KR100658089B1 - An easy-dyeable polyester film, a method of dye for the same - Google Patents

Abstract

The present invention relates to a method for dyeing a polyester film which is easy to dye, and is characterized in that a polyester film in which a monomer having a naphthalene group is copolymerized or a polymer having a naphthalene group is blended is laminated on a glass And is characterized by dyeing at a temperature higher than the transition temperature. The film of the present invention has an improved dyeing speed and is easy to dye, and uniform dyeing is also possible.

Dyeing, easy dyeing, polyester, film, naphthalene group, dyeing rate, uniform dyeing, sublimation solvent dye, dyeing carrier

Description

An easy-to-dye polyester film and an easy-dyeable polyester film,             

The present invention relates to a new polyester film capable of fast dyeing with a high dyeing speed and a dyeing method thereof.

Usually, the polyester film is dyed with a disperse dye or a solvent dye. However, since the dense crystal region is present in the film in an amount of 50% or more in the film, diffusion and adsorption of the dye into the film do not occur well during dyeing. It does not work.

In order to solve such a problem, a method of producing a polyester film by extrusion and stretching after adding a dye in polyester polymerization may be carried out. However, there is a problem that it is difficult to produce a small quantity of various products at a low cost, and a high heat resistant dye capable of withstanding melting and heat treatment is required.

On the other hand, U.S. Patent No. 5,338,318 discloses a continuous dyeing method in which a polyester film is dyed with a disperse dye or a solvent dye using glycerol triacetate as a dye carrier, followed by washing and drying. However, the above method has a disadvantage in that the dyeing speed is low, especially when the color is high, the dyeing color difference is deep and uniform dyeing is difficult.

In order to solve such a problem, the crystallinity in the film is lowered by controlling the stretching ratio in the production of the polyester film to increase the amorphous region where the dye penetrates and diffuses easily, and then the film is relaxed at high temperature A method of dyeing is proposed and carried out. However, this method has a problem in that the strength of the polyester film is lowered due to the lack of crystallinity of the film and the high-temperature treatment during dyeing.

Accordingly, an object of the present invention is to provide a polyester film and a method for dyeing the polyester film, which can maintain a high inherent property of a polyester film while allowing a fast dyeing rate and uniform dyeing.

The present invention aims to provide a polyester film which can be uniformly dyed at a fast dyeing rate without deteriorating the physical properties of the film. It is another object of the present invention to provide a dyeing method capable of more easily and uniformly dyeing the polyester film.

The present invention relates to a process for dyeing a polyester film in which a monomer having a naphthalene group is copolymerized or a polymer having a naphthalene group is blended by using a sublimable solvent dye and a dye carrier under a temperature higher than the glass transition temperature of the polyester film, Cleaning, and drying.

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Hereinafter, the present invention will be described in detail.

In the polyester film of the present invention, a monomer having a naphthalene group is copolymerized or a polymer having a naphthalene group is blended by a conventional method. The content of the naphthalene group-containing monomer or polymer is 1 to 98 mol%, more preferably 1 to 94 mol%. When the content of the naphthalene group-containing monomer or polymer is less than 1 mol%, the strength of the film is maintained, but the dyeing is difficult to produce, and the dyeing film of the salt salt is difficult to produce. When the content is more than 98 mol% Is lowered.

The films of the present invention can be readily dyed with sublimable solvent dyes at temperatures above the film glass transition temperature using a dye carrier.

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Examples of the dye carrier include (i) glycol compounds such as water, ethylene glycol and propylene glycol, (ii) glycerol compounds such as glycerol triacetate, (iii) linoleic acid, linolenic acid, Fatty acid glycerol esters such as oleic acid and palmitic acid and (iv) natural fatty acid glycerol esters such as linseed oil, soybean oil and safflower oil.

The fatty acid glycerol ester has a high boiling point of 230 to 235 DEG C and is excellent in solubility in disperse dyes for general polyester dyeing and sublimable solvent dyes and low in surface tension of 20 to 40 Dyne / Since it is a fatty acid, it does not corrode the film even at a high temperature and is harmless to the human body, so it is an environmentally friendly carrier for dyeing.

In the present invention, the dyeing rate is improved by using a sublimable solvent dye excellent in sublimation at a certain temperature or higher. The sublimable dye sublimates in the salt bath and diffuses into the polyester polymer chain faster than the conventional solvent type or disperse dye. As a result, the dyeing equilibrium is quickly reached and the rate of dyeing is also increased.

In addition, the sublimable solvent dyes of the present invention should have excellent solubility in the above-described carrier, and should have excellent fastness to light and ultraviolet rays. The sublimable solvent dyes used in the present invention can be classified into chemical structures such as monoazo, disazo, quinone, xanthene, anthraquinone, And Complex.

Next, a series of manufacturing processes for maximizing the effects of the present invention will be described.                     

