JP3229351B2 - Manufacturing method of heat resistant insulator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for manufacturing a heat-resistant insulator used as an electrically insulating material for electrical equipment, transmission / distribution facilities, and the like.

[0002]

2. Description of the Related Art Generally, a method for producing a heat-resistant insulator containing an inorganic material as a main component includes a material in which boric acid and zinc oxide or boric acid and calcium oxide are blended as a binder, and asbestos as a base material. There is known a method of mixing, introducing the mixture into a mold, and performing heat and pressure molding.

In addition, asbestos cement, which is known as a general-purpose heat-resistant inorganic insulator, is obtained by dry-mixing defatted asbestos and cement, then adding water and mixing the slurry into a slurry. They are laminated to a required thickness and pressed by a flat plate or a metal mold to produce a molded body of a required shape.

On the other hand, examples of organic insulating materials include synthetic resins such as vinyl chloride resin, polyamide, polyethylene, phenol resin, epoxy resin, and polyimide.

[0005] The thermosetting resin is heated by using a mold.
It is manufactured into an insulator having a required shape by a pressure molding method.

[0006]

However, in any of the above-mentioned methods for producing a heat-resistant insulator, after the raw materials are mixed at once, the insulating material having a required shape is used in addition to a flat shape using a mold or the like. Therefore, the production process is complicated and the production efficiency is low, so that the production cost cannot be sufficiently satisfied.

Further, asbestos, which is widely used as a heat-resistant inorganic insulating material, is feared to impair the health of manufacturers and consumers, and its use tends to be restricted. In addition, cement that solidifies by the hydration reaction retains a small amount of moisture even after drying, and has a hygroscopic property, so that it cannot sufficiently exhibit insulation properties under high humidity or water immersion. On the other hand, in the molded body obtained from the above-mentioned slurry-like mixture of the insulating base material and the binder, the physical properties of the binder tend to appear strongly, and the mechanical strength such as bending strength and compressive strength at a high temperature state is sufficiently satisfied. There is a problem that can not be.

The present invention solves the above-mentioned problems and has the same insulating properties as an insulator made of an organic material and can employ various kinds of inorganic insulating base materials, thereby contributing to improvement of the manufacturing environment. Further, it is an object of the present invention to manufacture a heat-resistant insulator that can sufficiently satisfy not only insulation properties but also mechanical strength such as bending strength and compression strength with a required thickness and with increased production efficiency.

[0009]

In order to solve the above problems, according to the present invention, aluminum phosphate, an acidic or neutral inorganic powder, a powdery inorganic thickener, a thermosetting resin, A fluid composition of an inorganic / organic composite comprising a solvent is temporarily adhered to a required thickness, and then the fluid composition is transferred and impregnated into a continuous sheet-like reinforcing material made of inorganic fibers to form a sheet material. A means for cutting the material, laminating a plurality of sheets, and integrating them under heat and pressure was adopted.

Further, a continuous sheet-like reinforcing material made of inorganic fibers is impregnated with a fluid composition of an inorganic / organic composite comprising aluminum phosphate, acidic or neutral inorganic powder, a thermosetting resin and a solvent. It is also possible to employ a method of drying the sheet-like material, cutting the sheet-like material, laminating a plurality of sheets, and integrating them under heat and pressure. Less than,
The details will be described.

First, the inorganic fiber reinforcing material used in the present invention is a continuous sheet-like woven or nonwoven fabric made of an inorganic material having excellent thermal decomposition resistance. Give. In particular, glass fiber, rock wool, and the like can be cited as the inorganic fibrous reinforcing material having excellent insulation properties. In addition, examples of the inorganic fibrous reinforcing material having particularly excellent heat insulating properties include metal fibers and carbon fibers. Such an inorganic fibrous reinforcing material is supplied in the form of a roll at the beginning at the speed of the production line.

The aluminum phosphate used in the present invention is used as a binder, and examples thereof include water-soluble aluminum monophosphates and aluminum phosphates alone or modified. Since aluminum tertiary phosphate is insoluble in water, it is unsuitable when the solvent is water. Water and methanol as solvents,
Examples include alcohols such as ethanol and organic solvents. It is needless to say that an organic solvent that is compatible with water is preferable in terms of work, and a solvent that is extremely harmful to the human body is not preferable. Water is harmless in handling and is considered to be best if workability is considered.

