JPS6147619B2 - - Google Patents
Info
- Publication number
- JPS6147619B2 JPS6147619B2 JP2598282A JP2598282A JPS6147619B2 JP S6147619 B2 JPS6147619 B2 JP S6147619B2 JP 2598282 A JP2598282 A JP 2598282A JP 2598282 A JP2598282 A JP 2598282A JP S6147619 B2 JPS6147619 B2 JP S6147619B2
- Authority
- JP
- Japan
- Prior art keywords
- mold
- coating agent
- coating
- microwave
- agent according
- 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
Links
- 239000011248 coating agent Substances 0.000 claims description 84
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 claims description 50
- 239000004576 sand Substances 0.000 claims description 36
- 238000000576 coating method Methods 0.000 claims description 33
- 239000000463 material Substances 0.000 claims description 32
- XEEYBQQBJWHFJM-UHFFFAOYSA-N Iron Chemical compound [Fe] XEEYBQQBJWHFJM-UHFFFAOYSA-N 0.000 claims description 26
- 229920001187 thermosetting polymer Polymers 0.000 claims description 22
- 229920005989 resin Polymers 0.000 claims description 21
- 239000011347 resin Substances 0.000 claims description 21
- 239000000843 powder Substances 0.000 claims description 19
- 239000002245 particle Substances 0.000 claims description 17
- XTXRWKRVRITETP-UHFFFAOYSA-N Vinyl acetate Chemical compound CC(=O)OC=C XTXRWKRVRITETP-UHFFFAOYSA-N 0.000 claims description 12
- 229910052742 iron Inorganic materials 0.000 claims description 12
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 11
- 238000002156 mixing Methods 0.000 claims description 10
- LFQSCWFLJHTTHZ-UHFFFAOYSA-N Ethanol Chemical compound CCO LFQSCWFLJHTTHZ-UHFFFAOYSA-N 0.000 claims description 9
- PNEYBMLMFCGWSK-UHFFFAOYSA-N aluminium oxide Inorganic materials [O-2].[O-2].[O-2].[Al+3].[Al+3] PNEYBMLMFCGWSK-UHFFFAOYSA-N 0.000 claims description 5
- 239000011134 resol-type phenolic resin Substances 0.000 claims description 5
- 239000000377 silicon dioxide Substances 0.000 claims description 5
- 239000005350 fused silica glass Substances 0.000 claims description 4
- 239000007921 spray Substances 0.000 claims description 4
- 229910052845 zircon Inorganic materials 0.000 claims description 4
- GFQYVLUOOAAOGM-UHFFFAOYSA-N zirconium(iv) silicate Chemical compound [Zr+4].[O-][Si]([O-])([O-])[O-] GFQYVLUOOAAOGM-UHFFFAOYSA-N 0.000 claims description 4
- 238000005554 pickling Methods 0.000 claims 1
- 238000000034 method Methods 0.000 description 14
- 239000005011 phenolic resin Substances 0.000 description 12
- KXGFMDJXCMQABM-UHFFFAOYSA-N 2-methoxy-6-methylphenol Chemical compound [CH]OC1=CC=CC([CH])=C1O KXGFMDJXCMQABM-UHFFFAOYSA-N 0.000 description 7
- 239000011230 binding agent Substances 0.000 description 7
- 229920001971 elastomer Polymers 0.000 description 7
- 239000010410 layer Substances 0.000 description 7
- 229920001568 phenolic resin Polymers 0.000 description 7
- 229920002379 silicone rubber Polymers 0.000 description 7
- 239000004945 silicone rubber Substances 0.000 description 7
- 239000011247 coating layer Substances 0.000 description 6
- 238000010438 heat treatment Methods 0.000 description 6
- 238000004898 kneading Methods 0.000 description 6
- 239000003795 chemical substances by application Substances 0.000 description 5
- 239000000126 substance Substances 0.000 description 5
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 4
- 229910002804 graphite Inorganic materials 0.000 description 4
- 239000010439 graphite Substances 0.000 description 4
- VKYKSIONXSXAKP-UHFFFAOYSA-N hexamethylenetetramine Chemical compound C1N(C2)CN3CN1CN2C3 VKYKSIONXSXAKP-UHFFFAOYSA-N 0.000 description 4
- 239000007788 liquid Substances 0.000 description 4
