Electromagnetic steel sheet adhesive coating composition, electromagnetic steel sheet laminate, and method for producing the same

Abstract

The present invention provides an electromagnetic steel sheet laminate having a fusion layer formed thereon that can bond (fasten) electromagnetic steel sheets without using conventional fastening methods such as welding, clamping, or interlocking, and a method for manufacturing the same. Specifically, the present invention provides an electromagnetic steel sheet adhesive coating composition that improves the adhesive strength between electromagnetic steel sheets by controlling the components of the fusion layer formed between the electromagnetic steel sheets. The adhesive resin is formed by reacting a monomer represented by the following formula 1, formula 2, or a combination thereof with a polyol. [Chemical formula 1] TIFF2023554122000040.tif56133

Description

Technical Field

[0001] The present invention relates to an electromagnetic steel sheet adhesive coating composition, an electromagnetic steel sheet laminate, and a method for manufacturing the same. Specifically, one embodiment of the present invention relates to an electromagnetic steel sheet adhesive coating composition containing a urethane resin, an electromagnetic steel sheet laminate, and a method for manufacturing the same.

Background Art

[0002] Non-oriented electromagnetic steel sheets are steel sheets with uniform magnetic properties in all directions on the rolled plate, and are widely used in cores of motors, generators, electric motors, small transformers, etc. Electromagnetic steel sheets can be classified into two forms: those that must undergo stress relief annealing (SRA) to improve magnetic properties after punching, and those that omit stress relief annealing when the cost loss due to heat treatment is greater than the magnetic property effect due to stress relief annealing. The insulating film is a film coated in the finishing manufacturing process of laminates such as cores of motors, generators, electric motors, small transformers, etc., and usually requires electrical properties to suppress the generation of eddy currents. In addition, continuous punching processability, anti-adhesion property, and surface adhesion property are also required. Continuous punching processability means the ability to suppress wear of the die when punching into a predetermined shape and then laminating a large number to form a core. The anti-adhesion property means the ability not to adhere between the core steel sheets after the stress relief annealing process that removes the processing stress of the steel sheet and restores the magnetic properties. In addition to such basic properties, excellent coating workability of the coating solution and solution stability that allows long-term use after compounding are also required. Such an insulating film must use separate fastening methods such as welding, clamping, and interlocking to manufacture an electromagnetic steel sheet laminate.

Summary of the Invention

Problems to be Solved by the Invention

[0003] An object of the present invention is to provide an electromagnetic steel sheet laminate having a fusion layer capable of bonding (fastening) electromagnetic steel sheets without using conventional fastening methods such as welding, clamping, and interlocking, and a method for manufacturing the same. Specifically, it is to provide an electromagnetic steel sheet adhesive coating composition in which the components of the fusion layer formed between electromagnetic steel sheets are controlled to improve the adhesive force between electromagnetic steel sheets.

Means for Solving the Problems

[0004] The bonding composition of the present invention contains an adhesive resin and a bonding additive, and the adhesive resin is a polyurethane formed by reacting a monomer and a polyol represented by the following Chemical Formula 1, Chemical Formula 2, or a combination thereof.

[0005] [Chemical Formula 1] TIFF0007701979000001.tif56133

[0006] [Chemical Formula 2] TIFF0007701979000002.tif65128

[0007] In the above Chemical Formula 1, R 1 ~R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, or an isocyanate group, and one of R 1 ~R 5 is an isocyanate, one of R 6 ~R 10 is an isocyanate, and when both R 3 and R 8 are isocyanates at the same time, they are excluded. L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group, and n is an integer from 1 to 10.

[0008] In the above Chemical Formula 2, R 11 ~R 16 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, an isocyanate group or a substituted or unsubstituted C1-C10 alkyl isocyanate group, and at least two of R 11 ~R 16 are isocyanate or a substituted or unsubstituted C1-C10 alkyl isocyanate.

