monomer and the oligomer each function as a reactive diluent for adjusting the viscosity at room temperature and adjusting the properties of the elastic molded article after curing.

[0057] The photopolymer composition of the present invention preferably contains a photopolymerization initiator. By containing a photopolymerization initiator, the curing of the aforementioned photopolymer composition can be promoted. As a photopolymerization initiator, there is no particular limitation, and known substances that generate free radicals by light irradiation can be used, such as alkyl phenone series (for example, 2-hydroxy-2-methylpropiophenone, 2,2-dimethoxy-2-phenylacetophenone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone, 2-(4-(methylthio)benzoyl)-2-(4-morpholino)propane, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 2-(dimethylamino)-1-(4-morpholinophenyl)-2-benzyl-1-butanone, 2-(dimethylamino)-2-methylpropiophen ...2-methylpropiophenone, 2-(dimethylamino)-2-methylpropiophenone, 2-(dimethylamino)-2-methylpropiophenone, 2-(dimethylamino)-2-methylpropiophenone, 2-(dimethylamino)-2-methylpropiophen Preferred photopolymerization initiators include acylphosphine oxide series (bis(2,4,6-trimethylbenzoyl)phenylphosphine oxide, 2,4,6-trimethylbenzoyldiphenylphosphine oxide, etc.), oxime ester series (1,2-octanedione-(1-(4-phenylthio)-2-(O-benzoyloxime)), 1-(9-ethyl-6-(2-methylbenzoyl)-9H-carbazole-3-yl)ethanone-1-(O-acetyloxime), etc.). In the photopolymerization method, it is preferred to mainly use a light source having a peak wavelength of light intensity at a wavelength of 390nm to 410nm, especially a light source having a peak wavelength of light intensity at a wavelength of 405nm, so that the free radical polymerization of the polymer composition for photopolymerization is started by irradiation with light from such a light source. The photopolymerization initiator may be used alone or in combination of two or more. In the photopolymerization method using the above-mentioned light source, from the viewpoint of properly curing the photopolymer composition, the photopolymer composition of the present invention preferably contains at least two or more photopolymerization initiators with different absorption bands. For example, it is preferred to use a photopolymerization initiator having an absorption band in the wavelength region of 405 nm and a photopolymerization initiator having an absorption band in the wavelength region of 300 to 380 nm.

[0058] As content of a photoinitiator, about 0.5-10 mass parts is preferable with respect to 100 mass parts of liquid polymers, and about 1-7 mass parts is more preferable.

[0059] The photo-shaped polymer composition of the present invention may also contain various additives within the scope of not impairing the effect of the present invention. As additives, there are no particular restrictions, for example, known additives that can be added to the photo-shaped composition can be listed, for example, diluent polymers, photosensitizers, fillers, UV blockers, dyes, pigments, leveling agents, fluidity regulators, defoamers, plasticizers, inhibitors, flame retardants, dispersion stabilizers, storage stabilizers, antioxidants, metals, metal oxides, metal salts, ceramics, etc. can be listed. The additives contained in the photo-shaped polymer composition can be either one or more than two. In addition, the total content of the additives contained in the photo-shaped polymer composition is preferably less than 5% by mass, more preferably less than 3% by mass, and can also be 0% by mass.

[0060] The polymer composition for photomodeling of the present invention can be easily produced by mixing a liquid polymer, a monomer, and, if necessary, an oligomer, a photopolymerization initiator, various additives, and the like.

[0061] <Elastic molded body>

[0062] The elastic molded article of the present invention is a cured product of the aforementioned polymer composition for photomodeling, and specifically, is a product obtained by curing the polymer composition for photomodeling by irradiating it with light.

[0063] The Shore A hardness of the elastic molded article of the present invention may be appropriately set according to the hardness level required for the product, but from the viewpoint of exerting excellent properties, it is preferably 25 or more, and more preferably in the range of 25 to 90. That is, the polymer composition for photomolding of the present invention is subjected to the photomolding method of the DLP method at a temperature of 25°C, a UV wavelength of 405nm, a stacking pitch of 0.05mm, a UV irradiation time of 20 seconds per layer, and a UV illuminance of 5.0mW / cm 2 The elastic molded body (in the shape of a compressed ball of φ29×12.5 mm in JIS K6262:2013) produced under the conditions of is preferably a material having a Shore A hardness of 25 or more, and more preferably a material having a Shore A hardness of 25 to 90. In the present invention, the Shore A hardness of the elastic molded body is a value measured according to the method specified in JIS K6253-3:2012.

