JPH05237587A - Sand composition for forming casting mold and production of casting mold - Google Patents
Sand composition for forming casting mold and production of casting moldInfo
- Publication number
- JPH05237587A JPH05237587A JP33313292A JP33313292A JPH05237587A JP H05237587 A JPH05237587 A JP H05237587A JP 33313292 A JP33313292 A JP 33313292A JP 33313292 A JP33313292 A JP 33313292A JP H05237587 A JPH05237587 A JP H05237587A
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- sand
- weight
- content
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Abstract
Description
【０００１】[0001]
【産業上の利用分野】本発明は、再生砂を主体として用
いた鋳型成型用砂組成物、鋳型の製造方法及び鋳型成型
用硬化剤組成物に関するものである。更に詳しくは、酸
硬化性フラン樹脂を硬化させて鋳型を製造する際、成型
された鋳型中の窒素含量、好ましくは窒素含量及びリン
含量、更に好ましくは、窒素含量、リン含量及び硫黄含
量が一定の範囲となる様調整することにより、また、再
生砂、硬化剤中の硫黄含量／（リン含量＋硫黄含量）で
表される重量比が一定の範囲となる様調製することによ
り作業環境が良好でガス欠陥のない鋳造品が得られる鋳
型成型用砂組成物、鋳型の製造方法及び鋳型成型用硬化
剤組成物に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a molding sand composition mainly composed of reclaimed sand, a method for producing a molding, and a curing agent composition for molding. More specifically, when a mold is produced by curing an acid-curable furan resin, the nitrogen content in the molded mold, preferably the nitrogen content and the phosphorus content, more preferably the nitrogen content, the phosphorus content and the sulfur content are constant. The working environment is good by adjusting so that the weight ratio represented by the sulfur content / (phosphorus content + sulfur content) in the reclaimed sand and the curing agent is within a certain range. The present invention relates to a molding sand composition, a method for producing a molding, and a curing agent composition for molding, which can provide a cast product free from gas defects.
【０００２】[0002]
【従来の技術】従来、砂型の製造において結合剤として
フラン樹脂を使用することは例えば特公昭39−1543号公
報等により公知であり、触媒としてリン酸等の酸水溶液
が使用できることも公知である。又、フラン樹脂の硬化
用触媒として五酸化リン（P205）を使用することも特開
昭47−16324 号公報により公知である。当初、フラン樹
脂の硬化用触媒として、このようにリン酸の濃厚溶液が
広く使用された。これらの溶液は比較的低毒性である
が、反応性が低く、鋳型へのリンの蓄積等によりしばし
ばピンホール等の鋳造欠陥を引き起こしたため、フラン
樹脂の硬化用触媒として、ベンゼンスルホン酸、トルエ
ンスルホン酸、キシレンスルホン酸のような芳香族スル
ホン酸が広く使用されるようになった。しかしながら、
芳香族スルホン酸は注湯時の熱により分解して有毒な分
解生成物を作業環境中に放出する。最近このような硫黄
含有ガス及び鋳物作業場を汚染する煙霧に関する苦情が
多発している。2. Description of the Related Art Conventionally, the use of furan resin as a binder in the production of sand molds has been known, for example, from Japanese Patent Publication No. 39-1543, and it is also known that an aqueous acid solution such as phosphoric acid can be used as a catalyst. . It is also known from JP-47-16324 discloses the use of phosphorus pentoxide (P 2 0 5) as a curing catalyst for a furan resin. Initially, such concentrated solutions of phosphoric acid were widely used as catalysts for curing furan resins. Although these solutions have relatively low toxicity, they have low reactivity and often cause casting defects such as pinholes due to the accumulation of phosphorus in the mold. Therefore, benzenesulfonic acid and toluenesulfone were used as catalysts for curing furan resin. Aromatic sulfonic acids such as acids and xylene sulfonic acids have become widely used. However,
Aromatic sulfonic acid decomposes due to heat during pouring and releases toxic decomposition products into the work environment. Recently, there have been many complaints about the sulfur-containing gas and fumes that contaminate the foundry.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、従来の
砂型製造においてリン酸系の化合物を含有する触媒を用
いたフラン樹脂の硬化は、硬化速度の点、混練時の流動
性の点、吸湿劣化の点、砂中の窒素、リン又は硫黄の蓄
積に起因する鋳造品のガス欠陥の点等において一長一短
があり、全ての点で満足できるものとは言えない。とり
わけ砂中の窒素、リン又は硫黄の蓄積に起因する鋳造品
のガス欠陥の発生、砂の吸湿性及び作業環境は最も重要
な解決すべき課題であり、その改善が望まれている。However, curing of a furan resin using a catalyst containing a phosphoric acid-based compound in the conventional sand mold production is difficult in terms of curing speed, fluidity during kneading, and moisture absorption deterioration. However, there are merits and demerits in terms of gas defects of the cast product due to the accumulation of nitrogen, phosphorus or sulfur in the sand, and it cannot be said that all points are satisfactory. In particular, generation of gas defects in castings due to accumulation of nitrogen, phosphorus or sulfur in sand, hygroscopicity of sand, and working environment are the most important problems to be solved, and improvement thereof is desired.
【０００４】[0004]
【課題を解決するための手段】本発明者らは前記問題点
を解決すべく鋭意研究の結果、鋳物砂に酸硬化性フラン
樹脂から成る結合剤と、リン酸、縮合リン酸、リン酸エ
ステル及びリン酸塩の群から選ばれる１種又は２種以上
のリン酸系化合物又はかかるリン酸系化合物及び芳香族
スルホン酸、脂肪族スルホン酸及び硫酸よりなる群から
選ばれる１種又は２種以上のスルホン酸系化合物を含有
する触媒を添加し、フラン樹脂を硬化させて砂型を製造
する際、得られる鋳型中の窒素％を一定値以下、好まし
くは窒素、リン％を一定の範囲内になる様調整すること
により、更に好ましくは窒素、リン、硫黄％を一定の範
囲内になる様調整することにより、ガス欠陥のない鋳造
品が得られるとの知見を得、更に、再生砂中或いは硬化
剤中の硫黄含量とリン含量の和に対する硫黄含量の比率
を一定の範囲となる様調製することにより、砂の吸湿性
及び作業環境の改善がなされるとの知見を得て、本発明
を完成するに至ったものである。Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have found that a binder composed of an acid-curing furan resin, a phosphoric acid, a condensed phosphoric acid, a phosphoric acid ester is used in a molding sand. And one or more kinds of phosphoric acid compounds selected from the group of phosphates, or one or more kinds selected from the group consisting of such phosphoric acid compounds and aromatic sulfonic acids, aliphatic sulfonic acids and sulfuric acid. When a sand mold is produced by curing a furan resin by adding a catalyst containing a sulfonic acid compound, the nitrogen% in the obtained mold is kept below a certain value, preferably nitrogen and phosphorus% are kept within a certain range. By adjusting the above, more preferably, nitrogen, phosphorus, and sulfur% are adjusted to fall within a certain range, and it was found that a cast product free of gas defects can be obtained. The sulfur content in the agent By adjusting the ratio of the sulfur content to the sum of the iron content within a certain range, it was found that the hygroscopicity of sand and the working environment can be improved, and the present invention has been completed. is there.
【０００５】即ち本発明は、繰り返し鋳型の製造に使用
される再生砂からなるか又は再生砂90重量部以上と新砂
10重量部以下からなる砂と、酸硬化性フラン樹脂からな
る結合剤と、リン酸、縮合リン酸、リン酸エステル及び
リン酸塩よりなる群から選ばれる１種又は２種以上のリ
ン酸系化合物を含有する触媒からなり、成型された鋳型
中の窒素含量が 0.3重量％以下であることを特徴とする
鋳型成型用砂組成物に関する。又本発明は、繰り返し鋳
型の製造に使用される再生砂からなるか又は再生砂90重
量部以上と新砂10重量部以下からなる砂に対し、酸硬化
性フラン樹脂からなる結合剤と、リン酸、縮合リン酸、
リン酸エステル及びリン酸塩よりなる群から選ばれる１
種又は２種以上のリン酸系化合物を含有する触媒とを添
加し、該フラン樹脂を硬化させる鋳物用砂型の製造に於
て、成型された鋳型中の窒素含量が 0.3重量％以下とな
る様再生砂を処理することを特徴とする鋳型の製造方法
に関する。更に本発明は、繰り返し鋳型の製造に使用さ
れる再生砂からなるか又は再生砂90重量部以上と新砂10
重量部以下からなる砂に対し、酸硬化性フラン樹脂から
なる結合剤と硬化剤とを添加し、該フラン樹脂を硬化さ
せて鋳物用砂型を製造する際に用いる硬化剤であって、
リン酸、縮合リン酸、リン酸エステル及びリン酸塩より
なる群から選ばれる１種又は２種以上のリン酸系化合物
と、芳香族スルホン酸、脂肪族スルホン酸及び硫酸より
なる群から選ばれる１種又は２種以上のスルホン酸系化
合物を含有し、かつ硬化剤中の硫黄含量／ (リン含量＋
硫黄含量) で表される重量比が、0.01以上、 0.7以下で
あることを特徴とする硬化剤組成物に関する。That is, the present invention consists of reclaimed sand which is used repeatedly in the manufacture of molds or which contains more than 90 parts by weight of reclaimed sand.
