KR20020012819A - An easy-dyeable polyester film, a method of dye for the same - Google Patents

Abstract

PURPOSE: A polyester film to be dyed easily and its dyeing method are provided, to improve the fixing velocity and to allow the film to be dyed uniformly without deterioration of the intrinsic physical properties of the film. CONSTITUTION: The polyester film comprises 1-98 mol% of copolymerized or blended naphthalenyl group. The tensile strength of the polyester film is 20-30 kg/inch. The dyeing method comprises the steps of dyeing the polyester film by using a sublimable solvent dye and a dyeing carrier at a temperature above the glass transition temperature of the polyester film; washing it with a washing solution containing an organic solvent continuously; and drying it. Preferably the dyeing carrier is selected from the group consisting of a glycol-based compound comprising water, ethylene glycol and propylene glycol; a glycerol-based compound comprising glycerol triacetate; a fatty acid glycerol ester comprising linoleic acid, linolenic acid, oleic acid and palmitic acid; and a natural fatty acid glycerol ester comprising a linseed oil, a soybean oil and a safflower oil.

Description

Easy dyeing polyester film and dyeing method thereof {An easy-dyeable polyester film, a method of dye for the same}

The present invention relates to a novel polyester film and a dyeing method thereof capable of fast dyeing and uniform dyeing.

Typically, polyester films are dyed with dispersible dyes or solvent dyes, but since there are more than 50% of the dense crystal regions in the films, dyes do not diffuse and adsorb into the film during dyeing. It doesn't work

For this reason, a method of producing an original polyester film by performing extrusion and stretching of a polymer after adding a dye during polyester polymerization may be performed. However, the original method has a problem in that it is difficult to produce small quantities of multi-products, and a high heat-resistant dye capable of withstanding melting and heat treatment is required.

On the other hand, US Patent No. 5,338,318 describes a continuous dyeing method of dyeing a polyester film with a dispersible dye or a solvent dye using a dye carrier, glycerol triacetate, followed by washing and drying. However, the method has a disadvantage in that the dyeing speed is slow, especially in the case of deep color, the dyeing color difference is so severe that uniform dyeing is difficult.

In order to solve this problem, the draw ratio is adjusted during the production of polyester film to decrease the crystallinity in the film to increase the amorphous region that is easy to penetrate and diffuse the dye, and then relax the film at a high temperature during dyeing. The method of dyeing is also proposed and implemented. 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, it is an object of the present invention to provide a polyester film and a dyeing method thereof which are capable of fast dyeing and uniform dyeing while maintaining the inherent physical properties of the polyester film.

The present invention is to provide a polyester film that can be uniformly dyed at a high dyeing speed without deteriorating the physical properties of the film. In addition, the present invention is to provide a dyeing method capable of dyeing the polyester film more easily and uniformly.

The polyester film of the present invention for achieving such a problem is characterized in that the naphthalene group is copolymerized or blended.

In the present invention, the polyester film having a naphthalene group copolymerized or blended with 1 to 98 mol% is dyed under a temperature higher than the glass transition temperature of the polyester film by using a sublimable solvent dye and a dye carrier, and subsequently washed and dried. It is characterized by.

EMBODIMENT OF THE INVENTION Hereinafter, this invention is demonstrated in detail.

In the polyester film of this invention, a naphthalene group is copolymerized or blended by a conventional method. At this time, the content of naphthalene group is 1 to 98 mol%, more preferably 1 to 94 mol%. When the content of naphthalene group is less than 1 mol%, the film strength is maintained, but the dyeing is not good, so that it is difficult to produce the dyeing film of the homogenate, and when it exceeds 98 mol%, dyeing is easy but the film strength is lowered. There is.

The strength of the film indicates tensile strength and elongation. If the intensity of the solar control film is weak, it is very important because the film cannot withstand heat during production and use. In the case of a solar control film, a tensile strength of 20 to 30 kg / inch, more preferably 22 to 28 kg / inch, is required.

The tensile strength of the film of the present invention is 20 ~ 30kg / inch, more preferably 22 ~ 28kg / inch. The film of the present invention can be easily dyed with a sublimable solvent dye at a temperature higher than the film glass transition temperature using a dye carrier.

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

The fatty acid glycerol ester has a high boiling point of 230 to 235 ° C., excellent solubility in general polyester dye dispersion dyes and sublimable solvent dyes, and has a low surface tension of 20 to 40 Dyne / cm for wettability to a polyester film. It is an excellent, fatty acid that does not corrode the film even at high temperatures and is harmless to the human body, making it an environmentally friendly dye carrier.

In the present invention, the dyeing speed is improved by using a sublimation solvent dye having excellent sublimation above a certain temperature. Sublimation dyes are sublimed in a salt bath and diffusion into the polyester polymer chain is faster than conventional solvent type or dispersible dyes. As a result, the dyeing equilibrium is reached quickly and the dyeing speed is also increased.

