JP2006193373A - Fine glass bubble and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fine glass hollow body contributing for the addition to a fine base component or the improvement of the surface smoothness of a base material and having remarkably small particle diameter, small particle density and large breaking strength and a method of manufacturing the fine glass hollow body with good yield. <P>SOLUTION: The high strength fine glass hollow body has a glass composition comprising 60-80 mass% SiO<SB>2</SB>, 2-12.5 mass% Na<SB>2</SB>O, 5-15 mass% CaO, 6-15 mass% B<SB>2</SB>O<SB>3</SB>and 0.05-1 mass% SO<SB>3</SB>wherein B<SB>2</SB>O<SB>3</SB>/Na<SB>2</SB>O (mass ratio) is 1.2-3.5, and has ≤50 μm D90 in the particle size distribution measured by a laser scattering particle size measurement, 0.55-0.75 g/cm<SP>3</SP>particle density and ≤2% volume breaking ratio in 500 kg/cm<SP>2</SP>hydrostatic pressure. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a high-strength and fine glass hollow body.

  A glass micro hollow body is generally called a glass balloon or a glass bubble, and has features such as being minute, hollow, relatively high strength, and excellent in water resistance. It is used for weight saving and heat insulation performance by adding to various materials. As an example of the field in which glass micro hollow bodies are used, it has spread to applications such as paints for moving bodies such as automobiles, ships and aircraft, putty, resin molding materials, various building materials, and paper clay.

On the other hand, especially in recent years, when various materials for moving bodies are desired to be reduced in weight, it is an important factor that the glass micro hollow body does not break when added to the materials. If the micro hollow body breaks, the glass hollow body becomes only the glass shell, and the density becomes about 2.5 g / cm ³ of the density of the glass, which is reversed rather than the weight reduction. Moreover, the improvement of the surface smoothness of a raw material and the addition to a fine raw material component are also desired, and it is desired to make the particle diameter further fine as a glass micro hollow body.

Conventionally, several patents have been filed for glass hollow bodies. Patent Document 1 discloses a glass microhollow body manufactured by using a borosilicate glass powder containing SO ₃ as a foaming component as a raw material and passing the raw glass powder through a flame. This glass hollow body has a particle density equivalent to 0.5 g / cm ³ and a compressive strength (hydrostatic pressure at which the volume is reduced by 10%) is equivalent to 1400 kg / cm ² . However, such a glass hollow body has an average particle diameter of 40 to 50 μm, and contains a large amount of coarse particles with a passing cumulative ratio 90% (D90) of 80 μm in the particle size distribution.

Patent Document 2 discloses a hollow glass body having a particle density of 0.3 to 0.4 g / cm ³ and a compressive strength of 600 kg / cm ² . However, the glass hollow body in this case is not only insufficient in pressure resistance, but also has an average particle diameter of 45 μm and a particle diameter of D90 of 65 μm, which contains many coarse particles.

Furthermore, in Patent Document 3, as a glass hollow body having a small particle diameter, the particle density is 0.485 g / cm ³ , the pressure strength is 660 kg / cm ² , the average particle diameter is 9.5 μm, and the particle diameter of D90 is 24 μm. A glass hollow body is shown. However, the glass hollow body of Patent Document 3 has insufficient pressure strength, and the micro hollow body is obtained by classifying a foamed product obtained by foaming a glass frit as a raw material with a sieve. . Therefore, it is not economical in terms of yield and sieving operation.

JP 58-156551 A JP-A-4-202025 International Publication WO01 / 002314

  In view of the above-described conventional technology, the present invention has a very small particle diameter that can contribute to the addition to fine material parts and the improvement of the surface smoothness of the material, and has a small particle density and a high breaking strength. An object of the present invention is to provide a hollow body and a method for producing the glass microhollow body with good yield.

