KR20090041363A - Heat-resistant tempered glass and process for producing the same - Google Patents

Abstract

A heat-resistant tempered glass that is for windows and doors of building and housing unit, having a strength satisfying flame shielding performance, and that realizes high image quality. The tempered glass is one resulting from physical strengthening processing of a glass plate cut into given size, characterized in that there is provided an edge portion polished plane inclined against the surface of glass plate and an end face thereof, and that the edge portion polished plane has an angle of 135° to 170° against the glass plate surface, and that a break in a corner portion made by the edge portion polished plane and the glass plate surface has a length of 200 mum or less in the direction of edge line and has a maximum width of 100 mum or less in the direction perpendicular to the edge line.

Description

Heat-resistant tempered glass and manufacturing method of heat-resistant tempered glass {HEAT-RESISTANT TEMPERED GLASS AND PROCESS FOR PRODUCING THE SAME}

The present invention relates to heat-resistant tempered glass, and more particularly, to a method for producing heat-resistant tempered glass and heat-resistant tempered glass used for fireproof windows and fire doors for buildings or houses.

In general soda-lime glass, the tensile stress which generate | occur | produces in an edge part at the time of the fire test of a fire door determined by the building standard method, and a fire generate | occur | produces damage. This tensile stress is caused by the temperature difference between the end portion sandwiched in the chassis frame and the surface portion exposed to the flame. Conventionally, as fire prevention glass used for the purpose of a combustion prevention etc., the wire mesh glass which embedded the metal mesh so that the opening by a fallout may not be produced | generated even if a glass breaks at the time of a fire is generally used. In recent years, the fire prevention glass which shows the fire prevention performance by not breaking a glass at the time of a fire occurrence even if there is no metal mesh from an external advantage etc. is proposed.

In order to secure the strength of the end part, such a fireproof glass heats a glass plate near a softening point, and raises a surface compressive stress by the heat processing for physical reinforcement which soaks a glass plate by spraying compressed air etc., so-called physical reinforcement process. It becomes necessary. Since this process injects compressed air etc. to a glass surface and quenchs in a state where a glass plate is comparatively flexible, the trace of a quench and curvature generate | occur | produce on the glass surface, and flatness may worsen, and the fall of image quality cannot be avoided.

In addition, in the state where the glass cut end surface after cutting is not polished, when a tensile stress is applied to the edge part, the glass plate has a fine crack in the corner portion at the boundary between the glass plate face and the end face, and in particular, a wheel cutter or a diamond cutter at the time of cutting. The stress is concentrated in the part where the furnace crack is generated, and the fracture occurs. For this reason, in order to improve the intensity | strength (henceforth "edge strength") of the end surface of a glass plate, how to chamfer becomes important. In addition, edge strength means the tensile stress which generate | occur | produced on the edge surface at the time of the break of the glass plate edge part.

Citation Document 1 proposes a fireproof glass in which the edge portion of the glass is polished to a curved shape, and then the boundary portion between the curved end portion and the planar portion (plate surface) is polished and the edge strength is improved by physical reinforcement treatment. However, in the edge grinding method of the glass plate of this reference document 1, the grinding wheel of a special curved shape must be used, production of a new grinding wheel is needed, and the processing cost and quality control cost of a glass edge part also increase.

In Citation Document 2, a fireproof glass in which only the slopes at both ends of a glass cross section are chamfered and the edge strength is further improved by physical reinforcement is proposed.

Thus, the glass which cut | disconnected the glass plate and grind | polished the edge part by the method different from usual, and performed the physical strengthening process and raised heat-resistant strength is especially called heat resistant tempered glass among fireproof glass. The performance required as heat-resistant tempered glass satisfies the flame retardant performance prescribed in Article 2 of Article 9 of the Building Standards Act and Article 64 of the Building Standards Act in Japan, for example. As a test to evaluate this, for example, there is a fire test based on a heating temperature curve of ISO834-1: 1999. In order to pass this, it is required to not cause damages such as cracks and flames that pass through the flame during the fire protection test. Therefore, the glass is not broken except for glass that does not fall even if the glass is broken, such as wire mesh glass. It is necessary not to. To this end, the edge strength before the physical reinforcement treatment after the end work and the surface compressive stress in the vicinity of the edge by the physical reinforcement treatment, that is, the edge strength retained by the glass plate after the physical reinforcement treatment are generated at least during the test. It is necessary to exceed the tensile stress of the edge. The edge strength after the physical reinforcement treatment increases as the surface compressive stress of the edge increases, and the reliability of the tensile stress generated at the time of the test is increased. However, if the glass temperature at the start of quenching is too high in the physical reinforcement treatment in order to increase the surface compressive stress at the edge, as described above, the glass plate may exhibit heat treatment traces or warpage, resulting in poor flatness and satisfactory image quality as the glass plate. It becomes impossible.

Moreover, although heat-resistant tempered glass has been used for buildings, such as an apartment and an office, the demand for residential use is also increasing recently. However, the glass used for the windows and doors for a house is thicker than the glass used for a building, if the cross section is processed using the method of either cited document 1 or 2, and the physical reinforcement process is performed on the same conditions as before. Because of its thinness, traces of heat treatment and warpage tend to occur, and image quality is a problem.

