JPH05178636A - Releasable powder - Google Patents

Abstract

PURPOSE:To provide the powder which is not aggregated or does not lose, its flowability, capable of being sprinkled soundlessly and oderlessly by an electronic spray, etc., at a low voltage, without distorting the glass surface when the powder is used on a glass sheet, etc., capable of being nicely released from the glass surface, etc., and without shifting the glass sheets from each other. CONSTITUTION:This globular inorg. powder is formed from an aluminosilicate, SiO2 alone or a material consisting essentially of the aluminosilicate and SiO2 and the balance K2O, Na2O or MgO, and has a sharp grain size distribution of 5 to 40mum or 5 to 20mum, and the refractive index is controlled to 1.40 to 1.60.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a peelable powder, and more particularly to a peelable powder used between laminated glass plates, ceramic plates, plastic films and the like. ..

[0002]

2. Description of the Related Art Conventionally, a vehicle windshield is laminated at a temperature of 700 ° C. by laminating a plurality of flat glass sheets into a heating furnace.
It is manufactured by bending the front and back with a constant curvature. In this processing method, since the laminated glass is heated to the vicinity of its softening point, the heat resistant powder was previously adhered between the glasses in order to prevent the above-mentioned hot fusion. The applicant of the present invention has improved the dispersibility of powder by coating inorganic powders such as gypsum, mica powder, talc, diatomaceous earth, and calcium carbonate powder with a silicone resin as a hot release agent of this type to improve the powder dispersibility and flowability. Provided is a hot release agent for glass capable of increasing the property (Japanese Patent Publication No. 56-21734).

[0003]

This hot stripping agent has been successfully put to practical use by improving its sprayability and fluidity, if not completely covered by coating with a silicone resin. I found such a problem.

Although this hot release agent can improve the powder dispersibility, when an electrospray is used, a discharge sound is emitted at a high voltage of about 6000 V or more and unpleasant ozone is generated. Good spraying could not be done unless the odor was maintained.

The flowability of the powder could be greatly improved by coating with a silicone resin, but it was affected by the proportion of fine powder, and as the proportion of fine powder increased, the fine powder aggregated with each other. It has been found that its fluidity is impaired. In addition, it is said that 2 μm is the maximum amount of fine powder that becomes dust during spraying and scatters to the surroundings, and enters the alveoli by inhalation, which is not preferable in terms of safety and hygiene.

As an inorganic powder, US John-Ma
Although Celite (trade name: High Flow Supercell) manufactured by Ville was used, it was found that if the particle size of this powder was too large, the glass surface was scratched or optical distortion occurred.

After the glass plate was hot-bent, it was taken out of the heating furnace and peeled off to remove the hot peeling agent on the surface by suction. However, some residue was observed on the glass surface. However, these have been a cause of diffused reflection of the windshield and the like. Although the stripping agent remaining on the glass surface can be completely removed by washing with water, a drying step after the washing step is required in addition to the washing step, which complicates the step and is very troublesome.

Therefore, the present invention was devised to solve these problems, and the spherical inorganic powder has a particle size distribution of 5 to 40 μm and a refractive index of 1.40 to 1.60. By using the body, even with a low voltage that does not generate ozone odor and discharge noise, uniform electron spraying property is obtained, and moderate fluidity is maintained, and even when spraying, it does not scatter to the surroundings, Scratching the glass surface,
No optical distortion occurs, the powder is easily sucked and removed from the glass surface even after bending, and even if it remains, there is no optical obstacle, and the particle size distribution is 5 to 20μ.
When m is set, it is an object to provide a powder that can prevent mutual displacement of the glass plates and can be peeled off without leaving a bubble after glass bending.

[0009]

Means for Solving the Problems The present inventors have reached the conclusion that the above problems were caused by the crystal shape and particle size distribution of naturally occurring inorganic materials such as diatomaceous earth, and as a result of diligent research, , A synthetic spherical hard powder with a particle size distribution of 5 to 40 μm and a refractive index of 1.40 to 1.6
It was found that the inorganic powder of No. 0 can solve the above-mentioned problems, and the powder capable of peeling according to the present invention was completed. That is, the powder capable of peeling according to the present invention has a particle size distribution of 5 to 40 μm and a refractive index of 1.40 to 1.60.
The spherical inorganic powder is used as a solution.

