Durability improver

Abstract

To provide a durability improver that is readily dispersed in resin and can improve the durability of the resin.SOLUTION: A durability improver has flaky carbon, and an organic compound including a hydrophilic group and a hydrophobic group having high affinity with carbon.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to a durability improver. [Background technology]

[0002] There is a demand for longer life for plastic materials (resins).

[0003] Deterioration of plastics is often caused by a combination of factors such as light, heat, oxygen, metal ions, acid, and water (see, for example, Non-Patent Documents 1 and 2). [Prior art documents] [Non-patent literature]

[0004] [Non-Patent Document 1] Hiroshi Yamanoi, "Mechanism of Degradation and Discoloration of Polymer Materials and Its Stabilization Techniques," Journal of Materials Life 19.3 (2007): 103-108. [Non-patent document 2] Tomonori Iizuka, Yoshito Otake, Keiji Tanaka, "Effect of Moisture on Photodegradation of Polypropylene," Materials 65.11(2016):812-817. Summary of the Invention [Problem to be solved by the invention]

[0005] An object of the present invention is to provide a durability improver that is easily dispersed in a resin and can improve the durability of the resin. [Means for solving the problem]

[0006] As a result of extensive research to achieve the above object, the present inventors have found that by containing flaky carbon and an organic compound having a hydrophilic group and a hydrophobic group that has high affinity with carbon, a durability improver can be obtained that is easily dispersed in a resin and can improve the durability of the resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Based on this finding, the present inventors have conducted further research and have completed the present invention. That is, the present invention includes the following features.

[0007] Item 1. A durability improver containing flaky carbon and an organic compound having a hydrophilic group and a hydrophobic group that has high affinity with carbon.

[0008] Item 2. The durability improver according to Item 1, wherein the thickness of the flaky carbon is 1 to 100 nm.

[0009] Item 3. The hydrophilic group has general formulas (1) to (4):

[0010] [ka] [wherein, -OH represents an alcoholic hydroxyl group or a phenolic hydroxyl group; R represents a divalent organic group; X 1 represents a hydrogen atom, an alkali metal, NH4, or an organic ammonium. 2 represents a hydrogen atom, an alkali metal, NH4, an organic ammonium, or an alkyl group. The oxygen atom in general formula (2) is an ether bond.] Item 3. The durability improver according to item 1 or 2, wherein the durability improver is at least one represented by the formula:

[0011] Item 4. The durability improver according to any one of Items 1 to 3, wherein the hydrophilic group is a phenolic hydroxyl group and / or a polyoxyethylene group.

[0012] Item 5. The durability improver according to any one of Items 1 to 4, wherein the hydrophobic group is at least one selected from the group consisting of an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, and a polyoxyalkylene group having 3 or more carbon atoms.

[0013] Item 6. The durability improver according to any one of Items 1 to 5, wherein the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon is a polyphenol.

[0014] Item 7. The durability improver according to any one of Items 1 to 6, comprising 1 to 1,000 parts by mass of an organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon, per 100 parts by mass of the flaky carbon.

[0015] Item 8. The durability improver according to any one of Items 1 to 7, which is an antioxidant.

[0016] Item 9. A method for producing the durability improver according to any one of items 1 to 8, (1) A production method comprising a step of removing a solvent from a dispersion containing the flaky carbon, an organic compound having a hydrophilic group and a hydrophobic group having high affinity with carbon, and a solvent.

[0017] Item 10. The production method according to Item 9, wherein the step of removing the solvent is a step of concentrating the dispersion.

[0018] Item 11. The method according to Item 9 or 10, wherein the solvent is water.

[0019] Item 12. A resin durability improving composition comprising the durability improver according to any one of items 1 to 8 and a resin.

[0020] Item 13. The resin durability composition according to Item 12, wherein the resin is an aromatic polymer compound.

[0021] Item 14. A method for producing the resin durability composition according to item 12 or 13, (2) A step of kneading the durability improver with a resin. A manufacturing method comprising: [Effects of the Invention]

[0022] According to the present invention, it is possible to obtain a durability improver that is easily dispersed in a resin and can improve the durability of the resin. [Brief explanation of the drawings]

[0023] [Figure 1] The structure of the durability improver of the present invention is shown below when the content of the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon is low (when the surface of the flaky carbon is coated with an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon). [Figure 2] The structure of the durability improver of the present invention is shown when the content of an organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon is high (when flaky carbon is dispersed in an organic compound having a hydrophobic group with high affinity for carbon). DETAILED DESCRIPTION OF THE INVENTION

[0024] In this specification, the term "containing" is a concept that encompasses all of "comprise," "consist essentially of," and "consist only of." Furthermore, in this specification, when a numerical range is expressed as "A to B," it means A or more and B or less.

[0025] 1. Durability improver The durability improver of the present invention contains flaky carbon and an organic compound having a hydrophilic group and a hydrophobic group that has high affinity with carbon.

[0026] (1-1) Flake carbon The flaky carbon mainly functions as a radical trapping agent, but also functions as an ultraviolet absorber, a heat dissipating material, a gas barrier material, a hydrophobic material, a strength improving agent, and the like.

[0027] Thinner flaky carbon is preferable because it has better reinforcing properties in terms of durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), and the thickness is preferably 1 to 100 nm, more preferably 1 to 20 nm. Similarly, the content of flaky carbon having a thickness of 1 to 10 nm is preferably 80% or more, more preferably 90% or more, where the total number of flaky carbons is 100%. In other words, thicker flaky carbons may be included, but the thickness of the majority of flaky carbons is preferably 10 nm or less. The thickness of the flaky carbon is measured by observation with a transmission electron microscope (TEM).

[0028] Thinner flaky carbon is preferable because it has better reinforcing properties in terms of durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Flaky carbon having a layered structure with 300 or fewer graphene layers (i.e., 1 to 300 layers) is preferred, and flaky carbon having a layered structure with 1 to 60 graphene layers is more preferred. Similarly, the content of flaky carbon having 1 to 30 layers is preferably 80% or more, and more preferably 90% or more, of the total number of flaky carbons, defined as 100%. In other words, thicker flaky carbons may be included, but the thickness of the majority of the flaky carbons is preferably 30 layers or less. The thickness of the flaky carbons is calculated from the thickness measured by transmission electron microscope (TEM) observation.

[0029] Since flake carbon usually has a planar shape with many convex and concave angles, it is difficult to define its size in general terms other than thickness. In this specification, the size of a piece of flake carbon is defined as the distance between the furthest convex angles in that piece of flake carbon.

[0030] The size of such flaky carbon is preferably 20 nm or more, more preferably 100 nm or more, and even more preferably 200 nm or more. Using flaky carbon of such a size facilitates further improvement of the reinforcing properties of durability against resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Since larger flaky carbon sizes are preferred because they provide superior reinforcing properties of durability against resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), the upper size limit is not limited, but is typically 100 μm. The size of the flaky carbon is measured by observation with a transmission electron microscope (TEM).

[0031] In the durability improver of the present invention, the content of flaky carbon is not particularly limited. However, from the viewpoint of enhancing durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) against resins, the content is preferably 10 to 95 mass% and more preferably 15 to 90 mass% based on 100 mass% of the total amount of the durability improver of the present invention. Note that when thermal conductivity to resins, radical trapping effect, light resistance, etc. are prioritized, a higher content of flaky carbon is preferred, and 50 to 95 mass% and more preferably 65 to 90 mass% based on 100 mass% of the total amount of the durability improver of the present invention. Furthermore, when prioritizing antioxidant effect, dispersibility of flaky carbon, etc., a lower content of flaky carbon is preferred, and 10 to 90 mass% and more preferably 15 to 75 mass% based on 100 mass% of the total amount of the durability improver of the present invention.

[0032] (1-2) Organic compounds with hydrophilic groups and hydrophobic groups with high affinity for carbon In the present invention, by using an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon, the flaky carbon that maintains the graphene structure does not aggregate, and the flaky carbon can be maintained in a uniformly dispersed state in the durability improver of the present invention, thereby improving durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Note that the organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon can also function as a dispersant for uniformly dispersing the flaky carbon.

[0033] The organic compound having such a hydrophilic group and a hydrophobic group that has a high affinity for carbon is not particularly limited, and a wide variety of organic compounds (especially water-soluble compounds) that can function as a dispersant for flaky carbon can be used.

[0034] Among these, the hydrophobic group contained in the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon is not particularly limited, but an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, a polyoxyalkylene group having 3 or more carbon atoms, etc. are preferred. The organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon can contain one or more types of such hydrophobic groups. Furthermore, when multiple hydrophobic groups are used, multiple same hydrophobic groups may be used, or multiple same hydrophobic groups or multiple different hydrophobic groups may be used.