Sand consisting of 10 parts by weight or less, a binder consisting of an acid-curing furan resin, and one or more phosphoric acid-based compounds selected from the group consisting of phosphoric acid, condensed phosphoric acid, phosphoric acid esters and phosphates. It relates to a sand composition for molding, which comprises a catalyst containing a compound and has a nitrogen content in the molded mold of 0.3% by weight or less. Further, the present invention, for the sand consisting of reclaimed sand used in the production of repeated molds or consisting of 90 parts by weight or more of reclaimed sand and 10 parts by weight or less of fresh sand, a binder comprising an acid-curable furan resin, and phosphoric acid. , Condensed phosphoric acid,
1 selected from the group consisting of phosphate ester and phosphate
One kind or a catalyst containing two or more kinds of phosphoric acid compounds is added, and in the production of a sand mold for casting, in which the furan resin is hardened, the nitrogen content in the molded mold is set to 0.3% by weight or less. The present invention relates to a method for producing a mold, which comprises treating recycled sand. Further, the present invention comprises reclaimed sand used in the production of repetitive molds, or 90 parts by weight or more of reclaimed sand and 10 parts of fresh sand.
For sand consisting of parts by weight or less, a binder and a curing agent comprising an acid-curable furan resin are added, which is a curing agent used when curing the furan resin to produce a sand mold for casting,
One or more phosphoric acid compounds selected from the group consisting of phosphoric acid, condensed phosphoric acid, phosphoric acid ester and phosphate, and selected from the group consisting of aromatic sulfonic acid, aliphatic sulfonic acid and sulfuric acid. Contains one or more sulfonic acid compounds and contains sulfur in curing agent / (phosphorus content +
The curing agent composition is characterized in that the weight ratio represented by (sulfur content) is 0.01 or more and 0.7 or less.
【０００６】酸硬化性フラン樹脂を結合剤とし、これを
リン酸、縮合リン酸、リン酸エステル、リン酸塩から選
ばれる１種又は２種以上のリン酸系化合物又はかかるリ
ン酸系化合物及び芳香族スルホン酸、脂肪族スルホン酸
及び硫酸よりなる群から選ばれる１種又は２種以上のス
ルホン酸系化合物を含有する触媒により硬化させて鋳物
用砂型を製造する場合、本発明で規定する鋳型成型用組
成物、鋳型の製造方法及び鋳型成型用硬化剤組成物を用
いれば、作業環境が良好でガス欠陥のない十分実用性の
ある鋳造品が得られる。従来、このような再生砂及び新
砂の比率で粘結剤を用いて一定値以下の窒素含量の鋳型
成型用砂組成物、好ましくは一定の範囲内の窒素含量、
リン含量の鋳型成型用砂組成物、更に好ましくは一定の
範囲内の窒素含量、リン含量、硫黄含量の鋳型成型用砂
組成物、また、一定範囲内の硫黄含量／（リン含量＋硫
黄含量）で表される重量比の再生砂、硬化剤を使用し
て、造型、鋳込み、再生を繰り返し行う場合、作業環境
が良好でガス欠陥のない鋳造品が得られることは全く知
られていなかった。本発明の実施に当って成型された鋳
型中の窒素含量、リン含量及び硫黄含量を低下させて一
定の範囲内に窒素含量、リン含量及び硫黄含量を調整す
る様再生砂を処理する手段としては、鋳型成型に用いる
再生砂表面の機械的摩耗による再生方法、又は焙焼によ
る再生方法、又は水洗による再生方法等が公知であり、
特に限定されるものではない。An acid-curable furan resin is used as a binder, and one or more kinds of phosphoric acid compounds selected from phosphoric acid, condensed phosphoric acid, phosphoric acid ester, and phosphoric acid salt, or such phosphoric acid compounds and When a sand mold for casting is produced by curing with a catalyst containing one or more sulfonic acid compounds selected from the group consisting of aromatic sulfonic acids, aliphatic sulfonic acids and sulfuric acid, the mold specified in the present invention By using the molding composition, the method for producing a mold, and the curing agent composition for molding, a cast product having a good working environment and no gas defects can be obtained. Conventionally, a sand composition for molding with a nitrogen content of a certain value or less using a binder at a ratio of such recycled sand and new sand, preferably a nitrogen content within a certain range,
Molding sand composition with phosphorus content, more preferably nitrogen content, phosphorus content, sulfur content in molding sand composition within a certain range, and sulfur content within a certain range / (phosphorus content + sulfur content) It has not been known at all that it is possible to obtain a cast product having a good working environment and no gas defects when molding, casting, and recycling are repeated by using a recycled sand and a curing agent having a weight ratio represented by. As a means for treating the reclaimed sand to reduce the nitrogen content, phosphorus content and sulfur content in the molded mold to adjust the nitrogen content, phosphorus content and sulfur content within a certain range in carrying out the present invention, , A reclaiming method by mechanical abrasion of the reclaimed sand surface used for molding, a reclaiming method by roasting, or a reclaiming method by washing with water is known,
It is not particularly limited.
【０００７】本発明に使用する酸硬化性フラン樹脂とし
ては、フルフリルアルコール、フルフリルアルコール−
尿素樹脂、フルフリルアルコール−ホルムアルデヒド樹
脂、フルフリルアルコール−フェノール樹脂、フルフリ
ルアルコール−レゾルシノール樹脂、フルフリルアルコ
ール−メラミン樹脂、フルフリルアルコールポリマー等
の一種、又は二種以上が使用される。又、公知技術で知
られている種々の変性剤等と共に使用されても差し支え
ない。Examples of the acid-curable furan resin used in the present invention include furfuryl alcohol and furfuryl alcohol.
One or more of urea resin, furfuryl alcohol-formaldehyde resin, furfuryl alcohol-phenol resin, furfuryl alcohol-resorcinol resin, furfuryl alcohol-melamine resin, furfuryl alcohol polymer and the like are used. Further, it may be used together with various modifying agents known in the art.
【０００８】更に、鋳型強度をより向上させる目的でシ
ランカップリング剤を加えても差し支えない。シランカ
ップリング剤としては、例えばγ−（ 2−アミノ）アミ
ノプロピルメチルジメトキシシラン、γ−アミノプロピ
ルトリメトキシシラン、γ−アミノプロピルトリエトキ
シシラン、γ−グリシドキシプロピルトリメトキシシラ
ン等が挙げられる。Further, a silane coupling agent may be added for the purpose of further improving the mold strength. Examples of the silane coupling agent include γ- (2-amino) aminopropylmethyldimethoxysilane, γ-aminopropyltrimethoxysilane, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane and the like. ..
【０００９】本発明に用いられるリン酸、結合リン酸、
リン酸エステル及びリン酸塩の群から選ばれる１種又は
２種以上のリン酸系化合物又はかかるリン酸系化合物及
び芳香族スルホン酸、脂肪族スルホン酸及び硫酸よりな
る群から選ばれる１種又は２種以上のスルホン酸系化合
物を含有する触媒としては各種のものが例示されるが、
リン酸、縮合リン酸、又はメチルリン酸、エチルリン酸
等のリン酸エステル、リン酸カリウム、リン酸水素カリ
ウム等のリン酸塩の群から選ばれる１種又は２種以上の
化合物の単独又はメチルスルホン酸、エチルスルホン酸
等の脂肪族スルホン酸、ベンゼンスルホン酸、トルエン
スルホン酸、キシレンスルホン酸等のアルキル若しくは
アリールスルホン酸、フェノールスルホン酸等の芳香族
スルホン酸或いは硫酸との混合物が好ましい。更に、カ
ルボン酸等の有機酸、塩酸、硝酸等の無機酸との混合物
を使用してもなんら差し支えない。また、それらの使用
量は所望の硬化時間に合わせて適宜調整される。The phosphoric acid used in the present invention, bound phosphoric acid,
One or more phosphoric acid compounds selected from the group of phosphate esters and phosphates, or one selected from the group consisting of such phosphoric acid compounds and aromatic sulfonic acids, aliphatic sulfonic acids and sulfuric acid, or Examples of various catalysts containing two or more sulfonic acid compounds include
One or more compounds selected from the group consisting of phosphoric acid, condensed phosphoric acid, phosphoric acid esters such as methyl phosphoric acid and ethyl phosphoric acid, and phosphate salts such as potassium phosphate and potassium hydrogen phosphate, or methyl sulfone. A mixture with an acid, an aliphatic sulfonic acid such as ethyl sulfonic acid, an alkyl or aryl sulfonic acid such as benzene sulfonic acid, toluene sulfonic acid, xylene sulfonic acid, an aromatic sulfonic acid such as phenol sulfonic acid, or sulfuric acid is preferable. Further, a mixture with an organic acid such as carboxylic acid or an inorganic acid such as hydrochloric acid or nitric acid may be used. Further, the amount of those used is appropriately adjusted according to the desired curing time.