On the other hand, by using spherical powder in the research process for solving the above-mentioned problems, the laminated glass slides during transportation or in the heating furnace, and as a result, the glass plates are displaced from each other and remain as they are. It was found that when bending is performed and further the resin film is sandwiched and adhered, residual bubbles occur due to poor pairing. Then, as a result of intensive studies to solve this problem, the present inventors set the particle size distribution of the inorganic powder according to the present invention to 5 to 20 μm, thereby making it possible to obtain a glass plate even if it is spherical powder. Based on the finding that it is possible to prevent the deviation, the powder according to the present invention, which enables peeling, was completed. That is, the peelable powder according to the present invention is a spherical inorganic powder having a particle size distribution of 5 to 20 μm and a refractive index of 1.40 to 1.60, which is a means for solving the problem. ..

The powder capable of peeling according to the present invention will be described in more detail below.

The powder capable of peeling according to the present invention is not particularly limited to the theory, but the conventional hot peeling agent is
It is a naturally occurring inorganic material such as diatomaceous earth, and its crystals are deformed into needles, plates, honeycombs, etc., and because it undergoes a crushing operation during the powdering process, it often has sharp corners. Further, it is based on the fact that the variation from the fine powder to the coarse powder is large in the range of about 1 to 70 μm, and therefore the particle size distribution also varies from lot to lot.

First, the exfoliatable powder used in the present invention is composed of chemically synthesized spherical powder. This is because, as described above, the conventional hot release agent is a naturally occurring inorganic material such as diatomaceous earth, so that the crystals have a shape with needle-shaped, plate-shaped, honeycomb-shaped or the like and sharp corners. Yes, as a result, it was concluded that the glass surface was scratched, the separation from the roll of the electrospray was poor, the adhesion to the glass surface was large, and there was a problem that it was not easily removed by suction after bending. It was concluded that it was a spherical powder when a material that could solve the above problem was selected. It is difficult to produce this spherical powder from a physical treatment step such as pulverization using a naturally occurring inorganic raw material, and it is suitably obtained by a chemical synthesis method. As this chemical synthesis method, a hydrothermal synthesis method is generally used, but in addition to this, a hydrolysis method, a granulation sintering method, a spray drying method of a sol, etc. can be mentioned. A powder is obtained.

Next, the powder according to the present invention has a thickness of 5 to 40 μm.
Those having a sharp particle size distribution between them are used.
Here, the particle size distribution of the powder is limited to “5 to 40 μm” because the uniform electron scattering property can be obtained only within this range. This is because conventional products obtained by physical methods such as pulverization of naturally occurring inorganic raw materials have a large variation in the range of about 1 to 70 μm from fine powder to coarse powder, and therefore uniform spraying by electronic spray is not possible. This is the conclusion made. The reason why the particle size distribution is set to "5 μm" or more is that
When 20% or more of the fine powder of less than 5 μm is contained, the fine powders agglomerate with each other to impede the fluidity, so that not only good electron spraying property cannot be obtained, but also the fine powder is scattered as dust during spraying. Therefore, it invades the alveoli by inhalation, which is not preferable for safety and hygiene. On the other hand, the reason why the particle size distribution is set to "40 μm" or less is that the glass surface is scratched or optical distortion occurs if the particle size distribution exceeds this value, but the limit is based on the conclusion that the particle size is 40 μm. Incidentally, the conventional product Celite (trade name: High Flow Supercell) manufactured by John John Maville of the United States contained 10 to 20% of hard coarse powder having a particle size of 40 μm or more.

On the other hand, in the powder according to the present invention, by restricting the particle size distribution in the range of "5 to 40 μm" to "5 to 20 μm", the electron dispersibility does not change and the deviation of the glass plate can be prevented. That is, the laminated glass can be prevented from slipping during transportation or in the heating furnace, and as a result, mutual deviation of the glass plates can be prevented, which is caused by poor pairability when performing glass bending. The cause of the remaining bubbles can be removed. Note that the glass slippage during transportation and in the heating furnace increases as the particle size of the powder increases, so to prevent this, the smaller the particle size of the powder, the better.
The particle size distribution is limited to “5 to 20 μm” in consideration of the above-mentioned electron dispersibility and fluidity.

The powder according to the present invention has a refractive index of 1.
It is configured in the range of 40 to 1.60. This is because if the refractive index of the glass is close to 1.5, it does not hinder the subsequent laminated glass process. That is, according to the powder according to the present invention, since it is formed into a spherical shape, it is easy to remove the dust from the glass surface with the dust suction device. Diffuse reflection can be prevented. It is not necessary to pass the release agent remaining on the glass surface through the subsequent drying process in addition to the water purification process, and the process can be simplified. Here, from 1.76 to 1.77 and Ti0 ₂ (titanium oxide) as an example in which the refractive index is outside the range of 1.4~1.6, Al ₂ 0 ₃ (aluminum oxide)
2.52 can be mentioned, but other ores are mostly 1.4 to 1.6 including many silica-based and calcined carbon-based.
Fits in the range.

