JP2006142189A - Heating control method of coating-baking furnace and exterior material using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a heating control method of a coating-baking furnace capable of controlling baking temperature and baking time freely within a range permitting retention of properties of a substrate and realizing drying conditions for satisfying the properties of individual layers in the case of forming a multi-layered coating, and to provide an exterior material using it. <P>SOLUTION: The coating-baking furnace is used for baking coating layers consisting of a plurality of coatings on the base material. The heating control method of the coating-baking furnace can execute control by individually calculating a desired heating amount to each of the coating layers. The method includes the steps of measuring heating time required for heating the substrate in a plurality of temperature-setting conditions in the furnace and surface temperature at the time of heating in advance, integrating the heating time and the surface temperature and regulating the quantity of heating to the quantity of heat before the substrate is changed into a state of being not good in performance by using a value calculated as the sum of integrated value as the quantity of heating required for curing. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a heating control method for a coating baking furnace and an exterior material using the same.

  Conventionally, for example, when multi-layer baking coating is applied to a base material that is an inorganic board of ceramics, for example, as an exterior material, the lower layer paint is not sufficiently baked on the base material. In such a state, when the upper layer which is the next layer is baked and coated, the two coatings may be mixed with each other and the coating film performance may not be sufficiently exhibited, or the appearance may become defective. On the other hand, when the upper layer is painted after the lower layer is excessively baked, adhesion failure between the two layers may occur. Therefore, in order to eliminate the above problems, it was necessary to check the coating film performance in each condition setting. Also, in the coating of other industrial products, many of the drying conditions are set by trial and error of performance and appearance.

  By the way, as a heating control method for painting metal plate baking, in Japanese Patent No. 3219927, in a heating furnace for painting metal plate baking having one or a plurality of regions in the furnace, each region is required to be independently heated. When calculating the amount, the necessary heating amount of the coating film is regarded as the necessary heat amount accompanying the change in the state of the coating film, the amount of heat necessary for raising the solid content of the paint applied just before the baking furnace, There is shown a technique of a heating control method for calculating the sum of one or more heat quantities of a group consisting of heat and the amount of heat required for volatilization.

  However, when this technique is applied to two-layer coating on a ceramic substrate, the required heating amount is the amount of heat required to raise the solid content of the paint, the temperature rise and volatilization of the volatile matter of the paint. It will be based on the amount of heat required for.

Therefore, considering the application of exterior materials to baking coating, it is assumed that the base material will be defective in performance when more heat is applied than necessary. It is not considered that.
Japanese Patent No. 3219927

  The present invention has been made in view of the above-described background art, and the problem is that when performing multi-layer coating, the baking temperature and baking time are freely set within a range in which the performance of the substrate can be maintained. The present invention is to provide a heating control method for a coating baking furnace and an exterior material using the same, which can realize drying condition control for satisfying performance.

  In order to solve the above problems, a heating control method for a coating baking furnace according to the present invention is a coating baking heating furnace in which a coating layer of a plurality of coatings is baked and coated on a base material in a heating furnace, In contrast to the heating control method of the baking furnace for coating baking, which calculates and controls the required heating amount independently for each coating layer, it is necessary to increase the temperature of the substrate under a plurality of temperature setting conditions in the heating furnace in advance. The warming time and the surface temperature at that time are measured, the heating time and the surface temperature are integrated, the value calculated as the sum of the integrated values is set as the required heating amount required for curing, and the required heating amount is It is characterized by controlling the amount of heat to be equal to or less than the amount of heat before the base material changes to a state that causes a problem in performance.

  And it is preferable that the said required heating amount includes the coating-curing time by the residual heat after heat-drying.

  In the exterior material according to the present invention, the base material is a ceramic-based inorganic plate exterior material, and the paint is a thermosetting paint and is baked.

  The heating control method of the coating baking heating furnace according to the present invention is such that the necessary heating amount required for curing when baking a coating layer of a plurality of coatings on a substrate is determined in advance by a plurality of temperatures in the coating baking heating furnace. As a value calculated as a total of the integrated values by measuring the temperature increase time required for temperature increase of the base material under the set conditions and the surface temperature at that time and integrating the temperature increase time and the surface temperature Because the heating furnace is controlled so that the amount of heat before the base material changes to a state in which the base material becomes defective in performance is controlled, when performing multi-layer coating, it is freely within the range where the base material performance can be maintained. By setting the baking temperature and baking time, it is possible to control the drying conditions to satisfy the performance of each layer.