[0064] The tensile strength of the elastic molded article of the present invention can be appropriately set according to the tensile strength required for the product, but is preferably 5.0 MPa or more, and more preferably 5.5 MPa or more. That is, the polymer composition for photomolding of the present invention is subjected to the DLP method of photomolding at a temperature of 25°C, a UV wavelength of 405 nm, a stacking pitch of 0.05 mm, a UV irradiation time of 20 seconds per layer, and a UV illuminance of 5.0 mW / cm2 The elastic molded body (in the shape of dumbbell No. 3 test piece of JIS K6251:2017) produced under the conditions of is preferably a material having a tensile strength at break of 5.0 MPa or more, and more preferably a material having a tensile strength at break of 5.5 MPa or more. In addition, in the present invention, the tensile strength at break of the elastic molded body is a value measured according to the method specified in JIS K6251:2017. As the upper limit of the tensile strength at break of the elastic molded body, for example, 50 MPa or less and 15.0 MPa or less can be cited.

[0065] The tensile elongation at break of the elastic molded article of the present invention may be appropriately set according to the elongation at break required by the product, but is preferably 30% or more, more preferably 70% or more, and further preferably 100% or more. That is, the polymer composition for photomolding of the present invention is subjected to a DLP photomolding method at a temperature of 25°C, a UV wavelength of 405nm, a stacking pitch of 0.05mm, a UV irradiation time of 20 seconds per layer, and a UV illuminance of 5.0mW / cm 2 The elastic molded body (in the shape of dumbbell No. 3 test piece of JIS K6251:2017) produced under the conditions of preferably has a tensile elongation at break of 30% or more, more preferably has a tensile elongation at break of 70% or more, and further preferably has a tensile elongation at break of 100% or more. In addition, in the present invention, the tensile elongation at break of the elastic molded body is a value measured according to the method specified in JIS K6251:2017. As an upper limit of the tensile elongation at break of the elastic molded body, for example, 1000% or less can be cited.

[0066] The permanent compression set of the elastic molded body of the present invention may be appropriately set according to the permanent compression set required for the product. However, from the viewpoint of exerting excellent properties, according to the method specified in JIS K6262:2013, after 25% compression at 23°C for 22 hours, the permanent compression set after 0.5 hours after the compression is released is preferably 10% or less, more preferably 7% or less, and further preferably 5% or less. That is, the polymer composition for photomolding of the present invention is subjected to the photomolding method of the DLP method at a temperature of 25°C, a UV wavelength of 405nm, a stacking pitch of 0.05mm, a UV irradiation time of 20 seconds per layer, and a UV illuminance of 5.0mW / cm 2 The elastic formed body (in the shape of a compressed ball of φ29×12.5 mm of JIS K6262:2013) made under the conditions is preferably a material having the aforementioned permanent compression deformation of 10% or less, more preferably a material having the aforementioned permanent compression deformation of 7% or less, and further preferably a material having the aforementioned permanent compression deformation of 5% or less.

[0067] The shape of the elastic molded article of the present invention is not particularly limited, and can be formed into a desired shape by photomolding.

[0068] The method for producing the elastic molded article of the present invention is not particularly limited, and the above-mentioned polymer composition for photomolding can be used as a raw material to produce it by a known photomolding method. The details of the method for producing the polymer molded article of the present invention are described in the following section <Method for producing elastic molded article>.

[0069] <Method for producing elastic molded body>

[0070] The method for producing an elastic molded body of the present invention can be appropriately carried out by using the polymer composition for photomolding of the present invention instead of the liquid resin in a conventionally known photomolding method using a liquid resin as a raw material. Specifically, for example, in various photomolding methods such as SLA method (Stereolithography Appratus), DLP method (Digital Light Processing), LCD method (Liquid Crystal Display), etc., the polymer composition for photomolding of the present invention is used as a raw material instead of the liquid resin to produce an elastic molded body.

