TW202204488A - Radiation sensitive sheet and patterned sheet - Google Patents

Abstract

The present invention addresses the problem of providing: a radiation sensitive sheet which is capable of being provided with a fine pattern, while exhibiting excellent transparency; and a patterned sheet which is obtained by removing at least a part of a light exposed part or a light unexposed part of this radiation sensitive sheet. A radiation sensitive sheet according to the present invention contains a radiation sensitive composition, microfibrous cellulose that has a fiber width of 1,000 nm or less, and a hydrophilic polymer; and the content of the hydrophilic polymer relative to 100 parts by mass of the microfibrous cellulose is 10 parts by mass or more.

Description

Radiation-sensitive sheet, patterned sheet, and radiation-sensitive composition

The present invention relates to a radiation-sensitive sheet, a patterned sheet from which at least a part of an exposed portion or an unexposed portion of the radiation-sensitive sheet has been removed, and a radiation-sensitive composition.

In the development of electronic devices, a substrate capable of fine patterning is required as the circuit structure is required to be miniaturized and densified. In addition, due to the increasing awareness of the utilization of renewable resources, studies are under way to apply compounds derived from plant materials such as cellulose nanofibers to various applications. In Patent Document 1, for the purpose of providing a fiber-reinforced composite material which is not affected by temperature conditions, wavelength, etc., maintains high transparency at all times, and provides various functionalities by combining fibers and matrix materials, it is disclosed. There is a fiber-reinforced composite material containing fibers with an average fiber diameter of 4 nm to 200 nm and a matrix material, and a light transmittance of 400 nm to 700 nm with a wavelength of 400 nm to 700 nm converted to a thickness of 50 μm.

Moreover, patent document 2 discloses a photosensitive composite sheet which is a photosensitive composite sheet containing a photosensitive resin and a photosensitive agent in a cellulose porous sheet, and which satisfies at least the following requirements. Requirement 1: The air permeability resistance of the porous cellulose sheet is 1 s/100 ml or more and 400,000 s/100 ml or less; Requirement 2: the photosensitive resin contains at least one of a polymerizable compound, an alkali-soluble resin, and a resin in which the photofunctional group of the resin is protected by a protective group; Requirement 3: The light transmittance of the photosensitive composite sheet at a wavelength of 280 nm to 433 nm at a thickness of 50 μm is 10% or more. [Prior Art Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open No. 2005-60680 [Patent Document 2] Japanese Patent Laid-Open No. 2018-132655

[The problem to be solved by the invention] In the sheet described in Patent Document 1, there is a problem that it is difficult to form a fine pattern. In addition, the sheet described in Patent Document 2 has a problem of low transparency. An object of the present invention is to provide a radiation-sensitive sheet that can form a fine pattern and is excellent in transparency, and a patterned sheet from which at least a part of an exposed portion or an unexposed portion of the radiation-sensitive sheet has been removed. [Means of Solving Problems]

The present inventors found that the above-mentioned problems can be solved by a radiation-sensitive sheet containing a specific amount of a hydrophilic polymer in addition to the radiation-sensitive composition and fine fibrous cellulose, and completed the present invention. That is, the present invention relates to the following <1> to <13>. <1> A radiation-sensitive sheet comprising a radiation-sensitive composition, fine fibrous cellulose having a fiber width of 1,000 nm or less, and a hydrophilic polymer, and the content of the hydrophilic polymer is 100% relative to the fine fibrous cellulose. The mass part is 10 mass parts or more. <2> The radiation-sensitive sheet according to <1>, wherein the radiation-sensitive composition comprises a radiation-sensitive compound and a resin for a radiation-sensitive composition, wherein the solubility of the resin for a radiation-sensitive composition to a solvent is limited. Increase or decrease by radiation-sensitive compounds that are exposed to radiation. <3> The radiation-sensitive sheet according to <2>, wherein the radiation-sensitive compound contains at least one of a photoacid generator and a photopolymerization initiator. <4> The radiation-sensitive sheet according to any one of <1> to <3>, wherein the content of the radiation-sensitive composition in the solid content of the radiation-sensitive sheet is 10 mass % or more. <5> The radiation-sensitive sheet according to any one of <1> to <4>, wherein the radiation-sensitive sheet has a total light transmittance of 70% or more. <6> The radiation-sensitive sheet according to any one of <1> to <5>, wherein the radiation-sensitive sheet has a haze of 10% or less. <7> The radiation-sensitive sheet according to any one of <1> to <6>, wherein the fine fibrous cellulose has an anionic group. <8> The radiation-sensitive sheet according to any one of <1> to <7>, wherein the fine fibrous cellulose has a phosphorus oxyacid group or a group derived from a phosphorus oxyacid group. <9> The radiation-sensitive sheet according to any one of <1> to <8>, wherein the radiation-sensitive composition is dissolved in at least one of water, alcohol, and a mixed solvent thereof. <10> The radiation-sensitive sheet according to any one of <1> to <9>, wherein the hydrophilic polymer is selected from the group consisting of polyethylene glycol, polyethylene oxide, polyvinyl alcohol, and modified polymer. in vinyl alcohol. <11> The radiation-sensitive sheet according to any one of <1> to <10>, wherein the radiation-sensitive sheet is a negative-type radiation-sensitive sheet. <12> A patterned sheet in which at least a part of an exposed portion or an unexposed portion of the radiation-sensitive sheet according to any one of <1> to <11> is removed. <13> A radiation-sensitive composition for use in the radiation-sensitive sheet according to any one of <1> to <11>. [Effect of invention]

ADVANTAGE OF THE INVENTION According to this invention, the radiation-sensitive sheet which can form a fine pattern and is excellent in transparency, and the patterned sheet|seat which removed at least a part of the exposed part or the unexposed part of this radiation-sensitive sheet can be provided.

[radiation sensitive sheet] The radiation-sensitive sheet of the present embodiment contains a radiation-sensitive composition, fine fibrous cellulose with a fiber width of 1,000 nm or less (hereinafter, also simply referred to as fine fibrous cellulose), and a hydrophilic polymer, and the hydrophilic polymer The content is 10 parts by mass or more with respect to 100 parts by mass of the fine fibrous cellulose. According to the present embodiment, a fine pattern can be formed, and a radiation-sensitive sheet excellent in transparency can be obtained. The detailed reasons for obtaining the above-mentioned effects are not clear, but some of them are considered as follows. In the present embodiment, the radiation-sensitive layer is not provided on the substrate, but the radiation-sensitive sheet itself has excellent shape stability and functions as a substrate. When a radiation-sensitive layer is provided on a substrate, problems such as generation of curl due to a difference in thermal expansion coefficient with the substrate and reflection of light at the interface may occur, but this does not occur in this embodiment. question. In addition, the sheet containing the fine fibrous cellulose has extremely high transparency, and since the fiber width is 1,000 nm or less, it is considered that a fine pattern can be formed. Furthermore, when a radiation-sensitive layer (resist) is provided on the substrate, regions where the radiation-sensitive layer (resist) is present and regions where the radiation-sensitive layer (resist) is not present are generated after patterning, so that the film thickness is uneven. . On the other hand, in this embodiment, after exposure, at least a part of the exposed portion or the unexposed portion of the radiation-sensitive composition is removed, but mainly only the radiation-sensitive composition is removed, and the fine fibrous cellulose and Since the hydrophilic polymer remains in the form of a sheet as it is, patterning can be performed without causing unevenness in the overall film thickness. Hereinafter, the present embodiment will be described in more detail.

＜Fine fibrous cellulose＞ The radiation-sensitive sheet of the present embodiment contains fine fibrous cellulose. The fine fibrous cellulose is fibrous cellulose having a fiber width of 1,000 nm or less. In addition, the fiber width of fibrous cellulose can be measured by electron microscope observation etc., for example. The fiber width of the fine fibrous cellulose is 1,000 nm or less. The fiber width of the fine fibrous cellulose is, for example, preferably 2 nm or more and 1,000 nm or less, more preferably 2 nm or more and 100 nm or less, still more preferably 2 nm or more and 50 nm or less, still more preferably 2 nm or more and 30 nm or less, particularly preferably 2 nm or more and 10 nm or less. By setting the fiber width of the fine fibrous cellulose to be 2 nm or more, dissolution in water as a cellulose molecule can be suppressed, and the effects of improving strength, rigidity, and dimensional stability by the fine fibrous cellulose are more likely to be exhibited.

The average fiber width of the fine fibrous cellulose is, for example, 1,000 nm or less. The average fiber width of the fine fibrous cellulose is preferably 2 nm or more and 1,000 nm or less, more preferably 2 nm or more and 100 nm or less, still more preferably 2 nm or more and 50 nm or less, still more preferably 2 nm or more and 30 nm or less, particularly preferably 2 nm or more and 10 nm or less. By setting the average fiber width of the fine fibrous cellulose to be 2 nm or more, the dissolution in water as cellulose molecules can be suppressed, and the effects of improving the strength, rigidity, and dimensional stability of the fine fibrous cellulose are more easily exhibited. . In addition, the fine fibrous cellulose is, for example, monofilament cellulose.

The average fiber width of the fine fibrous cellulose is measured as follows using, for example, an electron microscope. First, an aqueous suspension of fibrous cellulose with a concentration of 0.05 mass % or more and 0.1 mass % or less is prepared, and the suspension is cast on a carbon film-coated grid that has undergone a hydrophilization treatment, as a transmission electron microscope ( Transmission Electron Microscope, TEM) observation sample. In the case of including broad fibers, a Scanning Electron Microscope (SEM) image of the surface cast on glass can also be observed. Next, according to the width of the fiber to be observed, the electron microscope image was observed at any magnification of 1,000 times, 5,000 times, 10,000 times, or 50,000 times. However, the sample, observation conditions, and magnification were adjusted so as to satisfy the following conditions. (1) A straight line X is drawn at an arbitrary position in the observed image, and 20 or more fibers intersect the straight line X. (2) A straight line Y perpendicular to the straight line is drawn in the same image, and 20 or more fibers intersect the straight line Y.

The width of the fiber intersecting with the straight line X and the straight line Y is visually read for the observation image satisfying the above-mentioned conditions. As described above, at least three or more sets of observation images of surface portions that do not overlap each other are obtained. Next, the widths of the fibers intersecting the straight line X and the straight line Y are read for each image. Thereby, at least 20×2×3=120 fiber widths are read. And the average value of the fiber widths read was made into the average fiber width of fibrous cellulose.

The fiber length of the fine fibrous cellulose is not particularly limited, but is preferably, for example, 0.1 μm or more and 1,000 μm or less, more preferably 0.1 μm or more and 800 μm or less, and still more preferably 0.1 μm or more and 600 μm or less. By setting the fiber length within the above-mentioned range, the breakage of the crystal region of the fine fibrous cellulose can be suppressed. In addition, the slurry viscosity of the fine fibrous cellulose can also be adjusted to an appropriate range. In addition, the fiber length of the fine fibrous cellulose can be calculated|required by image analysis by TEM, SEM, atomic force microscope (AFM), for example.

The fine fibrous cellulose preferably has an I-type crystal structure. Here, the fine fibrous cellulose has a type I crystal structure and can be identified in the diffraction distribution by using a wide-angle X-ray diffraction photograph of CuKα (λ=1.5418 Å) monochromated with graphite and obtained. Specifically, it can be identified by having typical peaks at two positions in the vicinity of 2θ=14° or more and 17° or less and 2θ=22° or more and 23° or less. The proportion of the I-type crystal structure in the fine fibrous cellulose is, for example, preferably 30% or more, more preferably 40% or more, and still more preferably 50% or more. Thereby, in terms of exhibiting heat resistance and a low coefficient of linear thermal expansion, more excellent performance can be expected. Regarding the degree of crystallinity, the X-ray diffraction distribution was measured and obtained from the pattern by a conventional method (Seagal et al., Textile Research Journal, vol. 29, p. 786, 1959).

The axial ratio (fiber length/fiber width) of the fine fibrous cellulose is not particularly limited, but is, for example, preferably 20 or more and 10,000 or less, and more preferably 50 or more and 1,000 or less. By making the axial ratio equal to or more than the above lower limit value, it becomes easy to form a sheet containing fine fibrous cellulose. In addition, it is easy to obtain sufficient viscosity increase when preparing a solvent dispersion. By setting the axial ratio to be equal to or less than the above upper limit value, for example, when the fine fibrous cellulose is treated as an aqueous dispersion, operations such as dilution can be easily performed, which is preferable in this respect.

The fine fibrous cellulose of the present embodiment has, for example, at least one of an ionic group and a nonionic group. It is more preferable that the fine fibrous cellulose has an ionic group from the viewpoint of improving the dispersibility of the fibers in the dispersion medium and improving the defibrating efficiency in the defibrating treatment. As an ionic substituent, either or both of an anionic group and a cationic group may be contained, for example. In this embodiment, it is especially preferable to have an anionic group as an ionic substituent. In addition, the ionic substituent is preferably a group linked to fibrous cellulose via an ester bond. In this case, the ester bond is formed by dehydration condensation of the fibrous cellulose and the compound as an ionic substituent. In addition, the process of introducing an ionic group into the fine fibrous cellulose may not be performed.

The anionic group as an ionic group includes, for example, a phosphorus oxyacid group, a substituent derived from a phosphorus oxyacid group (sometimes simply referred to as a phosphorus oxyacid group), a carboxyl group, or a substitution derived from a carboxyl group. group (sometimes abbreviated as carboxyl group), sulfur oxyacid group or substituent derived from sulfur oxyacid group (sometimes abbreviated as sulfur oxyacid group), xanthate group, phosphonium (phosphono) group, phosphino group, sulfonyl group, carboxyalkyl group, etc. Among them, the anionic group is preferably selected from phosphorus oxyacid group, substituent derived from phosphorus oxyacid group, carboxyl group, sulfur oxyacid group, substituent derived from sulfur oxyacid group, carboxymethyl group, At least one of the group consisting of sulfoxides, more preferably selected from phosphorus oxyacid groups, substituents derived from phosphorus oxyacid groups, carboxyl groups, sulfur oxyacid groups, and sulfur oxyacid groups At least one of the group consisting of the substituents of , particularly preferably a phosphorus oxyacid group. By introducing a phosphorus oxyacid group as an anionic group, the dispersibility of fibrous cellulose can be further improved even under alkaline conditions or acidic conditions, for example, and as a result, a high-strength and highly transparent sheet can be easily obtained. As a cationic group which is an ionic group, an ammonium group, a phosphonium group, a perionium group, etc. are mentioned, for example. Among them, the cationic group is preferably an ammonium group.

The phosphorus oxyacid group or the substituent derived from the phosphorus oxyacid group is, for example, a substituent represented by the following formula (1). A plurality of substituents represented by the following formula (1) may be introduced into each fibrous cellulose. In this case, the substituents represented by the following formula (1) introduced in plural may be the same or different, respectively. The phosphorus oxyacid group is a divalent functional group corresponding to, for example, a hydroxyl group removed from phosphoric acid. Specifically, it is a group represented by -PO ₃ H ₂ . Substituents derived from a phosphorus oxyacid group include substituents such as a phosphorus oxyacid group salt and a phosphorus oxyester group. In addition, a substituent derived from a phosphorus oxyacid group may be included in the fibrous cellulose as a group in which a phosphoric acid group is condensed (for example, a pyrophosphoric acid group). In addition, the phosphorus oxyacid group may be, for example, a phosphorous acid group (phosphonic acid group), and the substituent derived from the phosphorus oxyacid group may be a salt of a phosphite group, a phosphite group, or the like.

[hua 1]

In formula (1), a, b, and n are natural numbers, and m is an arbitrary number (where a=b×m). At least one of n α and α′ is O ⁻ , and the rest are R or OR. In addition, each of α and α' may be all O ⁻ . The n pieces of α may all be the same or may be different from each other. β ^b+ is a monovalent or higher cation including an organic substance or an inorganic substance.

R is hydrogen atom, saturated-straight-chain hydrocarbon group, saturated-branched-chain hydrocarbon group, saturated-cyclic hydrocarbon group, unsaturated-straight-chain hydrocarbon group, unsaturated-branched-chain hydrocarbon group, unsaturated-cyclic hydrocarbon group, aromatic groups, or derivatives thereof. Moreover, in Formula (1), n is preferably 1. In addition, α in the formula (1) may be a group derived from a cellulose molecular chain.

As a saturated-straight-chain hydrocarbon group, a methyl group, an ethyl group, a n-propyl group, a n-butyl group, etc. are mentioned, It does not specifically limit. Examples of the saturated-branched hydrocarbon group include isopropyl group, tertiary butyl group, and the like, and are not particularly limited. As a saturated-cyclic hydrocarbon group, a cyclopentyl group, a cyclohexyl group, etc. are mentioned, and it does not specifically limit. As an unsaturated-straight-chain hydrocarbon group, a vinyl group, an allyl group, etc. are mentioned, It does not specifically limit. As an unsaturated-branched hydrocarbon group, an isopropenyl group, a 3-butenyl group, etc. are mentioned, and it does not specifically limit. As an unsaturated-cyclic hydrocarbon group, a cyclopentenyl group, a cyclohexenyl group, etc. are mentioned, and it does not specifically limit. As an aromatic group, a phenyl group, a naphthyl group, etc. are mentioned, It does not specifically limit.

