JP5097144B2 - Method for producing tempered glass - Google Patents

Description

  The present invention relates to a method for producing tempered glass.

  Conventionally, as a method for producing tempered glass, air-cooled tempering method in which the glass surface is softened at a high temperature in the glass production process, which is rapidly cooled with jet air or the like to apply compressive stress, or at room temperature by ion exchange or the like. A chemical strengthening method for imparting compressive stress to the surface is known. Also known is a method of strengthening the glass surface by removing fine scratches (griffids defects) on the glass surface by polishing or the like.

  Recently, a method for producing tempered glass is also known, in which ultra-short pulse laser light is focused and irradiated in a spot shape on the glass surface or inside the glass, and a heterogeneous layer is formed in the shape of dots, lines or meshes inside the glass. (Patent Document 1).

Japanese Patent No. 3956286

  However, the air-cooling strengthening method requires that the entire glass to be tempered be heated at a conventional facility, and the chemical strengthening method requires that the glass to be tempered be immersed in an ion exchange tank. Even with the method, it was difficult to partially strengthen the glass. On the other hand, strengthening by polishing or the like requires a long time for the polishing process and is difficult in terms of processing efficiency.

  Moreover, since the air-cooling strengthening method raises the glass to a temperature higher than the softening point, it tends to be deformed by the softening of the glass, and it is difficult to strengthen a thin glass of 2 mm or less.

  Furthermore, the method described in Japanese Patent No. 3956286 is excellent in that it can be partially strengthened by focused irradiation even with a thin glass, but the conventional air cooling strengthening is possible. Unlike the method of strengthening glass by using the compressive stress near the surface of the glass and the chemical strengthening method, it uses the fact that the crack progress direction changes in the heterogeneous phase when the glass material breaks. Thus, the glass strengthening method improves the breaking strength. For this reason, it is considered that the intensity changes depending on the position of the heterogeneous layer such as a dot shape, a line shape, or a mesh shape by the focused irradiation, the form of the pattern, etc., and the work of determining the form of the heterogeneous layer is not easy.

  Then, this invention sets it as the main objective to provide the manufacturing method of tempered glass which can reinforce the required part of the arbitrary glass manufactured easily.

  In order to achieve the above-mentioned object, a method for producing tempered glass according to the present invention comprises, as a first means, heating a glass tempered desired region of a glass surface layer by scanning irradiation with laser light having a wavelength absorbed by glass. It has a heating step for forming a heat-denatured layer, and a cooling step for cooling the glass on which the heat-denatured layer is formed.

  Moreover, the manufacturing method of the tempered glass which concerns on this invention forms an absorber layer by apply | coating the absorbent containing liquid containing the absorber with absorption with respect to a laser beam to a glass surface as a 2nd means, and making it dry. A heating step of heating the glass surface layer of the glass reinforced desired region to form a heat-denatured layer by scanning irradiation with a laser beam having a wavelength absorbed by the absorbent layer, and the heat-denatured layer is formed. And a cooling step for cooling the glass.

  It is preferable to perform a cooling process while performing scanning irradiation with laser light.

  According to the method for producing tempered glass according to the present invention, a heat-denaturing layer is formed in a desired region of the surface layer of the glass by scanning irradiation with laser light that is absorbed in the glass, and cooling treatment is performed, so that complicated condition setting and the like can be performed. Since only necessary portions can be efficiently reinforced without being required, convenience is greatly improved, and application in a wide range is possible.

  In addition, if an absorbent layer is formed by applying an absorbent to the glass surface, a laser beam is scanned on the absorbent layer to form a heat-denatured layer on the glass surface layer, and cooling treatment is performed. As long as the wavelength is absorbed by the absorbent, it is not limited to the wavelength absorbed by the glass. Further, since the absorbent layer is formed by a simple method of applying the absorbent, the practical effect is great.

It is a partial cross section perspective view which shows 1st Embodiment of the manufacturing method of the tempered glass which concerns on this invention. It is a partial cross section perspective view which shows 2nd Embodiment of the manufacturing method of the tempered glass which concerns on this invention.

