JP2018167839A - Protective lamination / removal method for glass plate for light guide plate and method for manufacturing glass light guide plate - Google Patents

Abstract

An object of the present invention is to perform screen printing without transporting a glass plate for a light guide plate after transporting the glass plate for the light guide plate as a laminate with interleaf between each other, and during long-term storage, Provided is a method for protective lamination / removal of a glass plate for a light guide plate, which has less influence on the wettability of the glass plate for a light guide plate due to a difference in storage conditions. A plurality of glass plates for a light guide plate are laminated vertically by interposing a paper between them to form a glass laminate, and then the glass for the light guide plate in units of one piece from the glass laminate. A method for protecting a glass plate for a light guide plate to be taken out and taking out the plate, wherein as the interleaving paper, an interleaving paper having a paper powder adhesion amount of less than 20/100 cm <2> measured by a predetermined procedure is selected. Carrying out a procedure in which a plurality of glass plates for a light guide plate are stacked in a vertical orientation with interleaving paper interposed between them, and guided from the glass laminate in units of one sheet. In the process of taking out the optical plate glass plate, the interface between the light guide plate glass plate and the slip sheet adsorbed on the light guide plate glass plate is sequentially peeled from the first end side to the second end side of the slip sheet. Having a procedure, wherein the light guide A method for protective lamination / removal of a glass plate for a light guide plate, wherein the slip sheet is peeled in a substantially vertical direction with respect to an interface between the glass plate for a plate and the slip sheet. [Selection figure] None

Description

The present invention relates to a method for protecting and laminating a glass plate for a light guide plate, in which a plurality of glass plates for a light guide plate are laminated with interleaving paper interposed therebetween.
In addition, the present invention has a purpose of transporting a plurality of glass plates for a light guide plate by laminating them with interleaving paper interposed between them, and then taking out the glass plates for the light guide plate in units of one piece at the destination. The invention relates to a method for protective lamination / removal of a glass plate for a light guide plate.
Moreover, this invention relates to the manufacturing method of the glass light-guide plate which forms a dot pattern in one surface of the glass plate for light-guide plates conveyed using the method of this invention, and obtains a glass light-guide plate.

Conventionally, a liquid crystal display device is used for a mobile phone, a PDA, a liquid crystal television, and the like. The liquid crystal display device has a basic configuration of a planar light emitting device as a backlight and a liquid crystal unit disposed on the light emitting surface side of the planar light emitting device.
As the planar light emitting device, there are a direct type and an edge light type. In the direct type, the light source is arranged on the back surface opposite to the light emitting surface, and therefore a light source having the same size as the light emitting surface is required. In the edge light type, the light source is arranged on the side surface that is orthogonal to the light emitting surface, so that a light source having a smaller size than the light emitting surface can be used, and the thickness of the planar light emitting device does not increase. Suitable for thin liquid crystal display devices.

Conventionally, a light guide plate made of a resin material (also referred to as a resin substrate) having a high light transmittance such as polymethyl methacrylate (hereinafter referred to as PMMA) has been widely used as the light guide plate of the edge light type planar illumination device (Patent Document). 1). However, since the light guide plate made of a resin material has low heat resistance and large thermal expansion, when it is used for a long time, it is exposed to a high temperature and high humidity environment. There was a problem of poor brightness. There is a concern that such a problem becomes more prominent when the planar light emitting device is made thinner.
Therefore, the use of a glass plate as a light guide plate as a material having higher heat resistance and less thermal expansion than a light guide plate made of a resin material has been studied (see Patent Document 2).

In the case of glass plates for FPD (Flat Panel Display) such as glass plates for liquid crystal and glass plates for plasma displays, glass plates and slip sheets (sheets) are used to prevent fouling and contamination of the glass plates during storage and transportation. Are alternately laminated to separate the surfaces of adjacent glass plates (see Patent Document 3). In the case of an FPD glass plate, the glass plate glass plate is adsorbed and held by a suction portion of a glass plate loading device in a glass plate manufacturing factory in order to prevent fouling and contamination of the glass plate during storage and transportation. After being stacked one by one through the interleaving paper, it is transported from the glass plate manufacturing factory to the display assembly factory by a transportation means such as a truck.
The same is true for glass plates for light guide plates, which are required to prevent wrinkles and contamination of glass plates during storage and transportation. Therefore, also in the case of a glass plate for a light guide plate, it is desirable to separate the surfaces of adjacent glass plates by alternately laminating glass plates and slip sheets (sheets).

As shown in Patent Document 1, in the light guide plate, in order to scatter the light incident on the glass plate from the light source and totally reflected inside the glass plate to be emitted from the light emission surface, the light reflection surface of the light guide plate An irregular reflection layer (light scattering layer) is provided. An example of the light scattering layer is a dot pattern formed by screen printing.
However, there are the following problems in forming the light scattering layer on the light guide plate made of glass.

