JP2019094388A - Adhesive composition - Google Patents

Abstract

To provide an adhesive composition that contains water-insoluble resin and has excellent adhesiveness.SOLUTION: An adhesive composition contains a water-insoluble resin, and a fine cellulose fiber containing an ionic group and/or a fine cellulose fiber complex formed by bonding the fine cellulose fiber containing the ionic group to a modifying group. The water-insoluble resin is a resin in which a solubility in 25°C water is 1 mg or less per 100 g water.SELECTED DRAWING: None

Description

  The present invention relates to adhesive compositions.

  In the past, petroleum-derived plastic materials, which are limited resources, were widely used, but in recent years, technology with less impact on the environment has come to be highlighted, and under such technological background, biomass is naturally abundant Various materials using cellulose fibers are attracting attention.

  For example, Patent Document 1 provides a water-based adhesive composition excellent in maximum point stress, maximum point elongation, and elastic modulus by containing a water-based resin adhesive and anion-modified or cation-modified cellulose nanofibers. It has been shown that it can.

JP, 2014-132072, A

  Patent Document 1 discloses only the invention relating to a water-based resin composition, and in the case of an adhesive composition containing a non-water-soluble resin, sufficient improvement in adhesion is required.

  The present invention relates to providing an adhesive composition containing a water-insoluble resin and having excellent adhesion.

That is, the gist of the present invention relates to the following [1].
[1] An adhesive composition comprising a non-water-soluble resin and a fine cellulose fiber composite comprising a fine cellulose fiber containing an ionic group and / or a fine cellulose fiber containing an ionic group and a modifying group bonded thereto.

  According to the present invention, it is possible to provide an adhesive composition containing a water-insoluble resin and having excellent adhesion.

[Adhesive composition]
The adhesive composition of the present invention comprises (1) a water-insoluble resin and (2) a cellulose-based component, that is, (a) fine cellulose fibers containing ionic groups and / or (b) fine cellulose fibers containing ionic groups And a fine cellulose fiber complex in which a modifying group is bonded to the In the present specification, “fine cellulose fiber having an ionic group” is referred to as “fine cellulose fiber”, and “fine cellulose fiber composite in which a modifying group is bonded to a fine cellulose fiber having an ionic group” is referred to as “fine cellulose fiber”. It may be described as "fine cellulose fiber composite".

  As a result of investigations by the present inventors, when various water-insoluble resins contain fine cellulose fibers and / or fine cellulose fiber composites containing ionic groups, the adhesiveness of the obtained adhesive composition to the substrate is obtained. Was found to improve. Although the detailed reason is unknown, addition of such a fine cellulose fiber and / or fine cellulose fiber composite improves dimensional stability, so that peeling with the substrate is less likely to occur. It is thought that the sex has improved.

  The concentration of the water-insoluble resin in the adhesive composition of the present invention is preferably 45.0% by mass or more, more preferably 50.0% by mass or more, and still more preferably 54. It is 0 mass% or more. On the other hand, from the same viewpoint, it is preferably 99.9% by mass or less, more preferably 99.5% by mass or less, and still more preferably 99.0% by mass or less.

  The concentration of the fine cellulose fiber or fine cellulose fiber composite containing an ionic group in the adhesive composition is preferably 0.1% by mass or more, more preferably 0.5% by mass or more from the viewpoint of adhesiveness. It is more preferably 1.0% by mass or more. On the other hand, from the same viewpoint, the content is preferably 40.0% by mass or less, more preferably 35.0% by mass or less, and still more preferably 30.0% by mass or less. In the case where both the fine cellulose fiber and the fine cellulose fiber composite containing an ionic group are contained in the adhesive composition, the concentration is the sum of both.

  The proportion of the fine cellulose fibers (converted amount) in the adhesive composition is preferably 0.1 parts by mass or more, more preferably 0.5 parts by mass with respect to 100 parts by mass of the water-insoluble resin from the viewpoint of adhesiveness. It is the above, More preferably, it is 1 mass part or more. On the other hand, from the same viewpoint, it is preferably 50 parts by mass or less, more preferably 30 parts by mass or less, and still more preferably 10 parts by mass or less based on 100 parts by mass of the water-insoluble resin. By setting the ratio of the fine cellulose fiber or the fine cellulose fiber composite in this manner, the fine cellulose fiber or the fine cellulose fiber composite is uniformly dispersed in the inside of the adhesive composition of the present invention, and as a result, the adhesion is improved. It is considered to improve.

  The term "fine cellulose fiber (equivalent amount)" refers to the mass of a fine cellulose fiber containing an ionic group (that is, one to which no modifying group is bonded) or modified to a fine cellulose fiber containing an ionic group It refers to the mass of the fine cellulose fiber complex in which the groups are bonded minus the mass of the modifying group. The fine cellulose fiber (converted amount) in the fine cellulose fiber composite can be measured by the method described in the examples described later.

[Water-insoluble resin]
The non-water-soluble resin in the present invention is a resin which does not dissolve in water or has extremely low solubility in water. Specifically, a resin whose solubility in water at 25 ° C. is 1 mg or less per 100 g of water is called a water-insoluble resin.

  The above solubility is as follows. 100 mg of resin is added to 1 L (25 ° C.) of water, and after stirring for 24 hours using a stirrer such as a stirrer, the solution (or suspension) is subjected to conditions of 3000 × g at 25 ° C. After centrifuging for 30 minutes to collect insoluble residue, the residue is dried at 105 ° C. for 3 days, and the mass after drying (dry mass) is measured. And when dry mass is less than 99 mg, it is judged that it is water-soluble, and the case of 99 mg or more is water-insoluble.

  As a non-water-soluble resin used by this invention, resin which has adhesiveness independently and resin which exhibits adhesiveness by using together with a hardening agent are mentioned as a preferable thing. The water-insoluble resin may be used alone or as a mixed resin of two or more.

  Specific examples of the water-insoluble resin include epoxy resin, urethane resin, acrylic resin, vinyl chloride resin, phenoxy resin, phenol resin, urea resin, melamine resin, polyimide resin, unsaturated polyester resin, diallyl phthalate resin and rubber resin Etc.

[Fine cellulose fiber containing an ionic group]
The fine cellulose fiber containing an ionic group used in the present invention is a fine cellulose fiber modified to contain an ionic group in the fine cellulose fiber. The fine cellulose fiber containing the ionic group used by this invention can obtain the adhesive composition excellent in adhesiveness by mixing with the non-water-soluble resin mentioned above. Fine cellulose fibers have a cellulose type I crystal structure due to the use of natural cellulose fibers as a raw material.

  The cellulose type I is a crystal form of natural cellulose, and the cellulose type I crystallinity means the ratio of the amount of crystalline region to the whole cellulose.

  The crystallinity of the fine cellulose fiber in the present invention is preferably 30% or more, more preferably 35% or more, still more preferably 40% or more, still more preferably 45% or more from the viewpoint of adhesion. It is. Further, from the viewpoint of the cost of the cellulose raw material to be used, it is preferably 95% or less, more preferably 90% or less, still more preferably 85% or less, and still more preferably 80% or less. In the present specification, the crystallinity of cellulose such as the fine cellulose fiber and the fine cellulose fiber composite in the present invention is specifically measured by the method described in the below-mentioned Examples.