  Embodiments of a method for producing tempered glass according to the present invention will be described below with reference to the drawings. In the following description, the same components in all drawings and all the embodiments are denoted by the same reference numerals, and redundant description may be omitted.

  First, a first embodiment of the method of the present invention will be described with reference to FIG. As shown in FIG. 1, a laser beam 1 a having a specific wavelength is irradiated onto a glass plate 2 from a laser oscillator 1. The laser beam only needs to have a beam profile with a condensing area that can efficiently scan and irradiate the desired region of glass reinforcement with the condensed beam. A line beam focused in a shape can be used, and preferably the maximum width of the focused beam profile is 1 mm or more.

  In the illustrated example, line beam laser light is used. The line beam laser beam 1a is moved to the surface of the glass plate 2 along a path indicated by a virtual arrow line, and is irradiated so as to scan the entire region of the glass plate 2 surface to be reinforced, that is, the entire surface of the glass reinforced desired region (scanning irradiation). To do. Note that the line beam laser beam 1a may be irradiated so that the irradiated portions overlap, and the same portion may be irradiated twice or more.

  As a laser oscillator that generates line beam laser light, for example, a known laser line beam oscillation device using a rod lens, a cylindrical lens, a Powell lens, or the like can be used.

  Scanning irradiation may be performed by moving at least one of the line beam laser beam 1 a and the glass plate 2. For example, instead of moving the laser oscillator 1 or with the movement of the laser oscillator 1, In the opposite direction, the glass plate 2 is moved on the XY table, and the glass plate 2 is moved relative to the laser oscillator 1 so that the line beam laser beam 1a is scanned and irradiated on the glass plate 2. You may make it do.

  Further, the irradiation width W of the line beam laser beam can be set as appropriate. For example, the irradiation width W may be fixed, or may be controlled so as to change the irradiation width W as necessary. good. The irradiation width W can be controlled, for example, by controlling the slit width of the slit through which the laser light passes and the deferred ocus of the lens.

In the first embodiment, the wavelength of the line beam laser beam 1 a is a wavelength that is absorbed by the glass plate 2. Silica, which is the main component of glass, has a large absorption at a wavelength of 9.5 μm, and silica-based glass absorbs a CO ₂ laser (wavelength 10.6 μm) well. Therefore, in this case, a CO ₂ laser is preferable. Can be used as laser light. A laser oscillator whose wavelength is variable continuously or stepwise may be used by adjusting to a required wavelength. As the laser light, continuous wave, that is, continuous laser light or pulsed laser light can be used.

  By scanning and irradiating the surface of the glass plate 2 with the line beam laser light as described above, the surface layer of the glass plate 2 is heated to, for example, 1000 ° C. or more, and the heat-denatured layer 3 is formed on the surface layer of the glass plate 2. .

  The heat-denatured layer 3 of the glass plate 2 is subjected to a cooling process by forced cooling. The heat-denatured layer 3 is forcibly cooled so as to drop to room temperature in a predetermined time (for example, several milliseconds to several tens of seconds). As a cooling method, for example, an inert gas such as nitrogen gas obtained by vaporizing liquid nitrogen or a method of blowing air with a blower, a method of blowing a mist of cooling water, or the like can be used. Cooling treatment is preferably performed by spraying a mist of cooling water while irradiating the surface of the glass plate 2 with a line beam laser beam.

  When the heat-denatured layer 3 is cooled as described above, it is considered that a compressive stress layer is formed on the surface layer of the glass plate 2, and the glass plate 2 is considered to be strengthened. This compressive stress layer is formed within a range of a depth of 100 μm or less (for example, about 20 to 30 μm or less) from the surface of the glass plate 2. If the compressive stress layer is formed on both surfaces of the glass plate 2, a tempered glass plate without deflection can be formed.

  In addition, it is considered that scratches on the glass surface are alleviated or removed by high-temperature heating by laser irradiation, and it is also considered that the glass surface is strengthened.

