3D modeling material, resin molded body, and method for manufacturing the same

Abstract

A resin molded body that uses a resin modified by an unsaturated silane compound, in which the ratio of the amount of silanol condensation catalyst on the surface of the resin molded body A and the amount of silanol condensation catalyst inside the resin molded body B satisfies formula (1). A / B>1 … Formula (1) A resin molded body having suppressed warping, a good modeling appearance, and excellent strength (tensile properties) in the Z axis direction, and a method for producing the same, can be provided.

Description

Technical Field

[0001] The present invention relates to a three-dimensional shaping material, a resin molded body using the same, and a method for manufacturing the same.

Background Art

[0002] A thermal lamination deposition system by extrusion, that is, a system generally called a three-dimensional printer (3D printer) today (for example, a thermal lamination deposition system manufactured by Stratasys, Incorporated in the United States), has a fluid raw material extruded from a nozzle part provided in an extrusion head and is used to construct a three-dimensional object in layers based on a computer-aided design (CAD) model. Among them, the material extrusion method (ME method) inserts the raw material as a filament made of a thermoplastic resin into the extrusion head, continuously extrudes it from the nozzle part provided in the extrusion head onto the X-Y plane base in the chamber while heating and melting, deposits and fuses the extruded resin onto the resin laminate that has already been deposited, and solidifies integrally as it cools. Because it is a simple system, it has come to be widely used. In the ME method, usually, the nozzle position relative to the base rises in the Z-axis direction perpendicular to the X-Y plane, and the extrusion process is repeated to construct a three-dimensional object similar to the CAD model (Patent Documents 1 and 2).

[0003] Conventionally, as raw materials for the ME method, thermoplastic resins such as acrylonitrile-butadiene-styrene-based resins and polylactic acid have been preferably used from the viewpoints of molding processability and fluidity (Patent Documents 3 to 5). As described above, in the ME method, since the layer formed by extruding the resin by heat melting is cooled and solidified to some extent before the next layer is laminated, the thermal fusion property between the layers is inferior. As a result, the resin molded body made of the filament has a problem that the strength in the height (Z-axis) direction is weak.

[0004] Therefore, in order to improve the strength in the Z-axis direction, various improvements have been made to the materials used for shaping. For example, a material for 3D printers in which warping is suppressed by adjusting the crystallinity and the cooling and solidification rate during molding has been disclosed (Patent Document 6). This material has excellent thermal fusion properties between layers, and because warping during molding is suppressed, strain inside the molded resin is reduced, and an improvement in strength in the Z-axis direction can be expected.

[0005] Furthermore, for example, it has been disclosed that modified polyolefins, in which polyolefins are graft-modified with unsaturated silane compounds, can be used to improve the adhesion between layers in a resin molded article through the reaction of reactive groups. It has also been disclosed that a silanol condensation catalyst may be included in the material for the 3D printer to promote the crosslinking reaction between these reactive groups (Patent Document 7). [Prior art documents] [Patent Documents]

[0006] [Patent Document 1] Special Publication No. 2003-502184 [Patent Document 2] Special Publication No. 2003-534159 [Patent Document 3] Special Publication No. 2010-521339 [Patent Document 4] Japanese Patent Publication No. 2008-194968 [Patent Document 5] International Publication No. 2015 / 037574 Brochure [Patent Document 6] Patent Application No. 2018-17468 [Patent Document 7] Japanese Patent Publication No. 2020-37259 [Overview of the Initiative] [Problems that the invention aims to solve]

[0007] However, the present inventors have found that the resin molded articles made from the warp-suppressed 3D printer material described in Patent Document 6 still do not have sufficient strength in the Z-axis direction. Furthermore, Patent Document 7 describes a method of providing a 3D printer molded article that exhibits excellent strength and toughness by improving the thermal adhesion between filaments, improving the strength in the Z-axis direction, and reacting silane functional groups with each other simultaneously during 3D printer molding. However, when a silanol condensation catalyst is included in the 3D printer filament as in Patent Document 7, a crosslinking reaction occurs during filament manufacturing, reducing the extrusion characteristics and moldability during molding, causing the molded object to warp or deteriorating its appearance. Moreover, before and during molding, moisture in the atmosphere promotes the crosslinking reaction between reactive groups in the filament, which does not sufficiently contribute to improving the strength in the Z-axis direction of the resin molded article and makes it unsuitable for continuous molding. Therefore, further improvements were expected.

[0008] This invention has been made in view of the above circumstances, and the object of this invention is to provide a resin molded article that has suppressed warping, a good molded appearance, and excellent strength (tensile properties) in the Z-axis direction, as well as a molding material used therefor, and a method for manufacturing the same. [Means for solving the problem]

[0009] As a result of diligent research to achieve the above objective, the present inventors have found that, in the first aspect of the present invention, a resin molded body using a resin modified with an unsaturated silane compound, where the ratio of the amount of silanol condensation catalyst A on the surface of the resin molded body to the amount of silanol condensation catalyst B inside the resin molded body satisfies the following formula (1), improves the strength (tensile properties) in the Z-axis direction, thus completing the present invention. A / B>1...Equation (1)

[0010] Furthermore, in another aspect of the present invention, it was discovered that by fabricating a resin molded body using a 3D printer filament made of a resin composition containing a resin modified with an unsaturated silane compound, then applying a silanol condensation catalyst to the surface of the resin molded body and subsequently performing a crosslinking treatment, the crosslinking reaction before fabrication can be suppressed, and the strength in the Z-axis direction (tensile properties) is improved by causing a crosslinking reaction between layers in the resin molded body after fabrication, thus completing the present invention. Furthermore, in yet another aspect of the present invention, it was discovered that using a 3D fabrication material containing a resin modified with an unsaturated silane compound and having a silanol condensation catalyst content of less than 0.015% by mass results in excellent fabricability, thus completing the present invention.

[0011] In other words, the gist of this invention is as follows: [1] A resin molded body using a resin modified with an unsaturated silane compound, wherein the ratio of the amount of silanol condensation catalyst A on the surface of the resin molded body to the amount of silanol condensation catalyst B inside the resin molded body satisfies the following equation (1). A / B>1...Equation (1) [2] The resin molded body described in [1], wherein the resin molded body is manufactured by a three-dimensional printer.

[0012] [3] The resin molded article according to [1] or [2], wherein the amount of modification of the resin modified with an unsaturated silane compound is 0.1% by mass or more and 5.0% by mass or less, based on 100% by mass of the base resin. [4] A resin molded article according to any one of [1] to [3], wherein the crystallization heat (ΔHc) of a resin modified with an unsaturated silane compound, measured by differential scanning calorimetry at a cooling rate of 10°C / min, is 0 J / g or more and 100 J / g or less.

[0013] [5] A resin molded article according to any one of [1] to [4], wherein the storage modulus (E') of the resin modified with an unsaturated silane compound, measured at 40°C and 10 Hz, is 200 MPa or more and 5000 MPa or less. The resin molded article according to any one of [1] to [5], wherein the crystal melting temperature (Tm) of the resin modified with an unsaturated silane compound is 50°C or higher and 200°C or lower.

[0014] [7] The resin molded article according to any one of [1] to [6], wherein the silanol condensation catalyst is one or more compounds selected from the group consisting of metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids, organic acids, and inorganic acid esters. [8] The resin molded article according to any one of [1] to [7], wherein the resin is one or more resins selected from the group consisting of polyolefins, ethylene-α-olefin-non-conjugated diene copolymer rubbers, ethylene-glycidyl methacrylate-vinyl acetate copolymers, vinyl aromatic polymers, saponified ethylene-vinyl ester copolymers, polyester thermoplastic elastomers, ethylene-vinyl acetate copolymers, and styrene resins.

[0015] [9] A method for producing a resin molded article, which uses a resin modified with an unsaturated silane compound, applies a silanol condensation catalyst to the surface of the resin molded article after shaping, and performs moisture crosslinking.

[10] The method for producing a resin molded article according to [9], wherein the above shaping is shaping by a 3D printer.

[11] The method for producing a resin molded article according to [9] or

[10] , wherein the modification amount of the resin modified with an unsaturated silane compound is 0.1% by mass or more and 5.0% by mass or less based on 100% by mass of the base resin.

[0016]

[12] The method for producing a resin molded article according to any one of [9] to [1], wherein the heat of crystallization (ΔHc) of the resin modified with an unsaturated silane compound measured at a temperature decrease rate of 10°C / min by differential scanning calorimetry is 0 J / g or more and 100 J / g or less.

[13] The method for producing a resin molded article according to any one of [9] to

[12] , wherein the storage elastic modulus (E') of the resin modified with an unsaturated silane compound measured at 40°C and 10 Hz is 200 MPa or more and 5000 MPa or less.