[0071] The elastic molded body of the present invention can be appropriately manufactured by the following methods, for example, a process of supplying the photomolding polymer composition of the present invention to a molding table, irradiating the photomolding polymer composition with light, thereby curing the photomolding polymer composition to form a first layer of a cured product; a process of supplying a photomolding polymer composition to form a second layer of a cured product on the first layer of a cured product, irradiating the photomolding polymer composition with light, and curing the photomolding polymer composition to form a second layer of a cured product; and repeatedly performing the same process as the process of forming the second layer of a cured product until N layers are formed, thereby manufacturing a three-dimensional elastic molded body (photomolded object). In the photomolding method, a known 3D printer is used, and as a 3D printer, a commercially available product can be used.

[0072] In the photomolding method, the thickness of one layer of the photomolding polymer composition when cured is, for example, about 0.01 to 0.5 mm. In addition, the irradiated light is generally ultraviolet light, preferably light having a wavelength of 405 nm. In addition, the intensity of the irradiated light is generally 0.1 to 100 mW / cm in the measurement wavelength range of 405 nm. 2The light irradiation time for curing a layer of the modeling polymer composition varies according to the method of the light modeling method and can be adjusted appropriately. For example, if it is a DLP method, it is about 1 to 60 seconds. The elastic molded body of the present invention is preferably manufactured in an environment of about room temperature (e.g., 20 to 30°C).

[0073] In addition, after the above-mentioned light shaping, according to the situation, a common secondary treatment such as high-pressure mercury lamp irradiation, metal halide lamp irradiation, UV-LED irradiation, heating, etc. can be added. Through these secondary treatments, the surface after shaping can be modified, the strength can be improved, or curing can be accelerated. There are cases where it is not necessary depending on the conditions of light shaping, so it is not necessary, but it can be performed together with light shaping.

[0074] [Example]

[0075] The following is an explanation of examples of the present invention. However, the present invention is not limited to the following examples. The details of each material used in the examples and comparative examples are shown in Table 1.

[0076]

Table 1

[0077]

[0078] <Examples 1 to 31 and Comparative Examples 1 to 6>

[0079] (Production of polymer composition for photomodeling)

[0080] The materials were mixed and defoamed in a rotating and revolving stirrer at the proportions (parts by mass) described in Tables 2 to 4 to prepare a polymer composition for photomodeling. The components were mixed to make them uniform. In Tables 2 to 4, "-" indicates that the components were not mixed.

[0081] (Viscosity of the polymer composition for photomodeling)

[0082] The photopolymer compositions obtained in the examples and comparative examples were viscometered at a temperature of 25°C (error ±2°C) and a relative humidity of 50% using an E-type viscometer (MCR301 manufactured by Anton-Paar) with a cone plate φ25 mm and a shear rate of 100 s -1 The viscosity was measured under the conditions of . The results are shown in Tables 2 to 4.

[0083] (Manufacturing of elastic molded body)

[0084] Using each of the photomolding polymer compositions obtained in each of the examples and comparative examples, an elastic molded body was manufactured by a DLP photomolding method. Specifically, a 3D printer with a light source (UV-LED) with a peak wavelength of 405 nm was used, and the temperature was 25°C, the stacking pitch was 0.05 mm, the irradiation time was 20 seconds per layer, and the illuminance at a wavelength of 405 nm was 5.0 mW / cm 2 The elastic formed body is manufactured under the conditions of. As the elastic formed body, three shapes are respectively produced. The first shape is the shape of the dumbbell-shaped No. 3 test piece of JIS K6251:2017 used in the tensile test described later, the second shape is the shape of the φ29×12.5mm compression ball of JIS K6262:2013 used in the measurement of hardness and permanent compression deformation described later, and the third shape is the test piece of JIS K6260:2017 used in the repeated fatigue test described later (dimensions are length 150mm, width 25mm, radius of curvature of the center groove 2.38mm, thickness 6.3mm).

