JP7826820B2 - Resin composition for forming water-disintegrable member, water-disintegrable member, and method for producing three-dimensional shaped object - Google Patents

Description

The present invention relates to a resin composition for forming water-disintegrable parts, and a method for producing water-disintegrable parts and three-dimensional objects using the same.

Water-disintegrating materials, which disintegrate when exposed to large amounts of water, can be easily removed by using water, so fixing part of the structure of an article with a water-disintegrating material makes it easy to disassemble the article. Furthermore, using a water-disintegrating material in packaging materials for agricultural chemicals makes it possible to release the chemicals by irrigation.
As a water-disintegrable composition that can be used to form fixing members, packaging materials, and the like having water-disintegrability, a water-disintegrable composition containing a block copolymer including, as constituent units, a unit containing an aliphatic polyoxyalkylene portion and an aliphatic polyester unit is known (Patent Document 1).

However, the molded articles made from the water-disintegrable composition described in Patent Document 1 have insufficient heat resistance, and are unable to maintain their shape in high-temperature environments, making them unusable.

JP 2008-69324 A

The object of the present invention is to provide a resin composition that can be used to produce molded parts that have excellent heat resistance and water disintegration properties.

The present inventors have conducted research to achieve the above object and have arrived at the present invention.
Specifically, the present invention provides a resin composition for forming a water-disintegrable member, which comprises at least one resin (A) selected from the group consisting of a polyetheresteramide resin (A1) having a polyoxyethylene group, a polyetheramide resin (A2) having a polyoxyethylene group, and a polyetheramideimide resin (A3) having a polyoxyethylene group, wherein the total weight proportion of the oxyethylene groups contained in the resin (A) is 20 to 85 wt % based on the weight of the resin (A); a water-disintegrable member comprising the resin composition for forming a water-disintegrable member; a resin filament for a fused deposition modeling three-dimensional modeling machine comprising the resin composition for forming a water-disintegrable member; and a method for producing a three-dimensional model using the resin filament for a fused deposition modeling three-dimensional modeling machine.

The resin composition for forming water-disintegrable parts of the present invention has high heat resistance, and molded articles thereof can maintain their shape even in higher temperature environments than conventional ones.

<Resin composition for forming water-disintegrable member>
The resin composition for forming a water-disintegrable member according to the first invention comprises at least one resin (A) selected from the group consisting of polyetheresteramide resins (A1) having polyoxyethylene groups, polyetheramide resins (A2) having polyoxyethylene groups, and polyetheramideimide resins (A3) having polyoxyethylene groups, and the total weight proportion of oxyethylene groups contained in the resin (A) is 20 to 85% by weight based on the weight of the resin (A).

Water disintegrability refers to the property of an article that, upon contact with water or a liquid containing water, the initial shape of the article changes as a result of the article being partially or completely dissolved in water, swollen in water, or decomposed by water, and the presence or absence of this property can be confirmed by immersing the article to be measured in water and visually observing the change in shape.
The degree of water disintegrability in the present invention is determined by immersing a test piece of 5 mm width x 5 mm length x 2 mm thickness in water at a temperature of 39 to 41°C and visually observing the state of dissolution or change in shape of the test piece.

There are no limitations on the water-disintegrating member as long as it has the water-disintegrating properties described above, and examples include a fixing member that secures two or more members that make up an article, a container (such as a capsule) that encapsulates a drug or the like, a protective layer that covers part or all of the surface of an article, and a support member for a three-dimensional molded structure.

The resin composition for forming water-disintegrable members of the present invention contains at least one resin (A) selected from the group consisting of polyetheresteramide resins (A1) having polyoxyethylene groups, polyetheramide resins (A2) having polyoxyethylene groups, and polyetheramideimide resins (A3) having polyoxyethylene groups.

<Polyetheresteramide resin (A1) having polyoxyethylene groups>
The polyether ester amide resin (A1) having a polyoxyethylene group is a compound having a structure in which a residue obtained by removing a carboxyl group from a polyamide (a11) having a carboxyl group at the end of the main chain and a residue obtained by removing a hydroxyl group from a polyether diol (a21) having a polyoxyethylene group are bonded via an ester group.
The main chain refers to the atomic group that constitutes the longest molecular chain in the molecular structure.

Examples of polyamide (a11) include ring-opening polymers of lactams, self-polycondensation polymers of aminocarboxylic acids, polycondensation polymers of diamines and dicarboxylic acids, and mixtures thereof.

As the lactam from which the ring-opening polymer constitutes the polyamide (a11), from the viewpoint of the heat resistance of the molded article, preferred are 6- to 8-membered ring lactams (2-oxopentamethyleneimine, 2-oxohexamethyleneimine, 2-oxooctamethyleneimine, etc.), and among the polyamides (a11), preferred lactam ring-opening polymers include nylon 5, nylon 6, nylon 8, etc.
These ring-opening polymers are obtained by a known method of ring-opening polymerization of the lactam in the presence of a dicarboxylic acid, which will be described later, to form polyamides having terminal carboxyl groups.

As the aminocarboxylic acid whose self-polycondensation polymer constitutes the polyamide (a11), from the viewpoint of the heat resistance of the molded article, preferred ones include aminocarboxylic acids having 6 to 12 carbon atoms (5-aminopentanoic acid, 7-aminoheptanoic acid, 11-aminoundecanoic acid, and 12-aminododecanoic acid), and the like. Among the polyamides (a11), preferred ones as the self-polycondensation polymer of aminocarboxylic acid include nylon 7 obtained by polycondensation of 7-aminoheptanoic acid, nylon 11 obtained by polycondensation of 11-aminoundecanoic acid, and nylon 12 obtained by polycondensation of 12-aminododecanoic acid.
The self-polycondensation products of these aminocarboxylic acids have an amino group at one end and a carboxyl group at the other, and become polyamides having a carboxyl group at one end.

Of the diamines and dicarboxylic acids whose polycondensates constitute polyamide (a11), from the viewpoint of the heat resistance of the molded product, preferred diamines include aliphatic diamines having 2 to 11 carbon atoms, aromatic diamines having 6 to 20 carbon atoms, and mixtures thereof.

Aliphatic diamines having 2 to 11 carbon atoms include ethylenediamine, propylenediamine, 1,4-butylenediamine, 1,6-hexamethylenediamine, and 1,11-undecanediamine. From the viewpoint of heat resistance of molded articles, aliphatic diamines having 4 to 11 carbon atoms (1,4-butylenediamine, 1,6-hexamethylenediamine, and 1,11-undecanediamine, etc.) are particularly preferred.

Examples of aromatic diamines having 6 to 20 carbon atoms include p-phenylenediamine, 2,4- or 2,6-toluylenediamine, 2,2-bis(4,4'-diaminophenyl)propane, 4-aminobenzylamine, xylylenediamine, bis(aminoethyl)benzene, bis(aminopropyl)benzene, and bis(aminobutyl)benzene, with p-phenylenediamine being preferred.

From the viewpoint of the heat resistance of the molded body, preferred dicarboxylic acids include aliphatic dicarboxylic acids having 6 to 13 carbon atoms, aromatic ring-containing dicarboxylic acids having 6 to 14 carbon atoms, their acid anhydrides, their alkyl (1 to 4 carbon atoms) esters, and mixtures of two or more of these.

Examples of aliphatic dicarboxylic acids having 6 to 13 carbon atoms include adipic acid, pimelic acid, suberic acid, azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, and tridecanedioic acid.