Patent Document 1: Japanese Patent Application Laid-Open No. 9-71429

Patent Document 2: Japanese Patent Application Laid-Open No. 11-79769

Problems to be Solved by the Invention

This invention is made | formed in view of the said situation, Comprising: It aims at provision of the manufacturing method of the heat resistant tempered glass and heat resistant tempered glass which satisfy | fills flame-proof performance even if surface compressive stress is small as glass for a building or a house window and a door. Moreover, an object of this invention is to provide the manufacturing method of the heat resistant tempered glass and heat resistant tempered glass which satisfy | fills flame-proof performance and is high image quality, even if surface compressive stress is small.

Means to solve the problem

This invention finds and implements the processing method of the edge part which can ensure the intensity | strength as heat resistant tempered glass even if surface compressive stress is reduced according to the said objective. In addition, the present invention finds and implements a physical reinforcement processing method that satisfies high image quality in addition to the processing method of this end portion.

That is, in order to achieve the said objective, in the tempered glass of this invention, the glass plate cut | disconnected to the predetermined dimension is the tempered glass by which the physical strengthening process was carried out, and has the ridge | polishing part polished surface inclined with respect to the said glass plate surface and the cross section, The ridge polishing surface has an angle of 135 degrees or more and 170 degrees or less with the glass plate surface, and the missing portion of the edge formed by the ridge polishing surface and the glass plate surface (also referred to as "chip") has a length of 200 in the ridge direction. The maximum width in the direction perpendicular to the ridgeline is 100 µm or less.

Moreover, in the said tempered glass of this invention, the compressive stress of the glass plate surface is 75 Mpa or more and 160 Mpa or less and 4.5 mm when the plate | board thickness is 70 Mpa or more and 155 Mpa or less, 3.5 mm or more and less than 4.5 mm when plate | board thickness is 2.5 mm or more and less than 3.5 mm. 85 MPa or more and less than 170 MPa or less, less than 5.5 mm, 95 MPa or more and 180 MPa or less, 5.5 mm or more and less than 6.3 mm, 105 MPa or more and 190 MPa or less, 7.0 mm or more and less than 9.0 mm or less, 120 MPa or more when more than 7.0 mm and less than 9.0 mm. When it is 205 Mpa or less, 9.0 mm or more and less than 11.0 mm, it is preferable that they are 150 Mpa or more and 240 Mpa or less when 135 Mpa or more and 220 Mpa or less, and 11.0 mm or more and 20.0 mm or less.

Moreover, in the said tempered glass of this invention, it is preferable that the cross section of a glass plate is polished.

Moreover, as for the said tempered glass of this invention, it is preferable that the projection width with respect to the glass end surface of the said ridge part polishing surface is 0.3 mm or more and 1.3 mm or less, and the projection width with respect to the glass plate surface side is 0.3 mm or more and 3 mm or less.

In the manufacturing method of the tempered glass of this invention, the manufacturing method of the tempered glass which includes the process of processing the edge part of the glass plate cut | disconnected by the predetermined dimension, and the process of physically strengthening the glass plate after the said end process, The said edge part is processed. In the step, the angle formed between the surface of the ridge and the glass plate surface with respect to the glass plate surface and the end is polished to 135 degrees or more and 170 degrees to form a ridge polishing surface, and the corner portion formed by the ridge polishing surface and the glass plate surface. The maximum width in the direction perpendicular to the ridgeline is 200 µm or less, and the maximum width in the ridgeline direction of the missing ridgeline is 100 µm or less.

Moreover, in the manufacturing method of the said tempered glass of this invention, the process of the said physical strengthening process is the process of heating the glass plate after the said grinding | polishing to 620 degreeC or more and 660 degrees C or less, and the glass plate after the said heating is 5 degreeC or more and 80 degrees C or less. And a step of quenching compressed air by spraying from both sides of the glass plate, wherein the pressure of the compressed air is 10 kPa or more and 25 kPa or less when the plate thickness is 2.5 mm or more and less than 3.5 mm, and 7 kPa or more when the thickness is 3.5 mm or more and less than 4.5 mm. Less than or equal to 4.5 mm and less than 7.0 mm Less than 6 mm and more than 15 mm and less than 7.0 mm and less than 9.0 mm 5 mm and more and less than 13 mm and less than 9.0 mm and more than 11.0 mm and less than 4 mm and more than 12 mm and less than 11.0 mm and more than 11.0 mm and more than 20.0 mm When it is below, it is preferable to set it as 2 GPa or more and 10 GPa or less.

Moreover, in the manufacturing method of the tempered glass of this invention, it is preferable that the process of processing the said edge part adds grinding | polishing of the said glass plate cross section.

Moreover, in the manufacturing method of the tempered glass of this invention, the process of processing the said edge part is 0.3 mm or more and 1.3 mm or less, the projection width with respect to the glass cross section side of a ridge part polishing surface is 0.3 mm or more 3 It is preferable to grind to mm or less.

