JP2000072999A - Preparation of calcined colored lead - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for preparing a calcined colored lead having a calcined lead body impregnated with an ink which is small in variability of strength and hardness and excellent in mechanical strength, i.e., flexural strength, tensile strength, impact strength and the like while having sufficient color developability and depicted line density. SOLUTION: A method for preparing a calcined colored lead comprises subjecting a compounded composition containing a body material and an organic excipient to kneading, extrusion molding and then, calcination in a non-oxidizing atmosphere to form a first calcined lead body having, as the binder, carbons by carbonization of the organic excipient, heating the first calcined lead body in an oxidizing atmosphere to remove the carbon binder by oxidation to form a second calcined lead body, impregnating the pores of the second calcined lead body with a perhydropolysilazane-containing fluid, heat-treating the resulting second calcined lead body in an inert atmosphere such as a nitrogen atmosphere or in an ammonia gas atmosphere to obtain a third calcined lead body in which silicon nitride has been formed and furthermore, filling an ink in the pores of the third calcined lead body.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、十分な発色性、描
線濃度をもちながら、機械的強度、即ち、曲げ強度、引
張強度、衝撃強度等に優れた、焼成芯体にインクを含浸
した焼成色鉛筆芯の製造方法に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fired core obtained by impregnating a fired core with ink while having sufficient color developing properties and drawing line density and excellent mechanical strength, that is, bending strength, tensile strength and impact strength. The present invention relates to a method for producing a colored pencil lead.

【０００２】[0002]

【従来の技術】従来の焼成色鉛筆芯は、結合材として一
種及び／又は二種以上の粘土等が用いられ、これに窒化
硼素等の体質材、更に必要に応じて耐熱性の顔料、反応
促進材を添加、配合した配合組成物を混練し、この混練
物を押出成形した後、熱処理を経て多孔質焼成芯体と
し、この芯体の気孔中に染料および顔料から成るインク
等を充填させて色鉛筆芯としていた。この時、色鉛筆芯
の重要特性としては、機械的強度が強く、発色性が良
く、筆記描線の濃度が濃いものが要求されている。2. Description of the Related Art A conventional baked color pencil lead uses one or / and two or more kinds of clays as a binder, a body material such as boron nitride, a heat-resistant pigment if necessary, and a reaction accelerator. The kneaded mixture was kneaded with the added composition, and the kneaded product was extruded, and then subjected to a heat treatment to form a porous fired core, and the pores of the core were filled with an ink or the like comprising a dye and a pigment. I had a colored pencil lead. At this time, as the important characteristics of the color pencil lead, those having high mechanical strength, good coloring properties, and high density of writing lines are required.

【０００３】ところが、従来の焼成色鉛筆芯は機械的強
度が充分でなく、濃度および発色性においても充分なも
のが得られていないのが現状である。そこで、上記の要
求を達成するためには、充分な機械的強度を保持しつ
つ、気孔率を増加させることにより芯体に充填されるイ
ンク量を多くする必要がある。また、従来結合材として
用いられている粘土等による焼成芯体は、窒化硼素等の
体質材と粘土等の結合材の焼結力が弱く、粘土等自身の
強度も低いため、得られる焼成色鉛筆芯は実用強度に達
していないのが現状である。更に、粘土は不純物を含ん
でいるため、得られる焼成芯体は一般に有色となり、描
線の発色性に悪影響を与えることとなる。特に、淡色系
の描線のくすんだ色の原因となっている。[0003] However, at present, conventional baked color pencil cores do not have sufficient mechanical strength and do not have sufficient density and coloring properties. Therefore, in order to achieve the above requirements, it is necessary to increase the porosity while maintaining sufficient mechanical strength to increase the amount of ink to be filled in the core. In addition, the fired core made of clay or the like, which has been conventionally used as a binder, has a weak sintering force between the body material such as boron nitride and the binder such as clay, and the strength of the clay or the like itself is low. At present, the core has not reached practical strength. Further, since the clay contains impurities, the fired core obtained is generally colored, which has an adverse effect on the coloring of the drawn lines. In particular, it causes the dull color of the light-colored lines.

【０００４】本発明者らは、上記の課題等を解決する方
法として、少なくとも体質材からなる第２焼成芯体の気
孔内に、ペルヒドロポリシラザン含有液を含浸し、窒素
雰囲気等の不活性雰囲気中又はアンモニアガス雰囲気中
での熱処理により結合材として窒化珪素を生成させた第
３焼成芯体の気孔内にインクを充填させてなる焼成色鉛
筆芯及びその製造方法を提案している（特開平８−４８
９３１号）。この製造方法等は、十分な発色性、描線濃
度をもちながら、機械的強度等に優れた焼成色鉛筆芯が
得られるものである。As a method for solving the above-mentioned problems and the like, the present inventors impregnate at least the pores of the second fired core made of a body material with a perhydropolysilazane-containing liquid and form an inert atmosphere such as a nitrogen atmosphere. There has been proposed a fired pencil lead obtained by filling ink into pores of a third fired core in which silicon nitride has been generated as a binder by heat treatment in a medium or in an atmosphere of ammonia gas, and a method for producing the same (Japanese Patent Application Laid-Open No. Hei 8 (1996)). -48
No. 931). This production method and the like can provide a fired colored pencil lead excellent in mechanical strength and the like while having sufficient coloring properties and drawing line density.