(1) In the case of a resin substrate, it is delivered to a display assembly factory with a double-sided protective film pasted on its surface. After the protective film is peeled off from the delivered resin substrate, the surface dust and the like are removed with a cleaning roller, air blow, etc., and a dot pattern can be formed immediately by screen printing. That is, it is not necessary to clean the substrate before screen printing.
On the other hand, in the case of a glass plate, as described above, it is delivered in a state of being loaded on a pallet one by one via a slip sheet. Since the delivered glass plate has no protective film on its surface, foreign matter may adhere to the glass plate during storage or transportation as a laminate. In addition, foreign substances may adhere to the glass plate when taking out from the laminated body one by one after delivery to the display assembly factory. Therefore, before carrying out screen printing, it is necessary to wash the glass plate, at least the surface on which the dot pattern of the glass plate is formed. As described above, in the case of a resin substrate, cleaning before screen printing is unnecessary. Therefore, when screen printing is performed on a glass plate, it is necessary to newly provide equipment for cleaning the glass plate. The manufacturing cost of the light emitting device increases. Moreover, there exists a possibility that a glass plate may be damaged by washing | cleaning.
Therefore, it is desirable that a glass plate can be screen printed without being washed.

(2) In the case of a light guide plate made of a resin material, when the light guide plate is stored for a long period of time due to the surface properties of the resin material such as PMMM and the protective film attached to the surface, the storage conditions such as temperature and humidity Regardless, the wettability (water contact angle) after storage is stable. As a result, the printing diameter of the dot pattern formed by screen printing is stable without being significantly affected by the storage conditions of the light guide plate. On the other hand, in the case of a light guide plate made of a glass material, the wettability changes before and after storage because the interleaf absorbs moisture during long-term storage. As a result, the wettability after storage varies depending on storage conditions such as temperature and humidity, and the print diameter of the dot pattern formed by screen printing may change. Thereby, stable printing may be hindered.
For this reason, it is desirable to reduce the influence on wettability due to the difference in storage conditions because it enables stable printing of the dot pattern.

JP 2014-67525 A JP 2009-199875 A JP 2008-143542 A

  In order to solve the problems in the case where the above-described manufacturing procedure of a light guide plate made of a resin material is applied to a glass light guide plate, the present invention provides a glass for a light guide plate as a laminate with interleaf interposed therebetween. After transporting the plate, it is possible to screen print without washing the glass plate for the light guide plate, and during long-term storage, there is little effect on the wettability of the glass plate for the light guide plate due to differences in storage conditions. An object of the present invention is to provide a method for protective lamination / removal of a glass plate for a light guide plate.

In order to achieve the above-described object, the present invention provides a glass plate for a light guide plate in which a plurality of glass plates for a light guide plate are laminated vertically by interposing a paper between them to form a glass laminate. A glass sheet for a light guide plate, wherein a slip sheet having a paper powder adhesion amount of less than 20 pieces / 100 cm ² measured by the following procedure is selected as the slip sheet. The lamination method is provided.
(Measurement of the amount of paper dust on the glass plate: Multiple glass plate samples are laminated with interleaving paper between them, and with the assumed load of pallet loading, the specified temperature and humidity conditions The difference in the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample before and after being left for 500 hours is defined as the paper dust adhesion amount.)

Further, the present invention provides a glass laminate by vertically laminating a plurality of glass plates for a light guide plate with interleaving paper interposed between them, and then the light guide plate in units of one piece from the glass laminate. A method for protecting and removing a glass plate for a light guide plate,
As the interleaving paper, selecting an interleaving paper whose glass powder adhesion amount measured by the following procedure is less than 20 pieces / 100 cm ² ,
(Measurement of the amount of paper dust on the glass plate: Multiple glass plate samples are laminated with interleaving paper between them, and with the assumed load of pallet loading, the specified temperature and humidity conditions The difference in the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample before and after being left for 500 hours is defined as the paper dust adhesion amount.)
Carrying out a procedure for laminating the glass plates for the plurality of light guide plates in a clean room with a slip sheet interposed therebetween, and in a clean room; and
In the process of taking out the light guide plate glass plate from the glass laminate in units of one sheet, the light guide plate glass plate and the light guide plate glass plate are adsorbed to each other, and the first end that is an arbitrary side and the first A step of sequentially peeling the interface with the slip sheet having the second end facing the end from the first end side to the second end side of the slip sheet. Provided is a method for protective lamination / removal of a glass plate for a light guide plate, wherein the slip sheet is peeled in a substantially vertical direction with respect to an interface with paper.

  In the protective laminating method for a light guide plate glass plate of the present invention or the protective laminating / removing method for a light guide plate glass plate of the present invention, a procedure for interposing a slip sheet between the plurality of light guide plate glass plates May be achieved by manually inserting a slip sheet between a plurality of light guide plate glasses.

  In the protective laminating method for a light guide plate glass plate of the present invention or the protective laminating / removing method for a light guide plate glass plate of the present invention, a procedure for interposing a slip sheet between the plurality of light guide plate glass plates May be achieved by electrostatically adsorbing a slip sheet on one surface of the light guide plate glass.

  In the protective laminating method of the light guide plate glass plate of the present invention or the protective laminating / extracting method of the light guide plate glass plate of the present invention, the glass plate for the light guide plate and the glass plate for the light guide plate adsorbed to each other. The procedure of sequentially peeling the interface with the paper from the first end side to the second end side of the slip sheet may be performed manually.

  In the protective laminating method of the light guide plate glass plate of the present invention or the protective laminating / extracting method of the light guide plate glass plate of the present invention, the glass plate for the light guide plate and the glass plate for the light guide plate adsorbed to each other. A mechanical means may be used for the procedure of sequentially peeling the interface with the paper from the first end side to the second end side of the slip sheet.

