KR20190097570A - Insulation·heat insulation board and manufacturingmethod thereof - Google Patents

Abstract

The present invention relates to an insulation and heat insulation board and a manufacturing method thereof. The insulation and heat insulation board is easy to manufacture at the low temperature by using an inorganic binder containing boric acid and zinc oxide, and excellent workability and dimensional stability because thermal deformation does not occur even at the high temperature. Conventionally, in the case of the insulation and heat insulation board using only an organic binder as a binder, a reinforcement is essentially included due to a problem of the deterioration in mechanical strength. In the present invention, the inorganic binder performs the role of the binder and the reinforcement at the same time, thereby having mechanical strength improvement, an excellent insulation effect and an excellent heat insulation effect.

Description

Insulation / heat insulation board and manufacturing method thereof {INSULATION · HEAT INSULATION BOARD AND MANUFACTURINGMETHOD THEREOF}

The present invention relates to an insulating and insulating board and a method for manufacturing the same, and more particularly, to an insulating and insulating board having excellent mechanical properties using an inorganic binder including boric acid and zinc oxide, and having excellent thermal and insulating effects. It relates to a manufacturing method thereof.

Insulation and insulation board is used in various fields such as electric chute, electric insulation parts such as insulators and plugs, electric heaters, glass production facilities, etc., and prevents heat loss caused by heat transfer by conduction. Or to minimize energy loss. In general, insulation and insulation boards are made of fillers, binders and reinforcing fibers that are cured under atmospheric or vapor pressure. Conventionally, calcium silicate, hydrated lime was used as a binder to react with silica and water. The structure of the binder produced after the reaction depends on the reinforcing fiber material added, and asbestos has been used as a reinforcing fiber material.

Asbestos, however, has been reported to cause pulmonary cancer or mesothelioma by inhalation of asbestos dust. Thus, insulation and insulation boards using organic materials as binders were developed. However, when heat or voltage is continuously applied, carbonization is weakened and thermal deformation occurs. In particular, there is a problem in the dimensional stability due to the change in dimensions easily during heat treatment at high temperature, the bond strength is weakened due to the vitrification of the reinforcing fiber material has a problem that the product easily deformed.

Therefore, the inventors of the present invention have excellent dimensional stability by using an inorganic binder containing boric acid and zinc oxide and an organic binder, and do not use the reinforcing fiber material, so that the problem of weakening of bond strength and thermal deformation does not occur. Efforts to provide an insulation and insulation board have led to the present invention.

Republic of Korea Patent Application No. 2016-26202

An object of the present invention is easy to manufacture a board for insulation and insulation at a low temperature using a binder containing boric acid and zinc oxide, and an insulation and insulation board having excellent workability and dimensional stability because no thermal deformation occurs at a high temperature. To provide.

Insulation and insulation board of the present invention is 10 to 50% by weight of an inorganic binder containing boric acid and zinc oxide;

1 to 8% by weight of an organic binder including a modified phenolic resin and a phenolic resin;

Alumina, mica, aluminum hydroxide, zirconia, silicon carbide, silicon nitride, barium sulfate, wollastonite, rock wool 50 to 80% by weight of the filler is included.

The content of boric acid in the inorganic binder is 50 to 80% by weight, the content of zinc oxide is characterized in that 20 to 50% by weight.

When the use temperature of the insulation and insulation board is 300 ℃ or more, the organic binder content is 1 to 4% by weight,

When the use temperature of the insulation board for insulation is less than 300 ℃ characterized in that the organic binder content is 5 to 8% by weight.

The insulation and insulation board manufacturing method of the present invention

Preparing an inorganic binder mixture by mixing 50 to 80% by weight of boric acid and 20 to 50% by weight of zinc oxide at 60 to 150 rpm for 10 to 20 minutes;

Drying the inorganic binder mixture at 100 to 150 ° C. for 5 to 10 hours;

Grinding the inorganic binder mixture to 100 to 300 mesh;

Mixing the inorganic binder mixture, the organic binder and the filler at 60 to 150 rpm for 10 to 20 minutes;

Molding at 130 to 250 ° C. and 100 to 250 kgf / cm 2 for 10 to 90 minutes using a heat press;

Heat treatment in an electric furnace at 90-700 ° C. for 5-48 hours; And

A surface polishing step.

By using inorganic binders containing boric acid and zinc oxide, it is easy to manufacture insulation and insulation boards at low temperatures, and it is excellent in workability and dimensional stability because no thermal deformation occurs at high temperatures. In addition, the present invention provides an insulation and insulation board with improved strength, insulation, and insulation.

The insulation / insulation board of the present invention is composed of a binder and a filler, and the binder is composed of an inorganic binder and an organic binder.