Examples of aromatic ring-containing dicarboxylic acids having 6 to 14 carbon atoms include ortho-, iso-, or terephthalic acid, naphthalene-2,6- or naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'-dicarboxylic acid, diphenoxyethanedicarboxylic acid, tolylenedicarboxylic acid, and xylylenedicarboxylic acid.

The dicarboxylic acid may have a sulfo group, and preferred dicarboxylic acids having a sulfo group include 5-sulfoisophthalic acid and its salts.

Preferred polycondensates of diamines and dicarboxylic acids include polycondensates of adipic acid, sebacic acid, azelaic acid, or dodecanedioic acid with hexamethylenediamine (nylon 66, nylon 610, nylon 69, or nylon 612), and polycondensates of tetramethylenediamine and adipic acid (nylon 46).

The polycondensate of diamine and dicarboxylic acid may be a copolymer nylon made using a combination of different monomers. Examples of copolymer nylon include nylon 6/66 (a copolymer of nylon 6 and nylon 66 [copolymerization ratio (weight ratio) = 5/95 to 95/5]) and nylon 6/12 (a copolymer of nylon 6 and nylon 12 [copolymerization ratio (weight ratio) = 5/95 to 95/5]).

Polyamide (a11) preferably has a structure in which amide groups are linked together by a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.

Among the polyamides (a11), from the viewpoint of heat resistance and the like, preferred polyamides are ring-opening polymers of caprolactam and polycondensates of adipic acid and hexamethylenediamine, and more preferred polyamides are ring-opening polymers of caprolactam.
The polyamide (a11) can be obtained by a known method described in JP-A-2016-166332, etc.

The number average molecular weight (hereinafter referred to as Mn) of the polyamide (a11) is preferably from 500 to 5,000, more preferably from 700 to 3,000, from the viewpoint of the heat resistance of the polyetheramide (A1).
The Mn of the polyamide (a11) is a calculated value calculated using the acid value of the polyamide.

Examples of polyether diols (a21) having polyoxyethylene groups include aliphatic polyether diols having polyoxyethylene groups and aromatic polyether diols having polyoxyethylene groups.

Examples of the aliphatic polyether diol having a polyoxyethylene group include alkylene oxide adducts obtained by adding an alkylene oxide (hereinafter sometimes abbreviated as AO) that essentially contains ethylene oxide (hereinafter abbreviated as EO) to a linear or branched aliphatic dihydric alcohol having 2 to 8 carbon atoms, and alkylene oxide adducts obtained by adding an alkylene oxide that essentially contains EO to an alicyclic dihydric alcohol having 6 to 10 carbon atoms.
Examples of the alkylene oxide to be used in combination with ethylene oxide (hereinafter sometimes abbreviated as EO) include alkylene oxides having 3 or 4 carbon atoms [1,2-propylene oxide (hereinafter sometimes abbreviated as PO), 1,3-propylene oxide, 1,2-, 2,3- or 1,3-butylene oxide, tetrahydrofuran, etc.].

When ethylene oxide and other alkylene oxides are used in combination in an aliphatic polyether diol having a polyoxyethylene group, the poly(oxyalkylene) group in the polyether diol may have a structural unit composed of two or more of the same type of alkylene oxide linked together, or may have a structure in which ethylene oxide and other alkylene oxides are alternately bonded, or may have both of these two types of structures.

Aliphatic polyether diols containing polyoxyethylene groups can be obtained by known methods, such as the ring-opening addition polymerization of alkylene oxides, essentially consisting of ethylene oxide, with linear or branched aliphatic dihydric alcohols having 2 to 8 carbon atoms or alicyclic dihydric alcohols having 6 to 10 carbon atoms in the presence of an alkali catalyst at temperatures between 100 and 200°C.

Examples of linear or branched aliphatic dihydric alcohols having 2 to 8 carbon atoms include ethylene glycol, diethylene glycol, 1,3-propanediol, 1,4-butanediol, 1,5-pentanediol, 1,6-hexanediol, 1,2-propanediol, neopentyl glycol, 3-methyl-1,5-pentanediol, 2,2-diethyl-1,3-propanediol, and 1,2-, 1,3-, or 2,3-butanediol.

Examples of alicyclic dihydric alcohols having 6 to 10 carbon atoms include 1,4-bis(hydroxymethyl)cyclohexane and 2,2-bis(4-hydroxycyclohexyl)propane.

Preferred aliphatic polyether diols having polyoxyethylene groups include polyoxyethylene polyols [such as polyethylene glycol (hereinafter abbreviated as PEG)] and copolymers of polyoxyethylene and propylene polyol.

Aromatic polyether diols having polyoxyethylene groups include alkylene oxide adducts of aromatic diols, which require ethylene oxide. Examples of alkylene oxides used in combination with ethylene oxide (hereinafter abbreviated as EO) include alkylene oxides having 3 or 4 carbon atoms [1,2-propylene oxide (hereinafter abbreviated as PO), 1,3-propylene oxide, 1,2-, 2,3-, or 1,3-butylene oxide, tetrahydrofuran, etc.].

When ethylene oxide and other alkylene oxides are used in combination in an aromatic polyether diol having a polyoxyethylene group, the poly(oxyalkylene) group in the polyether diol may have a structural unit composed of two or more of the same type of alkylene oxide linked together, or may have a structure in which ethylene oxide and other alkylene oxides are alternately bonded, or may have both of these two types of structures.

Aromatic polyether diols containing polyoxyethylene groups can be obtained by known methods, such as the ring-opening addition polymerization of an aromatic diol with an alkylene oxide, essentially containing ethylene oxide, in the presence of an alkali catalyst at a temperature of 100 to 200°C.

Aromatic diols include hydroquinone, benzyloxy-1,3-propanediol, and bisphenol A.

Preferred aromatic polyether diols having polyoxyethylene groups include EO adducts of bisphenol A (such as 2-mol EO adduct of bisphenol A, 4-mol EO adduct of bisphenol A, 6-mol EO adduct of bisphenol A, 8-mol EO adduct of bisphenol A, 10-mol EO adduct of bisphenol A, and 20-mol EO adduct of bisphenol A), and adducts of dihydroxybenzene.

From the viewpoint of water-disintegrability, the total weight proportion of polyoxyethylene groups in the polyether diol (a21) having polyoxyethylene groups is preferably 60% by weight or more, and more preferably 80 to 95% by weight, based on the weight of the polyether diol (a21).

The Mn of polyether diol (a21) is preferably 500 to 5,000, more preferably 1,000 to 3,000, from the viewpoints of water disintegrability and strength during molding.

The Mn of the polyether diol (a21) is measured using gel permeation chromatography (hereinafter abbreviated as GPC) under the following conditions.
Apparatus: "Waters Alliance 2695" [manufactured by Waters]
Column: "Guard column Super H-L" (1 column), "TSKgel Super H2000, TSKgel Super H3000, TSKgel Super H4000, each connected together" [all manufactured by Tosoh Corporation]
Sample solution: 0.25 wt% tetrahydrofuran solution Solution injection amount: 10 μl
・Flow rate: 0.6ml/min ・Measurement temperature: 40℃
・Detection device: Refractive index detector ・Reference material: Standard polyethylene glycol

The total weight proportion of all residues remaining after removing two hydroxyl groups from polyether diol (a21) constituting polyether ester amide resin (A1) is preferably 50% to 85% by weight, and more preferably 55% to 85% by weight, based on the weight of polyether ester amide resin (A1), from the viewpoint of achieving both water-disintegrability and strength of the component.

