KR100519572B1 - Conductive Glass Lining Composition - Google Patents

Abstract

The conductive glass lining composition comprises 100 parts by weight of frit and 0.05 to 1.5 parts by weight of metal fibers having a diameter of 0.1 to 30 μm, a length of 1.5 to 10 mm and a length to diameter ratio of 50 or more.

Description

Conductive Glass Lining Composition

The present invention relates to a conductive glass lining composition for a glass-embedded device using a low carbon steel sheet or a stainless steel sheet as a base material capable of withstanding high use conditions in the chemical, medical, and food industries.

Conventional glass lining apparatus typically has a thickness of about 0.2 to 0.4 mm on a substrate, such as a low carbon steel sheet or a stainless steel plate, for heating the ground coat glaze to the substrate strongly, and then typically 0.8 to 2.0 thick. It has been produced by cover coat glaze heating with high corrosion resistance at mm.

Since the glass lining material constituting the glass-embedded device is an insulating material having a volume resistivity of approximately 1 × 10 ¹³ to 10 ¹⁴ Ωcm, if the glass lining device is operated and stirred using a nonaqueous organic liquid, The amount of charged charge is much greater than the amount of leak charge and generates tens of thousands or hundreds of thousands of volts of static electricity, and even if the glass embedded device is grounded, this causes breakage or explosion of the glass lining material.

In order to overcome the above problems, when the glass-embedded device is operated to stir the non-aqueous organic liquid, the Ta metal chip is previously embedded in the glass lining layer or the Ta metal wire is wound on the surface of a baffle or the like. However, it is difficult to cover the entire surface of the glass lining with Ta metal, and sufficient measures against static electricity have not yet been obtained. Moreover, when a large amount of static electricity is expected, a metal device such as stainless steel is used instead of the glass embedded device.

As an example of the glass built-in apparatus which has an antistatic means, Japanese Utility Model Publication No. 7-28834 covers the interior of a glass-embedded metal can with a lower glass coating layer, wherein the glass is coated with an upper glass (where the upper glass is made of a conductive glass encapsulated with platinum wire in contact with the base of the metal can). A built-in metal can is described. However, parts not buried with platinum wire cannot be expected to have many antistatic properties of glass lining.

In addition, Japanese Patent Publication No. 60-25380 adds 0.1 to 3 mm inorganic fiber length to a frit strip having a predetermined glass composition that adds 2 to 10% of the fiber to 100% of the strip, and spray gun or in a deposition bath. It describes a method for producing a glass interior product by glazing. Inorganic fibers exemplified in this publication include enameled glass or glass having a composition different from commercial glass; Natural optical fibers such as rock fibers and kaowool; It is a fiberized material from artificial ceramic fibers or whiskers such as zirconia, alumina, chromium oxide and the like. The purpose of fiber addition is to reduce bubbles in the enamel product, to prevent large bubbles and to improve chromosomal blot resistance, glazing crack resistance, thermal shock resistance and mechanical impact resistance.

Japanese Patent Publication No. 4-8390 describes a glaze composition comprising a frit, wherein the glaze composition comprises 100 parts by weight of the frit and 20 to 100 parts by weight of inorganic whisker having a diameter of 0.2 to 1 μm and a length to diameter ratio of less than 20. Whiskers are inorganic single crystal fibers selected from the group consisting of titania, potassium titanate, alumina, silicon carbide and silicon nitride. The purpose of the addition of whiskers is to impart cutting machinability to the glass lining and to improve wear resistance.

Accordingly, it is an object of the present invention to provide a conductive glass lining composition capable of providing a conductive glass lining exhibiting excellent volume resistivity.

In the present invention, the conductive glass lining composition comprises 100 parts by weight of frit and 0.1 to 30 μm in diameter, 1.5 to 10 mm in length, and 0.05 to 1.5 parts by weight of metal fiber having a length to diameter ratio of 50 or more.