【０００５】しかしながら、上記製造方法では、第１焼
成芯体の炭素のバインダーを酸化雰囲気中で加熱除去し
て第２焼成芯体を形成する際、芯に吸着した水、酸素が
その後の工程で添加するペルヒドロポリシラザンを変
質、劣化させ、最終的に第３焼成芯体の曲げ強度、硬さ
等に品質のバラツキが大きくなる場合があり若干の課題
を有している。However, in the above manufacturing method, when the carbon binder of the first fired core is removed by heating in an oxidizing atmosphere to form the second fired core, water and oxygen adsorbed on the core are removed in the subsequent steps. The perhydropolysilazane to be added is deteriorated and deteriorated, and the quality of the third fired core finally varies in flexural strength and hardness.

【０００６】[0006]

【発明が解決しようとする課題】本発明の目的は、上記
従来技術の課題を解決すると共に、上記発明者らの先行
技術を更に改良することであり、格段に優れた機械的強
度、優れた発色性及び滑らかな書き味を有する焼成色鉛
筆芯の製造方法を提供することにある。SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art and to further improve the prior art of the present inventors. It is an object of the present invention to provide a method for producing a baked color pencil lead having coloring and smooth writing.

【０００７】[0007]

【課題を解決するための手段】本発明者らは、前記課題
を解決するために鋭意研究を行った結果、第１焼成芯体
の炭素のバインダーを酸化雰囲気中で加熱除去した後の
芯体の降温、冷却を乾燥させた特定の雰囲気中で行い、
降温途中で真空下で一定温度にて保持して生成した第２
焼成芯体の気孔内に、ペルヒドロポリシラザン含有液を
含浸、加熱して窒化珪素を生成させることによって解決
し得ることを見い出し、本発明を完成するに至ったので
ある。すなわち、本発明の焼成色鉛筆芯の製造方法は、
少なくとも体質材と有機質の賦形材を含む配合組成物を
混練、押出成形、非酸化性雰囲気で焼成することによ
り、該有機質の賦形材が炭素化された炭素をバインダー
とする第１焼成芯体を形成し、該第１焼成芯体を酸化雰
囲気中で加熱して炭素のバインダーを酸化除去して第２
焼成芯体を形成し、該第２焼成芯体の気孔内に、ペルヒ
ドロポリシラザン含有液を含浸し、窒素雰囲気等の不活
性雰囲気中又はアンモニアガス雰囲気中での熱処理によ
り窒化珪素を生成させた第３焼成芯体を得、更に該第３
焼成芯体の気孔内にインクを充填させる焼成色鉛筆芯の
製造において、上記第１焼成芯体の炭素のバインダーを
加熱除去した後、乾燥させた窒素雰囲気等の不活性雰囲
気中又はアンモニアガス雰囲気中で降温、冷却し、その
途中で少なくとも１度真空状態にて定温保持し、更に乾
燥させた窒素雰囲気等の不活性雰囲気中又はアンモニア
ガス雰囲気中で降温、冷却して、第２焼成芯体を形成す
ることを特徴とする。なお、本発明で規定する「窒素雰
囲気等の不活性雰囲気中」とは、窒素ガス雰囲気中、ま
たは、アルゴンガス雰囲気中等の不活性ガス雰囲気中を
いう。Means for Solving the Problems The inventors of the present invention have conducted intensive studies to solve the above-mentioned problems, and as a result, the core after heating and removing the carbon binder of the first fired core in an oxidizing atmosphere. Temperature, cooling in a dry specific atmosphere,
The second produced by holding at a constant temperature under vacuum during the temperature drop
The inventors have found that the problem can be solved by impregnating the perforated polysilazane-containing liquid into the pores of the fired core and heating to generate silicon nitride, thereby completing the present invention. That is, the method for producing a fired colored pencil lead of the present invention comprises:
By kneading, extruding, and sintering in a non-oxidizing atmosphere a compounded composition containing at least a body material and an organic excipient, a first fired core in which the organic excipient has carbonized carbon as a binder The first fired core is heated in an oxidizing atmosphere to oxidize and remove the carbon binder, thereby forming the second fired core.
A fired core was formed, the pores of the second fired core were impregnated with a perhydropolysilazane-containing liquid, and silicon nitride was generated by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. Obtaining a third fired core body,
In the manufacture of a fired colored pencil lead in which ink is filled in the pores of the fired lead, the carbon binder of the first fired lead is removed by heating and then dried in an inert atmosphere such as a nitrogen atmosphere or in an ammonia gas atmosphere. In the course of this, the temperature is kept at least once in a vacuum state at a constant temperature, and the temperature is lowered and cooled in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. It is characterized by forming. The “in an inert atmosphere such as a nitrogen atmosphere” defined in the present invention refers to a nitrogen gas atmosphere or an inert gas atmosphere such as an argon gas atmosphere.

