JP2008222513A - Laminated glass having conductive film and intermediate film for laminated glass - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To solve a problem that a laminated glass using an intermediate film for sound insulation which is formed by laminating three polyvinyl acetal layers causes defects due to bubbles in the vicinity of a conductive film formed by applying a conductive paste and heating. <P>SOLUTION: The distance D1 between a joint side main surface of a glass plate 1 on which the conductive film 5 is formed and a second polyvinyl acetal layer 12 having high plasticizer content is made larger than the distance D2 between a joint side main surface of another glass plate 2 and the second layer 12. Or, the end part of the second layer 12 is backed from the end part of the intermediate film 3 to remove the second layer 12 from a region where the conductive film 5 is formed and a polyvinyl acetal layer having the plasticizer content lower than that in the second layer 12 is arranged on the region. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a laminated glass including a conductive film and an interlayer film having improved sound insulation characteristics.

  Conventionally, laminated glass obtained by bonding two glass plates with an interlayer film has been used for a window glass of a vehicle or a building, particularly a windshield of an automobile. As the intermediate film, plasticized polyvinyl acetal, particularly plasticized polyvinyl butyral (PVB) is frequently used.

  In order to improve the comfort inside and in the vehicle, a window glass with improved sound insulation is required. The sound insulation of a normal laminated glass is reduced by the coincidence effect in the vicinity of 2000 Hz in the audible range. If the thickness of the glass plate is increased by increasing the thickness of the glass plate, the sound insulation of the window glass is improved. However, the coincidence effect is not eliminated, and the increase in the weight of the window glass is contrary to the demand for vehicle weight reduction. For this reason, the sound insulation of the laminated glass is improved by modifying the intermediate film.

  Generally, when the intermediate film is softened, the coincidence effect is relaxed and the sound insulation of the laminated glass is improved. However, if the intermediate film is simply made soft, the handleability of the intermediate film and the impact resistance of the laminated glass deteriorate. Many attempts have been made to modify the interlayer film. At present, the most suitable practically suitable interlayer film for sound insulation is a relatively soft pair of relatively hard polyvinyl acetal layers. An intermediate film having a three-layer structure sandwiching a polyvinyl acetal layer (for example, “S-LEC SAF” manufactured by Sekisui Chemical Co., Ltd.). The pair of outer layers in this intermediate film is a PVB layer usually used for bonding laminated glass, and the middle layer is a layer for enhancing sound insulation, and contains a plasticizer than the outer layer. High rate and soft. A three-layered sound insulation interlayer is disclosed in, for example, Patent Documents 1 and 2.

  By the way, an electrically conductive paste may be apply | coated and baked on the joining side main surface (surface on the side which contact | connects an intermediate film) of the glass plate near the edge part of a laminated glass, and a conductive film may be formed. As the conductive paste, a silver paste is usually used. A conductive film formed using a conductive paste as a coating material is not transparent, but its specific resistance is much lower than that of a transparent conductive film, and it is easy to arrange a desired pattern by screen printing or other techniques. It is.

  In laminated glass, a conductive film formed from a conductive paste is often used as a wiper deicer, a heated window bus bar, an antenna, or the like. The deicer locally heats the vicinity of the wiper stop position in order to make the wiper frozen on the glass surface movable. In the heated window, a transparent conductive film is formed so as to connect to the bus bar and cover the see-through region of the windshield, and the transparent conductive film generates heat by the current supplied from the bus bar. The antenna is formed on the glass surface as a filament having a length and shape designed based on the frequency of the radio wave to be received.

FIG. 14 illustrates a cross section in the vicinity of an end face of a laminated glass 110 having a conductive film 105 formed from a conductive paste. In this example, the two glass plates 101 and 102 are joined using the sound insulation intermediate film 103 having the three-layer structure described above. The sound insulation intermediate film 103 is formed by sandwiching a relatively soft polyvinyl acetal layer 112 containing a large amount of a plasticizer by a pair of relatively hard polyvinyl acetal layers 111 and 113 having a smaller amount of plasticizer than the layer 112. Layer film. A conductive film 105 is formed as a bus bar or the like on the bonding-side main surface near the end of the glass plate 101.
JP-A-5-104687 JP 2004-143008 A

  The laminated glass on which the conductive film is formed is exposed to a large temperature change when the conductive film is energized. In the case of laminated glass used as a windshield for vehicles, it is not uncommon for the exposed temperature to reach about 80 ° C. When exposed to such a high temperature, bubbles 120 may rarely be generated in the sound insulating intermediate film 103 of laminated glass provided with a conductive film formed from a conductive paste (see FIG. 14). It is considered that the bubbles 120 are generated due to air or moisture remaining between the conductive film 105 and the intermediate film 103.