  The average fiber diameter of the fine cellulose fiber containing an ionic group is preferably 0.1 nm or more, more preferably 0.5 nm or more, from the viewpoint of producing a fine cellulose fiber composite having a uniform fiber diameter, More preferably, it is 1.0 nm or more, more preferably 2.0 nm or more, and still more preferably 3.0 nm or more. From the same point of view, it is preferably 100 nm or less, more preferably 50 nm or less, still more preferably 20 nm or less, still more preferably 10 nm or less, still more preferably 6.0 nm or less, more preferably Is 5.0 nm or less. The average fiber diameter of the fine cellulose fiber containing an ionic group can be measured by the method described in the examples.

  The average fiber length of the fine cellulose fiber containing an ionic group is preferably 150 nm or more, more preferably 200 nm or more from the viewpoint of adhesion. From the same viewpoint, it is preferably 1000 nm or less, more preferably 750 nm or less, still more preferably 500 nm or less, and still more preferably 400 nm or less. The average fiber length of the fine cellulose fiber containing an ionic group can be measured by the method described in the examples.

  The average aspect ratio of the fine cellulose fiber containing an ionic group, that is, the value of fiber length / fiber diameter is preferably 1 or more, more preferably 10 or more, and still more preferably 20 or more from the viewpoint of adhesiveness. More preferably, it is 40 or more, more preferably 50 or more, and the upper limit thereof is preferably 250 or less, more preferably 200 or less, still more preferably 150 or less, still more preferably 100 or less. More preferably 90 or less. From the same viewpoint, when the average aspect ratio is in the above range, the standard deviation of the aspect ratio is preferably 60 or less, more preferably 50 or less, still more preferably 45 or less, and the lower limit is particularly set Although not preferred, it is preferably 4 or more from the viewpoint of economy. The average aspect ratio of the fine cellulose fiber containing an ionic group can be measured by the method described in the examples.

  The content of the ionic group is preferably 0.1 mmol / g or more, and more preferably 0.4 mmol / g, from the viewpoint of stable refinement and introduction of a modifying group, in the fine cellulose fiber containing the ionic group. Or more, more preferably 0.6 mmol / g or more. The upper limit thereof is preferably 3.0 mmol / g or less, more preferably 2.0 mmol / g or less, and still more preferably 1.8 mmol / g or less. The content of the anionic group when the ionic group is an anionic group can be measured by the method described in the examples.

  As an ionic group, an anionic group and a cationic group are mentioned, for example. As an anionic group, a carboxy group, a sulfuric acid group, a phosphoric acid group etc. are mentioned, for example, As a cationic group, the group which has oniums, such as ammonium, a phosphonium, a sulfonium, etc. in the group is mentioned. From the viewpoint of the introduction efficiency into the fine cellulose fiber, an anionic group is preferable as the ionic group, and a carboxy group is more preferable as the anionic group.

  In the present invention, the ion (counter ion) which becomes a pair of anionic group in the fine cellulose fiber containing an anionic group is preferably a proton from the viewpoint of dispersibility in the adhesive composition.

[Fine cellulose fiber composite]
In the present invention, one of the preferable embodiments of the fine cellulose fiber composite in which the modifying group is bonded to the fine cellulose fiber containing an ionic group is selected from the group consisting of an ionic group and a hydroxyl group contained in the fiber It is a fine cellulose fiber complex in which a modifying group is bonded to one or more groups. The fine cellulose fiber composite has a cellulose type I crystal structure due to the use of natural cellulose fibers as a raw material.

  The preferable range of the average fiber diameter, average fiber length, average aspect ratio, content of ionic group and crystallinity degree of cellulose of the fine cellulose fiber composite is the same as that of the fine cellulose fiber containing ionic group.

  The average bonding amount of the modifying group in the fine cellulose fiber composite is preferably 0.01 mmol / g or more, more preferably 0.05 mmol / g or more, and still more preferably 0.1 mmol / g from the viewpoint of adhesiveness. It is at least g, preferably at least 0.3 mmol / g, more preferably at least 0.5 mmol / g. Also, from the viewpoint of adhesion, it is preferably 3.0 mmol / g or less, more preferably 2.5 mmol / g or less, still more preferably 2.0 mmol / g or less, and still more preferably 1.8 mmol / g. It is at most g, more preferably at most 1.5 mmol / g. When arbitrary 2 or more types of modifying groups are simultaneously introduce | transduced into a fine cellulose fiber as a modifying group, it is preferable that the total amount of the modifying group currently introduce | transduced is within the said range for the average bonding amount of a modifying group.

  The introduction ratio of the modifying group in the fine cellulose fiber composite is preferably 10% or more, more preferably 30% or more, still more preferably 50% or more, and still more preferably 60% or more from the viewpoint of adhesiveness. Or more, more preferably 70% or more, and from the viewpoint of adhesiveness, preferably 99% or less, more preferably 97% or less, still more preferably 95% or less, still more preferably 90% It is below. When two or more arbitrary modifying groups are simultaneously introduced as the modifying group, it is preferable that the total introduction rate falls within the above range as long as the upper limit of 100% is not exceeded.

  In the present specification, the average bonding amount and introduction ratio of the modifying group can be adjusted by the addition amount of the compound having the modifying group, the type of the compound having the modifying group, the reaction temperature, the reaction time, the solvent and the like. The average bonding amount (mmol / g) and the introduction rate (%) of the modifying group mean the amount and ratio of the modifying group introduced to the ionic group or the hydroxyl group on the surface of the fine cellulose fiber. The ionic group content and hydroxyl group content of the fine cellulose fiber can be calculated by measurement according to a known method (for example, titration, IR measurement, etc.). For example, when the ionic group is an anionic group, the average bonding amount and the introduction rate of the modifying group are calculated by the method described in the examples.

  The ionic group in the fine cellulose fiber composite is the same as the fine cellulose fiber, and is preferably an anionic group, and the anionic group is preferably a carboxy group.

  The fine cellulose fiber composite can be used in the form of a dispersion, or a powdery fine cellulose fiber composite (powdered fine cellulose) obtained by removing the solvent from the dispersion by drying treatment or the like The fiber composite may optionally contain a predetermined amount of solvent). The method of the drying treatment is not particularly limited as long as it is a method capable of maintaining the quality of the fine cellulose fiber composite, and examples thereof include methods such as hot air, heater, drying by vacuum, freeze drying and spray drying.

[Method for producing fine cellulose fiber composite]
The method for producing the fine cellulose fiber composite can be produced according to a known method without particular limitation, as long as the modifying group can be introduced into the fine cellulose fiber containing the above-mentioned ionic group.

  The method for producing a fine cellulose fiber composite includes, for example, introducing ionic groups into raw material cellulose fibers to obtain cellulose fibers containing ionic groups, introducing modifying groups into cellulose fibers containing ionic groups And a step of obtaining a cellulose fiber composite in which a modifying group is bonded to a cellulose fiber containing an ionic group, and a cellulose fiber composite in which a modifying group is bonded to a cellulose fiber containing an ionic group And obtaining a fine cellulose fiber composite in which the modifying group is bonded to the fine cellulose fiber containing an ionic group.

  In the method for producing a fine cellulose fiber composite, as the first production mode, as described above, the step of introducing an ionic group, the step of introducing a modifying group, and the step of micronizing treatment may be performed in this order Instead of this, as the second embodiment, the step of introducing an ionic group, the step of miniaturizing treatment, and the step of introducing a modifying group may be performed in this order. The method of the refinement | miniaturization process in a refinement | miniaturization treatment process can be performed by disperse | distributing the cellulose fiber composite which the cellulose fiber or modification group containing an ionic group couple | bonds in a solvent. The specific processing method can be implemented, for example, with reference to the description of the miniaturization process described in JP-A-2013-151661.

