WO2022239463A1

WO2022239463A1 - Resin composite, method for producing resin composite, and method for disassembling resin composite

Info

Publication number: WO2022239463A1
Application number: PCT/JP2022/011726
Authority: WO
Inventors: 剛資近藤; 尚平寺田
Original assignee: 株式会社日立製作所
Priority date: 2021-05-11
Filing date: 2022-03-15
Publication date: 2022-11-17
Also published as: JP2022174379A

Abstract

Provided are a resin composite which combines high adhesion strength and high recyclability, a method for producing the resin composite, and a method for disassembling the resin composite. In order to solve this problem, a resin composite (101) comprises a first resin member (1) having a dynamic covalent bond capable of reversibly dissociating or bonding, and a second resin member (2) which is a different resin than the first resin member (1) and has, at least on the surface thereof, a target functional group capable of bonding with the dynamic covalent bond. The first resin member (1) and the second resin member (2) are joined by covalent bonding through the dynamic covalent bond and the target functional group. The resin composite (101) can be produced by bringing the first resin member (1) and the second resin member (2) into contact, and heating at least the contact portion. The resin composite (101) can be disassembled by heating a portion of the covalent bond.

Description

Resin composite, method for producing resin composite, and method for dismantling resin composite

The present disclosure relates to a resin composite, a resin composite manufacturing method, and a resin composite dismantling method.

In order to provide multiple functions, multiple resin members are sometimes used in combination. For example, along with environmental regulations and energy-saving measures, moving bodies such as automobiles, aircraft, and railroad vehicles are becoming lighter, and structural members can be made of resin members containing fibers, fillers, and the like. As a technique related to resin composites, the technique described in Patent Document 1 is known. The abstract of Patent Document 1 states, "The core material is composed of a plurality of foamed beads, and the core is formed of the foamed beads in which the air bubbles inside the beads in the vicinity of the bonding surface are flattened. .” is stated.

JP 2020-163733 A

In the technique described in Patent Literature 1, resin members are adhered to each other by using an adhesive to improve adhesion strength (paragraph 0014). Here, it is preferable to recycle the resin members that make up the resin composite that is no longer needed, such as defective products produced during the production of the resin composite and the resin composite after use. However, in the technique disclosed in Patent Document 1, it is difficult to separate the resin members from each other due to the use of the adhesive, and it is difficult to recycle the resin members.
The present disclosure provides a resin composite that achieves both high adhesive strength and high recyclability, a method for producing the resin composite, and a method for dismantling the resin composite.

The resin composite of the present disclosure includes a first resin member having a dynamic covalent bond capable of reversibly dissociating or binding, and a resin different from the first resin member, and a target capable of binding to the dynamic covalent bond. a second resin member having at least a functional group on its surface, wherein the first resin member and the second resin member are bonded by the dynamic covalent bond and the covalent bond via the target functional group. . Other solutions will be described later in the detailed description.

According to the present disclosure, it is possible to provide a resin composite that achieves both high adhesive strength and high recyclability, a method for manufacturing a resin composite, and a method for dismantling a resin composite.

1 is a cross-sectional view of a resin composite of the present disclosure; FIG. FIG. 4B is a diagram for explaining a dynamic covalent bond formed between a first functional group and a target functional group, and is a diagram showing bonding between the first resin member and the second resin member. It is a figure explaining the manufacturing method of the resin composite of this indication. It is a figure explaining the surface structure of a 1st resin member and a 2nd resin member. FIG. 4 is a diagram illustrating a dismantling method of the resin composite of the present disclosure;

Hereinafter, a form (referred to as an embodiment) for carrying out the present disclosure will be described with reference to the drawings. In the following description of one embodiment, other embodiments applicable to the one embodiment will also be described as appropriate. The present disclosure is not limited to one embodiment below, and different embodiments can be combined or arbitrarily modified within a range that does not significantly impair the effects of the present disclosure. Also, the same members are denoted by the same reference numerals, and overlapping descriptions are omitted. Furthermore, those having the same function shall have the same name. The contents of the drawings are only schematic, and for the convenience of the drawings, the actual configuration may be changed within a range that does not significantly impair the effects of the present disclosure, or the illustration of some members may be omitted or modified between drawings. sometimes

