JP4693300B2 - Synthetic resin film - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
In the present invention, while the transparent or translucent synthetic resin films printed with the printing ink containing the inorganic pigment are in surface contact with each other, the fine irregularities of the inorganic pigment particles are transferred to the film, and the light due to the irregularities is transferred. The present invention relates to a synthetic resin film that can prevent whitening from occurring due to irregular reflection.
[0002]
[Background Art and Problems to be Solved by the Invention]
Conventionally, a blindfold sheet, a decorative sheet, an underlay for office supplies, and a clear sheet used to stick to a window of a leisure tent made of materials such as vinyl chloride resin, polyolefin resin, or polyester resin, or a house window. As a folder or the like, a colorless and transparent sheet or film (in the present invention, “sheet or film” may be simply referred to as “film”) is used as it is, or transparent colored by adding a colorant to the resin. Or a translucent film or an opaque film is used.
[0003]
On the other hand, various pigments are used as a colorant for coloring the synthetic resin material as described above. When the affinity between the synthetic resin material and the pigment is low, When mixing failure occurs or when the affinity with the solvent used is low, there are disadvantages such as pigment aggregation.
In order to avoid such an inconvenience, a technique has been developed in which a pigment previously coated with a synthetic resin or a synthetic resin having a good affinity with a solvent as described above is used.
[0004]
In addition, 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, a long film wound in a roll shape is unwound, partial printing is performed at a predetermined location, and the roll film is wound again and stored or transported. Or partially printed on a film cut to a certain size, and a plurality of these are stacked and stored or transported.
In such a case, fine irregularities due to fine particles of the inorganic pigment present in the printing part of the film are wound in a roll shape, or in a state where a large number of sheets are stacked, The transparent or translucent film to which the unevenness is transferred may be whitened due to irregular reflection of light due to the fine unevenness, which may impair the commercial value.
[0005]
In particular, when a rolled state or a state where a large number of sheets are stacked for a long period of time, a large number of fine irregularities are transferred, so this transfer is prevented in products for long-term storage. It is necessary to establish a method to do this.
As this method, a method of sandwiching a film or paper for preventing uneven transfer between printed films is conceivable. In addition to the cost required for such a film or paper, the film or paper is sandwiched. However, it is also necessary to develop a technique for winding in a roll shape or stacking a large number of sheets, which is not practical.
[0006]
[Means for Solving the Problems]
As a result of various studies to solve the above problems, the present inventors have focused on the coating pigments used for coloring the above-mentioned conventional synthetic resin materials as pigments for printing inks, In the case of a transparent film printed with this ink, a pigment of a series is used in advance, and even if it is wound up in a roll and stored for a long period of time, the occurrence of fine irregularities in this transparent film is greatly increased. As a result, the present invention has been completed.
[0007]
That is, in the present invention, an inorganic pigment (hereinafter referred to as “coating pigment”) having a particle size of 0.05 to 5 μm, which is coated with a synthetic resin having a polymerization degree of 30 to 800 one by one or with secondary particles. Is printed partially on a transparent or translucent synthetic resin film having a thickness of 0.1 to 2 mm, and is rolled or rolled into a roll or a plurality of sheets. The gist is a synthetic resin film conveyed or stored in a stacked state.
[0008]
The inorganic pigment in the present invention may be any inorganic pigment that is generally used as a pigment for printing ink, such as carbon black, cobalt blue, chrome yellow, titanium oxide, iron oxide. (Eg, bengara), molybdic acid, cadmium-based selenide, mercury-based selenide, ferrocyanide, and the like can be used.
In these inorganic pigments, the smaller the particle size, the more difficult the transfer of irregularities by the pigment particles occurs, but it is technically difficult to produce an inorganic pigment having a small particle size, and the particle size Is too large, the unevenness due to the pigment particles becomes large, and even if it is previously coated with a synthetic resin, it becomes difficult to prevent the unevenness due to the pigment particles from being transferred. It is preferable to use one having a thickness of about 5 μm.
In the present invention, when an inorganic pigment having a function other than the function as a pigment is used, for example, when a titanium oxide having a photocatalytic function is used as an inorganic pigment in addition to the function as a pigment. Can impart functions such as deodorization and deodorization to the film of the present invention.
[0009]
In the present invention, the above inorganic pigment is coated with a synthetic resin. This synthetic resin is transparent or translucent, and when coated on various inorganic pigments as described above, Those that can visually recognize the color are preferable. Specifically, melamine resin, urea resin, urethane resin, polyethylene resin, polyethylene oxide resin, polyethylene wax, polypropylene wax, polybutadiene resin, polyvinylamide resin, polyvinyl chloride resin, polyvinylacetamide There are resins, polyester resins, polyacrylate resins, polymethacrylate resins, resins containing salts of acrylic acid and methacrylic acid, etc., and these may be used alone or in admixture of two or more. . Alternatively, a copolymer obtained by copolymerizing monomers as constituent components of these synthetic resins in an appropriate combination can also be used.
