KR20110024032A - Blanket for reverse off-set printing, and method of manufacturing the same - Google Patents

Abstract

PURPOSE: A reverse off-set printing blanket and a method for manufacturing the same are provided to improve the quality of a printing operation by improving the printing pressure margin property of a cushion layer. CONSTITUTION: A printing blanket includes a surface printing layer, a supporting layer, and a cushion layer. The cushion layer is formed on one side of the supporting layer as a base film. Liquid silicon resin containing hollow microspheres is coated on the base film, and the coated liquid silicon resin is hardened at room temperature in order to form the cushion layer. The surface printing layer is formed on opposite side of the base film.

Description

Reverse offset printing blanket and manufacturing method thereof {BLANKET FOR REVERSE OFF-SET PRINTING, AND METHOD OF MANUFACTURING THE SAME}

The present invention relates to a reverse offset printing blanket and a manufacturing method thereof, and more particularly, to a printing blanket having excellent cushioning characteristics of a cushion layer.

In general, electronic devices such as liquid crystal display devices and semiconductor devices are fabricated by forming a pattern of numerous layers on a substrate. In order to form such a pattern, a photolithography process has been mainly used until now.

However, the photolithography process has to produce a predetermined pattern mask, and the chemical etching and stripping processes have to be repeated, thus making the manufacturing process complicated and generating a large amount of chemical waste harmful to the environment. This, in turn, leads to an increase in manufacturing costs, which reduces the competitiveness of the product.

Accordingly, a roll printing method using a printing roll has been proposed as a new pattern forming method for solving the disadvantages of the photolithography process.

There are various methods of roll printing, but it can be roughly divided into two types, gravure printing and reverse offset printing.

Gravure printing is a printing method that scrapes excess ink by printing ink on a concave plate and prints it. It is known as a method suitable for printing in various fields such as publishing, packaging, cellophane, vinyl, polyethylene, and the like. Research has been made to apply the gravure printing method to the fabrication of the active element or circuit pattern to be applied.

Since gravure printing transfers ink onto a substrate by using a transfer roll, a pattern can be formed by one transfer even in the case of a display device having a large area by using a transfer roll corresponding to the area of a desired display element. . Such gravure printing not only forms an ink pattern for resist on a substrate, but also various patterns of the display device, for example, a TFT for gate lines, data lines, pixel electrodes, and capacitors connected to the TFT as well as a liquid crystal display device. It can be used to pattern metal patterns.

However, the blanket used for gravure printing is generally manufactured by casting a silicone-based resin on a rigid master mold. Thus, the blanket thus prepared is not only limited in manufacturing a uniform thickness, but also difficult to mass-produce on a pilot scale. There is this.

Therefore, a reverse offset printing method is mainly employed for precise fine pattern formation.

As a more detailed example of the prior art related to roll printing, ones of Documents 1 to 5, which are filed and published by the applicant of the present invention, can be illustrated. Document 1 is a printing roll; And a linear motor for moving in the front-rear direction while rotating the printing roll. The apparatus, by using a linear motor as a motor for driving printing rolls for coating and transfer, can minimize vibrations from the existing motors and provide a clean pattern without stains caused by vibrations.

Document 2 discloses a printing roll for a roll printing apparatus, and relates to a printing roll for a roll printing apparatus, characterized in that the cross-sectional area is reduced from the central region to both end regions.

Document 3 is a substrate; A substrate transfer device on which the substrate is mounted and which moves the substrate in one linear direction; A cliché disposed to face the plate surface of the substrate transfer device and having a pattern portion; A cliché on which the cliché is mounted so that the pattern portion of the cliché faces the plate surface of the substrate transfer device and moves the cliché in a straight line opposite the substrate transfer direction; A printing roll installed between the cliché feeder and the substrate transfer device to be rotatable in the same direction as the cliché feed direction; And a coater for coating a coating on the printing roll, wherein the distance from the leading end of each of the substrate and the cliché to the central axis of the printing roll perpendicular to the linear direction is different from each other. At the initial positions of the substrate and the cliché spaced apart on both sides of the roll, the substrate and the cliché are linearly moved in opposite directions toward the printing roll on both sides of the printing roll simultaneously with the rotation of the printing roll. The coating is coated on the printing roll by the coater, and as the cliché passes over the rotating printing roll, the coating of the printing roll is transferred to the pattern portion of the cliché, and the printing roll is rotating on the printing roll. As the substrate passes, the process of transferring the coating pattern remaining on the printing roll to the substrate is performed in one step. Disclosed is a roll printing apparatus characterized by the above-mentioned.

