Adhesive coating composition for electrical steel sheet, electrical steel sheet laminate, and method for manufacturing same

Abstract

An adhesive coating composition for an electrical steel sheet, according to an embodiment of the present invention, comprises a urethane resin and a metal inorganic salt, wherein the urethane resin comprises repeating units represented by chemical formula 1 and chemical formula 2.

Description

Electrical steel plate adhesive coating composition, electrical steel plate laminate, and method for manufacturing the same

[0001] One embodiment of the present invention relates to an electrical steel sheet adhesive coating composition, an electrical steel sheet laminate, and a method for manufacturing the same. Specifically, one embodiment of the present invention relates to an electrical steel sheet adhesive coating composition, an electrical steel sheet laminate, and a method for manufacturing the same, which forms a fusion layer capable of bonding (fastening) electrical steel sheets without using existing fastening methods such as welding, clamping, and interlocking. More specifically, one embodiment of the present invention relates to an electrical steel sheet adhesive coating composition, an electrical steel sheet laminate, and a method for manufacturing the same, which control the components of a fusion layer formed between electrical steel sheets to improve the adhesive strength and noise suppression characteristics of the electrical steel sheet laminate.

[0002] Non-oriented electrical steel is a steel sheet with uniform magnetic properties in all directions on the rolled sheet, and is widely used in motors, generator cores, electric motors, and small transformers.

[0003] Electrical steel sheets can be divided into two types: those that must undergo stress relief annealing (SRA) after punching to improve magnetic properties, and those that omit stress relief annealing when the cost loss due to heat treatment is greater than the magnetic properties effect of stress relief annealing.

[0004] Insulating films are films applied during the final manufacturing process of laminated bodies such as motor and generator cores, electric motors, and small transformers. They typically require electrical properties that suppress the generation of eddy currents. Additionally, continuous stamping processability, adhesion resistance, and surface adhesion are required. Continuous stamping processability refers to the ability to suppress die wear when multiple sheets are laminated to form a core after stamping into a predetermined shape. Adhesion resistance refers to the ability of core steel sheets to prevent adhesion after stress-relief annealing, which removes the working stress of the steel sheets and restores their magnetic properties.

[0005] In addition to these basic characteristics, the coating solution also requires excellent application workability and long-term solution stability after mixing. To manufacture this insulating film into an electrical steel laminate, a separate fastening method, such as welding, clamping, or interlocking, is required.

[0006] In one embodiment of the present invention, an electrical steel sheet adhesive coating composition, an electrical steel sheet laminate, and a method for manufacturing the same are provided. Specifically, in one embodiment of the present invention, an electrical steel sheet adhesive coating composition for forming a fusion layer capable of bonding (fastening) electrical steel sheets without using existing fastening methods such as welding, clamping, and interlocking, an electrical steel sheet laminate, and a method for manufacturing the same are provided. More specifically, an electrical steel sheet adhesive coating composition, an electrical steel sheet laminate, and a method for manufacturing the same are provided, which control the components of the fusion layer formed between electrical steel sheets to enhance adhesive strength between electrical steel sheets.

[0007] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention comprises a urethane resin and a metal inorganic acid salt, and the urethane resin comprises repeating units represented by the following chemical formula 1 and the following chemical formula 2.

[0008] [Chemical Formula 1]

[0009]

[0010] [Chemical Formula 2]

[0011]

[0012] (R in the above chemical formula 1 and chemical formula 2 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 , L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.)

[0013] With respect to 100 parts by weight of the sum of the urethane resin and the metal inorganic acid salt, the urethane resin may be included in an amount of 50 to 90 parts by weight, and the metal inorganic acid salt may be included in an amount of 10 to 50 parts by weight.

[0014] The urethane resin may include repeating units represented by the following chemical formula 3 and the above chemical formula 2.

[0015] [Chemical Formula 3]

[0016]

[0017] (In the above chemical formula 3, R 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 represents a single bond or a divalent linker.)

[0018] The urethane resin may be formed by the reaction of a diisocyanate monomer and a polyol represented by the following chemical formula 4.

[0019] [Chemical Formula 4]

[0020]

[0021] (In the above chemical formula 4, L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.)

[0022] The diisocyanate monomer may include an aromatic diisocyanate monomer.

[0023] The aromatic diisocyanate monomer may be a compound represented by the following chemical formula 5.

[0024] [Chemical Formula 5]

[0025]

[0026] (R in the above chemical formula 5 1 Inland R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, a halogen element, or an isocyanate group,

[0027] At least one of R1 to R5 is an isocyanate group,

[0028] At least one of R6 to R10 is an isocyanate group,

[0029] Except when R3 and R8 are both isocyanate groups,

[0030] L is a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group,

[0031] n is an integer between 1 and 10.)

[0032] The metal inorganic acid salt may include a phosphate, silicate, or titanate containing one or more of Al, Mg, Ca, Co, Zn, Zr, and Fe.

