JP2024055582A - 3D printer filament - Google Patents

Abstract

[Problem] The present invention aims to provide a filament for 3D printers that has excellent impact strength. [Solution] A filament for 3D printers that contains a biodegradable thermoplastic resin (A) and a polymer (D) that has a structural unit (b1) derived from a monomer represented by the following formula (1). TIFF2024055582000006.tif29102 (In the formula (1), j represents an integer of 1 to 5.) [Selected Figure] None

Description

The present invention relates to filaments for 3D printers.

Systems that directly create a solid model of a three-dimensional shape input on CAD are called rapid prototyping systems, rapid new fabrication systems, etc. These systems include a system that has a temperature-controlled room (build chamber) that is maintained at a predetermined temperature determined by the thermoplastic resin used, and a system that melts and bonds thermoplastic resin powder to laminate it.

Various thermoplastic resins have been considered as raw materials for modeling three-dimensional shapes. Among them, the use of plant-derived resins has been considered due to the recent increase in environmental awareness. For example, polylactic acid-based monofilaments have been disclosed as a modeling material for 3D printers using the fused deposition modeling method (Patent Document 1).

Patent Publication 2016-94679

However, although Patent Document 1 mentions the modeling properties when polylactic acid is used as a filament, it does not mention the strength of the object produced by using it. Objects produced by 3D printers using polylactic acid have a problem in that they have low impact strength in particular.

The present invention aims to solve the above problems and provide a filament for 3D printers that has excellent impact strength.

The present invention has the following aspects.
[1] A filament for 3D printers comprising a biodegradable thermoplastic resin (A) and a polymer (D) having a structural unit (b1) derived from a monomer represented by the following formula (1).

(In the formula (1), j represents an integer of 1 to 5.)
[2] The third aspect of the present invention relates to a method for manufacturing a thermoplastic resin having biodegradability, the thermoplastic resin (A) comprising the step of:
Filament for D printers.
[3] The polymer comprises a polymer chain (B) having the structural unit (b1) and a structural unit (
b1) is a copolymer having a polymer chain (C) substantially free of the polymer chain (C).
The filament for a 3D printer described in
[4] The polymer (D) relative to 100 parts by mass of the biodegradable thermoplastic resin (A).
The filament for 3D printers according to any one of [1] to [3], wherein the ratio of is 0.1 to 50 parts.

According to the present invention, a filament for a 3D printer having excellent impact strength can be obtained.

The present invention will be described in detail below. The filament for 3D printer according to this embodiment contains a biodegradable thermoplastic resin and a polymer (D) having a structural unit derived from a specific monomer. The present embodiment will be described in detail below, but the present invention is not limited to the following.

<Biodegradable Thermoplastic Resin (A)>
The biodegradable thermoplastic resin (A) is a component contained in the filament for 3D printers.
The biodegradable thermoplastic resin (A) may be any resin that is decomposed by hydrolysis or biodegradation in soil, water, a composting device, etc., and is ultimately converted into harmless decomposition products by the action of microorganisms. Examples of the biodegradable thermoplastic resin (A) include aliphatic polyester resins,
Aliphatic aromatic polyester resins, polysaccharides, polyvinyl alcohol resins, etc. can be used.

Examples of the aliphatic polyester resin include polylactic acid resin, polyglycolic acid resin,
Polyhydroxybutyrate resins, polycaprolactone resins, polybutylene succinate resins, or copolymers thereof can be used. Details of polylactic acid resins will be described later. These may be isomers or may be copolymerized with other components.
For example, specific examples of polyhydroxybutyrate-based resins include poly(3-hydroxybutyrate), poly(3-hydroxybutyrate.3-hydroxyhexanoate), and poly(
Specific examples of polybutylene succinate resins include polybutylene succinate, poly(butylene succinate-adipate), and poly(butylene succinate-lactide).

Specific examples of the aliphatic aromatic polyester resin include poly(ethylene succinate terephthalate), poly(butylene succinate terephthalate), poly(butylene adipate terephthalate), and copolymers thereof.
Specific examples of polysaccharides include starch and its derivatives, cellulose and its derivatives,
Examples of resins that contain starch include hemicelluloses such as glucomannan and their derivatives, chitin, chitosan and their derivatives. In addition, Novamont's biodegradable resin "
Mater-bi (registered trademark) and the like can be used.

The polyvinyl alcohol resin is not particularly limited, but may be polyvinyl alcohol,
Examples of the copolymer include ethylene-vinyl alcohol copolymer and acrylic acid-methyl methacrylate-vinyl alcohol copolymer.
The biodegradable thermoplastic resin (A) may be any of the above-mentioned resins used alone, or may be a blend of two or more of the above-mentioned resins, or may be a copolymer of two or more of the above-mentioned resins.

Among these, from the viewpoints of biomass properties, cost, processability, etc., it is preferable that the biodegradable thermoplastic resin (A) contains a polylactic acid resin. The proportion of the polylactic acid resin in the biodegradable thermoplastic resin (A) is preferably 50 to 100% by mass, more preferably 80 to 100% by mass, and even more preferably 100% by mass, in 100% by mass of the biodegradable thermoplastic resin (A). When the proportion of the polylactic acid resin is 50% by mass or more, the filament for 3D printers tends to be excellent in shapeability and cost. The polylactic acid resin will be specifically described below.

