JP2020070332A - Flame-retardant resin composition and molding - Google Patents

Abstract

To provide a flame-retardant resin composition having excellent flame retardancy and a molding.SOLUTION: A flame-retardant resin composition contains a nano cellulose material (A), a phosphorous flame retardant (B), and a resin (C) composed of at least one of a thermoplastic resin and a thermosetting resin.SELECTED DRAWING: None

Description

  The present invention relates to a flame-retardant resin composition and a molded product.

  Techniques for improving the flame retardancy of resin compositions suitable for applications requiring flame retardancy have been widely studied.

  As one of the techniques for improving the flame retardancy of a resin composition, an example of incorporating a compound called a so-called flame retardant has been proposed. As an example of the flame retardant used in the resin composition, an inorganic flame retardant such as metal hydroxide is known (see, for example, Patent Document 1).

JP, 2009-84324, A

However, a metal hydroxide or the like known as a so-called flame retardant is usually contained as a particulate filler component, so that it is not sufficiently diffused into the resin, and the flame retardant is locally unevenly distributed, In some cases, the desired flame retardant effect cannot be expected.
Further, in order to develop more excellent flame retardancy, it is necessary to contain a large amount of flame retardant with respect to the amount of resin, but when the content of flame retardant becomes too large, when molded into a sheet or the like. It may not be possible to maintain mechanical properties such as tensile properties.

  The present invention has been made in view of the above circumstances, and provides a flame-retardant resin composition having excellent flame retardancy and a molded article.

  The present inventors diligently studied to solve the above problems. As a result, they have found that the flame retardancy of a resin composition can be effectively improved by using a combination of a nanocellulose-based material and a phosphorus-based flame retardant, and completed the present invention.

  That is, according to the present invention, the following flame-retardant resin composition and molded article are provided.

[1]
A flame-retardant resin composition containing a nanocellulose-based material (A), a phosphorus-based flame retardant (B), and a resin (C) made of at least one of a thermoplastic resin and a thermosetting resin.
[2]
In the flame-retardant resin composition according to the above [1],
When the total content of the nanocellulose-based material (A) and the phosphorus-based flame retardant (B) is 100% by mass, the content of the phosphorus-based flame retardant (B) is 1% by mass or more and 50% by mass or less. A flame-retardant resin composition.
[3]
In the flame-retardant resin composition according to the above [1] or [2],
The above-mentioned phosphorus flame retardant (B) is a group consisting of red phosphorus flame retardant, non-halogen phosphate ester flame retardant, halogen-containing phosphate ester flame retardant, condensed phosphate ester flame retardant and polyphosphate flame retardant. A flame-retardant resin composition containing one or more phosphorus flame retardants selected from the group consisting of:
[4]
The flame-retardant resin composition according to any one of [1] to [3] above,
A flame-retardant resin composition in which the nanocellulose-based material (A) contains at least one selected from the group consisting of cellulose nanofibers and cellulose nanocrystals.
[5]
In the flame-retardant resin composition according to the above [4],
A flame-retardant resin composition in which the nanocellulose-based material (A) contains cellulose nanocrystals.
[6]
In the flame-retardant resin composition according to the above [5],
A flame-retardant resin composition wherein the cellulose nanocrystals have an average aspect ratio of less than 50 and an average fiber diameter of 1 nm or more and 100 nm or less.
[7]
In the flame retardant resin composition according to the above [5] or [6],
A flame-retardant resin composition in which the average fiber length of the cellulose nanocrystal is 45 nm or more and 500 nm or less.
[8]
The flame-retardant resin composition according to any one of [1] to [7] above,
When the total content of the nanocellulose-based material (A), the phosphorus-based flame retardant (B), and the resin (C) is 100% by mass, the nanocellulose-based material (A) and the phosphorus-based flame retardant ( A flame-retardant resin composition having a total content of B) of 1% by mass or more and 50% by mass or less.
[9]
The flame-retardant resin composition according to any one of [1] to [8] above,
The resin (C) is an ethylene / unsaturated ester copolymer, an ethylene / unsaturated carboxylic acid copolymer, an ionomer resin of the ethylene / unsaturated carboxylic acid copolymer, a polyolefin resin, a polyester resin and A flame-retardant resin composition containing one or more thermoplastic resins selected from the group consisting of polyamide resins.
[10]
A molded product obtained by molding the flame-retardant resin composition according to any one of the above [1] to [9].

  According to the present invention, it is possible to provide a flame-retardant resin composition having excellent flame retardancy and a molded article.

  Embodiments of the present invention will be described below.

[Flame-retardant resin composition]
First, the flame-retardant resin composition according to this embodiment will be described.
The flame-retardant resin composition according to the present embodiment comprises a nanocellulose-based material (A), a phosphorus-based flame retardant (B), and a resin (C) made of at least one of a thermoplastic resin and a thermosetting resin. ,including.
According to the flame-retardant resin composition according to the present embodiment, it is possible to obtain a molded article having excellent flame retardancy.
Although it is not clear why a molded article excellent in flame retardancy can be obtained by using the flame-retardant resin composition according to the present embodiment, the nano-cellulosic material (A) and the phosphorus-based flame retardant (B) are used. It is considered that the carbonized layer can be effectively formed on the surface of the molded body when used in combination when used in combination.
Since the carbonized layer has an excellent gas barrier property, if a carbonized layer is formed on the entire surface of the combustion part of the molded body in the initial stage of combustion, the contact between the molded body and oxygen is blocked, so that the combustion of the molded body is prevented. It can be stopped at the early stage of combustion.
Therefore, the molded body using the flame-retardant resin composition according to the present embodiment, the synergistic effect of the nanocellulosic material (A) and the phosphorus-based flame retardant (B), the combustion part of the molded body in the initial stage of combustion. A carbonized layer can be formed on the entire surface, and as a result, contact between the molded body and oxygen can be effectively suppressed, and thus it is considered to have excellent flame retardancy.
Here, it is considered that the nanocellulose-based material (A) serves as a raw material for the carbonized layer, and the phosphorus-based flame retardant (B) has an action of promoting the carbonization of the nanocellulose-based material (A).
That is, it is considered that a synergistic effect of the nanocellulose-based material (A) and the phosphorus-based flame retardant (B) can form a carbonized layer on the entire surface of the combustion part of the molded body in the initial stage of combustion.