[0033] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include at least one selected from the group consisting of a coupling agent, a wetting agent, a curing agent, and a curing catalyst.

[0034] The coupling agent may be included in an amount of 0.2 to 3 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0035] The hardener may be included in an amount of 0.5 to 2 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0036] The curing catalyst may be included in an amount of 0.1 to 1 part by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0037] The humectant may be included in an amount of 0.05 to 0.5 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0038] An electrical steel plate laminate according to one embodiment of the present invention comprises a plurality of electrical steel plates; and a fusion layer positioned between the plurality of electrical steel plates; wherein the fusion layer comprises a urethane resin and a metal inorganic acid salt, and the urethane resin comprises repeating units represented by the following chemical formulas 1 and 2.

[0039] [Chemical Formula 1]

[0040]

[0041] [Chemical Formula 2]

[0042]

[0043] (R in the above chemical formula 1 and chemical formula 2 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 , L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.)

[0044] The fusion layer may contain 50 to 90 parts by weight of the urethane resin and 10 to 50 parts by weight of the metal inorganic acid salt, based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0045] A method for manufacturing an electrical steel plate laminate according to one embodiment of the present invention includes a step of applying an adhesive coating composition to one or both sides of an electrical steel plate and then curing it to form an adhesive coating layer, and a step of laminating a plurality of electrical steel plates on which an adhesive coating layer has been formed and thermally fusing them to form a fusion layer.

[0046] According to one embodiment of the present invention, the adhesive strength between electrical steel sheets can be improved by controlling the components of the fusion layer formed between the electrical steel sheets.

[0047] According to one embodiment of the present invention, electrical steel sheets can be bonded without using conventional fastening methods such as welding, clamping, and interlocking, so that the noise and vibration suppression effect of the electrical steel sheet laminate is further improved.

[0048] Additionally, by using a urethane resin with a specific chemical structure, it has excellent adhesion even in an automotive transmission oil environment.

[0049] Figure 1 is a schematic diagram of an electrical steel plate laminate.

[0050] Figure 2 is a schematic diagram of a cross-section of an electrical steel plate laminate according to one embodiment of the present invention.

[0051] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used only to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0052] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0053] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0054] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0055] In this specification, unless otherwise defined, “substituted” means that at least one hydrogen in the compound is replaced with a C1 to C30 alkyl group; a C1 to C10 alkoxy group; a silane group; an alkylsilane group; an alkoxysilane group; or an ethyleneoxyl group.

[0056] As used herein, “hetero” means an atom selected from the group consisting of N, O, S and P, unless otherwise defined.

[0057] The above alkyl group may be an alkyl group having a carbon number of C1 to C20, and specifically, may be a lower alkyl group having a carbon number of C1 to C6, a middle alkyl group having a carbon number of C7 to C10, or a higher alkyl group having a carbon number of C11 to C20.

[0058] For example, a C1 to C4 alkyl group means that there are 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.

[0059] Typical alkyl groups include methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-butyl, pentyl, hexyl, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0060] Hereinafter, embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0061]

[0062] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention comprises a urethane resin and a metal inorganic acid salt.

[0063] Below, each component is explained.

[0064] First, urethane resin lowers the degree of crosslinking of the composition and increases the viscoelastic properties.

[0065] In one embodiment of the present invention, the coating adhesion, peel adhesion, and ATF resistance of the manufactured electrical steel sheet laminate can be improved by including a urethane resin having a specific chemical structure. Specifically, the urethane resin includes repeating units represented by the following chemical formulas 1 and 2.

[0066] [Chemical Formula 1]

[0067]

[0068] [Chemical Formula 2]

[0069]

[0070] (R in the above chemical formula 1 and chemical formula 2 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 , L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.)

[0071] Chemical formula 1 is a chemical structure derived from aromatic diisocyanate, which is used as a raw material in the synthesis process of urethane resin.

[0072] Due to the structure of chemical formula 1, heat resistance can be improved due to the rigid properties of the two benzene ring structures in the aromatic diisocyanate.

[0073] R in chemical formula 1 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. In Chemical Formula 1, R 1 is connected to the inside of the benzene ring, which means that it is substituted at any of the six substitution positions of the benzene ring. More specifically, R 1 Each of R can independently be hydrogen, deuterium, or a substituted or unsubstituted C1 to C10 alkyl group. 1 Each can independently be hydrogen or deuterium.

[0074] L in chemical formula 1 1represents a single bond or a divalent linking group. Specifically, the divalent linking group may be at least one of a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group, -O-, -(CO)-, -S-, -N-, and -P-. More specifically, L 1 may be a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group. More specifically, L 1 may be a substituted or unsubstituted C1 to C10 alkylene group.

[0075] Specifically, the repeating unit of chemical formula 1 can be represented as shown in chemical formula 3 below.

