JP2003062950A - Synthetic resin film - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a synthetic resin film preventing the generation of a whitening phenomenon due to the irregular reflection of light caused by inorganic pigment particles in a transparent or translucent synthetic resin film printed by printing ink containing inorganic pigment particles. SOLUTION: The transparent or translucent synthetic resin film 2 is partially printed by printing ink containing coated pigments 1 and 1' prepared by coating the inorganic pigment particles 11 with a synthetic resin 12 and the printed film is fed or kept in a state wound into a roll form or a stacked state of the printed films.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transparent or translucent synthetic resin film printed with a printing ink containing an inorganic pigment while the films are in surface contact with each other. The present invention relates to a synthetic resin film capable of preventing fine irregularities of inorganic pigment particles from being transferred to a film and preventing whitening due to irregular reflection of light due to the irregularities. 2. Description of the Related Art Conventionally, it has been pasted on windows of leisure tents, windows of houses and the like made of materials such as vinyl chloride resin, polyolefin resin and polyester resin. Colorless and transparent sheets and films (in the present invention, "sheets and films" may be simply referred to as "films") as blindfolding sheets, decorative sheets, office supplies underlays and clear folders. A transparent or translucent film or an opaque film colored by mixing a coloring agent or the like with a resin is used. On the other hand, various pigments have been used as a coloring agent for coloring the synthetic resin material as described above. However, when the affinity between the synthetic resin material and the pigment is low, the synthetic resin material is not used. When poor mixing with the pigment occurs, or when the affinity with the solvent used is low, there are inconveniences such as aggregation of the pigment. In order to avoid such inconvenience, a technique has been developed in which a pigment is coated in advance with a synthetic resin as described above or a synthetic resin having a good affinity for a solvent. Further, there is an increasing demand for products in which a transparent or translucent film made of a synthetic resin material as described above is partially printed. When performing partial printing on such a transparent or translucent film, usually,
Unwinding a long film wound in a roll shape and performing partial printing on a predetermined location, winding again in a roll shape for storage or transport, or performing partial printing on a film cut to a certain size, These are stacked and stored and transported. In such a case, the fine irregularities due to the fine particles of the inorganic pigment present in the printed portion of the film,
In the state of being wound in a roll or in a state where a large number of sheets are stacked, the film may be transferred to the back surface of the surface-contacting film. Due to the irregular reflection of light due to the fine irregularities, whitening may occur, which may impair the commercial value. [0005] In particular, when a state of being wound in a roll or a state of stacking a large number of sheets over a long period of time, a large number of transfer of fine irregularities occurs. It is necessary to establish a method to prevent transfer. As this method, a method of sandwiching a film or paper between printed films to prevent the transfer of unevenness is considered. In addition to the cost required for such a film or paper, a method of sandwiching a film or paper is considered. In addition, it is necessary to develop a technique of winding the sheet into a roll or stacking a large number of sheets, which is not practical. The present inventors have conducted various studies to solve the above-mentioned problems, and as a result, have found that the above-mentioned conventional synthetic resin material is colored as a pigment for printing ink. Paying attention to the coating pigment used for, when inorganic pigment was coated with resin in advance and used,
In the case of a transparent film printed with this ink, it has been found that even when the transparent film is wound up in a roll and stored for a long period of time, the occurrence of fine irregularities in the transparent film is greatly improved, and the present invention has been completed. Was. That is, the present invention provides a method for partially printing a transparent or translucent synthetic resin film with a printing ink containing an inorganic pigment coated with a synthetic resin (hereinafter sometimes referred to as a “coating pigment”). The present invention provides a synthetic resin film which is transported or stored in a rolled state or a state in which a plurality of sheets are stacked. The inorganic pigment in the present invention may be any inorganic pigment generally used as a pigment for a printing ink, such as carbon black, cobalt blue, chrome yellow, and titanium oxide. , Iron oxide (eg, red iron oxide), molybdic acid, cadmium selenide sulfide, mercury selenide sulfide, ferrocyanide, and the like. As for these inorganic pigments, as the particle size becomes smaller, the transfer of irregularities due to the pigment particles is less likely to occur, but it is technically difficult to produce an inorganic pigment having a smaller particle size. Is too large, the irregularities due to the pigment particles also become large, and it is difficult to prevent the transfer of the irregularities due to the pigment particles even if the particles are coated in advance with a synthetic resin.
