JP2008174656A - Highly water-resistant adhesive composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a highly water-resistant adhesive composition giving high adhesive force even to laminated lumber made of wood with higher specific gravity than that of lauan wood, and excellent in heat resistance and durability as well. <P>SOLUTION: The highly water-resistant adhesive composition comprises 100 pts.wt. of a main agent comprising an aqueous solution of a water-soluble polymer, an aqueous latex and one or more of aqueous emulsions, 5-40 pts.wt. of a curing agent consisting of isocyanate compounds including 2,4'-diphenylmethane diisocyanate, and 2-50 pts.wt., based on 100 pts.wt. of the curing agent, of a compound having an imido structure of general formula: -N=C=N-. In this adhesive composition, the above compound may be one having a structure of general formula: -C<SB>6</SB>H<SB>4</SB>-N=C=N-C<SB>6</SB>H<SB>4</SB>-, and 2,4'-diphenylmethane diisocyanate is included in the curing agent at 2-50 wt.% based on the total amount thereof. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a highly water-resistant adhesive composition used for bonding wood, particularly laminated wood.

  Conventionally, as a water-resistant adhesive composition for wood, an aqueous polymer-isocyanate-based adhesive composition in which a water-soluble polymer aqueous solution, an aqueous latex, an aqueous emulsion, or the like is mainly used and an isocyanate compound is blended as a curing agent in the main agent. It has been known.

  The aqueous polymer-isocyanate-based adhesive composition is, for example, a mixture of 4,4′-diphenylmethane diisocyanate and polymethylene polyphenyl polyisocyanate in a specific ratio to the main agent (for example, Patent Document 1). reference). Moreover, what mix | blended 4,4'- diphenylmethane diisocyanate, polymethylene poxyphenyl polyisocyanate, and 2,4'-diphenylmethane diisocyanate with the said main ingredient in the specific ratio is proposed (for example, patent document 2). reference).

  Since the water-based polymer-isocyanate adhesive composition does not contain an organic solvent, there is no risk of environmental contamination due to the organic solvent. In addition, according to the aqueous polymer-isocyanate-based adhesive composition, the required adhesive force can be obtained without pressing and pressing the object to be bonded, so that the application is not limited and can be further used. Since a long time is required, excellent coating workability can be obtained.

However, the water-based polymer-isocyanate-based adhesive composition has a disadvantage that sufficient adhesive force cannot be obtained for a laminated wood material having a specific gravity larger than that of a lauan material such as a birch material. In addition, the aqueous polymer-isocyanate-based adhesive composition is sufficient because when the ester compound is reacted with water or an aqueous polymer in which the isocyanate compound coexists, the ester compound has a problem in heat resistance. There is an inconvenience that high heat resistance and durability cannot be obtained.
JP-A-10-121021 JP 2002-194317 A Yoshio Iwakura, “Synthetic Organic Chemistry”, Corona, 1977

  The present invention eliminates such inconvenience, has excellent water resistance, and can obtain an excellent adhesive force even for laminated wood made of wood having a higher specific gravity than lauan material such as birch material. It aims at providing the highly water-resistant adhesive composition excellent also in the property and durability.

  In order to achieve such an object, the highly water-resistant adhesive composition of the present invention comprises a water-soluble polymer aqueous solution, an aqueous latex, an aqueous emulsion, one or more main ingredients, and 2,4′-diphenylmethane diisocyanate. It contains the hardening | curing agent which consists of an isocyanate compound containing, and the compound which has an imide structure represented by General formula (1).

  In the highly water-resistant adhesive composition of the present invention, excellent water resistance can be obtained by curing the main agent by reacting with a curing agent composed of an isocyanate compound containing 2,4'-diphenylmethane diisocyanate.

  Since the isocyanate compound constituting the curing agent reacts with water, the reaction with water contained in the main agent starts immediately after the preparation of the highly water-resistant adhesive composition of the present invention.