The acidic or neutral inorganic powder used in the present invention is added mainly for the purpose of further ensuring the electrical insulation of aluminum phosphate under high humidity.
Since they do not react with aluminum phosphate at room temperature and do not coagulate, they are preferable because the binding property and moldability under heating and pressure are not hindered. Typical examples of such acidic inorganic powders include silica, and examples of neutral inorganic powders include alumina, aluminum hydroxide, and kaolin, which are generally commercially available.

The mixing ratio of such an acidic or neutral inorganic powder and aluminum phosphate is 100 parts by weight of aluminum phosphate.
Acidic or neutral inorganic powder 15 to 130 parts by weight
Parts by weight are preferred. This is because a small amount of less than 15 parts by weight has no effect on insulating properties under high humidity, and a large amount of more than 130 parts by weight undesirably lowers mechanical strength.

Further, the powdery inorganic thickener used in the present invention is one which imparts viscosity so that the fluid composition can be temporarily attached to a film at a required thickness, and which has heat resistance and insulation properties. Preferable examples include powdered basic inorganic thickeners such as magnesium oxide, calcium oxide, magnesium hydroxide, calcium hydroxide, magnesium silicate, calcium silicate and talc.

The inorganic thickener is preferably a basic one. For example, magnesium silicate is preferably about 1 to 25 parts by weight. In the case of other thickeners such as magnesium oxide, 1 part by weight is sufficient because it is easy to solidify,
If it is more than this, solidification proceeds and it becomes impossible to obtain a varnish-like viscous solution. Since the mixed solution is diluted by increasing the amount of water, the amount of such a thickener can be increased according to the ratio. For this reason, it can be used even if it exceeds the above range, and it is used in an appropriate mixing ratio.

The above-mentioned acidic and neutral inorganic powders and powders as a thickener can be used without any particular limitation on the particle size. For example, those having a mesh size of about 200 to 300 mesh are suitable. Further, the range of the particle size distribution is narrow, and the smaller the particle size, the easier the dissolution, and the shorter the working time, which is convenient for the work.

The thermosetting resin used in the present invention can be used without any particular limitation, and examples thereof include a phenol resin, a silicone resin, a melamine resin, and a thermosetting polyimide.

The mixing ratio of such a thermosetting resin is 2
About 15 parts by weight is preferable, and when it is less than 2 parts by weight, there is no effect of adding the insulating property and the strength property, and there is no meaning to be mixed.

The amount of water used as a solvent in the flowable composition for temporary deposition on a film is preferably in the range of about 10 to 30 parts by weight. If the amount of water is less than 10 parts by weight, the viscosity is so high that uniform temporary attachment to the transfer sheet cannot be performed. If the amount of water is more than 30 parts by weight, the viscosity becomes so low that it becomes difficult to temporarily attach the required amount to the transfer sheet. , It is not possible to transfer and impregnate the required amount of reinforcing material uniformly,
As a result, a desired molded product cannot be obtained.

On the other hand, the mixing ratio of water as a solvent in the fluid composition to be directly impregnated without the transfer step is 50%.
１００100 parts by weight. If the amount is less than 50 parts by weight, the viscosity is too high to uniformly impregnate the reinforcing material. If the amount is more than 100 parts by weight, on the contrary, the viscosity becomes too low to impregnate the necessary amount.

[0022]

In the method for manufacturing a heat-resistant insulator according to the present invention,
A continuous sheet-like reinforcing material made of inorganic fiber is impregnated with a predetermined flowable inorganic / organic composite composition by immersion or the like or transferred and impregnated from a film. The mechanical properties of the insulator after molding can be sufficiently reinforced by the inorganic fibers described above. Further, since there is no batch mixing step of raw materials, a continuous sheet-like reinforcing material can be easily formed, and the production efficiency is improved.

[0023]

Embodiments of the present invention will be described below with reference to the drawings.

