JPH0445586B2 - - Google Patents
Info
- Publication number
- JPH0445586B2 JPH0445586B2 JP57226223A JP22622382A JPH0445586B2 JP H0445586 B2 JPH0445586 B2 JP H0445586B2 JP 57226223 A JP57226223 A JP 57226223A JP 22622382 A JP22622382 A JP 22622382A JP H0445586 B2 JPH0445586 B2 JP H0445586B2
- Authority
- JP
- Japan
- Prior art keywords
- parts
- weight
- iron plate
- dichromate
- coating
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 43
- 238000000576 coating method Methods 0.000 claims description 34
- 239000011248 coating agent Substances 0.000 claims description 29
- 239000011347 resin Substances 0.000 claims description 25
- 229920005989 resin Polymers 0.000 claims description 25
- 239000007788 liquid Substances 0.000 claims description 23
- 229910052742 iron Inorganic materials 0.000 claims description 21
- 230000007797 corrosion Effects 0.000 claims description 19
- 238000005260 corrosion Methods 0.000 claims description 19
- 238000000137 annealing Methods 0.000 claims description 18
- 229910019142 PO4 Inorganic materials 0.000 claims description 17
- 239000010452 phosphate Substances 0.000 claims description 16
- NBIIXXVUZAFLBC-UHFFFAOYSA-K phosphate Chemical compound [O-]P([O-])([O-])=O NBIIXXVUZAFLBC-UHFFFAOYSA-K 0.000 claims description 15
- 239000000243 solution Substances 0.000 claims description 15
- 239000007787 solid Substances 0.000 claims description 10
- KGBXLFKZBHKPEV-UHFFFAOYSA-N boric acid Chemical compound OB(O)O KGBXLFKZBHKPEV-UHFFFAOYSA-N 0.000 claims description 8
- 239000004327 boric acid Substances 0.000 claims description 8
- 239000007864 aqueous solution Substances 0.000 claims description 7
- 239000003638 chemical reducing agent Substances 0.000 claims description 7
- SOCTUWSJJQCPFX-UHFFFAOYSA-N dichromate(2-) Chemical compound [O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O SOCTUWSJJQCPFX-UHFFFAOYSA-N 0.000 claims description 7
- 229910052751 metal Inorganic materials 0.000 claims description 4
- 239000002184 metal Substances 0.000 claims description 4
- 238000007796 conventional method Methods 0.000 claims description 2
- 238000000034 method Methods 0.000 claims 1
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 description 18
- 235000021317 phosphate Nutrition 0.000 description 15
- 229940124024 weight reducing agent Drugs 0.000 description 10
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 8
- 239000000839 emulsion Substances 0.000 description 7
- WGLPBDUCMAPZCE-UHFFFAOYSA-N Trioxochromium Chemical compound O=[Cr](=O)=O WGLPBDUCMAPZCE-UHFFFAOYSA-N 0.000 description 6
- 230000000052 comparative effect Effects 0.000 description 6
- MHJAJDCZWVHCPF-UHFFFAOYSA-L dimagnesium phosphate Chemical compound [Mg+2].OP([O-])([O-])=O MHJAJDCZWVHCPF-UHFFFAOYSA-L 0.000 description 6
- 239000004137 magnesium phosphate Substances 0.000 description 6
- 229910000401 monomagnesium phosphate Inorganic materials 0.000 description 6
- 235000019785 monomagnesium phosphate Nutrition 0.000 description 6
- GIOZLVMCHDGNNZ-UHFFFAOYSA-N magnesium;oxido-(oxido(dioxo)chromio)oxy-dioxochromium Chemical compound [Mg+2].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O GIOZLVMCHDGNNZ-UHFFFAOYSA-N 0.000 description 5
- 238000012545 processing Methods 0.000 description 5
- 238000004080 punching Methods 0.000 description 5
- 239000013585 weight reducing agent Substances 0.000 description 5
- 229920000178 Acrylic resin Polymers 0.000 description 4
- 239000004925 Acrylic resin Substances 0.000 description 4
- NBIIXXVUZAFLBC-UHFFFAOYSA-N Phosphoric acid Chemical compound OP(O)(O)=O NBIIXXVUZAFLBC-UHFFFAOYSA-N 0.000 description 4
- 238000009413 insulation Methods 0.000 description 4
- QQFLQYOOQVLGTQ-UHFFFAOYSA-L magnesium;dihydrogen phosphate Chemical compound [Mg+2].OP(O)([O-])=O.OP(O)([O-])=O QQFLQYOOQVLGTQ-UHFFFAOYSA-L 0.000 description 4
- 238000002156 mixing Methods 0.000 description 3
- 229940035053 monobasic magnesium phosphate Drugs 0.000 description 3
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 2
- PEDCQBHIVMGVHV-UHFFFAOYSA-N Glycerine Chemical compound OCC(O)CO PEDCQBHIVMGVHV-UHFFFAOYSA-N 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- GWEVSGVZZGPLCZ-UHFFFAOYSA-N Titan oxide Chemical compound O=[Ti]=O GWEVSGVZZGPLCZ-UHFFFAOYSA-N 0.000 description 2