【０００８】[0008]

【発明の実施の形態】以下に、本発明の実施形態を詳し
く説明する。本発明の焼成色鉛筆芯の製造方法は、ま
ず、少なくとも体質材と有機質の賦形材を含む配合組成
物を混練、押出成形、非酸化性雰囲気で焼成することに
より、該有機質の賦形材が炭素化された炭素をバインダ
ーとする第１焼成芯体を得、該第１焼成芯体の炭素のバ
インダーを加熱除去した後、乾燥させた窒素雰囲気等の
不活性雰囲気中又はアンモニアガス雰囲気中で降温、冷
却し、その途中で真空状態にて定温保持し、更に乾燥さ
せた窒素雰囲気等の不活性雰囲気中又はアンモニアガス
雰囲気中で降温、冷却して、第２焼成芯体を得、該第２
焼成芯体の気孔内に、ペルヒドロポリシラザン含有液を
含浸し、窒素雰囲気等の不活性雰囲気中又はアンモニア
ガス雰囲気中での熱処理することにより、第２焼成芯体
の気孔内に窒化珪素を生成させた第３焼成芯体を形成
し、該第３焼成芯体の気孔内にインクを充填させること
を特徴とするものである。Embodiments of the present invention will be described below in detail. The method for producing a fired colored pencil lead of the present invention comprises first kneading a compounded composition containing at least a body material and an organic excipient, extruding, and firing in a non-oxidizing atmosphere, whereby the organic excipient is obtained. A first fired core having carbonized carbon as a binder is obtained, and the carbon binder of the first fired core is removed by heating, and then dried in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. The temperature is lowered and cooled, the temperature is kept constant in a vacuum state on the way, and the temperature is lowered and cooled in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to obtain a second fired core. 2
The pores of the fired core are impregnated with a perhydropolysilazane-containing liquid, and heat-treated in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to produce silicon nitride in the pores of the second fired core. A third fired core is formed, and the pores of the third fired core are filled with ink.

【０００９】本発明において、第１焼成芯体は、少なく
とも体質材と有機質の賦形材を含む配合組成物より得ら
れる。第１焼成芯体に用いる体質材としては、従来の焼
成型の色鉛筆芯に使用されているものであれば、いずれ
も使用可能である。例えば、酸化チタン、雲母、タル
ク、窒化硼素、シリカ、アルミナ、炭酸カルシウム等白
色系のものや、充填するインクの色相によっては二硫化
モリブデン、二硫化タングステン等有色系のものも使用
することができ、当然これら数種類の混合物も使用でき
る。また、必要に応じて耐熱性顔料を配合してもよい。In the present invention, the first fired core is obtained from a blended composition containing at least a body material and an organic excipient. As the constitution material used for the first fired core, any material can be used as long as it is used for a conventional fired colored pencil lead. For example, titanium oxide, mica, talc, boron nitride, silica, alumina, calcium carbonate and other white materials, and depending on the hue of the ink to be filled, molybdenum disulfide and tungsten disulfide can also be used. Of course, mixtures of these several types can also be used. Moreover, you may mix | blend a heat resistant pigment as needed.

【００１０】また、第１焼成芯体に用いる有機質の賦形
材としては、例えば、ポリ塩化ビニル樹脂、塩素化ポリ
塩化ビニル樹脂、ポリビニルアルコールなどの熱可塑性
樹脂、フラン樹脂、フェノール樹脂、エポキシ樹脂など
の熱硬化性樹脂、リグニン、セルロース、トラガントガ
ムなどの天然高分子物質、石油アスファルト、コールタ
ールピッチ、ナフサ分解ピッチ、合成樹脂の乾留ピッチ
などのピッチ類等いずれも使用可能で、当然これら数種
類の混合物も使用できる。更に、高せん断力を加えて行
う混練時の特性向上及び押出成形の特性向上の目的で、
水、ジオクチルフタレート（ＤＯＰ）、ジブチルフタレ
ート（ＤＢＰ）、リン酸トリクレジル（ＴＣＰ）、アジ
ピン酸ジオクチル（ＤＯＡ）、プロピレンカーボナー
ト、アルコール類、ケトン類、エステル類など有機質の
賦形材の可塑剤又は溶剤の一種又は二種以上を、必要に
応じて上記配合組成物に添加しても良い。The organic excipient used for the first fired core includes, for example, thermoplastic resins such as polyvinyl chloride resin, chlorinated polyvinyl chloride resin, polyvinyl alcohol, furan resin, phenol resin and epoxy resin. Thermosetting resins such as lignin, cellulose, natural polymer materials such as tragacanth gum, petroleum asphalt, coal tar pitch, naphtha cracking pitch, pitches such as synthetic resin pitch, etc. Mixtures can also be used. Furthermore, for the purpose of improving the characteristics at the time of kneading performed by applying a high shear force and improving the characteristics of extrusion molding,
Plasticizers for organic excipients such as water, dioctyl phthalate (DOP), dibutyl phthalate (DBP), tricresyl phosphate (TCP), dioctyl adipate (DOA), propylene carbonate, alcohols, ketones and esters One or two or more solvents may be added to the above composition as needed.