- 229910052751 metal Inorganic materials 0.000 description 4
- 239000002184 metal Substances 0.000 description 4
- 238000000465 moulding Methods 0.000 description 4
- 239000002904 solvent Substances 0.000 description 4
- 238000003756 stirring Methods 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000004927 clay Substances 0.000 description 3
- 239000003989 dielectric material Substances 0.000 description 3
- 239000006185 dispersion Substances 0.000 description 3
- 230000001678 irradiating effect Effects 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000012778 molding material Substances 0.000 description 3
- 239000002344 surface layer Substances 0.000 description 3
- 229910001018 Cast iron Inorganic materials 0.000 description 2
- PPBRXRYQALVLMV-UHFFFAOYSA-N Styrene Chemical compound C=CC1=CC=CC=C1 PPBRXRYQALVLMV-UHFFFAOYSA-N 0.000 description 2
- 238000007598 dipping method Methods 0.000 description 2
- 230000000694 effects Effects 0.000 description 2
- 235000010299 hexamethylene tetramine Nutrition 0.000 description 2
- 239000004312 hexamethylene tetramine Substances 0.000 description 2
- 238000004519 manufacturing process Methods 0.000 description 2
- 239000005416 organic matter Substances 0.000 description 2
- 239000011819 refractory material Substances 0.000 description 2
- 238000002791 soaking Methods 0.000 description 2
- 229920001169 thermoplastic Polymers 0.000 description 2
- 229920005992 thermoplastic resin Polymers 0.000 description 2
- 239000004416 thermosoftening plastic Substances 0.000 description 2
- 239000004925 Acrylic resin Substances 0.000 description 1
- 229920000178 Acrylic resin Polymers 0.000 description 1
- 229910000838 Al alloy Inorganic materials 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- 229920001807 Urea-formaldehyde Polymers 0.000 description 1
- -1 and for example Substances 0.000 description 1
- 239000007864 aqueous solution Substances 0.000 description 1
- 238000007664 blowing Methods 0.000 description 1
- 239000003575 carbonaceous material Substances 0.000 description 1
- 150000001875 compounds Chemical class 0.000 description 1
- 238000001723 curing Methods 0.000 description 1
- 238000005520 cutting process Methods 0.000 description 1
- 238000013016 damping Methods 0.000 description 1
- 238000005108 dry cleaning Methods 0.000 description 1
- 238000001035 drying Methods 0.000 description 1
- 239000000839 emulsion Substances 0.000 description 1
- 239000003822 epoxy resin Substances 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 239000007849 furan resin Substances 0.000 description 1
- 239000003365 glass fiber Substances 0.000 description 1
- 239000008187 granular material Substances 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 239000003350 kerosene Substances 0.000 description 1
- 238000002844 melting Methods 0.000 description 1
- 230000008018 melting Effects 0.000 description 1
- 238000011415 microwave curing Methods 0.000 description 1
- 230000000116 mitigating effect Effects 0.000 description 1
- 229920003986 novolac Polymers 0.000 description 1
- 239000010680 novolac-type phenolic resin Substances 0.000 description 1
- 239000003973 paint Substances 0.000 description 1
- 229920000647 polyepoxide Polymers 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 229920003987 resole Polymers 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 238000005507 spraying Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 239000002023 wood Substances 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B22—CASTING; POWDER METALLURGY
- B22C—FOUNDRY MOULDING
