JP2001026468A - Intermediate film for sandwich glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an intermediate film for sandwich glass which is excellent in handling workability during storage or at the time of processing of sandwich glass, is excellent in deaerating and sealing properties in a preliminary press bonding stage, is consequently suitable for obtaining the high-quality sandwich glass substantially free from the quality defect by the generation of air bubbles and is easily and efficiently dealable with diversified processing conditions of various users. SOLUTION: The emboss recessed parts on at least one surface of the intermediate film for the sandwich glass formed with many embosses consisting of micro-ruggedness on both surfaces of a thermoplastic resin sheet have continuous groove shapes 1 and the emboss projecting parts corresponding to these recessed parts have parting parts 2. In addition, the bases of the groove shapes in the parting parts are not at the same level of the bases of the continuous groove shapes of the emboss recessed parts.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

[0001] The present invention relates to an interlayer film for laminated glass.

[0002]

2. Description of the Related Art An interlayer film for laminated glass (hereinafter simply referred to as "intermediate film") formed by forming a thermoplastic resin such as plasticized polyvinyl butyral resin is interposed between glass plates and bonded together to form an integrated film. Laminated glass is used for automobiles,
It is widely used as window glass for aircraft and buildings.

[0003] In this kind of laminated glass, an interlayer film is sandwiched between at least two glass plates and handled by passing through a nip roll (pressing roll) (handling deaeration method) or a vacuum such as a rubber bag. It is put in a bag, suctioned under reduced pressure (vacuum degassing method), pre-press-bonded while degassing the air remaining between the glass plate and the interlayer, and then heated and pressurized in an autoclave for final press-bonding. Is done.

[0004] In addition to having good basic properties such as adhesiveness, weather resistance, penetration resistance, and transparency, the above-mentioned interlayer film has to prevent blocking between interlayer films during storage, and to have an interlayer film between glass plates. It is required to have good handling workability at the time of sandwiching, and to have good deaeration in the pre-compression bonding step in order to eliminate generation of air bubbles due to entrainment of air.

In order to satisfy such requirements, a large number of embosses having fine irregularities are usually formed on both surfaces of the intermediate film. Examples of the form of the fine unevenness include, for example, various uneven patterns including a large number of convex portions and a large number of concave portions corresponding to these convex portions, and a large number of convex portions and a large number of concave grooves for these convex portions. Various irregular patterns are disclosed.

[0006] As such an intermediate film, for example, Japanese Patent Publication No. 1-32776 discloses a film made of a soft thermoplastic resin and having a fine irregular surface (embossed) surface shape used as an intermediate film for lamination bonding. Alternatively, at least one side of the sheet has a large number of independent protrusions integrally formed with the film or the sheet, and all of the concave portions corresponding to the protrusions have a surface shape that is continuous at the same level. Characteristic thermoplastic resin interlayer "is disclosed.

[0007] However, the conventional interlayer film disclosed in the above disclosure has a considerably improved anti-blocking property during storage and handling workability, or degassing property in a pre-compression bonding step. In the case of manufacturing laminated glass with a large width or laminated glass with a large curvature, or when it is desired to increase the productivity during the processing of laminated glass, it is still not satisfactory in terms of deaeration in the pre-compression bonding step. There is a problem.

Further, when a laminated glass is manufactured using an intermediate film having the shape of the unevenness and the level of the concave portions uniform throughout as described in the above disclosure, the difference in thickness of the intermediate film itself and the difference in the thickness of the laminated glass can be considered. There is a problem that a pair difference due to a difference in thickness and a difference in curvature of glass used cannot be sufficiently absorbed.

That is, in the case of the interlayer film disclosed in the above disclosure, unless the sealing state of the interlayer film portion of the laminated glass is made uniform and complete over the entirety, for example, an incomplete sealing in the final pressure bonding step by an autoclave. Since pressurized air penetrates from the defective portion, bubbles are generated between the glass and the intermediate film after the final compression, and a laminated glass having excellent transparency cannot be obtained. Therefore, there is a problem that manufacturing conditions in the pre-compression bonding step are extremely restricted.