  As shown in an enlarged view in FIG. 15A, the bubble 120 is initially generated near the conductive film 105 of the intermediate film 103. As shown in FIG. 15 (b), the bubbles 121 that have gradually grown under a high temperature environment eventually reach the second polyvinyl acetal layer 112. When this stage is reached, a part 122 of the bubbles 121 starts to spread in the soft second polyvinyl acetal layer 112 containing a large amount of plasticizer in the film surface direction and is easily visible from the outside. As described above, bubbles generated from the vicinity of the conductive film 105 tend to grow to a visible size more easily in the laminated glass using the sound insulating intermediate film 103 than in the laminated glass using the conventional intermediate film. May cause defects that impair the appearance of the product.

  An object of the present invention is to provide a laminated glass capable of suppressing the generation of bubbles that impair the appearance when exposed to a high temperature for a long time while using both a sound insulating interlayer and a conductive film formed from a conductive paste. And Another object of the present invention is to provide an intermediate film suitable for producing the laminated glass of the present invention.

  The present invention includes a first glass plate, a second glass plate, and an intermediate film that joins the first glass plate and the second glass plate, and the intermediate film includes a first polyvinyl acetal layer and a second polyvinyl acetal. A layered structure in which a layer and a third polyvinyl acetal layer are laminated in this order, the plasticizer content of the second polyvinyl acetal layer is the plasticizer content of the first polyvinyl acetal layer and the third polyvinyl acetal It is higher than the content of the plasticizer in the layer, and has a conductive film formed by applying a conductive paste and heating on the main surface on the bonding side of the first glass plate, and bonding the first glass plate The distance between the side main surface and the second polyvinyl acetal layer is larger than the distance between the bonding side main surface of the second glass plate and the second polyvinyl acetal layer. To provide a lath.

  From another aspect, the present invention includes a first glass plate, a second glass plate, and an intermediate film that joins the first glass plate and the second glass plate, and the intermediate film is a first polyvinyl acetal. Layer, a second polyvinyl acetal layer, and a third polyvinyl acetal layer are laminated in this order, and the plasticizer content of the second polyvinyl acetal layer is the plasticizer content of the first polyvinyl acetal layer And a conductive film formed by applying and heating a conductive paste on the joining main surface in the vicinity of the end of the first glass plate, which is higher than the plasticizer content of the third polyvinyl acetal layer. And an end portion of the second polyvinyl acetal layer recedes from an end portion of the intermediate film so that the second polyvinyl acetal layer does not exist on the region where the conductive film is formed. On the conductive film is formed region, wherein a portion of the intermediate layer, the content of the plasticizer is present less polyvinyl acetal than the second polyvinyl acetal layer, combined to provide a glass.

  From another aspect, the present invention includes a laminated structure in which a first polyvinyl acetal layer, a second polyvinyl acetal layer, and a third polyvinyl acetal layer are laminated in this order, and the inclusion of a plasticizer in the second polyvinyl acetal layer A sound insulation region having a rate higher than the plasticizer content of the first polyvinyl acetal layer and the plasticizer content of the third polyvinyl acetal layer, and between the sound insulation region and the film end, An interlayer film for laminated glass comprising: a peripheral region composed of a polyvinyl acetal layer having a plasticizer content smaller than that of a second polyvinyl acetal layer.

  In the laminated glass of the present invention, 1) a polyvinyl acetal having a high content of plasticizer that allows the expansion of bubbles and the bonding-side main surface of the glass plate (first glass plate) on which the conductive film serving as the bubble generation point is formed The distance between the layers (second polyvinyl acetal layer) is set to be relatively larger than the distance between the bonding-side main surface of the opposite glass plate (second glass plate) and the second polyvinyl acetal layer. This makes it difficult for bubbles to reach the second polyvinyl acetal layer, or 2) remove the second polyvinyl acetal layer from the end of the intermediate film so as to exclude the second polyvinyl acetal layer from the region where the conductive film is formed. By retreating, the second polyvinyl acetal layer was prevented from reaching the second polyvinyl acetal layer even when the bubbles expanded in the film thickness direction.

  By using the interlayer film for laminated glass of the present invention, it is possible to produce a laminated glass having the feature 2) more easily, specifically by the same process as that conventionally used for mass production. It becomes.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. Below, the same code | symbol is attached | subjected to the same member and the overlapping description about the member may be omitted.