  As a raw material cellulose fiber, it is preferable to use natural cellulose fiber from an environmental load viewpoint. Examples of natural cellulose fibers include wood pulp such as softwood pulp and hardwood pulp; cotton pulp such as cotton linters and cotton lint; non-wood pulp such as straw pulp and bagasse pulp; bacterial cellulose and the like These 1 type can be used individually or in combination of 2 or more types.

(Aspect in which the ionic group is a cationic group)
When the ionic group is a cationic group, examples of the method of introducing the cationic group into the cellulose fiber include a method of treating the cellulose fiber with a cationizing agent in the presence of an alkali.

(Aspect in which the ionic group is an anionic group)
When the anionic group is a sulfonic acid group, as a method of introducing the sulfonic acid group to the cellulose fiber, there is a method of adding sulfuric acid to the cellulose fiber and heating it.
When the anionic group is a phosphoric acid group, as a method of introducing a phosphoric acid group to cellulose fiber, a method of mixing phosphoric acid or phosphoric acid derivative powder or aqueous solution with dry or wet cellulose fiber, cellulose The method of adding the aqueous solution of phosphoric acid or a phosphoric acid derivative to the dispersion liquid of a fiber, etc. are mentioned. When these methods are adopted, preferably, after mixing or adding phosphoric acid or a powder or an aqueous solution of a phosphoric acid derivative, dehydration treatment, heat treatment and the like are performed. As a method for introducing a modifying group, a compound having a modifying group, for example, a primary amine to a tertiary amine described later, etc., is mixed with a cellulose fiber having a phosphate group or a fine cellulose fiber having a phosphate group. Methods etc.

  When the anionic group is a carboxy group, as shown below, an embodiment (aspect A) in which the modifying group is bound to the cellulose fiber or the fine cellulose fiber by ionic bond, the modifying group is bound to the cellulose fiber or the fine cellulose fiber by covalent bond Aspect (aspect B). In addition, as a covalent bond, the case of an amide bond is shown below.

(Aspect A)
Step (1): A step of oxidizing natural cellulose fibers in the presence of an N-oxyl compound to obtain carboxy group-containing cellulose fibers.
Step (2A): a step of mixing the carboxy group-containing cellulose fiber (or carboxy group-containing fine cellulose fiber) obtained in step (1) with a compound having a modifying group.

(Aspect B)
Step (1): A step of oxidizing natural cellulose fibers in the presence of an N-oxyl compound to obtain carboxy group-containing cellulose fibers.
Step (2B): a step of amidating the carboxy group-containing cellulose fiber (or carboxy group-containing fine cellulose fiber) obtained in step (1) with a compound having a modifying group.

Process (1)
In this step, natural cellulose fibers are subjected, for example, to an oxidation treatment step (for example, oxidation treatment using TEMPO as a catalyst) described in JP-A-2015-143336, and, if necessary, a purification step. And cellulose fibers containing carboxy groups are obtained.

  The method for oxidizing the hydroxyl group of cellulose is not particularly limited. For example, sodium hypochlorite using a catalyst such as 2,2,6,6-tetramethyl-1-piperidine-N-oxyl (TEMPO) as a catalyst A method of reacting by oxidizing an oxidizing agent and a bromide such as sodium bromide can be applied. In more detail, the method of Unexamined-Japanese-Patent No. 2011-140632 can be referred to.

By performing oxidation treatment of cellulose fibers using TEMPO as a catalyst, the hydroxymethyl group (-CH ₂ OH) at the C6 position of the cellulose structural unit is selectively converted to a carboxy group. In particular, this method is advantageous in that it is excellent in the selectivity of the hydroxyl group at the C6 position to be oxidized on the surface of the raw material cellulose fiber, and the reaction conditions are also mild. Therefore, as a preferable aspect of the fine cellulose fiber containing the carboxy group in this invention, the cellulose fiber whose C6 position of a cellulose structural unit is a carboxy group is mentioned.

  By introducing a carboxy group into the cellulose fiber by any of the methods described above, the raw material cellulose fiber is modified with the carboxy group to become a cellulose fiber containing a carboxy group. At this point, the miniaturization process has not been performed. It is preferable to further carry out a reduction treatment and a low aspect ratio treatment on the cellulose fiber containing a carboxy group.

Process (2A)
This step is carried out by mixing (1) carboxy group-containing cellulose fiber or (2) carboxy group-containing fine cellulose fiber with a compound having a modifying group in a solvent. This process can be implemented with reference to the method as described in the process (B) of Unexamined-Japanese-Patent No. 2015-143336, for example.

Process (2B)
In this step, (1) carboxy group-containing cellulose fiber or (2) carboxy group-containing fine cellulose fiber and a compound having a modifying group are mixed in the presence of a condensing agent and contained in (fine) cellulose fiber The carboxy group and the amino group of the compound having a modifying group are condensed to form an amide bond. This process can be implemented with reference to the method as described in the process (B) of Unexamined-Japanese-Patent No. 2015-143337, for example.

  In the step (2A) or the step (2B), when the object to be in contact with the compound having a modifying group is (1) a carboxy group-containing cellulose fiber, the step of miniaturizing treatment is performed after the step (2A) or the step (2B) (Corresponding to the above-mentioned “first manufacturing mode”). Alternatively, in the step (2A) or the step (2B), when the object to be in contact with the compound having a modifying group is (2) a carboxy group-containing fine cellulose fiber, the micronization treatment is performed before the step (2A) or the step (2B) A process is implemented (it corresponds to the above-mentioned "2nd manufacturing form").

  In addition, the fine cellulose fiber composite may be a fiber composite obtained by combining aspect A and aspect B. In this case, any of the steps (2A) and (2B) may be performed first.

  As a specific bonding mode of the modifying group to the carboxy group, a compound having a modifying group at the carboxy group is more preferably bound via an ionic bond and / or a covalent bond. Specific bonding modes to the carboxy group include ionic bonds with amine salts and the like, and covalent bonds such as amide bonds, ester bonds and urethane bonds.

  In order to bind a modifying group to a carboxy group and / or a hydroxyl group contained in a cellulose fiber, for example, it is preferable to use a compound having a modifying group (also referred to as a “modifying compound”). As the modifying compound, an appropriate one may be selected according to the manner of bonding to the carboxy group or hydroxyl group of the cellulose fiber.

  When the bonding mode is ionic bonding, examples of the modifying compound include primary amines, secondary amines, tertiary amines, quaternary ammonium compounds and phosphonium compounds. In these compounds, various modifying groups such as hydrocarbon groups such as chain saturated hydrocarbon group, chain unsaturated hydrocarbon group, cyclic saturated hydrocarbon group, aromatic hydrocarbon group and the like, and And copolymerization sites can be introduced. These groups and sites may be introduced alone or in combination of two or more.

  Examples of primary amines to tertiary amines include propylamine, dipropylamine, butylamine, dibutylamine, hexylamine, hexylamine, dihexylamine, octylamine, dioctylamine, trioctylamine, dodecylamine, dodecylamine, didodecylamine, and the like. Examples include stearylamine, aniline, octadecylamine and dimethyl behenylamine. Examples of quaternary ammonium compounds include tetraethylammonium hydroxide (TEAH), tetrabutylammonium hydroxide (TBAH), and tetrapropylammonium hydroxide (TPAH). Among these, from the viewpoint of adhesion, hexylamine, dodecylamine, dihexylamine, octylamine, dioctylamine, trioctylamine, dodecylamine, didodecylamine and distearylamine are preferred.

