Composite and heat-ray absorbing film

Abstract

To provide a composite and a heat-ray absorbing film, having excellent heat-ray absorption properties without using raw materials with high environmental load.SOLUTION: One embodiment of the present invention is a composite comprising sulfate esterified fine cellulose fibers, in which the substitution level of sulfate ester groups represented by the general formula (1) is 1.0 mmol / g or more to 3.8 mmol / g or less (X represents a hydroxy group, -O-(Mn+)1 / n, or an alkyl group having 1 to 6 carbon atoms; n represents an integer of 1 to 3; Mn+ represents an n-valent cation; and the wavy line represents a bonding site to another atom), and polythiophene.SELECTED DRAWING: None

Description

Technical Field

[0001] The present disclosure relates to a composite and a heat ray absorbing film.

Background Art

[0002] Approximately 40% of the radiant energy of sunlight is light in the wavelength region of infrared rays or longer, and since these lights have a high thermal effect, they are called heat rays. Window materials that require transparency and are used in office buildings, automobiles, etc. generally transmit heat rays well, and it is known that the temperature inside a room or a vehicle rises as a result.

[0003] Therefore, for the purpose of energy conservation, it has been studied to impart a function of reflecting or absorbing heat rays to window materials. As a means of imparting a function of reflecting or absorbing heat rays (heat ray shielding property) to window materials, for example, a method of attaching an infrared absorbing film containing indium tin oxide (ITO) fine particles, antimony-doped tin oxide (ATO) fine particles, cesium tungstate, etc. to window glass has been proposed.

[0004] Both antimony and cesium are toxic, and indium is a rare metal, so the cost is high, and alternative materials for these materials are eagerly desired. In addition, in order to enhance the heat ray shielding property, if the addition amount of inorganic fine particles having heat ray shielding property is increased to lower the solar transmittance, the transmittance of visible light also becomes low. Conversely, if the transmittance of visible light is increased to take in outside light, there is a problem that the solar transmittance increases and the heat ray shielding property decreases.

[0005] For example, a heat ray absorber is known that contains sulfated cellulose nanocrystals represented by the following Chemical Formula 1 obtained from fibrous cellulose in the fiber width range of 3 nm to 1500 nm, and polythiophene doped with the sulfated cellulose nanocrystals (see, for example, Patent Document 1).

[0006]

Chemical Formula

Prior Art Documents

Patent Documents

[0007]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0008] According to the studies by the present inventors, the heat ray absorber disclosed in Patent Document 1 has insufficient near-infrared absorption ability for light in the range of, for example, 800 to 1800 nm, and the heat ray absorption characteristics (the absorbance of near-infrared light divided by the absorbance of visible light) are insufficient.

[0009] Therefore, an object of the present disclosure is to provide a composite and a heat ray absorption film having excellent heat ray absorption characteristics without using raw materials with a high environmental load.

Means for Solving the Problems

[0010] The present inventors conducted intensive studies to solve the above problems, and found that a composite containing sulfated fine cellulose fibers having a sulfated ester group in a specific amount of substituents and polythiophene is a composite having excellent heat ray absorption characteristics without using raw materials with a high environmental load, leading to the present disclosure.

[0011] Examples of the aspects of the present embodiment are described as follows.

[0012] [1] A composite comprising a sulfated microcrystalline cellulose fiber having a substituent amount of a sulfate group represented by the following general formula (1) of 1.0 mmol / g or more and 3.8 mmol / g or less, and polythiophene. [Chemical formula] (In the general formula (1), X is a hydroxy group, -O - (M n+ ) 1 / n , or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more and 3 or less, M n+ is an n-valent cation, and the wavy line is a bonding site with other atoms.) [2] The composite according to [1], wherein the average degree of polymerization of the sulfated cellulose constituting the sulfated microcrystalline cellulose fiber is less than 1500. [3] The composite according to [1] or [2], wherein the substituent amount of the sulfate group represented by the general formula (1) is 2.0 mmol / g or more and 3.8 mmol / g or less. [4] The composite according to any one of [1] to [3], wherein the average degree of polymerization of the sulfated cellulose constituting the sulfated microcrystalline cellulose fiber is 200 to 700. [5] The composite according to any one of [1] to [4], wherein the absorbance at 500 nm of an aqueous dispersion containing 0.01 wt% of the composite is 0.050 or more and 0.200 or less, and the absorbance at 1800 nm is 0.350 or more and 0.800 or less. [6] The composite according to any one of [1] to [5], wherein the value obtained by dividing the absorbance at 1800 nm of an aqueous dispersion containing 0.01 wt% of the composite by the absorbance at 500 nm is 4.5 or more. [7] An aqueous dispersion comprising a sulfated microcrystalline cellulose fiber having a substituent amount of a sulfate group represented by the following general formula (1) in the range of 1.0 mmol / g or more and 3.8 mmol / g or less, polythiophene, at least one resin selected from a water-soluble resin and an aqueous emulsion resin, and water. [Chemical formula] (In the general formula (1), X is a hydroxy group, -O- (M n+ ) 1 / n 、 or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more and 3 or less, and M n+ is an n-valent cation, and the wavy line is a bonding site with other atoms.) [8] A heat-absorbing film containing the complex according to any one of [1] to [6]. [9] The heat-absorbing film according to [8], wherein the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm is 4.5 or more.

[10] A laminate in which an adhesive layer and a release layer are laminated on one side of the heat-absorbing film according to [8] or [9]. [Advantages of the Invention]

[0013] According to the present disclosure, it is possible to provide a composite and a heat-absorbing film that do not use raw materials with a high environmental load and have excellent heat-absorbing properties. [Embodiments for Carrying Out the Invention]

[0014] Hereinafter, the composite, the aqueous dispersion, the heat-absorbing film, and the laminate of the present embodiment will be described in detail.

[0015] One aspect of the present embodiment is a composite containing sulfuric acid esterified microcrystalline cellulose fibers having a substituent amount of sulfuric acid ester groups represented by the following general formula (1) of 1.0 mmol / g or more and 3.8 mmol / g or less, and polythiophene. The composite of the present embodiment does not use raw materials with a high environmental load and has excellent heat-absorbing properties.

[0016] Hereinafter, the present embodiment will be described in detail.

[0017] (Sulfuric acid esterified microcrystalline cellulose fibers) The composite and the aqueous dispersion of the present embodiment contain sulfuric acid esterified microcrystalline cellulose fibers having a substituent amount of sulfuric acid ester groups represented by the following general formula (1) of 1.0 mmol / g or more and 3.8 mmol / g or less.

