JPH0586334B2 - - Google Patents

Description

[Detailed description of the invention]

[Technical Field] The present invention relates to an aircraft cabin window with improved scratch resistance, abrasion resistance, crushability, etc. [Prior art and its problems] A transparent plate for a cabin window of an aircraft passenger seat has sufficient impact resistance so that it will not be damaged even by an accidental collision with a bird or other foreign object during high-speed flight. In addition, it is required to have good optical properties, strength to withstand temperature changes and pressure changes to which an aircraft is subjected, and pressurization applied inside the aircraft body, and furthermore, it is required to reduce weight. Acrylic boards, especially stretch acrylic boards, have been widely used.
For example, as shown in Fig. 6, for the cabin window of a jumbo jet airliner, a stretch acrylic plate 10 with a thickness of 8 mm and a stretch acrylic plate 1 with a thickness of 4 mm are used.
1 and 1 are spaced apart so that the space layer is 10 mm, and the periphery is sealed, and a stretch acrylic plate with a thickness of 4 mm is placed on the outside of the machine. In such cabin windows, the scratch resistance and abrasion resistance of the stretch acrylic plate are insufficient, so if the stretch acrylic plate is used for a long period of time or under special conditions, the outer side of the stretch acrylic plate may deteriorate. This has the disadvantage that haze or cracks occur on the exposed surface of the aircraft, reducing visibility and impairing passengers' view of the outside of the aircraft. In order to improve the scratch resistance and abrasion resistance of the exposed surface of the stretched acrylic plate on the outside of the machine, a method has been proposed in which the surface is coated with a hard coat film.
Its scratch resistance, abrasion resistance, durability, etc. are still not sufficient. Composite transparent plates used in the front windshield windows for the captain and co-pilot in aircraft cockpits, such as one or several thick stretch acrylic plates and ion exchange reinforcement with a plate thickness of approximately 2.0 mm to 3.0 mm. It is also possible to apply a composite transparent plate that is bonded to a glass plate using a polyvinyl butyral laminated interlayer film to the cabin window of an aircraft, with the ion-exchange tempered glass plate facing the outside of the aircraft. Although such a composite transparent plate has sufficient scratch resistance, abrasion resistance, chemical durability, impact resistance strength, and optical properties, in the unlikely event that a bird or a If a foreign object collides with a crack in the outer ion-exchange tempered glass plate, the crack progresses and the fracture pattern becomes radial or spider web-like, and the inner stretch acrylic plate has sufficient safety. However, such a glass plate fracture pattern is undesirable because it gives passengers anxiety and fear as if the entire cabin will break. For example, a stretch acrylic plate with a plate thickness of 8 mm and an ion exchange tempered glass plate with a plate thickness of 2.0 mm (surface compressive stress 3000 Kg/cm ² , ion exchange layer thickness 20 μ)
and polyvinyl butyral interlayer film (film thickness)
When the later-described impact strength test was performed on the composite transparent plate made of 0.76 mm), the fracture pattern was radial as shown in FIG. 7, which is not a desirable fracture pattern. [Objective of the Invention] The present invention has a characteristic that even if a crack occurs due to an impact on the glass plate on the outside of the composite transparent panel as described above, a fracture pattern as shown in FIG. 7 will not occur. The purpose of this invention is to provide an aircraft cabin window that has a fracture pattern that prevents the crack from progressing even if the glass plate on the outside of the aircraft is cracked due to an impact, and does not cause anxiety or fear to passengers. It was invented as a result of research. [Structure of the Invention] The gist of the present invention is to provide a composite transparent plate in which an ion-exchange strengthened glass plate with a thickness of 0.5 mm to 1.5 mm and a plastic transparent plate with a plate thickness of at least 6 mm or more are bonded via an adhesive layer. An aircraft cabin window in which the ion-exchange tempered glass plate is arranged on the outside of the aircraft, wherein the ion-exchange strengthened glass plate has a surface compressive stress of 3500 Kg/cm ² to 5000 Kg/cm ² , and the adhesive layer The above composite transparent plate has a thickness of 0.1 mm to 0.4 mm, and in an impact strength test in which a spherical steel ball weighing 0.225 kg is naturally dropped from a height of 2 mm on the surface of the ion exchange tempered glass plate, the above ion This aircraft cabin window is characterized in that even when a crack occurs in a replacement tempered glass plate, the progress of the crack is limited within a circle with a radius of 2 cm from the point of impact. The present invention will be explained in more detail below. FIG. 1 is a sectional view of an aircraft cabin window according to a specific example of the present invention, and FIG. 2 is a sectional view of a composite transparent plate fitted into the cabin window. Transparent plate, 2 is a plastic transparent plate, 3 is an ion exchange tempered glass plate, 4