[0035] The alkyl group may be a chain alkyl group or a branched chain alkyl group, but from the viewpoint of affinity with carbon, a chain alkyl group is preferred. Furthermore, from the viewpoint of affinity with carbon, the number of carbon atoms in the alkyl group is preferably 2 or more, more preferably 3 to 22, and even more preferably 4 to 18. Examples of such an alkyl group include an n-butyl group, an n-pentyl group, an n-hexyl group, an n-octyl group, an n-decyl group, an n-undecyl group, an n-dodecyl group (or an n-lauryl group), an n-tridecyl group, an n-tetradecyl group (or an n-myristyl group), an n-pentadecyl group, an n-hexadecyl group (or an n-cetyl group), and an n-octadecyl group.

[0036] The alkyl group may or may not have a substituent. Examples of such a substituent include a cycloalkyl group, an aryl group, and an aralkyl group. Examples of the cycloalkyl group and the aryl group are described below.

[0037] The aralkyl group as a substituent of the alkyl group is preferably an aralkyl group having 7 to 14 carbon atoms and an aryl group described below and an alkyl group having 1 to 6 carbon atoms, specifically, a benzyl group, a phenethyl group, etc. are preferred.

[0038] The substituent is not limited to the above, and may have a group derived from a fluorene structure (such as a fluorenyl group). In particular, when importance is placed on water solubility, a phenyl group or the like is preferred as the substituent, and when importance is placed on compatibility with flaky carbon and durability to resins (such as light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability), a naphthyl group, a fluorenyl group or the like is preferred as the substituent.

[0039] From the viewpoints of affinity with carbon and water solubility, the alkenyl group preferably has 2 or more carbon atoms, more preferably 3 to 100, and even more preferably 4 to 30. Examples of such alkenyl groups include butenyl, hexenyl, octenyl, decenyl, dodecenyl, oleyl, and linoleyl groups.

[0040] The alkenyl group may or may not have a substituent. Examples of such a substituent include an alkyl group, a cycloalkyl group, an aryl group, and an aralkyl group. Examples of the aralkyl group include those described above, and examples of the cycloalkyl group and the aryl group include those described below.

[0041] The alkyl group as a substituent of the alkenyl group is preferably an alkyl group having 1 to 6 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. are preferred.

[0042] The substituent is not limited to the above, and may have a group derived from a fluorene structure (such as a fluorenyl group). In particular, when importance is placed on water solubility, a phenyl group or the like is preferred as the substituent, and when importance is placed on compatibility with flaky carbon and durability to resins (such as light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability), a naphthyl group, a fluorenyl group or the like is preferred as the substituent.

[0043] The cycloalkyl group is preferably a cycloalkyl group having 5 to 10 carbon atoms (preferably 5 to 8, particularly 5 to 6), and specifically, a cyclopentyl group, a cyclohexyl group, etc. are preferred.

[0044] The cycloalkyl group may or may not have a substituent, and examples of such a substituent include an alkyl group, an aryl group, and an aralkyl group.

[0045] The alkyl group as a substituent of the cycloalkyl group is preferably an alkyl group having 1 to 6 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc.

[0046] Examples of the aryl group and aralkyl group as the substituent of the cycloalkyl group include those exemplified above.

[0047] The substituent is not limited to the above, and may have a group derived from a fluorene structure (such as a fluorenyl group). In particular, when importance is placed on water solubility, a phenyl group or the like is preferred as the substituent, and when importance is placed on compatibility with flaky carbon and durability to resins (such as light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability), a naphthyl group, a fluorenyl group or the like is preferred as the substituent.

[0048] The aryl group is preferably an aryl group having 6 to 22 carbon atoms (particularly 6 to 18), and any of a monocyclic aryl group, a fused ring aryl group, and a polycyclic aryl group can be used, such as a phenyl group, a naphthyl group, an anthracenyl group, a tetracenyl group, a phenanthrenyl group, a biphenyl group, a terphenyl group, a fluorenyl group, an acenaphthenyl group, an acenaphthylenyl group, a pyrenyl group, a chrysenyl group, a triphenylenyl group, etc. From the viewpoint of affinity with carbon, an aryl group having two or more aromatic rings (a fused ring aryl group and a polycyclic aryl group) is preferred.

[0049] The aryl group may or may not have a substituent, and examples of such a substituent include an alkyl group, a cycloalkyl group, and an aralkyl group.

[0050] The alkyl group as a substituent of the aryl group is preferably an alkyl group having 1 to 6 carbon atoms, specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc.

[0051] Examples of the cycloalkyl group and aralkyl group as the substituent of the aryl group include those exemplified above.

[0052] The substituent is not limited to the above, and may have a group derived from a fluorene structure (such as a fluorenyl group).

[0053] Polyoxyethylene groups are usually hydrophilic, but polyoxyalkylene groups having 3 or more carbon atoms, such as polyoxypropylene and polyoxybutylene groups, become more hydrophobic as the degree of polymerization increases, and thus function as hydrophobic groups. Polyoxypropylene groups with a degree of polymerization of 4 or more and polyoxybutylene groups with a degree of polymerization of 3 or more are particularly preferred. However, from the viewpoint of improving durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), a degree of polymerization of 1000 or less is preferred. For example, when polyoxyethylene-polyoxypropylene or polyoxyethylene-polyoxybutylene is used as an organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon, the polyoxypropylene group and polyoxybutylene group can also function as hydrophobic groups.

[0054] This polyoxyalkylene group having 3 or more carbon atoms may or may not have a substituent, such as an alkyl group, a cycloalkyl group, an aralkyl group, or an aryl group.

[0055] The alkyl group as a substituent of the polyoxyalkylene group having 3 or more carbon atoms is preferably an alkyl group having 1 to 6 carbon atoms, and specifically, a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, a sec-butyl group, a tert-butyl group, etc. are preferred.

[0056] Examples of the cycloalkyl group, aralkyl group and aryl group as the substituent of the polyoxyalkylene group having 3 or more carbon atoms include those exemplified above.

[0057] The substituent is not limited to the above, and may have a group derived from a fluorene structure (such as a fluorenyl group). In particular, when importance is placed on water solubility, a phenyl group or the like is preferred as the substituent, and when importance is placed on compatibility with flaky carbon and durability to resins (such as light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability), a naphthyl group, a fluorenyl group or the like is preferred as the substituent.

[0058] From the viewpoints of affinity with carbon and durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), such hydrophobic groups are preferably aryl groups and polyoxyalkylene groups having 3 or more carbon atoms, more preferably aryl groups, and even more preferably aryl groups having two or more aromatic rings (fused aryl groups and polycyclic aryl groups).Specific examples of preferred hydrophobic groups include naphthyl groups, anthracenyl groups, tetracenyl groups, phenanthrenyl groups, biphenyl groups, terphenyl groups, fluorenyl groups, acenaphthenyl groups, acenaphthylenyl groups, pyrenyl groups, chrysenyl groups, triphenylenyl groups, polyoxypropylene groups with a degree of polymerization of 4 or more, and polyoxybutylene groups with a degree of polymerization of 3 or more.

[0059] The hydrophilic group possessed by the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon is not particularly limited as long as it can increase the solubility in water of the organic compound having the hydrophilic group and the hydrophobic group having a high affinity for carbon. However, from the viewpoint of improving the water solubility of the organic compound having the hydrophilic group and the hydrophobic group having a high affinity for carbon, the dispersibility of the flaky carbon, and durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), it is preferable to use a hydrophilic group represented by any one of the general formulas (1) to (4):

[0060] [ka] [wherein, -OH represents an alcoholic hydroxyl group or a phenolic hydroxyl group; R represents a divalent organic group; X 1 represents a hydrogen atom, an alkali metal, NH4, or an organic ammonium. 2 represents a hydrogen atom, an alkali metal, NH4, an organic ammonium, or an alkyl group. The oxygen atom in general formula (2) is an ether bond.] A hydrophilic group represented by the following formula is preferred. An organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon can contain one or more of such hydrophilic groups. When using multiple hydrophilic groups, multiple identical hydrophilic groups may be used, multiple types of hydrophilic groups represented by the same general formula may be used, or multiple types of hydrophilic groups represented by different general formulas may be used.

[0061] In general formula (1), -OH may be either an alcoholic hydroxyl group or a phenolic hydroxyl group. From the viewpoints of improving the water solubility of organic compounds having a hydrophilic group and a hydrophobic group with high affinity for carbon, the dispersibility of flaky carbon, and durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), an alcoholic hydroxyl group is preferred. However, when a phenolic hydroxyl group is contained (especially when multiple phenolic hydroxyl groups are contained), a benzene ring with excellent hydrophobicity is inevitably contained, which generally tends to particularly improve durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0062] In particular, when the compound has a benzenetriol structure (such as a pyrogallol structure, a hydroxyquinol structure, or a phloroglucinol structure), a benzenediol structure (such as a catechol structure, a resorcinol structure, or a hydroquinone structure) (especially when it has two or more of these), it is particularly excellent in strengthening properties such as improving durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) As organic compounds having a hydrophilic group with such a structure and a hydrophobic group with high affinity for carbon, not only artificially synthesized compounds but also naturally occurring polyphenols can be particularly preferably used.

