JPH09164592A - Manufacture of embossed sheet - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve thickness accuracy and to reduce the coefficient of contraction. SOLUTION: When an embossed pattern is transferred to a resin 10 film extruded in a molten state from a mold 11 with cooling, the resin 10 is pressed between an embossing roll 12 and a receiving roll 15 to apply linear pressure, surface pressure is applied by an endless metal belt, the resin 10 is cooled, and an embossed pattern is transferred.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing an embossed sheet having an embossed shape on both sides or one side, which is suitable for an interlayer film for laminated glass.

[0002]

2. Description of the Related Art A laminated glass in which an adhesive intermediate film made of a plasticized polyvinyl butyral resin or the like is sandwiched between two transparent glass plates has a large strength, is hard to be broken, and even if broken, fragments are not scattered. Glass material,
2. Description of the Related Art Conventionally, it has been widely used for transportation equipment such as automobiles and airplanes or window glass of buildings and the like.

[0003] The interlayer film used for such a laminated glass is free from a so-called blocking phenomenon in which the interlayer films adhere to each other to form a block during storage, and has good workability when laminating the glass and the interlayer film. , And good deaeration in the pre-compression bonding step. As an intermediate film satisfying this requirement, a resin film generally called an embossed sheet is used. The embossed sheet is formed by providing a large number of fine irregularities called embossed on both surfaces or one surface of a resin film.

A method of manufacturing an embossed sheet is disclosed, for example, in Japanese Patent Laid-Open No. 3-284935. In this method, as shown in FIG. 4, the film-shaped molten resin 40 extruded in a sheet form from the mold 41 is drawn into the water bath 43 by the take-up roll 44 and cooled, and then the draining roll 4
In this method, the sheet surface is heated by guiding it to the heating roll 47 via 6, and the embossed shape is transferred to the sheet surface by the embossing rolls 42 and 45.

Further, Japanese Patent Laid-Open No. 61-154919 discloses that
A method of generating a melt fracture with a lip of a mold to give an embossed shape is disclosed, and Japanese Patent Publication No. 57-326.
No. 55 discloses a method of imparting an embossed shape with a melt fracture of a lip of a mold on one side and a roll on the other side.

[0006]

However, Japanese Patent Laid-Open Publication No. Hei 3-2
In the technique disclosed in No. 84935, when the temperature accuracy of the cooling water bath is not sufficient, the thickness accuracy of the embossed sheet deteriorates due to deformation during cooling. In addition, there is a problem that stress is accumulated due to deformation caused during cooling and solidification and during transfer of the embossed shape, and the heat shrinkage rate increases.

Further, in the techniques disclosed in Japanese Patent Laid-Open No. 61-154919 and Japanese Patent Publication No. 57-32655, since the melt fracture at the lip of the mold is used, there is a problem that the degree of freedom of shape is small. there were.

The present invention has been made in view of the above problems, and an object of the present invention is to provide a method capable of producing an embossed sheet having high thickness accuracy and low heat shrinkage at a high transfer rate. To do.

[0009]

As a result of intensive studies to solve the above problems, it was found that the problems can be solved by simultaneously cooling and giving an embossed shape, and completed the present invention. .

That is, according to the first aspect of the invention, when the embossed shape is transferred to the film-shaped resin extruded in a molten state from the mold while being cooled, the resin is pinched and linear pressure is applied to the surface of the resin. Provided is a method for producing an embossed sheet, which comprises applying pressure to transfer the embossed shape.

Further, according to the invention of claim 2, the film-shaped resin extruded in a molten state from the mold is embossed with at least two belts arranged along the outer peripheral surface of the embossed roll. It is supplied between the endless metal belt guided along the outer peripheral surface of the embossing roll by the guide roll, and the embossed shape is imparted to one side while being pressed and cooled by the embossing roll and the endless metal belt, and further, Provided is a method for manufacturing an embossed sheet, which comprises applying an embossed shape to the other surface by sandwiching the embossing roll with another embossing roll.

Further, in the invention according to claim 3, the film-shaped resin extruded in a molten state from the mold is embossed with at least two belts arranged along the outer peripheral surface of the embossed roll. It is supplied between an embossing endless metal belt guided by an induction roll along the outer peripheral surface of the embossing roll, and is pressed by the embossing roll and the endless metal belt to cool and give an embossed shape to both surfaces. Provided is a method for manufacturing an embossed sheet.

In any of the above inventions, the surface of the belt and the roll is provided with a shape obtained by reversing the desired embossed shape, so that the degree of freedom in shape can be satisfied. Also, the transferability is improved by holding the pressure by the surface pressure.

[0014]

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates using FIG. 3 and FIG.