<Polylactic acid resin>
A polylactic acid resin is a polymer whose main constituent is an L-lactic acid unit and/or a D-lactic acid unit. The mass ratio of the lactic acid unit in 100% by mass of the polymer is preferably
It is 70% by mass to 100% by mass.
As the polylactic acid resin, poly-L-lactic acid, poly-D-lactic acid, etc. are preferably used. The poly-L-lactic acid in the present invention refers to a polylactic acid polymer in which the content of L-lactic acid units is more than 50 mol % and is not more than 100 mol % of the total lactic acid units in the polylactic acid polymer. On the other hand, the poly-D-lactic acid in the present invention refers to a polylactic acid polymer in which the content of L-lactic acid units is more than 50 mol % and is not more than 100 mol % of the total lactic acid units in the polylactic acid polymer.
The content of D-lactic acid units in the polymer is more than 50 mol % and not more than 100 mol %.

The crystallinity of the poly-L-lactic acid resin itself changes depending on the content of the D-lactic acid unit. In other words, if the content of the D-lactic acid unit in the poly-L-lactic acid increases, the crystallinity of the poly-L-lactic acid decreases and approaches amorphous, and conversely, if the content of the D-lactic acid unit in the poly-L-lactic acid decreases, the crystallinity of the poly-L-lactic acid increases. Similarly, the crystallinity of the poly-D-lactic acid resin itself changes depending on the content of the L-lactic acid unit. In other words, if the content of the L-lactic acid unit in the poly-D-lactic acid increases, the crystallinity of the poly-D-lactic acid decreases and approaches amorphous, and conversely, if the content of the L-lactic acid unit in the poly-D-lactic acid decreases, the crystallinity of the poly-D-lactic acid increases.

The content of L-lactic acid units in the poly-L-lactic acid used in the present invention, or the content of D-lactic acid units in the poly-D-lactic acid used in the present invention, is 80 to 100 mol % of the total lactic acid units in 100 mol % from the viewpoint of maintaining the mechanical strength of the filament for 3D printers.
It is preferably 1 mol %, and more preferably 85 to 100 mol %.
The polylactic acid resin used in the 3D printer filament of the present invention may be copolymerized with other monomer units besides lactic acid. Examples of other monomers include glycol compounds such as ethylene glycol, propylene glycol, butanediol, and polyethylene glycol; dicarboxylic acids such as oxalic acid, adipic acid, and terephthalic acid; hydroxycarboxylic acids such as glycolic acid and hydroxybutyric acid; and lactones such as caprolactone. The copolymerization amount of the other monomer units is 1/100 of the total monomer units in the polymer of the polylactic acid resin.
00 mol%, it is preferably 0 to 30 mol%, and more preferably 0 to 10 mol%. Among the above-mentioned monomer units, it is preferable to use a monomer unit having biodegradability depending on the application. It is also preferable to mix poly-L-lactic acid and poly-D-lactic acid with each other for the polylactic acid resin used in the 3D printer filament of the present invention. This is because the stereocomplex crystal formed by this has a higher melting point than normal polylactic acid crystals (α crystals), thereby improving the heat resistance of the 3D printer filament.

Furthermore, in terms of improving heat resistance, it is also preferable that the polylactic acid resin used in the present invention is a polylactic acid block copolymer composed of a segment consisting of an L-lactic acid unit and a segment consisting of a D-lactic acid unit. In this case, the polylactic acid block copolymer forms a stereocomplex crystal within the molecule, and the melting point is higher than that of normal crystals. For efficient stereocomplex crystal formation, it is preferable that the segment length satisfies Y<X/2, where X is the mass average molecular weight of the polylactic acid block copolymer and Y is the larger of the mass average molecular weight of the segment consisting of the L-lactic acid unit and the mass average molecular weight of the segment consisting of the D-lactic acid unit.

The mass average molecular weight of the polylactic acid resin used in the 3D printer filament of the present invention is
In order to satisfy practical mechanical properties, water resistance, and decomposability, the molecular weight is preferably 50,000 to 400,000, more preferably 70,000 to 300,000, and even more preferably 100,000 to 250,000. The mass average molecular weight referred to here is determined by gel permeation chromatography (
The molecular weight is measured by gel permeation chromatography (GPC) using chloroform as a solvent and calculated in terms of polystyrene.
The polylactic acid resin can be produced by a known polymerization method, such as a direct polymerization method from lactic acid or a ring-opening polymerization method via lactide.

<Polymer>
The polymer of the present invention is a polymer having a structural unit (b1) derived from the following monomer (1):
D).

In formula (1), j is an integer of 1 to 5. In particular, j is preferably an integer of 1 to 2, and more preferably 1. When j=1, the monomer (1) is myrcene, and when j=2, the monomer (1) is farnesene. The monomer (1) may be used alone or in combination of two or more kinds. The monomer (1) is preferably a plant-derived monomer. When the monomer (1) is plant-derived, the resin additive contributes to a carbon-circulating society.

In a preferred embodiment, the polymer (D) includes a polymer chain (B) having a structural unit (b1).
and a polymer chain (C) that is substantially free of a structural unit (b1) (hereinafter, referred to as "
The BC copolymer is also referred to as a "BC copolymer." Preferred examples of the BC copolymer having the polymer chain (B) and the polymer chain (C) will be described in detail below.

<Polymer Chain (B)>
As described above, the polymer chain (B) has the structural unit (b1) derived from the monomer (1). By having the structural unit (b1) in the polymer chain (B), when the BC copolymer is added to a resin material, the low-temperature impact properties of the resulting 3D printer filament can be improved.