In addition, as a derivative group in R, a carboxyl group, a carboxylate group (-COO ^- ), a hydroxyl group, an amino group, an ammonium group, etc. are added or substituted to the main chain or side chain of the various hydrocarbon groups. The functional group in the state of at least one of the functional groups is not particularly limited. In addition, the number of carbon atoms constituting the main chain of R is not particularly limited, but is preferably 20 or less, more preferably 10 or less. By setting the number of carbon atoms constituting the main chain of R to the above-mentioned range, the molecular weight of the phosphorus oxyacid group can be set in an appropriate range, and it is easy to permeate into the fiber raw material, and the yield of fine cellulose fibers can also be improved. Furthermore, when a plurality of Rs are present in the formula (1) or when a plurality of substituents represented by the formula (1) are introduced into the fibrous cellulose, the plurality of Rs may be the same, respectively. different.

β ^b+ is a monovalent or higher cation including an organic substance or an inorganic substance. As a monovalent or more cation containing an organic substance, an organic onium ion is mentioned. As an organic onium ion, an organic ammonium ion and an organic phosphonium ion are mentioned, for example. Examples of the organic ammonium ions include aliphatic ammonium ions and aromatic ammonium ions, and examples of the organic phosphonium ions include aliphatic phosphonium ions and aromatic phosphonium ions. Examples of the monovalent or more cations including inorganic substances include ions of alkali metals such as sodium, potassium, and lithium, ions of divalent metals such as calcium and magnesium, hydrogen ions, and ammonium ions. These can also be used in combination of one or two or more. Furthermore, when a plurality of β ^b+ are present in (1) or when a plurality of substituents represented by the formula (1) are introduced into fibrous cellulose, the plurality of β ^b+ may be the same or the same. can be different. The monovalent or higher cation containing an organic substance or an inorganic substance is preferably a sodium or potassium ion that is not particularly limited to yellowing when heating a fiber raw material containing β ^b+ and is industrially easy to use.

As the phosphorus oxyacid group or the substituent derived from the phosphorus oxyacid group, more specifically, a phosphoric acid group (-PO ₃ H ₂ ), a salt of a phosphoric acid group, a phosphorous acid group (phosphonic acid group) (- PO ₂ H ₂ ), phosphite (phosphonic acid) salt. In addition, the phosphorus oxyacid group or the substituent derived from the phosphorus oxyacid group may be a phosphoric acid group condensed group (eg, a pyrophosphoric acid group), a phosphonic acid condensed group (eg, a polyphosphonic acid group), a phosphate ester group (eg Monomethyl phosphoric acid group, polyoxyethylidene alkyl phosphoric acid group), alkylphosphonic acid group (such as methylphosphonic acid group), etc.

In addition, the sulfur oxyacid group (sulfur oxyacid group or a substituent derived from a sulfur oxyacid group) is, for example, a substituent represented by the following formula (2). A plurality of substituents represented by the following formula (2) may be introduced into each fibrous cellulose. In this case, the substituents represented by the following formula (2) introduced in plural may be the same or different, respectively.

[hua 2]

In the structural formula, b and n are natural numbers, p is 0 or 1, and m is an arbitrary number (wherein, 1=b×m). In addition, when n is 2 or more, a plurality of p may be the same number or different numbers. In the structural formula, β ^b+ is a monovalent or higher cation containing an organic or inorganic substance. As a monovalent or more cation containing an organic substance, an organic onium ion is mentioned. As an organic onium ion, an organic ammonium ion and an organic phosphonium ion are mentioned, for example. Examples of the organic ammonium ions include aliphatic ammonium ions and aromatic ammonium ions, and examples of the organic phosphonium ions include aliphatic phosphonium ions and aromatic phosphonium ions. Examples of the monovalent or more cations including inorganic substances include ions of alkali metals such as sodium, potassium, and lithium, ions of divalent metals such as calcium and magnesium, hydrogen ions, and ammonium ions. In addition, when introducing a plurality of substituents represented by the formula (2) into the fibrous cellulose, the plurality of β ^b+ present may be the same or different, respectively. The monovalent or higher cation containing an organic substance or an inorganic substance is preferably a sodium or potassium ion that is not particularly limited to yellowing when heating a fiber raw material containing β ^b+ and is industrially easy to use.

Per 1 g (mass) of cellulose fibers, the introduction amount of the ionic group to the cellulose fibers is, for example, preferably 0.10 mmol/g or more, more preferably 0.20 mmol/g or more, and still more preferably 0.40 mmol/g or more , more preferably 0.50 mmol/g or more, still more preferably 0.60 mmol/g or more, and particularly preferably 1.00 mmol/g or more. In addition, per 1 g (mass) of cellulose fibers, the introduction amount of the ionic group to the cellulose fibers is, for example, preferably 5.20 mmol/g or less, more preferably 3.65 mmol/g or less, and still more preferably 3.50 mmol/g. g or less, more preferably 3.00 mmol/g or less. By making the introduction amount of an ionic group into the said range, refinement|miniaturization of a fiber raw material can be made easy, and the stability of a microfibrous cellulose can be improved. Moreover, by making the introduction amount of an ionic group into the said range, favorable characteristics can be exhibited in various uses, such as a thickener of fine fibrous cellulose. Here, the denominator in the unit mmol/g represents the mass of the fine fibrous cellulose when the opposite ion of the ionic group is a hydrogen ion (H ⁺ ).

The introduction amount of the ionic group to the fibrous cellulose can be measured, for example, by a neutralization titration method. In the measurement by the neutralization titration method, the introduced amount is measured by adding an alkali such as a sodium hydroxide aqueous solution to the obtained fibrous cellulose-containing slurry, and calculating the change in pH.

FIG. 1 is a graph showing the relationship between the dropwise addition amount of NaOH and pH with respect to a slurry containing fibrous cellulose having phosphorus oxyacid groups. The introduction amount of the phosphorus oxyacid group with respect to the fibrous cellulose is measured, for example, as follows. First, the pulp containing fibrous cellulose is treated with a strongly acidic ion exchange resin. In addition, if necessary, before the treatment with the strongly acidic ion exchange resin, a defibration treatment similar to the defibration treatment step described later may be performed on the measurement object. Next, while adding sodium hydroxide aqueous solution, the change of pH was observed, and the titration curve as shown in the upper part of FIG. 1 was obtained. In the titration curve shown in the upper part of Fig. 1, the pH measured with respect to the amount of alkali added is plotted, and in the titration curve shown in the lower part of Fig. 1, the pH relative to the amount of alkali added is plotted. Increment (differential value) (1/mmol). In this neutralization titration, in a curve plotting the pH measured with respect to the amount of alkali added, two points where the increments (differential value of pH with respect to the amount of alkali dropwise added) are extremely large were confirmed. Among these, the maximum point of the increase first obtained after adding the base is called the first end point, and the maximum point of the increase obtained next is called the second end point. The amount of alkali required from the beginning of the titration to the first end point is equal to the amount of the first dissociated acid of the fibrous cellulose contained in the slurry used for the titration, and the amount of alkali required from the first end point to the second end point is equal to the amount of the first dissociated acid of the fibrous cellulose contained in the slurry used for the titration. The amount of the second dissociated acid of the fibrous cellulose contained in the slurry used is equal, and the amount of alkali required from the beginning of the titration to the second end point is equal to the total amount of the fibrous cellulose contained in the slurry used for the titration. The amount of dissociated acid is equal. Furthermore, the value obtained by dividing the amount of alkali required from the start of the titration to the first end point by the solid content (g) in the slurry to be titrated is the phosphorus oxyacid group introduction amount (mmol/g). In addition, when it is abbreviated as the phosphorus oxyacid group introduction amount (or phosphorus oxyacid group amount), it shows the 1st dissociated acid amount. In addition, in FIG. 1, the area|region from a titration start to a 1st end point is called a 1st area, and the area|region from a 1st end point to a 2nd end point is called a 2nd area. For example, in the case where the phosphorus oxyacid group is a phosphoric acid group and the phosphoric acid group is condensed, the amount of weakly acidic groups of the phosphorus oxyacid group (also referred to as the second dissociated acid in this specification) The amount of alkali required in the second zone becomes smaller than the amount of alkali required in the first zone. On the other hand, the amount of the strong acid group of the phosphorus oxyacid group (also referred to as the amount of the first dissociated acid in this specification) corresponds to the amount of phosphorus atoms, regardless of the presence or absence of condensation. In addition, in the case where the phosphorus oxyacid group is a phosphorous acid group, there is no weak acid group in the phosphorus oxyacid group, so the amount of alkali required in the second region is reduced, or the amount of alkali required in the second region also changes. case of zero. In this case, in the titration curve, there is one point where the increase in pH is extremely large. In addition, in the said phosphorus oxyacid group introduction amount (mmol/g), the denominator represents the mass of the acid fibrous cellulose, and therefore represents the phosphorus oxyacid group amount (hereinafter, the It is called the amount of phosphorus oxyacid group (acid type)). On the other hand, when the counter ion of the phosphorus oxyacid group is substituted with an arbitrary cation C so as to have a charge equivalent, by changing the denominator to the mass of the fibrous cellulose when the cation C is the counter ion, The amount of phosphorus oxyacid groups (hereinafter, the amount of phosphorus oxyacid groups (C type)) contained in the fibrous cellulose in which the cation C is a counter ion can be determined. That is, it is calculated by the following calculation formula. The amount of phosphorus oxyacid groups (C type) = the amount of phosphorus oxyacid groups (acid type)/{1+(W-1)×A/1000} A [mmol/g]: Total amount of anions derived from phosphorus oxyacid groups contained in fibrous cellulose (value obtained by adding the amount of strong acid groups and weak acid groups of phosphorus oxyacid groups) W: formula weight per valence of cation C (eg, 23 for Na and 9 for Al)

2 is a graph showing the relationship between the dropwise amount of NaOH and pH with respect to fibrous cellulose having carboxyl groups. The introduction amount of the carboxyl group to the fibrous cellulose is measured, for example, as follows. First, the pulp containing fibrous cellulose is treated with a strongly acidic ion exchange resin. In addition, if necessary, before the treatment with the strongly acidic ion exchange resin, a defibration treatment similar to the defibration treatment step described later may be performed on the measurement object. Next, while adding sodium hydroxide aqueous solution, the change of pH was observed, and the titration curve as shown in FIG. 2 was obtained. In addition, if necessary, a defibration treatment similar to the defibration treatment step described later may be performed on the measurement object. As shown in FIG. 2 , in this neutralization titration, a point where the increase (differential value of pH with respect to the dropwise addition amount of the alkali) is extremely large was observed in a curve plotting the pH measured with respect to the amount of alkali added. . The maximum point of this increment is called the first end point. Here, the region from the start of the titration to the first end point in FIG. 2 is referred to as the first region. The amount of alkali required in the first zone is equal to the amount of carboxyl groups in the slurry used for the titration. Then, the amount of the introduced carboxyl group (mmol/ g). In addition, the said carboxyl group introduction amount (mmol/g) represents the amount of substituents per 1 g mass of fibrous cellulose when the opposite ion of the carboxyl group is hydrogen ion (H ⁺ ) (hereinafter, referred to as the amount of carboxyl groups (acid type). )).

In addition, in the said carboxyl group introduction amount (mmol/g), since the denominator is the mass of acid-type fibrous cellulose, it represents the amount of carboxyl groups (hereinafter, referred to as the amount of carboxyl groups (acid-type)) possessed by acid-type fibrous cellulose. ). On the other hand, when the counter ion of the carboxyl group is substituted with an arbitrary cation C so as to be a charge equivalent, the cation can be obtained by converting the denominator to the mass of the fibrous cellulose when the cation C is the counter ion. C is the amount of carboxyl groups (hereinafter, the amount of carboxyl groups (C type)) (mmol/g) that the fibrous cellulose of the counterion has. That is, it is calculated by the following calculation formula. Amount of carboxyl group (C type) = amount of carboxyl group (acid type)/{1+(W-1) × (amount of carboxyl group (acid type))/1000} W: formula weight per valence of cation C (eg, 23 for Na and 9 for Al)

Furthermore, in the measurement of the amount of substituents by the titration method, when the dropwise amount of one drop of sodium hydroxide aqueous solution is too large, or when the titration interval is too short, it may not be possible to obtain the originally lower amount of substituents. and other exact values. As an appropriate dropping amount and titration interval, for example, it is desirable to titrate 10 μL to 50 μL of a 0.1 N aqueous sodium hydroxide solution every 5 seconds to 30 seconds. In addition, in order to eliminate the influence of carbon dioxide dissolved in the fibrous cellulose-containing slurry, it is desirable to measure, for example, from 15 minutes before the start of the titration to the end of the titration while blowing an inert gas such as nitrogen into the slurry Wait.

In addition, the introduction amount of the sulfur oxyacid group to the fibrous cellulose is obtained by wet-ashing the obtained fibrous cellulose with perchloric acid and concentrated nitric acid, and then diluting it at an appropriate ratio. Inductively coupled plasma (ICP) luminescence analysis was used to determine the amount of sulfur. The value obtained by dividing this sulfur amount by the absolute dry mass of the fibrous cellulose used for the test was taken as sulfur oxyacid group (unit: mmol/g).

The measurement of the amount of ionic groups by the method described above is suitable for fine fibrous cellulose with a fiber width of 1,000 nm or less, and is preferably used when measuring the amount of ionic groups in pulp fibers with a fiber width of more than 1,000 nm. The measurement is performed after the pulp fibers are made finer.

[Production method of fine fibrous cellulose] (fiber material containing cellulose) Microfibrous cellulose is produced from a fiber raw material containing cellulose. Although it does not specifically limit as a fiber raw material containing cellulose, It is preferable to use pulp from a point which is easy to obtain and inexpensive. As pulp, for example, wood pulp, non-wood pulp, and deinked pulp can be mentioned. Although it does not specifically limit as wood pulp, For example, hardwood kraft pulp (leaf bleached kraft pulp, LBKP), softwood kraft pulp (Needle Bleached Kraft Pulp, NBKP), sulfite pulp (sulfite pulp, SP), dissolving pulp (dissolving pulp, DP), sodium-alkali pulp (alkaline pulp (Alkaline Pulp, AP)), unbleached kraft pulp (Unbleached Kraft Pulp, UKP) and oxygen-bleached kraft pulp (oxygen-bleached kraft pulp, OKP) and other chemical pulps ; Semi-chemical pulp (Semi-Chemical Pulp, SCP) and chemical ground wood pulp (Chemical-ground wood pulp, CGP) and other semi-chemical pulp; ground wood pulp (Ground Pulp, GP) and thermomechanical pulp (thermomechanical pulp (Thermo-Mechanical Pulp, TMP), bleached chemi-thermo-mechanical pulp (bleached chemi-thermo-mechanical pulp, BCTMP)) and other mechanical pulps. Although it does not specifically limit as non-wood pulp, For example, cotton-based pulps, such as cotton linters (cotton lint) and lint (cotton lint); Non-wood-based pulps, such as hemp, straw, bamboo, and bagasse, are mentioned. Although it does not specifically limit as deinking pulp, For example, the deinking pulp which uses waste paper as a raw material is mentioned. The pulp of the present embodiment may be used alone or in combination of two or more. Among these pulps, from the viewpoint of availability, for example, wood pulp and deinked pulp are preferred. In addition, in wood pulp, the cellulose ratio is large, and the yield of fine fibrous cellulose at the time of defibration treatment is high, and the decomposition of cellulose in the pulp is small, and the fine fibrous long fibers with a large axial ratio are obtained. From the viewpoint of cellulose, for example, chemical pulp is more preferred, and kraft pulp and sulfite pulp are further preferred. Furthermore, when the fine fibrous cellulose of long fibers having a large axial ratio is used, the viscosity tends to increase. As a fiber raw material containing cellulose, for example, cellulose contained in sea squirts and bacterial (bacteria) cellulose produced by acetic acid bacteria can also be used. In addition, instead of the fiber raw material containing cellulose, fibers formed of linear nitrogen-containing polysaccharide polymers such as chitin and chitosan may be used.

In order to obtain the above-mentioned ionic group-introduced fine fibrous cellulose, an ionic group introduction step of introducing an ionic group into the cellulose-containing fiber raw material, a washing step, and an alkali treatment are preferably included in this order. The step (neutralization step) and the defibration treatment step can also replace the cleaning step, or include an acid treatment step in addition to the cleaning step. As the ionic group introduction step, a phosphorus oxyacid group introduction step and a carboxyl group introduction step can be exemplified. Hereinafter, each will be described.