Document 4 includes a large area blanket comprising laminating a dry film photoresist on a substrate to form a dry film photoresist layer and exposing and developing the dry film photoresist layer to form a master pattern. Disclosed is a method for forming a master pattern for production.

Document 5 relates to a master mold manufacturing method and a pattern blanket manufacturing method using the same. One of the methods for producing a master mold for blanket production provided by the present invention includes the steps of: (S11) preparing a substrate for a master mold; (S12) coating one or two or more materials selected from chromium (Cr), indium tin oxide (ITO), and methacrylate-based compounds on the upper surface of the master mold substrate prepared in step (S11); (S13) laminating a dry film resist layer on the coating layer on the substrate for the master mold; And (S14) exposing and developing the dry film resist layer to form a resist pattern. The method relates to a method of manufacturing a master mold for blanket production, which includes advancing. The method has the advantage that a large area patterned blanket having a constant depth can be easily manufactured by using a master mold having enhanced release properties.

Document 1 KR 10-2008-0090890 (published) 2008.10.09.

Document 2 KR 10-2009-0020076 (published) 2009.02.26.

Document 3 KR 10-2009-0003883 (published) 2009.01.12.

Document 4 KR 10-2008-0065017 (published) 2008.07.11.

Document 5 KR 10-2009-0044120 (published) 2009.05.07.

The entire contents of the specification of Documents 1 to 5 are incorporated into the specification of the present invention as prior art to ordinary technology of the present invention.

Reverse offset printing is a very popular technique in terms of cost reduction and production speed in pattern formation, but a high quality blanket is required to obtain a precise pattern. That is, manufacturing a high quality blanket for printing is a very important technical problem in that the quality of the pattern may depend on the characteristics of the blanket.

In particular, the role of the cushion layer is very important. It is preferable that the surface printed layer has no thickness variation in terms of printing characteristics, but in practice, the surface printed layer may exhibit a very small thickness variation, and the cushion layer alleviates the irregularities of the surface printed layer due to the thickness variation of the surface printed layer. Let it be. In other words, if the thickness of the surface printed layer is irregular, surface stains may occur in the final printed pattern. If the pressure distribution effect of the cushion layer is excellent, the disadvantages caused by the thickness variation of the surface printed layer may be alleviated.

Accordingly, the present invention is to provide a printing blanket and a method of manufacturing the same having a cushion layer of excellent characteristics capable of forming an excellent pattern with excellent thickness uniformity but no residue.

The present invention has been made to solve the above problems of the prior art,

In the printing blanket comprising a surface printing layer, a support layer, and a cushion layer, the cushion layer is a hollow microspheres contained in the silicone rubber, the hollow microspheres are contained within the range of 0.1 to 1% by weight compared to the silicone rubber A print blanket is provided.

In addition, in the present invention, the hollow microspheres provide a printing blanket, characterized in that the particle size is within the range of 40 ~ 150 ㎛.

In addition, in the present invention, the hollow microspheres provide a printing blanket, characterized in that the density is within the range of 10 ~ 900 kg / m ³ .

In addition, in the present invention, the content ratio in the cushion layer of the hollow microspheres provides a printing blanket, characterized in that it has a gradient in the thickness direction.

In addition, in the present invention, the gradient provides a printing blanket, characterized in that the content ratio in the cushion layer of the hollow microspheres decreases toward the support layer direction.

Also,

In the printing blanket manufacturing method comprising a surface printing layer, a support layer, and a cushion layer,

Forming a cushion layer on one surface of the base film as the support layer; And

Forming a surface printing layer on one surface opposite to the base film,

The step of forming the cushion layer provides a printing blanket manufacturing method characterized in that the liquid silicone resin containing hollow microspheres are coated on a horizontally maintained substrate, followed by curing at room temperature.

In the method of the present invention, the step of forming the cushion layer provides a printing blanket manufacturing method, characterized in that it is included before the step of forming the surface printing layer.