The proportion of the structural unit (b1) in the total of all structural units of the polymer chain (B) is 100 mass %,
Although there is no particular limitation, the content is preferably from 30 to 99.9 mass %.
When the proportion of the structural unit (b1) is 99.9% by mass or more, when the BC copolymer is added to a biodegradable thermoplastic resin and a filament for a 3D printer is molded, high impact properties are likely to be obtained. When the proportion of the structural unit (b1) is 99.9% by mass or less, when the BC copolymer is added to a biodegradable thermoplastic resin, optical properties are likely to be improved. Among the above, when the proportion of all structural units of the polymer chain (B) is 100%,
The proportion of the structural unit (b1) in terms of mass % is more preferably from 40 to 99.9 mass %, and even more preferably from 45 to 99.9 mass %.

It is preferable that the polymer chain (B) further has a structural unit (b2) derived from a (meth)acrylate in addition to the structural unit (b1). When the polymer chain (B) further has the structural unit (b2), the optical properties are easily improved when the BC copolymer is used as a filament for a 3D printer.
Examples of alkyl (meth)acrylates include methyl acrylate, ethyl acrylate, butyl acrylate, propyl acrylate, 2-ethylhexyl acrylate, glycidyl acrylate, octyl acrylate, phenyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, p-diphenyl acrylate, o-diphenyl acrylate, o-chlorophenyl acrylate, 4-methoxyphenyl acrylate, 4-chlorophenyl acrylate, and 2,4,6-trichlorophenyl acrylate.
Examples of the crosslinking agent include 4-tert-butylphenyl acrylate, methyl methacrylate, ethyl methacrylate, butyl methacrylate, propyl methacrylate, and 2-ethylhexyl methacrylate. In addition, a crosslinking agent such as allyl (meth)acrylate or 1,3-butylene dimethacrylate may also be used.

The structural unit (b2) may use one type alone, or two or more types in combination.
In particular, from the viewpoint of further improving the optical properties of the resulting 3D printer filament, it is preferable that the polymer chain (B) has a structural unit (b2) derived from an alkyl(meth)acrylate, and the alkyl group constituting the ester has 1 to 20 carbon atoms.
It is more preferable that the polymer chain (B) has a structural unit derived from an alkyl (meth)acrylate, more preferably that the polymer chain (B) has a structural unit derived from an alkyl (meth)acrylate having 2 to 6 carbon atoms in the alkyl group constituting the ester, and particularly preferably that the polymer chain (B) has at least one structural unit selected from the group consisting of a structural unit derived from methyl (meth)acrylate, a structural unit derived from ethyl (meth)acrylate, and a structural unit derived from butyl (meth)acrylate. In addition, since it is preferable that the polymer chain (B) is crosslinked, it is preferable that the polymer chain (B) has a structural unit having allyl (meth)acrylate as a crosslinking agent.

The proportion of the structural unit (b2) in 100% by mass of all structural units of the polymer chain (B) is 0.1
Preferably, the proportion of the structural unit (b2) is 0.1% by mass or more, the effect of improving the optical properties is easily obtained sufficiently when the BC copolymer is added to a resin material. Furthermore, if the proportion of the structural unit (b2) is 70% by mass or less, the effect of improving the impact properties is easily obtained sufficiently when the BC copolymer is added to a biodegradable thermoplastic resin. In particular, the polymer chain (
The proportion of the structural unit (b2) in 100% by mass of all structural units of B) is 0.1 to 60% by mass.
It is more preferable that the content is 0.1 to 55 mass %, and further more preferable that the content is 0.1 to 55 mass %.

The polymer chain (B) may further include a structural unit (b3) derived from a monomer other than the structural units (b1) and (b2).
Examples of other monomers include aromatic vinyl monomers such as styrene and α-methylstyrene; diene monomers such as 1,3-butadiene and isoprene; cyanide vinyl monomers such as acrylonitrile and methacrylonitrile; vinyl ether monomers such as vinyl methyl ether and vinyl ethyl ether; carboxylic acid vinyl monomers such as vinyl acetate and vinyl butyrate;
Examples of the structural unit (b3) include olefin monomers such as ethylene, propylene, isobutylene, etc.; halogenated vinyl monomers such as vinyl chloride, vinylidene chloride, etc.; and maleimide monomers such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, N-methylmaleimide, etc. One type of structural unit (b3) may be used alone, or two or more types may be used in combination.

The other monomer may be a crosslinking agent such as divinylbenzene.
A single species may be used, or two or more species may be used in combination.
When other monomers are used, it is preferable to contain a diene monomer or a crosslinking agent from the viewpoint of stably producing the BC copolymer.
The proportion of the structural unit (b3) in 100% by mass of all structural units in the polymer chain (B) is not particularly limited, but is preferably 0.1 to 10% by mass. When the content of the structural unit (b3) is 0.1% by mass or more, sufficient reactivity is likely to be obtained in the copolymerization of the polymer chain (B) and the polymer chain (C) described below. On the other hand, when the content of the structural unit (b3) is 10% by mass or less, excellent impact properties are likely to be obtained when the BC copolymer is added to a biodegradable thermoplastic resin. In particular, when the content of the structural unit (b3) in 100% by mass of all structural units in the polymer chain (B) is 0.1% by mass or more, excellent impact properties are likely to be obtained.
The proportion of b3) is more preferably from 0.1 to 7% by mass, and even more preferably from 0.1 to 1% by mass.

The polymer chain (B) preferably has a crosslinked structure. When the polymer chain (B) has a crosslinked structure, the effect of improving low-temperature impact properties when the BC copolymer is added to a resin material is easily obtained. The fact that the polymer chain (B) has a crosslinked structure can be confirmed by the fact that the polymer chain (B) remains undissolved when the polymer chain (B) is immersed in a good solvent such as acetone, toluene, or tetrahydrofuran.

