JP2015199615A - Manufacturing method of windshield for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a manufacturing method of a windshield for a vehicle capable of suppressing wrinkle generation in a deaeration step.SOLUTION: A manufacturing method of a windshield for a vehicle comprises a step 1 for inserting a laminate film between two curved glass plates, the laminate film being integrated in advance by wholly sticking an adhesive resin interlayer to a heat shielding film having a thermal shrinkage of 0.5-5% at 125-150°C and a thickness of 30-200 μm, a step 2 for deaerating gaps between the laminate film and the glass plates following the step 1, and a step 3 for performing heating so that the maximum temperature is in the range of 125-150°C while performing compressing to manufacture a windshield for a vehicle by thermocompression bonding, following the step 2. The laminate film has a hardness of 0.45 kgf or more in the step 2.

Description

  The present invention relates to a method for manufacturing a vehicle windshield.

  A windshield for a vehicle is a laminated glass in which two curved glass plates are bonded with an adhesive resin interlayer such as polyvinyl butyral resin. In recent years, a heat shielding film is held in the adhesive resin interlayer. Thus, there has been proposed a windshield that imparts heat insulation to a vehicle.

  As a method of imparting the above heat shielding properties, a heat shielding film exhibiting heat shielding properties is formed as a heat shielding film formed on a base film, and such a heat shielding film is sandwiched between adhesive resin intermediate films. Is common. Since the base film is rigid, the heat shield film is flat. On the other hand, as described above, since the windshield for vehicles uses a curved glass plate, it adheres to and adheres to the curved surfaces of the lower glass plates of the upper and lower two curved glass plates. The heat shield film sandwiched between the resin interlayers cannot follow this curved surface shape in the deaeration process, and wrinkles occur at the peripheral edge of the heat shield film in the thermocompression bonding process when manufacturing a vehicle windshield. There was a problem.

  The wrinkles described above are caused by bending of the peripheral portion of the heat-shielding film sandwiched between the adhesive properties in the deaeration process or the thermocompression bonding process. Therefore, various studies have been made in order to prevent this bending.

  In Patent Document 1, a heat ray reflective film is sandwiched between two adhesive resin interlayers, and only the end of the film is laminated in advance with a fastening means to fix wrinkles in the laminating process and degassing process. It is disclosed to suppress the occurrence.

  In addition, Patent Document 2 discloses that when a resin film such as PET is adhered between curved curved glasses and laminated, the peripheral edge of the resin film layer is solved in order to solve the problem that wrinkles are generated at the peripheral edge of the curved glass. The laminated glass which provided the some defect part in the part is disclosed. By providing the defect portion, the resin film is easily deformed, and the followability to the curved surface shape is improved.

  Further, for example, Patent Document 3 discloses using a laminate in which a thermal barrier layer made of a cholesteric liquid crystal phase is formed in advance between adhesive resin intermediate films. According to the document, after the liquid crystal phase is formed between the adhesive resin interlayers, the laminate has removed the film used as the base material of the liquid crystal phase and removed the rigid member itself that generates wrinkles. Yes.

  For example, as disclosed in Patent Documents 4 and 5, the present applicant performs the steps of laminating and delaminating each of the steps of laminating the laminated film and the glass plate and degassing within the range of 15 to 25 ° C. A patent application has been filed for an invention relating to a method for suppressing wrinkles generated in a gas process.

JP-A-6-321589 International Publication WO2010 / 093023 JP 2012-51219 A JP 2009-298661 A JP 2010-13311 A

  Among the vehicle windshields described above, in particular, automobiles, compact cars, and the like are required to improve design and increase the opening area. When the windshield of the vehicle windshield is bent, when the glass plate and the heat insulating film are deaerated after being laminated, the heat insulating film bends without following the curved surface at the center of each side of the glass plate. As a result, wrinkles are likely to occur at the peripheral edge of the heat-shielding film. If wrinkles are generated at the time of deaeration, wrinkles remain in the subsequent thermocompression bonding process, and thus it is required to suppress the generation of wrinkles at the time of deaeration.

  As shown in Patent Documents 4 and 5, the present applicant has proposed a method of deaeration in the deaeration process by setting the temperature of the heat insulating film to a temperature range of 10 to 25 ° C. However, the curved surface of the vehicle windshield is bent. It has been found that when the direction is larger, the generation of wrinkles at the peripheral edge of the heat-shielding film may not be suppressed even in the above temperature range.

  Accordingly, an object of the present invention is to provide a method for manufacturing a vehicle windshield capable of suppressing the generation of wrinkles in the peripheral portion of a heat-shielding film in a deaeration process.