FIG. 1 is a cross-sectional view of the resin composite 101 of the present disclosure. The resin composite 101 includes a first resin member 1 and a second resin member. The first resin member 1 has dynamic covalent bonds that can be reversibly dissociated or bonded. The second resin member 2 is a resin different from that of the first resin member 1 and has target functional groups capable of bonding with dynamic covalent bonds of the first resin member 1 at least on its surface. "Different" as used herein means that at least one of structure (type of unit monomer, etc.) or physical properties (molecular weight, etc.) is different.

FIG. 2 is a diagram for explaining the dynamic covalent bond formed between the first functional group and the target functional group, and is a diagram showing bonding between the first resin member 1 and the second resin member 2. FIG. . The first resin member 1 and the second resin member 2 are bonded by dynamic covalent bonding of the first resin member 1 and covalent bonding via target functional groups of the second resin member 2 .

In the illustrated example, the dynamic covalent bond is, for example, an ester bond, and the target functional group is, for example, a hydroxyl group, but neither is limited to these. Ester bonds are formed, for example, by dehydration condensation between a carboxylic acid or a carboxylic acid anhydride that constitutes the first resin member 1 and a hydroxyl group. A dynamic covalent bond is described with reference to formula (1).

Formula (1) is a chemical reaction formula that explains the dissociation and bonding of dynamic covalent bonds, and indicates a transesterification reaction. The chemical formula shown in formula (1) is part of the structure obtained by the transesterification reaction. R and R″ are organic groups derived from the first resin member 1 , and R′ is an organic group derived from the second resin member 2 . For example, the first resin member 1 and the second resin member 2 are joined together by forming a dynamic covalent bond between functional groups present on the surface.

On the other hand, in the state on the left side, dynamic covalent recombination occurs at least by heating the junction, and the reaction proceeds to the right side. As a result, a dynamic covalent bond is formed by RO of the first resin member 1 and R''OH of the second resin member 2, and the first resin member 1 shown in the first term on the right side and the second term on the right side A second resin member 2 is obtained. As a result, the ester bond formed between the first resin member 1 and the second resin member 2 is easily broken at the portion A, so that recombination of the dynamic covalent bond occurs and the bond is broken.

The first resin member 1 is not particularly limited as long as it is a resin having a dynamic covalent bond, and examples thereof include at least one of epoxy resin, phenol resin, polyester resin, and the like.

Above all, the first resin member 1 preferably contains the first resin, which is an epoxy resin. By including an epoxy resin, by adjusting the compositional ratio of the epoxy monomer and the acid anhydride that is the curing agent, the ester group and the hydroxyl group that are dynamic covalent bonds can be easily introduced by the curing reaction. Although the case where the first resin is an epoxy resin is exemplified below as an example, the first resin is not limited to the epoxy resin.

The epoxy resin is, for example, an epoxy compound having two or more epoxy groups in the molecule, at least one curing agent selected from a carboxylic acid or a carboxylic anhydride, and a transesterification reaction catalyst that promotes the transesterification reaction. obtained by curing a mixture comprising The mixture may further contain a polymerization initiation catalyst and the like.

For example, in the presence of a curing accelerator (described later), an ester bond (ester group) and a hydroxyl group are generated as a result of the reaction between the epoxy compound and the curing agent during curing. Then, these ester bonds and hydroxyl groups initiate a transesterification reaction by heating with a transesterification reaction catalyst. By setting the amounts of the ester bond, the hydroxyl group, and the transesterification reaction catalyst within a predetermined range and heating at an appropriate temperature, the transesterification reaction proceeds even after curing, resulting in a resin composite 101 with high bonding strength and easy peeling. is obtained.