【００１０】耐火性粒状材料としては石英質を主成分と
する珪砂の他、クロマイト砂、ジルコン砂、オリビン
砂、アルミナサンド等の新砂若しくは再生砂が使用さ
れ、再生砂としては通常の機械的摩耗式或は焙焼式で得
られるものが使用されるが、摩耗式で再生されたものが
収率も高く、経済的に優れ、一般的であり好ましい。As the refractory granular material, in addition to silica sand containing quartz as a main component, new sand or reclaimed sand such as chromite sand, zircon sand, olivine sand, and alumina sand is used. The one obtained by the formula or the roasting type is used, but the one regenerated by the abrasion type has a high yield, is economically excellent, and is generally preferable.
【００１１】本発明による鋳型成型用砂組成物を使用し
て鋳型を製造するには、従来の常法に従って、まず砂 1
00部（重量基準、以下同じ）に対し、触媒 0.2〜３部を
混合し、次いでフラン樹脂 0.6〜５部を混合して成型す
るのが一般的であるが、この方法、順序に限定されるも
のではない。混合、成型、硬化温度としても特に加熱、
冷却の必要はなく、雰囲気温度により使用して差し支え
ない。また本発明の硬化触媒を使用するに際し、例えば
硬化を促進するための添加剤等従来公知の添加剤の使用
は一向に差し支えなく、本発明の範囲に含まれるもので
ある。In order to produce a mold using the sand composition for molding according to the present invention, sand is first prepared by a conventional method.
It is general that 0.2 to 3 parts of the catalyst is mixed with 00 parts (weight basis, the same applies hereinafter), and then 0.6 to 5 parts of the furan resin is mixed and molded, but this method and order are not limited. Not a thing. Mixing, molding, heating especially as curing temperature,
It does not need to be cooled and may be used depending on the ambient temperature. Further, when using the curing catalyst of the present invention, the use of conventionally known additives such as additives for promoting the curing can be used without any problem and are included in the scope of the present invention.
【００１２】以上のようにして再生砂、触媒及びフラン
樹脂の三者が添加混練され、その硬化後の鋳型中の窒素
含量は、再生砂に新たに添加されたフラン樹脂中の窒素
量及び残留したフラン樹脂による再生砂中の窒素量の和
として定められる。一方、鋳型中のリン含量は、再生砂
に新たに添加された触媒中のリン量及び残留した触媒に
よる再生砂中のリン量の和として定められる。更に、鋳
型中の硫黄含量は、再生砂に新たに添加された触媒中の
硫黄量及び残留した触媒による再生砂中の硫黄量の和と
して定められる。As described above, the recycled sand, the catalyst and the furan resin were added and kneaded, and the nitrogen content in the mold after curing was determined by the amount of nitrogen and the residual nitrogen in the furan resin newly added to the recycled sand. It is defined as the sum of nitrogen content in the reclaimed sand due to the furan resin. On the other hand, the phosphorus content in the mold is defined as the sum of the phosphorus content in the catalyst newly added to the reclaimed sand and the phosphorus content in the reclaimed sand due to the residual catalyst. Further, the sulfur content in the mold is defined as the sum of the amount of sulfur in the catalyst newly added to the regenerated sand and the amount of sulfur in the regenerated sand due to the remaining catalyst.
【００１３】鋳型中の窒素含量は 0.3重量％以下の範囲
が必要であり、 0.002重量％以上、0.22重量％以下の範
囲が好ましい。窒素含量が 0.3重量％を越えると注入さ
れた鋳鉄溶湯が鋳型の空間を充満していく過程に於て、
溶解するアンモニウム化合物（NH X )が増加し、凝固の
際に窒素ガスとして外部に排出された時の軌跡としてピ
ンホールが発生し易いため好ましくない。また窒素含量
を 0.002重量％未満にするには、フラン樹脂中の尿素樹
脂量の低減、樹脂の添加量の低減が必要であり、実用的
な鋳型強度が得られず、また更に強力な再生或は多量の
新砂補給が必要であり、経済的でないため好ましくな
い。The nitrogen content in the mold must be 0.3% by weight or less, preferably 0.002% by weight or more and 0.22% by weight or less. When the nitrogen content exceeds 0.3% by weight, the injected cast iron molten metal fills the space of the mold,
This is not preferable because the amount of the dissolved ammonium compound (NH x ) increases and pinholes are easily generated as a trace when the nitrogen gas is discharged to the outside during solidification. Further, in order to reduce the nitrogen content to less than 0.002% by weight, it is necessary to reduce the amount of urea resin in the furan resin and the amount of resin to be added, so that practical mold strength cannot be obtained, and more powerful regeneration or Is not preferable because it requires a large amount of fresh sand supply and is not economical.
【００１４】また上記の窒素含量の範囲に加えて、鋳型
中のリン含量は 0.8重量％以下が好ましく、 0.008重量
％以上、0.55重量％以下の範囲が更に好ましい。鋳型中
のリン含量が 0.8重量％を越えると鋳型溶湯界面反応に
より、リン化鉄を生成し、鋳物表面にあばた状の欠陥が
生じ、好ましくない。またリン含量を 0.008重量％未満
にするには、用いられる硬化用触媒の低減が必要であ
り、実用的な硬化速度及び鋳型強度が得られず、また更
に強力な再生或は多量の新砂補給が必要であり、経済的
でないため、好ましくない。In addition to the above range of nitrogen content, the phosphorus content in the mold is preferably 0.8% by weight or less, more preferably 0.008% by weight or more and 0.55% by weight or less. If the phosphorus content in the mold exceeds 0.8% by weight, iron phosphide is produced by the interfacial reaction of the mold melt, and pit-like defects are generated on the surface of the casting, which is not preferable. Further, in order to reduce the phosphorus content to less than 0.008% by weight, it is necessary to reduce the curing catalyst used, so that a practical curing rate and mold strength cannot be obtained, and more powerful regeneration or a large amount of fresh sand supply is required. It is necessary and not economical, so it is not preferable.
【００１５】更に上記の窒素含量及びリン含量の範囲に
加えて、スルホン酸系化合物を含有する触媒を用いた場
合の鋳型中の硫黄含量は 0.005重量％以上、 0.7重量％
以下の範囲が更に好ましい。鋳型中の硫黄含量が 0.7重
量％を越えると溶湯により熱分解して生成する多量のSO
X ガスが作業環境を著しく悪化するため好ましくない。
また硫黄含量を 0.005重量％未満にするには、用いられ
る硬化剤の低減が必要であり、実用的な硬化速度及び鋳
型強度が得られず、また更に強力な再生或は多量の新砂
補給が必要であり、経済的でないため、好ましくない。Further, in addition to the above ranges of nitrogen content and phosphorus content, the sulfur content in the template when a catalyst containing a sulfonic acid compound is used is 0.005% by weight or more, 0.7% by weight or more.
The following range is more preferable. When the sulfur content in the mold exceeds 0.7% by weight, a large amount of SO is generated by thermal decomposition by the molten metal.
X gas is not preferable because it significantly deteriorates the working environment.
Further, in order to reduce the sulfur content to less than 0.005% by weight, it is necessary to reduce the amount of curing agent used, and it is not possible to obtain a practical curing rate and mold strength, and more powerful regeneration or replenishment of a large amount of fresh sand is required. It is not preferable because it is not economical.
【００１６】触媒としてスルホン酸系／リン酸系を併用
した場合の再生砂中の硫黄含量／ (リン含量＋硫黄含
量) で表される重量比は、0.005 以上、 0.5以下の範囲
が好ましく、0.01以上、 0.4以下の範囲が更に好まし
い。再生砂中の上記重量比が 0.005未満であると再生砂
の吸湿が激しく著しく鋳型の硬化を阻害し、好ましくな
い。また、再生砂中の上記重量比が 0.5を越えると硫黄
系熱分解ガスが多量に生成し作業環境が著しく悪化し、
好ましくない。The weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the reclaimed sand when a sulfonic acid-based / phosphoric acid-based catalyst is used in combination is preferably 0.005 or more and 0.5 or less, 0.01 The range of 0.4 or less is more preferable. If the above-mentioned weight ratio in the reclaimed sand is less than 0.005, the reclaimed sand will be highly absorbed by moisture and will significantly impede the hardening of the mold, which is not preferable. Further, if the above weight ratio in the reclaimed sand exceeds 0.5, a large amount of sulfur-based pyrolysis gas is generated and the working environment deteriorates significantly,
Not preferable.
