JPH08143345A - Intermediate film for laminated glass and production thereof and embossing roll - Google Patents

Abstract

PURPOSE: To remarkably reduce a generating rate of a deaeration failure represented by fine foaming at the time of producing a laminated glass. CONSTITUTION: In an intermediate film for the laminated glass having numerous fine embossment at least one surface, a roughness of the embossment is shown in a following condition. The condition: Rmax <=Rz ×1.5 (Rmax is the max. value of the roughness of the embossment and Rz is an average value of the roughness of the embossment.).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an interlayer film for laminated glass, a method for producing the same, and an embossing roll.

[0002]

2. Description of the Related Art Conventionally, between two transparent glass plates,
Laminated glass formed by sandwiching an adhesive intermediate film typified by a plasticized polyvinyl butyral resin has an excellent feature that it has high strength and is hard to break. For example, transportation equipment such as an automobile or an aircraft, or a building. Widely used for window glass.

When manufacturing such a laminated glass, an interlayer film made of an adhesive thermoplastic resin is inserted between two glass plates, and the obtained laminated body is pre-compressed to remain between the layers. After deaeration of the air to be used, main compression bonding is performed to completely adhere the laminate.

The interlayer film used for laminated glass does not cause a so-called blocking phenomenon, which is a phenomenon in which the interlayer films adhere to each other during storage and form a lump, and the workability in stacking the glass plate and the interlayer film is good. In addition, it is required that the degassing property in the pre-pressing process is good. In particular, the degassing property in the pre-compression bonding step influences the quality of the laminated glass, and if degassing failure occurs, the resulting laminated glass may have poor transparency, or bubbles may occur when an accelerated test is performed. is there.

The overall performance of the interlayer film including degassing properties as described above depends on the type of the thermoplastic resin as the material and the physical properties such as viscoelasticity. The surface shape of the is a major factor in determining its overall performance.

Particularly, it is known that it is effective to form a large number of fine irregularities called embosses on the surface of the intermediate film, and conventionally, an intermediate film having the embossed surface is used. As the form of the emboss, for example,
There are those in which irregularities having random sizes and shapes are formed, those in which a large number of grid-like grooves are formed, and the like.

As a method of forming such an emboss on the surface of an intermediate film, for example, in JP-A-62-52148, adjustment of roughness of emboss (main, fine) and pitch (interval between convex portions). Is disclosed. Further, in JP-A-5-294679, a large number of irregularities are formed on the surface of an embossing roll in advance, and further fine irregularities are shot and imparted to the surface of the roll, and the embossing thus obtained. A method of forming embosses on the surface of an intermediate film by using a roll is disclosed.

[0008]

In the conventional laminated glass, extremely deep valleys may be formed in the fine embosses. If the interlayer film is used for the bonding process, the delamination in the pre-compression bonding step may occur. There was a problem of bad temper.

The deep valleys as described above occur because embossing is applied to the intermediate film by using an embossing roll having extremely high protrusions on the roll surface. That is, during processing of the embossing roll itself, after forming the main irregularities on the embossing roll surface by a mother mill, by the shot blasting method, when imparting finer irregularities,
Large protrusions are formed on the roll surface, such as the blasting material biting into the roll surface and "rollback" of the roll itself occurring. Therefore, when fine embossing is applied to the surface of the intermediate film by using the embossing roll thus processed, the large protrusions may be transferred at the same time, and a deep recess may be formed on the surface of the intermediate film.

As a result, in the laminated glass using such an intermediate film, in the pre-compression bonding step, when the deep recess formed on the surface of the intermediate film is located at the central portion of the glass, the degassing property becomes less problematic. However, if it is accidentally located at the edge of the laminated glass, defective deaeration such as defective sealing and residual air occurs at a rate of several percent.

The present invention solves the above problems.
An object of the invention is to provide an interlayer film for laminated glass in which the occurrence rate of degassing failure represented by fine foaming is greatly reduced during the production of laminated glass, a method for producing the same, and an embossing roll used for the same. To do.

[0012]

As a result of intensive studies, the inventors of the present invention achieved the above object when the roughness of the emboss formed on the surface of the interlayer film for laminated glass meets specific conditions. The present invention has been completed and the present invention has been achieved.