  When a quaternary ammonium compound and a phosphonium compound are used as the modifying compound, halide ions such as chloride ion and bromide ion, hydrogen sulfate ion, and the like are preferably used as the anion component from the viewpoint of reactivity. A chlorate ion, a tetrafluoroborate ion, a hexafluorophosphate ion, a trifluoromethanesulfonate ion and a hydroxy ion can be mentioned, and more preferably a hydroxy ion can be mentioned.

  When the binding mode is a covalent bond, an appropriate modifying compound is used depending on whether the carboxy group is modified or the hydroxy group is modified. When modifying a carboxy group, for example, when modifying via an amide bond, it is preferable to use, for example, a primary amine and a secondary amine as a modifying compound. When modifying via an ester bond, it is preferable to use an alcohol such as butanol, octanol and dodecanol as the modifying compound. When modifying via a urethane bond, it is preferable to use, for example, an isocyanate compound as the modifying compound. In these compounds, various modifying groups such as hydrocarbon groups such as chain saturated hydrocarbon group, chain unsaturated hydrocarbon group, cyclic saturated hydrocarbon group, aromatic hydrocarbon group and the like, and And copolymerization sites can be introduced. These groups and sites may be introduced alone or in combination of two or more.

  When modifying a hydroxyl group, for example, when modifying it via an ester bond, it is preferable to use, for example, an acid anhydride as a modifying compound, and in particular, it is preferable to use acetic anhydride, propionic anhydride and succinic anhydride. In the case of modification via an ether bond, for example, epoxy compounds (for example, alkylene oxide and alkyl glycidyl ether), alkyl halides and derivatives thereof (for example, methyl chloride, ethyl chloride and monochloroacetic acid) are preferable as the modifying compound. When modifying via a urethane bond, it is preferable to use, for example, an isocyanate compound as the modifying compound. In these compounds, various modifying groups such as hydrocarbon groups such as chain saturated hydrocarbon group, chain unsaturated hydrocarbon group, cyclic saturated hydrocarbon group, aromatic hydrocarbon group and the like, and And copolymerization sites can be introduced. These groups and sites may be introduced alone or in combination of two or more.

  When the chain saturated hydrocarbon group described above as a modifying group is introduced into the modifying compound, the chain saturated hydrocarbon group may be linear or branched. The carbon number of the chain saturated hydrocarbon group is preferably 1 or more and 30 or less, more preferably 2 or more and 24 or less, and still more preferably 3 or more, from the viewpoint of handleability. It is 18 or less.

  When a chain unsaturated hydrocarbon group described above as a modifying group is introduced into the modifying compound, the chain unsaturated hydrocarbon group may be linear or branched. The number of carbon atoms in one modifying group is preferably 1 or more and 30 or less, more preferably 2 or more and 18 or less, and still more preferably 3 or more and 12 or less.

  When the cyclic saturated hydrocarbon group described above as the modifying group is introduced into the modifying compound, the carbon number of one cyclic saturated hydrocarbon group is preferably 3 or more and 20 or less. More preferably, it is 4 or more and 16 or less, and more preferably 5 or more and 16 or less.

  When the aromatic hydrocarbon group described above as the modifying group is introduced into the modifying compound, examples of the aromatic hydrocarbon group include substituted or unsubstituted aryl groups and aralkyl groups. The aryl group and the aralkyl group may be those in which the aromatic ring itself is substituted or unsubstituted. The carbon number of the aryl group is 6 or more, preferably 24 or less, more preferably 20 or less, still more preferably 14 or less, still more preferably 12 or less, still more preferably 10 or less. On the other hand, the total carbon number of the aralkyl group is 7 or more, preferably 8 or more, preferably 24 or less, more preferably 20 or less, still more preferably 14 or less, still more preferably 13 or less More preferably, it is 11 or less.

  When the modifying group is a hydrocarbon group and the hydrocarbon group has a substituent, the substituent may be, for example, a straight chain having 1 to 6 carbon atoms, provided that the number of carbons in the modifying group satisfies the above range. Or a branched alkoxy group; a linear or branched alkoxycarbonyl group having 1 to 6 carbon atoms of the alkoxy group; a halogen atom such as a bromine atom or an iodine atom; an acyl group having 1 to 6 carbon atoms; an aralkyl group; Group: an alkylamino group having 1 to 6 carbon atoms; a dialkylamino group having 1 to 6 carbon atoms in an alkyl group, a hydroxyl group, an ether, an amide or the like may be used. In addition, the various hydrocarbon groups described above may be bonded to another hydrocarbon group as a substituent.

  Commercial products can be used as primary amines, secondary amines, tertiary amines, quaternary ammonium compounds, phosphonium compounds, acid anhydrides and isocyanate compounds having as various modifying groups described above. It can be prepared according to the method of

  In the fine cellulose fiber composite in the present invention, the modifying group can include a copolymerization site. As such a copolymerization site, for example, an ethylene oxide / propylene oxide (EO / PO) copolymerization site can be used. The EO / PO copolymerization site means a structure in which ethylene oxide (EO) and propylene oxide (PO) are randomly or block-polymerized.

  From the viewpoint of adhesion, the content (mol%) of PO in the EO / PO copolymer site is preferably 1 mol% or more, more preferably 5 mol% or more, still more preferably 7 mol% or more More preferably, it is 10 mol% or more. From the same viewpoint, it is preferably 100 mol% or less, more preferably 90 mol% or less, still more preferably 85 mol% or less, still more preferably 75 mol% or less, still more preferably 60 mol% Or less, more preferably 50 mol% or less, still more preferably 40 mol% or less, and still more preferably 30 mol% or less.

  The molecular weight of the EO / PO copolymerized site is preferably 500 or more, more preferably 1,000 or more, and still more preferably 1,500 or more from the viewpoint of adhesion. From the same viewpoint, it is preferably 10,000 or less, more preferably 7,000 or less, still more preferably 5,000 or less, still more preferably 4,000 or less, more preferably 3,500. Or less, more preferably 2,500 or less.

  When the modifying compound is an amine having an EO / PO copolymerization site and an amino group, the EO / PO copolymerization site and the amino group may be directly bonded or may be bonded via a linking group. It may be done. As the linking group, for example, a hydrocarbon group is preferable, and an alkylene group having a carbon number of preferably 1 or more and 6 or less, more preferably 1 or more and 3 or less is used. As an alkylene group, an ethylene group and a propylene group are preferable, for example.

  Examples of the amine having an EO / PO copolymerization site (also referred to as "EOPO amine") include compounds represented by the following formula (i).

[Wherein, R ₁ represents a hydrogen atom or a linear or branched alkyl group having 1 to 6 carbon atoms, EO and PO are present in a random or block shape, and a is a positive average molar number of EO] And b is a positive number indicating the average added mole number of PO. ]

  A in the formula (i) represents the average addition mole number of EO and is preferably 11 or more, more preferably 15 or more, still more preferably 20 or more, still more preferably 25 or more from the viewpoint of adhesiveness More preferably, it is 30 or more. From the same viewpoint, it is preferably 100 or less, more preferably 70 or less, further preferably 60 or less, still more preferably 50 or less, and still more preferably 40 or less.