(First embodiment)
1st Embodiment is an example of the laminated glass which set relatively large distance between the surface of the glass plate in which the electrically conductive film was formed, and the 2nd polyvinyl acetal layer.

  A laminated glass 10 shown in FIG. 1A includes glass plates 1 and 2, and a sound insulating intermediate film 3 that is disposed between the glass plates 1 and 2 and joins the glass plates 1 and 2. A conductive film 5 is disposed as a heated window bus bar in the vicinity of the end of the main surface of the joining side of the plate 1.

  The intermediate film 3 is a sound insulation film having a three-layer structure in which polyvinyl acetal layers 11, 12, and 13 are laminated in this order. The polyvinyl acetal layers 11, 12, and 13 all contain a plasticizer, but the plasticizer content in the central layer (second polyvinyl acetal layer) 12 is the outer layer (first and third polyvinyl acetal layers). 11 and 13 higher than the plasticizer content. For this reason, the 2nd polyvinyl acetal layer 12 is softer than the 1st, 3rd polyvinyl acetal layers 11 and 13, and this softness has improved the sound insulation of the laminated glass. On the other hand, the relatively hard first and third polyvinyl acetal layers 11 and 13 play a role of improving the handleability and mechanical strength of the intermediate film 3.

  The plasticizer content in each of the layers 11, 12, and 13 is not particularly limited. If the content of each layer of a commercially available interlayer for sound insulation (for example, “S-LEC SAF” manufactured by Sekisui Chemical Co., Ltd.) is included, Good. In the commercially available interlayer film for sound insulation, the outer first layer 11 and the third layer 13 contain the same level of plasticizer as the normal PVB layer, while the plasticizer content in the central second layer 12 is increased. In addition, the sound insulation of laminated glass is improved.

  In the commercially available interlayer film for sound insulation, the thickness T1 of the first polyvinyl acetal layer 11 and the thickness T3 of the third polyvinyl acetal layer 13 are set equal. However, in this form, the layer 11 is thicker than the layer 13 (T1> T3; see FIG. 1B). For this reason, the distance D1 from the joining side main surface (inner surface) of the glass plate 1 on which the conductive film 5 is formed to the second polyvinyl acetal layer 12 is the joining side main surface of the glass plate 2 on which the conductive film 5 is not formed. It becomes larger than the distance D2 from the surface to the second polyvinyl acetal layer 12 (D1> D2).

  From the viewpoint of improving sound insulation, the thickness T2 of the second polyvinyl acetal layer 12 is preferably 0.08 mm or more, particularly 0.1 mm or more. If the total film thickness (T1 + T2 + T3) of the intermediate film 3 is too thin, the function as a safety glass is lowered, and if it is too thick, the weight is increased. Therefore, it is usually 0.5 to 1.4 mm, preferably 0.7 to 1. It is good to set to the range of 1 mm. In order to keep the distance D1 large, the thickness T1 of the layer 11 is preferably 0.25 mm or more, particularly 0.33 mm or more. The thickness T3 of the layer 13 is preferably 0.15 mm or more. The difference (T1-T3) between the thicknesses T1 and T3 is preferably 0.1 mm or more, particularly 0.2 mm or more. Since the thickness of the intermediate film does not substantially change before and after the alignment step, T1 is substantially equal to D1, and T3 is substantially equal to D2.

  As shown in FIG.1 (b), in one form of this invention, the 1st polyvinyl acetal layer 11, the 2nd polyvinyl acetal layer 12, and the 3rd polyvinyl acetal layer 13 include the laminated structure laminated | stacked in this order, The plasticizer content of the second polyvinyl acetal layer 12 is higher than the plasticizer content of the first polyvinyl acetal layer 11 and the plasticizer content of the third polyvinyl acetal layer 13, and the overall thickness (T1 + T2 + T3) is 0.5 to 1.4 mm, the thickness T2 of the second polyvinyl acetal layer 12 is 0.08 mm or more, and the first polyvinyl acetal layer 11 is thicker than the third polyvinyl acetal layer 13 (T1> T3). An interlayer film 3 for laminated glass is used.

  The conductive film 5 serving as a bus bar is not required to be transparent, but is required to have a low resistivity in order to prevent power loss. The conductive film 5 is usually formed by applying and heating a conductive paste containing fine particles of metal typified by silver. The conductive paste is usually applied by a printing method such as screen printing. The applied paste is dried by a temperature raising process in the bending process of the glass plate and further baked at a temperature of about 500 to 700 ° C. at which the glass plate is bent to become the conductive film 5.