【００１７】好ましい範囲としては、硬化剤中の硫黄含
量／ (リン含量＋硫黄含量) で表される重量比は、0.01
以上、 0.7以下の範囲が好ましく、0.03以上、 0.6以下
の範囲が更に好ましい。硬化剤中の上記重量比が0.01未
満であると再生砂の吸湿が激しく著しく鋳型の硬化を阻
害し、好ましくない。また、再生砂中の上記重量比が0.
7を越えると作業環境が著しく悪化し、好ましくない。As a preferable range, the weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the curing agent is 0.01
The above range is preferably 0.7 or less, more preferably 0.03 or more and 0.6 or less. If the above weight ratio in the curing agent is less than 0.01, the regenerated sand will be soaked up in moisture and will significantly impede the curing of the mold, which is not preferable. The weight ratio in the reclaimed sand is 0.
If it exceeds 7, the working environment is significantly deteriorated, which is not preferable.
【００１８】フラン樹脂及び触媒の砂に対する必要配合
量は要求される鋳型の強度により決定されるので、鋳型
中の窒素含量を 0.3重量％以下、リン含量を 0.8重量％
以下及び硫黄含量を 0.7重量％以下にするためには、上
記の窒素量、リン量及び硫黄量の分析により再生砂中の
窒素含有量、リン含有量及び硫黄含量を管理し、再生砂
が繰返し使用されて仮に鋳型中の窒素含量、リン含量及
び硫黄含量が限度を越えた場合には、更に繰返し再生
（１台の再生機では２パス以上で、又は数台の再生機を
直列に連結して砂を再生する）或は焙焼再生により再生
砂中の窒素含量、リン含量及び硫黄含量を低減するか、
又窒素含有量の更に低い樹脂及びリン含有量或は硫黄含
有量の更に低い触媒を用いる等により鋳型中の窒素含
量、リン含量及び硫黄含量を低減させれば良い。Since the required blending amount of furan resin and catalyst with respect to sand is determined by the required strength of the mold, the nitrogen content in the mold is 0.3% by weight or less and the phosphorus content is 0.8% by weight.
In order to keep the sulfur content below 0.7% by weight and below, the nitrogen content, phosphorus content and sulfur content in the reclaimed sand should be controlled by analyzing the above nitrogen content, phosphorus content and sulfur content, and the reclaimed sand should be repeatedly used. If the nitrogen content, phosphorus content, and sulfur content in the mold exceed the limits when used, repeat regeneration (one regenerator with two or more passes, or several regenerators connected in series). Regenerate the sand) or reduce the nitrogen content, phosphorus content and sulfur content in the reclaimed sand by roasting regeneration,
The nitrogen content, phosphorus content and sulfur content in the mold may be reduced by using a resin having a lower nitrogen content and a catalyst having a lower phosphorus content or a lower sulfur content.
【００１９】[0019]
【実施例】以下、実施例により本発明を詳細に説明する
が、本発明はこれらの実施例のみに限定されるものでは
ない。尚、実施例及び比較例中の％は重量％を示す。自
硬性鋳型造型法において、各鋳型中の窒素含量、リン含
量、硫黄含量及びガス欠陥について評価した。実施例１ 後述の再生砂の調整方法で得られた砂中窒素含量が0.12
％、リン含量が0.28％の再生砂 100重量部に対し、85％
濃度のリン酸を0.36重量部加え、次いで樹脂中の窒素含
量が 1.0％であるフラン樹脂を 0.8重量部添加混練して
なる混合砂を用い、鋳型中の窒素含量が0.13％、リン含
量が0.37％なる大同式ドーナツ型試験鋳型を作製し、こ
の鋳型に注湯して得られた鋳造品につき液体浸透探傷法
によりガス欠陥の発生個数を測定した。その結果を表１
に示す。EXAMPLES The present invention will be described in detail below with reference to examples, but the present invention is not limited to these examples. In the examples and comparative examples,% means% by weight. In the self-hardening mold making method, nitrogen content, phosphorus content, sulfur content and gas defects in each mold were evaluated. Example 1 The nitrogen content in the sand obtained by the method for adjusting recycled sand described below is 0.12.
%, Phosphorus content is 0.28%, 85% against 100 parts by weight of reclaimed sand
0.36 parts by weight of phosphoric acid at a concentration was added, and then 0.8 parts by weight of furan resin having a nitrogen content of 1.0% was added and kneaded. Using a mixed sand, the nitrogen content in the mold was 0.13% and the phosphorus content was 0.37%. % Of the same type of donut type test mold was prepared, and the number of gas defects generated was measured by the liquid penetration flaw detection method for the cast product obtained by pouring the mold into the mold. The results are shown in Table 1.
Shown in.
【００２０】ガス欠陥の発生個数を測定する「液体浸透
探傷法」の概要は、下記の通りである。 1)前処理 ： 洗浄液により試験品の表面を清浄にす
る。 2)浸透処理： 試験面に浸透液のスプレーを塗布し、十
分に濡らす。 3)洗浄処理： 20分の浸透時間経過後、洗浄液により欠
陥以外の試験面に付着している余剰の浸透液を除去す
る。 4)現像処理： 洗浄処理の終わった試験面に現像液を塗
布し、欠陥中に残留している浸透液を試験面に吸い出
す。 5)観察 ： 現像処理によってできた支持模様を目視
によって観察する。The outline of the "liquid permeation flaw detection method" for measuring the number of generated gas defects is as follows. 1) Pretreatment: Clean the surface of the test sample with a cleaning solution. 2) Penetration treatment: Apply a penetrant spray to the test surface and fully wet it. 3) Cleaning treatment: After the lapse of 20 minutes of infiltration time, the excess infiltration liquid adhering to the test surface other than the defect is removed by the cleaning liquid. 4) Development treatment: Apply the developing solution to the test surface that has been washed, and suck out the penetrant solution remaining in the defect to the testing surface. 5) Observation: Visually observe the supporting pattern formed by the development process.
【００２１】実施例２〜10 実施例１と同様に所定の窒素含量、リン含量の再生砂に
所定のリン含量の触媒、及び所定の窒素含量のフラン樹
脂を添加混練してなる混合砂を用い、鋳型中の窒素含
量、リン含量を表１に示した如くの値に設定し、大同式
ドーナツ型試験鋳型を作製し、この鋳型に注湯して得ら
れた鋳造品につき実施例１と同様に液体浸透探傷法によ
りガス欠陥の発生個数を測定した。その結果を表１に示
す。 Examples 2 to 10 As in Example 1, mixed sand prepared by adding and kneading regenerated sand having a predetermined nitrogen content and phosphorus content with a catalyst having a predetermined phosphorus content and a furan resin having a predetermined nitrogen content was used. The nitrogen content and phosphorus content in the mold were set to the values shown in Table 1, a doughnut-type test mold of the Daido formula was prepared, and the casting product obtained by pouring the mold into the mold was the same as in Example 1. The number of generated gas defects was measured by the liquid penetrant inspection method. The results are shown in Table 1.
【００２２】比較例１ 後述の再生砂の調製方法で得られた砂中の窒素含量が0.
26％、リン含量が0.48％の再生砂 100重量部に対し、85
％濃度のリン酸を0.36重量部加え、次いで樹脂中の窒素
含量が 6.0％のフラン樹脂を 0.8重量部添加混練してな
る混合砂を用い、鋳型中の窒素含量が0.31％、リン含量
が0.58％なる大同式ドーナツ型試験鋳型を作製し、この
鋳型に注湯して得られた鋳造品につき液体浸透探傷法に
よりガス欠陥の発生個数を測定した。その結果を表１に
示す。 Comparative Example 1 The nitrogen content in the sand obtained by the method for preparing reclaimed sand described below is 0.
85% against 100 parts by weight of reclaimed sand with 26% and phosphorus content of 0.48%
% Of phosphoric acid was added, and then 0.8 parts by weight of furan resin having a nitrogen content of 6.0% was added and kneaded. Using a mixed sand, the nitrogen content of the mold was 0.31% and the phosphorus content was 0.58. % Of the same type of donut type test mold was prepared, and the number of gas defects generated was measured by the liquid penetration flaw detection method for the cast product obtained by pouring the mold into the mold. The results are shown in Table 1.