[0009] In the above Chemical Formula 1, any one of R 1 ~R 5 is isocyanate, any one of R 6 ~R 10 is isocyanate, and the case where R 3 and R 8 are simultaneously isocyanate is excluded, and the case where R 1 and R 10 are simultaneously isocyanate is further excluded. In the above Chemical Formula 1, any one of R 1 ~R 5 is isocyanate, any one of R 6 ~R 10 is isocyanate, any one of R 1 ~R 5 and any one of R 6 ~R 10 being simultaneously isocyanate symmetrically about L is further excluded. The monomer represented by the above Chemical Formula 1 is the one represented by the following Chemical Formula 3.

[0010] [Chemical Formula 3] TIFF0007701979000003.tif42128

[0011] In the above Chemical Formula 3, L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group. Said L is a methylene group. The monomer represented by the above Chemical Formula 2 is the one represented by the following Chemical Formula 4.

[0012] [Chemical Formula 4] TIFF0007701979000004.tif59128

[0013] In the above Chemical Formula 4, R 11 may be hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group.

[0014] The electromagnetic steel sheet of the present invention includes an electromagnetic steel sheet base material and a bonding coating layer located on the base material of the electromagnetic steel sheet. The bonding coating layer includes an adhesive resin and a bonding additive. The adhesive resin includes a polyurethane containing a repeating unit represented by the following Chemical Formula 5, Chemical Formula 6, or a combination thereof.

[0015] [Chemical Formula 5] TIFF0007701979000005.tif34156

[0016] [Chemical Formula 6] TIFF0007701979000006.tif34150

[0017] In the above Chemical Formula 5 or Chemical Formula 6, L or the amide functional group (CONH) is bonded to any carbon of the benzene ring, and the carbons of the benzene ring to which L or the amide functional group is not bonded are, independently of each other, hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; n is any integer from 1 to 10; and m is 1 or more. The adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof.

[0018] [Chemical Formula 7] TIFF0007701979000007.tif64154

[0019] [Chemical Formula 8] TIFF0007701979000008.tif63131

[0020] In the above Chemical Formula 7 or Chemical Formula 8, R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; R 11is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, n is any integer from 1 to 10, and m is 1 or more.

[0021] The electromagnetic steel sheet laminate of the present invention includes a plurality of electromagnetic steel sheets; and a fusion layer located between the plurality of electromagnetic steel sheets, the fusion layer includes an adhesive resin and a bonding additive, and the adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 5, Chemical Formula 6, or a combination thereof.

[0022] [Chemical Formula 5] TIFF0007701979000009.tif34156

[0023] [Chemical Formula 6] TIFF0007701979000010.tif34150

[0024] In the Chemical Formula 5 or Chemical Formula 6, L or an amide functional group (CONH) is bonded to any carbon of the benzene ring, and the carbons of the benzene ring to which L or an amide functional group is not bonded are independently of each other hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group, n is any integer from 1 to 10, and m is 1 or more. The adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof.

[0025] [Chemical Formula 7] TIFF0007701979000011.tif64154

[0026] [Chemical Formula 8] TIFF0007701979000012.tif63131

[0027] In the above Chemical Formula 7 or Chemical Formula 8, R’ is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; R 11 is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; n is any integer from 1 to 10; and m is 1 or more.

Advantages of the Invention

[0028] According to the present invention, the components of the fused layer formed between electromagnetic steel sheets can be controlled to improve the adhesive force between the electromagnetic steel sheets. In addition, the electromagnetic steel sheets can be adhered without using conventional fastening methods such as welding, clamping, and interlocking. Furthermore, an electromagnetic steel sheet adhesive coating composition excellent in all of coating film adhesion, peeling characteristics, and ATF resistance characteristics can be provided.

Embodiments for Carrying Out the Invention

[0029] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are used only to distinguish one part, component, region, layer, or section from another. Thus, the first part, component, region, layer, or section described below can be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms also include the plural forms unless the context clearly dictates otherwise. The meaning of "comprising" used in the specification does not exclude the presence or addition of other characteristics, regions, integers, steps, operations, elements, and / or components while specifying a particular characteristic, region, integer, step, operation, element, and / or component. When a part is "on" or "above" another part, this can mean directly on or above the other part, or there may be other parts intervening therebetween. Conversely, when a part is "directly on" another part, there are no other parts intervening therebetween. Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms defined in commonly used dictionaries are further analyzed and have meanings consistent with the relevant technical literature and the presently disclosed content, and are not interpreted in an idealized or overly formal sense unless otherwise defined.