[0017]

[14] The method for manufacturing a resin molded body according to any one of [9] to

[13] , wherein the crystal melting temperature (Tm) of the resin modified with an unsaturated silane compound is 50°C or higher and 200°C or lower.

[15] The method for manufacturing a resin molded body according to any one of [9] to

[14] , wherein the silanol condensation catalyst is one or more compounds selected from the group consisting of metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids, organic acids, and inorganic acid esters.

[0018]

[16] The method for manufacturing a resin molded body according to any one of [9] to

[15] , wherein the resin is one or more resins selected from the group consisting of polyolefins, ethylene-α-olefin-non-conjugated diene copolymer rubbers, ethylene-glycidyl methacrylate-vinyl acetate copolymers, vinyl aromatic polymers, saponified ethylene-vinyl ester copolymers, polyester thermoplastic elastomers, ethylene-vinyl acetate copolymers, and styrene resins.

[0019]

[17] A three-dimensional modeling material using a resin modified with an unsaturated silane compound, characterized in that the content of the silanol condensation catalyst is less than 0.015% by mass.

[18] The three-dimensional modeling material according to

[17] , wherein the modification amount of the resin modified with an unsaturated silane compound is 0.1% by mass or more and 5.0% by mass or less with respect to 100% by mass of the base resin.

[19] The three-dimensional modeling material according to

[17] or

[18] , wherein the heat of crystallization (ΔHc) of the resin modified with an unsaturated silane compound measured at a temperature-lowering rate of 10°C / min by differential scanning calorimetry is 0 J / g or more and 100 J / g or less.

[20] The three-dimensional modeling material according to any one of

[17] to

[19] , wherein the storage elastic modulus (E') of the resin modified with an unsaturated silane compound measured at 40°C and 10 Hz is 200 MPa or more and 5000 MPa or less.

[21] The three-dimensional modeling material according to any one of

[17] to

[20] , wherein the crystal melting temperature (Tm) of the resin modified with an unsaturated silane compound is 50°C or higher and 200°C or lower.

Advantages of the Invention

[0020] This invention provides a 3D modeling material, a resin molded article, and a method for manufacturing the same, which exhibit suppressed warping, a good molded appearance, and excellent strength (tensile properties) in the Z-axis direction due to interlayer crosslinking.

[0021] [Why the invention is effective] The reason why this invention is effective is not yet clear, but it can be inferred to be for the following reasons. In other words, according to the present invention's method for manufacturing resin molded articles, viscosity increases due to resin crosslinking are less likely to occur before or during molding, resulting in good moldability (continuous molding capability) when molding continuously, suppressing warping of molded products, and enabling the production of resin molded articles with excellent productivity and a good molded appearance. Furthermore, it is presumed that by adding a silanol condensation catalyst after molding and crosslinking the interlayers of the resin molded article, a resin molded article with excellent Z-axis strength (tensile strength) can be obtained. Moreover, by using a resin modified with an unsaturated silane compound and a 3D molding material having a silanol condensation catalyst content of less than 0.015% by mass, it becomes possible to create resin molded articles using the above manufacturing method. [Modes for carrying out the invention]

[0022] The following describes in detail embodiments for carrying out the present invention (hereinafter referred to as "this embodiment"). This embodiment is illustrative for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be implemented in various modifications within the scope of its gist. The present invention relates to a resin molded article made of a resin modified with an unsaturated silane compound, characterized in that the ratio of the amount of silanol condensation catalyst A on the surface of the molded article to the amount of silanol condensation catalyst B inside the molded article satisfies the following formula (1). A / B>1...Equation (1)

[0023] <Resin modified with unsaturated silane compounds> The base resin included in the resin modified with an unsaturated silane compound used in the resin molded articles of the present invention is not particularly limited, but specific examples include the following: Polyolefin resins such as polyethylene, polypropylene, ethylene / propylene copolymer, ethylene / butene copolymer, and propylene / butene copolymer; ethylene-α-olefin-non-conjugated diene copolymer rubber; ethylene-glycidyl methacrylate-vinyl acetate copolymer; vinyl aromatic polymers (styrene-based, SEBS, SBS, ABS, etc.); ethylene-vinyl ester copolymer saponified products (EVOH, etc.); polyester thermoplastic elastomers; ethylene-vinyl acetate copolymer; and styrene-based resins are preferred. Of these, polyolefin resins and polyester-based resins are more preferred from the viewpoint of ease of modification and moldability. Furthermore, the base resin may consist of one resin selected from the above, or a combination of several resins may be used.

[0024] Note that the physical properties of the base resin described later refer to the physical properties of that single resin if it is a single type of resin, and to the physical properties of the mixture if multiple types of resins are used. The olefin resin used in the base resin described above is not particularly limited, but it can be obtained using monomers such as propylene, ethylene, and α-olefins, and known polymerization methods using known olefin polymerization catalysts. For example, slurry polymerization, solution polymerization, gas-phase polymerization, etc., using multi-site catalysts such as Ziegler-Natta type catalysts, metallocene catalysts, and post-metallocene catalysts, as well as bulk polymerization using radical initiators, etc. There are no restrictions on the molecular weight of the olefin resin, but the weight-average molecular weight is preferably 20,000 or more, more preferably 50,000 or more, and preferably 1,000,000 or less. The weight-average molecular weight referred to here is the weight-average molecular weight on a polystyrene basis measured by GPC using orthodichlorobenzene or the like as a solvent. Specific examples of olefin resins used in the three-dimensional molding materials of the present invention include, for example, ultra-low density polyethylene resin, low density polyethylene resin, linear low density polyethylene (ethylene-α-olefin copolymer) resin, medium density polyethylene resin, high density polyethylene resin, propylene homopolymer, and copolymers of propylene with other monomers copolymerizable with propylene. Examples of other monomers copolymerizable with propylene include ethylene, α-olefins having 4 to 12 carbon atoms such as 1-butene, 1-hexene, 4-methylpentene-1, and 1-octene, and dienes such as divinylbenzene, 1,4-cyclohexadiene, dicyclopentadiene, cyclooctadiene, and ethylidene norbornene. There are no particular restrictions on the copolymerization form (random, block, etc.), branching, branching degree distribution, or stereostructure of these polymers, and they can be isotactic, atactic, syndiotactic, or a mixture thereof.

[0025] The olefin resin used in the base resin described above is not particularly limited as long as it is within the scope of the present invention, but commercially available products can be used. Specific examples include the following: Engage (registered trademark, manufactured by DuPont Dow Elastomers), Infuse series (registered trademark, manufactured by Dow Chemical), Tuffmer series (registered trademark, manufactured by Mitsui Chemicals), Kernel series (registered trademark, manufactured by Nippon Polyethylene Co., Ltd.), Cataloy (registered trademark, manufactured by Liondale-Basel), Adflex series (registered trademark, manufactured by Sun Allomer Co., Ltd.), Wintec series (registered trademark, manufactured by Nippon Polypropylene Co., Ltd.), Wellnex series (registered trademark, manufactured by Nippon Polypropylene Co., Ltd.), and Zelas series (registered trademark, manufactured by Mitsubishi Chemical Corporation).

[0026] The lower limit of the density of the base resin mentioned above is not particularly limited, but from the perspective of preventing the filament from bending easily and the strength of the molded resin product, 0.850 g / cm³ is recommended. 3 The above is preferable, and 0.855 g / cm³ 3 The above is more preferable, 0.860 g / cm³ 3 The above is even more preferable. Furthermore, there is no particular upper limit to the density of the base resin, but from the viewpoint of suppressing warping of the molded object and interlayer thermal fusion properties, 0.940 g / cm³ is preferable. 3 The following is preferable: 0.935 g / cm³ 3 The following is more preferable: 0.930 g / cm³ 3 The following are even more preferable.

[0027] The lower limit of the melt index (MI) of the base resin is not particularly limited, but from the viewpoint of high-speed molding performance, it is preferably 0.1 g / 10 min or more, more preferably 1 g / 10 min or more, and even more preferably 2 g / 10 min or more, based on a value measured at 190°C and a load of 2.16 kgf. Furthermore, the upper limit of the melt index (MI) of the base resin is not particularly limited, but from the viewpoint of the mechanical properties of the base resin, it is preferably 100 g / 10 min or less, more preferably 50 g / 10 min or less, and even more preferably 35 g / 10 min or less, based on a value measured at 190°C and a load of 2.16 kgf.