Note that these resins are not limited to the above-described transparent or translucent, and may be opaque, for example, colored in the same color as the inorganic pigment to be coated. Therefore, even if it is a recycled resin etc. of waste plastic, there will be no problem as long as the object of the present invention (preventing transfer of fine irregularities by inorganic pigment particles) can be achieved.
[0010]
If the degree of polymerization of the above-mentioned synthetic resin for coating is too large, the polymer chain becomes long, and when coating an inorganic pigment, the possibility that one molecule of polymer will incorporate a large number of pigment particles increases. If the particle size of the coating pigment is increased and too small, the coating film cannot be formed satisfactorily and the technical significance of the coating pigment cannot be exhibited. It is preferable to do.
[0011]
Synthetic resins for coating may be transparent, translucent, or opaque as described above, and these synthetic resins are not limited to colorless, but are designed to be expressed by printing ink using coating pigments. Depending on the color, it may be colored.
As the colorant used for coloring the synthetic resin as described above, those generally used as the colorant for the synthetic resin as described above can be used. Specifically, a poorly soluble azo chelate, a soluble azo chelate, Azo pigments such as insoluble azo chelates, condensable azo chelates, and other azo chelates; phthalocyanine pigments such as phthalocyanine blue and phthalocyanine green; selenium pigments such as anthraquinone, perinone, perylene, and thioindigo; Organic colorants such as linone pigments; vat dyes pigments; nitroso pigments; acid dye lakes; basic dye lakes; quinacridone pigments; dioxazine pigments;
[0012]
Examples of the method for coating the inorganic pigment with the synthetic resin include a method in which raw materials such as an inorganic pigment, a synthetic resin, and a solvent are mixed and dispersed.
By these methods, one particle of inorganic pigment particles or several particles gather to form secondary particles, and the secondary particles are coated with a synthetic resin.
[0013]
When printing on a film with a printing ink containing an inorganic pigment coated with each particle or secondary particles, a synthetic resin coated with pigment particles and a synthetic resin emulsion serving as a base of the ink Or because of the familiarity with the film, the occurrence of unevenness on the printed surface of the film is alleviated, and the boundary between the film and the printing part or application part becomes smooth, so the printed film can be wound into a roll or a large number of sheets Even when the layers are stacked, it is possible to satisfactorily prevent transfer of fine irregularities due to pigment particles on the back surface of the film that is in surface contact.
Thereby, the irregular reflection of the light resulting from the unevenness | corrugation of a product film can be prevented, and the commercial value of a product film can be improved significantly.
[0014]
Moreover, the synthetic resin coated on the inorganic pigment may be appropriately blended with various additives such as an antifoaming agent, a bulking agent, a thickener, a catalyst, and a dye as necessary.
[0015]
Inorganic pigments coated with synthetic resin such as described above, by blending the synthetic resin Emarujo emissions as a base of an ordinary ink can be used as an ink in the present invention.
Examples of this synthetic resin emulsion include acrylic emulsion, vinyl acetate emulsion, urethane emulsion and the like.
[0016]
In addition, additives such as an antifoaming agent, a thickening agent, a thickening agent, a catalyst, a dye, and an ultraviolet absorber can be added to this ink in an appropriate amount.
In addition, when these additives are powders and granules, it is attributed to the additive to be added by coating the additive with the synthetic resin in the same manner as coating the inorganic resin with the synthetic resin. It is possible to further suppress the unevenness transfer to the film to be performed.
[0017]
The printing ink containing the coating pigment obtained as described above is a vinyl chloride resin, polyethylene, polypropylene, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, ethylene-methacrylic acid ester copolymer, It can be used for a film made of 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 relatively soft films such as polyvinyl chloride resin, ethylene-vinyl acetate copolymer, ethylene-acrylic acid ester copolymer, and ethylene-methacrylic acid ester copolymer. .
In addition, this film is colorless or colored transparent, translucent or opaque, with additives such as ultraviolet absorbers, colorants, heat stabilizers, light stabilizers, plasticizers, fillers, lubricants, etc., as necessary. It may be a film.
[0018]
The size of the film is not particularly limited and may be any size, but the thickness is preferably about 0.1 to 2 mm. If it is thinner than this, even if the 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. If it is thicker than this, there is a transfer of some fine irregularities. This is because it is absorbed by the thickness of the film and the whitening phenomenon may not occur, so that it is not meaningful to use the printing ink containing the coating pigment according to the present invention.
The above film can be produced by a general production method such as extrusion molding, calender molding, inflation molding or the like.
[0019]
A printing method using the coating pigment-containing printing ink of the present invention on the film surface configured as described above is a normal printing method, specifically, a printing method such as a gravure, a rotary screen, or a silk screen. It can be applied as it is.
In addition, although partial printing is performed in the present invention, when this printing area is about 70% or less of the total area of the film, the effect of the present invention (the effect of preventing the transfer of unevenness due to the inorganic pigment) is remarkable. Since it can obtain, it is preferable.