  An example of wrinkles to be the subject of the present invention is shown in the photograph of FIG. FIG. 1 is an enlarged photograph of the peripheral portion of a heat-shielding film, and the black belt portion at the bottom of the photo is a black ceramic color layer applied to the peripheral portion of a vehicle windshield for an automobile. From FIG. 1, it can be seen that wrinkles are generated at the periphery of the heat-shielding film, and the heat-shielding films are gathered in the wrinkled portions, and as a result, the transmission image greatly deteriorates the distortion visibility.

The present invention is a laminate in which an adhesive resin intermediate film and a heat-shielding film having a heat shrinkage rate of 0.5 to 5% at 125 to 150 ° C. and a thickness of 30 to 200 μm are laminated in advance and bonded together. Step 1 of laminating a film between two curved glass plates,
A step 2 of degassing the laminated film and the glass plate after the step 1;
In the method for manufacturing a vehicle windshield, comprising the step 3 of heating and pressure-bonding to form a vehicle windshield by heating so that the maximum temperature is within a range of 125 to 150 ° C. while applying pressure after the step 2.
When the curved glass plate is h / k> l / m, 0.30 ≦ (l / m) / (h / k) ≦ 0.80, or h / k <l / m, 0.30 ≦ (h / k) / (l / m) ≦ 0.80 (m: maximum length of the side in the vertical direction of the glass plate, h: maximum value of the bending depth of the glass plate, k: Satisfying the maximum value of the length of the side in the horizontal direction of the glass plate, l: the maximum value of the glass plate double),
In the step 2, the method of manufacturing a vehicle windshield is characterized in that the hardness of the laminated film measured by the following measuring method is 0.45 kgf or more.
Step A: Cutting the laminated film to produce a strip-shaped test piece, and bringing the strip-shaped test piece to the temperature at the time of degassing in Step 2,
Step B: Step of placing the strip-shaped test piece obtained in Step A horizontally on a flat table and bending it, and overlapping both end portions A and B of the strip-shaped test piece,
Step C: A step of applying a load of a load measuring device to the strip-shaped test piece vertically downward at a point C at a certain distance from both ends A and B overlapped in Step B,
Step D: A step of measuring the load applied when the test pieces overlap on the vertical line of the point C, and setting the magnitude of the load to hardness.

  In the present invention, when the curved glass plate is h / k> l / m, 0.30 ≦ (l / m) / (h / k) ≦ 0.80 or h / k <l / m In this case, 0.30 ≦ (h / k) / (l / m) ≦ 0.80 (m: maximum value of the length in the longitudinal direction of the glass plate, h: maximum value of the bending depth of the glass plate. K: the maximum value of the length of the side in the horizontal direction of the glass plate, l: the maximum value of the double of the glass plate). The “double” in the present invention refers to the value of the vertical line drawn from the surface of the glass plate with respect to the line connecting the midpoints of the two opposing sides in the lateral direction of the glass plate. And Further, when h / k = 1 / m, the shape is spherical, and since (h / k) / (l / m) = 1, the bending becomes large and wrinkle suppression may be insufficient. .

  A method for measuring the hardness of the laminated film of the present invention will be described with reference to FIG.

  First, as shown in FIG. 2 (1), a laminated film piece obtained by cutting a laminated film into a length of 200 mm and a width of 50 mm is prepared and left in an atmosphere adjusted to a predetermined temperature. It was made almost constant. The laminated film piece whose temperature was adjusted was placed horizontally on a flat table, and one end (end A) in the length direction of the laminated film piece was fixed.

  Next, as shown in (2) of FIG. 2, the laminated film piece has the other end (end B) to which the laminated film piece is not fixed, and the laminated film piece is bent so as not to be folded. Then, the end A and the end B were overlapped. In addition, after overlapping with the end A, the end B is not fixed.

  Next, as shown in (3) of FIG. 2, a load was applied vertically downward from above the laminated film at a position 80 mm from the end B (point C in FIG. 2). The load was applied using a load measuring device (manufactured by Aiko Engineering Co., Ltd., name: RX-20, model number: E00302). When the laminated film overlapped on the vertical line of the point C, the application of force was stopped, and the force applied at that time was measured. The measurement was performed 5 times, and the average value was taken as the hardness.