(Ionic group introduction step) -Phosphorus oxyacid group introduction step- In the step of introducing phosphorus oxyacid groups, at least one compound (hereinafter, also referred to as "compound A") selected from the group consisting of compounds capable of introducing phosphorus oxyacid groups by reacting with the hydroxyl groups of the fiber raw material containing cellulose ), acting on the cellulose-containing fibrous feedstock. Through this step, a phosphorus oxyacid group-introduced fiber can be obtained. In the phosphorus oxyacid group introduction step of the present embodiment, a fiber raw material and a compound containing cellulose may be carried out in the presence of at least one selected from the group consisting of urea and its derivatives (hereinafter, also referred to as "compound B"). A's response. On the other hand, the reaction of the fiber raw material containing cellulose and the compound A may be performed in a state in which the compound B does not exist. As an example of the method of making the compound A act on the fiber raw material in the coexistence with the compound B, the method of mixing the compound A and the compound B with respect to the fiber raw material in a dry state, a wet state, or a pulp state is mentioned. Among these, since the uniformity of the reaction is high, it is preferable to use a fiber raw material in a dry state or a wet state, and it is particularly preferable to use a fiber raw material in a dry state. The form of the fiber raw material is not particularly limited, but, for example, a cotton form or a sheet form is preferable. A method of adding the compound A and the compound B to the fiber raw material in the form of a powder, a solution dissolved in a solvent, or a state in which the compound A and the compound B are melted by heating to a melting point or higher, respectively, can be mentioned. Among these, since the uniformity of reaction is high, it is preferable to add in the state of the solution melt|dissolved in a solvent, especially the state of an aqueous solution. In addition, the compound A and the compound B may be added simultaneously to the fiber raw material, may be added separately, or may be added as a mixture. The method for adding the compound A and the compound B is not particularly limited, and when the compound A and the compound B are in the form of a solution, the fiber raw material may be immersed in the solution and taken out after liquid absorption, or it may be dropped into the fiber raw material. Add solution. In addition, a necessary amount of Compound A and Compound B can be added to the fiber raw material, or after adding an excess amount of Compound A and Compound B to the fiber raw material, the remaining Compound A and Compound can be removed by extrusion or filtration. B.

The compound A used in the present embodiment may be any compound that has a phosphorus atom and can form an ester bond with cellulose, and examples thereof include phosphoric acid or its salt, phosphorous acid or its salt, dehydrated condensed phosphoric acid or its salt, and anhydrous phosphoric acid. (phosphorus pentoxide) and the like, but are not particularly limited. As phosphoric acid, phosphoric acid of various purity can be used, for example, 100% phosphoric acid (orthophosphoric acid) and 85% phosphoric acid can be used. As phosphorous acid, 99% phosphorous acid (phosphonic acid) is mentioned, for example. The dehydration condensed phosphoric acid is a phosphoric acid in which two or more molecules are condensed by a dehydration reaction, and examples thereof include pyrophosphoric acid, polyphosphoric acid, and the like. Examples of phosphates, phosphites, and dehydrated condensed phosphates include phosphoric acid, phosphorous acid, or lithium salts, sodium salts, potassium salts, ammonium salts of dehydrated condensed phosphoric acid, and the like, and these can be set to various degrees of neutralization. Among these, phosphoric acid and sodium salts of phosphoric acid are preferred from the viewpoints of high introduction efficiency of phosphorus oxyacid groups, easier improvement of defibration efficiency in the defibration step described later, low cost, and easy industrial application , potassium salt of phosphoric acid, or ammonium salt of phosphoric acid, more preferably phosphoric acid, sodium dihydrogen phosphate, disodium hydrogen phosphate, or ammonium dihydrogen phosphate. The amount of compound A added to the fiber raw material is not particularly limited. For example, when the added amount of compound A is converted to phosphorus atomic weight, the added amount of phosphorus atom to the fiber raw material (absolute dry mass) is preferably 0.5% by mass. It is more than 100 mass %, More preferably, it is 1 mass % or more and 50 mass % or less, More preferably, it is 2 mass % or more and 30 mass % or less. The yield of fine fibrous cellulose can be further improved by making the addition amount of phosphorus atoms with respect to the fiber raw material within the above-mentioned range. On the other hand, by making the addition amount of phosphorus atoms with respect to a fiber raw material below the said upper limit, the balance between the effect of a yield improvement and cost can be acquired.

The compound B used in this embodiment is at least one selected from the group consisting of urea and derivatives thereof as described above. As compound B, urea, biuret, 1-phenylurea, 1-benzylurea, 1-methylurea, 1-ethylurea, etc. are mentioned, for example. From the viewpoint of improving the uniformity of the reaction, Compound B is preferably used as an aqueous solution. In addition, from the viewpoint of further improving the uniformity of the reaction, it is preferable to use an aqueous solution in which both the compound A and the compound B are dissolved. The amount of compound B added relative to the fiber raw material (absolute dry mass) is not particularly limited, but is preferably, for example, 1 mass % or more and 500 mass % or less, more preferably 10 mass % or more and 400 mass % or less, and still more preferably 100 mass %. mass % or more and 350 mass % or less.

In the reaction between the cellulose-containing fiber raw material and the compound A, in addition to the compound B, for example, amides or amines may also be included in the reaction system. As amides, carboxamide, dimethylformamide, acetamide, dimethylacetamide, etc. are mentioned, for example. Examples of the amines include methylamine, ethylamine, trimethylamine, triethylamine, monoethanolamine, diethanolamine, triethanolamine, pyridine, ethylenediamine, and hexamethylenediamine. Among these, especially triethylamine is known to function as a good reaction catalyst.

In the step of introducing a phosphorus oxyacid group, it is preferable to add or mix the compound A or the like to the fiber raw material, and then subject the fiber raw material to heat treatment. As the heat treatment temperature, it is preferable to select a temperature that can efficiently introduce phosphorus oxyacid groups while suppressing the thermal decomposition or hydrolysis reaction of the fibers. The heat treatment temperature is, for example, preferably 50°C or higher and 300°C or lower, more preferably 100°C or higher and 250°C or lower, and still more preferably 130°C or higher and 200°C or lower. In addition, equipment having various heat mediums can be used for the heat treatment. For example, a stirring drying apparatus, a rotary drying apparatus, a disc drying apparatus, a roll heating apparatus, a plate heating apparatus, a fluidized bed drying apparatus, and a belt drying apparatus can be used. , filter drying device, vibration flow drying device, airflow drying device, vacuum drying device, infrared heating device, far infrared heating device, microwave heating device, high frequency drying device.

In the heat treatment of the present embodiment, for example, a method of adding the compound A to the sheet-like fiber raw material by means of impregnation or the like and then heating, or kneading or stirring the fiber raw material and the compound A with a kneader or the like can be used. method of heating at the same time. Thereby, the concentration unevenness of the compound A in the fiber raw material can be suppressed, and the phosphorus oxyacid group can be introduced into the surface of the cellulose fiber contained in the fiber raw material more uniformly. The reason for this is considered to be that when the water molecules move to the surface of the fiber raw material with drying, the dissolved compound A is attracted by the water molecules due to surface tension, and the movement to the surface of the fiber raw material is also suppressed (that is, the occurrence of uneven concentration of the compound A). ). In addition, the heating device used for the heat treatment is preferably, for example, a device capable of dehydrating condensation (phosphoric acid esterification) of the moisture held in the slurry and the accompanying compound A with hydroxyl groups contained in cellulose and the like in the fiber raw material. The moisture generated by the reaction is continuously discharged to the outside of the device system. As such a heating apparatus, the oven of a ventilation system etc. are mentioned, for example. By continuously discharging the moisture in the apparatus system, in addition to suppressing the hydrolysis reaction of the phosphate bond, which is the reverse reaction of phosphorylation, the acid hydrolysis of the sugar chain in the fiber can be suppressed. Therefore, fine fibrous cellulose having a high axial ratio can be obtained. The time for the heat treatment is, for example, preferably 1 second or more and 300 minutes or less, more preferably 1 second or more and 1,000 seconds or less, and still more preferably 10 seconds or more and 800 seconds or less, from the time when moisture is substantially removed from the fiber raw material. In the present embodiment, by setting the heating temperature and the heating time in an appropriate range, the introduction amount of the phosphorus oxyacid group can be set within a preferable range.

The phosphorus oxyacid group introduction step may be performed at least once, but may be repeated twice or more. By performing the phosphorus oxyacid group introduction step twice or more, a large amount of phosphorus oxyacid groups can be introduced into the fiber raw material. In this embodiment, as an example of a preferable form, the case where a phosphorus oxyacid group introduction process is performed twice is mentioned.

Per 1 g (mass) of fine fibrous cellulose, the introduction amount of phosphorus oxyacid groups to the fiber raw material is, for example, preferably 0.10 mmol/g or more, more preferably 0.20 mmol/g or more, and still more preferably 0.50 mmol/g /g or more, particularly preferably 1.00 mmol/g or more. In addition, per 1 g (mass) of fine fibrous cellulose, the introduction amount of phosphorus oxyacid groups to the fiber raw material is preferably, for example, 5.20 mmol/g or less, more preferably 3.65 mmol/g or less, and still more preferably 3.00 mmol/g or less. By setting the introduction amount of the phosphorus oxyacid group within the above range, the miniaturization of the fiber raw material can be facilitated, and the stability of the fine fibrous cellulose can be improved.

-Carboxyl group introduction step- The carboxyl group introduction step is performed by subjecting the cellulose-containing fiber raw material to the following treatments: ozone oxidation, oxidation by the Fenton method, 2,2,6,6-tetramethylpiperidine-1-oxygen Oxidation treatment such as radical (2,2,6,6-tetramethylpiperidine-1-oxyl, TEMPO) oxidation treatment; The anhydrides of the compounds or their derivatives are treated. The compound having a group derived from a carboxylic acid is not particularly limited, and examples thereof include dicarboxylic acids such as maleic acid, succinic acid, phthalic acid, fumaric acid, glutaric acid, adipic acid, and itaconic acid. Acid compounds or tricarboxylic acid compounds such as citric acid and aconitic acid. Moreover, it does not specifically limit as a derivative of the compound which has a group derived from a carboxylic acid, For example, the imidate of the acid anhydride of the compound which has a carboxyl group, and the derivative of the acid anhydride of the compound which has a carboxyl group are mentioned. The imide compound of an acid anhydride of a compound having a carboxyl group is not particularly limited, and examples thereof include imide compounds of dicarboxylic acid compounds such as maleimide, succinimide, and phthalimide. .

The acid anhydride of the compound having a carboxylic acid-derived group is not particularly limited, and examples thereof include dicarboxylic acids such as maleic anhydride, succinic anhydride, phthalic anhydride, glutaric anhydride, adipic anhydride, and itaconic anhydride. Anhydrides of compounds. Moreover, it does not specifically limit as a derivative of the acid anhydride of the compound which has a group derived from a carboxylic acid, For example, dimethylmaleic anhydride, diethylmaleic anhydride, diphenylmaleic anhydride, etc. which have a carboxyl group are mentioned. In the acid anhydride of the compound, at least a part of hydrogen atoms are substituted with substituents such as an alkyl group and a phenyl group.

In the carboxyl group introduction step, when the TEMPO oxidation treatment is performed, it is preferable to perform the treatment under the conditions of pH 6 or more and 8 or less, for example. This treatment is also known as neutral TEMPO oxidation treatment. Neutral TEMPO oxidation treatment can be carried out, for example, by adding pulp as a fiber raw material and TEMPO (2,2,6,6-tetramethylpiperidine-1-oxygen free) as a catalyst to a sodium phosphate buffer (pH=6.8). nitroxy radicals such as radicals) and sodium hypochlorite as a sacrificial reagent. Furthermore, by coexisting sodium chlorite, the aldehyde generated in the oxidation process can be efficiently oxidized to the carboxyl group. In addition, the TEMPO oxidation treatment may be performed under the conditions of pH 10 or more and 11 or less. This treatment is also known as alkaline TEMPO oxidation treatment. The alkaline TEMPO oxidation treatment can be performed, for example, by adding nitroxide radicals such as TEMPO as a catalyst, sodium bromide as a cocatalyst, and sodium hypochlorite as an oxidizing agent to pulp as a fiber raw material. The amount of the carboxyl group to be introduced to the fiber material also varies depending on the type of the substituent. For example, when the carboxyl group is introduced by TEMPO oxidation, it is preferably 0.10 mmol/1 g (mass) of fine fibrous cellulose. g or more, more preferably 0.20 mmol/g or more, still more preferably 0.50 mmol/g or more, particularly preferably 0.90 mmol/g or more. Moreover, 2.5 mmol/g or less is preferable, 2.20 mmol/g or less is more preferable, and 2.00 mmol/g or less is still more preferable. Moreover, when a substituent is a carboxymethyl group, it may be 5.8 mmol/g or less per 1 g (mass) of fine fibrous cellulose.

-Sulfur oxoacid group introduction step- As an ionic substituent introduction step, a sulfur oxyacid group introduction step may be included. In the sulfur oxyacid group introduction step, cellulose fibers having sulfur oxyacid groups (sulfur oxyacid group-introduced fibers) can be obtained by reacting the hydroxyl groups of the fiber raw material containing cellulose with sulfur oxyacids.

In the sulfur oxyacid group introduction step, at least one compound (hereinafter, also referred to as "compound C") selected from the group consisting of compounds capable of introducing sulfur oxyacid groups by reacting with the hydroxyl groups of the cellulose-containing fiber raw material is used. ") in place of Compound A in the <Step of introducing phosphorus oxyacid group>. The compound C may be any compound as long as it has a sulfur atom and can form an ester bond with cellulose, and examples thereof include sulfuric acid or a salt thereof, sulfurous acid or a salt thereof, and amide sulfate, but are not particularly limited. As sulfuric acid, sulfuric acid of various purity can be used, for example, 96% sulfuric acid (concentrated sulfuric acid) can be used. As sulfurous acid, 5% sulfurous acid water is mentioned. Examples of the sulfate or sulfite include lithium, sodium, potassium, and ammonium salts of sulfate or sulfite, and these can be set to various degrees of neutralization. As amide sulfate, sulfamic acid or the like can be used. In the sulfur oxoacid group introduction step, it is preferable to use the compound B in the above-mentioned <phosphorus oxoacid group introduction step> in the same manner.

In the sulfur oxyacid group introduction step, it is preferable to heat-treat the cellulose raw material after mixing an aqueous solution containing sulfur oxyacid and urea and/or a urea derivative with the cellulose raw material. As the heat treatment temperature, it is preferable to select a temperature that can efficiently introduce sulfur oxyacid groups while suppressing the thermal decomposition or hydrolysis reaction of the fibers. The heat treatment temperature is preferably 100°C or higher, more preferably 120°C or higher, and still more preferably 150°C or higher. In addition, the heat treatment temperature is preferably 300°C or lower, more preferably 250°C or lower, and still more preferably 200°C or lower.

In the heat treatment step, it is preferable to heat until the moisture substantially disappears. Therefore, the heat treatment time varies depending on the amount of water contained in the cellulose raw material or the amount of addition of the aqueous solution containing sulfur oxyacids and urea and/or urea derivatives, but is preferably 10 seconds or more and 10,000 seconds, for example. the following. For the heat treatment, equipment having various heating media can be used, for example, hot air drying apparatus, stirring drying apparatus, rotary drying apparatus, disc drying apparatus, roll heating apparatus, plate heating apparatus, fluidized bed drying apparatus, belt drying apparatus can be used. Drying device, filter drying device, vibration flow drying device, airflow drying device, vacuum drying device, infrared heating device, far infrared heating device, microwave heating device, high frequency drying device.

The introduction amount of sulfur oxoacid groups with respect to the cellulose raw material is preferably 0.05 mmol/g or more, more preferably 0.10 mmol/g or more, still more preferably 0.20 mmol/g or more, and still more preferably 0.40 mmol/g or more, Particularly preferred is 0.50 mmol/g or more. In addition, the introduction amount of sulfur oxyacid groups with respect to the cellulose raw material is preferably 5.00 mmol/g or less, more preferably 3.00 mmol/g or less. By setting the introduction amount of the sulfur oxyacid group within the above-mentioned range, the micronization of the cellulose fibers in the micronization treatment step can be facilitated, and the stability of the microfibrous cellulose can be improved.

-Oxidation step with chlorine-based oxidizing agent (second carboxyl group introduction step)- As the ionic substituent introduction step, an oxidation step using a chlorine-based oxidizing agent may be included. In the oxidation step using the chlorine-based oxidizing agent, the carboxyl group can be introduced into the fiber raw material by adding the chlorine-based oxidizing agent to the fiber raw material having a hydroxyl group in a wet or dry state and reacting.

As a chlorine-type oxidizing agent, hypochlorous acid, hypochlorite, chlorous acid, chlorite, chloric acid, chlorate, perchloric acid, perchlorate, chlorine dioxide, etc. are mentioned. The chlorine-based oxidizing agent is preferably sodium hypochlorite, sodium chlorite, and chlorine dioxide in terms of the efficiency of introducing the substituent, furthermore, the defibration efficiency, cost, and ease of handling. When adding a chlorine-based oxidant, it can be directly added to the fiber raw material as a reagent (solid or liquid), or it can be dissolved in an appropriate solvent.

The concentration of the chlorine-based oxidizing agent in the solution in the oxidation step using the chlorine-based oxidizing agent is, for example, converted into an available chlorine concentration, preferably 1 mass % or more and 1,000 mass % or less, more preferably 5 mass % or more and 500 mass % or less, More preferably, it is 10 mass % or more and 100 mass % or less. The amount of chlorine-based oxidizing agent added relative to 100 parts by mass of the fiber raw material is preferably 1 part by mass or more and 100,000 parts by mass or less, more preferably 10 parts by mass or more and 10,000 parts by mass or less, and still more preferably 100 parts by mass or more and 5,000 parts by mass the following.

