KR20210131169A - High definition offset printing sheet - Google Patents

Abstract

The present invention relates to a high-definition offset printing sheet, which requires a strict quality level to be regarded as a defect despite a quality which is not problematic in a general printing product because it is not visible to the naked eye, when manufacturing a high-quality IT product (portable phone, electronic product) which requires almost no defect in reliability verification and appearance inspection. The high-definition offset printing sheet (1) may be prepared by preparing a printing sheet (2) which is printed on one surface of a film (10) with a high-definition FM SCREEN printing network and forms a printing layer (20), adhering a substrate layer (40) composed of a transparent sheet or film and the printing surface (20) of the prepared printing sheet (2) by adhering and curing the printing surface (20) of the prepared printing sheet (2) with a transfer adhesive (30) and a UV lamp, removing the film (10) of the adhered printing sheet (2), forming an optical pattern layer (50) which is formed by curing a UV resin on the surface of the printing layer (20) transferred to the substrate layer (40), and forming a reinforcement printing layer (70) for shielding protection on the surface of the reflective layer (60).

Description

High definition offset printing sheet

The present invention relates to a high-definition offset printing sheet capable of producing a high-quality print using a high-quality printing method on a thick and transparent double composite board in the production of a high-quality mobile phone surface material by minimizing the defect rate.

In general, a liquid crystal display provided as a mobile phone information communication display device, such as a smart phone or a tablet PC, falls or is liable to be damaged or damaged due to an impact. Accordingly, a protective back-cover is provided on the back side, and various decorations such as company logos, letters, symbols, and design patterns are sometimes performed through this.

In terms of shape, the application of 3D panels with curved edges of the panel is increasing in order to improve the three-dimensional effect and grip of the device.

In terms of material, the cover panel used in early smartphones was mainly a plastic injection panel using PC resin, which has the advantage of being inexpensive and easy to manufacture, but there is a limit to improving the design or appearance, and scratches occur due to its nature. There are problems that are easy to do and vulnerable to strength, heat, etc. Other metal panels such as aluminum and magnesium have also been used, but they are expensive and thick, and have a problem in hindering the realization of wireless communication performance.

A glass panel and a PC-PMMA composite sheet are proposed here. The former has the advantage of making the design glamorous and luxurious, but it is difficult to 3D molding, so the unit price is high, the productivity is low, and it has the disadvantages of being easily broken during the processing process or the user's use. In addition, the latter composite sheet has the advantage of being used as a structure that combines the high hardness of PMMA material and high strength of PC material. It is a disadvantage that it causes the defect yield to increase.

1. Printing method of resin film in parallel with UV offset printing and silk screen printing and its product Application No. 10-2009-0130087 2. Multifunctional thermal transfer paper with UV curable paint layer and its manufacturing method Application No. 10-2002-0051796 3. Transfer paper having UV offset printing layer and UV reinforcing layer and method for manufacturing the same Application No. 10-2005-0008501

The present invention produces high-quality IT products (mobile phones, electronic products) that require almost zero defects in reliability verification and visual inspection. This is for the production of 'high-definition offset printing sheets' that require a strict quality level to be considered defective.

That is, it is to solve the cause of the occurrence of moiré phenomenon and the deposition of particulates (dust foreign matter) or the pinhole (reflection) phenomenon caused by this. There should be no (moire) phenomenon, and secondly, in the printing sheet made of expensive thick plate or composite plate (PC-PMMA double rare), fine dust generated in the process of cutting to the required process size It solves problems such as poor foreign material deposition and pinhole defects, and thirdly, due to the fast printing speed due to the nature of offset printing for mass production, even if a foreign material defect is found and printing is stopped, there is a problem that there is no choice but to cause fixing defects in large quantities. Solves the problem of causing a loss in sheet cost, and other problems that are not mentioned can be clearly understood by those skilled in the art from the following description.

A printing sheet 2 that is printed with high-definition FM SCREEN printing dots on one side of the film 10 to form a printing layer 20 is prepared,

The base layer 40 made of a transparent sheet or film and the printed 20 side of the prepared printing sheet 2 are adhered by adhesion with a transfer adhesive 30 and curing with a UV lamp,

Peeling and removing the film 10 of the adhered printing sheet 2,

An optical pattern layer 50 formed by curing with UV resin on the surface of the printed layer 20 transferred to the base layer 40 is formed,

A reflective layer 60 is formed on the surface of the optical pattern layer 50,

This can be solved by manufacturing the high-definition offset printing sheet 1 characterized in that the reinforcing printed layer 70 for shielding protection is formed on the surface of the reflective layer 60 .