  The laminated film is a film in which an adhesive resin intermediate film and a heat shielding film are laminated and bonded in advance. The integrated laminated film can be obtained by stacking the adhesive resin intermediate film and the heat-shielding film, degassing, and then heating the entire film at about 50 to 80 ° C. for adhesion. By using a laminated film that has been integrated in advance as described above, it becomes possible to handle the film with higher rigidity than when non-integrated films are laminated. The hardness of the film can be 0.45 kgf or more.

  The curved glass plate is curved in a three-dimensional shape and has a concave surface and a convex surface. A glass plate used for a windshield for a vehicle usually has a concave surface inside the vehicle. In the said process 1, when laminating | stacking a glass plate and a laminated | multilayer film, let the concave surface of a vehicle inner side glass plate be a bottom, and laminate | stack in order of a laminated film and a vehicle outer side glass plate on the convex surface of this glass plate.

  In the step 2, after the hardness of the laminated film is adjusted to 0.45 kgf or more by the measurement method, the space between the laminated film and the glass plate is deaerated. When wrinkles occur at the peripheral edge of the heat-shielding film when deaeration between the laminated film and the glass plate, the wrinkles generated in the subsequent steps are not eliminated, resulting in a defective product. Examples of the method for setting the hardness of the laminated film to 0.45 kgf or more include lowering the temperature of the laminated film, increasing the thickness of the heat-shielding film, and increasing the thickness of the laminated film. The method of lowering the temperature is preferable because it can be easily used.

  By this invention, the manufacturing method of the windshield for vehicles which can suppress generation | occurrence | production of a wrinkle in the peripheral part of a heat insulation film at a deaeration process can be obtained.

It is the drawing substitute photograph which image | photographed the wrinkle which generate | occur | produces when the followable | trackability to the curved surface shape of a thermal insulation film is bad. It is a schematic diagram for demonstrating the measuring method of the hardness of the laminated film in this invention. BRIEF DESCRIPTION OF THE DRAWINGS It is a schematic diagram when the curved glass plate in this invention is seen from diagonally, (a) The schematic diagram explaining a double, (b) The schematic diagram explaining bending depth, (c) Front view of a glass plate It is a schematic diagram when it sees from. No. 1-No. It is a figure which shows the hardness with respect to temperature about the film of 5. FIG.

The present invention is a laminate in which an adhesive resin intermediate film and a heat-shielding film having a heat shrinkage rate of 0.5 to 5% at 125 to 150 ° C. and a thickness of 30 to 200 μm are laminated in advance and bonded together. Step 1 of laminating a film between two curved glass plates,
A step 2 of degassing the laminated film and the glass plate after the step 1;
In the method for manufacturing a vehicle windshield, comprising the step 3 of heating and pressure-bonding to form a vehicle windshield by heating so that the maximum temperature is within a range of 125 to 150 ° C. while applying pressure after the step 2.
When the curved glass plate is h / k> l / m, 0.30 ≦ (l / m) / (h / k) ≦ 0.80, or h / k <l / m, 0.30 ≦ (h / k) / (l / m) ≦ 0.80 (m: maximum length of the side in the vertical direction of the glass plate, h: maximum value of the bending depth of the glass plate, k: Satisfying the maximum value of the length of the side in the horizontal direction of the glass plate, l: the maximum value of the glass plate double),
In the step 2, the method of manufacturing a vehicle windshield is characterized in that the hardness of the laminated film measured by the following measuring method is 0.45 kgf or more.
Step A: Cutting the laminated film to produce a strip-shaped test piece, and bringing the strip-shaped test piece to the temperature at the time of degassing in Step 2,
Step B: Step of placing the strip-shaped test piece obtained in Step A horizontally on a flat table and bending it, and overlapping both end portions A and B of the strip-shaped test piece,
Step C: A step of applying a load of a load measuring device to the strip-shaped test piece vertically downward at a point C at a certain distance from both ends A and B overlapped in Step B,
Step D: A step of measuring the load applied when the test pieces overlap on the vertical line of the point C, and setting the magnitude of the load to hardness.

  When two adhesive resin interlayers are used, the laminated film of the present invention may be of the same or different type. In order to improve the adhesion between the adhesive resin intermediate film and the heat shielding film, a surface treatment agent such as a silane coupling material may be applied.

  As the adhesive resin interlayer, a hot melt type adhesive such as polyvinyl butyral (PVB) or ethylene vinyl acetate (EVA) can be suitably used. As the adhesive resin intermediate film, one partially colored, one having a layer having a sound insulating function sandwiched, one having an inclined thickness, one having an embossed surface, and the like can be used. Further, the adhesive resin intermediate film may be appropriately blended with an ultraviolet absorber, an antioxidant, an antistatic agent, a heat stabilizer, a colorant, and an adhesion regulator, and in particular, fine particles that absorb near infrared rays are dispersed. Is more preferably used for producing a high-performance vehicle windshield. In addition, the thickness of the adhesive resin interlayer used in the present invention may be 0.3 to 1.0 mm which is generally used, but is not limited to this thickness.