  A very small amount of air exists in the vicinity of the surface of the conductive film 5 formed by applying a conductive paste and heating it. The surface of the conductive film 5 is hardly smooth at a microscopic level, and minute gaps are likely to be generated at the interface with the intermediate film 3. There is a possibility that minute holes formed in the conductive film 5 when the conductive paste is applied remain. The air contained in the gaps and voids in these minute interfaces expands in a high-temperature environment and advances into a relatively soft intermediate film, which in some cases combines and further vaporizes and releases from the intermediate film. It is considered that bubbles that grow to the extent that they are taken in and that are visible are formed.

  According to the observation by the experiment, the bubbles grow slowly in the film thickness direction in the intermediate film layer 11 (111) at first, but in the relatively soft layer 12 (112) having a high plasticizer content. The layer grows relatively fast in the in-plane direction of the layer (see FIG. 15B). Since the soft layer 12 (112) having a high plasticizer content easily allows the bubble to grow, when the bubble reaches the layer 12 (112), the bubble tends to spread in the in-plane direction of the laminated glass. , Appearance defects are likely to occur.

  If the amount of air remaining in the vicinity of the surface of the conductive film 105 is very small, or the external temperature is relatively low, the bubble growth rate decreases or the growth itself does not continue, and the bubble 120 does not reach the layer 112. It may remain in the state (the state of FIG. 15A). Bubbles 120 do not grow as fast in the relatively hard layer 111 as in the layer 112. If the bubbles 120 reach the layer 112 and do not spread in the in-plane direction, the laminated glass will not have significant appearance defects to the extent that it should be eliminated. A black colored film is often formed on the surface in the vicinity of the end portion of the laminated glass used as the window of the vehicle in order to make the member for attaching the glass invisible from the outside. This colored film also serves to conceal the bubbles 120 that remain in the vicinity of the end.

  As can be seen from the above, the extension of the distance D1 is an extension of the time required for the bubbles to reach the layer 12 and the possibility of the bubbles reaching the layer 12 even if it is slight. There is an effect, and it is possible to suppress the appearance defects in the laminated glass.

  As shown in FIG. 3, the intermediate film 3 has, for example, a commercially available sound insulating intermediate film 22 (the film thicknesses of the first layer 11a and the third layer 13 are set equal) and the plasticizer content. A polyvinyl acetal film 21 of a general-purpose PVB film can be laminated. In this case, the first layer 11 a of the commercially available sound insulating film 22 and the layer 11 b (21) such as a general-purpose PVB film constitute the first polyvinyl acetal layer 11.

  As shown in FIG. 2, in the heated window, the conductive film 5 is formed so as to be in contact with the transparent conductive film 6 formed in advance on the surface of the glass plate 1. The transparent conductive film 6 is made of a material having a relatively higher specific resistance than the conductive film 5, and generates heat due to a current supplied from the conductive film 5 serving as a bus bar. In order to supply power to the conductive film 5, the glass plate 2 is partially cut away, and the conductive film 5 exposed from the part is connected to a power source (not shown) through the wiring 7. For electrical connection between the conductive film 5 and the wiring 7, a terminal may be fixed on the conductive film 5, and the wiring 7 may be connected to the terminal.

  FIG. 4 illustrates the arrangement of the conductive film (bus bar) 5 and the transparent conductive film 6 in the heated window. The laminated glass 10 is formed with a pair of bus bars 5a and 5b made of a conductive film. One bus bar 5a reaches from the lower side corner (lower right in the figure) where the glass plate 2 is cut out for power supply to the upper side along the glass side, extends along the upper side, and is transparent on the upper side. Power is supplied to the conductive film 6. The other bus bar 5b extends from the lower corner portion along the lower side, and supplies power to the transparent conductive film 6 on the lower side. A current flows in the transparent conductive film 6 formed so as to cover the transparent region in the vertical direction in the figure, and this film 6 becomes a heating element.

  Of course, the conductive film formed from the conductive paste may be formed for a purpose other than the bus bar of the heated window. FIG. 5 shows a laminated glass 30 in which a conductive film is formed as a wiper deicer. The conductive film 4 serving as a deicer extends along the illustrated lower side and side side of the laminated glass, is connected to the wiring 7 at the center of the lower side, and is connected to a power source (not shown) via the wiring 7. The de-icer 4 includes a wire 4a serving as a current forward path and a wire 4b serving as a current return path, and the plurality of wires 4a and 4b are designed to have resistance values suitable for heat generation. Since the de-icer is formed according to the stop position of the wiper, it may be arranged only on the lower side or only the side of the glass plate.

