KR20190075073A - Method of manufacturing ink pattern-containing curved glass - Google Patents

Abstract

A method of manufacturing an ink pattern-containing curved glass, comprising: a printing step; The film heating and bending steps and the flat film produced in the previous step are placed in a film heating and bending mold for heating and bending wherein the temperature at which the mold is closed for heating and bending is between 60 and 85 ° C, Heating and bending to form a curved film, wherein the size of the film heating and bending mold is such that the curvature of the curved film is greater than the curvature of the curved glass), leaving a rebound margin on the curved film; And an attachment step of creating an ink pattern-containing curved glass.

Description

Method of manufacturing ink pattern-containing curved glass

Cross-reference to related application

Priority is claimed on Chinese patent application No. 201610863923.9, filed on September 29, 2016 and entitled " Method of manufacturing ink pattern-containing curved glass ", the disclosure of which is incorporated herein by reference.

Technical field

The present invention relates to a method of processing glass, and more particularly, to a method of manufacturing a curved glass containing an ink pattern.

The traditional surface patterning process of flat glass is to flatten the ink pattern on flat glass, especially using silk screen printing, reverse printing, pad printing, and the like. The 3D curved glass may be a glass containing curved glass around the central flat area and its periphery, and the 3D screen has become trend and fashion, for example, cell phones, tablets, watches, headphones and other screen panels 3D screens are being used, so that glass surface printing has also changed from traditional flat printing to 3D curved printing. However, due to the structural nature of the 3D glass product, there are problems when using traditional glass printing methods to print 3D curved glass, for example, printed patterns have high dimensional accuracy on 3D curved glass And the pattern is unclear, and the ink may not be completely printed at some places, particularly on curved curved surfaces and at the four corners of the 3D curved glass.

Chinese Patent Application No. 201310624893.2 discloses a method for producing a three-dimensional glass film, comprising the steps of providing a thin film (e.g., a polyethylene terephthalate film) having a body layer and an adhesive layer; Positioning the three-dimensional glass and the thin film in a hot compression mold using the adhesive layer, wherein the adhesive layer and the three-dimensional glass are arranged in opposite directions to each other; Providing at least one of a predetermined temperature (50 캜 to 130 캜) and a predetermined pressure (1 atmospheric pressure to 3 atmospheres) to the thin film to pre-form the thin film; And hot-pressing the pre-formed thin film and the three-dimensional glass to attach the thin film and the three-dimensional glass to each other. This method allows the film to adhere smoothly and uniformly to the three-dimensional glass, and can also be applied to a three-dimensional glass having curved surfaces of different radii. At this time, the thin film further includes a functional layer, and the functional layer includes an ink layer, a conductive layer, or a combination thereof. However, this method has a high risk of fracture, and the manufactured three-dimensional glass product can not guarantee 100% absence of air bubbles in the adhesion portion of the thin film and the three-dimensional glass.

Therefore, there is a need in the art to provide a new method for producing curved glass containing an ink pattern, and more particularly, to a method for producing a curved glass containing an ink pattern that contains an ink pattern with little risk of breakage or even no risk of breakage, There is a need to provide a method of manufacturing a curved glass which is free from wrinkles at four corners or curved surfaces and which has no depression between the film layer containing the ink pattern and the three-dimensional glass.

A method of manufacturing a curved glass containing an ink pattern includes the following steps.

Step A, printing step: printing an ink pattern on a flat film, wherein the thickness of the film substrate of the film is 40 to 60 micrometers;

Step B: High Temperature Bending of the Film: Placing the flat film obtained in Step A in a film high temperature bending mold for high temperature bending where the mold clamping temperature of the high temperature bending is 60 to 85 캜, Bending to be formed into a curved film and causing the ink pattern to be positioned on the concave and / or convex surface of the curved film; Designing the dimensions of the film high temperature bending mold to allow a degree of curvature of the resultant curved film to be greater than a degree of curvature of the curved glass to allow a rebound margin of the curved film; And

Step C, Attachment step: Attaching the outer convex surface of the curved film obtained in step B to the inner concave surface of the curved glass using a vacuum attachment device to obtain a curved glass containing the ink pattern.