As a result of diligent research, the present inventor has arrived at a novel high-strength glass microhollow body made of borosilicate glass having a specific composition that satisfies the above-mentioned target characteristics, and a method for producing the same. The present invention has the following gist.
₍₁₎ SiO 2: 60~80 _wt%, Na 2 O: 2 to 12.5 wt%, CaO: 5 to 15 _wt% B ₂ O 3: _6~15 wt%, and _SO 3: 0.05 to It has a glass composition containing 1% by mass and B ₂ O ₃ / Na ₂ O (mass ratio) of 1.2 to 3.5, and D90 in a particle size distribution by laser scattering particle size measurement is 50 μm or less. A high-strength micro glass hollow body having a particle density of 0.55 to 0.75 g / cm ³ and a volume fracture rate of 2% or less at a hydrostatic pressure of 500 kg / cm ² .
(2) The high-strength micro glass hollow according to (1) above, wherein D90 is 45 μm or less and the volume fracture rate at a hydrostatic pressure of 600 kg / cm ² is 2% or less in the particle size distribution by laser scattering particle size measurement. body.
(3) The high-strength micro glass hollow body according to (1) or (2), wherein the alkali elution degree is 0.08 meq / g or less.
₍₄₎ SiO 2: 58~75 _wt%, Na 2 O: _3~12.5 wt%, CaO: 5 to 15 _{wt%, B} 2 O 3: _11~15% by weight and _SO 3: 0.05 to It has a composition containing 1% by mass and B ₂ O ₃ / Na ₂ O (mass ratio) (mass ratio) of 1.7 to 4, and D90 is 35 μm or less in the particle size distribution by laser scattering particle size measurement. The method for producing a high-strength fine glass hollow body according to any one of claims 1 to 3, wherein a glass frit having an average particle diameter D50 of 15 to 20 µm is foamed.
(5) The high-strength microscopic material as described in (4) above, in which the glass frit having a passing cumulative ratio D90 of 35 μm or less and an average particle diameter D50 of 15 to 20 μm is foamed in the particle size distribution by laser scattering particle size measurement of the glass frit. A method for producing a hollow glass body.

  According to the present invention, a novel glass microhollow body having an extremely small particle diameter that can contribute to the addition to fine material parts and the improvement of surface smoothness of the material, a small particle density, and a high breaking strength, and A method for producing the glass microhollow body with high yield is provided.

The glass micro hollow body of the present invention has a glass composition of SiO ₂ : 60 to 80% by mass, Na ₂ O: _{2 to} 12.5% by mass, CaO: 5 to 15% by mass B ₂ O ₃ : 6 to 15 mass%, and _SO 3: 0.05 to 1 comprises mass%, and _{B 2 O 3 / Na 2 O} ( weight ratio) having 1.2 to 3.5. By having such a composition, the above-described characteristics can be achieved, and a micro hollow body having a low hygroscopic property and a low alkali elution degree can be obtained. In addition, even when a minute hollow body is mixed in a resin or the like, the resin is foamed, the fluidity at the time of molding is reduced, and a decrease in moldability or the like can be suppressed.

Among them, glass microballoons of the present invention, the composition of the _glass, SiO 2: 65 to 75 _wt%, Na 2 O: _3~6 wt%, CaO: 8 to 13 _wt%, B _{2 O} 3: 7 12 wt%, and _SO 3: 0.05 to 1 comprises mass%, and _{B 2 O 3 / Na 2 O} ( weight ratio) preferably has a composition which is 1.35 to 3. The total alkali metal oxide is 2 to 12.5% by mass, preferably 4 to 8% by mass, and the total alkaline earth metal oxide is 5 to 15% by mass, preferably 8 to 15% by mass. Preferably there is.

Moreover, the glass which forms a glass micro hollow body can contain the following other components, and, thereby, the characteristic of a glass micro hollow body can be controlled. K ₂ O: 0 to 3% by weight, preferably from 0.5 to 1.5 _wt%, Li 2 O: 0 to 3% by weight, preferably from 0.5 to 1.2 wt%, MgO: 0 to 3 mass %, preferably 0 to 1.5 wt%, ZnO: 0 to 3% by weight, preferably from 1.0 to 2.5 _{wt%, Al} 2 O 3: _0~3 wt%, preferably 0.5 to 1 .5 _{wt%, P} 2 O 5: _0~3 wt%, preferably from 1.1 to 2.0 _{wt%, Sb} 2 O 3: _{0~1 wt%, As} 2 O 3: _0~1 wt%.

  The glass micro hollow body of the present invention is required to have a passing cumulative ratio D90 of 50 μm or less in the particle size distribution by laser scattering particle size measurement or JIS standard sieve. This particle size distribution has a large effect on the glass micro hollow body particle density, pressure strength and quality of the final product. When D90 exceeds 50 μm, the particle density is generally small and the pressure strength is small. Use under such high pressure is often difficult. D90 is preferably 45 μm or less, and particularly preferably 42 μm or less. Moreover, the passage integration ratio D50 in the particle size distribution by the laser scattering particle size measurement of the glass micro hollow body is preferably 25 to 35 μm, particularly preferably 25 to 30 μm.