  On the other hand, when the highly water-resistant adhesive composition of the present invention is applied to wood, which is an adherend, the water contained in the main agent is dispersed or vaporized in the wood.

  Here, in the 2,4'-diphenylmethane diisocyanate contained in the curing agent, the 2-position isocyanate group reacts slower than the 4-position isocyanate group due to steric hindrance. For this reason, 2,4'-diphenylmethane diisocyanate reacts slower than the isomer 4,4'-diphenylmethane diisocyanate.

  As described above, when the water contained in the main agent is dispersed in the wood, the resin component contained in the main agent and 2,4′-diphenylmethane diisocyanate are left after that, and the resin component and 2 , 4'-diphenylmethane diisocyanate is more likely to react. As a result, according to the highly water-resistant adhesive composition of the present invention, the resulting cured body has a higher crosslink density and higher hardness, so that it can only provide excellent adhesion to wood. In addition, further excellent water resistance, heat resistance and durability can be obtained.

  The compound having an imide structure represented by the general formula (1) has heat resistance. Therefore, the highly water-resistant adhesive composition of the present invention can obtain excellent heat resistance and durability by bonding the compound to a cured product produced by the reaction of the main agent with the curing agent.

  Moreover, the compound which has the imide structure represented by the said General formula (1) produces | generates the compound represented by General formula (1a) by reacting with water.

  The compound having an imide structure represented by the general formula (1a) also has heat resistance, and the highly water-resistant adhesive composition of the present invention has an imide structure represented by the general formula (1). By producing the compound represented by the general formula (1a), further excellent heat resistance and durability can be obtained.

  In the highly water-resistant adhesive composition of the present invention, the compound represented by the general formula (2) can be used as the compound having an imide structure represented by the general formula (1).

  Since the compound represented by the general formula (2) has an imide structure, it has heat resistance, and reacts with water to produce the compound represented by the general formula (2a). Therefore, the compound represented by the general formula (2) acts in the same manner as the compound having an imide structure represented by the general formula (1).

  The highly water-resistant adhesive composition of the present invention preferably contains the curing agent in a range of 5 to 40 parts by weight with respect to 100 parts by weight of the main agent in order to develop an adhesive force by the above-described mechanism.

  In the highly water-resistant adhesive composition of the present invention, when the content of the curing agent is less than 5 parts by weight with respect to 100 parts by weight of the main agent, it is difficult to obtain the effect of adding the curing agent, and the water resistance and heat resistance. The effect of improving the durability and durability cannot be obtained. Moreover, when content of the said hardening | curing agent exceeds 40 weight part with respect to 100 weight part of said main agents, application | coating workability | operativity may reduce.

  It is preferable that the highly water-resistant adhesive composition of this invention contains the compound which has an imide structure in 2-50 weight part with respect to 100 weight part of said hardening | curing agents.

  The highly water-resistant adhesive composition of the present invention has the effect of improving heat resistance and durability when the content of the compound having an imide structure is less than 2 parts by weight with respect to 100 parts by weight of the curing agent. There may not be. Further, in the highly water-resistant adhesive composition of the present invention, when the content of the compound having the imide structure exceeds 50 parts by weight with respect to 100 parts by weight of the curing agent, the hardness of the cured body has an appropriate hardness. In addition, the required adhesiveness may not be obtained, and heat resistance and durability may not be improved as compared with the amount of the compound having an imide structure.

  Moreover, in the highly water-resistant adhesive composition of the present invention, it is preferable to appropriately control the hardness of the cured body. If the hardness is too high, the required adhesive performance cannot be obtained. Therefore, the highly water-resistant adhesive composition of the present invention preferably contains 2,4'-diphenylmethane diisocyanate in the range of 2 to 50% by weight with respect to the total amount of the curing agent.