[0030] As used herein, "substituted" means that at least one hydrogen of a compound is substituted with a C1-C30 alkyl group; a C1-C10 alkoxy group; a silane group; an alkylsilane group; an alkoxysilane group; or an ethyleneoxyl group, unless otherwise defined. As used herein, "hetero" means an atom selected from the group consisting of N, O, S, and P, unless otherwise defined. The alkyl group may be a C1-C20 alkyl group, specifically, it may be a C1-C6 lower alkyl group, a C7-C10 middle alkyl group, or a C11-C20 higher alkyl group. For example, a C1-C4 alkyl group means one having 1 to 4 carbon atoms in the alkyl chain, which is selected from the group consisting of methyl, ethyl, propyl, iso-propyl, n-butyl, iso-butyl, sec-butyl, and t-butyl. Typical alkyl groups include methyl group, ethyl group, propyl group, isopropyl group, butyl group, isobutyl group, t-butyl group, pentyl group, hexyl group, cyclopropyl group, cyclobutyl group, cyclopentyl group, cyclohexyl group, and the like.

[0031] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement them. However, the present invention can be realized in various different forms and is not limited to the embodiments described herein. The present invention provides a bonding composition for an electromagnetic steel sheet. Among the descriptions of the present invention, the adhesive coating composition is also a term used to indicate the bonding composition. Further, the bonding composition of the present invention is a composition for bonding the surfaces of two or more steel sheets, and its use is not particularly limited. For example, it can be a self-bonding composition for an electromagnetic steel sheet for providing self-bonding of the electromagnetic steel sheet. The bonding composition for an electromagnetic steel sheet according to an embodiment of the present invention may contain an adhesive resin and a bonding additive, and the adhesive resin may be a polyurethane formed by reacting a monomer and a polyol represented by the following Chemical Formula 1, Chemical Formula 2, or a combination thereof.

[0032] [Chemical Formula 1] TIFF0007701979000013.tif56133

[0033] [Chemical Formula 2] TIFF0007701979000014.tif65128

[0034] In the above Chemical Formula 1, R 1 ~R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, or an isocyanate group, and any one of R 1 ~R 5 is an isocyanate, and any one of R 6 ~R 10 is an isocyanate. When R 3 and R 8 are simultaneously isocyanates, they are excluded. L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group, and n is any integer from 1 to 10.

[0035] In the above Chemical Formula 2, R 11 ~R 16 are each independently hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, a substituted or unsubstituted C5-C20 heteroaryl group, an isocyanate group, or a substituted or unsubstituted C1-C10 alkyl isocyanate group, and at least two of R 11 ~R 16 are isocyanates or substituted or unsubstituted C1-C10 alkyl isocyanates.

[0036] For the monomer represented by the above Chemical Formula 1, any one of R 1 ~R 5 is an isocyanate, and any one of R 6 ~R 10 is an isocyanate. When R 3 and R 8 are simultaneously isocyanates, they are excluded, and R 1 and R 10The case where it is simultaneously an isocyanate can be further excluded. The monomer represented by the chemical formula 1 is R 1 ~R 5 Any one of them is an isocyanate, and R 6 ~R 10 Any one of them is an isocyanate, and R 1 ~R 5 Any one of them and R 6 ~R 10 The case where any one of them is symmetrically an isocyanate centered on L can be further excluded. Specifically, the monomer represented by the chemical formula 1 may be the one represented by the following chemical formula 3.

[0037] [Chemical formula 3] TIFF0007701979000015.tif42128

[0038] In the chemical formula 3, L may be a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group. Specifically, in the chemical formula 1 or 3, L may be a methylene group. Specifically, the monomer represented by the chemical formula 2 may be the one represented by the following chemical formula 4.