In addition, in the method of the present invention, the room temperature curing provides a printing blanket manufacturing method, characterized in that made for a time of 1 to 3 days.

The printing blanket of the present invention is excellent in the in-pressure margin characteristics of the cushion layer is not only very good print quality of the final product, but also has an effect of improving the thickness uniformity of the surface printing layer due to the excellent cushioning of the cushion layer.

EMBODIMENT OF THE INVENTION Hereinafter, the printing blanket of this invention is demonstrated in detail.

The printing blanket of the present invention,

In the printing blanket comprising a surface printing layer, a support layer, and a cushion layer, the cushion layer is a hollow microspheres contained in the silicone rubber, the hollow microspheres are contained within the range of 0.1 to 1% by weight compared to the silicone rubber It features.

The silicone rubber cushion layer may be formed by curing a liquid silicone resin of polydimethylsiloxane (PDMS, polydimethylsiloxane) component (the method of forming each layer including the cushion layer will be described in detail below).

In particular, the hollow microspheres are preferably contained within 0.1 to 1% by weight compared to the silicone rubber. If it is less than 0.1 weight%, there exists a possibility that the effect of adjusting the pressure by a cushion layer may be inadequate. In addition, when the blending ratio of the hollow microspheres is more than 1% by weight, the cushion layer becomes too soft, and there is a fear that the printing accuracy is lowered.

The hollow microspheres are preferable in terms of improving the cushioning properties of the cushioning layer having a particle diameter within a range of 40 to 150 μm. If the thickness is less than 40 µm, the effect on improving the cushion characteristics may be minimal. If the thickness exceeds 150 µm, the hollow microspheres may be excessively subjected to the pressure applied to the cushion layer during roll printing, thereby breaking the hollow microspheres.

In particular, the content ratio in the cushion layer of the hollow microspheres has a gradient in the thickness direction, the gradient is preferably that the content ratio in the cushion layer of the hollow microspheres toward the support layer direction decreases. When the hollow microspheres are uniformly dispersed in the entire cushion layer area, the adhesion force with the base film as the support layer may be considerably lowered due to the presence of the hollow microspheres, and the hollow microspheres near the support layer may be broken by the pressure. Not good to be.

The blanket of the present invention may be produced by applying a polydimethylsiloxane (PDMS, polydimethylsiloxane) containing a hollow microsphere to the base film and then curing at room temperature. In general, the process of forming the cushion layer is formed by mainly thermosetting liquid silicone resin (polydimethylsiloxane (PDMS)) containing hollow microspheres. There is no content gradient of microspheres.

Therefore, in the present invention, it is preferable to cure the liquid silicone resin containing the hollow microspheres at room temperature for a relatively long time. When it is hardened at room temperature, due to the buoyancy difference between the polydimethylsiloxane and the hollow microspheres, the hollow microspheres slowly float upwards. When hardened through this process, the hollow microspheres are distributed in the vicinity of the support layer, and the hollow microspheres are distributed on the opposite side.

The hollow microspheres preferably have a density within the range of 10 to 900 kg / m ³ . If the density is less than 10 kg / m ³ hollow microspheres float too fast, it may not be able to form a concentration gradient of the appropriate hollow microspheres, and for the same reason, the hollow microspheres do not support well above 900 kg / m ³ It may not be possible to form a concentration gradient of suitable hollow microspheres. More preferably, the hollow microspheres have a density within the range of 15 to 50 kg / m ³ .

In addition, the present invention,

In the printing blanket manufacturing method comprising a surface printing layer, a support layer, and a cushion layer,

Forming a cushion layer on one surface of the base film as the support layer; And

Forming a surface printing layer on one surface opposite to the base film,

The step of forming the cushion layer relates to a printing blanket manufacturing method, characterized in that for coating the liquid silicone resin containing hollow microspheres on a substrate, and then curing it at room temperature.

In particular, the step of forming the cushion layer is preferably included before the step of forming the surface printing layer. This means that if the cushion layer is formed later than the surface printing layer, the cushion layer is laid on the floor when the surface printing layer is formed, and the cushion layer may serve to buffer the fine but irregular thickness uniformity of the horizontal band (or surface plate). Because. If the cushion layer is formed first, it is very preferable because it helps to ensure a better thickness uniformity in forming the surface printing layer.