【００２３】比較例２〜３ 比較例１と同様に所定の窒素含量、リン含量の再生砂に
所定のリン含量の硬化剤、及び所定の窒素含量のフラン
樹脂を添加混練してなる混合砂を用い、鋳型中の窒素含
量、リン含量を表１にに示した如くの値に設定し、大同
式ドーナツ型試験鋳型を作製し、この鋳型に注湯して得
られた鋳造品につき実施例１と同様に液体浸透探傷法に
よりガス欠陥の発生個数を測定した。その結果を表１に
示す。尚、大同式ドーナツ型試験鋳型の形状は図１、図
２及び図３に示す如く、中空円状のドーナツ上に40mmφ
のゲート１と90mmφのライザー２が同心円状に取付けら
れている。 Comparative Examples 2-3 As in Comparative Example 1, mixed sand prepared by adding and kneading a regenerated sand having a predetermined nitrogen content and a phosphorus content with a curing agent having a predetermined phosphorus content and a furan resin having a predetermined nitrogen content was used. Using a nitrogen content and a phosphorus content in the mold set to the values shown in Table 1, a doughnut type test mold of Daido formula was prepared, and a casting product obtained by pouring the mold into the mold was used. Similarly to the above, the number of generated gas defects was measured by the liquid penetration flaw detection method. The results are shown in Table 1. The shape of the Daido-style donut type test mold is 40 mmφ on a hollow circular donut as shown in FIGS. 1, 2 and 3.
The gate 1 and the 90mmφ riser 2 are mounted concentrically.
【００２４】[0024]
【表１】 [Table 1]
【００２５】実施例11〜13 比較例１で用いた再生砂を繰返し再生させて大同式ドー
ナツ型試験鋳型を作製し、この鋳型に注湯して得られた
鋳造品について、液体浸透探傷法によりガス欠陥の発生
個数を測定した。その結果を表２に示す。 Examples 11 to 13 The reclaimed sand used in Comparative Example 1 was repeatedly regenerated to prepare a Daido-type donut type test mold, and the casting product obtained by pouring the mold into the mold was subjected to a liquid permeation flaw detection method. The number of generated gas defects was measured. The results are shown in Table 2.
【００２６】[0026]
【表２】 [Table 2]
【００２７】実施例14 後述の再生砂の調整方法で得られた砂中窒素含量が0.12
％、リン含量が0.31％及び硫黄含量が0.30％の再生砂 1
00重量部に対し、トルエンスルホン酸12.5％、ベンゼン
スルホン酸20.0％、P2O5として40.0％を含有する硬化剤
を0.36重量部加え、次いで樹脂中の窒素含量が 1.0％で
あるフラン樹脂を 0.8重量部添加混練してなる混合砂を
用い、鋳型中の窒素含量が0.13％、リン含量が0.37％、
硫黄含量が0.32％なる大同式ドーナツ型試験鋳型を作製
し、この鋳型に注湯して得られた鋳造品につき液体浸透
探傷法によりガス欠陥の発生個数を測定した。その結果
を表３に示す。 Example 14 The nitrogen content in the sand obtained by the method for adjusting recycled sand described below is 0.12.
%, Phosphorus content 0.31% and sulfur content 0.30% reclaimed sand 1
0.36 parts by weight of a curing agent containing 12.5% of toluenesulfonic acid, 20.0% of benzenesulfonic acid, and 40.0% of P 2 O 5 is added to 00 parts by weight, and then a furan resin having a nitrogen content of 1.0% in the resin is added. Using 0.8 parts by weight of added sand and kneading, the content of nitrogen in the mold is 0.13%, phosphorus content is 0.37%,
A Daido-type donut type test mold having a sulfur content of 0.32% was prepared, and the number of gas defects generated in the cast product obtained by pouring the mold into the mold was measured by a liquid permeation flaw detection method. The results are shown in Table 3.
【００２８】実施例15〜23 実施例14と同様に所定の窒素含量、リン含量、硫黄含量
の再生砂に所定量のスルホン酸系化合物及びリン酸系化
合物を含有する硬化剤、及び所定の窒素含量のフラン樹
脂を添加混練してなる混合砂を用い、鋳型中の窒素含
量、リン含量及び硫黄含量を表３に示した如くの値に設
定し、大同式ドーナツ型試験鋳型を作製し、この鋳型に
注湯して得られた鋳造品につき実施例１と同様に液体浸
透探傷法によりガス欠陥の発生個数を測定した。その結
果を表３に示す。 Examples 15 to 23 As in Example 14, a curing agent containing a predetermined amount of a sulfonic acid compound and a phosphoric acid compound in regenerated sand having a predetermined nitrogen content, phosphorus content, and sulfur content, and a predetermined nitrogen content. Using the mixed sand obtained by adding and kneading the furan resin of the content, the nitrogen content, the phosphorus content and the sulfur content in the mold were set to the values as shown in Table 3 to prepare a Daido donut type test mold. With respect to the cast product obtained by pouring the molten metal into the mold, the number of gas defects generated was measured by the liquid permeation flaw detection method as in Example 1. The results are shown in Table 3.
【００２９】比較例４ 後述の再生砂の調製方法で得られた砂中の窒素含量が0.
32％、リン含量が０．５９％、硫黄含量が０．５５％の
再生砂 100重量部に対し、メタンスルホン酸 5.0％、ト
ルエンスルホン酸20.0％、P2O5として40.0％を含有する
硬化剤を0.36重量部加え、次いで樹脂中の窒素含量が
6.0％のフラン樹脂を 0.8重量部添加混練してなる混合
砂を用い、鋳型中の窒素含量が0.37％、リン含量が0.65
％、硫黄含量が0.57％なる大同式ドーナツ型試験鋳型を
作製し、この鋳型に注湯して得られた鋳造品につき液体
浸透探傷法によりガス欠陥の発生個数を測定した。その
結果を表３に示す。 Comparative Example 4 The nitrogen content in the sand obtained by the method for preparing reclaimed sand described below is 0.
Hardening containing 5.0% methanesulfonic acid, 20.0% toluenesulfonic acid and 40.0% as P 2 O 5 per 100 parts by weight of reclaimed sand with 32%, phosphorus content 0.59%, sulfur content 0.55% 0.36 parts by weight of the agent was added, and then the nitrogen content in the resin
0.8% by weight of 6.0% furan resin was added and kneaded, and mixed sand was used. The nitrogen content in the mold was 0.37% and the phosphorus content was 0.65.
%, And a sulfur content of 0.57%, a Daido-style donut type test mold was prepared, and the number of gas defects generated was measured by a liquid penetrant flaw detection method for the casting product obtained by pouring the melt into the mold. The results are shown in Table 3.
【００３０】比較例５〜６ 比較例４と同様に所定の窒素含量、リン含量、硫黄含量
の再生砂に所定のスルホン酸系化合物及びリン酸系化合
物を含有する硬化剤、及び所定の窒素含量のフラン樹脂
を添加混練してなる混合砂を用い、鋳型中の窒素含量、
リン含量、硫黄含量を表３にに示した如くの値に設定
し、大同式ドーナツ型試験鋳型を作製し、この鋳型に注
湯して得られた鋳造品につき実施例１と同様に液体浸透
探傷法によりガス欠陥の発生個数を測定した。その結果
を表３に示す。 Comparative Examples 5 to 6 As in Comparative Example 4, a curing agent containing predetermined sulfonic acid compounds and phosphoric acid compounds in reclaimed sand having predetermined nitrogen content, phosphorus content and sulfur content, and predetermined nitrogen content. Nitrogen content in the mold, using the mixed sand made by adding and kneading the furan resin
The phosphorus content and sulfur content were set to the values shown in Table 3, a doughnut-type test mold of the same type was prepared, and the casting product obtained by pouring the mold into the mold was liquid-penetrated in the same manner as in Example 1. The number of generated gas defects was measured by the flaw detection method. The results are shown in Table 3.
【００３１】[0031]
【表３】 [Table 3]
【００３２】実施例24〜26 比較例４で用いた再生砂を繰返し再生させて大同式ドー
ナツ型試験鋳型を作製し、この鋳型に注湯して得られた
鋳造品について、液体浸透探傷法によりガス欠陥の発生
個数を測定した。その結果を表４に示す。 Examples 24 to 26 The reclaimed sand used in Comparative Example 4 was repeatedly regenerated to prepare a Daido-type donut type test mold, and the casting product obtained by pouring the mold into the mold was subjected to a liquid permeation flaw detection method. The number of generated gas defects was measured. The results are shown in Table 4.
【００３３】[0033]
【表４】 [Table 4]
【００３４】実施例27 後述の再生砂の調整方法で得られた砂中窒素含量が0.04
％、リン含量が0.09％、硫黄含量が0.09％の再生砂 100
重量部に対し、フェノールスルホン酸10.5％、硫酸 9.4
％、P2O5として22.9％を含有する硬化剤を0.36重量部加
え、次いで樹脂中の窒素含量が 1.0％であるフラン樹脂
を 0.8重量部添加混練してなる混合砂を用い、鋳型中の
窒素含量が0.05％、リン含量が0.13％、硫黄含量が0.11
％なるチェーンホイール試験鋳型を作製し、この鋳型に
注湯して得られた鋳造品につき液体浸透探傷法によりガ
ス欠陥の発生個数を測定した。その結果を表５に示す。 Example 27 The nitrogen content in the sand obtained by the method for preparing reclaimed sand described below is 0.04.