  If the content of 2,4'-diphenylmethane diisocyanate is less than 2% by weight based on the total amount of the curing agent, the effect of improving heat resistance and durability may not be obtained. In addition, when the content of 2,4′-diphenylmethane diisocyanate exceeds 50% by weight with respect to the total amount of the curing agent, it is not possible to obtain an appropriate hardness in the cured body of the highly water-resistant adhesive composition. The required adhesion may not be obtained.

  The highly water-resistant adhesive composition of the present invention includes, for example, the curing agent containing 2,4′-diphenylmethane diisocyanate in a mixture of the main agent and a compound having an imide structure represented by the general formula (1). It can be prepared by mixing. The highly water-resistant adhesive composition of the present invention is a cured product comprising a compound having an imide structure represented by the general formula (1) and 2,4′-diphenylmethane diisocyanate in a mixture of a main agent and a filler. You may prepare by mixing an agent.

  The highly water-resistant adhesive composition of the present invention is a water-based adhesive and does not contain an organic solvent, so there is no risk of polluting the environment, the usable time (pot life) is long, and excellent water-resistant adhesive strength is provided. Water resistant adhesive strength can be maintained over a long period of time under heating or in a hot and humid environment. Therefore, the highly water-resistant adhesive composition of the present invention is a plywood, LVL, veneer, decorative board, laminated wood, wood fiber board such as particle board, furniture, joinery, exercise equipment and other wood adhesives for manufacturing woodwork products. It can be suitably used as an agent, and can be particularly suitably used as an adhesive for laminated materials.

  The highly water-resistant adhesive composition of the present invention includes the above-mentioned wood, corrugated cardboard, paper, cloth, metal, ceramics, glass, wood wool board, plastic board (vinyl chloride resin board, ABS board, FRP board, styrene resin board) Etc.), inorganic board (mineral fiber board such as asbestos, rock wool, etc.) and cement-based inorganic board (asbestos slate board, pulp cement board, concrete board, etc.) are bonded to the same material or different materials. It can also be applied to cases.

  Furthermore, the highly water-resistant adhesive composition of the present invention can also be used as a coating composition or a paint composition.

  Next, embodiments of the present invention will be described in more detail.

  The highly water-resistant adhesive composition of the present embodiment is a cured product comprising a main agent composed of one or more of a water-soluble polymer aqueous solution, an aqueous latex, and an aqueous emulsion, and an isocyanate compound containing 2,4′-diphenylmethane diisocyanate. And a compound having an imide structure represented by the general formula (1).

  First, water-soluble polymer solutions used as the main agent include polyvinyl alcohol aqueous solution, starch aqueous solution, protein aqueous solution, cellulose derivative aqueous solution such as carboxymethyl cellulose, hydroxyethyl cellulose, sodium polyacrylate aqueous solution, polyacrylamide aqueous solution, maleic imide co-polymer. Examples thereof include an aqueous polymer solution. In applications where formaldehyde emission is not an environmental problem, an aqueous formaldehyde condensation resin solution may be used as the water-soluble polymer solution.

  Examples of the aqueous latex or aqueous emulsion used as the main agent include styrene, butadiene, acrylamide, acrylonitrile, chloroprene, 1,3-hexadiene, isoprene, isobutene, acrylic ester, methacrylic ester, vinyl acetate, vinyl propionate, ethylene, An aqueous latex or aqueous emulsion of one compound selected from the group consisting of vinyl chloride, vinylidene chloride, and ethyl vinyl ether, or an aqueous solution comprising two or more copolymerizable unsaturated monomers selected from the above compound group Mention may be made of latex or aqueous emulsion. The aqueous latex or aqueous emulsion is a reactive group selected from the group consisting of carboxyl group, N-methylol group, N-alkoxymethyl group, glycidyl group, β-methylglycidyl group, hydroxyl group, amino group, and acid anhydride group. It may be a modified latex or modified emulsion obtained by emulsion polymerization of an unsaturated monomer comprising one or more of the above.