The reaction time with the chlorine-based oxidizing agent in the oxidation step using the chlorine-based oxidizing agent may vary depending on the reaction temperature, but is preferably, for example, 1 minute or more and 1,000 minutes or less, more preferably 10 minutes or more and 500 minutes or less, and still more preferably 20 minutes. minutes or more and 400 minutes or less. The pH during the reaction is preferably 5 or more and 15 or less, more preferably 7 or more and 14 or less, and still more preferably 9 or more and 13 or less. In addition, at the start of the reaction, the pH during the reaction is preferably kept constant (for example, pH 11) while adding hydrochloric acid or sodium hydroxide as appropriate. In addition, after the reaction, the remaining reaction reagents, by-products, etc. may be washed and removed by filtration or the like.

-Xanthogen ester group introduction step (xanthogen esterification step)- As an ionic substituent group introduction step, for example, a xanthate group introduction step (hereinafter, also referred to as a xanthate esterification step) may be included. In the xanthate esterification step, a xanthate group can be introduced into the fiber raw material by adding carbon disulfide and an alkali compound to the fiber raw material having a hydroxyl group in a wet or dry state and reacting. Specifically, carbon disulfide is added to the alkali cellulose-based fiber raw material by the method described later, and the reaction is carried out.

＜＜Alkaline cellulose＞＞ When introducing an ionic substituent into a fiber raw material, it is preferable to cause an alkali solution to act on the cellulose contained in the fiber raw material to alkalize the cellulose. By this treatment, a part of the hydroxyl groups of cellulose is ionically dissociated, and the nucleophilicity (reactivity) can be improved. The alkali compound contained in the alkali solution is not particularly limited, and may be an inorganic alkali compound or an organic alkali compound. In terms of high versatility, for example, sodium hydroxide, potassium hydroxide, tetraethylammonium hydroxide, and tetrabutylammonium hydroxide are preferably used. Alkali cellulose formation may be carried out simultaneously with the introduction of the ionic substituent, may be carried out as the preceding stage, or may be carried out at two timings.

The solution temperature at the time of starting alkali cellulose formation is preferably 0°C or higher and 50°C or lower, more preferably 5°C or higher and 40°C or lower, and still more preferably 10°C or higher and 30°C or lower.

The alkali concentration in the alkali solution is preferably 0.01 mol/L or more and 4 mol/L or less in terms of molar concentration, more preferably 0.1 mol/L or more and 3 mol/L or less, and still more preferably 1 mol/L or more and below 2.5 mol/L. In particular, when the treatment temperature of alkali cellulose is lower than 10° C., the alkali concentration is preferably 1 mol/L or more and 2 mol/L or less.

The treatment time for alkali cellulose formation is preferably 1 minute or more, more preferably 10 minutes or more, and still more preferably 30 minutes or more. In addition, the time of the alkali treatment is preferably 6 hours or less, more preferably 5 hours or less, and still more preferably 4 hours or less.

By adjusting the type, treatment temperature, concentration, and immersion time of the alkaline solution as described above, the penetration of the alkaline solution into the cellulose crystal region can be suppressed, the cellulose I-type crystal structure can be easily maintained, and the microfibrillar cellulose can be improved. yield.

When the introduction of the ionic substituent and the alkali cellulose formation are not performed at the same time, the alkali cellulose formation is preferably performed in the preceding stage of the introduction of the ionic substituent. In this case, the alkali cellulose obtained by the alkali cellulose treatment is preferably subjected to solid-liquid separation by a general deliquoring method such as centrifugal separation or filtration separation, and moisture is removed in advance. Thereby, the reaction efficiency in the ionic substituent introduction process performed next improves. The cellulose fiber concentration after solid-liquid separation is preferably 5% or more and 50% or less, more preferably 10% or more and 40% or less, and still more preferably 15% or more and 35% or less.

-Step of introducing a phosphino group or a phosphino group (step of phosphine alkylation)- As a step of introducing an ionic substituent, a step of introducing a phosphino group or a phosphino group (step of phosphine alkylation) may be included. In the phosphine alkylation step, a compound having a reactive group and a phosphine group or a phosphine group (compound E _A ) as an essential component, and an optional base compound selected from the group consisting of urea and its derivatives The compound B is added to the fiber raw material having a hydroxyl group in a wet or dry state for reaction, and a phosphine group or a phosphine group can be introduced into the fiber raw material.

As a reactive group, a halogenated alkyl group, a vinyl group, an epoxy group (glycidyl group), etc. are mentioned. As compound EA, vinylphosphonic acid, phenylvinylphosphonic acid, _{phenylvinylphosphinic} acid, etc. are mentioned, for example. _The compound EA is preferably vinylphosphonic acid from the viewpoints of the efficiency of introducing a substituent, further defibrating efficiency, cost, and ease of handling. Furthermore, as an optional component, it is also preferable to use the compound B in the above-mentioned <step of introducing a phosphorus oxyacid group> in the same manner, and the addition amount is also preferably as described above.

When compound EA is added, it can be directly added to the fiber raw material as _a reagent (solid or liquid), or it can be added by dissolving it in an appropriate solvent. The fiber raw material is preferably alkali cellulose-formed in advance, or alkali-cellulose-formed at the same time as the reaction. The method of alkali cellulose is as described above.

The temperature during the reaction is, for example, preferably 50°C or higher and 300°C or lower, more preferably 100°C or higher and 250°C or lower, and still more preferably 130°C or higher and 200°C or lower.

_The amount of compound EA added relative to 100 parts by mass of the fiber raw material is preferably 1 part by mass or more and 100,000 parts by mass or less, more preferably 2 parts by mass or more and 10,000 parts by mass or less, still more preferably 5 parts by mass or more and 1,000 parts by mass the following.

The reaction time may vary depending on the reaction temperature, but is preferably, for example, 1 minute or more and 1,000 minutes or less, more preferably 10 minutes or more and 500 minutes or less, and still more preferably 20 minutes or more and 400 minutes or less. In addition, after the reaction, the remaining reaction reagents, by-products, etc. may be washed and removed by filtration or the like.

-Step of introducing a sulfonyl group (sulfoalkylation step) (second step of introducing a sulfonyl group)- As the step of introducing a ionic substituent, a step of introducing a sulfonyl group (sulfoalkylation step) may be included. In the sulfoalkylation, a compound having a reactive group and a sulfonyl group (compound E _B ) as an essential component, a base compound as an optional component, and the compound B selected from urea and its derivatives are added to The reaction is carried out in a fiber raw material having a hydroxyl group in a wet or dry state, and a base group can be introduced into the fiber raw material.

As a reactive group, a halogenated alkyl group, a vinyl group, an epoxy group (glycidyl group), etc. are mentioned. Examples of the compound EB include sodium 2-chloroethanesulfonate, sodium vinylsulfonate, sodium p _- styrenesulfonate, 2-acrylamido-2-methylpropanesulfonic acid, and the like. Among them, the compound _EB is preferably sodium vinylsulfonate from the viewpoints of the efficiency of introducing a substituent, furthermore, the defibration efficiency, cost, and ease of handling. Furthermore, as an optional component, it is also preferable to use the compound B in the above-mentioned <step of introducing a phosphorus oxyacid group> in the same manner, and the addition amount is also preferably as described above.

When compound _EB is added, it can be directly added to the fiber raw material as a reagent (solid or liquid), or it can also be added by dissolving it in an appropriate solvent. The fiber raw material is preferably alkali cellulose-formed in advance, or alkali-cellulose-formed at the same time as the reaction. The method of alkali cellulose is as described above.

The temperature during the reaction is, for example, preferably 50°C or higher and 300°C or lower, more preferably 100°C or higher and 250°C or lower, and still more preferably 130°C or higher and 200°C or lower.

The amount of compound E _B to be added relative to 100 parts by mass of the fiber raw material is preferably 1 part by mass or more and 100,000 parts by mass or less, more preferably 2 parts by mass or more and 10,000 parts by mass or less, still more preferably 5 parts by mass or more and 1,000 parts by mass the following.

The reaction time may vary depending on the reaction temperature, but is preferably, for example, 1 minute or more and 1,000 minutes or less, more preferably 10 minutes or more and 500 minutes or less, and still more preferably 15 minutes or more and 400 minutes or less. In addition, after the reaction, the remaining reaction reagents, by-products, etc. may be washed and removed by filtration or the like.

-Carboxyalkylation step (third carboxyl group introduction step) - As an ionic substituent introduction step, a carboxyalkylation step may be included. By adding a compound having a reactive group and a carboxyl group (compound E _C ) as an essential component, an alkali compound as an optional component, and the compound B selected from urea and its derivatives to the wet or dry state having a hydroxyl group The carboxyl group can be introduced into the fiber raw material by reacting in the fiber raw material.

As a reactive group, a halogenated alkyl group, a vinyl group, an epoxy group (glycidyl group), etc. are mentioned. As the compound E _C , monochloroacetic acid, sodium monochloroacetate, 2-chloropropionic acid, and 3-chloropropionic acid are preferred in terms of the efficiency of introducing a substituent, furthermore, defibrating efficiency, cost, and ease of handling. , Sodium 2-chloropropionate, Sodium 3-chloropropionate. Furthermore, as an optional component, it is also preferable to use the compound B in the above-mentioned <step of introducing a phosphorus oxyacid group> in the same manner, and the addition amount is also preferably as described above.

When compound E _C is added, it can be directly added to the fiber raw material as a reagent (solid or liquid), or it can be dissolved in an appropriate solvent. The fiber raw material is preferably alkali cellulose-formed in advance, or alkali-cellulose-formed at the same time as the reaction. The method of alkali cellulose is as described above.

The temperature during the reaction is, for example, preferably 50°C or higher and 300°C or lower, more preferably 100°C or higher and 250°C or lower, and still more preferably 130°C or higher and 200°C or lower.

The amount of compound E _C added relative to 100 parts by mass of the fiber raw material is preferably 1 part by mass or more and 100,000 parts by mass or less, more preferably 2 parts by mass or more and 10,000 parts by mass or less, still more preferably 5 parts by mass or more and 1,000 parts by mass the following.

Although the reaction time may vary depending on the reaction temperature, for example, it is preferably 1 minute or more and 1,000 minutes or less, more preferably 3 minutes or more and 500 minutes or less, and still more preferably 5 minutes or more and 400 minutes or less. In addition, after the reaction, the remaining reaction reagents, by-products, etc. may be washed and removed by filtration or the like.

_-cationic group introduction step (cationization step) The compound B in the compound is added to a fiber raw material having a hydroxyl group in a wet or dry state and reacted, and a cationic group can be introduced into the fiber raw material.

As a reactive group, a halogenated alkyl group, a vinyl group, an epoxy group (glycidyl group), etc. are mentioned. As a cationic group, an ammonium group, a phosphonium group, a strontium group, etc. are mentioned. Among them, the cationic group is preferably an ammonium group. As the compound _ED , glycidyltrimethylammonium chloride, 3-chloro-2-hydroxypropyltrimonium, and glycidyltrimethylammonium chloride are preferred in terms of the efficiency of introducing a substituent, furthermore, defibrating efficiency, cost, and ease of handling. Methyl Ammonium Chloride, etc. Furthermore, as an optional component, it is also preferable to use the compound B in the above-mentioned <step of introducing a phosphorus oxyacid group>. The addition amount is also preferably as described above.

When compound _ED is added, it can be directly added to the fiber raw material as a reagent (solid or liquid), or it can be added by dissolving it in an appropriate solvent. The fiber raw material is preferably alkali cellulose-formed in advance, or alkali-cellulose-formed at the same time as the reaction. The method of alkali cellulose is as described above.

The temperature during the reaction is, for example, preferably 50°C or higher and 300°C or lower, more preferably 100°C or higher and 250°C or lower, and still more preferably 130°C or higher and 200°C or lower.

The amount of compound E _D added relative to 100 parts by mass of the fiber raw material is preferably 1 part by mass or more and 100,000 parts by mass or less, more preferably 2 parts by mass or more and 10,000 parts by mass or less, and still more preferably 5 parts by mass or more and 1,000 parts by mass the following.

The reaction time may vary depending on the reaction temperature, but is preferably, for example, 1 minute or more and 1,000 minutes or less, more preferably 5 minutes or more and 500 minutes or less, and still more preferably 10 minutes or more and 400 minutes or less. In addition, after the reaction, the remaining reaction reagents, by-products, etc. may be washed and removed by filtration or the like.

<Cleaning step> In the step of obtaining a cellulose fiber having an ionic substituent, a washing step may be performed on the ionic substituent-introduced fiber as necessary. The washing step is performed, for example, by washing the ionic substituent-introduced fibers with water or an organic solvent. In addition, the cleaning step may be performed after each step described later, and the number of times of cleaning performed in each cleaning step is not particularly limited.

<Alkali treatment step> In the step of obtaining the cellulose fiber having an ionic substituent, an alkali treatment step may be provided between the ionic substituent introduction step and the miniaturization treatment step. Although it does not specifically limit as a method of alkali treatment, For example, the method of immersing an ionic substituent-introduced fiber in an alkali solution is mentioned.

The alkali compound contained in the alkali solution is not particularly limited, and may be an inorganic alkali compound or an organic alkali compound. In the present embodiment, it is preferable to use, for example, sodium hydroxide or potassium hydroxide as the alkali compound in terms of high versatility. In addition, the solvent contained in the alkali solution may be either water or an organic solvent. Among them, the solvent contained in the alkaline solution is preferably a polar solvent containing water or a polar organic solvent exemplified by an alcohol, and more preferably an aqueous solvent containing at least water. As the alkaline solution, for example, an aqueous sodium hydroxide solution or an aqueous potassium hydroxide solution is preferable in terms of high versatility.

The temperature of the alkali solution in the alkali treatment step is not particularly limited, but, for example, it is preferably 5°C or higher and 80°C or lower, and more preferably 10°C or higher and 60°C or lower. The immersion time of the ionic substituent-introduced fibers in the alkali treatment step in the alkali solution is not particularly limited, but is preferably 5 minutes or more and 30 minutes or less, and more preferably 10 minutes or more and 20 minutes or less, for example. The amount of the alkali solution used in the alkali treatment is not particularly limited. For example, it is preferably 100% by mass or more and 100,000% by mass or less, more preferably 1,000% by mass or more and 10,000% by mass relative to the absolute dry mass of the ionic substituent-introduced fiber. mass % or less.

In order to reduce the usage-amount of the alkali solution in the alkali treatment step, after the ionic substituent introduction step and before the alkali treatment step, the ionic substituent introduced fibers may be washed with water or an organic solvent. From the viewpoint of improving handleability, the alkali-treated ionic substituent-introduced fibers are preferably washed with water or an organic solvent after the alkali treatment step and before the miniaturization treatment step.

<Acid treatment step> In the step of obtaining the cellulose fiber having an ionic substituent, an acid treatment step may be provided between the ionic substituent introduction step and the miniaturization treatment step. For example, an ionic substituent introduction step, acid treatment, alkali treatment, and miniaturization treatment may be performed in this order.

Although it does not specifically limit as the method of an acid treatment, For example, the method of immersing a fiber raw material in an acid liquid containing an acid is mentioned. The concentration of the acidic liquid to be used is not particularly limited, but is, for example, preferably 10% by mass or less, and more preferably 5% by mass or less. In addition, the pH of the acidic liquid to be used is not particularly limited, but, for example, it is preferably 0 or more and 4 or less, and more preferably 1 or more and 3 or less. As an acid contained in an acidic liquid, an inorganic acid, a sulfonic acid, a carboxylic acid, etc. can be used, for example. Examples of inorganic acids include sulfuric acid, nitric acid, hydrochloric acid, hydrobromic acid, hydroiodic acid, hypochlorous acid, chlorous acid, chloric acid, perchloric acid, phosphoric acid, and boric acid. As a sulfonic acid, methanesulfonic acid, ethanesulfonic acid, benzenesulfonic acid, p-toluenesulfonic acid, trifluoromethanesulfonic acid, etc. are mentioned, for example. Examples of the carboxylic acid include formic acid, acetic acid, citric acid, gluconic acid, lactic acid, oxalic acid, and tartaric acid. Among these, hydrochloric acid or sulfuric acid is particularly preferably used.

The temperature of the acid solution in the acid treatment is not particularly limited, but for example, it is preferably 5°C or higher and 100°C or lower, and more preferably 20°C or higher and 90°C or lower. The immersion time in the acid solution in the acid treatment is not particularly limited, but for example, it is preferably 5 minutes or more and 120 minutes or less, and more preferably 10 minutes or more and 60 minutes or less. The amount of the acid solution used in the acid treatment is not particularly limited, but is preferably 100% by mass or more and 100,000% by mass or less, more preferably 1,000% by mass or more and 10,000% by mass or less, for example, based on the absolute dry mass of the fiber raw material.