- B22C3/00—Selection of compositions for coating the surfaces of moulds, cores, or patterns
Landscapes
- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- Mold Materials And Core Materials (AREA)
Description
本発明は、マイクロ波硬化性鋳型用の塗型剤に
関するものである。
本発明者らは、先に、マイクロ波を透過し易い
素材より成る模型に、熱硬化性の粘結剤及びマイ
クロ波に対する誘電物質を含有する耐火物より成
る鋳型材料を充填し、その後当該鋳型材料にマイ
クロ波を照射することによつて、鋳型材料中に含
まれている誘電物質が発熱し、この熱によつて粘
結剤が硬化し、このようにして鋳型材料を硬化さ
せた後、抜型して鋳型を製造する鋳型造型法を提
案している。本発明は、この鋳型造型法において
使用する塗型剤に関するものである。
本発明者らはまた、通常の粉体塗型剤では種々
の不具合を有するため、上記鋳型造型法に用いる
塗型剤として、耐火物粒子、フエノール樹脂及び
水またはアルコールより成る液状塗型剤を提案し
ている（特願昭53−102930号）。
しかしながら、本発明者らのさらに鋭意研究の
結果、上記造型法に使用される塗型は、次のよう
な性質を持つ必要がある。
(1) 塗型と鋳型材料がマイクロ波照射により同時
に発熱・硬化するのだが、その際に塗型は鋳型
に密着しなければならない。すなわち、塗型剤
の塗膜が鋳型に密着していないと、塗型の剥離
によるすくわれやベーニングが製品面にでるこ
とがある。
(2) 塗型剤の塗膜は、0.1〜0.5mm程度の厚さの硬
質の層となつて鋳型に密着するので、塗膜（塗
型）と鋳型の熱膨張率がほぼ似たような値でな
ければならない。両者が著しく異なると、ベー
ニングの原因となる。
(3) 上記造型法に使用される模型としては、マイ
クロ波エネルギー損失が小さく、かつ適度の耐
熱性及び弾性を有することが要求されるので、
シリコーンゴムやフツ素ゴム、あるいは乾燥木
材、エポキシ樹脂、アクリル樹脂、スチレン樹
脂もしくはこれらの樹脂にガラス繊維等の剛性
を付与する物質を充填したものなどの基体の鋳
型側表面に上記シリコーンゴムやフツ素ゴムを
被覆したもので製作される。従つて、模型の表
面層の材質であるシリコーンゴム等に充分に塗
れなければならない（液状塗型剤の耐熱ゴム層
への塗れ性）
このような点からみて、本発明者らが先に具体
的に提案（特願昭53−102930号）している耐火物
粒子（300メツシユのシリカ100部）、水溶性レゾ
ール型フエノール樹脂（10部）及び水（60部）か
ら成る塗型は、模型表面層のシリコーンゴム等に
対しての塗れ性が悪く、マイクロ波加熱造型法に
より造型された鋳型は、しばしば塗型がまだら状
になつていることがあつた。また、他の具体例の
耐火物粒子（400メツシユのアルミナ微粉100
部）、フエノール樹脂（５部）、メタノール（30
部）から成る塗型は、シリコーンゴムに対する塗
れ性に関しては問題はないが、鋳型の砂層と塗膜
との接着が悪く、塗膜層が容易に剥離するという
欠点があつた。
したがつて、本発明の目的は、前記した塗型の
具有すべき特性を満足するマイクロ波硬化性鋳型
用に好適な塗型剤を提供することにある。
本発明者らの研究によると、上記目的は、基本
的には、耐火物粒子に熱硬化性樹脂、砂鉄、及び
水またはアルコールを配合してなる塗型剤により
達成される。
この基本組成から成る塗型剤を使用することに
より、模型の耐熱性ゴム層に対する塗れ性は著し
く改善され、塗膜層のベーニングの発生は完全に
防止され、またすくわれも殆んど防止できる。
ただし、上記塗型剤によれば、塗膜層にほんの
微少のすくわれが生ずる場合がある。この問題
は、本発明の第二の塗型剤、すなわち耐火物粒子
に熱硬化性樹脂、砂鉄、酢酸ビニル、及び水また
はアルコールを配合してなる塗型剤により、完全
に解消される。
本発明に係る塗型剤に使用される耐火物粒子
は、塗型の基材となるものであり、例えばジルコ
ン粉、溶融シリカ粉、アルミナ粉、硅石粉などが
ある。
熱硬化性樹脂は粘結剤として用いられ、例えば
フエノール樹脂、尿素樹脂等が使用できるが、特
にレゾール型フエノール樹脂が最も好適である。
本発明に係る塗型剤においては、上記成分の他
に砂鉄（Fe3O4）を添加する。これにより塗膜層
のベーニングを顕著に防止できる。
本発明に係る第一の塗型剤は、適量の水または
アルコールを溶剤として使用し、これに上記各成
分を添加し、所定時間混練することにより得られ
る。各成分の配合比は、前記した塗型に具備され
るべき特性を勘案すれば、耐火物粒子100重量部
に対して、熱硬化性樹脂は20〜40重量部、砂鉄は
20〜30重量が最も好適な範囲である。
本発明に係る第二の塗型剤では、上記各成分の
他にさらに酢酸ビニル、特に酢酸ビニルエマルジ
ヨンが添加される。この酢酸ビニルは、塗膜の熱
膨張に対するクツシヨン剤としての作用を有し、
該酢酸ビニルを塗型に添加することにより、溶融
金属が鋳込まれた際に生ずる鋳型の膨張に対して
追従性を持たせることができ、前記第一の塗型剤
で僅かな問題として残されていた塗膜層のすくわ
れが完全に防止できる。
酢酸ビニルの配合比は、耐火物粒子100重量部
に対して0.5〜1.0重量部が最も好適な範囲であ
る。
このようにして得られた塗型剤は、ついで注
入、どぶ漬け（浸漬）あるいはスプレイなどの塗
型方法によつて模型表面に塗布される。
塗型剤を模型表面に塗布するのに、模型キヤビ
テイ内に塗型剤を注入することによつて行なう場
合や、いわゆるどぶ漬けにより行なう場合には、
シリコーンゴム等の耐熱ゴム表面層への塗れ性の
点から、溶剤として水を用い、また75B′e以上、
好ましくは80B′e以上の濃度が必要である。これ
を添附図面で説明すれば、図面はどぶ漬けによる
液状塗型剤の耐熱ゴム層への濡れ性（従つて、塗
れ性を意味する）を示すグラフである。図面から
明らかなように、100％の濡れ面積（Wet
Area）を得るには約80B′e以上が必要である。同
様に、スプレイ法を採用する場合には、溶剤とし
て水及びアルコールのいずれでもよいが、その濃
度は約70B′e以上が好ましい。上記各濃度は、溶
剤の量を加減することによつて容易に調節可能で
ある。
以下に、本発明に係る塗型剤の好適な具体例を
示す。
塗型剤 １
ジルコン粉（JIS粒度指数500） 100 重量部
フエノール樹脂 30 〃
砂 鉄 20 〃
酢酸ビニル 0.5 〃
水 10 〃
混練は撹拌下で約３分間行なう。得られた塗型
剤の濃度は約82B′eであつた。
この塗型剤を模型表面に塗布する方法として
は、中子取りどぶ漬け法が適している。また、こ
の塗型剤には砂鉄が20重量部含まれており、この
塗型剤を用いて製造された鋳型は、アルミニウム
合金用及び鋳鉄用の鋳型としてだけでなく、鋳鋼
用の鋳型として用いても焼着は生じない。
塗型剤 ２
溶融石英微粉（JIS粒度指数490） 100 重量部
フエノール樹脂 30 〃
砂 鉄 30 重量部
酢酸ビニル 0.5 〃
水 31.5 〃
混練は撹拌下で約５分間行なう。得られた塗型
剤の濃度は80B′eで、主として鋳鉄用鋳型の塗型
として適している。模型表面に塗布する方法とし
ては、中子取りどぶ漬け法、スプレイ法の両方が
可能である。
塗型剤 ３
アルミナ粉（JIS粒度指数500） 100 重量部
フエノール樹脂 40 〃
砂 鉄 20 〃
酢酸ビニル 1.0 〃
アルコール 28 〃
混練は撹拌下で約４分間行なう。
塗型剤 ４
硅石粉（JIS粒度指数490） 100 重量部
フエノール樹脂 35 〃
砂 鉄 20 〃
酢酸ビニル 0.5 〃
アルコール 35 重量部
混練は撹拌下で約５分間行なう。
以上のようにして本発明に係る塗型剤が表面に
塗布された模型は、ついで前記したマイクロ波加
熱による鋳型造型に供される。すなわち、上記塗
型剤が塗布された模型に鋳型材料（鋳物砂）を充
填し、その後当該鋳型材料にマイクロ波を照射す
ることによつて、鋳型材料中に含まれている誘電
物質が発熱し、この熱によつて鋳型材料及び塗型
剤中の粘結剤が硬化し、このようにして鋳型材料
及び塗型を密着した状態で硬化させ、抜型して塗