As epoxy compounds having two or more epoxy groups in the molecule, bisphenol A type resins, novolac type resins, alicyclic resins, and glycidylamine resins are preferable. Examples of epoxies include bisphenol A diglycidyl ether phenol, bisphenol F diglycidyl ether, bisphenol S diglycidyl ether, resocinol diglycidyl ether, hexahydrobisphenol A diglycidyl ether, polypropylene glycol diglycidyl ether, neopentyl glycol diglycidyl ether. Glycidyl ether, diglycidyl phthalate, diglycidyl dimer acid, triglycidyl isocyanurate, tetraglycidyl diaminodiphenylmethane, tetraglycidyl metaxylene diamine, cresol novolac polyglycidyl ether, tetrabromobisphenol A diglycidyl ether, bisphenol hexafluoroacetone di At least one of glycidyl ether and the like may be used, but is not limited thereto.

Examples of carboxylic acids and acid anhydrides as curing agents include phthalic anhydride, tetrahydrophthalic anhydride, hexahydrophthalic anhydride, methyltetrahydrophthalic anhydride, 3-dodecenylsuccinic anhydride, octenylsuccinic anhydride, methylhexahydro Phthalic anhydride, methyl nadic anhydride, dodecyl succinic anhydride, chlorendic anhydride, pyromellitic anhydride, benzophenone tetracarboxylic anhydride, ethylene glycol bis(anhydrotrimate), methylcyclohexene tetracarboxylic anhydride, At least trimellitic anhydride, polyazelaic anhydride, ethylene glycol bisanhydrotrimellitate, 1,2,3,4-butanetetracarboxylic acid, 4-cyclohexene-1,2-dicarboxylic acid, polyvalent fatty acid, etc. 1 type is mentioned, but it is not limited to these.

The amount of acid anhydride added is, for example, 30 mol % or more and 70 mol % or less with respect to the epoxy group. It is more preferably 40 mol % or more and 60 mol % or less. By setting the amount of the acid anhydride within this range, hydroxyl groups are present after polymerization, so that the polymer structure can be efficiently rearranged by dynamic covalent bonding. In particular, when the amount is 30 mol % or more, curing can proceed sufficiently. By making it 70 mol % or less, it is possible to increase the production amount of hydroxyl groups and facilitate the progress of the transesterification reaction.

The first resin member 1 may contain a vinyl monomer having a hydroxyl group, an ester group and two or more vinyl groups, and a polymerization initiator that polymerizes the vinyl monomer. Specific examples of vinyl monomers include 2-hydroxy methacrylate, hydroxypropyl methacrylate, 4-hydroxybutyl acrylate, divinyl ethylene glycol, monomethyl fumarate, hydroxypropyl acrylate, ethyl 2-(hydroxymethyl) acrylate, glycerol dimethacrylate, allyl acrylate. , methyl crotonate, methyl methacrylate, methyl 3,3-dimethacrylate, diethylene glycol dimethacrylate, ethylene glycol dimethacrylate, triethylene glycol dimethacrylate, dimethyl fumarate, fumaric acid, 1,4-butanediol dimethacrylate , 1,6-hexanediol dimethacrylate, 1,3-butanediol dimethacrylate, tetraethylene glycol dimethacrylate, tetraethylene glycol diacrylate, vinyl crotonate, crotonic anhydride, diallyl maleate, neopentyl At least one of glycol diacrylate, neopentyl glycol dimethacrylate, trimethylolpropane triacrylate, trimethylolpropane trimethacrylate, bisphenol A glycerolate dimethacrylate, etc., but not limited thereto. do not have.