(Second Embodiment)
2nd Embodiment is an example of the laminated glass which excluded the 2nd polyvinyl acetal layer from the intermediate film on the area | region in which the electrically conductive film was formed.

  The laminated glass 20 shown in FIG. 6 includes the glass plates 1 and 2 and the intermediate film 3 that is disposed between the glass plates 1 and 2 and joins the glass plates 1 and 2 in the same manner as the laminated glass 10 in FIG. The conductive film 5 as a bus bar of a heated window is provided in the vicinity of the end portion of the main surface on the bonding side of the glass plate 1.

  Similarly to the laminated glass 10, the intermediate film 3 is also a sound insulation film having a three-layer structure in which polyvinyl acetal layers 11, 12, and 13 are laminated in this order. The polyvinyl acetal layers 11, 12, and 13 all contain a plasticizer, but the plasticizer content in the central layer (second polyvinyl acetal layer) 12 is the outer layer (first and third polyvinyl acetal layers). 11 and 13 higher than the plasticizer content.

  In the laminated glass 20, the end portion 12 a of the second polyvinyl acetal layer 12 is retreated from the end portion 3 a of the intermediate film 3 to the central portion side of the laminated glass 20. Since the end 12 a of the layer 12 is further retracted from the region where the conductive film 5 is formed, the second polyvinyl acetal layer 12 does not exist above the conductive film 5. On the other hand, the end portion 3 a of the intermediate film is arranged so as to substantially coincide with the end portions of the glass plates 1 and 2, and the conductive film 5 is covered with a polyvinyl acetal 16 (17) constituting a part of the intermediate film 3. . The plasticizer content of the polyvinyl acetal 16 (17) is set lower than the plasticizer content of the second polyvinyl acetal layer 12.

  In the laminated glass 20, even if bubbles are generated in the intermediate film 3 in the vicinity of the conductive film 5 and grow in the film thickness direction, the bubbles reach the second polyvinyl acetal layer 12, and the inside of the layer 12 extends in the film surface direction. There is no growth. In the laminated glass 20, it is not necessary to set the distance from the bonding side main surface of the glass plate 1 to the second polyvinyl acetal layer 12 larger than the distance from the bonding side main surface of the glass plate 2 to the second polyvinyl acetal layer 12. .

  With reference to FIG. 7 and FIG. 8, an example of the manufacturing method of the laminated glass 20 is demonstrated. First, for example, glass plates 1 and 2 that are bent into the same shape through a self-weight bending step or a press bending step are prepared, and the sound insulating interlayer 3 is disposed between the glass plates 1 and 2 (FIG. 7A). ), FIG. 8 (a)). A silver paste is applied to the main surface in the vicinity of the end of the glass plate 1 and is fired together with the bending of the glass plate 1 to form the conductive film 5. The intermediate film 3 is cut into a surface shape slightly smaller than the outer shape of the glass plates 1 and 2 so as not to contact the conductive film 5, in other words, the end 3 a of the film is larger than the region where the conductive film 5 is formed. It interposes between the glass plates 1 and 2 so as to retreat. A commercially available sound insulating intermediate film 22 may be used for the intermediate film 3.

  Next, a glass plate joining step comprising a pre-adhesion step and a heating and pressurizing step using an autoclave is performed (FIGS. 7B and 8B). In this joining step, the end of the intermediate film 3 approaches the end of the glass plates 1 and 2.

  The end portions of the layers 11, 12, and 13 are aligned before the bonding step, but the end portion 3 a of the intermediate film 3 is positioned outside the end portion 12 a of the second polyvinyl acetal layer 12 after the bonding step. . The stretched portion 15 of the intermediate film 3 extends and spreads outward while the end portions of the first polyvinyl acetal layer 11 and the third polyvinyl acetal layer 13 are mixed with the end portions of the second polyvinyl acetal layer 12 in the joining step (stretching). And a portion having a plasticizer content lower than that of the second polyvinyl acetal layer 12. The extending portion 15 covers the end portion 12 a of the second polyvinyl acetal layer 12 and forms the end portion 3 a of the intermediate film 3.