%, Phosphorus content 0.09%, sulfur content 0.09% recycled sand 100
Phenolsulfonic acid 10.5%, sulfuric acid 9.4
%, 0.36 parts by weight of a curing agent containing 22.9% as P 2 O 5 , and then 0.8 parts by weight of a furan resin having a nitrogen content of 1.0% is added and kneaded. Nitrogen content 0.05%, phosphorus content 0.13%, sulfur content 0.11
% Of the chain wheel was prepared, and the number of gas defects generated was measured by the liquid permeation flaw detection method for the cast product obtained by pouring the mold into the mold. The results are shown in Table 5.
【００３５】実施例28〜41 実施例27と同様に所定の窒素含量、リン含量、硫黄含量
の再生砂に所定のスルホン酸系化合物及びリン酸系化合
物を含有する硬化剤、及び所定の窒素含量のフラン樹脂
を添加混練してなる混合砂を用い、鋳型中の窒素含量、
リン含量を表５に示した如くの値に設定し、チェーンホ
イール試験鋳型を作製し、この鋳型に注湯して得られた
鋳型品につき実施例１と同様に液体浸透探傷法によりガ
ス欠陥の発生個数を測定した。その結果を表５に示す。 Examples 28 to 41 As in Example 27, a regenerated sand having a predetermined nitrogen content, a phosphorus content and a sulfur content, a curing agent containing a predetermined sulfonic acid compound and a phosphoric acid compound, and a predetermined nitrogen content. Nitrogen content in the mold, using the mixed sand made by adding and kneading the furan resin
The phosphorus content was set to a value as shown in Table 5, a chain wheel test mold was prepared, and the mold product obtained by pouring the mold into the mold was examined for gas defects by the liquid permeation flaw detection method as in Example 1. The number of occurrences was measured. The results are shown in Table 5.
【００３６】[0036]
【表５】 [Table 5]
【００３７】実施例42 後述の再生砂の調整方法で得られた砂中の窒素含量が0.
21％、リン含量が0.17％、硫黄含量が0.14％の再生砂 1
00重量部に対し、硫酸15.0％、キシレンスルホン酸29.7
％、P2O5として22.9％を含有する硬化剤を0.36重量部加
え、次いで樹脂中の窒素含量が 6.0％のフラン樹脂を
0.8重量部添加混練してなる混合砂を用い、鋳型中の窒
素含量が0.26％、リン含量が0.21％、硫黄含量が0.18％
なるチェーンホイール試験鋳型を作製し、この鋳型に注
湯して得られた鋳造品につき液体浸透探傷法によりガス
欠陥の発生個数を測定した。その結果を表６に示す。 Example 42 The nitrogen content in the sand obtained by the method for adjusting reclaimed sand described below is 0.
Reclaimed sand with 21%, phosphorus content 0.17%, sulfur content 0.14% 1
Sulfuric acid 15.0%, xylene sulfonic acid 29.7 based on 00 parts by weight
%, And 0.36 part by weight of a curing agent containing 22.9% as P 2 O 5 , and then a furan resin having a nitrogen content of 6.0% in the resin was added.
Using 0.8 parts by weight of mixed sand, kneaded, nitrogen content in the mold is 0.26%, phosphorus content is 0.21%, sulfur content is 0.18%
The following chain wheel test mold was prepared, and the number of gas defects generated was measured by a liquid penetration flaw detection method for the cast product obtained by pouring the mold into the mold. The results are shown in Table 6.
【００３８】実施例43〜48、比較例７〜12 実施例42と同様に所定の窒素含量、リン含量、硫黄含量
の再生砂に所定のスルホン酸系化合物及びリン酸系化合
物を含有する硬化剤、及び所定の窒素含量のフラン樹脂
を添加混練してなる混合砂を用い、鋳型中の窒素含量、
リン含量、硫黄含量を表６に示した如くの値に設定し、
チェーンホイール試験鋳型を作製し、この鋳型に注湯し
て得られた鋳造品につき実施例１と同様に液体浸透探傷
法によりガス欠陥の発生個数を測定した。その結果を表
６に示す。尚、チェーンホイール試験鋳型の形状は図３
に示す。 Examples 43 to 48 and Comparative Examples 7 to 12 A curing agent containing regenerated sand having a predetermined nitrogen content, a phosphorus content and a sulfur content and containing a predetermined sulfonic acid compound and phosphoric acid compound as in Example 42. , And a mixed sand obtained by adding and kneading a furan resin having a predetermined nitrogen content, the nitrogen content in the mold,
Set the phosphorus content and sulfur content to the values shown in Table 6,
A chain wheel test mold was prepared, and the cast product obtained by pouring the mold into the mold was measured for the number of gas defects generated by the liquid permeation flaw detection method as in Example 1. The results are shown in Table 6. The shape of the chain wheel test mold is shown in Fig. 3.
Shown in.
【００３９】[0039]
【表６】 [Table 6]
【００４０】実施例49 珪砂 100重量部に対し、トルエンスルホン酸35.0％、メ
タンスルホン酸 2.7％、硫酸20.0％、P2O5として15.3％
を含有する硬化剤を0.33重量部加え、次いで樹脂中の窒
素含量が 2.5％のフラン樹脂を0.65重量部添加混練して
なる混合砂を用い鋳型を作製し、熔湯／鋳型の重量比が
2.5の鋳物を鋳造し回収した砂をクラッシャーにかけ、
日本鋳造（株）製Ｍ型ロータリークレーマーを用いて再
生し、次いでその再生砂95重量部と新砂５重量部に対
し、上記樹脂、硬化剤を加え鋳型の作製、鋳造、回収、
再生のサイクルを20回繰り返し、20回目の鋳造時に作業
環境を測定した。その労働安全衛生法の管理区分結果を
表７に示す。また、上記20回目の再生砂を25℃、90％RH
の環境に24時間放置後、再生砂の吸湿量を後述の再生砂
の吸湿量の測定方法に基づき測定した。更に、上記の吸
湿した再生砂を用いて鋳型の圧縮強度を測定した。その
結果を表７に示す。 Example 49 To 100 parts by weight of silica sand, 35.0% toluenesulfonic acid, 2.7% methanesulfonic acid, 20.0% sulfuric acid and 15.3% as P 2 O 5
0.33 parts by weight of a curing agent containing, and then 0.65 parts by weight of a furan resin having a nitrogen content of 2.5% in the resin was mixed and kneaded to prepare a mold, and the weight ratio of the melt / the mold was
Cast 2.5 castings and crush the recovered sand,
It was regenerated by using M type rotary clay maker manufactured by Nippon Foundry Co., Ltd., and then 95 parts by weight of the regenerated sand and 5 parts by weight of the new sand were added with the above resin and curing agent to prepare a mold, cast, collect,
The regeneration cycle was repeated 20 times, and the working environment was measured during the 20th casting. Table 7 shows the management classification results of the Industrial Safety and Health Act. In addition, the above-mentioned 20th reclaimed sand at 25 ℃, 90% RH
After being left in this environment for 24 hours, the moisture absorption of the reclaimed sand was measured based on the method for measuring the moisture absorption of the reclaimed sand described below. Further, the compressive strength of the mold was measured by using the regenerated sand that had absorbed moisture. The results are shown in Table 7.
【００４１】実施例50〜54、比較例13〜14 実施例49と同様にして再生砂の吸湿量、作業環境測定、
及び圧縮強度を測定した。その結果を表７に示す。In the same manner as in Examples 50 to 54 and Comparative Examples 13 to 14, Example 49, the moisture absorption amount of the reclaimed sand, the work environment measurement,
And the compressive strength was measured. The results are shown in Table 7.
【００４２】[0042]
【表７】 [Table 7]
【００４３】再生砂の調製方法 新砂或いは再生砂、樹脂、酸性硬化触媒を用いて造型し
た鋳型を用い、鋳造し回収した砂をクラッシャーにか
け、日本鋳造（株）製Ｍ型ロータリーリクレマーを用い
て再生した。又、各表に示すように、各種再生砂の窒素
含量、リン含量、硫黄含量の値については上記のロータ
リーリクレマーを用いてパス回数を調整して得られたも
のを使用した。 Preparation Method of Reclaimed Sand Using a mold molded using new sand or recycled sand, resin, and an acid hardening catalyst, the sand recovered by casting is put into a crusher, and an M type rotary reclaimer manufactured by Nippon Foundry Co., Ltd. is used. Replayed. Further, as shown in each table, regarding the values of nitrogen content, phosphorus content, and sulfur content of each reclaimed sand, those obtained by adjusting the number of passes using the rotary reclaimer were used.