(Glass-transition temperature)
The glass transition temperature (Tg) of the polymer chain (B) is preferably less than 0° C., more preferably not more than −20° C., and even more preferably not more than −40° C. When the glass transition temperature of the polymer chain (B) is less than 0° C., excellent low-temperature impact properties are likely to be obtained when the BC copolymer is added to a resin material.
The glass transition temperature of the polymer chain (B) is calculated by the following Fox formula (2).
1/(273.15+Tg)=Σ(wi/(273.15+Tgi)) Formula (2)
The symbols in formula (2) represent the following.
Tg: Tg (° C.) of the polymer chain (B).
wi: weight fraction of monomer component i.
Tgi: Tg (° C.) of the homopolymer obtained by polymerizing the monomer component i.

The Tg value of the homopolymer is given in Polymer Handbook Volume 1 (Wille
The value is the value described in y-Interscience.
When the polymer chain (B) has a constituent unit derived from a monomer whose homopolymer Tg is not described in the above document, the Tg of the polymer chain (B) is measured as follows: That is, the polymer of the polymer chain (B) is subjected to dynamic viscoelasticity measurement on a test piece molded to a thickness of 2 mm, a width of 5 mm and a length of 2 cm, and the Tg can be determined from the peak temperature of tan δ when scanning at a frequency of 1 Hz from, for example, −100° C. to 25° C.

<Polymer Chain (C)>
The polymer chain (C) is substantially free of the structural unit (b1). The term "substantially free of the structural unit (b1)" means that the content of the structural unit (b1) in the polymer chain (C) is less than that of the polymer chain (
The content of the structural unit (b1) in the polymer chain (C) is preferably 0.8% by mass or less, more preferably 0.5% by mass or less, still more preferably 0.1% by mass or less, and even more preferably 0.01% by mass or less, based on the total amount of the polymer chain (C).
The following are particularly preferred:

The polymer chain (C) preferably has a structural unit (c1) derived from an alkyl (meth)acrylate. The polymer chain (C) may further have a structural unit (c2) derived from a monomer other than the alkyl (meth)acrylate, as necessary.

(Structural Unit (c1))
The structural unit (c1) is derived from an alkyl (meth) acrylate. Examples of the alkyl (meth) acrylate in the structural unit (c1) include the same as those exemplified as the alkyl (meth) acrylate in the structural unit (b2) described above. When the polymer chain (C) has the structural unit (c1), the dispersibility of the BC copolymer when added to a biodegradable thermoplastic resin is good, and it is easy to obtain a filament for 3D printers with excellent impact properties.

Among the above, from the viewpoint of dispersibility when the BC copolymer is added to a resin material, the polymer chain (C) preferably has a structural unit derived from an alkyl (meth)acrylate in which the alkyl group constituting the ester has 1 to 20 carbon atoms, more preferably has a structural unit derived from an alkyl (meth)acrylate in which the alkyl group constituting the ester has 2 to 6 carbon atoms, and particularly preferably is a structural unit derived from methyl methacrylate.

From the viewpoint of dispersibility when the BC copolymer is added to a biodegradable thermoplastic resin, the proportion of the structural unit (c1) in 100% by mass of all structural units in the polymer chain (C) is preferably 50 to 100% by mass, more preferably 70 to 100% by mass, and more preferably 80 to 100% by mass.
It is more preferably 0% by mass.

(Structural unit (c2))
The polymer chain (C) may further include a structural unit (b2) derived from a monomer other than alkyl (meth)acrylate, as necessary. Examples of the other monomer include:
Examples of the monomers include acrylate monomers other than alkyl (meth)acrylates, such as glycidyl acrylate, phenyl acrylate, 1-naphthyl acrylate, 2-naphthyl acrylate, p-diphenyl acrylate, o-diphenyl acrylate, o-chlorophenyl acrylate, 4-methoxyphenyl acrylate, 4-chlorophenyl acrylate, 2,4, trichlorophenyl acrylate, and 4-tert-butylphenyl acrylate; cyanide vinyl monomers, such as acrylonitrile and methacrylonitrile; aromatic vinyl monomers, such as styrene and α-methylstyrene; vinyl ether monomers, such as vinyl methyl ether and vinyl ethyl ether; carboxylic acid vinyl monomers, such as vinyl acetate and vinyl butyrate; olefin monomers, such as ethylene, propylene, and isobutylene; halogenated vinyl monomers, such as vinyl chloride and vinylidene chloride; and maleimide monomers, such as maleimide, N-phenylmaleimide, N-cyclohexylmaleimide, and N-methylmaleimide. Among these, BC
From the viewpoint of thermal decomposition resistance when the copolymer is added to a biodegradable thermoplastic resin, aromatic vinyl monomers are preferred, and styrene is more preferred. The monomers other than alkyl (meth)acrylate may be used alone or in combination of two or more.

From the viewpoint of low-temperature impact properties when the BC copolymer is added to a biodegradable thermoplastic resin, the proportion of the structural unit (c2) in 100% by mass of all structural units of the polymer chain (C) is 0 to
It is preferably 50% by mass, more preferably 0 to 30% by mass, and particularly preferably 0 to 20% by mass.