[0076] [Chemical Formula 3]

[0077]

[0078] (In the above chemical formula 3, R 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 represents a single bond or a divalent linker.)

[0079] Linker L as in chemical formula 3 1 By not bonding the linking group with -NCOO- and other repeating units at symmetrical positions of the two benzene rings, the film adhesion, peel adhesion, or ATF resistance of the manufactured electrical steel laminate can be further improved.

[0080] R in chemical formula 3 1 and L 1Since it is the same as the description in the chemical formula 1 mentioned above, the redundant description is omitted.

[0081] The repeating unit of Chemical Formula 1 may be comprised in an amount of 20 to 50 wt% in the urethane resin. If the repeating unit of Chemical Formula 1 is too small, a problem of reduced high-temperature bonding strength of the urethane resin may occur, and if it is too large, a problem of reduced heat-sealing properties may occur. More specifically, the repeating unit of Chemical Formula 1 may be comprised in an amount of 30 to 40 wt% in the urethane resin. The ratio of the repeating unit of Chemical Formula 1 can be controlled through the ratio of the aromatic diisocyanate monomer added during the manufacture of the urethane resin.

[0082]

[0083] Chemical formula 2 is a chemical structure derived from polyol used as a raw material in the synthesis process of urethane resin.

[0084] Due to the structure of chemical formula 2, the thermal sealing property can be improved due to the increase in softness characteristics with a large number of -COO- and -O- structures.

[0085] L in chemical formula 2 2 and L 3 Each independently represents a single bond or a divalent linking group. Specifically, the divalent linking group may be at least one of a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group, -O-, -(CO)-, -S-, -N-, and -P-. More specifically, L 1 Silver may be a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group. More specifically, L 1 may be a substituted or unsubstituted C1 to C10 alkylene group.

[0086] n can be an integer from 1 to 50. If n is too large, problems may arise in terms of heat resistance. More specifically, n can be from 1 to 20.

[0087] The repeating unit of Chemical Formula 2 may be comprised in an amount of 50 to 80 wt% in the urethane resin. If the amount of the repeating unit of Chemical Formula 2 is too small, a problem of reduced heat sealability may occur. If the amount of the repeating unit of Chemical Formula 2 is too large, a problem of reduced high-temperature bonding strength of the urethane resin may occur. More specifically, the repeating unit of Chemical Formula 2 may be comprised in an amount of 60 to 70 wt% in the urethane resin. The ratio of the repeating unit of Chemical Formula 2 can be controlled through the ratio of polyol added during the manufacture of the urethane resin.

[0088] Urethane resin can be formed by the reaction of a diisocyanate monomer and a polyol represented by the following chemical formula 4.

[0089] [Chemical Formula 4]

[0090]

[0091] (In the above chemical formula 4, L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.)

[0092] The polyol of chemical formula 4 has been described in relation to the description of the repeating unit of chemical formula 2 in the urethane resin, so the redundant description is omitted. L of chemical formula 4 2 , L 3 and n are the same as those described in Chemical Formula 2.

[0093] Polyols can have a number-average molecular weight of 400 to 1,000 g / mol. If the molecular weight is too low, problems with heat sealability may arise. If the molecular weight is too high, problems with heat resistance may arise. More specifically, the number-average molecular weight of the polyol can be 500 to 800.

[0094] The aromatic diisocyanate monomer may be a compound represented by the following chemical formula 5.

[0095] [Chemical Formula 5]

[0096]

[0097] (R in the above chemical formula 5 1 Inland R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, a halogen element, or an isocyanate group,

[0098] At least one of R1 to R5 is an isocyanate group,

[0099] At least one of R6 to R10 is an isocyanate group,

[0100] Except when R3 and R8 are both isocyanate groups,

[0101] L is a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group,

[0102] n is an integer between 1 and 10.)

[0103] The aromatic diisocyanate of chemical formula 5 has been described in relation to the description of the repeating unit of chemical formula 1 of the urethane resin, so the redundant description is omitted. R of chemical formula 5 1 Inland R 10 is the same as the description of R1 in chemical formula 1, and L in chemical formula 5 is L in chemical formula 1. 1 Same as the description.

[0104] The aromatic diisocyanate monomer may be represented by the following chemical formula 6.

[0105] [Chemical Formula 6]

[0106]

[0107] (In the above chemical formula 2, L is a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group.)

[0108] More specifically, L may be a substituted or unsubstituted C1 to C10 alkylene group. More specifically, L may be a methylene group. The aromatic diisocyanate monomer may be methylene diphenyl diisocyanate.

[0109] The urethane resin may be included in an amount of 50 to 90 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt. If the urethane resin is included in too little amount, the vibration suppression effect may be deteriorated due to the low viscoelasticity of the composition. If the urethane resin is included in too much amount, the high-temperature adhesiveness may be deteriorated due to the low degree of crosslinking of the composition. More specifically, the urethane resin may be included in an amount of 55 to 85 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

[0110]

[0111] One embodiment of the present invention includes a metal inorganic acid salt together with a urethane resin. The metal inorganic acid salt increases the degree of crosslinking and thus improves high-temperature adhesive strength.