The polymerization initiation catalyst includes peroxide polymerization initiators, azo compound polymerization initiators, etc. Specific examples include 2,2′-azobisisobutyronitrile, 2,2′-azobis(2,4-dimethyl valeronitrile), 2,2′-azobis(2,4-dimethyl-4-methoxyvaleronitrile), 1,1′-azobis(cyclohexanecarbonitrile), 2,2′-azobis(2,4,4-trimethyl Pentane) and other azo compounds, di-t-butyl peroxide, di-t-hexyl peroxide, dialkyl peroxides such as dicumyl peroxide, 1,1-bis(t-butylperoxy)cyclohexane, 1, Peroxyketals such as 1-bis(t-butylperoxy)-3,3,5-trimethylcyclohexane, 2,2-bis(4,4-di-t-butylperoxycyclohexyl)propane, t-butyl Peroxyesters such as peroxybenzoate, t-hexyl peroxybenzoate, t-butyl peroxyacetate, t-butyl peroxylaurate, t-hexyl peroxyneodecanoate, benzoyl peroxide, lauroyl peroxide, etc. diacyl peroxides, t-butylperoxyisopropylmonocarbonate, t-hexylperoxyisopropylmonocarbonate, di-n-propylperoxydicarbonate, diisopropylperoxydicarbonate, di-2-ethylhexylperoxydicarbonate and other peroxycarbonates, etc. at least one of, but not limited to.

The transesterification reaction catalyst is preferably one that disperses uniformly in the mixture and promotes the transesterification reaction. For example, manganese (III) acetylacetonate, zinc (II) acetate, zinc (II) acetylacetonate, zinc (II) naphthenate, iron (III) acetylacetonate, cobalt (II) acetylacetonate, cobalt (III) acetylacetonate, aluminum isopropoxide, titanium isopropoxide, methoxide (triphenylphosphine) copper (I) complex, ethoxide (triphenylphosphine) copper (I) complex, propoxide (triphenylphosphine) copper (I) complex, isopropoxide ( triphenylphosphine)copper(I) complex, methoxide bis(triphenylphosphine)copper(II) complex, ethoxide bis(triphenylphosphine)copper(II) complex, propoxide bis(triphenylphosphine)copper(II) complex, isopropoxy dobis(triphenylphosphine)copper(II) complex, tris(2,4-pentanedionato)cobalt(III), cobalt(II) naphthenate, cobalt(II) stearate, tin(II) diacetate, di (2-ethylhexanoic acid) tin (II), N,N-dimethyl-4-aminopyridine, diazabicycloundecene, diazabicyclononene, triazabicyclodecene, triphenylphosphine, 2-phenylimidazole, 2- At least one of phenyl-4-methylimidazole, 1-benzyl-2-phenylimidazole, 1-cyanoethyl-2-phenylimidazole and the like can be mentioned, but not limited thereto.

The first resin member 1 preferably contains at least one type of fiber. By including fibers, the strength of the first resin member 1 can be improved, and the strength and rigidity of the entire resin composite 101 including the second resin member 2 covalently bonded to the first resin member 1 can be improved.

Examples of fibers include inorganic fibers and organic fibers. Examples of inorganic fibers include aramid fibers, glass fibers, asbestos fibers, carbon fibers, silica fibers, silica/alumina fibers, alumina fibers, zirconia fibers, potassium titanate fibers, tyranno fibers, silicon carbide fibers, and metal fibers. Further, for example, organic fibers include high-strength polyethylene fibers, polyacetal fibers, aliphatic or aromatic polyamide fibers, polyacrylate fibers, fluorine fibers, boron fibers, polyacrylonitrile fibers, aramid fibers, PBO (poly-p-phenylenebenzobisoxazole ) fibers and the like. These fibers can be used singly or in combination of two or more.

Among these fibers, organic fibers, particularly carbon fibers, are preferable from the viewpoint of mechanical strength. Carbon fibers can be classified into synthetic polymer-derived carbon fibers (polyacrylonitrile-based, polyvinyl alcohol-based, rayon-based carbon fibers, etc.) and mineral-derived carbon fibers (pitch-based carbon fibers, etc.) according to their raw materials. Among these, synthetic polymer-derived carbon fibers are preferable from the viewpoint of mechanical strength. These fibers are used in the form of continuous fibers, long fibers, short fibers, chopped fibers, etc., and in the form of unidirectional materials, plain weaves, non-woven fabrics and the like. Although it may be directly added to the first resin member 1 and used, the present embodiment is not limited to these fiber shapes and fiber states.

The method for producing the first resin member 1 containing fibers is not particularly limited. For example, a method of stacking fibers impregnated with the first resin and then pressurizing and heating them, a method of injecting the first resin into a mold in which the fibers are laid and heating them, and a method of kneading the fibers into the first resin and injecting them. A molding method and the like can be mentioned.