[0039] [Chemical formula 4] TIFF0007701979000016.tif59128

[0040] In the chemical formula 4, R 11 may be hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group. More specifically, the monomer represented by Chemical Formula 1, 2, 3, or 4 may be at least one selected from the group consisting of 2,4-toluene diisocyanate, 2,6-toluene diisocyanate, p-phenylene diisocyanate, 2,2'-methylenediphenyl diisocyanate, 2,4'-methylenediphenyl diisocyanate, 4,4'-methylenediphenyl diisocyanate, and m-xylene diisocyanate. The polyol may be the polyol of Chemical Formula 9.

[0041] [Chemical Formula 9] TIFF0007701979000017.tif5128 In Chemical Formula 9, R' may be a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group.

[0042] The polyol may have a number average molecular weight of 400 to 1000 g / mol. Further, the polyol may be poly(propylene glycol).

[0043] The content of the polyurethane resin may be 98% by weight or more based on the total weight of the bonding composition for an electromagnetic steel sheet. The bonding composition for an electromagnetic steel sheet of the present invention can exhibit excellent steel sheet adhesion by minimizing the content of bonding additives other than the resin component contained in the composition and maximizing the content of the resin component. The bonding additive is not limited as long as it is used in a general bonding composition. For example, it may include a coupling agent, a wetting agent, a curing agent, a curing catalyst, and the like.

[0044] Specifically, the coupling agent may include a silane coupling agent. More specifically, one or more of vinyl-based silane coupling agents and methacryloxy-based silane coupling agents may be included. Examples of vinyl-based silane coupling agents include Vinyl trimethoxy silane and Vinyl triethoxy silane. Examples of methacryloxy-based silane coupling agents include 3-Methacryloxypropyl methyldimethoxysilane, 3-Methacryloxpropyl trimethoxysilane, 3-Methacyloxypropyl methyldiethoxysilane, and 3-Methacryloxpropyl triethoxysilane.

[0045] Specifically, the wetting agent may include a silicone-based wetting agent. An example of a silicone-based wetting additive is Polyether-modified polydimethylsiloxane. The wetting agent can be added to the bonding composition for electrical steel sheets to enhance the interfacial adhesion force between the electrical steel sheet and the fusion layer. Specifically, the curing agent may include aliphatic amine-based, aromatic amine-based, aminoamine-based, or imidazole-based. More specifically, dicyandiamide-based curing agents may be included. Specifically, the curing catalyst may include an imidazole-based curing catalyst.

[0046] The bonding composition for an electromagnetic steel sheet of the present invention may further contain 0.10 to 1.00 parts by weight of a coupling agent with respect to 100 parts by weight of the polyurethane resin. Specifically, it may further contain 0.40 to 0.60 parts by weight of the coupling agent. When the crosslinking agent is contained in an excessively small amount, the effect of strengthening the interfacial adhesion force between the electromagnetic steel sheet and the fusion layer cannot be sufficiently obtained. When the crosslinking agent is contained in an excessively large amount, precipitates may be generated in the adhesive coating composition due to the reaction between the crosslinking agents. The bonding composition for an electromagnetic steel sheet of the present invention may further contain 0.50 to 2.50 parts by weight of a curing agent with respect to 100 parts by weight of the polyurethane resin. Specifically, it may further contain 0.90 to 1.10 parts by weight of the curing agent. The curing agent plays a role in adjusting the reactivity of the surface of the adhesive coating layer. When the curing agent is contained in an excessively small amount, the curing reaction of the fusion layer may decrease, and a problem may occur in that the adhesiveness (sticky) of the surface of the fusion layer is poor. Conversely, when the curing agent is added in an excessively large amount, the fastening force after low-temperature fusion is poor.

[0047] The bonding composition for an electromagnetic steel sheet of the present invention may further contain 0.05 to 0.50 parts by weight of a wetting agent with respect to 100 parts by weight of the polyurethane resin. Specifically, it may further contain 0.09 to 0.11 parts by weight of the wetting agent. The bonding composition for an electromagnetic steel sheet of the present invention may further contain 0.10 to 1.00 parts by weight of a curing catalyst with respect to 100 parts by weight of the polyurethane resin. Specifically, it may further contain 0.40 to 0.60 parts by weight of the curing catalyst. The polyurethane resin of the present invention may have a number average molecular weight of 3,000 to 20,000 g / mol.