Effects of the Invention

According to this invention, since the edge strength before heat processing by a physical strengthening process can be improved, even if the surface compressive stress by heat processing is low, the manufacturing method of the heat resistant tempered glass and heat resistant tempered glass which satisfy | fills flame-proof performance can be obtained. Moreover, since the required surface compressive stress can be reduced, the glass temperature of heat processing can be made low, and the manufacturing method of the heat resistant tempered glass and heat resistant tempered glass which has high image quality can be obtained.

1 is a schematic cross-sectional view of a tempered glass sheet according to an embodiment of the present invention.

2 is a schematic explanatory diagram of a polishing processing method of an end of a glass plate according to an embodiment of the present invention.

3 is a schematic cross-sectional view of a polished state by a cylindrical grindstone of the tempered glass sheet according to the embodiment of the present invention.

4 is a schematic cross-sectional view of a polished state of a tempered glass sheet according to another embodiment of the present invention.

5 is a cross-sectional dimension and a site explanatory diagram of the glass plate end portion according to the present embodiment.

FIG. 6 shows a plot (Wibull plot) on the Weibull probability axis based on the test results in Table 1. FIG.

Explanation of the sign

1: glass plate 1a: glass plate surface

1b: cross section 1c: twill polishing surface

1d: corner part 2 (2a, 2b, 2c): grindstone

3: abrasive grain layer 4: rotation axis

5: disk 6: polishing belt

7: cylinder

EMBODIMENT OF THE INVENTION Hereinafter, the tempered glass which concerns on embodiment of this invention is demonstrated according to drawing.

1 is a schematic cross-sectional view of tempered glass according to an embodiment of the present invention. As shown in FIG. 1, the glass plate 1 is cut | disconnected by predetermined dimension, and only the thigh parts on both ends of the cross section 1b are polished, and the twill part polishing surface inclined with respect to the glass plate surface 1a and the cross section 1b ( 1c) is formed. The end face 1b of the glass plate 1 may be in a cut state, but in order to stabilize the variation in edge strength according to the cutting quality, it is preferable to be polished, in particular, in parallel grinding (feeding (transfer) direction for polishing of glass). And a polishing method in which the rotation direction of the grindstone is the same when the polishing surface of the glass and the grindstone abuts is good.

The angle A which the glass plate surface 1a and the twill polishing surface 1c make is 135 degrees or more and 170 degrees or less. When the angle A is smaller than 135 degrees, a fallout is likely to occur at the corner formed by the ridge polishing surface 1c and the glass plate surface 1a, the edge strength before the physical reinforcement treatment is insufficient, and the heating up to high temperature and the wind pressure are high. Cooling treatment is required, which causes distortion and deformation of the glass, resulting in poor image quality. Moreover, when angle A is larger than 170 degree | times, high precision ridge grinding | polishing is needed, and installation cost increases. It is preferable that 151 degrees or more and 170 degrees or less are hard to generate | occur | produce more preferably. More preferably, they are 154 degrees or more and 170 degrees or less. In addition, angle A of FIG. 1 does not need to be the same with respect to the upper and lower glass surfaces, if it falls in these ranges.

In the normal grinding of the twill, the angle A is in the range of 135 degrees plus the manufacturing error, because the edge is easily broken during the post-processing or transportation if the corner is left without polishing the twill. Actively improving the strength was not intended. In polishing of the twill portion according to the present invention, the angle A is made larger than usual in order to actively improve the edge strength. It is not clear why by increasing the angle A, the fracture starting from the edge portion 1d after the end polishing decreases and the edge strength is improved, as described below. However, the following factors are expected. In the end working, the direction of the reaction force vector by pressing the grindstone at the corner portion 1d is a direction substantially perpendicular to the ridge polishing surface 1c. In the case where the angle A is large, the reaction force vector is about half the angle A, so that the separation from the glass plate surface 1a and the ridge polishing surface 1c hardly occurs. On the other hand, when the angle A is small, the reaction force vector is close to the glass plate surface 1a, and therefore, the separation from the glass plate surface 1a easily occurs.

For the above reasons, it is considered that the larger the angle A is, the less the defect from the corner portion 1d occurs, and the edge strength after the end polishing is remarkably improved.

In general soda-lime glass, at the time of a fire, it is a factor of breakage that generate | occur | produces tensile stress which maximizes an edge part by the temperature difference etc. of the edge part inserted in the chassis frame, and the surface part exposed to a flame. Most cases of breakage are based on the missing presence in the probable area. Therefore, in the case of having a cutout on the ridgeline (ridgeline extending in the direction perpendicular to the sheet of Fig. 1) formed by the ridge polishing surface 1c and the glass plate surface 1a, the size of the dropout is It needs to be below a certain limit. The length of the ridgeline direction of this vacancy should be 200 micrometers or less. The length in the ridgeline direction of the dropout refers to the length of the ridgeline (virtual ridgeline) lost by the dropout that occurred on the ridgeline of the corner portion 1d. In addition, the maximum width in the direction perpendicular to the ridges of the missing lines needs to be 100 µm or less. The maximum width in the direction perpendicular to the ridge of the fallout refers to the maximum width in the vertical direction with respect to the ridgeline (virtual ridge) lost due to the fall generated on the ridgeline of the edge portion 1d. The size of the missing is obtained by observing the edge 1d of the glass after grinding | polishing using a digital microscope (for example, product number VH-6200 of Keyence Co., Ltd., product name digital microscope), and measuring each distance. Lose.