[0018] [Chemical formula] (In general formula (1), X is a hydroxy group, -O - (M n+ ), or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more and 3 or less, M 1 / n is an n-valent cation, and the wavy line is the bonding site with other atoms.) n+

[0019] In general formula (1), X is a hydroxy group, -O - (M n+ ), or an alkyl group having 1 to 6 carbon atoms. Examples of the alkyl group having 1 to 6 carbon atoms include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, a sec-butyl group, a tert-butyl group, an n-pentyl group, a 2-methyl-butyl group, a 3-methylbutyl group, a 2-ethyl-propyl group, an n-hexyl group, and the like. 1 / n

[0020] Examples of M n+ include metal ions, ammonium ions, and the like. When n is 2 or 3, that is, when M n+ is a polyvalent cation, M n+ forms an ionic bond with two or three -SO3 - . As M n+ , one preferred embodiment is that n is 1 and M n+ is M + (monovalent cation).

[0021] Examples of metal ions include alkali metal ions, alkaline earth metal ions, transition metal ions, and other metal ions.

[0022] Here, examples of alkali metal ions include lithium ion (Li + ), sodium ion (Na + ), potassium ion (K + ), rubidium ion (Rb + ), cesium ion (Cs +) and the like. Examples of alkaline earth metal ions include calcium ions (Ca 2+ ), strontium ions (Sr 2+ ), and the like. Examples of transition metal ions include iron ions, nickel ions, palladium ions, copper ions, silver ions, and the like. Examples of other metal ions include beryllium ions, magnesium ions, zinc ions, aluminum ions, and the like.

[0023] Examples of ammonium ions include NH4 + , and ammonium ions derived from various amines in which one or more hydrogen atoms of NH4 + are replaced by organic groups. Examples of ammonium ions include, for example, NH4 + , quaternary ammonium cations, alkanolamine ions, pyridinium ions, and the like.

[0024] As M n+ , from the viewpoint of the viscosity of the aqueous dispersion, sodium ions, potassium ions, calcium ions, or quaternary ammonium cations are preferable, more preferably sodium ions, potassium ions, or calcium ions, and particularly preferably sodium ions (Na + ).

[0025] In the general formula (1), X is preferably a hydroxy group or -O - (M n+ ), more preferably a hydroxy group or -O 1 / n M - , and particularly preferably a hydroxy group or -O + Na - + .

[0026] X in the group represented by the general formula (1) may be only one kind or two or more kinds.

[0027] ​The amount of substituents of the sulfate ester groups in the sulfated microcrystalline cellulose fibers represented by the general formula (1) is 1.0 mmol / g or more and 3.8 mmol / g or less, preferably 2.0 mmol / g or more and 3.8 mmol / g or less, and more preferably 3.0 mmol / g or more and 3.5 mmol / g or less. Within the above range, it is preferable because the sulfate ester groups can promote the dispersion of polythiophene and the spacing between the sulfate ester groups is appropriate.

[0028] The amount of substituents of the sulfate ester groups can be determined, for example, by the combustion absorption-ion chromatography (IC) method (combustion absorption-IC method, combustion IC method) described in the examples. The amount of sulfur introduced can be adjusted, for example, by controlling the concentration of reagents such as sulfuric acid in the solution (defibrillation solution) used when defibrating the pulp, the amount of pulp relative to the defibrillation solution, the reaction time, temperature, etc.

[0029] It is preferable that the average degree of polymerization of the sulfated cellulose constituting the sulfated microcrystalline cellulose fibers is less than 1500, more preferably 200 to 700, still more preferably 220 to 600, and particularly preferably 240 to 500. Within the above range, it is preferable because it can contribute to the improvement of the degree of polymerization of polythiophene while maintaining good dispersibility. The average degree of polymerization of the sulfated cellulose can be measured, for example, by the method described in the examples.

[0030] General cellulose (unmodified cellulose) is a polysaccharide in which glucose is β-1,4-glycosidically bonded, and is represented by (C6H 10 O5) n However, as is clear from the fact that the sulfated microcrystalline cellulose fibers having an amount of substituents of the sulfate ester groups represented by the general formula (1) of 1.0 mmol / g or more and 3.8 mmol / g or less have sulfate ester groups, they are fibers composed of modified cellulose.

[0031] The average fiber width of the sulfuric acid esterified microcellulose fiber is 1 nm to 1000 nm, preferably 1 nm to 100 nm, and more preferably 2 nm to 10 nm. The average fiber length of the microcellulose fiber is not particularly limited, but is usually 0.1 μm to 6 μm, preferably 0.1 μm to 2 μm.

[0032] The average fiber width and the average fiber length can be measured by, for example, using an atomic force microscope (SPM-9700HT, manufactured by Shimadzu Corporation) to measure the fiber width (fiber diameter (equivalent circular diameter)) and the fiber length in 50 arbitrarily selected fibers, and taking the arithmetic mean value respectively. The average fiber width and the average fiber length can be set within a desired range by adjusting the sulfuric acid esterification reaction time and the mixing ratio of the reagents.

[0033] In the sulfuric acid esterified microcellulose fiber, a part of the OH groups in the cellulose constituting the fiber is substituted with a sulfuric acid ester group represented by the general formula (1), whereby the sulfuric acid ester group is introduced. The microcellulose fiber can be produced, for example, by sulfuric acid esterifying and defibrating the raw material pulp as shown in the examples.

[0034] When a part of the OH groups in the cellulose constituting the fiber of the sulfuric acid esterified microcellulose fiber is substituted with a sulfuric acid ester group represented by the general formula (1), whereby the sulfuric acid ester group is introduced, the wavy line in the general formula (1) is the bonding site to the carbon atom to which the OH group was bonded.

[0035] The sulfuric acid esterified microcrystalline cellulose fiber may have other substituents in addition to the sulfuric acid ester group represented by the above general formula (1). Here, when the sulfuric acid esterified microcrystalline cellulose fiber has a group other than the sulfuric acid ester group represented by the above general formula (1), that is, another substituent, the other substituent is usually substituted with at least one of the OH groups in the cellulose constituting the microcrystalline cellulose fiber. Examples of the other substituents include, but are not particularly limited to, anionic substituents and their salts, ester groups, ether groups, acyl groups, aldehyde groups, alkyl groups, alkylene groups, aryl groups, combinations of two or more of these, and the like. When the other substituent is a combination of two or more, the content ratio of each substituent is not limited. Among the other substituents, from the viewpoint of nano-dispersibility, anionic substituents and their salts, or acyl groups are preferable. As the anionic substituent and its salt, a carboxy group, a phosphate ester group, a phosphite ester group, and a xanthate group are particularly preferable. When the anionic substituent is in the form of a salt, a sodium salt, a potassium salt, and a calcium salt are particularly preferable from the viewpoint of nano-dispersibility. Also, as the particularly preferable acyl group, an acetyl group is preferable from the viewpoint of nano-dispersibility.