- 229910000147 aluminium phosphate Inorganic materials 0.000 description 2
- 239000012298 atmosphere Substances 0.000 description 2
- 229910052791 calcium Inorganic materials 0.000 description 2
- 239000011575 calcium Substances 0.000 description 2
- ZCDOYSPFYFSLEW-UHFFFAOYSA-N chromate(2-) Chemical compound [O-][Cr]([O-])(=O)=O ZCDOYSPFYFSLEW-UHFFFAOYSA-N 0.000 description 2
- 229910052804 chromium Inorganic materials 0.000 description 2
- 239000011651 chromium Substances 0.000 description 2
- JOPOVCBBYLSVDA-UHFFFAOYSA-N chromium(6+) Chemical compound [Cr+6] JOPOVCBBYLSVDA-UHFFFAOYSA-N 0.000 description 2
- 230000006866 deterioration Effects 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 239000011229 interlayer Substances 0.000 description 2
- 150000003013 phosphoric acid derivatives Chemical class 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 238000012360 testing method Methods 0.000 description 2
- 229910052725 zinc Inorganic materials 0.000 description 2
- BNGXYYYYKUGPPF-UHFFFAOYSA-M (3-methylphenyl)methyl-triphenylphosphanium;chloride Chemical compound [Cl-].CC1=CC=CC(C[P+](C=2C=CC=CC=2)(C=2C=CC=CC=2)C=2C=CC=CC=2)=C1 BNGXYYYYKUGPPF-UHFFFAOYSA-M 0.000 description 1
- 229910000976 Electrical steel Inorganic materials 0.000 description 1
- 239000004372 Polyvinyl alcohol Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 229920002125 Sokalan® Polymers 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 description 1
- NIXOWILDQLNWCW-UHFFFAOYSA-N acrylic acid group Chemical group C(C=C)(=O)O NIXOWILDQLNWCW-UHFFFAOYSA-N 0.000 description 1
- 229910052782 aluminium Inorganic materials 0.000 description 1
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 description 1
- YYRMJZQKEFZXMX-UHFFFAOYSA-L calcium bis(dihydrogenphosphate) Chemical compound [Ca+2].OP(O)([O-])=O.OP(O)([O-])=O YYRMJZQKEFZXMX-UHFFFAOYSA-L 0.000 description 1
- 229910000389 calcium phosphate Inorganic materials 0.000 description 1
- RMISVBXFFXBNAD-UHFFFAOYSA-N calcium;oxido-(oxido(dioxo)chromio)oxy-dioxochromium Chemical compound [Ca+2].[O-][Cr](=O)(=O)O[Cr]([O-])(=O)=O RMISVBXFFXBNAD-UHFFFAOYSA-N 0.000 description 1
- 150000004649 carbonic acid derivatives Chemical class 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 229910001430 chromium ion Inorganic materials 0.000 description 1
- 239000008119 colloidal silica Substances 0.000 description 1
- 229920001577 copolymer Polymers 0.000 description 1
- 230000003247 decreasing effect Effects 0.000 description 1
- 238000010292 electrical insulation Methods 0.000 description 1
- 238000002474 experimental method Methods 0.000 description 1
- -1 glycenphosphorus Chemical compound 0.000 description 1
- 235000011187 glycerol Nutrition 0.000 description 1
- 150000004679 hydroxides Chemical class 0.000 description 1
- 238000011835 investigation Methods 0.000 description 1
- JEIPFZHSYJVQDO-UHFFFAOYSA-N iron(III) oxide Inorganic materials O=[Fe]O[Fe]=O JEIPFZHSYJVQDO-UHFFFAOYSA-N 0.000 description 1
- 229910052749 magnesium Inorganic materials 0.000 description 1
- 239000011777 magnesium Substances 0.000 description 1
- 229910000000 metal hydroxide Inorganic materials 0.000 description 1
- 229910044991 metal oxide Inorganic materials 0.000 description 1
- 150000004706 metal oxides Chemical class 0.000 description 1
- 150000002739 metals Chemical class 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 235000019691 monocalcium phosphate Nutrition 0.000 description 1
- 239000012299 nitrogen atmosphere Substances 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 239000004584 polyacrylic acid Substances 0.000 description 1
- 229920002451 polyvinyl alcohol Polymers 0.000 description 1
- 238000006722 reduction reaction Methods 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 150000003839 salts Chemical class 0.000 description 1
- 239000007921 spray Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 239000005720 sucrose Substances 0.000 description 1
- 150000005846 sugar alcohols Polymers 0.000 description 1