The room temperature curing is preferably made for a time of 1 to 3 days.

Hereinafter, the manufacturing method of the present invention will be described in more detail at each layer forming step.

First, a substrate to be used for the printing blanket is prepared. As a base material, it is preferable to use the film with a small elasticity in order to suppress the expansion and contraction of a surface printing layer and a cushion layer, and to improve the precision of printing. In particular, a film of a resin having a tensile modulus of at least 1000 MPa at room temperature, particularly 2000 to 5000 MPa, is suitable. Examples of such films include polyester films such as polyethylene terephthalate (PET), polycarbonate films, and the like.

Although the thickness of a base material is not restrict | limited, It is suitable that it is 0.1-0.5 mm, and 0.2-0.45 mm is preferable. If the thickness of the substrate is less than this range, the effect of reinforcing and supporting the cushion layer or the surface printed layer by the substrate may be insufficient.

Next, the liquid mixture which the cushion layer formed in one surface of the said base material has is manufactured. The mixture is prepared by blending the liquid silicone resin and the hollow microspheres, and mixing the hollow microspheres to be uniformly dispersed in the liquid silicone resin.

As the hollow microspheres, known ones can be used without limitation. However, in consideration of swelling prevention by ink, homopolymers of polymerizable monomers such as polymerizable monomers such as vinylidene chloride, (meth) acrylonitrile, or monomers thereof may be used. Hollow microspheres in which the shell is formed of a copolymer containing two or more kinds are preferable.

Although the particle size of a hollow microsphere is not specifically limited, In order to exhibit the effect of adjusting the phosphorus pressure by a cushion layer favorably, it is more preferable that the average particle diameter is 20-200 micrometers, especially 40-150 micrometers.

The hollow microspheres are suitably blended in a proportion of 0.1 to 1% by weight based on the entire liquid silicone resin. If the blending ratio of the hollow microspheres is less than this range, the effect of adjusting the pressure by the cushion layer is not obtained. In addition, when the blending ratio of the hollow microspheres exceeds this range, the cushion layer becomes soft and the printing precision is lowered. In addition, the viscosity of the mixture is high, making it difficult to uniformly apply the mixture to the desired thickness.

Next, at the same time, the mixture is applied to one surface of the substrate, and the silicone resin is cured in a state where the substrate is held horizontally to form a cushion layer. For this purpose, it is possible to use a leveling stone platform. In this case, the mixture is uniformly formed and cured by its own weight, and at the same time, the content ratio of the hollow microspheres has a gradient in the thickness direction.

In order to apply the mixture to one surface of the substrate, a roll coater, bar coater, flow coater, gravure coater, spray, applicator, or the like may be used. In addition, it is preferable that the substrate is in a state where the horizontal is completely exhausted, and it is preferable that the substrate is in a state where the substrate is in close contact with the horizontal object. To this end, a method of applying tension on both sides of the base film and bringing it into close contact with the surface of the horizontal band, having a fine suction hole in the horizontal band, and inhaling it through the horizontal band may be used.

Silicone resin can be divided into thermosetting type and room temperature curing type according to the type to be cured, but all of the above can be used as the silicone resin which can be used in the present invention, but the embodiment of the present invention used a room temperature curing type ( Hardening time should be appropriately added or subtracted according to the type of silicone resin to be cured). After the mixture is applied, it is allowed to stand for a certain period of time under a normal temperature environment (23 ± 3 ° C.) without heating and to undergo a curing reaction. This is preferable because it can prevent volatilization of low molecular weight silicone oil, prevent expansion and destruction of hollow microspheres, and save heat energy required for the curing process.

Although the thickness of the said cushion layer is not specifically limited, It is preferable that it is 0.1-2 mm, and it is more preferable that it is 0.3-1 mm. If the thickness of the cushion layer is less than this range, there is a fear that the effect of adjusting the pressure of the cushion layer may not be sufficiently obtained. If the thickness of the cushion layer is exceeded, the thickness of the substrate may be relatively small, resulting in a problem that the supporting effect of the layers of the substrate is lowered. There is.

Next, a surface printing layer is formed on one side of the other side of the substrate. The surface printed layer is a nonporous layer. Such a non-porous surface printing layer may be formed according to various forming methods. Specifically, the liquid silicone resin is cured while the liquid silicone resin is applied to the opposite side of the substrate and the substrate is kept horizontal. The method of forming the surface printing layer integrated with a base material is preferable.