  Hereinafter, each component constituting the flame-retardant resin composition according to this embodiment will be described.

(Nanocellulose material (A))
The nanocellulose-based material (A) according to the present embodiment further improves the dispersibility of the nanocellulose-based material (A) in the flame-retardant resin composition to be obtained, and the nanocellulose-based material in the obtained molded body. From the viewpoint of further improving the dispersibility of the material (A), it is preferable to contain at least one selected from cellulose nanofibers and cellulose nanocrystals, and it is more preferable to contain cellulose nanocrystals.

  Cellulose nanofibers can be obtained by a known method, for example, by defibrating a cellulose raw material and refining it until the fiber diameter becomes nanosize. Examples of the defibration treatment method for the cellulose raw material include mechanical defibration treatment and chemical treatment such as treatment with an oxidation catalyst liquid containing an N-oxyl compound.

  The cellulose raw material is not particularly limited as long as it contains cellulose, and examples thereof include various wood pulps, non-wood pulps, bacterial celluloses, regenerated celluloses, waste paper pulps, cottons, valonia celluloses and squirt celluloses. Further, various commercially available cellulose powders and microcrystalline cellulose powders may be used.

The mechanical defibration treatment of the cellulose raw material is not particularly limited, for example, high pressure homogenizer, ultra high pressure homogenizer, ball mill, roll mill, cutter mill, planetary mill, jet mill, attritor, grinder, juicer mixer, homomixer, ultrasonic homogenizer. , A nanogenizer, an underwater collision, a single-screw or twin-screw extruder, and the like.
By adjusting the conditions of the mechanical defibration treatment, the cellulose raw material can be adjusted to a desired fiber diameter or fiber length, and a nanocellulose-based material (A) having a desired size can be obtained.

  The above-mentioned cellulose nanofiber has excellent compatibility with the resin (C), and a molded product having further excellent transparency can be obtained. Therefore, carboxymethyl cellulose, oxidized cellulose and cellulose in which at least a part of hydroxyl groups are esterified (hereinafter, It is also preferable to include one or more selected from (also referred to as esterified cellulose). These cellulose nanofibers may be used alone or in combination of two or more.

  As the oxidized cellulose, those obtained by oxidizing the above cellulose raw material using an N-oxyl compound such as 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) as an oxidation catalyst are preferable. ..

When the oxidation treatment is performed using an N-oxyl compound, the primary hydroxyl group (hydroxyl group bonded to the carbon atom at the 6-position of the glucopyranose ring) in the cellulose molecule is oxidized with high selectivity, and -CH ₂ OH is generated. It is converted to a carboxy group via the formyl group. According to the oxidation treatment using the N-oxyl compound, the carboxy group can be introduced uniformly and efficiently.
In addition, the oxidation treatment using the N-oxyl compound is less likely to impair the crystallinity of cellulose. Therefore, the microfibrils of oxidized cellulose obtained by the oxidation treatment using the N-oxyl compound retain the high crystal structure of natural cellulose and can obtain high mechanical strength.

The oxidized cellulose is preferably obtained by subjecting the above cellulose raw material to an oxidizing treatment using an oxidation catalyst liquid containing an N-oxyl compound.
At this time, it is preferable to use an oxidizing agent together with the N-oxyl compound. When the oxidizing agent is used in combination, the N-oxyl compound is oxidized by the oxidizing agent to sequentially generate oxoammonium salt, and the oxoammonium salt oxidizes cellulose. According to such an oxidation treatment, the oxidation reaction can proceed even under mild conditions, and the introduction efficiency of the carboxy group can be further improved.

As the N-oxyl compound, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (TEMPO), 2,2,6,6-tetramethylpiperidine-N-oxyl, 2,2,6 , 6-Tetramethyl-4-hydroxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-phenoxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-benzylpiperidine -1-oxyl, 2,2,6,6-tetramethyl-4-acryloyloxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-methacryloyloxypiperidine-1-oxyl, 2,2 , 6,6-Tetramethyl-4-benzoyloxypiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-cinnamoyloxypiperidine-1- Xyl, 2,2,6,6-tetramethyl-4-acetylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-acryloylaminopiperidine-1-oxyl, 2,2,6, 6-Tetramethyl-4-methacryloylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-benzoylaminopiperidine-1-oxyl, 2,2,6,6-tetramethyl-4-cinna Moylaminopiperidine-1-oxyl, 4-propionyloxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-methoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4 -Ethoxy-2,2,6,6-tetramethylpiperidine-N-oxyl, 4-acetamido-2,2,6,6-tetramethylpiperidine N-oxyl, 4-oxo-2,2,6,6-tetramethylpiperidine-N-oxyl, 2,2,4,4-tetramethylazetidine-1-oxyl, 2,2-dimethyl-4,4 -Dipropylazetidine-1-oxyl, 2,2,5,5-tetramethylpyrrolidine-N-oxyl, 2,2,5,5-tetramethyl-3-oxopyrrolidine-1-oxyl, 2,2 6,6-Tetramethyl-4-acetoxypiperidine-1-oxyl, ditert-butylamine-N-oxyl, poly [(6- [1,1,3,3-tetramethylbutyl] amino) -s-triazine- 2,4-diyl] [(2,2,6,6-tetramethyl-4-piperidyl) imino] hexamethylene [(2,2,6,6-tetramethyl-4-piperidyl) imino and the like can be mentioned.
Among these, 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (TEMPO) is particularly preferable.