【００１１】これら配合組成物をヘンシェルミキサー、
加圧ニーダー、二本ロール等で十分混練した後、押出成
形機により細線状等に押出成形し、次いで、窒素雰囲気
中又はアルゴンガスなどの不活性ガス中等の非酸化性雰
囲気中で焼成することにより、有機質の賦形材が炭素化
された炭素をバインダーとする第１焼成芯体が得られ
る。[0011] These blended compositions are used in a Henschel mixer,
After sufficiently kneading with a pressure kneader, two rolls, etc., extrude into a fine wire shape using an extruder, and then fire in a non-oxidizing atmosphere such as a nitrogen atmosphere or an inert gas such as an argon gas. As a result, a first fired core using the carbonized carbon as the organic excipient is obtained.

【００１２】本発明において、第２焼成芯体は、上記で
得られた第１焼成芯体の炭素のバインダーを酸化雰囲気
中で加熱除去した後、乾燥させた窒素雰囲気等の不活性
雰囲気中又はアンモニアガス雰囲気中で降温、冷却し、
その途中で真空状態にて定温保持し、更に乾燥させた窒
素雰囲気等の不活性雰囲気中又はアンモニアガス雰囲気
中で降温、冷却することにより得られる。上記降温、冷
却は、水、酸素などの吸着を防ぐ目的で、純度の高い乾
燥させた窒素雰囲気等の不活性雰囲気中又はアンモニア
ガス雰囲気中にて行うものである。また、吸着した水な
どを完全に除去するために、降温途中で少なくとも１度
真空状態で定温保持して芯体を十分乾燥、脱水させるこ
とが必要である。本発明において、真空状態とは、１気
圧（１０１３２５Ｐａ）未満の減圧状態をいうが、完全
に乾燥、脱水させるためには、１０００Ｐａ以下が好ま
しい。定温に保持する温度としては、１５０〜１００℃
程度の範囲が好ましい。上記真空状態にて定温保持した
後の降温、冷却も乾燥させた窒素雰囲気等の不活性雰囲
気中又はアンモニアガス雰囲気中にて行う必要がある。
また、炭素のバインダーを加熱除去する上記酸化雰囲気
中も乾燥させた空気等により行うことが好ましい。この
酸化焼成、降温、冷却工程を経ることにより、多数の気
孔を備えた多孔質芯体からなる目的の第２焼成芯体が得
られる。In the present invention, the second fired core is obtained by heating and removing the carbon binder of the first fired core obtained above in an oxidizing atmosphere, and then drying the carbon binder in an inert atmosphere such as a nitrogen atmosphere. Cool down and cool in an ammonia gas atmosphere,
It is obtained by maintaining the temperature at a constant temperature in a vacuum state on the way, and then cooling and cooling in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. The temperature lowering and cooling are performed in an inert atmosphere such as a dried nitrogen atmosphere of high purity or in an ammonia gas atmosphere in order to prevent adsorption of water, oxygen and the like. Further, in order to completely remove the adsorbed water and the like, it is necessary to hold the constant temperature at least once in a vacuum state during the temperature lowering to sufficiently dry and dehydrate the core. In the present invention, the vacuum state refers to a reduced pressure state of less than 1 atmosphere (101325 Pa), but is preferably 1000 Pa or less for complete drying and dehydration. The temperature to be maintained at a constant temperature is 150 to 100 ° C.
The range of the degree is preferable. The temperature reduction and cooling after maintaining the constant temperature in the above-mentioned vacuum state also need to be performed in an inert atmosphere such as a dried nitrogen atmosphere or an ammonia gas atmosphere.
In addition, it is preferable that the above-mentioned oxidizing atmosphere in which the carbon binder is removed by heating is also performed with dried air or the like. Through the oxidizing, firing, cooling, and cooling steps, a target second fired core made of a porous core having a large number of pores is obtained.

【００１３】なお、第１焼成芯体にペルヒドロポリシラ
ザン含有液を含浸せしめ、窒素雰囲気等の不活性雰囲気
中又はアンモニアガス雰囲気中での熱処理により窒化珪
素を生成させた焼成芯体を得た後に、酸化雰囲気中で加
熱し、第１焼成芯体の炭素のバインダーを酸化除去する
ことにより、ペルヒドロポリシラザン含有液の含浸前の
焼成芯体の強度を満足できる範囲内で強めてもよいが、
当然この場合も、降温、冷却は上記と同様の方法で水、
酸素等の吸着を防ぐ必要がある。The first fired core is impregnated with a perhydropolysilazane-containing liquid, and a fired core in which silicon nitride is formed by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere is obtained. By heating in an oxidizing atmosphere and oxidizing and removing the carbon binder of the first fired core, the strength of the fired core before impregnation with the perhydropolysilazane-containing liquid may be increased within a range that can be satisfied.
Naturally, in this case as well, cooling and cooling are performed in the same manner
It is necessary to prevent adsorption of oxygen and the like.