The polyether ester amide resin (A1) preferably has a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.
By using the above-mentioned preferred lactams, aminocarboxylic acids, diamines, and dicarboxylic acids constituting the polyamide (a11), the polyetheresteramide (A1) can have a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.
When the polyether ester amide resin (A1) has a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring, the resin composition for forming a water-disintegrable member has better heat resistance and water-disintegrability, which is preferable.

As the polyether ester amide resin (A1) having polyoxyethylene groups, those described in JP-A-6-287547 and JP-B-4-5691 can be used. Among the polyether ester amides (A1), preferred are the polyether ester amides described in JP-A-6-287547, which are composed of a polyamide having an Mn of 200 to 5,000 and an AO adduct of a bisphenol having an Mn of 300 to 5,000 or a polyoxyalkylene.

The polyetheresteramide resin (A1) can be produced by known methods such as those described in JP 2016-166332 A, including a method in which a polyamide (a11) having a carboxyl group at its terminal, obtained by ring-opening or polycondensation polymerization of a dicarboxylic acid with the lactam or the aminocarboxylic acid (hereinafter, these two will be referred to as polyamide-forming monomers), is bonded to the resulting polyamide (a11) by esterification, and a method in which a polyetherdiol (a21) is bonded to a polyamide (a11) that is a polycondensation product of a diamine and a dicarboxylic acid using an excess of dicarboxylic acid, by esterification. The polyetheresteramide resin (A1) may contain an ester of the polyetherdiol (a21) and a dicarboxylic acid in its structure.
The ring-opening or polycondensation polymerization of polyamide-forming monomers and the polycondensation of diamines and dicarboxylic acids can be carried out by known methods described in, for example, JP-A-2016-166332.

The esterification reaction of the polyether diol with the polyamide having a carboxyl group at its terminal can be carried out by a known method, and a known esterification catalyst may be used.
Preferred esterification catalysts include antimony catalysts (antimony trioxide, etc.), tin catalysts (monobutyltin oxide, etc.), titanium catalysts (tetrabutyl titanate, etc.), zirconium catalysts (tetrabutyl zirconate, etc.), and metal acetate catalysts (zinc acetate, zirconyl acetate, etc.).

From the viewpoint of water-disintegrability, the total weight proportion of polyoxyethylene groups contained in the polyetheresteramide resin (A1) is preferably 20% by weight to 85% by weight, and more preferably 50% by weight to 80% by weight, based on the weight of the polyetheresteramide resin (A1).

From the viewpoint of the mechanical properties and heat resistance of the water-disintegrable member, the Mn of the polyether ester amide resin (A1) is preferably 10,000 to 100,000, and more preferably 10,000 to 50,000.

The Mn of the polyether ester amide resin (A1) is measured by GPC under the following conditions.
Apparatus: "HLC-8120" [manufactured by Tosoh Corporation]
Column: "TSKgel GMHXL" [manufactured by Tosoh Corporation] (2 columns), "TSKgel Multipore HXL-M" [manufactured by Tosoh Corporation] (1 column)
Sample solution: 0.3 wt% orthodichlorobenzene solution Solution injection amount: 100 μl
・Flow rate: 1ml/min ・Measurement temperature: 135℃
・Detection device: Refractive index detector ・Reference material: Standard polystyrene

<Polyetheramide resin (A2) having polyoxyethylene groups>
The polyetheramide resin (A2) having a polyoxyethylene group is a compound having a structure in which a residue obtained by removing a carboxyl group from a polyamide (a12) having a carboxyl group at the end of the main chain and a residue obtained by removing an amino group from a polyetherdiamine (a22) having a polyoxyethylene group are bonded via an amide group.

Examples of the polyamide (a12) having a carboxyl group at the end of the main chain include the same compounds as those exemplified as the polyamide (a11) constituting the polyetheresteramide resin (A1), such as ring-opening polymers of lactams, self-polycondensation polymers of aminocarboxylic acids, and polycondensation polymers of diamines and dicarboxylic acids, and the preferred compounds are also the same.

Examples of polyetherdiamines (a22) having polyoxyethylene groups include those obtained by converting the terminal hydroxyl groups of the above-mentioned polyetherdiols (a21) to amino groups. These can be obtained by known methods, such as cyanoalkylating the hydroxyl groups of a polyetherdiol and reducing the resulting terminal groups to amino groups.

From the viewpoint of water-disintegrability, the total weight proportion of polyoxyethylene groups in the polyetherdiamine (a22) having polyoxyethylene groups is preferably 60% by weight or more, and more preferably 80 to 95% by weight, based on the weight of the polyetherdiol (a22).

The Mn of polyetherdiamine (a22) is preferably 500 to 5,000, more preferably 1,000 to 3,000, from the viewpoints of water disintegrability and strength during molding.

The Mn of polyetherdiamine (a22) is measured under the same conditions as for polyetherdiol (a11) above.

The total weight proportion of the residues obtained by removing amino groups from polyetherdiamine (a22) constituting polyetheramide resin (A2) is preferably 50% to 85% by weight, and more preferably 55% to 85% by weight, based on the weight of polyetheresteramide resin (A2), from the viewpoint of achieving both water disintegrability and strength of the component.

The polyetheramide resin (A2) preferably has a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.
By using the above-mentioned preferred lactams, aminocarboxylic acids, diamines, and dicarboxylic acids constituting the polyamide (a12), the polyetheramide resin (A2) can have a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.
When the polyetheramide resin (A2) has a structure in which amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring, the resin composition for forming a water-disintegrable member has better heat resistance and water-disintegrability, which is preferable.

Examples of methods for producing polyetheramide resin (A2) include a method in which polyamide (a12) having carboxyl groups at its terminals is obtained by ring-opening or polycondensation polymerization of a dicarboxylic acid with the lactam or aminocarboxylic acid (hereinafter, these two will be referred to as polyamide-forming monomers), and then bonding the resulting polyamide (a12) to polyetherdiamine (a22) via an amidation reaction; and a method in which polyamide (a12), which is a polycondensation product of a diamine and a dicarboxylic acid using an excess of dicarboxylic acid, is then bonded to polyetherdiamine (a22) via an amidation reaction.

From the viewpoint of water-disintegrability, the total weight proportion of polyoxyethylene groups contained in the polyetheramide resin (A2) is preferably 20% by weight to 85% by weight, and more preferably 50% by weight to 80% by weight, based on the weight of the polyetheramide resin (A2).

From the viewpoint of the mechanical properties and heat resistance of the water-disintegrable member, the Mn of the polyetheramide resin (A2) is preferably 10,000 to 100,000, and more preferably 10,000 to 50,000.

The Mn of polyetheramide resin (A2) is measured by GPC under the same conditions as for polyetheresteramide resin (A1).

<Polyetheramideimide resin (A3) having polyoxyethylene groups>
The polyetheramideimide resin (A3) having a polyoxyethylene group is a compound obtained by bonding, via an amide group, a residue obtained by removing a carboxyl group from a polyamideimide (a13) having a carboxyl group bonded to the end of the main chain and at least one imide ring, and a residue obtained by removing a hydroxyl group from a polyetherdiol (a23) having a polyoxyethylene group.