Thus, when the angle A is 135 degrees or more and 170 degrees or less, and the length of the missing part which exists in the corner part 1d is 200 micrometers or less in a ridgeline direction, and the maximum width of the perpendicular | vertical direction to a ridgeline is 100 micrometers or less, a glass plate ( The lower limit of 3σ _n-1 of the edge strength of 1) exceeds 70 MPa. In order to secure the edge strength, the surface roughness after polishing of the ridge is also an influencing factor of the edge strength, but it is important to manage it by the presence and size of the missing.

As mentioned above, since edge strength can be improved remarkably by the processing method of the edge part which concerns on this invention, a flame-proof performance can be improved as a heat resistant tempered glass. In addition, the surface compressive stress at the end can be reduced by the amount of the edge strength to be improved, and even if the glass temperature at the start of cooling is lowered in the physical strengthening process, the image quality can be improved while maintaining the necessary flame resistance performance as the heat-resistant tempered glass. Can be.

As a method for evaluating the flame retardant performance, for example, in a fire protection test based on the heating curve of ISO 834-1: 1999, after tempered glass is inserted into a chassis, the glass is fired by the flame by the burner and the radiant heat in the furnace from one side of the glass plate. Heat it. In this case, to the tensile stress generated at the edge of the glass plate, the stress generated by the temperature difference between the center and the end of the glass plate is added to the bending stress generated by the deformation of the edge due to the deformation of the chassis. Edge strength after a physical reinforcement process needs to exceed this tensile stress.

The tensile stress generated at the edge during the fire protection test was not always obvious because at least the center of the glass plate was generated at a relatively high temperature and a change in rigidity as the glass plate caused by warpage occurred. For this reason, since it is a safety side as edge strength after a physical strengthening process conventionally, based on the result of the fire prevention test in the comparatively thick glass plate for buildings conventionally, the surface compression required by assuming the constant tensile stress irrespective of the thickness of a glass plate. The stress was determined.

In contrast, in the present invention, the relationship between the thickness of the glass plate and the tensile stress was determined by the fire protection test or the like in order to ensure the flameproof performance, and further ensure the flameproof performance and further improved image quality. As a result, the thinner the plate thickness, the shorter the time from the start of heating to which the maximum value is generated, the lower the glass temperature and the smaller the deformation of the end portion. I found out. As a result, although the surface compressive stress is set to be substantially the same as that of a thick plate (about 10 mm in thickness) even when the plate thickness is about 2.5 to 9.0 mm, it has flame retardant performance even at a relatively low surface compressive stress in the thin plate, and high image quality. You will get In fact, the tensile stress occurring at the edge during the fire protection test is reduced by about 60 MPa when 2.5 mm or more and less than 3.5 mm, and about 55 MPa when 3.5 mm or more and less than 4.5 mm, as compared with the case of 10 mm thickness. It decreases about 45 MPa when it is more than 5.5 mm, and decreases about 35 MPa when it is more than 5.5 mm and less than 6.3 mm, decreases about 25 MPa when it is more than 6.3 mm and less than 7.0 mm, and reduces about 15 MPa when it is more than 7.0 mm and less than 9.0 mm. . Moreover, when it is 11.0 mm or more and 20.0 mm or less, it increases about 15 Mpa.

Based on the above, reducing the required surface compressive stress as the sheet thickness becomes thinner and improving the edge strength by the processing method of the end according to the present invention described above, maintaining the flame resistance performance required as the heat-resistant tempered glass With this, the image quality can be further improved.

That is, the tempered glass according to the present invention is 75 MPa or more and 160 MPa when each surface compressive stress with respect to the plate thickness of the glass plate is 70 MPa or more and 155 MPa or less, 3.5 mm or more and less than 4.5 mm when the surface compressive stress is 2.5 mm or more and less than 3.5 mm. Less than or equal to 85 MPa and less than or equal to 170 MPa when less than or equal to 4.5 mm, less than or equal to 95 MPa and less than or equal to 180 MPa, less than or equal to 95 MPa and less than or equal to 180 MPa, greater than or equal to 105 MPa, less than or equal to 190 MPa, or less than 7.0 or less than 9.0 mm When it is 120 MPa or more and 205 MPa or less, 9.0 mm or more and less than 11.0 mm, it is preferable that it is 150 MPa or more and 240 MPa or less when 135 MPa or more and 220 MPa or less, 11.0 mm or more and 20.0 mm or less.

The more preferable range of surface compressive stress is 70 MPa or more and 130 MPa or less when the plate | board thickness of the said glass plate is 2.5 mm or more and less than 3.5 mm, when 75 MPa or more and 135 MPa or less, 4.5 mm or more and less than 5.5 mm when 3.5 mm or more and less than 4.5 mm. 85 MPa or more 140 MPa or less, 5.5 mm or more and less than 6.3 mm 95 MPa or more and 150 MPa or less, 6.3 mm or more and less than 7.0 mm 105 MPa or more and 160 MPa or less, 7.0 mm or more and less than 9.0 mm 120 MPa or more and 175 MPa or less It is 150 Mpa or more and 210 Mpa or less when it is 135 Mpa or more and 190 Mpa or less, and 11.0 mm or more and 20.0 mm or less when it is mm or more and less than 11.0 mm. By setting the surface compressive stresses in these ranges, the margin for the tensile stress generated during the fire protection test is lower than that in the relatively preferred range, but the necessary flame retardant performance is maintained, and the image quality before the physical reinforcement treatment is further closer. Tempered glass can be provided.