  In the highly water-resistant adhesive composition of the present embodiment, any one of the water-soluble polymer aqueous solution, the aqueous latex, or the aqueous emulsion can be used alone or in admixture of two or more.

  Next, as the isocyanate compound used for the curing agent, in addition to 2,4′-diphenylmethane diisocyanate, for example, hexamethylene diisocyanate, isophorone diisocyanate (IPDI), phenylene diisocyanate, cyclohexyl diisocyanate, 4,4′-dicyclohexylmethane. Diisocyanate, hydrogenated xylylene diisocyanate, hydrogenated trimethyl xylylene diisocyanate, 2-methylpentane-1,5-diisocyanate, 3-methylpentane-1,5-diisocyanate, 2,2,4-trimethylhexamethylene-1,6 Diisocyanate, 2,4,4-trimethylhexamethylene-1,6-diisocyanate, 4,4-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, Phenylene diisocyanate, 2,4- or 2,6-tolylene diisocyanate or mixtures thereof, tetramethylxylylene diisocyanate, 4,4-diphenyl ether diisocyanate, 2,2'-diphenylmethane diisocyanate, 4,4'-diphenylmethane diisocyanate, 1, 3- or 1,4-xylylene diisocyanate or a mixture thereof can be exemplified.

  Examples of the isocyanate compound further include dimers, trimers, burettes derived from polymethylene polyphenyl polyisocyanate monomers, carbon dioxide and 2,4 obtained from polymethylene polyphenyl polyisocyanate monomers. Mention may be made of polyisocyanates having a 1,6-oxaziridinetrione ring. The isocyanate compound may be an adduct of a low molecular weight polyol such as ethylene glycol, propylene glycol, butylene glycol, hexylene glycol, neopentyl glycol, or cyclohexanedimethanol and a polyisocyanate, or a polyester polyol, a polyether polyol, or the like. It may be an NCO terminal compound such as an adduct of a polymer polyol with isocyanate, or a mixture of two or more of these.

  Any one of these isocyanate compounds may be used alone, or two or more thereof may be used in combination.

Next, the compound having an imide structure represented by the general formula (1) is produced, for example, by a method of de-CO ₂ condensation from 2 mol of an isocyanate compound (see, for example, Non-Patent Document 1). The structure of the compound produced as described above is affected by the isocyanate compound as a raw material, and if the isocyanate compound as a raw material is a compound containing one or more isocyanate groups in the molecule, one in the molecule. A compound having the above imide structure can be obtained. In addition, when the isocyanate compound as a raw material is a compound containing only one isocyanate group in the molecule, a compound having only one imide structure in the molecule can be obtained.

  The compound having one or more imide structures in the molecule can be produced using, for example, an isocyanate compound exemplified as the curing agent as a raw material.

  The compound having an imide structure represented by the general formula (1) reacts with water to produce a compound having an imide structure represented by the general formula (1a).

  The compound having the imide structure represented by the general formula (1a) also has heat resistance, and the highly water-resistant adhesive composition of the present embodiment has the imide structure represented by the general formula (1). By forming the compound represented by the general formula (1a) by the compound having, further excellent heat resistance and durability can be obtained.

  The compound having an imide structure represented by the general formula (1) may have one or more imide structures in the molecule and one or more isocyanate groups in the molecule. . The compound having at least one imide structure represented by the general formula (1) in the molecule and having at least one isocyanate group in the molecule is an isocyanate compound having at least two isocyanate groups in the molecule. It can be manufactured as a raw material.

  The compound having an imide structure represented by the general formula (1) is chemically bonded to a cured product composed of the main agent and the curing agent by providing one or more isocyanate groups in the molecule. Can do. Therefore, the cured body contains the imide structure represented by the general formula (1) in the molecular structure, and can further obtain excellent heat resistance and durability.

  The compound having an imide structure represented by the general formula (1) may be a compound having a structure represented by the general formula (2).