Examples of polyamideimides (a13) having a carboxyl group bonded to the end of the main chain and at least one imide ring include polymers of aromatic tricarboxylic acids or aromatic tetrapolycarboxylic acids capable of forming at least one imide ring with the lactams exemplified for polyamide (a11) constituting polyetheresteramide resin (A1); polymers of aromatic tricarboxylic acids or aromatic tetrapolycarboxylic acids capable of forming at least one imide ring with the aminocarboxylic acids exemplified for polyamide (a11) constituting polyetheresteramide resin (A1); and polymers of aromatic tricarboxylic acids or aromatic tetrapolycarboxylic acids capable of forming at least one imide ring with the diamines and dicarboxylic acids exemplified for polyamide (a11) constituting polyetheresteramide resin (A1).

Preferred aromatic tricarboxylic acids and aromatic tetrapolycarboxylic acids capable of forming at least one imide ring include trimellitic acid, 1,2,5- or 2,6,7-naphthalenetricarboxylic acid, 3,3,'4-biphenyltricarboxylic acid, benzophenone-3,3',4-tricarboxylic acid, diphenylsulfone-3,3',4-tricarboxylic acid, diphenylether-3,3',4-tricarboxylic acid, pimellitic acid, phenyl-2,2',3,3'-tetracarboxylic acid, benzophenone-2,2',3,3'-tetracarboxylic acid, diphenylsulfone-2,2',3,3'-tetracarboxylic acid, diphenylether-2,2',3,3'-tetracarboxylic acid, and anhydrides thereof.

The polyamideimide (a13) preferably has a structure in which amide groups and amide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.

The Mn of the polyamideimide (a13) is preferably from 500 to 50,000, more preferably from 700 to 30,000, from the viewpoint of the heat resistance of the polyetheramideimide (A2).
The Mn of the polyamideimide (a13) is calculated using the acid value of the polyamide.

Examples of the polyether diol (a23) having a polyoxyethylene group include the same polyether diols (a21) constituting the polyether ester amide (A1), and the preferred examples are also the same.

From the viewpoint of water-disintegrability, the total weight proportion of polyoxyethylene groups in the polyether diol (a23) having polyoxyethylene groups is preferably 60% by weight or more, and more preferably 80 to 95% by weight, based on the weight of the polyether diol (a23).

The Mn of polyether diol (a23) is preferably 500 to 5,000, more preferably 1,000 to 3,000, from the viewpoints of water disintegrability and strength during molding.

The Mn of polyetherdiamine (a23) is measured under the same conditions as for polyetherdiol (a11) above.

The content of the residue obtained by removing two hydroxyl groups from polyetherdiol (a23) constituting polyetheramideimide resin (A3) is preferably 50% to 85% by weight, and more preferably 55% to 85% by weight, based on the weight of polyetheramideimide resin (A3), from the viewpoint of achieving both water-disintegratability and strength of the component.

The polyetheramideimide resin (A3) preferably has a structure in which an amide group and an imide group are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring.
By using the above-mentioned preferred lactams, aminocarboxylic acids, diamines and dicarboxylic acids, as well as aromatic tricarboxylic acids and aromatic tetrapolycarboxylic acids constituting the polyamideimide (a13), the polyetheramideimide resin (A3) can have a structure in which amide groups and imide groups are linked together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having an aromatic ring and having 6 to 14 carbon atoms.
When the polyetheramideimide resin (A3) has a structure in which an amide group and an imide group are bonded together via a divalent saturated aliphatic hydrocarbon group having 4 to 11 carbon atoms or a divalent hydrocarbon group having 6 to 14 carbon atoms and an aromatic ring, the resin composition for forming a water-disintegrable member has better heat resistance and water-disintegrability, which is preferable.

Examples of a method for producing polyetheramideimide resin (A3) include a method in which the polyamideimide (a13) and polyetherdiamine (a23) are bonded together by amidation reaction using a known method.

From the viewpoint of water-disintegrability, the weight proportion of polyoxyethylene groups contained in the polyetheramideimide resin (A3) is preferably 20% to 85% by weight, and more preferably 50% to 80% by weight, based on the weight of the polyetheramideimide resin (A3).

From the viewpoint of the mechanical properties and heat resistance of the water-disintegrable member, the Mn of the polyetheramideimide resin (A3) is preferably 10,000 to 100,000, and more preferably 10,000 to 50,000.

The Mn of polyetheramideimide resin (A3) is measured by GPC under the same conditions as for polyetheresteramide resin (A1).

The resin composition for forming a water-disintegrable member of the present invention may contain at least one resin selected from the group consisting of polyetheresteramide resins (A1), polyetheramide resins (A2), and polyetheramideimide resins (A3).
When two or more types of resin (A) are contained, the total weight proportion of oxyethylene groups contained in resin (A) is 20 to 85% by weight, preferably 50 to 80% by weight, based on the weight of resin (A).
When two or more types of resin (A) are contained, the total weight proportion of oxyethylene groups contained in resin (A) is calculated based on the total weight of oxyethylene groups contained in each of the polyetheresteramide resin (A1), the polyetheramide resin (A2), and the polyetheramideimide resin (A3).
Of the above (A1) to (A3), (A1) is preferred.

The resin composition for forming a water-disintegrable member of the present invention may contain, in addition to the polyether-containing polyamide resin (A), a polyurethane (B1) having a polyoxyalkylene chain and/or a polyoxyalkylene glycol (B2).
Furthermore, by including a polyurethane (B1) having a polyoxyalkylene chain and/or a polyoxyalkylene glycol (B2), the degree of water-disintegrability of the resin composition for forming a water-disintegrable member can be adjusted.
Of the above (B1) and (B2), (B1) is preferred.

<Polyurethane (B1) having polyoxyalkylene chain>
The polyurethane (B1) having a polyoxyalkylene chain is a polyurethane having a polyoxyalkylene glycol (b11) and a polyisocyanate (b21) as essential structural units.

The polyoxyalkylene glycol (b11) is preferably a polyoxyalkylene glycol having a polyoxyethylene group, such as polyoxyethylene glycol and copolymer diols of ethylene oxide and other alkylene oxides, with polyoxyethylene glycol being particularly preferred. Copolymer diols of ethylene oxide and other alkylene oxides can be obtained by the same method as for the polyether diol (a11) described above.

From the viewpoints of water disintegrability, shape retention, etc., the Mn of the polyoxyalkylene glycol (b11) is preferably 5,000 to 200,000, and more preferably 10,000 to 100,000. The Mn of the polyoxyalkylene glycol (b11) is measured under the same conditions as for the polyether diol (a11) described above.

Examples of diisocyanates (b21) include aromatic diisocyanates having 6 to 20 carbon atoms (excluding carbon atoms in NCO groups; the same applies below), aliphatic diisocyanates having 2 to 18 carbon atoms, modified products of these diisocyanates (such as modified products containing urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretoimine groups, isocyanurate groups, and oxazolidone groups), and mixtures of two or more of these.

Aromatic diisocyanates having 6 to 20 carbon atoms include 1,3- or 1,4-phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate (TDI), crude TDI, m- or p-xylylene diisocyanate (XDI), α,α,α',α'-tetramethylxylylene diisocyanate (TMXDI), 2,4'- or 4,4'-diphenylmethane diisocyanate (MDI), crude diaminophenylmethane diisocyanate (crude MDI), etc.