[0020]
Applications of the film of the present invention configured as described above include, for example, a window film for a leisure tent printed with a window frame, a blindfold used for a house window, a decorative film, and double-sided printing. Underlay for stationery.
In addition to the above applications, the coating pigment itself, a printing ink containing the coating pigment, or a film to be printed with the ink has a function such as an ultraviolet absorption effect, a deodorizing effect, and a deodorizing effect. In this case, or when an additive having these effects is added to each of the coating pigment, printing ink, or film, it goes without saying that a film having these functions can be obtained.
[0021]
FIG. 1 is an explanatory view schematically showing an example of a coating pigment contained in the printing ink of the present invention, in which (A) is an example in which a synthetic resin is coated on each of the inorganic pigment particles. (B) is an example in which secondary particles of an inorganic pigment are coated with a synthetic resin.
1 (A) and 1 (B), 1, 1 'indicates the coating pigment body, 11 is one inorganic pigment particle, and in FIG. The entire surface is coated with a synthetic resin (transparent synthetic resin in this example) 12 to form a coating pigment 1, and in FIG. 1B, the entire surface of secondary particles in which some of these particles 11 are collected is synthesized. Coating pigment 1 'is formed by coating with resin 12.
[0022]
FIG. 2 is an explanatory view schematically showing a film of the present invention printed with a printing ink containing the coating pigments 1, 1 ′ shown in FIG.
In FIG. 2, reference numeral 2 denotes a synthetic resin film, and the surface of the film 2 is printed with a printing ink containing the coating pigments 1 and 1 '. The entire surface of the coating pigments 1 and 1' The transparent resin 12 is coated with a synthetic resin emulsion layer (coating) 3 that forms the base of the printing ink so that a smooth printing surface appears on the surface of the film 2.
[0023]
【Example】
Example 1
A printing ink containing a pigment (trade name “V12 401” manufactured by Dainichi Seika Kogyo Co., Ltd., average particle size of 0.25 μm) coated with rutile titanium oxide as an inorganic pigment and coated with vinyl chloride-acrylic resin is used. Pattern printing was performed by gravure printing on a transparent film made of vinyl chloride resin having a length of 0.3 mm and a length of 50 m.
The area of the printed portion corresponds to 2% of the total area of the film, and the amount of ink applied was 10 g / m ² in a dry state.
The vinyl chloride resin transparent film after printing in this way was wound up in a roll and stored in a warehouse for one month.
When the film wound in this roll shape was tested after one month, there was no transfer of fine irregularities due to pigment particles on the back surface of the film in contact with the surface, and no whitening of the film due to irregular reflection of light was confirmed. It was.
[0024]
Example 2
Pattern printing was performed by gravure printing in the same manner as in Example 1 except that a transparent film having a square size of 0.3 mm × 1000 mm × 1000 mm was used.
1,000 transparent films made of vinyl chloride resin after printing in this way were stacked and stored for one month.
When a test was conducted one month later on the stacked film, there was no transfer of fine irregularities due to pigment particles on the back of the stacked film, and no whitening of the film due to irregular reflection of light was confirmed.
[0025]
Comparative Examples 1 and 2
Printing and testing were conducted in the same manner as in Example 1 (Comparative Example 1) and Example 2 (Comparative Example 2) except that rutile titanium oxide not coated with a transparent resin was used as an inorganic pigment. However, in both of the printed films of Comparative Examples 1 and 2, transfer of fine irregularities caused by the pigment particles on the back surface of the film in surface contact occurred, and whitening of the film due to irregular reflection of light was confirmed.
[0026]
【The invention's effect】
The coating pigment in the present invention is in a state where each inorganic pigment particle or secondary particle is coated with a synthetic resin, and when printing ink using such a pigment is printed on a film or the like Since the unevenness of the film surface that occurs in the film is eliminated or smoothed, even when this printed film is rolled up or stacked in large numbers, it is caused by pigment particles in the film that is in surface contact. Transfer of fine irregularities can be prevented, and whitening of the film due to irregular reflection of light can be prevented.
Therefore, there is no need to sandwich a film or paper that has been used in the past in order to prevent fine irregularities due to pigment particles in the printing ink from being transferred to the printed film, leading to a reduction in process time and economy. This is also advantageous.
In addition, since unevenness due to the inorganic pigment in the printing ink on the film surface, which occurs when printed on the film, is alleviated, it also has the effect of preventing irregular reflection of light due to the unevenness.
[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.
[Explanation of symbols]
1,1 'Coating pigment body 11 Inorganic pigment 12 Synthetic resin coating the entire surface of inorganic pigment 2 Synthetic resin film 3 Synthetic resin layer forming the base of printing ink

Claims (1)

A thickness of 0.1 by a printing ink in which an inorganic pigment having a particle size of 0.05 to 5 μm coated with a synthetic resin having a polymerization degree of 30 to 800 one by one or with secondary particles is blended in a synthetic resin emulsion. A synthetic resin film that is partially printed on a transparent or translucent synthetic resin film of ˜2 mm and is conveyed or stored in a rolled state or in a stacked state.

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