<Copolymer Composition>
In the BC copolymer, the ratio of the polymer chain (B) is preferably 50 to 90% by mass relative to the total 100% by mass of the polymer chain (B) and the polymer chain (C). When the ratio of the polymer chain (B) is 50% by mass or more relative to the total 100% by mass of the polymer chain (B) and the polymer chain (C), excellent impact properties are easily obtained when the BC copolymer is added to a biodegradable thermoplastic resin. When the ratio of the polymer chain (B) is 90% by mass or less relative to the total 100% by mass of the polymer chain (B) and the polymer chain (C), the dispersibility is good when the BC copolymer is added to a biodegradable thermoplastic resin. The lower limit of the ratio of the polymer chain (B) is preferably 55% by mass or more, more preferably 60% by mass or more. The upper limit of the ratio of the polymer chain (B) is preferably 80% by mass or less, more preferably 75% by mass or less. When the ratio of the polymer chain (B) is 80% by mass or less relative to the total 100% by mass of the polymer chain (B) and the polymer chain (C), excellent powder properties are obtained.

The volume average particle size (Dv) of the BC copolymer is preferably 50 to 300 nm, and more preferably 70 to 150 nm.
nm is more preferable, and 80 to 120 nm is even more preferable.
When the Dv of the BC copolymer is 300 nm or less, it is easy to obtain a filament for a 3D printer having excellent impact properties. When the Dv of the BC copolymer is 300 nm or less, it is easy to reduce the generation of cullets during the production of the BC copolymer. The Dv of the BC copolymer is determined by the method described in the examples.

The number average particle size (Dn) of the BC copolymer is preferably 30 to 200 nm, and more preferably 50 to 120 nm.
m is more preferable, and 60 to 100 nm is even more preferable. When the Dn of the BC copolymer is 30 nm or more, a 3D printer filament having excellent impact properties is easily obtained. When the Dn of the BC copolymer is 200 nm or less, the generation of cullets during the production of the BC copolymer is easily reduced.
The Dn of the BC copolymer is determined by the method described in the Examples.
The BC copolymer preferably has a structure in which a polymer chain (C) is grafted to a polymer chain (B).

<Method of Producing BC Copolymer>
The method for producing the BC copolymer is not particularly limited, but may be a method comprising the steps of:
It can be produced by polymerizing the monomers constituting the polymer chain (C).
This method will be described.

The polymer chain (B) can be obtained, for example, by polymerizing a monomer component including the monomer (1) using an emulsion polymerization method, a suspension polymerization method, a solution polymerization method or the like.
Among these, from the viewpoint of easy control of the particle size of the finally obtained BC polymer, it is preferable to produce the polymer chain (B) by the emulsion polymerization method. Hereinafter, the method of producing the polymer chain (B) by the emulsion polymerization method will be described in detail.

As the monomer for emulsion polymerization, a monomer necessary for obtaining the desired polymer chain (B) may be selected.
As the emulsion polymerization method, generally known methods such as batch addition polymerization method, continuous addition polymerization method, multi-stage polymerization method, etc. can be used. When the emulsion polymerization method is used, the polymer chain (B), i.e., a latex in which the polymer chain (B) is dispersed in water (hereinafter, also referred to as "polymer chain (B) latex") can be obtained.

The emulsifier may be an emulsifier having an ionic hydrophilic moiety and a nonionic hydrophilic moiety in the same molecule, or a nonionic emulsifier. Examples of the emulsifier having an ionic hydrophilic moiety and a nonionic hydrophilic moiety in the same molecule include carboxylic acid emulsifiers, phosphoric acid emulsifiers, and sulfonic acid emulsifiers.
Examples of carboxylic acid emulsifiers include caprylic acid, pelargonic acid, capric acid, lauric acid, myristic acid, palmitic acid, margaric acid, stearic acid, arachidic acid, behenic acid, lignoceric acid, cerotic acid, montanic acid, myristoleic acid, palmitoleic acid, oleic acid, elaidic acid, vaccenic acid, ricinoleic acid, gadoleic acid, eicosenoic acid, erucic acid, nervonic acid, linoleic acid, eicosadienoic acid, docosadienoic acid, linolenic acid, pinolenic acid, eleostearic acid, mead acid, eicosatrienoic acid, stearidonic acid, arachidonic acid, eicosatetraenoic acid, adrenic acid, bosseopentaenoic acid, eicosapentaenoic acid, osbondoic acid, sardine acid, tetracosapentaenoic acid, docosahexaenoic acid,
Metal salts of saturated or unsaturated fatty acids having an alkyl group having 8 to 28 carbon atoms, such as herbicid; metal salts of oligocarboxylic acid compounds, such as alkenylsuccinic acid; N-lauroylsarcosine, N
Metal salts of sarcosine derivatives such as cocoyl sarcosine.

Examples of the phosphoric acid emulsifier include polyoxyethylene phenyl ether phosphate, polyoxyethylene alkyl phenyl ether phosphate, polyoxyethylene alkyl ether phosphate, and alkyl phosphate.
Examples of the sulfonic acid emulsifier include polyoxyalkylene alkyl ether sulfonates, alkylbenzene sulfonates, α-sulfo fatty acid methyl ester salts, and α-olefin sulfonates.

Examples of nonionic emulsifiers include polyoxyalkylene alkyl ethers,
Examples of the polyoxyethylene alkylene alkyl ether include polyoxyethylene distyrenated phenyl ether, polyoxyethylene tribenzyl phenyl ether, sorbitan fatty acid ester, polyoxyethylene sorbitan fatty acid ester, and polyoxyethylene fatty acid ester.