In the case of the above-mentioned intermediate film, in order to cope with various processing conditions of various users, for example, a large number of embossing rolls having irregular shapes which can be respectively adapted are prepared, and the processing of each user is performed. It is necessary to manufacture various kinds of intermediate films provided with embosses having various irregularities conforming to the conditions, and there is also a problem that productivity is not efficient.

[0011]

DISCLOSURE OF THE INVENTION The present invention solves the above-mentioned conventional problems by providing excellent workability during storage and processing of laminated glass, as well as excellent deaeration and sealing properties in a pre-compression bonding step. Therefore, it is suitable for obtaining high-quality laminated glass that hardly causes poor quality due to the generation of air bubbles,
Moreover, an object of the present invention is to provide an interlayer film for laminated glass that can easily and efficiently cope with various processing conditions of various users.

[0012]

According to the present invention, there is provided an interlayer film for laminated glass in which a large number of embosses having fine irregularities are formed on both surfaces of a thermoplastic resin sheet. The embossed concave portion on at least one side has a continuous groove shape, the embossed convex portion for the concave portion has a divided portion, and the bottom of the groove shape of the divided portion is a continuous groove of the embossed concave portion. It is not at the same level as the bottom of the shape.

[0013] The interlayer film for laminated glass according to claim 2 is the interlayer film for laminated glass according to claim 1, wherein
The groove shape of the embossed concave portion and the groove shape of the divided portion of the embossed convex portion are lattice-shaped.

The interlayer film for laminated glass according to claim 3 is the interlayer film for laminated glass according to claim 1, wherein
The groove shape of the embossed concave portion and the groove shape of the dividing portion of the embossed convex portion are random shapes.

According to a fourth aspect of the present invention, there is provided the interlayer film for a laminated glass according to any one of the first to third aspects, wherein the depth of the groove at the dividing portion of the embossed convex portion is constant. There is a feature.

The interlayer film for laminated glass according to claim 5 is the interlayer film for laminated glass according to any one of claims 1 to 3, wherein the depth of the groove of the dividing portion of the embossed convex portion is random. There is a feature.

The thermoplastic resin sheet used in the present invention is not particularly limited. Examples thereof include a plasticized polyvinyl acetal resin sheet, a polyurethane resin sheet, an ethylene-vinyl acetate resin sheet, and an ethylene-ethyl resin sheet. A thermoplastic resin sheet conventionally used for an intermediate film, such as an acrylate resin sheet and a plasticized vinyl chloride resin sheet, is preferably used. These thermoplastic resin sheets have adhesive,
Excellent basic performance required for interlayers such as weather resistance, penetration resistance, and transparency.

Among the thermoplastic resin sheets, a plasticized polyvinyl acetal resin sheet represented by a plasticized polyvinyl butyral resin sheet is particularly preferably used. The thickness of these thermoplastic resin sheets may be set in consideration of the penetration resistance and the like required as a laminated glass, and is not particularly limited. It is preferably from 2 to 2 mm.

The interlayer film for laminated glass according to the present invention is an intermediate film in which a large number of embosses having fine irregularities are formed on both surfaces of the thermoplastic resin sheet, wherein at least one side of the embossed concave portion has a continuous groove shape. And
The embossed convex portion for the concave portion has a dividing portion,
Further, the bottom of the groove shape of the dividing portion is formed so as not to be at the same level as the bottom of the continuous groove shape of the embossed concave portion.

Here, the continuous groove shape of the embossed concave portion is as follows.
It mainly serves as a deaeration passage,
In particular, when performing pre-compression bonding by the vacuum degassing method using a vacuum bag, even if the embossed unevenness is crushed by heat or pressure during pre-compression bonding, the continuous groove shape of the above concave remains until the final stage of pre-compression bonding. Demonstrates the function of sufficient degassing.

On the other hand, the groove shape of the dividing portion of the embossed convex portion is as follows.
It mainly fulfills the function of controlling the size of the embossed irregularities.Because the volume of the embossed irregularities decreases when the groove shape is increased, it becomes easier to seal particularly the peripheral portion of the laminated glass. When the amount is reduced, the volume of the embossed concavo-convex becomes large, so that the peripheral portion of the laminated glass is sealed first and air can be effectively prevented from remaining in the central portion of the laminated glass.