5 is an adhesive layer, 5 is a mounting flange for an aircraft cabin window, and 6 is an aircraft cabin window. In the present invention, plastic board 2 used
is a flat plate with high transparency, excellent optical properties, characteristics that can sufficiently withstand the temperature and pressure changes experienced by aircraft, as well as the pressurization applied inside the aircraft, sufficient impact strength, and sufficient chemical properties. Alternatively, a plate-shaped material having a desired curved surface, such as a stretch acrylic plate or a polycarbonate plate, may be used. Among these, stretch acrylic plates are excellent in terms of optical properties such as transparency, flatness, and smoothness, so they are most suitable as plastic plates for cabin windows. The thickness of the plastic plate is preferably 6 mm or more in order to provide the above-mentioned mechanical strength and prevent bending or deformation, and more preferably in the range of 8 mm to 9 mm in order to reduce the weight of the cabin window. Optimal. In addition, the ion-exchange tempered glass plate placed on the outermost surface of the composite transparent plate 1 on the outside of the machine has a thickness of 0.5 mm or more.
Soda lime silicate glass, in the range of 1.5mm
A glass plate made of soda aluminum silicate glass, lithium silicate glass, etc. that has been subjected to ion-exchange strengthening treatment, that is, a glass plate for ion-exchange strengthening that has been cut to a specified size, chamfered the periphery, polished, and then washed is heated to a transition temperature. By contacting with a molten salt of an alkali having an ionic radius larger than the alkali contained in the surface layer of the glass plate at a temperature range not exceeding , for example, Li ⁺ ions in the glass plate and Na ⁺ ions in the molten salt, Alternatively, Na ⁺ ions in the glass are replaced with K ⁺ ions in the molten salt,
An ion-strengthened glass plate in which compressive stress is generated in the glass surface layer due to the difference in occupied volume of introduced alkali ions, or glass containing Na ₂ O or K ₂ O, is heated to a temperature above the transition point temperature and below the softening point. When the Li ^molten salt is ^brought into contact with the Li molten salt at a temperature of (or K) An ion-exchange strengthened glass plate in which compressive stress is generated on the glass surface due to the difference in expansion coefficient from glass, and the surface compressive stress value is 3500 Kg/cm ² to 5000 Kg/cm ² . In addition, the thickness of the surface compressive stress layer of such an ion exchange strengthened glass plate is preferably about 20 μm to 100 μm. If the thickness of the ion-exchange tempered glass plate exceeds 1.5 mm, when a crack occurs in the glass plate, the crack progresses into a radial or spider web-like fracture pattern, and the crack progresses within a radius of 2 cm. If the plate thickness is less than 0.5 mm, it will be undesirable because it will easily break during handling or use. Furthermore, if the surface compressive stress value of the ion exchange tempered glass plate is smaller than 3500 Kg/cm ² , sufficient strength improvement cannot be obtained, which is not preferable ^;
If it is larger, the fracture pattern becomes denser, which is not preferable. Note that even if compressive stress in this range is applied to the surface of the glass plate, the compressive stress layer
Because it is thin, about 20μ to 100μ, it is difficult for fracture cracks to progress. In addition, a method in which a glass plate heated to a temperature above the transition point and below the softening point is rapidly cooled with a cooling liquid such as silicone oil, or a method in which the heated glass plate is rapidly cooled by sandwiching and contacting the heated glass plate with cooling plates. A physically strengthened glass plate with a thickness of about 1.0 to 1.5 mm, which has a compressive stress layer generated on the surface layer of the cooled glass plate, has a thickness of about 1/2 to 1/4 of the glass plate from the surface of the glass plate. Because there is a compressive stress layer inside the glass plate, when a crack occurs in the glass plate,
This is not preferable because the crack progresses and the fracture pattern expands, resulting in small fragments. In addition, in the present invention, the adhesive forming the adhesive layer that joins the ion-exchange tempered glass plate 3 and the plastic transparent plate 2 is an adhesive that sufficiently adheres the two;
