JP6120148B2 - Low moisture glaze for eggplant - Google Patents

Description

  The present invention relates to an improvement of an insulator glaze applied to the surface of a porcelain insulator, and particularly relates to a low moisture glaze for insulator with reduced moisture.

  The glaze for the insulator applied to the surface of the porcelain insulator has the role of improving the product strength, improving the water repellency and improving the aesthetic appearance. In order to achieve these roles, it is necessary that the glazed glaze has a predetermined thickness (skin thickness). If the thickness is insufficient, the appearance will be poor, and sand adhesion with glaze will not be successful. Sand is a porcelain particle that is adhered to the surface of a porcelain insulator in order to increase the bonding strength when the metal fitting is bonded to the insulator.

  The present inventor has studied methods for increasing the viscosity of the glaze, methods for increasing the number of glazing, methods for reducing the glazing speed, methods for using a low-moisture glaze, and the like as measures for stably improving the thickness of the glaze. . However, increasing the viscosity of the glaze makes it difficult to spray the insulator surface with the spray. Increasing the number of times of glazing increases the production cost because the number of processes increases, and decreasing the glazing speed reduces productivity. Turned out to be. For this reason, it is considered that the method using a low moisture glaze is most effective as a measure for improving the thickness.

  However, when a low-moisture glaze is prepared and pulverized, it becomes highly viscous, which makes it impossible to pulverize and transport. In addition, it is possible to use a high-moisture glaze at the time of blending, and then lower the moisture content to lower the viscosity. However, there is a risk of precipitation after the blending, and a dehydration step is required when the moisture content is lowered, which complicates the process. There is a problem. For this reason, it is not preferable to reduce the water content after the preparation and pulverization, and it is desirable to reduce the water content of the glaze from the stage of preparation and pulverization.

  In addition, patent document 1 which concerns on the application of this applicant discloses adjusting the viscosity of the glaze for an insulator by adding CMC (carboxymethylcellulose) in a glaze. However, although CMC is effective for adjusting the viscosity of the glaze at the time of glazing, it cannot be expected to be effective in reducing the moisture content of the glaze from the stage of preparation and pulverization.

Japanese Patent Laid-Open No. 10-265240

  Therefore, the object of the present invention is effective in solving the above-mentioned conventional problems and stably increasing the thickness of the cocoon, and the moisture content is reduced from the stage of preparation and pulverization, and it is necessary to adjust the moisture during glazing. It is to provide a low moisture glaze for eggplant.

The low moisture glaze for insulators of the present invention made to solve the above problems comprises a basic glaze component, a pigment component, a dispersant, and moisture, and the dispersant is a polycarboxylic acid having a molecular weight of 5,000 to 300,000. It is an acid salt, and the external addition rate of water when the mass of the basic glaze component is 100% is 25 to 33 mass%.

In addition, it is preferable that polycarboxylic acid salt is either polycarboxylic acid sodium salt or polycarboxylic acid ammonium salt . Moreover, it is preferable that the addition rate of the said dispersing agent is 0.05-0.15 mass% when the mass of a basic glaze component is 100%. Further, the basic glaze component is preferably a pulverized product of feldspar, talc, dolomite, and quartz sand as a main component.

The low moisture glaze for insulators of the present invention contains a polycarboxylate having a molecular weight of 5,000 to 300,000 as a dispersant, so that the viscosity can be reduced even when the moisture is reduced to 25 to 33% by mass from the stage of preparation and pulverization. It can be suppressed to 10P or less as in the prior art. If such a low moisture glaze is applied to the insulator surface, the thickness can be stably controlled within a suitable range of 0.4 to 0.5 mm, improving product strength, improving water repellency, The role of improving aesthetics can be achieved. As will be described later, water glass (sodium silicate), which has been used as an inorganic dispersant in the past, cannot achieve a target viscosity of 18P or less unless the water content is 35% or more. It is not possible.

It is a graph which shows the relationship between a dispersing agent addition rate, a water | moisture content, and a viscosity at the time of using an inorganic dispersing agent (water glass). It is a graph which shows the relationship between a dispersing agent addition rate, a water | moisture content, and a viscosity at the time of using a polycarboxylate. It is a graph which shows the relationship between a dispersing agent addition rate at the time of using polycarboxylate (sodium polycarboxylate) as a dispersing agent, and a glaze water | moisture content. It is the graph which showed the relationship between the kinematic viscosity of a glaze and the obtained thickness.

Embodiments of the present invention will be described below.
The low moisture glaze for insulator of the present invention contains a basic glaze component, a pigment component, a dispersant, and moisture. The basic glaze component is the same as the conventional glaze glaze used in the past, and is prepared by pulverizing and crushing feldspar, talc, dolomite, silica sand and the like. As the pigment component, ZnO and other known pigments are added. When the mass of the basic glaze component is 100%, the pigment component is generally added in an amount of about 3 to 6% by external distribution.

  In the present invention, a polycarboxylate is used as a dispersant. Polycarboxylic acid is an organic substance conventionally used as a dispersant for concrete, but inorganic dispersants such as water glass have been used exclusively as dispersants for glazes for insulators. The present inventor uses a polycarboxylate as a dispersant for the glaze for coconut so as to suppress the viscosity to 18 P or less, which is the same as the conventional one, even if the moisture is reduced to 25 to 33 mass% from the stage of preparation and pulverization. I found out that I can. In addition, in this specification, all the values of moisture shall be displayed by the external addition rate when the mass of the basic glaze component is 100%.