  B in formula (i) represents the average added mole number of PO, and is preferably 1 or more, more preferably 3 or more, and still more preferably 5 or more from the viewpoint of adhesion. From the same viewpoint, it is preferably 50 or less, more preferably 40 or less, still more preferably 30 or less, still more preferably 25 or less, still more preferably 20 or less, still more preferably 15 or less. It is more preferably 10 or less.

  When the amine is represented by the formula (i), the content (mol%) of PO in the EO / PO copolymer site can be calculated based on the a and b, specifically, It can be determined from b × 100 / (a + b). The preferred range of the content of PO is as described above.

R ₁ in formula (i) is preferably a hydrogen atom from the viewpoint of adhesion. When R ₁ is a linear or branched alkyl group having 1 to 6 carbon atoms, the alkyl group is preferably a methyl group, an ethyl group, an n-propyl group and a sec-propyl group.

  The detail about the amine which has an EO / PO copolymerization site | part represented by Formula (i) is described, for example in the patent 6105139.

  As the EOPO amine, for example, a commercially available product can be suitably used. Specific examples thereof include Jeffamine M-2070, Jeffamine M-2005, Jeffamine M-2095, Jeffamine M-1000, and Jeffamine M-600 manufactured by HUNTSMAN. Surfoamine B200, Surfoamine L100, Surfoamine L200, Surfoamine L207, Surfoamine L300, XTJ-501, XTJ-506, XTJ-507, XTJ-508; BASF M3000, Jeffamine ED-900, Jeffamine ED-2003, Jeffamine D -2000, Jeffamine D-4000, XTJ-510, Je ffamine T-3000, Jeffamine T-5000, XTJ-502, XTJ-509, XTJ-510 etc. are mentioned.

[Hardener]
In the present invention, a curing agent may be used. The curing agent may be contained in the adhesive composition of the present invention, or may be filled in a container different from the adhesive composition. As the curing agent, known ones can be selected and used according to the type of water-insoluble resin to be used.

  When the water-insoluble resin is an epoxy resin, those used as curing agents for common epoxy resins, aliphatic polyamines, aromatic polyamines, dicyandiamides, polycarboxylic acids, polycarboxylic acid hydrazides, acid anhydrides, polymercaptans, There are a compound which undergoes a stoichiometric reaction such as polyphenol and a compound which acts catalytically such as imidazole, Lewis acid complex, onium salt. In the case of using a compound which undergoes a stoichiometric reaction, curing accelerators such as various amines, imidazole, Lewis acid complex, onium salt, phosphine and the like can be mentioned.

  When the non-water-soluble resin is a urethane resin, those used as a curing agent for ordinary urethane resins, specifically, aromatic isocyanates, may be mentioned.

  The amount of the curing agent in the present invention is not particularly limited, and an appropriate amount may be appropriately adopted depending on the type of the curing agent.

[Other ingredients]
The adhesive composition of the present invention may optionally contain components known in the field of adhesive compositions such as polymerization initiators, plasticizers, stabilizers, and lubricants. The amount of the component is not particularly limited, and an appropriate amount may be appropriately employed.

[Method of producing adhesive composition]
The adhesive composition of the present invention can be produced by mixing a non-water-soluble resin and a fine cellulose fiber and / or a fine cellulose fiber composite containing an ionic group. Furthermore, solvents, curing agents and other components described above can be mixed as required.

  The method of mixing each component which comprises adhesive composition is not specifically limited, For example, the method of using a stirrer, an ultrasonic homogenizer, a high pressure homogenizer, etc. is mentioned.

  As the solvent, for example, dimethylformamide, ethyl acetate, methyl methacrylate, ethanol, isopropanol, N, N-dimethylformamide (DMF), dimethylsulfoxide (DMSO), N, N-dimethylacetamide, tetrahydrofuran (THF), succinic acid And diesters of triethylene glycol monomethyl ether, acetone, methyl ethyl ketone (MEK), acetonitrile, dichloromethane, chloroform, toluene, acetic acid and the like, and one of these may be used alone or in combination of two or more. When a solvent is used, the amount is, for example, preferably 50 parts by mass or more, more preferably 100 parts by mass or more, and preferably 5000 parts by mass with respect to 100 parts by mass of the water-insoluble resin. It is the following, more preferably 2000 parts by mass or less.

  EXAMPLES Hereinafter, the present invention will be specifically described by showing Examples and Comparative Examples, but the present invention is not limited to the following Examples.

Crystallinity of Cellulose
The crystallinity of cellulose in the fine cellulose fiber and the fine cellulose fiber composite is a cellulose type I crystallinity calculated by the Segal method from the diffraction intensity value by the X-ray diffraction method, and is defined by the following formula (A) .
Cellulose type I crystallinity (%) = [(I22.6−I18.5) /I22.6] × 100 (A)
[Wherein, I22.6 is the diffraction intensity of the grating surface (002 plane) (diffraction angle 2θ = 22.6 °) in X-ray diffraction, I18.5 is the amorphous part (diffraction angle 2θ = 18.5 °) Shows the diffraction intensity of ]

[Average fiber diameter of fine cellulose fiber and fine cellulose fiber composite]
Water or ethanol is added to the fine cellulose fiber or the fine cellulose fiber composite to prepare a dispersion having a concentration of 0.0001% by mass, and the dispersion is dropped on mica (mica) and observed to be dried. As a sample, using an atomic force microscope (AFM, Nanoscope III Tapping mode AFM, manufactured by Digital instrument, using a point probe (NCH) manufactured by Nanosensors), the fiber height of the cellulose fiber in the observation sample Measure the At that time, in a microscope image in which the cellulose fibers can be confirmed, five or more fine cellulose fibers or a fine cellulose fiber complex are extracted, and the average fiber diameter is calculated from the heights of the fibers. The average fiber length is calculated from the distance in the fiber direction. The average aspect ratio is calculated from the average fiber length / average fiber diameter, and the standard deviation is also calculated.

[Anionic Group Content of Fine Cellulose Fiber and Fine Cellulose Fiber Complex]
A dry mass of 0.5 g of fine cellulose fiber or fine cellulose fiber complex is taken in a 100 mL beaker, ion exchange water is added to make a total of 55 mL, and 5 mL of an aqueous solution of 0.01 M sodium chloride is added thereto to prepare a dispersion. The dispersion is agitated until the fine cellulose fiber or fine cellulose fiber composite is sufficiently dispersed. The pH is adjusted to 2.5 to 3 by adding 0.1 M hydrochloric acid to this dispersion, and a 0.05 M aqueous solution of sodium hydroxide is added using an automatic titrator (trade name "AUT-50" manufactured by Toa DK Co., Ltd.). The dispersion is dropped on the condition of a waiting time of 60 seconds, and the conductivity and pH value are measured every minute. Measurement is continued until the pH is around 11, and a conductivity curve is obtained. The sodium hydroxide titer is determined from this conductivity curve, and the anionic group content of the fine cellulose fiber or the fine cellulose fiber composite is calculated by the following equation.
Anionic group content (mmol / g) = sodium hydroxide titer × sodium hydroxide aqueous solution concentration (0.05 M) / mass of fine cellulose fiber or fine cellulose fiber composite (0.5 g)

[Average binding amount and introduction ratio of modifying groups of fine cellulose fiber composite (ion binding)]
The binding amount of the modifying group is determined by the following IR measurement method, and the average binding amount and the introduction ratio are calculated by the following formula. Specifically for IR measurement, the dried fine cellulose fiber or fine cellulose fiber complex is subjected to an ATR method using an infrared absorption spectrometer (IR) (trade name: Nicolet 6700 manufactured by Thermo Fisher Scientific Co., Ltd.). The average binding amount and the introduction rate of the modifying group by ionic bonding are calculated by the following equation. The following shows the case where the anionic group is a carboxy group. The following “peak intensity at 1720 cm ⁻¹ ” is a peak intensity derived from a carbonyl group. In the case of an anionic group other than a carboxy group, the value of peak intensity may be appropriately changed to calculate the average bonding amount and the introduction ratio of the modifying group.