[0085] Among them, the polymer compositions for photomolding obtained by Comparative Examples 1 to 6 cannot produce elastic molded bodies under the aforementioned conditions due to their high viscosity. Therefore, the apparent viscosity is reduced by raising the temperature of the liquid of the composition to 40 to 80°C, or the workbench when making one layer is raised or lowered to a distance about 10 times the usual distance, and the layer is formed at a speed of 1 / 10, thereby obtaining an elastic molded body. In addition, when a commercially available 3D printer is used directly, it is difficult to produce the elastic molded bodies of Comparative Examples 1 to 6 under such conditions, and even if it can be produced, the productivity is very low. In addition, since the upper limit of the temperature adjustment in commercially available 3D printers is about 30°C, it is difficult to produce the elastic molded bodies of Comparative Examples 1 to 6 using a commercially available 3D printer.

[0086] (Hardness of elastic molded body)

[0087] The Shore A hardness of the elastic molded bodies (in the shape of a compressed ball of φ29×12.5 mm in JIS K6262:2013) obtained in Examples and Comparative Examples was measured in accordance with the method specified in JIS K6253-3:2012. The results are shown in Tables 2 to 4.

[0088] (Tensile test of elastic formed body)

[0089] The elastic molded bodies (in the shape of dumbbell No. 3 test pieces of JIS K6251:2017) obtained from the examples and comparative examples were measured for tensile strength at break and tensile elongation at break in accordance with the provisions of JIS K6251:2017. The results are shown in Tables 2 to 4. It can be seen that the larger the value of tensile strength at break, the higher the strength of the elastic molded body, and the larger the value of tensile elongation at break, the easier it is to elongate, and the better the mechanical properties of the elastic molded body.

[0090] (Permanent compression set)

[0091] The elastic molded bodies (in the shape of a compressed ball of φ29×12.5 mm in JIS K6262:2013) obtained from the examples and comparative examples were subjected to 25% compression at 23°C for 22 hours in accordance with the provisions of JIS K6262:2013, and the compression permanent deformation after 0.5 hours was measured after the compression was released. The results are shown in Tables 2 to 4. It can be seen that the smaller the value of the permanent compression deformation, the better the restoring force of the elastic molded body.

[0092] (Repeated fatigue test)

[0093] Regarding the elastic formed body obtained by the embodiment and the comparative example (test piece of JIS K6260:2017 (dimensions length 150mm, width 25mm, radius of curvature of the center groove 2.38mm, thickness 6.3mm)), repeated fatigue test was carried out using De Mattie bending tester in accordance with the provisions of JIS K6260:2017. A crack was engraved at the center groove of the test piece, and the growth amplitude of the split when repeatedly bent at 5Hz and 50% deformation at the center groove was measured. The split growth (times / mm) is calculated using the following formula. It can be judged that the number of bends for the split to grow 1mm is measured. The results are shown in Tables 2 to 4. The larger the value, the more time it takes for the split to grow 1mm, and the better the result of the repeated fatigue test (bending split growth resistance).

[0094] Split growth (times / mm) = number of bends (times) / split length (mm)

[0095] (Manufacturing time of elastic molded body)

[0096] The time required for producing the elastic molded body (molding time when producing a 2 mm thick sample) was measured. ◎ represents 25 minutes or less, 0 represents more than 25 minutes and within 60 minutes, and × represents more than 60 minutes or when the DLP method cannot produce the elastic molded body. The results are shown in Tables 2 to 4.

[0097]

Table 2

[0098]

[0099]

Table 3

[0100]

[0000]

[0102]

Table 4

[0103]

[0104] As shown in Tables 2 to 4, the photomolding polymer compositions of Examples 1 to 31 contain liquid polymers and monomers, and have a viscosity of 3,000 mPa·s or less at a temperature of 25°C. The photomolding polymer compositions of Examples 1 to 31 have low viscosity at room temperature, and photomolding methods such as SLA, DLP, and LCD can be appropriately applied to produce the desired elastic molded body. In addition, the obtained elastic molded body also has good hardness, tensile strength at break, tensile elongation at break, permanent compression set, and various physical properties of repeated fatigue.