【００１４】本発明において、ペルヒドロポリシラザン
含有液を含浸し、窒素雰囲気等の不活性雰囲気中又はア
ンモニアガス雰囲気中での熱処理により高強度の焼成芯
体を得るのに有用な芯体は、気孔が微細で充分に存在
し、かつ、均一に分散していて、体質材が高配向してい
る芯体となることが必要である。これによりペルヒドロ
ポリシラザン含有液は、芯体中に微細で均一に分散して
含浸され、窒化珪素が芯体中に微細で均一に分散して生
成するものとなる。従来の製造方法においては、ペルヒ
ドロポリシラザン含有液の含浸前の第２焼成芯体に水、
酸素等が吸着している場合があり、この水、酸素等が吸
着していると、ペルヒドロポリシラザンが加水分解され
て劣化しやすく、強度、硬さ等芯の物性がバラツキやす
くなるものであったが、本発明では、上述の酸化焼成、
降温、冷却工程を経ることにより、上記物性のバラツキ
がなく、目的の焼成芯体が得られるものとなる。In the present invention, a core useful for obtaining a high-strength sintered core by impregnating with a perhydropolysilazane-containing liquid and performing heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere is a porous material. It is necessary that the core material is fine and sufficiently present, uniformly dispersed, and the core material is highly oriented. As a result, the perhydropolysilazane-containing liquid is finely and uniformly dispersed and impregnated in the core, and silicon nitride is finely and uniformly dispersed in the core to be generated. In the conventional production method, the second calcined core before impregnation with the perhydropolysilazane-containing liquid contains water,
Oxygen or the like may be adsorbed, and if water or oxygen or the like is adsorbed, perhydropolysilazane is hydrolyzed and easily degraded, and the physical properties of the core such as strength and hardness are likely to vary. However, in the present invention, the above-described oxidation firing,
By going through the temperature lowering and cooling steps, there is no variation in the above physical properties, and the desired fired core can be obtained.

【００１５】本発明で用いるペルヒドロポリシラザン含
有液は、セラミックス前駆体ポリマーであり、ペルヒド
ロポリシラザンを有機溶剤で溶解したものであり、該ペ
ルヒドロポリシラザン含有液が第２焼成芯体に充填可能
なものであれば、使用する有機溶剤は特に限定されず、
いずれも使用可能である。使用できる有機溶剤として
は、例えば、ベンゼン、トルエン、キシレン、エーテ
ル、ＴＨＦ、塩化メチレン、四塩化炭素等、芳香族炭化
水素系等の有機溶剤が挙げられる。The perhydropolysilazane-containing liquid used in the present invention is a ceramic precursor polymer and is obtained by dissolving perhydropolysilazane in an organic solvent, and the perhydropolysilazane-containing liquid can be filled in the second fired core. As long as the organic solvent used is not particularly limited,
Both can be used. Examples of usable organic solvents include organic solvents such as benzene, toluene, xylene, ether, THF, methylene chloride, carbon tetrachloride, and aromatic hydrocarbons.

【００１６】本発明において、ペルヒドロポリシラザン
は、主鎖に〔−Ｓｉ−Ｎ−〕構造を有し、側鎖に水素の
みが結合しているものである。そのため、窒素雰囲気等
の不活性雰囲気中又はアンモニアガス雰囲気中での熱分
解で消去するのは水素のみであり、非常に高い収率で窒
化珪素が得られるものである。また、メチル基等の有機
成分を含まないため、炭素を含まない無色透明で高純度
の窒化珪素が得られる。更に、本発明では、窒化珪素が
他の焼結法より低い６００℃という低温度で得られるも
のとなる。In the present invention, perhydropolysilazane has a [-Si-N-] structure in the main chain, and has only hydrogen bonded to a side chain. Therefore, only hydrogen is erased by thermal decomposition in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere, and silicon nitride can be obtained with a very high yield. Further, since it does not contain an organic component such as a methyl group, colorless, transparent and high-purity silicon nitride containing no carbon can be obtained. Further, in the present invention, silicon nitride can be obtained at a low temperature of 600 ° C. which is lower than other sintering methods.

【００１７】第２焼成芯体にペルヒドロポリシラザン含
有液を含浸させる方法としては、第２焼成芯体をペルヒ
ドロポリシラザン含有液中に浸漬し、必要に応じて加
熱、減圧、加圧等の条件下で含浸させることにより行う
ことができる。As a method of impregnating the second fired core body with the perhydropolysilazane-containing liquid, the second fired core body is immersed in the perhydropolysilazane-containing liquid, and if necessary, heated, depressurized, and pressurized. This can be done by impregnating underneath.

【００１８】本発明において、第３焼成芯体は、上記ペ
ルヒドロポリシラザン含有液を含浸せしめた第２焼成芯
体を窒素雰囲気等の不活性雰囲気中又はアンモニアガス
雰囲気中で４００℃以上、好ましくは６００℃以上で熱
処理することにより得られる。更に、高強度の第３焼成
芯体を得るために、必要に応じてペルヒドロポリシラザ
ン含有液の含浸、焼成工程を繰り返し行ってもよい。な
お、当然、ペルヒドロポリシラザンの焼成時の窒素ガ
ス、アルゴンガス等も乾燥させ、純度が高いものを用い
ることが好ましい。In the present invention, the third fired core may be prepared by impregnating the second fired core impregnated with the perhydropolysilazane-containing liquid in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere, preferably at 400 ° C. or higher. It is obtained by heat treatment at 600 ° C. or higher. Furthermore, in order to obtain a high-strength third fired core, the impregnation and firing steps of the perhydropolysilazane-containing liquid may be repeated as necessary. Naturally, it is preferable to dry nitrogen gas, argon gas, and the like at the time of firing perhydropolysilazane and use high-purity nitrogen gas and argon gas.