Bonding amount of modifying group (mmol / g) = [carboxy group content of fine cellulose fiber (mmol / g)] × [(peak intensity of fine cellulose fiber at 1720 cm ⁻¹ -fine cellulose fiber composite after modification group introduction peak intensity of 1720 cm ^-1 of the peak intensity of 1720 cm ^-1) / fine cellulose fibers]

  Introduction ratio of modification group (%) = 100 × (binding amount of modification group (mmol / g)) / (carboxy group content in fine cellulose fiber before introduction (mmol / g))

[Average binding amount and introduction ratio of modifying groups of fine cellulose fiber composite (amide bond)]
The average bonding amount of the modifying group by an amide bond is calculated by the following formula.
Bonding amount of modifying group (mmol / g) = (carboxy group content in fine cellulose fiber before modifying group introduced (mmol / g))-(carboxy group content in fine cellulose fiber composite after modifying group introduced) (Mmol / g))

  Introduction ratio of modification group (%) = 100 × (binding amount of modification group (mmol / g)) / (carboxy group content in fine cellulose fiber before introduction (mmol / g))

[Fine cellulose fiber (converted amount) in fine cellulose fiber composite]
The fine cellulose fiber (converted amount) in the fine cellulose fiber composite is measured by the following method.
(1) When One Type of Modification Compound to be Added The amount (converted amount) of the fine cellulose fiber is calculated by the following formula A.
<Formula A>
Fine cellulose fiber amount (converted amount) (g) = mass of fine cellulose fiber composite (g) / [1 + molecular weight of compound for modification (g / mol) × modification amount of binding group (mmol / g) × 0.001 ]

(2) In the case where two or more kinds of modifying compounds are added, the molar ratio of each modifying compound (ie, the molar ratio when the total molar amount of the modifying compounds to be added is 1) is considered Calculate the amount of cellulose fiber (converted amount). Formula B below is a case where two types of modifying compounds are used, and the molar ratio of the first modifying compound to the second modifying compound is as follows: first modifying compound: second modifying compound = X: ( It is a formula which computes the amount (conversion amount) of fine cellulose fibers in the case of being 1-X).
<Formula B>
Fine cellulose fiber amount (converted amount) (g) = mass of fine cellulose fiber composite (g) / [1 + molecular weight of first modification compound (g / mol) × X × modification amount of bonding group (mmol / g) X 0.001 + molecular weight of the second modification compound (g / mol) x (1-X) x bonding amount of modifying group (mmol / g) x 0.001]

When the bonding mode of the fine cellulose fiber and the modifying compound is an ionic bond, in the above-mentioned Formula A and Formula B, the “molecular weight of the modifying compound” means that the modifying compound is a primary amine or a secondary When it is an amine or a tertiary amine, it refers to "the molecular weight of the whole modification compound including the copolymerized part", and when the compound having a modifying group is a quaternary ammonium compound or a phosphonium compound, "(copolymerized part And the molecular weight of the whole of the modifying compound), and the “molecular weight of the anion component”.
On the other hand, when the bonding mode between the fine cellulose fiber and the modifying compound is an amide bond, in the above-mentioned Formula A and Formula B, the "molecular weight of the modifying compound" means that the modifying compound is a primary amine or a secondary When it is an amine, it is "(The molecular weight of the whole compound which has a modifying group including a copolymerization part) -18".

[Preparation of Fine Cellulose Fiber]
Preparation Example 1
Softwood bleached kraft pulp (Fletcher Challenge Canada, trade name "Machenzie", CSF 650 ml) was used as a natural cellulose fiber. As TEMPO, a commercial item (manufactured by ALDRICH, Free radical, 98% by mass) was used. Sodium hypochlorite and sodium bromide were commercially available products.

  First, 100 g of softwood bleached kraft pulp fiber is sufficiently stirred with 9900 g of ion-exchanged water, and 1.25 g of TEMPO, 12.5 g of sodium bromide and 28.4 g of sodium hypochlorite with respect to 100 g of the pulp mass. It added in order. The pH was maintained at 10.5 by dropwise addition of a 0.5 M aqueous solution of sodium hydroxide using pH stat titration with an automatic titrator (trade name: AUT-701, manufactured by Toa DK Co., Ltd.). The reaction was carried out for 120 minutes (20 ° C.). The dropping of the sodium hydroxide aqueous solution was stopped to obtain an oxidized pulp. The obtained oxidized pulp was thoroughly washed with ion exchange water and then subjected to a dehydration treatment. After that, 3.9 g of oxidized pulp and 296.1 g of ion-exchanged water are subjected to refinement treatment of oxidized pulp twice at 245 MPa using a high pressure homogenizer (manufactured by Sugino Machine Co., Ltd., trade name: Starburst Lab HJP-25005), A dispersion (fines concentration 1.3 mass%) of a fine cellulose fiber containing a Na salt type carboxy group was obtained. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the content of carboxy groups was 1.8 mmol / g, and the degree of crystallinity was 60%.

Preparation Example 2
In a beaker were placed 5088.75 g (solid content concentration: 1.3% by mass) of the dispersion of fine cellulose fibers containing carboxy groups obtained in Preparation Example 1 and 4085 g of deionized water to make a 0.5% by mass aqueous solution, The mixture was stirred for 30 minutes at room temperature (25 ° C.) with a mechanical stirrer. Subsequently, 245 g of a 1 M aqueous hydrochloric acid solution was charged in a beaker, and stirred at room temperature for 1 hour for reaction.
After completion of the reaction, the reaction solution was filtered and then washed with ion exchanged water to remove hydrochloric acid and salts. After solvent substitution with acetone, solvent substitution with methyl ethyl ketone (MEK) was performed to obtain a dispersion (solid content concentration: 3.2 mass%) of MEK-containing acid type fine cellulose fibers in a state in which the fine cellulose fibers were swollen. The average fiber diameter of this fine cellulose fiber was 3.3 nm, the content of carboxy groups was 1.8 mmol / g, and the degree of crystallinity was 60%.

Preparation of EOPO Amine
Preparation Example 3
132 g (1 mol) of propylene glycol tertiary butyl ether was charged in a 1 L autoclave, heated to 75 ° C., 1.2 g of potassium hydroxide in the form of flakes was added, and stirred until it was dissolved. Next, ethylene oxide (EO) and propylene oxide (PO) in the amounts shown in Table 1 are supplied to the autoclave and reacted at 110 ° C. and 0.34 MPa, and then magnesium silicate (Dallas Group, Inc., trade name: 7.14 g of Magnesol 30/40 was added and neutralized at 95 ° C. To the obtained product, 0.16 g of di-tert-butyl-p-cresol was added, mixed, and filtered to obtain a polyether which is an EO / PO copolymer.