Claims

1. A polymer composition for photomodeling, comprising a liquid polymer and a monomer, and a photopolymerization initiator having an absorption band in the wavelength region of 405 nm and a photopolymerization initiator having an absorption band in the wavelength region of 300 to 380 nm, The photopolymer composition for photomodeling was measured by using an E-type viscometer at a temperature of 25° C. and a relative humidity of 50% at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions is 3,000 mPa·s or less. The liquid polymer is at least one selected from liquid isoprene having a (meth)acryloyl group and liquid isobutylene having a (meth)acryloyl group, The number average molecular weight of the liquid polymer is 5,000 to 500,000, and the photopolymer composition does not contain any polymer component other than the liquid polymer. The content of the liquid polymer is 15% by mass or more and 70% by mass or less, The monomer is at least one of monofunctional, difunctional, trifunctional, and tetrafunctional (meth)acrylates.

2. A polymer composition for photomodeling, which is composed of a liquid polymer, a monomer, an oligomer, and a photopolymerization initiator having an absorption band in the wavelength region of 405 nm and a photopolymerization initiator having an absorption band in the wavelength region of 300 to 380 nm, The photopolymer composition for photomodeling was measured by using an E-type viscometer at a temperature of 25° C. and a relative humidity of 50% at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions is 3,000 mPa·s or less. The liquid polymer is at least one selected from liquid isoprene having a (meth)acryloyl group and liquid isobutylene having a (meth)acryloyl group, The number average molecular weight of the liquid polymer is 5,000 or more and 500,000 or less, The content of the liquid polymer is 15% by mass or more and 70% by mass or less, The monomer is at least one of monofunctional, difunctional, trifunctional, and tetrafunctional (meth)acrylates, When the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the ratio of the monomer is 30% by mass or more and 90% by mass or less, The oligomer is at least one of urethane (meth)acrylate and epoxy (meth)acrylate.

3. A polymer composition for photomodeling, which is composed of a liquid polymer, a monomer, an oligomer, and a photopolymerization initiator having an absorption band in the wavelength region of 405 nm and a photopolymerization initiator having an absorption band in the wavelength region of 300 to 380 nm, The photopolymer composition for photomodeling was measured by using an E-type viscometer at a temperature of 25° C. and a relative humidity of 50% at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions is 3,000 mPa·s or less. The liquid polymer is at least one selected from liquid isoprene having a (meth)acryloyl group and liquid isobutylene having a (meth)acryloyl group, The number average molecular weight of the liquid polymer is 5,000 or more and 500,000 or less, The content of the liquid polymer is 15% by mass or more and 70% by mass or less, The monomer is at least one of monofunctional, difunctional, trifunctional, and tetrafunctional (meth)acrylates. When the total of the liquid polymer, the monomer, and the oligomer is 100% by mass, the total ratio of the monomer and the oligomer is 30% by mass or more and 90% by mass or less, The oligomer is at least one of urethane (meth)acrylate and epoxy (meth)acrylate.

4. The polymer composition for photomodeling according to any one of claims 1 to 3, wherein The liquid polymer was measured by using an E-type viscometer at a temperature of 25°C and a relative humidity of 50% at a cone plate diameter of 25 mm and a shear rate of 100 seconds. -1 The viscosity measured under the conditions is 100 mPa·s to 1,000,000 mPa·s.

5. An elastic molded article which is a cured product of the polymer composition for photomodeling according to any one of claims 1 to 4.

6. A method for manufacturing an elastic formed body, comprising: A step of supplying the polymer composition for photomodeling according to any one of claims 1 to 4 to a modeling table, irradiating the polymer composition for photomodeling with light, thereby curing the polymer composition for photomodeling to form a first layer of a cured product; A step of supplying the photomodeling polymer composition for forming a second layer of the cured product onto the first layer of the cured product, and irradiating the photomodeling polymer composition with light to cure the photomodeling polymer composition to form a second layer of the cured product; as well as The same steps as the step of forming the cured product of the second layer are repeated until the Nth layer is formed, thereby manufacturing an elastic molded body having a three-dimensional shape.

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