In the present invention, the main binder is an inorganic binder, and the organic binder is used as a sub binder. As an inorganic binder, a mixture of boric acid and zinc oxide is used, and boric acid and zinc oxide react at high temperatures to act as a binder. Since boric acid and zinc oxide are included, the insulation and insulation boards are glossy, and in particular, due to the pigment effect of zinc oxide, the color of the product is white. In the present invention, the fiber (fiber) is not used, so there is no problem of weakening of the bonding force due to vitrification, thermal deformation, fatigue fracture, and carbonization at a high temperature, so that workability and dimensional stability are high.

Boric acid in the inorganic binder is 50 to 80% by weight, zinc oxide is characterized in that it comprises 20 to 50% by weight. If the content of boric acid is less than 50% by weight, it is impossible to mold due to weakening of the binding force of the binder, and if it exceeds 80% by weight, bubbles and pores are generated during molding due to oversaturation, so that the mechanical and electrical properties are weak. In addition, if the zinc oxide content is less than 20% by weight, there is a problem in that the structure of the insulation / insulation board is not dense, so that mechanical and electrical properties are weak, and when the content of the zinc oxide is more than 50% by weight, the amount of boric acid is relatively decreased, so that the bonding strength is low. It is lowered and is not preferable.

As the organic binder, a modified phenolic resin and a phenolic resin mixture are used. In the case of using the inorganic binder alone in the insulation / insulation board of the present invention, there is a problem in that boric acid must be molded at a temperature exceeding 300 ° C. when mixed with zinc oxide and a filler. In order to solve this problem, there is an effect of lowering the forming temperature of the insulation / insulation board including a small amount of organic binder and increasing the bonding force.

In the present invention, the inorganic binder is 10 to 50% by weight, the organic binder is contained 1 to 8% by weight, if the content of the inorganic binder is less than 10% by weight the bonding strength is weakened, it is impossible to form the insulation / insulation board, When used in excess of 50% by weight, the content of filler is relatively insufficient, and the insulation and insulation performance is weakened.

In addition, the content of the organic binder varies depending on the temperature at which the board for insulation and insulation is used. If the temperature of the board is 300 ° C or higher, 1 to 4% by weight, and if the temperature is less than 300 ° C, 5 to 8% by weight. It is preferable to include. When boric acid is mixed with zinc oxide and a filler, it is difficult to mold at 300 ° C. or higher, so that a small amount of organic binder is included to lower the molding temperature. If the content of the organic binder is less than 1% by weight, the content of the organic binder is too small to reduce the low temperature bonding effect. If the content of the organic binder is more than 8% by weight, the carbonization phenomenon occurs during molding and heat treatment. weak.

In the insulation / insulation board of the present invention, the filler may be selected from the group consisting of alumina, mica, aluminum hydroxide, zirconia, silicon carbide, silicon nitride, barium sulfate, wollastonite, and rock wool. Filler is contained 50 to 80% by weight relative to the total weight of the insulation / insulation board, when less than 50% by weight insulation, heat insulation performance is reduced, wear resistance is weakened, the product processing is not easy. If it exceeds 80% by weight, the molding of the product is difficult due to the weakening of the bonding strength of the insulation / insulation board.

Diatomite, silica fume, perlite, etc. are used as a filler in the conventional insulation and insulation board, but the materials are not preferable because they lower the mechanical strength of the product and reduce the insulation and insulation effects.

The manufacturing method of the board for insulation and insulation of this invention is as follows.

50 to 80% by weight of boric acid and 20 to 50% by weight of zinc oxide are mixed at 60 to 120 rpm for 10 to 20 minutes, and then dried in a dryer at 100 to 150 ° C. for 5 to 10 hours. In the drying process, a pre-reaction occurs to facilitate the removal of the moisture from the mixture and the bonding of the mixture during molding. After drying, the mixture is ground to 100-300 mesh for even dispersion and penetration of the binder.

After mixing 10 to 50% by weight of an inorganic binder mixed with boric acid and zinc oxide, 1 to 8% by weight of an organic binder including a modified phenol resin and a phenolic resin, and 50 to 80% by weight of a filler 60 to 150 rpm, for 10 to 20 minutes Molded by a hot press for 10 to 90 minutes under a temperature of 130 ~ 250 ℃, pressure 100 ~ 250kgf / ㎠. The molded product is heat-treated for 5 to 48 hours at a temperature of 90 to 700 ° C and then surface polished.

Hereinafter, the present invention will be described in more detail with reference to Examples.

This embodiment is intended to illustrate the present invention in more detail, and the scope of the present invention is not limited by these examples.