Examples of aliphatic diisocyanates having 2 to 18 carbon atoms include chain aliphatic diisocyanates having 2 to 18 carbon atoms and cyclic aliphatic diisocyanates having 3 to 18 carbon atoms.

Examples of chain aliphatic diisocyanates having 2 to 18 carbon atoms include ethylene diisocyanate, tetramethylene diisocyanate, hexamethylene diisocyanate (HDI), dodecamethylene diisocyanate, 2,2,4-trimethylhexamethylene diisocyanate, lysine diisocyanate, 2,6-diisocyanatomethyl caproate, bis(2-isocyanatoethyl) fumarate, bis(2-isocyanatoethyl) carbonate, 2-isocyanatoethyl-2,6-diisocyanatohexanoate, and mixtures thereof.

Examples of cycloaliphatic diisocyanates having 3 to 18 carbon atoms include isophorone diisocyanate (IPDI), dicyclohexylmethane-4,4'-diisocyanate (hydrogenated MDI), cyclohexylene diisocyanate, methylcyclohexylene diisocyanate (hydrogenated TDI), bis(2-isocyanatoethyl)-4-cyclohexene-1,2-dicarboxylate, 2,5- or 2,6-norbornane diisocyanate, and mixtures thereof.

Modified diisocyanates include those containing at least one group selected from the group consisting of urethane groups, carbodiimide groups, allophanate groups, urea groups, biuret groups, uretdione groups, uretoimine groups, isocyanurate groups, and oxazolidone groups. Examples include modified MDI (urethane-modified MDI, carbodiimide-modified MDI, trihydrocarbyl phosphate-modified MDI, etc.), urethane-modified TDI, and mixtures thereof [for example, a mixture of modified MDI and urethane-modified TDI (isocyanate-containing prepolymer)].

Of these diisocyanates, aromatic diisocyanates with 6 to 15 carbon atoms and aliphatic diisocyanates with 4 to 15 carbon atoms are preferred in terms of durability, with TDI, MDI, HDI, hydrogenated MDI, and IPDI being even more preferred.

Polyurethane (B1) may contain a divalent active hydrogen-containing compound other than polyoxyalkylene glycol (b11) (such as the divalent active hydrogen-containing compound described in JP 2017-57166 A).

The weight proportion of units derived from polyoxyalkylene glycol (b11) (residues obtained by removing hydrogen atoms from hydroxyl groups of polyoxyalkylene glycol) contained in polyurethane (B1) is preferably 60 to 99 wt %, and more preferably 75 to 99 wt %, based on the weight of polyurethane (B1), from the viewpoints of water-disintegrability, shape retention, etc.

Polyurethane (B1) can be obtained by urethanizing polyoxyalkylene glycol (b11) and diisocyanate (b21) using a known method.

From the viewpoints of water disintegrability, shape retention, etc., the Mn of polyurethane (B1) is preferably 10,000 to 200,000, and more preferably 40,000 to 150,000. The Mn of polyurethane (B1) is measured under the same conditions as for polyether diol (a11) above.

<Polyoxyalkylene glycol (B2)>
As the polyoxyalkylene glycol (B2), the same polyoxyalkylene glycols as those (b11) constituting the polyurethane (B1) can be used, and the preferred ones are also the same.

From the viewpoints of water disintegrability, shape retention, etc., the Mn of the polyoxyalkylene glycol (B2) is preferably 10,000 to 10,000,000, and more preferably 50,000 to 5,000,000. The Mn of the polyoxyalkylene glycol (B2) is measured under the same conditions as for the polyether diol (a11) above.

When the resin composition for forming water-disintegrable members of the present invention further contains a polyurethane (B1) and/or a polyoxyalkylene glycol (B2) having a polyoxyalkylene chain, the total weight proportion of the polyurethane (B1) and the polyoxyalkylene glycol (B2) is preferably 20% to 80% by weight, and more preferably 50% to 80% by weight, based on the total weight of the resin (A), polyurethane (B1), and polyoxyalkylene glycol (B2), from the viewpoints of water-disintegrability, shape retention, etc.

The resin composition for forming water-disintegrable members of the present invention may contain, in addition to the resin (A), polyurethane (B1), and polyoxyalkylene glycol (B2), known thermoplastic resins (excluding the resin (A)) and resin additives.

The thermoplastic resin that may be contained in the resin composition for forming a water-disintegrable member of the present invention is not particularly limited, and can be selected depending on the intended use of the water-disintegrable member.
In particular, when the resin composition for forming water-disintegrable members of the present invention is used as a filament resin composition for a fused deposition modeling three-dimensional modeling machine, it is preferable that the resin composition for forming water-disintegrable members of the present invention contains, as a thermoplastic resin, polyvinyl alcohol, an ethylene-vinyl alcohol copolymer, a butylene-vinyl alcohol copolymer, a polyamide resin having an ionic group (such as a sulfo group) (such as polyamide 66 containing sodium sulfoisophthalate as a constituent monomer), or a polyester resin having an ionic group (such as a sulfo group) (such as a polyester resin containing sodium sulfoisophthalate as a constituent monomer).

Resin additives that can be contained in the resin composition for forming water-disintegrable members of the present invention include known fillers, dyes, pigments, stabilizers, lubricants, crystal nucleating agents, and antistatic agents. There are no restrictions on the content of resin additives, so long as the amount does not interfere with the water-disintegrability and shape-retention properties of the resin composition for forming water-disintegrable members of the present invention, and the amount can be adjusted depending on the intended use of the resin composition for forming water-disintegrable members.

When the resin composition for forming a water-disintegrable member of the present invention further contains a thermoplastic resin, the water-disintegrability, heat resistance, and shape retention of the resin composition for forming a water-disintegrable member can be adjusted by the total weight proportion of the resin (A), polyurethane (B1), and polyoxyalkylene glycol (B2) contained in the resin composition for forming a water-disintegrable member.
The water-disintegrability, heat resistance, and shape retention required for the resin composition for forming a water-disintegrable member of the present invention vary depending on the application for which the resin composition for forming a water-disintegrable member of the present invention is used, and it is preferable to adjust the total weight ratio of the resin (A), polyurethane (B1), and polyoxyalkylene glycol (B2) depending on the application.

From the viewpoints of water-disintegrability and shape retention, the total weight proportion of the polyurethane (B1) and polyoxyalkylene glycol (B2) contained in the resin composition for forming water-disintegrable members of the present invention is preferably 30% by weight to 80% by weight, and more preferably 45% by weight to 75% by weight, based on the total weight of the resin composition for forming water-disintegrable members.

The resin composition for forming a water-disintegrable member of the present invention can be obtained by melt-mixing the resin (A), polyurethane (B1), polyoxyalkylene glycol (B2), and, if necessary, other thermoplastic resins and resin additives, using a known method.
The melt-kneading temperature is not limited as long as it is a temperature at which the resin (A), polyurethane (B1), polyoxyalkylene glycol (B2), and other thermoplastic resins and resin additives used as needed are melted. However, for reasons such as reducing coloration of the resin composition for forming a water-disintegrable member, the melt-kneading temperature is preferably in the range from the same temperature as the melting point of the polyether-containing polyamide-based resin (A) to a temperature 40°C higher than the melting point.

The resin composition for forming water-disintegrable members of the present invention can be preferably used for water-disintegrable pressure-sensitive adhesives and water-disintegrable molded articles. Examples of water-disintegrable molded articles include packaging materials, agricultural and horticultural materials, and supports for three-dimensional structures formed by molten resin lamination techniques.