  And the amount of heat required for curing when baking coating layers with multiple paints on the substrate includes the paint curing time due to the residual heat after heat drying, so that the heat energy is efficiently It can be used to reduce the cost of painting.

  Further, the exterior material of the present invention is a ceramic-based inorganic plate exterior material, and as a result of baking and coating the base material as a ceramic-based inorganic plate exterior material and the paint as a thermosetting paint, the ceramic-based inorganic plate Since the thermosetting paint is baked and controlled so as to be equal to or less than the amount of heat before the exterior material changes to a state that causes a problem in performance, the performance is easily maintained.

  In order to clarify the above and other effects, features and advantages of the present invention, embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

  Referring to FIG. 1, a substrate temperature rising pattern as Example 1 of the present invention is shown. 2 and 3 are explanatory views according to different examples showing the relationship between the amount of heat and the performance of the base material shown in FIG.

  The heating control method of the coating baking furnace is a coating baking furnace in which a coating layer of a plurality of coatings is baked and coated on the base material in the heating furnace, and is independently required for each coating layer. In a heating control method for a coating baking furnace that calculates and controls the amount of heating, the heating time required for raising the temperature of the substrate under a plurality of temperature setting conditions in the heating furnace and the surface temperature at that time are measured in advance. Then, the temperature rise time and the surface temperature are integrated, and the value calculated as the sum of the integrated values is set as the required heating amount required for curing, and the required heating amount is set in a state where the base material becomes a malfunction. Control to keep below the amount of heat before the change.

  Further, the heating control method of the heating furnace for painting baking according to the present embodiment is an exterior material described below, wherein the base material is a ceramic-based inorganic board exterior material, and the paint is a thermosetting paint and is baked. It is effectively applied to the manufacture of

  Specifically, first, the temperature rise time required for raising the temperature of the substrate under a plurality of temperature setting conditions in the heating furnace and the surface temperature at that time are measured in advance. In this case, a thermocouple is attached to the base material, the base material is put into a heating furnace, and the change in surface temperature with time is measured. Note that the measurement time interval is, for example, every 1 second, and the measurement is continued until a time when a problem occurs in the substrate due to overdrying as a result of heating. Thereby, from the obtained measurement data of the surface temperature change, the elapsed time as the baking time and the surface temperature at that time are integrated, and an amount calculated as the sum of the integrated values is required for curing. The amount of heat for curing (maturity).

  Next, the time when the substrate is in a defective state, that is, the heating condition at which the failure occurs in performance is calculated. By the way, when the lower layer is not sufficiently baked and the upper layer is coated, there are cases where the two layers are mixed and the performance is not good or the appearance desired to be expressed is not obtained. Further, when the upper layer is painted after excessively baking the lower layer, adhesion failure may occur between the two layers. Therefore, in order to ascertain the baking conditions, first, the lower layer paint is applied to the base material, taken out every predetermined time under the same heating furnace temperature setting as above, and the upper layer paint is applied. Evaluate performance. Note that. The time until removal is not particularly limited, but it is preferable to uniformly include the range where the above-mentioned troubled state occurs to the range where it does not.

  Thereafter, the same evaluation as described above is performed from the surface temperature measurement under a plurality of temperature setting conditions of the heating furnace, and the surface temperature is measured from the range where the above-mentioned defective state occurs to the range where it does not. In this case, the temperature setting condition of the heating furnace is preferably a temperature condition setting of three or more levels, and for each, the amount of curing heat (maturity) is calculated, and the pass / fail judgment result of the evaluation of the temperature condition value and the coating film performance Therefore, the relationship between the amount of curing heat (maturity) and the coating film performance in the application of the target paint is required.

  The coating performance is greatly affected by the type and amount of the curing agent when the coating is prepared. In the case of a two-component curable coating, there is a baking temperature that greatly contributes to the curing. Similarly to the calculation of the heat quantity (maturity), an effective amount of curing heat (maturity) obtained by multiplying the contributing baking temperature and the time is obtained. By obtaining the relationship between this effective curing heat quantity value and determination of acceptance / rejection of the coating film performance, the accuracy can be further improved in many baking settings.