It is preferable that the diameter of the metal fiber used in the conductive glass lining composition of the present invention be small in view of the amount of metal fiber added to the glass lining composition and the spray glazing performance relationship of the composition. The diameter is in the range of 0.1 to 30 μm, preferably 0.5 to 10 μm. If the diameter of the metal fibers is less than 0.1 μm, the metal fibers are difficult to process and their cost currently hinders their use. If the diameter exceeds 30 μm, the slip viscosity of the glass lining composition is poor and the spray glazing performance is significantly lowered. Thus, less than 0.1 μm in diameter and more than 30 μm are undesirable. The smaller the diameter of the metal fibers, the larger their apparent volume, the reduction in the amount of added metal fibers is possible and the advantages of firing glass linings and from a production engineering point of view.

The length of the metal fiber is in the range of 1.5 to 10 mm, preferably 1.5 to 5.0 mm. If the length of the metal fiber is less than 1.5 mm, the metal fiber is difficult to cut short. If the length is more than 10 mm, the slip viscosity of the glass lining composition is poor and the spray glazing performance is significantly lowered. Thus, less than 1.5 mm in length and more than 10 mm are undesirable.

The length-to-diameter ratio of the metal fibers should be at least 50. If the length-to-diameter ratio of the metal fibers is less than 50, a large amount of metal fibers is needed to improve the conductivity of the glass lining. Thus, a length to diameter ratio of less than 50 is undesirable.

In the conductive glass lining composition of the present invention, the dimension of the metal fiber used herein is in the above range. However, the dimensions and some of the metal fibers may be smaller than the above range. When metal fibers are mixed with the following frits, the metal fibers are ground and cut into small dimensions. When glazing and coating the conductive glass lining composition, the pulverized metal fibers may also be mixed into metal fibers having dimensions in the above range. This mixture does not affect the conductivity obtained through the conductive glass lining coating layer.

The conductive glass lining composition of the present invention comprises the metal fiber. Similar advantages can be obtained by the addition of metal powder, such as platinum powder, instead of metal fiber to the frit. However, addition of at least 10% of the metal powder is necessary to obtain a volume resistivity similar to the volume resistivity of the glass lining composition comprising the metal fibers. As this increases the cost, the metal powder cannot actually be used. Moreover, when at least 10% of the metal powder is added, it is difficult to obtain a combustion smooth surface of the glass lining, and further bubbles are generated. Therefore, metal powder is not suitable in terms of quality.

The metal fiber is composed of a plurality of fibers selected from the group consisting of stainless steel type metal fibers, precious metal type metals, and alloy fibers of platinum and platinum group metals. Regarding the stainless steel metal, SUS-316 fibers having a volume resistivity of 7.4 × 10 ⁻⁵ μm cm, SUS-304 fibers having a volume resistivity of 7.2 × 10 ⁻⁵ μm cm, and the like can be used. As for the noble metal fiber, Ag fibers having a volume resistivity of 1.6 × 10 ^-6 cm ³ , Au fibers having a volume resistivity of 2.4 × 10 ^-6 cm ³ , Pt fibers having a volume resistivity of 10.6 × 10 ^-6 cm ³ , and the like can be used. Regarding alloy fibers of platinum and platinum group metals, alloys of Pt and Pd, Ir, Rh, Os and / or Ru can be used as an example.

The conductive glass lining composition of the present invention can be used as a ground coat or cover coat. For ground coats that do not require chemical oxidation resistance and require strong adhesion of the base metal, cheap stainless steel group metal fibers are preferred. As for the cover coat requiring chemical oxidation resistance, noble metal-type metal fibers, alloy fibers and the like are preferable.