[0063] Polyphenol is a general term for compounds also called polyhydric phenols, and refers to compounds in which two or more hydrogen atoms of an aromatic hydrocarbon are replaced with hydroxyl groups, or a mixture thereof. Such polyphenols are not particularly limited, and examples thereof include catechins (epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, epigallocatechin gallate, etc.), quercetin, hesperidin, tannic acid, theaflavin, procyanidins, leucoanthocyanidins, rutin, etc. Among these, tannic acid and catechins (green tea polyphenols, etc.) are preferred from the viewpoint of strengthening properties such as water solubility of organic compounds having a hydrophilic group and a hydrophobic group with high affinity for carbon, dispersibility of flaky carbon, and durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0064] These polyphenols are present in many plants, so plants may be used as they are, or plant extracts may be used. Alternatively, polyphenols may be purified by conventional methods and then used. It is particularly preferable to use purified products (e.g., purified alcohol products) because they are more likely to provide effects such as improved water solubility of organic compounds having stable hydrophilic groups and hydrophobic groups with high affinity for carbon, improved dispersibility of flaky carbon, and improved durability against resins (e.g., light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability).

[0065] In general formula (2), the divalent organic group represented by R is not particularly limited, and is preferably a divalent hydrocarbon group. Examples of the divalent hydrocarbon group include aliphatic hydrocarbon groups (such as alkylene groups (or alkylidene groups), cycloalkylene groups, alkylene (or alkylidene)-cycloalkylene groups, and bi- or tricycloalkylene groups), and aromatic hydrocarbon groups (such as arylene groups and alkylene (or alkylidene)-arylene groups).

[0066] In the general formula (2), the alkylene group (or alkylidene group) represented by the group R is preferably an alkylene group, and C 1-8 An alkylene group is more preferred, and C1-4 An alkylene group is more preferred, and C 2-4 Alkylene groups are particularly preferred, and C 2-3 Alkylene groups are most preferred, and specific examples include methylene, ethylene, ethylidene, trimethylene, propylene, propylidene, tetramethylene, ethylethylene, butan-2-ylidene, 1,2-dimethylethylene, pentamethylene, and pentane-2,3-diyl groups.

[0067] In the general formula (2), the cycloalkylene group represented by the group R is C 5-10 A cycloalkylene group is preferred, and C 5-8 A cycloalkylene group is more preferred, and specific examples thereof include a cyclopentylene group, a cyclohexylene group, a methylcyclohexylene group, and a cycloheptylene group.

[0068] In the general formula (2), the alkylene (or alkylidene)-cycloalkylene group represented by the group R is preferably an alkylene-cycloalkylene group, and C 1-6 Alkylene-C 5-10 A cycloalkylene group is more preferred, and C 1-4 Alkylene-C 5-8 Cycloalkylene groups are more preferred, and specific examples include a methylene-cyclohexylene group, an ethylene-cyclohexylene group, an ethylene-methylcyclohexylene group, and an ethylidene-cyclohexylene group.

[0069] In the general formula (2), specific examples of the bi- or tricycloalkylene group represented by the group R include a norbornane-diyl group.

[0070] In the general formula (2), the arylene group represented by the group R is C 6-10 An arylene group is preferred, and specific examples thereof include a phenylene group and a naphthalenediyl group.

[0071] In the general formula (2), the alkylene (or alkylidene)-arylene group represented by the group R is preferably an alkylene-arylene group, and C 1-6 Alkylene-C 6-20 An arylene group is more preferred, and C 1-4 Alkylene-C 6-10 An arylene group is more preferred, and C 1-2 Alkylene-phenylene groups are particularly preferred, and specific examples include methylene-phenylene groups, ethylene-phenylene groups, ethylene-methylphenylene groups, and ethylidenephenylene groups.

[0072] Among these, divalent aliphatic hydrocarbon groups, particularly alkylene groups (e.g., C groups such as methylene and ethylene groups) are preferred. 1-4 alkylene groups, etc.) are preferred.

[0073] The alkylene (or alkylidene)-cycloalkylene group and the alkylene (alkylidene)-arylene group refer to a group represented by -Ra-Rb- (wherein Ra represents an alkylene group or alkylidene group bonded to different oxygen atoms in general formula (2), and Rb represents a cycloalkylene group or an arylene group).

[0074] The hydrophilic group represented by general formula (2) is not particularly limited, and examples thereof include -OC2H4O-, -OC3H6O-, and -OCHO-. Those having a plurality of these (preferably 3 to 100) can also be preferably used, such as a trioxyethylene group, a tetraoxyethylene group, a polyoxymethylene group, a polyoxyethylene group, and a polyoxypropylene group. In particular, when the hydrophilic group represented by general formula (2) has a structure in which three or more hydrophilic groups are polymerized, the more carbon atoms in R (e.g., 3 or more carbon atoms), the more likely the hydrophilicity decreases and the more likely the hydrophobicity increases. Therefore, -OC2H4O- and -OCHO- are preferred, as they tend to retain their hydrophilicity even with an increased degree of polymerization.

[0075] When the hydrophilic group represented by such general formula (2), in particular a polyoxyalkylene group, further a polyoxyethylene group, is contained, the resin has particularly excellent reinforcing properties such as improved durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0076] In general formula (3), X 1 The alkali metal represented by the formula (I) is not particularly limited, and examples thereof include sodium, potassium, and lithium.

[0077] In general formula (3), X 1 As the organic ammonium represented by the formula (I), a quaternary ammonium is preferred, and tetramethylammonium, tetraethylammonium, tetrapropylammonium, tetrabutylammonium, etc. can be preferably used.

[0078] The hydrophilic group represented by the general formula (3) is not particularly limited, but for example, -SO3 - H + , -SO3 - Na + , -SO3 - K + , -SO3 - Li + , -SO3 - NH4 + , -SO3 - N(CH3)4 + , -SO3 - N(C2H5)4 + , -SO3 - N(C3H7)4 + , -SO3 - N(C4H9)4 + etc.

[0079] In general formula (4), X 2 Examples of the alkali metal and organic ammonium represented by the formula (I) include those exemplified above.

[0080] In general formula (4), X 2The alkyl group represented by the formula (I) may be a chain alkyl group or a branched chain alkyl group, but a chain alkyl group is preferred from the viewpoint of affinity with carbon and strengthening properties such as improved durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). In addition, the number of carbon atoms in the alkyl group is preferably 1 to 2 from the viewpoint of improved affinity with carbon and strengthening properties such as improved durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0081] The hydrophilic group represented by the general formula (4) is not particularly limited, but examples thereof include -COOH, -COONa, -COOK, -COOLi, -COONH4, -COON(CH3)4, -COON(C2H5)4, and -COON(C3H7)4. + , -COON(C4H9)4 + etc.

[0082] Among these hydrophilic groups, hydrophilic groups represented by general formula (1) or (2) are preferred from the viewpoints of improving the water solubility of organic compounds having a hydrophilic group and a hydrophobic group with high affinity for carbon, stability independent of pH, dispersibility of flaky carbon, and durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0083] However, when a compound has multiple identical hydrophilic groups represented by general formula (2), i.e., when it has a polymerized structure, the hydrophilicity of the water-soluble compound increases as the degree of polymerization increases for compounds with two or fewer carbon atoms, but the hydrophobicity of the compound may increase as the degree of polymerization increases for compounds with three or more carbon atoms.

[0084] Furthermore, in the present invention, when a nonionic material (such as a nonionic surfactant) is used as the organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon, the HLB value thereof is preferably 12 or more, more preferably 13 to 19, from the viewpoint of strengthening properties such as water solubility of the organic compound having the hydrophilic group and a hydrophobic group with high affinity for carbon, dispersibility of the flaky carbon, and improved durability against resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Note that, when the hydrophobic group is the same (when the affinity with the flaky carbon is about the same), the higher the HLB value, the better.