(Defibration processing step) Fine fibrous cellulose can be obtained by defibrating the ionically-group-introduced fibers in the defibrating step. In the defibration treatment step, for example, a defibration treatment device can be used. The defibrating treatment device is not particularly limited, and for example, a high-speed defibrating machine, a grinder (stone mill type pulverizer), a high-pressure homogenizer, an ultra-high-pressure homogenizer, a high-pressure impact pulverizer, a ball mill, Bead mill, disc refiner, cone refiner, twin shaft mixer, vibration mill, homomixer under high speed rotation, ultrasonic disperser, or beating machine, etc. In the defibration treatment device, it is more preferable to use a high-speed defibrillator, a high-pressure homogenizer, and an ultra-high-pressure homogenizer with little influence of the crushing medium and less risk of pollution.

In the defibration treatment step, for example, it is preferable to introduce an ionic group into the fiber and dilute it with a dispersion medium to prepare a slurry. As the dispersion medium, one or two or more selected from organic solvents such as water and polar organic solvents can be used. Although it does not specifically limit as a polar organic solvent, For example, alcohols, polyols, ketones, ethers, esters, aprotic polar solvents, etc. are preferable. As alcohols, methanol, ethanol, isopropanol, n-butanol, isobutanol, etc. are mentioned, for example. As polyhydric alcohols, ethylene glycol, propylene glycol, glycerol, etc. are mentioned, for example. As ketones, acetone, methyl ethyl ketone (MEK), etc. are mentioned. As ethers, diethyl ether, tetrahydrofuran, ethylene glycol monomethyl ether, ethylene glycol monoethyl ether, ethylene glycol mono-n-butyl ether, propylene glycol monomethyl ether, etc. are mentioned, for example. As esters, ethyl acetate, butyl acetate, etc. are mentioned, for example. Examples of the aprotic polar solvent include dimethyl sulfoxide (DMSO), dimethylformamide (DMF), dimethylacetamide (DMAc), N-methyl- 2-pyrrolidinone (N-methyl-2-pyrrolidinone, NMP), etc.

The solid content concentration of the fine fibrous cellulose at the time of defibration treatment can be appropriately set. In addition, the slurry obtained by dispersing the phosphorus oxyacid group-introduced fibers in a dispersion medium may contain, for example, a solid content other than the phosphorus oxyacid group-introduced fibers, such as urea having hydrogen bonding properties.

From the viewpoint of the transparency of the radiation-sensitive sheet and the ability to form a fine pattern, the content of the fine fibrous cellulose in the solid content of the radiation-sensitive sheet is preferably 5 mass % or more, more preferably 15 mass % or more. , more preferably 25 mass % or more, more preferably 35 mass % or more, and more preferably 85 mass % or less, more preferably 75 mass % or less, more preferably 65 mass % or less, and still more preferably 55 mass % %the following. As the fine fibrous cellulose, ionic group-containing fine fibrous cellulose and unmodified fine fibrous cellulose which will be described later may be used in combination.

＜Hydrophilic polymer＞ The radiation-sensitive sheet of this embodiment contains a hydrophilic polymer. The hydrophilic polymer refers to a polymer compound having a solubility of 1 g or more in 100 ml of ion-exchanged water under normal pressure and 25° C., and a weight average molecular weight of 5,000 or more. In addition, the hydrophilic polymer refers to a polymer other than the resin for a radiation-sensitive composition, which will be described later, and does not have solubility in a solvent due to acid or radical generated by irradiating the radiation-sensitive compound with radiation. A radically variable acid-decomposable group or radically polymerizable group.

The hydrophilic polymer is preferably a hydrophilic oxygen-containing organic compound (except for the cellulose fibers). The hydrophilic oxygen-containing organic compound preferably has an SP value of 9.0 or more, for example. Examples of hydrophilic polymers used in the present embodiment include polyalkylene glycols (polyethylene glycol, polypropylene glycol, etc.), cellulose derivatives (hydroxyethyl cellulose, carboxyethyl cellulose, carboxymethyl cellulose, etc.) base cellulose, etc.), casein, dextrin, starch, modified starch, polyvinyl alcohol, modified polyvinyl alcohol (acetylated polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene oxide polyvinyl alcohol) Vinyl alcohol, etc.), polyalkylene oxide (polyethylene oxide, etc.), polyvinylpyrrolidone, polyvinyl methyl ether, polyacrylates, polyacrylamide, alkyl acrylate copolymer, urethane Ester copolymers, etc. Among the above, polyethylene glycol, polyethylene oxide, polyvinyl alcohol and modified polyvinyl alcohol are particularly preferably used.

The weight-average molecular weight of the hydrophilic polymer is not particularly limited as long as it is 5,000 or more, but from the viewpoint of the shape stability of the radiation-sensitive sheet and the possibility of fine patterning, it is preferably 10,000 or more, more preferably 15,000 or more, more preferably 20,000 or more. In addition, the weight average molecular weight of the hydrophilic polymer is preferably 8 million or less, more preferably 5 million or less, still more preferably 1 million or less, and still more preferably 100,000 or less. In addition, the weight average molecular weight can be measured using gel permeation chromatography (gel permeation chromatography, GPC), for example.

From the viewpoint of the shape stability of the radiation-sensitive sheet and the ability to form fine patterns, the content of the hydrophilic polymer in the radiation-sensitive sheet is 10 parts by mass relative to 100 parts by mass of the solid content of the fine fibrous cellulose. parts by mass or more, preferably not less than 15 parts by mass, more preferably not less than 20 parts by mass, more preferably not less than 30 parts by mass, and preferably not more than 250 parts by mass, more preferably not more than 150 parts by mass, and more preferably not more than 100 parts by mass part or less, more preferably 50 parts by mass or less. The content of the hydrophilic polymer in the radiation-sensitive sheet is preferably 25 parts by mass relative to 100 parts by mass of the radiation-sensitive composition from the viewpoint of the shape stability of the radiation-sensitive sheet and the ability to form a fine pattern. More than that, and preferably 70 parts by mass or less.

In addition, the content of the hydrophilic polymer in the solid content of the radiation-sensitive sheet is preferably 1 mass % or more, more preferably 5, from the viewpoint of the shape stability of the radiation-sensitive sheet and the possibility of fine patterning. mass % or more, more preferably 10 mass % or more, more preferably 60 mass % or less, more preferably 55 mass % or less, still more preferably 50 mass % or less, still more preferably 40 mass % or less, still more preferably It is 30 mass % or less.

<Radiation sensitive composition> The radiation-sensitive sheet of the present embodiment includes a radiation-sensitive composition. In addition, depending on the type of the radiation-sensitive composition, the radiation-sensitive sheet of the present embodiment may be a positive-type radiation-sensitive sheet or a negative-type radiation-sensitive sheet. The radiation-sensitive composition includes a radiation-sensitive compound and a radiation-sensitive composition resin (hereinafter, also referred to as "radiation-sensitive resin"). The solubility of the resin for a radiation-sensitive composition to a solvent is increased or decreased by the radiation-sensitive compound irradiated with radiation. That is, it has the characteristic of being polymerized, cross-linked and/or decomposed under the action of reactive active species such as acid and radicals generated from the radioactive compound by irradiation with radiation. The radiation-sensitive compound is a compound that imparts radiation-sensitive properties to the radiation-sensitive composition. A radiation-sensitive compound is a compound that generates a reactive species by exposure to radiation. Here, the radiation includes at least visible light, ultraviolet rays, extreme ultraviolet rays, electron beams (charged particle beams), and X-rays. Among these, ultraviolet rays are preferable. The radiation-sensitive compound is preferably an acid generator, a polymerization initiator, or a combination of these. When an acid generator is used, it can be made into any of a positive-type and a negative-type radiation-sensitive composition according to other additive components. When a quinonediazide compound is used, a positive radiation-sensitive composition can be obtained. On the other hand, when a polymerization initiator is used, a negative radiation-sensitive composition can be obtained.

[Resin for Radiation Sensitive Composition] The resin for a radiation-sensitive composition (radiation-sensitive resin) includes, in addition to compounds generally called polymers, so-called oligomers and monomers of lower molecular weight. That is, as long as the radiation-sensitive resin is a compound whose solubility in a solvent is increased or decreased due to the reaction of reactive species such as acid and free radicals generated from the radiation-sensitive compound when irradiated with radiation, the There is no particular limitation.

When the radiation-sensitive resin is a polymer compound, examples of the structure constituting the skeleton include polyalkylene glycols (polyethylene glycol, polypropylene glycol, etc.), cellulose derivatives (hydroxyethyl cellulose, Carboxyethyl cellulose, carboxymethyl cellulose, etc.), casein, dextrin, polyvinyl alcohol, modified polyvinyl alcohol (acetoxylated polyvinyl alcohol, ethylene-vinyl alcohol copolymer, ethylene oxide polyvinyl alcohol, etc.), polyalkylene oxide (polyethylene oxide, etc.), polyvinyl pyrrolidone, polyvinyl methyl ether, polyacrylates, polyacrylamide, acrylate copolymer, urethane Ester-based copolymers, polyhydroxystyrene-based copolymers, and the like. Among the above, it is particularly preferable to use a structure containing polyethylene glycol, polyethylene oxide, polyvinyl alcohol, modified polyvinyl alcohol, polypropylene amide, and acrylate copolymer. When the radiation-sensitive resin is a polymer, in addition to the structure constituting the skeleton, in the case of a positive type, it is preferable to have an acidic hydroxyl group or an acid dissociable group, and in the case of a negative type, it is preferable It is a radical polymerizable group or a hetero-small-membered ring group.

As described above, the radiation-sensitive resin used for the positive radiation-sensitive sheet preferably has an acidic hydroxyl group or an acid dissociable group in addition to the structure constituting the skeleton. Examples of acidic hydroxyl groups include phenolic hydroxyl groups such as hydroxyaryl groups, carboxyl groups, and the like, and as the radiation-sensitive compound, it is particularly preferable to use them together with a quinonediazide compound. For example, when a part of the radiation-sensitive sheet is irradiated with radiation, the solubility to a developer or the like can be suppressed by the interaction between the acidic hydroxyl group and the quinonediazide compound in the part of the sheet that is not irradiated. On the other hand, the irradiated part (exposed part) loses the interaction with the acidic hydroxyl group by the photoreaction of the quinonediazide compound, and the solubility to a developer etc. can be improved. That is, the radiation-sensitive sheet generally exhibits positive radiation-sensitive properties. Examples of the acid dissociable group include a tertiary alkyl ester group, a tertiary butoxycarbonyl group, an acetal group, and the like, and the radiation-sensitive compound is particularly preferably an oxime sulfonate compound, a triaryl perionate, or a diaryl group. Onium salts such as iodonium, and photoacid generators such as sulfonimide compounds are used in combination. For example, when a part of the radiation-sensitive sheet is irradiated with radiation, a tertiary alkyl ester group, a tertiary butoxycarbonyl group, an acetal group, etc. can be used to suppress exposure to a developer or the like in the portion of the sheet that is not irradiated. solubility. On the other hand, in the irradiated part (exposed part), the acid generated by the photoreaction of the photoacid generator, the tertiary alkyl ester group, the tertiary butoxycarbonyl group, the acetal group, etc. which protect the hydroxyl group, generate The deprotection reaction can improve the solubility to developer and the like. That is, the radiation-sensitive sheet generally exhibits positive radiation-sensitive properties.

As described above, the radiation-sensitive resin used in the negative radiation-sensitive sheet preferably contains a small-molecule heterocyclic group or a polymerizable unsaturated group in addition to the structure constituting the skeleton. As a small molecular heterocyclic group, an epoxy group or an oxetanyl group is mentioned, for example, As a radiation sensitive compound, it is especially preferable to use together with a photoacid generator. For example, when a part of the radiation-sensitive sheet is irradiated with radiation, the non-irradiated sheet part does not undergo a cross-linking reaction via ring-opening of a reactive small-molecule heterocyclic functional group such as an epoxy group. etc. have high solubility. On the other hand, in the irradiated part (exposed part), the acid generated by the photoreaction of the photoacid generator, which is a radiation-sensitive compound, catalyzes the crosslinking reaction through the ring-opening of the reactive small-molecule heterocyclic group. Suppresses solubility in developer and the like. That is, the radiation-sensitive sheet generally exhibits negative radiation-sensitive properties. As a polymerizable unsaturated group, an acryl group or a methacryl group is mentioned, for example, As a radiation sensitive compound, it is especially preferable to use together with a photopolymerization initiator. For example, when a part of the radiation-sensitive sheet is irradiated with radiation, a cross-linking reaction via polymerization of a polymerizable unsaturated group such as an acryl group does not proceed in the portion of the sheet that is not irradiated, so the solubility in developing solutions and the like does not proceed. high. On the other hand, in the irradiated part (exposed part), the radical generated by the photoreaction of the photopolymerization initiator catalyzes the crosslinking reaction through the polymerization of the polymerizable unsaturated group, and the dissolution into the developer and the like can be suppressed. sex. That is, the radiation-sensitive sheet generally exhibits negative radiation-sensitive properties.

Furthermore, when the radiation-sensitive sheet is a negative type, as the radiation-sensitive resin, an oligomer or monomer having a lower molecular weight can also be used. The oligomer or monomer is particularly preferably an oligomer or monomer having a polymerizable unsaturated group (hereinafter, these are also collectively referred to as a "polymerizable unsaturated compound"). The polymerizable unsaturated compound is an unsaturated compound polymerized by irradiating a radiation-sensitive sheet with radiation in the presence of the radiation-sensitive compound in the radiation-sensitive composition. Although it does not specifically limit as such a polymerizable unsaturated compound, For example, from the point that the polymerizability is good and the intensity|strength of the radiation-sensitive sheet formed is improved, a polyfunctional (methyl) )Acrylate.

As said difunctional (meth)acrylate, for example, ethylene glycol di(meth)acrylate, propylene glycol di(meth)acrylate, diethylene glycol di(meth)acrylate, tetraethylene glycol di(meth)acrylate, Glycol diacrylate, tetraethylene glycol di(meth)acrylate, 1,6-hexanediol di(meth)acrylate, 1,9-nonanediol di(meth)acrylate, and the like. As these commercial items, Aronix (registered trademark) M-210, Aronix M-240, Aronix M-6200 are mentioned, for example, in terms of trade names. (The above are manufactured by Toa Gosei Co., Ltd.); KAYARAD (registered trademark) HDDA, KAYARAD HX-220, KAYARAD R-604 (the above are Japanese Pharmaceutical Co., Ltd.); Viscoat 260, Viscoat 312, Viscoat 335HP (the above are manufactured by Osaka Organic Chemical Industry Co., Ltd.), Light Acrylate 1,9 -NDA (manufactured by Kyoeisha Chemical Co., Ltd.), etc.

As the above-mentioned trifunctional (meth)acrylate, for example, trimethylolpropane tri(meth)acrylate, pentaerythritol tri(meth)acrylate, pentaerythritol tetra(meth)acrylate, Pentaerythritol penta(meth)acrylate, dipentaerythritol hexa(meth)acrylate; A mixture of dipentaerythritol penta(meth)acrylate and dipentaerythritol hexa(meth)acrylate; Ethylene oxide modified dipentaerythritol hexa(meth)acrylate, tris(2-(meth)acryloyloxyethyl)phosphate, succinic acid modified pentaerythritol tri(meth)acrylate, succinic acid Modified dipentaerythritol penta(meth)acrylate, tripentaerythritol hepta(meth)acrylate, tripentaerythritol octa(meth)acrylate, modified EO isocyanurate diacrylate and modified EO isocyanurate mixture of triacrylates;

Moreover, as a polyfunctional (meth)acrylate, the compound which has a linear alkyl group and an alicyclic structure, and has two or more isocyanate groups, and a molecule which has one or more hydroxyl groups and has three isocyanate groups can be mentioned. , a polyfunctional urethane acrylate-based compound obtained by reacting a compound of four or five (meth)acryloyloxy groups, etc. As a commercial item of the above-mentioned trifunctional (meth)acrylate, in terms of trade names, for example, Aronix (registered trademark) M-309 and Aronix M-400 can be mentioned. , Aronix M-405, Aronix M-450, Aronix M-7100, Aronix M-8030, Aronix M-8060 , Aronix (Aronix) TO-1450 (above, manufactured by Toa Gosei Co., Ltd.); KAYARAD (registered trademark) TMPTA, KAYARAD (KAYARAD) DPHA, KAYARAD (KAYARAD) DPCA-20, KAYARAD DPCA-30, KAYARAD DPCA-60, KAYARAD DPCA-120, KAYARAD DPEA-12 (above, Nippon Kayaku Co., Ltd.); Viscoat 295, Viscoat 300, Viscoat 360, Viscoat GPT, Viscoat 3PA, Viscoat 400 (The above, manufactured by Osaka Organic Chemical Industry Co., Ltd.), as a commercial product containing a polyfunctional urethane acrylate-based compound, New Frontier (registered trademark) R-1150 (Daiichi Industrial Co., Ltd.) can be mentioned. Pharmaceutical Co., Ltd.), KAYARAD (registered trademark) DPHA-40H (Nihon Kayaku Co., Ltd.), etc.