The emulsifiers may be used alone or in combination of two or more kinds.
The amount of the emulsifier used is not particularly limited. For example, 0.1 to 20 parts by mass is preferable relative to 100 parts by mass of the total of the monomers constituting the polymer chain (B). When the amount of the emulsifier used is 0.1 parts by mass or more, the emulsion stability is likely to be improved. When the amount of the emulsifier used is 20 parts by mass or less, the coagulation of the obtained latex is facilitated in the production of the BC copolymer described later.

The polymerization initiator is not particularly limited. For example, an azo-based initiator or a peroxide-based initiator can be used. The polymerization initiator may be used alone or in combination of two or more kinds. The amount of the polymerization initiator used is 0.0 to 100 parts by mass of the total of the monomers constituting the polymer chain (B).
The amount of the polymerization initiator used is preferably 0.5 to 1.0 parts by mass. The lower limit of the amount of the polymerization initiator used is more preferably 0.1 parts by mass or more. The upper limit of the amount of the polymerization initiator used is more preferably 0.3 parts by mass or less. When a peroxide-based initiator is used, it can be used as a redox-based initiator in combination with a reducing agent. The amount of the reducing agent used is 0.00 to 1.0 parts by mass based on 100 parts by mass of the total of the monomers constituting the polymer chain (B).
01 to 1 part by mass is preferred.

The volume average particle diameter of the polymer chain (B) in the polymer chain (B) latex is 50 to 1000 nm.
The volume average particle diameter of the polymer chain (B) is preferably 50 to 500 nm, and more preferably 70 to 500 nm.
When the volume average particle size of the polymer chain (B) is 1000 nm or less, it is easy to obtain excellent impact properties by adding the BC copolymer to a biodegradable thermoplastic resin. When the volume average particle size of the polymer chain (B) is 1000 nm or less, it is easy to reduce the amount of cullet generated during the production of the polymer chain (B).

The volume average particle size of the polymer chain (B) can be controlled by adding an enlarger to the polymer chain (B) latex. Various enlargers can be used. Examples of the enlarger include an acid group-containing copolymer and an oxyacid salt. Examples of the acid group-containing copolymer include a copolymer having acrylic acid, methacrylic acid, itaconic acid, or the like as a component. Examples of the oxyacid salt include at least one oxyacid salt selected from alkali metal salts or alkaline earth metal salts of oxyacids, or salts of zinc, nickel, and aluminum. Examples of the oxyacid salt include salts of sulfuric acid, nitric acid, phosphoric acid, or the like with potassium, sodium, magnesium, calcium, nickel, aluminum, or the like.

(Method for producing BC copolymer)
The BC copolymer can be synthesized, for example, by polymerizing a monomer constituting the polymer chain (C) in the presence of the polymer chain (B). The monomer constituting the polymer chain (C) is as described above.
The BC copolymer obtained by this can also be said to be a graft copolymer in which the polymer chain (C) is a graft chain. In this case, the amount of the monomer component used to obtain the polymer chain (C) is preferably 10 to 100 parts by mass, more preferably 25 to 80 parts by mass, and even more preferably 30 to 70 parts by mass, per 100 parts by mass of the polymer chain (B). When the amount of the vinyl monomer component used is equal to or greater than the lower limit of the numerical range, the powder characteristics of the BC copolymer are excellent. When the amount of the vinyl monomer component used is equal to or less than the upper limit of the numerical range, the low-temperature impact properties of the 3D printer filament obtained by adding the BC copolymer to a biodegradable thermoplastic resin and molding it are improved.

For example, a BC copolymer can be produced by polymerizing a monomer component constituting the polymer chain (C) in the polymer chain (B) latex.
After adding and impregnating the monomer components constituting the polymer chain (C) into the latex, various radical polymerization initiators are reacted to polymerize the monomer components constituting the polymer chain (C). Methods for adding the radical polymerization initiator include a method of adding the entire amount to the polymer chain (B) latex at once, and a method of adding it dropwise at a constant speed into the polymer chain (B) latex.

The method for polymerizing the monomer components constituting the polymer chain (C) is not particularly limited. For example, emulsion polymerization, suspension polymerization, and solution polymerization are included. Among these, emulsion polymerization is preferred from the viewpoint of controlling the particle size of the BC copolymer according to the type of resin material added and effectively expressing low-temperature impact properties.
The method for polymerizing the monomer components constituting the polymer chain (C) by emulsion polymerization will be described in detail below.

As the emulsion polymerization method, generally known methods such as batch addition polymerization of monomers, continuous addition polymerization, and multi-stage polymerization can be adopted. When the emulsion polymerization method is used, a latex in which the BC copolymer is dispersed in water (hereinafter also referred to as "BC copolymer latex") can be obtained as a powder by drying by spray drying or freeze drying, or by coagulation. The emulsifier used in the production of the BC copolymer latex can be, for example, the same as the emulsifier used in the production of the polymer chain (B). The emulsifier may be used alone or in combination with two or more kinds. The emulsifier used in the production of the BC copolymer latex may be the same as or different from the emulsifier used in the production of the polymer chain (B).

The amount of the emulsifier used is not particularly limited. For example, the amount of the emulsifier used is 1% by weight of the total of the monomers constituting the BC copolymer.
It is preferable that the amount of the emulsifier used is 0.1 to 20 parts by weight per 0.100 parts by weight.
When the amount of the emulsifier is 20 parts by mass or more, the emulsion stability is likely to be improved. When the amount of the emulsifier used is 20 parts by mass or less, the coagulation of the BC copolymer latex is facilitated. The emulsifier used in the production of the polymer chain (B) may be used as it is as the emulsifier for the production of the BC copolymer latex, or may be added separately.