型を具備した鋳型が得られる。
上記鋳型造型法において用いる鋳型材料は、熱
硬化性の粘結剤及びマイクロ波に対する誘電物質
とを含有する耐火物より成るもので、マイクロ波
の照射によつて発熱・硬化するものであれば何を
用いてもよいが、以下により好ましい具体例を説
明する。なお、ここでいう熱硬化性の粘結剤と
は、熱可塑性樹脂に硬化剤を配合して熱硬化性と
したものをも含む。
まず、第１の具体的な鋳型材料の例としては、
粘土分0.5〜６％および炭質有機物0.3〜５％を含
有する乾式再生砂100重量部に対し、熱硬化性樹
脂２〜５重量部を含有している材料が挙げられ
る。
この鋳型材料は、鋳造工場で大量に発生する回
収砂を傾斜回転容器内に収容し、該回収砂に回転
容器の回転により複合循環運動を与えると共に、
回転容器内に配設されかつ該容器の回転方向と対
向方向に回転するアジテーターの回転により、上
記循環運動状態の回収砂に衝撃摩擦作用を与える
ことによつて回収砂を所定時間乾式洗浄し、分級
および微粉除去をした後、このように再生処理さ
れた回収砂に熱硬化性樹脂を添加混練することに
よつて製造することができる。上記のようにして
製造された再生砂は、若干の粘土分と灼熱減量を
含んでいることが特長である。粘土分は鋳型が溶
湯注入時に受ける熱衝撃を適度に緩和する役目を
果たし、一方、灼熱減量は主に炭質有機物である
ためマイクロ波加熱に寄与する誘電物質として有
効な役割を果たすことができる。したがつて、上
記のようにして得られる再生砂は、そのままマイ
クロ波硬化用鋳型材料の原料として使用できる。
なお、この鋳型材料において用いる熱硬化樹脂
としては、レゾール型フエノール樹脂、レゾール
型＋ノボラツク型混合のフエノール樹脂、ノボラ
ツク型フエノール樹脂（但し、この樹脂は熱可塑
性であるため、ヘキサメチレンテトラミン等の硬
化剤を通常10〜15％程度含有させ、熱硬化性とす
ることが必要である）があるが、この他フラン樹
脂等の熱硬化性樹脂も使用できる。これらの熱硬
化性樹脂は、一般に新砂に混合される場合には２
〜７％添加されるが、上記により得られる再生砂
の場合は、再生砂100重量部に対し２〜５重量部
で充分である。例えば再生砂100重量部に粉末フ
エノール樹脂（ヘキサメチレンテトラミンを樹脂
に対し15％含有、融点70〜97℃、ゲルタイム35〜
67秒／150℃）３重量部および白灯油0.2部を配合
し、混練機により３分間混練処理することにより
鋳型材料を製造することができる。
また、鋳型材料の第２の好ましい具体例として
は、水溶性黒鉛分散体にフエノール樹脂（水溶
液）を添加し、新砂と混合したものを加熱乾燥し
て成るもので、新粒表面にカーボン質がコーテイ
ングされた状態となつた鋳型材料が挙げられる。
この鋳型材料は、新砂に水溶性黒鉛分散体とフエ
ノール樹脂（黒鉛分散体の重量の数パーセント）
を加え、ミキサーで数分間混砂し、次いでこれを
加熱乾燥させ、加熱時にフエノール樹脂が硬化す
ることによつて粒塊状になつた砂を、マラー等で
粉砕することによつて砂粒状にすることができ
る。
以上に好ましい鋳型材料の具体例を示したが、
さらにこの他に、新砂、熱硬化性樹脂（熱可塑性
樹脂に硬化剤を配合して熱硬化性としたものを含
む）および黒鉛等の誘電物質を混練して成る鋳型
材料や、熱硬化性樹脂と新砂に、マイクロ波に対
する誘電物質としての作用を有する炭化砂を混合
して成る鋳型材料を用いることもできる。
なお、上記の鋳型材料を模型内に充填するの
は、流し込みやダンピングあるいは吹込み等任意
の方法によつて行なうことができる。
以上にマイクロ波硬化性鋳型の製造方法に用い
る模型、塗型剤および鋳型材料について詳細に説
明したが、上記の材料等を用いれば、周波数
2450MHz、出力6KWのマイクロ波を２〜３分間
照射することにより金型面と同等な精度を有し、
鋳型肌面の秀れた鋳型を製造することができる。
またこの鋳型を用いることにより、きわめて高品
質の鋳型製品を製造することができる。
下記表−１に、本発明に係る各種塗型剤を用い
て鋳型を製造した場合の効果を、従来公知の各種
塗型剤を用いた場合と比較して示す。なお、模型
としてはシリコーンゴム被覆模型を用い、マイク
ロ波照射は2450MHz×6KWで１Kg当り１分の割
合で行なつた。
The present invention relates to a coating agent for microwave-curable molds. The present inventors first filled a model made of a material that easily transmits microwaves with a mold material made of a refractory material containing a thermosetting binder and a microwave-resistant dielectric material, and then the mold By irradiating the material with microwaves, the dielectric substance contained in the mold material generates heat, and this heat hardens the binder. After the mold material is cured in this way, We are proposing a mold making method in which molds are manufactured by cutting out molds. The present invention relates to a mold coating agent used in this mold making method. The present inventors also developed a liquid mold coating agent consisting of refractory particles, phenolic resin, and water or alcohol as a mold coating agent used in the above-mentioned mold making method, since ordinary powder mold coating agents have various problems. (Patent Application No. 53-102930). However, as a result of further intensive research by the present inventors, the coating mold used in the above molding method needs to have the following properties. (1) The coating mold and mold material heat and harden at the same time by microwave irradiation, but the coating mold must be in close contact with the mold at this time. That is, if the coating film of the mold coating agent does not adhere closely to the mold, the mold may peel off, causing scuffing or vening to appear on the product surface. (2) The coating film of the coating agent forms a hard layer with a thickness of about 0.1 to 0.5 mm and adheres to the mold, so the coefficient of thermal expansion of the coating film (coating mold) and the mold are almost similar. Must be a value. If the two differ significantly, it will cause vaning. (3) The model used in the above modeling method is required to have low microwave energy loss and appropriate heat resistance and elasticity.