  The said heat-shielding film uses the thing in the range whose thermal contraction rate in the temperature range of 125-150 degreeC is 0.5-5%. The heat shrinkage rate was measured as follows according to JIS C 2318.

  First, a strip-shaped heat-shielding film having a length of 150 mm and a width of 40 mm was cut out, and a marked line was marked with a diamond pen at a distance of about 100 mm in the vicinity of the center of each width direction. After marking the marked line, the strip-shaped heat-shielding film was divided into two equal parts of 150 mm × 20 mm.

  Next, one of the test pieces divided into two halves is suspended vertically in a hot-air circulating thermostat and the temperature is raised so that the measured temperature is within a temperature range of 125 to 150 ° C. at a rate of temperature increase of about 5 ° C./min. Warm and hold at measured temperature for about 20 minutes. Thereafter, the hot air circulating thermostat was opened to the atmosphere, naturally cooled at about 20 ° C./min, and further maintained at room temperature for 30 minutes. At this time, a thermocouple thermometer was used to measure the temperature, and the temperature distribution in the hot air circulating thermostat was set within ± 1 ° C.

  The distance between the marked lines L1 and L2 of the test piece held at room temperature and the test piece heated to the measurement temperature of the test piece divided into two equal parts is indicated by a scanning laser microscope (made by Lasertec, 1LM21D). It measured using. The thermal contraction rate (%) was calculated by (L1-L2) × 100 / L1.

  In addition, an average value of heat shrinkage rates measured for three sheets was cut out for each of the film flow direction (hereinafter sometimes referred to as MD direction) and the width direction (hereinafter also referred to as TD direction). Was used as the heat shrinkage rate of the present invention.

  Moreover, the heat-shielding film used by this invention becomes in the range whose thermal contraction rate of MD direction and TD direction is 0.5 to 5.0%. If the thermal shrinkage rate is less than 0.5%, wrinkles are generated at the peripheral edge of the glass during the thermocompression bonding in step 3, and if it exceeds 5.0%, excessive shrinkage occurs, resulting in defects in the peripheral edge of the glass. Occurs.

  The heat-shielding film used in the present invention is a film having a heat-shielding function formed on the surface or both surfaces of a heat-shrinkable base film, and does not use the base film as described above. A laminated film obtained by laminating a thin film having a thin film, a laminated film obtained by laminating a plurality of thin films to provide heat shielding properties, a film containing a substance having a heat shielding function therein, or the like may be used.

  When the base film is used for the heat-shielding film, the base film may be any film that is heat-shrinkable, such as polyethylene terephthalate, polyethylene naphthalate, polycarbonate, polymethyl methacrylate, polyether sulfone, nylon, polyarylate, And cycloolefin polymers. In particular, the crystalline polyethylene terephthalate film (PET film) formed by the biaxial stretching method has excellent heat resistance and can be used in a wide range of temperature environments, and is highly transparent and produced in large quantities. Therefore, the quality is stable and suitable. Examples of a method for obtaining the heat shrinkability of the substrate film include a method in which a raw material film is biaxially stretched at a temperature higher than the glass transition temperature and subjected to a heat setting treatment.

  The above-described film or layer having a heat shielding function is not particularly limited as long as it does not deteriorate significantly at the time of processing and has a heat shielding function. For example, two or more kinds of dielectric thin films having different refractive indexes are used. For example, a multilayer film formed by laminating films, a laminated film of polarizing liquid crystal layers, and a metal film or a laminated film of metal films. Of the above, multilayer films formed by laminating dielectric thin films, laminated films of liquid crystal layers, and the like can be suitably used without using a base film if the thickness and material are selected. .

  In addition, when a film is formed on the surface of the base film, depending on the thickness of the base film and the heat shrinkage rate, film cracking may occur, or when heat is applied to the heat shield film, the heat shield film curls due to the bimetallic effect. Sometimes. Although curl is not a problem in terms of the quality of the heat-shielding film, it may interfere with handling. In order to suppress the above film cracking, it is preferable to use an adhesive between the film and the base film, and in order to suppress curling, it is preferable to form a film or a layer on both sides of the base film. . The film formed at this time may have a heat shielding function or may be a layer of a silane coupling agent for improving adhesion without a heat shielding function.