[0085] The organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon that satisfies the above-mentioned conditions is not particularly limited, and may be an aromatic water-soluble compound or a non-aromatic water-soluble compound, but is preferably an aromatic water-soluble compound. Examples of the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon include polyoxyethylene lauryl ether, polyoxyethylene decyl ether, polyoxypropylene decyl ether, polyoxyethylene lauryl ether, polyoxyethylene naphthyl ether, polyoxypropylene lauryl ether, polyoxypropylene naphthyl ether, polyoxyethylene myristyl ether, polyoxypropylene myristyl ether, polyoxyethylene cetyl ether, polyoxypropylene cetyl ether, polyoxyethylene octylphenyl ether, polyoxypropylene octylphenyl ether, polyoxyethylene undecylphenyl ether, polyoxypropylene undecylphenyl ether, polyoxyethylene tridecylphenyl ether, and polyoxypropylene tridecylphenyl ether. phenyl ether, polyoxyethylene pentadecyl phenyl ether, polyoxypropylene pentadecyl phenyl ether, polyoxyethylene polyoxypropylene glycol, polyoxypropylene polyglyceryl ether, sodium cholate, potassium cholate, sodium dodecyl sulfonate, potassium dodecyl sulfonate, sodium dilauroyl glutamate lysine, potassium dilauroyl glutamate lysine, decaglycerin laurate, n-decyl alcohol, catechins (green tea polyphenols, etc.; epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate, epigallocatechin gallate, etc.), quercetin, hesperidin, tannic acid, theaflavin, procyanidins, leucoanthocyanidins, rutin, etc.

[0086] Examples of organic compounds having such a hydrophilic group and a hydrophobic group with high affinity for carbon include Emulgen 103, Emulgen 104P, Emulgen 105, Emulgen 106, Emulgen 108, Emulgen 109P, Emulgen 120, Emulgen 123P, Emulgen 130K, Emulgen 147, Emulgen 150, Emulgen 210P, and Emulgen 220 (all polyoxyethylene alkyl ethers manufactured by Kao Corporation), Triton X-100, Triton X-114, and Triton X-3. 05, Triton X-405 (polyoxyethylene octylphenyl ethers manufactured by Dow Chemical Co.), Noigen EN, Noigen EN-10 (polyoxyethylene naphthyl ethers manufactured by Daiichi Kogyo Seiyaku Co., Ltd.), tannic acid, catechins (including polyphenols such as epicatechin, epigallocatechin, epicatechin gallate, epigallocatechin gallate, gallocatechin, catechin gallate, and gallocatechin gallate), gallic acid, gallic acid esters, persimmon tannins (including tannins), etc.

[0087] The content of the organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon in the durability improver of the present invention is not particularly limited, but from the viewpoint of strengthening properties such as improving durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), it is preferably 5 to 90 mass% and more preferably 10 to 85 mass% relative to 100 mass% of the total amount of the durability improver of the present invention. Furthermore, the content of the organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon in the durability improver of the present invention is not particularly limited, but from the viewpoint of strengthening properties such as improving durability to resins (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), it is preferably 1 to 1000 mass parts and more preferably 2 to 500 mass parts per 100 mass parts of the flaky carbon. When prioritizing thermal conductivity to the resin, radical trapping effect, light resistance, etc., the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon is preferably low, and is preferably 1 to 50 mass% and more preferably 2 to 35 mass% based on 100 mass% of the total amount of the durability improver of the present invention. Similarly, when prioritizing thermal conductivity to the resin, radical trapping effect, light resistance, etc., the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon is preferably low, and the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon in the durability improver of the present invention is preferably 1 to 100 mass parts and more preferably 2 to 50 mass parts based on 100 mass parts of flaky carbon. Furthermore, when prioritizing antioxidant effect, dispersibility of the flaky carbon, etc., the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon is preferably high, and is preferably 10 to 90 mass% and more preferably 25 to 85 mass% based on 100 mass% of the total amount of the durability improver of the present invention. Similarly, when prioritizing thermal conductivity to the resin, radical trapping effect, light resistance, etc., it is preferable that the content of the organic compound having a hydrophilic group and a hydrophobic group that has high affinity for carbon is small, and the content of the organic compound having a hydrophilic group and a hydrophobic group that has high affinity for carbon in the durability improver of the present invention is preferably 10 to 1,000 parts by mass, more preferably 33 to 500 parts by mass, per 100 parts by mass of the flaky carbon.

[0088] When the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon is low, the durability improver of the present invention has a configuration in which the surface of the flaky carbon is coated with an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon (Figure 1). On the other hand, when the content of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon is high, the durability improver of the present invention has a configuration in which the flaky carbon is dispersed in an organic compound having a hydrophobic group with a high affinity for carbon (Figure 2). In either case, the presence of the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon around the flaky carbon suppresses the aggregation of the flaky carbon, resulting in a material that can improve the durability of the resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0089] (1-3) Other ingredients The durability improver of the present invention may contain other components in addition to the flaky carbon and the organic compound having a hydrophilic group and a hydrophobic group that has high affinity with carbon. Examples of such other components that can be used include carbon fiber (particularly carbon nanofibers with a fiber diameter of 500 nm or less), activated carbon, carbon black (acetylene black, oil furnace black, etc.; particularly ketjen black, which has high conductivity and a large specific surface area), glassy carbon, carbon microcoils, fullerenes, biomass-based carbon materials (materials made from bagasse, sorghum, wood chips, sawdust, bamboo, bark, rice straw, rice husks, coffee grounds, used tea leaves, soybean pulp refuse, rice bran, pulp waste, etc.; carbon fiber produced from lignin, etc.), cellulose nanofibers, boron nitride, molybdenum compounds (molybdenum disulfide, organic molybdenum, etc.), tungsten disulfide, melamine cyanurate, phthalocyanine, lead oxide, calcium fluoride, and layered minerals (mica, talc, etc.).

[0090] However, from the viewpoint of making the durability improver of the present invention more easily dispersible in the resin, further improving the uniformity and adhesion of the coating film when applied, and further improving reinforcing properties such as improved durability to the resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), it is preferable that the content of other components is small, and is preferably 0.01 to 10 mass%, and more preferably 0.02 to 5 mass%, assuming the total amount of the durability improver of the present invention to be 100 mass%.

[0091] The form of the durability improver of the present invention is not particularly limited, and examples thereof include a coating film, a sheet, and a mass.

[0092] As described above, the durability improver of the present invention is a material that is easily dispersed in a resin and can enhance the durability of the resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.). Compared with conventional additives, which have reduced durability, the durability improver of the present invention is an advantageous material for improving the durability of a resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0093] Such durability improvers of the present invention (light resistance improvers, heat resistance improvers, antioxidants, acid resistance improvers, water resistance improvers, radical-resistant trapping agents, etc.) can be used in applications such as various injection-molded products, extrusion-molded products, sheet-molded products, blow-molded products, compression-molded products, and various paints (including paints having functions such as electrical conductivity, heat conduction, electromagnetic wave shielding, lubrication, and abrasion resistance, as well as paints used for ordinary rust prevention and coloring).

[0094] 2. Manufacturing method of durability improver The durability improver of the present invention may be, for example, (1) A step of removing the solvent from a dispersion containing flaky carbon, an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon, and a solvent. It can be produced by

[0095] (2-1) Dispersion (flaky carbon dispersion) In a dispersion (flaky carbon dispersion) containing flaky carbon, an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon, and a solvent, the above-mentioned explanations can be applied to the flaky carbon and the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon. In addition, the flaky carbon dispersion can contain other components as needed.

[0096] This flaky carbon dispersion may be formed as a dispersion liquid or as a coating film on a substrate. In this case, it is preferable to use water as the main solvent for the solvent used to prepare the flaky carbon dispersion (flaky carbon dispersion liquid or flaky carbon coating film), from the viewpoints of improving the dispersibility of the flaky carbon and the durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) of the resulting durability improver.

[0097] The content of water in the solvent used is not particularly limited, but from the viewpoint of improving the dispersibility of the flaky carbon and the durability of the resulting durability improver (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), the content of water is preferably 70% by mass or more (70 to 100% by mass), and more preferably 75 to 100% by mass, of the total amount of the solvent taken as 100% by mass.

[0098] In the present invention, only water may be used as the solvent, and an organic solvent does not necessarily have to be used. However, in order to further improve the solubility in water of an organic compound having a hydrophilic group and a hydrophobic group that has high affinity for carbon, organic solvents such as monohydric alcohols such as methanol, ethanol, n-propyl alcohol, isopropyl alcohol, n-butyl alcohol, isobutyl alcohol, sec-butyl alcohol, and tert-butyl alcohol; polyhydric alcohols such as ethylene glycol and glycerin; and 2-methoxyethanol may be used.

[0099] The content of the organic solvent in the solvent used is preferably 30% by mass or less (0 to 30% by mass), and more preferably 5 to 25% by mass, based on 100% by mass of the total amount of the solvent, from the viewpoints of improving the solubility of the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon, and improving the durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) of the durability improver obtained.

