JP2010099862A - Medium for solvent ink with release layer - Google Patents

Abstract

An object of the present invention is to provide a solvent ink medium that prevents transfer of an image or print from an image receiving layer to a release layer in a conventional solvent ink medium and that does not damage the image or print even if it is wound immediately after printing.
A solvent ink medium according to the present invention includes a base material layer, an acrylic resin, a urethane resin, and an acrylic resin formed on an upper surface of the base material layer for receiving and fixing the solvent ink from the ink jet printer. An image receiving layer made of a vinyl chloride resin or a mixture thereof, an adhesive layer formed on the lower surface of the base material layer, and a release layer made of TPX or OPP adhered to the base material layer by the adhesive layer; It is the structure containing these.
[Selection] Figure 1

Description

  The present invention relates to a medium that can be printed by an ink jet printer that uses a solvent ink, and that does not easily peel off a printed image from an image receiving layer even after winding immediately after printing.

  A sheet or film-like printing medium that uses polyethylene terephthalate (PET) or vinyl chloride as the base material and can be printed by an inkjet printer on its surface is called "media" and can be attached to glass or the like with an adhesive layer. The type is widely used for signs and advertisements.

  Printing with an ink jet printer is a print that prints a monochrome or color image (or print) at high speed on the media surface by ejecting fine droplets of ink containing a coloring material consisting of a dye or pigment from the nozzle onto the media surface. It is a method. Inks used in ink jet printers are roughly classified into water-based inks and solvent inks (non-water-based inks). Usually, from the viewpoint of safety and recording characteristics, water is the main component, and a small amount of alcohol is used. Added aqueous ink is often used.

  For example, an adhesive sheet material that can be used as an object to be printed on an ink jet printer, and has a flexible substrate, an ink image-receiving layer on the upper surface, an adhesive layer on the opposite surface, and a release film. A sheet material is disclosed in Patent Document 1.

  In addition, the ink receiving layer has an anchor layer that prevents the ink receiving layer from peeling off near the ink receiving layer due to stimulation of the ink solvent or the like, and the surface ink receiving layer and the base sheet sheet being turned up. And the receiving layer comprises 55 to 75 parts by mass of water-insoluble resin containing 40 to 70% by mass of polyurethane resin and 60 to 30% by mass of other water-insoluble resin, polyvinyl alcohol and / 50 to 100 parts by mass of an inorganic pigment with respect to 100 parts by mass of a resin including 30 to 70% by mass of a modified product thereof and 25 to 45 parts by mass of a water-soluble resin containing 70 to 30% by mass of polyvinylpyrrolidone; An ink jet recording sheet comprising 2 to 20 parts by mass of a soluble magnesium salt (anhydrous salt equivalent) is disclosed in Patent Document 2.

On the other hand, in the case of a signboard used outdoors, it is preferable to use a solvent ink because water-based ink tends to cause blurring of images or prints due to rain and fading due to sunlight. Many solvent ink media use PET or vinyl chloride as a base material and acrylic resin or urethane resin as an image receptor layer. There is also an adhesive sheet-like medium in which a release layer made of PET resin is bonded to a base material via an adhesive layer on the opposite side of the image receiving layer.
JP-A-9-300520 JP 2007-160746 A

  However, when a release layer made of PET resin is provided on the ink solvent media, if the media sheet is wound immediately after printing, the image or print on the receiver layer and the release layer stick together, and then the media There is a problem that an image or print is easily damaged when the sheet is spread.

  In order to prevent this, after printing, it is necessary to leave the media after printing without winding up for about 15 to 30 minutes to completely dry the image or printing. For this reason, work efficiency has been significantly reduced.

  An object of the present invention is to solve the above-mentioned problems in conventional solvent ink media, and to provide a solvent ink media that does not damage the image or the print even if it is wound immediately after printing.

  If the present inventor uses methylpentene polymer (TPX) or biaxially stretched polypropylene (OPP) as the material of the release layer, the image receiving image can be obtained even after winding using a solvent ink with an ink jet printer. The present inventors have found that the image or print printed on the body layer does not transfer to the release layer, and have completed the present invention.