Although the thickness of the said surface printing layer is not limited to this, 0.01-1.2 mm is preferable and it is more preferable that it is 0.1-1 mm. In order to form the surface printed layer whose thickness is less than this range, the application amount of liquid silicone resin must be made extremely small, the leveling property may fall, and the uniformity of the surface printed layer thickness may be impaired. Moreover, when thickness exceeds this range, there exists a possibility that the effect of adjusting the pressure by a cushion layer may not fully be acquired.

It is preferable that the total thickness of the printing blanket which has each said layer is 0.7-3 mm, and it is more preferable that it is 0.9-2 mm. When the thickness of the printing blanket is less than this range, the effect of adjusting the pressure of the printing blanket may be lowered. In the range exceeding this range, the thickness of the blanket may be too large, making it difficult to wind the blanket onto the roll.

A primer layer may be formed between the substrate and the layers to increase adhesion and integrity between the substrate and the layers. The primer layer may be formed in any thickness to suit the purpose without limitation. The material of a primer layer can be used as what contains a silane coupling agent with favorable affinity with silicone resin. When the cushion layer and the surface printing layer are formed without the primer layer, the surface of the substrate is physically or chemically treated to give affinity for the silicone resin and the mixture is applied to one side of the substrate to secure the adhesion to the substrate. It is desirable to.

Hereinafter, the present invention will be described in more detail with reference to Examples. Embodiments herein are for the purpose of describing the invention only, and are not intended to limit the scope of the invention.

Example

The liquid silicone resin (of Shin-Etsu Silicone Co., KE1606, viscosity 50,000cP) hollow microspheres to 100 parts by weight of (EXPANCEL NOBEL company AKZO: the particles have a distribution of 60 ~ 100 ㎛, density will of 20 kg / m ³⁾ about 0.56 wt. Part was added, mixed and uniformly dispersed, and then about 10 parts by weight of the curing agent was added.

Next, a primer was applied to the surface of the substrate in a state where the polyethylene terephthalate (PET) substrate film having a thickness of about 0.35 mm was completely adhered to the surface plate, and the solvent was volatilized, and then the mixture was about 420 cm × The coating was evenly applied to an area of 600 cm using an applicator. This was cured at room temperature (23 ± 3 ° C.) for about 3 days to form a cushion layer having a thickness of 0.7 mm.

Next, while maintaining the state in which the base film is in close contact with the surface of the stone plate, silicone oil was applied to the surface of the cushion layer using a spray and dried at room temperature for 1 hour. The silicone oil is to alleviate the stickiness of the cushion layer, and serves to help the blanket to be well mounted on the roll.

Thereafter, the base film is inverted so that the opposite side of the base film is placed upward, and then a primer is applied to the surface of the substrate, the solvent is volatilized, and the silicone resin containing no hollow microspheres is completely in contact with the surface plate. It was evenly applied to the area of 420 cm × 600 cm by using an applicator. This was cured at room temperature (23 ± 3 ° C.) for about 3 days to form a surface printed layer with a thickness of 0.4 mm.

As a result, the fabrication of a printed blanket equipped with a cushion layer including about 0.5% by weight of hollow microspheres was completed. 1 shows the structure of an embodiment printed blanket, and FIG. 2 is a cross-sectional electron micrograph of an embodiment of the present invention.

Comparative example  One

In the cushion layer forming step of the above embodiment, except that the use of a liquid silicone resin containing no hollow microspheres, all were manufactured in the same manner as the printing blanket.

Comparative example  2

In the cushion layer forming step of the above embodiment, all of the same method except for using the liquid silicone resin to which the hollow microspheres were added 5.6 parts by weight (about 10 times the hollow microspheres content of the embodiment) to 100 parts by weight of the liquid silicone resin The printing blanket was produced.

Comparative example  3

In the cushion layer forming step of the above embodiment, all of the same as in the above embodiment, except that the liquid silicone resin (hollow microsphere content is the same as the embodiment) and the rapid thermal curing at about 100 ℃ temperature containing hollow microspheres The printing blanket was produced by the method.