  In the bonding step, the area of the intermediate film 3 increases by the amount of extension of the film, but the increase in area is slight compared to the total area of the intermediate film 3, so each polyvinyl before and after the bonding process. It can be said that the thickness of the acetal layer does not substantially change.

  Subsequently, the conductive film 5 is formed by applying, for example, polyvinyl acetal 16 that has been heated to increase the fluidity to the recesses 14 formed between the end portions of the glass plates 1 and 2 and the end portion 3a of the intermediate film. The region above is filled with polyvinyl acetal 16 (FIGS. 7C and 8C). The plasticizer content of the polyvinyl acetal 16 is set lower than the plasticizer content in the second polyvinyl acetal layer 12.

  As shown in FIG. 8B, immediately after the bonding process of the glass plates 1 and 2, the end portion 3a of the intermediate film 3 is moved back from the region where the conductive film 5 is formed (on the center side of the laminated glass). It is preferable to stay in the shifted position. This is because the conductive film 5 can be covered with the polyvinyl acetal 16 whose plasticizer content is adjusted in advance (see FIG. 8C).

  In the above method, the intermediate film 3 cut smaller than the outer shape of the glass plates 1 and 2 is used, and after joining, the polyvinyl acetal 16 having a plasticizer content smaller than that of the second polyvinyl acetal layer 12 is bonded to the end of the laminated glass. The laminated glass 20 may be manufactured by preparing an intermediate film in which a portion having a low plasticizer content is disposed in advance at the end portion and using the intermediate film.

  Hereinafter, an example of a method for producing the intermediate film 8 in which the end of the second polyvinyl acetal layer is retracted from the end of the intermediate film will be described with reference to FIG.

  First, the interlayer film for sound insulation formed by laminating the first, second, and third polyvinyl acetal layers 11, 12, and 13 is cut into a reduced surface shape of the laminated glass to be manufactured, and the interlayer film sound insulation region 31 is formed. Is obtained (FIG. 9A). Further, the intermediate film made of polyvinyl acetal 17 having a plasticizer content lower than that of the second polyvinyl acetal layer 12 is cut into a frame shape to obtain the intermediate film peripheral region 32 (FIG. 9B). The peripheral region portion 32 may be cut so that the inner edge thereof coincides with the outer edge of the sound insulation region portion 31 and the outer edge is a frame-like body that substantially coincides with the laminated glass to be manufactured. Subsequently, the sound insulation region 31 is fitted into the frame-shaped peripheral region 32 and, as necessary, the boundary of the film is heated and smoothed to obtain the intermediate film 8 (FIG. 9C).

  The intermediate film 8 has a three-layer structure in which the first, second, and third polyvinyl acetal layers 11, 12, and 13 are laminated in the central sound insulating region 31, as shown in FIG. The peripheral region 32 surrounding the sound insulation region has a single-layer structure made of polyvinyl acetal 17 having a plasticizer content lower than that of the second polyvinyl acetal layer 12.

  By continuous extrusion manufacturing of the intermediate film applied in the mass production process, it is also possible to obtain a long intermediate film having a different film configuration in the central sound insulation region and the peripheral region of the end. This intermediate film can be obtained, for example, from a manufacturing apparatus in which an extruder for forming a single-layer intermediate film is disposed on both sides of an extruder for forming an intermediate film having a three-layer structure.

  The intermediate film 9 shown in FIG. 11 is a long sheet continuous in the horizontal direction in the figure, and has a central part of a three-layer structure in which the first, second, and third polyvinyl acetal layers 11, 12, and 13 are laminated. (Sound insulation region) 36 has a configuration in which peripheral portions (peripheral regions) 37 and 37 of a single layer made of polyvinyl acetal 17 having a plasticizer content lower than that of the second polyvinyl acetal layer 12 are disposed at both ends of the sound insulation region 36. The intermediate film 9 also has a cross-sectional structure shown in FIG. 10 (FIG. 10 is also a II-II cross section of FIG. 11). The intermediate film 9 is normally used as a roll body in which the sheet is wound in the longitudinal direction, and the sheet fed from the roll body is cut.

  With reference to FIG. 12 and FIG. 13, an example of the manufacturing method of the laminated glass 20 (FIG. 6) using the intermediate film 8 (9) is demonstrated.

  First, glass plates 1 and 2 bent into the same shape are prepared, and a sound insulating intermediate film 8 (9) is disposed between the glass plates 1 and 2 (FIGS. 12A and 13A). ). A silver paste is applied to the main surface in the vicinity of the end of the glass plate 1 and is fired together with the bending of the glass plate 1 to form the conductive film 5. The intermediate film 8 (9) may be cut in accordance with the ends of the glass plates 1 and 2, as has been done in the conventional manufacturing process.