[0048] The electromagnetic steel sheet of the present invention includes an electromagnetic steel sheet substrate and a bonding coating layer located on the substrate of the electromagnetic steel sheet. The bonding coating layer includes an adhesive resin and a bonding additive. The adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 5, Chemical Formula 6, or a combination thereof.

[0049] [Chemical Formula 5] TIFF0007701979000018.tif34156

[0050] [Chemical Formula 6] TIFF0007701979000019.tif34150In Chemical Formula 5 or Chemical Formula 6, L or the amide functional group (CONH) is bonded to any carbon of the benzene ring, and the carbons of the benzene ring to which L or the amide functional group is not bonded are, independently of each other, hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; n is any integer from 1 to 10; and m is 1 or more. Specifically, m is the number of repeating units contained in the polyurethane and can be varied according to the target polyurethane molecular weight.

[0051] The repeating unit of Chemical Formula 5 can be produced by the polymerization reaction of the monomer of Chemical Formula 1 and a polyol, and can also be produced by the polymerization reaction of the monomer of Chemical Formula 2 and a polyol. Specifically, the adhesive resin contained in the bonding coating layer is a polyurethane containing repeating units represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof.

[0052] [Chemical Formula 7] TIFF0007701979000020.tif64154

[0053] [Chemical Formula 8] TIFF0007701979000021.tif63131

[0054] In the above Chemical Formula 7 or Chemical Formula 8, R’ is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; R 11 is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; n is any integer from 1 to 10; and m is 1 or more. Specifically, m is the number of repeating units contained in the polyurethane, and can be varied according to the target molecular weight of the polyurethane.

[0055] The repeating unit of the above Chemical Formula 7 can be produced by the polymerization reaction of the monomer of Chemical Formula 3 and the polyol, and the repeating unit of Chemical Formula 8 can be produced by the polymerization reaction of the monomer of Chemical Formula 4 and the polyol.

[0056] The bonding coating layer located on the substrate of the electromagnetic steel sheet may be derived from the above-mentioned bonding composition for electromagnetic steel sheets. Since the description of the more specific features of the bonding coating layer is detailed in the above-mentioned bonding composition, the description thereof is used instead here.

[0057] The electromagnetic steel sheet laminate of the present invention includes a plurality of electromagnetic steel sheets and a fusion layer located between the plurality of electromagnetic steel sheets; the fusion layer includes an adhesive resin and a bonding additive, and the adhesive resin may include a polyurethane containing a repeating unit represented by the following Chemical Formula 5, Chemical Formula 6, or a combination thereof.

[0058] [Chemical Formula 5] TIFF0007701979000022.tif34156

[0059] [Chemical Formula 6] TIFF0007701979000023.tif34150

[0060] In the above Chemical Formula 5 or Chemical Formula 6, L or the amide functional group (CONH) is bonded to any carbon of the benzene ring, and the carbons of the benzene ring to which L or the amide functional group is not bonded are, independently of each other, hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; n is any integer from 1 to 10; and m is 1 or more.

[0061] Specifically, m is the number of repeating units contained in the polyurethane and can be varied depending on the target polyurethane molecular weight. Specifically, the adhesive resin contained in the fusion layer may contain a polyurethane containing a repeating unit represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof.

[0062] [Chemical Formula 7] TIFF0007701979000024.tif64154

[0063] [Chemical Formula 8] TIFF0007701979000025.tif63131

[0064] In Chemical Formula 7 or Chemical Formula 8, R’ is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group; R 11 is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group; n is any integer from 1 to 10; and m is 1 or more

[0065] . Specifically, m is the number of repeating units contained in the polyurethane and can be varied depending on the target molecular weight of the polyurethane. The bonding coating layer located between the laminates may be derived from the above-described bonding composition for electromagnetic steel sheets. Since a more specific description of the bonding coating layer is provided in detail in the above bonding composition, that description is substituted therefor.