  The compound having the structure represented by the general formula (2), the so-called aromatic imide, has heat resistance like the compound having the imide structure represented by the general formula (1), and water and It reacts to become a compound having a structure represented by the general formula (2a). Therefore, the compound having the structure represented by the general formula (2) can act in the same manner as the compound having the imide structure represented by the general formula (1).

  The compound having the structure represented by the general formula (2) can be produced using a compound containing an isocyanate group bonded to a benzene ring in the molecule as a raw material. Examples of the compound containing an isocyanate group bonded to a benzene ring in the molecule include phenylene diisocyanate, 4,4-dibenzyl diisocyanate, 1,5-naphthylene diisocyanate, paraphenylene diisocyanate, 4,4-diphenyl ether diisocyanate, 2 , 2′-diphenylmethane diisocyanate, 2,4′-diphenylmethane diisocyanate, 4,4′-diphenylmethane diisocyanate, and the like. In addition, dimers, trimers, tetramers, or polymers of aromatic isocyanate compounds derived from aromatic isocyanate compound monomers can be used.

  In addition, the compound having the structure represented by the general formula (2) has one or more imide structures in the molecule similarly to the compound having the imide structure represented by the general formula (1). , One or more isocyanate groups may be provided in the molecule. The compound having the structure represented by the general formula (2), having one or more imide structures in the molecule and having one or more isocyanate groups in the molecule is bonded to the benzene ring in the molecule. Among the compounds containing an isocyanate group, a compound having two or more isocyanate groups in the molecule can be produced as a raw material.

  In addition, the compound having the structure represented by the general formula (2), having one or more imide structures in the molecule, and having one or more isocyanate groups in the molecule is cured by the isocyanate group. In order to chemically bond with the body, the imide modification rate is desirably 50% or less.

  On the other hand, the compound having an imide structure represented by the general formula (1) or the general formula (2) includes an isocyanate compound as a raw material as an unreacted product when synthesizing a condensation product of an isocyanate compound as described above. Yes. Since the compound having the imide structure becomes expensive when isolated and purified, by using the mixture of the compound having the imide structure and the raw material isocyanate compound as it is, the highly water-resistant adhesive composition of the present embodiment can be obtained. It can be manufactured at low cost.

  In the highly water-resistant adhesive composition of the present embodiment, any one of the compounds having an imide structure represented by the general formula (1) or the general formula (2) is used alone, or two or more kinds are mixed. Can be used.

  The highly water-resistant adhesive composition of the present embodiment may further contain a filler, a filler, and various additives as long as the adhesive performance is not impaired. Examples of the filler or extender include organic materials such as wheat flour, soybean flour, blood flour, wood flour, and walnut shell flour, and inorganic materials such as clay, kaolin, zeolite, calcium carbonate, talc, silica, and aluminum oxide. Etc. When using the filler, it is preferable to add, for example, sodium hexametaphosphate as a dispersant for dispersing the filler. Examples of the additive include an antifoaming agent, an antiseptic, a fireproofing agent, an antifungal agent, an antifungal agent, an insecticide, a foam stabilizer, a foaming agent, a rust inhibitor, a wetting agent, a wettability modifier, and the like Any one of the above additives can be added alone or in admixture of two or more.

  Next, examples and comparative examples of the present invention are shown.

  In this example, first, 100 parts by weight of a 15% polyvinyl alcohol aqueous solution (manufactured by Kuraray Co., Ltd., trade name: PVA217), 10 parts by weight of styrene-butadiene copolymer latex (manufactured by Asahi Kasei Kogyo Co., Ltd., trade name: DL-612). To the main agent, 60 parts by weight of calcium carbonate (trade name: Whiten P-30, manufactured by Toyo Fine Chemical Co., Ltd.) and 0.5 parts by weight of sodium hexametaphosphate are added and mixed to mix the main agent. A base mix containing was prepared.