The above-mentioned silicone rubber or base material is coated on the mold side surface of a substrate made of silicone rubber, fluorocarbon rubber, dried wood, epoxy resin, acrylic resin, styrene resin, or these resins filled with a substance that imparts rigidity such as glass fiber. Manufactured from raw rubber coated. Therefore, the material of the surface layer of the model, such as silicone rubber, must be sufficiently coated (applicability of the liquid mold coating agent to the heat-resistant rubber layer). A coating mold made of refractory particles (100 parts of 300 mesh silica), water-soluble resol type phenolic resin (10 parts) and water (60 parts), which was proposed in The coating properties of the surface layer, such as silicone rubber, are poor, and molds formed by microwave heating molding often have a mottled coating. In addition, other specific examples of refractory particles (400 mesh alumina fine powder 100
parts), phenolic resin (5 parts), methanol (30 parts)
Although the coating mold consisting of part) had no problems with respect to its applicability to silicone rubber, it had the disadvantage that the adhesion between the sand layer of the mold and the coating film was poor, and the coating layer easily peeled off. Therefore, an object of the present invention is to provide a mold coating agent suitable for microwave-curable molds that satisfies the characteristics that a coating mold should have as described above. According to the research conducted by the present inventors, the above object is basically achieved by a mold coating agent made by blending refractory particles with a thermosetting resin, iron sand, and water or alcohol. By using a coating agent consisting of this basic composition, the adhesion to the heat-resistant rubber layer of the model is significantly improved, the occurrence of vaning of the coating layer is completely prevented, and the occurrence of scooping can also be almost prevented. . However, the above-mentioned coating agent may cause slight scratches in the coating layer. This problem is completely solved by the second mold coating agent of the present invention, that is, the mold coating agent made by blending refractory particles with a thermosetting resin, iron sand, vinyl acetate, and water or alcohol. The refractory particles used in the mold coating agent according to the present invention serve as a base material for the mold coating, and include, for example, zircon powder, fused silica powder, alumina powder, and silica powder. The thermosetting resin is used as a binder, and for example, phenolic resin, urea resin, etc. can be used, but resol type phenolic resin is particularly suitable. In the mold coating agent according to the present invention, iron sand (Fe 3 O 4 ) is added in addition to the above components. This can significantly prevent vaning of the coating layer. The first mold coating agent according to the present invention is obtained by using an appropriate amount of water or alcohol as a solvent, adding the above-mentioned components to this, and kneading for a predetermined period of time. Considering the characteristics that the coating mold should have as described above, the blending ratio of each component is 20 to 40 parts by weight of thermosetting resin and 20 to 40 parts by weight of iron sand to 100 parts by weight of refractory particles.