  The amount of the N-oxyl compound used is not particularly limited, but is usually in the range of 0.1 parts by mass or more and 10 parts by mass or less, preferably 0.1 part by mass, relative to 100 parts by mass of the solid content of the cellulose raw material to be oxidized. It is in the range of 5 parts by mass or more and 5 parts by mass or less.

As the oxidizing agent, halogen, such as bromine, chlorine, iodine, hypohalous acid, halogenous acid or perhalogenic acid, or a salt thereof, halogen oxide, nitrogen oxide, peroxide, etc. There is no particular limitation as long as it can be promoted.
The amount of the oxidizing agent used is usually in the range of 1 part by mass or more and 100 parts by mass or less, preferably in the range of 5 parts by mass or more and 50 parts by mass or less, based on 100 parts by mass of the solid content of the cellulose raw material to be oxidized. Within.

In addition to the N-oxyl compound and the oxidizing agent, at least one selected from bromide and iodide may be used in combination as a catalyst other than the N-oxyl compound.
Examples of the bromide include alkali metal bromide salts such as sodium bromide. Further, examples of the iodide include alkali metal iodide salts such as sodium iodide.
The amount of the catalyst selected from bromide and iodide can be selected within a range that can accelerate the oxidation reaction, and is not particularly limited. It is usually in the range of more than 0 parts by mass and 100 parts by mass or less, preferably 5 parts by mass or more and 50 parts by mass or less with respect to 100 parts by mass of the solid content of the cellulose raw material to be oxidized.

  Water can be used as the solvent. In order to improve the permeability of the oxidation catalyst liquid, alcohols such as methanol and ethanol and various surfactants may be contained.

  The pH of the oxidation catalyst liquid can be set to, for example, 9 or more and 12 or less. Further, the temperature and time of the oxidation treatment are not particularly limited because they are appropriately set depending on the amount of the cellulose raw material to be treated, but for example, the temperature and time are 1 ° C or more and 60 ° C or less, and 1 minute or more and 500 minutes or less. You can

  By appropriately adjusting the above oxidation treatment conditions, the carboxyl group content of the above-mentioned oxidized cellulose can be adjusted within a desired range. Further, by adjusting the carboxyl group content of the oxidized cellulose, electrostatic repulsion of the carboxyl group can adjust the fiber diameter or fiber length of the cellulose fiber.

The average aspect ratio of the cellulose nanofiber according to the present embodiment is preferably 50 or more, more preferably 100 or more, and the upper limit is, for example, 5000 or less.
The average fiber diameter of the cellulose nanofiber according to the present embodiment is preferably 1 nm or more and 200 nm or less, more preferably 1 nm or more and 100 nm or less, and further preferably 1 nm or more and 50 nm or less. The average fiber length is preferably 100 nm or more.
Here, the average aspect ratio is an average fiber length / average fiber diameter.
When the average aspect ratio of the cellulose nanofibers, the average fiber diameter and the average fiber length are within the above ranges, the dispersibility of the cellulose nanofibers in the obtained flame-retardant resin composition can be further improved and obtained. The dispersibility of the cellulose nanofibers in the obtained molded article can be further improved.

  The cellulose nanocrystal according to this embodiment can be obtained by a known method. For example, the cellulose nanocrystals can be obtained by hydrolyzing and removing the amorphous portion by treating the cellulose raw material with an acid such as sulfuric acid, and then subjecting it to mechanical defibration treatment.

  The cellulose raw material is not particularly limited as long as it contains cellulose, and examples thereof include various wood pulps, non-wood pulps, bacterial celluloses, regenerated celluloses, waste paper pulps, cottons, valonia celluloses and squirt celluloses. Further, various commercially available cellulose powders and microcrystalline cellulose powders may be used.

  The mechanical defibration treatment is not particularly limited, for example, high pressure homogenizer, ultra high pressure homogenizer, ball mill, roll mill, cutter mill, planetary mill, jet mill, attritor, grinder, juicer mixer, homomixer, ultrasonic homogenizer, nanogenizer. A method using an apparatus such as an underwater collision, a single-screw or twin-screw extruder can be mentioned.

The average aspect ratio of the cellulose nanocrystal according to this embodiment is preferably less than 50. The average fiber diameter is preferably 1 nm or more and 100 nm or less, more preferably 1 nm or more and 85 nm or less, and further preferably 1 nm or more and 70 nm or less. The average fiber length is preferably 45 nm or more and 500 nm or less. When the average aspart ratio of the cellulose nanocrystals, the average fiber diameter and the average fiber length are within the above ranges, the dispersibility of the cellulose nanocrystals in the obtained flame-retardant resin composition can be further improved and obtained. It is possible to further improve the dispersibility of the cellulose nanocrystals in the obtained molded body.
Here, the average aspect ratio is an average fiber length / average fiber diameter.

  Here, the average fiber diameter and the average fiber length of the nanocellulose-based material (A) can be measured from an image of the nanocellulose-based material (A) taken with a microscope such as an atomic force microscope. As the average fiber diameter and average fiber length of the nanocellulose-based material (A), for example, the fiber diameter and fiber length at 10 points of cellulose fibers can be measured, and the average value thereof can be adopted.