Among these, particularly preferred are: 1,9-nonanediol dimethacrylate, trimethylolpropane triacrylate, pentaerythritol triacrylate, pentaerythritol tetraacrylate, dipentaerythritol pentaacrylate, dipentaerythritol hexaacrylate ester; A mixture of dipentaerythritol pentaacrylate and dipentaerythritol hexaacrylate; A mixture of tripentaerythritol hepta(meth)acrylate and tripentaerythritol octa(meth)acrylate; Ethylene oxide-modified dipentaerythritol hexaacrylate, polyfunctional urethane acrylate-based compound, succinic acid-modified pentaerythritol triacrylate, succinic acid-modified dipentaerythritol pentaacrylate; and commercially available products containing these products, etc. The polyfunctional polymerizable unsaturated compounds described above may be used alone or in combination of two or more.

The molecular weight (weight-average molecular weight in the case of having a molecular weight distribution) of the radiation-sensitive resin is not particularly limited, and from the viewpoint of enabling fine pattern formation, it may be 200 or more, preferably 300 or more, and more Preferably it is 500 or more. In addition, the molecular weight (weight average molecular weight) of the radiation-sensitive resin is preferably 100,000 or less, more preferably 10,000 or less. In addition, the weight average molecular weight can be measured using GPC, for example.

＜Radiation Sensitive Compounds＞ In this embodiment, the radiation-sensitive composition preferably contains at least one of a photoacid generator and a photopolymerization initiator as a radiation-sensitive compound. [Photoacid generator] Photoacid generators (also simply referred to as "acid generators") are compounds that generate acids by irradiation with radiation. By containing an acid generator, the radiation-sensitive composition of the present embodiment can exhibit, for example, positive-type radiation-sensitive properties with respect to an alkali developer. The acid generator is not particularly limited as long as it is a compound that generates an acid (eg, carboxylic acid, sulfonic acid, etc.) by irradiation with radiation. As an acid generator, an oxime sulfonate compound, an onium salt, a sulfonimide compound, a quinonediazide compound, etc. are mentioned, for example, It can be used individually or in combination of 2 or more types.

If the oxime sulfonate compound is exemplified, for example, (5-propylsulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, ( 5-Octylsulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, (camphorsulfonyloxyimino-5H-thiophene-2- subunit)-(2-methylphenyl)acetonitrile, (5-p-toluenesulfonyloxyimino-5H-thiophene-2-ylidene)-(2-methylphenyl)acetonitrile, (2 -Octylsulfonyloxyimino)-2-(4-methoxyphenyl)acetonitrile. If an onium salt is exemplified, for example, diphenyl iodonium trifluoromethane sulfonate, diphenyl iodopyrene sulfonate, diphenyl iodo dodecyl benzene sulfonate, and diphenyl iodonium nona are mentioned. Fluoro-n-butane sulfonate, bis(4-tert-butylphenyl) iodotrifluoromethane sulfonate, bis(4-tert-butylphenyl) iodododecylbenzene sulfonate, bis(4-tert-butylphenyl) iododecylbenzene sulfonate 4-Third-butylphenyl) iodonaphthalene sulfonate, bis(4-tert-butylphenyl) iodonium hexafluoroantimonate, bis(4-tert-butylphenyl) iodonium nonafluoro-n-butane Sulfonate, diphenyl iodonium hexafluoroantimonate, triphenylperylene trifluoromethanesulfonate, triphenylperylene hexafluoroantimonate, triphenylperylene naphthalene sulfonate, triphenylperylene nonafluoro - n-butane sulfonate, (hydroxyphenyl) benzyl perylene sulfonate, cyclohexylmethyl (2-oxocyclohexyl) perylene trifluoromethanesulfonate, dicyclohexyl (2-oxo Cyclohexyl) pericylium trifluoromethanesulfonate, dimethyl (2-oxocyclohexyl) pericylium trifluoromethanesulfonate, triphenyl pericyl camphorsulfonate, (4-hydroxyphenyl)benzylmethyl perylene toluenesulfonate, 1-naphthyldimethyl perylene trifluoromethanesulfonate, and "1-naphthyldimethyl" in 1-naphthyldimethyl perylene trifluoromethanesulfonate is replaced with 1 -Naphthyldiethyl, 4-cyano-1-naphthyldimethyl, 4-nitro-1-naphthyldimethyl, 4-methyl-1-naphthyldimethyl, 4-cyano Compounds of -1-naphthyl-diethyl, 4-nitro-1-naphthyldiethyl, 4-methyl-1-naphthyldiethyl, 4-hydroxy-1-naphthyldimethyl.

If the sulfonimide compound is exemplified, for example, N-(trifluoromethylsulfonyloxy)succinimide, N-(camphorsulfonyloxy)succinimide, N-(4 -Methylphenylsulfonyloxy)succinimide, N-(2-trifluoromethylphenylsulfonyloxy)succinimide, N-(4-fluorophenylsulfonyloxy)succinimide Imide, N-(trifluoromethylsulfonyloxy)phthalimide, N-(camphorsulfonyloxy)phthalimide, N-(2-trifluoromethyl) Phenylsulfonyloxy)phthalimide, N-(2-fluorophenylsulfonyloxy)phthalimide, N-(trifluoromethylsulfonyloxy)diphenyl Maleimide, N-(camphorsulfonyloxy)diphenylmaleimide, N-hydroxynaphthalimide-trifluoromethanesulfonate, etc.

As the quinonediazide compound, 4,4'-dihydroxydiphenylmethane, 4,4'-dihydroxydiphenyl ether, 2,3,4-trihydroxybenzophenone, 2,3 ,4,4'-tetrahydroxybenzophenone, 2,3,4,2',4'-pentahydroxybenzophenone, tris(4-hydroxyphenyl)methane, tris(4-hydroxyphenyl) Ethane, 1,1-bis(4-hydroxyphenyl)-1-phenylethane, 1,3-bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 1, 4-bis[1-(4-hydroxyphenyl)-1-methylethyl]benzene, 4,6-bis[1-(4-hydroxyphenyl)-1-methylethyl]-1,3 -Dihydroxybenzene, 1,1-bis(4-hydroxyphenyl)-1-[4-{1-(4-hydroxyphenyl)-1-methylethyl}phenyl]ethane, 4,4 '-[1-[4-[1-(4-hydroxyphenyl)-1-methylethyl]phenyl]ethylene]bisphenol and other compounds having one or more phenolic hydroxyl groups, and 1,2 -Ester compound of naphthoquinonediazide-4-sulfonic acid or 1,2-naphthoquinonediazide-5-sulfonic acid, etc.

When the radiation-sensitive sheet contains a photoacid generator, for example, when a part of the radiation-sensitive sheet is irradiated with radiation, the solubility of the irradiated portion (exposed portion) to a developer and the like can be improved. That is, the radiation-sensitive sheet generally exhibits positive radiation-sensitive properties. The content of the photoacid generator of the present embodiment is preferably 0.1 part by mass or more, more preferably 1 part by mass or more, preferably 30 parts by mass or less, more preferably 20 parts by mass relative to 100 parts by mass of the radiation-sensitive resin parts by mass or less. When the content of the photoacid generator with respect to the radiation-sensitive resin is within the above-described range, excellent radiation-sensitive properties can be imparted.

[Photopolymerization initiator] A photopolymerization initiator (hereinafter, also simply referred to as a "polymerization initiator") is a component that induces radiation and generates an active species capable of initiating polymerization of a polymerizable compound. By containing a polymerization initiator, the radiation-sensitive composition of the present embodiment can exhibit, for example, negative-type radiation-sensitive properties with respect to an alkali developer. As a photopolymerization initiator, a photoradical polymerization initiator is mentioned. The photopolymerization initiator can initiate a crosslinking reaction of a compound having a polymerizable group by exposure to radiation such as visible light, ultraviolet rays, extreme ultraviolet rays, electron beams, and X-rays, but it is preferably used as a photopolymerization initiator. , for example, the photopolymerization initiator that generates the most free radicals in the ultraviolet, especially around 365 nm. As this photoradical polymerization initiator, an O-acyl oxime compound, an acetophenone compound, a biimidazole compound, an acyl phosphine oxide compound, etc. are mentioned, for example. These compounds may be used alone or in combination of two or more.

Examples of the O-acyl oxime compound include 1-[4-(phenylthio)-2-(O-benzyl oxime)], 1,2-octanedione-1-[4-(benzene Thio)-2-(O-benzyl oxime)], ethanone-1-[9-ethyl-6-(2-methylbenzyl)-9H-carbazol-3-yl]- 1-(O-acetoxime), 1-[9-ethyl-6-benzyl-9.H.-carbazol-3-yl]octan-1-one oxime-O-acetate , 1-[9-ethyl-6-(2-methylbenzyl)-9.H.-carbazol-3-yl]-ethane-1-ketoxime-O-benzoate, 1-[9-n-Butyl-6-(2-ethylbenzyl)-9.H.-carbazol-3-yl]-ethane-1-ketoxime-O-benzoate, Ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydrofuranylbenzyl)-9.H.-carbazol-3-yl]-1-(O-acetoxime ), ethanone-1-[9-ethyl-6-(2-methyl-4-tetrahydropyranylbenzyl)-9.H.-carbazol-3-yl]-1-( O-acetoxime), ethanone-1-[9-ethyl-6-(2-methyl-5-tetrahydrofurylbenzyl)-9.H.-carbazol-3-yl]-1 -(O-acetoxime), ethanone-1-[9-ethyl-6-{2-methyl-4-(2,2-dimethyl-1,3-dioxolane) Methoxybenzyl}-9.H.-carbazol-3-yl]-1-(O-acetoxime) and the like.

As an acetophenone compound, an alpha-amino ketone compound, an alpha-hydroxy ketone compound, etc. are mentioned, for example. Examples of the α-amino ketone compound include 2-benzyl-2-dimethylamino-1-(4-morpholinophenyl)-butan-1-one, 2-dimethylamine Base-2-(4-methylbenzyl)-1-(4-morpholin-4-yl-phenyl)-butan-1-one, 2-methyl-1-(4-methylphenylsulfide) base)-2-morpholinopropan-1-one and the like. Examples of the α-hydroxy ketone compound include 1-phenyl-2-hydroxy-2-methylpropan-1-one, 1-(4-isopropylphenyl)-2-hydroxy-2-methyl Propan-1-one, 4-(2-hydroxyethoxy)phenyl-(2-hydroxy-2-propyl) ketone, 1-hydroxycyclohexyl phenyl ketone, 2-hydroxy-1-{4-[ 2-(2-Hydroxyethoxy)ethoxy]phenyl}-2-methylpropan-1-one, 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone Wait.

As the biimidazole compound, for example, 2,2'-bis(2-chlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'- Bis(2,4-dichlorophenyl)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, 2,2'-bis(2,4,6-trichlorobenzene base)-4,4',5,5'-tetraphenyl-1,2'-biimidazole, etc. Examples of the acyl phosphine oxide compound include 2,4,6-trimethylbenzyl-diphenyl-phosphine oxide, phenylbis(2,4,6-trimethylbenzyl) Phosphine oxide, lithium phenyl(2,4,6-trimethylbenzyl)phosphinate, etc.

By including the photopolymerization initiator in the radiation-sensitive sheet, for example, when a part of the radiation-sensitive sheet is irradiated with radiation, the solubility of the irradiated portion (exposed portion) to a developer or the like can be reduced. That is, the radiation-sensitive sheet generally exhibits negative radiation-sensitive properties.

The content of the photopolymerization initiator in the radiation-sensitive composition of the present embodiment is preferably 1 part by mass or more, more preferably 5 parts by mass or more, relative to 100 parts by mass of the radiation-sensitive resin, and more preferably It is 40 mass parts or less, More preferably, it is 20 mass parts or less. By using the photopolymerization initiator within this range, excellent radiation sensitivity can be imparted. In addition, by setting the content of the photopolymerization initiator to such a range, the radiation-sensitive sheet containing the radiation-sensitive composition of the present embodiment can express negative radiation sensitivity even at a low exposure amount. .

From the viewpoint of enabling fine patterning, the content of the radioactive composition in the solid content of the radiation-sensitive sheet is preferably 10% by mass or more, more preferably 20% by mass or more, and still more preferably 25% by mass or more. Moreover, 80 mass % or less is preferable, 70 mass % or less is more preferable, and 60 mass % or less is still more preferable.

The radiation-sensitive composition is preferably dissolved in at least one of water, alcohol, or a mixed solvent of these. Thereby, the process of coating or papermaking described later becomes easy, which is preferable. Furthermore, the term "radiation-sensitive composition dissolved in at least one of water, alcohol, or a mixed solvent of these" refers to an alcohol having 1 or more carbon atoms and 6 or less carbon atoms (preferably, one or more carbon atoms and less than 6 carbon atoms) with respect to water. 4 or less alcohol, more preferably an alcohol with 1 to 3 carbon atoms), or 100 g of a mixed solvent of water and an alcohol with 1 to 6 carbon atoms or less, the radiation-sensitive composition is dissolved at 25°C under atmospheric pressure for 1 g or more. In addition, by dissolving the radiation-sensitive composition in at least one of water, alcohol, or mixed solvent, it has high affinity with fine fibrous cellulose and hydrophilic polymers, and can prepare a uniform coating solution or pulp for papermaking , so it is better.

In addition, the radiation-sensitive sheet of the present embodiment is preferably a negative type from the viewpoint of preparing a radiation-sensitive composition dissolved in water, alcohol, or at least one of these mixed solvents. By making a negative radiation-sensitive sheet, a low-molecular-weight and hydrophilic monomer or oligomer can be selected as a radiation-sensitive resin, and a radiation-sensitive resin that can be dissolved in water, alcohol, or a mixed solvent of these can be prepared. composition.

＜Other ingredients＞ In addition to the fine fibrous cellulose, hydrophilic polymer, resin for radiation-sensitive composition, radiation-sensitive compound, acid generator, and photopolymerization initiator, the radiation-sensitive sheet of the present embodiment may contain other ingredients. As other components, monofunctional polymerizable unsaturated compounds, wet paper strength enhancers, organic ions, crosslinking agents, surfactants, coupling agents, inorganic layered compounds, inorganic compounds, leveling agents, preservatives, Defoamers, organic particles, lubricants, antistatic agents, UV absorbers, dyes, pigments, stabilizers, magnetic powders, alignment accelerators, plasticizers, and dispersants.

As the monofunctional (meth)acrylate, for example, 2-hydroxyethyl (meth)acrylate, diethylene glycol monoethyl ether (meth)acrylate, (2-(meth)acryloyloxy) ethyl) (2-hydroxypropyl) phthalate, ω-carboxy polycaprolactone mono(meth)acrylate, and the like. As these commercial products, Aronix (registered trademark) M-101, Aronix M-111, Aronix M-114 are mentioned, in terms of trade names, for example. , Aronix (Aronix) M-5300 (the above are manufactured by Toa Gosei Co., Ltd.); KAYARAD (registered trademark) TC-110S, KAYARAD (KAYARAD) TC-120S (the above are Japan Chemical Co., Ltd.); Viscoat 158, Viscoat 2311 (the above are manufactured by Osaka Organic Chemical Industry Co., Ltd.), etc.

Wetting paper strength enhancer is an agent used to suppress the decrease of paper strength when the paper is wetted by water. By adding it to pulp fibers that are easily loosened by water, even when wetted by water, the pulp fibers are kept bound and not easily loosened. , has the effect of increasing strength. As a wet paper strength enhancer, a polyamine polyamide epihalohydrin, a melamine formaldehyde resin, a urea formaldehyde resin, etc. can be illustrated. Polyamine polyamide epichlorohydrin is synthesized by adding epichlorohydrin (epichlorohydrin) to the main chain formed by condensation of a polybasic acid and polyethylene polyamine, for example. Polyamine polyamide epichlorohydrin can be used in a wide pH range, and in addition, a high wet paper strength enhancement effect can be obtained at a low addition amount. Melamine formaldehyde resin is synthesized by acid condensation after adding formaldehyde to melamine. In addition, the urea-formaldehyde resin is synthesized by adding formaldehyde to urea and then partially crosslinking. Among these, it is preferable to use a polyamine polyamide epihalohydrin from the viewpoint of obtaining a sheet having a low water absorption coefficient and a coefficient of linear thermal expansion and excellent transparency. Among the polyamine polyamide epihalohydrin, polyamine polyamide epichlorohydrin is more preferred.

As an organic ion, a tetraalkylammonium ion and a tetraalkylphosphonium ion are mentioned. Examples of tetraalkylammonium ions include tetramethylammonium ions, tetraethylammonium ions, tetrapropylammonium ions, tetrabutylammonium ions, tetrapentylammonium ions, tetrahexylammonium ions, and tetraheptylammonium ions. ion, tributylmethylammonium ion, lauryltrimethylammonium ion, cetyltrimethylammonium ion, stearyltrimethylammonium ion, octyldimethylethylammonium ion, lauryldimethylammonium ion ammonium ion, didecyl dimethyl ammonium ion, lauryl dimethyl benzyl ammonium ion, tributyl benzyl ammonium ion. As a tetraalkylphosphonium ion, a tetramethylphosphonium ion, a tetraethylphosphonium ion, a tetrapropylphosphonium ion, a tetrabutylphosphonium ion, and a lauryltrimethylphosphonium ion are mentioned, for example. Moreover, as a tetrapropyl onium ion and a tetrabutyl onium ion, a tetra-n-propyl onium ion, a tetra-n-butyl onium ion, etc. can also be mentioned, respectively.