[0112] There is no particular limitation on the metal inorganic acid salt, but it may include phosphate, silicate, or titanate containing one or more of Al, Mg, Ca, Co, Zn, Zr, and Fe.

[0113] More specifically, the metal inorganic acid salt may include a metal phosphate. The metal phosphate may include various metals without limitation. Specifically, the metal of the metal phosphate may include at least one of Al, Mg, Ca, Co, Zn, Zr, and Fe. More specifically, the metal phosphate may include at least one of monobasic magnesium phosphate (Mg(H2PO4)2) and monobasic aluminum phosphate (Al(H2PO4)3). More specifically, it may include monobasic magnesium phosphate (Mg(H2PO4)2) and monobasic aluminum phosphate (Al(H2PO4)3). In this case, the metal phosphate may include 10 to 60 parts by weight of monobasic aluminum phosphate and 40 to 90 parts by weight of monobasic magnesium phosphate based on the solid content, per 100 parts by weight of the total metal phosphate.

[0114]

[0115] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include at least one selected from the group consisting of a coupling agent, a wetting agent, a curing agent, and a curing catalyst.

[0116] The electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include a coupling agent to strengthen the interfacial adhesive strength between the electrical steel sheet (10) and the fusion layer (20). The coupling agent may include a silane coupling agent, and more specifically, at least one of an epoxy-based silane coupling agent and an amino-based silane coupling agent may be included. More specifically, the coupling agent may include 2(3,4 epoxycyclohexyl) ethyltrimethoxysilane, 3-glycidoxypropyl methyldimethoxysilane, 3-glycidoxypropyl trimethoxysilane, 3-glycidoxypropyl methyldiethoxysilane, 3-glycidoxypropyl triethoxysilane, 3-aminopropyltriethoxysilane, and 3-aminopropyltrimethoxysilane.

[0117] When a coupling agent is further included, it may be included in an amount of 0.2 to 3 parts by weight, based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt. If the coupling agent is included in too little amount, the effect of enhancing the interfacial adhesion between the electrical steel sheet and the fusion layer may not be sufficiently obtained. If the coupling agent is included in too much amount, precipitates may be generated in the adhesive coating composition due to a reaction between the coupling agents. Specifically, it may be included in an amount of 0.2 to 1 part by weight.

[0118] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include a silicone-based wetting agent in order to strengthen the interfacial adhesive strength between the electrical steel sheet (10) and the bonding layer (20). An example of the silicone-based wetting additive may be polyether-modified polydimethylsiloxane. The wetting agent may be added to the bonding composition for electrical steel sheets in order to strengthen the interfacial adhesive strength between the electrical steel sheet and the bonding layer.

[0119] According to one embodiment of the present invention, the electrical steel sheet adhesive coating composition may include a wetting agent in an amount of 0.05 to 0.5 parts by weight, based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt. If the content of the wetting agent is too high, a problem of coating layer defects may occur due to excessive bubble generation in the coating solution, and if the content of the wetting agent is too low, a problem of coating surface defects may occur due to reduced wettability of the coating layer. Specifically, the composition may include 0.05 to 0.15 parts by weight.

[0120] The electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include a curing agent to control the reactivity of the surface of the adhesive coating layer. The curing agent may include an aliphatic amine, an aromatic amine, an amino amine, or an imidazole. More specifically, a dicyandiamide-based curing agent may be included.

[0121] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may contain a curing agent in an amount of 1 to 10 parts by weight, based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt. The curing agent serves to control the reactivity of the surface of the adhesive coating layer. If too little curing agent is contained, the curing reaction of the fusion layer may be reduced, resulting in a problem of stickiness of the surface of the fusion layer. Conversely, if too much curing agent is added, the bonding strength after low-temperature fusion may be deteriorated. Specifically, the curing agent may be contained in an amount of 1 to 5 parts by weight.

[0122] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may further include a curing catalyst to improve sticky defects caused by non-curing due to rapid curing reaction during coil coating. The curing catalyst may include an imidazole-based curing catalyst.

[0123] An electrical steel sheet adhesive coating composition according to one embodiment of the present invention may contain 0.1 to 5 parts by weight of a curing catalyst, based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt. If the content of the curing catalyst is too high, a problem of reduced bonding strength after fusion may occur due to over-curing reaction, and if the content of the curing catalyst is too low, a problem of stickiness of the surface of the fusion layer may occur due to non-curing. Specifically, the composition may contain 0.5 to 3 parts by weight.