Since the groove shape of the dividing portion of the embossed convex portion can be arbitrarily controlled, excellent degassing by the continuous groove shape of the embossed concave portion and excellent groove shape of the dividing portion of the embossed convex portion are excellent. It is possible to easily and efficiently obtain an intermediate film having both sealing properties in accordance with various processing conditions of various users.

FIG. 1 is a perspective view showing an embossed pattern of an interlayer film for laminated glass according to the present invention, and FIG. 2 is a plan view thereof.

In the present invention, the groove shape 1 of the embossed concave portion and the groove shape of the dividing portion 2 of the embossed convex portion may be a lattice shape or a random shape. More preferably, it is in a form.

Further, in the present invention, the depth 3 of the groove of the dividing portion of the embossed convex portion may be a constant depth or a random depth, but may be a constant depth. Is more preferable.

In the interlayer film for laminated glass according to the present invention, it is preferable that embosses satisfying the specific conditions are formed on both surfaces of the intermediate film. However, only one surface of the intermediate film satisfies the specific conditions. May be formed, and a conventional ordinary emboss may be formed on the other surface.

The method of forming a large number of embosses made of fine irregularities on both surfaces of the thermoplastic resin sheet is not particularly limited. For example, an embossing roll method,
A calender roll method, a profile extrusion method, an extrusion lip embossing method using melt fracture, and the like are preferably used, and among them, an embossing roll capable of forming a large number of embosses composed of constant fine irregularities quantitatively is preferred. The method is more preferably employed.

The embossing roll used in the embossing roll method is not particularly limited. For example, the surface of a metal roll is subjected to a blast treatment using an abrasive such as aluminum oxide or silicon oxide, and then the surface is excessively enlarged. By performing lapping by vertical grinding etc. to reduce the peak, a roll with a fine uneven pattern formed on the roll surface, using an engraving mill (mother mill)
By transferring this uneven pattern to the metal roll surface,
A roll having a fine uneven pattern formed on the roll surface, a roll having a fine uneven pattern formed on the roll surface by etching (etching), and the like are used, and are preferably used.

The embossed concavo-convex pattern may be any pattern as long as it satisfies the above-mentioned conditions specified in the present invention, may be distributed regularly and regularly, or may be randomly and irregularly. It may be distributed. In addition, the height of each protrusion of the embossing may be the same or different.

The shape of the convex and concave portions of the emboss may be any shape as long as it satisfies the conditions specified in the present invention, and is not particularly limited. Are pyramids such as triangular pyramids, quadrangular pyramids, and cones; truncated pyramids such as truncated triangular pyramids, truncated quadrangular pyramids, and truncated cones; It is preferable that the projections and depressions have an uneven shape composed of a large number of convex portions and a large number of concave portions corresponding to these convex portions.

Further, the size of the embossed concavo-convex pattern may be any size as long as it satisfies the conditions specified in the present invention, and is not particularly limited. The interval between the protrusions is generally 10 to 2000 μm
And more preferably about 20
It is in the range of 0 to 1000 μm. Further, the height of the projection is preferably in the range of about 5 to 500 μm, more preferably in the range of about 20 to 100 μm. Further, it is preferable that the length of the base of the convex portion is approximately in the range of 30 to 900 μm.

The method of manufacturing a laminated glass using the interlayer film for a laminated glass according to the present invention is not particularly limited, and an intermediate film is interposed between at least a pair of glasses as in the case of a normal manufacturing method of a laminated glass. After sandwiching, pre-press bonding is performed first to perform deaeration and temporary bonding, and then to final press bonding, a desired laminated glass can be obtained.

When a laminated glass is produced using an interlayer composed of, for example, a plasticized polyvinyl butyral resin sheet as the interlayer for a laminated glass according to the present invention, the pre-compression bonding and the final compression bonding are performed as follows. Do.