<Manufacturing method of radiation sensitive sheet> The radiation-sensitive sheet of the present embodiment can be obtained by preparing an aqueous dispersion (slurry) containing fine fibrous cellulose, a hydrophilic resin, a radiation-sensitive composition, and other components, and forming it into a sheet. The method of sheet formation is not particularly limited, but is preferably a step of coating a sheet formed by peeling the slurry from the base material and drying the slurry, or making paper from the slurry. papermaking steps to obtain. In addition, a radiation-sensitive sheet can be continuously produced by using a coating apparatus and a tape-shaped base material. Among these, it is more preferable to obtain it by a coating step.

The material of the base material in the coating step is not particularly limited, and from the viewpoint of suppressing shrinkage of the sheet during drying, etc., a material having high wettability to the slurry is preferred, but drying is preferred. The later-formed sheet can be easily peeled off. Although resin-made films or plates and metal-made films or plates are preferably exemplified, they are not particularly limited. Specifically, acrylic, polyethylene terephthalate, vinyl chloride, polystyrene, polypropylene, polycarbonate, polyvinylidene chloride or other resin films or plates; aluminum, zinc, copper, Films or plates of metals such as iron plates; and films or plates of stainless steel, films or plates of brass, etc., obtained by oxidizing the surfaces of these.

In the coating step, when the slurry has a low viscosity and is spread on the substrate, in order to obtain a radiation-sensitive sheet of predetermined thickness and basis weight, a frame for blocking can be fixed on the substrate and used. It does not specifically limit as a frame for blocking, For example, it is preferable to select the thing which can peel easily the edge part of the sheet adhering after drying. From such a viewpoint, it is more preferable to form a resin plate or a metal plate. In this embodiment, for example, resin sheets such as acrylic sheets, polyethylene terephthalate sheets, vinyl chloride sheets, polystyrene sheets, polypropylene sheets, polycarbonate sheets, and polyvinylidene chloride sheets can be used. , or metal plates such as aluminum plates, zinc plates, copper plates, iron plates, and stainless steel plates, brass plates, etc. obtained by oxidizing the surface of these plates.

It does not specifically limit as a coater which apply|coats a slurry to a base material, For example, a roll coater, a gravure coater, a die coater, a curtain coater, an air knife coater, etc. can be used. In terms of making the thickness of the sheet more uniform, a die coater, a curtain coater, and a spray coater are particularly preferred.

The slurry temperature and ambient temperature when applying the slurry to the substrate are not particularly limited, but are preferably 5°C or higher and 80°C or lower, more preferably 10°C or higher and 60°C or lower, and still more preferably 15°C or higher. and 50°C or lower, particularly preferably 20°C or higher and 40°C or lower. When the coating temperature is equal to or higher than the lower limit value, the slurry can be more easily coated. When the coating temperature is equal to or lower than the upper limit value, volatilization of the dispersion medium during coating and side reactions due to heat can be suppressed.

The method of drying the slurry applied on the base material is not particularly limited, and examples thereof include a non-contact drying method, a method of drying while restraining the sheet, or a combination of these. The non-contact drying method is not particularly limited, but for example, a method of drying by heating with hot air, infrared rays, far infrared rays, or near infrared rays (heat drying method); or a method of drying in a vacuum ( vacuum drying). The heating drying method and the vacuum drying method may also be combined, but the heating drying method is usually applied. Drying by infrared rays, far infrared rays, or near infrared rays is not particularly limited, and for example, it can be performed using an infrared device, a far infrared device, or a near infrared device. The heating temperature of the heating drying method is not particularly limited, but is preferably 20°C or higher, more preferably 50°C or higher, and is preferably 150°C or lower, more preferably 120°C or lower, and further preferably 100°C or lower. When the heating temperature is made equal to or higher than the lower limit value, the dispersion medium can be rapidly volatilized. In addition, when the heating temperature is set to be equal to or less than the above-mentioned upper limit value, it is possible to suppress the cost required for heating and to suppress the discoloration of the fibrous cellulose or the occurrence of side reactions due to heat.

The papermaking step is performed by performing papermaking on the slurry using a paper machine. Although it does not specifically limit as a paper machine used in a papermaking process, For example, the continuous paper machine, such as a Fourdrinier type, a cylinder type, and an inclined type, or the multi-layer lamination paper machine which combines these, etc. are mentioned. In the papermaking step, a well-known papermaking method such as handwriting can also be employed. The papermaking step is performed by filtering and dewatering the slurry with a wire to obtain a sheet in a wet paper state, and then pressing and drying the sheet. The filter cloth used for filtration and dehydration of the slurry is not particularly limited. For example, it is more preferable that the fibrous cellulose, the hydrophilic resin, and the radiation-sensitive composition do not pass through, and the filtration rate does not exceed the filtration rate. Slow filter cloth. Although it does not specifically limit as such a filter cloth, For example, a sheet|seat, a woven fabric, and a porous membrane containing an organic polymer are preferable. The organic polymer is not particularly limited, but for example, non-cellulose-based organic polymers such as polyethylene terephthalate, polyethylene, polypropylene, and polytetrafluoroethylene (PTFE) are preferred. . In the present embodiment, for example, a porous membrane of polytetrafluoroethylene having a pore diameter of 0.1 μm or more and 20 μm or less, and a woven fabric of polyethylene terephthalate or polyethylene having a pore diameter of 0.1 μm or more and 20 μm or less can be mentioned.

In the papermaking step, the method for producing a sheet from the slurry can be performed using, for example, a production apparatus including a water-pressing section that ejects the slurry to the upper surface of the endless belt, and ejects the slurry from the ejected slurry. The dispersing medium is squeezed out of the feed to form a web; and a drying section is used to dry the web to form a web. An endless belt is arranged from the water squeezing section to the drying section, and the tablets produced in the water squeezing section are transported to the drying section in a state of being placed on the endless belt.

Although it does not specifically limit as a dehydration method used in a papermaking process, For example, the dehydration method generally used in the manufacture of paper is mentioned. Among these, after dehydration using a fourdrinier wire, a cylinder wire, an inclined wire rod, or the like, the method of dehydration using a roll press is preferred. Moreover, it does not specifically limit as a drying method used in a papermaking process, For example, the method used for manufacture of paper is mentioned. Among these, a drying method using a cylinder dryer, a yankee dryer, a hot air drying, a near-infrared heater, an infrared heater, or the like is more preferable.

<Characteristics of radiation-sensitive sheet> The thickness of the radiation-sensitive sheet is preferably 10 μm or more, more preferably 20 μm or more, still more preferably 25 μm or more, and more preferably 1,000 μm from the viewpoint of shape stability and fine pattern formation. Below, it is more preferable that it is 500 micrometers or less, and it is still more preferable that it is 100 micrometers or less. The coating amount and the papermaking amount may be appropriately adjusted so that the thickness of the radiation-sensitive sheet falls within the above-mentioned range.

The radiation-sensitive sheet of the present embodiment is preferably excellent in light transmittance, and the total light transmittance is preferably 70% or more, more preferably 80% or more, still more preferably 85% or more, still more preferably 90% or more, and is 100% or less is preferably 99.5% or less from the viewpoint of ease of manufacture. The total light transmittance was measured with a haze meter in accordance with Japanese Industrial Standards (JIS) K 7361-1:1997.

In addition, the radiation-sensitive sheet of the present embodiment is preferably excellent in transparency, and has a haze of preferably 10% or less, more preferably 3% or less, further preferably 2% or less, and 0% or more, for ease of manufacture From the viewpoint of , preferably 0.1% or more. The haze was measured with a haze meter in accordance with JIS K 7136:2000.

<Patterned sheet> The patterned radiation-sensitive sheet of the present embodiment is one that forms a pattern by exposing the radiation-sensitive sheet of the present embodiment and removing (developing) the unexposed portion or the exposed portion. The irradiation of radiation typically selectively exposes at least a portion of the radiation-sensitive sheet through a mask or the like, using, for example, a contact aligner, a stepper, or a scanner. The light source for exposure is not particularly limited, and examples thereof include high-pressure mercury lamps, metal halide lamps, ultra-high-pressure mercury lamps, KrF excimer lasers, ArF excimer lasers, EUV irradiation devices, soft X-ray irradiation devices, and electronic drawing devices. Known exposure techniques. There may also be a post-exposure bake (PEB) step. Among the radiation irradiated to the radiation-sensitive sheet, radiation having a wavelength of 313 nm or more is preferable, and radiation containing 365 nm ultraviolet rays is particularly preferable. Therefore, as an exposure light source, 313 nm radiation containing 365 nm ultraviolet rays is more preferable. High-pressure mercury lamps, metal halide lamps, and ultra-high-pressure mercury lamps of radiation having wavelengths above. By using these exposure light sources, in the wavelength region of 313 nm or more, even a sheet with a thickness of 10 μm or more can obtain high transmittance, and can fully expose to the back of the radiation-sensitive sheet without reducing the amount of light. . In addition, the exposure amount is a value obtained by measuring the intensity of radiation at a wavelength of 365 nm with an illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.), preferably 3 mJ /cm ² or more and 1,000 mJ/cm ² or less, more preferably 10 mJ/cm ² or more and 500 mJ/cm ² or less.

As a developing method, for example, a shower developing method, a spray developing method, a dipping developing method, a liquid-coating developing method, etc. may be adopted. As the developer, an alkaline developer, water, and a water-miscible organic solvent can be used. As the alkali developer, for example, sodium hydroxide, potassium hydroxide, sodium carbonate, sodium silicate, sodium metasilicate, ammonia water, ethylamine, n-propylamine, diethylamine, di-n-propylamine, triethylamine, Methyldiethylamine, ethyldimethylamine, triethanolamine, tetramethylammonium hydroxide (TMAH), pyrrole, piperidine, choline, 1,8-diazabicyclo-[5.4.0] -Aqueous alkali solution of at least one basic compound such as 7-undecene and 1,5-diazabicyclo-[4.3.0]-5-nonene, etc. Among these, TMAH aqueous solution is preferable. As a density|concentration of an alkali developing solution, 0.1 mass % or more and 2.38 mass % or less are preferable, and 0.4 mass % or more and 2.38 mass % or less are more preferable. Examples of the water-miscible organic solvent include methanol, ethanol, 1-propanol, isopropyl alcohol (IPA), tert-butanol, 1-methoxy-2-propanol (PGME), and the like. Alcohols; polyols such as ethylene glycol and glycerol; ketones such as acetone; ethers such as tetrahydrofuran; esters such as ethyl acetate and methyl acetate; Methylacetamide, N-methylpyrrolidone and other amides; dimethyl sulfoxide and other sulfites, etc. Any of these may be used, or two or more may be used in combination. Among these, alcohols, such as ethanol, IPA, and PGME, are preferable. The content of the organic solvent in the organic solvent developer is preferably 80% by mass or more, more preferably 90% by mass or more, and still more preferably 99% by mass or more. Examples of components other than the organic solvent in the organic solvent developer include water, silicone oil, and the like. In addition, after developing, the formed pattern may be further rinsed (cleaned) with a rinse solution.

The patterned sheet is particularly suitable for applications requiring transparency, such as color filters for displays and conductive films for touch panels. [Example]

The following describes the characteristics of the present invention in more detail with reference to Examples and Comparative Examples. Materials, usage amounts, ratios, processing contents, processing procedures, and the like shown in the following examples can be appropriately changed without departing from the gist of the present invention. Therefore, the scope of the present invention should not be construed limited by the specific examples shown below.

<Production Example 1> [Production of Microfibrous Cellulose Dispersion Liquid (1)] As raw material pulp, coniferous kraft pulp (solid content 93% by mass, basis weight 245 g/m ² , sheet kraft) manufactured by Oji Paper Co., Ltd. was used After dissociation, the Canadian Standard Freeness (CSF) measured according to JIS P 8121-2:2012 was 700 ml). This raw material pulp was subjected to phosphorus oxyacidizing treatment as follows. First, a mixed aqueous solution of ammonium dihydrogen phosphate and urea was added to 100 parts by mass of the raw material pulp (absolute dry mass), and adjusted to 45 parts by mass of ammonium dihydrogen phosphate, 120 parts by mass of urea, and 150 parts by mass of water to obtain a chemical solution Impregnated pulp. Next, the obtained chemical solution-impregnated pulp was heated for 250 seconds in a hot air dryer at 165° C., and phosphorus oxyacid groups were introduced into cellulose in the pulp to obtain phosphorus oxyacidized pulp 1 .

Next, the obtained phosphorus oxy-acidified pulp 1 is washed. The washing treatment was carried out by repeating the operation of stirring a pulp dispersion obtained by injecting 10 L of ion-exchanged water into 100 g (absolute dry mass) of phosphorus oxy-acidified pulp to uniformly disperse the pulp, followed by filtration and dehydration. When the conductivity of the filtrate reached 100 μS/cm or less, it was taken as the cleaning end point.

Next, the washed phosphorus oxy-acidified pulp was neutralized as follows. First, the washed phosphorus oxyacidified pulp was diluted with 10 L of ion-exchanged water, and then a 1 N aqueous sodium hydroxide solution was added in small amounts while stirring, thereby obtaining phosphorus oxyacidification with a pH of 12 or more and 13 or less. pulp pulp. Next, the phosphorus oxyacidified pulp slurry was dewatered to obtain a neutralized phosphorus oxyacidified pulp. Next, the washing treatment is performed on the neutralized phosphorus oxy-acidified pulp.

The measurement of the infrared absorption spectrum was performed using a Fourier transform infrared spectrometer (FT-IR) with respect to the phosphorus-oxygenated acidified pulp thus obtained. As a result, absorption of P=O based on a phosphoric acid group was observed around 1230 cm ⁻¹ , and it was confirmed that a phosphoric acid group was added to the pulp. In addition, the obtained phosphorus oxygen-containing acidified pulp was subjected to a test, and analyzed by an X-ray diffraction apparatus. As a result, two positions in the vicinity of 2θ=14° or more and 17° or less and 2θ=22° or more and 23° or less were obtained. A typical peak was observed, and cellulose I-type crystals were confirmed.

Ion-exchanged water was added to the obtained phosphorus oxy-acidified pulp 1 to prepare a slurry having a solid content concentration of 2% by mass. The slurry was treated twice under a pressure of 200 MPa using a wet micronizing apparatus (manufactured by Sugino Machine Co., Ltd., Star Burst) to obtain fine fibers containing fine fibrous cellulose. cellulose dispersion (1). By X-ray diffraction, it was confirmed that the fine fibrous cellulose maintained the cellulose I-type crystal. In addition, the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope and found to be 3 nm to 5 nm. The amount of phosphorus oxyacid groups (the first dissociated acid amount) was 1.45 mmol/g. Furthermore, the total amount of dissociated acid was 2.45 mmol/g.

<Production Example 2> [Production of Microfibrous Cellulose Dispersion Liquid (2)] Except having used 33 mass parts of phosphorous acid (phosphonic acid) instead of ammonium dihydrogen phosphate, it carried out similarly to manufacture example 1, and obtained the phosphorus oxyacidified pulp 2 and the fine fibrous cellulose dispersion liquid (2).

About the obtained phosphorus oxy-acidified pulp 2, the infrared absorption spectrum was measured using FT-IR. As a result, absorption of P=O based on a phosphoric acid group, which is a tautomer of a phosphoric acid group, was observed around 1210 cm ^-1 , and it was confirmed that a ()phosphorous acid group (phosphonic acid group) was added to the pulp.

In addition, the obtained phosphorus oxygen-containing acidified pulp 2 was subjected to a test, and analyzed by an X-ray diffraction apparatus. As a result, two locations in the vicinity of 2θ=14° or more and 17° or less and 2θ=22° or more and 23° or less were obtained. A typical peak was confirmed at the position, and it was confirmed that the cellulose I-type crystal was present.

It was confirmed by X-ray diffraction that the obtained fine fibrous cellulose maintained the cellulose I-type crystal. In addition, the fiber width of the fine fibrous cellulose was measured using a transmission electron microscope and found to be 3 nm to 5 nm. In addition, regarding the fine fibrous cellulose dispersion liquid (2), the amount of phosphorous acid groups introduced into cellulose (the first amount of dissociated acid) and the amount of total dissociated acid were 1.51 mmol/g and 1.54 mmol/g, respectively.

<Production Example 3> [Production of Microfibrous Cellulose Dispersion Liquid (3)] As raw material pulp, coniferous kraft pulp (undried) manufactured by Oji Paper Co., Ltd. was used. This raw material pulp was subjected to alkaline TEMPO oxidation treatment as follows. First, 100 parts by mass of the raw material pulp, 1.6 parts by mass of TEMPO (2,2,6,6-tetramethylpiperidine-1-oxyl radical), and 10 parts by mass of sodium bromide were dispersed in 100 parts by mass of dry mass. In 10,000 parts by mass of water. Next, 13 parts by mass of an aqueous sodium hypochlorite solution was added so as to be 3.8 mmol with respect to 1.0 g of pulp, and the reaction was started. During the reaction, a 0.5 M sodium hydroxide aqueous solution was added dropwise, the pH was kept at 10 or more and 10.5 or less, and the reaction was regarded as complete when no change in pH was seen.