Specifically, the present invention
A base material layer;
An image receiving layer made of an acrylic resin, a urethane resin, a vinyl chloride resin or a mixture thereof formed on the upper surface of the base material layer in order to receive and fix the solvent ink from the ink jet printer;
An adhesive layer formed on the lower surface of the base material layer;
And a release layer made of TPX or OPP adhered to the base material layer by the adhesive layer.

  In order to print with a solvent ink, the image receiving layer is preferably an acrylic resin, a urethane resin or a mixture thereof. However, if the release layer is TPX or OPP, the media is wound immediately after printing. Even if the image receptor layer and the release layer are brought into contact with each other, the print or image printed on the image receiver does not stick to the release layer. For this reason, unlike the conventional solvent ink media, the solvent ink media of the present invention does not require a drying step after printing, and the efficiency of printing work is high.

  The wetting tension of the outer surface of the release layer (the surface not in contact with the adhesive layer) is preferably 33 dyne or less in the wetting tension test specified in JIS K6768. This is because if the wetting tension exceeds 33 dyne, the image receiving layer after printing and the outer surface of the release layer will stick, but if it is 33 dyne or less, it will not stick. (In the case of winding)

  The surface roughness of the outer surface of the release layer is preferably an arithmetic average roughness (Ra) of 5 or more and 10 or less as defined in JIS B0601. When the roll is wound, the outer surface of the release layer (the surface that does not come into contact with the adhesive layer) that comes into contact with the image receiving layer has a certain degree of unevenness on the surface. . If Ra is less than 5, if the film is wound immediately after printing, the image or printing is easily transferred. On the other hand, if Ra exceeds 10, there arises a problem that irregularities are transferred to the surface of the image receiving layer.

  The substrate layer is preferably PET, polypropylene (PP), vinyl chloride or paper.

  The thickness of the image receiving layer and the release layer is preferably 25 μm or more and 150 μm or less, respectively. This is because if the image receiving layer is less than 25 μm, it is difficult to hold the solvent ink, and if it exceeds 150 μm, the manufacturing cost increases, making it difficult to use as a medium. For the release layer, if the surface roughness (Ra) is less than 25 μm, it is difficult to make the surface roughness (Ra) 5 or more. If it exceeds 150 μm, the manufacturing cost increases and winding after printing becomes difficult. .

The water vapor transmission rate of the release layer is preferably 20 g / m ² · 24 hr · atm or more and 150 g / m ² · 24 hr · atm or less. When the water vapor transmission rate of the release layer is within this range, even when using not only water-based ink but also solvent ink, the image receiving layer and the release layer are brought into contact by winding the media immediately after printing. Even if it makes it, it is hard to stick the printing or image printed on the image receiving layer to a mold release layer.

  The inner surface of the release layer (the surface in contact with the adhesive layer) is preferably subjected to corona treatment so that it becomes 36 dyne or more in the wetting tension test specified in JIS K6768. When PET or PP as the base material layer and TPX or OPP as the release layer are bonded via the adhesive layer, the adhesive layer moves to the base material layer side when the release layer is peeled later. If it is better to leave the adhesive layer on the substrate layer when using the printed media, it is not necessary to corona-treat the inner surface of the release layer.

  Conversely, when the adhesive layer is not required when using the media after printing, and it is better that the adhesive layer does not remain on the base material layer, the adhesive layer needs to be discarded while moving to the release layer.

  If corona treatment is applied so that the inner surface of the release layer is 36 dyne or higher in the wetting tension test specified in JIS K6768, the wetting tension of the inner surface of the release layer increases and the adhesion with the adhesive layer improves. When the release layer is peeled off, the adhesive layer moves to the inner surface of the release layer instead of the base material layer and can be discarded together with the release layer.

  According to the solvent ink medium of the present invention, the printing operation time can be shortened. Further, even if the film is wound after printing and stored as it is, the transfer of the image or printing to the release layer is unlikely to occur.

  Embodiments of the present invention will be described below with reference to the drawings as appropriate. The present invention is not limited to the following description.

  A schematic cross-sectional view of the solvent ink medium of the present invention is shown in FIG. In FIG. 1, the front surface means a surface facing the printing nozzle of the ink jet printer, and the back surface means the opposite side. On the outermost surface, there is formed an image receiving layer 1 for holding a solvent ink discharged from a printing nozzle of an ink jet printer and forming an image or printing.