That is, in the pre-compression bonding, for example, an intermediate film according to the present invention is sandwiched between two transparent inorganic glass plates, and the laminate is passed through a nip roll (pressing roll), for example, at a pressure of about ^{2 to} 10 kg / cm ² , A method of pre-press bonding while degassing at a temperature of about 50 to 80 ° C (handling degassing method)
Alternatively, the laminate is placed in a rubber bag, for example, and the rubber bag is connected to an exhaust system, and the temperature is increased while reducing the suction pressure so that the pressure is reduced to about −400 to −750 mmHg (absolute pressure: 360 to 10 mmHg). A method of pre-press bonding at about 50 to 100 ° C. (vacuum degassing method) or the like is employed.

Next, the pre-compressed laminate is subjected to full-compression bonding under a condition of, for example, a temperature of about 120 to 150 ° C. and a pressure of about 10 to 15 kg / cm ² by an ordinary method using an autoclave or a press. Manufactured.

The glass plate is not limited to an inorganic glass plate, but may be an organic glass plate such as a polycarbonate plate or a polymethyl methacrylate plate, or a combination of an inorganic glass plate and an organic glass plate. Is also good. The laminated structure of the laminated glass is not limited to the usual three-layer structure of a glass plate / intermediate film / glass plate.
It may have a multilayer structure such as an interlayer / glass plate / interlayer / glass plate.

[0037]

The interlayer film for laminated glass according to the present invention is an intermediate film for laminated glass in which a large number of embosses having fine irregularities are formed on both surfaces of a thermoplastic resin sheet. Therefore, in the pre-compression bonding step at the time of processing the laminated glass, even if the embossed surface is crushed by heat or pressure, the continuous groove shape of the concave portion remains until the final stage. Therefore, sufficient degassing can be performed.

Further, in the interlayer film for laminated glass according to the present invention, the embossed convex portion with respect to the embossed concave portion has a divided portion, and the bottom of the groove shape of the divided portion is a continuous groove shape of the embossed concave portion. Since it is not at the same level as the bottom side of the above, by controlling the groove shape of the dividing portion of the embossed convex portion, it is possible to improve the sealing property at the time of processing the laminated glass. Further, by controlling the groove shape of the dividing portion of the embossed convex portion, it is possible to easily and efficiently cope with various processing conditions of various users.

[0039]

BEST MODE FOR CARRYING OUT THE INVENTION The present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 D was used as a thermoplastic resin sheet.
X membrane (manufactured by Sekisui Chemical Co., Ltd.) was used.

Triangular oblique line type oblique line mill (75 mesh,
80 depth, manufactured by Yuri Roll Co., Ltd.) and a pair of rolls consisting of a metal roll whose surface is milled and a rubber roll having a JIS hardness of 45 to 75 are used as an uneven transfer device. Through the transfer device, a groove shape was formed on one surface of the DX film, in which the embossed concave portion was a continuous groove shape. The transfer conditions at this time were as follows. DX film temperature: normal temperature, roll temperature: 140 ° C, linear velocity: 1
0m / min, press linear pressure: 25Kg

Next, a triangular oblique hatching mill (75 mesh, 80 de) which is opposite to the above triangular oblique oblique mill.
pth, manufactured by Yuri Roll Co., Ltd.) and a pair of rolls consisting of a metal roll whose surface is milled and a rubber roll having a JIS hardness of 45 to 75 are used as a concave / convex shape transfer device, and a groove is formed on the one surface. The DX film provided with the mark was passed through this uneven shape transfer device to provide a grid-like divided portion on the continuous embossed convex portion. The transfer conditions at this time were as follows. DX film temperature: normal temperature, roll temperature: 110 ° C, linear velocity: 1
0m / min, press linear pressure: 20Kg

Next, the same operation as described above is performed on the other surface of the DX film to form an embossed concave portion having a continuous groove shape and an embossed convex portion having a dividing portion. An intermediate film was obtained.