(Phosphorus flame retardant (B))
Examples of the phosphorus-based flame retardant (B) according to the present embodiment include red phosphorus-based flame retardants such as red phosphorus; trimethyl phosphate, triethyl phosphate, triphenyl phosphate, tricresyl phosphate, trixylenyl phosphate, cresyl diphenyl. Phosphate, xylenyl diphenyl phosphate, nozorcinol-bis- (diphenyl phosphate), 2-ethylerhexyl diphenyl phosphate, dimethyl methyl phosphate, triallyl phosphate, non-halogen phosphate, cresyl di-2,6-xylenyl phosphate Non-halogen phosphate ester flame retardants such as trichloroethyl phosphate, trisdichloropropyl phosphate, tris (chloropropyl) phosphate, tris (tribromoneopentyl) phosphate Phosphate-containing flame retardants such as phosphates and tris-β-chloropropyl phosphate; condensed phosphate ester-based flame retardants such as aromatic condensed phosphate esters, halogen-containing condensed phosphate esters, and non-halogen condensed phosphate esters; Examples include polyphosphate flame retardants such as ammonium polyphosphate and polychlorophosphite. These phosphorus-based flame retardants may be used alone or in combination of two or more.
Among these, non-halogen phosphate ester flame retardants are preferable.

In the flame-retardant resin composition according to the present embodiment, when the total content of the nanocellulose-based material (A) and the phosphorus-based flame retardant (B) is 100% by mass, the content of the phosphorus-based flame retardant (B). Is 50% by mass or less, for example, to increase the content of the nanocellulosic material (A) in the flame-retardant resin composition, and to form a carbonized layer on the entire surface of the combustion part of the molded body in the initial stage of combustion. From the viewpoint of forming more effectively, the content is preferably 40% by mass or less, more preferably 30% by mass or less, further preferably 20% by mass or less, and particularly preferably 15% by mass or less.
In addition, the lower limit of the content of the phosphorus-based flame retardant (B) in the flame-retardant resin composition according to the present embodiment is, for example, 1% by mass or more, and the nanocellulose-based material on the surface of the molded body in the initial stage of combustion. From the viewpoint of further accelerating the formation rate of the carbonized layer (A), it is preferably 2% by mass or more, more preferably 3% by mass or more, further preferably 5% by mass or more, and particularly preferably 8% by mass or more.

(Resin (C))
The resin (C) according to this embodiment is made of at least one of a thermoplastic resin and a thermosetting resin. The resin (C) may be used alone or in combination of two or more. Of these, thermoplastic resins are preferable.

<Thermoplastic resin>
The thermoplastic resin according to this embodiment is not particularly limited, but examples thereof include polyolefin resins such as polyethylene, polypropylene, poly (4-methyl-1-pentene), and poly (1-butene); polyethylene terephthalate, polybutylene terephthalate. Polyester resins such as polyethylene naphthalate; polyamide resins such as nylon-6, nylon-66, polymethaxylene adipamide; ethylene / vinyl ester copolymers, ethylene / unsaturated carboxylic acid ester copolymers, etc. Ethylene / unsaturated ester copolymers; ethylene / unsaturated carboxylic acid copolymers or ionomer resins thereof; poly (meth) acrylic resins such as poly (meth) acrylic acid ester resins; polyvinyl chloride, polyvinylidene chloride Chlorine-based resin such as polytetrafluor Fluorine-based resins such as ethylene, ethylene tetrafluoroethylene copolymer, polyvinylidene fluoride and polyvinyl fluoride; polystyrene resins; polyether-based resins such as polyetheretherketone resins and polyetherketone resins; polycarbonate resins; polyphenylene oxide resins and polyphenylene sulfides Examples of the resin include polyphenylene resins such as resins; polyvinyl acetate resins; polyacrylonitrile resins; thermoplastic elastomers. These thermoplastic resins may be used alone or in combination of two or more.
Among these, ethylene / unsaturated ester copolymers, ethylene / unsaturated carboxylic acid copolymers, ethylene, from the viewpoint of excellent balance of mechanical properties, handleability, appearance, lightness, versatility, moldability, etc. -One or more thermoplastic resins selected from the group consisting of unsaturated carboxylic acid-based copolymer ionomer resins, polyolefin-based resins, polyester-based resins, and polyamide-based resins are preferable, and flame retardancy is inferior. From the point that improvement of the flammability is particularly required, from ethylene / unsaturated ester copolymers, ethylene / unsaturated carboxylic acid copolymers, ionomer resins and polyolefin resins of ethylene / unsaturated carboxylic acid copolymers One or more thermoplastic resins selected from the group consisting of are more preferable, and a parent with the nanocellulosic material (A) One or two selected from the group consisting of an ethylene / unsaturated ester copolymer, an ethylene / unsaturated carboxylic acid copolymer, and an ionomer resin of an ethylene / unsaturated carboxylic acid copolymer from the viewpoint of excellent properties. More than one thermoplastic resin is more preferred.
Hereinafter, the ethylene / unsaturated ester copolymer, the ethylene / unsaturated carboxylic acid copolymer, or the ionomer resin thereof will be described in detail.

<< Ethylene / Unsaturated Ester Copolymer >>
The ethylene / unsaturated ester copolymer according to this embodiment is a polymer obtained by copolymerizing ethylene and at least one kind of unsaturated ester. As the ethylene / unsaturated ester copolymer, a copolymer containing ethylene and an unsaturated ester can be exemplified.
Further, the ethylene / unsaturated ester copolymer according to the present embodiment preferably contains at least one polymer selected from an ethylene / vinyl ester copolymer and an ethylene / unsaturated carboxylic acid ester copolymer.
Further, the ethylene / unsaturated ester copolymer according to the present embodiment may contain a polymerizable monomer other than ethylene and unsaturated ester, and examples thereof include olefins such as propylene, butene, and hexene.