[0124] In addition to the aforementioned components, the adhesive coating composition may include a solvent to facilitate application and uniformly disperse the components. The solvent may include water, alcohol, or the like. The solvent may be present in an amount of 200 to 2,000 parts by weight, based on 100 parts by weight of the urethane resin and the metal inorganic acid salt. In one embodiment of the present invention, "parts by weight" refers to a relative weight ratio.

[0125]

[0126] In one embodiment of the present invention, an electrical steel plate laminate is provided.

[0127] An electrical steel plate laminate according to one embodiment of the present invention comprises a plurality of electrical steel plates; and a fusion layer positioned between the plurality of electrical steel plates. Fig. 1 is a schematic diagram of an electrical steel plate laminate according to one embodiment of the present invention. As shown in Fig. 1, a plurality of electrical steel plates are laminated.

[0128] FIG. 2 illustrates a schematic cross-section of an electrical steel plate laminate according to one embodiment of the present invention. As shown in FIG. 2, an electrical steel plate laminate (100) according to one embodiment of the present invention includes a plurality of electrical steel plates (10); and a fusion layer (20) positioned between the plurality of electrical steel plates.

[0129] An electrical steel plate laminate according to one embodiment of the present invention may be a laminate in which different electrical steel plates are heat-fused by simply forming a fusion layer using the aforementioned adhesive coating composition without using conventional methods such as welding, clamping, or interlocking.

[0130] At this time, the electrical steel plate laminate has excellent characteristics of high-temperature adhesiveness and high-temperature oil resistance even after heat fusion.

[0131] Below, each component is explained in detail.

[0132] The electrical steel sheet (10) can be a general non-oriented or oriented electrical steel sheet without limitation. In one embodiment of the present invention, the main configuration is to form a fusion layer (20) between a plurality of electrical steel sheets (10) to manufacture an electrical steel sheet laminate (100), so a detailed description of the electrical steel sheet (10) is omitted. More specifically, the electrical steel sheet (10) may be a non-oriented electrical steel sheet.

[0133] The fusion layer (20) is formed between a plurality of electrical steel plates (10), and has a strong adhesive strength that allows the plurality of electrical steel plates (10) to be bonded without using conventional fastening methods such as welding, clamping, or interlocking.

[0134] The fusion layer (20) is formed by coating an adhesive coating composition on the surface, curing it to form an adhesive coating layer, laminating it, and thermally fusing it to form the fusion layer (20). When a plurality of electrical steel plates (10) having adhesive coating layers formed thereon are laminated and thermally fused, the resin component within the adhesive coating layer is thermally fused to form a fusion layer.

[0135] In one embodiment of the present invention, the fusion layer (20) includes a urethane resin and a metal inorganic acid salt. Since the urethane resin and the metal inorganic acid salt have been described in detail above with respect to the adhesive coating composition, a redundant description thereof will be omitted. During the process of forming the fusion layer, the chemical structure, ratio, etc. of the urethane resin and the metal inorganic acid salt remain unchanged. In addition, a coupling agent, a curing agent, a curing catalyst, and a wetting additive also remain, and the content range thereof may be the same as that of the adhesive coating composition. Since the coupling agent, the curing agent, the curing catalyst, and the wetting additive have been described in detail above with respect to the adhesive coating composition, a redundant description thereof will be omitted.

[0136] The fusion layer (20) may include 50 to 90 parts by weight of the urethane resin and 10 to 50 parts by weight of the metal inorganic acid salt based on 100 parts by weight of the sum of the urethane resin and the metal inorganic acid salt.

[0137] In addition, the fusion layer (20) may further include 0.2 to 3 parts by weight of a coupling agent, 0.05 to 0.5 parts by weight of a wetting agent, 0.5 to 2 parts by weight of a curing agent, and 0.1 to 1 part by weight of a curing catalyst.

[0138] The thickness of the fusion layer (20) may be 1 μm to 8 μm. If the thickness of the fusion layer is too thin, the adhesive strength may be drastically reduced, and if it is too thick, defects due to stickiness may become a problem after the coating is wound. More specifically, the thickness of the fusion layer (20) may be 1 μm to 3 μm.

[0139]

[0140] In one embodiment of the present invention, the electrical steel laminate has improved film adhesion, peel adhesion, and ATF resistance. When a drive motor is used in an automobile, a large amount of heat is generated during long-term rotation at high speeds, and ATF (Automotive Transmission Fluid) is used to cool this heat. Therefore, to ensure adhesive reliability during long-term use, it is important to maintain the adhesive strength of the laminated coil while impregnated with high-temperature ATF.

[0141]

[0142] A method for manufacturing an electrical steel plate laminate according to one embodiment of the present invention includes the steps of applying an adhesive coating composition to one or both sides of an electrical steel plate and then curing the composition to form an adhesive coating layer; and the steps of laminating a plurality of electrical steel plates on which an adhesive coating layer has been formed and thermally fusing them to form a fusion layer.

[0143] Below, each step is explained in detail.