In the protective lamination method of the glass plate for light guide plates of the present invention or the lamination / removal method of the glass plate for light guide plates of the present invention, the water contact angle of the glass plate surface measured by the following procedure is 80 degrees or less. In addition, it is preferable to select a slip sheet in which the difference between the maximum value and the minimum value of the water contact angle on the glass plate surface measured by the following procedure is 40 degrees or less.
(Measurement of water contact angle of glass plate: A plurality of glass plate samples are laminated with interleaving paper interposed between them, and under the assumption that pallet loading is applied, the following (1) to (3) Among them, the water contact angle is measured on the surface of the glass plate after leaving the sheet under at least one condition and peeling the interleaf.
(1) Normal temperature, normal pressure, 500 hours (2) 60 ° C., normal pressure, 500 hours (3) 40 ° C., 90% RH, 500 hours

Further, the present invention is a method for producing a glass light guide plate using the glass plate for a light guide plate obtained by the method for protective lamination / removal of the glass plate for a light guide plate of the present invention,
After separating the slip sheet adsorbed on one surface of the glass plate for the light guide plate, a dot pattern is formed on the release surface by screen printing without washing the release surface. Production method.

  According to the present invention, after transporting the glass plate for a light guide plate as a laminate through interleaf paper between them, the glass plate for the light guide plate can be screen-printed without being washed, and can be stored for a long time. Sometimes, the influence on the wettability of the glass plate for a light guide plate due to the difference in storage conditions is small.

FIG. 1 is a plan view showing a procedure for laminating a plurality of glass plates for a light guide plate vertically to form a glass laminate while manually inserting interleaving paper between them. FIG. 2 is a side view showing a procedure in which a plurality of glass plates for a light guide plate are stacked vertically to form a glass laminate while manually inserting interleaving paper between them. 3 (a) and 3 (b) are diagrams showing a procedure for measuring the amount of foreign paper dust adhering to a glass plate, FIG. 3 (a) is a front view, and FIG. 3 (b) is a side view. FIGS. 4A to 4C show a procedure for manually peeling the slip sheet adsorbed to the glass plate for the light guide plate in the process of taking out the glass plate for the light guide plate from the glass laminate in units of one sheet. FIG. 5 (a) to 5 (c), in the process of taking out the light guide plate glass plate from the glass laminate in units of one sheet, the slip sheet adsorbed on the light guide plate glass plate is peeled off using the suction pad. It is the figure which showed the procedure. FIG. 6 is a diagram illustrating allocation of dots for screen printing in the embodiment.

The present invention will be described below with reference to the drawings.
In the method for protecting and laminating a glass plate for a light guide plate of the present invention or the method for protecting and laminating a glass plate for a light guide plate of the present invention, a plurality of glass plates for a light guide plate are interposed between them. And laminated vertically to make a glass laminate.
1 and 2 are diagrams showing a procedure for laminating a plurality of glass plates for a light guide plate vertically to form a glass laminate while manually inserting interleaving paper between them. 1 is a plan view and FIG. 2 is a side view. In the present specification, when “vertical placement” is used, not only the light guide plate glass plate is placed on a vertical vertical pallet, but also an arbitrary side of the glass plate is a pallet as shown in FIGS. It is also included that it is placed so as to be in contact with.
1 and 2, the light guide plate glass plate 10 is transported in the direction of arrow a on the transport conveyor 100 on which the rollers 110 are installed, and reaches the work table 200. The light guide plate glass plate 10 on the work table 200 is rotated 90 degrees in the direction of the arrow b by a manual operation (worker 300). However, the direction of the glass plate 10 for the light guide plate is rotated by 90 degrees because of the direction of the glass plate 10 for the light guide plate when transported on the transport conveyor 100 and the glass for the light guide plate when placed on the pallet 500. This is because the direction of the plate 10 is different. This procedure is not necessary when the direction of the glass plate 10 for the light guide plate when being transported on the transport conveyor 100 is coincident with the direction when being placed on the pallet 500.
Next, as shown by an arrow c, the glass plate 10 for the light guide plate is lifted in a standing state by a hand (operator 300), carried in the direction of the arrow d, and placed vertically on the pallet 500. The Although not shown, a protective member such as a packing film is disposed on the pallet 500 in order to prevent the light guide plate glass plate 10 from being scratched.

In the present invention, by repeating this procedure, a plurality of light guide plate glass plates 10 are stacked vertically on the pallet 500 to form a glass laminate. At this time, a slip sheet is interposed between the plurality of light guide plate glass plates 10. In the illustrated embodiment, a plurality of slip sheets 20 cut to a predetermined size are prepared on a rack 400, and one of the slip sheets 20 is manually pulled out in the direction of arrow e by a worker (operator 300). Thus, a slip sheet is interposed between the plurality of light guide plate glass plates 10.
However, the procedure for interposing the interleaf paper between the plurality of light guide plate glass plates is not limited to the illustrated embodiment. For example, as in the method described in Japanese Patent Laid-Open No. 2013-256315, a slip sheet cut into a predetermined size from a roll-shaped slip sheet may be interposed between a plurality of glass plates for a light guide plate. Further, the slip sheet may be electrostatically adsorbed on one surface of the light guide plate glass plate.

  In the present invention, in order to prevent foreign matter in the atmosphere from adhering to the glass plate for the light guide plate, the plurality of glass plates for the light guide plate described above are stacked vertically with interleaving paper interposed between them. The procedure for making a glass laminate is carried out in a clean room. The clean room in which this procedure is performed preferably has a cleanliness class 10000 or less, more preferably a class 1000 or less.

