JP2000319431A - Printed film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a single- or multi-layer film having a printed layer of excellent adhesion by applying a synthetic resin latex containing water-borne coating material containing an outermost tackifier to at least either surface of a plastic film. SOLUTION: The synthetic resin latex used is desirably the one containing an acrylic resin having a glass transition temperature of -60 to 20 deg.C. The tackifier used is desirably a rosin or a polyterpene resin. A desirable example of the process for producing the latex containing the tackifier consists of dissolving the tackifier in a monomer and incorporating the tackifier in the latex during the polymerization. The ratio tackifier/polymer is desirably 0.5/100 to 70/100 by weight. It is desirable that in the case of a single-layer film, the coating amount is 3-30 g/m2 (in terms of the dry solid weight) and in the case of a multi-layer film, it is 3-20 g/m2 in the upper layer and is 3-20 g/m2 in the lower layer and that the upper layer/lower layer ratio is 9/1 to 1/9. The plastic film used is exemplified by a polyester film, a PE film, or a polycarbonate film.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a printable film. More specifically, the present invention relates to a printing film having an advantage that printing can be performed in the same manner as ordinary printing paper without using a special ink.

[0002]

2. Description of the Related Art Conventionally, when a plastic film is printed with the same ink as ordinary printing paper, it has to be printed with a special ink, and satisfactory print reproducibility cannot always be obtained. In contrast, for example, Patent Publication 269
No. 1179 discloses a printing film having a surface coated with a printing layer mainly composed of styrene resin latex. By applying a printing layer on a plastic film, printing became possible in the same manner as ordinary printing paper. However, when the substrate is a hydrophobic resin such as a polyolefin film, the adhesion is poor, and a step of hydrophilizing the surface is required. This hydrophilic treatment requires an expensive device and often does not always provide satisfactory adhesion. For example, when offset printing is performed, there is a problem such as peeling between the film and the printing layer.

[0003]

SUMMARY OF THE INVENTION An object of the present invention is to provide a printing film having a printing layer that exhibits good adhesion to a plastic film such as a polyolefin film.

[0004]

Means for Solving the Problems As a result of intensive studies to solve the above problems, the present inventors have surprisingly found that the above problems can be solved by applying a synthetic resin-containing aqueous paint containing a tackifier. As a result, the present invention has been completed. That is, the present invention is a single-layer or multi-layer printing film in which at least one surface of a plastic film is coated with an aqueous paint containing a synthetic resin latex containing a tackifier in a lowermost layer.

Hereinafter, the present invention will be described in detail. (i) Plastic film Examples of the plastic film used in the present invention include a polyester film, a polyethylene film, a polypropylene film, a polycarbonate film, a triacetate film, a polyethersulfone film, and a vinyl chloride film.

(Ii) Synthetic resin latex 1) Production method In order to produce a synthetic resin latex containing a tackifier used in the present invention, a tackifier is dissolved in a solvent and added to the latex, A method of adding an emulsified / dispersed liquid of the property imparting agent to the latex is exemplified. JP-A-4-178402 also discloses a method in which a tackifier is dissolved in a monomer, and the tackifier is contained in latex during polymerization. Preferably, the production of a latex containing a tackifier is a method in which the tackifier is dissolved in a monomer and the tackifier is contained in the latex during polymerization. 2) Synthetic resin latex The synthetic resin (aqueous) latex used in the present invention includes:
An acrylic resin, a SB resin, a vinyl acetate resin, an EVA resin latex, and the like are mentioned, and one or a combination of two or more thereof is selected. Acrylic resin latex is preferred. The Tg of the latex is preferably -60 to 20C. Here, Tg refers to only the polymer component.
If the Tg is -60 ° C or higher, there is no problem with surface stickiness.
When the temperature is 0 ° C. or lower, the adhesiveness to the film is excellent. Preferred T
g is −60 to 10 ° C.

3) Tackifier As the tackifier, various generally known tackifiers can be used. For example, one or more selected from rosin resin, polyterpene resin, aliphatic petroleum resin, aromatic resin and the like are suitable. Particularly preferred tackifiers are rosin resins such as rosin, rosin ester, disproportionated rosin ester, hydrogenated rosin ester, and polyterpene resins such as α-pinene resin, β-pinene resin, and terpene phenol resin. Tackifier /
The weight ratio of the polymer is between 0.5 / 100 and 70/100. When the weight ratio is 0.5 / 100 or more, the adhesion to the film is excellent, and when the weight ratio is 70/100 or less, the flexibility is excellent. The preferred weight ratio is between 10/100 and 60/100.

(Iii) Others Examples of the pigment used in the water-based paint of the present invention include inorganic pigments such as calcium carbonate, clay, titanium oxide and silica, and organic pigments such as plastic pigments and hollow polymer particles. In addition, a pH adjuster, a thickener, a dispersant, a preservative, and the like may be included in the synthetic resin latex. (iv) Coating on plastic film, etc. 1) For coating, a coating device such as a roll coater, an air knife coater, a bar coater, or a blade coater can be used. The preferred coating amount is 3 to 30 g / m ² on a dry weight basis.