- 230000003313 weakening effect Effects 0.000 description 1
- 238000003466 welding Methods 0.000 description 1
- 239000011701 zinc Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/05—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions
- C23C22/06—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6
- C23C22/24—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds
- C23C22/33—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals using aqueous solutions using aqueous acidic solutions with pH less than 6 containing hexavalent chromium compounds containing also phosphates
-
- C—CHEMISTRY; METALLURGY
- C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
- C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
- C23C22/00—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals
- C23C22/73—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process
- C23C22/74—Chemical surface treatment of metallic material by reaction of the surface with a reactive liquid, leaving reaction products of surface material in the coating, e.g. conversion coatings, passivation of metals characterised by the process for obtaining burned-in conversion coatings
Description
この発明は、絶縁被膜を有する電気鉄板に関
し、とくに該被膜の有利な改善により、打抜性お
よび歪取焼鈍後の耐食性を向上させようとするも
のである。
モーターやトランスなどの電気機器用鉄心は、
電気鉄板の表面にまず絶縁被膜を被成したのち所
定の形状に打抜き、ついでそれらを積層してその
側面をTIG溶接したり、ピンで固定して組立てら
れる。また、場合によつては打抜き後に加工歪を
除去して磁気特性を向上させるための歪取焼鈍を
施すこともある。
従つて電気鉄板の絶縁被膜に要求される特性は
数多く、たとえば電気絶縁性のほか打抜性、溶接
性、密着性、耐食性、耐熱性および耐薬品性など
が優れていることが必要であるとされ、従来から
これらの要求特性を満足させるために種々の組成
の絶縁被膜が開発され、また改良されてきた。
なかでも打抜性に関しては有機樹脂の利用によ
り著しく向上することが見い出され、最近ではク
ロム酸塩ないしは重クロム酸塩（以下単に重クロ
ム酸塩系という）と有機樹脂を主成分とする混合
被膜が多用されている。
しかしながら、かような重クロム酸塩−有機樹
脂系被膜には、歪取焼鈍後の耐食性が劣るところ
に問題があつた。すなわち、この種被膜を被成し
た鉄心板を、たとえば約750℃，2hで歪取焼鈍し
た場合、雨季など高温多湿下で放置していると直
ちに発錆し、さらに鉄心板同志が強く密着接合し
ていたのである。これは重クロム酸塩−有機樹脂
系被膜においては耐熱性が十分でなく、従つて高
温の歪取焼鈍によつて被膜が多孔質になるためと
考えられる。
なお、耐食性に優れている被膜としては、たと
えば特公昭38−9409号公報に開示されているよう
な重クロム酸塩−りん酸系被膜があるが、かかる
りん酸系被膜は無機質であるため打抜性が極めて
悪いという欠点があり、また上記公報では歪取焼
鈍後の耐食性については何ら考察されていない。
そこで発明者らは、かような重クロム酸塩−有
機樹脂系被膜の歪取焼鈍後の耐食性の改善につい
て種々検討を行つた結果、被膜形成処理液中にり
ん酸塩をある範囲内で配合することにより、他の
特性の劣化を伴わずして歪取焼鈍後の耐食性を著
しく改善できることを突止め、この発明を完成さ
せたのである。
すなわちこの発明の要旨とするところは、有機
還元剤を含む重クロム酸塩−有機樹脂系処理液中
に、りん酸塩を、該処理液中に含まれるCrO3：
100重量部に対し30〜90重量部の割合で添加配合
し、この水性処理液を、基地鉄板の表面に、常法
に従つて塗布、ついで焼付けるところにある。
ここに重クロム酸塩−有機樹脂系処理液として
は、少くとも一種の２価金属を含む重クロム酸塩
系水溶液に、該水溶液中に含まれるCrO3：100重
量部に対し、有機樹脂を固形分で５〜120重量部
と有機還元剤を10〜60重量部と、ときにはさらに
ほう酸を20〜45重量部の割合で添加配合したもの
がとりわけ有利に適合する。
以下この発明を具体的に説明する。
この発明において使用する重クロム酸塩系水溶
液とは、Ca，MgおよびZnなどの２価の金属のう
ちから選ばれる何れか１種または２種以上を含む
重クロム酸塩、あるいはこれに少量の無水クロム
酸を加えた水溶液であり、それらは上記した２価
金属の酸化物、水酸化物あるいは炭酸塩を無水ク
ロム酸の水溶液に溶解させることによつて得るこ
とができる。
また打抜性を改善するために配合する有機樹脂
としては、アクリル系、酢酸ビニル系、スチレン
系およびそれらの共重合物のエマルジヨン、なら
びにポリビニルアルコール、ポリアクリル酸、セ
ルロース等の水溶性樹脂などいずれもが使用で
き、その配合量はCrO3：100重量部に対して樹脂
固形分で５〜120重量部とする必要がある。とい
うのは樹脂固形分が５重量部よりも少ないと打抜
性が悪く、一方120重量部よりも多くなると得ら
れる被膜が軟弱になるとともに耐熱性が劣化する
からである。
さらに被膜中に６価クロムが多量に残存する
と、大気中の水分を吸収して被膜が軟弱化し絶縁
被膜としての機能が失われる。そこで、この６価
クロムを還元し不溶性の３価クロムとして被膜を
不溶性化するために、クロムの有機還元剤とし
て、グリセンリン、エチレングリコール、しよ糖
などの多価アルコール類を、CrO3：100重量部に
対して10〜60重量部の割合で配合する。還元剤の
配合量が10重量部未満では被膜の耐水性に劣り、
一方60重量部を超えると処理液中において還元反
応が速やかに進行し、処理液が不安定となる不利
を生じる。
またときにはさらに、被膜の耐熱性改善成分と
してほう酸を配合することもできる。そしてその
配合量はCrO3：100重量部に対し20〜45重量部と
するのが効果的である。
なお層間絶縁性を向上させるために、さらにコ
ロイド状のシリカ、アルミナまたはチタニアなど
を添加配合してもさしつかえない。
さてこの発明では、上記の配合割合に調整した
重クロム酸塩−有機樹脂系処理液中に、さらにり
ん酸塩を、該処理液中に含まれるCrO3：100重量
部に対し30〜90重量部の割合で添加配合するので
ある。
第１図に、重クロム酸塩−有機樹脂系処理液中
にりん酸塩として第１りん酸マグネシウムを種々
の割合で添加配合した水性処理液を、下記の条件
で処理して、電気鉄板の表面に絶縁被膜を形成し
た場合の、歪取焼鈍後の耐食性について調べた結
果を示す。
１ 電気鉄板 JIS S50相当
２ 処理液
水 2000重量部
重クロム酸マグネシウム（CrO3として）
100重量部
アクリル系樹脂エマルジヨン（固形分で）
30重量部
有機還元剤（エチレングリコール） 20重量部
ほう酸 25重量部
第１りん酸マグネシウム ０〜120重量部
３ 塗布方法 ゴムロール法
４ 焼付け条件 450℃，70秒
５ 被膜付着量 2.0g／m2
６ 歪取焼鈍条件 N2雰囲気中 750℃，２時間
７ 耐食性試験 恒温恒湿槽、温度50℃
湿度80％ 期間20日、
第１図に示した試験結果から明らかなように、
第１りん酸マグネシウムの添加がない場合には、
発錆率が90％にも達していたが、第１りん酸マグ
ネシウムを添加すると、その添加量につれて発錆
率は激減し、CrO3：100重量部に対し30重量部以
上配合すると、20％以下まで発錆率を低下させる
ことができた。しかしながらCrO3100重量部に対
し90重量部を超えて配合しても耐食性改善効果は
飽和に達し、かえつて密着性が劣化すると共に処
理液の経時安定性も悪化した。
上記した第１りん酸マグネシウムの他、りん酸
塩として、Ca，ZnおよびAlのりん酸金属塩を単
独使用または併用した場合についても、同様の実
験を行つて歪取焼鈍後の耐食性改善効果について
調べたところ、第１図に示した結果とほぼ同等の
結果が得られた。
従つてりん酸塩の配合量は、処理液中に含まれ
るCrO3：100重量部に対し30〜90重量部の範囲に
限定したのである。