The amount of metal fibers added to 100 parts by weight of the frit is 0.05 to 1.5 parts by weight, preferably 0.05 to 1.0 parts by weight. If the addition amount of metal fiber is less than 0.05 weight part, the big improvement of electroconductivity cannot be anticipated. If the added amount exceeds 1.5 parts by weight, the slip viscosity of the glass lining composition is poor and the spray glazing performance is significantly lowered. Therefore, less than 0.05 parts by weight and more than 1.5 parts by weight is not preferable. Within this range of metal fiber addition amount, excellent glass lining quality without bubbles and irregularities on the combustion surface of the glass lining can be obtained.

The frit used in the conductive glass lining composition of the present invention is not particularly limited. You can use any regular frit. For example, the following frits of compositions (A) to (E) can be used:

(A) 46 to 67 wt% (40 to 75 mol%) of SiO ₂ + TiO ₂ + ZrO ₂ , wherein SiO ₂ is 46 to 67 wt% (40 to 75 mol%) and TiO ₂ is 0 to 18 Weight percent (O to 20 mol%) and ZrO ₂ is 0 to 12 weight percent (O to 12 mol%); weight percent of (A) is calculated as SiO ₂ );

(B) 8 to 22 wt% (7 to 22 mol%) of R ₂ O (wherein Na ₂ O is 8 to 22 wt% (7 to 22 mol%) and K ₂ O is 0 to 16 wt% ( 0-15 mole%) and Li ₂ O is 0-10% by weight (O-15 mole%); the weight% of (B) is calculated as Na ₂ O);

(C) 0.9-7 wt% (1-7 mol%) RO (wherein CaO is 0.9-7 wt% (1-7 mol%), BaO is 0-6 wt% (O-6 mol%) , ZnO is 0 to 6% by weight (O to 6 mol%) and MgO is 0 to 5% by weight (O to 6 mol%); the weight percent of (C) is calculated as CaO);

(D) 0 to 22% by weight (O to 20 mol%) of B ₂ O ₃ + Al ₂ O ₃ , wherein B ₂ O ₃ is 0 to 22% by weight (O to 20 mol%), A1 ₂ O ₃ is 0 to 6% by weight (O to 10 mol%), and the weight% of (D) is calculated as B ₂ O ₃ );

(E) 0 to 5 wt% (O to 4 mol%) of CoO + NiO + MnO ₂ , wherein CoO is 0 to 5 wt% (O to 4 mol%) and NiO is 0 to 5 wt% (O To 4 mole%) and MnO ₂ is 0 to 5% by weight (O to 4 mole%); the weight% of (E) is calculated as CoO).

As the coloring component, one or more components selected from Sb ₂ O ₅ , Cr ₂ O ₃ , Fe ₂ O ₃ and SnO ₂ may also be added. The amount of the component added to 100 parts by weight of the frit composition is 5% by weight (5 mol%) or less calculated for Fe ₂ O ₃ . To prepare frit fusions, up to 5 mol% of fluoride can be used for SiO ₂ , CaO or Na ₂ O. For example, Na ₂ SiF ₆ may be partially used in place of SiO ₂ or Na ₂ O, CaF ₂ in place of CaO and Na ₃ AlF ₆ in place of Al ₂ O ₃ . Moreover, all of these components are commonly used in frits.

The glass lining composition of this invention can be glazed on a general base material, for example, a low carbon steel plate, a stainless steel plate, etc. by a conventional method. Of course, various combinations of materials can be added and the glazing time can be varied with use. For example, a common glass lining composition can be used as a ground coat and the conductive glass lining composition of the present invention can be used as a cover coat; The conductive glass lining composition of the present invention can be used as a ground coat and the general glass lining composition as a cover coat; The conductive glass lining composition of the present invention can be used as both ground and cover coat.

According to the conductive glass lining composition of the present invention, it is possible to provide a glass lining having a low volume resistivity.

EXAMPLE

The conductive glass lining composition of the present invention will be further described by the following examples and comparative examples.

Example

Table 1 shows the blending ratio (% by weight) and the composition (mol%) used as the ground coat and the cover coat.

