JPS60156005A - Manufacture of laminated polarizing glass plates - Google Patents

Abstract

PURPOSE:To efficiently manufacture polarizing laminated glass plates large in area in a state of an adhesive free from any foam by coating two glass plates each with the adhesive uniformly in advance. CONSTITUTION:Two glass plates 1 are coated with a transparent adhesive 2, respectively on one side, and a polarizing sheet 3 is sandwiched with each adhesive-coated side. The sheet 3 is prepared by stretching a thin PVA film in one direction to arrange each chain molecule in parallel, dipping it into an alcohol soln. of iodine and uniformly attach iodine to both surfaces. In the stage of this operation, the molecules of iodine are adsorbed and aligned regularly at the intervals of about 0.13nm to the chain molecules, and imparted dichroism and polarizing ability. The obtained sheet 3 is placed between the two glass plates 1 both on the adhesive-coated sides and they are fed between a pair of rolls 4 and joined.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a method for manufacturing a polarizing laminated glass plate, and particularly to a technique for laminating a polarizing sheet between large area glass plates using an adhesive.

Background of the Invention With the spread of office computers, word processors, cameras, and home televisions, opportunities to view CRT (cathode ray tube) displays are increasing.
There have been complaints of eye fatigue and decreased vision. For this purpose, a suitable filter or the like is attached to the front of the CRT.

Prior Art However, most conventional filters of this kind have a structure in which a film is formed on a plastic plate that selectively absorbs light. As a result, diffused reflection tends to occur on the surface of the plastic plate, and the clarity of small figures and characters decreases, making it impossible to fully utilize the resolution of the CRT.

On the other hand, such a phenomenon of decrease in sharpness can be solved by using a glass polarizing plate. However, C.R.T.
It is difficult to manufacture a large glass polarizing plate that covers the entire screen. In other words, glass polarizing plates are usually made by interposing a polarizing sheet between two glass plates, but when the area becomes large, the bonding process between the two glass plates and the polarizing sheet becomes difficult. Adhesive bubbles remain on the mating surfaces, which causes a reduction in image quality. Due to these circumstances, the technology for small polarizing laminated lenses for eyeglasses and the like cannot be used as is for large polarizing plates.

OBJECTS OF THE INVENTION Accordingly, an object of the present invention is to establish a manufacturing technology for large-area polarizing glass laminated plates, thereby making it possible to efficiently manufacture large-area polarizing glass plates without bubbles in the adhesive. The purpose of this invention is to provide a manufacturing method.

Summary of the Invention Therefore, the present invention uses a pair of cylindrical rollers to bond two glass plates and a polarizing sheet with a transparent adhesive, and applies a predetermined pressure between the rollers to bond the two sheets together. The glass plate and polarizing sheet are sent out in a bonded state. Here, the speed and pressure at the time of feeding are determined with the aim of discharging bubbles of the adhesive to the outside, and are set in relation to the viscosity of the adhesive.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of the present invention will be specifically described below based on an embodiment shown in the drawings.

First, as shown in FIG. 1, a transparent adhesive 2 is uniformly applied to the bonding surfaces of two glass plates 1. Here, the thickness of the glass plate l is, for example, about 1 dragon, and its area is:
It is large enough to accommodate a 12-inch or larger cathode ray tube. For adhesive 2, prepare two types of transparent plastic-based photosensitive adhesives, mix them in an appropriate ratio, and have a viscosity of 400 to 550 ± 100 (CPS) at 25°C.
Used within the range of. Here, the upper limit of viscosity, that is, the maximum viscosity ηm
ax corresponds to a value that allows air bubbles to be discharged from the adhesive 2, and its lower limit, that is, the minimum viscosity ηmin, corresponds to a value that allows the adhesive 2 to remain on the bonded surface even during pressurization, which will be described later. are doing.

And between these, a polarizing sheet 3 is placed between each adhesive 2.
It is sandwiched in a state where it is in contact with. This polarizing sheet 3 is made by applying tension in one direction to a thin film of polyvinyl alcohol, for example, and aligning the chain molecules forming the film in parallel.
It is then soaked in an alcoholic solution of iodine to deposit iodine evenly on its surface. During this manufacturing process, the iodine atoms are distributed approximately 3.5 mm along the length of the chain molecule.
They are adsorbed in regular rows at intervals of one person, and it is only through this adsorption that dichroism appears and a polarization phenomenon occurs.

Subsequently, the two glass plates 1 in this bonded state and the polarizing sheet 3 between them are fed between a pair of rolls 4, as shown in FIG. The pair of rolls 4 are cylindrical, have an outer diameter of approximately 1303 mm, and have a surface thickness of 1 cIl.
It is provided with a rubber layer 4a of about 100 mL. These rolls 4 rotate to sandwich the two glass plates 1 and the polarizing sheet 3 between them, and send them out after a predetermined pressure is applied.