[Embodiment 1] As shown in FIG.
In the so-called wet method, a reinforcing material P made of a web-shaped glass fiber nonwoven fabric is unwound from a roll body 1 at a constant speed of 3 to 4 m / min and is advanced on a flat plate 2. At this time, a polyester release film 3a drawn from the roll body 3 was brought into close contact with the lower surface of the reinforcing material P, and was transported at the same speed as the reinforcing material P. On the other hand, the polyester transfer film 4a is unwound from the roll body 4 from above the reinforcing material P, and is passed along the lower surface of the frame type container 5 having the upper and lower openings in which the fluid composition L is accommodated. After turning upside down,
In a state where the tension was applied, the film was brought into close contact with the upper surface of the reinforcing material P and transported at the same speed as the release film 3a.

Above the frame type container 5, a rotary mixer 6 is installed. 100 parts by weight of aluminum phosphate, 100 parts by weight of alumina, 10 parts by weight of magnesium silicate, 10 parts by weight of phenol resin, and An inorganic / organic composite fluid composition L containing 20 parts by weight of water
Was fed continuously.

At the downstream end in the frame type container 5, a thickness control gap 5a adjusted to a uniform height (0.5 to 1 mm) over the width direction of the polyester transfer film 4a.
Was formed, and the fluid composition L having a thickness of about 0.8 mm was temporarily adhered to the surface of the proceeding polyester transfer film 4a uniformly due to its viscosity. Thickness control gap 5a
Alternatively, the mixed solution layer may be appropriately adjusted to a required thickness by changing the height of the mixed solution layer so that the downstream side surface of the frame-shaped container 5 can be slid vertically. The dimension in the width direction of the control gap 5a is equal to or slightly larger than the width dimension of the reinforcing member P, and the release film 3a and the transfer film 4a
If the width dimension of is larger than the width of the reinforcing material P, it can be held on the film when the solution flows, which is convenient without soiling the periphery.

In this way, the transfer film 4a made of polyester, on which the fluid composition L was temporarily attached, was inverted, and the upper surface of the reinforcing material P was transferred and impregnated with the fluid composition L. At this time, the ratio between the reinforcing material P and the fluid composition L is
The progress speed of the reinforcing material P and the viscosity of the flowable composition were adjusted so that the flowable composition was 60 parts by weight per 0 parts by weight. The range of the allowable ratio is 40 to 80.
When the amount is preferably less than 40 parts by weight, the reinforcing material P
When the amount exceeds 80 parts by weight, the moldability deteriorates.

Then, the continuous sheet-like reinforcing material P after transfer impregnation is composed of a release film 3a and a transfer film 4a.
With the upper and lower surfaces sandwiched, the plate is passed between the upper surface of the flat plate 2 and two rolls 8 pressed against the flat plate 2, and further rolls 9, 1.
The pressure is narrowed at 0, and further, the material is wrapped around a plurality of rolls 11 so that the mixed solution uniformly spreads over the entire portion of the reinforcing material P, thereby improving the impregnation accuracy, and a semi-cured sheet material (prepreg).
P1 was formed.

Next, the sheet-like material P1 has a predetermined size (1) by a cutting device 12 in which two blades are opposed to and separated from each other.
(000 mm square), and after peeling off the release film 3a and the transfer film 4a, a plurality of sheets were laminated and housed in a hot press 14 to be integrally formed by fusion.

The hot press 14 has a structure in which a plurality of heating / pressing plates 15 are stacked, and a pair of upper and lower end plates or heat-resistant films are interposed therebetween, and a sheet-like shape is placed between the interposed end plates or heat-resistant films. A plurality of materials P1 are stacked and arranged under a pressure of 100 kg / cm ^2.
The mixture was heated to 0 ° C. and integrated by welding. At this time, in order to enhance the releasability, a heat-resistant film may be interposed between the upper and lower surfaces of the required number of laminated sheet materials P1 and the end plate.

The range of the pressure under the above molding conditions is 80 to
150 kg / cm ² is appropriate. If it is less than 80 kg / cm ² , a high-density product cannot be obtained. If the pressure is higher than 150 kg / cm ² , there is a difference in characteristics in comparison with a pressure lower than 150 kg / cm ^2. Therefore, it is not preferable to apply an excessive pressure because energy is wasted and the product is deformed. The temperature range is 150-200 ° C
If the degree is appropriate, if it is lower than 150 ° C., it is difficult to obtain the properties of the mixture. If the temperature is higher than 200 ° C., energy is wasted similarly to the above, which is not economical.