  Next, a glass plate joining step including a pre-adhesion step and a heating and pressurizing step using an autoclave is performed (FIGS. 12B and 13B). The intermediate film 8 (9) is stretched by the joining process. However, the end portion of the second polyvinyl acetal layer 12 that is disposed so as to recede from the end portions of the glass plates 1 and 2 does not reach the region where the conductive film 5 is formed even after the bonding step, but recedes from this region. Stay in the position. On the other hand, the polyvinyl acetal 17 at the peripheral edge of the intermediate film 8 (9) protrudes from the ends of the glass plates 1 and 2.

  Subsequently, the polyvinyl acetal 17 at the peripheral edge of the intermediate film 8 (9) protruding outward from the end portions of the glass plates 1 and 2 is removed to obtain a laminated glass 5 (FIGS. 12C and 13C). ).

  Note that when the intermediate film 9 is used, care must be taken because there is a film edge where the peripheral region 37 is not disposed. There is no problem when the conductive film 5 is not formed at the end where the peripheral region 37 is not present. However, when the conductive film 5 is formed at this end portion, as described above, the intermediate film is cut to be smaller than the glass plate at the end portion without the peripheral region 37 and added later. It is preferable that the region above the region where the conductive film 5 is formed is filled.

  If the intermediate film 8 (9) is used, the arrangement and cutting of the intermediate film can be performed in the same manner as in the prior art, so there is no need to change the conventional process. A peripheral region 37.37 is disposed at both ends of the sound insulation region 36 in the short side direction, the sound insulation region 36 and the peripheral region 37 are continuous in a strip shape in the long side direction, and the intermediate film 9 of the roll body wound in the long side direction is It is also convenient for mass production of laminated glass.

  The widths of the peripheral regions 32 and 37 of the intermediate film (distances from the film end portions to the sound insulation regions 31 and 36) may be appropriately determined depending on the size of the laminated glass, and are, for example, 2 cm or more and 20 cm or less.

  As described above, in the second embodiment, the polyvinyl acetal 16 additionally supplemented with the polyvinyl acetal having a lower plasticizer content than the second polyvinyl acetal layer 12 present on the region where the conductive film is formed. Or a polyvinyl acetal 17 disposed in advance at the periphery of the sound insulation region of the interlayer film. Since the stretched portion 15 of the intermediate film 3 is also a polyvinyl acetal having a plasticizer content lower than that of the second polyvinyl acetal layer 12, a part of the intermediate film 3 disposed on the region where the conductive film is formed is a stretched portion. 15 may be included.

  Also in the second embodiment, the conductive film may be formed as a deicer (see FIG. 4) or the like.

  As described above, the laminated glass of the present invention further includes the wiring 7 connected to the conductive films 4 and 5 formed from the conductive paste, and the external power source and the conductive films 4 and 5 are connected via the wiring 7. May be connected so that power can be supplied. This wiring is connected to the conductive film directly or via a terminal disposed on the conductive film.

  For each member described in the above embodiment, members that have been used so far can be used without particular limitation. As the glass plates 1 and 2, soda lime silica glass is usually used. Each layer 11, 12, 13 constituting the intermediate film 3 contains polyvinyl acetal obtained by acetalizing polyvinyl alcohol with aldehyde and a plasticizer, and a stabilizer, an antioxidant and the like are appropriately blended as necessary. The intermediate film 3 may be obtained by processing a commercially available sound insulating intermediate film 22 (see FIG. 3). The conductive films 4 and 5 may also be formed by applying and baking a commercially available silver paste as conventionally performed.

  ADVANTAGE OF THE INVENTION According to this invention, deterioration of the quality of the laminated glass provided with the intermediate film which improves sound-insulation property, and the electrically conductive film formed by apply | coating and heating an electrically conductive paste can be prevented.