In addition, the sublimable solvent dye of the present invention should be excellent in solubility in the above-mentioned carrier, and excellent in light fastness and fastness to ultraviolet light. The sublimable solvent dyes used in the present invention are classified into chemical structures such as monoazo, disazo, quinoline, xanthene, anthraquinone and anthraquinone. Complex and the like.

The following describes a series of manufacturing processes to maximize the effect of the present invention.

The present invention enables continuous dyeing by dyeing in a salt bath, followed by a washing step for removing excess dye and carriers present on the surface of the film, and a drying step for removing carriers and residual carriers.

The salt bath of the present invention contains a dye and a carrier and improves the dyeing speed by heating to a high temperature. The suitable temperature is above 120 ° C to 180 ° C, more preferably 140 ° C to 160 ° C, above the glass transition temperature of the polyester film. The dyeing time depends on the size of the salt bath or on the thickness of the film but is usually 3 seconds to 60 seconds.

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

The drying process of the present invention is a heat treatment process for evaporating the detergent and the carrier remaining in the dyed film. If the above-mentioned cleaning agent and carrier remain inside the film, the removal of these is essential because the mechanical properties of the polyester film are lowered and the surface properties of the film are changed. As for the suitable heat processing temperature of this invention, 140 degreeC-150 degreeC is suitable, and it is more effective to accompany a hot air normally.

Next, the salt ratio will be described. Depending on the color and film thickness, it is usually 0.1% (wt./volume) to 5% (wt./vol.) For light colors and 3% (wt./vol.) To 15% (wt./vol. .) Is appropriate.

In this invention, the dyeing equilibrium arrival time and the various characteristics of a film are evaluated by the following method.

Dye equilibrium arrival time

Initial time without further optical density increase in staining by time

Optical concentration

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

Bactericidal

Measured by the optical density difference (ΔD) in a sample of 10 cm × 10 cm size.

·The tensile strength

Cut the produced solar control film 2.5cm wide, 15cm newly, remove the release film and measure the breaking strength in the universal testing machine.

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

Example 1

A polyester film having a naphthalene group content of 1 mol% and a thickness of 25 μm was dyed at 160 ° C. in a salt bath containing a sublimable solvent dye 24 and a carrier ethylene glycol (bath ratio: 3.5%). Subsequently, it is washed with a detergent in which methyl ethyl ketone and ethanol are mixed 1: 1, and then dried at a temperature of 145 ° C (with hot air). Table 2 shows the results of evaluating the dyeing equilibrium attainment time, optical density, uniformity and tensile strength of the dyed film.

Example 2 to Example 7 and Comparative Example 1 to Comparative Example 3

The polyester film is dyed, washed, and dried in the same process and conditions as in Example 1, except that the film thickness, the content of naphthalene group in the film, and the dyeing temperature are changed as shown in Table 1. Table 2 shows the results of evaluating the dyeing equilibrium attainment time, optical density, uniformity and tensile strength of the dyed film.

Dyeing condition division Naphthalene group content (mole%) Film thickness (㎛) 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

Deposition speed and film property evaluation results division Dye balance equilibrium time (sec) Optical density Leveling (ΔD) Tensile Strength (kg / inch) Example 1 40 0.25 0.00 24 Example 2 35 0.35 0.00 25 Example 3 26 0.45 0.00 25 Example 4 25 0.6 0.00 25 Example 5 27 0.7 0.00 24 Example 6 26 0.92 0.00 23 Example 7 25 100 0.01 23 Comparative Example 1 60 0.12 0.07 27 Comparative Example 2 25 1.00 0.00 20 Comparative Example 3 50 0.18 0.06 26

The polyester film of the present invention has a naphthalene group copolymerized or blended, so that the dyeing speed is increased and uniform dyeing is possible even when dyeing concentrated salts. In addition, the intrinsic physical properties such as the strength of the polyester film can be maintained as it is. In addition, the present invention dyes the polyester film of the present invention with a sublimable solvent salt using a dyeing carrier, so that the dyeing speed is faster and a uniform dyeing effect can be obtained.

Claims (5)

Easily dyed polyester film, characterized in that the naphthalene group is copolymerized or blended. The polyester film of claim 1, wherein the content of the copolymerized or blended naphthalene group is 1 to 98 mol%. The easy-to-dye polyester film according to claim 1, wherein the tensile strength is 20 to 30 kg / inch. A polyester film having a naphthalene group copolymerized or blended with 1 to 98 mol% is dyed at a temperature higher than the glass transition temperature of the polyester film using a sublimable solvent dye and a dye carrier, and then washed and dried continuously. The dyeing method of the polyester film made. The method for dyeing a polyester film according to claim 4, wherein an organic solvent is added to the cleaning liquid.