They are selected from those that have long-term chemical and physical durability, excellent optical properties, and appropriate impact absorption properties. However, because there is a difference in thermal expansion coefficient between a plastic transparent plate such as a stretch acrylic plate or a polycarbonate plate and an ion-exchange tempered glass plate (plastic transparent plate > ion-exchange tempered glass plate), the conventional normal bonding method, e.g. In the thermocompression bonding method, stress is generated in the composite transparent plate after they are bonded together due to the difference in thermal expansion coefficients, and this stress can cause the plastic transparent plate to bond with ions due to pressure changes, temperature changes, or long-term use of the aircraft. This has the disadvantage of causing peeling and warping from the replacement tempered glass plate. Therefore, the adhesive for bonding the plastic transparent plate and the ion-exchange tempered glass plate, which have different thermal expansion coefficients, should be used at room temperature to Particularly preferred are those that cure at temperatures below 0.degree. For example, an ultraviolet curable adhesive that is cured at room temperature by irradiation with ultraviolet rays, or an electron beam curable adhesive that is cured at room temperature by irradiation with an electron beam is most suitable. The thickness of the adhesive layer 4 exhibits a temperature shock absorbing effect, and when an impact is applied to the ion-exchange tempered glass plate on the outside of the machine, it allows the ion-exchange tempered glass plate to bend slightly and prevents the crack from progressing. The thickness should be 0.1 mm to 0.4 mm to prevent the expansion of the glass plate and to sufficiently cope with the expansion and contraction of the glass plate and stretch acrylic plate due to changes in atmospheric pressure and temperature. In the composite transparent plate of the present invention, even if an impact is applied to the ion-exchange tempered glass plate from the outside of the machine, and even if a crack occurs in the ion-exchange strengthened glass plate, this crack will progress, expand, and spread radially or downwards. I was worried that the cabin windows would be destroyed by passengers due to a nest of debris.
In order to avoid fear, cracks are controlled to occur within a radius of 2 cm from the point of impact in the impact strength test described below. Third
As shown in the figure, if the crack is prevented from progressing within a circle with radius R = 2 cm from the point of impact A, even if the crack does occur, it will not cause fear to the passengers. In addition, if the crack progresses beyond a circle with a radius of 2 cm from the point of impact A, the crack usually progresses for a long time toward the edge of the glass plate, and the fracture pattern is radial or spider web-like. It's something you get used to. In the present invention, as mentioned above, the crack progresses within a radius of 2 cm from the point of impact.
As mentioned above, the thickness of the ion-exchange tempered glass plate of the composite transparent plate, the stress value, the thickness of the plastic transparent plate, etc. are set within the predetermined ranges so as to be kept within the circle. In addition, this impact fracture test assumes the situation where it is actually installed on an aircraft, and in order to understand the actual condition, the sample is attached to a pressurized box, pressure is applied from the inside of the sample, and the entire device is heated and cooled. This is a test in which a shock is applied. The cabin window of the present invention has a composite transparent plate as shown in FIG. It is also possible to combine and layer. For example, as shown in FIG. 4, an ion-exchange tempered glass plate 3, a first transparent plastic plate 2, and a second transparent plastic plate 2' are bonded to a first adhesive layer 4' and a second adhesive layer 4'. Alternatively, as shown in FIG. 5, a composite transparent plate 1 and a first plastic transparent plate 2 may be used, in which an ion exchange strengthened glass plate 3 and a first plastic transparent plate 2 are bonded by an adhesive layer 4. It is also possible to use a spacer 7 to separate two plastic transparent plates 2' with an air space 8 of about 2 cm to 10 cm, and seal the periphery to form a multilayer structure. Of course, the present invention is not limited to those shown in FIGS. 1, 4, and 5, and there are various variations. Moreover, it goes without saying that the composite transparent plate of the present invention can be provided with coloring, heat ray reflection, anti-glare, and various other functions. In addition, the composite transparent plate can be attached to the cabin window mounting flange, frame, and various other mounting parts with bolts.