It is preferable to use one having a thickness of about 5 μm. In the present invention, when using, as the inorganic pigment, one having a function other than the function as a pigment, for example, in addition to the function as a pigment, when using titanium oxide having a photocatalytic function as an inorganic pigment Can impart functions such as deodorization and deodorization to the film of the present invention. In the present invention, the above-mentioned inorganic pigment is coated with a synthetic resin. The synthetic resin is transparent or translucent. Those capable of visually confirming the color of the inorganic pigment are preferred, and specifically, melamine resin, urea resin, urethane resin, polyethylene resin, polyethylene oxide resin, polyethylene wax, polypropylene wax, polybutadiene resin, polyvinylamide resin, polyvinyl chloride resin , Polyvinyl acetamide resins, polyester resins, polyacrylate resins, polymethacrylate resins, resins containing salts of acrylic acid and methacrylic acid, and the like. These may be used alone or as a mixture of two or more. You may. Alternatively, it is also possible to use a copolymer obtained by appropriately combining and copolymerizing monomers which are components of these synthetic resins.
In addition, these resins are not limited to transparent or translucent as described above, and may be, for example, opaque resins colored in the same color as the inorganic pigment to be coated. Therefore, even if it is a recycled resin of waste plastic or the like, there is no problem as long as the object of the present invention (prevention of transfer of fine irregularities due to inorganic pigment particles) can be achieved. If the degree of polymerization of the above-mentioned synthetic resin for coating is too large, the polymer chain lengthens, and when coating an inorganic pigment, the possibility of one molecule of polymer taking in many pigment particles increases. As a result, the particle size of the coating pigment is increased, and if the particle size is too small, the coating film cannot be formed satisfactorily and the technical significance as the coating pigment cannot be exhibited. Preferably, one is used. As described above, the synthetic resin for coating may be transparent, translucent, or opaque, and these synthetic resins are not limited to colorless but may be expressed by a printing ink using a coating pigment. It may be colored depending on the design. As the colorant used for coloring the synthetic resin as described above, those generally used as a colorant for the synthetic resin as described above can be used.Specifically, poorly soluble azochelates, soluble azochelates, Azo pigments such as insoluble azo chelates, condensable azo chelates, and other azo chelates; Phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; Slen pigments such as anthraquinone, perinone, perylene, and thioindigo;
Nitro pigments; isoindolinone pigments; vat dye pigments; nitroso pigments; acid dye lakes; basic dye lakes; quinacridone pigments;
And other organic coloring agents. As a method of coating the above-mentioned inorganic pigment with a synthetic resin, there is a method of mixing and dispersing raw materials such as an inorganic pigment, a synthetic resin and a solvent. According to these methods, one particle of the inorganic pigment or several particles gather to form secondary particles, and the secondary particles are coated with a synthetic resin. When printed on a film with a printing ink containing an inorganic pigment coated with individual particles or secondary particles, a synthetic resin coating the pigment particles and a base material of the ink are obtained. Due to the familiarity with the synthetic resin or the film, the occurrence of unevenness on the film printing surface is reduced, and the boundary between the film and the printing portion or the coating portion becomes smooth, so that the printed film is wound in a roll shape, Even when a large number of sheets are stacked, transfer of fine irregularities due to pigment particles to the back surface of the film in surface contact can be favorably prevented.