2) In the case of a multi-layer, for example, a paint composed of a pigment, a synthetic resin latex and other additives can be applied as a print layer provided on the upper layer. Examples of the synthetic resin latex include SB-based, acrylic-based, vinyl acetate-based, and EVA-based resin latex as in the case of the single layer. In that case, the coating weight, the upper layer is 3 to 20 g / m ^2, the lower layer is 3 to 20 g / m ^2, the upper / lower ratio of 9 / 1-1 / 9
Is preferable. 3) Printing etc. Printing can be performed by gravure printing, screen printing, offset printing, or the like. 4) The printing film of the present invention may be subjected to various antistatic treatments as necessary. For example, a resin solution containing an antistatic agent or a conductive paint may be applied to the back surface of the film, or a conductive layer may be provided.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below, but they do not limit the scope of the present invention. Parts are by weight unless otherwise specified. Also,
The evaluation method is as follows. Each characteristic was obtained as follows. (1) Adhesiveness: A cellophane tape was stuck to the coated surface and sufficiently adhered, then peeled off, and the cellophane tape surface was observed.無 し No peeling ○ Less than 10% peeling on the surface of the cellophane tape × Peeling of 10% or more on the surface of the cellophane tape (2) Stickiness: Evaluated by the tactile sensation of the coated surface of the obtained test piece. The evaluation criteria are as follows. ◎ No stickiness at all ○ Slight resistance × Sticky (3) Scratch resistance: The coated surface of the test piece was scratched with a thumb nail and the appearance was observed. The evaluation criteria are as follows. ◎ No damage at all. ○ Although the surface is scratched, no peeling of the coating layer has occurred. × The coating layer is partially peeled.

(Example 1) n-butyl acrylate 300
Parts, 50 parts of methyl methacrylate, and 150 parts of disproportionated rosin ester (manufactured by Arakawa Chemical Co., Superester 100) are added and uniformly dissolved. Thereafter, 0.9 parts of ammonium persulfate and polyoxyethylene alkyl phenyl ether sodium sulfate (trade name: Revenol WZ [Kao Corporation])
25 parts of a 25% aqueous solution and 175 parts of ion-exchanged water
The mixture was stirred and emulsified with a homogenizer to obtain a uniform emulsion containing the tackifier resin in the unsaturated monomer mixture. Subsequently, 300 parts of water was charged into a reaction vessel equipped with a stirrer, a reflux condenser, a dropping tank and a thermometer, and the temperature in the reaction vessel was reduced to 80%.
After the temperature was raised to 0 ° C, the above emulsion was added over 4 hours.
During the addition of the emulsion, the temperature in the reaction vessel was kept at 80 ° C, and after the addition was completed, stirring was continued for 1 hour while keeping the internal temperature at 83 ° C. After cooling, the pH was adjusted to 7.5 with ammonia and stable. Latex was obtained.

Using the obtained latex, an aqueous paint having a solid content of 60% was prepared according to the composition shown in Table 1 below. Next, the composition was applied to a polyester film at a thickness of 10 g / m ² using a bar coater and dried at 90 ° C. for 60 seconds. The resulting coated film was evaluated for stickiness, scratching, and adhesion. In addition, offset printing was performed using this coating film. As a result, printing was successful.

(Examples 2 to 4) In the same manner as in Example 1, a latex having the composition shown in Table 3 was obtained. Using the obtained latex,
In the same manner as in Example 1, a water-based paint having a composition shown in Table 1 and a solid content of 60% was prepared. Evaluation was performed in the same manner as in Example 1. Table 5 shows the results.

Example 5 Using the latex of Example 1, a coating liquid having the lower layer composition in Table 2 was obtained. Next, an aqueous paint having a composition of the upper layer of Table 2 and a solid content of 60% was prepared using SB latex (SB latex L-1272 manufactured by Asahi Kasei Corporation) to obtain a coating liquid. Next, this composition was applied to a polyester film using a bar coater at a rate of 5 g / m ^{2 of a} lower layer coating solution.
And dried at 90 ° C. for 30 seconds. Next, the upper layer coating solution was applied at a thickness of 5 g / m ² ,
Dried for seconds. Table 5 shows the results. (Example 6) The same procedure as in Example 1 was carried out except that a polypropylene film was used for the film to be coated. The results are shown in Table 5.

Comparative Example 1 A latex having the composition shown in Table 4 was obtained in the same manner as in Example 1. Using the obtained latex, an aqueous coating material having a composition shown in Table 1 and a solid content of 60% was prepared in the same manner as in Example 1. Evaluation was performed in the same manner as in Example 1. Table 5 shows the results. (Comparative Example 2) A water-based paint having a solid content of 60% was prepared by blending the upper layer in Table 2, and this composition alone was applied to a polyester film at a thickness of 10 g / m ² using a bar coater.
It was dried at 90 ° C. for 60 seconds. Table 5 shows the results.

[0016]

[Table 1]

[Table 2]

[0017]

[Table 3]

[Table 4]

[Table 5]

[0018]

The adhesiveness is improved by applying a synthetic resin latex containing a tackifier to the lowermost layer. In particular, excellent effects can be obtained for non-polar sheets.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09D 121/02 C09D 121/02 // B32B 27/00 B32B 27/00 F C08L 67:00 F term (reference ) 2H113 AA03 BA05 BB08 DA46 DA47 DA53 DA57 FA10 FA29 FA50 4F006 AA02 AA12 AA35 AA36 AA40 AB24 BA01 CA07 DA04 4F071 AA43 4F100 AK01A AK01B BA02 CA17B CC00B GB90 JB05B JL11 JM01B04102 CR021

Claims (1)

[Claims] 1. A single-layer or multi-layer printing film, characterized in that at least one surface of a plastic film is coated with an aqueous paint containing a synthetic resin latex containing a tackifier in a lowermost layer.