The refractive index of powder particles can be measured by using that of liquid. A liquid having a refractive index of 1.33 to 1.74 is known as a standard sample. This can be made by mixing liquids having different refractive indices and having an intermediate value. When the powder is dipped in such a liquid and placed in the visual field of an optical microscope, for example, the more the refractive index differs from that of the liquid, the clearer the image of the particle, that is, the contour, can be clearly identified. On the other hand, when the refractive indexes become close to each other, the particle image lacks clarity and eventually becomes almost indistinguishable. The refractive index of the particles is defined by this point.

The inorganic powder used in the present invention includes:
At least one selected from aluminosilicate and SiO ₂ is preferably used, and these may be used alone or as a mixture, or these are the main components and K is the balance.
₂ O, Na ₂ O or MgO may be added. All of these inorganic powders have a spherical shape and are common in that they are obtained by artificial synthesis, and their compounding ratio is S
iO ₂ is in the range of 40 to 100% by weight, and Al ₂ O ₃ is 0.
Range of 40%, it is preferable K ₂ 0, Na ₂ 0 or Mg0 in the balance in the range of 0 to 20%.

In the present invention, if necessary, a silicone resin may be coated to give the powder excellent electron-dispersing properties. The silicone resin is coated on the powder in an amount of 0.1 to 30% by weight, preferably 0.5 to 5% by weight. As this silicone resin, one that forms a reticulated vitreous film having a crosslinked structure is desirable,
Specific examples include sodium methylsiliconate, methylphenyl polysiloxane, and alkyl polysiloxane.

[0020]

EXAMPLES The detailed description of the powder capable of peeling according to the present invention will be described below based on examples, but the present invention is not limited to these examples.

Example 1 Sodium silicate and sodium aluminate were used as raw materials, and the ratio of each component was 60% for SiO ₂ , 30% for Al ₂ O ₃ , and 30% for Na ₂ 0. It was prepared by using dilute sulfuric acid so as to have a concentration of 10%, and finally prepared to have an aqueous solution concentration of 20%. After aging the aluminosilicate alkali gel thus obtained, it was crystallized under gentle stirring at 200 ° C. for 5 hours, with a particle size distribution of 10 to 20 μm.
Hard spheres were obtained, which were filtered, washed with water, and then dried.

Next, the surface of the obtained spherical powder was coated with 1% by weight of sodium methylsiliconate to modify it.

The powder produced in this manner is electrospray K type (Nikka Co., Ltd.) diameter 55 mm: length 500 mm.
Using a roll of No. ^2, the surface of one glass plate was sprayed in the range of 0.1 to 2.0 g per m ² . Two sheets of non-scattered material were stacked on top of this, put into a heating furnace, pressed at about 700 ° C. for bending, and then cooled. After cooling, it was peeled off, and the powder on the glass surface was sucked by a device such as an air dust collector. These results show that the electronic dispersibility, the scattering property, the angle of repose, the peeling effect, the scratches and distortions on the glass surface, and the brilliance caused by see-through,
The deviation of the glass surface was examined and shown in Table 1.

As shown in Table 1, it was found that the powder on the glass surface was removed with almost no residue, and that the glass surface had no scratches or optical distortions. This result indicates that after peeling after cooling, the remaining powder need not be washed with water or dried. Further, when a resin film of butyral or the like was sandwiched between the obtained glasses to form a laminated safety glass, no glaring was observed under fluoroscopy. Further, the mutual deviation of the laminated glass plates was prevented, and no bubble residue was observed.

Example 2 A gel was prepared in the same manner as in Example 1 except that the crystallization reaction was continued for 10 hours instead of 5 hours, and as a result, spheres having an average of 30 to 40 μm were obtained. It was This was washed with water and dried, and then its surface was modified with a silicone resin in the same manner as in Example 1. This powder was sprayed by an electrospray in the same manner as in Example 1 and subjected to bending, and then each effect was examined. The results were almost the same as in Example 1 as shown in Table 1, but the laminated glass plates were slightly deviated from each other, and very little bubble residue was observed.

Example 3 A gel was prepared in the same manner as in Example 1 except that sodium silicate was used as a raw material and SiO ₂ was 100%. As a result, spheres having an average diameter of 10 to 20 μm were obtained, washed with water and dried, and then the surface thereof was treated in Example 1.
It was modified with silicone resin in the same manner as in. This powder was sprayed by an electrospray in the same manner as in Example 1 and subjected to bending, and then each effect was examined. The result is
As shown in Table 1, it was almost the same as in Example 1.