[0028] The lower limit of the crystal melting temperature (Tm) of the base resin of the present invention is not particularly limited, but from the viewpoint of heat resistance, it is preferably 50°C or higher, more preferably 100°C or higher, and even more preferably 105°C or higher. Similarly, the upper limit of the crystal melting temperature (Tm) is not particularly limited, but from the viewpoint of versatility of usable 3D printers, it is preferably 300°C or lower, more preferably 250°C or lower, even more preferably 180°C or lower, even more preferably 170°C or lower, and even more preferably 168°C or lower.

[0029] The unsaturated silane compound used in the resin modified with the unsaturated silane compound used in the resin molded article of the present invention is not limited, but the unsaturated silane compound represented by the following formula (A) is preferably used. RSi(R')3···(A) In the above formula (A), R is an ethylenically unsaturated hydrocarbon group, and R' are independently a hydrocarbon group having 1 to 10 carbon atoms or an alkoxy group having 1 to 10 carbon atoms, with at least one of the R' being an alkoxy group having 1 to 10 carbon atoms.

[0030] In formula (1), R is preferably an ethylenically unsaturated hydrocarbon group having 2 to 10 carbon atoms, and more preferably an ethylenically unsaturated hydrocarbon group having 2 to 6 carbon atoms. Specifically, examples include alkenyl groups such as vinyl groups, propenyl groups, butenyl groups, and cyclohexenyl groups. In formula (A), R' is preferably a hydrocarbon group having 1 to 6 carbon atoms or an alkoxy group having 1 to 6 carbon atoms, and more preferably a hydrocarbon group having 1 to 4 carbon atoms or an alkoxy group having 1 to 4 carbon atoms. Furthermore, at least one of R' is preferably an alkoxy group having 1 to 6 carbon atoms, and more preferably an alkoxy group having 1 to 4 carbon atoms.

[0031] The hydrocarbon group R' having 1 to 10 carbon atoms may be an aliphatic group, an alicyclic group, or an aromatic group, but it is preferable that it be an aliphatic group. The alkoxy group R' having 1 to 10 carbon atoms may be linear, branched, or cyclic, but it is preferable that it be linear or branched. When R' is a hydrocarbon group, specific examples include alkyl groups such as methyl, ethyl, isopropyl, t-butyl, n-butyl, i-butyl, and cyclohexyl groups, or aryl groups such as phenyl groups. When R' is an alkoxy group, specific examples include methoxy, ethoxy, isopropoxy, and β-methoxyethoxy groups.

[0032] When an unsaturated silane compound is represented by formula (A), at least one of the three R' groups is an alkoxy group, but it is preferable that two of the R' groups are alkoxy groups, and it is more preferable that all of the R' groups are alkoxy groups. Among the unsaturated silane compounds, vinyltrialkoxysilanes, such as vinyltrimethoxysilane, vinyltriethoxysilane, and propenyltrimethoxysilane, represented by formula (A), are preferred. This is because the vinyl group enables modification to polyethylene, and the alkoxy group facilitates the crosslinking reaction described later. Specifically, the alkoxy group introduced by graft modification of modified polyethylene with an unsaturated silane compound reacts with water in the presence of a silanol condensation catalyst to hydrolyze and generate silanol groups. The silanol groups then undergo dehydration condensation, causing the modified polyethylenes to bond together and a crosslinking reaction to occur.

[0033] The lower limit of the amount of modification of the resin modified with the unsaturated silane compound used in the resin molded article of the present invention is not particularly limited, but from the viewpoint of improving the Z-axis strength after crosslinking, it is preferably 0.1% by mass or more, more preferably 0.3% by mass or more, and even more preferably 0.5% by mass or more, relative to 100% by mass of the base resin. Furthermore, the upper limit of the amount of modification of the resin modified with the unsaturated silane compound used in the resin molded article of the present invention is not particularly limited, but from the viewpoint of suppressing unnecessary crosslinking before molding, it is preferably 5% by mass or less, more preferably 4% by mass or less, even more preferably 3% by mass or less, particularly preferably 2% by mass or less, and most preferably 1% by mass or less, relative to 100% by mass of the base resin.

[0034] Here, the amount of resin modification by the unsaturated silane compound is the mass ratio of the unsaturated silane compound introduced by modification to the base resin before modification. The sample was heated and burned to produce ash, the ash was dissolved in pure water using alkali fusion, and then quantified. The measurement was performed using ICP emission spectrometry with a high-frequency plasma emission spectrometer. During the above modification, compounds other than unsaturated silane compounds can be added as long as they are within the scope of the gist of the present invention. Specific examples include the following: unsaturated carboxylic acids such as acrylic acid, methacrylic acid, ethacrylic acid, maleic acid, fumaric acid, tetrahydrophthalic acid, itaconic acid, citraconic acid, crotonic acid, and isocrotonic acid, and their acid anhydrides. Furthermore, the compounds other than unsaturated silane compounds may consist of one resin selected from the above, or a combination of several.

[0035] The resin modified with the unsaturated silane compound used in the resin molded articles of the present invention can be produced by modifying the above-mentioned base resin with the above-mentioned unsaturated silane compound. There are no particular restrictions on the modification method, and it can be carried out according to known methods, for example, solution modification, melt modification, solid-phase modification by irradiation with electron beams or ionizing radiation, and modification in a supercritical fluid are suitably used. Among these, melt modification is preferred because it is superior in terms of equipment and cost competitiveness, and melt-kneading modification using an extruder which is superior in continuous productivity is even more preferred. Examples of equipment used for melt-kneading modification include single-screw extruders, twin-screw extruders, Banbury mixers, roll mixers, etc. Among these, single-screw extruders and twin-screw extruders which are superior in continuous productivity are preferred.

[0036] In addition to electron beams and ionizing radiation, the above modification can also be carried out by methods such as high temperatures or by using radical generators such as organic or inorganic peroxides. From the viewpoint of cost and ease of operation, the use of organic peroxides is preferable. The radical generators used for denaturation are not particularly limited, but examples include organic peroxides included in the hydroperoxide group such as cumene hydroperoxide and tert-butyl hydroperoxide, the dialkylperoxide group such as dicumyl peroxide, diter-butyl peroxide, 2,5-dimethyl-2,5-diter-butyl peroxyhexane, and 2,5-dimethyl-2,5-diter-butyl peroxyhexine-3, the diacylperoxide group such as lauryl peroxide and benzoyl peroxide, the peroxyester group such as tert-peroxyacetate, tert-butyl peroxybenzoate, and tert-butyl peroxyisopropyl carbonate, and the ketone peroxide group such as cyclohexanone peroxide, as well as azo compounds such as azobisisobutyronitrile and methyl azoisobutyrate.

[0037] <Method for producing resin modified with unsaturated silane compounds> The method for producing the resin modified with the unsaturated silane compound used in the resin molded articles of the present invention is not particularly limited, but a commonly used melt extrusion modification operation involves blending the above-mentioned base resin, unsaturated silane compound, and organic peroxide, putting them into a kneader or extruder, extruding them while heating, melting, and kneading, and cooling the molten resin coming out of the tip die in a water bath or the like to obtain the modified resin.

[0038] The blending ratio of the base resin to the unsaturated silane compound in the resin molded article of the present invention is not particularly limited, but from the viewpoint of obtaining a sufficient amount of modification, it is preferable that the unsaturated silane compound be 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the base resin. Furthermore, from the viewpoint of suppressing the residue of unreacted and unwanted compounds, it is preferable that the unsaturated silane compound be 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the base resin.

[0039] The blending ratio of the unsaturated silane compound to the organic peroxide in the resin modified with the unsaturated silane compound used in the resin molded article of the present invention is not particularly limited. However, from the viewpoint of obtaining a sufficient amount of modification, it is preferable that the organic peroxide be 1 part by mass or more, more preferably 2 parts by mass or more, and even more preferably 3 parts by mass or more, per 100 parts by mass of the unsaturated silane compound. Furthermore, from the viewpoint of suppressing the residue of unwanted components, it is preferable that the organic peroxide be 30 parts by mass or less, more preferably 20 parts by mass or less, and even more preferably 10 parts by mass or less, per 100 parts by mass of the unsaturated silane compound.

[0040] The lower limit of the temperature when producing the resin modified with the unsaturated silane compound used in the resin molded articles of the present invention by melt extrusion modification is not particularly limited, but from the viewpoint of extrusion characteristics and productivity, 100°C or higher is preferred, 120°C or higher is more preferred, 140°C or higher is even more preferred, and 150°C or higher is particularly preferred. Furthermore, the upper limit of the temperature when producing the resin modified with the unsaturated silane compound used in the resin molded articles of the present invention by melt extrusion modification is not particularly limited, but from the viewpoint of thermal decomposition of the resin and handling during production, 420°C or lower is preferred, 400°C or lower is more preferred, 380°C or lower is even more preferred, and 360°C or lower is particularly preferred.