被膜の形成に当つては、上述した所定の配合割
合になる処理液を、電気鉄板の基地表面にロール
コーターやスプレーなどによつて均一に塗布した
のち、300〜700℃程度の温度で短時間焼付けるこ
とによつて、所期した良好な絶縁被膜を得ること
ができる。
このとき焼付け後の被膜付着量は、0.4〜
6.0g／m2程度とするのが好ましい。というのは
0.4g／m2未満では層間絶縁性や打抜性が不十分で
あり、一方6.0g／m2を超えると被膜の密着性が劣
化するからである。
かくして得られた絶縁被膜は、打抜性および歪
取焼鈍後の耐食性に優れるだけでなく、密着性、
耐油性および耐薬品性などの面でも十分満足のい
くものであることが確かめられている。
なお、有機樹脂を含有するクロム酸塩系処理液
にりん酸又はりん酸塩を少量添加することについ
てはすでに特公昭51−20018号公報で提案されて
いる。しかし、この場合の添加目的は、クロム酸
塩−有機樹脂系被膜が酸化性雰囲気中でブルーイ
ング処理を行うとステイツキングによる磁性劣化
が大きいという欠点を改善しようとするものであ
つて、この発明とは目指すところが全く異なり、
しかもクロム酸塩−有機樹脂系処理液に添加する
りん酸又はりん酸塩の量は、クロムイオン10部に
対して0.05〜５部と、この発明の下限値を下回る
ものである。
これに対し、この発明は上述したように、重ク
ロム酸塩−有機樹脂系処理液中に比較的多量のり
ん酸塩を添加することによつて歪取焼鈍後の耐食
性の改善を達成したものであり、かような多量の
りん酸塩の添加による歪取焼鈍後の耐食性の改善
は、この発明ではじめて実現されたものである。
次にこの発明の実施例を比較例と共に説明す
る。
実施例 １
板厚0.5mmの電気鉄板の表面に下記の成分から
なる処理液Ａをゴムロールで塗布し、45℃で70秒
間焼付けて被膜を形成した。ついで得られた絶縁
被膜付き電気鉄板を所定の形状に打抜いたのち、
複数枚積層して歪取焼鈍を施した。
このときの被膜特性について調べた結果を表１
に示す。
処理液 Ａ
水 2000重量部
重クロム酸マグネシウム（CrO3として）
100重量部
第１りん酸マグネシウム 40重量部
アクリル系樹脂エマルジヨン（固形分として）
30重量部
還元剤（エチレングリコール） 25重量部
ほう酸 25重量部
実施例 ２
実施例１と同じ要領で下記の成分からなる処理
液Ｂを処理して、電気鉄板の表面に絶縁被膜を形
成した。得られた電気鉄板の被膜の特性について
調べた結果を表１に示す。
処理液 Ｂ
水 2000重量部
重クロム酸マグネシウム（CrO3として）
100重量部
第１りん酸マグネシウム 55重量部
アクリル−スチレン
樹脂エマルジヨン（固形分として） 40重量部
還元剤（グリセリン） 25重量部
実施例 ８
下記の成分になる処理液Ｃを実施例１と同要領
で処理して、電気鉄板の表面に絶縁被膜を形成し
た。得られた電気鉄板の被膜特性を表１に示す。
処理液 Ｃ
水 2000重量部
重クロム酸カルシウム（CrO3として）
100重量部
第１りん酸カルシウム 70重量部
アクリル−酢ビ系
樹脂エマルジヨン（固形分として） 50重量部
還元剤（エチレングリコール） 20重量部
ほう酸 20重量部
比較例 １
りん酸塩の添加がない従来の処理液Ｄを実施例
１と同じ要領で処理して、電気鉄板の表面に絶縁
被膜を形成した。同じく被膜特性を表１に示す。
処理液 Ｄ
水 2000重量部
重クロム酸マグネシウム（CrO3として）
100重量部
アクリル系樹脂
エマルジヨン（固形分として） 30重量部
還元剤（エチレングリコール） 25重量部
ほう酸 25重量部
比較例 ２
りん酸塩の配合量が少ない下記の成分になる処
理液Ｅを実施例１と同じ要領で処理して、電気鉄
板の表面に絶縁被膜を形成した。同じく被膜特性
を表１に示す。
処理液 Ｅ
水 2000重量部
重クロム酸マグネシウム（CrO3として）
100重量部
第１りん酸マグネシウム 15重量部
アクリル系樹脂
エマルジヨン（固形分として） 30重量部
還元剤（エチレングリコール） 25重量部
ほう酸 25重量部
比較例 ３
有機樹脂を含まない下記の成分になる処理液Ｆ
を実施例１と同じ要領で処理して、電気鉄板の表
面に無機質の絶縁被膜を形成した。同じく被膜特
性を表１に示す。
処理液 Ｆ
水 7000重量部
CrO3 100重量部
第１りん酸マグネシウム 700重量部
硝酸アルミニウム 80重量部
The present invention relates to an electric iron plate having an insulating coating, and in particular aims to improve punchability and corrosion resistance after strain relief annealing by advantageously improving the coating. Iron cores for electrical equipment such as motors and transformers are
An insulating film is first coated on the surface of an electric iron plate, then punched into a predetermined shape, and then assembled by stacking them and TIG welding the sides or fixing them with pins. In some cases, strain relief annealing may be performed after punching to remove processing strain and improve magnetic properties. Therefore, the insulating coating for electrical iron plates has many properties, including excellent electrical insulation, punchability, weldability, adhesion, corrosion resistance, heat resistance, and chemical resistance. Insulating coatings of various compositions have been developed and improved in order to satisfy these required characteristics. In particular, it has been found that punching properties can be significantly improved by using organic resins, and recently, mixed coatings mainly composed of chromate or dichromate (hereinafter simply referred to as dichromate type) and organic resin have been developed. is frequently used. However, such dichromate-organic resin coatings have a problem in that they have poor corrosion resistance after strain relief annealing. In other words, if a core plate coated with this type of coating is strain-relief annealed at approximately 750°C for 2 hours, if it is left in a high temperature and high humidity environment such as during the rainy season, it will immediately rust, and the core plates will bond tightly together. That's what I was doing. This is thought to be because the dichromate-organic resin coating does not have sufficient heat resistance, and therefore the coating becomes porous due to high-temperature stress relief annealing. As a coating with excellent corrosion resistance, for example, there is a dichromate-phosphate coating as disclosed in Japanese Patent Publication No. 38-9409, but since such a phosphate coating is inorganic, it cannot be hammered. It has the disadvantage of extremely poor