(Example 2) A continuous groove shape was formed in the same manner as in Example 1 except that the transfer conditions when the continuous embossed projections were provided with the grid-like divided portions were as follows. An interlayer film for laminated glass was obtained in which an embossing composed of an embossed concave portion and an embossed convex portion having a dividing portion was formed on both surfaces. DX film temperature: normal temperature, roll temperature: 120 ° C, linear velocity: 1
0m / min, press linear pressure: 20Kg

(Example 3) The transfer conditions when the embossed concave portion was formed into a continuous groove shape were as follows: DX film temperature: normal temperature, roll temperature: 120 ° C, linear speed: 1
0 m / min, press linear pressure: 25 Kg Continuous groove shape in the same manner as in Example 1 except that the transfer conditions when a lattice-shaped cut portion was applied to a continuous embossed convex portion were as follows: An interlayer film for laminated glass was obtained in which an embossing composed of an embossed concave portion having an embossed portion and an embossed convex portion having a dividing portion was formed on both surfaces. DX film temperature: normal temperature, roll temperature: 130 ° C, linear velocity: 1
0m / min, press linear pressure: 20Kg

(Comparative Example 1) An embossed concave portion having a continuous groove shape and a divided portion were provided in the same manner as in Example 1 except that the continuous embossed convex portion was not provided with a lattice-shaped divided portion. An interlayer film for laminated glass was obtained in which an embossed portion having no embossed projections was formed on both sides.

Performance of four types of interlayer films for laminated glass obtained in Examples 1 to 3 and Comparative Example 1１Average surface roughness (R
z), film sliding property, blocking resistance, and bake test were evaluated by the following methods. The results were as shown in Table 1.

Average Surface Roughness (Rz) Digital type stylus electric surface roughness meter (trade name “S
E-2000 "(manufactured by Kosaka Laboratory Co., Ltd.) using a conical stylus (tip radius of curvature 5 μm, apex angle 90 °) and JIS.
The ten-point average surface roughness {Rz (μm)} of the interlayer film was measured according to B-0601.

The intermediate film cut into 50 cm × 50 cm is placed horizontally on a glass plate having a smooth surface (50 cm × 50 cm).
A sliding glass plate (length 10 cm × width 10 cm × thickness 2.5 mm) was placed thereon, and after 30 seconds, the sliding glass plate was pulled horizontally by a spring balance, and the maximum frictional resistance was measured from the reading of the spring balance. . The measurement was performed five times, and the average value was defined as the maximum frictional resistance (g). The measurement was performed in an atmosphere of 20 ° C. and 40% RH. The smaller the maximum frictional resistance, the better the slipperiness between the glass plate and the interlayer, the easier the positioning of the glass plate and the interlayer during the laminated glass processing, and the better the handling workability.

Blocking Resistance Two interlayer films cut to 15 cm × 15 cm are superimposed, a 13 kg weight is placed thereon, and the resultant is left to stand at room temperature for 24 hours. Then, a pulling speed of 500 mm / min is measured using a tensile tester. Was used to perform a 180-degree angle peel test, and the peel force was measured. The measurement was performed five times, and the average value was defined as the peeling force (g). The smaller the peeling force, the more difficult it is for the interlayer films to adhere to each other, the better the blocking resistance, and the better the handling workability during storage or when the interlayer film is sandwiched between glass plates.

Bake test After pre-compression bonding was performed by the following two methods {(a) handling deaeration method and (b) reduced pressure deaeration method>, final compression bonding was performed to produce a laminated glass.

(A) Handling and deaeration method The interlayer film is made of two transparent float glass plates (length 30 cm ×
30cm wide x 2mm thick, 1mm around the central part
(A curved glass), cut off the protruding portion, and place the thus obtained laminate in a heating oven at a temperature (preliminary compression temperature) of the laminate of 60 ° C. and 70 ° C., respectively.
And heated to 80 ° C., then a nip roll (air cylinder pressure 3.5 kg / cm ² , linear velocity 10 m
/ Min) to perform pre-compression bonding.

(B) Vacuum degassing method The interlayer film is made of two transparent float glass plates (length 30 cm ×
30cm wide x 2mm thick, 1mm around the central part
Between the curved glass), cut off the protruding part, transfer the resulting laminate into a rubber bag,
The rubber bag is connected to a suction decompression system, heated at the outside air heating temperature and simultaneously with -600 mmHg (absolute pressure 160 mmH
After holding the laminate under the reduced pressure of g) for 10 minutes and heating the laminate to a temperature (preliminary pressure bonding temperature) of 60 ° C., 80 ° C., and 100 ° C., respectively, the pressure was returned to the atmospheric pressure, and the preliminary pressure bonding was completed.