The high-definition offset printing sheet of the present invention was able to remove the moire phenomenon caused by the overlapping of the optical pattern and the printed halftone dots, and due to the fine dust already buried in the base layer, black spot printing caused by foreign matter or caused by foreign matter during the printing process It can solve the problem of non-printing, that is, pinhole defects, and because of the fast printing speed of the offset printing method, even if a foreign material defect is found during printing, it can solve the problem of fixed position defects that occur in large quantities, so product defects that occur in high-precision mass production It is possible to manufacture by minimizing

1 is a cross-sectional view illustrating a laminated cross-section of a 'high-definition offset printing sheet' according to an embodiment of the present invention.
2 is a view for explaining and exemplifying a printing sheet according to an embodiment of the present invention;
3 is a view illustrating a divided area of a printing sheet according to an embodiment of the present invention.
4 is a view illustrating an adhesion process of a printing sheet according to an embodiment of the present invention.
Figure 5 is a view illustrating a process of peeling off and removing the film after the bonding process according to an embodiment of the present invention.
6 is a view illustrating an optical pattern layer and an adhesive layer according to an embodiment of the present invention.
7 is a diagram illustrating an additional process according to an embodiment of the present invention.

The present invention produces high-quality IT products (mobile phones, electronic products) that require almost zero defects in reliability verification and visual inspection. This is for the production of 'high-definition offset printing sheets' that require a strict quality level to be considered defective.

1 is a view illustrating and explaining a structure laminated by the process of the present invention.

There is a base layer 40 at the lowermost end, and the base layer 40 may generally be a film, a plate sheet or a composite sheet. In particular, the composite sheet has the advantage of being used as a structure that combines the high hardness of PMMA material and the high strength of PC material. As mentioned above, it is a disadvantage that this amount is inevitable and causes a high defect yield.

Therefore, in order to print on the cut composite sheet, a process of removing fine particles (dust) using ultra-pure water 'water washing' or 'roll cleaning machine' was used before printing, but despite this method, if there is even a single dust , it was caused by a problem that it sticks to the printing roller and leads to a lot of fixing position defects.

Therefore, in order to solve the disadvantage of having to discard such an expensive composite sheet due to a large amount of defects, in the present invention, a low-cost thin film 10 that does not generate fine fragments, that is, PET, PP, PE, urethane, TPU, PVC, PC, Materials such as PMMA and silicone can be used. Therefore, the printing sheet 2 was prepared by first printing 20 on the film sheet selected according to the user's use. Then, by transferring this to the composite sheet 40 again, it was possible to solve a large amount of fixing position defects due to foreign substances continuously generated in the offset printing method.

However, another problem must be addressed here.

That is, it must be manufactured in a method that meets the moire removal printing condition and the complete transfer peeling condition of the printing surface.

Therefore, the moiré removal printing conditions are as follows.

The product of the present invention uses an optical pattern 50 for a high-grade surface design, and the optical pattern has different effects due to surface reflection depending on the design, and is converted with the light converted on the surface whenever the product moves. You can create a color image.

The optical pattern layer 50 is mainly manufactured by curing a UV resin material, and the pattern structure is mainly designed and molded in a finely etched line pattern.

However, the problem is that as the optical pattern 50 overlaps the printed dots of the printed layer 20 , a Moire phenomenon occurs.

The reason is because of the structural characteristics of the printing halftone dots of the offset printing method, which are mainly used as a printing method for mass production.

As exemplified in '(A) AM SCREEN DOT PRINT' in FIG. 2, the printing halftone dots of offset printing are made in a configuration in which fine halftone dots are vertically intersected to form an arrangement angle. Each arrangement angle is formed differently, and overlapping them creates a full natural color like the picture. However, as the dotted structure overlaps with the optical pattern 50 , a moire phenomenon occurs, which is a phenomenon that appears abruptly according to a similar density, arrangement structure, and angle change of the optical pattern 50 .

Therefore, in order to solve this problem, the halftone dots used in the present invention are to produce the printing layer 20 in the '(B) FM SCREEN DOT PRINT' printing halftone structure of FIG. 2, which is similar to the halftone dots of an inkjet printer. And it is composed of scattered printed dots, and is independent of the pattern arrangement structure of the optical pattern 50, so the moiré phenomenon disappears.

Another problem is that the printed layer 20 on the substrate layer 40 must be formed as a clean print without any flaws (defects), that is, the printed printed layer 20 of the print sheet 2 must be completely transferred and peeled off. .

Therefore, clean printing without flaws (defective) means that even if the printing layer is formed on one side of the film 10, there should be no residue (partial non-transfer) left in the process of transferring to one side of the base layer 40, and eventually perfect transfer And it is useless if the film is not peeled off.

However, the conventionally generally used transfer paper (or transfer film) has 'release coating treatment' and 'primer coating treatment' on one side of the film. In the case of release coating, it is manufactured so that the transfer can be carried out well as the release coating layer is peeled off between the printed layer adhered to the primer layer and the release coating layer.