That is, the present invention provides an interlayer film for laminated glass, which has a large number of fine embosses on at least one surface, characterized in that the roughness of the emboss is as follows. . Condition: Rmax ≦ Rz × 1.5 (where Rmax is the maximum value of embossed roughness, and Rz is the average value of embossed roughness.)

The emboss roughness referred to here is the depth or height of the emboss formed of a large number of fine irregularities formed on the surface of the intermediate film. The above Rmax is JI
It represents the maximum height described in SB0601, and is the value of the distance between two straight lines when sandwiching the extracted part with two straight lines parallel to the average line of the part extracted by the reference length from the sectional curve. . In addition, the above Rz is JIS B0601.
Represents the 10-point average roughness described in, in the portion extracted by the reference length from the sectional curve, parallel to the average line, and
From the straight line that does not cross the cross-section curve to the longitudinal magnification direction, the average of the highest to fifth peaks and the maximum depth is 5
It is the value of the difference from the average elevation of the valley bottom up to the third.

The present invention also provides an embossing roll having no convex portion on the roll surface, the convex portion having a height exceeding 1.5 times the average height of the irregularities formed on the roll surface.

Furthermore, the present invention is for laminated glass using an embossing roll having no convex portion on the roll surface, the convex portion having a height of more than 1.5 times the average value of the height of the irregularities formed on the roll surface. Provided is a method for producing an interlayer film for laminated glass, which comprises a step of applying embossing to the surface of the interlayer film.

In the above-mentioned method for producing an interlayer film for laminated glass, more specifically, at the time of embossing roll processing, the surface of the embossing roll finely engraved by the shot blasting method is further precision-polished with a grinding stone for several μm. The process may be included.

The shape of the emboss formed on the surface of the interlayer film is not particularly limited, and various shapes such as a cone, a pyramid, a pseudo-pyramid, a prism, and a cone can be adopted. There are various embossing arrangements such as regular ones and random ones, and there is no particular limitation. However, considering that the optical distortion phenomenon due to interface disorder is unlikely to occur, the embossing arrangement is regular. It is preferable that the target

Further, a conventionally known method is used to manufacture a laminated glass using the thus obtained interlayer film for a laminated glass. For example, the above interlayer film is sandwiched between two transparent inorganic glass plates or an organic glass plate such as a polycarbonate plate having a high rigidity or a polymethylmethacrylate plate, and this is put in a rubber bag and suctioned under reduced pressure for about Pre-compression bonding at 70 to 110 ° C, then using an autoclave or a press molding machine at a temperature of about 120 to 150 ° C for about 10 to 15
Laminated glass is manufactured by performing full pressure bonding with a pressure of kg / cm ² .

[0020]

In the present invention, the roughness of a large number of fine embosses provided on the surface of the interlayer film for laminated glass has a maximum value (Rmax) within 1.5 times the average value (Rz). . That is, since there is no extremely deep valley on the film surface, the use of such an intermediate film can significantly reduce the degassing failure.

Further, the intermediate film having no such extremely deep valleys on the surface has a convex portion having a height exceeding 1.5 times the average height of the irregularities formed on the roll surface. It is manufactured using an embossing roll that does not exist on the roll surface.
Such an embossing roll can be obtained, for example, by shot a blast material on the surface of the embossing roll during the embossing roll processing and then precision-polishing the roll surface by several μm with a grindstone. As a result, the maximum value of the depth of the recesses on the roll surface falls within 1.5 times the average value, and as in the conventional case, the blast material bites into the roll surface or "return" of the roll itself occurs. The extremely high protrusions formed do not exist. Therefore,
If a fine emboss is applied to the surface of the intermediate film using this embossing roll, the intermediate film for laminated glass as described above can be manufactured.

[0022]

EXAMPLES Examples and comparative examples of the present invention will be shown below.
The present invention will be described in more detail, but the present invention is not limited to these examples.

(Example 1) While rotating a mother mill having protrusions substantially equivalent to the protrusions of the interlayer film for laminated glass to be produced, the irregularities corresponding to the protrusions were pressure-transferred onto the rotating embossing roll, An embossing roll was manufactured. At this time, the average value of the roughness of the irregularities on the surface of the embossing roll was 30.0 μm.