Comparative Example 1 A gel was prepared in the same manner as in Example 1 except that the crystallization reaction was continued for 1 hour instead of 5 hours.
As a result, spheres having an average of 1 to 4 μm were obtained. This was washed with water and dried, and then its surface was modified with a silicone resin in the same manner as in Example 1. This powder was sprayed by an electrospray in the same manner as in Example 1 and subjected to bending, and then each effect was examined.

As a result, as shown in Table 1, no scratches or engineering strains were generated on the glass surface, and no glaring was observed, but the fluidity was lowered, and uniform dispersion was not possible. Further, powder was scattered during the spraying, but the mutual deviation of the laminated glass plates did not occur at all.

Comparative Example 2 A gel was prepared in the same manner as in Example 1 except that the crystallization reaction was continued for 20 hours instead of 5 hours, and as a result, spheres having an average of 40 to 60 μm were obtained. It was This was washed with water and dried, and then its surface was modified with a silicone resin in the same manner as in Example 1. This powder was sprayed by an electrospray in the same manner as in Example 1 and subjected to bending, and then each effect was examined. As a result, as shown in Table 1, the surface of the glass was scratched, an engineering strain was generated, and further, the deviation of the glass was clearly seen.

Comparative Example 3 A 20% aqueous solution of sodium aluminate was prepared and neutralized with diluted sulfuric acid to form an alumina gel. According to the hydrothermal synthesis, the crystallization reaction was continued under pressure at 200 ° C. for 5 hours to obtain spheres having an average of 10 to 20 μm, which were washed with water and dried. The surface of the obtained sphere was modified with a silicone resin in the same manner as in Example 1. This powder was sprayed by an electrospray in the same manner as in Example 1 and subjected to bending, and then each effect was examined. As a result, as shown in Table 2, scratches and engineering strains did not occur on the glass surface, but scratches were recognized. This is a result of the fact that alumina is out of the range of 1.40 to 1.60 which is the refractive index of glass, and shows that it becomes an obstacle when it is used for laminated glass.

[Table 1]

[Table 2]

[0031]

【The invention's effect】

(1) The present invention is a spherical inorganic powder having a sharp particle size distribution of 5 to 40 μm. Therefore, according to the inorganic powder according to the present invention, an appropriate composition,
Based on the total effect of particle size, shape and fluidity, even with a low voltage, uniform spraying can be carried out by a low voltage, rather than by a high voltage that produces an unpleasant ozone odor and discharge noise. (2) Since the present invention is spherical particles of 5 μm or more, it is possible to prevent deterioration of fluidity due to mutual aggregation of fine powder, and further, fine powder of around 1 μm does not become dust and scatter around. So it is a safe and hygienic inorganic powder. (3) Since the inorganic powder according to the present invention is spherical particles having a size of 40 μm or less, it does not cause scratches or distortion on the glass surface, and is almost completely removed by a dust collector after peeling. be able to. (4) The inorganic powder according to the present invention has a refractive index of 1.
Since it is in the range of 40 to 1.60, even if there is a residue when removing dust after peeling, the refractive index is close to that of glass. There is no need to do it, and there are no optical obstacles. (5) According to the inorganic powder according to the present invention, 10 to 20 μm
Since it is a spherical inorganic powder having a sharper particle size distribution of m, it is possible to prevent the laminated glass from slipping during transportation or in a heating furnace, and prevent the glass plates from being displaced from each other. As a result, after the glass bending process, no bubble residue occurs due to poor pairing.

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Claims (5)

[Claims] 1. A peelable powder characterized by being a spherical inorganic powder having a particle size distribution of 5 to 40 μm and a refractive index of 1.40 to 1.60. 2. A powder capable of exfoliation, which is a spherical inorganic powder having a particle size distribution of 5 to 20 μm and a refractive index of 1.40 to 1.60. 3. The peelable powder according to claim 1, wherein the spherical inorganic powder is at least one selected from aluminosilicate and SiO ₂ . 4. The spherical inorganic powder is at least one selected from aluminosilicate and SiO ₂ , and further K ₂ O,
The powder capable of peeling according to claim 1, 2 or 3, which contains at least one selected from Na ₂ O and MgO. 5. The peelable powder according to claim 1, 2, 3 or 4, wherein the surface of the spherical inorganic powder is coated with a silicone resin.