[0036] (Polythiophene) The composite and the aqueous dispersion of the present embodiment contain polythiophene. Polythiophene usually has monomer units having a thiophene skeleton. Here, the monomer unit means a constituent unit derived from a monomer that constitutes polythiophene, and means a repeating unit of polythiophene. Polythiophene preferably has a monomer unit (repeating unit) represented by the following general formula (2).

[0037] [Chemical formula] (In general formula (2), R 7 and R 8 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or R 7 and R 8are linked to represent a dioxoalkylene group having 1 to 8 carbon atoms, an aromatic ring or an alicyclic ring having 3 to 7 members, and n represents the number of repetitions in parentheses.)

[0038] In general formula (2), R 7 and R 8 When they are alkyl groups having 1 to 8 carbon atoms, they may be either linear or branched. The alkyl group preferably has 1 to 6 carbon atoms.

[0039] In general formula (2), R 7 and R 8 When they are alkoxy groups having 1 to 8 carbon atoms, they may be either linear or branched. The alkoxy group preferably has 1 to 6 carbon atoms.

[0040] R 7 and R 8 When they are linked to form a dioxoalkylene group having 1 to 8 carbon atoms, the number of carbon atoms of the dioxoalkylene group is preferably 1 to 6 carbon atoms, more preferably 2 to 4 carbon atoms.

[0041] R 7 and R 8 When they are linked to form an aromatic ring, for example, together with the carbon atom to which R 7 and R 8 are bonded, a benzene ring may be formed.

[0042] R 7 and R 8 When they are linked to form an alicyclic ring having 3 to 7 members, the alicyclic ring is preferably a 4 to 7 membered ring, more preferably a 5 to 6 membered ring.

[0043] Regarding the number of repeating units represented by general formula (2) that form polythiophene, that is, the value of n, there is no particular limitation, and for example, 2 to 50 can be mentioned. As the number of these repeating units increases, the properties such as the heat insulation property of polythiophene tend to improve.

[0044] The monomer (thiophene) constituting the repeating unit represented by the general formula (2) is represented by the following general formula (3).

[0045] [Chemical Formula] (In the general formula (3), R 7 and R 8 each independently represent a hydrogen atom, an alkyl group having 1 to 8 carbon atoms, an alkoxy group having 1 to 8 carbon atoms, or R 7 and R 8 are linked to represent a dioxoalkylene group having 1 to 8 carbon atoms, an aromatic ring or an alicyclic ring having 3 to 7 members.)

[0046] As the thiophene represented by the general formula (3), preferably, a compound in which an alkyl group having 1 to 8 carbon atoms and / or an alkoxy group having 1 to 8 carbon atoms are independently substituted at the 3-position and 4-position of the thiophene skeleton; a 3,4-disubstituted thiophene in which a dioxoalkylene group having 1 to 8 carbon atoms is formed at the 3-position and 4-position of the thiophene skeleton. More specifically, 3,4-dialkylthiophene, 3,4-dialkoxythiophene, 3,4-alkylenedioxythiophene, etc. are mentioned. Among these, 3,4-alkylenedioxythiophene is preferred.

[0047] As the thiophene represented by the general formula (3), for example, 3,4-dihexylthiophene, 3,4-diethylthiophene, 3,4-dipropylthiophene, 3,4-dimethoxythiophene, 3,4-diethoxythiophene, 3,4-dipropoxythiophene, 3,4-dibutoxythiophene, 3,4-methylenedioxythiophene, 3,4-ethylenedioxythiophene, 3,4-propylenedioxythiophene, etc. are mentioned. Among these, 3,4-ethylenedioxythiophene (hereinafter may be abbreviated as EDOT) is preferred.

[0048] Specific examples of the polythiophene represented by the general formula (2) include, for example, poly(3,4-dihexylthiophene), poly(3,4-diethylthiophene), poly(3,4-dipropylthiophene), poly(3,4-dimethoxythiophene), poly(3,4-diethoxythiophene), poly(3,4-dipropoxythiophene), poly(3,4-dibutoxythiophene), poly(3,4-methylenedioxythiophene), poly(3,4-ethylenedioxythiophene), poly(3,4-propylenedioxythiophene), and the like. Among these, poly(3,4-ethylenedioxythiophene), which is also abbreviated as PEDOT, is preferred.

[0049] (Composite) The composite of the present embodiment is a composite containing sulfated microcrystalline cellulose fibers in which the amount of the substituent of the sulfate group represented by the general formula (1) is 1.0 mmol / g or more and 3.8 mmol / g or less, and polythiophene. The composite of the present embodiment does not use raw materials with a high environmental load and has excellent heat ray absorption characteristics. The mass ratio of the sulfated microcrystalline cellulose fibers to the polythiophene constituting the composite of the present embodiment is not particularly limited, but the sulfated microcrystalline cellulose fibers / polythiophene (mass ratio) is preferably 10 / 90 to 70 / 30, more preferably 20 / 80 to 50 / 50, and particularly preferably 30 / 70 to 40 / 60. The mass ratio of the sulfated microcrystalline cellulose fibers to the polythiophene can be measured by the method described in the examples.

[0050] The complex has an absorbance at 500 nm of 0.050 or more and 0.200 or less, and an absorbance at 1800 nm of 0.350 or more and 0.800 or less in an aqueous dispersion containing 0.01 wt% of the complex. It is preferable that the absorbance at 500 nm in the aqueous dispersion containing 0.01 wt% of the complex is 0.075 or more and 0.150 or less, and the absorbance at 1800 nm is 0.400 or more and 0.650 or less. More preferably, the absorbance at 500 nm is 0.080 or more and 0.120 or less, and the absorbance at 1800 nm is 0.450 or more and 0.600 or less. Since the complex having such characteristics is excellent in heat ray absorption, the complex can be used as a heat ray absorber, a heat ray absorbing film, or the like.

[0051] For the complex, it is preferable that the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm in an aqueous dispersion containing 0.01 wt% of the complex is 4.5 or more, more preferably 5.0 or more, and particularly preferably 5.5 or more. Since the higher the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm, the better the heat ray absorption characteristics, there is no particular limitation on the upper limit, but it is usually 8.0 or less. The complex having such characteristics is particularly excellent in heat ray absorption and is preferable.

[0052] The complex may contain components other than sulfated microcrystalline cellulose fibers and polythiophene, such as additives. The additives may be inorganic additives or organic additives.

[0053] Examples of the inorganic additives include inorganic fine particles. Examples of the inorganic fine particles include silica, mica, talc, clay, carbon, carbonates (e.g., calcium carbonate, magnesium carbonate), oxides (e.g., aluminum oxide, titanium oxide, zinc oxide, iron oxide), ceramics (e.g., ferrite), or fine particles of a mixture thereof. The inorganic fine particles may be contained in the complex, for example, in an amount within the range of 0.09 to 5% by mass.