  To carry out the above procedure in a clean room and to cover the entire glass laminate with dust or single layer packaging film, the glass plate for the light guide plate is taken out from the glass laminate in single units. In this case, the foreign matter present on the surface of the light guide plate glass plate is substantially only paper dust generated from the slip sheet.

In the present invention, as the interleaving paper interposed between the plurality of glass plates for the light guide plate, the interleaving paper having a paper powder adhesion amount of the glass plate measured by the following procedure of less than 20 pieces / 100 cm ² is selected. By selecting a slip sheet that satisfies the above conditions, the amount of foreign matter adhering to the glass plate for the light guide plate taken out in units of one sheet from the glass laminate is extremely reduced, and the taken out glass plate for the light guide plate is not cleaned. The dot pattern can be screen printed.
In the present invention, as the interleaving paper interposed between the plurality of glass plates for the light guide plate, it is possible to select interleaving paper whose paper powder adhesion amount measured by the following procedure is less than 10 pieces / 100 cm ^2. preferable.

[Measurement of amount of paper dust on glass plate]
A plurality of glass plate samples are laminated with interleaving paper interposed between them, and the glass plate sample is placed before and after being left for 500 hours under predetermined temperature and humidity conditions with an assumed load of pallet loading. The difference in the number of foreign matters having a diameter of 40 μm or more existing on the front and back surfaces of the paper is defined as the paper dust adhesion amount.
In this procedure, a small glass plate sample is used instead of a glass plate of a size used as a light guide plate glass plate. By using a small glass plate sample, it is possible to carry out at a laboratory level, and it is possible to measure a large number of samples under the condition that the glass plate for a light guide plate to which the present invention is applied is assumed. As a result, it is possible to select an optimal slip sheet according to the conditions at the time of laminating the light guide plate glass plate to which the present invention is applied.
In the examples described later, a glass plate sample of 180 mm × 210 mm × t2.1 mm was used. However, the size of the glass plate sample to be used is not limited to this. For example, when using a glass plate sample to evaluate screen printability, A4 size, A3 size, and the like that can be screen-printed by a commercially available printing machine are preferable.

  The number of glass plate samples to be laminated is not particularly limited, and can be appropriately selected as necessary. For example, when measuring the amount of adhering paper dust before and after being left for 500 hours under a predetermined temperature condition and humidity condition, for the purpose of grasping the tendency at an early stage, before and after being left for a shorter time than 500 hours (an example) For example, the amount of adhering paper powder before and after being allowed to stand for 96 hours and before and after being allowed to stand for 240 hours can also be measured. In this case, the glass plate samples are laminated in consideration of the amount of paper dust adhesion measured in the middle. In the case of the above-described example, three glass plate samples are stacked, and when 96 hours have passed, one of the glass plate samples is taken out and the amount of paper dust attached is measured by the procedure described later. Next, when 240 hours have passed, one of the glass plate samples is taken out and the amount of paper dust attached is measured. And when 500 hours pass, the remaining one sheet is taken out and the amount of paper dust adhesion is measured. In addition, when comparing a plurality of types (3 to 8 types of slip sheets, for example) at one time, a glass plate sample corresponding to the number of slip sheets to be compared (in the case of the above example, 3 to 8 glass sheets). Laminate plate samples).

In the present invention, glass plate samples are stacked vertically, but in the measurement of the amount of paper dust on the glass plate, a predetermined weight is placed on the glass plate sample in order to apply an assumed load. Laminate.
The assumed load is set under conditions that assume the time when the glass plates for the light guide plate to which the present invention is applied are laminated. In the examples described later, it was assumed that 200 sheets of a t2.1 mm glass plate for a light guide plate were tilted 6 degrees and laminated on the pallet 500. The reason why only the plate thickness t is assumed for the glass plate for the light guide plate is that the load per unit area is assumed to be the assumed load. In this case, the load applied to the position where the load is most applied, that is, the glass plate for the light guide plate first placed on the pallet 500 and the slip sheet which is in direct contact with the glass plate for the light guide plate is 200 sheets × sin 6 degrees = 200. × 0.1045 = 20.9 sheets In other words, when the glass plates for the light guide plate are laminated in a flat manner, the number is equivalent to 20.9 sheets.
The weight of 180 mm × 210 mm × t2.1 mm used in the examples described later is 189 g. Therefore, the assumed loading load is 189 × 20.9 = 3780 g.
In the examples described later, a weight of 4 kg was placed on a glass plate sample laminated in a flat position.

The reason why the time for leaving a plurality of laminated glass sheet samples with interleaving paper under predetermined temperature and humidity conditions is 500 hours is as follows.
As an example, the product delivery specification for a glass plate for a light guide plate describes the following requirements for storage of the glass plate for the light guide plate.
Temperature: 15-25 ° C
Humidity: 60% or less Use period: 90 days after delivery Among conditions (1) to (3) described later, conditions (2) and (3) are more severe than the recommended storage environment described in the product delivery specifications. Because of the conditions, the time required for long-term storage (90 days after delivery) in the recommended storage environment was set to 500 hours.