【００１９】本発明において、焼成色鉛筆芯は、上記で
得た第３焼成芯体の気孔内に、インクを充填させること
により得られる。第３焼成芯体に含浸させるインクとし
ては、従来公知の色鉛筆芯用のものであればいずれも使
用することができる。例えば、染料、顔料等の着色剤
を、動植物油、合成油、アルコール類、炭化水素油、水
等に溶解、分散させ、あるいは必要に応じて樹脂、界面
活性剤等を更に添加し製造された一般的に用いられてい
る印刷用インク、スタンプインク、ボールペンインク、
水性筆記用インク等が用いられる。また、第３焼成芯体
にインクを含浸させる方法としては、第３焼成芯体をイ
ンク中に浸漬し、加熱、減圧、加圧等の条件下で気孔内
に充填させる。さらに、繰り返し含浸を行ってもよい。In the present invention, a fired colored pencil lead is obtained by filling the pores of the third fired lead obtained above with ink. As the ink to be impregnated into the third fired core, any conventionally known ink for a colored pencil can be used. For example, dyes, coloring agents such as pigments, animal and vegetable oils, synthetic oils, alcohols, hydrocarbon oils, dissolved and dispersed in water, etc., or, if necessary, a resin, further manufactured by adding a surfactant and the like. Commonly used printing ink, stamp ink, ballpoint pen ink,
An aqueous writing ink or the like is used. As a method for impregnating the third fired core with the ink, the third fired core is immersed in the ink and filled in the pores under conditions such as heating, decompression, and pressurization. Further, repeated impregnation may be performed.

【００２０】このように構成される焼成色鉛筆芯の製造
方法では、下記(1)及び(2)の作用等を有することとな
る。 (1) 第２焼成芯体は、水、酸素等が吸着しておらず、気
孔が微細で充分に存在し、かつ、均一に分散していて、
体質材が高配向しているため、高純度で高強度の窒化珪
素を第２焼成芯体中に少量生成させることが可能であ
る。その結果、濃い描線濃度を得るのに必要なインクを
充填する気孔を保持し、かつ、高強度でバラツキが少な
い第３焼成芯体が得られる。 (2) 書き味は、結合材に粘土等を用いた従来の焼成鉛筆
芯と比較しても同等以上に良好で、硬さのバラツキも少
ない。これは、第３焼成芯体中に結合材である高純度の
窒化珪素が微細、かつ、均一に分散して存在することに
より、高配向した体質材が均一に崩れるためと考えられ
る。The method for producing a fired pencil lead having the above-described structure has the following effects (1) and (2). (1) The second fired core body does not adsorb water, oxygen, etc., has fine and sufficient pores, and is uniformly dispersed,
Since the extender is highly oriented, it is possible to generate a small amount of high-purity, high-strength silicon nitride in the second fired core. As a result, it is possible to obtain a third fired core body which retains pores filled with ink necessary for obtaining a high drawn line density, has high strength, and has little variation. (2) The writing quality is equal to or better than that of a conventional baked pencil lead using clay or the like as a binder, and there is little variation in hardness. This is presumably because the high-purity body material, which is a binder, is finely and uniformly dispersed as a binder in the third fired core, so that the highly oriented body material is uniformly collapsed.

【００２１】[0021]

【実施例】次に、本発明を実施例により、更に具体的に
説明するが、本発明はこの実施例によって何等限定され
るものではない。Next, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

【００２２】 （実施例１） 窒化硼素 ４１．３重量％ 塩化ビニル樹脂 ４１．３重量％ ジオクチルフタレート（ＤＯＰ） １６．５重量％ ステアリン酸亜鉛 ０．９重量％ 上記配合組成物をヘンシェルミキサーで混合分散し、加
圧ニーダー、二本ロールで混練した後、細線状に押出成
形し、これから残留する可塑剤を除去すべく空気中で１
８０℃にて加熱処理して、しかるのち窒素雰囲気中にて
１０００℃まで昇温させた後、１０００℃にて焼成して
第１焼成芯体を得た。Example 1 Boron nitride 41.3% by weight Vinyl chloride resin 41.3% by weight Dioctyl phthalate (DOP) 16.5% by weight Zinc stearate 0.9% by weight The above composition was mixed with a Henschel mixer. After dispersing and kneading with a pressure kneader and two rolls, the mixture is extruded into a fine wire and then removed in air to remove the residual plasticizer.
A heat treatment was performed at 80 ° C., and then the temperature was raised to 1000 ° C. in a nitrogen atmosphere, followed by firing at 1000 ° C. to obtain a first fired core.