  In addition, since the peripheral part of the glass plate 2 has many latent scratches produced at the time of cutting, it is preferable to reinforce the glass plate by scanning and irradiating a desired portion or a desired region excluding the peripheral part of the glass plate 2 with a laser beam. In addition, line beam laser light can be irradiated to alleviate such latent scratches.

  According to the said 1st Embodiment, the desired area | region (part or whole surface) of glass can be strengthened by simple process which only scans and irradiates a laser beam to the glass surface. Since glass can be tempered by irradiating a laser in a room temperature environment, it is convenient and can be applied in a wide range. Moreover, according to this invention, since it reinforce | strengthens by heating only the surface layer of glass with a laser beam, it can strengthen also with a thin glass plate whose thickness is 2 mm or less.

  Next, 2nd Embodiment of the manufacturing method of the tempered glass which concerns on this invention is described with reference to FIG.

  In the second embodiment, an absorbent layer 4 that absorbs laser light is formed on the surface of the glass plate 2. Therefore, the wavelength of the line beam laser beam 1 a is a wavelength that is absorbed by the absorbent layer 4 and is not limited to the wavelength that is absorbed by the glass plate 2.

  The absorber layer 4 is not particularly limited as long as it can absorb laser light. For example, an infrared absorber or a near infrared absorber that can absorb a semiconductor laser (wavelength: about 0.6 to 1.8 μm), or It can be formed using an absorbent-containing liquid in which an absorbent that absorbs laser of any wavelength, such as carbon black or amorphous carbon, is dispersed in a dispersion medium such as water or an organic solvent, or partially dissolved. it can. Infrared absorbers and near-infrared absorbers are commercially available in various inorganic or organic powder products. Carbon black ink, black ink, etc. can be used as the carbon black dispersion.

The absorbent layer 4 is formed by applying the above-described absorbent-containing liquid onto the glass surface by various coating methods such as printing, brush coating, roller coating, spin coating, dipping, spraying, and the like, and then drying by heating or air drying. Is formed. The thickness of the absorbent layer 4 depends on the intensity of the irradiated laser beam, the material of the absorbent, and the like. For example, in the case of a carbon black dispersion liquid in which carbon black is dispersed in water or an organic solvent, the absorbent layer 4 The thickness is about 0.1 to 5 μm.

  By moving a line beam laser beam having a wavelength absorbed by the absorbent layer 4 relative to the glass plate 2 to the absorbent layer 4 formed on the surface of the glass plate 2, the glass plate 2 can be strengthened. Scanning irradiation is performed to heat the absorbent layer 4. As a result, when the surface layer of the glass plate 2 is heated via the absorbent layer 4, the surface layer temperature of the glass plate 2 becomes 1000 ° C. or higher, and the heat-denatured layer 3 is formed on the surface layer of the glass plate 2.

When using a semiconductor laser, by morphism irradiation a predetermined output and a semiconductor laser beam having a predetermined wavelength region to the absorbent layer 4, the temperature of the absorbent layer 4 a semiconductor laser is absorbed by the absorbent layer 4 in a short time The temperature can be increased to about 800 to 1000 ° C. When a CO ₂ laser is used, the CO ₂ laser (wavelength 10.6 μm) is also absorbed by the glass plate 2, and therefore, when the CO ₂ laser with a predetermined output is irradiated to the absorbent layer 4, the absorbent layer 4 By absorbing the CO ₂ laser in the glass plate 2, the temperature of the absorbent layer 4 and the glass plate 2 can be increased to about 800 to 1000 ° C. in a short time.

  As the laser light, as in the first embodiment, continuous wave, that is, continuous laser light or pulsed laser light can be used.