In step A according to the present invention, when the thickness of the film substrate is too thin, wrinkles are formed on the adhesion surface of the film product after high-temperature bending of the flat film, four corners protrude and ductility of the film sheet is poor, It can not withstand high temperatures. Further, if the thickness of the film base material is too large, wrinkles tend to occur on the attachment surface after high-temperature bending, and unstable molding tends to occur. Therefore, the thickness of the film substrate according to the present invention is suitably 40 to 60 micrometers. In a specific embodiment, if the ink pattern printed in step A is a border area pattern, the area size of the printed pattern is larger than the size after cutting. In step B, the mold temperature is most preferably between 60 and < RTI ID = 0.0 > 85 C. < / RTI > When the mold clamping temperature is higher than 85 占 폚, the film is severely shrunk due to the high temperature and severely twisted and deformed after the high temperature bending.

In certain embodiments, the film high temperature bending mold comprises an upper mold resilient block, and the downward exit stroke of the upper mold resilient block is 2 to 8 mm, preferably 3 to 5 mm, The film is squeezed during the mold clamping, and the film does not move during the high-temperature bending process, and the film does not adhere to the upper mold but remains in the lower mold after the mold is opened.

In a specific embodiment, step A further comprises cutting a flat film containing the ink pattern, wherein the cutting preferably comprises cutting the flat film according to the size of the plane spreading from the curved film obtained after molding will be.

In a particular embodiment, the film substrate is a PET film, wherein the film comprises a film substrate and an OCA adhesive layer covering one side of the film substrate, wherein the thickness of the OCA adhesive layer is 20 to 35 micrometers.

In a particular embodiment, in a film high temperature bending mold, the flat film is positioned by a plurality of outer positioning positioning blocks and vacuum adsorption, and after high temperature bending, the film first maintains the pressure cooled with cooling water, The mold is opened to take out the curved film, wherein the upper mold assembly and the lower mold assembly of the film high temperature bending mold are subjected to mold clamping positioning by a plurality of sets of guide rods and guide sleeves .

If the film is directly taken out without cooling after high-temperature bending, warpage deformation due to thermal expansion and contraction of the product is large, which affects the molding accuracy of the film; In the present application, the film maintains a cooled pressure in the mold. Since the heat of the surface of the film product is transferred to water, the temperature of the film is gradually lowered, the shrinkage is reduced, and the deformation is reduced to meet normal production demands.

In certain embodiments, the mold clamping temperature of the hot bending in step B is 65 to 75 占 폚, the mold clamping pressure is 500 to 650 kgf, preferably 520 to 620 kgf, the hot bending time is 90 to 150 seconds, The cooling time is 20 to 40 seconds. The curved film obtained by the operation under these parameters does not show the problem of wrinkles at the four corners.

In a particular embodiment, the degree of curvature of the curved film is greater than the degree of curvature of the curved film so that, after high-temperature bending of the film, the arc retraction distance, d, of the curvature of the curved film relative to the arc of curvature of the curved glass 0.2 to 1 mm, preferably 0.3 to 0.8 mm. d is the parallel tangential distance from the outer end point of the inner concave arc on the inner concave surface of the curved glass to the arc of the outer convex surface of the curved film.

In a particular embodiment, the cutting method in step A is die cutting using a cutting die or laser cutting, and the high temperature bending of the film in step B uses hydraulic driving. When a flat film is cut by die cutting using a cutting die, the cutting die is designed according to the size of the film, and the dimensional accuracy of the film after cutting is guaranteed within a tolerance of ± 0.02 mm. When cutting a flat film with a laser cut, the dimensional accuracy of the film after cutting is guaranteed within a tolerance of ± 0.05 mm.