[0066] The thickness of the fusion layer of the electromagnetic steel sheet laminate can be 0.1 to 10 μm. If the thickness of the fusion layer is too thin, the adhesive strength may decrease rapidly, and if it is too thick, problems due to adhesiveness may occur after coating winding. More specifically, the thickness of the fusion layer can be 5 to 7 μm. A coupling agent, a wetting agent, a curing catalyst, a curing agent, etc. may remain in the fusion layer of the electromagnetic steel sheet laminate.

[0067] The method for manufacturing the electromagnetic steel sheet laminate of the present invention may include a step of applying an adhesive coating composition to one or both surfaces of an electromagnetic steel sheet and then curing it to form an adhesive coating layer, and a step of laminating and thermally fusing a plurality of electromagnetic steel sheets having the adhesive coating layer formed thereon to form a fusion layer. Hereinafter, each step will be described in detail. First, prepare an adhesive coating composition. Since the adhesive coating composition has been described above, duplicate explanations are omitted. Next, after coating the surface of the electromagnetic steel sheet with the adhesive coating composition, it is cured to form an adhesive coating layer. This step is carried out in a temperature range of 150 to 250 °C based on the plate temperature for curing the adhesive coating composition. A plurality of electromagnetic steel sheets with the adhesive coating layer formed are laminated and heat-sealed to form a fusion layer 20. In the heat-sealing step, the polymer components in the adhesive coating layer are heat-sealed to form a fusion layer.

[0068] The heat-sealing step is carried out under heat-sealing conditions of a temperature of 150 to 250 °C, a pressure of 0.05 to 5.0 Mpa, and a pressurization time of 0.1 to 120 minutes. The above conditions may be satisfied independently, or two or more conditions may be satisfied simultaneously. By adjusting the temperature, pressure, and time conditions in the heat-sealing step in this way, it is possible to tightly heat-seal between the electromagnetic steel sheets without gaps or organic phases. Since the further limitation of the substituents in the isocyanate monomer is the same as that described in the bonding composition for electromagnetic steel sheets, the description of the electromagnetic steel sheet, the electromagnetic steel sheet laminate, and the manufacturing method is omitted.

[0069] Hereinafter, preferred examples and comparative examples of the present invention will be described. However, the following examples are only a preferred example of the present invention, and the present invention is not limited to the following examples. Experimental Example Anisotropic electromagnetic steel sheets (50 × 50 mm, 0.35 mm t) were prepared as test pieces. The adhesive coating solution was applied to the upper and lower parts of the prepared test pieces with a certain thickness using a bar coater and a roll coater respectively, cured at 150 to 200 °C for 20 seconds based on the plate temperature, and then slowly cooled in the air to form an adhesive coating layer. Subsequently, as the coating solution, bonding solutions with the compositions shown in Tables 1 and 2 were used. Table 1 shows the sole use of urethane resin, and Table 2 discloses the sole use of epoxy resin or the use of a resin mixture of epoxy and urethane. The composition of the adhesive coating solution other than the bonding resin contains 0.5 parts by weight of a silane coupling agent, 0.1 parts by weight of a silicone-based wetting agent, 1 part by weight of a dicyandiamide-based curing agent, and 0.5 parts by weight of an imidazole-based curing catalyst based on 100 parts by weight of the bonding resin.

[0070] MDI in Table 1 means Methylene Diphenyl Diisocyanate, TDI means Toluene Diisocyanate, and PPG is poly(propylene glycol) (hydroxyl molecular weight 425 g / mol). As the epoxy resin, a bisphenol A type epoxy resin with a number average molecular weight of 10,000 g / mol and a hydroxyl value of 10 mgKOH / g was used. Electromagnetic steel sheets coated with the adhesive coating layer were laminated at a height of 20 mm, and then pressure was applied at 0.5 MPa and heat fusion was carried out at 160 °C for 10 minutes. The thickness of the fusion layer after heat fusion was approximately 6 μm. The heat-fused fused bodies were evaluated by solution type. As the evaluation items, the peel adhesive strength (T-peel, N / mm) and the ATF resistance property were evaluated and shown in Tables 1 and 2 below.