[0054] The composite may contain a functional compound as an organic additive. Examples of the functional compound include a pigment, a UV absorber, an antioxidant, an antistatic agent, and a surfactant. The organic additive may be contained, for example, in an amount within the range of 0.09 to 5% by mass in the composite.

[0055] The composite is usually in a solid state. A dispersion of the composite in a dispersion medium is referred to as a dispersion of the composite, and a dispersion in water is referred to as an aqueous dispersion of the composite.

[0056] (Method for producing the composite) The composite can be obtained, for example, by polymerizing thiophene in the coexistence of sulfated microcrystalline cellulose fibers and thiophene to produce polythiophene. In one embodiment, the sulfated microcrystalline cellulose fibers are doped with polythiophene by the polymerization of the thiophene.

[0057] Specifically, the composite can be produced by oxidatively polymerizing the thiophene represented by the general formula (3) in the presence of sulfated microcrystalline cellulose fibers, a solvent, and an oxidizing agent. For example, the thiophene represented by the general formula (3) and an oxidizing agent are added to a dispersion (for example, an aqueous dispersion) prepared by previously dispersing sulfated microcrystalline cellulose fibers in a dispersion medium, and the thiophene is polymerized to produce polythiophene, whereby the composite can be obtained in a state where the composite is dispersed in the dispersion medium. In the obtained composite, the bonding mode between polythiophene and sulfated microcrystalline cellulose fibers is not intended to be limitedly interpreted, but it is considered that the composite is formed in a state where the anions of the sulfated microcrystalline cellulose fibers are doped into the polythiophene generated by the polymerization reaction.

[0058] In the production of the composite, the amounts of the thiophene represented by the general formula (3) and the sulfated microcrystalline cellulose fibers used as raw material compounds may be adjusted so that the above-described composite can be obtained.

[0059] As the oxidizing agent (which may be referred to as a polymerization initiator) used in the production of the composite, there is no particular limitation as long as it can oxidatively polymerize the thiophene represented by the general formula (3). For example, peroxydisulfuric acid, sodium peroxydisulfate, potassium peroxydisulfate, ammonium peroxydisulfate, inorganic ferric salts, organic ferric salts, hydrogen peroxide, potassium permanganate, potassium dichromate, alkali metal perborates, iron(III) sulfate, iron(III) chloride, etc. can be mentioned. Among these, peroxydisulfuric acid, sodium peroxydisulfate, potassium peroxydisulfate, ammonium peroxydisulfate, iron(III) sulfate, and iron(III) chloride are preferred. These oxidizing agents may be used alone or in combination of two or more.

[0060] In the production of the composite, the amount of the oxidizing agent used is not particularly limited. For example, in the range of 0.1 equivalent to 5 equivalents, more preferably in the range of 0.3 equivalent to 2 equivalents, per mole of the thiophene represented by the general formula (3) is preferred.

[0061] When the amount of the monosaccharide constituting the sulfated microcrystalline cellulose fiber is 1 mole in the production of the composite, the amount of thiophene is preferably in the range of 0.5 to 3.0 moles, more preferably in the range of 0.7 to 2.0.

[0062] In the production of the composite (polymerization of polythiophene (e.g., PEDOT)), the concentration of the polymerization initiator with respect to thiophene (e.g., EDOT) can be, for example, in the range of 5 mol% to 92.5 mol% or in the range of 5.7 mol% to 92.5 mol%. It is preferable to set the concentration of the polymerization initiator in the range of 11.6 mol% to 46.2 mol% because the near-infrared light absorption characteristics can be further improved. When the polymerization initiator is insufficient, the polymerization of polythiophene (e.g., PEDOT) becomes difficult to proceed. When there is too much polymerization initiator, the degree of polymerization of polythiophene (e.g., PEDOT) tends to be small. And it is considered that polymers (polythiophene) outside the system of the sulfated microcrystalline cellulose fiber with a very small degree of polymerization are produced.

[0063] Regarding the dispersion medium used in the production of the composite, any medium capable of performing the polymerization reaction of thiophene may be used. Specifically, an aqueous solvent is exemplified, and preferably water is mentioned. Further, as the solvent, an aqueous solvent in which a lower alcohol such as methanol or ethanol or a polar organic solvent such as acetone or acetonitrile is mixed with water may be used. These solvents may be used alone or in combination of two or more.

[0064] In the production of the composite, the amount of the solvent used is not particularly limited. For example, in the range of 1000 ml to 50000 ml per mole of thiophene represented by the general formula (3) is preferable, and more preferably in the range of 10000 ml to 40000 ml.

[0065] Regarding the reaction time and reaction temperature in the production of the composite, they may be appropriately set according to the type of thiophene and sulfuric acid esterified microcrystalline cellulose fiber used as the raw material compound, the type of oxidizing agent, etc. The reaction temperature in the production of the composite is preferably, for example, in the range of 5°C to 90°C, and more preferably in the range of 10°C to 80°C. The reaction time in the production of the composite is preferably, for example, in the range of 1 hour to 96 hours, and more preferably in the range of 5 hours to 48 hours.

[0066] As described above, in the presence of sulfuric acid esterified microcrystalline cellulose fiber, by polymerizing thiophene represented by the general formula (3), a dispersion solution of the composite can be obtained. The composite may be obtained as the state of the dispersion liquid obtained after the reaction (dispersion liquid of the composite). After the dispersion liquid of the composite is purified and additives are added as necessary, it may be coated on a substrate and dried to obtain a film-like composite (for example, a heat ray absorbing film), or the composite may be separated and purified as necessary to obtain a solid (for example, powder) composite. The solid (for example, powder) composite may be used as an additive for a heat ray absorbing film, or a film-like composite (for example, a heat ray absorbing film) may be produced by secondary processing.

[0067] (Aqueous dispersion) The aqueous dispersion of one embodiment contains sulfuric acid esterified microcrystalline cellulose fibers in which the amount of substituents of the sulfuric acid ester group represented by the general formula (1) is in the range of 1.0 mmol / g or more and 3.8 mmol / g or less, polythiophene, and water. The aqueous dispersion of another embodiment contains sulfuric acid esterified microcrystalline cellulose fibers in which the amount of substituents of the sulfuric acid ester group represented by the general formula (1) is in the range of 1.0 mmol / g or more and 3.8 mmol / g or less, polythiophene, at least one resin selected from a water-soluble resin and an aqueous emulsion resin, and water.

[0068] (Heat ray absorption film) The heat ray absorption film of the present embodiment contains the above-mentioned composite. In one embodiment, the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm of the heat ray absorption film is 4.5 or more, preferably 5.0 or more, and more preferably 5.5 or more. Also, the higher the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm, the more preferable it is, and although there is no particular limitation on the upper limit, it is usually 8.0 or less.