The glass microballoons of the present invention, the particle density is required 0.55~0.75g / cm ^3, among them, preferably 0.55~0.65g / cm ^3. When the particle density is greater than 0.75 g / cm ³ , the light weight effect is reduced when added to the material. In addition, when the particle density is smaller than 0.55 g / cm ^3, when the glass micro hollow body is added to the material and molded at a high pressure such as injection molding, the hollow body is broken and sufficiently light weight It becomes difficult to obtain an effect. When such a glass micro hollow body is used to reduce the weight of an injection molded part, attention must be paid to the injection molding pressure. If the micro hollow body breaks, the glass hollow body becomes only the glass shell, and the density becomes 2.5 g / cm ³ . When the destruction of the glass hollow body is large, it usually becomes larger than the density of the resin to be added, and it is not lightweight, but rather the density of the material becomes heavy.

According to the inventor's research, when a material containing a glass microhollow body is molded by injection molding or the like, the strength of the glass microhollow body requires a volume fracture rate of 2% or less at a hydrostatic pressure of 500 kg / cm ^2. It was found that the volume fracture rate at a hydrostatic pressure of 600 kg / cm ² is preferably 2% or less. When the hydrostatic pressure is less than 500 kg / cm ² , the specific gravity of the molded product becomes large when molding is performed at a high pressure. On the other hand, it is desirable that the strength of the glass micro-hollow body is large. However, since the particle density increases as the strength increases, the hydrostatic pressure at which the volume fracture rate is 2% or less is 1200 kg / cm ² or less, preferably 1000 kg. / Cm ² or less is preferable.

  Moreover, the glass micro hollow body of this invention has a small alkali elution degree, and has 0.08 meq / g or less, In particular, 0.06 meq / g or less. Thereby, the water absorption of the glass micro hollow body is improved, and when added to the resin, the resin does not foam or the fluidity during molding is not hindered.

Although the manufacturing method of the glass micro hollow body of this invention is not limited, Preferably, it manufactures as follows. That is, in the present _invention, SiO 2: _{58~75 wt%,} Na 2 O: from 3 to 12.5 wt%, CaO: 5 to 15 _{wt%, B} 2 O 3: _11~15% by weight and _SO 3: 0 It is manufactured by using a glass frit having a composition containing 0.05 to 1% by mass and B ₂ O ₃ / Na ₂ O being 1.7 to 4. The glass frit having such a composition has an appropriate foaming rate when producing a glass microhollow body, and is effective in reducing the particle density and alkali elution of the obtained glass microhollow body.

Among these glass frit, SiO ₂ : 58 to 70% by mass, Na ₂ O: 3 to 8% by mass, CaO: 7 to 12% by mass, B ₂ O ₃ : 12 to 19% by mass, and SO ₃ : It is preferable to have a composition containing 0.05 to 1% by mass and having B ₂ O ₃ / Na ₂ O of 1.35 to ₃ . Further, the total alkali metal oxide is 3 to 15% by mass, preferably 3 to 10% by mass, and the total alkaline earth metal oxide is 5 to 15% by mass, preferably 7 to 12% by mass. Is preferred.

In addition, the glass frit can contain other components such as the following, thereby controlling the characteristics of the glass microhollow body to be produced. K ₂ O: 0 to 3% by weight, preferably from 0.5 to 1.5 _wt%, Li 2 O: 0 to 3% by weight, preferably from 0.5 to 1.2 wt%, MgO: 0 to 3 mass %, preferably 0 to 1.5 wt%, ZnO: 0 to 3% by weight, preferably from 1.0 to 2.5 _{wt%, Al} 2 O 3: _0~3 wt%, preferably 0.5 to 1 .5 _{wt%, P} 2 O 5: _0~3 wt%, preferably from 1.2 to 2.0 _{wt%, Sb} 2 O 3: _{0~1 wt%, As} 2 O 3: _0~1 wt%.