  Moreover, when not using a base film, the resin multilayer film formed by laminating | stacking many polymer thin films from which a refractive index differs alternately can be used suitably. The resin multilayer film can select the wavelength of the reflected light by adjusting the refractive index and thickness of the polymer thin film. By designing so as to reflect the wavelength in the infrared region, the resin multilayer film can be used as a thermal barrier film. The number of laminated polymer thin films may be 40 to 200 layers, for example. The polymer film includes polyethylene terephthalate, polyethylene naphthalate, polymethyl methacrylate, polyethylene, polystyrene, polycarbonate, a mixture of polyvinylidene fluoride and polymethyl methacrylate, a copolymer of ethylene and an unsaturated monocarboxylic acid, and styrene and methyl methacrylate. It can be suitably selected from copolymers and the like. Since the multilayer film can be stretched as necessary for the purpose of improving mechanical strength, heat shrinkage properties, chemical resistance, transparency, etc., it can be suitably used as a film having heat shrinkability. .

  Moreover, the thickness of said heat-shielding film exists in the range of 30-200 micrometers. If the thickness is out of the above range, a deaeration defect may occur in the manufacturing process, or the obtained fluoroscopic image of the vehicle windshield may be easily distorted.

  The laminated film is deaerated after the hardness is set to 0.45 kgf or more by the measurement method. When the hardness is less than 0.45 kgf, suppression of wrinkles at the peripheral portion of the heat-shielding film at the time of deaeration becomes insufficient, and the upper limit is not particularly limited, but may be, for example, 1.5 kgf or less. When the hardness exceeds 1.5 kgf, the followability to the curved surface shape of the glass plate is lowered, and degassing may be insufficient. Moreover, since it is possible to suppress the wrinkle at the time of deaeration more stably when it is 0.50 kgf or more, it is preferable.

  The laminated film used in the present invention has an adhesive resin intermediate film thickness within a range of 0.33 to 1.2 mm when the adhesive film is integrated with a heat-shielding film using one adhesive resin intermediate film. It is preferable to use a film having a thickness in the range of 0.63 to 2.2 mm when two sheets are integrated with a heat-shielding film. Since the vehicle windshield is required not to obstruct the driver's field of view, it is desirable that the laminated film does not become thicker than necessary so as not to impair the visibility as in the case of the heat-shielding film described above.

  The glass plate is a glass plate having a curved shape. The curved surface shape is a glass plate having a convex side and a concave side that are three-dimensionally bent in advance, and particularly a curved surface that has a deep bending in both the horizontal and vertical directions, or a curved surface having a locally small radius of curvature. It can be suitably used for a glass plate having a shape that tends to be difficult to suppress wrinkles. The horizontal direction is the direction of the vehicle width when the glass plate is installed on the vehicle body, and the vertical direction is the direction of the vehicle height.

  In the present invention, when the curved glass plate is h / k> l / m, 0.30 ≦ (l / m) / (h / k) ≦ 0.80, or h / k <l / When m, 0.30 ≦ (h / k) / (l / m) ≦ 0.80 (m: maximum length of side in the vertical direction of the glass plate, h: maximum bending depth of the glass plate Value, k: the maximum value of the length of the side in the horizontal direction of the glass plate, and l: the maximum value of the double of the glass plate).

  The curved surface shape will be described below with reference to FIG. 3A and 3B are schematic views when the glass plate 2 is viewed obliquely, and FIG. 3C is a schematic view when the glass plate is viewed from the front, with the AA ′ direction described above. The horizontal direction and the BB ′ direction are the above-described vertical directions. M is the maximum length of the side in the vertical direction of the glass plate, and k is the maximum length of the side in the horizontal direction of the glass plate. When viewed from the vertical direction and the horizontal direction, the surface of the glass plate 2 has a shape protruding in one direction.

  The glass plate double will be described with reference to FIG. The double of the glass plate refers to the value of the vertical line drawn from the surface of the glass plate with respect to the line connecting the midpoints of the two opposite sides in the horizontal direction (line segment β in the figure), l is the maximum value of the double.

  The bending depth of a glass plate is demonstrated using (b) of FIG. The bending depth of a glass plate is the value of a vertical line drawn from the surface of the glass plate with respect to a line (a line segment α in the figure) connecting arbitrary points on two opposite sides in the vertical direction. The h is the maximum value of the bending depth. Further, as shown in FIG. 3C, the line segment α is orthogonal to the above-described line segment β when the glass plate is viewed from the front.