  The image receptor layer 1 is bonded to the base material layer 2. The image receptor layer 1 and the base material layer 2 are bonded by an adhesive layer (not shown). In addition, since both are not isolate | separated here, the adhesion method of both is not specifically limited.

  The image receptor layer 1 is an acrylic resin, a urethane resin, or a mixture (mixed resin) thereof. The thickness is preferably 25 μm or more and 150 μm or less. On the other hand, the base material layer 2 is preferably made of PET, PP, vinyl chloride or paper, and the thickness thereof is preferably 50 μm or more and 250 μm or less, more preferably 80 μm or more and 150 μm or less. This is because it is preferable in terms of dimensional stability and handling properties.

  An adhesive layer 3 is formed on the back surface side of the base material layer 2, and the release layer 4 and the base material 2 are bonded to each other by the adhesive layer 3. The release layer 4 is peeled off at the time of use, and the image receptor layer 1, the base material layer 2, and the adhesive layer 3 are attached to the non-adhesive surface. The image receptor layer 1, the base material layer 2, and the adhesive layer 3 may be transparent or opaque depending on the application. Moreover, you may give appropriate coloring.

  In addition, since the release layer 4 is removed from the adhesive layer 3 during use, the solvent ink medium of the present invention does not need to firmly bond the base material layer 2 and the release layer 3. The adhesive layer 3 is preferably made of acrylic, natural rubber or the like, and the thickness is preferably 5 μm or more and 20 μm or less.

[Example 1]
Solvent ink media with PVC resin (thickness 40 μm) as the image receptor layer, PET (thickness 100 μm) as the base layer, adhesive layer (thickness 10 μm, adhesive is acrylic), and TPX (thickness 100 μm) as the release layer Manufactured. In addition, the wetting tension of the outer surface of the release layer was tested by the wetting tension test specified in JIS K6768. .

  Using an ink jet printer for large solvent ink (XJ-540, manufactured by Roland), printing on the ink receiving layer, and using a winder, the medium for solvent ink so that the printed image receiving layer is inside Rolled up. At this time, the image receiving layer on which printing has been performed is in contact with the release layer located on the back side of the solvent ink medium. The ink jet printer used a solvent ink manufactured by Ginichi Co., Ltd. (main solvent: isopropylene glycol acetate), the printing mode was applied three times for the decoration media, and the heater temperature was 40 ° C.

  The wound-up solvent ink medium was allowed to stand at room temperature all day and night, and then developed into a flat shape, and the printing state of the solvent ink medium image receptor layer was confirmed.

[Comparative Example 1]
Solvent ink media were produced under the same conditions as in Example 1 except that PET (thickness 50 μm) was used as the release layer. Then, printing, winding, standing and unfolding were performed under the same conditions as in Example 1, and the printing state of the media receiver layer for solvent ink was confirmed. The wetting tension of the release layer was confirmed to be reagent No. 36 (36 dyne) by conducting a wetting tension test specified in JIS K6768.

  In Example 1, as shown in FIG. 2A, the print (solvent ink) on the image receiving layer was not transferred at all to the release layer (white portion on the left side of the photograph). On the other hand, in Comparative Example 1, as shown in FIG. 2B, the print on the image receiving layer is partially transferred to the release layer, and the print is damaged (the portion surrounded by circles is the transfer of the print). ).

[Example 2]
Solvent ink media were manufactured under the same conditions as Example 1 except that OPP (thickness: 100 μm) was used as the release layer. This solvent ink medium was printed, wound up, allowed to stand and developed under the same conditions as in Example 1, and the printing state of the solvent ink medium image receptor layer was confirmed. Was not transcribed at all. In addition, the wetting tension of the release layer was subjected to a wetting tension test specified in JIS K6768, and it was confirmed that it was not wet with Reagent No. 30 (30 dyne), and was confirmed to be 30 dyne or less.

[Example 3]
The printing state of the media receiver layer for solvent ink was confirmed in the same manner as in Example 1 except that NAZDAR solvent ink (main solvent: diethyl glycol diethyl ether) was used as the solvent ink.

[Comparative Example 2]
The printing state of the media receiver layer for solvent ink was checked in the same manner as in Comparative Example 1 except that the solvent ink manufactured by NAZDAR was used as the solvent ink.