  The particle size distribution of the glass frit is important because it affects the resulting glass microhollow body. The particle size of the glass frit is preferably D90 of 35 μm or less. When D90 is larger than 35 μm, the desired particle size distribution of the glass micro hollow body obtained after foaming cannot be obtained. The average particle diameter D50 of the raw glass frit also greatly affects the particle density after foaming, and D50 is preferably 15 to 20 μm, and particularly preferably 17 to 20 μm. When D50 is smaller than 15 μm, the particle density of the obtained glass microhollow body is increased, which is not suitable as a lightweight filler. On the other hand, when D50 exceeds 20 μm, the particle density becomes small, but the pressure resistance becomes weak and it is difficult to use as a lightweight filler for injection molding.

  Known means can be used as the means for producing the glass micro hollow body by foaming the raw glass frit. For example, by passing through a flame of 1000 to 1200 ° C. for 0.1 to 5 seconds, a glass micro hollow body is produced with a foaming rate of 70% or more, particularly 75% or more. Here, the foaming rate means the percentage of the weight of the glass micro hollow body that is a water floating product in a product including a non-foamed product obtained from the foaming process of the glass frit.

What is characteristic in the production of the glass micro hollow body of the present invention is that the D90 is 50 μm or less and the particle density is 0.55 to 0.75 g even if the foamed product obtained by foaming the glass frit is not classified with a sieve. / Cm ³ , and a high strength micro glass hollow body having a volume fracture rate of 2% or less at a hydrostatic pressure of 500 kg / cm ² is obtained. Therefore, in the case of the present invention, a desired glass microhollow body having a small particle diameter, a small particle density, and a high breaking strength can obtain a high yield without performing a sieving operation. Of course, if necessary, classification with a sieve may be performed to further adjust the particle size distribution.

EXAMPLES Next, although an Example is given and this invention is demonstrated further more concretely, this is an illustration and does not restrict | limit this about the interpretation of this invention. In the following,
Analysis of the glass composition, alkali elution degree, particle size distribution of the glass microhollow body, particle density, and volume fracture rate were determined as follows.
Analysis of glass composition:
Each component was quantitatively analyzed by fluorescent X-ray analysis or ICP emission analysis.
Alkaline dissolution rate:
The water floating product (bubble) of the glass micro hollow body was measured according to ANS / ASTN D3100-78.
Particle size distribution of glass micro hollow body:
It measured by the method by sieving with a laser scattering type particle size measuring device or a JIS standard sieve.
Particle density of glass micro hollow body:
It was measured by a gas displacement measurement method.
Volume fracture rate of glass micro hollow body:
A hydrostatic pressure was applied, and the volume change rate of the sample density before and after loading the pressure was determined and calculated according to the following formula.
Volume fracture rate = (density after pressure load−density before pressure load) × 100
/ Density after pressure loading

Examples 1-3
The following raw materials were mixed, put in a crucible, and melted at a furnace temperature of 1300 ° C. for 4 hours. Next, the melted product was put into a water bath and rapidly cooled to obtain 8000 g of a granulated glass frit.

Silicon dioxide: 5030 g, lime: 1210 g,
Borax (pentahydrate): 2590g, Aluminum oxide: 30g
Dicalcium phosphate: 339 g, Lithium carbonate: 138 g
Potassium carbonate: 118 g Zinc oxide: 82 g
Bow glass: 36g

The water of the granulated glass frit was drained and dried for 2 hours in a drier maintained at 150 ° C. After drying, 8 kg of this glass frit was put in a dry ball mill together with 40 kg of alumina ball mill, and pulverized so as to have a particle size distribution (D90, D50) shown in Table 1. The ground glass frit is referred to as a raw material powder in the present invention. The raw material powder had the following composition (unit: mass%).
_{SiO 2: 62.3 Na 2 O:} 7.2 LiO 2: 0.7
K ₂ O: 1.0 CaO: 10.1 ZnO: 1.0
B ₂ O ₃ : 14.9 Al ₂ O ₃ : 0.4 P ₂ O ₅ : 2.2
SO ₃ : 0.2
B ₂ O ₃ / Na ₂ O: 2.1 (mass ratio)