The polymerization initiator may be the same as the polymerization initiator used in the production of the polymer chain (B). The polymerization initiator may be used alone or in combination of two or more. The polymerization initiator in the production of the BC copolymer latex may be the same as or different from the polymerization initiator used in the production of the polymer chain (B). The amount of the polymerization initiator used is not particularly limited.
The amount is preferably 0.05 to 1.0 part by mass per 100 parts by mass of the total of the monomers constituting the copolymer.

The BC copolymer latex obtained by emulsion polymerization may be blended with additives such as antioxidants as necessary. The BC copolymer latex may be produced by blending the antioxidant beforehand and then carrying out emulsion polymerization. As the antioxidant, it is preferable to use at least one selected from the group consisting of phenol-based antioxidants, thioether-based antioxidants, and phosphite-based antioxidants. The antioxidant may be blended as a powder or tablet, or may be blended in a state dispersed in water. In the present invention, a method in which the antioxidant is blended in a state dispersed in water into the BC copolymer latex is preferable. This allows the antioxidant to be added more uniformly. Therefore, it is easy to suppress oxidative deterioration of the polymer chain (B). In addition, it is easy to obtain better optical properties.

The amount of the antioxidant used was 0.00 based on 100 parts by mass of the monomers constituting the BC copolymer.
When the amount of the antioxidant added is 0.0001 part by mass or more,
In the resin composition described later, the deterioration of optical properties during molding is easily suppressed. Furthermore, when the amount of the antioxidant used is 10 parts by mass or less, a molded product with good surface appearance is easily obtained. The lower limit of the amount of the antioxidant used is more preferably 0.001 parts by mass, and even more preferably 0.01 parts by mass. Furthermore, the upper limit of the amount of the antioxidant used is more preferably 6 parts by mass, and even more preferably 3 parts by mass.

(Production of BC copolymer powder)
The BC copolymer latex obtained by emulsion polymerization can be dried by spray drying or freeze drying, or coagulated to recover it as a BC copolymer powder. Among these, drying or coagulation by spray drying is preferred. When drying is performed using the spray drying method, the dispersibility of the BC copolymer powder when added to a biodegradable thermoplastic resin is easily improved. When coagulation is performed, impurities such as the emulsifier used in the emulsion polymerization can be easily removed, so that a BC copolymer powder with high purity is easily obtained. When drying is performed by the spray drying method, the BC copolymer latex is sprayed onto fine droplets and dried by applying hot air to the droplets. Examples of devices that generate droplets include devices of a rotating disk type, a pressure nozzle type, and a two-fluid nozzle type. Any device may be used. It is preferred to dry the BC copolymer latex by applying hot air of 100°C or more and 200°C or less. When the hot air temperature is 10
When the hot air temperature is 0° C. or higher, the latex can be dried sufficiently. When the hot air temperature is 200° C. or lower, the thermal decomposition of the powder can be easily suppressed.

When carrying out coagulation, the BC copolymer latex is put into hot water in which a coagulant is dissolved, and the BC copolymer is salted out, separated, purified, coagulated, and made wet, and then dehydrated and dried. Examples of the coagulant include inorganic salts such as aluminum chloride, aluminum sulfate, sodium sulfate, magnesium sulfate, sodium nitrate, and calcium acetate, and acids such as sulfuric acid. Among them, calcium acetate is particularly preferred. The coagulant may be used alone or in combination of two or more kinds, but when used in combination, it is necessary to select a combination that does not form a salt that is insoluble in water.
For example, the combined use of calcium acetate and sulfuric acid or its sodium salt is not preferred because it produces a water-insoluble calcium salt.

<3D printer filament>
A 3D printer filament is a thread-like molded body used to output data in a 3D printer; specifically, it is supplied to the 3D printer and molded into the shape of the input data.
The 3D printer filament according to this embodiment is made of a biodegradable thermoplastic resin and
The filament for 3D printers may contain other compounds. There are no particular limitations on the other compounds, but examples of such compounds include antiblocking agents, plasticizers (phthalic acid esters, etc.), colorants (red lead, yellow lead, titanium oxide, etc.), fillers (calcium carbonate, clay, talc, etc.), antioxidants (alkylphenols, organic phosphites, etc.), ultraviolet absorbers (salicylic acid esters, benzotriazole, etc.), flame retardants (phosphate esters, antimony oxide, etc.), antistatic agents, foaming agents, lubricants (fatty acid esters), antibacterial and antifungal agents, and other known additives. These can also be made of known materials.
The ratio of the polymer (D) to 100% by mass of the biodegradable thermoplastic resin is preferably 0.1% by mass to 50% by mass in order to impart impact resistance to the 3D printer filament, more preferably 3% by mass to 50% by mass, and particularly preferably 5% by mass to 30% by mass.

The ratio of the biodegradable thermoplastic resin in 100% by mass of the 3D printer filament is preferably 50% by mass to 99% by mass for the moldability of the 3D printer filament, more preferably 70% by mass to 95% by mass, and more preferably 75% by mass to 90% by mass.
Mass % is particularly preferred.
The proportion of polymer (D) in 100% by mass of the 3D printer filament is preferably 0.1% by mass to 50% by mass, more preferably 1% by mass to 35% by mass, and particularly preferably 5% by mass to 20% by mass, in order to impart impact resistance to the 3D printer filament.