Thereby, irregular reflection of light due to unevenness of the product film can be prevented, and the commercial value of the product film can be greatly improved. [0014] The synthetic resin to be coated on the inorganic pigment may be a resin appropriately blended with various additives such as an antifoaming agent, a bulking agent, a thickening agent, a catalyst and a dye, if necessary. The inorganic pigment coated with the synthetic resin as described above can be used as an ink in the present invention by blending it with a synthetic resin emulsion or the like which is a base of ordinary ink. Examples of the synthetic resin emulsion include an acrylic emulsion, a vinyl acetate emulsion, and a urethane emulsion. If necessary, additives such as an antifoaming agent, an extender, a thickener, a catalyst, a dye, and an ultraviolet absorber can be added to the ink in an appropriate amount. In the case where these additives are powders or granules, the additives to be compounded are coated with the synthetic resin in the same manner as the coating of the inorganic pigment with the synthetic resin, thereby causing the additive to be added. The transfer of unevenness to the film to be formed can be further suppressed. The printing ink containing the coating pigment obtained as described above includes vinyl chloride resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer,
It can be used for a film composed of an ethylene-acrylic acid ester copolymer, an ethylene-methacrylic acid ester copolymer, an ethylene-acrylic acid copolymer, an ethylene-methacrylic acid copolymer, a polyamide resin, a polyester resin, or the like. . In particular, the present invention is suitable for printing on a relatively soft film such as a polyvinyl chloride resin, an ethylene-vinyl acetate copolymer, an ethylene-acrylate copolymer, and an ethylene-methacrylate copolymer. . In addition, this film is blended with additives such as an ultraviolet absorber, a colorant, a heat stabilizer, a light stabilizer, a plasticizer, a filler, and a lubricant, if necessary, and is colorless or colored transparent, translucent or opaque. Film. The size of the film is not particularly limited, and may be of any size.
A size of about 2 mm is desirable. If the thickness is smaller than this, even if a printing ink containing the coating pigment according to the present invention is used, the transfer of the fine irregularities of the inorganic pigment particles cannot be eliminated. This is because the ink is absorbed by the thickness of the film, and the whitening phenomenon may not occur. Therefore, there is no point in using the printing ink containing the coating pigment according to the present invention. The above-mentioned film can be produced by a general production method such as extrusion molding, calender molding, and inflation molding. On the film surface configured as described above,
As a printing method using the coating ink containing a coating pigment of the present invention, a normal printing method, specifically, a printing method such as gravure, rotary screen, or silk screen can be applied as it is. In the present invention, partial printing is performed, but the printing area is 70% of the total area of the film.
% Is preferable because the effect of the present invention (the effect of preventing the transfer of unevenness caused by the inorganic pigment) can be remarkably obtained. Examples of applications of the film of the present invention constituted as described above include a film for a window of a leisure tent printed with a window frame, a film for a blindfold or a decoration used for a window of a house, and the like. An underlay for stationery printed on both sides is exemplified. In addition to the above-mentioned applications, a coating pigment itself, a printing ink containing the same, or a film to be printed with the ink, each having a function such as an ultraviolet absorbing effect or a deodorizing / deodorizing effect is used. Needless to say, in the case where an additive having these effects is added to each of the coating pigment, the printing ink, and the film, a film having these functions can be obtained. FIG. 1 is an explanatory view schematically showing an example of a coating pigment contained in the printing ink of the present invention.
(A) is an example in which the synthetic resin is coated on each of the inorganic pigment particles, and (B) is an example in which the secondary particles of the inorganic pigment are coated with the synthetic resin. FIG.
In (A) and (B), 1,1 ′ indicates the coating pigment main body, 11 indicates one inorganic pigment particle,
In FIG. 1A, the entire surface of each of the particles 11 is coated with a synthetic resin (transparent synthetic resin in this example) 12 to constitute a coating pigment 1, and in FIG. The entire surface of the secondary particles in which some of the particles 11 are gathered is coated with the synthetic resin 12 to constitute the coating pigment 1 '. FIG. 2 shows the coating pigments 1 and 2 shown in FIG.
It is explanatory drawing which shows typically the film of this invention printed by the printing ink containing 1 '. In FIG. 2, 2
Is a film made of a synthetic resin, and the surface of the film 2 is printed with a printing ink containing the coating pigments 1 and 1 ′.