Each of the laminates preliminarily pressed by the methods (a) and (b) was heated at a temperature of 14 ° C. in an autoclave.
After maintaining the temperature at 0 ° C. and the pressure of 13 kg / cm ² for 10 minutes, the temperature was lowered to 50 ° C. and returned to the atmospheric pressure to complete the final pressure bonding, thereby producing a laminated glass.

The laminated glass obtained above was heated in an oven at 140 ° C. for 2 hours. Next, after taking out from the oven and allowing to cool for 3 hours, the appearance of the laminated glass was visually observed, the number of foams (bubbles) generated in the laminated glass was examined, and the degassing property and sealing property were evaluated. The number of test sheets was 100. The smaller the number of foamed laminated glasses, the better the degassing and sealing properties.

[0056]

[Table 1]

As is evident from Table 1, the interlayer films for laminated glass of Examples 1 to 3 according to the present invention were all excellent in film sliding property and blocking resistance. This indicates that the handling workability during storage and processing of laminated glass is excellent.

Further, the laminated glasses of Examples 1 to 3 produced using the interlayer films for laminated glass of Examples 1 to 3 according to the present invention were subjected to the respective pre-compression temperatures in the handling degassing method and the respective pressure bonding in the vacuum degassing method. For any of the pre-compression bonding temperatures, the number of foams due to air bubbles during the bake test (defective number)
Was few. This indicates that the deaeration and sealing properties in the pre-compression bonding step were excellent.

On the other hand, the laminated glass of Comparative Example 1 produced using the interlayer film for laminated glass of Comparative Example 1 in which the embossed convex portion was not provided with the cut portion was subjected to the deaeration method and the deaeration method under reduced pressure. When the pre-compression bonding temperature was low, the number of foams (defective number) due to bubbles during the bake test was large. This indicates that there was a problem in the sealing property in the pre-compression bonding step, and thus the degassing was insufficient. It also shows that there are restrictions on the manufacturing conditions in the pre-compression bonding step.

[0060]

As described above, the interlayer film for laminated glass according to the present invention has excellent handling workability during storage and processing of laminated glass, and also has excellent deaeration and sealing properties in the pre-compression bonding step. It is suitable for obtaining a high-quality laminated glass which hardly causes poor quality due to the generation of the glass.
Further, it is possible to easily and efficiently cope with various processing conditions of various users. Therefore, the laminated glass produced using the above-mentioned interlayer film is of high quality and is suitably used for window glasses of automobiles, vehicles, aircraft, buildings and the like.

[0061]

[Brief description of the drawings]

FIG. 1 is a perspective view showing an embossed pattern of an interlayer film for laminated glass according to the present invention.

FIG. 2 is a plan view showing an embossed pattern of an interlayer film for laminated glass according to the present invention.

[Explanation of symbols]

 1 Groove shape of embossed concave portion 2 Divided portion of embossed convex portion 3 Depth of groove of divided portion of embossed convex portion

Claims (5)

[Claims] 1. An intermediate film for laminated glass in which a large number of fine embossments having fine irregularities are formed on both surfaces of a thermoplastic resin sheet, at least one of the embossed concave portions has a continuous groove shape. Wherein the embossed convex portion has a dividing portion, and the bottom of the groove shape of the dividing portion is not at the same level as the bottom of the continuous groove shape of the embossed concave portion. 2. The interlayer film for laminated glass according to claim 1, wherein the groove shape of the embossed concave portion and the groove shape of the divided portion of the embossed convex portion are lattice-shaped. 3. The interlayer film for laminated glass according to claim 1, wherein the groove shape of the embossed concave portion and the groove shape of the divided portion of the embossed convex portion are random. 4. The interlayer film for laminated glass according to claim 1, wherein the depth of the groove of the dividing portion of the embossed convex portion is constant. 5. The method according to claim 1, wherein the depth of the groove of the dividing portion of the embossed convex portion is a random depth.
The interlayer film for laminated glass according to 1.