[0041] <Physical properties of resins modified with unsaturated silane compounds> The lower limit of the heat of crystallization (ΔHc) of the resin modified with the unsaturated silane compound used in the resin molded article of the present invention, measured by differential scanning calorimetry at a cooling rate of 10°C / min, is not particularly limited. However, from the viewpoint of heat resistance, it is preferably 0 J / g or more, more preferably 10 J / g or more, even more preferably 20 J / g or more, particularly preferably 30 J / g or more, and most preferably 40 J / g or more. The upper limit is also not particularly limited, but from the viewpoint of reducing warpage of the resin molded article, it is preferably 100 J / g or less, more preferably 90 J / g or less, even more preferably 80 J / g or less, particularly preferably 75 J / g or less, and most preferably 70 J / g or less. This makes it possible to reduce warpage of the molded object (resin molded article) due to crystallization shrinkage during three-dimensional molding. Furthermore, the heat of crystallization (ΔHc) can be adjusted by the composition of the resin and the blend ratio of the base resin and the unsaturated silane compound as described above.

[0042] The lower limit of the storage modulus (E') of the resin modified with an unsaturated silane compound used in the resin molded article of the present invention, measured at 40°C and 10 Hz, is not particularly limited. However, from the viewpoint of suppressing bending during molding, it is preferably 10 MPa or higher, more preferably 20 MPa or higher, even more preferably 100 MPa or higher, preferably 200 MPa or higher, more preferably 300 MPa or higher, even more preferably 400 MPa or higher, particularly preferably 500 MPa or higher, and most preferably 600 MPa or higher. This suppresses bending during filament feeding, resulting in excellent moldability and superior strength of the molded resin article. The upper limit is not particularly limited, but it is preferably 5000 MPa or lower, more preferably 4000 MPa or lower, even more preferably 3000 MPa or lower, particularly preferably 2000 MPa or lower, and most preferably 1500 MPa or lower. Within this range, the filament has an appropriate hardness, making handling during the molding process (such as setting the filament in the printer) easier, which is preferable. Furthermore, the storage modulus (E') can be adjusted by the composition of the resin and the blending ratio of the base resin and the unsaturated silane compound mentioned above.

[0043] The lower limit of the melt index (MI) of the resin modified with an unsaturated silane compound used in the resin molded article of the present invention, measured at a nozzle temperature during molding with a load of 2.16 kg, is not particularly limited. However, from the viewpoint of improving moldability, it is preferably 0.1 g / 10 min or higher, more preferably 0.2 g / 10 min or higher, and even more preferably 0.3 g / 10 min or higher. Similarly, the upper limit is not particularly limited, but from the viewpoint of maintaining good mechanical properties of the resin, it is preferably 80 g / 10 min or lower, more preferably 50 g / 10 min or lower, and even more preferably 40 g / 10 min or lower. This MI can be achieved by adjusting the MI of the base resin as described above.

[0044] The lower limit of the crystal melting temperature (Tm) of the resin modified with an unsaturated silane compound used in the resin molded article of the present invention is not particularly limited, but from the viewpoint of heat resistance, it is preferably 50°C or higher, more preferably 100°C or higher, and even more preferably 105°C or higher. Furthermore, the upper limit of the crystal melting temperature (Tm) is not particularly limited, but from the viewpoint of versatility of usable 3D printers, it is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, even more preferably 170°C or lower, and even more preferably 168°C or lower.

[0045] <3D modeling materials> The three-dimensional molding material used in the production of the resin molded articles of the present invention contains a resin modified with the above-mentioned unsaturated silane compound, and the content of the silanol condensation catalyst described later is 0.015% by mass or less relative to the amount of resin modified with the unsaturated silane compound. The content of the silanol condensation catalyst is preferably 0.01% by mass or less, more preferably 0.005% by mass or less, and most preferably 0% by mass. This suppresses the progression of crosslinking within the molding material before the molding of the resin molded article, thereby enabling the production of resin molded articles with excellent productivity and a good molded appearance. Furthermore, by adding the silanol condensation catalyst after molding and crosslinking the interlayers of the resin molded article, a resin molded article with excellent Z-axis strength (tensile strength) can be obtained.

[0046] The lower limit of the crystallization heat (ΔHc) of the 3D fabrication material of the present invention, measured by differential scanning calorimetry at a cooling rate of 10°C / min, is not particularly limited, but from the viewpoint of heat resistance, it is preferably 0 J / g or more, more preferably 10 J / g or more, even more preferably 20 J / g or more, particularly preferably 30 J / g or more, and most preferably 40 J / g or more. The upper limit is also not particularly limited, but from the viewpoint of reducing warpage of the resin molded article, it is preferably 100 J / g or less, more preferably 90 J / g or less, even more preferably 80 J / g or less, particularly preferably 65 J / g or less, and most preferably 60 J / g or less. This makes it possible to reduce warpage of the fabricated object (resin molded article) due to crystallization shrinkage during 3D fabrication. Furthermore, the crystallization heat (ΔHc) can be adjusted by the composition of the resin and the blend ratio of the base resin and the unsaturated silane compound as described above.

[0047] The lower limit of the storage modulus (E') of the 3D printing material of the present invention, measured at 40°C and 10Hz, is not particularly limited, but from the viewpoint of suppressing bending during printing, it is preferably 10 MPa or higher, more preferably 20 MPa or higher, even more preferably 100 MPa or higher, preferably 200 MPa or higher, more preferably 300 MPa or higher, even more preferably 400 MPa or higher, particularly preferably 500 MPa or higher, and most preferably 600 MPa or higher. This results in excellent strength for the printing material and the printed resin molded article. The upper limit is not particularly limited, but it is preferably 5000 MPa or lower, more preferably 4000 MPa or lower, even more preferably 3000 MPa or lower, particularly preferably 2000 MPa or lower, and most preferably 1500 MPa or lower. Within this range, the printing material has an appropriate hardness, making it easier to handle during the printing process (setting the filament in the printer, etc.), which is preferable. Furthermore, the storage modulus (E') can be adjusted by the composition of the resin and the blending ratio of the base resin and the unsaturated silane compound mentioned above.

[0048] The lower limit of the melt index (MI) of the 3D printing material of the present invention, measured at a nozzle temperature during printing with a load of 2.16 kg, is not particularly limited, but from the viewpoint of improving moldability, it is preferably 0.1 g / 10 min or higher, more preferably 0.2 g / 10 min or higher, and even more preferably 0.3 g / 10 min or higher. The upper limit is also not particularly limited, but from the viewpoint of maintaining good mechanical properties of the resin, it is preferably 80 g / 10 min or lower, more preferably 50 g / 10 min or lower, and even more preferably 40 g / 10 min or lower. This MI can be achieved by adjusting the MI of the base resin as described above.

[0049] The lower limit of the crystal melting temperature (Tm) of the 3D printing material of the present invention is not particularly limited, but from the viewpoint of heat resistance, it is preferably 50°C or higher, more preferably 100°C or higher, and even more preferably 105°C or higher. Furthermore, the upper limit of the crystal melting temperature (Tm) is not particularly limited, but from the viewpoint of versatility of usable 3D printers, it is preferably 200°C or lower, more preferably 190°C or lower, even more preferably 180°C or lower, even more preferably 170°C or lower, and even more preferably 168°C or lower.

[0050] The 3D printing material used in the manufacture of the resin molded body of the present invention may be used in a shape appropriate to the embodiment. Examples of shapes include pellets, powders, granules, and filaments. Among these, it is preferable to use it in filament form (hereinafter referred to as 3D printer filament).

[0051] The three-dimensional molding material used in the manufacture of the resin molded articles of the present invention may contain, in addition to the resin modified with an unsaturated silane compound, fillers (organic particles, inorganic particles, reinforcing materials, etc.), other resins, and other components to an extent that does not impair the effects of the present invention. Details of the fillers (organic particles, inorganic particles, and reinforcing materials, etc.) are described below. Other components include heat stabilizers, ultraviolet absorbers, light stabilizers, antioxidants (phenol-based, sulfur-based, phosphorus-based), antistatic agents, crystal nucleating agents, rust inhibitors, viscosity modifiers, pigments, other resins, rubber, fillers, acidic compounds and their derivatives, lubricants, flame retardants, impact modifiers, foaming agents, colorants, organic peroxides, inorganic additives, spreading agents, anti-blocking agents, tackifiers, and the like.

[0052] Here, specific examples of organic particles among the fillers include acrylic resin particles, melamine resin particles, silicone resin particles, and polystyrene resin particles. Here, specific examples of inorganic particles among the fillers include silica, alumina, kaolin, titanium dioxide, calcium carbonate, magnesium carbonate, zinc carbonate, calcium stearate, magnesium stearate, and zinc stearate.