[0069] The heat ray absorption film only needs to contain the above-mentioned sulfuric acid esterified microcrystalline cellulose fibers and polythiophene derived from the composite, and other components may be contained. Examples of other components include the above-mentioned additives and other polymers.

[0070] In one embodiment, by adding the composite to a polymer, a heat ray absorption film having excellent heat ray absorption characteristics derived from the composite can be obtained. Examples of the polymer that is the matrix of the heat ray absorption film include vinyl acetate-polyvinyl alcohol copolymer, polypropylene glycol, polyethylene glycol, polyvinyl alcohol, polyvinyl alcohol-ethylene copolymer, polyvinyl alcohol-butenediol copolymer, polyethylene-vinyl acetate copolymer, cellulose monoalkylate (alkyl group having 1 to 18 carbon atoms), cellulose dialkylate (alkyl group having 1 to 18 carbon atoms), cellulose trialkylate (alkyl group having 1 to 18 carbon atoms), polyethylene, polypropylene, polystyrene, polyalkyl (alkyl group having 1 to 18 carbon atoms) (meth)acrylate, sodium carboxymethyl cellulose, cellulose alkyl ether (alkyl group having 1 to 18 carbon atoms), polyethylene terephthalate, polyethylene naphthalate, polyacrylamide and its derivatives, poly(meth)acrylic acid, polyvinyl chloride, cellulose, starch, gelatin, pullulan, dextran, hydroxyalkylene (alkylene having 1 to 18 carbon atoms) (meth)acrylate, polyurethane, nylon-6,6, nylon-6, nylon-6,10, polyvinyl alkylal (alkyl group having 1 to 18 carbon atoms), polyimide, syndiotactic 1,2-polybutadiene, 1,4-polybutadiene, polyisoprene, polystyrene-butadiene copolymer, ABS resin, phenol resin, silosakin polymer, silsesquioxane, and the like.

[0071] The thickness of the heat ray absorption film is not particularly limited, but is, for example, 1 to 10000 μm, preferably 10 to 1000 μm, and more preferably 10 to 100 μm. Among the heat ray absorption films, those having a small thickness, for example, those having a thickness of 0.1 to 10 μm, may sometimes be referred to as heat ray absorption films, but in the present disclosure, the heat ray absorption film is included in the heat ray absorption film.

[0072] The manufacturing method of the heat ray absorbing film is not particularly limited. For example, it can be obtained by applying a dispersion of the composite to a substrate and drying it. The method of applying the dispersion of the composite to the substrate is not particularly limited. For example, methods by coating such as spray coating method, spin coating method, air knife coating method, curtain coating method, blade coating method, dip coating method, casting method, two-roll coating method, gate roll press method, roll coating method, bar coating method, die coating method, gravure method, mist method, etc.; wet processes such as methods by patterning such as printing and inkjet are exemplified. Among these, the spin coating method and the casting method are preferred.

[0073] The drying method is not particularly limited. For example, natural drying, heat drying, freeze drying, vacuum drying, hot air drying, heat pressure drying, infrared drying, supercritical drying, etc. are exemplified. The drying temperature is appropriately set according to the drying method. For example, a range of 50°C to 250°C is preferred, more preferably a range of 60°C to 150°C. The drying temperature is even more preferably in the range of 80°C to 120°C. By setting the drying temperature to 250°C or lower, it is possible to suppress the decrease in the heat ray absorption characteristics of the composite during drying. Also, by setting the drying temperature higher, the drying time and the quality of the coating film during drying can be improved.

[0074] Examples of the substrate include a glass plate, a plastic sheet, a plastic film, etc. Examples of the plastic include polyester, polyethylene, polypropylene, polystyrene, polyimide, poly(meth)acrylate, polyamide, polyethylene terephthalate, polyethylene naphthalate, epoxy resin, chlorine-based resin, silicon-based resin, phenol resin, and blends thereof.

[0075] The laminate of the present embodiment is a laminate in which an adhesive layer and a release layer are laminated on one side of the above-described heat ray absorbing film. By laminating the adhesive layer and the release layer on one side of the heat ray absorbing film, it is possible to easily peel off the release layer during use and attach the heat ray absorbing film to a substrate or the like via the adhesive layer. There are no particular restrictions on the adhesive layer and the release layer, and for example, conventionally known ones can be appropriately used.

[0076] (Paint) The composite is usually in a solid state, but a dispersion of the composite can be used as a paint (for example, a heat insulating paint). That is, the paint of the present embodiment is a paint containing the above-described composite. In one embodiment, a paint containing the above-described composite and a dispersion medium (for example, water) can be mentioned. As another embodiment, a paint containing the above-described composite, at least one resin selected from a water-soluble resin and an aqueous emulsion resin, and a dispersion medium (for example, water) can be mentioned.

[0077] For example, by coating a substrate such as a glass plate with a paint, a laminate in which a composition containing the composite is coated on the substrate may be obtained.

Examples

[0078] Hereinafter, the present embodiment will be described with reference to examples, but the present disclosure is not limited to these examples.

[0079] (Synthesis of Sulfated Microcrystalline Cellulose Fibers (S-CNF)) [Synthesis Example 1] 150 g of DMSO, 16.5 g of acetic anhydride, and 1.0 g of 98% sulfuric acid were placed in a 500 ml sample bottle and stirred for about 30 seconds using a magnetic stirrer at room temperature of 23°C to prepare a fibrillation solution.

[0080] Next, 5.0 g of softwood kraft pulp NBKP (manufactured by Nippon Paper Industries Co., Ltd.) was added to the fibrillation solution, and the mixture was further stirred at room temperature of 23°C for 120 minutes to carry out the sulfuric acid esterification reaction. After stirring, 250 ml of distilled water was added to the fibrillation solution containing cellulose to stop the reaction, and then a 5% by mass aqueous sodium hydroxide solution was added until the pH reached 7 to neutralize the reaction solution. Thereafter, the supernatant was removed by centrifugation to obtain a crude product containing sulfuric acid esterified microcrystalline cellulose.

[0081] Furthermore, 1350 ml of distilled water and 1350 ml of ethanol were added to the crude product, and the mixture was stirred until it was uniformly dispersed. Then, the supernatant was removed by centrifugation to obtain a solid content. The same procedure was repeated for a total of 6 washings. The centrifugation speed in each operation was 12,000 rpm, and the centrifugation time was 50 minutes. After washing by centrifugation, distilled water was added to the solid content and diluted until the total weight reached 1000 g to obtain a non-uniform mixture containing sulfuric acid esterified microcrystalline cellulose fibers and water.