In addition, surface compressive stress can be measured with the differential refractometer which is described in JIS R3222 (2003 edition). The surface compressive stress is more likely to cause warpage of the glass plate when the end portion and the center portion of the glass plate are largely different in image quality, and therefore, it is more preferable that there is no distribution in the plane of the glass plate. It is preferable to satisfy the said range at least in the part from a cross section to 50 mm.

Although the magnitude | size of the projection width B with respect to the cross section 1b side of the ridge polishing surface 1c, and the projection width C with respect to the glass plate surface 1a side of the ridge polishing surface 1c is suitably determined according to the thickness of a glass plate, it cuts a glass plate B is 0.3 mm or more and 1.3 mm or less, C is 0.3 mm or more and 3 mm in order to suppress the stress concentration in case tensile stress generate | occur | produces in a glass edge part by the crack which generate | occur | produces in the process of forming a cutting line in the city. It is preferable that it is below, and it is especially preferable that C is 0.5 mm or more and 1.3 mm or less.

It is a schematic explanatory drawing of the grinding | polishing process method of the glass plate edge part which concerns on embodiment of this invention, and FIG. 3 is a schematic sectional drawing of the grinding | polishing state by the cylindrical grindstone of the tempered glass which concerns on embodiment of this invention. 4 is a schematic sectional drawing of the grinding | polishing state of the tempered glass which concerns on other embodiment of this invention.

As shown in FIG. 2, the glass plate 1 to be polished is conveyed as arrow D, and a plurality of (three in the example of the drawing) cylindrical grindstones 2a, 2b, and 2c are polished along the conveying path. ) Are continuously arranged in a straight line. As for the grindstone grindstone 2a, 2b, 2c which plurally lined up, the grindstone 2a which has a large average grain diameter is big initially, and the polishing efficiency is high, and the next grindstone 2b made the grain diameter smaller than the grindstone 2a. Using this, the last grindstone 2c arrange | positions the grindstone of the abrasive grain count corresponding to the finishing surface (rough rubbing finish, polishing finish, polished finish etc.) considered necessary. On the other hand, grinding stones of # 200 (average grain size of 100 µm) in rough rubbing finish, # 500 (average grain size of 45 µm) in polishing finish, and # 800 (average grain size of 30 µm) in polishing finish are usually Used.

As shown to Fig.3 (a), the cylindrical grindstone 2 which formed the abrasive grain layer 3 of the substantially U shape in cross section in the cylinder circumference, and formed the rotating shaft 4 in the center of the cylinder is a glass plate ( It is arrange | positioned parallel to the cross-sectional direction of the cross section 1b of 1), and when cutting and forming a cutting line (cut groove) in the glass plate surface 1a with the wheel cutter etc. of the glass plate 1, The glass positive part that becomes a weak part (the part where the crack by a wheel cutter remains) is polished by each grindstone 2.

The length of the missing present in the corner portion 1d formed by the ridge polishing surface 1c and the glass plate surface 1a subjected to this polishing step is 200 μm or less in the ridge direction, and the maximum width in the direction perpendicular to the ridge line is 100 μm or less. Since it finishes, the stress concentration in the fallout when a tensile stress generate | occur | produces at the edge part can be suppressed small.

The cross section 1b may or may not be subjected to polishing depending on the shape of the cylindrical grindstone 2, as shown in Fig. 3 (b), but the polishing is performed regardless of the quality of the cut surface. It has a stable high edge strength. When polishing using such a grindstone 2, the edge formed by the end face 1b of the glass plate 1 and the ridge polishing surface 1c is subjected to the real R chamfering, but this shape does not affect the edge strength much. none. Further, if the cross section 1b is polished in parallel before the twill polishing of the present invention, higher edge strength can be obtained.

This grinding | polishing process is not limited to the grinding | polishing method using the cylindrical grindstone 2 mentioned above, For example, as shown to FIG. 4 (a), the abrasive grain layer 3 is mounted on the disk 5, Using the cup-shaped grindstone 2 which formed the rotating shaft 4 in the center, the rotating shaft 4 was inclined with respect to the cross section 1b, and the ridge part 1c (glass plate surface 1a and end surface 1b) Method of polishing only the boundary edges between them, as shown in FIG. 4 (b), a buff polishing method in which the outer circumferential surface of the polishing belt 6 is brought into contact with and polished by the ridge 1c of the glass plate 1 that is the workpiece, As shown in FIG.4 (c), the cylindrical grinding wheel 2 which mounted the abrasive grain layer 3 on the cylinder 7, and formed the rotating shaft 4 in the center is used, and the rotating shaft 4 is made into the cross section. You may perform it by the method of making it incline with respect to (1b), or the polishing method which uses these together. In any case, the ridge portion 1c according to the embodiment of the present invention described above is polished, and the length of the missing portion present in the corner portion 1d is 200 µm or less in the ridge direction, and the maximum width in the direction perpendicular to the ridge line is 100. What is necessary is just to finish it to micrometer or less.