The raw material powder is continuously supplied to the foaming furnace at 500 g / min with a mixed gas of air and LPG (air / LPG volume ratio = 21) at an input rate of 25 g / min, and immediately cooled and collected by a bag filter. did. Table 1 shows the results of measuring the particle size distribution, the particle density, and the volume fracture rate of the collected glass hollow bodies without performing classification operation. Moreover, this glass micro hollow body had the following composition (unit; mass%), and the alkali elution degree was 0.07 milliequivalent / g.
_{SiO 2: 72.2 Na 2 O:} 4.2 LiO 2: 0.5
K ₂ O: 0.8 CaO: 11.1 ZnO: 1.0
B ₂ O ₃ : 8.2 Al ₂ O ₃ : 0.6 P ₂ O ₅ : 1.3
SO ₃ : 0.1
B ₂ O ₃ / Na ₂ O: 2.0 (mass ratio)

Examples 4-5
The raw material powder having the particle size distribution shown in Table 1 was manufactured in the same manner as in Example 1 except that the amount of bow glass was 30 g. Using this raw material powder, a glass microhollow was produced in the same manner as in Example 1. Table 1 shows the physical properties of the raw material powder and the glass micro hollow body produced.

Comparative Examples 1 and 2
Although it implemented like Example 1, the raw material powder which has the particle size distribution of Table 1 was manufactured by changing grinding | pulverization conditions. Using this raw material powder, a glass microhollow was produced in the same manner as in Example 1. Table 1 shows the physical properties of the raw material powder and the glass micro hollow body produced.

Comparative Example 3
Although it implemented like Example 4, the raw material powder which has a particle size distribution of Table 1 was manufactured by changing grinding | pulverization conditions. Using this raw material powder, a glass microhollow was produced in the same manner as in Example 1. Table 1 shows the physical properties of the raw material powder and the glass micro hollow body produced.

  The glass micro hollow body according to the present invention has excellent particle characteristics and particle size characteristics, and has sufficient particle strength, and is used for filling resin molded parts such as SMC for automobile exterior boards and heat insulating paints. When used as a material, an extremely smooth resin molding surface or painted surface can be obtained, and a desired lightening effect or heat insulation effect can be obtained. Moreover, it can be widely used for applications in which the thickness of a composite material such as a low dielectric constant filler is regulated.

  Applications of the hollow glass spheres of the present invention are not limited to the above-mentioned applications, but light weight fillers such as cement, mortar, synthetic wood, low melting point metals and alloys such as aluminum and magnesium, and heat insulation and light weight filling of building materials. Materials, explosive sensitizing fillers, electrical insulating layer fillers, soundproofing fillers, cosmetic fillers, filter media, blast media and spacers can be used very suitably in various fields and applications. Moreover, if mixed with a large hollow glass sphere having an average particle diameter of about 90 to 110 μm, the space between the large particles can be filled with the present small hollow glass sphere, resulting in higher weight reduction, heat insulation effect, and low dielectric constant. A rate-raising effect is obtained.

Claims (5)

SiO _2: 60-80 _wt%, Na 2 O: _2~12.5 wt%, CaO: 5 to 15 _{wt%, B} 2 O 3: _6~15 wt% and _SO 3: 0.05 to 1 wt% hints, and _{B 2 O 3 / Na 2 O} ( mass ratio) has a composition of the glass is 1.2 to 3.5, in the particle size distribution by a laser scattering type particle size measuring, D90 is at 50μm or less, A high-strength micro glass hollow body having a particle density of 0.55 to 0.75 g / cm ³ and a volume fracture rate of 2% or less at a hydrostatic pressure of 500 kg / cm ² . 2. The high-strength micro glass hollow body according to claim 1, wherein D90 is 45 μm or less and a volume fracture rate at a hydrostatic pressure of 600 kg / cm ² is 2% or less in a particle size distribution by laser scattering particle size measurement.   The high-strength micro glass hollow body according to claim 1 or 2, wherein the alkali elution degree is 0.08 meq / g or less. SiO _2: from 58 to 75 _wt%, Na 2 O: _3~12.5 wt%, CaO: 5 to 15 _{wt%, B} 2 O 3: _11~15% by weight and _SO 3: 0.05 to 1 wt% includes, and _{B 2 O 3 / Na 2 O} ( mass ratio) has a composition which is 1.7 to 4, in the particle size distribution by a laser scattering type particle size measuring, D90 is at 35μm or less, and D50 of 15 The manufacturing method of the high intensity | strength micro glass hollow body in any one of Claims 1-3 which foams glass frit which is -20 micrometers.   The method for producing a high-strength micro glass hollow body according to claim 4, wherein D90 of the glass frit is 35 µm or less and D50 is 15 to 20 µm.