20-30 weight is the most preferred range. In the second mold coating agent according to the present invention, vinyl acetate, particularly vinyl acetate emulsion, is added in addition to the above-mentioned components. This vinyl acetate acts as a cushioning agent against thermal expansion of the coating film,
By adding vinyl acetate to the coating mold, it can be made to follow the expansion of the mold that occurs when molten metal is cast, and it is possible to make it follow the expansion of the mold that occurs when molten metal is cast. The scuffing of the paint film layer, which had previously been caused, can be completely prevented. The most suitable blending ratio of vinyl acetate is 0.5 to 1.0 parts by weight per 100 parts by weight of the refractory particles. The mold coating agent thus obtained is then applied to the surface of the model by a mold coating method such as injection, dipping, or spraying. When applying a mold coating agent to the model surface by injecting the mold coating agent into the model cavity or by so-called dobuzuke,
From the viewpoint of coating the surface layer of heat-resistant rubber such as silicone rubber, water is used as a solvent, and 75B′e or higher,
Preferably, a concentration of 80 B'e or more is required. To explain this with reference to the attached drawing, the drawing is a graph showing the wettability (therefore, it means the spreadability) of the liquid mold coating agent to the heat-resistant rubber layer by soaking. As is clear from the drawing, 100% wetted area (Wet
Approximately 80B′e or more is required to obtain a Similarly, when a spray method is employed, either water or alcohol may be used as the solvent, but the concentration is preferably about 70 B'e or more. Each of the above concentrations can be easily adjusted by adjusting the amount of solvent. Preferred specific examples of the mold coating agent according to the present invention are shown below. Coating agent 1 Zircon powder (JIS particle size index 500) 100 parts by weight Phenol resin 30 Iron sand 20 Vinyl acetate 0.5 Water 10 Kneading is performed for about 3 minutes under stirring. The concentration of the mold coating obtained was approximately 82 B'e. As a method for applying this mold coating agent to the model surface, the core removal method is suitable. In addition, this coating agent contains 20 parts by weight of iron sand, and molds manufactured using this coating agent can be used not only as molds for aluminum alloys and cast iron, but also as molds for cast steel. However, no burning occurs. Coating agent 2 Fine fused silica powder (JIS particle size index 490) 100 parts by weight Phenol resin 30 Parts by weight Sand Iron 30 Parts by weight Vinyl acetate 0.5 Water 31.5 Kneading is performed for about 5 minutes under stirring. The concentration of the mold coating agent obtained was 80B'e, and it is suitable mainly as a coating mold for cast iron molds. As a method of coating the model surface, both the core-dipping method and the spray method are possible. Coating agent 3 Alumina powder (JIS particle size index 500) 100 parts by weight Phenol resin 40 Sand Iron 20 Vinyl acetate 1.0 Alcohol 28 Kneading is performed for about 4 minutes under stirring. Coating agent 4 Silica powder (JIS particle size index 490) 100 parts by weight Phenol resin 35 Sand Iron 20 Vinyl acetate 0.5 Alcohol 35 parts by weight Knead for about 5 minutes with stirring. The model whose surface has been coated with the mold coating agent according to the present invention as described above is then subjected to the mold forming process using the microwave heating described above. That is, by filling a model coated with the above-mentioned molding agent with molding material (foundry sand) and then irradiating the molding material with microwaves, the dielectric substance contained in the molding material is heated. The binder in the mold material and coating agent is cured by this heat, and in this way, the mold material and coating mold are hardened in a close contact state, and the mold is removed to obtain a mold equipped with a coating mold. . The mold material used in the above mold making method is made of a refractory material containing a thermosetting binder and a microwave-resistant dielectric material, and can be made of any material that generates heat and hardens when irradiated with microwaves. may be used, but more preferable specific examples will be described below. Note that the term "thermosetting binder" as used herein also includes one made thermosetting by blending a curing agent with a thermoplastic resin. First, as an example of the first specific mold material,
Examples include materials containing 2 to 5 parts by weight of thermosetting resin per 100 parts by weight of dry recycled sand containing 0.5 to 6% clay content and 0.3 to 5% carbonaceous organic matter. This mold material stores recovered sand generated in large quantities in a foundry in an inclined rotating container, gives the recovered sand a compound circulation motion by the rotation of the rotating container, and
Dry cleaning the recovered sand for a predetermined period of time by imparting an impact friction effect to the recovered sand in the circulating motion state by rotation of an agitator disposed in a rotating container and rotating in a direction opposite to the rotational direction of the container; After classification and removal of fine powder, a thermosetting resin can be added and kneaded to the recovered sand thus recycled. The recycled sand produced as described above is characterized by containing some clay content and loss on ignition. The clay content plays a role in moderately mitigating the thermal shock that the mold receives when pouring the molten metal, while the ignition loss is mainly carbonaceous organic matter, so it can play an effective role as a dielectric material that contributes to microwave heating. Therefore, the recycled sand obtained as described above can be used as it is as a raw material for a mold material for microwave curing. The thermosetting resins used in this mold material include resol type phenolic resin, resol type + novolac type mixed phenolic resin, and novolac type phenolic resin (However, since this resin is thermoplastic, hardening of hexamethylenetetramine etc.) It is necessary to normally contain about 10 to 15% of a thermosetting agent to make the resin thermosetting. In addition, thermosetting resins such as furan resins can also be used. When these thermosetting resins are mixed with new sand, they generally have a
In the case of recycled sand obtained as described above, 2 to 5 parts by weight is sufficient for 100 parts by weight of recycled sand. For example, 100 parts by weight of recycled sand is mixed with powdered phenolic resin (contains 15% hexamethylenetetramine based on the resin, melting point is 70-97℃, gel time is 35-35%).