As an embodiment corresponding to claim 1,
After extruding the thermoplastic resin into a film form in a molten state from the mold, apply linear pressure to the thermoplastic resin with a take-up device, apply surface pressure before the linear pressure reaches 0, and emboss the thermoplastic resin. There is a method in which the thermoplastic resin is cooled at the same time as the above-mentioned, and the deformation of the film is prevented and the embossed shape is fixed.

When no surface pressure is applied, the resin in the semi-molten state is deformed in the machine direction by the tension, and distortion occurs.
Further, when the linear pressure becomes zero, the shape of the resin becomes smaller than the shape of the mold due to elastic recovery of the resin and cooling shrinkage (so-called sink mark generation). On the other hand, when the linear pressure is applied and the strong pressure is not applied to the resin, the resin does not sufficiently flow into the embossed mold and the emboss formation is insufficient.

In the present invention, the linear pressure, the surface pressure and the cooling conditions are set appropriately. The mechanism for applying the linear pressure and the surface pressure may be either a roll and a belt or a belt and a belt, and a method of pinching is particularly suitable. Further, the surfaces of the belt and the roll have a mirror surface or an embossed shape depending on the application, and the manufacturing method thereof is not particularly limited.

Next, as an embodiment corresponding to claim 2, a thermoplastic resin is extruded in a film state in a molten state from a mold, and then sandwiched between an embossing roll and an endless metal roll to form a thermoplastic resin. There is a method of imparting an embossed shape to one surface of the resin and cooling the same at the same time, and thereafter, sandwiching the thermoplastic resin between the embossing roll and another embossing roll to finally impart the embossed shape to both surfaces.

Next, as an embodiment corresponding to claim 3, a thermoplastic resin is extruded in a film state in a molten state from a mold, and then, between the embossing roll and the endless metal roll provided with the embossing shape. There is a method in which both sides of the thermoplastic resin are clamped by applying an embossed shape and then cooled at the same time.

FIG. 1 is an explanatory view showing an example of an embodiment corresponding to claims 1 and 2. In this example, the mold 11, the embossing roll 12, the endless metal belt 1
3 and the belt guide roll 14 and the take-up roll 15 that guide the rolls 3 are the main components.

In this structure, the resin 10 extruded in a film form in a molten state from the die 11 is pinched by the embossing roll 12 and the take-up roll 15 to apply a linear pressure to the circumference of the embossing roll 12. To move. Also,
The resin 10 is cooled while being pinched between the endless metal belt 13 guided by the belt guiding roll 14 and the embossing roll 12, and the surface on the embossing roll 12 side is given an embossed shape.

FIG. 6 is an explanatory view showing another example of the embodiment corresponding to claim 1. In this example, the mold 6
1. Endless embossed metal belt 63 with embossing
The main components are a belt guide roll 62 for guiding it, an endless metal belt 64, a belt guide roll 65 for guiding it, and a take-up roll 66.

In this construction, the resin 60 extruded in a film form in a molten state from the mold 61 is pinched by the endless embossed metal belt 63 and the take-up roll 66 to give a linear pressure, while the endless embossed metal belt is applied. It is pinched by 63 and the endless metal belt 64, cooled, and an embossed shape is given to the surface of the endless embossed metal belt 63 side.

FIG. 2 is an explanatory view showing an embodiment corresponding to claims 1 and 2. In this example, the mold 21, the embossing rolls 22 and 55, the endless metal belt 2
3 and the belt guide roll 24 for guiding it are main components.

In this structure, the resin 20 extruded in a film form in a molten state from the mold 21 is pinched by the embossing rolls 22 and 25 to give a linear pressure, while the embossing roll 22 and the endless metal belt 23 are Clamped by
While being cooled, an embossed shape is given to the surface of the embossing roll 22 side. Resin 20 is further embossing roll 2
It is pinched between 2 and 25, and the embossed shape is also given to the surface on the embossing roll 25 side.

FIG. 3 is an explanatory view showing another example of the embodiment corresponding to claim 3. The basic structure of this example is a mold 3
1, embossing roll 32, endless embossing metal belt 33
The belt guide roll 34 and the take-up roll 35 that guide the rolls are the main components.

In this structure, the resin 30 extruded in a film form in a molten state from the mold 31 is guided by the belt guide roll 34 while being pinched by the embossing roll 32 and the take-up roll 35 to give a linear pressure. It is pressed between the endless embossed metal belt 33 and the embossing roll 22 and cooled, and at the same time, both sides are embossed.

The die used in the present invention is not particularly limited as long as it is a flat die capable of extruding a resin in a film shape, and a die such as a T die, a coat hanger die or a fish tail die is used.

The resin used in the present invention is not particularly limited as long as it is a thermoplastic resin, and it is a vinyl chloride resin, an acrylic resin, a polyester resin, an olefin resin, a butyral resin, a polycarbonate resin, a polyimide resin. Etc. can be used.