(A) It is a fragmentary sectional view of an example of the laminated glass of this invention. (B) It is a fragmentary sectional view of an example of an intermediate film. It is sectional drawing of another part of the laminated glass of Fig.1 (a). It is a fragmentary sectional view of the intermediate film suitable for the laminated glass of Fig.1 (a). It is a top view of the laminated glass of Fig.1 (a). It is a top view for showing a different use of the laminated glass of the present invention. It is a fragmentary sectional view of another example of the laminated glass of this invention. It is process drawing which shows an example of each process which manufactures the laminated glass of FIG. 6 with a top view. It is process drawing which shows an example of each process which manufactures the laminated glass of FIG. 6 with a fragmentary sectional view. It is process drawing which shows each process which manufactures an example of the intermediate film of this invention with a top view. It is II sectional drawing of the intermediate film of FIG.9 (c), and is also II-II sectional drawing of the intermediate film of FIG. It is a top view which shows a part of another example of the intermediate film of this invention. It is process drawing which shows another example of each process which manufactures the laminated glass of FIG. 6 with a top view. It is process drawing which shows another example of each process which manufactures the laminated glass of FIG. 6 with a fragmentary sectional view. It is a fragmentary sectional view of the conventional laminated glass. It is an intermediate film for demonstrating the bubble growth in the conventional laminated glass, and its fragmentary sectional drawing of the vicinity, (a) shows the state immediately after generation | occurrence | production, (b) shows the state after growing, respectively.

Explanation of symbols

1, 2, 101, 102 Glass plate 3, 8, 9, 103 Sound insulation intermediate film 3a End of intermediate film 4, 4a, 4b Conductive film (wiper deicer)
5, 5a, 5b, 105 Conductive film (bus bar)
6 Transparent conductive film 7 Wiring 10, 20, 30, 110 Laminated glass 11, 111 First polyvinyl acetal layer 12, 112 Second polyvinyl acetal layer 12a End portion 13, 113 of third polyvinyl acetal layer Recessed portion 15 Stretched portion 16 of intermediate film Polyvinyl acetal 17 (prepared separately from intermediate film) Polyvinyl acetal 21 (which is a part of the intermediate film) Single-layer polyvinyl acetal film 22 Commercially available three-layer sound insulation film 31, 36 Sound insulation region 32, 37 peripheral area 120, 121, 122 bubble

Claims (5)

A first glass plate, a second glass plate, and an intermediate film that joins the first glass plate and the second glass plate;
The intermediate film includes a laminated structure in which a first polyvinyl acetal layer, a second polyvinyl acetal layer, and a third polyvinyl acetal layer are laminated in this order, and the plasticizer content of the second polyvinyl acetal layer is the first polyvinyl acetal layer. Higher than the plasticizer content of the polyvinyl acetal layer and the plasticizer content of the third polyvinyl acetal layer,
On the joining side main surface of the first glass plate, a conductive paste is applied and heated to form a conductive film,
The distance between the bonding side main surface of the first glass plate and the second polyvinyl acetal layer is larger than the distance between the bonding side main surface of the second glass plate and the second polyvinyl acetal layer, Laminated glass. A first glass plate, a second glass plate, and an intermediate film that joins the first glass plate and the second glass plate;
The intermediate film includes a laminated structure in which a first polyvinyl acetal layer, a second polyvinyl acetal layer, and a third polyvinyl acetal layer are laminated in this order, and the plasticizer content of the second polyvinyl acetal layer is the first polyvinyl acetal layer. Higher than the plasticizer content of the polyvinyl acetal layer and the plasticizer content of the third polyvinyl acetal layer,
On the bonding side main surface in the vicinity of the end of the first glass plate, a conductive paste is applied and heated to form a conductive film,
An end portion of the second polyvinyl acetal layer recedes from an end portion of the intermediate film so that the second polyvinyl acetal layer does not exist on the region where the conductive film is formed,
Laminated glass in which a polyvinyl acetal having a plasticizer content lower than that of the second polyvinyl acetal layer is present as a part of the intermediate film on a region where the conductive film is formed.   The laminated glass according to claim 1, further comprising a wiring connected to the conductive film. It includes a laminated structure in which a first polyvinyl acetal layer, a second polyvinyl acetal layer, and a third polyvinyl acetal layer are laminated in this order, and the plasticizer content of the second polyvinyl acetal layer is that of the first polyvinyl acetal layer. A sound insulation region higher than the plasticizer content and the plasticizer content of the third polyvinyl acetal layer;
An intermediate film for laminated glass, comprising: a peripheral region made of a polyvinyl acetal layer that is present between the sound insulation region and the film end and has a plasticizer content less than that of the second polyvinyl acetal layer.   The said peripheral area is arrange | positioned at the both ends of the said sound insulation area | region about the short side direction, the said sound insulation area | region and the said peripheral area | region continue in a strip | belt shape about the long side direction, and it is the roll body wound about the long side direction. An interlayer film for laminated glass as described in 1.

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