The ratio of other compounds in 100% by mass of the 3D printer filament is preferably 0 to 10% by mass, more preferably 0 to 5% by mass, and particularly preferably 0 to 3% by mass, for the sake of the formability of the 3D printer filament.
There is no particular limit to the diameter of the filament for a 3D printer, but it is preferable that the diameter be 1 to 5 mm.
The method for producing the filament for 3D printers is not particularly limited, and it can be produced by a known method. For example, it can be shaped by a molding method such as an injection method, a melt extrusion method, a calendar method, or a blow molding method.

The present invention will be described below with reference to examples. In the examples, "parts" refers to "parts by mass."

(Production of Polymer D1)
99.6 parts of myrcene and 0 parts of allyl methacrylate (manufactured by Mitsubishi Chemical Corporation) as monomers
0.4 parts of ethylhexyl benzene sulfonate as an emulsifier and 0.8 parts of sodium dodecylbenzenesulfonate as an emulsifier were added to 64 parts of deionized water and stirred at 15,000 rpm for 5 minutes to obtain a stable premixed emulsion.

The obtained premixed emulsion and 240 parts of deionized water were placed in a polymerization apparatus equipped with a stirrer, a cooling tube, and a thermometer, and the inside of the polymerization apparatus was thoroughly replaced with nitrogen, and then the temperature was raised to 70° C. Next, 4.2 parts of Percumyl P (manufactured by NOF Corp.) as a polymerization initiator, and 0.002 parts of ferrous sulfate, 0.006 parts of sodium ethylenediaminetetraacetate, and 0.3 parts of sodium formaldehyde sulfoxylate as reducing agents were added to start polymerization, and after 6 hours,
A polymer chain (B) latex containing a polymer chain (B) having a crosslinked structure was obtained. Next, a solution obtained by adding 0.4 parts by mass of t-butyl hydroperoxide to a monomer component of 99 parts by mass of methyl methacrylate and 1 part by mass of butyl acrylate was continuously added dropwise to the polymer chain (B) latex over a period of 60 minutes to carry out polymerization. Thereafter, the temperature inside the polymerization apparatus was raised to 75°C, and stirring was continued for 120 minutes. Irg1076 (n-octadecyl-3-(3',5'di-t-butyl-4'-
hydroxyphenyl)propionate, manufactured by BASF Japan Ltd.) 0.25 parts, and DLDTP (didodecyl 3,3'-thiodipropionate, manufactured by BaSF Japan Ltd.) as a thioether-based antioxidant.
This was added to 460 parts of deionized water containing 5 parts by mass of calcium acetate to cause coagulation, followed by washing with water, dehydration, and drying, thereby obtaining polymer D1 in the form of powder.

(Preparation of Polymer D2)
Polymer D2 was produced in the same manner as polymer D1, except that the proportion of the through polymer chain (B) was changed to Table 1.

The proportion of the polymer chain (B) in the polymers D1 and D2 is as shown in Table 1.
The particle sizes of the resulting polymers D1 and D2 were measured by the following method. The results are shown in Table 2.

(Polymer Particle Size)
5 ml of polymer latex was measured using a laser diffraction scattering type particle size distribution analyzer (LA-960S
The volume average particle size (Dv) and number average particle size (Dn) were measured using a HORIBA, Ltd.
The volume average particle diameter (Dv) was determined as the 50% cumulative volume particle diameter. The number average particle diameter (Dn) was determined by dividing the 50% cumulative volume particle diameter by the degree of particle size distribution.

Example 1
10 parts of the obtained polymer D1 and polylactic acid resin (Ingeo 3001D, Natu
The mixture was then hand-blended by shaking the polyethylene bag well. The mixture was then extruded in a twin-screw extruder (manufactured by Ikegai Corporation, product name: PCM30).
The mixture was melt-kneaded at 190° C. using a melt-kneading apparatus, and the extruded strand was cut to obtain pellets.
The pellets were molded into a 4 mm thick molded article using an injection molding machine (SE100DU, manufactured by Sumitomo Heavy Industries, Ltd.) at a molding temperature of 190° C. and a mold temperature of 30° C. The impact properties of the molded article were evaluated by the following method. The results are shown in Table 2.

(Impact properties)
The impact properties were evaluated by measuring the Charpy strength at 23° C. of a resin composition molded to a thickness of 4 mm in accordance with JIS K7111.

<Example 2 and Comparative Example 1>
Molded articles were produced in the same manner as in Example 1, except that the components were changed as shown in Table 2, and the impact properties were evaluated. The obtained results are shown in Table 2.

As shown in Table 1, the impact strength of the molded bodies of Examples 1 and 2 using the polymer D1 or D2 was significantly improved compared to the molded body of Comparative Example 1 in which the polymer D1 or D2 was not used.
It is clear that this is suitable as a filament for D printers.

Claims (4)

A filament for 3D printers comprising a biodegradable thermoplastic resin (A) and a polymer (D) having a structural unit (b1) derived from a monomer represented by the following formula (1).

(In the formula (1), j represents an integer of 1 to 5.) The 3D thermoplastic resin according to claim 1, wherein the biodegradable thermoplastic resin (A) contains a polylactic acid resin.
Printer filament. The polymer comprises a polymer chain (B) having the structural unit (b1), and
The filament for 3D printers according to claim 1 or 2, which is a copolymer having a polymer chain (C) that is substantially free of a polymer chain (C). The filament for 3D printers according to any one of claims 1 to 3, wherein the ratio of the polymer (D) to 100 parts by mass of the biodegradable thermoplastic resin (A) is 0.1 to 50 parts.