[0144] First, prepare an adhesive coating composition. Since the adhesive coating composition has been described above, a detailed explanation will be omitted.

[0145] Next, the adhesive coating composition is coated on the surface of the electrical steel sheet and then cured to form an adhesive coating layer. This step may be performed at a temperature range of 150 to 250°C for curing the adhesive coating composition.

[0146] A plurality of electrical steel plates having an adhesive coating layer formed thereon are laminated and thermally fused to form a fusion layer (20). Through the thermal fusion step, the polymer components within the adhesive coating layer thermally fuse to form a fusion layer.

[0147] The thermal bonding step can be performed under the 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 can be satisfied independently, and two or more conditions can be satisfied simultaneously. By controlling the temperature, pressure, and time conditions in the thermal bonding step in this way, dense thermal bonding can be performed between the electrical steel sheets without a gap or organic phase.

[0148] The heat-melting step includes a temperature-raising step and a fusion step, and the temperature-raising rate of the temperature-raising step can be 10°C / min to 1000°C / min.

[0149]

[0150] Hereinafter, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement them. However, the present invention may be implemented in various different forms and is not limited to the embodiments described herein.

[0151]

[0152] Experimental Example 1

[0153] Non-oriented electrical steel sheets (50 X 50 mm, 0.35 mmt) were prepared as blank specimens. An adhesive coating solution was applied to the top and bottom of each prepared blank specimen at a constant thickness using a bar coater and a roll coater, cured at 200°C for 20 seconds based on the plate temperature, and then slowly cooled in air to form an adhesive coating layer.

[0154] An adhesive coating solution was used containing 100 parts by weight of a polyurethane resin and a metal inorganic acid salt, 0.5 parts by weight of a silane coupling agent (3-glycidoxypropyl triethoxysilane), 0.1 parts by weight of a silicone-based wetting agent (polyether-modified siloxane), 1 part by weight of a dicyandiamide-based curing agent (adipic acid dihydrazide), and 0.5 parts by weight of an imidazole-based curing catalyst (1,2 dimethylimidazole).

[0155] The polyurethane resin was prepared by reacting 40 wt% of 2,4-methylene diphenyl diisocyanate monomer and 60 wt% of polyethylene carbonate diol having a water content of 425 g / mol based on the total weight of the polyurethane resin, and then used. The metal inorganic acid salt used was Al phosphate.

[0156] The content ratio of the polyurethane resin and Al phosphate used, and the types and content ratios of the isocyanate monomer and polyol used in the production of the polyurethane resin are as shown in Table 1 below.

[0157] MDI in Table 1 stands for methylene diphenyl diisocyanate, TDI stands for toluene diisocyanate, and PCD stands for polyethylene carbonate diol (moisture content 425 g / mol).

[0158] Electrical steel sheets coated with an adhesive coating layer were laminated to a height of 20 mm, and then heat-sealed at 160°C for 10 minutes under a pressure of 0.5 MPa to produce an electrical steel sheet laminate. The thickness of the fusion layer after heat-sealing was approximately 3 μm. The heat-sealed laminate was evaluated according to the mixing ratio of the mixed resin in the coating composition and the type of aromatic diisocyanate monomer used. Specifically, the film adhesion, peel adhesion (T-peel, N / mm), ATF resistance, and high-temperature adhesiveness were evaluated, and the results are shown in Table 1 below.

[0159] The measurement method for each characteristic is as follows.

[0160]

[0161] Coating Adhesion Measurement Method: The specimen specifications for measuring coating adhesion were prepared according to ISO 1519. The coated specimen was prepared as a sample measuring 30 x 300 mm, bent 180° around a 10 mm diameter iron cylinder, and tape was adhered to the area. The presence or absence of coating layer peeling was visually observed. If peeling occurred, it was evaluated as NG, and if no peeling occurred, it was judged as OK.

[0162]

[0163] Peel adhesion (T-peel, N / mm): The specimen specifications for the peel off method (T-peel off) were manufactured according to ISO 11339. Two 25 x 200 mm specimens were made into a 25 x 150 mm 2 After bonding with an area of ​​, the non-bonded area was bent at 90° to produce a T-shaped tensile specimen. The specimen manufactured by the peeling method (T-Peeloff) was fixed to the upper / lower jigs (JIG) with a certain force, and then the tensile force of the laminated sample was measured using a device that measures the tensile force while pulling at a certain speed. In this case, in the case of the shear method, the measured value was measured at the point where the interface with the minimum adhesive force among the laminated samples fell off. The temperature of the specimen was maintained at 60℃ using a heating device, and then the adhesive force was measured.