[0071] Each measurement method is as follows. Peel adhesive strength (T-peel, N / mm): The specifications of the test pieces for the peel method (T-Peel off) measurement were fabricated in accordance with ISO11339. Two 25×200 mm test pieces were 25×150 mm 2After adhering with the area of , the unadhered part was bent at 90 degrees to fabricate a T-shaped tensile test piece. After fixing the test piece fabricated by the peel-off method (T-Peeloff) to the upper / lower jig (JIG) with a constant force, the tensile force of the laminated sample was measured using a device that measures while pulling at a constant speed. At this time, in the case of the shear method, the measured value was the point where the interface having the minimum bonding force among the interfaces of the laminated sample dropped off. After maintaining the temperature of the test piece at 60 °C with a heating device, the adhesive strength was measured.

[0072] Evaluation method for ATF resistance characteristics: When using a drive motor in an automobile, a lot of heat is generated when it rotates at high speed for a long time, and ATF (Automotive Transmission Fluid, automotive transmission oil) is used to cool this. Therefore, in order to ensure the adhesion reliability during long-term use, it is important that the adhesive strength of the laminated coil is maintained in a state impregnated with high-temperature ATF. Therefore, the ATF resistance characteristics were evaluated. After impregnating the manufactured laminated coil in ATF at a temperature of 150 °C for 500 hours, the shear adhesive strength was tested.

[0073] The shear adhesive strength for measuring the ATF resistance characteristics was measured by the shear method (Shear Strength). The specifications of the test piece for shear method measurement were fabricated according to ISO4587. Two 25×100 mm test pieces were adhered with the area of 12.5×25 mm 2 and heat-sealed under the above conditions to fabricate a shear method test piece. After fixing the test piece fabricated by the shear method to the upper / lower jig (JIG) with a constant force, the tensile force of the laminated sample was measured using a device that measures while pulling at a constant speed. At this time, in the case of the shear method, the measured value was the point where the interface having the minimum bonding force among the interfaces of the laminated sample dropped off.

[0074]

Table 1

[0075]

Table 2

[0076] From the results of Tables 1 and 2 above, it was confirmed that the examples containing only polyurethane as the bonding resin were excellent in both T-peel properties and AFT resistance properties. In particular, from the results of Table 2, it was confirmed that not only the single use of epoxy but also the case of mixing urethane with epoxy resulted in inferior T-peel properties (peeling properties).

[0077] The present invention is not limited to the above-described examples and can be manufactured in various different forms. Those having ordinary knowledge in the technical field to which the present invention pertains can understand that it can be implemented in other specific forms without changing the technical idea and essential features of the present invention. Therefore, it must be understood that the above-described one example is illustrative in all respects and not restrictive.

Claims

1. An electromagnetic steel sheet substrate; and A bonding coating layer located on the substrate of the electromagnetic steel sheet, The bonding coating layer contains an adhesive resin and a bonding additive, The electromagnetic steel sheet is characterized in that the adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof. [Chemical Formula 7] [Chemical Formula 8] In Chemical Formula 7 or Chemical Formula 8, R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group, R11 is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, n is any integer from 1 to 10, m is 1 or more.

2. A plurality of electromagnetic steel sheets and A fusion layer located between the plurality of electromagnetic steel sheets, The fusion layer contains an adhesive resin and a bonding additive, The electromagnetic steel sheet laminate is characterized in that the adhesive resin is a polyurethane containing a repeating unit represented by the following Chemical Formula 7, Chemical Formula 8, or a combination thereof. [Chemical Formula 7] [Chemical Formula 8] In Chemical Formula 7 or Chemical Formula 8, R' is a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, L is a substituted or unsubstituted C1-C10 alkylene group, a substituted or unsubstituted C2-C10 alkynylene group, a substituted or unsubstituted C6-C20 arylene group, or a substituted or unsubstituted C5-C20 heteroarylene group, R11 is hydrogen, deuterium, a substituted or unsubstituted C1-C10 alkyl group, a substituted or unsubstituted C6-C20 aryl group, or a substituted or unsubstituted C5-C20 heteroaryl group, n is any integer from 1 to 10, m is 1 or more.

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