[0100] In the flaky carbon dispersion, the content of the flaky carbon is not particularly limited, but from the viewpoint of easily forming the composition of the durability improver of the present invention, it is preferably 50% by mass or less, more preferably 0.0001 to 40% by mass, and even more preferably 0.001 to 30% by mass, of the total amount of the flaky carbon dispersion as 100% by mass. Similarly, the content of the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon is not particularly limited, but from the viewpoint of easily forming the composition of the durability improver of the present invention, it is preferably 0.00001 to 70% by mass, more preferably 0.0001 to 50% by mass, and even more preferably 0.01 to 30% by mass, of the total amount of the flaky carbon dispersion as 100% by mass. Similarly, the content of the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon in the flaky carbon dispersion is not particularly limited, but from the viewpoint of easily forming a composition of the durability improver of the present invention, it is preferably 5 to 1000 parts by mass, more preferably 10 to 500 parts by mass, per 100 parts by mass of the flaky carbon. Furthermore, the content of the solvent is not particularly limited, but from the viewpoint of easily forming a composition of the durability improver of the present invention, it is preferably 40 to 99.9998% by mass, more preferably 63 to 99.998% by mass, and even more preferably 85 to 99.98% by mass, of the total amount of the flaky carbon dispersion as 100% by mass.

[0101] (2-2) Method for producing flaky carbon dispersion In the present invention, the method for producing the flaky carbon dispersion is not particularly limited, and it is also possible to add flaky carbon and an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon to a solvent. Specifically, flaky carbon can be added to a dispersion of an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon, or an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon can be added to a dispersion of flaky carbon. Furthermore, flaky carbon and an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon can be simultaneously added to a solvent.

[0102] However, from the viewpoint of further improving the dispersibility of the flaky carbon, making it less likely to aggregate, and further enhancing the durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) of the durability improver of the present invention to be obtained, it is preferable to place a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon between a rotating turntable and a turntable placed approximately parallel to the turntable, and to apply shear to the carbonaceous material in the composition while adjusting the shortest distance between the turntable and the turntable to be 200 μm or less (grinding method).

[0103] Alternatively, the flaky carbon dispersion can be preferably produced by subjecting a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon to a pressure treatment of 30 MPa or more (high-pressure dispersion method).

[0104] Conventionally, when producing flaky carbon by a wet method, a water dispersion containing flaky carbon oxide and an aqueous solvent was subjected to a reduction treatment. However, this method made it difficult to maintain the graphene structure and the resulting flaky carbon severely aggregated, making it difficult to obtain a flaky carbon aqueous dispersion. There were also safety issues. In contrast, the present invention uses an organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon, allowing the flaky carbon to be obtained in a uniformly dispersed state (flaky carbon dispersion) without aggregating while maintaining the graphene structure. The resulting flaky carbon is also less likely to be broken, can be obtained in a short time, and is less likely to leave any clumps that failed to peel. In this case, the organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon can also function as a dispersant for uniformly dispersing the flaky carbon.

[0105] Furthermore, with the shearing method, the direction of force application is parallel to the surface direction of the carbonaceous material having a layered structure, and processing is performed in a narrow space. Therefore, compared with conventional manufacturing methods using high-speed stirring, ultrasonic processing, etc., there is less destruction and larger-sized flaky carbon (for example, flaky carbon with a size of 1 μm or more) can be obtained. The peeling efficiency is high, processing can be performed in a short time (few passes), and thick lumps that fail to peel are less likely to remain.

[0106] Carbonaceous material with layered structure The carbonaceous material having a layered structure is not particularly limited, and examples thereof include natural graphite, artificial graphite, expanded graphite, amorphous graphite, and graphite oxide. Graphite oxide can be graphite oxidized with one or more oxidizing agents, such as sulfuric acid, nitric acid, potassium permanganate, and hydrogen peroxide. For example, when graphite oxide is obtained by the Hummers process, graphite is immersed in concentrated sulfuric acid, potassium permanganate is added to oxidize the graphite, and the reaction product is quenched with dilute sulfuric acid and / or hydrogen peroxide, and then washed with distilled water, whereby oxygen atoms are bonded to the carbon atoms, introducing oxygen atoms between the layers, and graphite oxide can be obtained.

[0107] Among these, when attempting to obtain high-purity flaky carbon that does not contain heteroatoms such as oxygen, it is preferable to use graphite as the raw material, and natural graphite and expanded graphite are more preferable. When using expanded graphite, it is preferable to adopt expanded graphite that has less oxidation of the graphene structure. When using expanded graphite, it may be used after being subjected to a heat treatment at about 300 to 1000°C for about 10 seconds to 5 hours. This makes it possible to obtain expanded graphite that has been suitably expanded.

[0108] Furthermore, when ease of production is important, graphite oxide may be used. By using graphite oxide, solvent molecules are easily inserted between the layers, making it easy to exfoliate only in the layer direction, and the exfoliation efficiency and dispersibility are improved, making it possible to further shorten the processing time. However, when graphite oxide is used, a subsequent reduction treatment is required, and from the viewpoint of better maintaining the graphene structure, conductivity, and strength, other materials (natural graphite, artificial graphite, expanded graphite, amorphous graphite) are preferred.

[0109] On the other hand, amorphous graphite can be used to further improve dispersibility, but from the viewpoints of crystallinity, purity, and structural maintenance, other materials (natural graphite, artificial graphite, expanded graphite, and graphite oxide) are preferred.

[0110] Furthermore, when emphasis is placed on the crystallinity, strength, structural integrity, etc. of the resulting flaky carbon, artificial graphite can also be used.

[0111] In the present invention, the content of the carbonaceous material having a layered structure in a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon is not particularly limited. However, it is preferably 50% by mass or less, more preferably 0.0001 to 40% by mass, and even more preferably 0.001 to 30% by mass, based on 100% by mass of the total amount of the composition used to produce the flaky carbon dispersion. A lower content of the carbonaceous material having a layered structure is more likely to cause exfoliation (delamination), which tends to result in more efficient production of flaky carbon, fewer treatment cycles, and tends to facilitate maintaining an appropriate viscosity and performing shearing treatments, etc. On the other hand, a higher content of the carbonaceous material having a layered structure results in better productivity. Therefore, it is preferable to appropriately set the content of the carbonaceous material having a layered structure from the viewpoint of balancing exfoliation efficiency, viscosity, productivity, and the like. When a carbonaceous material dispersion is used, it is preferable to set the content of the carbonaceous material having a layered structure in the flaky carbon dispersion within the above-mentioned range.

[0112] Organic compounds with hydrophilic groups and hydrophobic groups that have a high affinity for carbon As the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon, those mentioned above can be used.

[0113] In the present invention, the content of the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon in the composition used to produce the flaky carbon dispersion is not particularly limited, but is preferably 0.00001 to 70 mass%, more preferably 0.001 to 50 mass%, and even more preferably 0.01 to 30 mass%, based on 100 mass% of the total amount of the composition used to produce the flaky carbon dispersion. Meanwhile, in the present invention, the content of the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon in the composition used to produce the flaky carbon dispersion is preferably 5 to 1,000 mass parts, more preferably 10 to 500 mass parts, per 100 mass parts of carbonaceous material having a layered structure. The lower the content of the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon, the higher the content of the carbonaceous material having a layered structure. This increases the relative content of the carbonaceous material having a layered structure, which improves the durability of the resin (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) and makes it easier to process inexpensively. On the other hand, a higher content of organic compounds having hydrophilic groups and hydrophobic groups with high affinity for carbon tends to result in more efficient production of flaky carbon because exfoliation (delamination) occurs more easily, but higher viscosity may also result in lower exfoliation efficiency. Therefore, it is preferable to appropriately set the content of organic compounds having hydrophilic groups and hydrophobic groups with high affinity for carbon from the viewpoint of balancing durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), cost, exfoliation efficiency, etc. In addition, when a carbonaceous material dispersion is used in this production method, it is preferable to set the content of organic compounds having hydrophilic groups and hydrophobic groups with high affinity for carbon in the carbonaceous material dispersion within the above range.

[0114] solvent In the above-mentioned method for producing a flaky carbon dispersion, as described above, it is preferable to perform a specific treatment using a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon. However, from the viewpoint of improving the exfoliation efficiency of the carbonaceous material having a layered structure and the durability of the resulting durability improver (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), it is preferable to perform a specific treatment on a carbonaceous material dispersion containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon.

[0115] The carbonaceous material dispersion may be formed as a dispersion liquid or may be formed as a coating film on a substrate.

[0116] In this case, the solvent used to prepare the carbonaceous material dispersion (carbonaceous material dispersion or carbonaceous material coating) can be any of the solvents described above.

[0117] In the present invention, when a specific treatment is carried out using a carbonaceous material dispersion using a solvent, the total amount of solvent in the carbonaceous material dispersion is not particularly limited, but from the viewpoints of the exfoliation efficiency of the carbonaceous material having a layered structure, the solubility of an organic compound having a hydrophilic group and a hydrophobic group that has high affinity for carbon, and the like, the total amount of solvent is preferably 40 to 99.9998 mass%, more preferably 63 to 99.998 mass%, and even more preferably 85 to 99.98 mass%, where the total amount of the carbonaceous material dispersion is taken as 100 mass%.