  In Example 3, as shown in FIG. 3A, the print (solvent ink) on the image receiving layer was not transferred to the release layer (white portion on the left side of the photograph) at all. On the other hand, in Comparative Example 2, as shown in FIG. 3B, the print on the image receiving layer was transferred to the release layer at a plurality of locations, and the print was damaged (the portion surrounded by ○ is the transfer of the print). Is).

[Example 4]
First, a corona surface treatment device (Kasuga Electric high frequency power supply AGF-010) was used on one side of the same TPX (thickness 100 μm) as the release layer of Example 1 under the conditions of current 2.5 A and line speed 5 m / min. Processed. The same adhesive layer as in Example 1 was applied to the corona-treated surface, and a PET film having a silicon-treated surface was laminated. Thereafter, the adhesive layer was cured by allowing it to stand at room temperature for 1 week.

  Next, the PET film was peeled off, and the same PET base material (base material layer) as in Example 1 was bonded to the adhesive layer remaining on the corona-treated surface of TPX, and allowed to stand at 40 ° C. for 48 hours. After standing for 30 minutes in an atmosphere of a temperature of 23 ° C. and a humidity of 50%, the TPX layer (release layer) was peeled off, and the migration state of the adhesive layer was confirmed. The same operation is performed when corona treatment is not performed on TPX (the manufactured solvent medium is the ink solvent of Example 1), and the adhesive layer moves after the TPX layer (release layer) is removed. It was confirmed.

  In the case of Example 1, as shown in FIG. 4A, the adhesive layer was transferred from the release layer to the base material layer when the corona treatment was not performed. In FIG. 4A, the central part of the base material layer appears to be cloudy because of the irregular reflection of the adhesive layer that has moved to the surface of the base material layer. On the other hand, in the case of Example 3, as shown in FIG. 4 (b), the adhesive layer has moved to the release layer, and no fogging due to the transfer of the adhesive layer is observed on the surface of the base material layer. It was.

  The solvent ink medium of the present invention is useful in fields such as printing and advertising.

It is a schematic sectional drawing of the medium for solvent inks of this invention. It is the photograph which image | photographed the surface of the medium for solvent inks after expansion | deployment, (a) is a photograph of Example 1, (b) is a photograph of the comparative example 1. FIG. It is the photograph which image | photographed the surface of the medium for solvent inks after expansion | deployment, (a) is a photograph of Example 3, (b) is a photograph of the comparative example 2. FIG. It is the photograph which image | photographed the base-material layer surface at the time of release layer peeling, (a) is a photograph of Example 1, (b) is a photograph of Example 4. FIG.

Explanation of symbols

1: Image receptor layer 2: Base material layer 3: Adhesive layer 4: Release layer

Claims (7)

A base material layer;
An image receiving layer made of an acrylic resin, a urethane resin, a vinyl chloride resin or a mixture thereof formed on the upper surface of the base material layer in order to receive and fix the solvent ink from the ink jet printer;
An adhesive layer formed on the lower surface of the base material layer;
A solvent ink medium comprising: a release layer made of methylpentene polymer or biaxially stretched polypropylene adhered to the base material layer by the adhesive layer.   The solvent ink medium according to claim 1, wherein the wetting tension of the outer surface of the release layer is 33 dyne or less in a wetting tension test specified in JIS K6768.   The medium for solvent ink according to claim 1 or 2, wherein the surface roughness of the outer surface of the release layer is an arithmetic average roughness (Ra) of 5 or more and 10 or less as defined in JIS B0601.   The solvent ink medium according to claim 1, wherein the base material layer is made of polyethylene terephthalate, polypropylene, vinyl chloride, or paper.   5. The solvent ink medium according to claim 1, wherein the image receiving layer and the release layer each have a thickness of 25 μm or more and 150 μm or less. The solvent ink medium according to claim 1, wherein the release layer has a water vapor permeability of 20 g / m ² · 24 hr · atm to 150 g / m ² · 24 hr · atm. The medium for solvent ink according to any one of claims 1 to 6, wherein the inner surface of the release layer is subjected to a corona treatment so as to be 36 dyne or more in a wetting tension test specified in JIS K6768.