Further fine irregularities were formed on the roll surface by the shot blast method. As a result of measuring the roughness of the embossing at this time with a stylus type roughness meter, the average value was 3
It was 5.5 μm. Further, the roll surface was precision-polished using a grindstone, and the average depth of the irregularities on the emboss roll surface was set to 34.5 μm.

The embossing roll thus obtained was used to emboss the interlayer film. When the average value and the maximum value of the roughness of the embossing of the obtained interlayer film were measured, the average value Rz was 30.4 μm, and the maximum value Rm
The ax was 44.2 μm. The above Rz and Rma
x was measured according to JIS B0601.

This intermediate film is sandwiched between two glass plates,
The obtained laminated body is passed through a heating oven and heated to 80 ° C., and then pre-compression bonding is performed by an ironing method using a nip roll, and then pressure is applied under conditions of 13 kg / cm ² and 130 ° C. After heating, it was gradually cooled to produce 1000 pieces of laminated glass. At this time, the occurrence rate of fine foaming was 0.
It was 2%.

(Embodiment 2) From the average value of the unevenness of the embossing roll surface of 35.5 μm by the shot blasting method, the roll surface was precision-polished with a grindstone, except that this was set to 32.0 μm. Embossing was applied to the interlayer film in the same manner as in Example 1. When the average value and the maximum value of the roughness of the embossing on the surface of the obtained interlayer film were measured, the average value Rz was 30.5 μm and the maximum value Rmax was 36.5 μm.
Met.

As a result of producing 1000 pieces of laminated glass by using this interlayer film in the same manner as in Example 1, no fine foaming occurred.

Comparative Example 1 Embossing was applied to the intermediate film in the same manner as in Example 1 except that precision polishing with a grindstone was omitted during the processing of the embossing roll of Example 1. The average value and the maximum value of the height of the protrusions on the surface of the obtained interlayer film were measured, and the average value Rz was 29.8 μm and the maximum value Rm.
The ax was 46.7 μm.

As a result of producing 1000 pieces of laminated glass using this interlayer film in the same manner as in Example 1, the occurrence rate of fine foaming was 5%.

The average value Rz and the maximum value Rz of the emboss roughness on the surface of the interlayer film in Examples 1 and 2 and Comparative Example 1 described above.
Table 1 collectively shows max and the occurrence rate of fine foaming of laminated glass using the same.

[0032]

[Table 1]

As can be seen from the obtained results, the maximum depth of the irregularities on the surface of the intermediate film in Example 1 or Example 2 of the present invention is within 1.5 times the average value. As a result, it can be seen that the occurrence rate of fine bubbles during the production of a laminated glass using the same is significantly reduced as compared with Comparative Example 1.

[0034]

As described above, according to the interlayer film for laminated glass, the method for producing the same and the embossing roll of the present invention,
The maximum value of the roughness of many fine embosses provided on the surface of the interlayer film is within 1.5 times the average value. That is, since there is no large unevenness on the film surface,
Degassing failure of laminated glass using such an intermediate film is
Significantly reduced. Further, after the blasting material is shot on the surface of the embossing roll, the roll surface is ground with a grindstone.
Further, by carrying out precision polishing for several μm, large protrusions do not exist on the roll surface. Therefore, if a fine emboss is applied to the surface of the intermediate film using this embossing roll, the surface of the intermediate film as described above can be manufactured. Therefore, it becomes possible for the interlayer film to form the ideal embossing that has been conventionally sought, and the incidence of degassing defects in laminated glass is greatly reduced, speeding up the manufacturing process line for laminated glass and labor saving. Can be achieved.

Claims (3)

[Claims] 1. An interlayer film for laminated glass, which has a large number of fine embosses on at least one surface, wherein the roughness of the embossment satisfies the following conditions. Condition: Rmax ≦ Rz × 1.5 (where Rmax is the maximum value of embossed roughness, and Rz is the average value of embossed roughness.) 2. An embossing roll having no protrusions on the roll surface, the protrusions having a height that exceeds 1.5 times the average height of the irregularities formed on the roll surface. 3. A method for producing an interlayer film for laminated glass, which comprises using the embossing roll according to claim 2.