【００４４】鋳型中及び再生砂中の窒素含量 (窒素％)
の測定方法 鋳型砂或いは再生砂を 150メッシュ以下に微粉砕したも
のを試料とし、ケルダール窒素分析法にて測定した。鋳型中及び再生砂中のリン含量 (リン％) の測定方法 鋳型砂或いは再生砂を 150メッシュ以下に微粉砕したも
のを試料とし、 ICP（誘導結合プラズマ発光分析装置）
にて測定した。鋳型中及び再生砂中の硫黄含量 (硫黄％) の測定方法 鋳型砂或いは再生砂を 150メッシュ以下に微粉砕したも
のを試料とし、燃焼中和滴定法にて測定した。 Nitrogen content (nitrogen%) in the mold and in the reclaimed sand
Method of measurement Mold sand or reclaimed sand was finely pulverized to 150 mesh or less and used as a sample for measurement by the Kjeldahl nitrogen analysis method. Method for measuring phosphorus content (phosphorus%) in mold and reclaimed sand ICP (inductively coupled plasma optical emission spectrometer) using mold sand or reclaimed sand pulverized to 150 mesh or less
It was measured at. Method for measuring the sulfur content (sulfur%) in the mold and reclaimed sand A sample of finely ground mold sand or reclaimed sand to 150 mesh or less was used as a sample and measured by the combustion neutralization titration method.
【００４５】樹脂中の窒素含量 (窒素％) の測定方法 ケルダール窒素分析法にて測定した。硬化剤中のリン含量 (リン％) の測定方法 ICP（誘導結合プラズマ発光分析装置）にて測定した。硬化剤中の硫黄含量 (硫黄％) の測定方法 燃焼中和滴定法にて測定した。 Method for measuring nitrogen content (nitrogen%) in the resin The Kjeldahl nitrogen analysis method was used. Method of measuring phosphorus content (phosphorus%) in the curing agent It was measured by ICP (inductively coupled plasma emission spectrometer). Method for measuring sulfur content (sulfur%) in the curing agent It was measured by combustion neutralization titration method.
【００４６】再生砂の吸湿量の測定方法 供試再生砂を 105℃の乾燥炉に１時間放置後、デシケー
ター中で25℃まで冷却し以下の式により再生砂の吸湿量
を測定した。 Method for measuring moisture absorption of reclaimed sand The test reclaimed sand was left in a drying oven at 105 ° C for 1 hour, cooled to 25 ° C in a desiccator, and the moisture absorption of the reclaimed sand was measured by the following formula.
【００４７】[0047]
【数１】 [Equation 1]
【００４８】[0048]
【発明の効果】本発明の鋳型成型用砂組成物、鋳型の製
造方法及び鋳型成型用硬化剤組成物は、以上述べたよう
に窒素を含有するフラン樹脂とリン酸、縮合リン酸、リ
ン酸エステル及びリン酸塩よりなる群から選ばれる１種
又は２種以上のリン酸系化合物及び／又は芳香族スルホ
ン酸、脂肪族スルホン酸等の有機スルホン酸、硫酸等の
群から選ばれる１種又は２種以上のスルホン酸系化合物
を含有する触媒を用い、且つ再生砂に残留する窒素含
量、リン含量、硫黄含量を低減させることにより、鋳型
を造型する際に新たに添加されるフラン樹脂の窒素量及
び触媒のリン量、硫黄量と、使用する再生砂中に残留し
ていた窒素量、リン量及び硫黄量との和によって決定さ
れる鋳型中の窒素含量、好ましくは窒素含量及びリン含
量、更に好ましくは窒素含量、リン含量及び硫黄含量を
一定の範囲内に調整してなることを特徴とするもので、
作業環境が良好で、得られる鋳造品のガス欠陥の発生が
大幅に減少し、健全な鋳物が製造でき、実用上非常に有
益なものとなる。As described above, the sand composition for molding a mold, the method for producing a mold, and the curing agent composition for molding a furan resin containing nitrogen and phosphoric acid, condensed phosphoric acid, or phosphoric acid as described above. One or more phosphoric acid compounds selected from the group consisting of esters and phosphates and / or one or more selected from the group consisting of organic sulfonic acids such as aromatic sulfonic acids and aliphatic sulfonic acids, and sulfuric acid; By using a catalyst containing two or more sulfonic acid compounds and reducing the nitrogen content, phosphorus content, and sulfur content remaining in the reclaimed sand, the nitrogen of the furan resin newly added when molding the mold And the phosphorus content of the catalyst, the sulfur content, and the nitrogen content in the mold, preferably the nitrogen content and the phosphorus content, which are determined by the sum of the nitrogen content remaining in the reclaimed sand used, the phosphorus content and the sulfur content. More preferably Element content, that the phosphorus content and sulfur content becomes adjusted within a certain range as it is characterized,
The working environment is good, the generation of gas defects in the obtained casting is significantly reduced, and a sound casting can be produced, which is very useful in practice.
【図１】大同式ドーナツ型試験鋳型の試験片の形状を示
す平面図である。FIG. 1 is a plan view showing the shape of a test piece of a Daido donut type test mold.
【図２】大同式ドーナツ型試験鋳型の試験片の形状を示
す正面図である。FIG. 2 is a front view showing the shape of a test piece of the Daido-style donut type test mold.
【図３】大同式ドーナツ型試験鋳型の試験片の形状を示
す右側面図である。FIG. 3 is a right side view showing the shape of a test piece of the Daido-style donut type test mold.
【図４】チェーンホイール型試験鋳型の形状を示す平面
図である。FIG. 4 is a plan view showing the shape of a chain wheel type test mold.
１ ゲート ２ ライザー ３ 上型 ４ 下型 1 Gate 2 Riser 3 Upper mold 4 Lower mold
───────────────────────────────────────────────────── フロントページの続き (72)発明者 加藤 雅之 愛知県豊橋市富士見台６−２−１ (72)発明者 水野 渉 愛知県豊橋市中浜町182 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Masayuki Kato 6-2-1 Fujimidai, Toyohashi City, Aichi Prefecture (72) Inventor Wataru Mizuno 182 Nakahama Town, Toyohashi City, Aichi Prefecture
Claims (16)
からなるか又は再生砂90重量部以上と新砂10重量部以下
からなる砂と、酸硬化性フラン樹脂からなる結合剤と、
リン酸、縮合リン酸、リン酸エステル及びリン酸塩より
なる群から選ばれる１種又は２種以上のリン酸系化合物
を含有する触媒からなり、成型された鋳型中の窒素含量
が 0.3重量％以下であることを特徴とする鋳型成型用砂
組成物。1. Sand comprising reclaimed sand used in the production of repetitive molds or comprising 90 parts by weight or more of reclaimed sand and 10 parts by weight or less of fresh sand, and a binder comprising an acid-curing furan resin.
It consists of a catalyst containing one or more phosphoric acid compounds selected from the group consisting of phosphoric acid, condensed phosphoric acid, phosphoric acid esters and phosphates, and the nitrogen content in the molded mold is 0.3% by weight. The following is a sand composition for molding.
量％以上、0.22重量％以下であることを特徴とする請求
項１記載の鋳型成型用砂組成物。2. The sand composition for molding according to claim 1, wherein the nitrogen content in the molded mold is 0.002% by weight or more and 0.22% by weight or less.
％以下であることを特徴とする請求項１又は２記載の鋳
型成型用砂組成物。3. The sand composition for molding according to claim 1, wherein the phosphorus content in the molded mold is 0.8% by weight or less.
量％以上、0.55重量％以下であることを特徴とする請求
項１〜３の何れか１項に記載の鋳型成型用砂組成物。4. The sand composition for molding according to claim 1, wherein the phosphorus content in the molded mold is 0.008% by weight or more and 0.55% by weight or less.
ン酸及び硫酸よりなる群から選ばれる１種又は２種以上
のスルホン酸系化合物を含有し、かつ成型された鋳型中
の硫黄含量が 0.005重量％以上、 0.7重量％以下である
ことを特徴とする請求項１〜４の何れか１項に記載の鋳
型成型用砂組成物。5. The catalyst contains one or more sulfonic acid compounds selected from the group consisting of aromatic sulfonic acids, aliphatic sulfonic acids and sulfuric acid, and the sulfur content in the molded mold is 0.005. The sand composition for molding according to any one of claims 1 to 4, wherein the sand content is not less than 0.7% by weight and not more than 0.7% by weight.
含量) で表される重量比が、 0.005以上、 0.5以下であ
ることを特徴とする請求項５記載の鋳型成型用砂組成
物。6. The sand composition for molding according to claim 5, wherein the weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the reclaimed sand is 0.005 or more and 0.5 or less. ..
含量) で表される重量比が、0.01以上、 0.4以下である
ことを特徴とする請求項５又は６記載の鋳型成型用砂組
成物。7. The molding sand according to claim 5, wherein a weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the reclaimed sand is 0.01 or more and 0.4 or less. Composition.