  Examples of the ethylene / vinyl ester copolymer according to the present embodiment include ethylene / vinyl acetate copolymer, ethylene / vinyl propionate copolymer, ethylene / vinyl butyrate copolymer, ethylene / vinyl stearate copolymer. One kind or two or more kinds selected from the above can be used.

The ethylene / unsaturated carboxylic acid ester copolymer according to the present embodiment is a polymer obtained by copolymerizing ethylene and at least one kind of unsaturated carboxylic acid ester.
Specifically, a copolymer composed of ethylene and an unsaturated carboxylic acid alkyl ester can be exemplified.

Examples of the unsaturated carboxylic acid in the unsaturated carboxylic acid ester include acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, fumaric anhydride and itaconic anhydride. , Monomethyl maleate, monoethyl maleate and the like.
Among these, the unsaturated carboxylic acid preferably contains at least one selected from acrylic acid and methacrylic acid from the viewpoints of productivity and hygiene of the ethylene / unsaturated ester copolymer. These unsaturated carboxylic acids may be used alone or in combination of two or more.

  Examples of the alkyl moiety in the unsaturated carboxylic acid alkyl ester include those having 1 to 12 carbon atoms, and more specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, secondary butyl, Examples thereof include alkyl groups such as 2-ethylhexyl and isooctyl. In the present embodiment, the alkyl moiety of the alkyl ester preferably has 1 to 8 carbon atoms.

  Examples of unsaturated carboxylic acid esters include methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, isobutyl (meth) acrylate, and (meth) acrylic acid. It is preferable to contain one or more selected from (meth) acrylic acid esters such as n-butyl, isooctyl (meth) acrylate, and 2-ethylhexyl (meth) acrylate. These unsaturated carboxylic acid esters may be used alone or in combination of two or more. Among these, methyl (meth) acrylate, ethyl (meth) acrylate, isopropyl (meth) acrylate, n-propyl (meth) acrylate, isobutyl (meth) acrylate, and n-butyl (meth) acrylate It is more preferable to contain one kind or two or more kinds selected from

  In the present embodiment, a preferred ethylene / unsaturated carboxylic acid ester copolymer is an ethylene / (meth) acrylic acid ester copolymer. Among them, a copolymer composed of one type of compound as the (meth) acrylic acid ester is preferable. Examples of such a copolymer include ethylene / methyl (meth) acrylate copolymer, ethylene / ethyl (meth) acrylate copolymer, ethylene / isopropyl (meth) acrylate copolymer, ethylene / (meth). N-propyl acrylate copolymer, ethylene / isobutyl (meth) acrylate copolymer, ethylene / (meth) acrylic acid n-butyl copolymer, ethylene / isooctyl acrylate copolymer, ethylene (( 2-Ethylhexyl methacrylic acid copolymer etc. are mentioned.

Ethylene / unsaturated ester copolymers include ethylene / vinyl acetate copolymers, ethylene / methyl (meth) acrylate copolymers, ethylene / ethyl (meth) acrylate copolymers, ethylene / isopropyl (meth) acrylate. One or two selected from a copolymer, an ethylene / (meth) acrylic acid n-propyl copolymer, an ethylene / (meth) acrylic acid isobutyl copolymer, and an ethylene / (meth) acrylic acid n-butyl copolymer. It is preferable to contain one or more kinds, and it is more preferable to contain an ethylene / vinyl acetate copolymer.
In the present embodiment, the ethylene / unsaturated ester copolymer may be used alone or in combination of two or more kinds.

  The method for producing the ethylene / unsaturated ester copolymer according to this embodiment is not particularly limited, and it can be produced by a known method. For example, it can be obtained by radical-copolymerizing each polymerization component under high temperature and high pressure. A commercially available ethylene / unsaturated ester copolymer may be used.

<< Ethylene / Unsaturated Carboxylic Acid Copolymer or Its Ionomer Resin >>
Next, the ethylene / unsaturated carboxylic acid copolymer or the ionomer resin thereof according to the present embodiment will be described.

The ethylene / unsaturated carboxylic acid copolymer according to the present embodiment is a polymer obtained by copolymerizing ethylene and at least one kind of unsaturated carboxylic acid. The ionomer resin of the ethylene / unsaturated carboxylic acid copolymer according to the present embodiment (also simply referred to as an ionomer resin) is a metal ion in which at least a part of the carboxyl groups is added to the ethylene / unsaturated carboxylic acid copolymer. It is a resin neutralized with.
As the ethylene / unsaturated carboxylic acid copolymer, a copolymer containing ethylene and an unsaturated carboxylic acid can be exemplified.

  In the ethylene / unsaturated carboxylic acid copolymer or its ionomer, the transparency and the availability are easy when the total amount of the constituent units of the ethylene / unsaturated carboxylic acid copolymer is 100% by mass. Therefore, the content of the structural unit derived from ethylene is preferably 65% by mass or more and 99% by mass or less, more preferably 75% by mass or more and 95% by mass or less, and particularly preferably 77% by mass or more and 91% by mass or less. The content of the structural unit derived from the unsaturated carboxylic acid is preferably 1% by mass or more and 35% by mass or less, more preferably 5% by mass or more and 25% by mass or less, and particularly preferably 9% by mass or more. It is 23 mass% or less.