[0164]

[0165] Evaluation of ATF properties: The manufactured laminated coil was immersed in ATF (SP4M-1) at 160℃ for 1000 hours, and then the shear adhesion was tested. The shear adhesion to measure the above ATF properties was measured by the shear method (Shear Strength). The specimen specifications for the shear method measurement were manufactured according to ISO 4587. Two 25 x 100 mm specimens were bonded to an area of ​​12.5 x 25 mm2 and heat-sealed under the above conditions to produce a shear method specimen. The specimen manufactured by the shear method was fixed to the upper and lower jigs (JIG) with a constant force, and then the tensile force of the laminated sample was measured using a device that pulls the specimen at a constant speed. In this case, in the case of the shear method, the measured value was the point where the interface with the minimum adhesive strength among the laminated samples fell off.

[0166]

[0167] High-temperature adhesion evaluation: Shear adhesion to measure high-temperature adhesion was measured using the shear method (shear strength). The specimen specifications for shear method measurements were prepared according to ISO 4587. Two 25 x 100 mm specimens were bonded to an area of ​​12.5 x 25 mm2 using a coating agent and heat-sealed under the conditions described above to prepare shear specimens. After setting the high-temperature atmosphere temperature in a tensile machine with a heating furnace, the specimens prepared by the shear method were fixed to the upper and lower jigs at a constant force and then pulled at a constant speed, and a device was used to measure the tensile force of the laminated sample. In this case, for the shear method, the measured value was determined as the point where the interface with the minimum adhesive strength among the laminated samples fell off. The adhesion was measured after maintaining the specimen temperature at 180℃ through a heating device.

[0168]

[0169] ClassificationPolyurethane resin (weight parts)Al phosphate (weight parts)Polyurethane resinCoating film adhesionPeel adhesion (N / mm)ATF resistance property (MPa)High temperature adhesion (MPa)Aromatic diisocyanatePolyolTypeContent (weight%)TypeContent (weight%)Example 180202,4'-MDI40PCD60OK1.55.03.0Example 270302,4'-MDI40PCD60OK1.04.02.0Example 360402,4'-MDI40PCD60OK0.73.01.5Comparative example 110002,4'-MDI40PCD60OK3.50.50.1Comparative example 240602,4'-MDI40PCD60OK0.18.09.0Comparative example 380202,4'-TDI30PCD70OK0.33.02.5Comparative Example 480202,2'-MDI40PCD60OK0.42.52.0Comparative Example 580204,4'-MDI40PCD60OK0.41.50.7Comparative Example 670302,4'-TDI30PCD70OK0.23.53.2Comparative Example 770302,2'-MDI40PCD60OK0.33.23.0Comparative Example 870304,4'-MDI40PCD60OK0.41.72.0Comparative Example 960402,4'-TDI30PCD70OK0.24.03.3Comparative Example 1060402,2'-MDI40PCD60OK0.33.33.5Comparative example 1160404,4'-MDI40PCD60OK0.31.82.0Comparative example 1270302,4'-MDI40PPG60OK1.02.00.5

[0170] As shown in Table 1, when the polyurethane resin and the metal inorganic acid salt were mixed and used in an appropriate content ratio as in Examples 1 to 3, and 2,4'-MDI (2,4-methylene diphenyl diisocyanate) was used as the aromatic diisocyanate monomer, excellent properties were exhibited in film adhesion, peel adhesion, ATF resistance, and high-temperature adhesion.

[0171] Comparative Example 1 is a case where only urethane resin was used without mixing metal inorganic acid salt. In this case, the peeling adhesion is excellent, but the high-temperature adhesion and ATF resistance are inferior, showing values ​​of less than 1 MPa.

[0172] Comparative Example 2 is a case where a small amount of urethane resin was used. In this case, the high-temperature adhesive strength and ATF resistance characteristics are excellent, but the peel adhesive strength shows a value of less than 0.5, confirming that the adhesive strength is poor.

[0173] Comparative Examples 3 to 11 are adhesive coating layers manufactured by changing the aromatic diisocyanate monomer in Examples 1 to 3 to a compound other than 4'-MDI (2,4-methylene diphenyl diisocyanate).

[0174] In Comparative Examples 3, 6 and 9 using 2,4'-TDI (2,4-toluene diisocyanate) as an aromatic diisocyanate, it can be confirmed that the film adhesion, ATF resistance and high-temperature adhesion are good, but the peel adhesion is inferior to that of the examples.

[0175] In the case of Comparative Examples 4, 7 and 10 using 2,2'-MDI (2,2-methylene diphenyl diisocyanate) as an aromatic diisocyanate, it can be confirmed that the film adhesion, ATF resistance and high-temperature adhesion are good, but the peel adhesion is inferior to that of the examples.

[0176] In Comparative Examples 5, 8 and 11 using 4,4'-MDI (4,4-methylene diphenyl diisocyanate) as an aromatic diisocyanate, it can be confirmed that the film adhesion and high-temperature adhesion are good, but the peel adhesion and ATF resistance are inferior to those of the examples.