  Next, a mixture of 15 parts by weight of a curing agent and 1.1 parts by weight of a compound having an imide structure is added and stirred to 100 parts by weight of the main agent that has been heated to the same temperature in advance. Prepared and glued. The curing agent is a mixture of isocyanate compounds including 40.0% by weight of 2,4′-diphenylmethane diisocyanate, 55.0% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate. It is.

  The compound having the imide structure is a carbodiimide condensate of 4,4'-diphenylmethane diisocyanate obtained by modifying the isocyanate group of 4,4'-diphenylmethane diisocyanate to 37% carbodiimide. In the adhesive composition of this example, the content of the compound having an imide structure (1.1 parts by weight) is 7 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested based on “JIS K 6806”.

In the test, 250 g / m ^{2 of the} adhesive composition was applied to a 10 mm thick birch grain board having a moisture content of 6 to 8% and a specific gravity of 0.72 to 0.75, and an open deposition time of 20 ° C. Within 1 minute, closed deposition time within 20 minutes at 20 ° C., clamped at 20 ° C. with a pressure of 1.2 N / cm ² for 24 hours, then decompressed and cured for 7 days at 20 ° C. It was. And the compression shear adhesive strength of each said test piece was measured on the conditions of "normal state." The test results are shown in Table 1.

The test results are shown as adhesive strength (N / cm ² ) obtained by measuring the maximum load until the test piece breaks with a testing machine defined in “JIS K 6808” and dividing by the actually measured adhesion area. Here, the “normal state” is used for the test immediately after preparing the test piece, and indicates an adhesive force irrespective of water resistance.

  Moreover, the adhesive performance of the adhesive composition obtained in this example was tested based on a boiling peeling test and a reduced pressure test of a structural laminated material according to Japanese Agricultural Standards.

In the test, 250 g / m ^{2 of the} adhesive composition was applied to a 22.0 mm-thick bay pine grain board having a water content of 6 to 10% and a specific gravity of 0.48 to 0.68, and an open deposition time of 20 ° C. Within 1 minute at 20 ° C., within 10 minutes at 20 ° C., after pressing for 40 minutes at 20 ° C. with a pressure of 1.2 N / cm ² , decompressed and tested for 7 days at 20 ° C. It was a piece. Moreover, based on the test method defined in the Japanese Agricultural Standards, the separation length at the both ends was measured, and the separation rate at both ends was calculated. The test results are shown in Table 1.

  Here, the “boiling peeling test” means that the test piece is immersed in boiling water for 4 hours and further immersed in water at room temperature (10 to 25 ° C.) for 1 hour, and then the test piece taken out from the water is 70 ± 3 ° C. Place in a high-temperature dryer and dry for 24 hours or more so that moisture does not accumulate in the vessel, so that the moisture content after drying is less than the moisture content before the test, water resistance, heat resistance and It becomes an index of durability.

  The “depressurization and pressure test” refers to immersing a test piece in water at room temperature (10 to 25 ° C.), performing a depressurization of 0.085 MPa for 5 minutes, and further applying a pressure of 0.51 ± 0.03 MPa for 1 hour. After repeating this treatment twice, the test piece is taken out of water, placed in a high-temperature dryer at 70 ± 3 ° C., and dried for 24 hours or more so that moisture does not accumulate in the vessel. The moisture content is not more than the pre-test moisture content, and is a stricter index of durability than the “boiling peeling test”.

  In this example, as the curing agent, 24.8% by weight of 2,4′-diphenylmethane diisocyanate, 70.2% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared and glued in exactly the same manner as in Example 1 except that the isocyanate compound mixture was used and the content of the compound having an imide structure was 2.6 parts by weight. In the adhesive composition of this example, the content (2.6 parts by weight) of the compound having the imide structure corresponds to 17 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 1.