extractability, and the above-mentioned publication does not give any consideration to corrosion resistance after stress relief annealing. Therefore, the inventors conducted various studies on improving the corrosion resistance of such a dichromate-organic resin coating after strain relief annealing, and as a result, they decided to incorporate phosphate within a certain range into the coating forming treatment solution. This led to the discovery that the corrosion resistance after strain relief annealing could be significantly improved without deterioration of other properties, and the present invention was completed. That is, the gist of the present invention is that phosphate is added to a dichromate-organic resin treatment solution containing an organic reducing agent, and CrO 3 contained in the treatment solution:
The aqueous treatment liquid is added at a ratio of 30 to 90 parts by weight to 100 parts by weight, and this aqueous treatment liquid is applied to the surface of the base iron plate according to a conventional method, and then baked. Here, as the dichromate-organic resin treatment liquid, an organic resin is added to a dichromate-based aqueous solution containing at least one type of divalent metal, based on 100 parts by weight of CrO 3 contained in the aqueous solution. Particularly advantageous are those containing 5 to 120 parts by weight of solids, 10 to 60 parts by weight of an organic reducing agent, and sometimes 20 to 45 parts by weight of boric acid. This invention will be explained in detail below. The dichromate-based aqueous solution used in this invention is a dichromate containing one or more divalent metals such as Ca, Mg, and Zn, or a small amount of dichromate containing this. These are aqueous solutions containing chromic anhydride, which can be obtained by dissolving the above divalent metal oxides, hydroxides or carbonates in an aqueous solution of chromic anhydride. Examples of organic resins to be blended to improve punching properties include emulsions of acrylic, vinyl acetate, styrene, and copolymers thereof, and water-soluble resins such as polyvinyl alcohol, polyacrylic acid, and cellulose. The amount of resin solid content should be 5 to 120 parts by weight per 100 parts by weight of CrO 3 . This is because if the resin solid content is less than 5 parts by weight, punching properties will be poor, while if it is more than 120 parts by weight, the resulting coating will become weak and its heat resistance will deteriorate. Furthermore, if a large amount of hexavalent chromium remains in the coating, it absorbs moisture from the atmosphere, weakening the coating and losing its function as an insulating coating. Therefore, in order to reduce this hexavalent chromium and make the coating insoluble as insoluble trivalent chromium, polyhydric alcohols such as glycenphosphorus, ethylene glycol, and sucrose were used as an organic reducing agent for chromium in a CrO 3 :100 ratio. It is blended at a ratio of 10 to 60 parts by weight. If the amount of the reducing agent is less than 10 parts by weight, the water resistance of the film will be poor.
On the other hand, if the amount exceeds 60 parts by weight, the reduction reaction proceeds rapidly in the processing solution, resulting in a disadvantage that the processing solution becomes unstable. In some cases, boric acid may also be added as a component for improving the heat resistance of the coating. It is effective that the blending amount is 20 to 45 parts by weight per 100 parts by weight of CrO3 . In order to improve interlayer insulation, colloidal silica, alumina, titania, etc. may be further added and blended. Now, in this invention, phosphate is further added to the dichromate-organic resin treatment liquid adjusted to the above blending ratio in an amount of 30 to 90 parts by weight per 100 parts by weight of CrO 3 contained in the treatment liquid. It is added and blended in the ratio of 1 part. Figure 1 shows that an aqueous treatment solution in which dichromate-organic resin treatment solution is mixed with monobasic magnesium phosphate as a phosphate in various proportions is treated under the following conditions to produce electric iron plates. The results of investigating the corrosion resistance after strain relief annealing when an insulating film is formed on the surface are shown. 1 Electric iron plate JIS S50 equivalent 2 Treatment liquid Water 2000 parts by weight Magnesium dichromate (as CrO 3 )