When forming a thick plate, the sheet-like material P1
Was converted into a desired molded product by weight, and the sheet-like material P1 corresponding to the converted amount was piled up and stored between the heating / pressing plates 15. The molded body of the sheet material P1 having been subjected to the heating and pressure molding in this manner was then cut into a predetermined size by the cutting machine 16 to obtain a heat-resistant insulator A as a final product.

In the above-described embodiment, the one-side transfer and impregnation method from the upper surface of the reinforcing material P has been described in order to simplify the operation.
Needless to say, double-sided transfer impregnation can also be performed from the lower surface of the reinforcing material P. Also, the release film 3 described above.
a, the transfer film 4a is made of polyester, but may be made of other synthetic resin or paper.

[Embodiment 2] As shown in FIG.
In the so-called dry method, first, a reinforcing material Q made of a web-like glass fiber woven fabric was unwound from a roll body 20 at a constant speed of 5 m / min and passed through a dissolution tank 21. In the dissolution tank 21, a fluid composition M containing 100 parts by weight of alumina, 100 parts by weight of phenol resin, and 80 parts by weight of water with respect to 100 parts by weight of first aluminum phosphate was accommodated. The reinforcing material Q was transported between the rolls so that tension was applied, and was immersed in the above solution in that state to perform uniform impregnation. The speed of the reinforcing material Q at this time may be appropriately adjusted within a range of 3 to 10 m / min.

Next, the reinforcing material Q impregnated with the first aluminum phosphate solution was withdrawn from the dissolving tank 21 and introduced into a hot air circulating drier 22 to remove the solvent. The hot air circulating dryer 22 is set at a temperature in the range of, for example, 80 ° C. to 150 ° C. so that the temperature gradually increases from the inlet to the outlet. A semi-cured sheet material (prepreg) Q1 impregnated with the reinforcing material Q was formed.

Thereafter, a heat-resistant inorganic insulator A as a final product was obtained via a cutting device 12, a hot press 14, and a cutting machine 16 in exactly the same manner as in Example 1.

Although the above examples do not show the use of a thickener, it was confirmed that the addition of a very small amount of the thickener promoted the solidification and increased the working efficiency.

[0038]

According to the present invention, as described above, an inorganic / organic composite fluid composition comprising a predetermined binder and a thermosetting resin or these and a thickener is reinforced by a connection sheet made of inorganic fibers. Since the material impregnated in the material is heated and pressed, there is no complicated or complicated molding process in the continuous production process, the production efficiency can be increased and the production cost can be reduced, and the production environment using a suitable insulating base material In addition, there is an advantage that a heat-resistant insulator having remarkable heat resistance and insulation properties and sufficiently excellent mechanical strength can be provided.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram schematically showing a manufacturing process of a first embodiment.

FIG. 2 is an explanatory view schematically showing a manufacturing process of a second embodiment.

[Explanation of symbols]

P, Q reinforcement P _1, Q ₁ sheet material L, M flowable composition 4a transfer film

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-50-76600 (JP, A) JP-A-64-17334 (JP, A) JP-A-53-68900 (JP, A) JP-A-50-76900 84899 (JP, A) JP-B 35-14982 (JP, B1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H01B 19/00

Claims (2)

(57) [Claims] An inorganic / organic composite fluid composition comprising aluminum phosphate, an acidic or neutral inorganic powder, a powdery inorganic thickener, a thermosetting resin and a solvent, having a required thickness on a film. Temporarily adhered, and then transferred and impregnated this fluid composition into a continuous sheet-like reinforcing material made of inorganic fiber to form a sheet-like material, cut and laminated a plurality of such sheet-like materials, and integrated under heat and pressure. Manufacturing method of conductive insulator. 2. A continuous sheet-like reinforcing material made of inorganic fibers is impregnated with an inorganic / organic composite fluid composition comprising aluminum phosphate, acidic or neutral inorganic powder, a thermosetting resin and a solvent. A method for manufacturing a heat-resistant insulator in which a sheet material is dried, cut and then laminated, and a plurality of sheets are integrated under heat and pressure.