  Moreover, it is also preferable to utilize the paint hardening effect | action by the remaining heat after performing heat drying. For example, in the drying process, up to 90% of the target curing is performed, and the remaining 10% is cured by the residual heat immediately after drying.

  By calculating the amount of curing heat (maturity) according to the above procedure, it is possible to grasp the time for handling the coating target immediately after drying, or to determine the time for stacking the coating target. .

  In addition, although this invention can be applied when multicolor coating of said ceramics-type exterior material is carried out, if a temperature change of a base material can be measured, a base material will include things other than ceramics-type exterior material. Of course. Furthermore, it is needless to say that the paint used may be a water-based paint in addition to the solvent system, and the coating method is not limited.

Hereinafter, the present invention will be described in detail by way of examples.
<Example 1>
Attach a thermocouple to the surface of the ceramic exterior packaging material, put it in a heating furnace under each temperature setting condition of 140 ° C., 160 ° C., 180 ° C., and 200 ° C. for 20 minutes. The amount of heat (maturity) under each temperature setting condition was calculated from the temperature rise patterns of the four types of substrates. (See Figure 1)
Next, a two-component curable urethane enamel paint, which is a thermosetting paint, is applied to a newly prepared similar base material using a spray so that the coating amount is about 30 g / m @ 2 at regular time intervals. The base material was taken out every time, and thereafter, the urethane-based clear was applied so that the coating amount was about 10 g / m @ 2. At this time, an adhesive tape peeling test was performed with respect to coating film adhesion, and the appearance was visually evaluated. The results are indicated by ○ × in the figure (see FIG. 2: ○ is no problem in appearance performance, × is a problem in appearance or performance).
<Example 2>
The heating time and surface temperature are integrated, and the value calculated as the sum of the integrated values is taken as the required heating amount required for curing. In this case, the amount of heat is calculated except that the effective temperature is 80 ° C. or higher. Evaluated the external appearance by preparing a sample for evaluation in the same manner as in Example 1. The results are shown in FIG. 3 with the horizontal axis as the drying time (unit: minutes) and the vertical axis as the heat quantity (unit: maturity).

After heating and drying at 160 ° C. for 6 minutes under the temperature setting conditions of Example 1, an interval of 120 seconds was applied until the two coated substrates were stacked. The result was good without blocking.
<Comparative Example 1> A sample was prepared and evaluated in the same manner as in Example 1 except that a 10-second interval was left until two substrates were stacked. Became a bug.

  As a result of the above, when multi-layer coating is performed, the drying conditions for satisfying the performance of each layer are specified in advance in the calorific value (maturity) range, and the baking temperature and baking time can be freely designed within that range. can do.

  It should be noted that the present invention is not limited to the above-described embodiments, and it is obvious that the embodiments can be appropriately changed within the scope of the technical idea of the present invention.

Explanatory drawing which shows the base-material temperature rising pattern in Example 1 of this invention. Explanatory drawing which shows the relationship between the calorie | heat amount (maturity) and board | substrate performance as the Example 1. FIG. Explanatory drawing which shows the relationship between the amount of heat | fever (maturity) when the effective temperature is 80 degreeC as the Example 2, and board | substrate performance.

Claims (3)

A paint baking heating furnace in which a coating layer of a plurality of paints is baked and coated on a base material in a heating furnace, and the necessary heating amount is calculated and controlled independently for each coating layer. In the heating control method of
The temperature rise time required for raising the temperature of the substrate under a plurality of temperature setting conditions in the heating furnace and the surface temperature at that time are measured in advance, and the temperature rise time and the surface temperature are integrated. Paint baking, characterized in that the value calculated as the sum is the required heating amount required for curing, and the required heating amount is controlled to be equal to or less than the amount of heat before the base material changes to a state in which the base material becomes defective in performance. Control method for the heating furnace.   2. The heating control method for a coating baking furnace according to claim 1, wherein the required heating amount includes a paint curing time due to residual heat after heat drying.   An exterior material obtained by baking the base material according to claim 1 or 2 as a ceramic-based inorganic board exterior material and using the paint as a thermosetting paint.

Images