[0118] In the present invention, when a specific treatment is performed using a carbonaceous material dispersion using a solvent, the carbonaceous material dispersion may be prepared by adding a carbonaceous material having a layered structure to an organic compound dispersion having a hydrophilic group and a hydrophobic group that has a high affinity for carbon, or by adding an organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon to a carbonaceous material dispersion having a layered structure. Alternatively, the carbonaceous material having a layered structure and the organic compound having a hydrophilic group and a hydrophobic group that has a high affinity for carbon may be simultaneously added to a solvent.

[0119] Other ingredients In the present invention, other components may be contained in a composition (e.g., a carbonaceous material dispersion) containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon. This allows these other components to be contained in the final flaky carbon dispersion or durability improver. The above-mentioned components can be used as such other components, provided that the effects of the present invention are not impaired. However, from the viewpoint of easily dispersing the other components in a resin and easily obtaining a durability improver that further improves the uniformity, adhesion, and durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.) of the coating film upon application, the content of the other components is preferably small, preferably 0.00001 to 5 mass %, and more preferably 0.0001 to 2 mass %, of the total amount of the carbonaceous material dispersion as 100 mass %.

[0120] Shearing treatment (grinding method) In the present invention, when the attrition method is adopted, as described above, it is preferable to place a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon between a rotating turntable and a turntable placed approximately parallel to the turntable, and to perform a treatment to apply shear to the carbonaceous material in the composition while adjusting the shortest distance between the turntable and the turntable to 200 μm or less. Note that, when a carbonaceous material dispersion is used, it is preferable to place the carbonaceous material dispersion between a rotating turntable and a turntable placed approximately parallel to the turntable, and to perform a treatment to apply shear to the carbonaceous material in the carbonaceous material dispersion while adjusting the shortest distance between the turntable and the turntable to 200 μm or less.

[0121] Shearing treatment causes atomization of the carbonaceous material having a layered structure, and although it may not be possible to maintain the graphene structure depending on the conditions, it can efficiently exfoliate the carbonaceous material having a layered structure and reduce the processing time. When performing such shearing treatment, the rotating disk and the disk are placed approximately parallel, but they do not have to be strictly parallel. Specifically, the angle between the axis perpendicular to the rotating disk and the axis perpendicular to the disk is preferably 10° or less, more preferably 5° or less. It is most preferable that the axis perpendicular to the rotating disk and the axis perpendicular to the disk are strictly parallel. The shortest distance between the two surfaces when performing such shearing treatment is not particularly limited as long as it can sufficiently exfoliate the carbonaceous material having a layered structure, but is preferably 200 μm or less, more preferably 50 μm or less, and even more preferably 30 μm or less. The shorter the shortest distance between the two surfaces when performing shearing treatment, the higher the exfoliation efficiency, and it is usually 0 μm. In the present invention, the shortest distance between the two surfaces during shearing refers to the measured shortest distance between the turntables, excluding the thickness of the composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon. In other words, a measured shortest distance of 0 μm between the turntables means that the composition containing the carbonaceous material having a layered structure and the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon is placed in close contact between the turntables and the disks. In other words, no space exists between the turntables and the disks other than the carbonaceous material having a layered structure and the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon. Although the turntables and the disks are arranged approximately parallel, the distance between the turntables and the disks may vary depending on the location. In this case, the shortest distance between the turntables and the disks refers to the shortest distance between the turntables and the disks. Furthermore, it is not necessary to space the turntables apart in advance, and the material to be processed may be sandwiched between the turntables and the disks. Alternatively, the turntables and the disks may be brought into contact with each other, and the space between the turntables and the disks may be widened by sandwiching a carbonaceous material having a layered structure therebetween.Such shearing treatment can be carried out using any device that can rotate a disk-like object, such as a millstone, a vibration mixer, a spin coater, or a grinder.

[0122] The size of the turntable that can be used in this case is not particularly limited, and is preferably 5 to 500 mm, more preferably 10 to 200 mm. The rotation speed of the turntable when performing the shearing treatment is not particularly limited, and is preferably within a range that allows the carbonaceous material having a layered structure to be sufficiently exfoliated, for example, 1000 to 10000 ppm, more preferably 1500 to 3000 ppm.

[0123] By carrying out such a shearing treatment, the disk and the carbonaceous material having a layered structure, and the carbonaceous material having a layered structure and the carbonaceous material having a layered structure can be brought into contact with each other, and shear can be applied to the carbonaceous material having a layered structure in a direction parallel to the graphene layers of the carbonaceous material having a layered structure.

[0124] By reducing the minimum distance between the rotating disks and increasing the rotation speed of the rotating disks during the shearing treatment, it is possible to make the conditions stronger, thereby more efficiently flaking the carbonaceous material having a layered structure and further reducing the treatment time. This shearing operation can be performed one or more times, preferably three or more times.

[0125] The temperature at which the shearing treatment is carried out is not particularly limited, and may be any temperature that can sufficiently exfoliate the carbonaceous material having a layered structure, and may be 0° C. or higher, preferably 0 to 100° C., and particularly 20 to 95° C. The temperature at which the shearing treatment is carried out is preferably under conditions that result in high solubility of an organic compound having a hydrophilic group and a hydrophobic group that has high affinity for carbon, and if the higher the temperature, the higher the temperature, the greater the solubility.If a water-soluble compound having a cloud point is used, the temperature is preferably maintained at or below the cloud point.

[0126] Before carrying out the shearing treatment, in order to bring the carbonaceous material having a layered structure and the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon into intimate contact with each other, the materials may be stirred in advance using a stirring device, ultrasonic dispersing device, or the like before preparing the composition, thereby allowing the organic compound having a hydrophilic group and a hydrophobic group having a high affinity for carbon to blend with the surface of the carbonaceous material having a layered structure.

[0127] In the present invention, when graphite oxide is used as the carbonaceous material having a layered structure, it exists as a flaky carbon oxide in the dispersion after the shearing treatment. Therefore, when graphite oxide is used as the carbonaceous material having a layered structure, it is preferable to perform a reduction treatment as a post-treatment. Various methods, such as chemical reduction and electrochemical reduction, can be used for the reduction treatment, but chemical reduction is preferred. Among these, chemical reduction using a reducing agent such as hydrazine or sodium borohydride is preferred. The amount of the reducing agent is preferably 1 to 1,000 parts by mass, more preferably 10 to 500 parts by mass, and even more preferably 50 to 300 parts by mass, per 100 parts by mass of the flaky carbon oxide. Furthermore, heating during reduction facilitates the reduction. The heating temperature is preferably 40 to 200°C, more preferably 50 to 150°C, and even more preferably 60 to 120°C. The reduction time is preferably 10 minutes to 64 hours, more preferably 30 minutes to 48 hours, and even more preferably 1 to 24 hours. However, it is preferable that the amount be such that the graphene structure is not excessively destroyed.

[0128] According to the above-described manufacturing method, flaky carbon can be obtained as the above-described flaky carbon dispersion. This manufacturing method contains an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon, and therefore the flaky carbon dispersion also contains an organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon. This organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon can adsorb onto the flaky carbon surface and disperse the flaky carbon at a high concentration in a solvent, thus functioning as a dispersant in the flaky carbon dispersion. Furthermore, the organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon can be commercially available and is superior to conventional products in both cost and dispersibility. Furthermore, this organic compound having a hydrophilic group and a hydrophobic group with a high affinity for carbon remains on the flaky carbon surface, thereby exhibiting sufficient improvements in durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.).

[0129] Furthermore, in conventional methods of performing oxidation and reduction treatments, it was impossible to form a flaky carbon dispersion on a plastic substrate because the plastic substrate was hydrolyzed during the reduction treatment and the flaky carbon aggregated when the reduction treatment was performed, making it impossible to exist as a dispersion.However, in the present invention, by adding an organic compound having the above-mentioned hydrophilic group and a hydrophobic group that has a high affinity for carbon and performing a specific treatment, it is also possible to form a flaky carbon dispersion on a plastic substrate such as polyethylene terephthalate (PET) without the substrate being hydrolyzed.

[0130] Pressure treatment (high pressure dispersion method) In the present invention, when a high-pressure dispersion method is adopted, as described above, it is preferable to subject a composition containing a carbonaceous material having a layered structure and an organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon to a pressure treatment of 30 MPa or more.