In a specific embodiment, in step C, a CCD image sensor is used to capture the adhesion criteria of the curved film and the curved glass prior to attachment of the vacuum, and after the curved film and the curved glass are in close contact with each other in the vacuum attachment device, A defoaming process is further included.

In a particular embodiment, the thickness of the PET substrate of the film in Step A is 50 micrometers, and the thickness of the OCA adhesive layer of the film is 25 micrometers.

The present invention has the following beneficial effects.

1. In the present invention, a flat film is first bent at a high temperature to form a curved surface of the 3D glass in the mold, leaving a rebound margin on the film, and then a curved film is attached to the 3D curved glass. The present invention relates to a process for producing a curved glass containing an ink pattern by separately forming a film, setting a rebound margin of the film, selecting a specific thickness of the film substrate and a mold clamping temperature of the high temperature bending of the film, Solves the bubble problem that occurs.

2. The printing ink material selected in the present invention is a high temperature resistant and flexible film. The present invention completely solves the problems of wrinkles, bubbles and depressions upon adhesion between the film and the glass, the curved film has stable size and formability and good adhesion accuracy, and the bending deformation of the film after high temperature bending is small.

3. In this specification, the temperature of the high temperature bending of the film is low, and the quality of the ink layer printed thereon is not affected by the high temperature bending process of the film. In the present invention, the glass is not used as a mold for high-temperature bending of the film after individually high-temperature bending at a high temperature of 700 to 800 ° C, greatly reducing the risk of fracture of the 3D curved glass. Since the present invention separately provides mold and high temperature bending parameters for film bending of the film, the film optimally matches the 3D curved glass after high temperature bending.

4. The curved glass obtained in the present invention has a high ink pattern accuracy on its surface, and the product has a sophisticated appearance. The present invention is simple in process, high in reliability, good in operability, low in cost, high in practical value, easy to be improved and applied.

Fig. 1 is a schematic view showing a positional structure of a curved film before adhering and a curved glass, wherein reference numeral 1 is a curved glass, and reference numeral 2 is a curved film.

The present invention will be described in more detail with reference to specific embodiments.

A flat film according to the present invention comprises a film substrate and an OCA adhesive layer, one side of which is coated with a " light release film " having a thickness of, for example, 0.05 mm, Quot; film "and then used for ink printing; One side of the OCA adhesive layer is coated with a "release film" having a thickness of, for example, 0.1 mm, and the surface is used to adhere to the curved glass after peeling off the "release film ".

The curved film obtained after the high-temperature bending according to the present invention is similar to the structure of the 3D curved glass, but has a structure of a central planar structure having a rebound margin for the film and a structure of a surrounding arc edge structure.

Example  1 to 3 and Comparative Example  1 and 2

The present invention provides a method for producing a curved glass containing an ink pattern, comprising the following steps.

Step A, Printing and Cutting Step: An ink pattern is printed on a flat film having a thickness of the film base of the film of 40 to 60 micrometers (the thickness of the film base in Comparative Examples 1 and 2 is less than 40 micrometers) Cutting the flat film into the ink pattern;

Step B, High Temperature Bending of the Film: After cutting the flat film is placed in a film high temperature bending mold for high temperature bending where the mold clamping temperature of the high temperature bending is 60 to 85 占 폚, To be shaped into a curved film and to position the ink pattern on a concave surface of the curved film; Designing the dimensions of the film high temperature bending mold to allow a rebound margin of the curved film to be greater than a degree of curvature of the curved film obtained; And

Step C, Attachment step: Attaching the outer convex surface of the curved film obtained in step B to the inner concave surface of the curved glass using a vacuum attachment device to obtain a curved glass containing the ink pattern.