[0082] Next, the non-uniform mixture was stirred for 3 minutes using a mixer (G5200, manufactured by Biolomix) to obtain 1000 g of an aqueous dispersion in which 0.5% by mass of sulfuric acid esterified microcrystalline cellulose fibers were uniformly dispersed. Subsequently, the obtained aqueous dispersion of sulfuric acid esterified microcrystalline cellulose fibers was dried using a freeze dryer (FDU-2110, manufactured by Tokyo Rikakikai Co., Ltd.) for 72 hours to obtain a dried body of sulfuric acid esterified microcrystalline cellulose fibers.

[0083] Subsequently, 5 g of the dried body of sulfuric acid esterified microcrystalline cellulose fibers was treated with a dry pulverizer (Wonder Blender WB1, manufactured by Osaka Chemical Co., Ltd.) for 3 minutes to obtain Sample No. 1, which is a powder of sulfuric acid esterified microcrystalline cellulose fibers.

[0084] [Synthesis Example 2] Sample No. 2, which is a powder of sulfuric acid esterified microcrystalline cellulose fibers, was obtained in the same manner as in Synthesis Example 1, except that 1.0 g of 98% sulfuric acid was changed to 2.0 g of 98% sulfuric acid, and the 5% by mass aqueous sodium hydroxide solution used for neutralization was changed to a 15% by mass aqueous sodium hydroxide solution.

[0085] [Synthesis Example 3] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 2.0 g of 98% sulfuric acid and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 10 mass% sodium hydroxide aqueous solution, to obtain Sample No. 3 which is a sulfuric acid esterified fine cellulose fiber powder.

[0086] [Synthesis Example 4] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 2.0 g of 98% sulfuric acid, to obtain Sample No. 4 which is a sulfuric acid esterified fine cellulose fiber powder.

[0087] [Synthesis Example 5] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 2.0 g of 98% sulfuric acid and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 5 mass% sodium carbonate aqueous solution, to obtain Sample No. 5 which is a sulfuric acid esterified fine cellulose fiber powder.

[0088] [Synthesis Example 6] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 3.0 g of 98% sulfuric acid and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 10 mass% sodium hydroxide aqueous solution, to obtain Sample No. 6 which is a sulfuric acid esterified fine cellulose fiber powder.

[0089] [Synthesis Example 7] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 3.2 g of 98% sulfuric acid and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 10 mass% sodium hydroxide aqueous solution, to obtain Sample No. 7 which is a sulfuric acid esterified fine cellulose fiber powder.

[0090] [Synthesis Example 8] The procedure of Synthesis Example 1 was repeated except that 1.0 g of 98% sulfuric acid was changed to 3.4 g of 98% sulfuric acid and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 5 mass% sodium carbonate aqueous solution, to obtain Sample No. 8 which is a sulfuric acid esterified fine cellulose fiber powder.

[0091] [Synthesis Example 9] The procedure of Synthesis Example 1 was repeated, except that 1.0 g of 98% sulfuric acid was changed to 3.6 g of 98% sulfuric acid, and the 5 mass% aqueous sodium hydroxide solution used for neutralization was changed to a 10 mass% aqueous sodium hydroxide solution, to obtain Sample No. 9, which is a sulfuric acid esterified microcrystalline cellulose fiber powder.

[0092] [Synthesis Example 10] 5.0 g of softwood kraft pulp NBKP (manufactured by Nippon Paper Industries) was added to 500 ml of N,N-dimethylformamide (DMF) and cooled to 10°C. 3.0 ml of chlorosulfonic acid was added dropwise to the DMF containing softwood kraft pulp NBKP over 50 minutes under a nitrogen atmosphere, and the mixture was stirred for 1 hour to obtain a reaction solution.

[0093] The reaction solution was poured into 5000 ml of a saturated sodium acetate solution for reprecipitation, and then the supernatant was removed by centrifugation to obtain a solid content. The solid content was washed once with a saturated ethanol solution of sodium acetate, and then washed with ethanol until the supernatant became neutral. Thereafter, the supernatant was removed by centrifugation to obtain a solid content, distilled water was added to the solid content, and the mixture was diluted until the total weight reached 1000 g to obtain a heterogeneous mixture containing sulfuric acid esterified microcrystalline cellulose fibers and water.

[0094] Next, the heterogeneous mixture was stirred for 3 minutes using a mixer (G5200, manufactured by Biolomix) to obtain 1000 g of an aqueous dispersion in which 0.5 mass% of sulfuric acid esterified microcrystalline cellulose fibers was uniformly dispersed. Subsequently, the obtained aqueous dispersion of sulfuric acid esterified microcrystalline cellulose fibers was dried for 72 hours using a freeze dryer (FDU-2110, manufactured by Tokyo Rikakikai Co., Ltd.) to obtain a dried product of sulfuric acid esterified microcrystalline cellulose fibers.

[0095] Subsequently, 5 g of the dried product of sulfuric acid esterified microcrystalline cellulose fibers was treated with a dry pulverizer (Wonder Blender WB1, manufactured by Osaka Chemical Co., Ltd.) for 3 minutes to obtain Sample No. 10, which is a sulfuric acid esterified microcrystalline cellulose fiber powder.

[0096] [Synthesis Example 11] 1.0 g of 98% sulfuric acid was changed to 0.5 g of 98% sulfuric acid, and the 5 mass% sodium hydroxide aqueous solution used for neutralization was changed to a 5 mass% sodium carbonate aqueous solution, and the procedure was the same as in Synthesis Example 1, to obtain Sample No. 11 which is a sulfuric acid esterified fine cellulose fiber powder.

[0097] [Synthesis Example 12] 3.0 ml of chlorosulfonic acid was changed to 3.6 ml of chlorosulfonic acid, and the dropping time was changed from 50 minutes to 60 minutes, and the procedure was the same as in Synthesis Example 10, to obtain Sample No. 12 which is a sulfuric acid esterified fine cellulose fiber powder.

[0098] [Synthesis Example 13] 3.0 ml of chlorosulfonic acid was changed to 3.6 ml of chlorosulfonic acid, and the dropping time was changed from 50 minutes to 180 minutes, and the procedure was the same as in Synthesis Example 10, to obtain Sample No. 13 which is a sulfuric acid esterified fine cellulose fiber powder.

[0099] (Analysis of S-CNF) (Method for measuring average degree of polymerization) 0.12 g of the solid content of the sulfuric acid esterified fine cellulose fiber powder was dissolved in 63.0 g of a 0.5 M copper ethylenediamine solution, and after maintaining the temperature at 25 °C, the flow-down time of the sulfuric acid esterified fine cellulose fiber - copper ethylenediamine solution was measured using a Cannon-Fenske viscometer tube to measure the viscosity.