The output (energy intensity) of the laser light to be irradiated is preferably about 1 to 3 kW / cm ^{2 in} the case of near-infrared semiconductor laser light, for example. The speed at which the line beam laser beam 1a moves on the surface of the glass plate 2, that is, the relative speed at which the line beam laser beam 1a applied to the glass plate 2 moves on the glass plate 2 varies depending on the intensity of the laser beam, for example. In the case of a near-infrared semiconductor laser beam having a fluence of 2.8 kW / cm ^2, the speed is about 2 mm / second.

  The glass plate 2 that has been scanned and irradiated with the line beam laser light is subjected to a cooling process by forced cooling, as in the first embodiment. The cooling process is preferably performed as quickly as possible. It is desirable that the surface layer of the heated glass plate 2 is subjected to a cooling treatment so as to lower it to room temperature. For example, as in the first embodiment, the heat-denatured layer 3 is cooled by forced cooling using inert gas blowing, cooling mist spraying, jet air, or the like. It is preferable to perform the cooling process while performing scanning irradiation with a line beam laser beam.

  When the heat-denatured layer 3 is cooled as described above, the glass plate 2 is strengthened by generating a compressive stress layer on the surface layer of the glass plate 2 as in the first embodiment.

  In the second embodiment as well, since the peripheral edge of the glass plate 2 has a great number of latent scratches, a line beam laser is applied to a desired portion or a desired region excluding the peripheral edge of the absorbent layer 4 formed by spin coating or the like. Scanning irradiation with light is preferable. In addition, line beam laser light can be irradiated to alleviate such latent scratches.

  After the temperature of the substrate, which has become high due to laser irradiation, decreases, the absorbent layer is removed using an organic solvent, an alkaline solution, or the like.

  According to the second embodiment, similarly to the first embodiment, the glass can be tempered by a simple process of simply irradiating a desired region with laser light on the absorbent layer formed on the glass surface. The glass can be tempered by irradiating the laser in the environment, so it is convenient and can be applied in a wide range. Furthermore, since the glass can be tempered locally, there are great practical advantages. Can play. Further, according to the second embodiment, the glass to be reinforced does not necessarily need to be a glass that absorbs the irradiated laser light in order for the absorbent layer 4 to absorb the laser light. Increased freedom of type. Furthermore, according to the second embodiment, as in the first embodiment, only the glass surface layer is strengthened by heating and cooling with a laser beam, so that even a thin glass plate having a thickness of 2 mm or less can be strengthened. is there.

  In the first and second embodiments, the strengthening of the glass plate has been described. However, in the method of the present invention, the glass to be strengthened is not limited to the plate glass, and other shapes of glass can be strengthened.

  The present invention will be described in further detail using examples.

Example 1
As a glass plate to be strengthened, a plurality of soda-lime glasses having a square shape with a thickness of 3 mm and a length and width of 50 mm × 50 mm were prepared.

Output 70 W, a CO ₂ laser oscillator which emits a line beam laser beam is moved in a constant direction at a speed 50 mm / sec relative to the glass plate was scanned with a line beam laser light in the region of 45 mm × 50 mm. The beam profile of the line beam laser beam was 10 mm × 150 μm wide, and defocused from a focal length of 62.5 mm to +10 mm.

  As an irradiation method, the line beam laser beam transmitter is supported so as to be movable in the XY direction, and after moving the line beam laser beam by 50 mm in the + X direction, the irradiation is stopped and moved in the + Y direction by 2.5 mm. Then, the operation of moving 50 mm in the −X direction, starting irradiation again and moving 50 mm in the + X direction was repeated, and scanning irradiation was performed on a 45 mm × 50 mm region. Accordingly, there is a region irradiated with the line beam laser light a plurality of times. The scanning irradiation of the line beam laser beam was performed on both surfaces of the glass plate.

  Simultaneously with the laser beam irradiation, nitrogen gas taken out from the liquid nitrogen cylinder was sprayed from a pipe having an inner diameter of 4 mm to the rear of the laser beam irradiation position at a spraying pressure of 0.5 MPa to perform a cooling process.

  As described above, Example 1 of the present invention was manufactured, and as a comparative example, a glass plate using the same material with the same dimensions and not irradiated with laser was prepared.