Next, the obtained TEMPO oxidized pulp is washed. The washing treatment was performed by repeating the operation of dewatering the TEMPO-oxidized pulp slurry to obtain a dewatered sheet, pouring 5,000 parts by mass of ion-exchanged water, stirring to uniformly disperse it, and then filtering and dewatering. When the conductivity of the filtrate reached 100 μS/cm or less, it was taken as the cleaning end point.

In addition, the obtained TEMPO oxidized pulp was subjected to a test, and analyzed by an X-ray diffraction apparatus. As a result, it was confirmed at two positions in the vicinity of 2θ=14° or more and 17° or less and 2θ=22° or more and 23° or less. A typical peak was confirmed to have cellulose type I crystals.

Ion-exchanged water was added to the obtained TEMPO oxidized pulp to prepare a slurry having a solid content concentration of 2% by mass. The slurry was treated twice under a pressure of 200 MPa using a wet micronizing apparatus (manufactured by Sugino Machine Co., Ltd., Star Burst) to obtain fine fibers containing fine fibrous cellulose. cellulose dispersion (3).

Regarding the fine fibrous cellulose dispersion liquid (3), the amount of carboxyl groups introduced into cellulose was 1.30 mmol/g.

<Method for Measuring Fiber Width and Ionic Radical Content of Microfibrous Cellulose> [Measurement of fiber width] The fiber width of the fine fibrous cellulose was measured by the following method. The supernatant of the fine fibrous cellulose dispersion was diluted with water so that the concentration of the fine fibrous cellulose was 0.01 mass % or more and 0.1 mass % or less, and was dropped onto the hydrophilized carbon gate film. After drying, it was stained with uranyl acetate, and observed with a transmission electron microscope (manufactured by Nippon Electronics Co., Ltd., JEOL-2000EX).

[Determination of the amount of phosphorus oxyacid groups] The phosphorus oxyacid group content of the fine fibrous cellulose was measured by diluting the dispersion liquid containing the target fine fibrous cellulose with ion-exchanged water so that the content was 0.2 mass %, and the prepared After the slurry containing the fine fibrous cellulose was treated with an ion exchange resin, titration with an alkali was performed. The treatment with the ion exchange resin is carried out by adding 1/10 of the volume of a strongly acidic ion exchange resin (Amberjet 1024; Orga) to the slurry containing the fine fibrous cellulose Organo Co., Ltd., after conditioning), after vibrating for 1 hour, it was injected into a mesh with a pore size of 90 μm to separate the resin from the slurry. In addition, the titration using an alkali was performed by adding 10 μL of a 0.1 N aqueous sodium hydroxide solution every 5 seconds to the fine fibrous cellulose-containing slurry treated with the ion exchange resin, while The change in pH exhibited by the slurry was measured. In addition, 15 minutes before the start of titration, titration was performed, blowing nitrogen gas into the slurry. In this neutralization titration, in a curve plotting the pH measured with respect to the amount of alkali added, two points where the increase (differential value of pH with respect to the amount of alkali dropwise added) is extremely large were observed. Among these, the maximum point of the increase obtained first after adding the base is called the first end point, and the maximum point of the increase obtained next is called the second end point ( FIG. 1 ). The amount of base required from the beginning of the titration to the first end point is equal to the amount of the first dissociated acid in the slurry used for the titration. In addition, the amount of alkali required from the start of the titration to the second end point is equal to the total amount of dissociated acid in the slurry used for the titration. In addition, the value obtained by dividing the alkali amount (mmol) required from the start of the titration to the first end point by the solid content (g) in the slurry to be titrated was used as the amount of phosphoric acid groups (mmol/g).

[Measurement of the amount of carboxyl groups] Regarding the amount of carboxyl groups of the fine fibrous cellulose, 50 μL of a 0.1 N aqueous sodium hydroxide solution was added every 30 seconds to the slurry containing the fine fibrous cellulose treated with the ion exchange resin, except that , and measured in the same manner as in [Measurement of Phosphorus Oxy Acid Group Content]. The amount of carboxyl groups (mmol/g) was calculated by dividing the amount of alkali (mmol) required in the region corresponding to the first region shown in FIG. 2 by the solid content (g) in the slurry to be titrated in the measurement results.

<Production Example 4> [Manufacture of radiation-sensitive composition (1)] Into a flask equipped with a cooling pipe and a stirrer, 14.6 parts by mass of triethylenetetramine (manufactured by Tokyo Chemical Industry Co., Ltd.), 51 parts by mass of triethylamine, and 200 parts by mass of dichloromethane were charged. In an ice bath, 45 parts by mass of acryl chloride (manufactured by Tokyo Chemical Industry Co., Ltd.) was added dropwise to the solution over 1 hour, and after the dropwise addition was completed, the solution was stirred at room temperature for 1 hour. After adding 1 N of hydrochloric acid water to the reaction solution and washing, it was washed with an aqueous sodium hydrogencarbonate solution, and then washed with a 10% aqueous sodium chloride solution, and magnesium sulfate was added to the organic layer. After the solvent was distilled off under reduced pressure from the organic layer from which magnesium sulfate was removed by filtration, 36 g of a polymerizable acrylamide compound was obtained by drying under reduced pressure. IPA was added to make a mixture of 1.0 parts by mass of the obtained compound and 0.1 part by mass of 2-hydroxy-4'-(2-hydroxyethoxy)-2-methylpropiophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) to be 0.5 mass % and dissolve. Then, the radiation-sensitive composition (1) was prepared by filtering with a microporous filter having a pore diameter of 0.5 μm.

<Production Example 5> [Manufacture of radiation-sensitive composition (2)] 1-Methoxy-2-propanol was added to make dipentaerythritol hexaacrylate (DPHA) (manufactured by Shin-Nakamura Chemical Co., Ltd., NK ester A-DPH) 1.0 parts by mass and 2-hydroxy-4'-(2-hydroxyl Ethoxy)-2-methylpropiophenone (manufactured by Tokyo Chemical Industry Co., Ltd.) 0.1 part by mass of the mixture was dissolved in 0.5 mass %. Then, the radiation-sensitive composition (2) was prepared by filtering with a microporous filter having a pore diameter of 0.5 μm.

<Example 1> (dissolution of polyvinyl alcohol) Polyvinyl alcohol (PVA) (manufactured by Kuraray Co., Ltd., POVAL 105, degree of polymerization: 500, degree of saponification: 98 mol% to 99 mol%) was added to ion-exchanged water so that it became 0.5 mass % %, stirred at 95° C. for 1 hour and dissolved to obtain an aqueous polyvinyl alcohol solution.

(Manufacture of Radiation Sensitive Sheet) Ion-exchanged water was added to the fine fibrous cellulose dispersion liquid (1) having a solid content concentration of 2.0 mass % to prepare a fine fibrous cellulose dispersion liquid having a solid content concentration of 0.5 mass % (A). To 50 parts by mass of the obtained fine fibrous cellulose dispersion (A), 20 parts by mass of the polyvinyl alcohol aqueous solution and 30 parts by mass of the solution of the radiation-sensitive composition (1) were added and stirred. Furthermore, the liquid after mixing was measured so that the final basis weight of the sheet might be 50 g/m ² , spread on a commercially available acrylic plate, and dried with a dryer at 50° C. for 24 hours. In addition, a 150 mm-square barrier plate is arranged on the acrylic plate so that it becomes a predetermined basis weight. Through the above process, a radiation-sensitive sheet is obtained. The thickness of the obtained radiation-sensitive sheet was 38 μm.

<Example 2> With respect to 43 parts by mass of the fine fibrous cellulose dispersion liquid (A), except that the polyvinyl alcohol aqueous solution was set to 17 parts by mass and the solution of the radiation-sensitive composition (1) was set to 40 parts by mass, the same procedures were carried out. A radiation-sensitive sheet was obtained in the same manner as in Example 1.

<Example 3> With respect to 36 parts by mass of the fine fibrous cellulose dispersion liquid (A), except that the polyvinyl alcohol aqueous solution was set to 14 parts by mass and the solution of the radiation-sensitive composition (1) was set to 50 parts by mass, the same procedures were carried out. A radiation-sensitive sheet was obtained in the same manner as in Example 1.

<Example 4> Ion-exchanged water was added to the fine fibrous cellulose dispersion liquid (2) having a solid content concentration of 2.0 mass % to prepare a fine fibrous cellulose dispersion liquid (B) having a solid content concentration of 0.5 mass %. A radiation-sensitive sheet was obtained in the same manner as in Example 1, except that the fine fibrous cellulose dispersion liquid (B) was used instead of the fine fibrous cellulose dispersion liquid (A).

<Example 5> Ion-exchanged water was added to the fine fibrous cellulose dispersion liquid (3) having a solid content concentration of 2.0 mass % to prepare a fine fibrous cellulose dispersion liquid (C) having a solid content concentration of 0.5 mass %. A radiation-sensitive sheet was obtained in the same manner as in Example 1, except that the fine fibrous cellulose dispersion liquid (C) was used instead of the fine fibrous cellulose dispersion liquid (A).

<Example 6> A radiation-sensitive sheet was obtained in the same manner as in Example 1, except that the radiation-sensitive composition (2) was used instead of the radiation-sensitive composition (1).

<Comparative Example 1> (porous sheet) A wet sheet was prepared while decompressing the fine fibrous cellulose dispersion (A) on a 500-mesh polyester mesh. The solid content of the wet sheet was 10%. With respect to 100 parts of wet sheets, 100 parts of diethylene glycol dimethyl ether (manufactured by Toho Chemical Industry Co., Ltd., trade name: "Hisolve MDM") was uniformly applied to the obtained wet sheets. a. The pressure was further reduced to form a wet sheet containing water and an organic solvent. The solid content of the wet sheet was 10%. The wet sheet was dried with a 500-mesh polyester mesh at 80° C. for 3 minutes using a roll roll so that the wet sheet was in contact with the mirror surface to obtain a first dried sheet. The obtained first dried sheet was in a moist state. The sheet after the first drying was dried for 3 minutes using a dryer at 130° C. (second drying step). The obtained second dried sheet was in a dry state. The sheet was peeled off from the polyester web to obtain a sheet containing fine fibrous cellulose.

(Impregnation of Radiation Sensitive Resin) The sheet containing the fine fibrous cellulose was immersed in the solution of the radiation sensitive composition (1) and left to stand for 3 minutes. Then, the sheet was taken out, and the sheet was dried under reduced pressure using a decompression apparatus (MUE-2000) manufactured by ULVAC, and the solvent in the sheet was removed under reduced pressure. The basis weight of the resulting sheet was 50 g/m ² . In addition, the thickness of the obtained radiation-sensitive sheet was 70 μm.

<Comparative Example 2> A filter paper for chromatography (No51B, 87 g/m ² manufactured by Toyo Filter Paper Co., Ltd.) was immersed in the solution of the radiation-sensitive resin composition (1), and left to stand for 3 minutes. Then, the sheet was taken out, and the sheet was dried under reduced pressure using a decompression apparatus (MUE-2000) manufactured by ULVAC, and the basis weight of the sheet obtained by removing the solvent in the sheet under reduced pressure was 124 g. /m ² . In addition, the thickness of the obtained radiation-sensitive sheet was 170 μm.

[test methods] <Total light transmittance of sheet> The total light transmittance was measured according to JIS K 7361-1: 1997 using a haze meter (manufactured by Murakami Color Institute Co., Ltd., HM-150). The results are shown in Table 1.

＜Haze of sheet＞ The haze was measured according to JIS K 7136:2000 using a haze meter (manufactured by Murakami Color Technology Laboratory Co., Ltd., HM-150). The results are shown in Table 1.

<Patterning of sheet> A radiation-sensitive sheet or a resin-impregnated sheet was set in an exposure apparatus equipped with a metal halide lamp (manufactured by Eye Graphics Co., Ltd., model Eye Grandage ECS-4011GX/N, wavelengths from 200 nm to 450 nm). Next, a photomask (manufactured by Toppan Printing Co., Ltd., manufactured by synthetic quartz, L/S=400/400, 1100/1100 μm) was set on the sheet. At this time, a Shim Tape (manufactured by MISUMI Group Headquarters Co., Ltd., thickness 500 μm, made of SUS) was used, and the gap between the patterning substrate and the mask was set to 500 μm. Next, after setting the intensity of radiation at a wavelength of 365 nm to 500 mJ/cm ² using an illuminometer (OAI model 356, manufactured by OAI Optical Associates Inc.), exposure was performed using an exposure device.

Next, the exposed sheet was developed by immersion in IPA for 3 minutes. By the above, the patterned sheet|seat which removed the resin for radiation sensitive compositions only in the unexposed part of a sheet|seat was obtained.

Next, after immersing the sheet in an IPA solution of Solvent Red 49 for 3 minutes, it was immersed in IPA for 3 minutes for washing. By the above, the sheet|seat which was impregnated with Solvent Red 49 only in the part from which the resin for radiation sensitive compositions was removed was obtained.

The sheet was observed with an optical microscope, and if both L/S=400/400 μm and 1100/1100 μm were patterned, it was evaluated as “A”, and if the L/S=400/400 μm pattern was not formed, but the pattern was formed A pattern with L/S=1100/1100 μm was evaluated as “B”, and a pattern was not formed at both L/S=400/400 μm and 1100/1100 μm, it was evaluated as “C”. The results are shown in Table 1.

[Table 1] Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Comparative Example 1 Comparative Example 2 Microfibrous cellulose dispersion used A A A B C A A (filter paper) The radiation-sensitive resin composition used 1 1 1 1 1 2 1 (impregnated) 1 (impregnated) deployment Microfibrous cellulose (parts by mass) 50 43 36 50 50 50 70 70 PVA (parts by mass) 20 17 14 20 20 20 〇 〇 Radiation sensitive resin composition (parts by mass) 30 40 50 30 30 30 30 30 Evaluation results Total light transmittance (%) 91.7 91.6 91.8 91.2 91.6 80.0 41.1 24.0 Haze (%) 1.1 1.1 1.1 1.9 1.2 3.0 76.8 98.4 Pattern forming evaluation A A A A A B C C [Industrial Availability]

According to the present invention, a radiation-sensitive sheet having excellent transparency and capable of fine patterning can be provided, and a patterned sheet obtained by exposing and developing the radiation-sensitive sheet can be expected to be used in color filters for displays Or applications requiring transparency, such as conductive films for touch panels.

without

FIG. 1 is a graph showing the relationship between the dropwise addition amount of NaOH and pH with respect to a slurry containing fibrous cellulose having phosphorus oxyacid groups. FIG. 2 is a graph showing the relationship between the dropwise amount of NaOH and pH with respect to pulp containing fibrous cellulose having carboxyl groups.

Claims (13)

A radiation-sensitive sheet, comprising a radiation-sensitive composition, fine fibrous cellulose with a fiber width of 1,000 nm or less, and a hydrophilic polymer, and The content of the hydrophilic polymer is 10 parts by mass or more with respect to 100 parts by mass of the fine fibrous cellulose. The radiation-sensitive sheet according to claim 1, wherein the radiation-sensitive composition comprises a radiation-sensitive compound and a resin for a radiation-sensitive composition, and the solubility of the resin for a radiation-sensitive composition in a solvent is obtained by exposure to radiation. increase or decrease in response to irradiated radioactive compounds. The radiation-sensitive sheet according to claim 2, wherein the radiation-sensitive compound comprises at least one of a photoacid generator and a photopolymerization initiator. The radiation-sensitive sheet according to any one of Claims 1 to 3, wherein the content of the radiation-sensitive composition in the solid content of the radiation-sensitive sheet is 10% by mass or more. The radiation-sensitive sheet according to any one of claim 1 to claim 4, wherein the total light transmittance of the radiation-sensitive sheet is 70% or more. The radiation-sensitive sheet according to any one of claim 1 to claim 5, wherein the haze of the radiation-sensitive sheet is 10% or less. The radiation-sensitive sheet according to any one of Claims 1 to 6, wherein the fine fibrous cellulose has an anionic group. The radiation-sensitive sheet according to any one of Claims 1 to 7, wherein the fine fibrous cellulose has a phosphorus oxyacid group or a group derived from a phosphorus oxyacid group. The radiation-sensitive sheet according to any one of Claims 1 to 8, wherein the radiation-sensitive composition is dissolved in at least one of water, alcohol, and a mixed solvent of these. The radiation-sensitive sheet according to any one of claim 1 to claim 9, wherein the hydrophilic polymer is selected from polyethylene glycol, polyethylene oxide, polyvinyl alcohol and modified polyvinyl alcohol . The radiation-sensitive sheet according to any one of claim 1 to claim 10, wherein the radiation-sensitive sheet is a negative-type radiation-sensitive sheet. A patterned sheet in which at least a portion of an exposed portion or an unexposed portion of the radiation-sensitive sheet as claimed in any one of Claims 1 to 11 is removed. A radiation-sensitive composition for use in the radiation-sensitive sheet according to any one of claim 1 to claim 11.

Images