The pressing force P at this time is set to a value that allows bubbles inside to be discharged to the outside in relation to the viscosity η of the adhesive 2, within a range that does not break the two glass plates 1. The feed rate V at the time of levering is similarly determined in relation to the viscosity η of the adhesive 2. That is, if the feeding speed V is faster than a certain value and the pressing force P of the pair of rolls 4 is insufficient, the air bubbles formed inside the adhesive 2 will cause the two glass plates l and the polarizing sheet 3 to At the same time, it passes between a pair of rolls 4,
It will remain inside the product. However, if the pressing force P of the pair of rolls 4 and the feeding speed V thereof are set appropriately,
The air bubbles in the adhesive 2 are pushed by a pair of rolls 4, squeezed out between the glass plate 1 and the polarizing sheet 3, and finally pushed out to the end faces of the glass plate 1 and the polarizing sheet 3, and discharged to the outside. . As a result, the two glass plates 1 and the polarizing sheet 3 in a bonded state that have passed between the pair of rolls 4 do not contain any air bubbles from the adhesive 2.

Now, FIG. 3 shows the relationship between the pressing force P of the pair of rolls 4 and the feed rate ■. The maximum pressing force Pmax is the maximum value within a range that does not break the two glass plates 1, and the minimum pressing force Pwin is the maximum value that is effective without allowing air bubbles inside the adhesive 2 to pass between the pair of rolls 4. determined by the minimum value that can be discharged to the outside. Therefore, the pressurizing force P is the maximum pressurizing force P tnax and the minimum pressurizing force P min
Must be set within the range.

On the other hand, the feed speed V is directly related to the viscosity η of the adhesive 2. In other words, when the viscosity l of the adhesive 2 is high, it loses its fluidity, so the moving speed of the bubbles inside the adhesive 2 in the discharge direction does not follow the feed speed V, so that bubbles still form in the product. It will remain. Therefore, the feed rate V must be above the maximum viscosity ηmax and below the minimum viscosity ηmin on the graph. Note that the feed rate V is proportional to the pressing force P when the viscosity η is constant. After all, the pressurizing force P and the feed rate V must be set within the shaded range of the graph.

According to experiments by the patent applicant, the viscosity η of adhesive 2 is 450
The most ideal feed rate V was about 13 values per minute.

As mentioned above, the pressing force P of the pair of rolls 4 is
The feed rate V is determined in relation to the strength of the adhesive 2 and the residual air bubbles of the adhesive 2, and the feed rate V is determined in relation to the viscosity V in relation to the residual air bubbles. When an appropriate pressing force P and appropriate feeding speed V are determined in this manner, no bubbles in the adhesive 2 remain on the bonding surface after bonding. This was confirmed.

However, the specific numerical values of the pressing force P and the feed rate V vary depending on the strength of the glass plate 1 and the like. This method can also be applied to −dimensional curved surfaces.

Effect of the invention The present invention provides the following unique effects.

First of all, a pair of rolls can apply a uniform pressing force to the entire bonding surface of two large-area glass plates and a polarizing sheet, so that a large-area polarizing bonded plate can be produced efficiently without distortion. can be manufactured according to Secondly, the pressing force and feed speed of the pair of rolls are set in relation to the cracking of the glass plate and the viscosity of the adhesive, and are set within a range that does not leave adhesive bubbles on the product. No air bubbles remain, increasing light transmittance and preventing light from scattering due to diffuse reflection from air bubbles. Thirdly, such a large area polarized laminated glass plate. manufacturing capabilities,
4□Ah, Ai37/Wu device. 1 A polarizing plate can be attached to the front of the CRT, and as a result, the glare from the CRT's bright spot is eliminated, and eye fatigue and deterioration of visual acuity can be prevented even during long-term staring work.

[Brief explanation of the drawing]

Figure 1 is a side view of two glass plates and a polarizing sheet before they are pasted together, Figure 2 is a side view of the two glass plates when they are pasted together using a roll, and Figure 3 is a side view of two glass plates and a polarizing sheet before they are pasted together. It is a graph showing the relationship with viscosity. 1. Glass plate, 2. Adhesive, 3. Polarizing sheet, 4
··roll.

Claims (1)

[Claims] A transparent adhesive is applied to the bonded surfaces of two glass plates, a polarizing sheet is interposed between the two glass plates, and the glass plates and polarizing sheet are pressed between a pair of press rolls. During the feeding process, the feeding speed and pressing force are adjusted to 1. in relation to the viscosity of the adhesive. A method for producing a polarized laminated glass plate, characterized in that the adhesive is set within a range that allows air bubbles to be discharged.