Examples of the unsaturated carboxylic acid in the ethylene / unsaturated carboxylic acid copolymer include acrylic acid, methacrylic acid, 2-ethylacrylic acid, crotonic acid, maleic acid, fumaric acid, itaconic acid, maleic anhydride, and anhydrous. Examples include fumaric acid, itaconic anhydride, monomethyl maleate, monoethyl maleate and the like. Among these, the unsaturated carboxylic acid is preferably at least one selected from acrylic acid and methacrylic acid from the viewpoints of productivity and hygiene of the ethylene / unsaturated carboxylic acid copolymer. These unsaturated carboxylic acids may be used alone or in combination of two or more.
In the present embodiment, a particularly preferred ethylene / unsaturated carboxylic acid copolymer is an ethylene / (meth) acrylic acid copolymer.

In the ethylene / unsaturated carboxylic acid copolymer, when the total of the constituent units constituting the ethylene / unsaturated carboxylic acid copolymer is 100% by mass, preferably 0% by mass or more and 30% by mass or less, More preferably, it may contain a structural unit derived from another copolymerizable monomer of 0% by mass or more and 25% by mass or less. Other copolymerizable monomers include unsaturated esters, for example, vinyl esters such as vinyl acetate and vinyl propionate; methyl (meth) acrylate, ethyl (meth) acrylate, propyl (meth) acrylate, (meth) acrylic. Unsaturated carboxylic acid esters such as isopropyl acid ester, isobutyl (meth) acrylate, n-butyl (meth) acrylate, 2-ethylhexyl (meth) acrylate, isooctyl (meth) acrylate, dimethyl maleate and diethyl maleate Etc. It is preferable that the constitutional unit derived from the other copolymerizable monomer is included in the above range, since the flexibility of the molded article obtained by using the flame-retardant resin composition is improved.
Among these, unsaturated carboxylic acid esters are preferable, and at least one selected from the group consisting of acrylic acid esters and methacrylic acid esters is particularly preferable. In addition, these other copolymerization components may be used individually by 1 type, and may be used in combination of 2 or more type.

  The ethylene / unsaturated carboxylic acid copolymer has a melt flow rate (according to JIS K7210-1999) at 190 ° C. and a load of 2160 g of preferably 1 g / 10 minutes or more and 1000 g / 10 minutes or less, and more preferably 5 g. / 10 minutes or more and 750 g / 10 minutes or less, and particularly preferably 10 g / 10 minutes or more and 500 g / 10 minutes or less. When the MFR is within the above range, it is preferable in terms of moldability and workability.

The method for producing the ethylene / unsaturated carboxylic acid copolymer according to the present embodiment is not particularly limited, and it can be produced by a known method. For example, it can be obtained by radical-copolymerizing each polymerization component under high temperature and high pressure.
The ethylene / unsaturated carboxylic acid copolymer according to this embodiment is usually a random copolymer.

  Further, in the ethylene / unsaturated carboxylic acid copolymer according to the present embodiment, some or all of the carboxyl groups are ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine. It is preferably neutralized with an amino compound such as 1,3-dimethylaminocyclohexane.

  The degree of neutralization of the carboxyl group of the ethylene / unsaturated carboxylic acid copolymer is preferably 10 mol% or more and 100 mol% or less, more preferably 15 mol% or more and 85 mol% or less, and particularly preferably It is 20 mol% or more and 80 mol% or less. When the degree of neutralization is within the above range, the dispersibility of the nanocellulose-based material (A) in the flame-retardant resin composition can be further improved.

  The ethylene / unsaturated carboxylic acid copolymer neutralized with the amino compound can be obtained, for example, by mixing the ethylene / unsaturated carboxylic acid copolymer and the amino compound and reacting them.

The ionomer resin according to the present embodiment refers to a resin in which an ethylene / unsaturated carboxylic acid copolymer is used as a base polymer and a carboxyl group in the ethylene / unsaturated carboxylic acid copolymer is neutralized with a metal ion.
The degree of neutralization of the ionomer resin according to the present embodiment is not particularly limited, but 100 mol% or less from the viewpoint of further improving the dispersibility of the nanocellulose-based material (A) in the obtained flame-retardant resin composition. Is preferable, 90 mol% or less is more preferable, 85 mol% or less is further preferable, and 80 mol% or less is particularly preferable.
The degree of neutralization of the ionomer resin according to this embodiment is not particularly limited, but it is 5 mol from the viewpoint of further improving the dispersibility of the nanocellulose-based material (A) in the obtained flame-retardant resin composition. % Or more is preferable, 10 mol% or more is more preferable, 15 mol% or more is further preferable, and 20 mol% or more is particularly preferable.
Here, the degree of neutralization of the ionomer resin refers to the ratio (%) of the carboxyl groups that have been neutralized by the metal ions to the total carboxyl groups contained in the ethylene / unsaturated carboxylic acid copolymer.

Examples of the metal ion forming the ionomer resin include alkali metal ions such as lithium ion, sodium ion and potassium ion; magnesium ion, calcium ion, zinc ion, cobalt ion, nickel ion, manganese ion, lead ion and copper ion. And polyvalent metal ions such as titanium ion, iron ion, aluminum ion and zirconium ion.
Among these, sodium ion, zinc ion or magnesium ion is particularly preferable. These metal ions may be used alone or in combination of two or more.

  Further, the ionomer resin according to the present embodiment is, in addition to metal ions, ammonia, methylamine, dimethylamine, trimethylamine, ethylamine, diethylamine, triethylamine, ethylenediamine, diethylenetriamine, triethylenetetramine, 1,3-dimethylaminocyclohexane and other amino acids. It may include a compound.

  The ionomer resin can be obtained, for example, by reacting an ethylene / unsaturated carboxylic acid-based copolymer with the oxide, hydroxide, carbonate or the like containing the metal ion.

  In the present embodiment, as the ionomer resin, one type may be used alone, or two or more types may be used in combination.