  In this example, as the curing agent, 9.6% by weight of 2,4′-diphenylmethane diisocyanate, 85.4% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared and glued in exactly the same way as in Example 1 except that the content of the compound having an imide structure was 4.1 parts by weight using a mixture of isocyanate compounds contained. In the adhesive composition of this example, the content of the compound having an imide structure (4.1 parts by weight) corresponds to 27 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 1.

  In this example, 15.4% by weight of 2,4′-diphenylmethane diisocyanate, 79.8% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used as the curing agent. An adhesive composition was prepared and glued in exactly the same manner as in Example 1 except that the content of the compound having an imide structure was changed to 5.6 parts by weight using a mixture of isocyanate compounds. In the adhesive composition of this example, the content of the compound having an imide structure (5.6 parts by weight) corresponds to 37 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 1.

  In this example, as the curing agent, 5.6% by weight of 2,4′-diphenylmethane diisocyanate, 89.4% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared and glued in exactly the same way as in Example 1 except that the content of the compound having an imide structure was 7.1 parts by weight using a mixture of isocyanate compounds contained. In the adhesive composition of this example, the content (7.1 parts by weight) of the compound having an imide structure corresponds to 47 parts by weight with respect to 100 parts by weight of the curing agent.

Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 1.
[Comparative Example 1]
In this comparative example, the curing agent does not contain 2,4′-diphenylmethane diisocyanate at all, and an isocyanate containing 50.0% by weight of 4,4′-diphenylmethane diisocyanate and 50.0% by weight of polymethylenephenyl polyisocyanate. An adhesive composition was prepared and glued in exactly the same manner as in Example 1 except that a mixture of compounds was used and no compound having the imide structure was used.

  Next, the adhesive performance of the adhesive composition obtained in this comparative example was tested in exactly the same manner as in Example 1. The results are shown in Table 1.

  From Table 1, in all the adhesive compositions of Examples and Comparative Examples, the “normal state” compression shear adhesive strength showed excellent adhesive strength, and test pieces were prepared under the same conditions in both Examples and Comparative Examples. It is clear.

  Moreover, the Example which contains 5.6-40 weight% of 2,4'- diphenylmethane diisocyanate with respect to whole quantity of a hardening | curing agent, and contains 7-47 weight part of compounds which have an imide structure with respect to 100 weight part of hardening | curing agents. It is clear that the adhesive compositions 1 to 5 have superior water resistance, heat resistance, and durability as compared with Comparative Example 1 in any of the conditions of the boiling peeling test and the reduced pressure test. is there.