Next, the physical strengthening process which concerns on embodiment of this invention is demonstrated. In the physical reinforcement process which concerns on this invention, the heating plate which heats while mounting the glass plate which passed the above-mentioned grinding | polishing process of the glass plate edge part on a some conveyance roller, and moves horizontally, and compressed air for rapid cooling continuously there, The horizontal reinforcement apparatus provided with the cooling area | region which sprays from upper and lower surfaces is used.

Since the surface compressive stress is caused by the temperature difference between the surface of the glass plate and the inside, if the glass plate thickness is different, the heat capacity is different, and it is necessary to change and adjust the cooling rate in accordance with the glass plate thickness. The cooling rate is changed by the temperature of the glass plate before quenching, the temperature of compressed air, and the pressure. Moreover, the smaller the plate thickness, the smaller the heat capacity, and in order to increase the temperature difference in the glass plate thickness direction, it is necessary to increase the cooling rate. For this reason, in order to ensure the surface compressive stress required when the plate thickness is small, compared with the case where the plate thickness is large, it is necessary to increase the glass temperature before quenching, lower the temperature of the compressed air, or increase the pressure of the pressure air. There is.

In the physical strengthening process which concerns on this invention, in order to heat the glass plate after a grinding | polishing process to 620 degreeC or more and 660 degrees C or less, and to give surface compressive stress uniformly to a glass surface, it is 5 degreeC or more with respect to the upper and lower whole surface of a glass plate. It is preferable to blow out compressed air below degrees C from a nozzle and to quench. By setting the glass plate temperature before quenching to 620 ° C. or more to prevent cracking due to tensile stress that temporarily occurs during the cooling process, and to generate sufficient residual distortion, ie, surface compressive stress, to secure the flame retardant performance and to 660 ° C. or less. In addition, it prevents traces and warpage of heat treatment to ensure good image quality. The temperature of the compressed air is higher than the outside air temperature due to the rotational energy of the blower because the air is compressed by the blower, and in some cases, the temperature of the compressed air may rise to around 80 ° C. However, it can be lowered to near 5 degreeC by cooling a cooling wind with a cooler.

Based on the relationship between the surface compressive stress and the cooling conditions described above, in the physical reinforcing treatment according to the present invention, since the required surface compressive stress is set smaller as the thin plate, the pressure of the compressed air required for the expression of the surface compressive stress is determined by the plate. 10 mm or more and 25 mm or less when thickness is 2.5 mm or more and less than 3.5 mm, 7 mm or more and 20 mm or less when 3.5 mm or more and less than 4.5 mm, 6 mm or more and 15 mm or less and 7.0 mm or more and less than 9.0 mm when more than 7 mm and 20 mm or less when 4.5 mm or more and less than 4.5 mm When it is 5 kPa or more and 13 kPa or less, 9.0 mm or more and less than 11.0 mm, it is preferable that it is 2 kPa or more and 10 kPa or less when it is 4 kPa or more and 12 kPa or less, and 11.0 mm or more and 20.0 mm or less. Thereby, the pressure in the case of a thin plate may be small compared with the case where the conventional thick plate for buildings is assumed.

A more specific embodiment of the present invention will be described below.

By the method shown in FIG. 2, the float glass plate 1 (10 cm x 100 cm) of nominal thickness 3mm and 4mm was made to run at a feed rate of 4 m / min, and three grindstones were rotated at a rotational speed of 3400 to 4000 rpm, respectively. By rotating, the sample was processed as follows.

[Example 1]: 29 sheets of float glass (average plate thickness measured value 3.15 mm) having a nominal thickness of 3 mm were used in the order of cylindrical grindstone # 140, # 325, and # 600 to grind and finish the ridges and cross sections.

EXAMPLE 2 29 sheets of float glass of 3 mm of nominal thickness (average plate thickness actually 3.17 mm) were used in the order of cylindrical grindstone # 120, # 270, and # 500, and the ridge part and the cross section were polished and finished.

EXAMPLE 3 26 sheets of float glass (average plate thickness measured 3.75 mm) of nominal thickness 4mm were used in the order of cylindrical grindstone # 120, # 270, and # 500, and the ridge and cross section were polished and finished.

[Comparative Example 1]: 21 sheets of float glass having a nominal thickness of 4 mm (average plate thickness found 4.26 mm) were chamfered from both ends of the cross section in the same manner as in the known technique of Cited Reference 2 (# 500 by the method of FIG. 4 (a)). Using the grindstone).