The high-temperature bending and forming process of the film in step B specifically includes the following steps: positioning of the film → vacuum adsorption of the film → mold clamping and high-temperature squeezing → cooling → mold opening → film take-off. The heating device was switched off between the mold clamping and the high-temperature compression step and the cooling step, and the heating device was operated between the cooling step and the mold opening step. The film is hot-bend using a four-pillar hydraulic drive apparatus, the process parameters of which are as follows: the product positioning and adsorption time of the hot bending of the film is 5 seconds, the upper mold heating time and the lower mold The heating time was all 70 seconds, and the flow rate of the cooling water pump was 50 L / min. During the high-temperature bending, the initial compression time was 1 second, the re-compression time was 30 seconds, and the cooling water pump operation time was 35 seconds. The pressure of the upper oil pipe before the mold opening was 1205 kgf (gauge pressure), the pressure of the lower oil pipe was 508 kgf, the temperature of the upper mold was 66.3 캜, and the temperature of the lower mold was 65.2 캜; The pressure of the upper oil pipe after the mold opening was 1021 kgf, the pressure of the lower oil pipe was 464 kgf, the temperature of the upper mold was 51.5 ° C, and the temperature of the lower mold was 53.7 ° C. The product took 5 seconds to take out and the high temperature bending cycle was 120 seconds.

Considering that there is no functional hole or auxiliary positioning feature in the film prior to the high temperature bending process of the film, the present inventors have found that in order to achieve the high temperature bending and molding precision of the film, an upper mold press block (upper mold resilient block) Peripheral and four-side positioning and close contact. 1, the arc retraction distance d of the curvature arc of the film 2 to the arc of the curvature of the curved glass 1 was 0.5 mm, and the mold for film molding had a curvature of the curvature of the 3D glass Lt; RTI ID = 0.0 > 0.5 mm < / RTI >

In the vacuum deposition and high pressure defoaming process of step C, the reference of the curved film and the 3D curved glass is captured through the CCD using a vacuum attachment machine, and after the curved film and the curved glass are closely contacted, High-pressure defoaming technology was performed to achieve high ink pattern accuracy and a sophisticated appearance effect. In the defoaming process, firstly defoamed for 15 minutes at a pressure of 6.5 kgf and a temperature of 45 ° C, then defoamed for 15 minutes using a pressure of 6.5 kgf and a temperature of 25 ° C and finally a pressure of 6.5 kgf and a pressure of 45 Deg.] C for 3 minutes.

In Examples 1 to 3 and Comparative Examples 1 and 2, a manufacturing method of a curved glass containing an ink pattern obtained by a film substrate having a different thickness was examined as shown in Table 1 below.

Comparative Example 1 Comparative Example 2 Example 1 Example 2 Example 3 Film thickness PET substrate 20 μm + OCA 10 μm PET substrate 35 μm + OCA 15 μm PET substrate 40 μm + OCA 20 μm PET substrate 50 μm + OCA 25 μm PET substrate 60 μm + OCA 30 μm Mold clamping temperature (℃) 65 65 65 65 65 Pressure holding time (s) 30 30 30 30 30 Influence of flat film on product surface after high temperature bending There are wrinkles on the attachment side and recesses at the four corners There are wrinkles on the attachment side and recesses at the four corners No wrinkles on the mounting surface, no recesses at all four corners No wrinkles on the mounting surface, no recesses at all four corners No wrinkles on the mounting surface, no recesses at all four corners Characteristic General ductility
Not resistant to high temperatures (80 to 90 ° C)
General ductility
Not resistant to high temperatures (90 to 100 ° C)
Superior ductility
Resistant to high temperatures (120 to 180 ° C)
Superior ductility
Resistant to high temperatures (120 to 180 ° C)
Superior ductility
Resistant to high temperatures (120 to 180 ° C)
Influence of mold clamping temperature on ink none none none none none conclusion Bad Bad Great Great Great

In addition, the inventors have experimentally found that if the thickness of the film substrate is too large (for example, greater than 60 micrometers), the film is easily wrinkled after high temperature bending and the molding is unstable. It can be seen from the experimental results in Table 1 that the effect is ideal when the thickness of the PET substrate of the film is 40 to 60 micrometers and the thickness of the OCA adhesive layer is 20 to 30 micrometers. According to the experimental results, finally, films of SKC brand (PET substrate 50 μm + OCA 25 μm) were selected as films for large-scale applications.