  In the case of a curved surface shape that is three-dimensionally bent as in the present invention, both the longitudinal bending depth and the lateral bending depth affect the ease of occurrence of wrinkles during degassing. Since the glass plate having a value of less than 0.30 approaches a two-dimensionally bent shape, it is possible to suppress the generation of wrinkles during deaeration by a conventional method. If the value exceeds 0.80, wrinkles may be insufficiently generated. The value is preferably 0.40 or more and 0.70 or less.

  Step 1 of the present invention is a step of sequentially laminating a vehicle inner glass plate, a laminated film, and a vehicle outer glass plate. At this time, as described above, it is preferable to perform lamination on the convex surface of the vehicle interior glass plate because the laminated film is laminated in a state of being stretched against the curved surface of the glass.

  Step 2 is a step of deaeration between the members laminated in Step 1. Before deaeration, adjustment is performed so that the hardness of the laminated film is 0.45 kgf or more. At this time, since the hardness of the laminated film increases as the temperature decreases, it is preferable to adjust by specifically reducing the temperature of the laminated film. It becomes possible to adjust the temperature of the laminated film by blowing air from the surface of the glass plate or leaving it in an environment where the temperature is adjusted.

  After adjusting the hardness of the laminated film, the members laminated in step 1 are deaerated. Deaeration can be performed by passing the laminated members between rolls or by attaching a tube made of rubber-based resin around the glass plate and exhausting air from the exhaust nozzle, or by vacuum bag Alternatively, a method may be used in which degassing is performed by putting a laminated member into the inside and exhausting air from an exhaust nozzle.

  In addition, it is preferable that the laminated film is one in which the heat insulating film is overlapped between two adhesive resin intermediate films and the whole surface is bonded and integrated to improve hardness. is there.

  After the above step 2, before performing the thermocompression bonding step of step 3, preheating may be performed at 80 to 90 ° C. for 30 to 50 minutes. By preliminarily adhering by performing the preliminary heating, it is possible to expel air remaining between the glass and PVB, the heat-shielding film and PVB, and to improve the subsequent thermocompression bonding process, which is preferable. is there.

  Step 3 is a step in which a vehicle windshield is obtained by thermocompression bonding. In this step, it is preferable to pressurize and heat using an autoclave. When an autoclave is used, a vehicle windshield can be obtained by increasing the maximum temperature in the autoclave until it falls within the range of 125 to 150 ° C. and maintaining the temperature for 20 to 40 minutes. At this time, pressurization is performed so as to be within a pressure range of 0.9 to 1.5 MPa. Further, pressurization and heating may be performed simultaneously or after pressurization, or may be performed after heating.

  Moreover, before the said process 1, after making the said laminated | multilayer film into a core material and making it into a roll-shaped laminated film, the process which makes this roll-shaped laminated film 6-8 degreeC, from this roll-shaped laminated film of 6-8 degreeC A step of drawing out the laminated film and cutting it into a predetermined shape, and a step of bringing the laminated film of the predetermined shape to 10 to 25 ° C. In the step 1, the inner side of the laminated film is the inside of the vehicle It is preferable to laminate | stack on a curved-surface glass plate so that it may become. By making it into a roll-shaped laminated film, the effect of suppressing the wrinkles at the peripheral portion of the heat-insulating film at the time of deaeration can be expected. In addition, in the case of a laminated film obtained by integrating three films obtained by laminating a heat-shielding film between two adhesive resin intermediate films, since the rigidity is high, if a deformation is applied in advance as a roll-shaped laminated film It is preferable because it can be expected to apply tension to the surface of the heat-shielding film more effectively.

  The films used in the examples and comparative examples are described below. In addition, the elastic modulus of the following heat shield films a and b is a value measured by a cantilever support beam method using a film piece obtained by cutting the heat shield film into a length of 75 mm and a width of 50 mm.

Adhesive resin interlayer: PVB film (thickness: 0.38 mm)
Thermal barrier film a: Multi-laminate film in which polyethylene terephthalates having different refractive indexes are laminated (total thickness: 0.106 mm, thermal shrinkage: 2.4% (150 ° C.), elastic modulus: 340 MN / mm ² (20 ° C.))
Thermal barrier film b: Multi-laminate film in which polyethylene terephthalates having different refractive indexes are laminated (total thickness: 0.069 mm, heat shrinkage rate: 3.1% (150 ° C.), elastic modulus: 370 MN / mm ² (20 ° C.))