<Water-disintegrating member>
The water-disintegrable member of the second invention is a member made of the resin composition for forming a water-disintegrable member. Note that the term "member" refers to a material that constitutes a part of an article, and there are no limitations on its shape.

Preferred examples of the water-disintegrable member of the present invention include water-disintegrable pressure-sensitive adhesives and water-disintegrable molded articles. Examples of water-disintegrable molded articles include fibers, nonwoven fabrics thereof, films, and parts molded into any shape.

The water-disintegrable adhesive comprising the water-disintegrable member of the present invention can be used in a variety of applications, including sanitary materials, packaging, insulation, and woodworking, and the parts fixed with the adhesive can be easily separated by washing with water.

When the water-disintegrable molded article made from the water-disintegrable member of the present invention is a fiber or a nonwoven fabric made from the same, it can be preferably used in draining bags, medical clothing, medical sheets, etc.

When the water-disintegrable molded article made from the water-disintegrable member of the present invention is a film, it can be used for packaging films, packaging bags, compost bags, shopping bags, garbage bags, etc. In particular, it is preferred when used as a garbage bag for disposing of food waste, because the bag disintegrates when exposed to water, allowing the food waste to be recycled together with the bag.

The water-disintegrable molded article made of the water-disintegrable member of the present invention can also be preferably used for agricultural and horticultural materials (mulch films, seedling raising pots, agricultural and horticultural tapes, fruit cultivation bags, stakes, fumigation sheets, films for greenhouses, etc.), packaging materials for pesticides, etc.
For example, when used as a seedling pot, it can maintain sufficient strength during the seedling growth and distribution stages, and can be decomposed by water after being buried in soil, eliminating the need to remove the seedling pot. Also, when used as a packaging material for enclosing an agricultural chemical active ingredient or formulation, the packaging material can be decomposed by contact with sprayed water, releasing the active ingredient.

In addition, molded articles made from the water-disintegratable material of the present invention can also be used as structural support members for three-dimensional molding machines using the fused polymer deposition modeling method, binding components for chemicals (medicines, pesticides, veterinary medicines, and fertilizers), housings for electrical equipment, and materials for treating pet waste, etc.

<Resin filament for fused deposition modeling 3D modeling machines>
The third invention, a resin filament for a fused deposition modeling three-dimensional modeling machine, is a resin filament made of the above-mentioned resin composition for forming a water-disintegrable member.
A fused deposition modeling 3D printer is a printing machine that heats and melts a material called a resin filament (a thermoplastic resin molded into a thread-like form) and expels it from a nozzle. The resin that comes out of the nozzle is then layered based on data from 3D-CAD or similar to create a three-dimensional object (a three-dimensional model). When creating a three-dimensional object, support members (also known as support materials) are also required to maintain its shape and reinforce it, and these support members are formed simultaneously with the creation of the three-dimensional object by the fused deposition modeling 3D printer.

Support members need to be heat-resistant and easily removable so that they can maintain their support structure even while the three-dimensional object is being formed. The resin filament for a fused deposition modeling three-dimensional modeling machine of the present invention is made from the resin composition for forming water-disintegrable members, which has excellent heat resistance and water-disintegrability, and therefore can provide support members that are heat-resistant and easily removable so that they can maintain their support structure even while the three-dimensional object is being formed.

The resin filament for a fused deposition modeling three-dimensional modeling machine of the present invention can be obtained by molding the resin composition for forming water-disintegrable parts into a filament shape (preferably a filament with a diameter of 1.75 mm to 3 mm, etc.) using a known method.

<Method of manufacturing a three-dimensional object>
The fourth invention is a method for manufacturing a three-dimensional object using the resin filament for a fused deposition modeling three-dimensional modeling machine, and includes a step of forming a support member made of the resin filament for a fused deposition modeling three-dimensional modeling machine.

The manufacturing method of the present invention can use any known method for manufacturing a three-dimensional object by fused deposition modeling, except that the support member is formed using a resin filament for a fused deposition modeling three-dimensional modeling machine, which is made from the resin composition for forming water-disintegrable members described above.

In the manufacturing method of the present invention, the step of forming a support member for a three-dimensional model using the resin filament for a fused deposition modeling three-dimensional modeling machine is carried out by heating the resin filament (preferably to 170 to 240°C, more preferably 190 to 230°C) to melt it, and then discharging the molten resin from a discharge nozzle at a predetermined position based on three-dimensional data, such as 3D-CAD data, input into the three-dimensional modeling machine to form a structural support member.

The manufacturing method of the present invention preferably further includes a step of removing the support member made of the resin filament for the fused deposition modeling three-dimensional modeling machine.

The support member of the three-dimensional object can be removed by bringing the support member into contact with a dissolving liquid. Methods that can be used include bringing part or all of the support member into contact with the dissolving liquid, and immersing the entire support member in the dissolving liquid.
The dissolving liquid is preferably water, and a water-soluble compound may be dissolved in water for use. Examples of compounds that can be dissolved in water for use include organic acids, inorganic acids, alkali metal hydroxides, and alkali metal carbonates.

The present invention will be further explained below with reference to examples, but the present invention is not limited thereto.
In the examples, parts are by weight.

[Production Example 1: Polyether Urethane (B-1)]
A stainless steel autoclave (a simple pressurized reactor equipped with a heater and a stirrer) was charged with 100 parts of polyethylene glycol (Mn 20,000) (a21-6), and the atmosphere inside the autoclave was replaced with nitrogen. The autoclave was then heated to 110°C while the pressure was reduced to 1.0 to 2.0 kPa, and stirring was continued for 1 hour to carry out dehydration. The pressure was then returned to normal, and 0.8 parts of toluene diisocyanate was charged. The temperature was raised to 150°C with stirring, and the mixture was allowed to react for 2 hours to obtain polyether urethane (B-1). The Mn of the polyether urethane (B-1) was 80,000.

[Production Example 2: Polyetheresteramide Resin (A-1)]
A stainless steel autoclave similar to that used in Production Example 1 was charged with 170 parts of ε-caprolactam, 20.0 parts of terephthalic acid, 5.0 parts of isophthalic acid, 0.4 parts of an antioxidant, and 10 parts of water. The autoclave was then purged with nitrogen and heated and stirred for 4 hours at 220°C under pressure (0.3 to 0.4 MPa, the same applies hereinafter) while sealed, to obtain polyamide (a11-1) having carboxyl groups at both ends and an acid value of 111. The Mn of polyamide (a11-1) was 1,000. The Mn of polyamide (a11-1) was calculated using the formula [{mg of potassium hydroxide per mole (56,100)/acid value (111)} × number of functional groups (2)], assuming that polyamide (a11-1) was bifunctional and had carboxyl groups at both ends.
Next, 300 parts of polyamide (a11-1), 300 parts of polyethylene glycol (Mn 2,000) (a21-1), 600 parts of an EO adduct of bisphenol A (Mn 4,000) (a21-2), and 0.6 parts of zirconyl acetate were heated to 240°C with stirring in a stainless steel autoclave, and then heated for 6 hours while reducing the pressure to 0.13 kPa or less to polymerize, thereby obtaining a viscous polyether ester amide resin (A-1). The Mn of polyether ester amide resin (A-1) was 28,000, and the content of oxyethylene groups contained in (A-1) was 75 wt% based on the weight of resin (A-1).