[0053] Here, specific examples of reinforcing materials among fillers include inorganic fillers and inorganic fibers. Specific examples of inorganic fillers include calcium carbonate, zinc carbonate, magnesium oxide, calcium silicate, sodium aluminate, calcium aluminosilicate, magnesium silicate, potassium titanate, glass balloons, glass flakes, glass powder, silicon carbide, silicon nitride, boron nitride, gypsum, calcined kaolin, zinc oxide, antimony trioxide, zeolite, hydrotalcite, wollastonite, silica, talc, metal powder, alumina, graphite, carbon black, and carbon nanotubes. Specific examples of inorganic fibers include glass cut fibers, glass milled fibers, glass fibers, gypsum whiskers, metal fibers, metal whiskers, ceramic whiskers, carbon fibers, and cellulose nanofibers.

[0054] Here, the filler content is not particularly specified, but from the viewpoint of the strength of the molded resin article, it is preferably 1% by mass or more, more preferably 5% by mass or more, and even more preferably 10% by mass or more, based on 100% by mass of the resin modified with an unsaturated silane compound. Furthermore, from the viewpoint of suppressing a decrease in interlayer adhesion of the molded resin article, it is preferably 50% by mass or less, more preferably 40% by mass or less, and even more preferably 30% by mass or less.

[0055] Specific examples of the other resins mentioned above include polyester resin, polyamide resin, styrene resin, acrylic resin, polycarbonate resin, polyvinyl chloride resin, polyolefin resin, and various elastomers. The other resins mentioned above may be used individually or in combination of two or more. The content of the other resins mentioned above is not particularly limited, but from the viewpoint of obtaining the effects of the present invention, it is preferably 50% by mass or less, and more preferably 30% by mass or less, based on 100% by mass of the resin modified with the unsaturated silane compound.

[0056] The other ingredients mentioned above may be used individually or in combination of two or more. Furthermore, the amount of other components is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, even more preferably 10 parts by mass or less, and particularly preferably 5 parts by mass or less, per 100 parts by mass of the resin modified with the unsaturated silane compound of the present invention.

[0057] Here, specific examples of antioxidants among the other components include phenolic, sulfuric, and phosphorus-based antioxidants. Furthermore, although the content of antioxidants is not specifically defined, from the viewpoint of the strength of the molded resin article, it is preferable to have 0.1% to 1% by mass relative to 100% by mass of the resin modified with an unsaturated silane compound.

[0058] Here, specific examples of UV absorbers among the other components include benzophenone-based compounds such as 2-hydroxy-4-n-octyloxybenzophenone, 2-hydroxy-4-methoxybenzophenone, 2,2-dihydroxy-4-methoxybenzophenone, 2-hydroxy-4-methoxy-4-carboxybenzophenone, and 2-hydroxy-4-N-octoxybenzophenone; benzotriazole-based compounds such as 2-(2-hydroxy-3,5-di-t-butylphenyl)benzotriazole and 2-(2-hydroxy-5-methylphenyl)benzotriazole; and salicylic acid ester-based compounds such as phenyl salicylate and p-octylphenyl salicylate.

[0059] Furthermore, although there are no specific regulations regarding the content of the ultraviolet absorber, from the viewpoint of the strength of the molded resin article, it is preferable that it be 0.01% to 1% by mass relative to 100% by mass of the resin modified with an unsaturated silane compound. Here, specific examples of viscosity modifiers among the other components include rubber compounding oils, and more specifically, paraffin-based process oils. Furthermore, although the viscosity modifier content is not specifically defined, from the viewpoint of the strength of the molded resin article, it is preferable to have a content of 0.5% to 5% by mass relative to 100% by mass of the resin modified with an unsaturated silane compound.

[0060] Here, specific examples of tackifiers among the other components include rosin and its derivatives, terpene resins and petroleum resins and their derivatives, alkyd resins, alkylphenol resins, terpenephenol resins, coumarone indene resins, synthetic terpene resins, alkylene resins, polyisobutylene, polybutadiene, polybutene, copolymers of isobutylene and butadiene, mineral oil, process oil, pine oil, anthracene oil, pine root oil, plasticizers, animal and vegetable oils, polymerized oils, etc. Furthermore, although the viscosity modifier content is not specifically defined, from the viewpoint of the strength of the molded resin article, it is preferable to have a content of 0.5% to 5% by mass relative to 100% by mass of the resin modified with an unsaturated silane compound.

[0061] <Manufacturing method> The 3D printer filament used in the production of the resin molded articles of the present invention is manufactured using a resin modified with the above-mentioned unsaturated silane compound. There are no particular limitations on the method of mixing the resin modified with the unsaturated silane compound, but known methods, such as single-screw extruders, multi-screw extruders, Banbury mixers, kneaders, and other melt-kneading equipment, can be used. In the present invention, it is preferable to use a co-directional twin-screw extruder from the viewpoint of the dispersibility and miscibility of each component. Excellent dispersibility and miscibility are preferable because they can improve the accuracy of the filament diameter and roundness.

[0062] The method for manufacturing the 3D printer filament used in the production of the resin molded article of the present invention is not particularly limited, but it can be obtained by molding a resin modified with the above-mentioned unsaturated silane compound using a known molding method such as extrusion molding, or by using the resin modified with the unsaturated silane compound as filament during production. For example, when obtaining the 3D printer filament of the present invention by extrusion molding, the conditions are appropriately adjusted depending on the flow characteristics and moldability of the resin composition used, but are usually 80 to 400°C, preferably 100 to 300°C.

[0063] <Physical properties of 3D printer filaments> When using a 3D printer filament in the manufacture of the resin molded article of the present invention, it is preferable that the 3D printer filament satisfies the following physical properties. The lower limit of the crystallization heat (ΔHc) of the 3D printer filament used in the manufacture of the resin molded article of the present invention, measured by differential scanning calorimetry at a cooling rate of 10°C / min, is not particularly limited. However, from the viewpoint of heat resistance, it is preferably 0 J / g or more, more preferably 10 J / g or more, even more preferably 20 J / g or more, particularly preferably 40 J / g or more, and most preferably 50 J / g or more. The upper limit is also not particularly limited, but from the viewpoint of reducing warpage of the resin molded article, it is preferably 75 J / g or less, more preferably 60 J / g or less, and even more preferably 55 J / g or less. This makes it possible to reduce warpage of the molded object (resin molded article) due to crystallization shrinkage during 3D printing.

[0064] Furthermore, the heat of crystallization (ΔHc) can be adjusted by the composition of the resin, the blending ratio of the base resin and the unsaturated silane compound mentioned above, and the addition of fillers or other resins to the filament.

[0065] The lower limit of the storage modulus (E') of the 3D printer filament used in the manufacture of the resin molded articles of the present invention, measured at 40°C and 10Hz, is not particularly limited. However, from the viewpoint of suppressing bending during molding, it is preferably 400 MPa or higher, more preferably 500 MPa or higher, even more preferably 800 MPa or higher, particularly preferably 1000 MPa or higher, and most preferably 1300 MPa or higher. This suppresses bending during filament feeding, resulting in excellent moldability and superior strength of the molded resin articles. The upper limit is not particularly limited, but it is preferably 5000 MPa or lower, more preferably 4500 MPa or lower, even more preferably 4000 MPa or lower, particularly preferably 3500 MPa or lower, and most preferably 3000 MPa or lower. Within this range, the filament has an appropriate hardness, making it easier to handle during the molding process (setting the filament in the printer, etc.), which is preferable. Furthermore, the storage modulus (E') can be adjusted by the composition of the resin, the blending ratio of the base resin and the unsaturated silane compound mentioned above, and the addition of fillers or other resins to the filament.

[0066] The lower limit of the melt index (MI) of the 3D printer filament of the present invention, measured at a nozzle temperature during printing with a load of 2.16 kg, is not particularly limited, but from the viewpoint of improving moldability, it is preferably 0.1 g / 10 min or higher, more preferably 0.2 g / 10 min or higher, and even more preferably 0.3 g / 10 min or higher. The upper limit is also not particularly limited, but from the viewpoint of maintaining good mechanical properties of the resin, it is preferably 50 g / 10 min or lower, more preferably 40 g / 10 min or lower, and even more preferably 30 g / 10 min or lower. This MI can be achieved by adjusting the MI of the base resin as described above, or by adding fillers, additives, other resins, etc. to the filament. Furthermore, since the filament of the present invention does not contain the crosslinking accelerator described later, the decrease in MI due to the crosslinking reaction in the filament before printing is suppressed, resulting in a filament with excellent moldability.