(1) Hardness evaluation of laminated film The hardness of the film used with the following method was measured and it described in Table 1 and FIG. No. in Table 1 1 and no. No. 4 is a laminated film composed of three layers obtained by integrating three layers in advance. No. 2 is a laminated film consisting of two layers in which two layers are integrated in advance, No. 2; 3 and no. Reference numeral 5 denotes three films which are not laminated and integrated with three layers.

  First, a film piece for measurement in which the film was cut into a length of 200 mm and a width of 50 mm was prepared and left in an atmosphere adjusted to a predetermined temperature so that the temperature of the film for measurement was substantially constant. The film piece for measurement whose temperature was adjusted was placed horizontally, and one end portion in the length direction of the laminated film piece was fixed.

  Next, the other end of the measurement film piece that was not fixed was held, and the end of the measurement film piece was bent so that the crease was not formed. At this time, the end of the upper film piece for measurement was not fixed.

  Next, a load was applied vertically downward from above the film piece for measurement at a position 80 mm from the end. The load was applied using a load measuring device (manufactured by Aiko Engineering Co., Ltd., name: RX-20, model number: E00302). When the film pieces for measurement overlapped on the vertical line of the point where the load was applied, the force was stopped and the force applied at that time was measured. The measurement was performed 5 times, and the average value was taken as the hardness.

  From Table 1 and FIG. As for any film of 1-5, hardness fell as temperature raised. In addition, NO. 1, no. 2 and no. No. 4 laminated film is No. 4. 3 and no. No. 5 having a higher hardness than the non-laminated film No. 5 and integrating the three layers. 1, no. No. 4 is a No. 4 in which two layers are integrated. It was found that the hardness was higher than 2.

(2) Production of vehicle windshield Using the films 1 to 5, a vehicle windshield was produced by the following method.

Example 1
A curved glass plate (h = 64.1 mm, l = 26.1 mm, (l / m) / (h / k) = 0.0) obtained by curving a glass plate (k = 1370 mm, m = 1049 mm, thickness 2 mm). 53) No. 2 in Table 1 was prepared between the two curved glass plates. A laminate was obtained by sandwiching 1 laminated film. At this time, the laminated film and another glass plate were sequentially laminated on the convex surface of the glass plate.

  Next, the laminate was allowed to stand in an environment adjusted to 20 ° C. for about 10 minutes to adjust the average hardness according to the measurement method to 0.61 kgf, and the laminate was wrapped with a vacuum bag, Deaeration was performed at 90 kPa. When the appearance of the laminate was visually observed after deaeration, no wrinkles were observed near the center of each glass side.

  Next, it heated so that it might become in the range of 130-135 degreeC using an autoclave, and this pressure was maintained for about 20 minutes, and thermocompression bonding was performed. As a result of observing the appearance of the obtained vehicle windshield, no wrinkles were observed even during thermocompression bonding.

Example 2
The vehicle windscreen was manufactured in the same manner as in Example 1 except that the laminate before degassing was left in an environment adjusted to 25 ° C. for about 10 minutes and the average hardness according to the above measurement method was adjusted to 0.49 Kgf. Got a shield. In this example as well, no wrinkles were observed in either the degassing process or the thermocompression bonding process.

Example 3
A laminated film sandwiched between glass plates is designated as “No. A windshield for a vehicle was obtained in the same manner as in Example 1 except that the laminated film of No. 4 was used and the average hardness according to the above measurement method was adjusted to 0.45 kgf. In this example as well, no wrinkles were observed in either the degassing process or the thermocompression bonding process.

Example 4
A curved glass plate (h = 64.1 mm, l = 26.1 mm, (l / m) / (h / k) = 0.0) obtained by curving a glass plate (k = 1370 mm, m = 1049 mm, thickness 2 mm). 53) No. 2 in Table 1 was prepared between the two curved glass plates. A laminate was obtained by sandwiching the laminate film 2 and the adhesive resin interlayer. At this time, on the convex surface of the glass plate, the laminated film with the heat-shielding film surface up, the adhesive resin intermediate film, and another glass plate were sequentially laminated.

  Next, the laminate was allowed to stand in an environment adjusted to 18 ° C. for about 10 minutes to adjust the average hardness according to the above-described measurement method to 0.47 Kgf. Deaeration was performed at 90 kPa. When the appearance of the laminate was visually observed after deaeration, no wrinkles were observed.

  Next, it heated so that it might become in the range of 130-135 degreeC using an autoclave, and this pressure was maintained for about 20 minutes, and thermocompression bonding was performed. As a result of observing the appearance of the obtained vehicle windshield, no wrinkles were observed even during thermocompression bonding.