【００２３】次いで、この第１焼成芯体を乾燥空気雰囲
気中、約７００℃で加熱焼成して残留している炭素化し
た樹脂分を除去し、その後乾燥窒素雰囲気に変更して降
温、冷却した。その途中、１５０℃で減圧して真空（５
００Ｐａ）とし、３時間保持した。次に、再度乾燥窒素
雰囲気中で室温まで降温して白色の第２焼成芯体を得
た。この第２焼成芯体に、ペルヒドロポリシラザン含有
液（２０％キシレン溶液）を室温下で１日含浸後、窒素
雰囲気中で６００℃まで昇温させて、６００℃にて焼成
して焼成芯体を得た。更に、この焼成芯体にペルヒドロ
ポリシラザン含有液（２０％キシレン溶液）を含浸し、
焼成する工程を１回繰り返し、直径０．５７ｍｍの白色
の第３焼成芯体を得た。次に、赤色インクに上記第３焼
成芯体を浸し、７０℃で２４時間放置した。この赤色イ
ンクが充填された第３焼成芯体表面をアルコールで洗浄
し、直径０．５７ｍｍの赤色の焼成色鉛筆芯を得た。Next, this first fired core was heated and fired in a dry air atmosphere at about 700 ° C. to remove the remaining carbonized resin, and then changed to a dry nitrogen atmosphere and cooled and cooled. . On the way, the pressure was reduced at 150 ° C. and the vacuum (5
00 Pa) and held for 3 hours. Next, the temperature was again lowered to room temperature in a dry nitrogen atmosphere to obtain a white second fired core. The second fired core is impregnated with a perhydropolysilazane-containing liquid (20% xylene solution) at room temperature for 1 day, heated to 600 ° C. in a nitrogen atmosphere, and fired at 600 ° C. I got Further, the fired core body is impregnated with a perhydropolysilazane-containing liquid (20% xylene solution),
The firing step was repeated once to obtain a white third fired core having a diameter of 0.57 mm. Next, the third fired core was immersed in red ink and left at 70 ° C. for 24 hours. The surface of the third fired core filled with the red ink was washed with alcohol to obtain a red fired colored pencil lead having a diameter of 0.57 mm.

【００２４】（比較例１）実施例１と同様の第１焼成芯
体を得た後、通常の室内の乾燥させていない空気を流し
ながら約７００℃で加熱焼成して残留している炭素化し
た樹脂分を除去し、同様の室内の空気雰囲気中で室温ま
で降温して白色の第２焼成芯体を得た。次に、実施例１
と同様にしてペルヒドロポリシラザン含有液の含浸、焼
成工程を２回繰り返し、直径０．５７ｍｍの白色の第３
焼成芯体を得た。次に、赤色インクに上記第３焼成芯体
を浸し、７０℃で２４時間放置した。この赤色インクが
充填された第３焼成芯体表面をアルコールで洗浄し、直
径０．５７ｍｍの赤色の焼成色鉛筆芯を得た。(Comparative Example 1) After obtaining a first fired core body similar to that of Example 1, the remaining carbonized material was fired at about 700 ° C. while flowing air which had not been dried in a normal room. The resin component thus removed was removed, and the temperature was lowered to room temperature in the same indoor air atmosphere to obtain a white second fired core. Next, Example 1
The impregnation and baking steps of the perhydropolysilazane-containing liquid were repeated twice in the same manner as described above to obtain a white third liquid having a diameter of 0.57 mm.
A fired core was obtained. Next, the third fired core was immersed in red ink and left at 70 ° C. for 24 hours. The surface of the third fired core filled with the red ink was washed with alcohol to obtain a red fired colored pencil lead having a diameter of 0.57 mm.

【００２５】 （比較例２） 窒化硼素 ４０重量％ ベントナイト ３５重量％ ポリビニルアルコール １８重量％ ポリエチレングリコール ７重量％ 上記配合組成物と同重量の水とをヘンシェルミキサーで
混合分散し、加圧ニーダー、二本ロールで混練し水分調
整した後、細線状に押出成形し、１１０℃で乾燥した
後、アルゴンガス中で１２００℃まで昇温して、１２０
０℃にて焼成し、次に、空気中で約７００℃まで昇温し
て、７００℃で焼成して直径０．５７ｍｍの白色の第３
焼成芯体を得た。次に、赤色インクに上記第３焼成芯体
を浸し、７０℃で２４時間放置した。この赤色インクが
充填された第３焼成芯体表面をアルコールで洗浄し、直
径０．５７ｍｍの赤色の焼成色鉛筆芯を得た。(Comparative Example 2) Boron nitride 40% by weight Bentonite 35% by weight Polyvinyl alcohol 18% by weight Polyethylene glycol 7% by weight The above composition and the same weight of water were mixed and dispersed by a Henschel mixer, After kneading with this roll and adjusting the water content, the mixture was extruded into a thin wire, dried at 110 ° C., heated to 1200 ° C. in argon gas,
Firing at 0 ° C., then heating to about 700 ° C. in air, firing at 700 ° C.
A fired core was obtained. Next, the third fired core was immersed in red ink and left at 70 ° C. for 24 hours. The surface of the third fired core filled with the red ink was washed with alcohol to obtain a red fired colored pencil lead having a diameter of 0.57 mm.