[0131] Pressure treatment causes atomization of the carbonaceous material having a layered structure, and although it may not be possible to maintain the graphene structure depending on the conditions, it can efficiently exfoliate the carbonaceous material having a layered structure and reduce the treatment time. The pressure level when performing such pressure treatment is not particularly limited as long as it can sufficiently exfoliate the carbonaceous material having a layered structure, but is preferably 30 MPa or higher, more preferably 50 to 400 MPa, and even more preferably 100 to 300 MPa. Such pressure treatment can be performed using a high-pressure dispersion device, a supercritical water production device, or the like. A high-pressure dispersion device can disperse by applying mechanical pressure, and a supercritical water production device can increase the pressure of the system by heating the water.

[0132] Such pressure can, for example, (i) causing two or more of the carbonaceous material dispersions to collide with each other; (ii) colliding the carbonaceous material dispersion with a metal or ceramic material (a high-hardness material such as silicon carbide or alumina); (iii) The carbonaceous material dispersion is formed into a film having a cross-sectional area of ​​1 cm 2 Passing through the following spaces Processing such as the above can be performed.

[0133] According to the above (i) and (ii), it is possible to apply stronger pressure conditions, which allows the carbonaceous material having a layered structure to be exfoliated more efficiently and the processing time to be further reduced. Furthermore, according to the above (iii), the carbonaceous material having a layered structure can be more appropriately exfoliated while maintaining the graphene structure. This pressure operation can be performed one or more times, preferably ten or more times.

[0134] The pressurizing temperature is not particularly limited as long as it is a temperature at which the carbonaceous material having a layered structure can be sufficiently exfoliated, and in the cases of (i) and (ii) above, it can be 0 to 100°C, particularly 20 to 95°C. In the case of (iii) above, when pressure is applied mechanically, the temperature is preferably 0 to 100°C, and when pressure is generated by the supercritical state of water, the temperature is preferably 373 to 700°C, more preferably 380 to 450°C.

[0135] When the pressure treatment is carried out, it is preferable to carry out an ultrasonic dispersion treatment as a preliminary treatment (pretreatment) to atomize the carbonaceous material having a layered structure, which can have the effect of preventing clogging, etc.

[0136] Although there are no particular limitations on the output power when carrying out ultrasonic dispersion treatment, from the viewpoint of flaking the carbonaceous material having a layered structure, it is preferable to use an output power that is stronger than that of a commonly performed ultrasonic dispersion treatment (about 40 to 50 W). Specifically, the output power of the ultrasonic dispersion treatment is preferably 100 W or more, more preferably 300 to 20,000 W, and even more preferably 400 to 18,000 W.

[0137] The ultrasonic dispersion temperature is not particularly limited as long as it is a temperature at which the carbonaceous material having a layered structure can be sufficiently exfoliated, and may be 0 to 80° C., particularly 10 to 70° C. The ultrasonic dispersion time is not particularly limited as long as it is a time at which the carbonaceous material having a layered structure can be sufficiently exfoliated, and may be 1 to 600 minutes, particularly 3 to 120 minutes.

[0138] Furthermore, as a pre-treatment or post-treatment of these treatments, dispersion treatment using other dispersion devices such as ordinary mechanical stirring, dispersion treatment using an emulsifying device, dispersion treatment using a bead mill, etc. may be used in combination.

[0139] In the present invention, when graphite oxide is used as the carbonaceous material having a layered structure, it exists as a flaky carbon oxide in the dispersion subjected to the pressure treatment. Therefore, when graphite oxide is used as the carbonaceous material having a layered structure, it is preferable to perform a reduction treatment as a post-treatment. Various methods, such as chemical reduction and electrochemical reduction, can be used for the reduction treatment, but chemical reduction is preferred. Among these, chemical reduction using a reducing agent such as hydrazine or sodium borohydride is preferred. The amount of the reducing agent is preferably 1 to 1,000 parts by mass, more preferably 10 to 500 parts by mass, and even more preferably 50 to 300 parts by mass, per 100 parts by mass of the flaky carbon oxide. Furthermore, heating during reduction facilitates the reduction. The heating temperature is preferably 40 to 200°C, more preferably 50 to 150°C, and even more preferably 60 to 120°C. The reduction time is preferably 10 minutes to 64 hours, more preferably 30 minutes to 48 hours, and even more preferably 1 to 24 hours. However, it is preferable that the amount be such that the graphene structure is not excessively destroyed.

[0140] (2-3) Method for producing the durability improver of the present invention The durability improver of the present invention can be obtained by removing the solvent from the above-mentioned flaky carbon dispersion.

[0141] To remove the solvent, methods for concentrating the flaky carbon dispersion include drying the flaky carbon dispersion, spin-coating the flaky carbon dispersion onto a substrate, drying the flaky carbon dispersion thereafter, and recovering the thermal conductive material of the present invention by conventional solid-liquid separation. Examples of methods for performing solid-liquid separation include methods commonly used for solid-liquid separation, such as filtration using filter paper or a glass filter; filtration after centrifugation; and methods using a vacuum filter. Next, the drying method is not particularly limited, and examples include drying using a hot air dryer or the like at about 50 to 200°C for about 1 to 24 hours.

[0142] 3. Resin durable composition The resin durability improving composition of the present invention contains the durability improver of the present invention described above and a resin.

[0143] The durability improver of the present invention suppresses the aggregation of flaky carbon and is a material that is easily dispersed in other materials (e.g., resins, etc.). Therefore, by mixing it with other materials, it can be applied to nanocomposites containing flaky carbon, etc.

[0144] More specifically, examples of such other materials include resins such as polyethylene resin, polypropylene resin, polystyrene resin, polyvinyl chloride resin, polyvinylidene chloride resin, polyvinyl acetate resin, thermoplastic polyurethane resin, polyvinylidene fluoride resin, acrylonitrile-butadiene-styrene copolymer (ABS) resin, acrylonitrile-styrene copolymer (AS) resin, polymethyl methacrylate resin, polyamide resin, polyacetal resin, polycarbonate resin, polyarylate resin, polyphenylene ether resin, polyethylene terephthalate resin, polybutylene terephthalate resin, cyclic polyolefin resin, polyphenylene sulfide resin, polyether ether ketone resin, thermoplastic polyimide resin, polyamide-imide resin, and styrene-butadiene-styrene copolymer. These materials can be used alone or in combination of two or more. These other materials can be known or commercially available.

[0145] Among these resins, aromatic polymer compounds are preferred from the viewpoint of further improving compatibility with the durability improver of the present invention by interacting (e.g., π-electron interaction) with the hydrophobic group of an organic compound having a hydrophilic group and a hydrophobic group with high affinity for carbon. Specifically, styrene-butadiene-styrene copolymers and the like are preferred. Furthermore, polyamide-based thermoplastic resins and thermoplastic elastomers are also preferred from the viewpoint of affinity with carbon materials.

[0146] In the resin durability improving composition of the present invention, the content of the above-mentioned other materials is not particularly limited, and from the viewpoint of durability (light resistance, heat resistance, oxidation resistance, acid resistance, water resistance, radical trapping ability, etc.), the content is preferably 5 to 9900 parts by mass, and more preferably 10 to 9700 parts by mass, per 100 parts by mass of the durability improver of the present invention. [Example]

[0147] The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

[0148] In the following examples, the oxidation induction time refers to the time from switching the atmospheric gas from N to O to the rise of the exothermic peak due to oxygen absorption in DSC measurement. The obtained oxidation induction time can be used as a measure of the degree of deterioration, and a longer time indicates higher antioxidant properties and improved durability. In measuring the oxidation induction time, the measurement holding temperature is optimized taking into account the melting point and ease of oxidation of the resin.

[0149] Example 1 A mixed liquid was obtained by mixing and stirring 500 g of natural graphite (manufactured by Ito Graphite Industries Co., Ltd.), 250 g of polyoxyethylene naphthyl ether (HLB value 18) and 10,000 g of water.

[0150] This mixture was subjected to a shearing treatment once for 30 minutes at 1500 rpm using a ceramic grinder with a radius of 300 mm. The minimum distance of the ceramic grinder was approximately 10 μm.

[0151] 1000 g of ethanol was added to 200 g of the obtained dispersion (containing 10 g of carbon derived from graphite) and the mixture was filtered under reduced pressure. 800 g of ethanol was further added to the obtained cake and the mixture was filtered under reduced pressure. 800 g of acetone was further added to the obtained cake and the resulting cake was filtered under reduced pressure and dried at 60°C for 16 hours, yielding 51 g of a black solid.

[0152] The solid was heated to 600°C at a heating rate of 3°C / min by TG-DTA and thermal analysis was performed, and it was found that the weight loss from room temperature to 450°C, which was due to the dispersion of polyoxyethylene naphthyl ether, was approximately 3%. Therefore, the obtained solid contained 3.1 parts by mass of tannic acid per 100 parts by mass of flaky carbon.

[0153] When the carbon content contained in the cake after the acetone washing was analyzed by TEM, flaky carbon with a thickness of about 10 nm (number of layers: 30) was observed.