A mold material can be produced by blending 3 parts by weight (67 seconds/150°C) and 0.2 parts of white kerosene and kneading for 3 minutes using a kneader. A second preferred example of the mold material is one made by adding a phenol resin (aqueous solution) to a water-soluble graphite dispersion, mixing it with new sand, and heating and drying the mixture, so that carbonaceous material is formed on the surface of the new particles. Examples include mold materials that are in a coated state.
This mold material consists of fresh sand, water-soluble graphite dispersion and phenolic resin (a few percent of the weight of the graphite dispersion).
and mix the sand with a mixer for several minutes, then heat and dry it, and the sand that has become granular due to the hardening of the phenolic resin during heating is crushed into sand granules by crushing with a muller etc. be able to. Although specific examples of preferable mold materials have been shown above,
In addition, there are mold materials made by kneading new sand, thermosetting resins (including thermosetting resins made by adding a hardening agent to thermoplastic resins), and dielectric substances such as graphite, and thermosetting resins. It is also possible to use a mold material made by mixing new sand with carbonized sand that acts as a dielectric substance against microwaves. The mold material may be filled into the model by any method such as pouring, damping, or blowing. The model, coating agent, and mold material used in the manufacturing method of microwave-curable molds have been explained in detail above.
By irradiating microwaves of 2450MHz and 6KW output for 2 to 3 minutes, it has the same precision as the mold surface.
A mold with excellent mold surface can be manufactured.
Furthermore, by using this mold, it is possible to manufacture molded products of extremely high quality. Table 1 below shows the effects when molds are manufactured using various mold coating agents according to the present invention in comparison with cases where conventionally known various mold coating agents are used. A silicone rubber coated model was used as the model, and microwave irradiation was performed at 2450 MHz x 6 KW at a rate of 1 minute per 1 kg.
【表】【table】
【表】
以上述べたように、本発明に係る塗型剤を使用
することにより、
(1) 塗膜はそれ自体が硬質の膜なので、鋳物砂の
骨材の影響が比較的少なく、低級な再生砂でも
使用可能である、
(2) 造型用の模型の中で鋳物砂と共に硬化させる
ので、塗膜の表面自体が模型表面を転写でき
る、
(3) 従来の塗型に比べて粘結剤（レジン）の量を
多くしたことにより、硬化後の塗型が模型にし
みつくことなく離型できる、
(4) 熱可塑性の酢酸ビニルを塗型に添加したこと
により、溶融金属が鋳込まれた際に生ずる鋳型
の膨張に対し追従性を持たせることができ、塗
膜層のすくわれが防止できる。
(5) 砂鉄（Fe3O4）が塗型に添加されたことによ
り、塗膜層のベーニングが防止できる、などの
種々の利点が得られる。従つて、本発明に係る
塗型をマイクロ波加熱による造型法に用いるこ
とにより、鋳型肌面の優れた鋳型を製造でき
る。[Table] As mentioned above, by using the mold coating agent of the present invention, (1) Since the coating film itself is a hard film, the influence of the aggregate of the foundry sand is relatively small, and it can be used as a low-grade coating material. (2) Since it is hardened together with foundry sand in the mold, the coating surface itself can transfer the model surface. (3) Compared to conventional coating molds, it requires less binder. (4) By adding thermoplastic vinyl acetate to the coating mold, the molten metal can be easily cast. It is possible to provide followability to the expansion of the mold that occurs when the mold is heated, and it is possible to prevent the coating layer from being scooped out. (5) By adding iron sand (Fe 3 O 4 ) to the coating mold, various advantages can be obtained, such as being able to prevent veining of the coating layer. Therefore, by using the coating mold according to the present invention in a molding method using microwave heating, a mold with an excellent mold surface can be manufactured.
図面は、どぶ漬けによる液状塗型剤の耐熱ゴム
層への濡れ性を示すグラフである。
The drawing is a graph showing the wettability of a liquid mold coating agent to a heat-resistant rubber layer by soaking.