The temperature condition and humidity condition in which a plurality of glass plate samples laminated with interleaving paper are allowed to stand for 500 hours are assumed to be when the glass plates for a light guide plate to which the present invention is applied are laminated. In the examples described later, the following three conditions were used, but at least one of the three conditions may be executed. However, it is more preferable to implement all three conditions.
(1) Normal temperature, normal pressure, 500h
(2) 60 ° C, normal pressure, 500h
(3) 40 ° C., 90% RH, 500 h

Remove the glass plate sample after standing for 500 hours. A slip sheet having a first end which is an arbitrary side and a second end facing the first end is adsorbed to the glass plate sample. Sequentially peel from the first end side of the slip sheet to the second end side so that the interface between the glass sheet sample and the slip sheet is peeled in a direction substantially perpendicular to the interface between the glass plate sample and the slip sheet. To do.
The paper powder adhesion amount of the glass plate sample from which the interleaving paper has been peeled is measured by the following procedure. 3 (a) and 3 (b) are diagrams showing a procedure for measuring the amount of paper dust on the glass plate, FIG. 3 (a) is a front view, and FIG. 3 (b) is a side view.
As shown in FIGS. 3A and 3B, the LED unit 50 is disposed at one end of the glass plate sample 30. In the LED unit 50, an LED light 51 is provided in the housing 52. In this state, one end portion of the glass plate sample 30 is irradiated with LED light, and the number of foreign matters 40 having a diameter of 40 μm or more from the front position where the foreign matters 40 existing on the front and back surfaces of the glass plate sample 30 appear to float. Measure. At this time, an opaque shading plate 60 is arranged and sequentially moved in accordance with the confirmation position, thereby preventing foreign objects from being overlooked and overlapping counting.
For the glass plate sample before laminating, after hand washing, the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample is measured in the same procedure as described above, and the difference between the measured values of the two is measured by the glass plate. Of paper dust.

In the present invention, as a slip sheet interposed between a plurality of light guide plate glass plates, the water contact angle of the glass plate surface measured by the following procedure is 80 degrees or less, and the following procedure: It is preferable to select a glass plate having a difference between the maximum value and the minimum value of the water contact angle on the surface of the glass plate of 40 degrees or less. By selecting a slip sheet that satisfies the above conditions, when the dot pattern is formed by screen printing on the glass plate for the light guide plate taken out from the glass laminate in units of one sheet, the storage conditions for the glass laminate The variation in the printing diameter of the dot pattern due to the difference is reduced.
In the present invention, it is preferable to select a slip sheet interposed between a plurality of light guide plate glass plates that has a water contact angle of 70 degrees or less on the glass plate surface measured by the following procedure. It is more preferable to select one that is 60 degrees or less. Moreover, it is more preferable to select a glass plate whose surface has a difference between the maximum value and the minimum value of the water contact angle measured by the following procedure of 30 degrees or less.

[Measurement of water contact angle of glass plate]
In the same procedure as the measurement of the amount of adhering paper dust on the glass plate described above, a plurality of glass plate samples are laminated with interleaving paper interposed between them, and a predetermined load is applied in a state where an assumed load of pallet loading is applied. For 500 hours under the temperature and humidity conditions. In the examples described later, the following three conditions were used, but at least one of the three conditions may be executed. However, it is more preferable to implement all three conditions.
(1) Normal temperature, normal pressure, 500 hours (2) 60 ° C., normal pressure, 500 hours (3) 40 ° C., 90% RH, 500 hours Therefore, at least one of the conditions (1) to (3) The water contact angle on the surface of the glass plate sample measured at is 80 degrees or less, and the difference between the maximum value and the minimum value of the water contact angle on the surface of the glass plate sample is 40 degrees or less.

  Remove the glass plate sample after standing for 500 hours. The interface between the glass plate sample and the slip sheet is peeled sequentially from the first end side to the second end side of the slip sheet so that the interface is peeled in a direction substantially perpendicular to the interface between the glass plate sample and the slip sheet. . A water droplet is dropped on the surface (surface) of the glass plate sample on the side from which the interleaving paper has been peeled off, and the water contact angle on the surface of the glass plate sample is measured using a contact angle meter.

In this invention, it is preferable from a viewpoint of protection of the glass plate for light-guide plates to select what has a basic weight of 40-75 g / m < ² > as a slip sheet interposed between the glass plates for several light-guide plates. .

  In the present invention, it is preferable to select an interleaving paper interposed between a plurality of glass plates for a light guide plate that does not contain foreign substances that may cause scratches on the glass plate for a light guide plate. Specifically, it is preferable to select a material that does not contain foreign matters having a size of φ10 μm or more.

The interleaving paper interposed between the plurality of glass plates for the light guide plate is not particularly limited as long as it satisfies the above-described conditions regarding the amount of paper powder adhering to the glass plate, preferably the water contact angle of the glass plate. Paper can be used. Therefore, the glass interleaving paper of the present invention is a chemical pulp such as kraft pulp (KP), sulfite pulp (SP), soda pulp (AP), semi-chemical pulp (SCP), chemi-ground wood pulp (CGP), etc. Semi-chemical pulp, groundwood pulp (GP), thermomechanical pulp (TMP, BCTMP), refiner groundwood pulp (RGP) and other mechanical pulp, non-wood fiber pulp made from cocoon, sardine, hemp, kenaf, etc., synthetic Known glass interleaving paper made of various raw materials such as pulp can be used. Furthermore, the glass interleaving paper of the present invention may be a raw material of a mixture thereof, or a raw material containing cellulose or the like.
These raw materials may be used paper, virgin pulp, or a mixture of used paper and virgin pulp. Among these, virgin pulp is preferable.
Moreover, these interleaving papers may be impregnated with a resin during paper making, or may be smoothed after paper making.