FIG. 5 (a) is a cross-sectional dimension and a portion explanatory diagram of the glass plate end according to the present embodiment, and FIG. 5 (b) is a cross-sectional dimension and a portion explanatory diagram of the glass edge according to the comparative example. In this embodiment, the starting point of breakage is the glass plate surface e, m, the angle f, l formed by the glass plate surface and the ridge polishing surface g, k, k, k, and the h, j, cross section i formed by the ridge polishing surface and the cross section. Classified into sites. In addition, since the samples of Examples 1 to 3 polished the ridges and the cross section with a circular grindstone, each h and j formed between the ridges polished surface and the cross section are R chamfered. The strength test was carried out at a temperature of 16 to 21 ° C and a relative humidity of 45 to 55% under a load span of 30 cm and a support span of 90 cm, capable of applying uniform tensile stress to a central 30 cm portion of the processing edge of the sample. By a four-point bending test. Table 1 shows the strength test results (destructive stress, the position of the fracture starting point and the number thereof) and the cross-sectional dimension of the glass plate 1. The magnitude | size of the deletion was obtained by observing the edge part 1d of the glass after grinding | polishing using the digital microscope (the product number VH-6200 of Keyence Co., Ltd., product name digital microscope), and measuring each distance. In addition, the breakdown stress of Table 1 is a value with respect to glass before the physical reinforcement process after an edge process.

FIG. 6 shows a plot (hereinafter, referred to as a “wibull plot”) on the Weibull probability axis based on the test results in Table 1. FIG. The Weibull plot is frequently used for the strength evaluation of materials having a large variation in fracture stress such as glass, and the results of all fracture stresses are plotted except for samples whose fracture origin is out of the load span. In this figure, the larger the plot is to the right, the greater the fracture stress.

As can be seen from Table 1, in Examples 1 to 3, compared to Comparative Example 1 in which both ends of the cross section were chamfered, the average fracture stress value was increased by 30 MPa or more (about 1.5 times), and the fracture stress was 3σ. Even at the lower limit of _n-1 , the increase was about 19 MPa or more (about 1.4 times). In addition, the lower limit of 3 sigma _n-1 means about 1/1000 fracture probability when σ is a standard deviation value and n is the number of samples. When the stress represented by the lower limit of 3 sigma _n-1 occurs, about 1000 sheets are generated. It means that a crack occurs in one of the glass plates.

In addition, it can be seen from FIG. 6 that the breakdown stresses of Examples 1 to 3 are larger than the breakdown stress of Comparative Example 1 in the entire region from the small to the large region where the cumulative fracture probability important in the design of the heat-resistant tempered glass is small. .

In the case of Examples 1-3, the position of the fracture origin in this strength test is the generation rate in the edge part 1d (f, l in FIG. 5) which the frequency of occurrence was conventionally high is 5% or less. . That is, the breakage of the glass is performed by forming an edge A formed between the ridge polishing surface 1c and the glass plate surface 1a by 135 degrees or more and 170 degrees or less, and by the corner portion formed by the ridge polishing surface 1c and the glass plate surface 1b ( It was confirmed that the length in the ridgeline direction of the deletions in 1d) was 200 μm or less and the maximum width in the direction perpendicular to the ridgeline was 100 μm or less.

The edge strength required for flame retardant performance is obtained by subjecting the glass plate after the end working to a physical reinforcement treatment having a surface compressive stress of 150 MPa (for example, a glass temperature of 650 ° C., a compressed air temperature of 42 ° C., and a compressed air pressure of 15.2 kPa). Together high image quality is obtained. Moreover, the edge strength required for flame retardant performance is obtained by performing physical strengthening process of surface compressive stress 105 Mpa (for example, glass temperature before quenching, 635 degreeC, compressed air temperature 41 degreeC, compressed air pressure 8.0 kPa) to the glass plate after the said end process. Higher image quality is obtained with the load.

Thus, when edge processing is carried out on the conditions of an Example, 3σ _n-1 lower limit of the edge strength of the glass plate 1 exceeds 70 Mpa. Therefore, in order to obtain the edge strength required for flame-proof performance, the glass plate 1 should just perform the physical reinforcement process which gives a low surface compressive stress compared with the conventional one, productivity improves, and especially plate | board thickness of 3-6 mm The degradation of the image quality of the glass plate by the physical strengthening process of the heat resistant tempered glass plate can be avoided.

Moreover, in order to confirm that the tempered glass which concerns on this invention satisfy | fills the flame-proof performance as a heat resistant tempered glass, the fire prevention test based on the heating curve of ISO834-1: 1999 using the tempered glass manufactured on the conditions shown in Table 2. Was carried out. The size of glass in a fire prevention test was 1676 mm in length and 1176 mm in width, and the edge part 8 mm was inserted into the steel chassis. Moreover, about the tempered glass of the conditions shown in Table 2, the image quality was evaluated by reflecting the stripe of the board | substrate (Zebra board) which provided the stripe before a fire prevention test on the surface of the tempered glass. This result is also shown in Table 2. The surface compressive stress measured each 1 point of 50 mm area | region from the cross section of the center part of each 4 sides, and used the product name FSM-30 (made by Orihara Corporation), and took the average value. In the evaluation of the image quality in the table, as the glass subjected to the physical strengthening treatment, the image quality was evaluated as ◎, a good case as ○, and a case where it was not good but not a problem as Δ. The criterion for the flame performance in the fire protection test in the table is that there is no flame eruption that continues for more than 10 seconds on the unheated side, there is no flame eruption that lasts for more than 10 seconds on the non-heating side, cracks through which the flame passes, etc. No damage and gap were generated, and when all of these were satisfied, the result was passed.