Therefore, in the present invention, such a transfer film may be used, but by using the material properties of the printing film, the UV offset printing ink, and the transfer adhesive resin 30, perfect transfer is possible without the 'release coating' and 'primer coating' processes. In the end, it is possible to reduce the cost and time due to the reduction of the process.

However, in general, the printing sheet or film for 'UV offset printing' is corona-treated, plasma-treated, or primer-coated on its surface to increase surface friction, so that the printing ink adheres well and the adhesion of the print layer is well maintained. lose Conversely, the untreated film 10 has very weak surface adhesion with the film surface in 'UV offset printing'.

Therefore, in the transfer adhesive resin 30 used in the present invention, the printing layer 20 (cured UV offset ink) and the substrate layer 40 material are well adhered to each other, and the film 10 surface has a weak adhesive force. .

Therefore, when describing the printing sheet 2 manufactured according to another embodiment of FIG. 3 , the printing area 23 within the film area of the printing sheet is a 'product applied printing surface 21' and a 'product non-applied printing surface ( 22)'. In addition, it is preferable that the application area 31 to which the adhesive resin is applied is within the printing area 23, and even within the printing area 22, the product non-applied printing surface 22 is formed as a blank space without printing ink. .

However, since the adhesive resin 30 has a property of strongly bonding the surface of the printing layer 20 to the surface of the film 10, transparent or white or other colored ink, etc. It is preferable to print This is because if the adhesive resin 30 in direct contact with the film surface exposed to the product non-applied (blank part) area is cured, there is a risk of chemical property changes or changes over time, so the possibility of defective peeling and removal can be eliminated in advance. let there be This is because, when curing the UV adhesive resin 30 , compared to the printed surface 21 to which the product is applied, the amount of UV light is projected to the transparent portion somewhat more, so there is a risk of physical property change due to overcuring.

4 is a view illustrating the process of adhering the printing sheet 2 and the base layer 40 with the transfer adhesive resin of the present invention, and FIG. 5 is a view illustrating the process of peeling and removing the film after the adhesion process. .

The transfer adhesive resin 30 is made of UV-curable resin and is for adhesion of the substrate layer 40 surface and the printing layer 20 formed on the printing sheet 2 .

In the case of the composite sheet, since the base layer 40 is a sheet made of a double layer of PC and PMMA on both sides, specifically, the PC side of the composite sheet and the printed layer 20 of the printed sheet 2 are in contact with each other. make it adhere. This is because, in terms of durability and abrasion resistance, it is advantageous that the PMMA surface with high surface hardness should be exposed to the outside.

Therefore, as shown in FIG. 4, the adhesive resin 30 in a liquid state is pressed between the printing sheet 2 and the base layer 40, and then cured by a UV lamp and adhered to an integrated sheet state.

Then, as shown in FIG. 5, the film peeling process of the adhesive sheet made through the bonding process leaves only the printed layer 20 adhered to the base layer 40 PC surface and only the film 10 of the printed sheet 2 It is lightly peeled off and removed.

6 is a view for explaining the subsequent optical pattern forming process and the reflector application process.

An optical pattern layer 50 is formed on the surface of the printing layer 20 by a fine concavo-convex pattern. As mentioned above, the optical pattern layer 50 is made of a UV resin material and has a fine pattern pattern composition. Depending on the shape, the design effect that reflects the light is different.

Depending on the design of the fine pattern, a wave pattern or iridescent light may be produced, and the moiré phenomenon will be recognized visually when it overlaps the printed dots according to the pitch or angle of the pattern constituting the concavo-convex shape of the fine pattern. Therefore, one of the two elements of 'concave-convex pattern' and 'print halftone dots' is a method to prevent the moiré phenomenon only when an irregular pattern composition is formed.

Therefore, the soft mold etched in the fine pattern is covered on the upper surface of the printing layer 20, and the liquid UV resin is pressed between the soft mold and the printing layer 20 so that the liquid UV resin is applied, and the optical pattern layer 50 is cured with a UV lamp. It is made by copying and molding the fine pattern shape etched in the soft mold as it is.

Then, the reflective layer 60 is formed on the concave-convex surface of the optical pattern layer 50, and the reflector is coated with silver mirror or Miller ink, or the reflective material is brought into close contact through a deposition process.

Therefore, as mentioned above and as seen in the drawings, assuming that it is visually transmitted from the entire surface of the substrate layer, the printed halftone dots and the shape of the fine pattern of the printed layer overlap each other, and this is reflected by the reflective layer 60 to form a moire (Moire). ) phenomenon, the printed layer 20 mentioned above has a surface (tint) configuration without halftone dots, or an FM screen halftone dot that does not generate moiré even if there are halftone dots. can

Then, the reinforcing printed layer 70 is produced through silk screen printing. For the back shielding or durability, the reinforcing printed layer 70 is coated on the reflective layer 60 surface and manufactured, and is generally overprinted by 3 degrees or more. do. This completes the high-definition offset printing sheet 1 .