The embossing roll used in the present invention may be any one as long as the metal roll has an embossed shape, and the embossing method may be any method including general methods such as engraving, corrosion and sandblasting. good. In addition, the roll surface is plated, ceramic treated,
It may be coated with silicon or Teflon. Further, it is preferable that the temperature can be controlled, and the control method is not particularly limited.

The endless metal belt used in the present invention may be in the form of a loop, and for example, both ends of the metal belt may be connected by welding or the like. The surface may be mirror-finished or satin-finished without any problem, and may be subjected to various treatments such as plating, ceramics, silicon coating, and Teflon coating.

The belt guide roll used in the present invention is
The rolls are arranged to guide the endless metal belt, and at least two rolls are arranged along the outer peripheral surface of the embossing roll. The belt guide roll also has a function of adjusting the temperature of the belt, and its adjusting method is not particularly limited. Two belt guide rolls with this temperature adjustment function
By arranging more than one along the outer peripheral surface of the embossing roll and running the endless metal belt along the outer peripheral surface of the embossing roll, the thermoplastic resin film supplied between the embossing roll and the endless metal belt is Since it is cooled in a state of being sandwiched by, the deformation of the film during cooling is prevented.

The endless embossed metal roll used in the present invention may be, for example, a loop-shaped one in which both ends of a metal belt are connected by welding or the like, and the surface of which has an embossed shape. The embossing method and the belt surface treatment may be the same as those of the embossing roll.

The take-up roll used in the present invention may be an ordinary metal roll and is not particularly limited.

The pressure of the pinching portion between the embossing roll and the endless (embossing) metal belt, between the embossing rolls, or between the embossing roll and the take-up roll is appropriately set depending on the application of the embossing sheet to be manufactured. The temperature of the belt is also set appropriately.

[0036]

EXAMPLES Next, examples and comparative examples of the present invention will be shown. In addition, in the following Examples and Comparative Examples, the resin having the composition shown in Table 1 (hereinafter referred to as “PVB”) was used.

[Table 1]

The evaluation items and evaluation methods are as follows. (Thickness accuracy) Anritsu contact thickness gauge (K306C)
Was used to measure the thickness in the width direction, and the maximum value of the (maximum value-minimum value) in the width of 150 mm was adopted. (Heat Shrinkage) A sample having a width of 100 mm and a length of 1100 mm was immersed in warm water at 50 ° C. for 10 minutes, and the dimensional change rate was measured. (Surface roughness) ISO 3274 10-point average surface roughness R _Z
Was used. (Distortion level) Distortion is a phenomenon in which the subject appears distorted, and it is better that the distortion level has a smaller number. Laminated glass produced using the embossed sheets of Examples and Comparative Examples was placed at a position of 5 m away from a mercury fluorescent lamp at an inclination of 20 degrees, and a projected image was projected on a screen. 91% and haze value 0.4%) were set as 100 and relative evaluation was carried out. The relationship between the brightness and the distortion level is as shown in Table 2.

[Table 2]

(Example 1) With the apparatus configuration shown in FIG. 1, PVB was extruded with a T die having a width of 1500 mm and a lip gap of 2.5 mm at an extrusion temperature of 200 ° C., and the PVB film surface temperature at the time of peeling from the endless metal belt. (Both sides) 130 ° C., PVB film surface temperature after embossing on both sides (both sides) 10
0 ℃, roll pressure 40kg / cm, belt pressure 2kg
/ Cm ² , embossing roll embossing roughness R _Z = 40μ
m, and a drawdown rate (ratio of product thickness and die lip gap) of 4, an embossed shape was imparted while cooling. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

(Example 2) According to the apparatus configuration shown in FIG. 2, PVB was extruded with a T die having a width of 1500 mm and a lip gap of 2.5 mm at an extrusion temperature of 200 ° C., and the PVB film surface temperature at the time of peeling from the endless metal belt. (Both sides) 120 ° C., PVB film surface temperature after embossing on both sides (both sides) 10
0 ℃, roll pressure 40kg / cm, belt pressure 2kg
/ Cm ² , embossing roll embossing roughness R _Z = 40μ
An embossed shape was applied while cooling under the conditions of m and drawdown rate of 4. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

(Example 3) With the apparatus configuration shown in FIG. 3, PVB was extruded with a T die having a width of 1500 mm and a lip gap of 2.5 mm at an extrusion temperature of 200 ° C., and the PVB film surface was peeled from the endless embossed metal belt. Temperature 100 ° C, roll line pressure 40 kg / cm, belt pressure 2 kg / c
The embossed shape was imparted while cooling under the conditions of m ² , embossing roll and endless embossing metal belt embossing roughness R _Z = 40 μm, and drawdown rate 4. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