[Production Example 3: Polyetheresteramide resin (A-2)]
A stainless steel autoclave similar to that used in Production Example 1 was charged with 190 parts of ε-caprolactam, 23.7 parts of the sodium salt of 5-sulfoisophthalic acid, 0.4 parts of an antioxidant, and 10 parts of water. The autoclave was then purged with nitrogen and heated and stirred for 4 hours under pressure (0.3 to 0.4 MPa, the same applies hereinafter) at 220°C while sealed, to obtain polyamide (a11-2) having carboxyl groups at both ends and an acid value of 55. The Mn of polyamide (a11-2) was 2,000. The Mn of polyamide (a11-2) was calculated using the formula [{mg of potassium hydroxide per mole (56,100) / acid value (55)} × number of functional groups (2)], assuming that polyamide (a11-2) was bifunctional and had carboxyl groups at both ends.
A stainless steel autoclave similar to that used in Production Example 1 was charged with 190 parts of polyethylene glycol (Mn600) (a21-3), 76 parts of the sodium salt of 5-sulfoisophthalic acid dimethyl ester, and 0.2 parts of dibutyltin oxide, and the temperature was raised to 190°C. A transesterification reaction was carried out for 6 hours while distilling off methanol, thereby obtaining a polyether (a21-4).
Next, 300 parts of polyamide (a11-2), 750 parts of polyether ester (a21-4), and 0.6 parts of zirconyl acetate were heated to 240°C with stirring in a stainless steel autoclave, and thermal polymerization was carried out for 6 hours while reducing the pressure to 0.13 kPa or less, to obtain a viscous polyether ester amide resin (A-2). The Mn of polyether ester amide resin (A-2) was 41,000, and the content of oxyethylene groups contained in resin (A-2) was 51 wt% based on the weight of resin (A-2).

[Examples 1 and 2]
The polyether ester amide resins (A-1) and (A-2) obtained in Production Examples 2 and 3 were designated as resin compositions (Y-1) and (Y-2) for forming water-disintegrable members, respectively.

[Examples 3-4: Mixture of polyetheresteramide resin and polyetherurethane]
50 parts of the polyether ester amide resins (A-1) and (A-2) obtained in Production Examples 2 and 3 and 50 parts of the polyether urethane (B-1) obtained in Production Example 1 were melt-kneaded for 5 minutes using a Laboplastomill (manufactured by Toyo Seiki Seisakusho, Ltd.) at 220°C and 50 rpm to obtain resin compositions (Y-3) and (Y-4) for forming water-disintegrable members each comprising a mixture of the polyether ester amide resins (A-1) and (A-2) and the polyurethane (B-1).

[Examples 5-6: Mixture of polyether ester amide resin and polyoxyalkylene glycol]
40 parts of the polyether ester amide resins (A-1) to (A-2) obtained in Production Examples 2 and 3 and 60 parts of the polyoxyalkylene glycol (B-2) [polyethylene glycol (Mn 20,000)] obtained in Production Example 1 were melt-kneaded for 5 minutes using a Laboplastomill (manufactured by Toyo Seiki Seisakusho, Ltd.) at 220°C and 50 rpm to obtain resin compositions (Y-5) to (Y-6) for forming water-disintegrable members each comprising a mixture of the polyether ester amide resins (A-1) to (A-2) and the polyoxyalkylene glycol (B-2).

[Examples 7 to 10]
Polyether ester amide resin (A-1), polyether ester amide resin (A-2), polyether urethane (B-1), and polyoxyalkylene glycol (B-2) were melt-kneaded for 5 minutes at 220°C and 50 rpm using a Laboplastomill (manufactured by Toyo Seiki Seisakusho, Ltd.) according to the compositions (parts by weight) in Table 1, to obtain resin compositions (Y-7) to (Y-10) for forming water-disintegrable members.

[Comparative Example 1]
50 parts of the polyamide (a11-1), 1,000 parts of polyethylene glycol (Mn 20,000) (a21-6), and 0.6 parts of zirconyl acetate used in Production Example 2 were heated to 240°C with stirring in a stainless steel autoclave, and polymerized for 6 hours while reducing the pressure to 0.13 kPa or less to obtain a comparative resin composition (Z-1) containing a polyether ester amide resin (Comparative A-1). The Mn of the polyether ester amide resin (Comparative A-1) was 31,000, and the content of oxyethylene groups contained in the resin composition (Comparative A-1) was 95 wt% based on the weight of the resin composition (Comparative A-1).

[Comparative Example 2]
850 parts of the polyamide (a11-1) used in Production Example 2, 170 parts of polyethylene glycol (Mn 600) (a21-7), and 0.6 parts of zirconyl acetate were heated to 240°C with stirring in a stainless steel autoclave, and polymerization reaction was carried out for 6 hours while reducing the pressure to 0.13 kPa or less to obtain a comparative resin composition (Z-2) containing a viscous polyether ester amide (Comparative A-2). The resin composition (Comparative A-2) had an Mn of 30,000, and the content of oxyethylene groups in (Comparative A-2) was 17 wt% based on the weight of the resin composition (Comparative A-2).

[Comparative Example 3]
A stainless steel autoclave was charged with 90.40 g of succinic anhydride, 990.10 g of polyethylene glycol (Mn 1000) (a21-8), 1.63 g of titanium isopropoxide, and 800 ml of diethylbenzene, and the mixture was heated to reflux for 8 hours. The diethylbenzene was then distilled off under reduced pressure, and the mixture was stirred at 200°C for 5 hours under a reduced pressure of 5 mmHg to carry out a polyesterification reaction, yielding a polyester with an Mn of 12,000, a terminal hydroxyl value of 9.55 KOHmg/g, and an acid value of 1.27 KOHmg/g.
27.30 g of the polyester, 3.30 g of poly(butylene adipate) (PBA) diol (Mitsui Chemicals Polyurethanes, Inc.; average molecular weight 2000), and 30 ml of toluene were added to a stainless steel autoclave similar to that used in Production Example 1 and mixed at 90°C. 0.63 g of hexamethylene diisocyanate and 50 mg of dibutyltin dilaurate were then added and stirred at 90°C for 4 hours. Next, 0.30 g of 2,6-di-tert-butyl-4-methylphenol was added and mixed, and the toluene was then distilled off under reduced pressure to obtain a comparative resin composition (Z-3) consisting of a block copolymer (Comparative A-3) containing aliphatic polyoxyalkylene units and aliphatic polyester units as structural units. The Mn of the resulting resin composition (Comparative A-3) was 52,000.

The melting points of the resin compositions for forming water-disintegrable members (Y-1) to (Y-10) obtained in Examples 1 to 10 and the comparative resin compositions (Z-1) to (Z-3) obtained in Comparative Examples 1 to 3 were measured by the following method, and the results are shown in Table 1.
Furthermore, the shape retention and water disintegration properties of the formed film at high temperatures (180° C.) were evaluated by the following method. The results are shown in Table 1.