The present invention enables continuous dyeing by staining in a salt bath, washing step for removing excess dye and carrier present on the surface of the film, and drying step for removing the cleaning agent and the remaining carrier continuously.

The salt bath of the present invention contains a dye and a carrier and is heated to a high temperature to increase the dyeing speed. The suitable temperature is not lower than the glass transition temperature of the polyester film, especially 120 to 180 ° C, more preferably 140 to 160 ° C. The dyeing time varies depending on the size of the salt bath or the thickness of the film, but is usually from 3 seconds to 60 seconds.

Further, the cleaning tank of the present invention is characterized by containing the aforementioned sublimable dye and an organic solvent having affinity for the carrier. Examples of the organic solvent include ketone compounds such as acetone and methyl ethyl ketone, and ester compounds such as ethyl acetate and butyl acetate. The cleaning agent of the present invention should not erode the polyester film as an organic solvent having a low boiling point capable of adequately removing excess dyes and carriers on the surface of the film at room temperature.

The drying process of the present invention is a heat treatment process for evaporating a cleaning agent and a carrier remaining on a dyed film. If the above-mentioned detergent and carrier remain in the film, it is necessary to remove them because the mechanical properties of the polyester film are deteriorated and the surface characteristics of the film are changed. A suitable heat treatment temperature of the present invention is more preferably 140 to 150 DEG C, and usually accompanied by hot air.

The following describes the saline solution ratio. (Wt./volume) to 5% (wt./vol.) In the case of pale color and 3% (wt./vol.) To 15% (wt./vol. .) Is appropriate.

In the present invention, the arrival equilibrium reaching time and various characteristics of the film are evaluated by the following methods.

· Time to reach equilibrium

The initial time without any further increase in optical density in staining by time

· Optical density

Optical density (D) is measured with a Macbeth transmission photometer (Kollmorgen Instruments Corp.) Model TR-927 as white light.

· Evenness

The optical density difference (? D) in a sample of 10 cm × 10 cm size is measured.

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Hereinafter, the present invention will be described in more detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the following examples.

Example 1

A polyester film having a naphthalene group-containing monomer (dimethyl-2,6-naphthalenedicarboxylate) in an amount of 1 mol% and a thickness of 25 mu m was mixed with Solvent Yellow 24 as a sublimable solvent dye and ethylene glycol as a carrier (Bath ratio: 3.5%) at a temperature of 160 캜. Subsequently, this is washed with a cleaning agent mixed with methyl ethyl ketone and ethanol at a ratio of 1: 1, and then dried at a temperature of 145 ° C (accompanied by hot air). Table 2 shows the results of evaluating the arrival time of the equilibrium in dyeing and the optical density and uniformity of the dye film.

Examples 2 to 7 and Comparative Examples 1 to 3

The polyester film was dyed, washed, and dried under the same conditions and conditions as in Example 1 except that the film thickness, the content of naphthalene groups in the film, and the dyeing temperature were changed as shown in Table 1. Table 2 shows the results of evaluating the arrival time of the equilibrium in dyeing and the optical density and uniformity of the dye film.

Dyeing condition division The monomer content (mole%) having a naphthalene group Film thickness (탆) Dyeing temperature (℃) Example 1 One 25 160 Example 2 10 25 160 Example 3 20 25 160 Example 4 50 25 160 Example 5 70 25 160 Example 6 80 25 160 Example 7 94 50 170 Comparative Example 1 0.7 25 170 Comparative Example 2 99 50 170 Comparative Example 3 0.9 50 180

Results of evaluation of dyeing rate and film properties division Time to reach equilibrium in seawater (sec) Optical density Uniformity (ΔD) Example 1 40 0.25 0.00 Example 2 35 0.35 0.00 Example 3 26 0.45 0.00 Example 4 25 0.6 0.00 Example 5 27 0.7 0.00 Example 6 26 0.92 0.00 Example 7 25 100 0.01 Comparative Example 1 60 0.12 0.07 Comparative Example 2 25 1.00 0.00 Comparative Example 3 50 0.18 0.06

The polyester film of the present invention can be uniformly dyed even in the case of dyeing with a high dyeing rate because a monomer having a naphthalene group is copolymerized or a polymer having a naphthalene group is blended. Further, the present invention can dye the polyester film of the present invention with a sublimable solvent salt using a dye carrier to achieve a higher dyeing rate and obtain a uniform dyeing effect.

Claims (5)

delete delete delete A polyester film in which a monomer having a naphthalene group is copolymerized or a polymer having a naphthalene group is blended is dyed at a temperature higher than the glass transition temperature of the polyester film using a sublimable solvent dye and a dyeing carrier and then washed, ≪ / RTI > 4. The method for dyeing a polyester film according to claim 4, wherein an organic solvent is added to the cleaning liquid.