JPH05310481A - Porous sheetlike refractory and its production - Google Patents

Abstract

PURPOSE:To obtain a sheet having low reactivity with a product without causing uneven burning by forming moderate pores and reducing the thickness in a porous sheetlike refractory used for burning electronic parts. CONSTITUTION:The objective porous sheetlike refractory is obtained by bonding 50-90 pts.wt. aggregate having >=30mum diameter composed of a refractory material with 10-50 pts.wt. inorganic binder having <=10mum diameter in a ceramic tool used for mainly burning electronic parts. Alumina, mullite, zirconia, magnesia, spinel or andalusite can be used alone or in combination with these aggregate and inorganic binder. The apparent porosity thereof is >=10% and its thickness is 0.3-5mm. The method for producing the sheetlike refractory is to form a green sheet by wet molding according to the extrusion or roll molding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a porous sheet-like refractory as a kiln tool mainly used for firing electronic parts and a method for producing the same.

[0002]

2. Description of the Related Art At present, as a sheet-shaped refractory used as a kiln tool for firing electronic parts and the like, a porcelain alumina-based ceramic having few pores is used to maintain strength. However, since these conventional sheet-shaped refractories have almost no pores, there is no air permeability and the gas flow is poor, and when firing electronic parts or the like using this, firing unevenness occurs and the characteristics are adversely affected, Further, since the decomposed products or volatile products of the binder do not permeate the sheet, there is a problem that these decomposed products or volatile products adhere to the product. There is also a problem that the product adheres to the sheet because the surface is too smooth. Further, the sheet for firing electronic parts needs to have a low heat capacity in order to improve the heat spalling property and prevent baking unevenness. Therefore, a sheet having a small thickness has been desired. Since a sheet is manufactured by semi-dry and semi-wet press molding, and uneven density is likely to occur, it is difficult to manufacture a uniform thin sheet.

The present invention provides a sheet-shaped kiln tool used for firing electronic parts and the like, which is a porous sheet-shaped refractory having low reactivity with a product, a small thickness, and no uneven baking of the product. The purpose is.

[0004]

The porous sheet-like refractory of the present invention is an aggregate 5 having a diameter of 30 μm or more, which is composed of a refractory material in a kiln tool mainly used for firing electronic parts.
The inorganic binder having a diameter of 10 μm or less is bonded to 10 to 50 parts by weight with respect to 0 to 90 parts by weight, which solves the above problems. In such a sheet-shaped refractory material of the present invention, alumina, mullite, zirconia, magnesia, spinel, and undaleusite can be used alone or in combination as the aggregate and the inorganic binder. Then, in order to manufacture this sheet-shaped refractory, an aggregate 50 composed of a refractory material and having a diameter of 30 μm or more is used.
To 90 parts by weight of inorganic binder 1 having a diameter of 10 μm or less
By kneading 0 to 50 parts by weight and forming a green sheet by wet molding such as extrusion molding or roll molding. The green sheet obtained by wet molding can be fired as it is, or can be fired after being machined by a press or the like.

In the present invention, when the aggregate composed of the refractory material is less than 30 μm and the particle size of the inorganic binder is less than 10 μm, the apparent porosity of the sheet-like refractory fired using this is less than 10%, It will not have sufficient breathability. If the proportion of the aggregate is less than 50 parts by weight, the air permeability will decrease, and conversely, if the amount of the aggregate exceeds 90 parts by weight, the strength will decrease. On the other hand, if the amount of the inorganic binder is less than 10 parts by weight, the strength is lowered, and conversely, if it exceeds 50 parts by weight, the air permeability is lowered.

The sheet-like refractory according to the present invention has the apparent porosity of 10% or more, and becomes a breathable sheet because of the structure in which the aggregate and the inorganic binder are bonded as described above. Unevenness can be prevented. In addition, the decomposition products or volatile substances of the binder permeate the sheet, and the product is not adversely affected. Further, since the surface of the sheet has microscopic unevenness and is porous, the contact portion between the product and the sheet is small, so that the product and the sheet are not fixed to each other.

Further, in the method of the present invention, since a green sheet can be formed by wet molding such as extrusion molding or roll molding, a thin sheet having a thickness of 0.3 to 5 mm can be molded. Furthermore, the raw sheet is baked as it is,
Alternatively, it can be fired after performing mechanical processing such as concavo-convex processing such as a mesh pattern, bending processing, punching processing and punching processing with a press machine or the like, and it can be applied to various applications. The sheets can be fired by stacking them.