  Further, as interleaving paper interposed between a plurality of glass plates for light guide plate, Japanese Patent No. 4195719, Japanese Patent Application Laid-Open No. 2012-20766, Japanese Patent Application Laid-Open No. 2014-136754, Japanese Patent Application Laid-Open No. 2011-11478, Even if slip sheets made of a synthetic resin material such as those disclosed in JP 2003-226354 A, JP 2005-239242 A, JP 2005-239184 A, and JP 10-20285 A are used. Good. In the case of slip sheets made of these synthetic resin materials, paper dust does not occur in the literal sense, but particles (fine foreign matter) are generated during post-processing such as cutting and slitting and adhere to the cut edge of the slip sheet. . When using synthetic paper made of synthetic resin material, the above particles are treated as paper powder.

  In the method for protective lamination / removal of a light guide plate glass plate of the present invention, a plurality of glass plate for light guide plates are laminated in a vertical manner on a pallet 500 with interleaving paper 20 interposed therebetween. The body is transported to a destination such as a display assembly factory in this state. When the glass laminate that has arrived at the destination is brought into the clean room, an air shower is applied to the entire packaging of the glass laminate to scatter and reduce foreign matter adhering to the packaging. From the unpacked glass laminate, light guide plate glass plates are taken out in units of one sheet. When taking out the light guide plate glass plate from the glass laminate in units of one sheet, the slip sheet adsorbed on the light guide plate glass plate is peeled off from the light guide plate glass plate. However, it is mechanically difficult to peel off the entire interface between the glass plate for light guide plate and the interleaving paper at the same time, and reliable separation is difficult, which is not practical. Therefore, peeling is started from the first end side of the interleaving paper, and the peeling is sequentially advanced toward the second end side of the interleaving paper.

In the present invention, during the procedure of sequentially peeling the interface between the glass plate for a light guide plate and the slip sheet adsorbed thereto from the first end side to the second end side of the slip sheet, the glass for the light guide plate The slip sheet is peeled off in a substantially vertical direction with respect to the interface between the board and the slip sheet.
FIGS. 4A to 4C are procedures for manually peeling the interleaf paper 20 adsorbed to the light guide plate glass plate 10 in the process of taking out the light guide plate glass plate 10 from the glass laminate in units of one sheet. FIG. 4 (a) is a glass laminate before the start of peeling, FIG. 4 (b) is a glass laminate when peeling is started from the first end side of the slip sheet, and FIG. 4 (c) is a slip of the slip sheet. It is the glass laminated body peeled one by one to the 2nd end side. As shown in FIGS. 4 (b) and 4 (c), in the present invention, when starting peeling from the first end side of the slip sheet and sequentially peeling to the second end side, the glass for the light guide plate is always used. The slip sheet is peeled off in a substantially vertical direction with respect to the interface between the board and the slip sheet.

In the glass laminate shown in FIG. 4, when the interface between the light guide plate glass plate 10 and the interleaf paper 20 is sequentially peeled from the first end side to the second end side of the interleaf paper, the light guide plate glass plate 10 and The interleaf paper 20 is peeled off in a horizontal direction with respect to the interface with the interleaf paper 20, for example, pulling down the interleaf paper 20 in the drawing downward to peel off the interleaf paper mechanically. It is common because it is easy.
However, when the interleaf paper 20 is peeled in the horizontal direction with respect to the interface between the light guide plate glass plate 10 and the interleaf paper 20, the end surface of the second end side interleaf paper 20 is in contact with the surface of the light guide plate glass substrate 10. High possibility of contact. As the slip sheet 20, a slip sheet cut into a predetermined size from a roll-shaped slip sheet is usually used. The end surface of the slip sheet 20 on the second end side becomes a cut end when the roll-shaped slip sheet is cut into a predetermined size. Paper dust from interleaving paper is most often generated from such cut ends. Therefore, when the end surface of the interleaf paper 20 on the second end side, which is a cut end, comes into contact with the surface of the light guide plate glass substrate 10, there is a high possibility that paper powder adheres to the surface of the light guide plate glass plate 10.

In the present invention, when peeling is started from the first end side of the slip sheet and then sequentially peeled to the second end side, the slip sheet is always aligned in a substantially vertical direction with respect to the interface between the light guide plate glass plate and the slip sheet. Since the paper is peeled off, there is a low possibility that the end surface of the interleaf paper 20 on the second end side comes into contact with the surface of the glass substrate 10 for the light guide plate, and there is a possibility that paper dust adheres to the surface of the glass plate 10 for the light guide plate. Low. Therefore, the foreign matter adhering to the glass plate for light-guide plates taken out from the glass laminated body per sheet becomes very few.
Specifically, the glass plate for the light guide plate taken out from the glass laminate in units of one sheet preferably has a paper powder adhesion amount measured by the above-described procedure of less than 20/100 cm ² , preferably 10/100 cm. More preferably, it is less than ² , and more preferably less than 5/100 cm ² .
The amount of paper dust adhered to the front and back surfaces of the light guide plate glass here refers to the number of foreign matters having a diameter of 40 μm or more in the procedure shown in FIGS. It is the difference between the numerical value measured and the numerical value measured in the same procedure after cleaning the surface of the glass plate for the light guide plate before lamination.
In the present invention, since there is very little foreign matter adhering to the glass plate for the light guide plate taken out from the glass laminate in units of one sheet and clogging during screen printing is reduced, the glass plate for light guide plates taken out in units of one piece is washed. Without doing so, it becomes possible to screen-print the dot pattern.

