Heat resistant adhesive film and electromagnetic steel sheet with said heat resistant adhesive film, iron core using said electromagnetic steel sheet, and process for manufacturing the same

A technology of insulating coating and electrical steel plate, applied in the direction of bonding method, metal material coating process, coating, etc., can solve the problems of abrasive die hole, deterioration of bonding strength, hard coating, etc.

Active Publication Date: 2007-09-19
NIPPON STEEL CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

These so-called adhesive coating techniques can alleviate problems caused by interlocking or welding, but because these techniques only use organic compositions to coat the surface of the steel plate, if stress relief annealing is performed, the Most of the composition decomposes at temperature, thus deteriorating the bond strength
Therefore, there is a problem that electrical steel sheets with an adhesive coating can be used for cores that are not subjected to stress relief annealing, but not for cores that are subjected to stress relief annealing in order to reduce core loss
The coatings disclosed in Japanese Patent Laid-Open (A) No. 58-128715 and Japanese Patent Laid-Open (B) No. 47-47499 are inorganic coatings composed only of low-melting point glass, which results in coatings that are hard and abrade die holes and Hence the problem of having a lot of powder

Method used

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  • Heat resistant adhesive film and electromagnetic steel sheet with said heat resistant adhesive film, iron core using said electromagnetic steel sheet, and process for manufacturing the same
  • Heat resistant adhesive film and electromagnetic steel sheet with said heat resistant adhesive film, iron core using said electromagnetic steel sheet, and process for manufacturing the same

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0090] Aqueous suspensions mixed with glass frits having a softening point of 450° C. and having various particle sizes were prepared, the aqueous suspensions each containing 20% ​​by mass (based on the mass of 100% total solids) composed of acrylic resin:epoxy resin:phenol resin= A resin with a composition of 10:4:3 (mass%). The resin / glass frit mixing ratio in each solution containing glass frit was adjusted to 200%. Each coating solution was applied to a thickness of 0.5 mm on a finish annealed non-oriented electrical steel sheet without an insulating coating to a coating weight of 6 g / m on each side using a roll coater 2 . The board was dried at 150°C and cooled. The coating thickness was 10 μm on each side. A test piece having a length of 10 cm in the rolling direction and a length of 3 cm in the direction perpendicular to the rolling direction was cut from each sample. Alternatively, let two such specimens overlap a length of 1 cm on the short side and an overlapping...

Embodiment 2

[0096] Prepared with B 2 o 3 =25% by mass, SiO 2 = 65% by mass, Na 2 O=10% by mass composition and a linear thermal expansion coefficient of 30°C-300°C is 40×10 -7 (℃ -1 ) glass frit mixed aqueous suspension (example of the invention) and the same but with 2 o 3 =50% by mass, SiO 2 = 25% by mass, K 2 O=25% by mass composition and a linear thermal expansion coefficient of 30°C-300°C of 170×10 -7 (℃ -1 ) glass frit mixed suspension (comparative example), the aqueous suspensions each comprise 20% by mass (based on the mass of 100% total solids) by acrylic resin: epoxy resin: phenolic resin = 11: 3: 4 (mass %) composed of resins. The glass frit used in each example had an average particle size of 10 μm. The resin / glass frit mixing ratio in the glass frit-containing solution was adjusted to 100% in each case.

[0097] Each coating solution was applied to a thickness of 0.5 mm on a finish annealed non-oriented electrical steel sheet having an insulating coating of magnes...

Embodiment 3

[0102] The following four types of coating solutions were prepared.

[0103] Coating Solution A

[0104] To 100 parts by mass of water, 40 parts by mass of an acryl-modified epoxy resin emulsion containing 20% ​​by mass of a latent curing agent and 5 parts by mass of methyl ethyl ketone were mixed. The resin obtained by coating and baking this coating solution had a glass transition temperature of 104°C and softened at 120°C or higher.

[0105] Coating Solution B

[0106] Into 100 parts by mass of water, 40 parts by mass of acrylic resin emulsion, 40 parts by mass of epoxy resin emulsion and 4 parts by mass of amino epoxy curing agent were mixed. The resin obtained by coating and baking this coating solution softens at 150°C or higher.

[0107] Coating Solution C

[0108]To a mixed solution of 178 g of methyltriethoxysilane and 138 g of ethanol, 35.3 g of water and 1.04 g of an aqueous solution of 35% hydrochloric acid were added dropwise for hydrolysis. The hydrolyzed so...

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Abstract

This invention provides an electromagnetic steel sheet, which, after lamination, can be bonded by pressing and heating, can realize strain relieving annealing, and has a surface covered with a heat resistant adhesive insulating film, an iron core using the electromagnetic steel sheet, and a process for manufacturing the same. The electromagnetic steel sheet is covered with a heat resistant adhesive insulating film comprising a resin, which softens at room temperature or above and 300 DEG C or below, and a low-melting inorganic component having a softening temperature of 1000 DEG C or below asmeasured by a differential thermal analysis method. A strain relieving annealable bonded fixed iron core is provided by stacking this electromagnetic steel sheet and conducting press fixation.

Description

technical field [0001] The present invention relates to bonding by stacking, pressing and heating (in the present invention, unless otherwise stated, "heating" means heating at a temperature from room temperature to 300° C.) and after annealing such as stress relief annealing (in this invention In the invention, unless otherwise stated, "annealing" refers to a heat-resistant adhesive coating composition that further maintains adhesiveness after heating at a temperature greater than 300° C., and a surface-coated electrical steel sheet. Background technique [0002] Electrical steel sheets are mainly used as magnetic cores for motors, transformers, etc. Generally, electrical steel sheets are coated with insulating coatings on their surfaces. The sheets are sequentially stamped into a predetermined shape, stacked and joined together by welding, by a method called "interlocking" in which the recesses and protrusions fit together, or by other methods to form a magnetic core. ...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09J1/02C09J201/00H01F1/18C23C26/00
CPCC09J11/04H01F1/18H01F3/02C23C26/00C09J1/00C09J1/02C09J5/00
Inventor 山田纪子藤井浩康久保祐治竹田和年高桥史明有田吉宏大畑喜史
Owner NIPPON STEEL CORP
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