From the results in Table 2, the tempered glass according to the present invention satisfies flame retardant performance, and achieves flame retardant performance by satisfying flame retardant performance and image quality by making the surface compressive stress within a preferable range, and furthermore by setting the surface compressive stress into a more preferable range. It can be seen that it is possible to maintain higher image quality.

In addition to Table 2, the fire protection test was performed under the processing conditions (surface compressive stress is 162 MPa) of Example 3 and the processing conditions (surface compressive stress is 198 MPa) of Example 3 with respect to thickness 7.7 mm. In view of these data, about the preferable surface compressive stress with respect to other thickness, the smaller the plate | board thickness discovered with respect to this invention mentioned above, the smaller the required surface compressive stress, and by the grinding | polishing which concerns on this invention. It determined based on the edge strength improvement obtained. In addition, the pressure of the compressed air required at each plate thickness was also determined based on the required surface compressive stress.

Industrial Applicability The present invention can provide a heat resistant tempered glass for homes that has edge strength that satisfies flame retardant performance and that is high in image quality. Moreover, it is suitable for the physical strengthening process of the heat ray reflecting glass and the heat ray absorptive glass which are normally considered that heat resistance is needed.

In addition, all the content of the JP Patent application 2006-221114 for which it applied on August 14, 2006, a claim, drawing, and the abstract is referred here, and it introduces as an indication of the specification of this invention.

Claims (8)

A glass plate cut to a predetermined dimension is a tempered glass obtained by physically strengthening treatment, and has a ridge polished surface that is inclined with respect to the glass plate surface and the end face, and the ridge polished surface has an angle of 135 degrees or more and 170 degrees or less with the glass plate surface, The edge part formed by the said ridge | polishing part polished surface and the said glass plate surface is 200 micrometers or less in length of a ridgeline direction, and the largest width | variety in a direction perpendicular to a ridgeline is 100 micrometers or less. The method of claim 1, wherein the compressive stress of the tempered glass surface, 70 MPa or more and 155 MPa or less when plate | board thickness is 2.5 mm or more and less than 3.5 mm, 75 MPa or more and 160 MPa or less when 3.5 mm or more and less than 4.5 mm, 85 MPa or more and 170 MPa or less when 4.5 mm or more and less than 5.5 mm, 95 MPa or more and 180 MPa or less when it is 5.5 mm or more and less than 6.3 mm, 105 MPa or more and 190 MPa or less when 6.3 mm or more and less than 7.0 mm, 120 MPa or more and 205 MPa or less when it is 7.0 mm or more and less than 9.0 mm, 135 MPa or more and 220 MPa or less when it is 9.0 mm or more and less than 11.0 mm, Tempered glass which is 150 Mpa or more and 240 Mpa or less when it is 11.0 mm or more and 20.0 mm or less. The tempered glass according to claim 1 or 2, wherein a cross section of the glass plate is polished. The tempered glass according to any one of claims 1 to 3, wherein the projection width to the cross-sectional side of the glass plate of the ridge polishing surface is 0.3 mm or more and 1.3 mm or less, and the projection width to the glass plate surface side is 0.3 mm or more and 3 mm or less. . The manufacturing method of the tempered glass containing the process of processing the edge part of the glass plate cut | disconnected by the predetermined dimension, and the process of physically strengthening the glass plate after the said end process, The process of processing the said end is a said ridge part of the said glass plate edge part. The angle formed with the glass plate surface is polished to be 135 degrees or more and 170 degrees or less to form a ridge polishing surface, and the length in the ridgeline direction of the ridge line in the corner portion formed by the ridge polishing surface and the glass plate surface is 200 μm or less, The maximum width in the vertical direction is set to 100 µm or less. The said physically strengthening process is a process of heating the said glass plate after the said grinding | polishing to 620 degreeC or more and 660 degrees C or less, and compressed air of 5 degreeC or more and 80 degrees C or less to the glass plate after the said heating on both surfaces of a glass plate. Injecting and quenching, the pressure of the compressed air, 10 mm or more and 25 mm or less when the sheet thickness is 2.5 mm or more and less than 3.5 mm, 7 mm or more and 20 mm or less when 3.5 mm or more and less than 4.5 mm, When it is 4.5 mm or more and less than 7.0 mm, 6 mmW or more and 15 mmW or less, 5 mm or more and 13 mm or less when it is 7.0 mm or more and less than 9.0 mm, 4 mm or more and 12 mm or less when it is 9.0 mm or more and less than 11.0 mm, The manufacturing method of the tempered glass set to 2 kPa or more and 10 kPa or less when it is 11.0 mm or more and 20.0 mm or less. The manufacturing method of the tempered glass of Claim 5 or 6 by which the process of the said edge part adds grinding | polishing of the said glass plate cross section. The process of processing the said edge part is a projection width with respect to the cross section side of the glass plate of the said ridge | polishing surface, 0.3 mm or more and 1.3 mm or less, The projection width with respect to the glass plate surface side in any one of Claims 5-7. The manufacturing method of the tempered glass grind | polished to 0.3 mm or more and 3 mm or less.

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