On the other hand, in a 1.250 mL tubular reaction vessel filled with a catalyst of nickel oxide / copper oxide / chromium oxide (molar ratio: 75/23/2) (Wako Pure Chemical Industries, Ltd.), the polyether obtained above (8 .4 mL / min), ammonia (12.6 mL / min) and hydrogen (0.8 mL / min) were respectively supplied. The temperature of the vessel was maintained at 190 ° C. and the pressure was maintained at 14 MPa. The crude effluent from the vessel was evaporated under reduced pressure at 70 ° C. and 3.5 mmHg for 30 minutes. The flask was charged with 200 g of the resulting aminated polyether and 93.6 g of a 15% aqueous hydrochloric acid solution, the mixture was heated at 100 ° C. for 3.75 hours, and the tertiary butyl ether was cleaved with hydrochloric acid. The product was then neutralized with 144 g of a 15% aqueous potassium hydroxide solution. Next, the neutralized product was distilled off under reduced pressure at 112 ° C. for 1 hour and filtered to obtain a monoamine having an EO / PO copolymer represented by the formula (i). In the monoamine obtained, the EO / PO copolymer and the amine were directly bonded, and R ₁ in the formula (i) was a hydrogen atom.

The molecular weight of the EO / PO copolymer part is, for example, in the case of the amine of Table 1,
1409 [EO molecular weight (44.03) × EO addition mole number (32)] + 522 [PO molecular weight (58.04) × PO addition mole number (9)] + 58.04 [PO partial molecular weight in starting material (propylene glycol ) = 1989
Was rounded off to calculate 2000.

[Production of fine cellulose fiber composite]
Production Example 1
In a beaker equipped with a magnetic stirrer and a stirrer, 50 g (solid content concentration: 3.2 mass%) of the dispersion of carboxy group-containing fine cellulose fiber obtained in Preparation Example 2 is charged, and solvent substitution is performed with dimethylformamide (DMF). went. Subsequently, a quantity of hexylamine corresponding to 1 mol of amine group per 1 mol of carboxyl group of the carboxyl group-containing fine cellulose fiber was charged as a compound for modification into this beaker and dissolved in 150 g of DMF. Then, it was reacted by stirring at room temperature (25 ° C.) for 14 hours. After completion of the reaction, the mixture was filtered to obtain a fine cellulose fiber composite in which hexyl groups are linked to fine cellulose fibers via ionic bonds.

Production Examples 2 to 4 and 8 to 10
A fine cellulose fiber composite was obtained in the same manner as in Production Example 1 except that the type and amount of amine used were changed to those shown in Table 2 to obtain a fine cellulose fiber composite in which amines were connected to fine cellulose fibers via ionic bonds. .

Production Example 5
In a beaker equipped with a magnetic stirrer and a stirrer, 35 g (solid content concentration: 3.2% by mass) of the dispersion of carboxy group-containing fine cellulose fiber obtained in Preparation Example 2 was charged, and solvent substitution was performed with DMF. Subsequently, the amount of EOPO amine (obtained in Preparation Example 3) corresponding to 0.3 mol of amine group and the amount of condensation agent corresponding to 0.4 mol based on 1 mol of carboxyl group of the carboxyl group-containing fine cellulose fiber Certain 4- (4,6-dimethoxy-1,3,5-triazin-2-yl) -4-methylmorpholinium chloride (DMT-MM), and an amount corresponding to 0.4 mol of N-methyl formalin ( NMM) was charged into this beaker and dissolved in 150 g DMF. Then, it was reacted by stirring at room temperature (25 ° C.) for 14 hours. After completion of the reaction, filtration, washing with ion-exchanged water, removal of DMT-MM salt etc., washing with acetone and solvent substitution, a fine cellulose fiber in which EOPO amine is linked to the fine cellulose fiber via an amide bond The complex was obtained.

Production Examples 6 to 7
Fine cellulose in which an amine is linked to a fine cellulose fiber via an amide bond in the same manner as in Production Example 5 except that the type and amount of amine used and the amount of condensing agent are changed to those shown in Table 2. A fiber complex was obtained.

  The EOPO amine in Table 2 is the EOPO amine obtained in Preparation Example 3.

[Production of Epoxy Resin-Containing Adhesive Composition]
Example 1-1
In the fine cellulose fiber composite manufactured in Production Example 1, an epoxy resin (manufactured by Mitsubishi Chemical Corp., trade name: JER 828), a curing agent (2-ethyl-4-methylimidazole, manufactured by Wako Pure Chemical Industries, Ltd.) and a solvent (DMF) Was added to the compounding amount shown in Table 3 and stirred for 2 minutes with an ultrasonic homogenizer (manufactured by Nippon Seiki Seisakusho, trade name: US-300E). Then, it was finely processed in three passes at 150 MPa with a high pressure homogenizer (trade name: Nanoveita L-ES, manufactured by Yoshida Kikai Co., Ltd.). The obtained solution was stirred for 7 minutes using a stirrer (trade name: Awatori Neritaro, manufactured by Shinky Co., Ltd.) to obtain an adhesive composition.

Example 1-2
An adhesive composition was obtained in the same manner as Example 1-1 except that the fine cellulose fiber composite was changed to the fine cellulose fiber composite produced in Production Example 2.

Comparative Example 1-1
An adhesive composition was obtained in the same manner as Example 1-1 except that the fine cellulose fiber composite was not used.

  Each adhesive composition obtained by said Example and comparative example was coated on copper foil by application thickness 1.8mm using a bar coater. Then, another copper foil was stacked on the coated surface, dried at 80 ° C. for 1 hour, the solvent was removed, and then thermally cured at 150 ° C. for 1 hour to produce an evaluation sample in which the copper foils were adhered to each other . The following tests were performed for each evaluation sample.

Test Example 1 (adhesiveness)
The adhesiveness at the time of peeling off the copper foil of the side piled up on the coated surface was evaluated in five steps of 1-5 according to the following evaluation criteria. 5 shows that the adhesion is most excellent.
1: Adhesion of the cured product is not observed at all on the copper foil on the coated surface (adhesion amount is 0% or more and less than 5%; adhesion amount means copper before peeling in visual judgment. The percentage of the area where the adhesive adheres to the copper foil when peeled off, assuming that the area where the foil and the adhesive overlap is 100%.)
2: Almost no adhesion of the cured product is observed on the copper foil on the coated side (the adhesion amount is more than 5% and less than 20%)
3: Adherence of a little cured product is observed on the copper foil of the side overlaid on the coated surface (adhesion amount is 20% or more and less than 50% 4: Cured on the copper foil of the side overlaid on the coated surface Adherence of substances is observed (adhesion amount is 50% or more and less than 70%)
5: A large amount of adhesion of the cured product is observed on the copper foil on the side of the coated surface (the adhesion amount is 70% or more)

[Production of Urethane Resin-Containing Adhesive Composition]
Example 2-1, 2-2
The fine cellulose fiber composite obtained in Production Example 3, main agent (polyester polyol (product of DIC, trade name: LX-500, 60 wt% active ingredient) which is a urethane resin, and curing agent (aromatic isocyanate) (DIC) Co., Ltd., trade name: KW-75, 75 wt. The mixture was then stirred for 2 hours and then finely treated at a pressure of 100 MPa for 1 pass and a pressure of 150 MPa for 2 passes using a high-pressure homogenizer to prepare an adhesive composition having a solid content concentration of 40.7%.

