KR0145057B1 - High transparent and colored polyester film - Google Patents

Abstract

0.1-0.01% by weight of a magnesium compound was added to the polyester resin condensation-polymerized by a conventional method, and an anthraquinone dye was used as a colorant, and 100-1000 PPM was added to the total polyester resin. A method for producing a biaxially stretched polyester film, characterized in that the polyester resin is mixed at a predetermined ratio and the film is formed, stretched, and heat treated.

Description

High transparency colored polyester film

The present invention relates to a high-quality, high-transparent polyester biaxially oriented film that is undiluted in blue color used as a support for a photoresist in a lentgen photographic film, and more specifically, 0.01-0.1% by weight of a magnesium mixture is added to a conventional method. A highly transparent colored polyester film prepared by mixing, stretching and heat treating a polyester resin prepared by mixing anthraquinone dye 100-1000PPM and a general polyester resin not mixed with a dye, and a method for preparing the same. It is about.

In the conventional textile field, blue has been added to the polyester resin in various ways to produce the color of the fabric. In the film field, the base film is colored in blue to facilitate the identification of the photograph in the rental film. come.

The film coloring methods known so far include solution coloring, surface coating, and the like, but color development by these methods does not have a physical and chemically stable structure, and thus color fading and discoloration are likely to occur. Uniform staining was difficult. Therefore, the method mainly used commercially is the undiluted solution coloring method which adds and mixes a coloring agent at the time of a polyester synthesis | combination, or heat-melting molding, and makes it uniformly disperse | distributes in a polymer, and makes it color.

When using the undiluted solution coloring method, the colorant used requires high heat resistance to withstand the high temperature conditions subjected to the polymerization and processing. That is, the polyester film is generally formed in a tenter method and the edge portion of the film is recovered and reused, so that a film using a colorant with poor thermal stability is changed in color by recovery and reuse, and the value of the product is remarkably decreased. On the other hand, when the coloring agent is added during the polymerization may cause a problem of inhibiting the polymerization of the polyester or lowering the degree of polymerization under melting, it is necessary to select a chemically stable dye at a high temperature. In addition, sublimation resistance is required in addition to heat resistance in order for the colorant to be used for coloring the stock solution of a polyester film. In other words, when a sublimable colorant is added and used during the polymerization reaction to color the polyester film, the colorant sublimates out of the recovered glycol to reduce the amount of the colorant in the polymer and contaminate the recovery system. In addition, even when the polyester resin is colored by the master batch method, a colorant is sublimed by vacuum high temperature during drying in the film forming process, thereby causing a problem of contaminating the drying apparatus and the peripheral device.

On the other hand, the colorant used in the polyester film should be easy to disperse or dissolve in the polyester, it is preferable that the dispersion is excellent in compatibility with the polyester. Particularly, when used as a base film for rentent photographs, a film having high transparency and no optical defects is required. Therefore, when the dispersion of the colorant is insufficient, granular foreign matters are formed in the film and the dispersibility is good even in the stretching process. In order to solve these problems, voids are generated at the interface between the finely dispersed particles of the colorant and the polyester, and the turbidity of the film due to light scattering is increased.

Among the blue colorants, there are various kinds of colors ranging from blue having a red hue to blue representing a greenish hue, and from bright blue to dark blue. Films colored in blue with a red tint irritate the eyes of the observer, making it easier for the eyes to feel fatigue, and blue with a strong green tint is not good because it causes defects to sharpen the image of the renten photograph. The color tone of the base film to be obtained is not broad blue, and a limited color tone is required.

Therefore, the object of the present invention is to provide a film. The present invention provides a biaxially stretched polyester film and a method for preparing the same, wherein the absorption peak appears in the range of 590-640 nm when measured by the U.V absorption spectrum and is 1.0 or less when measured by film haze.

In order to achieve the above object as well as another object easily expressed in the present invention, a polyester obtained by mixing an anthraquinone dye 100.1000PPM to a polyester resin prepared by the conventional method by adding a magnesium compound 0.01-0.1% by weight A biaxially stretched polyester film having high transparency and excellent blue coloration was obtained by mixing, stretching and heat treating a polyester resin which did not mix resin and dye.

The present invention is described in more detail as follows.

In the polyester film of the present invention, a polyester resin prepared by mixing an anthraquinone dye 100-1000PPM with a polyester resin prepared by a conventional method by adding 0.1-0.01% by weight of a magnesium compound, and a polyester not mixed with a dye It is produced by mixing a resin in a proportion, stretching and heat treatment. Absorption peak appears in the range of 590-640 nm when measuring the V absorption spectrum, 1.0 or less when measuring the film haze. Generally, the metal compounds used in the manufacture of polyester are alkali and alkaline earth metals, and mainly compounds such as calcium, magnesium, manganese and zinc are used.However, when the calcium and manganese compounds are used in resin production, they react with the phosphate compounds used as thermal stabilizers. Since the internal particles are formed, the transparency of the film is lowered, and the zinc compound is less reactive than calcium, manganese, and magnesium compounds, so that the reaction time is long when the polyester is manufactured. Therefore, in the present invention, by using a magnesium compound, for example, magnesium oxide, magnesium acetate, magnesium chloride as the metal compound, not only the reactivity of the polymer was improved, but internal particles were not formed, thereby obtaining a film having excellent transparency.