When attaching using adhesives or other attachment methods, please be aware that when attaching the composite transparent plate to the cabin window, or due to unexpected impact during use,
Or, in order to prevent the ion-exchange tempered glass plate from being damaged due to various other circumstances, cut out the ion-exchange tempered glass plate at the flange, frame, or other attachment part of the cabin window of the composite transparent plate. Preferably, the periphery of the plastic transparent plate of the composite transparent plate allows for attachment to a cabin window flange, frame, or other attachment point. For example, the first
As shown in Figures 2, 4, and 5, the ion exchange tempered glass plate 3
The dimensions of the plastic transparent plate 2 are smaller than the dimensions of the plastic transparent plate 2, and a margin 9 is formed on the outer periphery of the plastic transparent plate 2 on the outer periphery of the ion-exchange tempered glass plate 3, for example.
It is preferable to attach the composite transparent plate 1 to the cabin window using the margin 9 around the plastic transparent plate 2 so that a margin of about 1.5 cm to 4 cm is left. Note that since the transparent portion of the cabin window is substantially covered by the ion-exchange tempered glass plate, it is possible to prevent haze from occurring on the exposed surface of the composite transparent plate on the outside of the aircraft. Next, examples of the present invention will be described. Example 1 A flat rectangular soda-lime silicate glass plate measuring 25 cm x 35 cm (thickness: 0.5 mm)
After preparing, chamfering, polishing, and cleaning, this glass plate is immersed in a bath of KNO ₃ molten salt (temperature of about 450°C) and held for 12 hours to remove the Na ⁺ of the surface layer of the glass plate.
Ion-exchange the ions with K ⁺ ions in the _KNO3 melt,
Then, it was washed and dried. The thickness of the ion exchange layer of this ion exchange tempered glass plate was 20 μm, and the average surface pressure value was 4800 Kg/cm ² . On the other hand, 30cm x 40cm
After cleaning and drying a flat rectangular stretch acrylic board (8 mm thick), the thickness of the adhesive layer after curing is 0.2 mm between this stretch acrylic board and the ion exchange tempered glass board. A UV-curable adhesive was interposed so that a 2.5 cm margin was created around the ion-exchange tempered glass plate, and this assembly was irradiated with UV light for 0.5 minutes at 40°C to harden the adhesive. A composite transparent plate in which an ion-exchange tempered glass plate and a stretch acrylic plate were bonded was prepared. The composite transparent plate sample prepared in this manner was designated as sample No. 1. Example 2 A flat rectangular soda-lime silicate glass plate measuring 25 cm x 35 cm (thickness: 1.0 mm)
After preparing, chamfering, polishing, and cleaning, this glass plate is immersed in a bath of KNO ₃ molten salt (temperature of about 450°C) and held for 12 hours to remove the Na ⁺ of the surface layer of the glass plate.
The ions were ion-exchanged with K ⁺ ions of _KNO3 molten salt, then washed and dried. The thickness of the ion exchange layer of this ion exchange tempered glass plate was 20 μm, and the average surface pressure value was 4800 Kg/cm ² . On the other hand, 30cm×
After cleaning and drying a flat rectangular stretch acrylic plate (8 mm thick) with a size of 40 cm, the thickness of the adhesive layer after curing is 0.2 between this stretch acrylic plate and the above-mentioned ion exchange tempered glass plate. A UV-curable adhesive was applied to the ion-exchange tempered glass plate so that a margin of 2.5 cm was created around the periphery of the ion-exchange tempered glass plate, and this assembly was irradiated with UV rays for 0.5 minutes at 40°C to bond the adhesive. harden,
A composite transparent plate in which an ion-exchange tempered glass plate and a stretch acrylic plate were bonded was prepared. A sample of a composite transparent plate created in this way
It was set as No.2. Example 3 A flat rectangular soda-lime silicate glass plate measuring 25 cm x 35 cm (thickness: 1.5 mm)
After preparing, chamfering, polishing, and cleaning, this glass plate is immersed in a bath of KNO ₃ molten salt (temperature of about 450°C) and held for 12 hours to remove the Na ⁺ of the surface layer of the glass plate.