<Example 1>

35% by weight of the inorganic binder (65% by weight of boric acid, 35% by weight of zinc oxide) was pulverized to 150mesh after drying for 9 hours at 150 ° C. After mixing the inorganic binder with 3% by weight of novolak powder resin, 62% by weight of filler (54% by weight of alumina, 31% by weight of mica, 15% by weight of aluminum hydroxide) at 100 rpm for 20 minutes, the mixed raw material was 20T thick, It weighed at 64 kg in mass and heat-compressed at 180 kg / cm <2>, 200 degreeC for 30 minutes. The compressed board was heat-treated at 400 ° C. for 15 hours, and then subjected to surface polishing to prepare an insulating and insulating board.

<Example 2>

Example 1 except that 40% by weight of inorganic binder (60% by weight boric acid, 40% by weight zinc oxide), 57% by weight filler (50% by weight alumina, 25% by weight mica, 25% by weight aluminum hydroxide) were used. In the same manner as to prepare an insulation and insulation board.

<Example 3>

35 wt% of inorganic binder (60 wt% boric acid, 40 wt% zinc oxide), 5 wt% novolak powder resin, 60 wt% filler (58 wt% alumina, 25 wt% mica, 17 wt% aluminum hydroxide) Except for the use, it carried out in the same manner as in Example 1 to prepare a board for insulation and insulation.

Comparative Example 1

30% by weight of novolak powder resin, 65% by weight of filler (50% by weight of alumina, 25% by weight of mica, 25% by weight of aluminum hydroxide) and 5% by weight of aramid fibers were dry mixed at 100 rpm for 20 minutes to form a mixture. The mixture was weighed at a thickness of 20T and a mass of 64 kg and then thermally compressed at 180 kg / cm 2 and 150 ° C. for 30 minutes. The compressed board was heat-treated at 105 ° C. for 4 hours, and then subjected to surface polishing to prepare an insulating and insulating board.

Comparative Example 2

Except for using 62% by weight of the filler (50% by weight of diatomaceous earth, 25% by weight of perlite, 25% by weight of silica fume) was carried out in the same manner as in Example 1 to prepare an insulation and insulation board.

Experimental Example

1. Flexural Strength (MPa)

The prepared thermal insulation plate was cut to a thickness of 10T, 20mm × 140mm to prepare a test piece, and the load was measured when the load was cut by gradually placing the load horizontally on two points 100mm apart. At this time, the bending strength was calculated by the following Equation 1. Steady state tests are carried out at room temperature, and the flexural strength after heating is tested by heating the specimen in a furnace at 500 ° C for 3 hours and then cooling to room temperature.

(Equation 1)

(In Formula 1, P: force (kgf (N)), L: distance between points (100 mm), b: width of the test piece (10-20 mm), and h: thickness of the test piece (mm).)

2. Impact strength (kJ / m ² )

After preparing the test piece of the manufactured insulation board to a thickness of 10T, 10mm × 90mm, using a Charpy impact tester (capacity about 30 kgf · cm) {Ncm} to make a distance of 60mm between the points, the prepared test piece The minimum kgf · cm {N · cm} cut on the point and impacted once with the hammer at the center was divided by the circular cross-sectional area (cm ² ) at the incision to determine the impact value.

3. Apparent specific gravity (g / cm 3)

Prepared by cutting the test piece of the prepared insulation plate to a thickness of 10T, 25mm × 25mm, dried in a thermostat at 150 ± 5 ℃ for at least 4 hours, and placed in a desiccator and left at room temperature for 30 minutes, and then measured the weight of the test piece The apparent specific gravity was calculated.

4. Insulation breakdown strength (kv / mm)

Under the test temperature of 23 ° C and a relative humidity of 50%, in order to prevent flashover, the insulating plates prepared in Examples and Comparative Examples were placed in the center between cylindrical electrodes of 25.0 mm diameters up and down in an oil bath containing insulating oil. Cut the specimen into thickness of 5T, 70mm × 70mm, and measure the breakdown voltage when the specimen is broken by raising the commercial frequency voltage of AC 60Hz from 0 to 3000V / s by short time test method.

5. Arc resistance (sec)

After cutting the test piece of the manufactured insulation plate in a circular shape having a thickness of 3T and a diameter of 100mm, the arc resistance was measured using an electrode device at 20 ° C. and a relative humidity of 65%.

6. Surface resistivity (Ω)

The test piece of the prepared insulation plate is cut into a circle having a thickness of 3T and a diameter of 100mm, and the surface resistivity is measured using an insulation resistance measuring instrument at 20 ° C. and a relative humidity of 65%.

7. Volume resistivity (Ω · cm)

The test piece of the prepared insulation plate is cut in a circular shape having a thickness of 3T and a diameter of 100mm, and the volume resistivity is measured using an insulation resistance measuring instrument at 20 ° C. and a relative humidity of 65%.