As the polycarboxylic acid salt, either a polycarboxylic acid sodium salt or a polycarboxylic acid ammonium salt can be used. There was no significant difference in effect between them. However, if the molecular weight is outside this range, the ability to reduce viscosity in the low moisture region is lost. In addition, the polycarboxylic acid sodium salt can use what is marketed by the brand name of "SN Dispersant 5045", "Nop Cospers 44-C", and "SN Dispersant 2010" from San Nopco, for example. Their molecular weight is 5,000 to 300,000. Moreover, as polycarboxylic acid ammonium salt, what is marketed with the brand name of "Nopcos Perth 6100" from San Nopco Co., Ltd. can be used.

  FIG. 1 is a graph showing the relationship between a dispersant addition rate, moisture and viscosity when a conventional inorganic dispersant (water glass) is used. When the dispersant addition rate indicated by a triangle is 0.2%, the moisture must be 33% or more in order to make the glaze viscosity 18P or less, and even when the dispersant addition rate is 0.4%. In order to make 18P or less, the water content must be 31% or more.

  On the other hand, when a polycarboxylate (sodium polycarboxylate) is used as the dispersant shown in FIG. 2, the viscosity of the glaze is 10 P or less even when the dispersant addition rate is 0.1%. The difference in the effect was remarkable.

  FIG. 3 is a graph showing the relationship between the dispersant addition rate and the water content of the glaze when polycarboxylate (sodium polycarboxylate) is used as the dispersant. As shown in this graph, when the addition rate of the dispersant is 0.05 to 0.15%, the moisture content of the glaze can be reduced to 33% or less. If the dispersant addition rate is less than this range, it becomes highly viscous and pulverization and transportation becomes difficult. Conversely, if the dispersant addition rate is more than this range, precipitation occurs, which is not preferable.

  Thus, the low-moisture glaze for insulators of the present invention can suppress the viscosity to a conventional level even when the moisture is reduced to 25 to 33% by mass from the stage of preparation and pulverization. For this reason, by applying cocoon to the insulator with low moisture and proper viscosity, as shown in the following data, the thickness of the cocoon can be made thicker than before and the incidence of defective glazing can be reduced.

  Based on 100% by mass of the basic glaze component, 5% by mass of a pigment component mainly composed of zinc oxide, 0.1% by mass of sodium polycarboxylate, and 32% by mass of water were prepared and pulverized. A low moisture glaze for eggplant was produced. The sodium polycarboxylate used is “Nopcosperth 44-C” manufactured by San Nopco Co., Ltd., and has a molecular weight of about 10,000 to 100,000. For comparison, 5% by mass of a pigment component mainly composed of zinc oxide, 0.2% by mass of water glass, and 37% by mass of water are prepared and pulverized with respect to 100% by mass of the basic glaze component. A conventional glaze for eggplant was manufactured. The viscosity at the time of preparation and pulverization was in the range of 5 to 10P. About 35% by mass of CMC and PVA as binder components are added to these glazes for coconut, and the viscosity is adjusted. Then, spray glazing is applied to the surface of the long trunk cocoon provided with a number of shades, followed by drying and firing by a conventional method. .

  In order to perform spray glazing smoothly, it is necessary to make the kinematic viscosity coefficient of the glazed glaze within a predetermined range, and the applicant company puts 500 mL of the glazed glaze into a conical container, and the diameter formed at the lower end thereof The kinematic viscosity coefficient of the glaze for the insulator is controlled by the time (unit: second) required to completely flow out from the 1 mm hole. In addition, adjustment of the kinematic viscosity of the glaze at the time of glazing can be easily performed by adding CMC and PVA as in the prior art.

  FIG. 4 is a graph showing the relationship between the above-described kinematic viscosity of the glaze supplied to the glazing apparatus and the obtained thickness. A preferable range of the thickness, that is, an appropriate range is 0.4 to 0.5 mm. On the other hand, glazing is difficult unless the kinematic viscosity value of the glaze is in the range of 50 to 100 s.

  As shown in the figure, in the conventional glaze for cocoon, the kinematic viscosity of the glaze must be 100 s or more in order to set the thickness to 0.45 mm which is the center value of the appropriate range, which is a region where glazing is difficult. is there. For this reason, when the conventional glaze for insulators was used, the thickness was inevitably near the lower limit of the appropriate range. On the other hand, in the case of the low-moisture glaze for insulators of the present invention, it was confirmed that the thickness of the cocoon can be set to 0.45 mm which is the center value of the appropriate range.

  For both glazes, the thermal expansion coefficient and melt flowability of the glazed layer were confirmed, but there was no difference between the conventional glaze for the glaze and the low moisture glaze for glaze of the present invention. It was confirmed that there was no hindrance.

  As described above, the low-moisture glaze for insulators of the present invention has been reduced in moisture from the stage of preparation and pulverization, and it is not necessary to adjust the moisture during glazing. Further, the thickness of the cocoon can be increased stably, which can greatly contribute to the improvement of the product strength of the insulator, the improvement of water repellency, the improvement of aesthetics, the improvement of the sand adhesion, and the like.

Claims (4)

A basic glaze component, a pigment component, a dispersant, and moisture. The dispersant is a polycarboxylate having a molecular weight of 5,000 to 300,000, and the amount of the basic glaze component is 100%. A low-moisture glaze for eggplant characterized by a distribution ratio of 25 to 33% by mass. Polycarboxylates is sodium polycarboxylates, insulators for low moisture glaze of claim 1, wherein a is any one of ammonium polycarboxylate.   The low-moisture glaze for insulators according to claim 1, wherein when the mass of the basic glaze component is 100%, the addition rate of the dispersant is 0.05 to 0.15 mass%.   2. The low-moisture glaze for coconuts according to claim 1, wherein the basic glaze component comprises a pulverized product of feldspar, talc, dolomite, and silica sand as a main component.