<Thermosetting resin>
The thermosetting resin according to the present embodiment is not particularly limited, for example, phenol resin, urea resin, melamine resin, unsaturated polyester resin, epoxy resin, diallyl phthalate resin, polyurethane resin, silicon resin, polyimide resin, polyaminoamide Resin etc. can be mentioned. Among these, a phenol resin, an epoxy resin, and an unsaturated polyester resin are preferable, and an epoxy resin is more preferable. The thermosetting resin may be a liquid resin at room temperature (23 ° C.) or a solid resin at room temperature.

(Other ingredients)
In the flame-retardant resin composition according to the present embodiment, other components other than the nanocellulose-based material (A), the phosphorus-based flame retardant (B) and the resin (C) are used as long as the object of the present invention is not impaired. Can be included.
Other components are not particularly limited, but include, for example, resin components other than resin (C), coupling agents, inorganic fillers, organic fillers, ultraviolet absorbers, antioxidants, light stabilizers, antioxidants, light diffusion Agents, plasticizers, organic dyes, dyes, pigments, lubricants, impact modifiers, metal deactivators, flame retardants other than phosphorus-based flame retardants (B), flame retardant aids, slip agents, reinforcing agents, release agents , Wax, and the like. The other components may be used alone or in combination of two or more.

(Method for preparing flame-retardant resin composition)
The flame-retardant resin composition according to the present embodiment uses, for example, a single-screw extruder, a twin-screw extruder, a Banbury mixer, a roll, a kneader and the like, and a nanocellulose-based material (A) and a phosphorus-based flame retardant ( It can be prepared by simultaneously or sequentially mixing or melting / kneading B), the resin (C), and optionally other components.

In the flame-retardant resin composition according to the present embodiment, when the total content of the nanocellulose-based material (A), the phosphorus-based flame retardant (B) and the resin (C) is 100% by mass, the nanocellulose-based material ( The upper limit of the total content of A) and the phosphorus-based flame retardant (B) is, for example, 50 mass% or less, and further improves the dispersibility of the nanocellulose-based material (A) in the flame-retardant resin composition. From the viewpoint, it is preferably 45% by mass or less, more preferably 40% by mass or less, further preferably 35% by mass or less, and particularly preferably 30% by mass or less.
Further, the lower limit of the total content of the nanocellulose-based material (A) and the phosphorus-based flame retardant (B) in the flame-retardant resin composition according to the present embodiment is, for example, 1% by mass or more, and the obtained flame retardant From the viewpoint of further improving the property, it is preferably 3% by mass or more, more preferably 5% by mass or more, further preferably 10% by mass or more, and particularly preferably 15% by mass or more.

  The total content of the nanocellulose-based material (A), the phosphorus-based flame retardant (B), and the resin (C) contained in the flame-retardant resin composition according to this embodiment is 100 for the entire flame-retardant resin composition. When it is defined as mass%, it is preferably 50 mass% or more and 100 mass% or less, more preferably 70 mass% or more and 100 mass% or less, and further preferably 90 mass% or more and 100 mass% or less.

[Molded body]
The molded body according to the present embodiment, for example, a flame-retardant resin composition according to the present embodiment, a sheet shape, a film by a known molding method such as extrusion molding, injection molding, compression molding, hollow molding, press molding. It can be obtained by molding into various shapes such as a shape, a plate shape, and other three-dimensional shapes.
Further, the molded body according to the present embodiment can also be obtained by applying the flame-retardant resin composition according to the present embodiment to the object to be treated, spraying, etc., and then drying to form a film. ..

  Further, the molded body according to the present embodiment may be subjected to a hard coat treatment with an inorganic or organic compound, an antistatic treatment, an antireflection treatment, an electromagnetic shielding treatment or the like on the surface thereof within a range that does not impair the effects of the present invention. Good. These treatments can be performed on the surface of the molded body by vapor deposition, sputtering, dipping, thermal transfer, or the like.

  The flame-retardant resin composition according to the present embodiment is excellent in flame retardancy as described above, and the molded article according to the present embodiment using the same is also excellent in flame retardancy. Therefore, the molded body according to the present embodiment is not particularly limited, for example, optical materials, interior or exterior parts of electric / electronic devices, electronic component trays, automotive materials, various machine parts, housing / construction materials, civil engineering. It can be used in a wide range of fields such as materials, pipes, tubes, toys, daily necessities, stationery, OA equipment, home appliance parts, storage cases, storage cases and the like.

  The embodiments of the present invention have been described above, but these are examples of the present invention, and various configurations other than the above can be adopted.

  Hereinafter, the present embodiment will be described in detail with reference to examples and comparative examples. The present embodiment is not limited to the description of these examples.

1. Raw Materials The raw materials used in Examples and Comparative Examples are shown below.
(1) Nanocellulose-based material (A)
Nanocellulose 1: Cellulose nanocrystal (CNC manufactured by InnoTech Alberta, average fiber length: 165 nm, aspect ratio: 18)
(2) Phosphorus flame retardant (B)
Flame retardant 1: tricresyl phosphate (TCP, manufactured by Daihachi Chemical Industry Co., Ltd.)
(3) Other flame retardants Flame retardant 2: anhydrous zinc borate (manufactured by Rio Tinto Minerals Asia Pte Ltd, Firebreak 500)
Flame retardant 3: Magnesium hydroxide (Kyowa Chemical Industry Co., Ltd.)
(4) Thermoplastic resin EMAA1: ethylene / methacrylic acid copolymer (content of structural units derived from methacrylic acid: 10% by mass, melt flow mass flow rate (190 ° C., 2160 g load) 500 g / 10 minutes)
(5) Other components Wax 1: Anhydrous maleic oxide of ethylene / propylene copolymer (Mitsui Chemicals, Inc., Hiwax 1105A)

2. Measurement and Evaluation Method (1) Oxygen Index With respect to the sheet-shaped flame-retardant resin composition (molded body) obtained in Examples and Comparative Examples, a candle method combustion tester (D-2 type: Toyo Seiki Co., Ltd.) (Manufactured by Seisakusho Co., Ltd.), a combustion test was carried out by a method based on JIS K7201-1995, and the oxygen index was measured. The flame retardancy was evaluated using the measured oxygen index as an index.
Regarding the oxygen index, for example, an oxygen index of 25 indicates that it is combustible at an oxygen concentration of 25%, and therefore a larger value indicates that the flame retardancy is excellent (that is, the flame retardancy is high).