からなるか又は再生砂90重量部以上と新砂10重量部以下
からなる砂に対し、酸硬化性フラン樹脂からなる結合剤
と、リン酸、縮合リン酸、リン酸エステル及びリン酸塩
よりなる群から選ばれる１種又は２種以上のリン酸系化
合物を含有する触媒とを添加し、該フラン樹脂を硬化さ
せる鋳物用砂型の製造に於て、成型された鋳型中の窒素
含量が0.3重量％以下となる様再生砂を処理することを
特徴とする鋳型の製造方法。8. A binder comprising an acid-curable furan resin and a phosphoric acid for sand consisting of reclaimed sand used in the production of repetitive molds or consisting of 90 parts by weight or more of reclaimed sand and 10 parts by weight or less of new sand. , For producing a sand mold for foundry in which a catalyst containing one or more phosphoric acid compounds selected from the group consisting of condensed phosphoric acid, phosphoric acid ester and phosphate is added to cure the furan resin. In the method for producing a mold, the reclaimed sand is treated so that the nitrogen content in the molded mold is 0.3% by weight or less.
量％以上、0.22重量％以下となる様再生砂を処理するこ
とを特徴とする請求項８記載の鋳型の製造方法。9. The method for producing a mold according to claim 8, wherein the reclaimed sand is treated so that the nitrogen content in the molded mold is 0.002% by weight or more and 0.22% by weight or less.
量％以下となる様再生砂を処理することを特徴とする請
求項８又は９記載の鋳型の製造方法。10. The method for producing a mold according to claim 8, wherein the reclaimed sand is treated so that the phosphorus content in the molded mold is 0.8% by weight or less.
重量％以上、0.55重量％以下となる様再生砂を処理する
ことを特徴とする請求項８〜１０の何れか１項に記載の
鋳型の製造方法。11. The phosphorus content in the molded mold is 0.008.
The method for producing a mold according to any one of claims 8 to 10, characterized in that the reclaimed sand is treated so as to have a content of not less than 0.5% by weight and not more than 0.55% by weight.
ホン酸及び硫酸よりなる群から選ばれる１種又は２種以
上のスルホン酸系化合物を含有し、かつ成型された鋳型
中の硫黄含量が 0.005重量％以上、 0.7重量％以下とな
る様再生砂を処理することを特徴とする請求項８〜１１
の何れか１項に記載の鋳型の製造方法。12. The catalyst contains one or more sulfonic acid compounds selected from the group consisting of aromatic sulfonic acids, aliphatic sulfonic acids and sulfuric acid, and the sulfur content in the molded mold is 0.005. The recycled sand is treated so that the content of the reclaimed sand is not less than 0.7% and not more than 0.7% by weight.
The method for producing a mold according to any one of 1.
黄含量) で表される重量比が、 0.005以上、 0.5以下で
あることを特徴とする請求項１２記載の鋳型の製造方
法。13. The method for producing a mold according to claim 12, wherein a weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the reclaimed sand is 0.005 or more and 0.5 or less.
黄含量) で表される重量比が、0.01以上、 0.4以下であ
ることを特徴とする請求項１２又は１３記載の鋳型の製
造方法。14. The method for producing a mold according to claim 12 or 13, wherein a weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the reclaimed sand is 0.01 or more and 0.4 or less. ..
砂からなるか又は再生砂90重量部以上と新砂10重量部以
下からなる砂に対し、酸硬化性フラン樹脂からなる結合
剤と硬化剤とを添加し、該フラン樹脂を硬化させて鋳物
用砂型を製造する際に用いる硬化剤であって、リン酸、
縮合リン酸、リン酸エステル及びリン酸塩よりなる群か
ら選ばれる１種又は２種以上のリン酸系化合物と、芳香
族スルホン酸、脂肪族スルホン酸及び硫酸よりなる群か
ら選ばれる１種又は２種以上のスルホン酸系化合物を含
有し、かつ硬化剤中の硫黄含量／ (リン含量＋硫黄含
量) で表される重量比が、0.01以上、 0.7以下であるこ
とを特徴とする硬化剤組成物。15. A binder comprising an acid-curing furan resin and a curing agent for sand comprising reclaimed sand used in the production of repetitive molds or comprising reconstituted sand in an amount of 90 parts by weight or more and fresh sand in an amount of 10 parts by weight or less. Is a curing agent used in the production of a sand mold for casting by curing the furan resin, and phosphoric acid,
One or more kinds of phosphoric acid compounds selected from the group consisting of condensed phosphoric acid, phosphoric acid ester and phosphate, and one kind selected from the group consisting of aromatic sulfonic acid, aliphatic sulfonic acid and sulfuric acid, or A curing agent composition containing two or more sulfonic acid compounds and having a weight ratio represented by sulfur content / (phosphorus content + sulfur content) in the curing agent of 0.01 or more and 0.7 or less. object.
表される重量比が、0.03以上、 0.6以下であることを特
徴とする請求項１５記載の硬化剤組成物。16. The curing agent composition according to claim 15, wherein a weight ratio represented by sulfur content / (phosphorus content + sulfur content) is 0.03 or more and 0.6 or less.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP33313292A JP3173906B2 (en) | 1991-12-13 | 1992-12-14 | Sand composition for mold molding and method for producing mold |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP32938591 | 1991-12-13 | ||
| JP3-329385 | 1991-12-13 | ||
| JP33313292A JP3173906B2 (en) | 1991-12-13 | 1992-12-14 | Sand composition for mold molding and method for producing mold |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH05237587A true JPH05237587A (en) | 1993-09-17 |
| JP3173906B2 JP3173906B2 (en) | 2001-06-04 |
Family
ID=26573179
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP33313292A Expired - Lifetime JP3173906B2 (en) | 1991-12-13 | 1992-12-14 | Sand composition for mold molding and method for producing mold |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP3173906B2 (en) |
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996005925A1 (en) * | 1994-08-19 | 1996-02-29 | Kao Corporation | Binder composition for mold production and process for producing mold |
| US6426374B1 (en) | 2000-07-28 | 2002-07-30 | Ashland Inc. | Foundry binder compositions and mixes that contain a divalent sulfur compound |
| JP2003503211A (en) * | 1999-07-02 | 2003-01-28 | インターナショナル エンジン インテレクチュアル プロパティー カンパニー リミテッド ライアビリティ カンパニー | Casting method and apparatus |
| JP2006247716A (en) * | 2005-03-11 | 2006-09-21 | Kao Corp | Method for making mold |
| WO2007105347A1 (en) * | 2006-03-14 | 2007-09-20 | Hitachi Chemical Company, Ltd. | Resin composition for shell molds and resin-coated sand |
| JP2011212746A (en) * | 2010-03-18 | 2011-10-27 | Kao Corp | Binder composition for manufacturing mold |
-
1992
- 1992-12-14 JP JP33313292A patent/JP3173906B2/en not_active Expired - Lifetime
Cited By (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| WO1996005925A1 (en) * | 1994-08-19 | 1996-02-29 | Kao Corporation | Binder composition for mold production and process for producing mold |
| JP2012121072A (en) * | 1999-07-02 | 2012-06-28 | Internatl Engine Intellectual Property Co Llc | Casting method and apparatus |
| JP2003503211A (en) * | 1999-07-02 | 2003-01-28 | インターナショナル エンジン インテレクチュアル プロパティー カンパニー リミテッド ライアビリティ カンパニー | Casting method and apparatus |
| US6426374B1 (en) | 2000-07-28 | 2002-07-30 | Ashland Inc. | Foundry binder compositions and mixes that contain a divalent sulfur compound |
| JP2006247716A (en) * | 2005-03-11 | 2006-09-21 | Kao Corp | Method for making mold |
| JP2007275988A (en) * | 2006-03-14 | 2007-10-25 | Hitachi Chem Co Ltd | Resin composition and resin-coated sand for shell mold |
| KR101014453B1 (en) * | 2006-03-14 | 2011-02-14 | 히다치 가세고교 가부시끼가이샤 | Resin composition for shell molds and resin-coated sand |
| US7928151B2 (en) | 2006-03-14 | 2011-04-19 | Hitachi Chemical Company, Ltd. | Resin composition for shell mold and resin coated sand |
| WO2007105347A1 (en) * | 2006-03-14 | 2007-09-20 | Hitachi Chemical Company, Ltd. | Resin composition for shell molds and resin-coated sand |
| JP2011212746A (en) * | 2010-03-18 | 2011-10-27 | Kao Corp | Binder composition for manufacturing mold |
| CN102802833A (en) * | 2010-03-18 | 2012-11-28 | 花王株式会社 | Binder composition for use in mold manufacturing |
| US20130008625A1 (en) * | 2010-03-18 | 2013-01-10 | Kao Corporation | Binder composition for use in mold manufacturing |
| KR101423506B1 (en) * | 2010-03-18 | 2014-07-25 | 가오 가부시키가이샤 | Binder composition for use in mold manufacturing |
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|---|---|
| JP3173906B2 (en) | 2001-06-04 |
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