Example 5
Curved glass plate (h = 78.0 mm, l = 20.9 mm, (l / m) / (h / k) = 0.0) obtained by curving a glass plate (k = 1314 mm, m = 872 mm, thickness 2 mm). A vehicle windshield was obtained in the same manner as in Example 1 except that two 40) were used. In this example as well, no wrinkles were observed in either the degassing process or the thermocompression bonding process.

Comparative Example 1
A laminated film sandwiched between glass plates is designated as “No. Example 4 except that the laminated film of No. 2 was allowed to stand in an environment adjusted to 20 ° C. for about 10 minutes and the average hardness according to the above measurement method was adjusted to 0.43 Kgf. The windshield for vehicles was obtained by the same method. In this comparative example, wrinkles were generated during deaeration, and wrinkles remained even after thermocompression bonding.

Comparative Example 2
A vehicle windscreen was produced in the same manner as in Example 3 except that the laminate before degassing was left in an environment adjusted to 25 ° C. for about 10 minutes and the average hardness according to the above measurement method was adjusted to 0.38 Kgf. Got a shield. In this comparative example, wrinkles were generated during deaeration, and wrinkles remained even after thermocompression bonding.

Comparative Example 3
As a laminated film sandwiched between glass plates, No. The three films of No. 3 were sequentially laminated with an adhesive resin intermediate film, a heat-shielding film, and an adhesive resin intermediate film, and left in an environment adjusted to 20 ° C. for about 10 minutes. A vehicle windshield was obtained in the same manner as in Example 1 except that the hardness was adjusted to 0.29 Kgf. In this comparative example, wrinkles were generated during deaeration, and wrinkles remained even after thermocompression bonding.

  From the above, it has been clarified that the occurrence of wrinkles can be suppressed by adjusting the hardness of the laminated film at the time of deaeration to 0.45 kgf or more in the above measurement method.

1 Laminated film 2 Curved glass plate

Claims (3)

A laminated film in which an adhesive resin intermediate film and a heat-shielding film having a thermal shrinkage ratio of 0.5 to 5% at 125 to 150 ° C. and a thickness of 30 to 200 μm are laminated and bonded together in advance are integrated. Step 1 of laminating between a plurality of curved glass plates,
A step 2 of degassing the laminated film and the glass plate after the step 1;
In the method for manufacturing a vehicle windshield, comprising the step 3 of heating and pressure-bonding to form a vehicle windshield by heating so that the maximum temperature is within a range of 125 to 150 ° C. while applying pressure after the step 2.
When the curved glass plate is h / k> l / m, 0.30 ≦ (l / m) / (h / k) ≦ 0.80, or h / k <l / m, 0.30 ≦ (h / k) / (l / m) ≦ 0.80 (m: maximum length of the side in the vertical direction of the glass plate, h: maximum value of the bending depth of the glass plate, k: Satisfying the maximum value of the length of the side in the horizontal direction of the glass plate, l: the maximum value of the glass plate double),
The method for manufacturing a windshield for a vehicle according to step 2, wherein the hardness of the laminated film measured by the following measurement method is 0.45 kgf or more.
Step A: Cutting the laminated film to produce a strip-shaped test piece, and bringing the strip-shaped test piece to the temperature at the time of degassing in Step 2,
Step B: Step of placing the strip-shaped test piece obtained in Step A horizontally on a flat table and bending it, and overlapping both end portions A and B of the strip-shaped test piece,
Step C: A step of applying a load of a load measuring device to the strip-shaped test piece vertically downward at a point C at a certain distance from both ends A and B overlapped in Step B,
Step D: A step of measuring the load applied when the test pieces overlap on the vertical line of the point C, and setting the magnitude of the load to hardness. The method for manufacturing a windshield for a vehicle according to claim 1, wherein the laminated film is obtained by laminating a heat shielding film between two adhesive resin intermediate films. Before the said process 1, after making the said laminated | multilayer film into a core material and making it into a roll-shaped laminated film, the process which makes this roll-shaped laminated film 6-8 degreeC,
A step of drawing the laminated film from the roll-shaped laminated film at 6 to 8 ° C. and cutting it into a predetermined shape;
A step of bringing the laminated film of a predetermined shape to 10 to 25 ° C.,
3. The vehicle windshield according to claim 1, wherein in the step 1, the laminated film is laminated on a curved glass plate so that a winding inner side of the laminated film is a vehicle inner side. Manufacturing method.

Images