The first resin member 1 may contain at least one inorganic filler. Inorganic fillers include fused silica, crystalline silica, alumina, zircon, calcium silicate, calcium carbonate, potassium titanate, silicon carbide, aluminum nitride, boron nitride, beryllia, zircon, fosterite, stearite, spiral, mullite, titania, etc. powder, beads obtained by spheroidizing these, glass fibers, and the like. Moreover, the shape of the inorganic filler is not limited, and any shape such as a spherical shape or a scaly shape may be used.

If necessary, the first resin member 1 contains at least one additive such as a curing accelerator, flame retardant, antioxidant, light stabilizer, dispersant, lubricant, plasticizer, antistatic agent, pigment, dye, etc. may include

As described above, the second resin member 2 has at least a target functional group capable of dynamic covalent bonding on its surface. Although the method of forming the target functional group on the surface of the second resin member 2 is not particularly limited, the target functional group can be arranged on the surface of the second resin member 2 by surface modification, for example. Surface modification can be performed, for example, by oxidation.

The second resin member 2 preferably also has target functional groups inside. As a result, the second resin member 2 can be easily formed because the second resin member 2 can be formed by, for example, molding a resin having the target functional group. The second resin member 2 can be configured by containing, for example, at least one of urethane, epoxy resin, phenol resin, polyvinyl alcohol resin, and the like.

Above all, the second resin member 2 preferably contains a second resin that is urethane having a hydroxyl group as the target functional group. By including the second resin, which is urethane, the following effects can be obtained, for example. That is, when a conventional adhesive is used to adhere urethane, the urethane impregnates the adhesive, so the amount of adhesive used increases, and the resin composite 101 tends to become heavy. However, in the present disclosure, no adhesive is used or only a small amount of adhesive is used, so even when urethane is adhered, the weight of the resin composite 101 can be reduced. Urethane may be either foamed (foamed urethane) or non-foamed. Although the case where the second resin is urethane is exemplified below, the second resin is not limited to urethane.

Urethane is obtained, for example, by polymerization of polyol and polyisocyanate. Any desired shape can be obtained by mixing these in a predetermined ratio and heat curing.

The specific type of polyol is not particularly limited. For example, at least one of polyester polyols, polyether polyols, acrylic polyols, low-molecular-weight polyols, and the like can be used. Examples of polyester polyols include polyethylene adipate diol, polybutylene adipate diol, polyethylene butylene adipate diol, polyhexamethylene isophthalate adipate diol, polyethylene succinate diol, polybutylene succinate diol, polyethylene sebacate diol, and polybutylene sebacate. diol, poly-ε-caprolactonediol, poly(3-methyl-1,5-pentylene adipate)diol, polycondensate of 1,6-hexanediol and dimer acid, and the like. Examples of polyether polyols include polyethylene glycol, polypropylene glycol, polytetramethylene glycol, random copolymers or block copolymers of ethylene oxide and propylene oxide, and random copolymers or block copolymers of ethylene oxide and butylene oxide. etc. Furthermore, a polyether polyester polyol or the like having ether bonds and ester bonds can also be used. Low molecular weight polyols are not particularly limited, and examples include ethylene glycol, 1,4-butanediol, 1,5-pentanediol, 3-methyl-1,5-pentanediol, 1,6-hexanediol, 1,9 -nonanediol, 2-methyl-1,8-octanediol, 1,4-cyclohexanedimethanol, 1,3-cyclohexanedimethanol, 1,4-cyclohexanediol and the like. Furthermore, low molecular weight polyhydric alcohols such as trimethylolpropane, pentaerythritol and sorbitol may be used. These can be used alone or in combination of two or more.