In the glass laminate shown in FIG. 4, the size of the interleaf paper 20 is larger than that of the light guide plate glass plate 10, and the upper end of the interleaf paper 20 on one end side protrudes above the upper end of the light guide plate glass plate 10. .
From the viewpoint of protecting the light guide plate glass plate 10, it is preferable that the interleaf paper 20 is adsorbed on the entire surface of the light guide plate glass plate 10. Therefore, it is preferable that the dimension of the interleaf paper 20 is larger than the glass plate 10 for light guide plates like the glass laminated body shown in FIG.
Further, the end surface of the interleaf paper 20 on one end side is often a cut end when the roll-shaped interleaf paper is cut into a predetermined size, and the glass plate for the light guide plate than the upper end of the interleaf paper 20 on the one end side. If the upper end of 10 protrudes upward, the end face of the interleaf paper 20 on one end side may come into contact with the surface of the glass substrate 10 for light guide plate. Therefore, as in the glass laminate shown in FIG. 4, it is preferable that the upper end of the interleaf paper 20 on one end side protrudes above the upper end of the light guide plate glass plate 10.

4 (a) to 4 (c), the procedure of sequentially peeling the interface between the light guide plate glass plate 10 and the slip sheet 20 from the first end side to the second end side of the slip sheet is performed manually. However, mechanical means may be used for this procedure. FIGS. 5A to 5C show, as a mechanical means, the slip sheet 20 adsorbed to the light guide plate glass plate 10 in the process of taking out the light guide plate glass plate 10 from the glass laminate in units of one sheet. It is the figure which showed the procedure which peels using the suction pad 600. FIG.
FIG. 5 (a) is a glass laminate before the start of peeling, FIG. 5 (b) is a glass laminate at the time when peeling is started from the first end side of the slip, and FIG. 5 (c) is a slip of the slip. It is the glass laminated body peeled one by one to the 2nd end side. As shown in FIGS. 5 (b) and 5 (c), when mechanical means is used to peel the slip sheet 20 adsorbed on the light guide plate glass plate 10, the first end side of the slip sheet is also used. When sequentially peeling to the two ends, the slip sheet is always peeled in a substantially vertical direction with respect to the interface between the light guide plate glass plate and the slip sheet.

Fourteen sample slip sheets were prepared. Sample sheets were interposed between the 180 mm × 210 mm × t2.1 mm glass plate samples and laminated in a flat position, and a weight of 4 kg was placed as an assumed load, and left under the following three conditions.
(1) Normal temperature, normal pressure, 500 hours (2) 60 ° C., normal pressure, 500 hours (3) 40 ° C., 90% RH, 500 hours Take a glass plate sample after standing for 500 hours. The slip sheet adsorbed on the glass plate sample is sequentially peeled from the first end side to the second end side of the slip sheet so that the slip sheet is peeled in a direction substantially perpendicular to the interface between the glass plate sample and the slip sheet. .
The amount of paper dust adhered to the glass plate sample from which the interleaving paper was peeled was measured by the following procedure. 3 (a) and 3 (b) are diagrams showing a procedure for measuring the amount of paper dust on the glass plate, FIG. 3 (a) is a front view, and FIG. 3 (b) is a side view.
As shown in FIGS. 3A and 3B, the LED unit 50 is disposed at one end of the glass plate sample 30. In the LED unit 50, an LED light 51 is provided in the housing 52. In this state, one end portion of the glass plate sample 30 is irradiated with LED light, and the number of foreign matters 40 having a diameter of 40 μm or more from the front position where the foreign matters 40 existing on the front and back surfaces of the glass plate sample 30 appear to float. Was measured. At this time, an opaque shading plate 60 is arranged and sequentially moved in accordance with the confirmation position, thereby preventing foreign objects from being overlooked and overlapping counting.
For the glass plate sample before laminating, after hand washing, the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample is measured in the same procedure as described above, and the difference between the measured values of the two is measured by the glass plate. The amount of paper powder adhering to. The results are shown in the table below. In addition, the paper dust adhesion amount shown in the following table is the largest numerical value among the measured values under the above three conditions.
Also, the glass plate sample after being left for 500 hours under the above three conditions is taken out, and the slip sheet adsorbed on the glass plate sample is peeled off in a direction substantially perpendicular to the interface between the glass plate sample and the slip sheet. In addition, after peeling sequentially from the first end side to the second end side of the interleaving paper, water drops are dropped on the surface (front surface) of the glass plate sample on the side from which the interleaving paper has been peeled off, and a glass plate is obtained using a contact angle meter. The water contact angle on the sample surface was measured. The results are shown in the table below. In addition, the water contact angle shown to the following table | surface has the largest numerical value among the measured values on said 3 conditions. Further, the difference in water contact angle is the difference between the measured value under the above three conditions and the value having the largest value and the value having the smallest value.
Screen printing was performed on the surface of the glass plate sample after the water contact angle measurement from which the interleaving paper was peeled off. FIG. 6 is a diagram illustrating allocation of dots for screen printing in the embodiment. There are six types of dot diameters of φ150 μm, φ210 μm, φ300 μm, φ420 μm, φ600 μm, and φ850 μm, and 92 × 13 = 1196 dots were assigned to A to G in the figure, respectively. After screen printing and drying, dot printability (bleeding, clogging, missing dots) was visually evaluated. The evaluation criteria are as shown below.
○: Bleeding, clogging, dot missing 0: Δ: Bleeding, clogging, 1 missing dot ×: Bleeding, clogging, 2 or more missing dots In addition, the dot diameter is changed from each region of A to G. = 10 pieces were measured, and the dot diameter change (Δ = (actually measured diameter−design value) / design value × 100) was evaluated according to the following criteria. The results are shown in the table below.
○: Dot diameter change Δ is 5% or less Δ: Dot diameter change Δ is over 5% and 10% or less ×: Dot diameter change Δ is over 10%
Samples 8 to 14 having a paper dust adhesion amount of 20 pieces / cm ² or less had a dot printability of ◯. Further, in Samples 8 and 10 to 13 having a water contact angle of 80 degrees or less and a water contact angle difference of 40 degrees or less, the dot diameter change was good.