  In this example, as the curing agent, 9.6% by weight of 2,4′-diphenylmethane diisocyanate, 85.4% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used. The adhesive composition was prepared in the same manner as in Example 1 except that 30.0 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 8.1 parts by weight. did. In the adhesive composition of this example, the content (8.1 parts by weight) of the compound having an imide structure corresponds to 27.0 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 21.7% by weight of 2,4′-diphenylmethane diisocyanate, 71.9% by weight of 4,4′-diphenylmethane diisocyanate, and 6.4% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 23.4 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 6.7 parts by weight. did. In the adhesive composition of this example, the content (6.7 parts by weight) of the compound having the imide structure is 28.5 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 17.6% by weight of 2,4′-diphenylmethane diisocyanate, 77.2% by weight of 4,4′-diphenylmethane diisocyanate, and 5.2% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 14.4 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 0.6 parts by weight. did. In the adhesive composition of this example, the content (0.6 parts by weight) of the compound having an imide structure corresponds to 3.9 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, 18.4% by weight of 2,4′-diphenylmethane diisocyanate, 76.3% by weight of 4,4′-diphenylmethane diisocyanate, and 5.3% by weight of polymethylenephenyl polyisocyanate were used as the curing agent. An adhesive composition was prepared in the same manner as in Example 1 except that 13.9 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 1.1 parts by weight. did. In the adhesive composition of this example, the content (1.1 parts by weight) of the compound having the imide structure corresponds to 8.0 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 19.1% by weight of 2,4′-diphenylmethane diisocyanate, 75.5% by weight of 4,4′-diphenylmethane diisocyanate, and 5.4% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 13.3 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 1.7 parts by weight. did. In the adhesive composition of this example, the content (1.7 parts by weight) of the compound having an imide structure corresponds to 12.6 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 19.8% by weight of 2,4′-diphenylmethane diisocyanate, 74.3% by weight of 4,4′-diphenylmethane diisocyanate, and 5.9% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 12.8 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 2.2 parts by weight. did. In the adhesive composition of this example, the content of the compound having an imide structure (2.2 parts by weight) corresponds to 17.3 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 20.8% by weight of 2,4′-diphenylmethane diisocyanate, 73.1% by weight of 4,4′-diphenylmethane diisocyanate, and 6.1% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 12.2 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 2.8 parts by weight. did. In the adhesive composition of this example, the content of the compound having an imide structure (2.8 parts by weight) corresponds to 22.8 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 21.7% by weight of 2,4′-diphenylmethane diisocyanate, 71.9% by weight of 4,4′-diphenylmethane diisocyanate, and 6.4% by weight of polymethylenephenyl polyisocyanate were used. The adhesive composition was prepared in the same manner as in Example 1 except that 11.7 parts by weight of the mixture of isocyanate compounds was used and the content of the compound having the imide structure was 3.3 parts by weight. did. In the adhesive composition of this example, the content of the compound having an imide structure (3.3 parts by weight) is 28.5 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  In this example, as the curing agent, 24.8% by weight of 2,4′-diphenylmethane diisocyanate, 70.2% by weight of 4,4′-diphenylmethane diisocyanate, and 5.0% by weight of polymethylenephenyl polyisocyanate were used. An adhesive composition was prepared in the same manner as in Example 1 except that 7.5 parts by weight of the isocyanate compound mixture was used and the content of the compound having the imide structure was 1.3 parts by weight. did. In the adhesive composition of this example, the content (1.3 parts by weight) of the compound having an imide structure corresponds to 17.0 parts by weight with respect to 100 parts by weight of the curing agent.

  Next, the adhesive performance of the adhesive composition obtained in this example was tested in exactly the same manner as in Example 1. The results are shown in Table 2.

  From Table 2, it is clear that in all the adhesive compositions of the examples, the “normal” compression shear bond strength showed excellent adhesion, and the specimens were prepared under the same conditions.

  Moreover, the implementation which contains 7.5-30.0 weight part of hardening | curing agents with respect to 100 weight part of main ingredients, and 3.9-28.5 weight parts of compounds which have an imide structure with respect to 100 weight parts of hardening | curing agents. It is apparent that the adhesive compositions of Examples 6 to 14 have excellent water resistance, heat resistance, and durability under any conditions of the boiling peeling test and the pressure reduction test.

Claims (5)

A main agent composed of one or more of a water-soluble polymer aqueous solution, an aqueous latex, and an aqueous emulsion, a curing agent composed of an isocyanate compound containing 2,4′-diphenylmethane diisocyanate, and an imide represented by the general formula (1) A highly water-resistant adhesive composition comprising a compound having a structure.

The highly water-resistant adhesive composition according to claim 1, wherein the compound having an imide structure represented by the general formula (1) is a compound having a structure represented by the general formula (2).

  The highly water-resistant adhesive composition according to claim 1 or 2, wherein the curing agent is contained in an amount of 5 to 40 parts by weight with respect to 100 parts by weight of the main agent.   The compound having an imide structure represented by the general formula (1) is contained in an amount of 2 to 50 parts by weight with respect to 100 parts by weight of the curing agent. The highly water-resistant adhesive composition according to item 1.   The highly water-resistant adhesive according to any one of claims 1 to 4, comprising 2,4'-diphenylmethane diisocyanate in an amount of 2 to 50% by weight based on the total amount of the curing agent. Composition.