7 is a view illustrating an embodiment showing an additional process of the high-definition offset printing sheet (1).

Therefore, the high-definition offset printing sheet 1 made above is molded into a plate shape with a curved outer side through a thermoforming process. In particular, although the transfer adhesive layer 30 and the optical pattern layer 50 are already in a cured state, it will be preferable that the properties to be softened and hardened by heat together with other laminate structures should be well maintained.

In addition, the high-definition offset printing sheet 1 formed in this way is subjected to a hard coating on the surface of the substrate layer 40 to increase abrasion resistance and hardness, and is mainly manufactured by applying and curing UV resin by a spray method.

In the above, the technical idea of the present invention has been described along with the accompanying drawings, but this is an exemplary embodiment of the present invention and does not limit the present invention, and anyone with ordinary skill in the art can see this It is a clear fact that various modifications and imitations can be made without departing from the scope of the technical spirit of the present invention, and such modifications and imitations are included in the scope of the operational spirit of the present invention.

1. High-definition offset printing sheet
2. Print sheet
10. Film
20. Printed layer
21. Product application printing side
22. Non-product printed side
23. Print area
30. Transfer adhesive layer
40. Base layer
50. Optical pattern layer
60. Reflective layer
70. Reinforcement Printed Layer

Claims (11)

A substrate layer 40 made of a transparent film, sheet, or composite plate (PC, PMMA) is formed;
A transfer adhesive layer 30 for transfer adhesion of the printed surface is formed on one surface of the base layer;
The transfer adhesive layer 30 is adhered to the surface to form a 'FM SCREEN printed halftone dot' and transferred to form a bonded printing layer 20;
forming an optical pattern layer 50 made of a fine pattern formed by curing with UV resin on the surface of the printing layer 20;
A reflective layer 60 is formed on the surface of the optical pattern layer 50;
A reinforcing printed layer 70 for shielding protection is formed on the surface of the reflective layer 60;
High-definition offset printing, characterized in that the base layer 40, the transfer adhesive layer 30, the printing layer 20, the optical pattern layer 50, the reflective layer 60, and the reinforcing printing layer 70 are sequentially stacked and integrated seat(1) The method according to claim 1, wherein the base layer (40) is made of a composite plate (PC, PMMA 2 layers), and the PC side of the composite plate and the printed layer (20) are adhered to each other by a transfer adhesive layer (30). High Definition Offset Printing Sheet (1) [2] The high-definition offset printing sheet (1) according to claim 1, wherein the print layer (20) has a dot-printed dot structure instead of a dotted print. The high-definition offset printing sheet (1) according to claim 1, wherein the printing layer (20) is also printed with a transparent or other colored ink on the non-product-applied printing surface (22). The high-definition offset printing sheet (1) according to claim 1, wherein the optical pattern layer (50) has an irregular pattern or a holographic concave-convex pattern. The high-definition offset printing sheet (1) according to claim 1, wherein the optical pattern layer (50) is formed of an irregular pattern or a hologram concavo-convex pattern, and the printing layer (20) is formed of an AM screen halftone dot. The high-definition offset printing sheet (1) according to claim 1, wherein the reflective layer (60) is applied and dried (cured) with silver mirror or reflector ink on the surface of the optical pattern layer (50), or the reflector is adhered by deposition. The printing sheet 2 which is printed with high-definition FM SCREEN printing halftone dots on one side of the film 10 to form the printing layer 20 is prepared:
Adhering the substrate layer 40 made of a transparent sheet or film and the printed 20 side of the prepared printing sheet 2 with a transfer adhesive 30 and curing with a UV lamp;
peeling and removing the film (10) of the adhered printing sheet (2);
forming an optical pattern layer 50 cured with UV resin on the surface of the printed layer 20 transferred to the base layer 40;
a reflective layer 60 is formed on the surface of the optical pattern layer 50;
High-definition offset printing sheet (1) and manufacturing method, characterized in that the reinforcing printing layer (70) is formed on the surface of the reflective layer (60) for shielding protection. The high-definition offset printing sheet ( One). The high-definition offset printing sheet (1) according to any one of claims 1 to 8, wherein the film (10) of the printing sheet (2) has a film surface untreated. The method according to any one of claims 1 to 8, wherein the manufactured high-definition offset printing sheet (1) is additionally formed by thermoforming;
High-definition offset printing sheet (1) and manufacturing, characterized in that the forming-molded high-definition offset printing sheet (1) is manufactured by adding a hard coating process in which UV resin is applied and cured on the surface of the substrate layer (40) by a spray method Way.

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