[0100] Regarding the viscosity of this sulfuric acid esterified fine cellulose fiber - copper ethylenediamine solution as η and the viscosity of the 0.5 M copper ethylenediamine solution as η0, the average degree of polymerization was calculated by the following calculation formula. Limiting viscosity [η] = (η / η0) / {c(1 + A×η / η0)} (However, c is the concentration of the sulfuric acid esterified fine cellulose fiber (g / dL) at the time of viscosity measurement, and A is a specific value depending on the type of solution. In the case of a 0.5 M copper ethylenediamine solution, A = 0.28.) Average degree of polymerization DP = [η] / aK (K and a are values determined by the type of polymer and the solvent used. In the case of cellulose dissolved in cuprammonium solution, K = 5.7×10 -3 , and a = 1.) The average degree of polymerization of the sulfated nanocellulose was defined as the number of constituent monosaccharides.

[0101] <Quantification of the amount of sulfated ester groups introduced> Using the combustion absorption-IC method, the sulfur content rate due to the sulfated fine cellulose fibers was quantified. Specifically, dry sulfated fine cellulose fiber powder (0.01 g) was placed on a magnetic board and burned in an oxygen atmosphere (flow rate: 1.5 L / min) in a circular furnace (1350 °C), and the generated gas components were absorbed into 3% hydrogen peroxide solution (20 ml). The obtained absorption solution was made up to 100 ml with pure water, and the sulfate ion concentration (mass%) of the diluted solution was measured by ion chromatography. Based on the measurement results, the sulfur introduction amount (mmol / g) due to the sulfated ester groups per 1 g of the sulfated fine cellulose fiber powder was calculated.

[0102] The production methods and analysis results of the sulfated fine cellulose fibers (S-CNF) obtained in each synthesis example are shown in Table 1.

[0103]

Table 1

[0104] (Synthesis of PEDOT / S-CNF) [Examples 1 to 10, Comparative Examples 1 to 3] To 0.375 g of the sulfated microcrystalline cellulose fibers of Synthesis Examples 1 to 13, ion exchange was added to prepare 37.5 g of a 1.0 wt% aqueous dispersion. To this, 0.332 g of 3,4-ethylenedioxythiophene (EDOT) was added, and internal ultrasonic waves were irradiated for 1 minute to disperse EDOT. Next, 2.0 g of concentrated hydrochloric acid, 1.0 g of an aqueous solution of iron(III) chloride hexahydrate at 0.48 g / L, and 0.14 g of potassium peroxydisulfate were added, and the mixture was stirred at room temperature for 24 hours. After stirring, dialysis was performed with a dialysis membrane for 72 hours or more to obtain an aqueous dispersion of a poly(3,4-ethylenedioxythiophene) (PEDOT) / sulfated microcrystalline cellulose fiber composite as shown in Examples 1 to 10 and Comparative Examples 1 to 3.

[0105] (Change in amount of EDOT) [Example 11] An aqueous dispersion of a PEDOT / sulfated microcrystalline cellulose fiber composite was obtained in the same manner as in Example 7 (using the sulfated microcrystalline cellulose fibers of Synthesis Example 7), except that the charged amount of EDOT was changed from 0.332 g to 0.266 g.

[0106] [Example 12] An aqueous dispersion of a PEDOT / sulfated microcrystalline cellulose fiber composite was obtained in the same manner as in Example 7 (using the sulfated microcrystalline cellulose fibers of Synthesis Example 7), except that the charged amount of EDOT was changed from 0.332 g to 0.199 g.

[0107] (Analysis of PEDOT / S-CNF) <Method for measuring absorbance> The aqueous dispersions of the PEDOT / sulfated microcrystalline cellulose fiber composites obtained in Examples 1 to 12 and Comparative Examples 1 to 3 were diluted to 0.01 wt%, and using a near-infrared spectrophotometer manufactured by Agilent Technologies, Inc., the absorbance was measured every 1 nm in the wavelength range of 200 nm to 1800 nm. The absorbance at 500 nm obtained was evaluated as the "absorbance of visible light", and the absorbance at 1800 nm was evaluated as the "absorbance of near-infrared light". The value obtained by dividing the absorbance value at 1800 nm by the absorbance value at 500 nm was evaluated as the heat ray absorption characteristic.

[0108] Table 2 shows the absorbance at 500 nm, the absorbance at 1800 nm, and the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm (Absorbance at 1800 nm / Absorbance at 500 nm) of the aqueous dispersion (0.01 wt%) of each composite of PEDOT / sulfated microcrystalline cellulose fibers.

[0109] <Quantification of sulfated microcrystalline cellulose fiber content> The obtained aqueous dispersion of the composite of PEDOT / sulfated microcrystalline cellulose fibers was diluted to 0.1 wt%, and 50 mL was collected. 5 mL of 1 mol / L sulfuric acid was added thereto, and the mixture was heated in an autoclave at 120 °C for 60 minutes. After adding 1 mL of galactosamine hydrochloride as an internal standard thereto, 20 μL was aliquoted, 80 μL of 0.5 mol / L aqueous sodium hydroxide solution and 100 μL of PMP (1-phenyl-3-methyl-5-pyrazolone) solution were added, and the mixture was heated at 60 °C for 30 minutes. Thereafter, 1 mL of ion-exchanged water, 50 μL of 0.5 mol / L sulfuric acid, and 2 mL of toluene were added, and the mixture was stirred with a touch mixer for 30 seconds or more and then centrifuged to remove the supernatant. 2 mL of toluene was added to the lower layer, and washing was performed by stirring, centrifuging, and removing the supernatant, and the filtered product through a membrane filter was injected into an HPLC (high performance liquid chromatography, apparatus: Ultimate 3000 HPLC manufactured by Thermo Fisher Scientific) at 5 μL to quantify the glucose component. From the glucose concentration after hydrolysis, the ratio (mass ratio) of PEDOT and sulfated microcrystalline cellulose fibers in the composite of PEDOT / sulfated microcrystalline cellulose fibers was determined.

[0110]

Table 2

[0111] (Preparation of PEDOT / S-CNF film) [Examples 13 to 22, Comparative Examples 4 to 6] The aqueous dispersion of the composite of PEDOT / sulfuric acid esterified microfibrillated cellulose fibers obtained in Examples 1 to 10 and Comparative Examples 1 to 3 was dried by an evaporator and then redispersed in water to prepare an aqueous dispersion having a solid content concentration of 0.50 wt%. To 100 g of this aqueous dispersion, 0.1 g of octylphenol ethoxylate (manufactured by Nacalai Tesque, Triton X-100) was added as a surfactant and stirred well to prepare a coating solution.

[0112] The coating solution was applied to a polyester film (manufactured by Toray, Lumirror (registered trademark) T60) with a doctor blade set at a gap of 200 μm, and after drying at 80°C for 30 minutes, a heat ray absorbing film was obtained.