[Melt point measurement]
Each of the resin compositions for forming water-disintegrable members (Y-1) to (Y-10) obtained in Examples 1 to 10 and the comparative resin compositions (Z-1) to (Z-3) obtained in Comparative Examples 1 to 3 was placed in a standard temperature condition Class 2 environment according to JIS K 7100 for 24 hours, weighed out to about 5 mg, and measured using a differential scanning calorimeter (DSC) [trade name: DSC2910, manufactured by TA Instruments Co., Ltd.] at a heating rate of 10 ° C. per minute to 240 ° C., held for 10 minutes, and then cooled to -50 ° C. at a cooling rate of 10 ° C. per minute. After further holding at -50 ° C. for 10 minutes, the DSC curve obtained by heating to 240 ° C. at a heating rate of 10 ° C. per minute was used to determine the transition temperature (the apex of the melting peak) due to heating, which was taken as the melting point.
The higher the melting point, the more likely it is that the shape can be maintained even at a higher temperature.

[Shape retention of molded film at high temperatures]
Each of the resin compositions (Y-1) to (Y-10) for forming water-disintegrable members obtained in Examples 1 to 10 and the comparative resin compositions (Z-1) to (Z-3) obtained in Comparative Examples 1 to 3 was molded into a film having a thickness of 2 mm using a heat press. The molded films were cut into a size of 5 mm wide x 5 mm long x 2 mm thick and left to stand in a circulating air dryer at 180°C for 2 hours. After cooling to room temperature, the thickness of the film was measured and the results are shown in Table 1.
In Table 1, the case where there was no change in thickness was recorded as "GOOD", and the case where the thickness was 1 mm or less was recorded as "BAD".

[Water disintegration]
For the resin compositions (Y-1) to (Y-10) for forming water-disintegrable members obtained in Examples 1 to 10 and the comparative resin compositions (Z-1) to (Z-3) obtained in Comparative Examples 1 to 3, samples were cut to a size of 5 mm x 5 mm from films molded to a thickness of 2 mm in the same manner as the samples used in [Heat Resistance Performance] above. Samples were placed in a beaker containing ion-exchanged water (100 g) adjusted to 39 to 41 ° C. and a cylindrical magnetic stirrer (diameter 5 mm, length 30 mm), and immediately stirred at 400 rpm. 10 minutes after the start of stirring, the stirring was stopped and the film was left to stand for 20 minutes. The state of the film in the ion-exchanged water after 30 minutes from the start of stirring) was visually observed to evaluate the water disintegration of the molded film, and the results are shown in Table 1.
In Table 1, the case where the molded film was completely dissolved or where there was undissolved residue but its size was less than 0.5 ^mm3 was recorded as "Water-disintegrability A", and the case where there was undissolved residue but its size was 0.5 ^mm3 or more was recorded as "Water-disintegrability B". In the present invention, a resin composition that leaves less undissolved residue when immersed in water can be more preferably used for a water-disintegrable member, and an evaluation result of water-disintegrability of "Water-disintegrability A" is more preferable.

[Examples 11 to 20, Comparative Examples 4 to 6: Resin filaments for fused deposition modeling three-dimensional modeling machines and modeling using the same with a fused deposition modeling three-dimensional modeling machine]
A long die with a diameter of 1.75 mm and a flow path length of 5 mm was attached to a capillary rheometer (IMATEC R6000). Each of the resin compositions for forming water-disintegrable members (Y-1) to (Y-10) obtained in Examples 1 to 10 and the comparative resin compositions (Z-1) to (Z-3) obtained in Comparative Examples 1 to 3 was extrusion-molded under conditions of a melt temperature of 220°C and an extrusion speed of 75 mm/min, and processed into filaments with a diameter of 1.75 ± 0.15 mm, to obtain resin filaments (F-1) to (F-10) for fused deposition modeling three-dimensional modeling machines and comparative resin filaments (Z-4) to (Z-6).
The obtained resin filaments (F-1) to (F-10) and the comparative resin filaments (Z-4) to (Z-6) were evaluated for moldability using a 3D printer, water disintegration of the molded object, and shape retention of the molded object at high temperatures using the following methods.

[Formability using a 3D printer]
Each of the resin filaments (F-1) to (F-10) and the comparative resin filaments (Z-4) to (Z-6) was supplied to a Replicator X2 manufactured by MakerBot, to which data for the shape of the object (a rectangular parallelepiped of 5 mm x 5 mm x 2 mm) had been input, and extruded from a heat nozzle having a temperature of 250 ° C. to be molded. Visual observation was made to determine whether or not the desired shape had been formed, and the results are shown in Table 2.
In Table 2, when the moldability is marked as ◯, it means that the material could be molded into the desired shape.

[Water disintegration of molded objects]
A 3D printed object (shape: 5 mm x 5 mm x 2 mm) was placed in a beaker containing ion-exchanged water (100 g) adjusted to 39-41°C and a cylindrical magnetic stirrer (diameter 5 mm, length 30 mm), and immediately stirred at 400 rpm. Stirring was stopped 10 minutes after the start of stirring, and the object was allowed to stand for 20 minutes. The state of the object in the ion-exchanged water was then visually observed to evaluate the water disintegration of the object, and the results are shown in Table 2.
In Table 2, the case where the shaped object was completely dissolved or where there was residual dissolution but the size was less than 0.5 ^mm3 was recorded as "Water-disintegrability A," and the case where there was residual dissolution but the size was 0.5 ^mm3 or more was recorded as "Water-disintegrability B." In the present invention, a shaped object that leaves less residual dissolution when immersed in water is more preferable as a water-disintegrable member, and an evaluation result of water-disintegrability of "Water-disintegrability A" is preferable.

[Shape retention of molded objects at high temperatures]
A 3D printer-produced object (shape: 5 mm × 5 mm × 2 mm) was placed in a circulating air dryer at 180°C for 2 hours, and the thickness of the film was measured after cooling to room temperature. The results are shown in Table 2.
In Table 2, the case where there was no change in thickness was recorded as "GOOD", and the case where the thickness was 1 mm or less was recorded as "BAD".

As shown in Tables 1 and 2, the resin composition for forming water-disintegrable parts of the present invention and shaped articles made using the same are capable of achieving both water-disintegrability and heat resistance, which cannot be achieved with the resin compositions of the comparative examples.

The resin composition for water-disintegrable members of the present invention has heat resistance and can be easily removed by immersion in water, and therefore can be preferably used for molded articles that require water-disintegrability, adhesives used for temporary fixing of members, and filaments for fused deposition modeling three-dimensional modeling machines.

Claims (5)

A resin composition for forming a water-disintegrable member, comprising at least one resin (A) selected from the group consisting of a polyetheresteramide resin (A1) having a polyoxyethylene group, a polyetheramide resin (A2) having a polyoxyethylene group, and a polyetheramideimide resin (A3) having a polyoxyethylene group, wherein the total weight proportion of the oxyethylene groups contained in the resin (A) is 20 to 85 wt % based on the weight of the resin (A), and further comprising a polyurethane (B1) having a polyoxyalkylene chain and/or a polyoxyalkylene glycol (B2), wherein the total weight of the polyurethane (B1) having a polyoxyalkylene chain and the polyoxyalkylene glycol (B2) is 20 to 80 wt % based on the total weight of the resin composition for forming a water-disintegrable member. The resin composition for forming water-disintegrable members according to claim 1, wherein the number average molecular weight of resin (A) is 10,000 to 100,000. A water-disintegrable member comprising the resin composition for forming a water-disintegrable member according to claim 1 or 2 . A resin filament for a fused deposition modeling three-dimensional modeling machine, comprising the resin composition for forming a water-disintegrable member according to claim 1 or 2 . A method for manufacturing a three-dimensional object using the resin filament for a fused deposition modeling three-dimensional modeling machine according to claim 4 .