The specific type of polyisocyanate is not particularly limited. For example, 2,4-tolylene diisocyanate, 2,6-tolylene diisocyanate, xylene-1,4-diisocyanate, xylene-1,3-diisocyanate, 4,4′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4'-diphenyl ether diisocyanate, 2-nitrodiphenyl-4,4'-diisocyanate, 2,2'-diphenylpropane-4,4'-diisocyanate, 3,3'-dimethyldiphenylmethane-4,4'-diisocyanate, 4,4'-diphenylpropane diisocyanate, m-phenylene diisocyanate, p-phenylene diisocyanate, naphthylene-1,4-diisocyanate, naphthylene-1,5-diisocyanate, 3,3'-dimethoxydiphenyl-4,4'-diisocyanate, etc. aromatic polyisocyanates such as polyphenylene polymethylene polyisocyanate, crude tolylene diisocyanate, aliphatic diisocyanates such as tetramethylene diisocyanate, hexamethylene diisocyanate, decamethylene diisocyanate and lysine diisocyanate, isophorone diisocyanate, hydrogenated tolylene diisocyanate , hydrogenated xylene diisocyanate, hydrogenated diphenylmethane diisocyanate, organic diisocyanates such as alicyclic diisocyanates such as tetramethylxylene diisocyanate, biuret-modified, uretdione-modified, carbodiimide-modified, isocyanurate-modified, and uretonimine-modified organic polyisocyanates and mixed modifications thereof. These can be used alone or in combination of two or more.

For the second resin member 2, the same matters as those of the first resin member 1 can be applied as necessary, except for the above matters.

FIG. 3 is a diagram illustrating a method for manufacturing the resin composite 101 of the present disclosure. In the resin composite 101, the first resin member 1 having a dynamic covalent bond and the second resin member 2, which is a resin different from the first resin member 1 and have a target functional group, are brought into contact with each other, and at least the contact portion can be produced by heating. By heating, the first resin member 1 and the second resin member 2 are bonded by dynamic covalent bonding and covalent bonding via target functional groups. Although the first resin member 1 and the second resin member 2 are flat plates in the illustrated example, their shapes are not limited to flat plates.

4A and 4B are diagrams for explaining the surface structures of the first resin member 1 and the second resin member 2. FIG. On the surface of the first resin member 1, there are a plurality of dynamic covalent bonds such as ester bonds. On the other hand, on the surface of the second resin member 2, there are, for example, a plurality of hydroxyl groups as target functional groups. Then, when the first resin member and the second resin member are brought into contact (for example, superimposed) and at least the contact portion (for example, the entire portion) is heated, the ester bond is cut and a carbonyl group having an unpaired electron is generated. . Since the generated carbonyl group has high reactivity, it easily bonds with the hydroxyl group existing on the surface of the second resin member 2 , and a new ester bond is generated with the second resin member 2 . The resulting ester bond is a dynamic covalent bond that can be cleaved by heating again, as shown in FIG. By these reactions, the first resin member 1 and the second resin member 2 are joined by covalent bonds, and the joint strength between the first resin member 1 and the second resin member 2 can be improved.

"Heating can be done by any method." For example, the heating may be performed by heating the whole in a constant temperature bath or the like, or by irradiating a desired position with microwaves or infrared rays to heat partially. Furthermore, for example, heating may be performed by pressing a heated metal plate using an electric heater or the like to a desired position. The heating may be performed while pressing (while applying a pressing force) in the contact direction (for example, the stacking direction) of the first resin member 1 and the second resin member 2, or may be performed without pressing. . When heating without pressing, for example, pressing may be performed after heating and before cooling.

The heating temperature varies depending on the material composition and compounding ratio of the first resin member 1 and the second resin member 2. For example, the glass transition temperature (the temperature at which dynamic covalent bond recombination occurs) ) above and below the temperature at which the first resin and the second resin are not thermally decomposed. Specifically, for example, when the first resin is epoxy resin and the second resin is urethane, the temperature can be set to, for example, 100° C. or higher, preferably 150° C. or higher, and the upper limit thereof, for example, 300° C. or lower, preferably 200° C. or lower. The heating time can be, for example, 1 hour or more and 10 hours or less. The heating temperature and the heating time may be the same or different when joining the first resin member 1 and the second resin member 2 and when separating them.