The present invention relates to a method of printing an ink pattern on a film material to be adhered to a curved glass, separately forming a film, setting a rebound margin of the film, and determining the specific thickness of the film substrate and the mold clamping temperature Wrinkles, depressions, and breakage problems that occur during adhering in the process of producing a curved glass containing an ink pattern. The curved glass obtained according to the present invention has high ink pattern accuracy on its surface, and the product has a sophisticated appearance.

The foregoing description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Those skilled in the art can variously modify and change the present invention. Any modifications, equivalent substitutions, improvements, etc., which are made within the spirit and scope of the present invention are intended to be included within the scope of protection of the present invention.

Claims (10)

A method for producing a curved glass containing an ink pattern,
Step A, printing step: printing an ink pattern on a flat film, wherein the thickness of the film substrate of the film is 40 to 60 micrometers;
Step B: High Temperature Bending of the Film: Placing the flat film obtained in Step A in a film high temperature bending mold for high temperature bending where the mold clamping temperature of the high temperature bending is 60 to 85 캜, Bending to be formed into a curved film and causing the ink pattern to be positioned on the concave and / or convex surface of the curved film; Designing the dimensions of the film high temperature bending mold to allow a rebound margin of the curved film to be greater than a degree of curvature of the curved film obtained; And
Step C, Attachment step: Attaching the outer convex surface of the curved film obtained in step B to the inner concave surface of the curved glass using a vacuum attachment apparatus to obtain a curved glass containing the ink pattern
≪ / RTI > The method of claim 1, wherein the film high temperature bending mold comprises an upper mold resilient block and the downward stroke of the upper mold resilient block is 2 to 8 mm, preferably 3 to 5 mm, Wherein the block squeezes the film upon mold clamping and the film is not moved during the high temperature bending process and the film is ensured to remain in the bottom mold after unfolding without sticking to the top mold. The method according to claim 1, wherein step A further comprises cutting the flat film containing the ink pattern, wherein the cutting is preferably carried out in accordance with the size of the plane spreading from the curved film obtained after molding, Wherein the flat film is cut. The method of claim 1, wherein the film substrate is a PET film and the film comprises an OCA adhesive layer covering the film substrate and one side of the film substrate, wherein the thickness of the OCA adhesive layer is 20 to 35 micrometers. The method of claim 1, wherein in the film high temperature bending mold, the flat film is positioned by a plurality of outer positioning positioning blocks and vacuum adsorption, and after hot bending, the film is first cooled , And then the mold is opened to take out the curved film, wherein the upper mold assembly and the lower mold assembly of the film high temperature bending mold are assembled by a plurality of sets of guide rods and guide sleeves To perform mold clamping positioning. The method of claim 1, wherein the mold clamping temperature of the hot bending in step B is 65 to 75 占 폚, the mold clamping pressure is 500 to 650 kgf, preferably 520 to 620 kgf, the hot bending time is 90 to 150 seconds , And the cooling time is 20 to 40 seconds. 7. The method of any one of claims 1 to 6, wherein the curvature of the curved film is greater than the curvature of the curved glass, and after bending the film at a high temperature, Wherein the arc retraction distance, d, of the curvature of the curved film is 0.2 to 1 mm, preferably 0.3 to 0.8 mm. 4. The method of claim 3, wherein the cutting method in step A is a die cutting using a cutting die and the high temperature bending of the film in step B uses hydraulic driving. 9. The method according to any one of claims 1 to 8, wherein in step C, the adhesion criteria of the curved film and the curved glass are captured using a CCD image sensor prior to the vacuum attachment, Wherein a high pressure defoaming process is further included after the curved glass is brought into close contact with the vacuum deposition apparatus. 10. The method according to any one of claims 1 to 9, wherein the thickness of the PET substrate of the film in Step A is 50 micrometers and the thickness of the OCA adhesive layer of the film is 25 micrometers.

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