Ion-exchange the ions with K ⁺ ions in the _KNO3 melt,
It was then washed and dried. The thickness of the ion exchange layer of this ion exchange tempered glass plate was 20 μm, and the average surface pressure value was 4800 Kg/cm ² . On the other hand, after cleaning and drying a flat rectangular stretch acrylic plate (8 mm thick) with a size of 30 cm x 40 cm, a cured adhesive layer was formed between this stretch acrylic plate and the ion exchange tempered glass plate. A UV-curable adhesive was applied so that the thickness of the glass plate was 0.2 mm, and a 2.5 cm margin was left around the ion-exchange tempered glass plate, and this assembly was exposed to UV rays for 0.5 minutes at 40°C. The adhesive was cured by irradiation to prepare a composite transparent plate in which an ion-exchange tempered glass plate and a stretch acrylic plate were joined. The composite transparent plate sample prepared in this manner was designated as sample No. 3. Comparative Example 1 Flat rectangular soda-lime silicate glass plate measuring 25cm x 35cm (thickness: 2.0mm)
After preparing, chamfering, polishing, and cleaning, this glass plate is immersed in a bath of KNO ₃ molten salt (temperature of about 450°C) and held for 12 hours to remove the Na ⁺ of the surface layer of the glass plate.
The ions were ion-exchanged with K ⁺ ions of _KNO3 molten salt, then washed and dried. The thickness of the ion exchange layer of this ion exchange tempered glass plate was 20 μm, and the average surface pressure value was 4800 Kg/cm ² . On the other hand, 30cm×
After cleaning and drying a flat rectangular stretch acrylic plate (8 mm thick) with a size of 40 cm, the thickness of the adhesive layer after curing is 0.2 between this stretch acrylic plate and the above-mentioned ion exchange tempered glass plate. A UV-curable adhesive is inserted so that the thickness of the adhesive is 2.5 mm, and a 2.5 cm margin is created around the ion-exchange tempered glass plate.The assembly is irradiated with ultraviolet rays for 0.5 minutes at 40°C to remove the adhesive. A composite transparent plate was prepared by curing and bonding an ion exchange tempered glass plate and a stretch acrylic plate. The sample of the composite transparent plate created in this way is sample No.
It was set as 4. Comparative Example 2 Flat rectangular soda-lime silicate glass plate measuring 25cm x 35cm (thickness: 1.0mm)
were prepared, chamfered, polished, and cleaned. On the other hand, after cleaning and drying a flat rectangular stretch acrylic board (8 mm thick) with a size of 30 cm x 40 cm, the thickness of the adhesive layer after curing is determined between the stretch acrylic board and the raw glass board. A UV-curable adhesive was inserted so that the thickness was 0.2 mm, and a 2.5 cm margin was created around the ion-exchange tempered glass plate.The assembled product was irradiated with UV rays at 40°C for 0.5 minutes to bond the adhesive. was cured to prepare a composite transparent plate in which an ion-exchange tempered glass plate and a stretch acrylic plate were joined. Sample No.5 of the composite transparent plate created in this way
And so. Comparative Example 3 Flat rectangular soda-lime silicate glass plate measuring 25cm x 35cm (thickness: 2.0mm)
After preparing, chamfering, polishing, and cleaning, this glass plate is immersed in a bath of KNO ₃ molten salt (temperature of about 450°C) and held for 12 hours to remove the Na ⁺ of the surface layer of the glass plate.
The ions were ion-exchanged with K ⁺ ions of _KNO3 molten salt, then washed and dried. The thickness of the ion exchange layer of this ion exchange tempered glass plate was 18 μm, and the average surface pressure value was 4800 Kg/cm ² . On the other hand, 30cm x 40
After cleaning and drying a flat rectangular stretch acrylic plate (8 mm thick) with a size of cm, the thickness of the adhesive layer after curing is 0.2 cm between this stretch acrylic plate and the ion exchange tempered glass plate. A UV-curable adhesive was applied so that the thickness of the glass plate was 2.5 cm, and a 2.5 cm margin was created around the ion-exchange tempered glass plate.