[0154] The obtained powder was added to polypropylene (BC06C manufactured by Japan Polypropylene Corporation) so that the amount was 3% by mass, with the total amount of the composition being 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 180℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0155] As a result, the oxidation induction time was 38 minutes.

[0156] Example 2 A mixed liquid was obtained by mixing and stirring 500 g of natural graphite (manufactured by Ito Graphite Industries Co., Ltd.), 250 g of tannic acid (manufactured by Kishida Chemical Co., Ltd.), and 10,000 g of water.

[0157] This mixture was subjected to a shearing treatment once for 30 minutes at 1500 rpm using a ceramic grinder with a radius of 300 mm. The minimum distance of the ceramic grinder was approximately 50 μm.

[0158] The obtained dispersion was dried under conditions of 90°C and 30 hPa to remove the solvent (water) and obtain a powder. As a result, the obtained powder contained 50 parts by mass of tannic acid per 100 parts by mass of flaky carbon.

[0159] Separately, 50 g of ethanol was added to 10 g of the obtained dispersion and filtered under reduced pressure. 40 g of acetone was added to the obtained cake and filtered under reduced pressure. Acetone was further added to the obtained cake and filtered under reduced pressure. The black substance obtained was analyzed by TEM, and flake-like carbon with a thickness of approximately 10 nm (30 layers) was observed.

[0160] The obtained powder was added to polypropylene (BC06C manufactured by Japan Polypropylene Corporation) so that the amount was 7.5% by mass, assuming the total amount of the composition to be 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 180℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0161] As a result, the oxidation induction time was 96.4 minutes.

[0162] Example 3 A mixed solution was obtained by mixing and stirring 500 g of natural graphite (manufactured by Ito Graphite Industries Co., Ltd.), 250 g of green tea polyphenol (manufactured by Pharma Foods Co., Ltd.), and 10,000 g of water.

[0163] This mixture was subjected to a shearing treatment once for 30 minutes at 1500 rpm using a ceramic grinder with a radius of 300 mm. The minimum distance of the ceramic grinder was approximately 50 μm.

[0164] The obtained dispersion was dried under conditions of 90°C and 30 hPa to remove the solvent (water) and obtain a powder. As a result, the obtained powder contained 50 parts by mass of green tea polyphenols per 100 parts by mass of flaky carbon.

[0165] The obtained powder was added to polypropylene (BC06C manufactured by Japan Polypropylene Corporation) so that the amount was 7.5% by mass, assuming the total amount of the composition to be 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 180℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0166] As a result, the oxidation induction time was 97.4 minutes.

[0167] Example 4 A mixed liquid was obtained by mixing and stirring 500 g of natural graphite (manufactured by Ito Graphite Industries Co., Ltd.), 250 g of tannic acid (manufactured by Kishida Chemical Co., Ltd.), and 10,000 g of water.

[0168] This mixture was subjected to a shearing treatment once for 30 minutes at 1500 rpm using a ceramic grinder with a radius of 300 mm. The minimum distance of the ceramic grinder was approximately 50 μm.

[0169] The obtained dispersion was dried under conditions of 90°C and 30 hPa to remove the solvent (water) and obtain a powder. As a result, the obtained powder contained 50 parts by mass of tannic acid per 100 parts by mass of flaky carbon.

[0170] The obtained powder was added to a styrene-butadiene-styrene block copolymer (Tufprene A manufactured by Asahi Kasei Chemicals Corporation) so that the amount was 6% by mass, with the total amount of the composition being 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 170℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0171] As a result, the oxidation induction time was 41.4 minutes.

[0172] Example 5 A mixed solution was obtained by mixing and stirring 500 g of natural graphite (manufactured by Ito Graphite Industries Co., Ltd.), 250 g of green tea polyphenol (manufactured by Pharma Foods Co., Ltd.), and 10,000 g of water.

[0173] This mixture was subjected to a shearing treatment once for 30 minutes at 1500 rpm using a ceramic grinder with a radius of 300 mm. The minimum distance of the ceramic grinder was approximately 50 μm.

[0174] The obtained dispersion was dried under conditions of 90°C and 30 hPa to remove the solvent (water) and obtain a powder. As a result, the obtained powder contained 50 parts by mass of green tea polyphenols per 100 parts by mass of flaky carbon.

[0175] The obtained powder was added to a styrene-butadiene-styrene block copolymer (Tufprene A manufactured by Asahi Kasei Chemicals Corporation) so that the amount was 6% by mass, with the total amount of the composition being 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 170℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0176] As a result, the oxidation induction time was 43.3 minutes.

[0177] Comparative Example 1 Polypropylene (BC6C manufactured by Japan Polypropylene Corporation) was kneaded at 210°C using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D = 30) to obtain pellets. The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 180℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0178] As a result, the oxidation induction time was 29.2 minutes.

[0179] Comparative Example 2 PAN-based carbon nanofibers (manufactured by iCarbon Co., Ltd.) were added to polypropylene (BC06C manufactured by Japan Polypropylene Co., Ltd.) so that the amount was 5% by mass, with the total amount of the composition being 100% by mass, and the mixture was kneaded using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Co., Ltd., diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 180℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0180] As a result, the oxidation induction time was 17.9 minutes.

[0181] Comparative Example 3 A styrene-butadiene-styrene block copolymer (Tufprene A manufactured by Asahi Kasei Chemicals Corporation) was kneaded at 210°C using a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D = 30) to obtain pellets. The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 170℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0182] As a result, the oxidation induction time was 15.4 minutes.

[0183] Comparative Example 4 Graphite (UF-G5 manufactured by Showa Denko K.K.) was added to a styrene-butadiene-styrene block copolymer (Tufprene A manufactured by Asahi Kasei Chemicals Corporation) in an amount of 4 mass% based on 100 mass% of the total amount of the composition, and the mixture was kneaded in a twin-screw kneader (KZW15TW-30MG-NH manufactured by Technovel Corporation, diameter 15 mm, L / D=30). The obtained pellets were kneaded under the following conditions: Equipment used: TA Instruments Q20 Measurement holding temperature 170℃ Heating rate: 99.9℃ / min Atmosphere N2 (50 mL / min) O2 (switches on 5 minutes after reaching the holding temperature) The oxidation induction time was measured by the following method.

[0184] As a result, the oxidation induction time was 12.3 minutes.

[0185] In this way, by kneading a composite of flaky carbon and a specific organic substance into the resin, it was possible to slow down oxidation.

[0186] In Examples 1 to 7, despite the addition of a large amount of 3 to 7.5 mass % of the flaky carbon of the present invention, i.e., a durability improver containing a carbon component, the oxidation induction time was longer and the antioxidant properties were improved compared to Comparative Examples 1 and 3. On the other hand, when additives such as carbon nanofibers or graphite, which are carbon components, were added as in Comparative Examples 2 and 4, the oxidation induction time was shorter and the antioxidant properties were worsened compared to Comparative Examples 1 and 3. Therefore, considering that the addition of additives usually reduces durability, the improvement in durability despite the addition of a large amount of carbon component in Examples 1 to 7 is an unexpected result.

Claims

1. The present invention relates to a method for producing a carbon fiber composite, and a method for producing the same. the hydrophilic group is a phenolic hydroxyl group and / or a polyoxyethylene group, the hydrophobic group is an aryl group having two or more aromatic rings; An agent that improves the oxidation resistance of resins.

2. The oxidation resistance improver for resin according to claim 1, wherein the thickness of the flaky carbon is 1 to 100 nm.

3. 3. The oxidation resistance improver for resins according to claim 1, wherein the organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon is a polyphenol.

4. The oxidation resistance improver for a resin according to any one of claims 1 to 3, containing 1 to 1000 parts by mass of an organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon per 100 parts by mass of the flaky carbon.

5. The resin oxidation resistance improver according to any one of claims 1 to 4, which is an antioxidant.

6. A method for producing the oxidation resistance improver for resin according to any one of claims 1 to 5, comprising: (1) A production method comprising a step of removing a solvent from a dispersion containing the flaky carbon, an organic compound having a hydrophilic group and a hydrophobic group having high affinity for carbon, and a solvent.

7. The method according to claim 6 , wherein the step of removing the solvent is a step of concentrating the dispersion.

8. The method according to claim 6 or 7, wherein the solvent is water.

9. A resin composition having improved oxidation resistance, comprising the agent for improving the oxidation resistance of resin according to any one of claims 1 to 5 and a resin.

10. 10. The resin composition with improved oxidation resistance according to claim 9, wherein the resin is an aromatic polymer compound.

11. A method for producing the resin composition having improved oxidation resistance according to claim 9 or 10, (2) A step of kneading the resin with the agent for improving the oxidation resistance of the resin. A manufacturing method comprising:

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