DESCRIPTION OF SYMBOLS 10: Glass plate for light-guide plates 20: Interleaf 30: Glass plate sample 40: Foreign material 50: LED unit 51: LED light 52: Case 60: Light-shielding plate 100: Conveyor 110: Roller 200: Worktable 300: Worker 400: Mounting table 500: Pallet 600: Suction pad

Claims (8)

A plurality of glass plates for a light guide plate are laminated in a vertical orientation with interleaving paper interposed between them to form a glass laminate, a method for protective lamination of a glass plate for a light guide plate,
A method for protecting and laminating a glass plate for a light guide plate, wherein a slip sheet having a paper powder adhesion amount of less than 20 pieces / 100 cm ² measured by the following procedure is selected as the slip sheet.
(Measurement of the amount of paper dust on the glass plate: Multiple glass plate samples are laminated with interleaving paper between them, and with the assumed load of pallet loading, the specified temperature and humidity conditions The difference in the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample before and after being left for 500 hours is defined as the paper dust adhesion amount.) A plurality of glass plates for a light guide plate are stacked vertically by interposing an interleaf between them to form a glass laminate, and then the glass plate for the light guide plate is taken out from the glass laminate in units of one piece. A method for protective lamination / removal of a glass plate for a light guide plate,
As the interleaving paper, selecting an interleaving paper whose glass powder adhesion amount measured by the following procedure is less than 20 pieces / 100 cm ² ,
(Measurement of the amount of paper dust on the glass plate: Multiple glass plate samples are laminated with interleaving paper between them, and with the assumed load of pallet loading, the specified temperature and humidity conditions The difference in the number of foreign matters having a diameter of 40 μm or more present on the front and back surfaces of the glass plate sample before and after being left for 500 hours is defined as the paper dust adhesion amount.)
Carrying out a procedure for laminating the glass plates for the plurality of light guide plates in a clean room with a slip sheet interposed therebetween, and in a clean room; and
In the process of taking out the light guide plate glass plate from the glass laminate in units of one sheet, the light guide plate glass plate and the light guide plate glass plate are adsorbed to each other, and the first end that is an arbitrary side and the first A step of sequentially peeling the interface between the first end side of the slip sheet and the second end side of the slip sheet having a second end opposite to the end, and in the procedure, the glass plate for the light guide plate and the slip sheet A method for protective lamination / removal of a glass plate for a light guide plate, wherein the slip sheet is peeled off in a substantially vertical direction with respect to an interface with the light guide plate.   The procedure for interposing a slip sheet between the plurality of light guide plate glass plates is achieved by manually interposing a slip sheet between the plurality of light guide plate glasses. A method for protective lamination of a glass plate for a light guide plate, or a method for protective lamination / removal of a glass plate for a light guide plate according to claim 2.   2. The guide according to claim 1, wherein the procedure of interposing a slip sheet between the plurality of light guide plate glass plates is achieved by electrostatically adsorbing the slip sheet on one surface of the light guide plate glass. The protective lamination method of the glass plate for optical plates, or the protective lamination / extraction method of the glass plate for light-guide plates of Claim 2.   The step of sequentially peeling the interface between the light guide plate glass plate and the slip sheet adsorbed on the light guide plate glass plate from the first end side to the second end side of the slip sheet is performed manually. The lamination method of the glass plate for light-guide plates in any one of 2-4, or the lamination | stacking / take-out method of the glass plate for light-guide plates.   Mechanical means is used for the procedure of sequentially peeling the interface between the glass plate for the light guide plate and the slip sheet adsorbed to the glass plate for the light guide plate from the first end side to the second end side of the slip sheet. Item 5. A method for laminating a glass plate for a light guide plate according to any one of Items 2 to 4, or a method for laminating / retrieving a glass plate for a light guide plate. The water contact angle of the glass plate surface measured by the following procedure is 80 degrees or less, and the difference between the maximum and minimum values of the water contact angle of the glass plate surface measured by the following procedure is 40 degrees or less. A method for laminating a glass plate for a light guide plate according to any one of claims 1 to 6, or a method for laminating / removing a glass plate for a light guide plate.
(Measurement of water contact angle of glass plate: A plurality of glass plate samples are laminated with interleaving paper interposed between them, and under the assumption that pallet loading is applied, the following (1) to (3) Then, the water contact angle on the surface of the glass plate after peeling the interleaving paper is measured.
(1) Normal temperature, normal pressure, 500 hours (2) 60 ° C., normal pressure, 500 hours (3) 40 ° C., 90% RH, 500 hours A method for producing a glass light guide plate using the glass plate for a light guide plate obtained by the method for laminating / removing a glass plate for a light guide plate according to any one of claims 2 to 7,
After separating the slip sheet adsorbed on one surface of the glass plate for the light guide plate, a dot pattern is formed on the release surface by screen printing without washing the release surface. Production method.