In the case of less than 0.01% by weight of the metal compound content, the polymer reactivity is worsened, the productivity is lowered. When the film is formed, defects are generated due to the poor application of static electricity. It caused eyestrain.

In the present invention, as a coloring agent, an anthraquinone dye, for example, 1,4-bis (2,6-dimethylaniline) anthraquinone, 1,4-diarylaminoanthraquinone, 1,4-bis (2-isopropyl- 6-methylamino) anthraquinone, 1,4-bis- (3-siacolohexylsulformyl-2,4,6-trimethylphenylamino) anthraquinone, 1,4-bis (2,6-diethylanilino Anthraquinone was used.

In addition to the anthraquinone-based dyes, blue-colored colorants include diazo-based compounds and phthalocyanine-based pigments. An anthraquinone-based dyes have higher resistance to diazo-based dyes and discolor at high temperatures while coloring polyester resins. Unlike the phthalocyanine-based pigments, there is no affinity with the polyester resin, so that it is dissolved during the melting of the resin, and thus no problem of transparency decrease due to dye mixing. Especially the polyester film of this invention using anthraquinone type dye is oil. In the case of V spectrum measurement, the position of absorption peak is observed within the range of 590-640 nm. Dye having a V absorption peak position of more than 640 nm has a greenish blue color, and is present at less than 590 nm. The dye in which the V absorption peak is observed has a dark blue color, causing eye strain when lentgen photographs are observed, or a photographic image is not clear. In the present invention, the amount of the dye used is preferably about 100-1000PPM with respect to the total resin weight, and when the amount of the dye used is less than 1000PPM, the colorability is poor. .

In the present invention, the addition time of the dye may be added at the time of polyester production and at the time of melting before film forming, but the resin obtained by mixing the dye after preparing the polyester resin and the mixture of the dye and the resin not added the dye A method of mixing and forming a film is preferable in view of dispersibility and solubility of the dye.

The following examples illustrate the invention in more detail, but do not limit the scope of the invention.

Example 1

0.05% by weight of magnesium acetate was added to dimethylene lephthalate and diethylene glycol to prepare a polyester resin according to a conventional method, and 1,4-bis (2,6-dimethylaniline) anthraquinone was added to all polyester resins. The master bezel dye chip was prepared by mixing in an injection machine together with the polyester resin prepared to be 1000PPM. The prepared dye chip and the resin not mixed with the dye were mixed in a ratio of 1: 5 and introduced into a film forming process, and a 175 μm biaxially stretched polyester film was prepared through drying, cooling, stretching, and heat treatment. Yu into the film produced. V spectrum and haze were measured, and the resultant film of the present Example was used. The position of the V absorption peak was measured at 593 nm and 637 nm, and the haze was 0.3.

Example 2

A polyester dye chip was prepared in the same manner as in Example 1 by adding 1,4-diarylaminoanthraquinone to dimethylene terephthalate and diethylene glycol at 0.05% by weight of magnesium acetate and 300 PPM relative to the total polyester resin. It was. Thereafter, the resultant was introduced into a film forming step, and a 175 µm biaxially stretched polyester film was produced through drying, cooling, stretching, and heat treatment. Yu into the film produced. V spectrum and haze were measured, and the resultant film of the present Example was used. The positions of the V absorption peaks were measured at 598 nm and 630 nm, and the haze was measured at 0.4.

[Examples 3-5]

A film was prepared in the same manner as in Example 1 except for changing the type and amount of the dye and the content of magnesium acetate to those shown in Table 1. V absorption peak and haze were measured and the results are shown in Table 1.

Claims (3)

0.1-0.01% by weight of a magnesium compound was added to the polyester resin condensation-polymerized by a conventional method, and an anthraquinone dye was used as a colorant, and 100-1000 PPM was added to the total polyester resin. A method for producing a biaxially stretched polyester film, characterized in that the polyester resin is mixed at a predetermined ratio and the film is formed, stretched, and heat treated. The anthraquinone-based coloring agent according to claim 1, wherein the colorant is 1,4-bis (2,6-dimethylaniline) anthraquinone, 1,4-diarylaminoanthraquinone, 1,4-bis (2, -isopropyl- 6-methylamino) anthraquinone, 1,4-bis (3-cyclohexylsulformyl-2,4,6-trimethylphenylamino) anthraquinone, 1,4-bis (2,6-dimethylanilino) anthra A method for producing a biaxially stretched polyester film, characterized in that one of the anthraquinone dyes selected from quinones. The method for producing a biaxially stretched polyester film according to claim 1, wherein the magnesium compound uses magnesium oxide, magnesium acetate, magnesium chloride, or the like.