TABLE 1

As shown in Table 2, wheat flour was prepared by mixing various parts by weight, 2 parts by weight of clay, 0.05 parts by weight of CMC, 0.3 parts by weight of barium chloride and 100 parts by weight of a ground coat or cover coat with an appropriate amount of water. Metallic fibers are stainless steel fibers, and platinum fibers (1) and (2). Stainless steel fibers are available from Nasu Bussan K.K. It is prepared by the process and is 8 탆 in diameter and 2 mm in length. Platinum Fiber (1) Silver Tanaka Kikinzoku K.K. It is prepared by the process and is 0.5 micrometer in diameter and 2 mm in length. The platinum powder used in the comparative example is Koujundokagaku Kenkyuusho K.K. It is prepared by and has a diameter of 1 to 10 μm.

TABLE 2a

TABLE 2b

The volume resistivity of the specimen obtained using the three-terminal method is evaluated as shown in FIG. 1. The results are also shown in Table 2.

From Table 2, Examples 1 to 3 and 6 to 11 which add metal fibers to the ground and cover coat have significantly lower volume resistivity and better conductivity than Comparative Examples 12 and 13 which do not add metal fibers to the ground and cover coat. It is clear to indicate.

The volume resistivity of Example 4 which does not add a metal fiber to a ground coat is 1.5 * 10 <^10> Pacm. The volume resistivity of Example 5 which does not add a metal fiber to a cover coat is 1.3 * 10 <^11> Pacm. Although these results do not show significantly lower values compared to Examples 1 to 3 and 6 to 11, they show better values compared to Comparative Examples 12 and 13. Thus, Examples 4 and 5 may also be sufficient for actual use, depending on cost and use.

The volume resistivity of the comparative example 14 which adds 5 weight part of platinum powders is 2.5 * 10 <^14> Pacm. The volume resistivity of the comparative example 15 which adds 20 weight part of platinum powders is 4.7x10 <^3> cm <cm>. The addition of 20 parts by weight of the platinum powder obviously indicates a value of the volume resistivity of the glass lining similar to that of the conductive glass lining composition of the present invention. However, platinum powder is expensive and cannot be used in glass linings in terms of cost.

The present invention provides a conductive glass lining composition exhibiting excellent volume resistivity.

1 is a layout showing the three-terminal measurement of the volume resistivity in the samples obtained through Examples and Comparative Examples.

Claims (3)

A conductive glass lining composition comprising 100 parts by weight of frit and 0.05 to 1.5 parts by weight of a metal fiber having a diameter of 0.1 to 30 μm, a length of 1.5 to 10 mm, and a length to diameter ratio of 50 or more, wherein the metal fiber is formed of platinum or platinum group metals. Compositions that are alloy fibers or precious metal fibers. The composition of claim 1 wherein the metal fibers are platinum fibers. The composition of claim 1 wherein the frit has the following compositions (A)-(E): (A) 46 to 67 weight percent SiO ₂ + TiO ₂ + ZrO ₂ , wherein SiO ₂ is 46 to 67 weight percent, TiO ₂ is 0 to 18 weight percent and ZrO ₂ is 0 to 12 weight percent; (B) 8 to 22% by weight of R ₂ O, wherein Na ₂ O is 8 to 22% by weight, K ₂ O is 0 to 16% by weight, and Li ₂ O is 0 to 10% by weight; (C) 0.9-7 weight percent RO (wherein CaO is 0.9-7 weight percent, BaO is 0-6 weight percent, ZnO is 0-6 weight percent, MgO is 0-5 weight percent); (D) 0-22 weight percent B ₂ O + Al ₂ O ₃ , wherein B ₂ O ₃ is 0-22 weight percent and A1 ₂ O ₃ is 0-6 weight percent; (E) 0-5% by weight of CoO + NiO + MnO ₂ , wherein CoO is 0-5% by weight, NiO is 0-5% by weight and MnO ₂ is 0-5% by weight.