[0177] Comparative Example 12 is an example using polypropylene glycol as the polyol compound. Although the film adhesion, peel adhesion, and ATF resistance are good, it can be confirmed that the high-temperature adhesion is poor.

[0178]

[0179] The present invention is not limited to the embodiments described herein, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

[0180]

[0181] [Explanation of symbols]

[0182] 100: Electrical steel laminate 10: Electrical steel

[0183] 20: Fusion layer

Claims

1. Contains urethane resin and metal inorganic acid salt, An electrical steel plate adhesive coating composition, wherein the urethane resin comprises repeating units represented by the following chemical formula 1 and the following chemical formula 2. [Chemical Formula 1] [Chemical formula 2] (R in the above chemical formula 1 and chemical formula 2 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 , L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.) 2. In paragraph 1, An electrical steel sheet adhesive coating composition comprising 50 to 90 parts by weight of the urethane resin and 10 to 50 parts by weight of the metal inorganic acid salt, based on 100 parts by weight of the sum of the urethane resin and the metal inorganic acid salt.

3. In paragraph 1, The above urethane resin is an electrical steel plate adhesive coating composition containing repeating units represented by the following chemical formula 3 and the above chemical formula 2. [Chemical Formula 3] (R in the chemical formula 3 above 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 represents a single bond or a divalent linker.) 4. In paragraph 1, An electrical steel plate adhesive coating composition wherein the above urethane resin is formed by the reaction of a diisocyanate monomer and a polyol represented by the following chemical formula 4. [Chemical Formula 4] (L in the chemical formula 4 above 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.) 5. In paragraph 4, The above diisocyanate monomer is an electrical steel plate adhesive coating composition containing an aromatic diisocyanate monomer.

6. In paragraph 5, An electrical steel sheet adhesive coating composition wherein the aromatic diisocyanate monomer is a compound represented by the following chemical formula 5. [Chemical Formula 5] (R in the above chemical formula 5 1 Inland R 10 are each independently hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, a halogen element or an isocyanate group, At least one of R1 to R5 is an isocyanate group, At least one of R6 to R10 is an isocyanate group, Except when R3 and R8 are both isocyanate groups, L is a substituted or unsubstituted C1 to C10 alkylene group, a substituted or unsubstituted C2 to C10 alkynylene group, a substituted or unsubstituted C6 to C20 arylene group, or a substituted or unsubstituted C5 to C20 heteroarylene group, n is an integer between 1 and 10.) 7. In paragraph 1, An electrical steel sheet adhesive coating composition comprising a phosphate, silicate, or titanate, wherein the metal inorganic acid salt comprises at least one of Al, Mg, Ca, Co, Zn, Zr, and Fe.

8. In paragraph 1, An electrical steel sheet adhesive coating composition further comprising at least one selected from the group consisting of a coupling agent, a wetting agent, a curing agent, and a curing catalyst.

9. In paragraph 8, An electrical steel sheet adhesive coating composition comprising 0.2 to 3 parts by weight of the coupling agent relative to 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

10. In paragraph 8, An electrical steel sheet adhesive coating composition, wherein the curing agent is contained in an amount of 0.5 to 2 parts by weight based on 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

11. In paragraph 8, An electrical steel sheet adhesive coating composition comprising 0.1 to 1 part by weight of the curing catalyst relative to 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

12. In paragraph 8, An electrical steel sheet adhesive coating composition comprising 0.05 to 0.5 parts by weight of the wetting agent relative to 100 parts by weight of the total of the urethane resin and the metal inorganic acid salt.

13. Multiple electrical steel plates; and Including a fusion layer positioned between the plurality of electrical steel plates; The above-mentioned fusion layer comprises a urethane resin and a metal inorganic acid salt, The above urethane resin is an electrical steel laminate comprising repeating units represented by the following chemical formula 1 and the following chemical formula 2. [Chemical Formula 1] [Chemical formula 2] (R in the above chemical formula 1 and chemical formula 2 1 Each independently represents hydrogen, deuterium, a substituted or unsubstituted C1 to C10 alkyl group, a substituted or unsubstituted C6 to C20 aryl group, a substituted or unsubstituted C5 to C20 heteroaryl group, a hydroxy group, or a halogen element. L 1 , L 2 , L 3 represents a single bond or a divalent linker, respectively. n represents an integer from 1 to 50.) 14. In paragraph 13, An electrical steel plate laminate in which the fusion layer comprises 50 to 90 parts by weight of the urethane resin and 10 to 50 parts by weight of the metal inorganic acid salt, based on 100 parts by weight of the sum of the urethane resin and the metal inorganic acid salt.

15. A step of applying the adhesive coating composition described in paragraph 1 to one or both sides of an electrical steel plate and then curing it to form an adhesive coating layer; and A method for manufacturing an electrical steel laminate, comprising the step of laminating a plurality of electrical steel plates having the adhesive coating layer formed thereon and thermally fusing them to form a fusion layer.

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