Claims (1)
たはアルコールを配合してなることを特徴とす
る、鋳型用模型面に塗型剤を塗布した後マイクロ
波硬化性鋳型材料を充填し、マイクロ波照射によ
り鋳型材料と塗型剤を同時に硬化させて鋳型表面
に塗膜を転写する方式のマイクロ波硬化性鋳型用
塗型剤。 ２ 耐火物粒子がジルコン粉、アルミナ粉、硅石
粉、溶融シリカ粉である特許請求の範囲第１項に
記載の塗型剤。 ３ 熱硬化性樹脂がレゾール型フエノール樹脂で
ある特許請求の範囲第１項に記載の塗型剤。 ４ ボーメ度が70B′e以上であり、スプレイ用に
好適な特許請求の範囲第１項に記載の塗型剤。 ５ ボーメ度が80B′e以上であり、どぶ漬け用に
好適な特許請求の範囲第１項に記載の塗型剤。 ６ 耐火物粒子に熱硬化性樹脂、砂鉄、酢酸ビニ
ル、及び水またはアルコールを配合してなること
を特徴とする、鋳型用模型面に塗型剤を塗布した
後マイクロ波硬化性鋳型材料を充填し、マイクロ
波照射により鋳型材料と塗型剤を同時に硬化させ
て鋳型表面に塗膜を転写する方式のマイクロ波硬
化性鋳型用塗型剤。 ７ 耐火物粒子がジルコン粉、アルミナ粉、硅石
粉、溶融シリカ粉である特許請求の範囲第６項に
記載の塗型剤。 ８ 熱硬化性樹脂がレゾール型フエノール樹脂で
ある特許請求の範囲第６項に記載の塗型剤。 ９ ボーメ度が70B′e以上であり、スプレイ用に
好適な特許請求の範囲第６項に記載の塗型剤。 １０ ボーメ度が80B′e以上であり、どぶ漬け用
に好適な特許請求の範囲第６項に記載の塗型剤。[Scope of Claims] 1. A microwave-curable mold after applying a coating agent to the mold surface, which is characterized by being made by blending refractory particles with a thermosetting resin, iron sand, and water or alcohol. A microwave-curable mold coating agent that is filled with material and simultaneously cures the mold material and coating agent by microwave irradiation to transfer a coating film to the mold surface. 2. The mold coating agent according to claim 1, wherein the refractory particles are zircon powder, alumina powder, silica powder, or fused silica powder. 3. The mold coating agent according to claim 1, wherein the thermosetting resin is a resol type phenolic resin. 4. The mold coating agent according to claim 1, which has a Baume degree of 70 B'e or more and is suitable for spray use. 5. The mold coating agent according to claim 1, which has a Baume degree of 80 B'e or more and is suitable for dobuzuke. 6 Characterized by blending refractory particles with a thermosetting resin, iron sand, vinyl acetate, and water or alcohol, a coating agent is applied to the surface of the mold model, and then a microwave-curable mold material is filled. A microwave-curable mold coating agent that simultaneously cures the mold material and coating agent by microwave irradiation and transfers a coating film to the mold surface. 7. The mold coating agent according to claim 6, wherein the refractory particles are zircon powder, alumina powder, silica powder, or fused silica powder. 8. The mold coating agent according to claim 6, wherein the thermosetting resin is a resol type phenolic resin. 9. The mold coating agent according to claim 6, which has a Baume degree of 70 B'e or more and is suitable for spray use. 10. The mold coating agent according to claim 6, which has a Baume degree of 80 B'e or more and is suitable for pickling.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2598282A JPS58145330A (en) | 1982-02-22 | 1982-02-22 | Mold coating material for casting mold having microwave hardenability |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2598282A JPS58145330A (en) | 1982-02-22 | 1982-02-22 | Mold coating material for casting mold having microwave hardenability |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS58145330A JPS58145330A (en) | 1983-08-30 |
| JPS6147619B2 true JPS6147619B2 (en) | 1986-10-20 |
Family
ID=12180920
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP2598282A Granted JPS58145330A (en) | 1982-02-22 | 1982-02-22 | Mold coating material for casting mold having microwave hardenability |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS58145330A (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0575623B2 (en) * | 1988-11-17 | 1993-10-20 | Toyo Seikan Kaisha Ltd | |
| CN107537970A (en) * | 2016-09-28 | 2018-01-05 | 湖北工业大学 | A kind of powdery cast paint and its preparation and application method |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP5037112B2 (en) * | 2006-12-25 | 2012-09-26 | 花王株式会社 | Casting structure |
| CN109047661B (en) * | 2018-08-27 | 2019-12-24 | 贵州贵材创新科技股份有限公司 | Preparation method of aluminum alloy door and window profile |
-
1982
- 1982-02-22 JP JP2598282A patent/JPS58145330A/en active Granted
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0575623B2 (en) * | 1988-11-17 | 1993-10-20 | Toyo Seikan Kaisha Ltd | |
| CN107537970A (en) * | 2016-09-28 | 2018-01-05 | 湖北工业大学 | A kind of powdery cast paint and its preparation and application method |
| CN107537970B (en) * | 2016-09-28 | 2018-11-13 | 湖北工业大学 | A kind of powdery cast paint and its preparation and application method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS58145330A (en) | 1983-08-30 |
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