FIG. 5 is a diagram for explaining a dismantling method for the resin composite 101 of the present disclosure. The target functional group is dissociated from the dynamic covalent bond by heating at least the part of the resin composite 101 that has the dynamic covalent bond and the covalent bond via the target functional group, and the resin composite 101 becomes the first resin. It is dismantled into the member 1 and the second resin member 2 . As a result, it can be easily dismantled and the recyclability can be improved.

The heating can be performed under the same conditions as during the bonding described with reference to FIG. For example, the heating may be performed while applying a pulling force in the contact direction (for example, the stacking direction) between the first resin member 1 and the second resin member 2, or the heating may be performed without applying such a force. Moreover, when heating is performed without applying such a force, a pulling force can be applied after heating to separate them.

Hereinafter, the present disclosure will be described more specifically with examples, but the present disclosure is not limited to the examples.

<Example 1>
A first resin member 1 (FIG. 1) was produced as follows. First, with respect to 100 parts by mass of a bisphenol A diglycidyl ether type epoxy compound (jER828, manufactured by Mitsubishi Chemical), 47 parts by mass of acid anhydride (MHAC-P, manufactured by Showa Denko Materials), manganese (III) acetylaceto 19 parts by mass of nate (transesterification reaction catalyst, manufactured by Tokyo Kasei Co., Ltd.) and 0.3 parts by mass of 2E4MZ-CN (manufactured by Shikoku Kasei Co., Ltd.) as a curing accelerator were stirred and mixed in the atmosphere to obtain a mixture. The amount of acid anhydride used is 50 mol% (half of the stoichiometric ratio) relative to the amount of epoxy compound used, and the amount of manganese (III) acetylacetonate used is 10 mol% relative to the amount of epoxy compound used. is. Next, the mixture was heated at 100° C. for 1 hour and then at 200° C. for 1 hour to cure the mixture and obtain a flat first resin member 1 . The first resin member 1 has an ester bond formed by dehydration condensation between an acid anhydride and a hydroxyl group as a dynamic covalent bond on the surface and inside.

A second resin member 2 (Fig. 1) was produced as follows. First, 7 parts by mass of polyol (NIPPOLAN982R, manufactured by Nippon Polyurethane Co., Ltd.), 16 parts by mass of polyisocyanate (CORONATE HXR, manufactured by Nippon Polyurethane Co., Ltd.), and 3 parts by mass of amine (Polycat8, manufactured by Sun-Apro Co., Ltd.) are mixed to form a mixture. Obtained. Then, the mixture was heated at 80° C. for 1 hour to obtain a flat second resin member 2 . The second resin member 2 is a resin different from the first resin member 1 and has hydroxyl groups as target functional groups on the surface and inside.

A flat plate-shaped first resin member 1 and a flat plate-shaped second resin member were superimposed, heat-pressed at 190° C. for 1 hour, and then cooled to room temperature to obtain a resin composite 101 (FIG. 1). By grasping the first resin member 1 with one hand and grasping the second resin member 2 with the other hand, an attempt was made to separate them. However, even if they were pulled with both hands, they were not peeled off, and it was confirmed that they were strongly bonded. It is considered that this is because the first resin member 1 and the second resin member 2 are bonded by dynamic covalent bonding.

Next, the resin composite 101 was placed in a constant temperature bath, and the whole was heated in the air at 200°C for 1 hour. Immediately after heating for 1 hour, when an attempt was made to remove them by putting on gloves and pulling them with both hands, they could be removed with a slight force. Therefore, it was confirmed that the resin composite 101 can be easily disassembled by heating. This is probably because the dynamic covalent bond was recombined by heating, and the dynamic covalent bond formed between the first resin member 1 and the second resin member 2 was cut.