[0067] The gel fraction of the 3D printer filament of the present invention is not particularly specified, but from the viewpoint of suppressing the increase in the melt viscosity of the filament and improving moldability, it is preferably 10% or less, more preferably 5% or less, even more preferably 1% or less, and most preferably 0%. Since the filament of the present invention does not contain a crosslinking accelerator described later, the increase in gel fraction due to the crosslinking reaction in the filament before printing is suppressed, resulting in a filament with excellent moldability. The gel fraction can be measured by the method described later.

[0068] The density of the 3D printer filament of the present invention is not particularly specified, but from the viewpoint of suppressing deformation due to crystallization shrinkage and improving moldability, it is preferably 1.0 or less, more preferably 0.95 or less, and even more preferably 0.90 or less. Furthermore, from the viewpoint of suppressing bending during molding, it is preferably 0.80 or more, more preferably 0.83 or more, and even more preferably 0.85 or more.

[0069] The diameter of the 3D printer filament of the present invention depends on the specifications of the system used for molding resin molded articles by fused deposition modeling, but is usually 1.0 mm or more, preferably 1.5 mm or more, more preferably 1.6 mm or more, and particularly preferably 1.7 mm or more, while the upper limit is 5.0 mm or less, preferably 4.0 mm or less, more preferably 3.5 mm or less, and particularly preferably 3.0 mm or less. Furthermore, from the viewpoint of the stability of raw material supply, it is preferable that the diameter accuracy be kept within ±5% of the error for any measurement point on the filament. In particular, it is preferable that the standard deviation of the diameter of the 3D printing filament of the present invention is 0.07 mm or less, and particularly preferably 0.06 mm or less.

[0070] Furthermore, the 3D printer filament of the present invention preferably has a roundness of 0.93 or higher, and more preferably 0.95 or higher. The upper limit of roundness is 1.0. Thus, if a 3D printer filament has a small standard deviation of diameter and high roundness, extrusion unevenness during molding is suppressed, and resin molded articles with excellent appearance and surface properties can be stably manufactured. By using a resin modified with the aforementioned unsaturated silane compound, a 3D printer filament that satisfies such standard deviation and roundness can be manufactured relatively easily.

[0071] <Method for manufacturing resin molded products> In the present invention, a resin molded article is obtained before crosslinking by using a 3D printer filament and molding it with a 3D printer. Examples of molding methods using a 3D printer include material extrusion (ME method), powder sintering method, inkjet method, and stereolithography (SLA method). The 3D printer filament of the present invention can be suitably used in fused deposition modeling (FDM) and powder sintering methods, and is particularly preferred for use in material extrusion (ME) method. The following explanation will use the material extrusion (ME) method as an example.

[0072] 3D printers generally have a chamber, which contains a heatable substrate, an extrusion head mounted in a gantry structure, a heating and melting chamber, a filament guide, and a filament cartridge mounting section, among other raw material supply components. Some 3D printers have the extrusion head and heating and melting chamber integrated into one unit. Furthermore, for manufacturing the objects according to the present invention, it is preferable to use a 3D printer in which the temperature inside the chamber (the temperature of the printing atmosphere) can be controlled.

[0073] The extrusion head is installed in a gantry structure, allowing it to be moved arbitrarily on the XY plane of the substrate. The substrate is a platform for constructing the target three-dimensional object or support material, and it is preferable that it is designed to allow for adhesion to the laminate by heating and maintaining its temperature, and to improve the dimensional stability of the resulting resin molded body to become the desired three-dimensional object. Furthermore, to improve the adhesion between the substrate and the laminate, an adhesive glue may be applied to the substrate, or a sheet with good adhesion to the laminate may be attached. Examples of sheets with good adhesion to the laminate include sheets with fine irregularities on the surface, such as inorganic fiber sheets, and sheets made of the same type of resin as the laminate. Typically, at least one of the extrusion head and the substrate is movable in the Z-axis direction perpendicular to the XY plane.

[0074] The filament is fed from the raw material supply unit and delivered to the extrusion head by a pair of opposing rollers or gears. There, it is heated and melted, and then extruded from the nozzle at the tip. Based on signals transmitted using a CAD model, the extrusion head moves its position while supplying the raw material onto the substrate, creating layers of stacked material. The resin molded body of the present invention may be fabricated using only the aforementioned filament, or it may be fabricated simultaneously with a filament consisting of a support material for supporting the shape of the fabricated body. The portion fabricated using the support material may be removed after the fabrication is complete, if necessary.

[0075] The resin molded article of the present invention is manufactured by applying a crosslinking accelerator to the aforementioned resin molded article before crosslinking and causing it to crosslink. The type of crosslinking accelerator is not particularly limited, but a silanol condensation catalyst is preferred. Here, specific examples of silanol condensation catalysts among crosslinking accelerators include one or more compounds selected from the group consisting of metal organic acid salts, titanates, borates, organic amines, ammonium salts, phosphonium salts, inorganic acids and organic acids, and inorganic acid esters.

[0076] Specific examples of metal organic salts include dibutyltin dilaurate, dioctyltin dilaurate, dibutyltin diacetate, dibutyltin dioctoate, stannous acetate, stannous octanoate, cobalt naphthenate, lead octoate, lead naphthenate, zinc octoate, zinc caprylate, iron 2-ethylhexanoate, iron octoate, and iron stearate. Examples of titanates include tetrabutyl titanate, tetranonyl titanate, and bis(acetylacetonitrile) di-isopropyl titanate. Examples of organic amines include ethylamine, dibutylamine, hexylamine, triethanolamine, dimethyl soyamine, tetramethylguanidine, and pyridine. Examples of ammonium salts include ammonium carbonate and tetramethylammonium hydroxide. Examples of phosphonium salts include tetramethylphosphonium hydroxide. Examples of inorganic and organic acids include sulfonic acids such as sulfuric acid, hydrochloric acid, acetic acid, stearic acid, maleic acid, toluenesulfonic acid, and alkylnaphthylsulfonic acid. Examples of inorganic acid esters include phosphate esters.

[0077] Preferably, examples include metal organic acid salts, sulfonic acids, and phosphate esters, and more preferably, tin metal carboxylates, such as dioctyl tin dilaurate, alkyl naphthyl sulfonic acid, and ethylhexyl phosphate ester. Although the method for applying the silanol condensation catalyst to the resin molded body is not specified, one possible method is as follows: the manufactured resin molded body is immersed in a silanol condensation catalyst solution and then air-dried at room temperature.

[0078] A silanol condensation catalyst solution is a solution containing a silanol condensation catalyst. This solution may consist solely of the silanol condensation catalyst, or it may be dispersed / mixed with any solvent. The latter is preferable due to the ease of adjusting the viscosity of the solution. While no specific solvent is required, those that do not easily dissolve the resin molded article are preferred. Examples include ethyl acetate, ethanol, isopropanol, xylene, acetic acid, ethylene glycol, acetylene, and formaldehyde. From the viewpoint of ease of crosslinking of the resin molded article, the content of the silanol condensation catalyst in the silanol condensation catalyst solution is preferably 10 vol% or more, and more preferably 20 vol% or more, relative to the total volume of the solution. Furthermore, from the viewpoint of controlling the viscosity of the solution to a range suitable for impregnation, it is preferably 95 vol% or less, and more preferably 90 vol% or less.

[0079] While there are no specific requirements for the immersion time, it is preferable to immerse it for 1 second or longer from the viewpoint of allowing the condensation catalyst to sufficiently penetrate the resin molded body. Furthermore, from the viewpoint of productivity, it is preferable to immerse it for 24 hours or less, and more preferably for 12 hours or less. While there are no specific regulations regarding the time required for natural drying after immersion, it is preferable to allow at least one hour, and more preferably 12 hours, to ensure sufficient removal of excess liquid.

[0080] While there are no specific temperature requirements for the application of the catalyst, a temperature of 40°C or higher is preferable, and 50°C or higher is more preferable, from the viewpoint of ensuring sufficient crosslinking. A humidity of 30% RH or higher is preferable, and 50% RH or higher is more preferable. Furthermore, although there are no specific restrictions on the processing time when applying the catalyst, it is preferably 1 hour or more, and more preferably 5 hours or more. From the viewpoint of suppressing thermal deformation of the resin molded article, the temperature is preferably less than 100°C, and preferably 90°C or lower.

[0081] Furthermore, although there are no specific humidity requirements for the application of the catalyst, a humidity of 95% RH or less is preferred, and 90% RH or less is more preferred, from the viewpoint of ease of control using a general constant temperature and humidity chamber. Also, from the viewpoint of productivity, the processing time is preferably 48 hours or less, and 24 hours or less is more preferred.