(Embodiment 4) With the apparatus configuration shown in FIG. 6, PVB was extruded with a T die having a width of 1500 mm and a lip gap of 2.5 mm at an extrusion temperature of 200 ° C., and the PVB film surface temperature at the time of peeling from the endless metal belt. (Both sides) 100 ° C, roll part linear pressure 40 kg / cm, belt pressure 2 kg / c
m ² , embossed roughness R _Z = 40 of the endless embossed metal belt
An embossed shape was imparted while cooling under conditions of μm and drawdown rate (ratio of product thickness and die lip gap) 4. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

(Comparative Example 1) According to the apparatus configuration shown in FIG. 4, PVB was extruded with a T die having a width of 1500 mm and a lip gap of 3.5 mm at an extrusion temperature of 200 ° C. and introduced into a water bath 43 at a water temperature of 50 ° C. to be cooled. . The drawdown rate at this time was set to 2.5. Next, the surface temperature 1 with the heating roll 47
It was heated to 10 ° C., embossing roughness R _Z = 40 [mu] m roll unit line by embossing rolls 42 and 45 of the pressure 50 kg /
Embossed in cm. At this time, the surface temperature of the PVB film after giving the embossed shape was controlled to 90 ° C. Further, the draw ratio when the embossed shape was applied was 2 times. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

(Comparative Example 2) As shown in FIG.
1, embossing rolls 52 and 55, endless metal belt 53
And a belt guide roll 54 for guiding the endless metal belt 53 as a main component, and only one belt guide roll 54 is provided along the outer peripheral surface of the embossing roll 52, and the other two are arranged at other positions. Except for the above, the PVB film surface temperature (both sides) 130 at the time of exfoliation from the endless metal belt by extruding PVB with a T-die having a width of 1500 mm and a lip gap of 2.5 mm at an extrusion temperature of 200 ° C by the same apparatus configuration as in FIG. ℃, PVB film surface temperature after embossing on both sides (both sides) 100 ℃, roll part linear pressure 40kg / c
m, belt pressure 0 kg / cm ² , embossing roll embossing roughness R _Z = 40 μm, drawdown rate 4
The embossed shape was imparted while cooling. The thickness accuracy, heat shrinkage ratio, distortion level and surface roughness of the resulting sample were evaluated.

The evaluation results are shown in Table 3.

[Table 3]

[0045]

As described above, according to the present invention, when the molten film-shaped resin is cooled, the resin is prevented from being deformed by being pinched by the embossing roll and the endless metal belt, and high thickness accuracy is provided. To do. Further, by giving the embossed shape at the same time, the stress generated at the time of molding can be suppressed as much as possible, and an embossed sheet having a low heat shrinkage can be manufactured. Then, the transferability is also improved by maintaining the pressure by the surface pressure.

[Brief description of the drawings]

FIG. 1 is a configuration diagram of an apparatus used in Example 1 of the present application.

FIG. 2 is a configuration diagram of an apparatus used in Example 2 of the present application.

FIG. 3 is a configuration diagram of an apparatus used in Example 3 of the present application.

FIG. 4 is a configuration diagram of an apparatus used in Comparative Example 1.

5 is a configuration diagram of an apparatus used in Comparative Example 2. FIG.

FIG. 6 is a configuration diagram of an apparatus used in Example 4 of the present application.

[Explanation of symbols]

 10, 20, 30, 40, 50, 60 Resin 11, 21, 31, 41, 51, 61 Mold 12, 22, 25, 32, 52, 55 Embossing roll 13, 23, 63, 64 Endless metal belt 14, 24,34,62,65 Belt guide roll 15,35,66 Take-up roll 33,63 Endless embossed metal belt

Claims (3)

[Claims] 1. When transferring an embossed shape to a film-shaped resin extruded in a molten state from a mold while cooling the embossed shape, the resin is pinched to apply a linear pressure and a surface pressure is applied to transfer the embossed shape. A method for manufacturing an embossed sheet, comprising: 2. A film-shaped resin extruded in a molten state from a mold is embossed by an embossing roll and at least two belt guiding rolls arranged along the outer peripheral surface of the embossing roll. Supply between the endless metal belt guided along the surface, and after applying an embossed shape on one side while cooling by pressing with the embossing roll and the endless metal belt, further with the embossing roll and another embossing roll A method for manufacturing an embossed sheet, characterized in that the embossed shape is applied to the other surface by pinching with. 3. A film-like resin extruded in a molten state from a mold is embossed by an embossing roll and at least two belt guiding rolls arranged along the outer peripheral surface of the embossing roll. Supply between the embossed endless metal belt guided along the surface,
A method for producing an embossed sheet, which comprises applying an embossed shape to both surfaces while sandwiching and cooling with the embossing roll and an endless metal belt.