Comparative Example 2-1
An adhesive composition was prepared in the same manner as in Example 2-1 except that the fine cellulose fiber composite was not used.

  Each adhesive composition obtained by said Example and comparative example was coated by 22 micrometers of coating thickness using the bar coater on PET film. The solvent was removed by drying at 80 ° C. for 10 seconds to form an adhesive layer. Another PET film was attached to the adhesive layer and aged at 40 ° C. for 72 hours to prepare a laminate film-shaped evaluation sample. The following tests were performed for each evaluation sample.

Test example 2 (adhesiveness)
With the same evaluation criteria as in Test Example 1, "the copper foil on the coated surface" was bonded to the adhesive layer using the same evaluation criteria as in Test Example 1. It replaced with and evaluated in five steps of 1-5.

[Production of Acrylic Resin-Containing Adhesive Composition]
Example 3-1
In a beaker equipped with a magnetic stirrer, 50 g (solid content concentration: 3.2% by mass) of the dispersion of carboxy group-containing fine cellulose fiber obtained in Preparation Example 2 was charged, and methyl methacrylate was adjusted to the amount shown in Table 5. Substitution was performed with (MMA). This dispersion was finely treated in one pass at 60 MPa and in one pass at 100 MPa using a high pressure homogenizer. To the resulting solution is added a polymerization initiator 2,2'-azobis (2,4-dimethylvaleronitrile) (manufactured by Wako Pure Chemical Industries, Ltd., trade name: V-65B), and a stirrer (manufactured by Shinky Co., Ltd.) The product was stirred for 7 minutes using Awatori Neritaro) to obtain an adhesive composition.

Example 3-2 to 3-7
As shown in Table 5, an adhesive composition was produced in the same manner as in Example 3-1 except that the carboxy group-containing fine cellulose fiber was changed to a composite, and the amount thereof was also changed.

Comparative Example 3-1
An adhesive composition was produced in the same manner as in Example 3-1 except that the carboxy group-containing fine cellulose fiber was not used.

  The adhesive compositions obtained in the above Examples and Comparative Examples were made to face each other with a thickness of 10 mm and a glass of 300 mm square, and a gap of 0.2 mm was provided between them. Material was injected into the hollow portion of the formed cell. Vacuum degassing and nitrogen substitution were carried out, and polymerization was carried out at 65 ° C. for 2 hours. Thereafter, it was dried at 120 ° C. for 1 hour to produce a sheet-like evaluation sample having a thickness of about 0.2 mm. The following tests were performed for each evaluation sample.

Test example 3 (adhesiveness)
The adhesion at the time of fixing one side of the glass and peeling the other glass from the sheet of the evaluation sample was evaluated using the same evaluation criteria as in Test Example 1. It was read as "a sealing material in contact with" and evaluated in five steps of 1 to 5.

[Production of Adhesive Composition Containing Polyvinyl Chloride Resin]
Example 4-1
In a beaker equipped with a magnetic stirrer, 50 g (solid content concentration: 3.2% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 2 was charged, and solvent substitution was performed with DMF. Polyvinyl chloride resin (manufactured by Shin-ichi Daiichi PVC Co., Ltd., trade name: ZEST 1400 Z), plasticizer (manufactured by Kao Corp., trade name: Vinicizer 80 K), Stabilizer for polyvinyl chloride (manufactured by ADEKA, trade name: Adekastab RUP-103) A lubricant (stearic acid) (manufactured by Kao Corporation, trade name: Lucac S70V) was mixed to a blending amount of Table 6 and a DMF solution was added. The obtained mixed solution was stirred for 2 minutes with an ultrasonic homogenizer, then finely treated with a high pressure homogenizer at 100 MPa for 2 passes and at 150 MPa for 1 pass to obtain an adhesive composition.

Examples 4-2 to 4-4
As shown in Table 6, an adhesive composition was produced in the same manner as in Example 4-1 except that the carboxy group-containing fine cellulose fiber was changed to a composite, and the amount thereof was also changed.

Comparative Example 4-1
An adhesive composition was obtained in the same manner as Example 4-1 except that the carboxy group-containing fine cellulose fiber was not used.

  Each adhesive composition obtained by said Example and comparative example was coated on copper foil with 1.0 mm of application | coating thickness using the bar coater. Thereafter, another copper foil was stacked on the coated surface, and dried at 80 ° C. for 1 day to remove the solvent, thereby producing an evaluation sample in which the copper foils were adhered to each other. The following tests were performed for each evaluation sample.

Test Example 4 (adhesiveness)
The adhesion was evaluated in the same manner as in Test Example 1 above.

[Production of Phenoxy Resin-Containing Adhesive Composition]
Example 5-1
In a beaker equipped with a magnetic stirrer, 50 g (solid content concentration: 3.2% by mass) of the carboxy group-containing fine cellulose fiber dispersion obtained in Preparation Example 2 was charged, and solvent substitution was performed with DMF. Phenoxy resin (manufactured by Nippon Steel & Sumikin Co., Ltd.) was mixed so as to have the amount shown in Table 7, and a DMF solution was added and stirred. The obtained mixed solution was stirred for 2 minutes with an ultrasonic homogenizer, and was finely treated with a high pressure homogenizer at 100 MPa for 2 passes and at 150 MPa for 1 pass. The obtained solution was stirred for 7 minutes using Awatori Nritaro (manufactured by Shinky Co., Ltd.) to obtain an adhesive composition.

Examples 5-2 to 5-5
As shown in Table 7, an adhesive composition was produced in the same manner as in Example 5-1 except that the carboxy group-containing fine cellulose fiber was changed to a composite, and the amount thereof was also changed.

Comparative Example 5-1
An adhesive composition was produced in the same manner as in Example 5-1 except that the carboxy group-containing fine cellulose fiber was not used.

  Each adhesive composition obtained by said Example and comparative example was coated on copper foil with 1.0 mm of application | coating thickness using the bar coater. Thereafter, another copper foil was stacked on the coated surface, dried at 120 ° C. for 8 hours, the solvent was removed, and an evaluation sample in which the copper foils were adhered to each other was manufactured. The following tests were performed for each evaluation sample.

Test example 5 (adhesiveness)
The adhesion was evaluated in the same manner as in Test Example 1 above.

  From the above results, it was found that the adhesive composition of the present invention has high adhesiveness. On the other hand, it was found that the composition containing no fine cellulose fiber or fine cellulose fiber composite according to the present invention is clearly inferior to the present invention in terms of adhesiveness.

  The adhesive composition of the present invention can be utilized as an adhesive.

Claims (5)

  An adhesive composition comprising a water-insoluble resin and a fine cellulose fiber composite comprising a fine cellulose fiber containing an ionic group and / or a fine cellulose fiber containing an ionic group and a modifying group bonded thereto.   The adhesive composition according to claim 1, wherein the water-insoluble resin has a solubility in water at 25 ° C. of 1 mg or less per 100 g of water.   A group consisting of an epoxy resin, a urethane resin, an acrylic resin, a vinyl chloride resin, a phenoxy resin, a phenol resin, a urea resin, a melamine resin, a polyimide resin, an unsaturated polyester resin, a diallyl phthalate resin, and a rubber-based resin. The adhesive composition according to claim 1 or 2, which is at least one resin selected from the group consisting of   The adhesive composition according to any one of claims 1 to 3, wherein the ionic group is an anionic group.   The adhesive composition according to claim 4, wherein the anionic group is a carboxy group.