[0082] The gel fraction of the resin molded article after crosslinking according to the present invention is greater than 0%. Although not specifically defined, the gel fraction of a resin molded article sufficiently crosslinked by this method is approximately 10% to 80%. From the viewpoint of sufficiently crosslinking the interlayers, 15% or more is preferred, 20% or more is more preferred, 30% or more is even more preferred, and 50% or more is most preferred. Although there is no specific upper limit, since this method does not contain a silanol condensation catalyst in the filament, the gel fraction tends to be lower compared to resin molded articles produced with a silanol condensation catalyst in the filament, and is usually 80% or less.

[0083] <Physical properties of resin molded products> The resin molded article of the present invention satisfies the following formula (1) in terms of the ratio of the amount of silanol condensation catalyst A on the surface to the amount of silanol condensation catalyst B inside the molded article. By satisfying this formula, crosslinking during molding can be suppressed while the molded resin molded article can be sufficiently crosslinked, achieving both moldability and strength of the resin molded article.

[0084] A / B>1...Equation (1) As in the present invention, by adding a silanol condensation catalyst to a molded resin body after it has been formed, a molded object that satisfies the above formula can be obtained. Furthermore, catalyst amounts A and B can be evaluated by the ratio of the amount of any element contained in the catalyst to the amount of Si detected in the XPS measurement. Specifically, A is determined by calculating the ratio of the amount of any element contained in the catalyst to the amount of Si in the spectrum obtained from the XPS measurement of the surface of the resin molded body, and B is determined by calculating the ratio of the amount of any element contained in the catalyst to the amount of Si in the spectrum obtained from the XPS measurement of the center of the cross-section after cutting the resin molded body at an arbitrary location.

[0085] <Applications of resin molded products> The molded objects of the present invention are excellent in terms of appearance and strength. While there are no particular limitations on their use, they can be suitably used in stationery, toys, covers for mobile phones and smartphones, grips and other parts, school teaching materials, home appliances, repair parts for office automation equipment, various parts for automobiles, motorcycles, bicycles, aircraft, etc., materials for electrical and electronic equipment, agricultural materials, horticultural materials, fishing materials, civil engineering and construction materials, medical supplies, and the like. [Examples]

[0086] The present invention will be further explained in the following examples, but these examples do not limit the present invention in any way. The various measurements and evaluations shown in this specification were performed as follows.

[0087] (1) Crystallization heat (ΔHc) Using a differential scanning calorimeter manufactured by PerkinElmer, Ltd., product name "Pyris1 DSC," approximately 10 mg of a sample was heated from room temperature to the melting point (Tm) + 20°C at a heating rate of 10°C / min, held at this temperature for 1 minute, and then cooled to 30°C at a cooling rate of 10°C / min. The heat of crystallization (ΔHc) (during the cooling process) was determined from the thermogram measured during this process. All values ​​are rounded to two decimal places.

[0088] (2) Tensile storage modulus (E') Raw material pellets or filaments were formed into sheets approximately 0.5 mm thick by hot pressing to serve as measurement samples. Using a dynamic viscoelasticity measuring instrument (manufactured by IT Measurement Co., Ltd., product name: Viscoelastic Spectrometer DVA-200), the storage modulus (E') was measured from -100°C to 250°C under the conditions of vibration frequency: 10 Hz, heating rate: 3°C / min, and strain: 0.1%. From the obtained data, the storage modulus at 30°C (E'30°C) was determined.

[0089] (3) Crystal melting temperature (melting point Tm) Using a differential scanning calorimeter manufactured by PerkinElmer, Ltd., product name "Pyris1 DSC," approximately 10 mg of the sample was heated from room temperature to the crystal melting temperature (melting point Tm) + 20°C at a heating rate of 10°C / min, held at this temperature for 1 minute, then cooled to 30°C at a cooling rate of 10°C / min, and then heated again to 280°C at a heating rate of 10°C / min. The crystal melting temperature (melting point Tm) (°C) (during the reheating process) was determined from the thermograms measured at this time. All values ​​are rounded to two decimal places.

[0090] (4) Z-axis tensile properties Using a 3D printer (Muto Industries Co., Ltd., product name: MF-2200D), dumbbell-shaped test specimens were fabricated with a build table temperature of 60°C, a nozzle temperature of 230°C, a build speed of 7-20 mm / s, and 100% infill, ensuring that the layering direction (Z-axis direction) was aligned to the longitudinal direction. Tensile tests were performed on the specimens before and after crosslinking at a test speed of 50 mm / min. After obtaining stress-strain curves, the yield strength and elongation at break were calculated. (5) Melt Index (MI) Using a melt indexer (manufactured by Toyo Seiki Seisakusho Co., Ltd.), MI (g / 10min) was measured at 230°C with a 2.16 kg load, in accordance with JIS K7210.

[0091] (6) Surface / internal ratio of catalyst amount (A / B) Elemental analysis was performed on the surface of the dumbbell fabricated as described above, and on the central part of the cross-section obtained by cutting the tensile test section (the narrower part of the dumbbell) perpendicular to the length of the dumbbell, using an XPS spectrometer (Thermo Fisher Scientific "K-Alpha"). Sn was used as the arbitrary element to be included in the catalyst. From the obtained spectra, the ratio of Sn peaks to Si peaks on the dumbbell surface was determined as A, and the ratio of Sn peaks to Si peaks on the dumbbell cross-section was determined as B, and A / B could be calculated. If the ratio of detected Sn peaks was 0.05% or less, it was considered undetectable, and it was determined that Sn was not present. Furthermore, in the table below, the ratio of Sn peaks to Si peaks on the dumbbell surface A and the ratio of Sn peaks to Si peaks on the dumbbell cross-section B were compared, and A / B was qualitatively evaluated.

[0092] (7) Gel fraction The resin molded body was heat-treated in xylene at 140°C for 20 hours, and the gel fraction was measured from the amount of undissolved components.

[0093] (8) Formability As an evaluation sample, a dumbbell-shaped sample with a length of 75 mm, a width of 10 mm, and a thickness of 5 mm was fabricated using a 3D printer (Muto Industries Co., Ltd., product name: MF-2200D) with the thickness direction of the sample as the Z-axis direction (layering direction). PP tape (3M Scotch 315SN) was attached to the build plate, and the sample was manufactured under the following conditions: build plate temperature 70°C, nozzle temperature 220°C, printing speed 7-20 mm / s, and 100% infill. After manufacturing the evaluation sample, it was removed from the build plate and placed on a horizontal surface. The distance between the four corners of the sample and the horizontal surface was measured, and the average value of these measurements was defined as the warp. The warp during fabrication was evaluated based on this warp according to the following criteria. ○ (good): The amount of warping was less than 5 mm. × (bad): The warp was 5mm or more, or significant warping occurred during the printing process, preventing the printing from being completed.

[0094] (9) Dischargeability Using 3D printer filament that had been left in an atmosphere at 23°C and 50% relative humidity for more than 24 hours, the filament was extruded from a nozzle heated to 230°C on a 3D printer (Muto Industries Co., Ltd., product name: MF-2200D), and the extrusion process and stability were visually confirmed.

[0095] The raw materials used in the examples and comparative examples are as follows. [Raw materials] <Resin modified with unsaturated silane compounds> • PP-1: Linkron (registered trademark) PK500N (manufactured by Mitsubishi Chemical Corporation, silane-modified polypropylene, ΔHc: 35 J / g, Tm: 107℃, E'30℃: 7 MPa) • PP-2: Linkron (registered trademark) XPM800HM (manufactured by Mitsubishi Chemical Corporation, silane-modified polypropylene, ΔHc: 94 J / g, Tm: 162℃, E'30℃: 1600 MPa) PP-3: Silane-modified polypropylene, silane modification amount 0.8 wt%, ΔHc: 45 J / g PP-4: Silane-modified polypropylene, silane modification amount 0.7 wt%, ΔHc: 60 J / g <Polyolefin> • PP-5: Wellnex® RMG02 (manufactured by Nippon Polypropylene Co., Ltd., propylene-ethylene copolymer, ΔHc: 45 J / g, Tm: 129℃, E'30℃: 440 MPa)

[0096] [Example 1] <Fabrication of filaments for 3D printers> Filaments were manufactured using a dry blend of 40 parts by mass of PP-1 and 60 parts by mass of PP-2 as raw materials, by melt extrusion. The manufacturing conditions were as follows: the resin composition was laminated and extruded from a die with a diameter of 3 mm at a set temperature of 220 °C, and then taken up at 10 m / min by a take-up device after passing through a 40 °C water bath. The cross-sectional diameter of the obtained filaments ranged from 1.70 mm to 1.85 mm. The results of various evaluations performed on the obtained filaments are shown in Table 1.