[0008]

Example 1 80 parts by weight of fused alumina having a diameter of 0.1 mm or less and 30 μm or more as an aggregate, and 1 as an inorganic binder.
10 parts by weight of finely calcined alumina powder having a diameter of 0 μm or less and 10 parts by weight of kibushi clay were mixed, a small amount of organic binder and water were added thereto, and the mixture was kneaded with a clay kneader and a three-roll mill. This is molded into a sheet thickness of 0.5 mm with a vacuum extrusion molding machine,
It was baked at 1750 ° C. to obtain a test piece, and the bulk specific gravity, porosity, room temperature bending strength and spalling resistance were measured. The results are shown in Table 1. The bulk specific gravity and the porosity were calculated by the underwater weight method, and the room-temperature bending strength was measured by the 2-fulcrum-one-point load method.

[0009]

Example 2 70 parts by weight of sintered alumina having a diameter of 0.2 mm or less and 30 μm or more as an aggregate, and 10 as an inorganic binder.
30 parts by weight of calcined alumina fine powder having a diameter of μm or less was mixed, a small amount of an organic binder and water were added thereto, and the mixture was kneaded with a clay kneader. The subsequent steps were the same as in Example 1, but the sheet thickness was 1 mm and the firing temperature was 1600 ° C. The results are also shown in Table 1.

[0010]

Example 3 40 parts by weight of fused alumina having a diameter of 0.5 mm or less and 30 μm or more and 40 parts by weight of fused mullite are used as an aggregate, and 15 parts by weight of finely calcined alumina powder having a diameter of 10 μm or less and a high content as an inorganic binder. This was mixed with 5 parts by weight of fine silica fine powder, a small amount of organic binder and water were added thereto, and the mixture was kneaded with a clay kneader. The following steps were the same as in Example 1, but
The sheet thickness was 2 mm and the firing temperature was 1750 ° C. The results are also shown in Table 1.

[0011]

Example 4 90 parts by weight of CaO-stabilized fused-iron zirconia having a diameter of 1 mm or less and 30 μm or more as an aggregate, and 10 parts by weight of fine zirconia powder having a diameter of 10 μm or less as an inorganic binder were mixed with a small amount of an organic binder. Water was added and the mixture was kneaded with a clay kneader. The subsequent steps were the same as in Example 1, but the sheet thickness was 2 mm and the firing temperature was 1600 ° C. The results are also shown in Table 1.

[0011]

[Table 1]

Table 1 shows comparative examples of Examples 1 to 4 of the present invention and a conventional porcelain product. The porcelain product has almost no pores, and problems such as adhesion of the product and the sheet are caused. In contrast to the above, in each of the examples, there was a proper porosity, and therefore, no problem occurred. Further, the spalling resistance in each of the examples was significantly improved as compared with the conventional product. Further, the room-temperature bending strength was lower than that of the conventional product, but the strength of the example was sufficient under normal use conditions.

[0013]

As described above, according to the present invention, in the porous sheet-like refractory used for firing electronic parts, by forming appropriate pores and reducing the thickness, reactivity with the product can be improved. It is possible to obtain a sheet that is low and has no baking unevenness.

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁵ Identification number Reference number within the agency FI technical display location C04B 35/64 J F27D 5/00 6977-4K (72) Inventor Toshiyuki Fukuyama Asmuta, Omuta City, Fukuoka Prefecture 1 in Mitsui Mining & Smelting Co., Ltd. Omuta Plant (72) Inventor Yuji Suyama 3 in Asmuta-cho, Omuta City, Fukuoka Prefecture 1 In Mitsui Metal Mining Co., Ltd. Omuta Plant

Claims (6)

[Claims] 1. In a kiln tool mainly used for firing electronic parts, 10 to 50 parts by weight of an inorganic binder having a diameter of 10 μm or less is bonded to 50 to 90 parts by weight of an aggregate having a diameter of 30 μm or more made of a refractory material. A porous sheet-like refractory characterized by being made. 2. The porous sheet-shaped refractory material according to claim 1, wherein alumina, mullite, zirconia, magnesia, spinel, and underluesite are used alone or in combination as the aggregate and the inorganic binder. 3. The apparent porosity is 10% or more.
Porous sheet refractory described. 4. The porous sheet-like refractory material according to claim 1, which has a thickness of 0.3 to 5 mm. 5. When manufacturing a kiln tool mainly used for firing electronic parts, 10 to 50 parts by weight of an inorganic binder having a diameter of 10 μm or less is used with respect to 50 to 90 parts by weight of an aggregate having a diameter of 30 μm or more, which is made of a refractory material. A method for producing a porous sheet-shaped refractory material, which comprises kneading parts and forming a green sheet by extrusion molding or wet molding by roll molding. 6. The method according to claim 5, wherein the green sheet obtained by the wet forming is fired as it is or is fired after being machined by a press or the like.