100 parts by weight acrylic resin emulsion (solid content)
30 parts by weight Organic reducing agent (ethylene glycol) 20 parts by weight Boric acid 25 parts Magnesium monophosphate 0-120 parts by weight 3 Coating method Rubber roll method 4 Baking conditions 450°C, 70 seconds 5 Amount of film deposited 2.0 g/m 2 6 Strain relief annealing conditions N2 atmosphere 750℃, 2 hours 7 Corrosion resistance test Constant temperature and humidity chamber, temperature 50℃, humidity 80% Duration 20 days As is clear from the test results shown in Figure 1,
If monobasic magnesium phosphate is not added,
The rusting rate had reached 90%, but when monomagnesium phosphate was added, the rusting rate drastically decreased as the amount added increased, and when 30 parts by weight or more of CrO 3 was added to 100 parts by weight, the rusting rate increased to 20%. We were able to reduce the rusting rate to below. However, even when more than 90 parts by weight is added to 100 parts by weight of CrO 3 , the corrosion resistance improvement effect reaches saturation, and the adhesion deteriorates and the stability of the treatment liquid over time also deteriorates. In addition to the monomagnesium phosphate mentioned above, similar experiments were conducted to investigate the corrosion resistance improvement effect after strain relief annealing when Ca, Zn, and Al phosphate metal salts were used alone or in combination as phosphates. Upon investigation, results almost identical to those shown in FIG. 1 were obtained. Therefore, the amount of phosphate salt added was limited to 30 to 90 parts by weight per 100 parts by weight of CrO 3 contained in the treatment liquid. To form the film, the treatment liquid with the prescribed mixing ratio described above is uniformly applied to the base surface of the electric iron plate using a roll coater or spray, and then heated at a temperature of about 300 to 700°C for a short time. By baking, it is possible to obtain the desired good insulation coating. At this time, the amount of film attached after baking is 0.4~
It is preferable to set it to about 6.0g/m2. I mean
If it is less than 0.4 g/m 2 , interlayer insulation and punchability will be insufficient, while if it exceeds 6.0 g/m 2 , the adhesion of the coating will deteriorate. The insulating coating thus obtained not only has excellent punchability and corrosion resistance after strain relief annealing, but also has excellent adhesion and
It has been confirmed that it is fully satisfactory in terms of oil resistance and chemical resistance. Note that Japanese Patent Publication No. 51-20018 has already proposed adding a small amount of phosphoric acid or phosphate to a chromate-based treatment solution containing an organic resin. However, the purpose of the addition in this case is to improve the drawback that magnetic deterioration due to statesking is large when a chromate-organic resin coating is subjected to bluing treatment in an oxidizing atmosphere. The aim is completely different from
Moreover, the amount of phosphoric acid or phosphate added to the chromate-organic resin treatment solution is 0.05 to 5 parts per 10 parts of chromium ion, which is below the lower limit of the present invention. In contrast, as described above, this invention achieves improvement in corrosion resistance after strain relief annealing by adding a relatively large amount of phosphate to the dichromate-organic resin treatment solution. This invention is the first to realize improvement in corrosion resistance after stress relief annealing by adding such a large amount of phosphate. Next, examples of the present invention will be described together with comparative examples. Example 1 A treatment solution A consisting of the following components was applied to the surface of an electric steel plate with a thickness of 0.5 mm using a rubber roll, and baked at 45° C. for 70 seconds to form a film. Then, after punching the obtained electrical steel plate with insulation coating into a predetermined shape,