(2) Carbonized layer The burned part of the molded body after the combustion test used in the oxygen index measurement was visually observed, and the carbonized layer of the flame-retardant resin composition was evaluated according to the following criteria.
◯: The surface of the combustion part of the molded body is black, and a carbonized layer is formed over the entire surface of the combustion part ×: There are scattered black parts in the combustion part of the molded body, and the entire surface of the combustion part Carbonized layer is not formed over

[Example 1 and Comparative Example 1]
Each component (excluding the flame retardant) was blended in the blending ratio shown in Table 1, and a resin composition containing EMMA1 and nanocellulose 1 was extrusion molded. A flame retardant was added to the obtained resin composition at a mixing ratio shown in Table 1, melt-kneaded with a Labo Plastomill, and press-molded into a sheet with a press molding machine. Next, each evaluation was performed on the obtained sheet-shaped flame-retardant resin composition (molded body).
The extrusion molding conditions are as follows.
Molding machine: 15mmφ extrusion molding machine Extrusion setting temperature: 174 ° C
Extrusion rate: 500 g / h
Screw rotation speed: 400 rpm

[Comparative example 2]
EMMA1 and flame retardant 3 were blended in the blending ratio shown in Table 1, melt-kneaded in a Labo Plastomill, and then press-molded into a sheet by a press molding machine. Next, each evaluation was performed on the obtained sheet-shaped flame-retardant resin composition (molded body).

(Evaluation results)
The above evaluation results are summarized in Table 1. As can be seen from Table 1, the flame-retardant resin composition of Example 1 had a high oxygen index, and in the combustion test, a carbonized layer was formed over the entire surface of the combustion part. From this, it can be understood that the flame-retardant resin composition of Example 1 has excellent flame retardancy.
On the other hand, in the flame-retardant resin composition of Comparative Example 1, although the carbonized layer was formed over the entire surface of the combustion part, the oxygen index was low and the flame retardancy was poor. Since the flame-retardant resin composition of Comparative Example 1 does not contain a phosphorus-based flame retardant, the formation of the carbonized layer was not promoted, and the carbonized layer was not formed on the entire surface of the combustion part of the molded article in the initial stage of combustion. it is conceivable that.
Further, since the flame-retardant resin composition of Comparative Example 2 contains a large amount of flame retardant, it was inferior in processability and it was difficult to form a sheet.

Claims (10)

  A flame-retardant resin composition comprising a nanocellulose-based material (A), a phosphorus-based flame retardant (B), and a resin (C) made of at least one of a thermoplastic resin and a thermosetting resin. The flame-retardant resin composition according to claim 1,
When the total content of the nanocellulose-based material (A) and the phosphorus-based flame retardant (B) is 100% by mass, the content of the phosphorus-based flame retardant (B) is 1% by mass or more and 50% by mass or less. A flame-retardant resin composition. The flame-retardant resin composition according to claim 1 or 2,
The phosphorus-based flame retardant (B) is a group consisting of a red phosphorus-based flame retardant, a non-halogen phosphate ester-based flame retardant, a halogen-containing phosphate ester-based flame retardant, a condensed phosphate ester-based flame retardant, and a polyphosphate-based flame retardant. A flame-retardant resin composition containing one or more phosphorus flame retardants selected from the group consisting of: The flame-retardant resin composition according to any one of claims 1 to 3,
A flame-retardant resin composition in which the nanocellulose-based material (A) contains at least one selected from the group consisting of cellulose nanofibers and cellulose nanocrystals. The flame-retardant resin composition according to claim 4,
A flame-retardant resin composition in which the nanocellulose-based material (A) contains cellulose nanocrystals. The flame-retardant resin composition according to claim 5,
A flame-retardant resin composition in which the average aspect ratio of the cellulose nanocrystals is less than 50 and the average fiber diameter is 1 nm or more and 100 nm or less. The flame-retardant resin composition according to claim 5 or 6,
A flame-retardant resin composition in which the average fiber length of the cellulose nanocrystal is 45 nm or more and 500 nm or less. The flame-retardant resin composition according to any one of claims 1 to 7,
When the total content of the nanocellulose-based material (A), the phosphorus-based flame retardant (B) and the resin (C) is 100% by mass, the nanocellulose-based material (A) and the phosphorus-based flame retardant ( A flame-retardant resin composition having a total content of B) of 1% by mass or more and 50% by mass or less. The flame-retardant resin composition according to any one of claims 1 to 8,
The resin (C) is an ethylene / unsaturated ester copolymer, an ethylene / unsaturated carboxylic acid copolymer, an ionomer resin of the ethylene / unsaturated carboxylic acid copolymer, a polyolefin resin, a polyester resin, and A flame-retardant resin composition containing one or more thermoplastic resins selected from the group consisting of polyamide resins.   A molded body obtained by molding the flame-retardant resin composition according to any one of claims 1 to 9.