[0097] <Manufacturing of resin molded products before crosslinking> Using the above filament, a dumbbell test piece was fabricated using a fused deposition modeling (FDM) extrusion system with a 3D printer (Muto Industries Co., Ltd., product name: MF-2200D), with a build plate temperature of 60°C, a nozzle temperature of 230°C, a build speed of 7-20 mm / s, and an internal fill density of 100%, so that the layering direction (Z-axis direction) of the resin molded body was the longitudinal direction. PP adhesive tape (3M Scotch 315SN) was attached to the build plate. The results of the tensile test performed on the resulting resin molded body before crosslinking are shown in Table 1. The amount of warpage in the buildability evaluation was 4.8 mm, and the warpage evaluation result was ○ (good). Furthermore, the appearance of the dumbbell used in the tensile test was good, with no significant stringing or lumps.

[0098] <Catalyst immersion and drying of resin molded products> Dioctyl tin dilaurate was used as a silanol condensation catalyst and mixed with xylene in a volume ratio of 1:4 to prepare a catalyst solution. The catalyst solution was placed in a tray and the resin molded body obtained above was immersed in the solution so that the entire surface was in contact with the solution. The resin molded body was removed from the catalyst solution, wiped to remove any dripping solution, and then air-dried for 24 hours.

[0099] <Cross-linking treatment of resin molded products> The resin molded body obtained above after catalyst immersion was subjected to a crosslinking treatment at a temperature of 85°C and a relative humidity of 85% for 16 hours. The results of a tensile test performed on the obtained resin molded body are shown in Table 1. Furthermore, when the amount of catalyst was evaluated in this crosslinked resin molded body, the elemental ratio of Sn / Si on the surface of the resin molded body was approximately 0.1, but although a Si peak was observed in the cross-section of the resin molded body, no clear peak of Sn was observed. From this, it was found that in this resin molded body, the ratio of the amount of silanol condensation catalyst A on the surface to the amount of silanol condensation catalyst B inside the molded body satisfies the following equation (1). A / B>1...Equation (1)

[0100] [Example 2] <Fabrication of filaments for 3D printers> A 3D printer filament was prepared in the same manner as in Example 1, except that 100 parts by mass of PP-3 resin was used. The results of various evaluations performed with the obtained filament are shown in Table 1.

[0101] <Manufacturing of resin molded products before crosslinking> Using the above filament, a dumbbell test specimen was fabricated in the same manner as in Example 1. The results of the tensile test performed on the obtained resin molded body before crosslinking, and the results of the moldability evaluation are shown in Table 1.

[0102] <Catalyst immersion and drying of resin molded products> The catalyst was immersed in the resin molded body and dried in the same manner as in Example 1.

[0103] <Cross-linking treatment of resin molded products> The resin molded body obtained above after catalyst immersion was subjected to crosslinking treatment in the same manner as in Example 1. The results of tensile tests performed on the obtained resin molded body are shown in Table 1. Furthermore, when the amount of catalyst was evaluated in this crosslinked resin molded body, the elemental ratio of Sn / Si on the surface of the resin molded body was approximately 0.1, but although a Si peak was observed in the cross-section of the resin molded body, no clear peak of Sn was observed. From this, it was found that in this resin molded body, the ratio of the amount of silanol condensation catalyst A on the surface to the amount of silanol condensation catalyst B inside the molded body satisfies the following equation (1). A / B>1...Equation (1)

[0104] [Example 3] <Fabrication of filaments for 3D printers> A 3D printer filament was prepared in the same manner as in Example 1, except that 100 parts by mass of PP-4 resin was used. The results of various evaluations performed with the obtained filament are shown in Table 2.

[0105] <Manufacturing of resin molded products before crosslinking> Using the above filament, a dumbbell test specimen was fabricated in the same manner as in Example 1.

[0106] <Catalyst immersion and drying of resin molded products> The catalyst was immersed in the resin molded body and dried in the same manner as in Example 1.

[0107] <Cross-linking treatment of resin molded products> The resin molded body obtained above after catalyst immersion was subjected to crosslinking treatment in the same manner as in Example 1. Furthermore, when the amount of catalyst was evaluated in this crosslinked resin molded body, it was found that the Sn / Si elemental ratio on the surface of the resin molded body was approximately 2.5, and the Sn / Si elemental ratio in the cross-section of the resin molded body was approximately 0.25. From this, it was found that in this resin molded body, the ratio of the amount of silanol condensation catalyst A on the surface to the amount of silanol condensation catalyst B inside the molded body is approximately 10, and that the following equation (1) is satisfied. A / B>1...Equation (1)

[0108] <Extrusion performance of 3D printer filaments> Using the above filament, which had been left in an atmosphere at 23°C and 50% relative humidity for more than 24 hours, we extruded it from a nozzle heated to 230°C on a 3D printer (Muto Industries Co., Ltd., product name: MF-2200D). Visual inspection of the extrusion process and stability revealed that it maintained good extrusion performance.

[0109] [Comparative Example 1] After fabricating a filament using polyolefin PP-5, a dumbbell piece was printed using a 3D printer, and a tensile test was performed. Table 1 shows the physical properties of the obtained filament and the tensile test results of the dumbbell piece. The amount of warpage in the printability evaluation was 2.2 mm, and the warpage evaluation result was ○ (good). In addition, the appearance of the dumbbell used in the tensile test was good, with no significant stringing or lumps.

[0110] [Comparative Example 2] Filament preparation and evaluation were carried out using the same method as in Example 3, except that 0.1 parts by mass of silanol condensation catalyst were blended into the filament during filament preparation. Discharge evaluation was also performed and compared with Example 3. When the catalyst amount was evaluated in the cross-linked resin molded body, no clear peaks of Sn were detected on the surface or inside the resin molded body; therefore, theoretical values ​​are shown in Table 2.

[0111] [Table 1]

[0112] [Table 2]

[0113] Table 1 shows that the resin molded articles made from cross-linked silane-modified resin as defined in the present invention exhibited superior Z-axis elongation at break (Examples 1 and 2). In contrast, those that did not satisfy the elements defined in the present invention were found to have inferior Z-axis elongation in the evaluation of the resin molded articles (Comparative Example 1).

[0114] Furthermore, as shown in Table 2, when the filament does not contain a crosslinking accelerator, the crosslinking reaction is less likely to proceed during filament spinning, storage, or 3D printing, and good extrusion performance is maintained even when stored in the air. Moreover, it was confirmed that it also exhibits excellent continuous printing performance during long printing times (Example 3). In contrast, when a silanol condensation catalyst is present in the 3D printer filament, a crosslinking reaction occurs during filament manufacturing, resulting in a decrease in extrusion performance and printability during printing (Comparative Example 2).

[0115] In other words, the resin molded article and its manufacturing method of the present invention, as well as the 3D printing material of the present invention, suppress warping of the molded article, resulting in a good printed appearance. Furthermore, by performing a crosslinking treatment on the resin molded article made of silane-modified resin, interlayer crosslinking improves adhesion. Therefore, it was confirmed that this leads to an increase in Z-axis elongation at break. In addition, the resin molded article and its manufacturing method of the present invention maintain good extrusion even after long-term storage in the atmosphere, resulting in good continuous printing performance.

Claims

1. A resin molded body produced by a 3D printer using a resin modified with an unsaturated silane compound, wherein the ratio of the amount of silanol condensation catalyst A on the surface of the resin molded body to the amount of silanol condensation catalyst B inside the resin molded body satisfies the following equation (1). A / B>1...Formula (1)

2. A method for manufacturing a resin molded article, comprising using a resin modified with an unsaturated silane compound, applying a silanol condensation catalyst to the surface of the resin molded article after molding, and performing moisture crosslinking, wherein the molding is performed by a 3D printer.

3. A three-dimensional molding material using a resin modified with an unsaturated silane compound, characterized in that the content of the silanol condensation catalyst is less than 0.015% by mass.

4. The three-dimensional molding material according to claim 3, wherein the amount of modification of the resin modified with an unsaturated silane compound is 0.1% by mass or more and 5.0% by mass or less, based on 100% by mass of the base resin.

5. The three-dimensional molding material according to claim 3 or 4, wherein the crystallization heat (ΔHc) of the resin modified with an unsaturated silane compound, measured by differential scanning calorimetry at a cooling rate of 10°C / min, is 0 J / g or more and 100 J / g or less.

6. A three-dimensional molding material according to any one of claims 3 to 5, wherein the storage modulus (E') of the resin modified with an unsaturated silane compound, measured at 40°C and 10 Hz, is 200 MPa or more and 5000 MPa or less.

7. A three-dimensional molding material according to any one of claims 3 to 6, wherein the crystal melting temperature (Tm) of the resin modified with an unsaturated silane compound is 50°C or higher and 200°C or lower.

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