  About the Example 1 and comparative example of this invention, the drop test of the ceramic ball was done and the intensity | strength was compared. The ceramic ball used has a mass of 7 g and a diameter of 15 mm.

  As a result of the test, cracks occurred when the ceramic balls were dropped from a height of 80 cm in the comparative example. However, cracks did not occur even when the ceramic balls were dropped from a height of 110 cm in Example 1, and about 1.5 It was found that it was doubled.

Example 2
As a glass plate to be strengthened, a plurality of soda-lime glasses having a square shape with a thickness of 3 mm and a length and width of 50 mm × 50 mm were prepared.

  A carbon black dispersion was evenly applied to both surfaces of this glass plate by spin coating so that the thickness after curing was about 1 μm, and air-dried to form an absorbent layer.

A near-infrared semiconductor laser oscillator that emits a line beam laser beam with a maximum output of 4 W and a wavelength of 808 nm is moved at a speed of 2 mm / second with respect to the glass plate, and a line beam laser beam (laser fluence of 2.8 kW) in a 45 mm × 50 mm region. / Cm ² ). The beam profile of the line beam laser beam was 0.06 × 1000 μm, and irradiation was performed with a lens having a focal length of 50 mm.

  As an irradiation method, a line beam laser beam transmitter is supported so as to be movable in the X and Y directions, and is moved by 50 mm in the + X direction while irradiating the line beam laser beam. Then, the irradiation was started and moved 45 mm in the −X direction, and again the operation of stopping the irradiation and moving 0.25 mm in the + Y direction was repeated, and scanning irradiation was performed on a 45 mm × 50 mm region. Accordingly, there is a region irradiated with the line beam laser light a plurality of times. Laser beam scanning was performed on both sides of the glass plate.

  Simultaneously with the laser beam irradiation, nitrogen gas taken out from the liquid nitrogen cylinder was sprayed from a pipe having an inner diameter of 4 mm to the rear of the laser beam irradiation position at a spraying pressure of 0.5 MPa to perform a cooling process.

  As described above, an example of the present invention was manufactured, and as a comparative example, an absorbent layer and a glass plate not subjected to laser irradiation were prepared using the same material with the same dimensions.

  The drop test of the ceramic ball was performed on the product of the example of the present invention and the product of the comparative example, and the strength was compared. The ceramic ball used has a mass of 7 g and a diameter of 15 mm. The ceramic balls were dropped from the height of 8 steps every 40 cm to 5 cm in height to test whether the glass was broken. The test results are shown in Table 1.

  From the results in Table 1, it was found that in this example, the strength was improved by about 50% with respect to the comparative example.

DESCRIPTION OF SYMBOLS 1 Laser oscillator 1a Laser beam 2 Glass plate 3 Thermal modification layer 4 Absorbent layer

Claims (5)

A heating step of forming a heat-denatured layer by heating a glass-reinforced desired region of the glass surface layer by scanning irradiation with laser light having a wavelength absorbed by the glass,
A cooling step of cooling the glass on which the heat-denatured layer is formed;
A method for producing tempered glass, comprising: Forming an absorbent layer by applying an absorbent containing liquid containing an absorbent that absorbs laser light to the glass surface and drying;
A heating step of heating the glass surface layer of the glass-reinforced desired region to form a heat-denatured layer by scanning irradiation with laser light having a wavelength absorbed by the absorbent layer,
A cooling step of cooling the glass on which the heat-denatured layer is formed;
A method for producing tempered glass, comprising:   The method for producing tempered glass according to claim 1 or 2, wherein the cooling process in the cooling step is performed while performing the scanning irradiation of the laser beam in the heating step.   The manufacturing method of the tempered glass in any one of Claims 1-3 in which the said cooling step contains the mist injection of a cooling water. The method for producing tempered glass according to any one of claims 1 to 4, wherein in the cooling step, the heat-denatured layer is forcibly cooled so as to drop to room temperature in a few milliseconds to a few tens of seconds.

Images