JPS5914287A - Method of producing ignition heater - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing an ignition heater used for the purpose of igniting a liquid-burning appliance such as kerosene (for example, an indoor open portaple kerosene stove), and particularly relates to a method for forming a surface coating thereof. It is something.

Conventional ignition heaters of this kind have been used as an ignition source by forming various metal resistor wires into a coil shape and heating the coil with current through a dry battery power supply to generate heat of about 100°C. Since the environment in which ignition heaters are used is extremely harsh both chemically and physically, platinum (-rhodium) wire has been exclusively used as the material for the heater. It is used by winding a white rhodium wire with a diameter of about 0.1 fin into a coil with a diameter of about 1 fin, and setting it on a support such as stainless steel with a dimension of about 6 fin lengths. It's here.

Platinum (-1dium) has excellent physical and chemical properties, but its use, including repeated ignition, is extremely harsh, so it can break in a relatively short period of time. There was a problem with it.

The reasons for this include the following points.

(1) Platinum metal is strong in an oxidizing atmosphere but weak in a reducing atmosphere. Through repeated oxidation and reduction, platinum powder is detached from the surface, the wire diameter gradually becomes thinner, and the resistance value increases. Heating will lead to disconnection.

(2) Platinum metals have a catalytic effect, so they carry out oxidation reactions, dehydrogenation reactions, etc.

The oxidation reaction is exothermic and results in a significant increase in heater temperature. As a result of the temperature rise, creep deformation becomes more severe; this effect, when combined with the impact caused by the repeated operation of crimping and releasing the wick in actual use, also causes a local temperature rise, leading to wire breakage. Ru.

Another drawback is that the catalytic action may oxidize and burn the vaporized kerosene that spontaneously volatilizes when not in use, causing spontaneous combustion, so mechanical measures are not recommended.

In order to solve these conventional problems, the present invention has developed a method for forming a coating to prevent the above-mentioned reactions that lead to disconnection of metal resistor wires (heater wires) and the risk of spontaneous combustion. The object of the present invention is to provide a manufacturing method that has a good preventive effect and can industrially realize 7"L at low cost.

In order to achieve this object, in the present invention, a paint containing an organosilicon polymer is applied to the surface of a metal resistor wire, and then a coating is formed by firing the paint by energizing an ignition heater.

This coating protects the metal resistor wire from chemical reactions that can lead to deterioration of the metal resistor wire. That is, since the exposure of the platinum (rhodium) wire is extremely reduced, the reduction reaction that would lead to deterioration of the platinum (rhodium) wire is prevented, and the influence of the catalytic action is hardly observed.

In addition, due to the effect of silicon carbide compounds formed on the surface,
By imparting rigidity to the platinum (rhodium) wire having a diameter of about 0.1 mm, uneven winding density caused by deformation of the coil can be prevented.

This difference in the density of the coils X leads to local heating and there is a risk of wire breakage, but this coating has the effect of keeping the pitch of the coils constant. When an organosilicon polymer is fired, it is thermally decomposed and becomes ceramic. It becomes amorphous at temperatures around 1oOO°C, where an ignition heater is used.

In this state, the coating exhibits a linear expansion coefficient that almost matches that of the platinum (rhodium) wire, and achieves good adhesion to the platinum (rhodium) wire, which is originally extremely difficult to coat.

In addition, by using this ignition heater, abnormal heating as mentioned above can be prevented, and abnormal heating that would melt the glass wick can be avoided, so the arrangement of glass lamps and wicks that could not be controlled conventionally can be avoided. Contact arrangement is also possible in relation to each other, which has a great practical effect.

Furthermore, since the catalytic action of platinum (-rhodium) is suppressed, there is no fear of spontaneous combustion, and the mechanism can be simplified.

As the organosilicon polymer, polycarbosilane series using dimethylsynchrosilane as a starting material and polyborosiloxane series using schiff-nyldichlorosilane as a starting material are applicable, but polyborosiloxane A series of paints containing resin as a main component is desirable from the viewpoint of coating workability and the physical properties of the coated product.

Generally, for products used in corrosive environments, it is not unusual to coat the surface of the product for the purpose of corrosion prevention.

Paints containing organosilicon polymers are applied to heat-resistant coated wires by coating them on nickel-plated copper wires.
There is an example.

However, in this case, the upper limit of heat resistance is estimated to be about 800° C., and there are no known examples that can withstand application at about 1000° C. like the present invention.

The present invention has achieved a coating that can withstand applications at approximately 1000''C by attempting a new coating method.

In other words, in the case of conventional baking, when applying paint onto an object and curing it, the object is placed in a high-temperature atmosphere and baked, whereas in the case of the present invention, the heater itself A method of heating from the inside by applying electricity is adopted.

FIG. 1 shows a sectional view of the coil wire of the present invention. In FIG. 1, 1 is a metal resistor wire, and 2 is an organosilicon polymer coating layer.

When coating this heater using the conventional general method,
The curing reaction proceeds from the surface side, that is, the side B in Figure 1,
Proceed to A's side. In such cases, the gas components generated during internal curing pass through the external layer that has already been cured and are released. Foaming occurs and a large number of pinholes are formed, resulting in a coating film that is brittle and brittle.

This is the reason why conventional products were only able to achieve heat resistance of around 600°C.

However, when curing is carried out from the inside by electrical heating, the generated gas passes through the parts that have not yet progressed to hardening and the curing progresses in stages. A dense film f'i and excellent strength can be obtained. This is something that can only be achieved with ignition heaters because such special current heating can be performed.

The effects will be explained below, focusing on examples.

"Inorganic polymer paint" manufactured by Showa Denshin Co., Ltd. was used as a paint to form a coating containing polyborosiloxane resin as the main component.

Various types of coatings shown in Table 1 were trial produced. Next, tests were conducted on untreated products and the above samples to evaluate their effects. The test results are shown in Table 2. In Table 2, sample S-0 indicates an untreated product. The adhesion test M in Table 2 evaluates the adhesion state of the coating after applying a DC voltage of 3 cm and repeating the ON-OFF cycle for a total of 10 times.

In addition, the overload accelerated deterioration test evaluates the relationship between the number of repetitions and disconnection when a voltage of 4 cm is applied and the operation of crimping and releasing the wick for 1 minute is forcibly repeated.

In the manufacturing method of the present invention, it has been found that a better coating can be formed by gradually increasing the temperature from the low temperature side, rather than by applying electricity at a high temperature all of a sudden.

(The following is a blank space) Table 2 Evaluation test results for coated objects This manufacturing method can be applied to metal resistor wires other than platinum (rhodium) d1, such as nichrome wire and Kanthal wire.

According to the manufacturing method of the present invention, the coating can be formed in an extremely short time.
He is a T-noh and excels at the industrial applicability of Tendo physiology.
A highly durable and reliable ignition heater can be obtained.

[Brief explanation of the drawing]

The drawing is a sectional view of a coil wire showing an embodiment of the present invention. 1...Heater main body, 2...Coating layer.

Claims (2)

[Claims] (1) A method for manufacturing an ignition heater, in which a paint containing an organic silicon composite polymer is applied onto the surface of a metal resistor wire of the ignition heater, and then the coating is heated and fired by applying electricity to the ignition heater to form a coating. (2) A method for producing an ignition heater according to claim 1, wherein a polyborosiloxane resin is used as the organosilicon cumulative polymer.