The adhesive was cured by irradiation with ultraviolet rays for 0.5 minutes to prepare a composite transparent plate in which an ion-exchange tempered glass plate and a stretch acrylic plate were bonded. Sample No.6 of the composite transparent plate created in this way
And so. The fracture patterns (fracture patterns near and around the impact point, solid lines are cracks) obtained by the impact strength test for the above-mentioned samples No. 1 to No. 6 are shown in FIGS. 7 to 12. Also, sample No.1
Regarding ~6, abrasion resistance test, light resistance test,
Table 1 shows the results of the temperature impact resistance test.

[Table] The various tests described above were conducted as follows. Γ Impact strength test A sample is mounted horizontally in a pressurized box, pressure is applied from inside the box, and a 0.225Kg spherical steel ball is sampled from a height of 2m above the sample (an ion-exchange tempered glass plate is placed on top). This test examines the fracture state of a sample by dropping it into the center of the - Abrasion resistance test The haze state of the sample was observed after performing an abrasion test on the surface of the ion-exchange tempered glass plate of the sample using a Taber abrasion tester with a load of 500 kg and 500 reciprocating cycles. - Light resistance test After irradiating the sample surface with ultraviolet rays for 100 hours using a fade meter tester, the changes in the sample were observed. - Temperature shock resistance test (heat cycle) One test cycle consists of holding the sample in a cold room at -40°C for 4 hours and then holding it in a high temperature room at 80°C for 4 hours, and this cycle is repeated 10 times. be. After the test, the sample is visually observed and evaluated. As is clear from Figures 7 to 9, which show the fracture patterns, when glass plates with thicknesses ranging from 0.5 to 1.5 mm were subjected to ion-exchange reinforcement, cracks did not progress from the point of impact, and cracks within 2 cm from the point of impact occurred. It is recognized that it is restricted within a circle of radius (R). On the other hand, the fracture pattern of sample No. 4 with a glass plate thickness of 2.0 mm is as shown in Figure 10.
The fracture pattern of No. 5 is as shown in Figure 11, and the fracture pattern of Sample No. 6, where the glass plate is too thin, is as shown in Figure 12. This is an undesirable pattern because it progresses far beyond that point.

[Brief explanation of drawings]

1, 2, 4, and 5 are vertical cross-sectional views of specific examples of the composite transparent plate according to the present invention, FIG. 3 is an enlarged explanatory view of the crushing pattern of the composite transparent plate of the present invention, and FIG.
10 to 12 are fracture pattern diagrams of a composite transparent plate according to a comparative example, and FIGS. 7 to 9 are fracture pattern diagrams of a composite transparent plate of the present invention. 1...Composite transparent plate, 2...Plastic transparent plate, 3...Ion exchange tempered glass plate, 4...Adhesive layer, 6...Cabin window.

Claims (1)

[Scope of Claims] 1. A composite transparent plate in which an ion-exchange tempered glass plate with a thickness of 0.5 mm to 1.5 mm and a plastic transparent plate with a plate thickness of at least 6 mm or more are bonded via an adhesive layer,
In an aircraft cabin window in which the above-mentioned ion-exchange strengthened glass plate is arranged on the outside of the aircraft, the flange, frame, or other attachment part of the cabin window of the composite transparent plate is ion-exchange strengthened. It has a structure with a cut out glass plate,
The surface compressive stress of the above ion exchange tempered glass plate is
3500Kg/cm ² to 5000Kg/cm ² and the thickness of the adhesive layer above is
In an impact strength test in which a spherical steel ball weighing 0.225 kg was naturally dropped from a height of 2 m above the surface of the ion exchange tempered glass plate, the composite transparent plate had a diameter of 0.1 mm to 0.4 mm. An aircraft cabin window characterized in that, even when a crack occurs, the advancement of the fracture crack is limited within a circle with a radius of 2 cm from the point of impact. 2. The aircraft cabin window according to claim 1, wherein the adhesive layer is made of a room temperature curing adhesive. 3. The aircraft cabin window according to claim 2, wherein the room temperature curable adhesive is an ultraviolet curable adhesive.