Experimental Example

Pattern uniformity was measured, the bottom contact phenomenon observation, and the pressure-pressure margin measurement were performed about the said Example and Comparative Examples 1-3.

The measurement method is as shown below, and the measurement results were as shown in Table 1 below.

* Pattern uniformity measuring method

When printing the data electrode of the TFT-LCD using a reverse offset printing machine, the shape and line width of the pattern were checked through a microscope over the entire area to quantify the effective area relative to the printed surface.

* How to observe floor contact

The pattern shape was measured to observe whether there was a bottom contact phenomenon.

3A is a photograph of the pattern shape of the embodiment, and FIG. 3B is a photograph showing the pattern shape of Comparative Example 1. FIG.

* How to measure the pressure margin

The pressure is the pressure applied to the blanket when the plate and the blanket are bonded to each other when printing a pattern with a reverse offset printing press. The larger the pressure margin is, the easier it is to print the thickness variation of the blanket. The pressure margin measurement measured whether or not good printing occurred without pattern pattern NG when increasing the printing pressure by narrowing the interval by 10 μm with a negative value with the contact point of the blanket and the plate as '0'.

Example Comparative Example 1 Comparative Example 2 Comparative Example 3 Pattern uniformity 100% 50% 80% 80% Floor contact Very good Bad Good Good Pressure margin △ 50㎛ No margin △ 30㎛ △ 20㎛

As shown in Table 1, the cushion layer containing the hollow microspheres (Example, Comparative Example 2, Comparative Example 3) showed an overall excellent pattern uniformity, excellent pattern shape, high pull pressure margin than otherwise. In particular, as shown in Figure 3a, Figure 3b, when the cushion layer contains the hollow microspheres, the bottom contact phenomenon, the pattern of the pattern is thinned compared to the cliché, the tail of the pattern is curled, the tail length is longer than the cliché It can be seen that the curling phenomenon is significantly improved.

In addition, it can be seen that it is better to contain a suitable amount than that containing too many hollow microspheres (Comparative Example 2). If too many hollow microspheres are included, it is presumed that the cushion layer becomes too soft and rather deteriorates printing accuracy. This can also be seen from the fact that the floor shows a poor performance compared to the embodiment.

In addition, it was confirmed through Example and Comparative Example 3 that even in the case of containing an appropriate amount of hollow microspheres having a suitable gradient in the thickness direction can improve the print quality. In the case of Comparative Example 3, the shape of the pattern such as the bottom contact was not as good as that of the Example. This is due to the rapid hardening condition. It is presumed that the function is weakened, which causes the local pressure on the surface printed layer to be locally changed, thereby degrading the print quality.

1 is a view schematically showing a cross-sectional structure of an embodiment blanket of the present invention.

Figure 2 is a photograph taken with an electron microscope of the cross section of the embodiment blanket of the present invention.

Figure 3a is a photograph showing the pattern shape of the embodiment.

Figure 3b is a photograph showing the pattern shape of Comparative Example 1.

Claims (8)

In the printing blanket comprising a surface printing layer, a support layer, and a cushion layer, the cushion layer is a hollow microspheres contained in the silicone rubber, the hollow microspheres are contained within the range of 0.1 to 1% by weight compared to the silicone rubber A print blanket characterized by the above-mentioned. The printing blanket of claim 1, wherein the hollow microspheres have a particle diameter within a range of 40 μm to 150 μm. The printing blanket of claim 1, wherein the hollow microspheres have a density within the range of 10 to 900 kg / m ³ . The printing blanket according to claim 1, wherein the content ratio of the hollow microspheres in the cushion layer has a gradient in the thickness direction. The printing blanket of claim 4, wherein the gradient is a content ratio in the cushion layer of the hollow microspheres decreasing toward the supporting layer. In the printing blanket manufacturing method comprising a surface printing layer, a support layer, and a cushion layer, Forming a cushion layer on one surface of the base film as the support layer; And Forming a surface printing layer on one surface opposite to the base film, The step of forming the cushion layer is a printing blanket manufacturing method, characterized in that for coating the liquid silicone resin containing hollow microspheres on a horizontally maintained substrate, and then curing it at room temperature. The method of claim 6, wherein the forming of the cushion layer is performed before the forming of the surface printing layer. 7. The method of claim 6, wherein the room temperature curing is performed for a time of 1 to 3 days.

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