【００２６】上記実施例１及び比較例１、２で得られた
焼成色鉛筆芯について、ＪＩＳ−Ｓ−６００５−１９８
９に準拠して、Ａ．曲げ強度平均値（ＭＰａ）、Ｂ．曲
げ強度標準偏差（ＭＰａ）及びＢの曲げ強度標準偏差を
Ａの曲げ強度平均値で割った値、並びに、官能評価によ
る書き味について評価した。これらの結果を下記表１に
示す。The baked colored pencil cores obtained in Example 1 and Comparative Examples 1 and 2 were subjected to JIS-S-6005-198.
According to A.9. Bending strength average value (MPa), B. A value obtained by dividing the bending strength standard deviation (MPa) and the bending strength standard deviation of B by the bending strength average value of A, and the writing taste by the sensory evaluation were evaluated. The results are shown in Table 1 below.

【００２７】[0027]

【表１】 [Table 1]

【００２８】上記表１の結果から明らかなように、本発
明範囲の実施例１の焼成色鉛筆芯は、本発明の範囲外と
なる比較例１、２に較べて、曲げ強度が強く、また、曲
げ強度の標準偏差から曲げ強度のバラツキは少なく、書
き味も良好となる焼成色鉛筆芯が得られることが判明し
た。As is evident from the results in Table 1, the fired pencil lead of Example 1 of the present invention has a higher bending strength than Comparative Examples 1 and 2, which are out of the scope of the present invention. From the standard deviation of the bending strength, it was found that a variation in the bending strength was small, and a fired pencil lead having good writing quality was obtained.

【００２９】[0029]

【発明の効果】本発明によれば、少なくとも体質材と炭
素のバインダーからなる第１焼成芯体を酸化雰囲気中で
加熱して炭素のバインダーを酸化除去し、更に乾燥させ
た窒素雰囲気等の不活性雰囲気中又はアンモニアガス雰
囲気中で降温、冷却し、その途中で真空状態にて定温保
持し、更に乾燥させた窒素雰囲気等の不活性雰囲気中又
はアンモニアガス雰囲気中で降温、冷却することによ
り、第２焼成芯体の気孔内に結合材として窒化珪素を生
成することにより、機械的強度に優れ、実用上折れ難
く、きわめて優れた発色性と良好な書き味を有する品質
のバラツキが少ない焼成色鉛筆芯の製造方法が提供され
る。According to the present invention, the first fired core comprising at least the body material and the carbon binder is heated in an oxidizing atmosphere to oxidize and remove the carbon binder. By cooling and cooling in an active atmosphere or an ammonia gas atmosphere, maintaining a constant temperature in a vacuum state on the way, and further cooling and cooling in an inert atmosphere such as a dried nitrogen atmosphere or an ammonia gas atmosphere, By producing silicon nitride as a binder in the pores of the second calcined core, a calcined colored pencil having excellent mechanical strength, practically difficult to be broken, extremely excellent coloring and good writing quality, and little variation in quality. A method for manufacturing a wick is provided.

Claims (1)

【特許請求の範囲】[Claims] 【請求項１】 少なくとも体質材と有機質の賦形材を含
む配合組成物を混練、押出成形、非酸化性雰囲気で焼成
することにより、該有機質の賦形材が炭素化された炭素
をバインダーとする第１焼成芯体を形成し、該第１焼成
芯体を酸化雰囲気中で加熱して炭素のバインダーを酸化
除去して第２焼成芯体を形成し、該第２焼成芯体の気孔
内に、ペルヒドロポリシラザン含有液を含浸し、窒素雰
囲気等の不活性雰囲気中又はアンモニアガス雰囲気中で
の熱処理により窒化珪素を生成させた第３焼成芯体を
得、更に該第３焼成芯体の気孔内にインクを充填させる
焼成色鉛筆芯の製造において、上記第１焼成芯体の炭素
のバインダーを加熱除去した後、乾燥させた窒素雰囲気
等の不活性雰囲気中又はアンモニアガス雰囲気中で降
温、冷却し、その途中で真空状態にて定温保持し、更に
乾燥させた窒素雰囲気等の不活性雰囲気中又はアンモニ
アガス雰囲気中で降温、冷却して、第２焼成芯体を形成
することを特徴とする焼成色鉛筆芯の製造方法。1. A kneading composition comprising at least a body material and an organic excipient, kneading, extruding, and firing in a non-oxidizing atmosphere to convert the carbonized carbon of the organic excipient into a binder. A first fired core to be formed, and heating the first fired core in an oxidizing atmosphere to oxidize and remove the carbon binder to form a second fired core; Is impregnated with a perhydropolysilazane-containing liquid, and a third fired core is produced by heat treatment in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to produce silicon nitride. In the manufacture of a fired pencil lead in which ink is filled in the pores, the carbon binder of the first fired core is removed by heating, and then the temperature is lowered and cooled in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere. And on the way Manufacturing a fired colored pencil lead, wherein the temperature is kept constant in a vacuum state, and the temperature is lowered and cooled in an inert atmosphere such as a nitrogen atmosphere or an ammonia gas atmosphere to form a second fired lead. Method.