[0113] (Analysis of PEDOT / S-CNF Film) (Measurement Method of Film Thickness) The film thickness of the obtained heat ray absorbing film was measured using a 3D measurement laser microscope (manufactured by Olympus, OLS5100).

[0114] (Measurement Method of Absorbance) The obtained heat ray absorbing film was measured for absorbance every 1 nm in the wavelength range of 200 nm to 1800 nm using a near-infrared spectrophotometer manufactured by Agilent Technologies, Inc. The absorbance at 500 nm obtained was defined as the "absorbance of visible light", and the absorbance at 1800 nm was evaluated as the "absorbance of near-infrared light". The value obtained by dividing the absorbance value at 1800 nm by the absorbance value at 500 nm was evaluated as the heat ray absorption characteristic.

[0115] [Table 3]

[0116] [Example 23] (Preparation of PEDOT / S-CNF-Water Soluble Resin Film) Butanediol vinyl alcohol copolymer (manufactured by Mitsubishi Chemical Corporation, Nichigo G Polymer TM)91.7 g and 569.1 g of water were stirred in a 1000 mL container at 40 °C for 12 hours to prepare a 13.9 wt% aqueous resin solution.

[0117] Next, the aqueous dispersion of the PEDOT / sulfated microcrystalline cellulose fiber composite obtained in Example 6 was dried by an evaporator and then redispersed in water to prepare an aqueous dispersion with a solid content concentration of 0.81 wt%.

[0118] To 22.1 g of this aqueous dispersion, 0.017 g of octylphenol ethoxylate (manufactured by Nacalai Tesque, Triton X-100) was added as a surfactant, and subsequently 66.1 g of the 13.9 wt% aqueous resin solution was added and stirred well to prepare a water-soluble resin coating solution.

[0119] The coating solution was applied to a polyester film (manufactured by Toray, Lumirror (registered trademark) T60) with a doctor blade set at a gap of 500 μm, and after drying at 80 °C for 30 minutes, a water-soluble resin heat ray absorbing film was obtained.

[0120] [Example 24] (Preparation of PEDOT / S-CNF-aqueous emulsion resin film) The aqueous dispersion of the PEDOT / sulfated microcrystalline cellulose fiber composite obtained in Example 6 was dried by an evaporator and then redispersed in water to prepare an aqueous dispersion with a solid content concentration of 1.5 wt%.

[0121] To 12.8 g of this aqueous dispersion, 14.1 g of urethane acrylate (manufactured by Daicel Allnex Co., Ltd., UCECOAT 7200, solid content concentration 65 wt%) was added while stirring well, 0.49 g of a photoinitiator (manufactured by BASF, IRGACURE 1173) and 0.10 g of a surface conditioner (manufactured by Nissin Chemical Industry Co., Ltd., Surfynol 104E) were added, and after stirring well, an aqueous emulsion resin coating solution was prepared.

[0122] The coating liquid was applied to a polyester film (manufactured by Toray Industries, Inc., Lumirror (registered trademark) T60) with a doctor blade set at a gap of 140 μm, and after drying at 80 °C for 10 minutes, it was irradiated with an ultraviolet irradiation device (manufactured by Eye Graphics Co., Ltd., Eye Grance ECS-401GX type) at an illuminance of 200 mW·cm 2 −2 and an integrated light quantity of 800 mJ / cm 2 to cure it, obtaining a water-soluble resin heat ray absorption film.

[0123]

Table 4

[0124] It was confirmed that the composite of this embodiment has excellent heat ray absorption characteristics in any state of the aqueous dispersion and the film.

[0125] The upper limit value and / or the lower limit value of the numerical range described in this specification can respectively define a preferable range by arbitrarily combining them. For example, the upper limit value and the lower limit value of the numerical range can be arbitrarily combined to define a preferable range, the upper limit values of the numerical range can be arbitrarily combined to define a preferable range, and the lower limit values of the numerical range can be arbitrarily combined to define a preferable range. Also, in this application, the numerical range represented by the symbol "~" includes the numerical values described before and after the symbol "~" as the lower limit value and the upper limit value respectively.

[0126] Although the present embodiment has been described in detail above, the specific configuration is not limited to this embodiment, and even if there are design changes within the scope not departing from the gist of the present disclosure, they are included in the present disclosure.

Claims

1. A composite comprising a sulfated microcrystalline cellulose fiber having a substituent amount of a sulfate ester group represented by the following general formula (1) of 1.0 mmol / g or more and 3.8 mmol / g or less, and polythiophene. 【Chemical 1】 (In the general formula (1), X is a hydroxy group, -O － (M ｎ＋ ) １／ｎ , or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more and 3 or less, M ｎ+ is an n-valent cation, and the wavy line is a bonding site with other atoms.)

2. The composite according to claim 1, wherein the average degree of polymerization of the sulfated cellulose constituting the sulfated microcrystalline cellulose fiber is less than 1500.

3. The composite according to claim 1, wherein the substituent amount of the sulfate ester group represented by the general formula (1) is 2.0 mmol / g or more and 3.8 mmol / g or less.

4. The composite according to claim 1, wherein the average degree of polymerization of the sulfated cellulose constituting the sulfated microcrystalline cellulose fiber is 200 to 700.

5. The composite according to claim 1, wherein the absorbance at 500 nm of an aqueous dispersion containing 0.01 wt% of the composite is 0.050 or more and 0.200 or less, and the absorbance at 1800 nm is 0.350 or more and 0.800 or less.

6. The composite according to claim 1, wherein the value obtained by dividing the absorbance at 1800 nm of an aqueous dispersion containing 0.01 wt% of the composite by the absorbance at 500 nm is 4.5 or more.

7. An aqueous dispersion comprising a sulfated microcrystalline cellulose fiber having a substituent amount of a sulfate ester group represented by the following general formula (1) in the range of 1.0 mmol / g or more and 3.8 mmol / g or less, polythiophene, at least one resin selected from a water-soluble resin and an aqueous emulsion resin, and water. [Chemical Formula 2] (In general formula (1), X is a hydroxy group, -O － (M ｎ＋ ) １／ｎ , or an alkyl group having 1 to 6 carbon atoms, n is an integer of 1 or more and 3 or less, M ｎ＋ is an n-valent cation, and the wavy line is a bonding site with other atoms.)

8. A heat ray absorbing film comprising the composite according to claim 1.

9. The heat ray absorbing film according to claim 8, wherein the value obtained by dividing the absorbance at 1800 nm by the absorbance at 500 nm is 4.5 or more.

10. A laminate in which an adhesive layer and a release layer are laminated on one side of the heat ray absorbing film according to claim 8.

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