The transparent resin 12 coating the entire surface of 1 ′
Synthetic resin layer (coating) 3 forming the base of printing ink
And a smooth printed surface appears on the surface of the film 2. EXAMPLE 1 Rutile-type titanium oxide as an inorganic pigment was treated with vinyl chloride
Pigment coated with acrylic resin (trade name “V12 401” manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size 0.25μ)
m) using a printing ink containing 0.3 mm thick and 5 mm long
A pattern printing was performed by gravure printing on a transparent film of vinyl chloride resin having a length of 0 m. The area of the printed portion was equivalent to 2% of the total area of the film, and the applied amount of the ink was 10 g / m ² in a dry state. The thus-printed transparent film made of a vinyl chloride resin was wound into a roll and stored in a warehouse for one month. When the film wound up in the form of a roll was tested after one month, no fine irregularities caused by pigment particles were transferred to the back surface of the film in surface contact, and whitening of the film due to irregular reflection of light was not confirmed. Was. Example 2 0.3 mm × 1000 m as a transparent film to be printed
A pattern was printed by gravure printing in the same manner as in Example 1 except that a square having a size of mx 1000 mm was used. The transparent films made of the vinyl chloride resin after printing in this manner were stacked for 1,000 sheets and stored for one month. When a test was carried out one month later on the stacked films, there was no transfer of fine irregularities due to the pigment particles on the back surface of the stacked films, and no whitening of the films due to irregular reflection of light was confirmed. Comparative Examples 1 and 2 Example 1 except that rutile-type titanium oxide not coated with a transparent resin was used as an inorganic pigment.
(Comparative Example 1) Printing was performed in the same manner as in Example 2 (Comparative Example 2), and the test was performed. As a result, the printed films of Comparative Examples 1 and 2 were caused by pigment particles on the back surface of the film in surface contact. Transfer of fine irregularities occurred, and whitening of the film due to irregular reflection of light was confirmed. The coating pigment according to the present invention is in a state in which inorganic pigment particles are coated one by one or secondary particles are coated with a synthetic resin, and a printing ink using such a pigment is used. Since the unevenness of the film surface that occurs when printed on film etc. is eliminated or smoothed, even if this printed film is rolled or stacked many times, Transfer of fine irregularities due to pigment particles on the film can be prevented, and whitening of the film due to irregular reflection of light can be prevented. Therefore, on the printed film,
In order to prevent the transfer of fine irregularities caused by pigment particles in the printing ink, there is no need to pinch a film or paper, which has been performed conventionally, leading to a reduction in process time,
It is economically advantageous. In addition, since irregularities due to the inorganic pigment in the printing ink on the surface of the film, which occur when the film is printed, are alleviated, the effect of preventing irregular reflection of light due to the irregularities is also provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an explanatory view schematically showing a coating pigment in the present invention. FIG. 2 is an explanatory view schematically showing a film of the present invention printed with a printing ink containing the coating pigment shown in FIG. DESCRIPTION OF THE SYMBOLS 1,1 'Coating pigment main body 11 Inorganic pigment 12 Synthetic resin coating the entire surface of inorganic pigment 2 Synthetic resin film 3 Synthetic resin layer forming base of printing ink

   ────────────────────────────────────────────────── ─── Continuation of front page    F term (reference) 3F064 AA03 EA03 EA17                 4F100 AA01B AA21 AK01A AK01B                       AK15 AK25 BA02 BA07 CA13B                       GB07 GB87 HB31B JN01A                 4J037 AA02 AA08 AA12 AA15 AA19                       AA22 AA23 AA28 AA30 CC12                       CC14 CC16 CC17 CC22 CC24                       CC26 CC30 EE03 FF23 FF30                 4J039 AD08 AD09 AE04 BC16 BC17                       BC32 BC33 BC39 BC50 BC53                       BC54 BC60 FA02

Claims (1)

Claims: 1. A transparent or translucent synthetic resin film is partially printed with a printing ink containing an inorganic pigment coated with a synthetic resin and wound in a roll shape. Or a synthetic resin film that is transported or stored in a state in which a plurality of sheets are stacked.