Multiple sheets were laminated and subjected to strain relief annealing. Table 1 shows the results of investigating the film properties at this time.
Shown below. Treatment liquid A Water 2000 parts by weight Magnesium dichromate (as CrO 3 )
100 parts by weight Monomagnesium phosphate 40 parts by weight Acrylic resin emulsion (as solid content)
30 parts by weight Reducing agent (ethylene glycol) 25 parts by weight Boric acid 25 parts by weight Example 2 Treatment liquid B consisting of the following components was treated in the same manner as in Example 1 to form an insulating coating on the surface of an electric iron plate. Table 1 shows the results of investigating the properties of the coating on the obtained electric iron plate. Treatment liquid B Water 2000 parts by weight Magnesium dichromate (as CrO 3 )
100 parts by weight Monomagnesium phosphate 55 parts by weight Acrylic-styrene resin emulsion (as solid content) 40 parts by weight Reducing agent (glycerin) 25 parts by weight Example 8 Processing liquid C having the following components was prepared in the same manner as in Example 1. An insulating film was formed on the surface of the electric iron plate. Table 1 shows the coating properties of the obtained electric iron plate. Treatment liquid C Water 2000 parts by weight Calcium dichromate (as CrO 3 )
100 parts by weight Monobasic calcium phosphate 70 parts by weight Acrylic-vinyl acetate resin emulsion (as solid content) 50 parts by weight Reducing agent (ethylene glycol) 20 parts by weight Boric acid 20 parts by weight Comparative example 1 Conventional without addition of phosphate The treatment solution D was treated in the same manner as in Example 1 to form an insulating film on the surface of an electric iron plate. Similarly, the film properties are shown in Table 1. Treatment liquid D Water 2000 parts by weight Magnesium dichromate (as CrO 3 )
100 parts by weight Acrylic resin emulsion (as solid content) 30 parts by weight Reducing agent (ethylene glycol) 25 parts by weight Boric acid 25 parts by weight Comparative example 2 An example of treatment liquid E with the following components containing a small amount of phosphate An insulating film was formed on the surface of the electric iron plate by processing in the same manner as in 1. Similarly, the film properties are shown in Table 1. Treatment liquid E Water 2000 parts by weight Magnesium dichromate (as CrO 3 )
100 parts by weight Monomagnesium phosphate 15 parts by weight Acrylic resin Emulsion (as solid content) 30 parts by weight Reducing agent (ethylene glycol) 25 parts by weight Boric acid 25 parts by weight Comparative example 3 Treatment to produce the following components that do not contain organic resin Liquid F
was treated in the same manner as in Example 1 to form an inorganic insulating film on the surface of the electric iron plate. Similarly, the film properties are shown in Table 1. Treatment liquid F Water 7000 parts by weight CrO 3 100 parts by weight Monomagnesium phosphate 700 parts by weight Aluminum nitrate 80 parts by weight
【表】【table】
【表】
比較例１および２のりん酸塩を含まない処理液
Ｄおよびりん酸塩の含有量が少ない処理液Ｅを用
いた場合には、歪取焼鈍後の耐食性が悪く、一方
有機樹脂を含まない処理液Ｆを用いた場合（比較
例３）には耐食性は良好であつたものの、打抜性
は著しく劣化した。
これに対しこの発明に従う絶縁被膜付き電気鉄
板（実施例１〜３）はいずれも、打抜性および歪
取焼鈍後の耐食性とも極めて良好であつた。[Table] When using treatment liquid D that does not contain phosphate and treatment liquid E that contains a small amount of phosphate in Comparative Examples 1 and 2, the corrosion resistance after strain relief annealing was poor; In the case of using treatment liquid F that did not contain it (Comparative Example 3), although the corrosion resistance was good, the punchability was significantly deteriorated. On the other hand, all of the electrical iron plates with insulating coatings according to the present invention (Examples 1 to 3) had extremely good punchability and corrosion resistance after strain relief annealing.