8. Thermal conductivity

Cut the test piece of the manufactured insulation plate to a thickness of 20T, 300mm x 300mm, install at least one temperature measuring contact in the effective measurement area on both surfaces of the test body, and sufficiently insulate around the test body using a thermostat, It gives a temperature difference of not less than ℃. After the specimen surface temperature is not changed in the same direction, the measurement is terminated when the steady state is not changed by more than 1% per 30 minutes with respect to the specimen temperature difference, and the thermal conductivity is calculated according to Equation 2.

(Equation 2)

(In the above, ι: thickness of the test body (m), Rc: thermal resistance of the test body (m ² · h · ℃ / kcal) (m ² · K / W), θ ₁ : temperature of the test object hot surface (℃), θ ₂ : temperature of test specimen cold surface (° C.), q: heat flow rate per unit area (kcal / m ² · h) (W / m ² ), K ₁ K ₂ : sensitivity coefficient of heat flow meter (kcal / m ² · h) (W / m ² · V), e ₁ e ₂ : output of heat flow meter (V))

The values measured in the above experiments are shown in Table 1 below.

Example 1 Example 2 Example 3 Comparative Example 1 Comparative Example 2 Steady State Flexural Strength (MPa) 29.4 27.2 25.4 24.5 25.1 Flexural strength after heating at 500 ℃ for 3 hours (MPa) 30.9 42.8 23.5 0.8 19.5 Impact strength (kJ / m ² ) 3.3 2.9 2.7 1.5 2.2 Apparent specific gravity (g / cm3) 2.4 2.6 2.4 1.9 1.8 Dielectric breakdown strength (kv / mm) 7.2 7.1 6.6 6.0 5.5 Arc resistance (sec) 420 420 420 250 280 Surface resistivity (Ω) 1.8 × 10 ¹⁵ 1.6 × 10 ¹⁶ 6.4 × 10 ¹⁵ 6.8 × 10 ¹³ 2.1 × 10 ¹³ Volume resistivity (Ωcm) 5.9 × 10 ¹⁵ 5.5 × 10 ¹⁵ 4.7 × 10 ¹⁵ 4.4 × 10 ¹⁴ 9.5 × 10 ¹³ Thermal Conductivity (W / mK) 0.38 0.37 0.38 0.43 0.45

As shown in Table 1, it can be seen that in Examples 1 to 3, the mechanical strength is superior to Comparative Example 1 in which the inorganic binder is not used. In particular, the steady state flexural strength was similar, but the flexural strength was increased in the case of Examples 1 to 3 in the conditions after heating for 3 hours at 500 ℃ temperature, in Comparative Example 1 using only an organic binder carbonized and Thermal deformation occurred and flexural strength decreased. In addition, the apparent specific gravity of the insulation board / insulation board manufactured in Examples 1 to 3 has a small dimensional change during processing, it can be confirmed that the electrical properties and thermal insulation performance is improved.

In the case of Comparative Example 2 using a filler including diatomaceous earth, perlite, silica fume, the strength is weaker than Examples 1 to 3, it can be confirmed that the insulation effect is reduced, the thermal conductivity is reduced by the degradation of the electrical properties.

Claims (4)

10 to 50% by weight of an inorganic binder including boric acid and zinc oxide;
1 to 8% by weight of an organic binder including a modified phenolic resin and a phenolic resin;
An insulation / insulation board comprising 50 to 80% by weight of a filler, which is any one or two or more compounds selected from the group consisting of alumina, mica, aluminum hydroxide, zirconia, silicon carbide, silicon nitride, barium sulfate, wollastonite, and rock wool. The method of claim 1,
Boron acid content of the inorganic binder is 50 to 80% by weight, zinc oxide content is 20 to 50% by weight of the insulation and insulation board. The method of claim 1,
When the use temperature of the insulation and insulation board is 300 ℃ or more, the organic binder content is 1 to 4% by weight,
The insulation / insulation board having an organic binder content of 5 to 8% by weight when the use temperature of the insulation / heat insulation board is less than 300 ° C. Preparing an inorganic binder mixture by mixing 50 to 80% by weight of boric acid and 20 to 50% by weight of zinc oxide at 60 to 150 rpm for 10 to 20 minutes;
Drying the inorganic binder mixture at 100 to 150 ° C. for 5 to 10 hours;
Grinding the inorganic binder mixture to 100 to 300 mesh;
Mixing the inorganic binder mixture, the organic binder and the filler at 60 to 150 rpm for 10 to 20 minutes;
Molding at 130 to 250 ° C. and 100 to 250 kgf / cm 2 for 10 to 90 minutes using a heat press;
Heat treatment in an electric furnace at 90-700 ° C. for 5-48 hours; And
Surface polishing step; insulating, insulating board manufacturing method comprising a.