<Example 2>
A resin composite 101 (FIG. 1) was produced in the same manner as in Example 1, except that a polyester resin (having a dynamic covalent bond) was used as the first resin member 1 (FIG. 1) instead of the epoxy resin. Then, when peeling was attempted in the same manner as in Example 1, the film could not be peeled off before heating, but was easily peeled off immediately after heating. As a result, high bonding strength and high recyclability were confirmed. The polyester resin was obtained by curing a vinyl monomer containing an ester group and a hydroxyl group with a reaction initiator. 100 parts by weight of styrene (manufactured by Tokyo Chemical Industry Co., Ltd.), 100 parts by weight of bisphenol A glycerolate dimethacrylate (manufactured by Sigma-Aldrich), 25.6 parts by weight of 2-hydroxymethacrylate, 6 parts by weight of diethylmethoxyborane (manufactured by Sigma-Aldrich) part, manganese (III) acetylacetonate (transesterification reaction catalyst, manufactured by Tokyo Chemical Industry Co., Ltd.) 19
It was obtained by stirring mass parts and curing at 120° C. for 4 hours.

<Example 3>
A resin composite 101 (Fig. 1) was used in the same manner as in Example 1 except that a phenol resin (having a hydroxyl group, which is a target functional group, on the surface and inside) was used instead of urethane as the second resin member 2 (Fig. 1). 1) was produced. Then, when peeling was attempted in the same manner as in Example 1, the film could not be peeled off before heating, but was easily peeled off immediately after heating. As a result, high bonding strength and high recyclability were confirmed. The phenolic resin was obtained by curing DG-630 (manufactured by DIC) at 180° C. for 4 hours.

<Comparative Example 1>
A resin composite was produced in the same manner as in Example 1, except that the amount of acid anhydride used was 100 mol % (equivalent in stoichiometric ratio) with respect to the amount of epoxy compound used. In the first resin member of Comparative Example 1, the epoxy compound and the acid anhydride reacted according to the stoichiometric ratio during production, and the first resin member did not have dynamic covalent bonds.

When peeling was attempted in the same manner as in Example 1, it was easily peeled off without applying a large force both before and immediately after heating. It is considered that this is because the first resin member does not have a dynamic covalent bond and is not bonded to the second resin member 2 using a dynamic covalent bond.

<Comparative Example 2>
A resin composite was produced in the same manner as in Example 1, except that an acrylic resin without a hydroxyl group (an example of a target functional group) was used as the second resin member. In Comparative Example 2, the first resin member 1 has a dynamic covalent bond, but the second resin member does not have a target functional group capable of bonding with the dynamic covalent bond.

When peeling was attempted in the same manner as in Example 1, it was easily peeled off without applying a large force both before and immediately after heating. It is considered that this is because the second resin member did not have the target functional group and was not bonded to the first resin member using dynamic covalent bonding.

From the above results, it is possible to achieve high bonding strength and high recyclability by bonding dissimilar resins using dynamic covalent bonds.

1 first resin member 2 second resin member 101 resin composite

Claims

a first resin member having a reversibly dissociable or bondable dynamic covalent bond;
a second resin member, which is a different resin from the first resin member and has at least on its surface a target functional group capable of bonding with the dynamic covalent bond;
with
The resin composite, wherein the first resin member and the second resin member are bonded to each other by a covalent bond via the dynamic covalent bond and the target functional group.
The resin composite according to claim 1, wherein the second resin member further has the target functional group inside.
The resin composite according to claim 1 or 2, wherein the second resin member includes a second resin that is urethane having a hydroxyl group as the target functional group.
The resin composite according to claim 1 or 2, wherein the first resin member contains a first resin that is an epoxy resin.
The resin composite according to claim 1 or 2, wherein the first resin member contains fibers.
a first resin member having dynamic covalent bonds capable of reversibly dissociating or bonding; The first resin member and the second resin member are bonded by the dynamic covalent bond and the covalent bond via the target functional group by bringing the two resin members into contact and heating at least the contact portion. A method for producing a resin composite, characterized by:
a first resin member having dynamic covalent bonds capable of reversibly dissociating or bonding; 2 resin members, wherein the first resin member and the second resin member are bonded to each other by the dynamic covalent bond and the covalent bond via the target functional group, and at least the The resin composite is disassembled into the first resin member and the second resin member by heating the covalent bond portion to dissociate the target functional group from the dynamic covalent bond. body dismantling method.