第１図は、重クロム酸塩−有機樹脂系処理液中
への第１りん酸マグネシウムの配合量と歪取焼鈍
後の耐食性（発錆率）との関係を示したグラフで
ある。
FIG. 1 is a graph showing the relationship between the amount of monobasic magnesium phosphate blended into the dichromate-organic resin treatment solution and the corrosion resistance (rusting rate) after strain relief annealing.
Claims (1)
あつて、該被膜は、有機還元剤を含む重クロム酸
塩−有機樹脂系処理液に、該処理液中に含まれる
CrO3：100重量部に対しりん酸塩を30〜90重量部
の割合で添加配合した水性処理液を、基地鉄板の
表面に塗布し、常法による焼付け工程を経て得た
ものであることを特徴とする打抜性および歪取焼
鈍後の耐食性に優れた絶縁被膜を有する電気鉄
板。 ２ 重クロム酸塩−有機樹脂系処理液が、少くと
も一種の２価金属を含む重クロム酸塩系水溶液
に、該水溶液中に含まれるCrO3：100重量部に対
し、有機樹脂を固形分で５〜120重量部と有機還
元剤を10〜60重量部と、ときにはさらにほう酸を
20〜45重量部の割合で添加配合したものである特
許請求の範囲第１項記載の電気鉄板。 ３ 焼付け後の絶縁被膜の付着量が、基地鉄板の
単位面積１mm2当り0.4〜6.0gである特許請求の範
囲第１項または第２項記載の電気鉄板。[Scope of Claims] 1. An electric iron plate having an electrically insulating coating on its surface, the coating being contained in a dichromate-organic resin treatment solution containing an organic reducing agent.
An aqueous treatment solution containing 30 to 90 parts by weight of phosphate per 100 parts by weight of CrO 3 is applied to the surface of the base iron plate, and a baking process is performed using a conventional method. An electric iron plate with an insulating coating that has excellent punchability and corrosion resistance after stress relief annealing. 2. The dichromate-organic resin treatment liquid is a dichromate-based aqueous solution containing at least one type of divalent metal, and a solid content of the organic resin is added to 100 parts by weight of CrO 3 contained in the aqueous solution. and 10 to 60 parts by weight of an organic reducing agent, and sometimes additional boric acid.
The electric iron plate according to claim 1, which is added in a proportion of 20 to 45 parts by weight. 3. The electric iron plate according to claim 1 or 2, wherein the amount of the insulating coating deposited after baking is 0.4 to 6.0 g per 1 mm 2 of unit area of the base iron plate.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22622382A JPS59116382A (en) | 1982-12-24 | 1982-12-24 | Electrical sheet formed with insulating film having excellent punchability and corrosion resistance after stress relief annealing |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP22622382A JPS59116382A (en) | 1982-12-24 | 1982-12-24 | Electrical sheet formed with insulating film having excellent punchability and corrosion resistance after stress relief annealing |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS59116382A JPS59116382A (en) | 1984-07-05 |
| JPH0445586B2 true JPH0445586B2 (en) | 1992-07-27 |
Family
ID=16841820
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP22622382A Granted JPS59116382A (en) | 1982-12-24 | 1982-12-24 | Electrical sheet formed with insulating film having excellent punchability and corrosion resistance after stress relief annealing |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS59116382A (en) |
Families Citing this family (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2637071B2 (en) * | 1985-11-21 | 1997-08-06 | 株式会社東芝 | Manufacturing method of thin sheet core |
| JPS6384671A (en) * | 1986-09-29 | 1988-04-15 | Kawasaki Steel Corp | Insulating film of electrical steel sheet and formation thereof |
| US4976558A (en) * | 1987-11-19 | 1990-12-11 | Brother Kogyo Kabushiki Kaisha | Device for feeding recording medium in the longitudinal recording direction |
| JP2005317683A (en) * | 2004-04-27 | 2005-11-10 | Nippon Steel Corp | Grain-oriented electromagnetic steel plate for three-phase laminated iron core |
Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5379296A (en) * | 1976-12-23 | 1978-07-13 | Kawasaki Steel Co | Method of forming insulating film on electrical sheet * wherein nasty smell occurs little upon welding and workability for punching is excellent |
-
1982
- 1982-12-24 JP JP22622382A patent/JPS59116382A/en active Granted
Patent Citations (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5379296A (en) * | 1976-12-23 | 1978-07-13 | Kawasaki Steel Co | Method of forming insulating film on electrical sheet * wherein nasty smell occurs little upon welding and workability for punching is excellent |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS59116382A (en) | 1984-07-05 |
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